WO2016104619A1

WO2016104619A1 - Negative-pressure-type booster

Info

Publication number: WO2016104619A1
Application number: PCT/JP2015/086052
Authority: WO
Inventors: 祐司後藤
Original assignee: 株式会社アドヴィックス
Priority date: 2014-12-25
Filing date: 2015-12-24
Publication date: 2016-06-30
Also published as: JP2016120815A

Abstract

A valve (41) for a negative-pressure-type booster is equipped with a movement stopping part (41c) provided integrally with an attachment part (41a) or a moveable part (41b), the movement stopping part (41c) stopping the movable part (41b), which moves with the motion of a plunger (32), from moving relative to a valve body (22) at or before a contact time when the valve body (22) and a key member (39) moving with the motion of the plunger (32) come into contact with each other, at or after a point in time when an input operation on an input shaft (31) is canceled.

Description

Negative pressure booster

The present invention relates to a negative pressure type booster.

As a type of negative pressure booster, one shown in Patent Document 1 is known. As shown in FIG. 1 of Patent Document 1, the negative pressure type booster includes a booster casing (7). The inner chamber of the booster casing is divided into a negative pressure chamber (30) and a working chamber (20) by a movable wall. Furthermore, a control valve (1) for controlling the pressure difference acting on the movable wall is provided, and this control valve is arranged in a control casing (2) which supports the movable wall. The control valve (1) is provided with seal seats (9, 10) and an elastically deformable valve body (11) arranged concentrically with each other. The transverse member (60) passes through the void (40) of the control casing (2). The transverse member limits the axial movement of the valve piston (16) relative to the control casing (2) and is elastic within the area of contact between the control casing (2) and the transverse member (60). At least one protrusion (66, 84, 85, 88, 90) made of material is provided.

In the negative pressure type booster configured as described above, when the brake pedal is strongly depressed, when the piston rod (14) moves forward in the axial direction, the lateral member moves forward of the control casing along with the valve piston. It abuts on a contact portion (a portion formed in a space of the transverse member and abutting the transverse member). Thereafter, the lateral member moves while being sandwiched between the valve piston and the front contact portion of the control casing.
When the depression of the depressed brake pedal is released, the control casing is returned to the rear in the axial direction. At this time, the valve piston is also returned to the rear in the axial direction, but is returned by the biasing force different from that of the control casing, so that the valve piston is returned to the rear in the axial direction faster than the control casing. For this reason, the state in which the transverse member is sandwiched between the valve piston and the front contact portion of the control casing is released, and moves in the axial rearward direction faster than the control casing. As a result, the lateral member comes into contact with the rear contact portion of the control casing (the space formed in the opposite side of the front contact portion, which is a void of the lateral member, and the lateral member abuts). Thereafter, the lateral member moves while being sandwiched between the valve piston and the rear contact portion of the control casing.

JP 2005-515935 A

In the negative pressure type booster described above, when the brake pedal being depressed is released, when the lateral member contacts the rear contact portion of the control casing, the sound (impact generated) Sound and the like) are suppressed to a small extent by at least one protrusion (66, 84, 85, 88, 90) made of an elastic material. However, in order to attach a projection as a separate member to the lateral member, processes such as adhesion, fitting, and vulcanization welding are required, which may lead to a decrease in productivity and high cost related to the negative pressure booster. .

Therefore, the present invention has been made to solve the above-described problem, and in the negative pressure type booster, the depression of the brake pedal that has been depressed is released without incurring a decrease in productivity or cost. The purpose is to reduce the sound generated at the time.

