JP2021115948A - Negative pressure type booster and sleeve member - Google Patents

Abstract

To obtain a negative pressure type booster comprising a valve mechanism which can improve assembly workability.SOLUTION: A negative pressure type booster comprises: a valve body; a plunger which is so accommodated as to be movable in an axial direction with respect to the valve body, and is provided with a recess opened to the other side in the axial direction; an inlet rod which extends in the axial direction and has, at an end part on one side in the axial direction, a spherical part having a maximum diameter portion which is inserted in the recess and overhangs to the outermost in a radial direction orthogonal to the axial direction, and a reduced diameter portion of which an outer diameter decreases as approaching the other side in the axial direction from the maximum diameter portion; and a sleeve member having a bottomed cylindrical part which is interposed between an inner peripheral surface of the recess and an outer peripheral surface of the spherical part, accommodates the spherical part, and is opened to the other side in the axial direction, and an anti-falling-out part which is provided on the other side in the axial direction with respect to the cylindrical part, and becomes a first state that an outer diameter thereof is larger than an inner diameter of the inner peripheral surface in a state of non-press-fitted in the recess, and becomes a second state that the anti-falling-out part is positioned on the other side in the axial direction with respect to the reduced diameter portion and on an inner side of the inner peripheral surface in a state of press-fitted in the recess.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a negative pressure booster and a sleeve member.

Conventionally, for example, a negative pressure type booster disclosed in Patent Document 1 below is known. The conventional negative pressure type booster has, for example, a housing composed of a front shell and a rear shell, a movable partition wall that divides the inside of the housing into a negative pressure chamber on the front side and a transformer chamber on the rear side, and an atmosphere in the transformer chamber. It is equipped with a valve mechanism that communicates with or shuts off the valve. When the transformer chamber communicates with the atmosphere, the movable partition wall is pushed toward the negative pressure chamber side by the differential pressure between the transformer chamber and the negative pressure chamber and moves forward. It is configured to supplement the pedaling force input from the brake pedal by advancing the operating partition wall and generate a large control pressure in the master cylinder.

China Utility Model No. 2049786828

However, the connection portion between the plunger (air valve) constituting the valve mechanism in the conventional negative pressure type booster and the input rod to which the brake pedal is connected corresponds to the swinging due to the stepping operation of the brake pedal, and also corresponds to the swing of the plunger. It is necessary to secure the strength that can withstand the operating force when moving forward or backward, especially the strength to prevent it from coming off. Therefore, there are problems that the structure becomes complicated and the assembly workability is lowered.

Therefore, one of the problems of the present disclosure is, for example, to obtain a negative pressure type booster having an input rod retaining structure and capable of improving assembly workability.

The negative pressure type booster of the present disclosure includes, for example, a first shell forming an outer wall on one side in the axial direction and a second shell forming the outer wall on the other side in the axial direction with respect to the first shell. The housing to be provided, the inside of the housing is divided into a negative pressure chamber on one side in the axial direction and a transformer chamber on the other side in the axial direction, and a movable partition wall movable in the axial direction, the transformer chamber and the atmosphere. A negative pressure type booster including a valve mechanism that communicates with or shuts off between the valve body and the valve body.
A plunger that is movably housed in the valve body in the axial direction and is provided with a recess that is open on the other side in the axial direction, and an end portion that extends in the axial direction and is provided on one side in the axial direction. It has a maximum diameter portion that is inserted into the recess and projects outward in the radial direction orthogonal to the axial direction, and a reduced diameter portion whose outer diameter decreases from the maximum diameter portion toward the other side in the axial direction. A bottomed cylinder that is interposed between the input rod provided with the sphere and the inner peripheral surface of the recess and the outer peripheral surface of the sphere to accommodate the sphere and is open to the other side in the axial direction. In the state where the shape portion and the tubular portion are provided on the other side in the axial direction and are not press-fitted into the recess, the outer diameter is larger than the inner diameter of the inner peripheral surface and is press-fitted into the recess. A sleeve member having a retaining portion in a second state located on the other side in the axial direction and inside the inner peripheral surface in the reduced diameter portion in the reduced diameter portion is provided.

In the above negative pressure type booster, when a sleeve member having an outer diameter larger than the inner diameter of the inner peripheral surface of the recess of the plunger is press-fitted into the recess, the retaining portion is configured to be positioned inward in the radial direction, and the maximum of the input rod. Surround the reduced diameter part with a smaller diameter than the diameter part. That is, it is possible to prevent the input rod from coming off at the same time as press-fitting. As a result, the workability of assembling the input rod for the plunger can be improved, and a structure for preventing the input rod from coming off from the plunger can be easily obtained.

FIG. 1 is an exemplary and schematic configuration diagram of a vehicle brake device to which the negative pressure type booster of the embodiment is applied. FIG. 2 is an exemplary and schematic cross-sectional view showing the configuration of the negative pressure type booster of the embodiment. FIG. 3 is an exemplary and schematic cross-sectional view showing a state of a sleeve member mounted on an input rod before being inserted into a recess of a plunger in the negative pressure type booster of the embodiment. FIG. 4 is an exemplary and schematic side view showing a maximum diameter portion and a reduced diameter portion of the spherical portion of the input rod of the negative pressure type booster of the embodiment. FIG. 5 is an exemplary and schematic perspective view showing the shape of the sleeve member used in the negative pressure type booster of the embodiment, and is a view showing the first state before being inserted into the recess of the plunger. FIG. 6 is an exemplary and schematic cross-sectional view showing the shape of the sleeve member used in the negative pressure type booster of the embodiment, and is a diagram showing a first state before being inserted into the recess of the plunger. FIG. 7 shows a state in which the input rod equipped with the sleeve member is inserted into the recess of the plunger of the negative pressure type booster of the embodiment, and the assembly of the plunger and the input rod is completed (second state of the sleeve member). It is an exemplary and schematic cross-sectional view which shows. FIG. 8 is a modified example of the sleeve member applicable to the negative pressure type booster of the embodiment, and is an exemplary and schematic cross-sectional view showing a state in which the assembly of the plunger and the input rod is completed. FIG. 9 is another modification of the sleeve member applicable to the negative pressure type booster of the embodiment, and is an exemplary and schematic cross-sectional view showing a state in which the plunger and the input rod have been assembled.

Hereinafter, exemplary embodiments and modifications of the present invention will be disclosed. The configurations of the embodiments and modifications shown below, and the actions and results (effects) brought about by the configurations are examples. The present invention can also be realized by configurations other than those disclosed in the following embodiments and modifications. Further, according to the present invention, it is possible to obtain at least one of various effects (including derivative effects) obtained by the configuration.

