HK1181448B - Brake cylinder device and disc brake device - Google Patents

Description

Brake cylinder device and disc brake device

Technical Field

The present invention relates to a brake cylinder device having a clearance adjustment mechanism for automatically adjusting a clearance from a brake-released state to a brake-operated position, and a disc brake device having the same.

Background

There is known a brake cylinder device disclosed in patent document 1 having a clearance adjustment mechanism for automatically adjusting a clearance from a brake released state to a brake operation position (a position where a braking force can be generated). The brake cylinder device disclosed in patent document 1 includes a pressure lever having an uneven surface formed on an outer surface thereof, and a guide member movable together with the pressure lever. An O-ring engaged with the concave-convex surface is disposed in a space between the guide member and the pressure lever, and when a predetermined force or more is applied to the guide member, the O-ring goes over the convex portion of the concave-convex surface, thereby automatically adjusting a gap from a state where braking is released to a braking operation position. In this way, since the clearance adjustment mechanism is constituted by the concave-convex surface and the O-ring engaged with the concave-convex surface, the brake cylinder device having the clearance adjustment mechanism that is easy to adjust and manage the sliding resistance can be realized with a simple structure.

On the other hand, a brake cylinder device having a clearance adjustment mechanism without using an O-ring, which is different from the above-described one, is known from patent document 2. The clearance adjustment mechanism of the brake cylinder device disclosed in patent document 2 is provided with a cylindrical sheath rod supported by a piston via a bearing so as to be rotatable relative to the piston, and having a linear key groove and a spiral key groove formed on an outer periphery thereof, and a pressure rod attached to a pressure rod holder screwed to an inner periphery of the sheath rod. Further, teeth of a gear of the ratchet mechanism whose rotation direction is restricted by engagement with the pawl are fitted into the respective key grooves of the sheath rod. Therefore, when the stroke of the piston is equal to or greater than a predetermined stroke during the braking operation, the engagement positions of the pawl and the ratchet gear are shifted. Thereby, the clearance from the brake-released state to the brake-operating position is automatically adjusted.

Patent document 1: japanese laid-open patent publication No. 2007-131203

Patent document 2: japanese Kokai publication Sho-61-59158

Since the clearance adjustment mechanism in the brake cylinder device disclosed in patent document 1 utilizes elastic deformation of the O-ring, the clearance adjustment mechanism is susceptible to the influence of the surrounding environment such as temperature and humidity during operation. Therefore, the gap adjusting mechanism needs to be configured by using an O-ring made of a special material that is not easily affected by the surrounding environment such as temperature and humidity, which leads to an increase in cost. On the other hand, since the clearance adjustment mechanism in the brake cylinder device disclosed in patent document 2 does not use an O-ring, the cost for suppressing the influence of the surrounding environment such as temperature and humidity is not substantially required. However, in the case of the gap adjustment mechanism disclosed in patent document 2, a bearing for rotatably supporting the sheath rod is required on the side opposite to the brake output portion disposed on the front side, which is the distal end side of the pressure rod, and on the rear side, which is the piston side. Therefore, it is a main limiting factor to reduce the diameter of the rear side of the cylinder main body in which the piston is disposed.

Disclosure of Invention

In view of the above circumstances, an object of the present invention is to provide, at low cost, a brake cylinder device having a clearance adjustment mechanism for automatically adjusting a clearance from a brake-released state to a brake-operated position, which is less susceptible to an influence of an ambient environment such as temperature and humidity, and which is capable of reducing a radial dimension of a cylinder main body. Another object of the present invention is to provide a disc brake device having the brake cylinder device.

A brake cylinder device according to a first aspect for achieving the above object includes: a cylinder main body, the interior of which is formed to be hollow; a piston that is partitioned into a pressure chamber in the cylinder main body, receives an urging force of a piston spring, and moves relative to the cylinder main body against the urging force of the piston spring by supplying a pressure fluid to the pressure chamber; and a brake output unit that is provided so as to be movable together with the piston or so as to be movable by a force increasing mechanism that increases a force generated in the piston in accordance with the movement of the piston, and that is movable in a braking direction protruding from the cylinder body and in a direction opposite to the braking direction toward the cylinder body. In addition, a first aspect is characterized in that the brake cylinder device further includes: a threaded shaft coupled to the brake output unit and having a thread formed on an outer periphery thereof; a guide tube attached to the piston or the force increasing mechanism and accommodating the threaded shaft therein; a thrust spring (push spring) disposed on the guide tube or the piston so as to be capable of biasing the threaded shaft in the braking direction; a clutch nut that is screwed to a distal end side of the threaded shaft, the distal end side of the threaded shaft being disposed closer to the brake output portion side than the cylinder body; a front stopper disposed to be capable of abutting against the clutch nut from a front side, which is a side of the brake output unit, to restrict movement of the clutch nut relative to the guide pipe, the front stopper being capable of biasing the clutch nut and the threaded shaft in a direction opposite to the braking direction in accordance with movement of the guide pipe in the direction opposite to the braking direction; a first clutch disposed so as to be capable of coming into contact with the clutch nut at a predetermined interval from a rear side, which is an opposite side of the clutch nut to the brake output portion, to the front stopper; an adjustment stopper that is disposed so as to be movable in the axial direction of the threaded shaft relative to the clutch nut and the guide pipe, and that limits a movable range relative to the cylinder body; a second clutch fixed to the adjustment stopper and configured to be capable of coming into contact with the clutch nut from the rear side; and an adjustment spring having one end abutting against or coupled to the adjustment stopper or the second clutch and capable of biasing the clutch nut in a direction opposite to the braking direction.

In the present invention, when the brake is operated, the pressure fluid is supplied to the pressure chamber, the piston moves against the biasing force of the piston spring, and the brake output portion moves in the braking direction via the guide tube, the first clutch, the clutch nut, and the threaded shaft, thereby outputting the braking force. In addition, when the force increasing mechanism is provided, the force from the piston is transmitted via the force increasing mechanism. On the other hand, by discharging the pressure fluid in the pressure chamber, the piston is moved in the opposite direction by the biasing force of the piston spring, and the brake output portion is moved in the opposite direction to the braking direction by the guide pipe, the front stopper, the clutch nut, and the threaded shaft, thereby releasing the braking. When the clearance from the brake released state to the brake operating position increases due to wear of the brake pads or the like, the clearance is automatically adjusted by a clearance adjustment mechanism including a clutch nut, first and second clutches, a threaded shaft, a guide pipe, a thrust spring, a front stopper, an adjustment stopper, and an adjustment spring.

When adjusting the clearance, first, by limiting the movement range of the adjustment stopper at the time of braking operation, a biasing force that can be applied to the clutch nut in a direction opposite to the braking direction is accumulated in the adjustment spring as an accumulated force of the adjustment spring. At this time, the clutch nut is released from contact with the second clutch to which the adjustment stopper is fixed, and a gap is formed between the second clutch and the clutch nut. When the guide pipe starts to move in the direction opposite to the braking direction during the brake release operation, the thrust spring biases the screw shaft in the braking direction, and therefore, the following state occurs: the threaded shaft and the brake output portion do not move in the direction opposite to the braking direction, and the clutch nut is biased in the direction opposite to the braking direction by the accumulated force of the adjusting spring. At this time, the clutch nut is in a state in which the contact between the clutch nut and the first clutch is released and the clutch nut is not in contact with the front stopper, and the clutch nut is not in contact with the second clutch, so that the clutch nut is rotatable with respect to the threaded shaft. Then, the clutch nut is rotated relative to the threaded shaft so as to move in the direction opposite to the braking direction by the power storage force of the adjustment spring. Then, the gap between the clutch nut and the second clutch disappears, the clutch nut comes into contact with the second clutch, the clutch nut becomes a state in which the clutch nut cannot rotate, and as the guide pipe moves in the direction opposite to the braking direction, the brake output portion moves in the direction opposite to the braking direction together with the front stopper, the clutch nut, and the threaded shaft, and the braking is released. In this way, since the clutch nut moves in the opposite direction to the braking direction with respect to the screw shaft during the brake release operation, the brake release operation is terminated in a state where the position of the screw shaft has moved in the braking direction from the state before the brake release operation. That is, the state is shifted to a state where the threaded shaft and the brake output portion are moved to a position protruding from the cylinder main body, compared to the state before the braking operation. Thereby, the clearance from the brake-released state to the brake-operating position is automatically adjusted.

As described above, according to the present invention, the clearance adjustment mechanism includes the clutch nut, the first clutch and the second clutch, the threaded shaft, the guide tube, the thrust spring, the front stopper, the adjustment stopper, and the adjustment spring. Therefore, a brake cylinder device that performs clearance adjustment by elastic deformation of rubber or the like is not used, and a structure that is less susceptible to the influence of the surrounding environment such as temperature and humidity can be realized at low cost. Further, since the structure in which the guide pipe is attached to the piston or the force increasing mechanism does not require the provision of a bearing, the diameter dimension of the rear side of the cylinder main body can be reduced.

Therefore, according to the present invention, it is possible to provide at low cost a brake cylinder device having a clearance adjustment mechanism for automatically adjusting a clearance from a brake released state to a brake operation position, which is less susceptible to the influence of the surrounding environment such as temperature and humidity, and which is capable of reducing the radial dimension of a cylinder main body.

Further, according to the brake cylinder device of the present invention, in a state where the automatic gap adjustment operation by the gap adjustment mechanism is not performed, the second clutch and the clutch nut are kept in contact with each other both at the time of the braking operation and at the time of the braking release, and the second clutch and the clutch nut are prevented from being disengaged. That is, in a state where the gap adjusting operation is not performed, the clutch nut is biased in a direction opposite to the braking direction by an adjusting spring having one end side abutting or coupled to the adjusting stopper or the second clutch, and the state where the second clutch abuts the clutch nut is maintained. Thus, the clutch nut is prevented from rotating with respect to the threaded shaft at a time other than the time of the gap adjustment operation, and the position of the clutch nut with respect to the threaded shaft is prevented from being displaced due to vibration or the like.

A second aspect is the brake cylinder device according to the first aspect, wherein the threaded shaft is formed hollow so as to open to a side opposite to the brake output portion, and the thrust spring biases the clutch nut, which is screwed to the threaded shaft, toward the front stopper by biasing the threaded shaft from inside.

In the present invention, the thrust spring for urging the threaded shaft is disposed inside the threaded shaft formed in a hollow structure, and urges the clutch nut screwed to the threaded shaft toward the front stopper. Therefore, the thrust spring can be disposed by efficiently utilizing the space of the brake cylinder device. This improves the space efficiency of the brake cylinder device, and further reduces the size of the brake cylinder device.

A third aspect of the present invention is the brake cylinder device according to the second aspect, further comprising a thrust spring guide formed as a shaft-like portion provided so as to be movable together with the guide pipe, the thrust spring guide being inserted into an inner side of the thrust spring provided as a coil spring to restrict deformation of the thrust spring in a buckling direction, a tip end portion of the thrust spring guide being disposed inside the screw shaft so as to be slidable with respect to an inner side of the screw shaft.

With the present invention, there is provided a thrust spring guide extending inside the helical thrust spring so as to restrict deformation of the thrust spring in the buckling direction. Therefore, even when the adjusted gap size is increased and a long thrust spring is required as the gap adjustment mechanism, buckling of the thrust spring can be prevented efficiently. Further, a tip end portion of a thrust spring guide provided so as to be movable together with the guide pipe is slidably disposed inside the screw shaft. Therefore, with a simple structure in which a shaft-shaped thrust spring guide is provided, a structure in which the positional relationship between the screw shaft and the piston is maintained in a displaced relationship on the same axis can be easily realized.

A fourth aspect is the brake cylinder device according to any one of the first to third aspects, wherein the front stopper and the first clutch are provided as separate members integrally formed with each other, and are fixed to the guide pipe.

According to the invention, the front stop piece and the first clutch are respectively arranged as an integral independent component and are respectively fixed on the guide tube. Therefore, it is not necessary to provide the front stopper and the first clutch disposed in front and rear of the clutch nut with a separate structure and to couple them with another coupling member. Similarly, it is not necessary to provide a clutch nut having a front stopper and a first clutch disposed in front and rear of the clutch nut in a split structure and to couple the clutch nut with another coupling member. This can simplify the structure relating to the front stopper, the first clutch, and the clutch nut, and as a result, the brake cylinder device as a whole can be reduced in size and weight. Further, since the front stopper and the first clutch are each an integral separate member and are fixed to the guide pipe, the inner periphery of the front stopper and the inner periphery of the first clutch can be set to a size configuration in which they are closer to the outer periphery of the threaded shaft, and the brake cylinder device can be further downsized.

A fifth aspect of the brake cylinder device according to the fourth aspect of the present invention is characterized in that at least one of the front stopper and the first clutch is fixed to an inner periphery of the guide pipe by screwing.

In the present invention, at least either one of the front stopper and the first clutch, which are formed as separate members integrally with each other, is fixed to the inner periphery of the guide tube by screwing. Therefore, the front stopper and the first clutch fixed to the guide pipe by screwing can be easily replaced during maintenance, and the maintainability can be improved.

