JP2014202524A - Movable member connection mechanism and load sensor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a movable member connection mechanism that can suppress the axial runout of a shaft member when the shaft member moves relatively with a housing and has high assembling workability, and to provide a load sensor using the connection mechanism.SOLUTION: A housing 2 includes a regulation section 23 for regulating the movement of a bearing member 6 in the axial direction, the bearing member 6 includes an engaging section 62 engaging with the regulation section 23, and the regulation section 23 engages with the engaging section 62 that is disposed inside both ends of the bearing member 6 in the axial direction. Thus, the axial runout of the shaft member 3 is suppressed.

Description

  The present invention relates to a movable member connection mechanism that suppresses shaking of a shaft member when the shaft member moves relative to a housing, and a load sensor using the same.

  2. Description of the Related Art Conventionally, a load sensor used for detecting a brake operation force of an electric parking brake is known. As such a load sensor, in Patent Document 1, a case that holds a Hall IC, and an end wall on one side of the case are provided so as to be movable with respect to the case, and a magnet is provided at the end. Load transmitting member, a spring that elastically biases the load transmitting member against the load applied to the load transmitting member, a secondary spring for returning the load transmitting member to the no-load region, and the opposite side of the case And a rod whose end is locked to the end wall of the load sensor. In this load sensor, the load applied to the load transmission member and the rod is detected by the output voltage from the Hall IC that changes according to the relative movement between the case and the load transmission member.

JP 2008-202957 A

  However, in the load sensor of Patent Document 1, since the shaft member (load transmission member) that supports the magnet has a cantilever structure, the shaft member is shaken when the shaft member moves relative to the housing (case). There is a risk that the relative position with the Hall IC changes unintentionally and a load error occurs. In order to suppress such blurring, a method using a bearing is also conceivable. However, since the housing also contains other members such as a connecting member (rod) and a shaft member, the assembly work is complicated. There is a risk of becoming.

  The present invention has been made in view of the problems as described above, and is capable of suppressing the shake of the shaft member when the shaft member moves relative to the housing, and connecting the movable member with good assembling workability. An object is to provide a mechanism and a load sensor using the mechanism.

  In order to achieve the above object, a movable member connection mechanism of the present invention includes a housing, a shaft member that is movable in the axial direction relative to the housing, and a connection member that connects the housing and the movable member. A movable member connection mechanism comprising a bearing member having a shaft member accommodating portion that accommodates a proximal end of the shaft member and a connection member accommodating portion that accommodates a distal end of the connecting member, wherein the housing includes the bearing A restricting portion that restricts movement of the member in the axial direction, the bearing member has an engaging portion that engages with the restricting portion, and the restricting portion is located at both ends of the bearing member in the axial direction. By engaging with the engaging portion provided on the inner side, shaft shake of the shaft member is suppressed.

  (1) According to the movable member connection mechanism of the present invention, the housing has a restricting portion that restricts the movement of the bearing member in the axial direction having the shaft member housing portion that houses the base end of the shaft member, Since the bearing member has an engaging portion that engages with the restricting portion, the restricting portion engages with the engaging portions provided on the inner side of the both ends in the axial direction of the bearing member, whereby the bearing member Can be used to suppress shaking of the shaft member when the shaft member moves relative to the housing. Further, since only the position of the bearing member needs to be adjusted with respect to the housing when assembling, the assembling work of the shaft member, the bearing member, and the connecting member becomes easy.

  (2) According to the movable member connecting mechanism of the present invention, the connecting member has a tip structure in which an engagement piece that engages with the housing is fastened to the tip of the rod that is the main body of the connecting member by a bolt / nut fastening structure. Since it has, the intensity | strength with respect to the force applied to an engagement piece when the load by a movable member is added to the connection member can be improved.

  (3) According to the movable member connecting mechanism of the present invention, even when the shaft member moves relative to the housing, it can be returned to the original position by the spring member provided on the shaft member.