Further, in the present specification, the ordinal numbers are given for convenience in order to distinguish parts, parts, etc., and do not indicate the priority order or the order. Further, each diagram used for explanation is a conceptual diagram, and the shape of each part may not always be exact.

FIG. 1 is an exemplary and schematic configuration diagram of a vehicle brake device 1 to which the negative pressure type booster 100 of the embodiment is applied. The vehicle braking device 1 includes a cylinder mechanism 2. The cylinder mechanism 2 includes a master cylinder 21, master pistons 22 and 23, and a master reservoir 24. The master pistons 22 and 23 are slidably arranged in the master cylinder 21. The master pistons 22 and 23 divide the inside of 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 pipeline communicating with the first master chamber 21a and the second master chamber 21b. The master reservoir 24, the first master chamber 21a, and the second master chamber 21b are communicated or cut off by the movement of the master pistons 22 and 23.

The cylinder mechanism 2 provides control pressure to the wheel cylinders 25, 26, 27, 28. The wheel cylinder 25 is arranged on the left rear wheel RL of the vehicle. The wheel cylinder 26 is arranged on the right rear wheel RR of the vehicle. The wheel cylinder 27 is arranged on the left front wheel FL of the vehicle. The wheel cylinder 28 is arranged on the right front wheel FR of the vehicle. The master cylinder 21 and the wheel cylinders 25 to 28 are connected to each other via an actuator 3. As a result, each of the wheel cylinders 25 to 28 applies a braking force to the left rear wheel RL, the right rear wheel RR, the left front wheel FL, and the right front wheel FR. Although detailed description will be omitted, the actuator 3 is composed of a pipeline, an electric pump, a solenoid valve, a check valve, and the like, which are not shown.

In the brake device 1 of the vehicle, when the driver depresses the brake pedal 29, the pedaling force is boosted by the negative pressure type booster 100 airtightly connected to the master cylinder 21, and the master piston 22 in the master cylinder 21 23 is pressed. As a result, 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 3, and braking control is executed on each wheel.

FIG. 2 is an exemplary and schematic cross-sectional view showing the configuration of the negative pressure type booster 100 of the embodiment. The negative pressure type booster 100 includes a hollow booster shell 110 (housing), and the movable partition wall 120 and the piston 130 are integrally assembled with the booster shell 110 so as to be movable in the front-rear direction. The inside of the booster shell 110 is divided into a front negative pressure chamber R1 and a rear transformer chamber R2 by a movable partition wall 120.

The booster shell 110 includes, for example, a front shell 111 (first shell) forming an outer wall on one side and a rear shell 112 (second shell) forming an outer wall on the other side, which are formed of iron, aluminum, resin (reinforced plastic) or the like. Shell) consists of. The front shell 111 is formed with a negative pressure introduction port 111a for communicating the negative pressure chamber R1 with a negative pressure source (for example, an intake manifold of an engine (not shown)). A check valve 113 is provided at the negative pressure introduction port 111a. The check valve 113 is configured to allow air communication from the negative pressure chamber R1 side to the negative pressure source side and block air communication from the negative pressure source side to the negative pressure chamber R1 side. Further, the booster shell 110 has tie rod bolts 114 that airtightly penetrate the front shell 111 and the rear shell 112 at two locations in the radial direction. In FIG. 2, only one tie rod bolt 114 is shown. Further, the booster shell 110 has a rear bolt 115 that airtightly penetrates the rear shell 112. When the positional relationship and the arrangement direction of each member are shown in the following description, the direction of the booster shell 110 on the front shell 111 side is referred to as one side or the front in the axial direction, and the direction on the rear shell 112 side is the other side in the axial direction. Or it may be called backward.

The tie rod bolt 114 is, for example, a bolt manufactured by forging using a forging die, and the front shell 111 side is fastened to the master cylinder 21 with a nut or the like. As a result, the two tie rod bolts 114 support the master cylinder 21 on the front shell 111 side. The tie rod bolt 114 has an annular diameter-expanded portion 114a whose diameter is expanded outward in the radial direction so as to face the inner surface 111b of the front shell 111. Further, the rear shell 112 side of the tie rod bolt 114 and the rear bolt 115 are fixed to a stationary member, for example, a vehicle body (not shown). The rear bolt 115 is also a bolt manufactured by forging using a forging die.

Further, the booster shell 110 includes a retainer 118 arranged between the inner surface 111b of the front shell 111 and the enlarged diameter portion 114a of the tie rod bolt 114. The retainer 118 is made of a metal material (for example, aluminum or the like) having a lower rigidity than the front shell 111 and the tie rod bolt 114 in an annular shape, and has a through hole through which the tie rod bolt 114 is inserted.

The movable partition wall 120 is provided in the booster shell 110 so as to be movable in the front-rear direction along the direction of the axis of the piston 130. The movable partition wall 120 includes a diaphragm 121 formed of an annular elastic member (for example, an annular rubber material). The diaphragm 121 includes an outer peripheral bead portion 121a, an inner peripheral bead portion 121b, and an annular seat portion 121c that connects the outer peripheral bead portion 121a and the inner peripheral bead portion 121b. The outer peripheral bead portion 121a is arranged at a connecting portion between the front shell 111 and the rear shell 112, and is airtightly sandwiched by the front shell 111 and the rear shell 112. The inner peripheral bead portion 121b is airtightly fixed to the outer peripheral portion of the piston 130.

The piston 130 is connected to the movable partition wall 120, that is, the inner peripheral portion of the diaphragm 121. The piston 130 includes a main body 131 (valve body) made of resin and formed in a cylindrical shape. The main body 131 is airtightly attached to the rear shell 112 of the booster shell 110 at the central portion so as to be movable in the front-rear direction along the direction of the axis. Further, the main body 131 is urged rearward by a return spring S1 interposed between the booster shell 110 and the front shell 111. The portion of the main body 131 (that is, the piston 130) that protrudes outside the booster shell 110 is covered and protected by the boots B.

Inside the main body 131, a pair of negative pressure continuous passages 132 (only one is shown in FIG. 2) are provided. The negative pressure communication passage 132 communicates with the negative 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. Further, inside the main body 131, the input rod 141 and the plunger 142 (air valve) are assembled so as to be coaxial, and the valve mechanism 150 and the filter 143 are assembled so as to be coaxial. Further, inside the main body 131, a reaction member 144 made of an elastic member (for example, a rubber material) and an output shaft 145 are assembled coaxially in front of the plunger 142.

