KR100945776B1 - Pneumatic booster - Google Patents

Abstract

An object of the present invention is to secure a necessary braking force by rapidly generating a servo force during sudden braking in a pneumatic booster.

The valve body 2 is connected to a power piston that partitions the housing into a constant pressure chamber (negative pressure) and a transformer chamber. A brake assist mechanism 10 is interposed between the reaction disk 3 and the plunger 9 in the valve body 2. The poppet seal 12 is opened by the movement of the plunger 9, air is introduced into the transformer chamber, and thrust is generated in the power piston. At the time of sudden braking, the plunger rod 23 advances with respect to the sleeve 21, and the ball 30 runs outward so that the plunger rod 23 directly contacts the reaction rod 22. As a result, since the brake assistance mechanism 10 is shortened, the amount of movement of the plunger 9 can be increased without receiving reaction force from the reaction disk 3, so that the servo force can be generated quickly.

Description

Pneumatic boosting equipment {PNEUMATIC PRESSURE DOUBLING APPARATUS}

BRIEF DESCRIPTION OF THE DRAWINGS It is axial sectional drawing of the principal part which shows the pneumatic power booster which concerns on 1st Embodiment of this invention.

FIG. 2 is a view showing a state in which a servo force is generated by a jump-in (JUMP-IN) action during normal braking in the apparatus of FIG. 1.

3 is a view showing a state during sudden braking in the apparatus of FIG.

FIG. 4 is a view showing a state in which a servo force is generated by a jump-in action during sudden braking in the apparatus of FIG. 1.

Fig. 5 is an axial sectional view of an essential part showing the pneumatic force booster according to the first modification of the first embodiment of the present invention.

FIG. 6 is an axial sectional view of an essential part showing a pneumatic booster according to a second modification of the first embodiment of the present invention. FIG.

7 is a diagram showing the relationship between the input and the output of the pneumatic pressure booster according to the first embodiment of the present invention.

8 is an axial sectional view of an essential part of the pneumatic power booster according to the second embodiment of the present invention.

FIG. 9 is a view showing a state in which a servo force is generated by a jump-in action during normal braking in the apparatus of FIG. 8.

FIG. 10 is a view illustrating a state during sudden braking in the apparatus of FIG. 8.

FIG. 11 is a view showing a state in which a servo force is generated by a jump-in action during sudden braking in the apparatus of FIG. 8.

12 is an axial longitudinal sectional view of an essential part of the pneumatic power booster according to the first modification of the second embodiment of the present invention.

Fig. 13 is an axial longitudinal sectional view of an essential part of the pneumatic booster according to the second modification of the second embodiment of the present invention.

FIG. 14 is a diagram illustrating a state in which a servo force is generated during rapid braking in the apparatus of FIG. 13.

Fig. 15 is an axial longitudinal sectional view of an essential part of the pneumatic booster according to the third modification of the second embodiment of the present invention.

FIG. 16 is a diagram illustrating a state in which a servo force is generated during sudden braking in the apparatus of FIG. 15.

FIG. 17 is a diagram illustrating a relationship between an input and an output of the pneumatic power booster shown in FIG. 15.

18 is an axial longitudinal sectional view of an essential part of a pneumatic power booster according to a fourth modification of the second embodiment of the present invention.

FIG. 19 is a view showing an operating state at an initial power ratio during normal braking of the apparatus shown in FIG. 18.                 

FIG. 20 is a view showing an operating state when the power ratio during normal braking of the apparatus shown in FIG. 18 is changed.

FIG. 21 is a view showing an operating state during sudden braking of the apparatus shown in FIG. 18; FIG.

Fig. 22 is an axial longitudinal sectional view of an essential part of the pneumatic power booster according to the fifth modification of the second embodiment of the present invention.

FIG. 23 is a view showing an operating state during normal braking of the apparatus shown in FIG. 22.

24 is a view showing an operating state during sudden braking of the apparatus shown in FIG. 22.

FIG. 25 is a diagram illustrating a relationship between an input and an output of the apparatus shown in FIG. 18.

FIG. 26 is a diagram illustrating a relationship between an input and an output of the apparatus shown in FIG. 22.

Fig. 27 is a diagram showing a relationship between an input and an output of a pneumatic booster equipped with a conventional brake assist mechanism.

<Description of the symbols for the main parts of the drawings>

1: pneumatic booster

2: valve body

3: Reaction disc (reaction member)

4: load output

9: plunger

10: brake aids

12: poppet seal (valve means)                 

11: input load

21: sleeve

22: Reaction Load

23: Plunger Rod

30: ball

55: brake aid

57: elastic member

59: sleeve (control means)

66: relief part (concave part)

67: reaction plate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic booster mounted on a brake device of a vehicle such as an automobile.

Generally, the brake device of an automobile is equipped with a pneumatic boosting device in order to increase braking force. As a pneumatic booster, generally, the housing is divided into a positive pressure chamber (always maintained at negative pressure by the engine intake negative pressure) and a transformer chamber by a power piston, and a plunger provided in the valve body connected to the power piston is connected to the input rod. By moving the air, the atmosphere (static pressure) is introduced into the transformer chamber, and a pressure difference is generated between the constant pressure chamber and the transformer chamber, and the pressure difference acts on the output rod through the reaction member by the reaction member. It is known to feed back part of the reaction force acting on the reaction member to the input rod.

