JP2001097207A - Brake system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake system capable of freely controlling the output of a brake boosting device regardless of treading force of a brake pedal accord ing to the request for increasing or decreasing brake force and of being applied to a wide range of vehicular brake systems each provided with an engine brake, exhaust brake system or brake assist device. SOLUTION: An air-pressure type brake booster device VBB and a hydraulic type brake booster device are each provided with a valve mechanism for switching a passage by being energized by the treading force applied to a brake pedal BP and for generating an output according to the magnitude of the treading force. The valve mechanism is so structured as to be energized in the same direction as or the opposite direction to the treading force by a solenoid SOL, and a control device ECL increases or decreases energizing force applied to the valve mechanism by the solenoid when a brake force increase requesting signal or decrease requesting signal is provided, so that the output of the brake booster device is increased or decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake system having a brake booster used for a brake of an automobile or the like.

[0002]

2. Description of the Related Art Conventionally, as a brake system, a brake system provided with a pneumatic brake booster or a hydraulic brake booster is well known. And, for example, a pneumatic brake booster includes a valve body slidably provided in a shell, a power piston provided in the valve body,
The constant-pressure chamber and the variable-pressure chamber formed before and after this power piston, a valve mechanism provided in the valve body for switching and controlling a flow path, and a valve plunger which constitutes the valve mechanism interlocked with a brake pedal is advanced to advance the valve plunger. An input shaft for switching the flow path, wherein the valve mechanism is urged by a depression force applied to the brake pedal to switch the flow path, and generates an output according to the magnitude of the depression force. I have.

[0003]

In the above-mentioned brake system, the output of the brake booster is obtained in accordance with the magnitude of the depression force of the brake pedal. It may be required to freely control the output of the booster. For example, a case where the output of the brake booster is required to be reduced during the operation of the brake regardless of the input of the brake booster is a case of a vehicle brake system including a regenerative brake device. This regenerative braking device generates a braking force during operation, so even if the brake pedal depressing force is kept constant, if the braking force of the regenerative braking device fluctuates, the overall braking force will fluctuate. Will give. Therefore, in this case, if the braking force by the brake booster can be reduced by an amount corresponding to the increase in the braking force due to the operation of the regenerative braking device, the entire braking force can be kept constant. Does not cause discomfort to the person. Such a situation also occurs when an engine brake or an exhaust brake is operated. On the other hand, as a case where it is required to increase the output of the brake booster regardless of the input of the brake booster during the operation of the brake, there is a case of a brake system including a brake assist device. This brake assist device is designed to obtain an output that is larger than the output obtained by the pedaling force at the time of normal braking when sudden braking is performed, whereby even a weak woman or an elderly person can perform a sudden braking operation. Other cases where the output of the brake booster is required to be increased include a case where the vehicle is traveling on a downhill and a case where the weight of the vehicle is increased. As described above, it has been conventionally required to freely control the output of the brake booster in various cases. However, conventionally, the brake booster has been exclusively configured for each device and has not been versatile. Further, in order to meet this demand, many parts such as an electromagnetic valve and a pump are required, so that not only the configuration is complicated but also the cost is high. In view of such circumstances, the present invention can freely control the output of the brake booster irrespective of the depression force of the brake pedal in response to the various requests for increasing or decreasing the braking force as described above. A brake system is provided.

[0004]

That is, the present invention relates to a valve mechanism of a brake booster which is urged by a pedaling force applied to a brake pedal to switch a flow path and generates an output corresponding to the magnitude of the pedaling force. A solenoid for urging the valve mechanism in the same direction as or the opposite direction to the pedaling force, wherein the solenoid increases or reduces the urging force applied to the valve mechanism in response to a braking force increase request signal or a decrease request signal. The output of the brake booster is increased or decreased by decreasing the output.