A sixth aspect is the brake cylinder device according to any one of the first to fifth aspects, further comprising an adjustment sleeve that is a flexible cylindrical member disposed around the threaded shaft, and that is biased in the direction opposite to the braking direction by the other end side of the adjustment spring that is in contact with or coupled to the adjustment stopper or the second clutch at one end side, wherein the clutch nut and the adjustment sleeve are integrally formed by engagement between an engagement portion formed on the adjustment sleeve and an engaged portion formed on the clutch nut.

In the present invention, the adjustment spring is disposed between the adjustment stopper or the second clutch and the cylindrical adjustment sleeve disposed around the threaded shaft, and the adjustment spring accumulates a force that moves the clutch nut in a direction opposite to the braking direction with respect to the threaded shaft during the gap adjustment operation as the adjustment sleeve moves with respect to the adjustment stopper and the second clutch. The adjustment sleeve is provided as a flexible member, and the adjustment sleeve and the clutch nut are integrated by engaging the engagement portion on the adjustment sleeve side with the engaged portion on the clutch nut side. Therefore, the flexible adjustment sleeve is temporarily elastically deformed to engage the engagement portion with the engaged portion, so that the adjustment sleeve and the clutch nut can be integrated without using a separate coupling member. In this way, in the structure in which the adjustment sleeve and the clutch nut are integrated, since no additional coupling member is required, the brake cylinder device can be further downsized.

A seventh technical means is the brake cylinder device as defined in the sixth technical means, wherein the engaging portion of the adjustment sleeve is engaged with the engaged portion formed on an inner peripheral side of the clutch nut from an inner side, and a dimension of a gap formed between the inner periphery of the adjustment sleeve and a crest of a thread of the threaded shaft in a radial direction of the adjustment sleeve is smaller than a dimension of a concave-convex portion in the radial direction of the adjustment sleeve, the concave-convex portion being engaged with the engaging portion and the engaged portion.

In the present invention, the adjustment sleeve is engaged from the inside of the clutch nut, and the dimension of the gap between the inner periphery of the adjustment sleeve and the crest of the thread of the threaded shaft is set smaller than the dimension in the radial direction of the concave-convex portion (the amount of overlap of the concave-convex portion in the radial direction of the adjustment sleeve) of the engagement portion and the engaged portion that are engaged with each other. Therefore, the engaging portion of the flexible adjustment sleeve is disposed between the clutch nut and the threaded shaft, which are formed of a metal material, and the dimension relationship is set so that the engaging portion of the adjustment sleeve can be prevented from being deformed toward the threaded shaft and being disengaged from the engaged portion. Thus, the adjustment sleeve and the clutch nut can be firmly integrated despite the simple engagement structure.

An eighth aspect of the brake cylinder device according to the seventh aspect is characterized in that the adjustment spring is disposed so that the other end side thereof biases a spring seat attached to the adjustment sleeve, and the spring seat is disposed so that a gap formed between an outer periphery of the spring seat and an inner periphery of the guide pipe has a dimension in a radial direction of the guide pipe substantially zero, or is disposed so that the outer periphery of the spring seat is in sliding contact with the inner periphery of the guide pipe.

In the present invention, the spring seat is disposed so that the clearance between the spring seat and the guide tube is substantially zero or the spring seat is in sliding contact with the guide tube, and therefore the threaded shaft can be supported by the guide tube via the spring seat, and the threaded shaft can be prevented from being inclined with respect to the guide tube.

A ninth aspect is the brake cylinder device according to the eighth aspect, characterized in that the spring seat includes a bearing.

In the present invention, since the other end side of the adjustment spring applies a force to the adjustment sleeve via the bearing in the spring seat, when the adjustment sleeve is applied with a force by the accumulated force of the adjustment spring, the clutch nut smoothly rotates together with the adjustment sleeve and moves in the braking direction.

A tenth aspect is the brake cylinder device according to any one of the first to ninth aspects, further comprising a spring stopper for limiting a displacement amount by which the other end side of the adjustment spring is relatively displaced with respect to abutment of the adjustment spring or one end side connected to the adjustment stopper or the second clutch to elastically deform the adjustment spring to a predetermined amount or less.

The present invention provides a spring stopper that performs a force accumulation for the gap adjustment operation by limiting the displacement amount of the adjustment spring when the adjustment spring is elastically deformed to a predetermined amount or less. Therefore, in the operation of performing the clearance adjustment operation as in the related art, the stroke of the adjustment spring can be restricted by the spring stopper even when the clearance adjustment operation is forcibly performed, because the clearance adjustment is performed by the force generated when the brake pad is not in contact with the disc (in the case where the brake cylinder device is applied to the disc brake, the brake pad is not in contact with the disc). Therefore, the gap adjusting operation can be forcibly performed even in an idling state without excessively compressing or extending the adjusting spring. In addition, since the clearance is increased to be larger than a range in which the clearance can be adjusted in order to easily perform the replacement work of the brake pad, it is necessary to manually adjust the clearance for each brake pad when performing the replacement work of the brake pad as in the related art. However, according to the present invention, as described above, the gap adjusting operation can be forcibly performed even in an idling state without excessively compressing or extending the adjusting spring. Therefore, the brake operation and the brake release operation are repeated a plurality of times at a time in the vehicle or the entire trailer, and the clearance of all the brake cylinder devices can be automatically adjusted. Thus, even when the brake pads are replaced, it is not necessary to manually adjust the clearance for each brake cylinder device, and the clearance can be automatically adjusted for all the brake cylinder devices of the vehicle or the trailer in a unified manner.

An eleventh aspect of the brake cylinder device according to any one of the first to tenth aspects is characterized in that teeth capable of engaging the second clutch with the clutch nut are formed on at least one of a surface of the front clutch facing the clutch nut and a surface of the clutch nut facing the second clutch.

In the present invention, the second clutch and the clutch nut are engaged with each other via the teeth formed on the surfaces facing each other in a state where the gap adjustment operation is not performed while the second clutch and the clutch nut are maintained in contact with each other, and therefore, the clutch nut can be reliably prevented from rotating relative to the threaded shaft due to vibration or the like.

A twelfth aspect is the brake cylinder device according to any one of the first to eleventh aspects, wherein the threaded shaft is provided at a tip end portion thereof with an operation engagement portion that is engageable with a tool for operation, and the tip end portion is disposed so as to penetrate the brake output portion and face outward, the brake cylinder device further being provided with an engagement mechanism that is disposed on an outer periphery of the tip end side of the threaded shaft and that engages the threaded shaft and the brake output portion, the engagement mechanism including an outer periphery engagement portion that has engagement teeth engageable with the brake output portion and that is fixed to an outer periphery of the threaded shaft, and an engagement spring that biases the outer periphery engagement portion in the braking direction so that the engagement teeth are engaged with the brake output portion.

In the present invention, the operation engagement portion is provided at the distal end portion disposed to face the outside through the brake output portion, and the threaded shaft is engaged with the brake output portion by the engagement mechanism disposed on the outer periphery of the distal end side of the threaded shaft. The engagement mechanism includes an engagement spring and an outer peripheral engagement portion having engagement teeth, and the outer peripheral engagement portion is biased in a braking direction by the engagement spring, and the threaded shaft and the brake output portion are engaged with each other via the engagement teeth. Therefore, the engagement between the threaded shaft and the brake output portion is released by releasing the engagement between the outer peripheral engagement portion and the brake output portion via the engagement teeth against the spring force of the engagement spring, and the threaded shaft is rotated by a tool for operation, so that the threaded shaft can be manually rotated. This makes it possible to easily restore the positional relationship between the threaded shaft and the clutch nut to the initial state before the clearance is adjusted.

As another aspect, a disc brake device including the brake cylinder device according to any one of the above aspects can be configured. That is, a disc brake device according to a thirteenth aspect is characterized by comprising a caliper main body equipped with the brake cylinder device and mounted so as to be displaceable in an axle direction with respect to a vehicle, and a brake cylinder device according to any one of the first to twelfth aspects, wherein a braking force is generated by sandwiching a disc on the axle side by a pair of brake pads mounted to the caliper main body by operation of the brake cylinder device.

The present invention can provide a disc brake device including a brake cylinder device provided with a clearance adjustment mechanism for automatically adjusting a clearance from a brake released state to a brake operation position at low cost, which is less susceptible to an influence of ambient environments such as temperature and humidity, and which can reduce the radial dimension of a cylinder main body.

The present invention can provide a brake cylinder device having a clearance adjustment mechanism for automatically adjusting a clearance from a brake released state to a brake operation position, which is less susceptible to the influence of ambient environments such as temperature and humidity, and which can reduce the radial dimension of a cylinder main body at low cost. Further, a disc brake device having the brake cylinder device can be provided at low cost.

Drawings

Fig. 1 is a side view of a disc brake apparatus according to an embodiment of the present invention.

Fig. 2 is a plan view of the disc brake apparatus shown in fig. 1.

Fig. 3 is a sectional view of a brake cylinder device according to a first embodiment of the present invention.

Fig. 4 is a diagram showing a state in which the brake output portion and the distal end portion of the threaded shaft of the brake cylinder device shown in fig. 3 are viewed from the direction of arrow C.

Fig. 5 is an enlarged cross-sectional view showing a part of the brake cylinder device shown in fig. 3 in an enlarged manner.

Fig. 6 is a sectional view of the brake cylinder device shown in fig. 3, which is a sectional view for explaining a case where the brake cylinder device is operated without automatically adjusting the clearance by the clearance adjusting mechanism.

Fig. 7 is a sectional view of the brake cylinder device shown in fig. 3, which is a sectional view for explaining a case where the brake cylinder device is operated without automatically adjusting the clearance by the clearance adjusting mechanism.

Fig. 8 is a sectional view of the brake cylinder device shown in fig. 3, which is a sectional view for explaining a case where the brake cylinder device is operated without automatically adjusting the clearance by the clearance adjusting mechanism.

Fig. 9 is a sectional view of the brake cylinder device shown in fig. 3, and is a sectional view for explaining a case where the brake cylinder device is operated without automatically adjusting the clearance by the clearance adjusting mechanism.

Fig. 10 is a sectional view of the brake cylinder device shown in fig. 3, and is a sectional view for explaining an operation in a case where the gap is automatically adjusted by the gap adjustment mechanism.

Fig. 11 is a sectional view of the brake cylinder device shown in fig. 3, and is a sectional view for explaining an operation in a case where the gap is automatically adjusted by the gap adjustment mechanism.

Fig. 12 is a sectional view of the brake cylinder device shown in fig. 3, and is a sectional view for explaining an operation in a case where the gap is automatically adjusted by the gap adjustment mechanism.

Fig. 13 is a sectional view of the brake cylinder device shown in fig. 3, and is a sectional view for explaining an operation in a case where the clearance is automatically adjusted by the clearance adjustment mechanism.

Fig. 14 is a sectional view of the brake cylinder device shown in fig. 3, and is a sectional view for explaining an operation in a case where the gap is automatically adjusted by the gap adjustment mechanism.

Fig. 15 is a sectional view of the brake cylinder device shown in fig. 3, and is a sectional view for explaining an operation in a case where the gap is automatically adjusted by the gap adjustment mechanism.

Fig. 16 is a sectional view of the brake cylinder device shown in fig. 3, and is a sectional view for explaining an operation in a case where the gap is automatically adjusted by the gap adjustment mechanism.

Fig. 17 is a sectional view of the brake cylinder device shown in fig. 3, and is a sectional view for explaining an operation in a case where the gap is automatically adjusted by the gap adjustment mechanism.

Fig. 18 is a cross-sectional view of the brake cylinder device shown in fig. 3, and is a cross-sectional view for explaining an operation in a case where the gap adjusting operation is performed in an idling state.

Fig. 19 is a cross-sectional view of the brake cylinder device shown in fig. 3, and is a cross-sectional view for explaining an operation in a case where the gap adjusting operation is performed in an idling state.

Fig. 20 is a cross-sectional view of the brake cylinder device shown in fig. 3, and is a cross-sectional view for explaining an operation in a case where the gap adjusting operation is performed in an idling state.

Fig. 21 is a cross-sectional view of the brake cylinder device shown in fig. 3, and is a cross-sectional view for explaining an operation in a case where the gap adjusting operation is performed in an idling state.

Fig. 22 is a sectional view of a brake cylinder device according to a second embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. A brake cylinder device and a disc brake device having the same according to the present invention will be described by taking a case of being used for a railway vehicle as an example. In addition, the drawings are made with a precision equivalent to the design drawing.

First embodiment

Fig. 1 is a side view of a disc brake device 1 according to an embodiment of the present invention as viewed from the axle direction. Fig. 2 is a plan view of the disc brake device 1 shown in fig. 1, as viewed from above. The disc brake apparatus 1 shown in fig. 1 and 2 includes: a brake cylinder device 2; a caliper body 11 that is equipped with the brake cylinder device 2 and is attached to the vehicle body 100 so as to be capable of relative displacement in the axle direction with respect to the vehicle body 100; and a pair of backing plates (12, 12) which are brake pad holding portions for holding a pair of brake pads (13, 13) as brake pads, respectively.