The relationship between the input (brake pedal operating force) and the output (braking force) of this type of pneumatic booster is shown by the solid line in FIG. 27, and the jump-in output due to the gap between the plunger and the reaction member in the initial braking stage (A ), After which the output is linearly proportional to the input to reach the total load point (B).

By the way, in a characteristic in which the brake pedal operation force and the braking force are linearly proportional to each other as in the conventional pneumatic booster, when a large braking force is generated in an emergency, a large operating force is naturally required. Therefore, when a large braking force is required in an emergency, in order to reduce brake pedal operation force, there is a need for a pneumatic booster having a so-called brake assist mechanism. The pneumatic booster provided with the brake assistance mechanism can be expected to significantly improve the braking force in case of emergency, in addition to the anti-lock brake device that prevents the locking of the wheels during braking.

As a pneumatic booster provided with a brake assistance mechanism, for example, as described in Patent Literature 1, by using a plunger that expands and contracts through a spring, the spring is urgent when the brake pedal effort exceeds a certain value. It is known that a pneumatic booster of the type which can be compressed and the displacement of the plunger with respect to the valve body is greatly increased as shown in part C of FIG.

Patent Document 1

Patent Publication No. 2000-25603

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and an object thereof is to provide a pneumatic power boosting device which can generate an output quickly in an emergency and reliably generate necessary braking force in an emergency.

In order to solve the above problem, the invention according to claim 1 divides the housing into a constant pressure chamber and a transformer chamber by a power piston, and moves the plunger disposed in the valve body connected to the power piston by an input rod, thereby providing a valve means. Opening, the working gas is introduced into the transformer chamber, and a pressure difference is generated between the positive pressure chamber and the transformer chamber, and the pressure difference acts on the output rod through the reaction member by the thrust generated in the power piston, and the reaction member is removed from the output rod. In the pneumatic booster device for transmitting a part of the reaction force acting on the input rod,

It is characterized by interposing a flexible brake assist mechanism that is shortened when the speed or the amount of movement of the plunger with respect to the valve body reaches a predetermined value between the plunger and the reaction member.

With such a configuration, when the input speed to the input rod is fast, there is a difference in the moving speed of the plunger due to the input rod and the moving speed of the valve body due to the thrust of the power piston, and this speed difference causes the valve main body of the plunger. The amount of movement with respect to reaches a predetermined value, whereby the amount of movement of the plunger is further increased because the brake assist mechanism is shortened, and the opening of the valve means is increased.

In addition, the pneumatic booster according to the above-described invention is the configuration of claim 1, wherein the brake assist mechanism includes a sleeve slidably guided in the valve body, a plunger rod inserted in the sleeve and connected to the plunger, and inserted into the sleeve. And a reaction rod facing the reaction member, and a ball interposed between the plunger rod and the reaction rod in the sleeve, and when the speed or the movement amount of the plunger with respect to the valve body reaches a predetermined value, The ball may be pushed by the relative movement between the reaction rod and the plunger rod in the radial direction of the plunger rod to approach the reaction rod and the plunger rod.

With this configuration, when the speed or the movement amount of the plunger with respect to the valve body reaches a predetermined value, the ball is pushed out between the reaction rod and the plunger rod by the relative movement of the sleeve and the plunger rod, and the reaction rod and the plunger rod By approaching, the brake aid is shortened.

In addition, the pneumatic force booster according to the above-described invention is the configuration of claim 1, wherein the brake assist mechanism includes a reaction rod facing the reaction member, an elastic member interposed between the reaction rod and the plunger, and usually an elastic member. Limiting the compression of the plunger movement direction, it may be characterized by including a control means for allowing the compression of the plunger movement direction of the elastic member when the speed or the movement amount with respect to the valve body of the plunger reaches a predetermined value.

With such a configuration, when the speed or the movement amount of the plunger with respect to the valve body reaches a predetermined value, compression of the elastic member is allowed by the control means, and the brake assist mechanism is shortened by the compression of the elastic member.

In addition, according to the configuration of claim 3, the pressure boosting device according to the above-described invention is a sleeve in which the control means is slidably installed on the outer circumference of the elastic member, the speed or the movement amount of the plunger with respect to the valve body of the plunger on the inner circumference of the sleeve. When this predetermined value is reached, the groove which accommodates the diameter expansion part according to compression of the plunger movement direction of an elastic member can be formed, It is characterized by the above-mentioned.

In addition, the pneumatic booster according to the above-described invention, in the configuration of claim 4, the sleeve is pressed to the reaction disk side by the pressing member provided between the plunger, is configured to be caught by the reaction rod, the valve of the plunger The valve body may be contacted when the speed or the movement amount with respect to the main body reaches a predetermined value.

In addition, the pneumatic boosting device according to the above-described invention, in the configuration of claim 5, wherein the pressing member is configured to be caught separately from the plunger, the holder is in contact with the plunger, so that between the holder and the reaction rod can be shortened shortly. It is characterized in that the coupling member for coupling the holder, the elastic member, and the reaction rod is installed.

Further, the pneumatic pressure booster according to the above-described invention, in the configuration of claim 1, by forming a recess in the pressure receiving surface of the reaction member of the valve body, by expanding the reaction member into the recess, the hydraulic pressure to the reaction member of the valve body It is possible to increase the area.

