JP2018162024A - Negative pressure type booster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a negative pressure type booster which can prevent leakage of a lubricant existing in a boot to the outside.SOLUTION: A negative pressure type booster 100 includes a cylindrical boot 160 which has: a connection part 161 connected to a cylinder part 112a of a booster shell at one end side; an insertion part 162 having an insertion hole 162a, into which an input shaft 141 is inserted, at the other end side; and a bellows part 163 connecting the connection part 161 to the insertion part 162 and covers a valve body 130 from the outer side. The boot 160 includes: a lip part 161a serving as a block part which blocks a lubricant applied to an outer peripheral surface 131a of the valve body 130 from flowing to a gap K, which is a communication part, along an inner peripheral surface 161b and an inner peripheral surface 163b of the boot 160 on the inner peripheral surface 161b of the connection part 161 and the inner peripheral surface 163b of the bellows part 163; a housing part 161c; and a circumferential protrusion 163a.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a negative pressure booster that is mounted on a vehicle and constitutes a brake device.

  Conventionally, for example, a negative pressure booster disclosed in Patent Document 1 below is known. This conventional negative pressure type booster includes an input shaft to which an input is applied, a valve body disposed so as to be movable relative to the rear shell, and a telescopic boot provided between the rear shell and the input shaft. It is equipped with. The boot covers the valve body from the outside so as to prevent foreign matter and the like from entering the valve body when air flows into the valve body.

JP 2008-179184 A

  By the way, in the negative pressure type booster, in general, a lubricant is applied to the outer peripheral surface of the valve body in order to smoothly slide the seal member fixed to the rear shell and the valve body. In the above-described conventional negative pressure booster, the shell (booster shell) and the valve body are vertically upward or downward in the vertical direction after assembly or transportation with the lubricant applied to the outer peripheral surface of the valve body. If placed, the lubricant present inside the boot may leak out of the boot.

  The present invention has been made to solve the above problems. That is, an object of the present invention is to provide a negative pressure type booster capable of preventing the lubricant present inside the boot from leaking to the outside.

  In order to solve the above-mentioned problem, the invention of the negative pressure type booster according to claim 1 includes a hollow booster shell, and a movable partition wall that is movable by dividing the booster shell into a constant pressure chamber and a variable pressure chamber in an airtight manner. And a cylindrical valve body that is inserted so as to be relatively movable with respect to the cylindrical portion provided in the booster shell, and moves integrally with the movable partition wall in the booster shell, and is relatively movable in the valve body. An input member that is provided to input operating force, an output member that outputs the driving force of the valve body, a connecting portion that is connected to the cylindrical portion of the booster shell on one end side, and the input member is inserted on the other end side. A cylindrical boot that has an insertion portion having an insertion hole, a bellows portion that connects the coupling portion and the insertion portion, and covers the valve body from the outside, and a valve body that exists inside the boot and is against the cylinder portion The relative movement of The boot is directed toward a communicating portion that communicates the inside and the outside of the boot through the inner peripheral surface of the boot on the inner peripheral surface of the boot. Inhibiting part that inhibits flow.

  According to this, the boot can be provided with the inhibition part on the inner peripheral surface. The inhibiting part can inhibit the lubricant present inside the boot from flowing toward the communicating part along the inner peripheral surface. Thereby, the boot can prevent the lubricant from leaking out of the boot. Therefore, the boot inhibits and prevents leakage of the lubricant to the outside even when the booster shell and valve body of the negative pressure type booster are held upward or downward in the vertical direction. Can do.

It is the schematic which shows the structure of the brake device provided with the negative pressure type booster which concerns on embodiment of this invention. FIG. 2 is an overall view showing a configuration of the negative pressure booster of FIG. 1. It is sectional drawing which expands and shows the structure of the lip | rip part of FIG. 2, an accommodating part, and a circumferential convex part. FIG. 3 is a cross-sectional view showing a grease application state after a seal member and a valve body are assembled to the rear shell member of FIG. 2. It is sectional drawing which shows the assembly | attachment state and assembly | attachment attitude | position of a boot with respect to the valve body of FIG. It is sectional drawing which shows the attitude | position at the time of storage of the valve body and boots of FIG. It is sectional drawing which shows the attitude | position at the time of conveyance of the valve body and boots of FIG. It is sectional drawing which shows the attitude | position at the time of transport of the valve body and boot of FIG. 5, and demonstrates the action | operation of a lip | rip part and an accommodating part. It is sectional drawing which shows the attitude | position at the time of transport of the valve body and boot of FIG. 5, and demonstrates the action | operation of a circumferential convex part. It is sectional drawing which shows the structure of the connection part which concerns on the 1st modification of embodiment of this invention. It is sectional drawing which shows the structure of the connection part which concerns on the 2nd modification of embodiment of this invention. It is sectional drawing which shows the other modification of embodiment of this invention. It is sectional drawing which shows the other modification of embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments and each modification, the same or equivalent parts are denoted by the same reference numerals in the drawings. Each figure used for explanation is a conceptual diagram, and the shape of each part may not necessarily be exact.

  A negative pressure booster 100 according to the present embodiment constitutes a vehicle brake device 10 as shown in FIG. The vehicle brake device 10 includes a cylinder mechanism 20. The cylinder mechanism 20 includes a master cylinder 21, master pistons 22 and 23, and a master reservoir 24. The master pistons 22 and 23 are slidably disposed in the master cylinder 21. The master pistons 22 and 23 partition the master cylinder 21 into a first master chamber 21a and a second master chamber 21b. The master reservoir 24 is a reservoir tank having a conduit communicating with the first master chamber 21a and the second master chamber 21b. The master reservoir 24 and the master chambers 21a and 21b are communicated or blocked by the movement of the master pistons 22 and 23.