[0005] According to the above configuration, during normal braking operation, the valve mechanism is urged by the depression force applied to the brake pedal to switch the flow path, and generates an output corresponding to the magnitude of the depression force. For example, when there is a braking force increase request signal, the solenoid increases the urging force applied to the valve mechanism according to the signal, so that the output of the brake booster can be increased. As described above, since the biasing force applied to the valve mechanism by the solenoid can be increased or decreased,
The output of the brake booster can be freely controlled even when the brake pedal force is constant.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. FIG. 1 shows an embodiment in which the present invention is applied to a brake system using a pneumatic brake booster VBB. 1 shows an embodiment in which the present invention is applied to a brake system using a hydraulic brake booster HBB. The pneumatic brake booster VBB and the hydraulic brake booster HBB are conventionally known,
A valve mechanism is provided which is urged by the pedaling force applied to the brake pedal BP to switch the flow path and generates an output according to the magnitude of the pedaling force. The brake booster VB
B and HBB are provided with a master cylinder MCY.
When the piston of the master cylinder MCY is moved forward by the brake booster, the resulting brake fluid pressure is supplied to the wheel cylinder W / C to perform the braking action. As will be described in detail later, each of the brake boosters VBB and HBB is provided with a solenoid SOL for urging the valve mechanism in the same direction as the pedaling force or in the opposite direction.
Is controlled by the control unit ECU. The control device ECU, as shown in FIG.
When an increase request signal or a decrease request signal for the braking force is received (S1), the value of the current supplied to the solenoid SOL is determined according to the magnitude of the request signal (S2), and based on the determined current value. By operating the solenoid, the urging force is increased or decreased (S3), and the output of the brake booster is increased or decreased.

The above-mentioned brake force increase request signal and decrease request signal can be obtained from various devices. For example, there is a regenerative braking device as a device for generating a braking force reduction request signal. That is, in the brake system including the regenerative braking device, the braking force is generated while the regenerative braking device is operating. Therefore, even if the depressing force of the brake pedal BP is kept constant, the braking force by the regenerative braking device is maintained. Fluctuates, the overall braking force fluctuates, giving the driver an uncomfortable feeling. In such a case, a signal indicating the operating state of the regenerative brake device, that is, a signal requesting a decrease in the braking force is input from the regenerative brake device to the control device ECU. The relationship between the magnitude of the braking force reduction request signal and the value of the current supplied to the solenoid SOL corresponding to the magnitude of the braking force reduction request signal is previously determined in the control device ECU by a table or an arithmetic expression. At this time, the relationship between the value of the current supplied to the solenoid SOL and the braking force reduced thereby is also measured in advance. Therefore, when the braking force reduction request signal is input from the regenerative braking device, the control device ECU determines the magnitude of the braking force reduction request signal calculated based on the magnitude or based on the input value from the regenerative braking device. Then, the value of the current supplied to the solenoid SOL is determined, and the solenoid SO is determined based on the determined current value.
Activate L. When the solenoid SOL is actuated in this way, the urging force of the valve mechanism is reduced according to the current value, and the output of the brake booster is reduced.
The braking force of the brake booster can be reduced by an amount corresponding to an increase in the braking force caused by the operation of the regenerative braking device. The braking force of the vehicle can be kept constant, and the driver does not feel uncomfortable. As another device for generating a braking force reduction request signal, there is a device for generating a braking force by operating an engine brake or an exhaust brake.

On the other hand, as a device for generating a brake force increase request signal, there is a brake assist device for increasing a brake force in accordance with a brake depression force at the time of sudden braking.
More specifically, the brake assist device detects the depressing speed of the brake pedal BP, the increasing speed of the brake fluid pressure, and the like, and when these values exceed a predetermined value, it is determined that the vehicle is suddenly braked. Then, a brake force increase request signal is input to the control unit ECU. The control unit ECU includes:
The relationship between the magnitude of the braking force increase request signal and the value of the current supplied to the solenoid SOL corresponding to the magnitude is previously determined by a table or an arithmetic expression. At this time, the relationship between the value of the current supplied to the solenoid SOL and the braking force increased by the current is also measured in advance. Therefore, when the brake force increase request signal is input from the brake assist device, the control device ECU increases the brake force obtained from the magnitude or the difference between the input value from the brake assist device and the predetermined value. The value of the current supplied to the solenoid SOL is determined from the magnitude of the request signal, and the solenoid SOL is operated based on the determined current value. When the solenoid SOL is actuated, the urging force of the valve mechanism is increased in accordance with the current value and the output of the brake booster is increased, thereby increasing the braking force at the time of sudden braking. Even women and the elderly can perform sudden braking. Further, as described above, since the amount of increase in the braking force depends on the brake depression force, the amount of increase in the braking force can be controlled by the driver's intention. Other devices that generate a braking force increase request signal include a device that detects the descending slope of a slope and increases the braking force according to the amount of the slope, and a device that detects the on-board weight and detects the amount of on-board There are devices that increase the braking force accordingly.