In order to solve the above-mentioned problems, the structural feature of the invention according to claim 1 is that the housing is assembled with a movable partition wall that divides the inside of the housing into a front negative pressure chamber and a rear variable pressure chamber, and is movable in the housing. A valve body connected to the movable partition in the housing and a shaft hole formed in the valve body. The valve body can be moved back and forth along the axial direction of the shaft hole and integrated with the input member. An air valve that moves to and from the valve body, and a negative pressure valve that communicates and blocks between the negative pressure chamber and the variable pressure chamber as the air valve moves forward and backward, and an atmospheric valve that communicates and blocks the variable pressure chamber from and to the atmosphere. Negative pressure provided with a valve mechanism, and a key member that is capable of coming into contact with and detaching from the valve body, the air valve, and the housing, and that defines an amount of movement of the air valve along the axial direction with respect to the valve body. This is a booster, and the valve mechanism has an atmospheric pressure formed by a negative pressure valve seat provided on the valve body, an atmospheric valve seat provided on the air valve, and a negative pressure valve section that constitutes a negative pressure valve and an atmospheric valve seat. A valve body provided with an atmospheric valve portion constituting the valve and formed of an elastic material, and the valve body is connected to the valve body via a connection portion and a mounting portion attached to the valve body. The movable part is movable relative to the attachment part, and is provided integrally with either the movable part in which the negative pressure valve part and the atmospheric valve part are formed, and the attachment part or the movable part, and the input to the input member After the operation is released, the movable part that moves with the movement of the air valve is stopped relative to the valve body before the contact point at which the key member that moves with the movement of the air valve comes into contact with the valve body. Transfer It is that further includes a stop.

According to this, since the movement stop portion is provided integrally with either the existing mounting portion or the movable portion, a process of assembling a separate member as in the conventional case is not necessary, and the negative pressure type booster is not required. Such a decrease in productivity and cost can be suppressed. Furthermore, when the input operation to the input member that is being depressed is released (for example, when the brake pedal is released), the movement stop unit moves with the movement of the air valve after the release. Before the contact point at which the valve body comes into contact, the movable part that moves with the movement of the air valve is stopped relative to the valve body. As a result, since the key member can be prevented from coming into contact with the valve body, it is possible to reduce the sound generated when the input operation to the input member being input is canceled. Further, even when the key member comes into contact with the valve body, the impact generated at the time of contact can be dispersed and absorbed in the contact between the movement stop portion and the valve body. As a result, it is possible to reduce the sound generated when the input operation to the input member being input is canceled. As described above, in the negative pressure type booster, it is possible to reduce the sound generated when the depressed brake pedal is released without causing a decrease in productivity and cost.

It is sectional drawing which shows one Embodiment of the negative pressure type booster by this invention. FIG. 2 is an enlarged cross-sectional view mainly showing the valve body shown in FIG. 1 and showing a brake pedal inoperative state. FIG. 2 is an enlarged cross-sectional view mainly showing the valve body shown in FIG. 1 and showing a brake pedal depression holding state. FIG. 2 is an enlarged sectional view mainly showing the valve body shown in FIG. 1 and showing a state immediately after the brake pedal is returned. FIG. 2 is an enlarged cross-sectional view mainly showing the valve body shown in FIG. 1, showing a state immediately before the brake pedal returns completely. It is sectional drawing which shows the 1st modification of the negative pressure type booster by this invention. It is sectional drawing which shows the 2nd modification of the negative pressure type booster by this invention. It is sectional drawing which shows the 3rd modification of the negative pressure type booster by this invention. It is sectional drawing which shows the 4th modification of the negative pressure type booster by this invention.

Hereinafter, a negative pressure booster according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the negative pressure type booster 1 includes a housing 10 in which a power piston 20 including a movable partition wall 21 and a valve body 22 is assembled so as to be movable in the front-rear direction (left-right direction in FIG. 1). The housing 10 is partitioned by a movable partition wall 21 into a front negative pressure chamber R1 and a rear variable pressure chamber R2.

The housing 10 includes a front shell 11 and a rear shell 12. The front shell 11 is provided with a negative pressure introducing pipe 11a for constantly communicating the negative pressure chamber R1 with a negative pressure source (for example, an intake manifold of an engine not shown). The housing 10 is fixed to a stationary member, that is, a vehicle body (not shown) by a plurality of mounting

bolts

12a and 12b that pass through the rear shell 12 in an airtight manner, and is attached to the plurality of mounting bolts 12a that pass through the front shell 11 in an airtight manner. The brake master cylinder (not shown) is supported.

The brake master cylinder is a well-known cylinder and is airtightly assembled to the front shell 11 at the rear end of the cylinder body (not shown). Also, the piston (not shown) of the brake master cylinder protrudes rearward from the cylinder body and enters the negative pressure chamber R1, and is configured to be pushed forward by a distal end portion 35a of an output shaft 35 described later. Has been.