A pair of brake pads (13, 13) are attached to the caliper body 11 via a backing plate 12. The disc brake device 1 generates braking force by sandwiching a disc-shaped brake disc 101, which is a disc on the axle side that rotates in conjunction with rotation of a wheel (not shown) of the railway vehicle, between a pair of brake pads (13, 13) by operation of the brake cylinder device 2. The brake disc 101 is formed in a disc shape and has front and rear braking surfaces (101 a ) formed so as to be orthogonal to the rotation axis. Then, by the operation of the brake cylinder device 2, the brake pads (13, 13) are pressed against the braking surfaces (101 a ) so as to sandwich the brake disc 101 from both sides in a direction substantially parallel to the rotation axis direction of the brake disc 101.

The caliper body 11 includes a coupling member 14 and a pair of brake levers (15, 15). The coupling member 14 is attached to a bracket 100a via a swing pin 14a so as to be swingable about an axis parallel to the vehicle traveling direction with respect to the bracket 100a, and the bracket 100a is fixed to the bottom surface of the vehicle body 100. The pair of brake levers (15, 15) are provided to the coupling member 14 so as to be swingable with respect to the coupling member 14 via a pair of fulcrum pins 15a and so as to be substantially symmetrical with respect to the coupling member 14. The fulcrum pin 15a is provided so as to extend in a direction perpendicular to the axial direction of the pivot pin 14a when viewed from the rotational axis direction of the disc brake 101.

The pair of brake levers (15, 15) are attached with the brake cylinder device 2 at one end thereof via a cylinder support pin 15b, and the one end is driven by the brake cylinder device 2. Further, a pair of backing plates (12, 12) for holding the brake pad 13 are attached to the other end side of the pair of brake levers (15, 15) with the fulcrum pin 15a interposed therebetween from the one end side to which the brake cylinder device 2 is attached. The backing plate 12 is attached to the brake lever 15 via a support pin 12a extending parallel to the fulcrum pin 15a so as to be swingable with respect to the brake lever 15.

In the disc brake device 1, as will be described later, the cylinder body 20 of the brake cylinder device 2 is attached to one brake lever 15, the brake output portion 21 is attached to the other brake lever 15, and the brake output portion 21 is operated to protrude from or approach the cylinder body 20 by the operation of the brake cylinder device 2. Thereby, the cylinder support pins 15b of the pair of brake levers (15, 15) are driven to move away from or close to each other.

By driving as described above, the disc brake device 1 operates such that the pair of brake levers (15, 15) operate with the fulcrum pins 15a as support shafts, and the brake disc 101 is sandwiched by the brake pads 13. At this time, in the pair of brake levers (15, 15), the one brake pad 13 provided in the one brake lever 15 first contacts the braking surface 101a of the brake disc 101. The other brake lever 15 presses the other brake pad 13 against the braking surface 101a of the brake disc 101 by a reaction force received from the one brake pad 13 that is in contact with the braking surface 101 a. Thus, the brake disc 101 is sandwiched by the pair of brake pads (13, 13), and the rotation of the brake disc 101 is braked by the frictional force generated between the brake pads (13, 13) and the braking surfaces (101 a ), thereby braking the rotation of the wheel of the railway vehicle disposed coaxially with the brake disc 101.

Next, the brake cylinder device 2 according to the first embodiment of the present invention will be described in detail. Fig. 3 is a sectional view of the brake cylinder device 2. The brake cylinder device 2 shown in fig. 3 is configured similarly to the brake cylinder device 2 shown in fig. 1 and 2, but a part of the external shape is modified and shown in the drawings. Both ends of the brake cylinder device 2 in the brake actuation direction are coupled to the cylinder support pins 15b, respectively. The brake cylinder device 2 includes a cylinder body 20, a brake output portion 21, a piston 22, a piston spring 23, a threaded shaft 24, a guide pipe 25, a thrust spring 26, a clutch nut 27, a front stopper 28, a first clutch 29, an adjustment stopper 30, an adjustment spring 31, a second clutch 32, an adjustment sleeve 33, a spring stopper 34, a thrust spring guide 38, a bearing 40, an engagement mechanism 42, and the like. Of the above-described components, the members other than the adjustment sleeve 33 are formed of a metal material such as an iron-based material, for example, and the adjustment sleeve 33 is formed of a resin material, for example. In fig. 3, the adjustment stopper 30, the thrust spring guide 38, and the like are not shown in cross section but are shown in outer shape.

The cylinder main body 20 is constituted by a first housing portion 35 and a second housing portion 36, and the inside thereof is formed to be hollow. The cylinder body 20 accommodates a piston 22, a piston spring 23, a part of a threaded shaft 24, a guide pipe 25, a thrust spring 26, a clutch nut 27, a front stopper 28, a first clutch 29, an adjustment stopper 30, an adjustment spring 31, a second clutch 32, a thrust spring guide 38, an adjustment sleeve 33, a spring stopper 34, and the like. The first casing section 35 is formed in a substantially cup shape having a bottom, and the second casing section 36 is fixed by bolts so as to close the open side of the first casing section 35. Further, an end portion of the first housing portion 35 is connected to one brake lever 15 by a cylinder support pin 15 b. In addition, a flat plate-like portion 36a and a cylindrical portion 36b are provided in the second casing section 36, the flat plate-like portion 36a being formed in a flange shape so as to close the first casing section 35, and the cylindrical portion 36b being formed in a cylindrical shape protruding perpendicularly to the flat plate-like portion 36 a.

The piston 22 is disposed to partition the inside of the cylinder main body 20, is in airtight sliding contact with the inner peripheral surface of the first housing portion 35, and is provided slidably in the axial direction with respect to the first housing portion 35. A pressure chamber 37 is formed in the cylinder main body 20 by a space defined by the piston 22 and the first housing portion 35. In the pressure chamber 37, compressed air as a pressure fluid is supplied and discharged through a communication path, not shown.

The piston spring 23 is provided as a spiral spring disposed on the opposite side of the pressure chamber 37 with the piston 22 interposed therebetween in the cylinder main body 20, and the piston spring 23 is disposed between the piston 22 and the flat plate portion 36a of the second housing portion 36. Thereby, the urging force generated by the piston spring 23 is transmitted to the piston 22 that partitions the pressure chamber 37 in the cylinder main body 20. The piston spring 23 is disposed in the cylinder body 20 so as to bias the piston 22 toward the pressure chamber 37. Then, by supplying compressed air to the pressure chamber 37, the piston 22 is moved relative to the cylinder main body 20 against the urging force of the piston spring 23, and is moved in the braking direction (the direction indicated by the arrow a in fig. 3). On the other hand, by discharging the compressed air from the pressure chamber 37, the piston 22 is moved in a counter braking direction (a direction indicated by an arrow B in fig. 3) opposite to the braking direction by the urging force of the piston spring 23.

The brake output unit 21 is connected to the piston 22 via a threaded shaft 24, a guide pipe 25, and the like, which will be described later, and is provided so as to be movable together with the piston 22. Thus, the brake output unit 21 is provided so as to be movable in a braking direction (arrow a direction) protruding from the cylinder body 20 and in a direction (arrow B direction) opposite to the braking direction and approaching the cylinder body 20. The brake output unit 21 is connected to the other brake lever 15 by a cylinder support pin 15 b. Further, a corrugated structure disposed so as to cover the periphery of the cylindrical portion 36b of the second housing part 36 is provided as a protective cover between the brake output part 21 and the cylinder main body 20.

The threaded shaft 24 is a shaft-shaped member coupled to the brake output unit 21 and having a thread 24a formed on the outer periphery thereof. The screw shaft 24 is hollow so as to open toward the side opposite to the brake output portion 21 (the piston 22 side in the present embodiment). That is, a hollow region of the interior of the threaded shaft 24 is provided as an axial hole 24b extending in the axial direction, and is open only on the side opposite to the brake output portion 21.

Fig. 4 is a view showing a state where the brake output unit 21 and the distal end portion of the threaded shaft 24 are viewed from the direction of arrow C in fig. 3. As shown in fig. 3 and 4, the screw shaft 24 is provided at a distal end thereof with a hexagonal head 24c as an operation engagement portion that can be engaged with an operation tool (e.g., a hexagonal wrench). The hexagonal head 24c is formed as a portion having a hexagonal prism-shaped side surface (for example, formed in the same manner as the head of a hexagonal bolt), and is fixed to the threaded shaft 24 so as to rotate integrally with the main body portion of the threaded shaft 24. A through hole is formed in the center portion of the brake output portion 21, and the tip end portion of the screw shaft 24 is disposed so as to penetrate the through hole of the brake output portion 21 and face outward. The hexagonal head 24c at the distal end of the screw shaft 24 is disposed in the open hole 21a, and the open hole 21a constitutes a part of the through hole and is formed so as to open at the end face of the brake output portion 21.

The engagement mechanism 42 is disposed on the outer periphery of the distal end side of the screw shaft 24, and is provided as a mechanism for engaging the screw shaft 24 with the brake output unit 21. The engaging mechanism 42 includes an outer peripheral engaging portion 43 and an engaging spring 44. In the brake output unit 21, an engagement block 45 is provided at a central portion where the through hole is formed. The engaging block 45 is provided as a portion that engages with the engaging mechanism 42 in the brake output unit 21, and the engaging block 45 is fixed to the main body portion of the brake output unit 21 in the through hole. The engagement block 45 has a hole formed therethrough, and the distal end side of the screw shaft 24 is disposed so as to be slidably inserted therethrough.

The outer peripheral engaging portion 43 of the engaging mechanism 42 has a cylindrical fixed portion and an engaging tooth portion formed integrally. The cylindrical fixing portion is formed in a cylindrical shape and fixed to the outer periphery of the threaded shaft 24. The engaging tooth portion is provided at one end of the cylindrical fixing portion, and is formed as a portion expanded in a flange shape or a portion expanded in an umbrella shape having a large opening at the center, and has engaging teeth 43a capable of engaging with the brake output portion 21. The engaging tooth portion is disposed opposite to the engaging block 45 in a through hole in the center of the brake output portion 21. In addition, an engaging tooth 45a for engaging with the engaging tooth 43a of the engaging tooth portion is formed in a portion of the engaging block 45 of the brake output unit 21 that faces the engaging tooth portion.

The engaging spring 44 of the engaging mechanism 42 is a spiral spring disposed in a through hole at the center of the brake output portion 21 and in the outer periphery of the cylindrical fixed portion of the outer peripheral engaging portion 43. The engaging spring 44 is disposed such that one end thereof abuts against the side of the engaging tooth portion opposite to the side where the engaging teeth 43a are formed. The engagement spring 44 is disposed such that the other end thereof abuts against an annular brake member fixed to the brake output portion 21 so as to close a part of an opening of the through hole in the center of the brake output portion 21 on the side opposite to the side of the opening hole 21 a. Thus, the engagement spring 44 biases the outer circumferential engagement portion 43 in the braking direction so that the engagement teeth 43a of the outer circumferential engagement portion 43 integrally fixed to the main body portion of the threaded shaft 24 are engaged with the engagement teeth 45a of the engagement block 45 of the brake output portion 21. In this way, the threaded shaft 24 and the brake output portion 21 are engaged with each other by the engagement mechanism 42.

The guide pipe 25 is formed as a cylindrical member, is disposed with one end fixed and attached to the piston 22, and penetrates the cylindrical portion 36b of the second housing part 36 of the cylinder body 20. In the guide pipe 25, a bottom plate 25a is attached to an end fixed to the piston 22, and an end opposite to the brake output portion 21 is opened. The guide pipe 25 accommodates a threaded shaft 24 in a space region inside thereof.

Further, a pair of slit holes (25 b ) formed to penetrate in a slit shape are provided in the circumferential wall of the guide tube 25 at a middle position in the cylinder axial direction. The pair of slit holes (25 b ) are provided so as to be arranged at positions along the diameter direction of the cylindrical guide pipe 25, and are formed as openings through which an adjustment stopper 30 described later is arranged so as to penetrate from the inside to the outside.

The thrust spring 26 is a helical spring and is disposed in the axial hole 24b of the threaded shaft 24. Further, the axial hole 24b is provided with a stepped portion which is tapered in a stepwise manner toward the inside (japanese: austenitic). The thrust spring 26 is a compression spring, and is disposed such that one end thereof abuts against the step portion of the axial hole 24b and the other end thereof abuts against the bottom plate 25a of the guide pipe 25. Thereby, the thrust spring 26 is disposed on the guide pipe 25 so as to be able to bias the threaded shaft 24 in the braking direction from inside.

The thrust spring guide 38 is fixed to the bottom plate 25a of the guide pipe 25 and is formed as a shaft-like portion provided so as to be movable together with the guide pipe 25. The thrust spring guide 38 is disposed so as to protrude toward the axial hole 24b of the threaded shaft 24, and is inserted inside the thrust spring 26. Thereby, the thrust spring guide 38 restricts the deformation of the thrust spring 26 in the buckling direction. The thrust spring guide 38 is inserted into the axial hole 24b of the threaded shaft 24 in a state where its tip end portion is in sliding contact with a portion of the hole of the axial hole 24b of the threaded shaft 24, the hole having a diameter reduced on the inner side. Thereby, the tip end portion of the thrust spring guide 38 is disposed inside the threaded shaft 24 so as to be slidable with respect to the inside of the threaded shaft 24.