Next, a specific configuration of a brake system using the pneumatic brake booster VBB shown in FIG. 1 and a regenerative brake device RB (FIG. 4) as a device for generating a braking force reduction request signal. In FIG. 4, the inside of the shell 2 of the tandem brake booster VBB is front and rear
And a rear chamber 5 are defined. Then, a cylindrical valve body 6 is slidably penetrated through the rear side of the shell 2 and the center plate 3 by sealing means 7 and 8 while maintaining airtightness. Front power piston 10 and rear power piston 1 are provided on the outer peripheral portions of valve body 6 located in front chamber 4 and rear chamber 5, respectively.
1 and each power piston 10, 11
A front diaphragm 12 and a rear diaphragm 13 are respectively stretched on the back of the vehicle. And the front room 4
A constant-pressure chamber A before and after the front diaphragm 12
A constant pressure chamber C and a variable pressure chamber D are formed before and after the rear diaphragm 13 in the rear chamber 5. In the valve body 6, a valve mechanism 1 for switching a communication state between the constant pressure chambers A and C and the variable pressure chambers B and D.
5 are provided.

[0010] As shown in FIG.
Reference numeral 5 denotes a first valve seat 16 formed at the tip of a large-diameter annular projection extending rearward from the inner peripheral portion of the valve body 6, slidably fitted in the valve body 6, and an input shaft 17.
A second valve seat 19 is formed at the rear end of the valve plunger 18. Further, the valve element 21 is biased to the front side by the poppet return spring 20, and the first seat portion S <b> 1 seated on the first valve seat 16 and the second seat portion S <b> 2 seated on the second valve seat 19.
The seat unit S2 is provided. The valve element 21 has a rolling part 24 whose rear end is fixed to the valve body 6 while maintaining the airtightness by a substantially cylindrical retainer 23, and a rolling part 2.
4 has a backup plate 25 connected to the front end thereof, and a cylindrical portion 26 connected to the backup plate 25 and extending to the front side. The first seat portion S1 made of an elastic body seated on the base plate 16 is provided, and the second seat portion S2 made of an elastic body seated on the second valve seat 19 is provided on the front end face of the backup plate 25.
Further, a valve return spring 27 is elastically mounted between the retainer 23 and the input shaft 24, and the input shaft 17 and the valve plunger 18 connected to the input shaft 17 and the valve plunger 18 by the elastic force of the valve return spring 27. The valve body 21 seated on the second valve seat 19 is biased rearward. The valve plunger 18 is prevented from being pulled out of the valve body 6 by a conventionally well-known key member 28. When the booster is not operated, the key member 28 is not operated.
Is brought into contact with the seal member 7 attached to the shell 2 so that the valve plunger 18 is held at a forward position with respect to the valve body 6.

Further, the valve mechanism 15 is provided with the first valve seat 1.
An axial constant-pressure passage 31 formed in the valve body 6 for communicating a space outside the vacuum valve 30 constituted by the pressure valve 6 and the first seat portion S1 with the constant-pressure chamber A;
And a constant-pressure passage 32 in the radial direction for communicating with the constant-pressure chamber C. The constant-pressure chamber A is connected to an intake manifold of the engine through a negative-pressure introducing pipe (not shown) provided in the shell 2 so as to maintain a constant pressure. A negative pressure is always introduced into the chambers A and C. The second valve seat 19 and the second seat portion S
The space between the atmospheric valve 33 constituted by 2 and the above-mentioned vacuum valve 30 is communicated with a variable pressure chamber B via a radial variable pressure passage 34, and the constant pressure chamber B is connected via an axial variable pressure passage 35. To the other transformer chamber D. And the above atmospheric valve 3
The space on the inner side of 3 is communicated with the atmosphere through an atmosphere passage 36, and a filter 37 is provided in the atmosphere passage 36.