The input rod 141 can move in the front-rear direction along the direction of the axis of the main body 131, and is jointed to the connecting portion (recess described later) of the plunger 142 by the spherical portion 141a provided at the tip of the input rod 141. It is connected in a shape. The input rod 141 is connected to the brake pedal 29 (see FIG. 1) via a yoke (not shown) by a screw portion provided at the rear end, and moves forward with the pedaling force acting on the brake pedal 29 as an input. It is configured as follows. Further, the input rod 141 is engaged with the return spring S2 via the annular member 146, and is urged rearward by the return spring S2.

The plunger 142 comes into contact with the central portion of the rear surface of the recoil member 144 at the tip end portion. Further, the plunger 142 engages with the key member K in the annular groove portion formed in the central portion. Further, the plunger 142 is provided with an annular atmospheric valve seat 150a in the valve mechanism 150 at the rear end portion. The key member K has a function of restricting the movement of the plunger 142 in the front-rear direction with respect to the main body 131 of the piston 130, and a rearward movement limit position of the piston 130 with respect to the booster shell 110 (rear return position of the piston 130). It is a member having a specified function.

The recoil member 144 is housed in the rear cylindrical portion 145a of the output shaft 145, and is assembled to the main body 131 of the piston 130 together with the rear cylindrical portion 145a of the output shaft 145. The recoil member 144 is accommodated in the rear cylindrical portion 145a, and the central portion of the rear surface is bulged and deformed toward the rear.

The output shaft 145 pushes the master pistons 22 and 23 (see FIG. 1) of the master cylinder 21 at the tip end portion. 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 150b integrally formed at the rear end of the negative pressure communication passage 132 in the main body 131 of the piston 130, and an atmospheric valve seat 150a integrally formed at the rear end of the plunger 142. It has. Further, the valve mechanism 150 includes a tubular valve body 151 arranged so as to be coaxial with the atmospheric valve seat 150a. The valve body 151 has an annular mounting portion 151a and a tubular movable portion 151b integrally formed with the mounting portion 151a and movable along the direction of the axis. The mounting portion 151a of the valve body 151 is airtightly assembled in the main body portion 131 of the piston 130, and is held by the main body portion 131 by the annulus member 146.

The movable portion 151b of the valve body 151 communicates with the negative pressure chamber R1 and the transformer chamber R2 together with the negative pressure valve seat 150b by seating or leaving the negative pressure valve seat 150b (the outer peripheral side of the movable portion 151b). Alternatively, it has a negative pressure valve portion 151b1 that constitutes a negative pressure valve that shuts off. Further, the movable portion 151b of the valve body 151 communicates with the atmosphere valve seat 150a and the transformer chamber R2 and the atmosphere by seating or leaving the atmospheric valve seat 150a (the inner peripheral side of the movable portion 151b). Alternatively, it has an atmospheric valve portion 151b2 that constitutes an atmospheric valve that shuts off.

Then, in the negative pressure type booster 100, the transformer chamber R2 can communicate with the negative pressure chamber R1 or the atmosphere according to the movement of the input rod 141 and the plunger 142 in the front-rear direction with respect to the main body 131. That is, when the input rod 141 and the plunger 142 move forward from the position shown in FIG. 2 (the original position and the non-operating position) with respect to the main body 131, the negative pressure valve portion 151b1 is seated on the negative pressure valve seat 150b and the atmosphere. The valve seat 150a is separated from the atmospheric valve portion 151b2. In this case, the transformer chamber R2 is cut off from the negative pressure chamber R1 and communicates with the atmosphere. Then, the atmosphere flows into the transformer chamber R2 through the filter 143, the inside of the valve body 151, the gap with the atmospheric valve seat 150a, the communication passage provided in the main body 131, and the like. As a result, the pressure in the transformer chamber R2 becomes larger than the pressure in the negative pressure chamber R1, so that the movable partition wall 120 and the piston 130 operate forward as the input rod 141 operates forward, and the output shaft 145 operates. Acts forward. As a result, the output shaft 145 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 3.

On the other hand, when the input rod 141 and the plunger 142 return to the non-operating position (original position) with respect to the main body 131, the atmospheric valve seat 150a is seated on the atmospheric valve portion 151b2, and the negative pressure valve portion 151b1 is a negative pressure valve. Leave the seat 150b. In this case, the air valve closes to cut off the communication between the transformer chamber R2 and the atmosphere, and the negative pressure valve opens to communicate the negative pressure chamber R1 and the transformer chamber R2. Then, air is sucked from the transformer chamber R2 into the negative pressure chamber R1 through the communication passage provided in the main body 131, the gap between the negative pressure valve portion 151b1 and the negative pressure valve seat 150b, the negative pressure communication passage 132, and the like. As a result, the pressure in the transformer chamber R2 and the pressure in the negative pressure chamber R1 become substantially equal, so that the movable partition wall 120 and the piston 130 operate rearward as the input rod 141 operates rearward due to the urging force of the return spring S2. Then, the output shaft 145 operates rearward. As a result, the pressure on 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.

In the negative pressure type booster 100 configured as described above, in the plunger 142 constituting the valve mechanism 150, the input rod 141 is moved in the front-rear direction (swing operation) in response to the depressing and depressing release operations (swinging operations) of the brake pedal 29. It moves in the axial direction of the input rod 141). Therefore, the plunger 142 and the input rod 141 are jointly connected so as to be rotatably connected in the axial direction so that the input rod 141 can smoothly move in the front-rear direction. That is, a spherical portion 141a is provided at the tip of the input rod 141, and the input rod 141 can rotate with respect to the plunger 142 in a state of being inserted into the recess provided in the plunger 142. Further, the input rod 141 moves forward against the return spring S2 when the brake pedal 29 is depressed (during braking operation), and when the brake pedal 29 is released from being depressed, the urging force of the return spring S2 causes the input rod 141 to move forward. Move backwards. That is, the input rod 141 receives a force in the pulling direction with respect to the plunger 142. Therefore, the input rod 141 needs to have a structure that is rotatable with respect to the plunger 142 and is connected so that the spherical portion 141a does not come off from the recess of the plunger 142.