Fig. 5 is an enlarged cross-sectional view showing a part of the brake cylinder device 2 shown in fig. 3 in an enlarged manner. As shown in fig. 3 and 5, the clutch nut 27 is provided as a cylindrical member having a female screw portion formed on an inner periphery thereof, and is screwed to the distal end side of the threaded shaft 24 disposed closer to the brake output portion 21 than the cylinder main body 20. A projection 27a is provided on the outer periphery of the clutch nut 27 at a halfway position in the axial direction, and the projection 27a is formed so as to extend in the entire circumferential direction and project outward in the radial direction and can be brought into contact with a front stopper 28 and a first clutch 29, which will be described later. Further, by providing the clutch nut 27 as described above, the thrust spring 26 biases the threaded shaft 24 from the inside, and the clutch nut 27 screwed to the threaded shaft 24 is biased toward the front stopper 28.

The front stopper 28 is formed as an integral member, and is provided as a cylindrical member having a short axial length and an external thread portion formed on an outer periphery thereof. The male screw portion of the front stopper 28 is screwed to a female screw portion formed on the inner periphery of the distal end portion of the guide pipe 25 facing the brake output portion 21. That is, the front stopper 28 is fixed to the inner periphery of the guide tube 25 by screwing. Further, a groove extending in the circumferential direction is formed on the inner periphery of the distal end portion of the guide pipe 25 at a position closer to the brake output portion 21 than the front stopper 28. Then, the snap ring 41 that engages with the end portion of the front stopper 28 on the brake output portion 21 side is fitted into the groove, whereby the front stopper 28 can be prevented from coming off.

The front stopper 28 is disposed concentrically (with the center position in the radial direction coinciding) with the outer side of the threaded shaft 24 with respect to the end of the clutch nut 27 on the brake output portion 21 side. The front stopper 28 is disposed so as to be able to abut against the convex portion 27a from the front side, which is the brake output portion 21 side, with respect to the clutch nut 27, so as to restrict the clutch nut 27 from moving with respect to the guide pipe 25. Thus, the front stopper 28 can urge the clutch nut 27 and the threaded shaft 24 screwed with the clutch nut 27 in the direction opposite to the braking direction together with the movement of the guide pipe 25 in the direction opposite to the braking direction.

The first clutch 29 is provided as a cylindrical member having a short axial length, and is formed as an integral member as another member with respect to the front stopper 28. The first clutch 29 is press-fitted into the guide pipe 25 and fixed to the guide pipe 25. Further, an end of the first clutch 29 is positioned in contact with a portion formed in a stepped shape on the inner periphery of the guide pipe 25.

The first clutch 29 is disposed concentrically (with the center position in the radial direction coinciding) with the outer side of the threaded shaft 24 with respect to the end of the clutch nut 27 on the piston 22 side. The first clutch 29 is disposed so as to be able to contact the convex portion 27a of the clutch nut 27 with a predetermined gap from the front stopper 28 on the rear side opposite to the brake output portion 21 side with respect to the clutch nut 27.

The surface of the first clutch 29 facing the clutch nut 27 is formed as a tapered surface inclined with respect to the axial direction so as to form a part of a conical curved surface having the axial direction of the threaded shaft 24 as a center line. Further, the surface of the convex portion 27a of the clutch nut 27 facing the first clutch 29 is also formed as a tapered surface inclined with respect to the axial direction so as to constitute a part of a conical curved surface having the axial direction of the threaded shaft 24 as a center line. The surfaces of the first clutch 29 and the clutch nut 27 facing each other are inclined at substantially the same angle in the axial direction of the threaded shaft 24, and are provided as surfaces that are in contact with each other.

The adjustment stoppers 30 are provided as a pair and fixed to a second clutch 32, which will be described later, formed as an annular member or a cylindrical member having a short axial length. Each adjustment stopper 30 is provided as a block-shaped member that protrudes outward in the radial direction of the second clutch 32.

The pair of adjustment stoppers (30, 30) are fixed to a second clutch 32 described later so as to be disposed at positions along the diameter direction of the guide pipe 25 and the threaded shaft 24. The pair of adjustment stoppers (30, 30) are disposed so as to protrude so as to penetrate the pair of slit portions (25 b ) of the guide tube 25. Further, a pair of stopper stroke limiting portions (39, 39) are provided in the cylindrical portion 36b of the second housing portion 36 of the cylinder body 20 at positions along the diameter direction of the cylindrical portion 36b, and the pair of stopper stroke limiting portions (39, 39) are provided as holes extending parallel to the axial direction of the threaded shaft 24 and formed to penetrate in a slit shape. The projecting end portions of the adjustment stoppers 30 are disposed so as to be movable along the stopper stroke limiting portion 39, and are disposed so as to be capable of abutting against an end portion of the stopper stroke limiting portion 39 in the braking direction and an end portion of the stopper stroke limiting portion 39 in the direction opposite to the braking direction.

By providing the adjustment stopper 30 as described above, the adjustment stopper is disposed so as to be movable relative to the clutch nut 27 and the guide pipe 25 in the axial direction of the threaded shaft 24, and the range of movement relative to the cylinder main body 20 is limited.

The second clutch 32 fixed to the adjustment stopper 30 is formed as a ring or a cylindrical member having a short axial length, and is disposed around the threaded shaft 24 and an adjustment sleeve 33 described later and at a position inside the guide pipe 25.

Further, teeth 32a are formed along the entire circumferential direction on a surface facing the clutch nut 27 at an end portion of the second clutch 32 in the braking direction. On the other hand, teeth 27b are formed along the entire circumferential direction on the surface of the clutch nut 27 facing the second clutch 32 at the end portion in the direction opposite to the braking direction. The teeth 32a on the second clutch 32 side and the teeth 27a on the clutch nut 27 side are formed as teeth that can engage the second clutch 32 with the clutch nut 27.

The adjustment sleeve 33 is a flexible cylindrical member formed of resin, and is disposed around the threaded shaft 24. An engaging portion 33a formed as a concave-convex portion is provided on the outer periphery of the end portion side of the adjustment sleeve 33 in the braking direction. An engaged portion 27c formed as an uneven portion to be engaged with the uneven portion of the engaging portion 33a is provided on the inner periphery of the end portion side of the clutch nut 27 in the direction opposite to the braking direction. The adjustment sleeve 33 and the clutch nut 27 are integrated by engaging the engaging portion 33a on the adjustment sleeve 33 side with the engaged portion 27c on the clutch nut 27 side.

The engaging portion 33a of the adjustment sleeve 33 is provided so as to engage with an engaged portion 27c formed on the inner peripheral side of the clutch nut 27 from the inside. Further, the dimension of the gap formed between the inner periphery of the adjustment sleeve 33 and the crest of the thread 24a of the threaded shaft 24 in the radial direction of the adjustment sleeve 33 is smaller than the dimension of the concave-convex portion of the engagement portion 33a and the engaged portion 27c fitted to each other in the radial direction of the adjustment sleeve 33 (the amount of overlap of the concave-convex portion in the radial direction of the adjustment sleeve 33).

The adjustment spring 31 is provided as a spiral spring disposed around the adjustment sleeve 33. The adjustment spring 31 is disposed such that one end side thereof is in contact with (or connected to) an end portion side of the second clutch 32 in the direction opposite to the braking direction and the other end side thereof biases a spring seat attached to the end portion side of the adjustment sleeve 33 in the direction opposite to the braking direction. In the present embodiment, the spring stopper 34 and the bearing 40 constitute the spring seat described above. Thereby, the adjustment sleeve 33 is biased in the direction opposite to the braking direction by the other end side of the adjustment spring 31 having one end side in contact with the second clutch 32. The adjustment spring 31 can bias the clutch nut 27 engaged with the adjustment sleeve 33 and integrated with the adjustment sleeve 33 in the direction opposite to the braking direction.

The bearing 40 included in the spring seat is disposed between the outer periphery of the adjustment sleeve 33 and the inner periphery of the guide pipe 35, and is attached to the adjustment sleeve 33 by a flange-like projection that engages with the outer periphery of an end portion of the adjustment sleeve 33 in the opposite direction to the braking direction over the entire circumferential direction. The bearing 40 of the spring bearing is disposed such that a gap formed between an outer periphery of the bearing 40 (i.e., an outer periphery of the spring bearing) and an inner periphery of the guide pipe 25 has a substantially zero dimension in the radial direction of the guide pipe 25. The spring seat including the bearing 40 may be disposed such that the outer periphery of the bearing 40 (the outer periphery of the spring seat) is in sliding contact with the inner periphery of the guide pipe 25.

The spring stopper 34 is provided as a cylindrical member disposed around an end portion side of the adjustment sleeve 33 in the direction opposite to the braking direction. Further, a flange-like portion is formed at an end portion of the spring stopper 34 in the direction opposite to the braking direction, and the end surface of the flange-like portion in the direction opposite to the braking direction abuts on the bearing 40. The end surface in the braking direction of the flange-like portion abuts against the other end side (end side in the direction opposite to the braking direction) of the adjustment spring 31. Further, since the bearing 40 is disposed between the spring stopper 34 and the adjustment sleeve 33, the adjustment sleeve 33 is rotatable with respect to the spring stopper 34.

In addition, an end of the cylindrical portion of the spring stopper 34 in the braking direction faces an end of the second clutch 32 in the direction opposite to the braking direction with a gap. Further, an end portion of the cylindrical portion of the spring stopper 34 in the braking direction is disposed so as to abut against an end portion of the second clutch 32 in the direction opposite to the braking direction when the adjustment spring 31 is compressed to a large extent and contracted. Thus, the spring stopper 34 relatively displaces the other end side of the adjustment spring 31, which has one end side in contact with the adjustment stopper 30, with respect to the one end side of the adjustment spring 31, and limits the amount of displacement of the adjustment spring 31, which is elastically deformed, to a predetermined amount or less.

Further, even if the biasing force of the adjustment spring 31 is increased due to the accumulation of pressure, since the bearing 40 is included in the constituent element of the spring seat, the frictional force generated by the biasing force does not hinder the rotation of the clutch nut 27 engaged with the adjustment sleeve 33 and integrated with the adjustment sleeve 33, as compared with the case where the grease is applied only to the disk-shaped member without using the bearing. That is, since the bearing 40 is provided, the above-described biasing force does not substantially affect the rotational direction of the adjustment sleeve 33 and the clutch nut 27 that rotate together with the bearing 40, and therefore, as will be described later, the gap can be reliably adjusted. The bearing 40 may be a rolling bearing, a sliding bearing, or any of a radial bearing and a thrust bearing as long as the sliding resistance between the adjustment spring 31 and the adjustment sleeve 33 can be reduced.

Next, the operation of the brake cylinder device 2 will be described with reference to fig. 6 to 21, which are cross-sectional views of the brake cylinder device 2. In fig. 6 to 21, the bellows structure disposed between the brake output unit 21 and the cylinder main body 20 is not shown. In fig. 6 to 21, the position of the cylinder body 20 is shown as a reference, and the relative position of each component other than the cylinder body 20 with respect to the cylinder body 20 is shown.

In fig. 6 to 17, a position of an end portion 21b in the braking direction of the brake output portion 21 that is movable relative to the cylinder main body 20 to enable braking operation is indicated by a two-dot chain line P (hereinafter, the position indicated by the two-dot chain line P is referred to as a "braking operation position P"). That is, in a state where the position of the end portion 21b of the brake output portion 21 with respect to the cylinder main body 20 reaches the brake operating position P (a position where the braking force can be generated), the pair of brake pads (13, 13) of the disc brake device 1 come into contact with the brake disc 101.

Fig. 6 to 9 are cross-sectional views of the brake cylinder device 2 for explaining a case where the brake cylinder device 2 is operated without performing automatic gap adjustment by the gap adjustment mechanism. Fig. 6 is a sectional view showing a state before the braking operation is performed, that is, a state after the braking is released. In the figure, a distance D1 between the end 21b of the brake output unit 21 and the brake operating position P in this state is indicated by an arrow.

When the brake operation is performed, compressed air is supplied to the pressure chamber 37, and the state shown in the cross-sectional view of fig. 6 is first transited to the state shown in the cross-sectional view of fig. 7. That is, as the compressed air is supplied to the pressure chamber 37, the piston 22 moves in the braking direction together with the guide pipe 25 against the biasing force of the piston spring 23. Then, the threaded shaft 24 moves in the braking direction together with the guide pipe 25 and the thrust spring 26, and the end 21b of the brake output portion 21 reaches the brake operating position P. The state shown in fig. 7 is a state at the moment when the end portion 21c of the brake output portion 21 reaches the brake operating position P and the pair of brake pads (13, 13) contact the brake disc 101, and is a state in which no braking force is generated.