On the front side of the valve plunger 18,
A solenoid 41 for urging the valve plunger 18 rearward;
And a solenoid plunger 42. The solenoid 41 is formed in a ring shape, and a small-diameter cylindrical member 43 is attached to the right end thereof. The large-diameter tubular member 44 is mounted in the valve body 6 in a state where the solenoid 41 and the small-diameter tubular member 43 are accommodated in the stepped large-diameter tubular member 44. The solenoid plunger 42
Is composed of a tubular member 46 and contact members 47 and 48 press-fitted and fixed to both ends of the tubular member 46, respectively. The tubular member 46 is connected to a solenoid 41 on the front side of the small-diameter tubular member 43. The rear contact member 47 is slidably fitted in the small-diameter tubular member 43. The distal end of the valve plunger 18 is slidably fitted in the small-diameter cylindrical member 43 so that the distal end of the valve plunger 18 can come into contact with the rear end of the contact member 47. It is. At this time, the rear end surface of the contact member 47 is formed in a spherical surface, and an elastic member 49 such as rubber is attached to the rear end surface of the cylindrical member 46 so that the cylindrical member 46 is attached to the small-diameter cylindrical member 43. The striking sound at the time of a collision can be prevented.

Further, a cylindrical holder 51 is mounted on the front side of the stepped large-diameter cylindrical member 44, and a plate plunger 52 is inserted into a central small-diameter hole 51a of the cylindrical holder 51.
Is slidably provided. The left end of the cylindrical member 46 constituting the solenoid plunger 42 and the contact member 48 are slidably fitted in the medium diameter hole 51b connected to the rear side of the small diameter hole 51a, so that the contact is achieved. The member 48 and the plate plunger 52 can contact each other. At this time, similarly to the contact member 47, the front end surface of the contact member 48 is formed into a spherical surface, so that it is difficult to transmit the inclination of the valve plunger 18 and the plate plunger 52 to the solenoid plunger 42. The stick of the plunger 42 can be prevented. A large-diameter hole 51c is continuously provided on the front side of the small-diameter hole 51a, and the reaction disk 53 and the base of the output shaft 54 are fitted into the large-diameter hole 51c.
The tip of the output shaft 54 projects outward from the shaft of the shell 2 and is linked to a piston of a master cylinder (not shown). Then, a return spring 56 is elastically mounted between the front inner wall of the shell 2 and the retainer 55 which is in contact with the valve body 6, so that the valve body 6 is normally held at a non-operating position in the drawing. This retainer 55
The base of the output shaft 54 and the reaction disk 53 are prevented from dropping out of the large-diameter hole 51c.

The wiring 61 drawn from the solenoid 41
Is drawn out to the front side of the valve body 6 through the inside of the constant pressure passage 31, and further connected to the connection terminal 6 provided on the retainer 55.
2 The connection terminal 62 and a connection terminal 63 provided on the front end surface of the shell 2 are connected by a flexible wiring 64, and the connection terminal 63 is connected to the above-described control unit ECU. The above control device EC
U receives a signal from the regenerative braking device RB, and the control unit ECU calculates the magnitude of the regenerative braking force by the regenerative braking device RB, that is, the magnitude of the braking force reduction request signal from the signal, and calculates the signal. By controlling the current supplied to the solenoid 41 based on the result by PWM or the like, the solenoid plunger 42 is urged rearward with an urging force corresponding to the regenerative braking force. The regenerative braking device RB performs a regenerative braking operation at the time of braking by using a drive motor that drives wheels of an electric vehicle. Since the regenerative braking device RB has been conventionally known, a description of a specific configuration thereof will be omitted.