The movable partition wall 21 of the power piston 20 includes an annular plate 21a and an annular diaphragm 21b, and is installed in the housing 10 so as to be movable in the front-rear direction (the axial direction of the power piston 20). The diaphragm 21b is airtightly sandwiched between the housing 10 by an annular outer peripheral bead portion 21a1 formed on the outer peripheral edge thereof. The diaphragm 21b is hermetically fixed to the outer peripheral portion of the valve body 22 together with the inner peripheral portion of the plate 21a at an annular inner peripheral bead portion 21a2 formed on the inner peripheral edge thereof.

The valve body 22 of the power piston 20 is a resin hollow body connected to the inner peripheral portion of the movable partition wall 21, and is airtight and front-rear to the rear shell 12 of the housing 10 at an intermediate portion formed in a cylindrical shape. It is assembled so as to be movable in the direction (the axial direction of the power piston 20). The valve body 22 is urged rearward by a return spring 13 interposed between the front shell 11 and the housing 10. The portion of the valve body 22 that protrudes outside the housing 10 is covered and protected by a boot 19 having a plurality of vent holes 19a at the rear end.

Further, as shown in FIG. 2, the valve body 22 has a stepped shaft hole 22a penetrating in the front-rear direction. The valve body 22 is a pair of negative pressure communication passages (only one of which is shown in FIGS. 1 and 2) communicating with the intermediate step portion of the shaft hole 22a at the rear end and communicating with the negative pressure chamber R1 at the front end. 22b is formed. The valve body 22 is formed with a key attachment hole 22c that is substantially orthogonal to the front portion of the shaft hole 22a and through which the key member 39 can be inserted from the outer periphery.

In the shaft hole 22a, the input shaft 31 and the plunger 32 (corresponding to an air valve) are coaxially assembled, and the valve mechanism V and the

filters

51 and 52 are coaxially assembled. A connecting member 33, a reaction member 34, and an output shaft (output member) 35 are coaxially assembled in the shaft hole 22 a described above in front of the plunger 32.

The input shaft 31 can be moved back and forth with respect to the valve body 22, and is connected to the receiving connection portion 32c of the plunger 32 in a joint shape by a spherical tip portion 31a. The input shaft 31 is connected to a brake pedal (both not shown) via a yoke at a rear end thread portion (not shown), and is configured to receive a pedal force acting on the brake pedal as an input toward the front. ing. The input shaft 31 is an input member for inputting the pedal force to the master cylinder. The input shaft 31 is engaged with a return spring 37 via a retainer 36 locked to the intermediate step portion, and is urged rearward by the return spring 37. The plunger 32 connected to the input shaft 31 is also urged rearward by the return spring 37.

The plunger 32 can come into contact with the central portion of the rear surface of the reaction member 34 via the connecting member 33 at the tip 32a. The distal end portion 32 a is a portion that partially receives an output reaction force from the reaction member 34 via the connecting member 33. The plunger 32 can be engaged with the key member 39 by an annular groove 32b formed in the intermediate portion thereof. An annular atmospheric valve seat 32d in the valve mechanism V is formed at the rear end of the plunger 32.

The reaction member 34 can be deformed rearward at the central portion of the rear surface thereof, and is accommodated in the rear cylindrical portion 35b of the output shaft 35 so that the entire front surface is engaged with the rear surface of the rear end portion of the output shaft 35 (the contact member 34). In this state, it is assembled to the front end portion of the valve body 22 together with the rear cylindrical portion 35b of the output shaft 35. The reaction member 34 can be brought into contact with the front surface of the distal end portion 32a of the plunger 32 via the connecting member 33 at the rear surface, and in contact with the annular front end surface of the valve body 22.

The output shaft 35 is assembled in the front end portion of the shaft hole 22a of the valve body 22 together with the reaction member 34 so as to be movable in the front-rear direction. The output shaft 35 is in contact with the piston engaging portion (recessed portion) of the brake master cylinder at its distal end portion 35a so as to be able to be pushed, and transmits the reaction force received from the piston of the brake master cylinder to the reaction member 34 during braking operation. It is supposed to be.