  The cylinder mechanism 20 includes a wheel cylinder 25, a wheel cylinder 26, a wheel cylinder 27, and a wheel cylinder 28. The wheel cylinder 25 is disposed on the left rear wheel RL of the vehicle. The wheel cylinder 26 is disposed on the right rear wheel RR of the vehicle. The wheel cylinder 27 is disposed on the left front wheel FL of the vehicle. The wheel cylinder 28 is disposed on the right front wheel FR of the vehicle. The master cylinder 21 and the wheel cylinders 25 to 28 are connected via an actuator 30. Thereby, each wheel cylinder 25-28 gives braking force to left rear wheel RL, right rear wheel RR, left front wheel FL, and right front wheel FR. In addition, although detailed description is abbreviate | omitted, the actuator 30 is comprised from the pipe line of illustration abbreviation, an electric pump, a solenoid valve, a check valve, etc.

  In the vehicle brake device 10, when the driver depresses the brake pedal 29, the pedaling force is boosted by the negative pressure booster 100 airtightly connected to the master cylinder 21, and the master piston 22 in the master cylinder 21, 23 is pressed. Thereby, the same master cylinder pressure is generated in the first master chamber 21a and the second master chamber 21b. The master cylinder pressure is transmitted to the wheel cylinders 25 to 28 via the actuator 30.

  The negative pressure booster 100 includes a hollow booster shell 110 as shown in FIG. A movable partition 120 and a valve body 130 are assembled to the booster shell 110 so as to move integrally (forward and backward). The interior of the booster shell 110 is partitioned by a movable partition 120 into a front constant pressure chamber R1 and a rear variable pressure chamber R2.

  The booster shell 110 includes a front shell member 111 and a rear shell member 112 formed from, for example, iron, aluminum, or resin (reinforced plastic). The front shell member 111 is formed with a negative pressure introduction port 111a for communicating the constant pressure chamber R1 with a negative pressure source (for example, an intake manifold of an engine not shown). A check valve 113 is provided in the negative pressure inlet 111a. The check valve 113 is configured to permit air communication from the constant pressure chamber R1 side to the negative pressure source side and to block air communication from the negative pressure source side to the constant pressure chamber R1 side. Yes.

  The booster shell 110 has tie rod bolts 114 that hermetically penetrate the front shell member 111 and the rear shell member 112 at two locations in the radial direction. In FIG. 2, only one tie rod bolt 114 is shown. The two tie rod bolts 114 support the master cylinder 21 on the front shell member 111 side. Therefore, the retainer 115 is disposed between the inner surface 111 b of the front shell member 111 and the enlarged diameter portion 114 a of the tie rod bolt 114. The booster shell 110 has a rear bolt 116 that penetrates the rear shell member 112 in an airtight manner. The rear bolt 116 is fixed to a stationary member, for example, a cowl C provided on the vehicle body of the vehicle.

  The movable partition 120 is provided in the booster shell 110 so as to be movable in the front-rear direction along the axial direction of the valve body 130. The movable partition 120 includes an annular plate member 121 and an annular diaphragm 122. The plate member 121 is made of metal (for example, iron) and is disposed on the front side (the front shell member 111 side) with respect to the diaphragm 122.

  The diaphragm 122 is formed of an annular elastic member (for example, an annular rubber material) and can be expanded and contracted, and the outer peripheral edge is hermetically fixed to the booster shell 110 (the front shell member 111 and the rear shell member 112). In addition, the inner peripheral edge is hermetically fixed to the valve body 130 together with the plate member 121. Specifically, as shown in FIG. 2, the diaphragm 122 includes an outer peripheral bead portion 122a, an inner peripheral bead portion 122b, and a seat portion 122c. The outer peripheral bead portion 122 a is provided in an annular shape on the outer peripheral edge of the diaphragm 122, and is airtightly held at the connection portion between the front shell member 111 and the rear shell member 112. The inner peripheral bead portion 122 b is annularly provided on the inner peripheral edge of the diaphragm 122, and is hermetically fixed to the outer peripheral surface 131 a of the valve body 130 together with the plate member 121. The sheet part 122c connects the outer peripheral bead part 122a and the inner peripheral bead part 122b to each other.

  The valve body 130 is provided so as to be relatively movable with respect to the booster shell 110 (more specifically, the rear shell member 112), and moves forward toward the front shell member 111 and the rear shell member 112 integrally with the movable partition wall 120. Go backwards. The valve body 130 includes a main body 131 made of resin and formed in a cylindrical shape.

  The main body 131 is engaged with a return spring S provided between the front shell member 111 and the body 131 and is urged rearward by the return spring S. The main body 131 is assembled at a central portion with a cylindrical portion 112a provided on the rear shell member 112 of the booster shell 110 so as to be relatively movable in the front-rear direction along the direction of the axis. A lip-shaped sealing member 112b is provided at the opening end of the cylindrical portion 112a. The outer peripheral surface 131a of the main body 131 is hermetically assembled to the rear shell member 112 (boost shell 110) by a seal member 112b.