In addition, the pneumatic pressure booster according to the above-described invention has a reaction plate which transmits reaction force from the reaction member to the input rod side in the configuration of claim 1, which reacts to the valve body when the reaction force from the reaction member increases. It can be characterized in that the contact force transmits the reaction force from the reaction member to the valve body. In addition, the invention according to claim 9 divides the inside of the housing into a constant pressure chamber and a transformer chamber by a power piston, and moves the plunger disposed in the valve body connected to the power piston by an input rod, whereby the valve means is opened to operate as a transformer chamber. The gas is introduced to generate a pressure difference between the positive pressure chamber and the transformer chamber. The pressure difference causes the thrust generated in the power piston to act on the output rod through the reaction member, and a part of the reaction force acting on the reaction member from the output rod. In the pneumatic booster to be delivered to the input rod,

When the speed or the movement amount of the plunger with respect to the valve body reaches a predetermined value, a brake auxiliary mechanism for moving the valve body of the valve means in the valve opening direction is provided.

With this arrangement, when the input speed to the input rod is high, a difference occurs in the movement speed of the valve body due to the plunger movement by the input rod and the thrust of the power piston, and this difference in speed causes the valve body of the plunger to be moved. The movement amount with respect to a predetermined value reaches, and a valve body is moved to a valve opening direction by a brake assistance mechanism, and the opening degree of a valve means becomes large.                     

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

A first embodiment of the present invention will be described with reference to FIGS. 1 to 4 and 7. FIG. 1 shows the inside of the valve body 2 which is a main part of the pneumatic booster 1 according to the present embodiment. As in the conventional pneumatic booster, the inside of a housing (not shown) is divided into a constant pressure chamber and a transformer chamber by a power piston, and one end of the substantially cylindrical valve body 2 is connected to the power piston. The other end side of the valve main body 2 is slidably inserted into the rear wall of the housing and is airtightly inserted to extend outward. An output rod 4 is connected to one end of the valve body 2 via a reaction disk 3 (reaction member), and a front end of the output rod 4 of the master cylinder (not shown) attached to the front wall of the housing. Connected to the piston.

The inside of the valve body 2 has a stepped shape having a small diameter bore 5, a medium diameter bore 6 and a large diameter bore 7, the small diameter bore 5 having a reaction disc 3. The contact plate (8: ratio plate) which contacts is fitted so that sliding is possible. The small diameter bore 5 is formed with an end 5A for restricting the amount of retraction of the raceway plate 8 to prevent excessive deformation of the reaction disk 3. The plunger 9 is slidably fitted in the middle diameter bore 6, and the brake assistance mechanism 10 is interposed between the plunger 9 and the raceway plate 8. One end of the input rod 11 is connected to the plunger 9, and the other end of the input rod 11 is inserted into a breathable dust seal (not shown) mounted at the end of the valve body 2. It extends outward.                     

A poppet seal 12 (valve means) is attached to the large diameter portion 7 of the valve body 2, and the seat portion 13 formed at an end between the large diameter portions 6 and 7 of the valve body 2. ) And a seat portion 14 formed at the rear end of the plunger 9 are situated in the poppet seal 12. The middle diameter part 6 of the valve main body 2 communicates with the transformer chamber in a housing through the passage 15 provided in the side wall of the valve main body 2. The inside of the poppet seal 12 of the large diameter portion 7 is open to the atmosphere through the dust seal. Moreover, the room 16 formed in the outer side of the poppet seal 12 of the large diameter part 7 is communicating with the positive pressure chamber of the housing through the channel | path (not shown) provided in the side wall of the valve main body 2. As shown in FIG.

As a result, the seat 14 of the plunger 9 is seated or detached from the poppet seal 12 so that communication and interruption between the transformer chamber and the atmosphere are performed, and the seat 13 of the valve body 2 is poppet seal. By mounting or leaving (12), communication and interruption between the positive pressure chamber and the transformer chamber are performed.

A stop key 17 is inserted through the passage 15 of the valve body 2, and the stop key 17 is coupled to the stop ring 18 and the plunger 9 fixed to the housing, whereby the valve body 2 ) The retraction position and the relative amount of movement of the valve body 2 with the plunger 9. Reference numeral 19 in FIG. 1 denotes a return spring of the input rod 11, and reference numeral 20 denotes a poppet spring that imparts sheet force to the poppet seal 12. As shown in FIG.

Next, the brake assistance mechanism 10 which is the main part of this embodiment is demonstrated.

The brake assistance mechanism 10 includes a cylindrical sleeve 21 slidably fitted in the middle diameter portion 6 of the valve body 2, a reaction rod 22 in contact with the raceway plate 8, and a plunger. It has the plunger rod 23 which contacts (9). The sleeve 21 has a small diameter guide portion 24 formed therein, and a tapered portion 25 is formed at an inner circumferential edge portion of one end of the guide portion 24.

The reaction rod 22 has a small diameter projection 26 inserted into the small diameter portion 5 of the valve body 2 to contact the raceway plate 8, and the large diameter flange portion 27 has a sleeve ( 21 is inserted into the end face of which the tapered portion 25 of the guide portion 24 is formed.

The plunger rod 23 is slidably inserted into the guide portion 24 of the sleeve 21, and a tapered portion 28 is formed at the outer peripheral edge portion of the end portion thereof, and is convex at the tip end of the tapered portion 28. The part 29 is formed. The plurality of balls 30 (steel balls) are formed between the outer circumferential surface of the convex portion 29 and the inner circumferential surface of the guide portion 24 of the sleeve 21 and are loaded in the annular space.