In the state shown in fig. 7, the movement of the threaded shaft 24 and the clutch nut 27, which is screw-fitted to the threaded shaft 24, in the braking direction is restricted. Then, by further continuing the supply of the compressed air to the pressure chamber 37 from the state shown in fig. 7, as shown in the sectional view of fig. 8, the guide pipe 25 moves in the braking direction together with the piston 22, and the front stopper 28 and the first clutch 29 move forward (in the braking direction) together with the guide pipe 25. Thus, the front stopper 28 abutting against the clutch nut 27 is separated from the clutch nut 27, and the first clutch 29 separated from the clutch nut 27 abuts against the clutch nut 27. By achieving the state shown in fig. 8, the pair of brake pads (13, 13) presses the brake disc 101, and braking force is output.

On the other hand, when the brake release operation is performed, the compressed air is discharged from the pressure chamber 37. When the compressed air in the pressure chamber 37 is discharged, the piston 22 moves in the direction opposite to the braking direction together with the guide pipe 25 by the biasing force of the piston spring 23. The front stopper 28 and the first clutch 29 move rearward (in the direction opposite to the braking direction) together with the guide pipe 25. At this time, the threaded shaft 24 is biased in the braking direction by the thrust spring 26, and therefore, as shown in the cross-sectional view of fig. 9, a state occurs in which the clutch nut 27 screwed to the threaded shaft 24 is temporarily separated from either the first clutch 29 or the front stopper 28. That is, the first clutch 29 that is in contact with the clutch nut 27 is temporarily separated from the clutch nut 27, and the front stopper 28 that is separated from the clutch nut 27 is not yet in contact with the clutch nut 27.

As shown in fig. 9, in a state where the clutch 27 is caused to be disengaged from any one of the first clutch 29 and the front stopper 28, the rotation of the clutch nut 27 is not restricted by any one of the front stopper 28 and the first clutch 29. However, even in this state, one end side of the adjustment spring 31 abuts on the second clutch 32, and the other end side thereof biases the clutch nut 27 in the direction opposite to the braking direction via the spring seat (spring stopper 34, bearing 40) and the adjustment sleeve 33. Therefore, the state in which the second clutch 32 and the clutch nut 27 are in contact with each other is maintained in a state in which the teeth 32a on the second clutch 32 side and the teeth 27b on the clutch nut 27 side are engaged with each other. Thereby, in the state shown in fig. 9, the clutch nut 27 is prevented from rotating with respect to the threaded shaft 24.

Therefore, when the brake cylinder device 2 is actuated without the need for adjusting the clearance by the clearance adjustment mechanism, even if the clutch nut 27 is separated from both the front stopper 28 and the first clutch 29, the state in which the second clutch 32 is in contact with the clutch nut 27 can be maintained. Even if vibration or the like occurs, the clutch nut 27 is prevented from rotating, and the clutch nut 27 is prevented from rotating relative to the threaded shaft 24 and being displaced.

The compressed air in the pressure chamber 37 is further discharged from the state shown in fig. 8 through the state shown in fig. 9, and the brake cylinder device 2 instantaneously transits to the same state as the state shown in fig. 7. That is, the clutch nut 27, which is separated from the first clutch 29 and is thus separated from both the front stopper 28 and the first clutch 29, abuts against the front stopper 28.

After the state of the brake cylinder device 2 is instantaneously transited to the same state as that shown in fig. 7, the compressed air in the pressure chamber 37 is further continuously discharged, and the piston 22 and the guide pipe 25 are further moved in the direction opposite to the braking direction. Thereby, the front stopper 28 biases the clutch nut 27 and the threaded shaft 24 in the direction opposite to the braking direction together with the movement of the guide pipe 25 in the direction opposite to the braking direction. That is, the clutch nut 27 abutting the front stopper 28 and the threaded shaft 24 screwed to the clutch nut 27 also move in the direction opposite to the braking direction. As a result, as shown in fig. 6, the brake is released. In the braking operation and the braking release operation shown in fig. 6 to 9, as described above, the clutch nut 27 does not rotate with respect to the threaded shaft 24, and therefore, it is not necessary to perform automatic gap adjustment by the gap adjustment mechanism. That is, the distance D1 between the end 21b of the brake output unit 21 and the brake operating position P does not change at the time before and after the brake operation and the brake release operation.

Next, the operation of the brake cylinder device 2 in the case where automatic gap adjustment is performed by the gap adjustment mechanism will be described with reference to fig. 10 to 17. Fig. 10 is a sectional view showing a state before the braking operation is performed, that is, a state in which the braking is released. In the figure, a distance D2 between the end 21b of the brake output unit 21 and the brake operating position P in this state is indicated by an arrow. In the state shown in fig. 10, the distance D2, which is the gap from the end 21b of the brake output unit 21 in the brake released state to the brake operating position P, is increased by wear of the brake pad 13. That is, the distance D2 is greater than the distance D1 (D2 > D1). In this case, as described below, the clearance is automatically adjusted by a clearance adjustment mechanism including the clutch nut 27, the first clutch 29, the second clutch 32, the threaded shaft 24, the guide tube 25, the thrust spring 26, the front stopper 28, the adjustment stopper 30, the adjustment spring 31, and the like.

When the brake operation is performed, compressed air is supplied to the pressure chamber 37, and the state shown in the cross-sectional view of fig. 10 is first transited to the state shown in the cross-sectional view of fig. 11. That is, as the compressed air is supplied to the pressure chamber 37, the piston 22 moves in the braking direction together with the guide pipe 25 against the biasing force of the piston spring 23. The threaded shaft 24 moves in the braking direction together with the guide tube 25 and the thrust spring 26, and the spring seat (spring stopper 34, bearing 40), the adjustment spring 31, the second clutch 32, and the adjustment stopper 30 also move in the braking direction together with the adjustment sleeve 33, and the adjustment sleeve 33 engages with the clutch nut 27 that is screwed to the threaded shaft 24. At this time, the teeth 32a on the second clutch 32 side and the teeth 27b on the clutch nut 27 side are engaged and kept engaged, and the second clutch 32 and the clutch nut 27 are maintained in a contact state. As shown in the sectional view of fig. 11, the adjustment stopper 30 fixed to the second clutch 32 abuts on an end of the stopper stroke limiting portion 39 in the braking direction. Thereby, the adjustment stopper 30 reaches the forward limit, and the movement of the adjustment stopper 30 in the forward direction (braking direction) with respect to the cylinder body 20 is restricted.

In the state shown in fig. 11, the movement of the adjustment stopper 30 and the second clutch 32 with respect to the cylinder main body 20 is restricted, but the guide pipe 25, the thrust spring 26, the threaded shaft 24, the clutch nut 27, the adjustment sleeve 33, the spring stopper 34, and the bearing 40 are in a state of being movable together with the piston 22. Then, by further continuing the supply of the compressed air to the pressure chamber 37 from the state shown in fig. 11, the end portion 21b of the brake output portion 21 reaches the brake actuation position P, and the state transitions to the state shown in the cross-sectional view of fig. 12. At this time, while the above-described constituent elements (24 to 27, 33, 34, 40) move, the adjustment spring 31 is compressed between the second clutch 32 to which the adjustment stopper 30 is fixed and the spring stopper 34 disposed on the end portion side of the adjustment sleeve 33 in the direction opposite to the braking direction.

When the state shown in fig. 11 is shifted to the state shown in fig. 12, the movement range of the adjustment stopper 30 is limited, and therefore, in the adjustment spring 31, the force that can urge the clutch nut 27 in the direction opposite to the braking direction is accumulated as the accumulated force of the adjustment spring 31 via the spring stopper 34, the bearing 40, and the adjustment sleeve 33. Then, as shown by an arrow in fig. 12, the clutch nut 27 integrally formed with the adjustment sleeve 33 moves by a distance F1 relative to the second clutch 32 to which the adjustment stopper 30 whose movement range is restricted by the cylinder body 20 is fixed. That is, the engagement between the teeth 32a on the second clutch 32 side and the teeth 27b on the clutch nut 27 side is released, the contact between the second clutch 32 and the clutch nut 27 is released, and a gap of a distance F1 is formed between the second clutch 32 and the clutch nut 27. The adjustment spring 31 is compressed by the same size as the distance F1 (size F1), and the adjustment spring 31 accumulates the stored force.

The state shown in fig. 12 is a state in which the end portion 21b of the brake output portion 21 reaches the brake operating position P and the pair of brake pads (13, 13) contact the brake disc 101, and the braking force is not yet generated. In this state, the threaded shaft 24 and the clutch nut 27 screw-fitted to the threaded shaft 24 are restricted from moving in the braking direction. Then, by further continuing the supply of the compressed air to the pressure chamber 37 from the state shown in fig. 12, as shown in the sectional view of fig. 13, the guide pipe 25 moves in the braking direction together with the piston 22, and the front stopper 28 and the first clutch 29 move forward (in the braking direction) together with the guide pipe 25. Thus, the front stopper 28 abutting against the clutch nut 27 is separated from the clutch nut 27, and the first clutch 29 separated from the clutch nut 27 abuts against the clutch nut 27. When the state shown in fig. 13 is reached, the pair of brake pads (13, 13) presses the brake disc 101, and braking force is output. In this state, the adjustment spring 31 still maintains the stored force corresponding to the compressed dimension of the dimension F1 shown in fig. 13.

In the present embodiment, as described later, the case where the backlash adjustment operation is performed only at the time of the brake release operation is described as an example, but this case may not be employed. In the process of the brake cylinder device 2 transitioning from the state shown in fig. 12 to the state shown in fig. 13, when the clutch nut 27 is in a state of being separated from both the front stopper 28 and the first clutch 29, the clutch nut 27 that is also separated from the second clutch 32 may be rotated by the accumulated force of the adjustment spring 31 to move relative to the threaded shaft 24, thereby performing the gap adjustment operation.

On the other hand, when the brake release operation is performed, the compressed air is discharged from the pressure chamber 37. When the compressed air in the pressure chamber 37 is discharged, the piston 22 starts to move in the direction opposite to the braking direction together with the guide pipe 25 by the biasing force of the piston spring 23. Then, the front stopper 28 and the first clutch 29 start to move rearward (in the direction opposite to the braking direction) together with the guide pipe 25. At this time, the clutch nut 27 should be separated from the first clutch 29 and brought into contact with the front stopper 28, but the threaded shaft 24 is biased in the braking direction by the thrust spring 26. Therefore, as shown in the sectional view of fig. 14, the following state is produced: the threaded shaft 24 and the brake output portion 21 do not move in the direction opposite to the braking direction, and the clutch nut 27 is biased in the direction opposite to the braking direction by the accumulated force of the adjustment spring 31 corresponding to the dimension F1. At this time, the clutch nut 27 is in a state in which the contact with the first clutch 29 is released and the clutch nut 27 is not in contact with the front stopper 28, and the clutch nut 27 is not in contact with the second clutch 32, so that the clutch nut 27 is rotatable with respect to the threaded shaft 24.

As described above, when the clutch nut 27 is in a state in which it is not in contact with any of the front stopper 28, the first clutch 29, and the second clutch 32 and is rotatable with respect to the threaded shaft 24, the clutch nut 27 is rotated with respect to the threaded shaft 24 so as to move in the direction opposite to the braking direction by the stored force of the adjustment spring 31 corresponding to the dimension F1. By rotating the clutch nut 27 relative to the threaded shaft 24 as described above, the dimension F1 shown in fig. 14 is reduced. As shown in fig. 15, the state in which the clutch nut 27 is not in contact with the front stopper 28, the first clutch 29, and the second clutch 32 and is rotated relative to the threaded shaft 24 continues until the gap between the clutch nut 27 and the second clutch 32 disappears and the clutch nut 27 is in contact with the second clutch 32, that is, the dimension F1 becomes zero. By setting the dimension F1 to zero in this manner, the clutch nut 27 is in a non-rotatable state. The rotation of the clutch nut 27 until the dimension F1 becomes zero is not limited to the case where the rotation is completed in a period in which one braking operation and one braking release operation are performed, and may be completed in a period in which a plurality of braking operations and a plurality of braking release operations are performed.

The compressed air in the pressure chamber 37 is further discharged from the state shown in fig. 15, whereby the piston 22, the guide pipe 25, and the front stopper 28 further move in the direction opposite to the braking direction. Then, as shown in the sectional view of fig. 16, the front stopper 28 abuts against the clutch nut 27. As the guide pipe 25 moves in the direction opposite to the braking direction, the clutch nut 27 in contact with the front stopper 28 and the threaded shaft 24 screwed to the clutch nut 27 also move in the direction opposite to the braking direction. As a result, as shown in fig. 17, the brake output unit 21 also moves in the direction opposite to the braking direction, and the brake is released.

In the brake released state shown in fig. 17, the distance between the end 21b of the brake output unit 21 and the brake operating position P is changed to a distance D3 (D3 < D2) smaller than the distance D2, as compared with the state before the brake operation and the brake release operation. That is, since the clutch nut 27 is relatively moved in the opposite direction to the braking direction with respect to the threaded shaft 24 in the middle of the brake release operation, the brake release operation is ended in a state where the position of the threaded shaft 24 is moved in the braking direction from the state before the brake release operation. Then, the state is shifted to a state in which the threaded shaft 24 and the brake output portion 21 are moved to a position protruding from the cylinder main body 20 compared to the state before the braking operation and the braking release operation are performed. This makes it possible to automatically adjust the clearance from the brake-released state to the brake operating position P.