In the above configuration, the control device ECU
Energizes the solenoid 41 only when a brake pedal (not shown) is depressed and the regenerative braking device RB is operating, and in this case, the solenoid 41 is energized according to the regenerative braking force as described above. The amount is calculated, and the solenoid plunger 42 is urged by an urging force corresponding to the regenerative braking force. In other words, when the regenerative braking device RB is not operated during parking or when the battery is fully charged, the solenoid 41 is not excited, and if the brake pedal is depressed in this state, the valve mechanism 15 causes the solenoid 41 to operate. The flow path is switched in the same manner as a conventional general brake booster not provided. A characteristic diagram of the brake booster VBB at this time is shown by a diagram A in FIG. On the other hand, when the solenoid 41 is excited, the solenoid plunger 42 is urged to the rear side to urge the valve plunger 18 to the rear side. As shown by the diagram B in FIG. Is reduced by the urging force, that is, by the regenerative braking force. At this time, if the regenerative braking force is large, the urging force for urging the valve plunger 18 to the rear side is also large, so that the diagram B moves to the right side in FIG. 6, and if the regenerative braking force is small, the valve plunger 18 is moved. The diagram B moves to the left in FIG. 6 because the urging force for urging toward the rear side is also reduced.

When the brake pedal is depressed, the brake booster VBB operates to generate an output corresponding to the depressing force, whereby a braking force is obtained. Then, when the regenerative braking device RB operates from this state to generate a regenerative braking force, the control unit ECU issues the regenerative braking device R
When the operation of B is detected, the solenoid 41 is excited. At this time, the control unit ECU urges the solenoid plunger 42 to the rear side with the urging force corresponding to the regenerative braking force via the solenoid 41. Therefore, when the regenerative braking force increases, the solenoid plunger 42 moves to the rear side of the solenoid plunger 42. Is increased, and as a result, the output of the brake booster VBB decreases. During this time, the output of the brake booster decreases, whereby the brake reaction force transmitted from the piston of the master cylinder to the brake pedal via the output shaft 54, the reaction disc 53, the solenoid plunger 42, the valve plunger 18 and the input shaft 17 However, since the urging force corresponding to the decrease is applied from the solenoid plunger 42 to the valve plunger 18, the pedaling force of the brake pedal is kept constant, and the driver does not feel uncomfortable. When the regenerative braking force becomes constant, the output of the brake booster is also kept constant, and when the regenerative braking force decreases, the output of the brake booster increases accordingly. When the regenerative braking force becomes zero, that is, when the operation of the regenerative braking device RB is stopped, the control unit ECU deenergizes the solenoid 41.

FIG. 7 shows a third embodiment of the present invention. In contrast to the first embodiment in which the second valve seat 19 is provided directly at the rear end of the valve plunger 18, this embodiment is different from the first embodiment. In the example, the valve plunger 118 is composed of an input shaft side member 118A and a valve side member 118B, and the input shaft side member 118A
Is connected to the input shaft 117, and a second valve seat 119 constituting the atmosphere valve 133 is provided on the valve side member 118B. That is, the valve-side member 118B is formed in a cylindrical shape, and a stopper portion 171 extending inward in the radial direction is formed at a rear side portion thereof, and the second valve seat 119 is formed on a rear end surface of the stopper portion 171. Is formed. The valve-side member 118B is slidably provided on the outer periphery of the input shaft-side member 118A while maintaining airtightness by a seal member 172. A spring 173 is elastically provided between the valve-side member 118B and the input shaft-side member 118A. Forward end which biases the valve-side member 118B toward the front side with respect to the input shaft-side member 118A, and normally causes the front end surface of the stopper portion 171 to abut the rear end surface of the input shaft-side member 118A. They are held in position and connected together. At this time, the outer diameter d of the seal member 172 and the effective diameter d of the rolling portion 124 of the valve body 121 are substantially equal to each other.
3 is configured to be less likely to generate a differential pressure. The key member 128 engages with the input shaft side member 118A through a notch formed in the cylindrical valve side member 118B. The input shaft side member 118A slidably penetrates through the solenoid plunger 142, and its tip directly contacts the plate plunger 152, and the reaction disk 15 via the plate plunger 152.
3 is linked. Further, the poppet return spring 12 for urging the valve element 121 to the front side.
Numeral 0 is mounted between the backup plate 125 and the retainer 123. The rest of the configuration is the same as that of the first embodiment.
The same reference numerals as those of the embodiment are added with reference numerals obtained by adding 100.