  (4) According to the load sensor of the present invention, since the shake of the shaft member when the shaft member moves relative to the housing can be suppressed, the relative movement distance of the shaft member is appropriately detected by the detection sensor. be able to.

  (5) According to the load sensor of the present invention, even if the bearing member moves in the axial direction by the operation of the movable member, the contact portion of the housing and the extension portion of the shaft member come into contact with each other. Since the shaft member can be stopped at the same position when the member is moved relative to the member, it is possible to suppress the shift of the zero point position of the shaft member, and it is possible to suppress a decrease in accuracy of the load sensor.

It is a sectional side view showing one embodiment of a load sensor concerning the present invention. It is the sectional view on the AA line in FIG. It is the BB sectional view taken on the line in FIG. It is an expanded plane sectional view of the load sensor concerning the present invention. It is an exploded plane sectional view showing an example of a connection member.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. The load sensor 1 of the present invention is used for detecting, for example, a brake operation force of an electric parking brake. As shown in FIG. 1, the load sensor 1 includes a housing 2, a shaft member 3 that can move relative to the housing 2 in the axial direction, a connection member 5 that connects the housing 2 and the movable member 4, and A movable member connecting mechanism including a bearing member 6 and a detection sensor 7 for detecting relative movement of the shaft member 3 in the axial direction with respect to the housing 2 are provided.

  The housing 2 is formed in a substantially rectangular parallelepiped box shape, and one side surface (hereinafter referred to as “upper side”) of the side surfaces forming a quadrangular shape is opened. At both ends of the housing, there are formed substantially U-shaped cutout grooves 21 and 22 that open upward to allow the rods 51 of the main body of the shaft member 3 and the connecting member 5 to pass through. A restricting portion 23 for restricting movement of the bearing member 6 in the axial direction is formed on the bottom surface and the side wall surface on the side. As shown in FIGS. 1 and 4, the restricting portion 23 is formed in a convex shape so as to protrude inward from the inner peripheral surface of the housing 2.

  Further, as shown in FIG. 1, the housing 2 is provided with a lid 8 so as to close the opening above the housing 2. The housing 2 and the lid body 8 can be formed of, for example, metal or synthetic resin. The housing 2 and the lid 8 are preferably made of a non-magnetized material such as aluminum, specific stainless steel, or synthetic resin in order to prevent magnetization by the magnet 71 provided above the shaft member 3.

  The shaft member 3 is attached to the housing 2 so as to be relatively movable in the opposite direction to the bearing member 6 in the axial direction. As shown in FIGS. 1 and 3, the proximal end portion 31 side of the shaft member 3 is formed in a cylindrical shape so as to have a space inside, and the distal end side located outside the housing 2 is described in detail. Although not shown, for example, the actuator is connected to a housing of an actuator to which the load sensor 1 is attached, an inner cable that transmits a driving force of a motor used in the actuator to the load sensor 1, and the like. Further, the shaft member 3 is provided with an extending portion 32 extending outward in the radial direction of the shaft member 3.

  As shown in FIG. 4, the extending portion 32 is formed so as to protrude inward from the bottom surface or the side wall surface of the inner peripheral surface side of the housing 2 when the shaft member 3 moves in the axial direction of the bearing member. The contact is made with the planar contact portion 24 and the movement of the shaft member 3 is stopped. In this embodiment, as shown in FIGS. 1 and 2, the holding member that is fixed to the outer periphery of the flange portion 33 that extends outward in the radial direction of the shaft member 3 and holds the magnet 71 above the shaft member 3 extends. It functions as the exit 32. The holding member functioning as the extending portion 32 is preferably made of a non-magnetized material such as aluminum, specific stainless steel, or synthetic resin in order to prevent magnetization by the magnet 71. In addition, the extension part 32 is not limited to this embodiment, What is necessary is just the thing which can stop the movement of the shaft member 3 by contacting with the contact part 24, for example, a flange part 33 or a protruding piece extending radially outward from a part of the outer periphery of the shaft member 3 may be used.