In the non-braking position shown in FIG. 1, a predetermined gap C1 is formed between the reaction rod 22 and the ball 30, and as shown in FIG. 2, the guide portion 24 of the sleeve 21. The gap C2 is formed between the convex portion 29 and the reaction rod 23 when the plunger rod 23 moves forward and the ball 30 comes into contact with the reaction rod 22 in the.

3, when the plunger rod 22 advances with respect to the sleeve 21, and these taper parts 28 and 25 matched with each other, the ball 30 raises the taper part 28. As shown in FIG. Therefore, it deviates to the outer side, and the front-end | tip of the convex part 29 is made to contact the reaction rod 22 directly.                     

A spring 31 (compression spring) is provided between the end portion of the guide portion 24 of the sleeve 21 and the flange portion formed at the end portion of the plunger rod 23. A holding spring 32 (compression spring) having a smaller spring force than the spring 31 is provided between the reaction rod 22 and the race plate 8 to stabilize the position of the reaction rod 22.

The operation of the present embodiment configured as described above will be described next.

In the non-braking position shown in FIG. 1, the seat portion 13 of the valve body 2 and the seat portion 14 of the plunger 9 rest on the poppet seal 12, and the transformer chamber is atmosphere (working gas). ) And the constant pressure chamber (which is always maintained at the negative pressure by the engine intake negative pressure, etc.), and the pressure in the transformer chamber and the constant pressure chamber with respect to the power piston is balanced so that no thrust occurs in the power piston.

When the driver performs normal brake operation, when the plunger 9 is moved forward by pressing the input rod 11, the seat 14 of the plunger 9 is separated from the poppet seal 12 and waits in the transformer chamber ( Static pressure) is introduced. As a result, a pressure difference occurs between the constant pressure chamber and the transformer chamber, and thrust is generated on the power piston, and the valve body 2 presses the output rod 4 through the reaction disk 3 to generate the servo force. Then, when the valve body 2 moves and follows the plunger 9 due to the thrust of the power piston, the seat 14 seats on the poppet seal 12, and the introduction of the atmosphere into the transformer chamber is stopped to The pressure difference in the transformer chamber is maintained.

At this time, since the sleeve 21 is pressed by the spring 31 to move with the valve body 2 and follows the plunger rod 23 moving with the plunger 9, the ball 30 is plunger. It is formed between the outer peripheral surface of the convex part 29 of the rod 23, and the inner peripheral surface of the guide part 24 of the sleeve 21, and is hold | maintained in annular space. Part of the reaction force acting on the reaction disc 3 from the output rod 4 is transmitted to the raceway plate 8 so that the reaction rod 22, the ball 30, the plunger rod 23 and the plunger ( It is fed back to the input rod 11 via 9). Accordingly, the servo force corresponding to the brake pedal effort can be generated.

In the initial stage of braking, the braking force is applied because the plunger rod 23 and the plunger 9 can move forward without the reaction force of the reaction disc 3 due to the gap C1 between the reaction rod 22 and the ball 30. It can be raised quickly (jump-in action). The state which generate | occur | produces a servo force by this jump-in action is shown in FIG. In the state of FIG. 2, the plunger rod 23 contacts the reaction rod 22 via the ball 30, and the reaction disc 3 is compressed by δ1 (jumped clearance) by the valve body 2. .

Therefore, the relationship between the input to the input rod 11 (braking pedal effort) and the output of the output rod 4 (braking force) is shown by the solid line in FIG. And then thereafter, the output is linearly proportional to the input to reach the total load point (B).

When the operating force to the input rod 11 is released, the seat portion 14 of the plunger 9 retracts the poppet seal 12 and is separated from the seat portion 13 of the valve body 2. As a result, the air in the transformer chamber flows into the constant pressure chamber, the pressure difference between the constant pressure chamber and the transformer chamber is eliminated, the thrust force of the power piston is lost, and the valve body 2 retreats and returns to the non-braking position shown in FIG. Braking is released.                     

In the case of rapid braking, that is, the speed at which the driver presses the brake pedal is high, the movement speed of the plunger 9 due to the stepping force of the input rod 11 and the movement speed of the valve body 2 due to the thrust of the power piston are applied. There is a difference. This speed difference causes a delay in the following operation of the valve body 2, and the spring 31 is compressed by the sleeve 21 contacting the end face of the middle diameter part 6 of the valve body 2, thereby plunging the plunger. The rod 23 advances with respect to the sleeve 21 so that the plunger rod 23 and the tapered portions 28 and 25 of the sleeve 21 match. As a result, the ball 30 escapes to the outer tapered portion 25, and the brake assist mechanism 10 is shortened by the convex portion 29 of the plunger rod 23 directly contacting the reaction rod 22.

As a result, as shown in FIG. 3, the plunger 9 can be further advanced without increasing the reaction force from the reaction disk 3, and the seat portion 14 and the poppet seal 12 of the plunger 9 are increased. A large amount of air can be introduced into the transformer chamber by increasing the opening degree? As a result, a large pressure difference is generated between the constant pressure chamber and the transformer chamber, and due to the thrust generated on the power piston due to the pressure difference, as shown in FIG. 4, the valve body 2 moves forward to the output rod 4. Provide servo power. At this time, the plunger rod 23 is in direct contact with the reaction rod 22, and the valve body 2 is a jump δ2 (δ2 = δ1 which is a jump larger than the clearance δ1 in which the reaction disc 3 is a jump). Compressed by + C2). Thus, as shown by the dotted line in FIG. 7, the output D which is a big jump can be generated, and braking force can be raised significantly.