Therefore, as shown in FIG. 3, the negative pressure type booster 100 of the embodiment has a spherical portion between the inner peripheral surface 160a of the recess 160 of the plunger 142 and the outer peripheral surface 141a1 of the spherical portion 141a of the input rod 141. A sleeve member 162 having a function of preventing the 141a (input rod 141) from coming off is interposed. The sleeve member 162 has a tubular portion 164 that rotatably includes and supports (rotatably fits) the spherical portion 141a of the input rod 141, and is inserted into the recess 160 of the plunger 142 together with the input rod 141. It has a retaining portion 166 that prevents the spherical portion 141a from coming off the sleeve member 162 (recessed portion 160) by being elastically deformed due to the above.

FIG. 4 is an exemplary and schematic view showing the shape of the input rod 141. As described above, the input rod 141 is formed by a spherical portion 141a for realizing joint connection and a pedaling force transmitting portion 141b that supports the spherical portion 141a at the tip portion. The spherical portion 141a and the pedaling force transmitting portion 141b are made of, for example, metal. As shown in FIG. 1, a brake pedal 29 is connected to the other end side of the pedal force transmission unit 141b. Specifically, the input rod 141 has a spherical portion 141a extending in the axial direction and being inserted into the recess 160 of the plunger 142 at one end in the axial direction. The spherical portion 141a has a maximum diameter portion 141L projecting to the outermost side in the radial direction orthogonal to the axial direction, and a reduced diameter portion 141S whose outer diameter decreases toward the other side in the axial direction from the maximum diameter portion 141L. From the position of the maximum diameter portion 141L (outermost diameter M) toward the other side in the axial direction (the other end side of the pedaling force transmitting portion 141b), it is connected to the pedaling force transmitting portion 141b via the reduced diameter portion 141S. In the case of FIG. 4, the reduced diameter portion 141S is a portion on the pedaling force transmission portion 141b side (a part of the spherical surface of the spherical portion 141a) from the maximum diameter portion 141L (outermost diameter M) of the spherical portion 141a, but the maximum diameter portion The outer diameter may be smaller than 141L (outermost diameter M). In another embodiment, for example, the connecting portion between the spherical portion 141a and the pedaling force transmitting portion 141b may be the reduced diameter portion 141S.

FIG. 5 is an exemplary and schematic perspective view showing the shape of the sleeve member 162, and FIG. 6 is a cross-sectional view of the sleeve member 162 shown in FIG. In each figure, the sleeve member 162 is a diagram showing a first state of an outer diameter larger than the inner diameter of the inner peripheral surface of the recess 160 before being inserted into the recess 160 of the plunger 142. As described above, the sleeve member 162 is a metal component that can be interposed between the inner peripheral surface 160a of the recess 160 of the plunger 142 and the outer peripheral surface 141a1 of the spherical portion 141a.

As shown in FIGS. 3, 5, and 6, the sleeve member 162 has a bottomed tubular portion 164 that is open to the other side in the axial direction and includes a bottom portion 164a that houses the spherical portion 141a. The tubular portion 164 has an outer diameter M2 larger than the inner diameter M1 of the inner peripheral surface 160a of the recess 160 in a non-inserted (non-press-fitted) state (first state shown in FIGS. 5 and 6) of the plunger 142. (Fig. 6). That is, the outer diameter M2 of the tubular portion 164 is in the inner circumference by the press-fitting allowance so as to be in the press-fitting state when the sleeve member 162 is inserted into the recess 160 (when the second state shown in FIG. 7 is reached). The diameter is larger than the inner diameter M1 of the surface 160a. As will be described later, the plunger 142 and the sleeve member 162 formed of the metal material are set so that [hardness of the plunger 142] <[hardness of the sleeve member 162]. Therefore, when the sleeve member 162 is inserted into the recess 160 of the plunger 142, the sleeve member 162 is press-fitted while plastically deforming the inner peripheral surface 160a of the recess 160. As a result, the depression of the brake pedal 29 is released, and the return spring S2 can secure the pull-out strength for maintaining the connection between the plunger 142 and the input rod 141 even when the pull-out load acts on the input rod 141.

Further, the cylinder inner diameter M3 of the tubular portion 164 is set to be slightly larger than the maximum diameter portion 141L (outermost diameter M) of the spherical portion 141a of the input rod 141. As a result, even when the spherical portion 141a of the input rod 141 is inserted into the sleeve member 162 and further press-fitted into the recess 160 of the plunger 142 together with the sleeve member 162, the outer peripheral surface 141a1 of the spherical portion 141a and the inner wall surface of the tubular portion 164 A gap M5 (see FIG. 7) is formed between the sphere and the 164b, and the spherical portion 141a can be maintained in a rotatable state with respect to the sleeve member 162. In addition, it is easy to avoid the occurrence of biting of the spherical portion 141a with respect to the inner wall surface 164b. That is, it is possible to realize a state in which the input rod 141 can be smoothly rotated with respect to the plunger 142.

The sleeve member 162 is provided with a retaining portion 166 on the other side in the axial direction of the tubular portion 164 (the open end side opposite to the end portion on which the bottom portion 164a is formed). As shown in FIGS. 5 and 6, in the first state of the outer diameter larger than the inner diameter of the inner peripheral surface 160a of the recess 160 before the sleeve member 162 is press-fitted (inserted) into the recess 160 of the plunger 142. The retaining portion 166 is further expanded in diameter outward from the tubular portion 164 in the radial direction orthogonal to the axial direction. The retaining portion 166 is in a second state in which the sleeve member 162 is press-fitted into the recess 160 and is located on the other side in the axial direction and inside the inner peripheral surface 160a with respect to the reduced diameter portion 141S. The retaining portion 166 has the sleeve member 162 press-fitted into the recess 160 in the radial direction from the first portion 166a in contact with the inner peripheral surface 160a, the first portion 166a, and the first portion 166a via the gap M4. It comprises a second portion 166b located on the inside. In the case of the sleeve member 162 shown in FIGS. 5 and 6, the second portion 166b is an axially opposite end portion (open end side of the sleeve member 162) of the first portion 166a and is a tubular portion 164. It bends inward in the radial direction and extends from its end to one side in the axial direction. The second portion 166b is elastically deformed when the sleeve member 162 is press-fitted into the recess 160. Since the first portion 166a is continuously provided at the other end of the tubular portion 164 in the axial direction, the first portion 166a is inserted into the recess 160 to be inside the first portion 166a. The second portion 166b bent in the above direction is located radially inside the inner diameter M3 of the cylinder member 162 of the sleeve member 162. As a result, the retaining portion 166 surrounds the reduced diameter portion 141S of the input rod 141 inserted into the sleeve member 162. Therefore, the retaining portion 166 serves as a portion for preventing the spherical portion 141a (input rod 141) from coming off from the sleeve member 162 (cylindrical portion 164) after the sleeve member 162 is press-fitted (inserted) into the plunger 142. ..