  Moreover, the contact part 24 should just be what stops the movement of the shaft member 3 when the extension part 32 contact | abuts. Since the movement range of the shaft member 3 toward the bearing member 6 is restricted, for example, the position of the shaft member 3 when the extended portion 32 comes into contact with the contact portion 24 is set as the zero point position of the load sensor 1. It ’s fine. In the present embodiment, as shown in FIG. 4, the contact portion 24 is formed as a stepped portion formed continuously from the restriction portion 23, but is not limited to the present embodiment. A convex portion formed on the bottom surface or the side wall surface on the inner peripheral surface side of the housing 2 may be used.

  Further, as shown in FIG. 1, the distal end side of the shaft member 3 is engaged with a notch groove 21 of the housing 2 via a bearing 9 that suppresses blurring on the distal end side of the shaft member 3. The shaft member 3 is provided with a spring member 10 between the flange portion 33 of the shaft member 3 and the bearing 9 in a state where the shaft member 3 is disposed in the housing 2. The spring member 10 is elastically deformed by relative movement of the shaft member 3 with respect to the housing 2, and biases the bearing member 6 side (left side in FIG. 1) so as to return the shaft member 3 to the original position. For example, a compression coil spring or the like is used. Although not shown in detail, an auxiliary spring may be provided on the outer periphery of the shaft member 3 inside the spring member 10 between the flange portion 33 and the bearing 9.

  The connecting member 5 connects the housing 2 and the movable member 4, and in this embodiment, as shown in FIG. 5, a rod 51, which is a main body of the connecting member 5, an engagement piece 53, And nuts 54 (54a, 54b). The rod 51 is formed in a substantially cylindrical shape, and although not shown in detail, for example, an inner cable for a pull control cable or the like is connected to the proximal end side as the movable member 4. In addition to the pull control cable for transmitting the driving force of the motor, the movable member 4 is moved in the operating direction by driving the motor or the like in order to operate an operation target such as a parking brake and transmits the load to the load sensor 1. Any member may be used. Further, a bolt portion 52 formed with a male screw is formed on the distal end side of the rod 51. The distal end structure of the connecting member 5 has a structure in which the engaging piece 53 is fastened by a bolt / nut fastening structure. The movable member connecting mechanism of the present invention is not limited to being used as a load sensor for detecting the brake operation force of the electric parking brake, but other sliding movable members 4 and the like are used. It can also be used as a connecting mechanism.

  As shown in FIGS. 1 and 4, the engagement piece 53 engages with the inner peripheral surface of the housing 2 and is formed in a substantially disc shape, and a bolt portion 52 can be inserted through the center. Bolt holes 53a are formed. Each of the nuts 54a and 54b is formed with a female screw so as to be screwed with the bolt portion 52, and is connected to the nut 54a and 54b by fastening the bolt portion 52 in a state where the bolt portion 52 is inserted into the bolt hole 53a of the engagement piece 53. 5 is configured. In this embodiment, as shown in FIG. 4, the convex part of the nut 54a fits into the concave part of the nut 54b at the time of fastening, and a stronger fastening structure can be constituted. Thereby, when a load is applied from the movable member 4 to the connection member, the strength against the force applied to the engagement piece 53 can be improved. In the present embodiment, two nuts 54 a and 54 b are used. However, the bolt portion 52 may be fastened with one nut 54 inserted into the bolt hole 53 a of the engagement piece 53. As shown in FIGS. 1 and 5, the base end portion of the connecting member 5 is a flat portion 55 having a flat structure in a direction perpendicular to the axial direction, and the tip is a bolt / nut fastening structure. As a result, even if it is difficult to connect the movable member 4 and the connecting member 5 such that the connecting portion of the connecting member 5 in the movable member 4 is narrow, the movable member 4 is provided at the distal end portion of the main body 41. By simply inserting the rod 51 of the connecting member 5 into the through hole 42 and attaching the engaging piece and the nut to the tip, the flat portion 55 and the tip of the movable member 4 are engaged, and the movable member 4 and the connecting member 5 Can be connected, making connection easy. Moreover, since the tip of the connection member 5 has a bolt / nut fastening structure, the length of the tip of the connection member 5 can be adjusted by using a washer or the like. Further, when the movable member 4 has a mechanism or the like in the main body 41 that strokes in the axial direction in order to operate the operation target, the connecting member 5 has the flat surface portion 55. Inhibiting the stroke of the mechanism, such as when the base end of the stroke hits the stroke mechanism during the stroke, is suppressed, and the apparatus can be downsized.