The key member 39 can be brought into contact with and separated from the valve body 22, the plunger 32 and the housing 10 (contact portion 12 c), and defines the amount of movement along the axial direction of the plunger 32 with respect to the valve body 22. The key member 39 defines the function of regulating the forward / backward movement of the plunger 32 with respect to the valve body 22 of the power piston 20 and the limit position of the rearward movement of the power piston 20 with respect to the housing 10 (rear return position of the valve body 22). It has a function. The key member 39 is assembled to the valve body 22 and the plunger 32 so as to be movable relative to each other in the axial direction of the power piston 20.

The valve mechanism V communicates / blocks the negative pressure valve V1 for communicating / blocking between the negative pressure chamber R1 and the variable pressure chamber R2 and the variable pressure chamber R2 to / from the atmosphere according to the advance / retreat of the plunger 32 with respect to the valve body 22. And an atmospheric valve V2. The valve mechanism V includes a negative pressure valve seat 22 d provided on the valve body 22. The negative pressure valve seat 22 d is formed integrally with the rear end portion of the negative pressure communication path 22 b in the valve body 22. The negative pressure valve seat 22d is formed in an arc shape or a circular shape.
The valve mechanism V includes an atmospheric valve seat 32 d provided on the plunger 32. The atmospheric valve seat 32 d is formed in an annular shape integrally with the rear end portion of the plunger 32.
The valve mechanism V includes a valve body 41. The valve body 41 is provided with a negative pressure valve portion 41b1 that constitutes a negative pressure valve V1 with the negative pressure valve seat 22d, and an atmospheric valve portion 41b2 that constitutes an atmospheric valve V2 with the atmospheric valve seat 32d, and an elastic material (for example, rubber) Material, silicon material (having elasticity).

The valve body 41 includes an annular attachment portion 41a attached to the valve body 22, a cylindrical movable portion 41b formed integrally with the attachment portion 41a and movable in the axial direction, and an integral portion with the attachment portion 41a. The movement stop part 41c formed in this.
The mounting portion 41 a is assembled in an airtight manner in the shaft hole 22 a of the valve body 22, and is fixedly held at a fixed position (step portion) of the shaft hole 22 a in the valve body 22 by the retainer 42. The retainer 42 is urged forward by a return spring 37 and is fixed to a step portion of the shaft hole 22 a in the valve body 22.

The movable part 41b is connected to the attachment part 41a via the connection part 41d, and is movable relative to the attachment part 41a. The movable portion 41b can be seated / separated from the negative pressure valve seat 22d, and the negative pressure valve portion 41b1 constituting the negative pressure valve V1 capable of communicating / blocking between the negative pressure chamber R1 and the variable pressure chamber R2 by the negative pressure valve seat 22d. have. The movable part 41b can be seated / separated with respect to the atmospheric valve seat 32d, and the atmospheric valve seat 32d includes an annular atmospheric valve part 41b2 constituting an atmospheric valve V2 capable of communicating / blocking between the variable pressure chamber R2 and the atmosphere. Have. The movable portion 41 b is biased forward by the compression spring 43.
The movable portion 41b includes an elastic movable portion 41e made of an elastic material and a metal movable portion 41f formed in an annular plate shape made of a metal material fixed to the rear surface of the elastic movable portion 41e. The elastic movable portion 41e is connected integrally with the connection portion 41. The movable portion 41b (and thus the valve body 41) is integrally formed by vulcanization molding or the like.

With the configuration of the valve mechanism V described above, the variable pressure chamber R2 can communicate with the negative pressure chamber R1 or the atmosphere according to the movement of the input shaft 31 and the plunger 32 in the front-rear direction with respect to the valve body 22. That is, the input shaft 31 and the plunger 32 move forward from the original position (return position) in FIG. 1 with respect to the valve body 22, the negative pressure valve portion 41b1 is seated on the negative pressure valve seat 22d, and the atmospheric valve seat 32d is atmospheric. When separated from the valve portion 41b2, the variable pressure chamber R2 is disconnected from the negative pressure chamber R1 and communicates with the atmosphere. At this time, the air is passed into the variable pressure chamber R2 through the vent hole 19a of the boot 19, the

filters

51 and 52, the inside of the valve body 41, the gap between the atmospheric valve seat 32d and the atmospheric valve portion 41b2, the communication path provided in the valve body 22, and the like. Flows in.