Further, since the second portion 166b has a gap M4 with respect to the first portion 166a, the second portion 166b is elastically deformed even after the sleeve member 162 is press-fitted (inserted) into the plunger 142. obtain. Therefore, even when the spherical portion 141a also formed of metal is inserted into the sleeve member 162 formed of metal, the bite between the metals is suppressed and the input rod 141 can smoothly rotate with respect to the sleeve member 162. Can be maintained. In other words, since it is possible to prevent the sleeve member 162 from biting into the input rod 141, the sleeve member 162 can be formed of metal, and the strength of the sleeve member 162 can be easily ensured and deformation can be easily avoided. When the sleeve member 162 is press-fitted into the recess 160 of the plunger 142, the second portion 166b of the retaining portion 166 comes into contact with or slightly pressed against the reduced diameter portion 141S while maintaining the gap M4. Is set to. As a result, for example, even if there is a variation in the processing accuracy of the reduced diameter portion 141S, the variation is absorbed by the elastic deformation of the second portion 166b, and the input rod 141 with respect to the sleeve member 162 (plunger 142). It is possible to prevent rattling and conversely making it difficult to rotate.

Further, as shown in FIGS. 5 and 6, the sleeve member 162 includes a plurality of notches 168 extending in the axial direction (axial direction of the input rod 141). The cutout portion 168 divides the retaining portion 166 into a plurality of arm AMs in the circumferential direction of the tubular portion 164. That is, the arm AM individually elastically deforms to support the reduced diameter portion 141S, and functions as a movable mechanism that prevents the spherical portion 141a (input rod 141) from coming off, rattling, and biting. The notch 168 extends beyond the tip of the second portion 166b, which is bent and extends unilaterally in the axial direction, to the bottom 164a side. For example, the first portion 166a extends to the vicinity of a position where it is elastically deformed inward when it is press-fitted into the recess 160. The axial length of the notch portion 168 can be appropriately set according to the strength of the sleeve member 162, the mobility of the arm AM (removing portion 166), and the like. Further, the cutout portion 168 can easily displace the retaining portion 166 inward in the radial direction. Further, by forming the notch portion 168, the workability when the second portion 166b is bent inward can be improved. Note that FIG. 5 shows an example in which the cutout portions 168 are formed at five locations at equal intervals, but the number of cutout portions 168 formed and the formation interval are determined by the strength of the retaining portion 166 and the second portion 166b. It can be changed as appropriate in consideration of workability during bending. Further, as shown in FIG. 5, at least one slit 169 extending toward the bottom portion 164a is formed on the side opposite to the open end of the cutout portion 168. The slits 169 are formed for each notch 168, for example, and each communicates with the notch 168. The slit 169 can function as a through passage for allowing air existing in the recess 160 to escape when the sleeve member 162 is press-fitted into the recess 160 of the plunger 142. By forming an air vent passage and reducing the resistance of the remaining air, it is possible to prevent the sleeve member 162 from tilting during press-fitting or insufficient press-fitting of the sleeve member 162, resulting in stable press-fitting. Can be made possible.

As described above, the hardness of the sleeve member 162 is set higher than the hardness of the plunger 142. As a result, the recess 160 side of the plunger 142 is deformed at the time of press fitting. Since the slit 169 is formed, a part of the deformed plunger 142 can easily escape to the inside of the slit 169. That is, a part of the plunger 142 that has escaped to the slit 169 can be a wedge when connecting the plunger 142 and the sleeve member 162. As a result, the depression of the brake pedal 29 is released, and the return spring S2 can contribute to the improvement of the pull-out strength against the case where the pull-out load acts on the input rod 141. Therefore, the slit 169 also functions as a pull-out strength increasing portion.

FIG. 7 is an exemplary and schematic cross-sectional view showing a state in which the input rod 141 equipped with the sleeve member 162 is inserted into the plunger 142 and the assembly of the plunger 142 and the input rod 141 is completed. Hereinafter, the procedure for assembling the plunger 142 including the sleeve member 162 and the input rod 141 will be described.

First, as shown in FIG. 3, the spherical portion 141a of the input rod 141 is inserted into the sleeve member 162 in the first state before being inserted (press-fitted) into the recess 160 of the plunger 142. As described above, the inner diameter M3 of the tubular portion 164 of the sleeve member 162 is set to be larger than the maximum diameter portion 141L (outermost diameter M) of the spherical portion 141a. Further, the retaining portion 166 connected to the tubular portion 164 extends to the outer shape side from the tubular portion 164 in the first state. In this case, the second portion 166b of the retaining portion 166 in the first state is positioned further radially outward from the inner wall surface 164b of the tubular portion 164. That is, when the spherical portion 141a is inserted into the sleeve member 162, the shape is such that the surface of the spherical portion 141a and the second portion 166b do not come into contact with each other. As a result, the surface of the sphere portion 141a is prevented from being scratched, and the sphere portion 141a (input rod 141) can rotate smoothly and stably with respect to the plunger 142 (sleeve member 162). By setting the hardness of the spherical portion 141a higher than that of the sleeve member 162, scratches can be effectively prevented.

Subsequently, the input rod 141 having the sleeve member 162 mounted on the spherical portion 141a is moved to one side in the axial direction with respect to the recess 160 of the plunger 142 already mounted on the main body portion 131 of the negative pressure type booster 100. Insert (press fit). As described above, the outer diameter M2 of the sleeve member 162 has a press-fitting allowance with respect to the inner diameter of the inner peripheral surface 160a of the recess 160 of the plunger 142. Further, the hardness of the metal material forming the sleeve member 162 is set higher than the hardness of the metal material forming the plunger 142. The hardness of the retaining portion 166 connected to the tubular portion 164 of the sleeve member 162 is also set higher than the hardness of the plunger 142. Therefore, when the sleeve member 162 (input rod 141) is inserted into the plunger 142, the recess 160 side of the plunger 142 is plastically deformed. Further, in the first state, the retaining portion 166 that extends radially outward from the tubular portion 164 is elastically deformed inward in the radial direction when inserted into the recess 160. Since the second portion 166b of the retaining portion 166 is formed radially inward from the first portion 166a, the first portion 166a elastically deforms following the inner peripheral surface 160a of the recess 160, resulting in a sphere. The portion 141a is displaced so as to approach the reduced diameter portion 141S whose outer diameter is smaller than the maximum diameter portion 141L (outermost diameter M). Further, the second portion 166b is also displaced so as to approach the reduced diameter portion 141S in conjunction with the first portion 166a. The second portion 166b is located inside the maximum diameter portion 141L of the spherical portion 141a having a diameter larger than that of the reduced diameter portion 141S. As a result, the second portion 166b is caught in a portion having a diameter larger than that of the reduced diameter portion 141S (a portion on the other side in the axial direction from the maximum diameter portion 141L of the spherical portion 141a) to prevent the second portion 166b from coming off.