  The bearing member 6 is formed in a cylindrical shape whose both ends are open, and as shown in FIGS. 3 and 4, the shaft member accommodating portion for accommodating the proximal end portion 31 of the shaft member 3 and the distal end of the connecting member 5. It has the accommodating part 61 which plays the role of both the connection member accommodating part which accommodates. The inner diameter of the bearing member 6 is such that the shaft member 3 can move in the axial direction within the housing portion 61 without being displaced, and the base end portion 31 of the shaft member 3 can be inserted into the housing portion 61. (It is substantially the same as the outer diameter of the base end portion 31 of the shaft member 3). Further, the proximal end portion 31 of the shaft member 3 is formed in a cylindrical shape, and the distal end of the connecting member 5 is formed smaller than the inner diameter of the proximal end portion 31 of the shaft member 3. As shown in FIG. 4, the distal end of the connecting member 5 can be accommodated in the proximal end portion 31 of the shaft member 3 accommodated in the accommodating portion 61. As described above, since not only the proximal end portion 31 of the shaft member 3 but also the distal end of the connection member 5 can be accommodated in the accommodation portion 61 of the bearing member 6, the load sensor 1 can be reduced in size and the housing. Assembly to 2 becomes easy. In the present embodiment, the base end portion 31 of the shaft member 3 and the distal end of the connecting member 5 are accommodated in the same accommodating portion 61, but the accommodating portion of the bearing member 6 is configured so that each can be accommodated separately. May be.

  At both ends of the outer peripheral surface of the bearing member 6, flanges are formed over the entire circumferential direction, and as shown in FIGS. 1 and 4, the flanges are inside surfaces that are opposed to each other. The surface serves as an engaging portion 62 that engages with the restricting portion 23. That is, the restricting portion 23 is engaged with the engaging portion 62 provided inside the both ends of the bearing member 6. As shown in FIG. 4, a space S is provided between the engaging portion 62 and the restricting portion 23 with a space having a dimension W <b> 1 in the axial direction. The space S is a space that can move in the axial direction by a distance W1 when the bearing member 6 is engaged with the restricting portion 23, and is axially interposed between the restricting portion 23 and the engaging portion 62. Any space may be used as long as it is engaged in a loosely fitted state that allows movement. Therefore, as shown in FIG. 4, the bearing member 6 is configured such that the engaging portion 62 and the restricting portion 23 are engaged with each other with a gap W <b> 1 between the engaging portion 62 and the restricting portion 23. Yes. Thus, by providing the space S, the assembly of the bearing member 6 to the housing 2 is facilitated. The space S is not necessarily provided, and the bearing member 6 may be engaged with the restricting portion 23 without a gap.