In this state, when the operating force to the input rod 11 is released, the valve body 2 is retracted to release the brake as in the above-described normal braking, and the braking is released. With the retraction of the plunger 9 and the input rod 11, the spring The plunger rod 23 retreats with respect to the sleeve 21 by 31, and the ball 30 returns to the initial position shown in FIG.

In this manner, during braking, by increasing the output by the jump-in, a large braking force can be generated quickly while reducing the operating force, thereby improving the braking force in an emergency.

Next, modifications of the first embodiment will be described with reference to FIGS. 5 and 6. In addition, in description of these modifications, the same code | symbol is attached | subjected to the same part about the said 1st Example, and only another part is demonstrated in detail.

In the first modification illustrated in FIG. 5, the plunger rod 23 is formed integrally with the plunger 9, and further, the protruding length of the convex portion 29 of the plunger rod 23 is increased, and the reaction rod 22 is formed. The recessed part 33 which accommodates the front-end | tip part of the convex part 29 is formed in the side. By integrating the plunger rod 23 and the plunger 9, the number of parts can be reduced, and the holding position of the ball 30 can be stabilized at the non-braking position by increasing the protruding length of the convex portion 29. Moreover, in this modification, the relief part 34 of the reaction disk 3 pressed by the valve main body 2 is further formed in the inner peripheral edge part of the small diameter part 5 of the valve main body 2 of the 2nd step | paragraph. A so-called two raceway type having a power ratio is used.

In the second modification shown in FIG. 6, the raceway plate 8 and the reaction rod 22 are integrally formed to omit the excessive deformation preventing mechanism of the reaction disk 3. In addition, the plunger rod 23 may be formed integrally with the plunger 9 as in the first modification.

Next, a second embodiment of the present invention will be described with reference to Figs. In addition, in the following description, the same code | symbol is attached | subjected to the same part about the thing of the said 1st Example (2nd modification shown in FIG. 6), and only a different part is demonstrated in detail.

As shown in FIG. 8, in the present embodiment, a brake assist mechanism 55 is provided in place of the brake assist mechanism 10 with respect to the second modification of the first embodiment shown in FIG. 6. The brake assist mechanism 55 has a holder 56 in contact with the plunger 9 and a reaction rod 22 coupled by a pin 58 with an elastic member 57 interposed therebetween. A substantially cylindrical sleeve 59 is fitted on the outer circumference so as to be slidable. The pin 58 is slidably inserted into the holder 56 so that the brake assist mechanism 55 is compressible in the axial direction by the elasticity of the elastic member 57.

The inner circumferential groove 60 is formed in the sleeve 59. A spring 61 is interposed between the holder 56 and the sleeve 59, and the sleeve 59 is pushed toward the output rod 4 side by the spring force of the spring 61, so that the plan of the reaction rod 22 is fixed. It contacts the branch 27. In this state, the inner circumferential surface of the sleeve 59 is in contact with the elastic member 57, and the sleeve 59 is moved toward the input rod 11 side, whereby the inner circumferential groove 60 of the sleeve 59 is moved to the elastic member 57. To face. A predetermined gap is provided between the one end of the sleeve 59 and the end face 6A of the middle diameter part 6 of the valve body 2. By coupling the reaction rod 22 and the holder 56 by the pins 58, the reaction rod 22, the holder 56, the elastic member 57, and the spring 61 can be subassembled.

The operation of the present embodiment configured as described above will be described next.

In normal braking, the sleeve 59 is in contact with the flange portion 27 of the reaction rod 22 by the spring force of the spring 61, and the elastic member 57 is provided on the inner circumferential surface of the sleeve 59. Is in a sealed space. In this state, the compression of the axial dimension L1 of the elastic member 57 depends on the volume elasticity, and since the elastic modulus is large, the axial dimension of the brake assistance mechanism 55 hardly changes. Therefore, as in the first embodiment, the atmosphere is introduced into the transformer chamber by the movement of the plunger 9 by the input rod 11, and the thrust generated in the power piston by the pressure difference between the positive pressure chamber and the transformer chamber is reduced to the reaction disk ( 3) acts on the output rod 4 to generate a servo force, and inputs a part of the reaction force acting on the reaction disk 3 from the output rod 4 through the reaction rod 22 and the elastic member 57. Feedback to rod 11. Then, a jump-in action is obtained by the gap C1 between the reaction disc 3 and the reaction rod 22 in the initial braking step. 9 shows a state in which the servo force is generated by the jump-in action.

Accordingly, the relationship between the input to the input rod 11 (braking pedal effort) and the output of the output rod 4 (braking force) is shown by the solid line in FIG. And then the output to the input is linearly proportional to reach the total load point B.

At the time of sudden braking, as shown in FIG. 10, a difference occurs in the movement speed of the plunger 9 by the input rod 11 and the movement speed of the valve body 2 due to the thrust of the power piston, There is a delay in the following operation, and the sleeve 59 contacts the end face 6A of the middle diameter portion 6 of the valve body 2 and retracts, so that the inner circumferential groove 60 of the sleeve 59 becomes an elastic member ( 57) Move up. In this state, since the compressed elastic member 57 is pushed into the inner circumferential groove 60 of the sleeve 59 to expand its diameter, the elastic modulus with respect to the axial compression becomes small, and accordingly, the reaction disk 3 The axial dimension of the brake assistance mechanism 55 is shortened by the reaction force from Thereby, the opening degree (DELTA) 1 of the seat part 48 and the poppet seal 12 of the atmospheric valve member 44 can be enlarged.