As described above, even when the sleeve member 162 is press-fitted into the recess 160, the sleeve member 162 having a hardness higher than that of the plunger 142 can maintain the cylinder inner diameter M3. As a result, a gap M5 is formed between the spherical portion 141a having the maximum diameter portion 141L (outermost diameter M) smaller than the cylinder inner diameter M3. Further, since the sleeve member 162 has a gap M4 between the first portion 166a and the second portion 166b even after being press-fitted into the recess 160, elastic deformation of the second portion 166b is allowed. As a result, the bite between the metal sleeve member 162 and the spherical portion 141a (diameter reduced portion 141S) is suppressed, and it is easy to maintain the smooth rotation of the input rod 141 with respect to the plunger 142 (main body portion 131). can do. Further, even if an error in the forming dimension occurs in the sleeve member 162, the reduced diameter portion 141S, or the like, the error can be absorbed by the elastic deformation (displacement) of the second portion 166b. For example, the sleeve member of the input rod 141. It is possible to suppress rattling with respect to 162 (plunger 142). In the case of the present embodiment, the reduced diameter portion 141S is formed on the spherical portion 141a on the pedaling force transmission portion 141b side from the maximum diameter portion 141L of the spherical portion 141a, and the second portion 166b is on the spherical surface of the spherical portion 141a. It is designed to come into contact. As a result, the input rod 141 can realize smoother rotation than when the second portion 166b comes into contact with the portion of the pedaling force transmitting portion 141b.

Further, as described above, a part of the plunger 142 that is plastically deformed when the sleeve member 162 is press-fitted into the recess 160 of the plunger 142 can escape to the inside of the slit 169 and become a wedge with respect to the slit 169. As a result, the depression of the brake pedal 29 is released, and the return spring S2 can contribute to the improvement of the pull-out strength against the case where the pull-out load acts on the input rod 141.

As described above, according to the negative pressure type booster 100 of the present embodiment, by performing the assembly work of press-fitting the input rod 141 having the sleeve member 162 attached to the spherical portion 141a into the plunger 142, the plunger 142 can be prevented from coming off. At the same time, it is possible to suppress the bite between the sleeve member 162 and the spherical portion 141a and the rattling of the input rod 141. Since the elastic deformation of the retaining portion 166 is performed during the press-fitting operation, prior work (sub-assembly) such as crimping the sleeve member 162 with respect to the input rod 141 becomes unnecessary, which simplifies the work process. Can also contribute. Further, the sleeve member 162 is press-fitted and connected to the inner peripheral surface 160a of the recess 160. Therefore, the inner peripheral surface 160a of the recess 160 can have a straight shape, the shape of the plunger 142 can be avoided from becoming complicated, and the increase in component cost can be suppressed.

<Modification example>
8 and 9 are modifications of the sleeve member applicable to the negative pressure booster 100 of the embodiment, and are exemplary and schematic cross sections showing a state in which the plunger 142 and the input rod 141 have been assembled. It is a figure.

The sleeve member 162A shown in FIG. 8 is the other side in the axial direction of the tubular portion 164 (the open end side opposite to the end portion on which the bottom portion 164a is formed), similarly to the sleeve member 162 shown in FIG. Is provided with a retaining portion 166. However, the shape of the retaining portion 166 of the sleeve member 162A is different from that of the sleeve member 162.

The retaining portion 166 of the sleeve member 162A has an outer diameter larger than the inner diameter of the inner peripheral surface 160a of the recess 160 before the sleeve member 162A is press-fitted (inserted) into the plunger 142, similarly to the retaining portion 166 of the sleeve member 162. In the first state, the diameter is further expanded outward in the radial direction from the tubular portion 164. Further, the outer diameter M2 of the sleeve member 162A is larger than the inner diameter M1 of the recess 160 of the plunger 142, and has a press-fitting allowance. Further, the inner diameter M3 of the tubular portion 164 of the sleeve member 162A is set to be larger than the maximum diameter portion 141L (outermost diameter M) of the spherical portion 141a. The plunger 142 and the sleeve member 162A formed of the metal material are set so that [hardness of the plunger 142] <[hardness of the sleeve member 162A]. Therefore, even when the sleeve member 162A is press-fitted into the recess 160, the sleeve member 162A having a hardness higher than that of the plunger 142 can maintain the cylinder inner diameter M3. That is, the tubular portion 164 can maintain a gap M5 between the tubular portion 164 and the outer peripheral surface 141a1 of the spherical portion 141a having the maximum diameter portion 141L (outermost diameter M) smaller than the cylinder inner diameter M3. As a result, it is possible to prevent the metal-to-metal sleeve member 162A and the spherical portion 141a from biting each other, and it is possible to realize smooth rotation of the input rod 141 with respect to the sleeve member 162A.

As shown in FIG. 8, the retaining portion 166 of the sleeve member 162A is bifurcated toward the other side (open end side) in the axial direction. The retaining portion 166 has a first portion 166a on the outer peripheral side and a second portion 166b on the inner peripheral side in a direction orthogonal to the axial direction. A gap M4 is formed between the first portion 166a and the second portion 166b. The gap M4 can be formed by, for example, cutting.

When the sleeve member 162A is inserted (press-fitted) into the recess 160 of the plunger 142 toward one side in the axial direction, the sleeve member 162A plastically deforms the recess 160 side of the plunger 142 while retaining the retaining portion 166 ( The first portion 166a and the second portion 166b) are elastically deformed to a second state located inside the inner peripheral surface 160a with respect to the reduced diameter portion 141S. In this case, as shown in FIG. 8, the first portion 166a is in contact with the inner peripheral surface 160a of the recess 160, and the second portion 166b is located radially inside the first portion 166a. , Displace so as to surround the reduced diameter portion 141S. As a result, the second portion 166b is caught in a portion having a diameter larger than the reduced diameter portion 141S (the portion on the other side in the axial direction from the maximum diameter portion 141L of the spherical portion 141a), and the spherical portion 141a (input) with respect to the sleeve member 162A. Prevents the rod 141) from coming off. Since the gap M4 is formed in the second portion 166b, the sleeve member 162A allows elastic deformation of the second portion 166b even after being press-fitted into the recess 160. As a result, even if an error in dimensional accuracy occurs in the retaining portion 166, the spherical portion 141a, the reduced diameter portion 141S, etc., the error can be absorbed and the bite between the second portion 166b and the reduced diameter portion 141S is suppressed. .. On the contrary, the rattling between the second portion 166b and the reduced diameter portion 141S is suppressed. As a result, smooth rotation of the input rod 141 with respect to the sleeve member 162A can be realized.