  The bearing member 6 and the housing 2 have a predetermined interval W between the extension portion 32 and the bearing member 6 when the bearing member 6 and the extension portion 32 are in a position where they are closest to each other. It is configured as follows. The predetermined interval W is an interval provided so that the bearing member 6 and the extending portion 32 do not contact each other, and is an interval that does not contact the extending portion 62 even when the bearing member 6 moves in the axial direction. If it is good. Therefore, in the load sensor 1 according to the present embodiment, as shown in FIG. 4, the bearing member in a state having a space S between the engaging portion 62 on the connection member 5 side (left side in FIG. 4) and the restricting portion 23. 6 is a space provided between the engaging portion 62 and the restricting portion 23, with an interval W <b> 2 from the end face on the shaft member 3 side (right side in FIG. 4) to the extending portion 32 in contact with the contact portion 24. It is configured to be larger than the interval W1 of S (W2−W1 = W> 0). Thereby, since the end surface located in the shaft member 3 side of the bearing member 6 can prevent going to the shaft member 3 side (right side of FIG. 4) rather than the position in which the contact part 24 is provided, the shaft member 3 can be prevented. The stop position of the shaft member 3 can be prevented from going to the right side of the contact portion 3, and the shift of the zero point position of the shaft member 3 can be suppressed. Further, as shown in FIGS. 1 and 3, the cover 8 is covered so as to close the opening above the housing 2, so that the bearing member 6 is pressed by the holding piece 81, so that the base end 31 is the bearing. Shaking of the shaft member 3 housed in the housing portion 61 of the member 6 is suppressed.

  The detection sensor 7 detects relative movement of the shaft member 3 in the axial direction with respect to the housing 2, and as shown in FIGS. 1 and 2, a magnet 71 and a Hall IC 72 (Hall element as a magnetic field sensor). Sensor). As shown in FIG. 1, the magnet 71 is provided above the shaft member 3 by an extension portion 32 fixed to the flange portion 33 of the shaft member 3. A part of the upper surface of the body 8 is formed so as to protrude upward, so that the body 8 can move in a moving space 82 that is long in the axial direction. As shown in FIGS. 1 and 2, the Hall IC 72 is provided in a cutout portion 83 formed by cutting out a part of the protruding portion of the upper surface of the lid body 8, and faces the magnet 71. At the zero point position of the member 3, it is arranged at the center position of the magnetic field of the magnet 71, that is, the position where the detected magnetic flux density becomes zero.

  The basic principle of load detection by the detection sensor 7 is the same as that of a conventionally known load sensor, and the shaft member 3 is attached to the spring member 10 as long as no load is applied to the movable member 5 or the shaft member 3. It is designed to return to the zero point position by force. When a load is applied from this state and the movable member 4 operates, the housing 2 also moves through the connecting member 4 accordingly. At this time, since the Hall IC 72 moves together with the housing 2, the magnetic field in the vicinity of the Hall IC 72 changes according to the relative movement distance between the housing 2 and the shaft member 3. As a result, the output voltage from the Hall IC 72 changes, and the amount of movement of the magnet 71 detected by this output voltage is converted into a load applied to the movable member 4. The positions of the magnet 71 and the Hall IC 72 are not limited to the present embodiment, and may be arranged at positions where the relative movement of the shaft member 3 with respect to the housing 2 in the axial direction can be detected.

  Thus, in the load sensor 1, the bearing member 3 is engaged with the restricting portion 23 of the housing 2, and the base end 31 of the shaft member 3 is accommodated in the accommodating portion 61 of the bearing member 3. Can be prevented from shaking of the shaft member 3 when moving relative to the housing 2. Thereby, when the shaft member 3 moves relative to the housing 2, it is possible to suppress the relative position between the magnet 71 and the Hall IC 72 from unintentionally changing due to the shaft member 3 being shaken and causing a load error. Further, in the load sensor 1, when the shaft member 3 moves in the direction of the bearing member 6, the extending portion 32 provided on the shaft member 3 comes into contact with the contact portion 24 formed on the housing 2, and the shaft member 3 It is configured to stop the movement. Therefore, even if the movable member 4 and the connecting member 5 are shaken, the zero point position of the shaft member 3 can be prevented from shifting, and the accuracy of the load sensor 1 can be prevented from being lowered.