As a result, a large pressure difference is generated between the constant pressure chamber and the transformer chamber, and due to the thrust generated on the power piston due to the pressure difference, as shown in FIG. 11, the valve body 2 is advanced and the servo is output to the output rod 4. Gives power. At this time, the reaction disc 3 is compressed by the valve body 2 by a jump clearance δ2 (δ2 = δ1 + (L1-L2)) larger than the jump δ1. Thus, as shown by the dotted line in FIG. 7, the output D which is a jump larger than normal operation can be generated, and a large braking force can be produced quickly.

When the braking (input to the input rod 11) is released, the reaction force from the reaction disk 3 decreases at the same time as the output of the power piston decreases, and the expansion of the diameter of the elastic member 57 is eliminated. By this, the sleeve 59 returns to the reaction rod 22 side and returns to the non-braking position shown in FIG.

Next, modifications of the second embodiment will be described with reference to FIGS. 12 to 26. In addition, in description of this modification, the same code | symbol is attached | subjected to the same part about the said 2nd Example, and only another part is demonstrated in detail.

In the first modification shown in FIG. 12, a return sleeve 35 is provided between the stop key 17 and the sleeve 59. The return sleeve 35 is slidably fitted to the middle diameter portion 6 of the valve body 2 and has a ring-shaped contact portion in contact with the sleeve 59. In addition, the contact portion has a pair of extension portions extending rearward through the axial grooves formed in the inner circumferential surface of the middle diameter portion 6 to contact the stop key 17. In addition, since FIG. 12 is sectional drawing which cut | disconnected the valve main body 2 by 90 degree of center, only one extension part is shown. Accordingly, when the braking is released after the operation at the time of braking, the movement of the stop key 17 in contact with the stop ring 18 is transmitted to the sleeve 59 by the return sleeve 35, and the sleeve 59 is provided. Can be reliably returned to the reaction rod 22 side. In this case, the spring 61 can be omitted.

In the second modified example shown in FIG. 13, the pin 58 is omitted from the brake assistance mechanism 55 and the reaction rod 22 is slidably moved from each other. The rod 63 is divided into the rods 63, and the inner rod 62 penetrates the elastic member 57 and the holder 56 to directly contact the plunger 9. With such a configuration, since only the outer rod 63 is retracted by compression of the elastic member 57 during sudden braking as shown in FIG. 14, the reaction disk 3 is moved from the reaction disk 3 through the inner rod 62. Since the reaction force transmitted to the plunger 9 becomes small, the same effect as that of the jump-in clearance is increased, and the characteristic shown in FIG. 7 can be obtained.                     

In the third modification shown in FIG. 15, an annular raceshow plate having a larger diameter than the outer rod 63 is formed between the outer rod 63 and the reaction disk 3 with respect to the second modification shown in FIG. 13. 64 is provided, and a small gap is provided between the raceway plate 64 and the shoulder 5B of the small diameter portion 5 of the valve body 2 in contact with the raceway plate 64. With this arrangement, as shown in FIG. 16, when the outer rod 63 retreats due to the compression of the elastic member 57 during rapid braking, the reaction force received by the raceway plate 64 from the reaction disk 3 is reduced. It is transmitted to the valve body 2 by the shoulder 5B, and in this state, only the reaction force acting on the inner rod 62 from the reaction disk 3 is transmitted to the plunger 9. Accordingly, in FIG. 17, the braking force of the characteristic shown by the broken line is generated with respect to the characteristic during normal braking shown by the solid line, whereby a large braking force can be obtained quickly. Moreover, although normal operation force is needed until the power ratio increases at the point E of FIG. 17, this is because a certain load is required to push the elastic member 57 into the inner circumferential groove 60 of the sleeve 59. .

Next, a fourth modification of the second embodiment will be described with reference to FIGS. 18 to 21 and 25. As shown in Figs. 18 to 21, in the fourth modification, the pin 58 is integrated with the reaction rod 22 in the second embodiment shown in Figs. The reaction rod 22 and the holder 56 are coupled to each other. In addition, by forming the relief portion 66 (concave portion) of the reaction disk 3 pressed by the valve body 2 at the inner circumferential edge portion of the small diameter portion 5 of the valve body 2, the two-stage double It is a so-called 2 raceshow type having a power ratio.                     

With this configuration, as shown in FIG. 19, the brake assist mechanism 55 is not shortened shortly during normal braking as in the second embodiment, and the plunger 9 is moved by the input rod 11. Air is introduced into the transformer chamber, and the thrust generated in the power piston due to the pressure difference between the constant pressure chamber and the transformer chamber is applied to the output rod 4 through the reaction disk 3 to generate a servo force. A portion of the reaction force acting on the reaction disk 3 from the feedback) is fed back to the input rod 11 through the reaction rod 22 and the elastic member 57.

When the input increases to the input rod 11 to some extent, the reaction disk 3 expands and fills the relief portion 66 as shown in FIG. 20 by the reaction force from the output rod 4. As a result, the hydraulic pressure area of the valve body 2 with respect to the reaction disk 3 increases. As a result, as shown by the arrow 1 in Fig. 25, the power ratio increases, so-called two-race type servo force is generated.