  Here, a thick grease G as a lubricant is applied and held on the outer peripheral surface 112b1 of the seal member 112b in order to ensure slidability between the outer peripheral surface 131a of the main body 131 and the seal member 112b. (See FIG. 4). Accordingly, the grease G is supplied from the seal member 112b to the outer peripheral surface 131a of the main body 131 with the movement of the main body 131 that moves relative to the cylindrical portion 112a of the rear shell member 112. . Note that the grease G is thinly applied in advance to the outer peripheral surface 131a of the main body 131 (see FIG. 4). And the part which protrudes out of the booster shell 110 of the outer peripheral surface 131a (namely, valve body 130) of the main-body part 131 is coat | covered and protected by the cylindrical boot 160 mentioned later, as shown in FIG.

  A pair of negative pressure communication passages 132 is provided inside the main body 131. In FIG. 2, only one negative pressure communication path 132 is shown. The negative pressure communication path 132 communicates with the constant pressure chamber R1 of the booster shell 110 at the front end, and communicates with the inside of the main body 131 at the rear end. In addition, an input shaft 141 as an input member and a plunger 142 are assembled in the body 131 so as to be coaxial, and the valve mechanism 150 and the filter 143 are assembled so as to be coaxial. Furthermore, a reaction member 144 made of an elastic member (for example, a rubber material) and an output shaft 145 as an output member are assembled in the main body 131 in front of the plunger 142 so as to be coaxial.

  The input shaft 141 is movable in the front-rear direction along the direction of the axis of the main body 131 and is articulated to the connecting portion of the plunger 142 at the spherical tip. The input shaft 141 is connected to the brake pedal 29 via a yoke (not shown) by a screw portion provided at the rear end, and is configured to receive the pedaling force acting on the brake pedal 29 forward as an operating force. Yes. The input shaft 141 is engaged with a return spring via an annular member 146 and is urged rearward by the return spring.

  The plunger 142 abuts on the central portion of the rear surface of the reaction member 144 at the tip. The plunger 142 engages with the key member in an annular groove formed in the central portion. Furthermore, the plunger 142 is provided with an annular atmospheric valve seat in the valve mechanism 150 at the rear end. The key member functions to restrict the movement of the plunger 142 in the front-rear direction relative to the main body 131 of the valve body 130, and the movement limit position of the valve body 130 relative to the booster shell 110 (returning back of the valve body 130). (Position) is a member having a function of defining.

  The reaction member 144 is accommodated in the rear cylindrical portion 145a of the output shaft 145, and is assembled to the main body 131 of the valve body 130 together with the rear cylindrical portion 145a of the output shaft 145. The reaction member 144 is configured such that the central portion of the rear surface bulges and deforms toward the front while being accommodated in the rear cylindrical portion 145a.

  Although not shown, the output shaft 145 pushes the master pistons 22 and 23 of the master cylinder 21 at the tip. Further, the output shaft 145 transmits the reaction force received from the master pistons 22 and 23 of the master cylinder 21 to the reaction member 144 during the braking operation.

  The valve mechanism 150 includes a negative pressure valve seat integrally formed at the rear end portion of the negative pressure communication path 132 in the main body portion 131 of the valve body 130, an atmospheric valve seat integrally formed at the rear end portion of the plunger 142, It has. The valve mechanism 150 includes a cylindrical valve body 151 disposed so as to be coaxial with the atmospheric valve seat. The valve body 151 has an annular mounting portion and a cylindrical movable portion that is formed integrally with the mounting portion and is movable along the direction of the axis. The attachment portion of the valve body 151 is airtightly assembled in the main body 131 of the valve body 130 and is held by the main body 131 by the annular member 146.

  The movable portion of the valve body 151 is a negative pressure control valve that constitutes a negative pressure valve that communicates or blocks between the constant pressure chamber R1 and the variable pressure chamber R2 together with the negative pressure valve seat by being seated or separated from the negative pressure valve seat. Part. The movable portion of the valve body 151 is an atmospheric control valve portion that constitutes an atmospheric valve that communicates or blocks between the variable pressure chamber R2 and the atmosphere together with the atmospheric valve seat by being seated or separated from the atmospheric valve seat. Have

  The boot 160 is formed of a rubber material in a cylindrical shape, and includes a connecting portion 161 provided on one end side (front side), an insertion portion 162 provided on the other end side (rear side), and a connecting portion 161. And an accordion portion 163 connecting the insertion portion 162.

  As shown in an enlarged view in FIG. 3, the connecting portion 161 has an inner diameter that is smaller than the outer diameter of the flange portion 112 a 1 provided on the cylindrical portion 112 a of the rear shell member 112 and an inner diameter that is larger than the flange portion 112 a 1. It has a stepped cylindrical shape. The connecting portion 161 is fixed to the cylindrical portion 112a with a metal band or the like (not shown) in a state where the cylindrical portion 112a is inserted through the connecting portion 161.

  A lip portion 161a as a projecting portion that constitutes an obstructing portion projects from the connecting portion 161 so as to project toward the inside of the boot 160 along the large-diameter inner peripheral surface 161b. The lip portion 161a has a gap K as a communication portion where grease G (see FIG. 4) existing inside the boot 160 passes through the inner peripheral surface 161b of the connecting portion 161 to communicate the inside and the outside of the boot 160. It is provided on the passage which flows toward. The gap K is formed between the outer peripheral surface of the cylindrical portion 112a and the small inner peripheral surface of the connecting portion 161. The lip portion 161a inhibits the flow of the grease G toward the gap K (outside of the boot 160), and the grease G flows through the passage and reaches the gap K (outside of the boot 160). The flow length, which is the length up to, is increased.