Further, as shown in FIG. 8, the sleeve member 162A is also formed with at least one slit 169 extending in the axial direction (axial direction of the input rod 141) to the end of the first portion 166a. Although not shown, in the case of FIG. 8, a plurality of slits 169 are formed at equal intervals in the circumferential direction of, for example, the tubular portion 164. As a result, the slit 169 forms an air vent passage in the recess 160 when the sleeve member 162A is press-fitted. By forming the air vent passage, it is possible to prevent the sleeve member 162A from tilting at the time of press-fitting or the sleeve member 162A from being insufficiently press-fitted, so that stable press-fitting can be performed. Further, the slit 169 accepts a part of the plunger 142 side deformed at the time of press fitting and can serve as a wedge when connecting the plunger 142 and the sleeve member 162A, which contributes to the improvement of the pull-out strength. Although not shown in FIG. 8, the sleeve member 162A also has a plurality of notches extending in the axial direction (axial direction of the input rod 141), for example, at equal intervals in the circumferential direction of the tubular portion 164. It is formed. The notch portion makes it easy to elastically deform the retaining portion 166.

As described above, also in the case of the sleeve member 162A shown in FIG. 8, by performing the assembly work of press-fitting the input rod 141 having the sleeve member 162A attached to the spherical portion 141a into the plunger 142, the plunger 142 can be prevented from coming off and can be prevented from coming off. It is possible to suppress the bite between the sleeve member 162A and the spherical portion 141a and the rattling of the input rod 141. Further, in the sleeve member 162A, similarly to the sleeve member 162 shown in FIG. 7, elastic deformation of the retaining portion 166 can be performed during the press-fitting operation. As a result, for example, prior work (sub-assembly) such as crimping the sleeve member 162A with respect to the input rod 141 becomes unnecessary, which can contribute to simplification of the work process. Further, the sleeve member 162A is press-fitted and connected to the inner peripheral surface 160a of the recess 160. Therefore, the inner peripheral surface 160a of the recess 160 can have a straight shape, the shape of the plunger 142 can be avoided from becoming complicated, and the increase in component cost can be suppressed.

Similar to the sleeve member 162 shown in FIG. 6 and the like, the sleeve member 162B shown in FIG. 9 is located on the other side in the axial direction of the tubular portion 164 (the open end side opposite to the end on which the bottom portion 164a is formed). A retaining portion 166 is provided. However, the shape of the retaining portion 166 of the sleeve member 162B is different from that of the sleeve member 162.

The retaining portion 166 of the sleeve member 162B has an outer diameter larger than the inner diameter of the inner peripheral surface 160a of the recess 160 before the sleeve member 162B is press-fitted (inserted) into the plunger 142, similarly to the retaining portion 166 of the sleeve member 162. In the first state, the diameter is further expanded outward in the radial direction from the tubular portion 164. Further, the outer diameter M2 of the sleeve member 162B is larger than the inner diameter M1 of the recess 160 of the plunger 142, and has a press-fitting allowance. Further, the inner diameter M3 of the tubular portion 164 of the sleeve member 162B is set to be larger than the maximum diameter portion 141L (outermost diameter M) of the spherical portion 141a. The plunger 142 and the sleeve member 162B formed of the metal material are set so that [hardness of the plunger 142] <[hardness of the sleeve member 162B]. Therefore, even when the sleeve member 162B is press-fitted into the recess 160, the sleeve member 162B having a hardness higher than that of the plunger 142 can maintain the cylinder inner diameter M3. That is, the tubular portion 164 can maintain a gap M5 between the tubular portion 164 and the outer peripheral surface 141a1 of the spherical portion 141a having the maximum diameter portion 141L (outermost diameter M) smaller than the cylinder inner diameter M3. As a result, it is possible to prevent the metal-to-metal sleeve member 162B and the spherical portion 141a from biting each other, and it is possible to realize smooth rotation of the input rod 141 with respect to the sleeve member 162B.

As shown in FIG. 9, the retaining portion 166 of the sleeve member 162B has a first portion 166a and a second portion 166a because the other side (open end side) in the axial direction is bent radially outward through the gap M4. It forms with 166b. With the sleeve member 162B inserted into the recess 160, the portion on the tip end side bent outward in the radial direction becomes the first portion 166a in contact with the inner peripheral surface 160a of the recess 160. Further, the portion on the tubular portion 164 side of the first portion 166a becomes the second portion 166b located radially inward with respect to the first portion 166a via the gap M4. The first portion 166a can be formed by, for example, bending.

When the sleeve member 162B is inserted (press-fitted) into the recess 160 of the plunger 142 toward one side in the axial direction, the sleeve member 162B plastically deforms the recess 160 side of the plunger 142 while retaining the retaining portion 166 ( The first portion 166a and the second portion 166b) are elastically deformed to a second state located inside the inner peripheral surface 160a with respect to the reduced diameter portion 141S. In this case, the first portion 166a is in contact with the inner peripheral surface 160a of the recess 160, and the second portion 166b surrounds the reduced diameter portion 141S at a position inside the first portion 166a in the inner diameter direction. Displace like. As a result, the second portion 166b is caught in a portion having a diameter larger than the reduced diameter portion 141S (the portion on the other side in the axial direction from the maximum diameter portion 141L of the spherical portion 141a), and the spherical portion 141a (input) with respect to the sleeve member 162B. Prevents the rod 141) from coming off. When the sleeve member 162B is press-fitted into the recess 160, the sleeve member 162B is smoothly deformed into the recess 160 by elastically deforming the first portion 166a whose diameter is expanded and spreads outward by a jig or the like. Can be inserted into. Since the gap M4 is formed in the second portion 166b, the sleeve member 162B allows elastic deformation of the second portion 166b even after being press-fitted into the recess 160. As a result, even if an error in dimensional accuracy occurs in the retaining portion 166, the spherical portion 141a, the reduced diameter portion 141S, etc., the error can be absorbed and the bite between the second portion 166b and the reduced diameter portion 141S is suppressed. .. On the contrary, the rattling between the second portion 166b and the reduced diameter portion 141S is suppressed. As a result, smooth rotation of the input rod 141 with respect to the sleeve member 162B can be realized.