Next, with reference to fig. 18 to 21, the operation of the brake cylinder device 2 in the case where the clearance adjusting operation is forcibly performed in a state where the brake pad 13 is not in contact with the brake disc 101 and no braking force is generated, that is, in a so-called idling state (the clearance adjustment is performed by a force generated when the brake pad 13 is in contact with the brake disc 101, and therefore the clearance cannot be adjusted if the brake pad is not in contact) in the operation of performing the clearance adjusting operation as in the related art will be described. Fig. 18 is a sectional view showing a state before compressed air is supplied to the pressure chamber 37 in the idling state (i.e., a state corresponding to the brake released state). For example, a state in which the clearance adjusting operation is to be performed after the replacement operation of the brake pads 13 of the disc brake device 1 is performed is shown.

In the above case, by supplying compressed air to the pressure chamber 37, first, the state shown in the cross-sectional view of fig. 18 is transited to the state shown in the cross-sectional view of fig. 19. That is, as the compressed air is supplied to the pressure chamber 37, the piston 22 moves in the braking direction together with the guide pipe 25 against the biasing force of the piston spring 23. The threaded shaft 24 moves in the braking direction together with the guide tube 25 and the thrust spring 26, and the second clutch 32, the adjustment stopper 30, and the adjustment spring 31 also move in the braking direction together with the adjustment sleeve 33, and the adjustment sleeve 33 engages with the clutch nut 27 that is screwed to the threaded shaft 24. As shown in the sectional view of fig. 19, the adjustment stopper 30 fixed to the second clutch 32 abuts on an end of the stroke limiting portion 39 in the braking direction. Thereby, the adjustment stopper 30 reaches the forward limit, and the movement of the adjustment stopper 30 in the forward direction (braking direction) with respect to the cylinder body 20 is restricted.

In the state shown in fig. 19, the movement of the adjustment stopper 30 and the second clutch 32 with respect to the cylinder main body 20 is restricted, but predetermined components (24 to 27, 33, 34, 40) such as the screw shaft 24 are in a state of being movable together with the piston 22. By further continuing the supply of the compressed air to the pressure chamber 37 from the state shown in fig. 19, the above-described constituent elements (24 to 27, 33, 34, 40) move, and the adjustment spring 31 is compressed between the second clutch 32 to which the adjustment stopper 30 is fixed and the spring stopper 34 disposed on the end portion side of the adjustment sleeve 33 in the direction opposite to the braking direction. Then, the end portion of the spring stopper 34 in the braking direction abuts on the end portion of the second clutch 32 in the direction opposite to the braking direction, and the state shown in the cross-sectional view of fig. 20 is transited.

In the state shown in fig. 20, in the adjustment spring 31, a force that can urge the clutch nut 27 in the direction opposite to the braking direction is accumulated as an accumulated force of the adjustment spring 31 via the spring stopper 34, the bearing 40, and the adjustment sleeve 33. At this time, as shown by the arrow in fig. 20, the clutch nut 27 integrally formed with the adjustment sleeve 33 is moved by a distance F2 relative to the second clutch 32 to which the adjustment stopper 30 whose movement range is restricted by the cylinder body 20 is fixed. The adjustment spring 31 is compressed by the same size as the distance F2 (size F2), and the adjustment spring 31 accumulates the stored force.

As shown in fig. 20, when the movement of the adjustment stopper 30 is restricted and the second clutch 32 to which the adjustment stopper 30 is fixed is in contact with the spring stopper 34, the adjustment sleeve 33 having an end portion side in the opposite direction to the braking direction engaged with the bearing 40 in contact with the spring stopper 34 cannot move forward (the braking direction). Therefore, the clutch nut 27 engaged with the adjustment sleeve 33 cannot move in the braking direction, and the clutch nut 27 cannot move in the braking direction together with the piston 22, the guide pipe 25, the thrust spring 26, and the threaded shaft 24.

However, since the brake pad 13 does not abut on the brake disc 101, the piston 22, the guide pipe 25, the front stopper 28, the first clutch 29, the thrust spring 26, and the thrust spring guide 38 are further moved in the braking direction by further continuing the supply of the compressed air to the pressure chamber 37 from the state shown in fig. 20. As a result, as shown in the cross-sectional view of fig. 21, the clutch nut 27 is separated from the front stopper 28, and also separated from the first clutch 29 without coming into contact therewith. Therefore, the clutch nut 27 is not in contact with the front stopper 28, the first clutch 29, and the second clutch 32, and is rotatable with respect to the threaded shaft 24. At this time, since the threaded shaft 24 is urged by the thrust spring 26, the clutch nut 27 is rotated relative to the threaded shaft 24 by the urging force of the thrust spring 26. Therefore, the threaded shaft 24 protrudes in the braking direction relative to the clutch nut 27. When the brake pad 13 abuts against the brake disc 101, the movement of the threaded shaft 24 due to the biasing force of the thrust spring 26 is stopped, and the rotation of the clutch nut 27 with respect to the threaded shaft 24 is stopped. Further, even when the brake pad 13 is not in contact with the brake disc 101, if the thrust spring 26 is extended and the biasing force of the thrust spring 26 is sufficiently reduced, the rotation of the clutch nut 27 relative to the threaded shaft 24 due to the biasing force of the thrust spring 26 is stopped.

As described above, even in a state where the rotation of the clutch nut 27 relative to the threaded shaft 24 is stopped by the biasing force of the thrust spring 26, the clutch nut 27 is not in contact with the front stopper 28, the first clutch 29, and the second clutch 32, and is rotatable relative to the threaded shaft 24. Therefore, the clutch nut 27 is biased by the accumulated force accumulated in the adjustment spring 31 to rotate relative to the threaded shaft 24 so as to move in the direction opposite to the braking direction. As described above, the clutch nut 27 is rotated with respect to the threaded shaft 24, whereby the clutch nut 27 abuts against the first clutch 29. In this state, the state of the gap adjustment mechanism is the same as that shown in the cross-sectional view of fig. 13, that is, the same as that of the braking force output when the gap adjustment mechanism automatically performs the gap adjustment. In this state, the operation corresponding to the braking operation is ended. After the operation corresponding to the braking operation is completed, the compressed air is discharged from the pressure chamber 37, and the operation corresponding to the braking release operation is performed in the same manner as the braking release operation described in fig. 14 to 16. By performing the operation corresponding to this brake release operation, the same operation as the gap adjustment operation described with reference to fig. 14 to 16 is performed in the gap adjustment mechanism. Further, a state in which the clutch nut 27 is not in contact with the front stopper 28, and the first clutch 29 and the second clutch 32 and is rotated relative to the threaded shaft 24, which is a state in which the same operation as the backlash adjustment operation is performed, continues until the backlash between the clutch nut 27 and the second clutch 32 disappears and the clutch nut 27 and the second clutch 32 are in contact. The rotation of the clutch nut 27 until the clutch nut 27 comes into contact with the second clutch 32 is not limited to the case where the rotation is completed in a period in which the operation corresponding to the braking operation and the braking release operation is performed once, and may be completed in a period in which the operation corresponding to the braking operation and the braking release operation is performed a plurality of times.

As described above, even in the idling state, since the clutch nut 27 is moved in the direction opposite to the braking direction with respect to the screw shaft 24 by performing the operation corresponding to the braking operation and the operation corresponding to the brake release operation, the above-described operation is ended in a state where the position of the screw shaft 24 is moved in the braking direction than in the state before performing the operation corresponding to the braking operation and the operation corresponding to the brake release operation. Then, the state is shifted to a state in which the threaded shaft 24 and the brake output portion 21 are moved to a position protruding from the cylinder main body 20 compared to the state before the operation corresponding to the braking operation and the operation corresponding to the brake release operation are performed. Thus, when the brake is enabled from the idle state after the maintenance work such as the replacement work of the brake pads 13 is completed, the clearance from the brake released state to the brake operating position P is automatically adjusted.

As described above, with the brake cylinder device 2, the clearance adjustment mechanism is constituted by the clutch nut 27, the first clutch 29, the second clutch 32, the threaded shaft 24, the guide pipe 25, the thrust spring 26, the front stopper 28, the adjustment stopper 30, the adjustment spring 31, and the like. Therefore, the gap adjustment is not performed by elastic deformation of rubber or the like, and a structure that is less susceptible to the influence of the surrounding environment such as temperature and humidity can be realized. Further, since no bearing is required in the structure in which the guide pipe 25 is attached to the piston 22, the diameter size of the rear side (the end side in the direction opposite to the braking direction) of the cylinder body 20 can be reduced.

Thus, according to the present embodiment, there is provided the brake cylinder device 2 having the clearance adjustment mechanism for automatically adjusting the clearance from the brake released state to the brake operation position P, which is less susceptible to the influence of the surrounding environment such as temperature and humidity, and which can reduce the radial dimension of the cylinder main body 20 at low cost.

Further, with the brake cylinder device 2, in a state where the automatic gap adjustment operation is not performed by the gap adjustment mechanism, the state of contact between the second clutch 32 and the clutch nut 27 is maintained regardless of whether the brake is operated or released, and the second clutch 32 and the clutch nut 27 are prevented from being separated. That is, in the state where the gap adjusting operation is performed, the clutch nut 27 is biased in the direction opposite to the braking direction by the adjusting spring 31 having one end side in contact with the second clutch 32, and the state where the second clutch 32 and the clutch nut 27 are in contact is maintained. This prevents the clutch nut 27 from rotating with respect to the threaded shaft 24 at a time other than when the gap adjustment operation is performed, and prevents the clutch nut 27 from being positionally displaced with respect to the threaded shaft 24 due to vibration or the like.

When the clutch nut 27 is positionally displaced with respect to the threaded shaft 24 due to vibration or the like, the brake output portion 21 projects excessively in the braking direction with respect to the cylinder main body 20, or the projection amount of the brake output portion 21 in the braking direction with respect to the cylinder main body 20 is insufficient. When the clutch nut 27 is displaced from the threaded shaft 24 and the brake output portion 21 is excessively protruded in the braking direction with respect to the cylinder main body 20, that is, when the clearance is excessively adjusted, the brake pad 13 and the brake disc 101 are in a state of being in contact with and rubbing against each other at all times. In this case, the wear of the brake pads 13 is promoted, and the replacement cycle of the brake pads 13 may be advanced. On the other hand, if the clutch nut 27 is positionally displaced with respect to the threaded shaft 24 and the amount of projection of the brake output portion 21 with respect to the braking direction of the cylinder main body 20 is in a state of insufficient backlash adjustment, that is, a state of insufficient backlash adjustment, the timing of generation of the braking force at the time of the braking operation is delayed even in a state where backlash adjustment is not originally required.

However, with the brake cylinder device 2, as described above, the clutch nut 27 is prevented from rotating with respect to the threaded shaft 24 at a time other than when the gap adjustment operation is performed, and the position of the clutch nut 27 with respect to the threaded shaft 24 is prevented from being displaced due to vibration or the like. Therefore, it is possible to prevent the occurrence of a situation in which the wear of the brake pads 13 is promoted and the replacement cycle of the brake pads 13 is advanced, or a situation in which the generation timing of the braking force during the braking operation is delayed even in a situation in which the clearance adjustment is not originally necessary.

Further, with the brake cylinder device 2, the thrust spring 26 that biases the threaded shaft 24 is disposed inside the threaded shaft 24 formed in a hollow structure, and biases the clutch nut 27, which is screwed to the threaded shaft 24, toward the front stopper 28. Therefore, the thrust spring 26 can be disposed by efficiently utilizing the space of the brake cylinder device 2. This can improve the space efficiency of the brake cylinder device 2, and can further reduce the size.

Further, with the brake cylinder device 2, a thrust spring guide 38 is provided, and the thrust spring guide 38 extends inside the spiral thrust spring 26 to restrict deformation of the thrust spring 26 in the buckling direction. Therefore, even when the size of the gap to be adjusted is increased and a long thrust spring 26 is required as the gap adjustment mechanism, buckling of the thrust spring 26 can be prevented efficiently. Further, a tip end portion of a thrust spring guide 38 provided movably together with the guide pipe 25 is slidably disposed inside the screw shaft 24. Therefore, with a simple structure in which the shaft-like thrust spring guide 38 is provided, a structure in which the positional relationship between the screw shaft 24 and the piston 22 is maintained in a shifted relationship on the same axis can be easily realized.

In addition, with the brake cylinder device 2, the front stopper 28 and the first clutch 29 are provided as separate integral members and are fixed to the guide pipe 25 independently of each other. Therefore, it is not necessary to provide the front stopper 28 and the first clutch 29 disposed in front of and behind the clutch nut 27 in a separate structure and to couple them with a separate coupling member. Similarly, it is not necessary to provide the clutch nut 27, in which the front stopper 28 and the first clutch 29 are arranged in the front and rear, with a separate structure and to couple them with another coupling member. This can simplify the structure of the front stopper 28, the first clutch 29, and the clutch nut 27, and as a result, the brake cylinder device 2 as a whole can be reduced in size and weight. Further, since the front stopper 28 and the first clutch 29 are each an integral separate member and are fixed to the guide pipe 25, the inner periphery of the front stopper 28 and the inner periphery of the first clutch 29 can be set to a dimensional structure closer to the outer periphery of the threaded shaft 24, and the brake cylinder device 2 can be further downsized.