  The lip portion 161a protrudes from the inner peripheral surface 161b of the connecting portion 161 toward the inside of the boot 160 (the bellows portion 163) and extends in a tongue shape so as to contact the outer peripheral surface of the cylindrical portion 112a. In addition, the connecting portion 161 is provided with an accommodating portion 161c that constitutes an obstructing portion. The accommodating portion 161c is formed by the lip portion 161a and the inner peripheral surface 161b, and accommodates the grease G that has flowed in the boot 160 as will be described later.

  As shown in FIG. 2, the insertion portion 162 covers the end portion (end portion on the side where the input shaft 141 is inserted) of the main body portion 131 of the valve body 130 from the outside. The insertion portion 162 has an insertion hole 162 a that passes through the input shaft 141 and engages with a circumferential groove formed in the input shaft 141. The insertion portion 162 covers the filter 143 on the inner side.

  2 and 3, the bellows portion 163 is connected to the end portion on the inner peripheral surface 161b side of the connecting portion 161 so that the cross-sectional shape in the direction along the axis of the boot 160 becomes uneven. Is formed. As shown in an enlarged view in FIG. 3, the bellows portion 163 is formed in a cylindrical shape so as to have a larger inner diameter than the outer diameter of the outer peripheral surface 131 a of the main body portion 131 of the valve body 130. The bellows part 163 covers the main body part 131 from the outside without contacting the outer peripheral surface 131a of the main body part 131 with the main body part 131 inserted inside. The bellows portion 163 is provided with a circumferential convex portion 163a that protrudes in a circumferential shape as a projecting portion constituting the inhibition portion.

  The circumferential convex portion 163 a is provided on a passage through which the grease G existing inside the boot 160 flows toward the gap K along the inner circumferential surface 163 b of the bellows portion 163. Thereby, the circumferential convex part 163a inhibits the flow of the grease G toward the gap K. Specifically, the circumferential convex portion 163a is provided on the inner circumferential surface 163b of the bellows portion 163 so as to protrude toward the seal member 112b to which the grease G is applied. As will be described later, the circumferential convex portion 163a changes the flow direction of the grease G flowing toward the gap K along the inner peripheral surface 163b of the bellows portion 163 toward the seal member 112b.

  In the negative pressure type booster 100 configured in this way, the valve mechanism 150 is actuated in response to the input shaft 141 and the plunger 142 moving in the front-rear direction with respect to the main body 131, whereby the variable pressure chamber R2 Can communicate with the constant pressure chamber R1 or the atmosphere. That is, when the input shaft 141 and the plunger 142 move forward from the position shown in FIG. 2 (the original position and the return non-actuated position) with respect to the main body 131, the negative pressure control valve portion is seated on the negative pressure valve seat. The atmospheric valve seat is separated from the atmospheric control valve portion.

  In this case, the variable pressure chamber R2 is disconnected from the constant pressure chamber R1 and communicates with the atmosphere. In this case, the atmosphere flows into the variable pressure chamber R2 through the filter 143, the inside of the valve body 151, the gap with the atmosphere valve seat, the communication path provided in the main body 131, and the like. As a result, the pressure in the variable pressure chamber R2 becomes larger than the pressure in the constant pressure chamber R1. Thereby, the movable partition 120 and the valve body 130 move forward (toward the front shell member 111) and the output shaft 145 moves forward in accordance with the forward operation of the input shaft 141. Then, the output shaft 145 moved forward (toward the front shell member 111) presses the master pistons 22 and 23 of the master cylinder 21, and the master cylinder pressure is transmitted to the wheel cylinders 25 to 28 via the actuator 30. .

  When the input shaft 141 and the plunger 142 return to the return non-operating position (original position) with respect to the main body 131, the atmospheric control valve portion is seated on the atmospheric valve seat, and the negative pressure control valve portion is the negative pressure valve seat. Get away from. In this case, the communication between the variable pressure chamber R2 and the atmosphere is blocked, and the constant pressure chamber R1 and the variable pressure chamber R2 communicate with each other. In this case, air is sucked from the variable pressure chamber R2 to the constant pressure chamber R1 through the communication passage provided in the main body 131, the gap between the negative pressure control valve portion and the negative pressure valve seat, the negative pressure communication passage 132, and the like. . As a result, since the pressure in the variable pressure chamber R2 and the pressure in the constant pressure chamber R1 become equal, the movable partition 120 and the valve body 130 are moved rearward by the urging force of the return spring S, and the output shaft 145 is moved rearward. Thereby, the pressing of the master pistons 22 and 23 of the master cylinder 21 by the output shaft 145 is released, and the master cylinder pressure is reduced.

  By the way, the negative pressure type booster 100 configured as described above is completed through an assembly process in which the valve body 130 and the boot 160 are assembled to the booster shell 110. In this case, the booster shell 110 is lowered in the vertical direction in the negative pressure booster 100 during temporary storage after completion of assembly, when the finished product is shipped, or when assembled to the vehicle. May be maintained in posture. In a state in which the booster shell 110 is maintained in a vertically downward position, the grease G applied to the outer peripheral surface 131a of the valve body 130 and the outer peripheral surface 112b1 of the seal member 112b is applied to the inner peripheral surface of the boot 160. It flows along the gap K. Hereinafter, when the negative pressure booster 100 is maintained in a different posture, the lip portion 161a, the accommodating portion 161c, and the circumferential convex portion 163a specifically inhibit the flow of the grease G toward the gap K is specifically described. To do.