Further, the input shaft 31 and the plunger 32 return to the return position (original position) with respect to the valve body 22, the atmospheric valve seat 32d is seated on the atmospheric valve portion 41b2, and the negative pressure valve portion 41b1 is separated from the negative pressure valve seat 22d. A state in which the atmosphere valve V2 is closed, the communication between the variable pressure chamber R2 and the atmosphere is interrupted, and the negative pressure valve V1 is opened, and the negative pressure chamber R1 and the variable pressure chamber R2 are in communication with each other. ), The variable pressure chamber R2 is disconnected from the atmosphere and communicated with the negative pressure chamber R1. At this time, air is sucked from the variable pressure chamber R2 to the negative pressure chamber R1 through the communication passage provided in the valve body 22, the gap between the negative pressure valve portion 41b1 and the negative pressure valve seat 22d, the negative pressure communication passage 22b, and the like.

The movement stop part 41c is provided integrally with any one member of the attachment part 41a and the movable part 41b. Specifically, the movement stop portion 41c extends along the whole (or a part) of the mounting portion 41a in the circumferential direction and is formed to protrude toward the movable portion 41b, and comes into contact with the movable portion 41b. The first projecting portion 41c1 is made possible. The first protrusion 41c1 moves the plunger 32 after the input operation on the input shaft 31 is released and before the contact point where the key body 39 moving with the movement of the plunger 32 contacts the valve body 22. The movable portion 41b that moves together with the valve body 22 is stopped relatively.
The axial length of the first protruding portion 41c1 is such that the distance between the front end of the first protruding portion 41c1 and the rear surface of the movable portion 41b (the distance when the connecting portion 41d is not bent) is the key member 39 and the key mounting hole. The distance between the inner wall rear surface 22c2 of 22c and the distance between the key member 39 and the inner wall front surface 22c1 of the key attachment hole 22c are preferably set to be substantially the same or smaller.

Next, the operation of the negative pressure booster 1 configured as described above will be described with reference to FIGS.

・ Brake pedal inactive state (Fig. 2)
FIG. 2 shows a non-operating state. As described above, the input shaft 31 and the plunger 32 that are urged rearward are located in the original position with respect to the valve body 22. At this time, the atmospheric valve V2 is closed and the negative pressure valve V1 is open. Further, the key member 39 is sandwiched between the rear shell 12 and the valve body 22 urged rearward by the return spring 13. The rear surfaces of the upper and lower end portions of the key member 39 are in contact with the contact portion 12 c of the rear shell 12. The contact portion 12c is formed in an annular shape with an elastic material (for example, a rubber material). The front surface of the central portion of the key member 39 in the vertical direction is in contact with the inner wall front surface 22c1 of the key attachment hole 22c. Further, since the plunger 32 is urged rearward, the front surface of the key member 39 abuts on the front surface of the annular groove portion 32b of the plunger 32 and is fixedly positioned.

・ Brake pedal depression holding state (Fig. 3)
FIG. 3 shows the brake pedal depression holding state. When the brake pedal is held in a depressed state, the atmospheric valve V2 and the negative pressure valve V1 are closed. Further, since the key member 39 is separated from the contact portion 12c of the rear shell 12, the key member 39 is in a free state in the key attachment hole 22c. Further, the front surface of the key member 39 is separated from the front surface of the annular groove portion 32 b of the plunger 32.

-State immediately after the brake pedal is returned (Fig. 4)
FIG. 4 shows a state immediately after the brake pedal is returned. When the stepping operation on the depressed brake pedal is released, the valve body 22 is returned (moved) backward by the urging force of the return spring 13. At this time, the input shaft 31 and the plunger 32 are also returned to the rear, but are also returned by the urging force of the return spring 37 and the urging force against a brake pedal (not shown), so that they are returned to the rear faster than the valve body 22.