At the time of sudden braking, as shown in FIG. 21, the sleeve 21 moves, the elastic member 57 is compressed, and the brake auxiliary mechanism 55 is shortened. As a result, a jump-in output is generated and a large braking force is generated quickly. As a result, as shown by the arrow 2 in FIG. 25, the braking force required can be secured quickly by generating a braking force having a characteristic in which the jump-in output and the two race-type servo force can be combined.

Next, a fifth modification of the second embodiment will be described with reference to FIGS. 22 to 24 and 26. In addition, about the said 4th modified example, the same code | symbol is attached | subjected to the same part and only another part is demonstrated in detail.                     

22 to 24, in the fifth modification, the reaction plate 67 is interposed between the reaction rod 22 and the reaction disk 3 with respect to the fourth modification. The reaction plate 67 is convex, and is slidably fitted into the stepped bore 69 of the plate 68 attached to the distal end of the valve body 2, so that the end of the smaller diameter side is connected to the reaction rod 22. And the reaction disc 3 is brought into contact with the clearance C1 which is the end of the large diameter side which is a jump. Further, the reaction plate 67 is in contact with the end 70 of the stepped bore 69 to restrict the retracted position. In the non-braking state (state of FIG. 22), a clearance C2 is provided between the opposing surface 67A and the end 70 of the reaction plate 67 with respect to the end 70, and the clearance C2. Is set smaller than the shorter length L1-L2 of the brake assist mechanism 55 due to the compression of the elastic member 57 at the time of rapid braking (the axial length at the time of compression is set to L2 (see FIG. 24)). It is.

With this configuration, as shown in FIG. 23 during normal braking, the brake assistance mechanism 55 is not shortened shortly, and air is supplied to the transformer chamber by the movement of the plunger 9 by the input rod 11. The thrust generated in the power piston due to the pressure difference between the positive pressure chamber and the transformer chamber is applied to the output rod 4 through the reaction disk 3 to generate a servo force, and the reaction disk 3 from the output rod 4. A portion of the reaction force acting on the feedback is fed back to the input rod 11 through the reaction plate 67, the reaction rod 22 and the elastic member 57. As a result, as shown by ① in FIG. 26, an output (braking force) that is linearly proportional to the input (operating force) occurs.                     

At the time of sudden braking, as shown in FIG. 24, the sleeve 21 moves, the elastic member 57 is compressed, and the brake auxiliary mechanism 55 is shortened. As a result, a jump-in output is generated and a large braking force is generated quickly. At this time, with the increase of the output (braking force), the reaction plate 67 is pushed back by the reaction disk 3, and comes in contact with the end 70 of the plate 68. As a result, the reaction forces from the reaction disk 3 are all transmitted to the valve body 2 and are not transmitted to the plunger 9 side. Therefore, the operating force is greatly reduced, and the output ( Braking force) takes place at once up to the total load point shown by the broken line in FIG. In this way, it is possible to secure the required braking force quickly during sudden braking. In the case of rapid braking, the braking force occurs to the entire load point at once, and therefore it is preferable to use in combination with the anti-lock brake device.

As described above, according to the pneumatic pressure booster according to the invention of claim 1, when the input speed to the input rod is fast, there is a difference in the movement speed of the plunger and the moving speed of the valve body due to the thrust of the power piston and By this speed difference, the amount of movement of the plunger with respect to the valve body reaches a predetermined value. As a result, the brake assist mechanism is shortened, so that the amount of movement of the plunger is further increased, and the opening of the valve means is increased. As a result, since the output is increased, a large braking force can be generated quickly while reducing the operating force, and an braking force in an emergency can be increased.

According to the pneumatic boosting device according to the invention of claim 2, when the speed or the moving amount of the plunger with respect to the valve body reaches a predetermined value, the ball is pushed out between the reaction rod and the plunger rod by the relative movement of the sleeve and the plunger rod. And the brake aid is shortened by the proximity of the reaction rod and the plunger rod.

According to the pneumatic boosting device according to the invention of Claims 3 to 6, when the speed or the movement amount of the plunger with respect to the valve body reaches a predetermined value, the compression of the elastic member is permitted by the control means, and the brake is compressed by the compression of the elastic member. Auxiliaries are shortened. In this case, since the brake assist mechanism is shortened by the compression of the elastic member, the noise generated when the brake assist mechanism is shortened is small, and noise reduction is possible at the time of sudden braking of the pneumatic booster.

According to the pneumatic boosting device according to the invention of claim 7, when the speed or the moving amount of the plunger with respect to the valve body reaches a predetermined value, the ball is moved to the allowable position by the control means, the valve body is moved in the valve opening direction, The opening degree of the valve means becomes large.

According to the pneumatic pressure boosting device according to the invention of claim 8, when the reaction member expands into the recessed portion by reaction force from the output rod, the hydraulic pressure area of the valve body increases with respect to the reaction member, so that the power ratio can be changed. .

Further, according to the pneumatic pressure boosting device according to the invention of claim 7, when the reaction force from the reaction member increases and the reaction plate contacts the valve body, the reaction force from the reaction member is transmitted to the valve body by the reaction plate. Reaction force transmitted to it becomes small, and operation force is reduced.