Further, with the brake cylinder device 2, the front stopper 28, which is an integral member, is fixed to the inner periphery of the guide pipe 25 by screwing. Therefore, the front stopper 28 can be easily replaced during maintenance, and the maintainability can be improved.

In the brake cylinder device 2, the adjustment spring 31 is disposed between the second clutch 32 to which the adjustment stopper 30 is fixed and the cylindrical adjustment sleeve 33 disposed around the threaded shaft 24, and the adjustment spring 31 accumulates a force that moves the clutch nut 27 in a direction opposite to the braking direction with respect to the threaded shaft 24 during the clearance adjustment operation as the adjustment sleeve 33 moves relative to the adjustment stopper 30 and the second clutch 32. The adjustment sleeve 33 is provided as a flexible member, and the adjustment sleeve 33 and the clutch nut 27 are integrated by engaging the engaging portion 33a on the adjustment sleeve 33 side with the engaged portion 27c on the clutch nut 27 side. Therefore, the flexible adjustment sleeve 33 is temporarily elastically deformed to engage the engagement portion 33a with the engaged portion 27c, so that the adjustment sleeve 33 and the clutch nut 27 can be integrated without using a separate coupling member. In this way, in the structure in which the adjustment sleeve 33 and the clutch nut 27 are integrated, since no additional coupling member is required, the brake cylinder device 2 can be further downsized.

Further, with the brake cylinder device 2, the adjustment sleeve 33 is engaged from the inside of the clutch nut 27, and the dimension of the gap between the inner periphery of the adjustment sleeve 33 and the crest of the thread ridge of the thread 24a of the threaded shaft 24 is set smaller than the dimension in the radial direction of the concave-convex portion of the engagement portion 33a and the engaged portion 27c that are fitted to each other (the amount of overlap of the concave-convex portion in the radial direction of the adjustment sleeve 33). Therefore, the engaging portion 33a of the flexible adjustment sleeve 33 is disposed between the clutch nut 27 and the threaded shaft 24, which are formed of a metal material, and the dimension relationship is set so as to prevent the engaging portion 33a of the adjustment sleeve 33 from being deformed toward the threaded shaft 24 and being disengaged from the engaged portion 27 c. Thus, the adjustment sleeve 33 and the clutch nut 27 can be firmly integrated despite the simple engagement structure.

In addition, with the brake cylinder device 2, since the other end side of the adjustment spring 31 biases the adjustment sleeve 33 via the bearing 40, when the adjustment sleeve 33 is biased by the accumulated force of the adjustment spring 31, the clutch nut 27 smoothly rotates together with the adjustment sleeve 33 and moves in the braking direction. Further, since the bearing 40 of the spring seat is disposed so that the clearance between the bearing 40 and the guide pipe 25 is substantially zero or the bearing is in sliding contact with the guide pipe 25, the screw shaft 24 can be supported by the guide pipe 25 via the bearing 40 of the spring seat, and the screw shaft 24 can be prevented from tilting with respect to the guide pipe 25.

Further, in the brake cylinder device 2, a spring stopper 34 is provided, and the spring stopper 34 limits the displacement amount of the adjustment spring 31 when it is elastically deformed to accumulate the force for the gap adjustment operation to a predetermined amount or less. Therefore, in the operation of performing the conventional clearance adjustment operation, even when the clearance adjustment operation is forcibly performed in the operation in the idling state in which the braking force is not generated, the stroke of the adjustment spring 31 can be limited by the spring stopper 34. Therefore, the adjustment spring 31 is not excessively compressed or extended, and the gap adjustment operation can be forcibly performed even in an idling state.

Further, with the brake cylinder devices 2, since the clearance adjustment operation can be forcibly performed even in the idle state as described above, the clearance in all the brake cylinder devices 2 can be automatically adjusted by repeating the operation corresponding to the braking operation and the braking release operation a plurality of times in a batch manner in the entire vehicle or the trailer vehicle. Thus, even when the brake pads 13 are replaced, it is not necessary to manually perform clearance adjustment for each brake cylinder device 2, and clearance adjustment can be performed automatically and collectively for all the brake cylinder devices 2 of the vehicle or the trailer, and in the work accompanying replacement of the brake pads 13, the number of man-hours and the amount of work can be significantly reduced, thereby achieving high efficiency.

Further, with the brake cylinder device 2, in a state where the clutch nut 27 and the second clutch 32 are maintained in contact without performing the gap adjustment operation, since the second clutch 32 and the clutch nut 27 are engaged with each other via the teeth (27 b, 32 a) formed on the surfaces facing each other, it is possible to reliably prevent the clutch nut 27 from rotating with respect to the threaded shaft 24 due to vibration or the like. Further, since the clutch nut 27 and the second clutch 32 are engaged with each other via the teeth (27 b, 32 a), even if the clutch nut 27 and the second clutch are engaged with only the tip end portions of the teeth (27 b, 32 a) engaged with each other, the clutch nut 27 can be reliably prevented from rotating with respect to the threaded shaft 24.

Further, in the brake cylinder device 2, a hexagonal head 24c as an operation engagement portion is provided at a distal end portion disposed so as to penetrate the brake output portion 21 to face outward, and the threaded shaft 24 and the brake output portion 21 are engaged with each other by an engagement mechanism 42 disposed on an outer periphery of the distal end side of the threaded shaft 24. The engagement mechanism 42 includes an engagement spring 44 and an outer peripheral engagement portion 43 having an engagement tooth 43a, and the engagement spring 44 biases the outer peripheral engagement portion 43 in the braking direction to engage the threaded shaft 24 with the brake output portion 21 via the engagement tooth 43 a. Therefore, the engagement between the outer peripheral engagement portion 43 and the brake output portion 21 via the engagement teeth 43a is released against the spring force of the engagement spring 44, so that the engagement between the screw shaft 24 and the brake output portion 21 is released, and further, the screw shaft 24 is rotated by a tool for operation, so that the screw shaft 24 can be manually rotated. This makes it possible to easily restore the positional relationship between the threaded shaft 24 and the clutch nut 27 to the initial state before the backlash adjustment.

Further, according to the present embodiment, there is provided a disc brake device 1 including a brake cylinder device 2, in which the brake cylinder device 2 is provided with a clearance adjustment mechanism for automatically adjusting a clearance from a brake released state to a brake operating position P, and which is less susceptible to an influence of an ambient environment such as temperature and humidity, and which can reduce the radial dimension of the cylinder body 20 at low cost.

Second embodiment

Next, a brake cylinder device 3 according to a second embodiment of the present invention will be described. Fig. 22 is a sectional view of the brake cylinder device 3 of the second embodiment. The brake cylinder device 3 shown in fig. 22 is provided as a brake cylinder device provided in the disc brake device 1, similarly to the brake cylinder device 2 of the first embodiment. In fig. 22, a part of the components of the brake cylinder device 3 is not shown in cross section but is shown in outer diameter.

The brake cylinder device 3 includes a cylinder body 20, a brake output portion 21, a piston 50, a piston spring 23, a threaded shaft 24, a guide pipe 25, a thrust spring 26, a clutch nut 27, a front stopper 28, a first clutch 29, an adjustment stopper 30, an adjustment spring 31, a second clutch 32, an adjustment sleeve 33, a spring stopper 34, a thrust spring guide 38, a bearing 40, an engagement mechanism 42, and the like, as in the brake cylinder device 2 of the first embodiment. The members other than the adjustment sleeve 33 among the above-described constituent elements are formed of, for example, a metal material such as an iron-based material, and the adjustment sleeve 33 is formed of, for example, a resin material.

As described above, the brake cylinder device 3 is configured in the same manner as the brake cylinder device 2 according to the first embodiment. However, the brake cylinder device 3 is also provided with the force increasing mechanism 51, and the moving direction of the piston 50 is the opposite direction to the moving direction of the piston 22 of the first embodiment, which is different from the brake cylinder device 2 of the first embodiment in the point described above. In the following description of the brake cylinder device 3, a structure different from that of the first embodiment will be described, and elements configured to have the same functions as those of the first embodiment will be denoted by the same reference numerals and will not be described.

The piston 50 includes a disk-shaped portion 52 and a pair of plate-shaped portions 53 (only one plate-shaped portion 53 is shown in fig. 22), and the pair of plate-shaped portions 53 protrude from the disk-shaped portion 52 in parallel with the threaded shaft 24 and the guide pipe 25 in a direction opposite to the braking direction (the direction indicated by the arrow B in fig. 22). Further, a cylindrical portion 54 extending toward the first housing portion 35 side (i.e., in the direction opposite to the braking direction) is formed inside the second housing portion 36 of the cylinder block 20. A through hole 52a is formed in the center of the disk-shaped portion 52, and a cylindrical portion 54 of the cylinder main body 20 is inserted through the through hole 52 a. Thereby, the piston 50 is disposed between the outer peripheral surface of the cylindrical portion 54 and the inner peripheral surface of the second housing portion 36. That is, the piston 50 is disposed so as to divide a space between the outer peripheral surface of the cylindrical portion 54 and the inner peripheral surface of the second housing portion 36 into two parts, and is movable relative to the cylinder main body 20 in the axial direction. Further, a pressure chamber 37 is defined between the piston 50 and the second housing portion 36.

Further, the cylinder body 20 is provided with a pair of guide shafts 55 (only one guide shaft 55 is illustrated in fig. 22) extending in parallel with the axial directions of the screw shaft 24 and the guide pipe 25. The disc-shaped portion 52 of the piston 50 is provided with guide holes 52b through which the guide shafts 55 are inserted. A piston spring 23 is disposed around each guide shaft 55, and the piston spring 23 biases the piston 50 toward the brake output unit 21 (i.e., in the direction indicated by the arrow a in fig. 22, i.e., in the braking direction).

Each plate-shaped portion 53 of the piston 50 is provided with an inclined surface 53a, and the inclined surface 53a is inclined spirally with respect to the central axis direction of the threaded shaft 24 and the guide pipe 25 and the circumferential direction around the central axis. Further, the rollers 61 attached to the turning member 56 to be described later so as to be rotatable with respect to the turning member 56 are disposed so as to be in contact with the inclined surfaces 53a of the plate-like portions 53, respectively.

The force increasing mechanism 51 is provided as the following mechanism: when the piston 50 moves in the direction opposite to the braking direction, the force generated by the piston 50 is increased and applied to the guide pipe 25, so that the guide pipe 25, the thrust spring 26, the threaded shaft 24, and the like move in the braking direction (the direction indicated by the arrow a in fig. 22) opposite to the movement direction of the piston 50. That is, when the compressed air is supplied to the pressure chamber 37 and the piston 50 is moved in the direction opposite to the braking direction in the cylinder body 20, the force increased by the force increasing mechanism 51 acts on the guide pipe 25 attached to the force increasing mechanism 51, and the guide pipe 25, the thrust spring 26, the screw shaft 24, and the like are moved in the braking direction. Therefore, the brake output portion 21 connected to the threaded shaft 24 is moved in the braking direction by the force increasing mechanism 51, and the force generated in the piston 50 is increased by the force increasing mechanism 51 as the piston 50 is moved in the direction opposite to the braking direction.

The force increasing mechanism 51 includes the inclined surface 53a provided on the piston 50, a rotating member 56, a first support member 57, a second support member 58, a first rolling member 59, a second rolling member 60, and the like.

The rotating member 56 is a disk-shaped member that rotates in a predetermined rotational direction about the center axis of the screw shaft 24 and the guide pipe 25, and has a through hole formed at the center thereof. The turning member 56 is biased by the inclined surface 53a of the piston 50 when the piston 50 moves in the direction opposite to the braking direction, and is configured to turn in the predetermined rotational direction about the center axis of the threaded shaft 24 and the guide pipe 25. The threaded shaft 24 and the guide pipe 25 are provided so as not to rotate about the center axis with respect to the cylinder body 20, but move in the braking direction as the rotating member 56 rotates in the predetermined rotational direction. The turning member 56 is provided with a pair of shaft portions projecting radially outward from the outer peripheral surface of the disc-shaped portion, and a roller 61 that abuts against the inclined surface 53a of the piston 50 on the outer peripheral surface is attached to each shaft portion so as to be rotatable relative to the shaft portion.

The first support member 57 is a disk-shaped member having a through hole formed in the center thereof, is disposed around the center axis of the screw shaft 24 and the guide pipe 25, and is fixed to the outer periphery of the guide pipe 25. The first support member 57 is disposed on the braking direction side in the direction parallel to the center axis direction of the threaded shaft 24 and the guide pipe 25 so as to face the rotary member 56.