  First, in the assembling process, as shown in FIG. 4, after the grease G is thinly applied to the outer peripheral surface 131 a of the main body 131 of the valve body 130, it is integrally fixed to the cylindrical portion 112 a of the rear shell member 112. The main body 131 is inserted into the sealing member 112b. In order to maintain good slidability (lubrication) between the main body 131 and the cylindrical portion 112a (more specifically, the seal member 112b) of the rear shell member 112 over a long period of time, grease is applied to the outer peripheral surface 112b1 of the seal member 112b. G is applied thickly.

  Further, in the assembling step, the boot portion is exposed to a portion (exposed portion) where the main body 131 of the valve body 130 assembled so as to be movable relative to the rear shell member 112 (booster shell 110) protrudes from the rear shell member 112. 160 is assembled from the outside. In this case, as shown in FIG. 5, for example, the boot 160 is assembled to the cylindrical portion 112 a of the rear shell member 112 in a posture in which the booster shell 110 side is downward in the vertical direction. As a result, as shown in FIG. 5, the grease G applied to the outer peripheral surface 112b1 of the seal member 112b is applied to the outer peripheral surface 112b1 of the seal member 112b (and the outer peripheral surface 131a of the main body 131) and the bellows 163 of the boot 160. The state of being held (stored) with the inner peripheral surface 163b, that is, the state existing inside the boot 160, completes the assembly process of the negative pressure booster 100.

  Thus, when the assembly process is completed, the negative pressure booster 100 is temporarily stored in a posture in which the booster shell 110 side is upward in the vertical direction, for example, as shown in FIG. When the negative pressure type booster 100 is stored in this posture, the grease G slowly flows toward the inner peripheral surface 163b of the bellows part 163 of the boot 160 by gravity, as shown by a thick solid arrow in FIG. (Drip). In this case, the grease G travels along the outer peripheral surface 131a of the main body portion 131 of the valve body 130 or along the inner peripheral surface 163b of the bellows portion 163 toward the inside of the bellows portion 163 (that is, the boot 160). Flows slowly. The grease G that travels along the outer peripheral surface 131a of the main body 131 improves the slidability (lubrication) with the seal member 112b.

  The master cylinder 21 and the like are assembled to the negative pressure booster 100 that has completed the assembly process in the next process. For this reason, as shown in FIG. 7, the negative pressure type booster 100 is conveyed in a posture (packing form) in which the main body 131 of the valve body 130 has an angle with respect to the vertical direction. In this case, the grease G flows along the inner peripheral surface 163b of the bellows part 163 of the boot 160 into the bellows part 163 as shown by the thick solid arrow in FIG. Grease G that has traveled along the outer peripheral surface 131 a of the portion 131 drips onto the inner peripheral surface 163 b of the bellows portion 163. That is, in the negative pressure type booster 100 being conveyed, the grease G may accumulate on the inner peripheral surface 163b of the bellows part 163.

  In this state, the negative pressure booster 100 to which the master cylinder 21 and the like are assembled is then transported to the vehicle assembly factory. In this case, since the master cylinder 21 and the like are assembled, the negative pressure booster 100 is shown in FIGS. 8 and 9 from the posture (packing form) of the negative pressure booster 100 during the conveyance shown in FIG. It is changed to the posture (packaging) at the time of transportation shown. Specifically, at the time of transportation, the booster shell 110 is transported in a posture (packing form) that is again downward in the vertical direction. As a result, the grease G that has flowed toward the inside of the bellows portion 163 and the grease G applied to the outer peripheral surface 112b1 of the seal member 112b are the flange portion 112a1 provided on the cylindrical portion 112a and the inner peripheral surface 161b of the connecting portion 161. It flows so as to pass through a passage formed by a gap between them. Accordingly, the grease G flows along the inside of the boot 160 toward the direction of the connecting portion 161 of the boot 160, that is, toward the gap K as a communicating portion that communicates the inside and the outside of the boot 160.

  By the way, in the boot 160 of the negative pressure type booster 100, the lip part 161a and the accommodating part 161c are provided on the inner peripheral surface 161b of the connecting part 161 as an inhibition part. As a result, as indicated by the thick solid arrow in FIG. 8, the grease G that has reached the connecting portion 161 through the passage is inhibited from flowing toward the gap K by the lip portion 161a. That is, in this case, since the lip portion 161a is in contact with the outer peripheral surface of the cylindrical portion 112a, the lip portion 161a blocks the passage toward the gap K and inhibits the flow of the grease G toward the gap K. Further, the lip portion 161 a protrudes toward the inside of the boot 160. Accordingly, the lip portion 161 a increases the flow length of the grease G that flows toward the gap K along the inner peripheral surface 161 b of the connecting portion 161. Thereby, the lip part 161a gains time until the grease G reaches the gap K, and inhibits the flow of the grease G.

  Further, the connecting portion 161 is provided with an accommodating portion 161c. As a result, the grease G that has reached the connecting portion 161 is stored in the housing portion 161 c, so that the housing portion 161 c inhibits the flow of the grease G. Accordingly, by providing the connecting portion 161 with the lip portion 161a and the accommodating portion 161c, the grease G reaching the connecting portion 161 is prevented from leaking outside through the gap K.