According to the pneumatic pressure booster according to the invention of claim 9, when the input speed to the input rod is fast, there is a difference between the moving speed of the plunger and the moving speed of the valve body due to the thrust of the power piston, and the amount of movement of the plunger to the valve body. When this predetermined value is reached, the valve body is moved in the valve opening direction by the brake assistance mechanism, and the opening degree of the valve means is increased. As a result, since the output is increased, a large braking force can be generated quickly while reducing the operating force, and an braking force in an emergency can be increased.

Claims (9)

The housing is divided into a constant pressure chamber and a transformer chamber by a power piston, and the plunger disposed in the valve body connected to the power piston is moved by an input rod, thereby opening the valve means and introducing a working gas into the transformer chamber, thereby introducing the positive pressure. A pressure difference is generated between the chamber and the transformer chamber, and the pressure difference causes the thrust generated in the power piston to act on the output rod through the reaction member, and a part of the reaction force acting on the reaction member from the output rod is input to the input rod. In the pneumatic booster to deliver to the Between the plunger and the reaction member, via a flexible brake assist mechanism that shortens when the speed or movement amount of the plunger with respect to the valve body reaches a predetermined value, The brake assist mechanism, A sleeve slidably guided in the valve body; A plunger rod inserted in the sleeve and connected to the plunger, A reaction rod inserted in the sleeve and opposed to the reaction member; A ball interposed between the plunger rod and the reaction rod in the sleeve, When the speed or the movement amount of the plunger with respect to the valve body reaches a predetermined value, the ball is pushed in the radial direction of the plunger rod between the reaction rod and the plunger rod by the relative movement of the sleeve and the plunger rod. And the reaction rod and the plunger rod are approached. The housing is divided into a constant pressure chamber and a transformer chamber by a power piston, and the plunger disposed in the valve body connected to the power piston is moved by an input rod, thereby opening the valve means and introducing a working gas into the transformer chamber, thereby introducing the positive pressure. A pressure difference is generated between the chamber and the transformer chamber, and the pressure difference causes the thrust generated in the power piston to act on the output rod through the reaction member, and a part of the reaction force acting on the reaction member from the output rod is input to the input rod. In the pneumatic booster to deliver to the Between the plunger and the reaction member, via a flexible brake assist mechanism that shortens when the speed or movement amount of the plunger with respect to the valve body reaches a predetermined value, The brake assist mechanism, A reaction rod facing the reaction member, An elastic member interposed between the reaction rod and the plunger, Control means for restricting compression of the plunger movement direction of the elastic member and allowing compression of the plunger movement direction of the elastic member when the speed or the movement amount of the plunger with respect to the valve body reaches a predetermined value. Atmospheric pressure boosting device comprising a. The said control means is a sleeve which is slidably installed in the outer periphery of the said elastic member, This sleeve is said elasticity when the speed or the movement amount with respect to the said valve body of the said plunger reaches predetermined value. A pneumatic pressure characterized by receiving a deformation in the radial direction of the member, and moving from the position where the compression in the plunger movement direction is restricted to a position allowing the deformation in the radial direction of the elastic member to allow the compression in the plunger movement direction. Power system. The said control means is a sleeve which is slidably installed in the outer periphery of the said elastic member, When the speed or the movement amount with respect to the said valve main body of the said plunger reaches the predetermined value in the inner periphery of this sleeve, A pneumatic force booster, characterized in that a groove is provided for receiving a diameter-expanded portion in accordance with the compression of the elastic member in the direction of movement of the plunger. 5. The sleeve according to claim 3 or 4, wherein the sleeve is urged to the reaction disc side by an urging member provided between the plunger and caught by the reaction rod, and the velocity of the plunger relative to the valve body is set. Or the valve main body is brought into contact with the valve body when the amount of movement reaches a predetermined value. The holder, the resilient member and the mounting member of claim 5, wherein the pressing member is provided to be separable from the plunger and is caught by a holder in contact with the plunger, so that the distance between the holder and the reaction rod can be shortened. A pneumatic force booster, characterized in that a coupling member for coupling the reaction rod is provided. The water pressure area with respect to the said reaction member of the said valve body is increased by forming a recessed part in the pressure receiving surface with respect to the said reaction member of the said valve body, and expanding the said reaction member in the said recessed part. A pneumatic booster device, characterized in that. The housing is divided into a constant pressure chamber and a transformer chamber by a power piston, and the plunger disposed in the valve body connected to the power piston is moved by an input rod, thereby opening the valve means and introducing a working gas into the transformer chamber, thereby introducing the positive pressure. A pressure difference is generated between the chamber and the transformer chamber, and the pressure difference causes the thrust generated in the power piston to act on the output rod through the reaction member, and a part of the reaction force acting on the reaction member from the output rod is input to the input rod. In the pneumatic booster to deliver to the Between the plunger and the reaction member, via a flexible brake assist mechanism that shortens when the speed or movement amount of the plunger with respect to the valve body reaches a predetermined value, The reaction plate has a reaction plate that transmits reaction force from the reaction member to the input rod side, and the reaction plate contacts the valve body when the reaction force from the reaction member increases, thereby transmitting reaction force from the reaction member to the valve body. A pneumatic booster device, characterized in that. The pneumatic force boosting device according to claim 2, wherein the brake auxiliary mechanism moves the valve body of the valve means in the valve opening direction by compressing the elastic member in the plunger movement direction.

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