Further, as shown in FIG. 9, at least one slit 169 extending in the axial direction (axial direction of the input rod 141) is also formed in the sleeve member 162B. Although not shown, in the case of FIG. 9, a plurality of slits 169 are formed at equal intervals in the circumferential direction of, for example, the tubular portion 164. As a result, the slit 169 forms an air vent passage in the recess 160 when the sleeve member 162B is press-fitted. By forming the air vent passage, it is possible to prevent the sleeve member 162B from tilting at the time of press-fitting or the sleeve member 162B from being insufficiently press-fitted, so that stable press-fitting can be performed. Further, the slit 169 accepts a part of the plunger 142 side deformed at the time of press fitting and can serve as a wedge when connecting the plunger 142 and the sleeve member 162B, which contributes to the improvement of the pull-out strength. Although not shown in FIG. 9, a plurality of notches extending in the axial direction (axial direction of the input rod 141) are formed in the sleeve member 162B at equal intervals in the circumferential direction of, for example, the tubular portion 164. Has been done. The notch portion makes it easy to elastically deform the retaining portion 166.

As described above, also in the case of the sleeve member 162B shown in FIG. 9, by performing the assembly work of press-fitting the input rod 141 having the sleeve member 162B attached to the spherical portion 141a into the plunger 142, the plunger 142 can be prevented from coming off and can be prevented from coming off. It is possible to suppress the bite between the sleeve member 162B and the spherical portion 141a and the rattling of the input rod 141. Further, in the sleeve member 162B, similarly to the sleeve member 162 shown in FIG. 7, the elastic deformation of the retaining portion 166 is an implementation warning during the press-fitting operation. As a result, for example, prior work (sub-assembly) such as crimping the sleeve member 162B with respect to the input rod 141 becomes unnecessary, which can contribute to simplification of the work process. Further, the sleeve member 162B is press-fitted and connected to the inner peripheral surface 160a of the recess 160. Therefore, the inner peripheral surface 160a of the recess 160 can have a straight shape, the shape of the plunger 142 can be avoided from becoming complicated, and the increase in component cost can be suppressed.

Although the embodiments and modifications of the present invention have been illustrated above, the above-described embodiments and modifications are merely examples, and the scope of the invention is not intended to be limited. For example, in the above-described embodiment and modification, the sleeve member is applied to the negative pressure type booster, but the sleeve member can be applied to the input rod and another braking device having a recess connecting the spherical portion of the input rod. Needless to say. That is, the above-described embodiment and modification can be implemented in various other forms, and various omissions, replacements, combinations, and changes can be made without departing from the gist of the invention. In addition, specifications such as each configuration and shape (structure, type, direction, type, size, length, width, thickness, height, number, arrangement, position, material, etc.) are changed as appropriate. Can be carried out.

100 ... Negative pressure booster, 141 ... Input rod, 141a ... Sphere, 141L ... Maximum diameter part, 141S ... Reduced diameter part, 142 ... Plunger, 150 ... Valve mechanism, 160 ... Recess, 160a ... Inner peripheral surface, 162 , 162A, 162B ... Sleeve member, 164 ... Cylindrical part, 164a ... Bottom part, 164b ... Inner wall surface, 166 ... Stopping part, 166a ... First part, 166b ... Second part, 168 ... Notch part, 169 ... Slit , AM ... arm, M ... outermost diameter, M1 ... inner diameter, M2 ... outer diameter, M3 ... cylinder inner diameter, M4 ... gap, M5 ... gap.

Claims (6)

A housing having a first shell forming an outer wall on one side in the axial direction and a second shell forming an outer wall on the other side in the axial direction with respect to the first shell, and the inside of the housing in the axial direction. A movable partition wall that is partitioned into a negative pressure chamber on one side and a transformer chamber on the other side in the axial direction and that can move in the axial direction, and a valve mechanism that communicates or shuts off between the transformer chamber and the atmosphere. It is a negative pressure type booster equipped with
With the valve body
A plunger that is movably housed in the valve body in the axial direction and has a recess that is open on the other side in the axial direction.
A maximum diameter portion extending in the axial direction, inserted into the recess and projecting to the outermost side in the radial direction orthogonal to the axial direction at one end in the axial direction, and the other in the axial direction from the maximum diameter portion. An input rod provided with a spherical portion having a reduced diameter portion whose outer diameter decreases toward the side, and
With respect to a bottomed tubular portion that is interposed between the inner peripheral surface of the concave portion and the outer peripheral surface of the spherical portion to accommodate the spherical portion and is open to the other side in the axial direction, and the tubular portion. When it is provided on the other side in the axial direction and is not press-fitted into the recess, it is in the first state of an outer diameter larger than the inner diameter of the inner peripheral surface, and is press-fitted into the recess with respect to the reduced diameter portion. A sleeve member having a retaining portion in a second state located on the other side in the axial direction and inside the inner peripheral surface.
A negative pressure type booster equipped with. The retaining portion has a first portion in contact with the inner peripheral surface of the recess and a second portion located radially inward from the first portion through a gap with the first portion. , The negative pressure type booster according to claim 1. A claim that the second portion is bent inward in the radial direction of the tubular portion at the other end of the first portion in the axial direction and extends from the end to one side in the axial direction. 2. The negative pressure type booster according to 2. The negative pressure type booster according to any one of claims 1 to 3, wherein the sleeve member has a slit extending in the axial direction. The negative pressure type booster according to claim 4, wherein the hardness of the material forming the sleeve member is higher than the hardness of the material forming the plunger. A maximum diameter portion formed at one end of the input rod that transmits the driver's braking operation in the axial direction and projecting to the outermost side in the radial direction orthogonal to the axial direction, and the other of the input rod from the maximum diameter portion. The outer peripheral surface of a sphere having a reduced diameter portion whose outer diameter decreases toward the side and the inner peripheral surface of a recess in which the sphere of the input rod is rotatably fitted and receives a load due to a braking operation on the input rod. A bottomed tubular portion that is interposed between the two and accommodates the spherical portion and is open to the other side in the axial direction of the input rod.
When the tubular portion is provided on the other side in the axial direction and is not press-fitted into the recess, the outer diameter is in the first state larger than the inner diameter of the inner peripheral surface, and the recess is press-fitted. A retaining portion in a second state located on the other side in the axial direction and inside the inner peripheral surface with respect to the reduced diameter portion,
Sleeve member with.

Images