At this time, after the front surface of the annular groove 32 b of the plunger 32 abuts on the front surface of the key member 39, the key member 39 moves rearward together with the plunger 32 in this state. On the other hand, the plunger 32 moves backward while pressing the movable portion 41b. As a result, since the connection part 41d bends, the movable part 41b approaches the attachment part 41a relatively. Further, when the movable portion 41b moves rearward together with the plunger 32, the movable portion 41b moves before the contact point when the key member 39 moving with the movement of the plunger 32 and the valve body 22 (the inner wall rear surface 22c2 of the key attachment hole 22c) contact each other. The part 41b contacts the first projecting part 41c1 (movement stop part 41c). As a result, the movable portion 41 b and thus the plunger 32 and the input shaft 31 are stopped relative to the valve body 22. As a result, the key member 39 can be prevented from coming into contact with the valve body 22 (the inner wall rear surface 22c2 of the key attachment hole 22c), so that when the input operation to the input shaft 31 being input is released. The generated sound can be reduced.
Even when the key member 39 is in contact with the valve body 22 (the inner wall rear surface 22c2 of the key attachment hole 22c), the impact generated at the time of contact is affected by the first protrusion 41c1 and the valve body 22 (key attachment hole). 22c can be dispersed and absorbed in contact with the rear surface 22c2) of the inner wall. As a result, it is possible to reduce the sound generated when the input operation to the input shaft 31 that is being input is canceled.

・ The state just before the brake pedal returns (Figure 5)
FIG. 5 shows a state immediately before the brake pedal is completely returned. The valve body 22 moves rearward while the key member 39 is sandwiched between the front surface of the annular groove portion 32b of the plunger 32 and the inner wall rear surface 22c2 of the key attachment hole 22c. Then, immediately before the brake pedal is completely returned to the original position, the rear surfaces of the upper and lower ends of the key member 39 abut on the abutting portion 12 c of the rear shell 12. Since the contact portion 12c is formed of an elastic material, it is possible to reduce the sound generated at the time of contact.
Thereafter, the negative pressure booster 1 returns to the inoperative state shown in FIG.

As is clear from the above description, the negative pressure booster 1 according to the present embodiment includes a movable partition wall 21 that divides the inside of the housing 10 into a front negative pressure chamber R1 and a rear variable pressure chamber R2, and the housing 10 advances and retreats. A valve body 22 that is assembled and connected to the movable partition wall 21 in the housing 10 and a shaft hole 22a formed in the valve body 22 are provided in the axial direction of the shaft hole 22a with respect to the valve body 22. A plunger 32 (air valve) that can move forward and backward along the input shaft 31 and communicates and blocks between the negative pressure chamber R1 and the variable pressure chamber R2 in accordance with the advance and retreat of the plunger 32 relative to the valve body 22. A valve mechanism V including a negative pressure valve V1 and an atmospheric valve V2 that communicates and blocks the variable pressure chamber R2 from the atmosphere, and the valve body 22, the plunger 32, and the housing 10. Te is capable abutting and separating a vacuum booster which includes a key member 39 which defines the amount of movement along the axial direction of the plunger 32 relative to the valve body 22, a. The valve mechanism V includes a negative pressure valve seat 22d provided in the valve body 22, an atmospheric valve seat 32d provided in the plunger 32, and a negative pressure valve portion 41b1 and an atmospheric valve seat 32d constituting the negative pressure valve V1 by the negative pressure valve seat 22d. Is provided with an air valve portion 41b2 constituting the air valve V2, and a valve body 41 formed of an elastic material. The valve body 41 is connected to the attachment portion 41a attached to the valve body 22 via the connection portion 41d via the connection portion 41d, and is movable relative to the attachment portion 41a. The negative pressure valve portion 41b1 and the atmospheric valve Movement of the plunger 32 after the time point when the input operation to the input shaft 31 is released and the movable portion 41b in which the portion 41b2 is formed is provided integrally with any one of the attachment portion 41a and the movable portion 41b. A moving stop portion 41c for stopping the movable portion 41b moving with the movement of the plunger 32 relative to the valve body 22 before the contact point when the key member 39 moving together with the valve body 22 comes into contact is further provided. ing.