  Moreover, in the boot 160, the circumferential convex part 163a as an obstruction part is provided in the inner peripheral surface 163b of the bellows part 163. As a result, the grease G accumulated in the bellows portion 163 is inhibited from flowing toward the gap K by the circumferential convex portion 163a as shown in FIG. That is, since the circumferential convex portion 163a protrudes toward the seal member 112b, the circumferential convex portion 163a flows toward the gap K as shown by a thick solid arrow in FIG. The direction is changed toward the seal member 112b. Thereby, the circumferential convex part 163a inhibits the flow of the grease G toward the gap K. Furthermore, since the circumferential convex portion 163a protrudes toward the inside of the boot 160, the flow length of the grease G that flows toward the gap K along the inner circumferential surface 163b of the bellows portion 163 is increased. Thereby, the circumferential convex part 163a earns time until the grease G reaches the outside through the gap K, and inhibits the flow of the grease G.

  As can be understood from the above description, the negative pressure booster 100 of the above-described embodiment moves in a hollow booster shell 110 and the booster shell 110 which are airtightly divided into a constant pressure chamber R1 and a variable pressure chamber R2. The movable movable partition 120 and a cylindrical shape that is inserted so as to be relatively movable with respect to the cylindrical portion 112 a provided on the booster shell 110 (rear shell member 112) and moves integrally with the movable partition 120 in the booster shell 110. The valve body 130, the input shaft 141 as an input member that is provided so as to be relatively movable in the valve body 130 and inputs the pedaling force as the operating force, and the output as the output member that outputs the driving force of the valve body 130 Insert the shaft 145, the connecting portion 161 connected to the cylindrical portion 112a of the booster shell 110 on one end side, and the input shaft 141 on the other end side. A cylindrical boot 160 having an insertion portion 162 having an insertion hole 162a to be connected, a bellows portion 163 connecting the coupling portion 161 and the insertion portion 162, and covering the valve body 130 from the outside; A negative pressure type booster having a grease G as a lubricant that lubricates the relative movement of the valve body 130 with respect to the cylindrical portion 112a, and the boot 160 has an inner peripheral surface 161b of the connecting portion 161. The grease G flows along the inner peripheral surface 163b of the bellows part 163 through the inner peripheral surface 161b and the inner peripheral surface 163b of the boot 160 toward the gap K as a communication part that communicates the inside and the outside of the boot 160. A lip portion 161a as an obstructing portion that inhibits the operation, an accommodating portion 161c, and a circumferential convex portion 163a.

  According to this, the boot 160 has the lip portion 161a, the accommodating portion 161c, and the circumferential convex that prevent the grease G existing therein from flowing toward the gap K along the inner circumferential surface 161b and the inner circumferential surface 163b. A portion 163a can be provided. Therefore, even when the booster shell 110 and the valve body 130 are held upward or downward in the vertical direction during the assembly process of the negative pressure booster 100 and the transportation of the negative pressure booster 100. The grease G present inside the boot 160 can be prevented from leaking out of the boot 160 through the gap K. Thereby, it is possible to effectively prevent the grease G leaked from the negative pressure booster 100 from contaminating the surroundings.

  The boot 160 can hold (fasten) the grease G inside the boot 160, for example, on the outer peripheral surface 131 a of the main body 131 of the valve body 130. Therefore, the grease G can maintain the lubrication between the seal member 112b and the outer peripheral surface 131a of the main body 131 for a long period of time, and can satisfactorily reduce the sliding resistance. As a result, the seal member 112b and the valve Wear of the body 130 (main body 131) can be suppressed. Further, since the sliding resistance can be reduced, the valve body 130 can be moved with good responsiveness to the input of the operating force to the input shaft 141, and the output shaft 145 can provide the driving force of the valve body 130 to the master cylinder 21. Can be output with good responsiveness.

  In this case, the lip portion 161a and the circumferential convex portion 163a as the protrusions of the inhibition portion protrude from the inner peripheral surface 161b of the connecting portion 161 of the boot 160 and the inner peripheral surface 163b of the bellows portion 163 toward the inside of the boot 160. To do.

  According to this, the protruding lip portion 161a and the circumferential convex portion 163a can block the grease G flowing from the inside of the boot 160 toward the gap K through the inner circumferential surface 161b and the inner circumferential surface 163b. . Thereby, the lip part 161a and the circumferential convex part 163a can effectively inhibit (prevent) the grease G from leaking outside through the gap K. Further, the protruding lip portion 161 a and the circumferential convex portion 163 a can increase the flow length when the grease G flows from the inside of the boot 160 toward the gap K. Thereby, the boot 160 can earn time until the grease G reaches the gap K (outside of the boot 160), and the grease G can be prevented from leaking.

  Further, in this case, the lip portion 161a constituting the inhibition portion is provided in a circumferential shape on the inner peripheral surface 161b of the connecting portion 161 and is formed in a tongue shape. In addition, the accommodating portion 161c constituting the inhibition portion is provided on the inner peripheral surface 161b of the connecting portion 161 in a circumferential shape, and the grease G formed by the lip portion 161a and the inner peripheral surface 161b of the connecting portion 161 flows. To accommodate.

  According to this, the lip portion 161 a provided in the connecting portion 161 can stop (damage) the grease G flowing from the inside of the boot 160 toward the gap K. Furthermore, the accommodating part 161c provided in the connecting part 161 can accommodate and hold the grease G stopped by the lip part 161a. Accordingly, the lip portion 161a and the accommodating portion 161c constituting the inhibition portion can reliably inhibit the grease G from leaking out of the boot 160 through the gap K. In particular, in a situation where the negative pressure booster 100 is held in a posture in which the booster shell 110 and the valve body 130 are directed downward in the vertical direction, the lip portion 161a and the accommodating portion 161c prevent leakage of the grease G to the outside. It can be reliably inhibited (prevented).