Further, a first inclined groove (not shown) is provided on the surface of the rotating member 56 facing the first support member 57, and the first inclined groove is formed so that the depth thereof changes obliquely to the rotating direction of the rotating member 56. A first rolling member 59 (shown by a broken line in fig. 22) capable of rolling along the inner surface of the first inclined groove is disposed in the first inclined groove. The first rolling member 59 is provided as a spherical member, and is supported in a state of being sandwiched by the first support member 57 and the rotating member 56. The first inclined grooves and the first rolling members 59 are provided in plural numbers so as to be located along the circumference of one circle centered on the center axes of the threaded shaft 24 and the guide pipe 25. Further, a spring 62 is disposed between a step portion formed on the inner peripheral side of an end portion in the braking direction of the first support member 57 and a step portion formed on the inner wall of the cylindrical portion 54 of the second housing portion 36. The spring 62 biases the first support member 57 in a direction opposite to the braking direction. In addition, in the cylinder main body 20 of the brake cylinder device 3, a portion of the cylindrical portion 54 constituting a stepped portion which abuts against the spring 62 also functions as the stopper stroke limiting portion 39.

The second support member 58 is a disk-shaped member having a through hole formed in the center thereof, is disposed centering on the central axis of the screw shaft 24 and the guide pipe 25, and is fixed to the first housing portion 35 of the cylinder main body 20. The second support member 58 is disposed so as to face the rotary member 56 on the side opposite to the braking direction in the direction parallel to the central axis direction of the threaded shaft 24 and the guide pipe 25, that is, the second support member 58 is disposed so as to face the surface of the rotary member 56 on the side opposite to the surface facing the first support member 57.

Further, a second inclined groove (not shown) is provided on the surface of the rotating member 56 facing the second support member 58, and the second inclined groove is formed so that the depth thereof changes obliquely in the rotating direction of the rotating member 56. A second rolling member 60 (shown by a broken line in fig. 22) capable of rolling along the inner surface of the second inclined groove is disposed in the second inclined groove. The second rolling member 60 is provided as a spherical member, and is supported in a state of being sandwiched by the rotating member 56 and the second supporting member 58. The second inclined grooves and the second rolling members 60 are provided in plural numbers so as to be located along the circumference of one circle centered on the center axes of the screw shaft 24 and the guide pipe 25.

In the brake cylinder device 3, during a braking operation, compressed air is supplied to the pressure chamber 37, the piston 50 moves in a direction opposite to the braking direction against the biasing force of the piston spring 23, and the roller 61 abutting against the inclined surface 53a of the piston 50 rotates. Then, the roller 61 rotates relative to the shaft portion of the rotating member 56, and the rotating member 56 rotates in a predetermined rotational direction about the center axis of the screw shaft 24 and the guide pipe 25. As the rotary member 56 rotates, the first rolling member 59 rolls in the first inclined groove, and the second rolling member 60 rolls in the second inclined groove, whereby the rotary member 56 and the first support member 57 move in the braking direction with respect to the cylinder main body 20. Then, the guide pipe 25, the thrust spring 26, the threaded shaft 24, and the like move in the braking direction, and the brake output unit 21 moves in the braking direction.

On the other hand, when the brake release operation is performed in the brake cylinder device 3, compressed air is discharged from the pressure chamber 37, and the piston 50 moves in the braking direction by the biasing force of the piston spring 23. Then, the rotary member 56, the first support member 57, the first rolling member 59, and the second rolling member 60 move in the opposite direction to the braking operation. Thereby, the guide tube 25, the thrust spring 26, the threaded shaft 24, and the like move in the direction opposite to the braking direction, and the brake output portion 21 moves in the direction opposite to the braking direction. Also, during the brake release operation, the first support member 57 is biased in the direction opposite to the braking direction by the spring 62, and therefore, the first rolling member 59 rolls in the first inclined groove, and the second rolling member 60 rolls in the second inclined groove.

Further, the clearance adjustment mechanism constituted by the clutch nut 27, the front stopper 28, the first clutch 29, the second clutch 32, the threaded shaft 24, the guide pipe 25, the thrust spring 26, the adjustment stopper 30, the adjustment spring 31, and the like operates in the same manner as in the case of the first embodiment. Therefore, in the present embodiment, as in the first embodiment, the brake cylinder device 3 having the clearance adjustment mechanism for automatically adjusting the clearance from the brake released state to the brake operation position is provided, which is less susceptible to the influence of the surrounding environment such as temperature and humidity, and which can reduce the radial dimension of the cylinder main body 20 at low cost.

Modification example

While the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be implemented by being variously modified within the scope of the claims. For example, the following modifications can be implemented.

(1) In the first embodiment, the description has been given taking as an example a case where the thrust spring is disposed on the guide pipe so as to be able to urge the screw shaft in the braking direction. The thrust spring may be disposed on the piston so as to bias the threaded shaft in the braking direction.

(2) The shapes and arrangements of the adjustment spring, the adjustment stopper, the front stopper, the adjustment sleeve, and the spring stopper are not limited to those illustrated in the embodiments, and may be modified and implemented. The shapes of the clutch nut, the first clutch, and the second clutch may be modified.

(3) In the above-described embodiment, the description has been given by taking as an example the case where only the front stopper is fixed to the inner periphery of the guide pipe by screwing, but this need not be the case, and the first clutch may also be fixed to the inner periphery of the guide pipe by screwing. The front stopper may be fixed to the inner periphery of the guide tube by press fitting.

(4) In the above-described embodiment, the description has been given taking as an example the case where the teeth that can engage the second clutch and the clutch nut are formed on both the surface of the second clutch that faces the clutch nut and the surface of the clutch nut that faces the second clutch, but this need not be the case, and teeth may be formed on either of the surfaces that face each other.

(5) In the above-described embodiment, the case where compressed air is used as the pressure fluid for operating the brake cylinder device has been described as an example, but the present invention is not limited to this, and other pressure fluids (for example, pressure oil) may be used for operation.

(6) In the above-described embodiment, the example in which one end side of the adjustment spring is in contact with or connected to the second clutch has been described, but this may not be the case, and one end side of the adjustment spring may be in contact with or connected to the adjustment stopper.

(7) The case where the force-increasing mechanism is provided in the brake cylinder device is not limited to the embodiment illustrated in the second embodiment, and the embodiment of the force-increasing mechanism may be variously modified. For example, the following method is also possible: the force increasing mechanism includes a support member fixed to the guide pipe, a rotating member provided to be screwed into a thread formed on an outer peripheral surface of the support member, and the support member is moved in a braking direction by rotating the rotating member in a predetermined rotating direction. The support member included in the force increasing mechanism is not limited to the form in which two members, i.e., the first support member and the second support member, are provided, and may be a form in which only one support member is provided.

Industrial applicability

The present invention is widely applicable to a brake cylinder device having a clearance adjustment mechanism for automatically adjusting a clearance from a brake released state to a brake operation position, and a disc brake device having the brake cylinder device.

Description of the reference numerals

2. A brake cylinder device; 20. a cylinder main body; 21. a brake output section; 22. a piston; 23. a piston spring; 24. a threaded shaft; 25. a guide tube; 26. a thrust spring; 27. a clutch nut; 28. a front stopper; 29. a first clutch; 30. adjusting the stop member; 31. adjusting the spring; 32. a second clutch.

Claims (13)

1. A brake cylinder device is characterized in that,

the brake cylinder device includes:

a cylinder main body, the interior of which is formed to be hollow;

a piston that is partitioned into a pressure chamber in the cylinder main body, receives an urging force of a piston spring, and moves relative to the cylinder main body against the urging force of the piston spring by supplying a pressure fluid to the pressure chamber;

a brake output unit that is provided so as to be movable together with the piston or so as to be movable by a force increasing mechanism that increases a force generated in the piston in accordance with the movement of the piston, and that is movable in a braking direction protruding from the cylinder body and in a direction opposite to the braking direction toward the cylinder body;

a threaded shaft coupled to the brake output unit and having a thread formed on an outer periphery thereof;

a guide tube attached to the piston or the force increasing mechanism and accommodating the threaded shaft therein;

a thrust spring disposed on the guide tube or the piston so as to be capable of biasing the threaded shaft in the braking direction;

a clutch nut that is screwed to a distal end side of the threaded shaft, the distal end side of the threaded shaft being disposed closer to the brake output portion side than the cylinder body;

a front stopper disposed to be capable of abutting against the clutch nut from a front side, which is a side of the brake output unit, to restrict movement of the clutch nut relative to the guide pipe, the front stopper being capable of biasing the clutch nut and the threaded shaft in a direction opposite to the braking direction in accordance with movement of the guide pipe in the direction opposite to the braking direction;

a first clutch disposed so as to be capable of coming into contact with the clutch nut at a predetermined interval from a rear side, which is an opposite side of the clutch nut to the brake output portion, to the front stopper;

an adjustment stopper that is disposed so as to be movable relative to the clutch nut and the guide pipe in an axial direction of the threaded shaft, and whose range in which the adjustment stopper is movable relative to the cylinder main body is limited;

a second clutch fixed to the adjustment stopper and configured to be capable of coming into contact with the clutch nut from the rear side; and

and an adjustment spring having one end abutting against or coupled to the adjustment stopper or the second clutch and capable of biasing the clutch nut in a direction opposite to the braking direction.

2. Brake cylinder arrangement according to claim 1,

the screw shaft is formed to have a hollow interior so as to open toward the side opposite to the brake output portion,

the thrust spring biases the clutch nut screwed to the threaded shaft toward the front stopper by biasing the threaded shaft from inside.

3. Brake cylinder arrangement according to claim 2,

the brake cylinder device further includes a thrust spring guide formed as a shaft-like portion provided so as to be movable together with the guide pipe and inserted into an inner side of the thrust spring provided as a coil spring to restrict deformation of the thrust spring in a buckling direction,

the tip end portion of the thrust spring guide is disposed inside the threaded shaft so as to be slidable with respect to the inside of the threaded shaft.

4. Brake cylinder device according to one of the claims 1 to 3,

the front stopper and the first clutch are provided as separate members integrally formed with each other and are fixed to the guide tube.

5. Brake cylinder arrangement according to claim 4,

at least one of the front stopper and the first clutch is fixed to an inner periphery of the guide tube by screwing.

6. Brake cylinder device according to one of the claims 1 to 3,

the brake cylinder device further includes an adjustment sleeve that is provided as a flexible cylindrical member disposed around the threaded shaft and is biased in the direction opposite to the braking direction by the other end side of the adjustment spring having one end side abutting against or coupled to the adjustment stopper or the second clutch,

the clutch nut and the adjustment sleeve are integrated by engagement between an engagement portion formed on the adjustment sleeve and an engaged portion formed on the clutch nut.

7. Brake cylinder arrangement according to claim 6,

the engaging portion of the adjustment sleeve engages with the engaged portion formed on the inner peripheral side of the clutch nut from the inside,

a dimension of a gap formed between an inner periphery of the adjustment sleeve and a crest of a thread of the threaded shaft in a radial direction of the adjustment sleeve is smaller than a dimension of a concave-convex portion in which the engagement portion and the engaged portion are fitted to each other in the radial direction of the adjustment sleeve.

8. Brake cylinder arrangement according to claim 7,

the adjusting spring is disposed so that the other end side thereof biases a spring seat attached to the adjusting sleeve,

the spring seat is disposed such that a gap formed between an outer periphery of the spring seat and an inner periphery of the guide pipe has a substantially zero dimension in a radial direction of the guide pipe, or such that the outer periphery of the spring seat is in sliding contact with the inner periphery of the guide pipe.

9. Brake cylinder arrangement according to claim 8,

the spring seat contains a bearing.

10. Brake cylinder device according to one of the claims 1 to 3,

the brake cylinder device further includes a spring stopper for limiting a displacement amount, by which the other end side of the adjustment spring is relatively displaced with respect to the adjustment spring by abutting against the adjustment spring or by being coupled to the adjustment stopper or one end side of the second clutch, so that the adjustment spring is elastically deformed, to a predetermined amount or less.

11. Brake cylinder device according to one of the claims 1 to 3,

teeth capable of engaging the second clutch with the clutch nut are formed on at least one of a surface of the second clutch facing the clutch nut and a surface of the clutch nut facing the second clutch.

12. Brake cylinder device according to one of the claims 1 to 3,

the threaded shaft is provided at a distal end portion thereof with an operation engagement portion engageable with an operation tool, and the distal end portion is disposed so as to penetrate the brake output portion and face outward,

the brake cylinder device further includes an engagement mechanism that is disposed on an outer periphery of a distal end side of the threaded shaft and that engages the threaded shaft with the brake output portion,

the engagement mechanism includes an outer peripheral engagement portion having engagement teeth engageable with the brake output portion and fixed to an outer periphery of the threaded shaft, and an engagement spring that urges the outer peripheral engagement portion in the braking direction so that the engagement teeth are engaged with the brake output portion.

13. A disc brake device, characterized in that,

the disc brake device including a caliper body equipped with the brake cylinder device and mounted in a manner displaceable in an axle direction with respect to a vehicle, and the brake cylinder device as recited in any one of claims 1 to 12,

by the operation of the brake cylinder device, a disc on the axle side is sandwiched by a pair of brake pads attached to the caliper body, and braking force is generated.