According to this, since the movement stop part 41c is integrally provided in either one of the existing mounting part 41a and the movable part 41b, the process of assembling a separate member as in the prior art becomes unnecessary, and the negative pressure type doubler It is possible to suppress a decrease in productivity and cost increase related to the force device. Further, when the input operation on the input shaft 31 that has been depressed is released (for example, when the depression of the brake pedal is released), the movement stop unit 41c moves with the movement of the plunger 32 after the release time. The movable portion 41b that moves together with the movement of the plunger 32 is stopped relative to the valve body 22 before the contact point at which the key member 39 and the valve body 22 contact each other. As a result, since the key member 39 can be prevented from coming into contact with the valve body 22, it is possible to reduce the sound generated when the input operation to the input shaft 31 on which the input operation is performed is released. Even if the key member 39 is in contact with the valve body 22, the impact generated at the time of contact can be dispersed and absorbed in the contact between the movement stop portion 41 c and the valve body 22. As a result, it is possible to reduce the sound generated when the input operation to the input shaft 31 that is being input is canceled. As described above, in the negative pressure type booster, it is possible to reduce the sound generated when the depressed brake pedal is released without causing a decrease in productivity and cost.

Moreover, in the negative pressure type booster 1 of this embodiment, as shown in FIG. 6, you may make it provide the 1st protrusion part 41c1 (movement stop part 41c) in the movable part 41b. That is, the attachment portion 41a and the movable portion 41b are each formed in an annular shape, and the movement stop portion 41c is provided on one member of the attachment portion 41a and the movable portion 41b, and the circumferential direction of the one member is The first protrusion 41c1 extends along the whole or a part and protrudes toward the other member, and can contact the other member.
According to the negative pressure type booster device according to the first modified example configured as described above, it is easy to integrally provide the movement stop portion 41c on either the existing mounting portion 41a or the movable portion 41b. It can be realized by the method.

In the above-described embodiment, the movement stopping portion 41c is configured by the first protruding portion 41c1 extending along all or part of the circumferential direction of either one of the attachment portion 41a and the movable portion 41b. However, instead of this, a second projecting portion 41c2 shown in FIG. 7 may be used. The second protruding portion 41c2 is provided on any one member of the attachment portion 41a and the movable portion 41b, extends along the radial direction of one member, and protrudes toward the other member. It can be brought into contact with the other member. In addition, it is preferable to provide a plurality of second projecting portions 41c2. In this case, one member on which the second protrusion 41c2 is formed is formed in a cylindrical shape. Furthermore, the 2nd protrusion part 41c2 is provided in one member formed cyclically | annularly so that it may extend linearly from the inner periphery to the outer periphery of the surface formed cyclically | annularly. Moreover, you may make it the 2nd protrusion part 41c2 be radially provided in one member.
In addition, what extends along the radial direction extends linearly from the center to the outside from the center of an annular surface (for example, an annular surface). It includes not only an annular surface that extends linearly from the inner periphery to the outer periphery. For example, the second protrusion 41c2 may be configured by a portion where an annular portion and a plurality of straight portions parallel to each other overlap.

In the negative pressure booster according to the second modified example configured as described above, the movement stop portion 41c is provided on one member of the attachment portion 41a and the movable portion 41b, and the radial direction of the one member The second projecting portion 41c2 is formed so as to extend toward the other member and project toward the other member, and can be brought into contact with the other member.
According to this, it is realized by a simpler method (a method that makes it possible to use a mold that is easier to remove) that the movement stopping portion 41c is integrally provided on either the existing mounting portion 41a or the movable portion 41b. can do.

Further, the movement stopping portion 41c may be configured by a third protruding portion 41c3 shown in FIG. The third protruding portion 41c3 is provided on the metal movable portion 41f of the movable portion 41b, is formed to protrude toward the attachment portion 41a, and can contact the attachment portion 41a. For example, the third protruding portion 41c3 is provided to protrude rearward from the outer edge of the metal movable portion 41f. In this case, the third protrusions 41c3 may be provided along the entire circumference, or a plurality of the third protrusions 41c3 may be formed at predetermined intervals in the circumferential direction.

In the negative pressure type booster according to the third modified example configured as described above, the movement stop portion 41c is provided on the metal movable portion 41f of the movable portion 41b and is formed so as to protrude toward the mounting portion 41a. It is comprised from the 3rd protrusion part 41c3 which can contact | abut to the attachment part 41a.
According to this, it is possible to realize the movement stop portion 41c integrally with the existing movable portion 41b by a simple method.