  Further, in these cases, the negative pressure booster 100 includes a cylindrical seal member 112b that hermetically seals the cylindrical portion 112a and the valve body 130 so that the grease G is held on the outer peripheral surface 112b1 of the seal member 112b. The circumferential convex portion 163a serving as the inhibition portion protrudes toward the seal member 112b on the inner circumferential surface 163b of the bellows portion 163.

  According to this, the circumferential convex part 163a is provided to project toward the seal member 112b holding the grease G on the inner circumferential surface 163b of the bellows part 163. Accordingly, when the grease G flows along the inner peripheral surface 163b, the circumferential convex portion 163a changes the flow direction of the grease G so that the grease G flows toward the seal member 112b. Can do. Here, since the grease G is thickly applied and held between the outer peripheral surface 112b1 of the seal member 112b and the inner peripheral surface 163b of the bellows portion 163, the circumferential convex portion 163a changes the flow direction. The once-flowed grease G can be held again (stored).

  Therefore, the grease G can maintain the lubrication between the seal member 112b and the outer peripheral surface 131a of the main body 131 for a long period of time, and can satisfactorily reduce the sliding resistance. As a result, the seal member 112b and the valve Wear of the body 130 (main body 131) can be suppressed. Further, since the sliding resistance can be reduced, the valve body 130 can be moved with good responsiveness to the input of the operating force to the input shaft 141, and the output shaft 145 can provide the driving force of the valve body 130 to the master cylinder 21. Can be output with good responsiveness.

(First modification)
In the above embodiment, the tongue-shaped lip portion 161 a extending toward the inside of the boot 160 is provided on the inner peripheral surface 161 b of the connecting portion 161 of the boot 160. Instead, for example, as shown in FIG. 10, a protrusion 161 d as a protrusion that is shorter than the lip portion 161 a and constitutes an obstruction portion is provided along the inner peripheral surface 161 b toward the inside of the boot 160. It is also possible. Also in the case of the first modification example in which the protrusion 161d is provided in this manner, the protrusion 161d can inhibit the grease G from flowing toward the gap K, and the inner peripheral surface as in the above embodiment. It is also possible to form the accommodating part 161c between 161b. Therefore, also in this first modified example, the same effect as in the above embodiment can be obtained.

(Second modification)
In the above-described embodiment, the inner peripheral surface 161b of the connecting portion 161 is provided with the lip portion 161a as the protruding portion constituting the hindering portion and the accommodating portion 161c. Instead of this, as shown in FIG. 11, the lip portion 161 a that is a protrusion is omitted, while the small-diameter inner peripheral surface that faces the cylindrical portion 112 a in the connecting portion 161 and contacts the cylindrical portion 112 a. It is also possible to provide a circumferential concave groove 161e. Even when the concave groove 161 e is provided in this way, the concave groove 161 e can inhibit the grease G from flowing from the inside of the boot 160 toward the outside through the gap K. In this case, it is also possible to accommodate the grease G in the concave groove 161e. Therefore, also in this second modification, it is possible to prevent and prevent the grease G from leaking out of the boot 160 as in the above embodiment.

  In carrying out the present invention, the present invention is not limited to the above-described embodiments and modifications, and various modifications can be made without departing from the object of the present invention.

  For example, in the above-described embodiment, the inner peripheral surface 161b of the connecting portion 161 is provided with the inhibition portion including the lip portion 161a and the accommodating portion 161c, and the inner peripheral surface 163b of the bellows portion 163 is provided with the circumferential convex portion 163a as the inhibition portion. I made it. Instead of this, for example, as shown in FIG. 12, it is possible to omit the circumferential convex portion 163 a from the bellows portion 163. In this case, the lip portion 161a and the accommodating portion 161c provided on the inner peripheral surface 161b of the connecting portion 161 can inhibit the flow of the grease G toward the outside through the gap K. Therefore, the grease G can be prevented from leaking outside.

  Further, in the above embodiment, the inner peripheral surface 161b of the connecting portion 161 is provided with an inhibition portion including the lip portion 161a and the accommodating portion 161c, and the inner peripheral surface 163b of the bellows portion 163 is provided with the circumferential convex portion 163a as the inhibition portion. I made it. Instead of this, for example, as shown in FIG. 13, the lip portion 161 a and the accommodating portion 161 c can be omitted from the connecting portion 161. In this case, the circumferential convex portion 163a provided on the inner peripheral surface 163b of the bellows portion 163 lengthens the flow length of the grease G flowing from the inside of the boot 160 to the outside and changes the flow direction to the seal member 112b. The direction can be changed. Thereby, the circumferential convex part 163a can inhibit the flow of the grease G toward the outside through the gap K. Therefore, the grease G can be prevented from leaking outside.