Regarding the assembly of the movable member connection mechanism of the present embodiment, the base end of the shaft member 3 is housed in the shaft member housing portion of the bearing member 6, and the distal end of the connection member 5 is housed in the connection member housing portion of the bearing member 6. By simply adjusting the position of the engaging portion 62 of the bearing member 6 to the position where the restricting portion 23 of the housing 2 is disposed, the assembly positions of the shaft member 2, the bearing member 6, and the connecting member 5 are adjusted to the housing 2. Since it is assembled, the assembling work becomes easy.
Further, when the housing 2 is provided with the contact portion 24 and is accommodated in the housing 2 in a state where the space W is provided between the bearing member 6 and the extending portion 32 of the shaft member 3, the shaft member 3, When the bearing member 6 and the connecting member 5 are assembled, a position where the restricting portion 23 is arranged in a state where the base end of the shaft member 3 and the distal end of the connecting member 5 are accommodated in the bearing member 6 in the accommodating portion 61. Then, the position of the engaging portion 62 is adjusted, and the assembly positions of the shaft member 2, the bearing member 6, and the connection member 5 are aligned and assembled to the housing 2. In that case, since the space S is formed between the engaging portion 62 of the bearing member 6 and the restricting portion 23 of the housing 2, the space between the bearing member 6 and the extending portion 32 of the shaft member 3 is between. The bearing member 6 can be moved in a direction approaching the connecting member 5 in a state where the restricting portion 23 and the engaging portion 62 are loosely fitted so that a predetermined interval W is formed. Thus, even if it is a case where it accommodates in the housing 2 so that it may have the predetermined space | interval W, assembly | attachment becomes easy.

  The embodiment of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the scope of the idea of the present invention.

DESCRIPTION OF SYMBOLS 1 Load sensor 2 Housing 23 Restriction part 24 Contact part 3 Shaft member 31 Base end part 32 Extension part 4 Movable member 5 Connection member 51 Rod 52 Bolt part 53 Engagement piece 54 Nut 6 Bearing member 61 Housing part 62 Engagement part 7 Detection sensor 10 Spring member

Claims (5)

A housing;
A shaft member movable in the axial direction relative to the housing;
A connecting member for connecting the housing and the movable member;
A movable member connection mechanism comprising a shaft member housing portion for housing a base end of the shaft member and a bearing member having a connection member housing portion for housing a distal end of the connection member,
The housing has a restricting portion that restricts movement of the bearing member in the axial direction,
The bearing member has an engaging portion that engages with the restricting portion,
The movable member connecting mechanism, wherein the restricting portion is engaged with the engaging portion provided on an inner side than both ends in the axial direction of the bearing member, thereby suppressing the shaft shake of the shaft member. The said connection member has the front-end | tip structure which fastened the engagement piece engaged with the said housing by the volt | bolt nut fastening structure at the front-end | tip of the rod which is the main body of the said connection member. Movable member connection mechanism. The shaft member is attached to the housing such that the shaft member can move in the axial direction relative to the bearing member, and is elastically deformed by the relative movement of the shaft member relative to the housing. The movable member connection mechanism according to claim 1, wherein a spring member that urges the shaft to return to the shaft member is provided on the shaft member. A detection sensor for detecting relative movement of the shaft member;
The load sensor using the movable member connection mechanism according to any one of claims 1 to 3, wherein a load applied to the movable member is detected according to a relative movement distance of the shaft member. The shaft member is provided with an extending portion extending radially outward,
The housing is provided with a contact portion that can contact the extension portion when the shaft member moves in the axial direction toward the bearing member,
Between the engaging portion and the restricting portion, there is a space in which the bearing member can move in the axial direction,
When the bearing member and the extension portion are in a position where they are closest to each other, a predetermined interval is provided between the extension portion and the bearing portion. The load sensor according to claim 4.

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