Moreover, the movement stop part 41c may be configured by a fourth projecting part 41c4 shown in FIG. The fourth protruding portion 41c4 is provided to protrude rearward from the movable portion 41b, and can come into contact with a contacted portion 41g that is positioned relative to the valve body 22. Specifically, the fourth protruding portion 41c4 is provided to protrude rearward from the inner edge portion of the movable portion 41b formed in an annular shape. The abutted portion 14 g is a step portion formed at the central portion in the axial direction of the input shaft 31.

In the negative pressure type booster according to the fourth modified example configured as described above, the movement stop portion 41c is provided on the movable portion 41b and is positioned relative to the valve body 22. It is comprised from the 4th protrusion part 41c4 which can contact | abut 41g.
According to this, it is possible to realize the movement stop portion 41c integrally with the existing movable portion 41b by a simple method.

DESCRIPTION OF SYMBOLS 1 ... Negative pressure type booster, 10 ... Housing, 11 ... Front shell, 12 ... Back shell, 20 ... Power piston, 21 ... Movable partition, 21a ... Plate, 21b ... Diaphragm, 22 ... Valve body, 22a ... Shaft hole, 22c ... Key mounting hole, 31 ... Input shaft (input member), 32 ... Plunger (air valve), 39 ... Key member, 41 ... Valve element, 41a ... Mounting portion, 41b ... Moving portion, 41c ... Moving stop portion, 41c1 ... 1st protrusion part, 41c2 ... 2nd protrusion part, 41c3 ... 3rd protrusion part, 41c4 ... 4th protrusion part, R1 ... negative pressure chamber, R2 ... variable pressure chamber, V ... valve mechanism.

Claims

A movable partition that divides the inside of the housing into a front negative pressure chamber and a rear transformer chamber;
A valve body assembled to the housing so as to be capable of moving forward and backward and connected to the movable partition wall in the housing;
An air valve provided in a shaft hole formed in the valve body, capable of moving forward and backward along the axial direction of the shaft hole with respect to the valve body, and moving integrally with the input member;
A negative pressure valve that communicates and blocks between the negative pressure chamber and the variable pressure chamber in accordance with advancement and retreat of the air valve relative to the valve body, and an atmospheric valve that communicates and blocks the variable pressure chamber from the atmosphere. A valve mechanism;
A negative pressure type booster comprising: a key member that is capable of contacting and detaching from the valve body, the air valve, and the housing, and that defines a movement amount of the air valve along the axial direction with respect to the valve body. A device,
The valve mechanism includes the negative pressure valve seat provided in the valve body, the atmospheric valve seat provided in the air valve, and the negative pressure valve portion constituting the negative pressure valve by the negative pressure valve seat and the atmospheric valve seat. A valve body provided with an atmospheric valve part constituting the valve and formed of an elastic material,
The valve body is connected to an attachment portion attached to the valve body, and is connected to the attachment portion via a connection portion, and is movable relative to the attachment portion, the negative pressure valve portion and the atmospheric valve portion And a movable portion formed integrally with the mounting portion and the movable portion, and move with the movement of the air valve after the input operation on the input member is released. A movement stop portion that stops the movable portion that moves together with the movement of the air valve relative to the valve body before the contact point at which the key member and the valve body abut. A negative pressure booster.
The attachment portion and the movable portion are each formed in an annular shape,
The movement stop portion is provided on any one member of the attachment portion and the movable portion, extends along all or part of the circumferential direction of the one member, and protrudes toward the other member. The negative pressure type booster according to claim 1, wherein the negative pressure type booster is formed of a first protrusion that is formed and is capable of contacting the other member.
The attachment portion and the movable portion are each formed in an annular shape,
The movement stop portion is provided on any one member of the attachment portion and the movable portion, extends along the radial direction of the one member, and protrudes toward the other member, The negative pressure type booster according to claim 1, wherein the negative pressure type booster is configured by a second projecting portion that can contact the other member.
The movable part is composed of an elastic movable part made of an elastic material and a metal movable part made of a metal material,
The said movement stop part is provided in the said metal movable part of the said movable part, and is formed so that it may protrude toward the said attachment part, and is comprised from the 3rd protrusion part which can contact | abut to the said attachment part. Item 2. A negative pressure booster according to item 1.