  Further, in the above-described embodiment and each of the above-described modifications, the circumferential convex portion 163a is opposed to the seal member 112b on the inner circumferential surface 163b of the bellows portion 163, specifically, a position adjacent to the connecting portion 161. It was made to provide in. However, the position where the circumferential convex portion 163a is provided is not limited to this as long as the inner circumferential surface 163b of the bellows portion 163 is provided. Specifically, for example, at a position adjacent to the insertion portion 162 having the insertion hole 162a, or a position adjacent to this through hole when a through hole for introducing air into the bellows portion 163 is formed, It is also possible to provide a circumferential convex portion 163a. In this case, a gap formed between the insertion hole 162a and the input shaft 141 and a through hole for introducing air serve as a communicating portion. In this way, when the circumferential convex portion 163a is provided, the grease G is prevented from flowing toward the communicating portion (the insertion hole 162a or the air introduction through hole) along the inner circumferential surface 163b. As a result, it is possible to prevent the grease G from leaking out from the communicating portion.

  Further, in the above-described embodiment and each of the modifications, the convex peripheral convex portion 163a is provided on the inner peripheral surface 163b of the bellows portion 163. However, it is also possible to provide the circumferential convex portion 163a in a tongue shape (lip shape). Even in this case, the grease G can be prevented from flowing toward the communicating portion such as the gap K along the inner peripheral surface 163b, and as a result, the grease G can be prevented from leaking to the outside from the communicating portion. can do.

  Further, in the above-described embodiment and each of the modifications, the lip portion 161a, the circumferential convex portion 163a, and the protrusion 161d as the convex portions are provided over the entire circumference along the inner peripheral surface 161b and the inner peripheral surface 163b. . Instead of this, it is also possible to intermittently provide the lip portion 161a, the circumferential convex portion 163a, and the protrusion 161d as convex portions along the circumferential direction of the inner peripheral surface 161b and the inner peripheral surface 163b.

DESCRIPTION OF SYMBOLS 10 ... Brake device, 20 ... Cylinder mechanism, 21 ... Master cylinder, 21a ... First master chamber, 21b ... Second master chamber, 22, 23 ... Master piston, 24 ... Master reservoir, 25-28 ... Wheel cylinder, 30 ... Actuator, 100 ... Negative pressure type booster, 110 ... Booster shell, 111 ... Front shell member, 111a ... Negative pressure inlet, 111b ... Inner surface, 112 ... Rear shell member, 112a ... Cylindrical part, 112a1 ... Flange part, 112b ... Seal Member, 112b1 ... outer peripheral surface, 113 ... check valve, 114 ... tie rod bolt, 114a ... expanded diameter part, 115 ... retainer, 116 ... rear bolt, 120 ... movable partition, 121 ... plate member, 122 ... diaphragm, 122a ... outer peripheral bead Part, 122b ... inner peripheral bead part, 122c ... sheet part, 130 ... bar Bubody, 131 ... main body, 131a ... outer peripheral surface, 132 ... negative pressure communication path, 141 ... input shaft (input member), 142 ... plunger, 143 ... filter, 144 ... reaction member, 145 ... output shaft (output member), 145a ... Back cylindrical part, 146 ... Ring member, 150 ... Valve mechanism, 151 ... Valve body, 160 ... Boot, 161 ... Connection part, 161a ... Lip part (inhibition part, convex part), 161b ... Inner peripheral surface, 161c ... accommodating part (inhibiting part), 161d ... protrusion (inhibiting part, convex part), 161e ... concave groove (inhibiting part), 162 ... inserting part, 162a ... inserting hole, 163 ... bellows part, 163a ... circular convex part ( 163b ... inner peripheral surface, C ... cowl, G ... grease (lubricant), K ... gap (communication part), R1 ... constant pressure chamber, R2 ... transformer chamber, S ... return spring, FL ... Left front wheel, FR ... Right front wheel, RL The left rear wheel, RR ... right rear wheel

Claims (4)

With a hollow booster shell,
A movable partition wall capable of moving the booster shell in an airtight manner into a constant pressure chamber and a variable pressure chamber;
A cylindrical valve body that is inserted so as to be relatively movable with respect to a cylindrical portion provided in the booster shell, and moves integrally with the movable partition wall in the booster shell;
An input member that is provided so as to be relatively movable in the valve body and inputs an operation force;
An output member for outputting the propulsive force of the valve body;
A connecting portion connected to the cylindrical portion of the booster shell on one end side, an insertion portion having an insertion hole for inserting the input member on the other end side, and a bellows connecting the connecting portion and the insertion portion. A cylindrical boot that has a portion and covers the valve body from the outside;
A negative pressure booster comprising: a lubricant that lubricates the valve body that is present inside the boot and moves relative to the cylindrical portion;
The boots
A negative pressure type booster provided with an inhibition portion that inhibits the lubricant from flowing toward the communicating portion that communicates the inside and the outside of the boot through the inner circumferential surface on the inner circumferential surface. The inhibition part is
2. The negative pressure type booster according to claim 1, further comprising a protrusion protruding toward the inside of the boot from the inner peripheral surface of at least one of the connecting portion of the boot and the bellows portion. The inhibition part is
A lip portion which is a tongue-like projection provided circumferentially on the inner peripheral surface of the connecting portion;
And an accommodating portion that accommodates the lubricant that is formed by the lip portion and the inner peripheral surface of the connecting portion and flows around the inner peripheral surface of the connecting portion. Item 3. A negative pressure booster according to Item 2. The negative pressure booster is
A cylindrical sealing member that hermetically seals the cylindrical portion and the valve body;
The lubricant is held on the outer peripheral surface of the seal member;
The inhibition part is
The negative pressure type booster according to claim 2 or 3, wherein the inner peripheral surface of the bellows portion is a circumferential convex portion as the protrusion protruding toward the seal member.

Images