In the above configuration, in this embodiment, the solenoid 1 is operated when the regenerative braking device is not operated.
41 is not excited. In this state, the input shaft-side member 118A and the valve-side member 118B constituting the valve plunger 118 operate integrally while being held in the state shown in FIG. 7 by the spring 173. It is the same as the brake booster of the above. When the regenerative braking device is operated from a state in which the brake pedal is depressed to generate regenerative braking force, the control device detects the operation of the regenerative braking device and excites the solenoid 141 as in the first embodiment. The solenoid plunger 142 is biased rearward by a biasing force corresponding to the regenerative braking force. Then, as shown in FIG. 8, the valve-side member 118B is displaced rearward against the spring 173 and the poppet return spring 120 while leaving the input shaft-side member 118A. A vacuum valve 130 is opened away from 116, thereby reducing the output of the brake booster. At this time, the urging force of the solenoid plunger 142 by the solenoid 141 is equal to the urging force of the poppet return spring 120 and the valve-side member 1.
The valve side member 118B may be displaced rearward by overcoming the biasing force of the spring 173 elastically mounted between the input shaft side member 118A and the input shaft side member 118A. Since there is no need to overcome and retract the valve plunger 18, the output of the solenoid 141 can be reduced, and therefore, the power consumption can be reduced. At this time, the front end surface of the stopper portion 171 is separated from the rear end surface of the input shaft side member 118A.

When the vacuum valve 130 is opened, the pressure in the variable pressure chamber escapes to the constant pressure chamber, so that the pressure difference between the atmospheric pressure acting on the valve element 121 and the pressure in the variable pressure chamber increases. Thereby, the valve element 1
When the urging force on the front side of the motor 21 increases and the output of the brake booster decreases by the urging force of the solenoid plunger 142, that is, by the regenerative braking force,
The valve element 121 sits on the first valve seat 116 to close the vacuum valve 130 (FIG. 9). In this state, the stopper 171
Of the input shaft-side member 118A remain separated from the rear-side end surface of the input shaft-side member 118A. Further, at this time, the output of the brake booster is reduced, whereby the brake reaction force transmitted from the output shaft to the brake pedal via the reaction disk 153, the plate plunger 152, the input shaft side member 118A, and the input shaft 117 is reduced. However, the urging force corresponding to the decrease is applied to the solenoid plunger 14.
2 through a spring 173, the input shaft side member 118A
, The pedal effort of the brake pedal is kept constant, and the driver does not feel uncomfortable. When the regenerative braking force becomes constant, the output of the brake booster is also kept constant, and when the regenerative braking force decreases, the output of the brake booster increases accordingly. When the regenerative braking force becomes zero, that is, when the operation of the regenerative braking device is stopped, the control device deenergizes the solenoid 141.

Next, the specific structure of a brake system using the hydraulic brake booster HBB shown in FIG. 2 will be described. As shown in FIG. The master cylinder is operated by the output of the brake booster HBB. The brake booster HBB includes a brake booster housing 202.
The housing 20 for the brake booster is provided.
2, an input piston 203 is fitted in a liquid-tight and slidable manner. The input piston 203 is connected to the above-mentioned brake pedal BP, and an input shaft 204 is connected to the input piston 203. Have been. A power piston 205 is provided in the brake booster housing 202 coaxially with the input shaft 204 in a liquid-tight manner. A power chamber 206 is defined by the power piston 205 in front of the power piston 205. As described above, the power piston 205 is the brake booster HBB of this example.
Then, it functions as a plug that defines the power chamber 206,
The function of generating the output of the brake booster HBB is not performed. Lever support portion 205a at the rear end of this power piston 205
Are the first and second step portions 202a, 2 of the housing 202.
02b between the power chambers 20b.
6, the second stepped portion 2
02b. As shown in FIGS. 10 and 11, the front end 204 a of the input shaft 204 is formed with a small-diameter step on the front end side, and the small-diameter portion maintains the power piston 205 in a fluid-tight manner in the power chamber 206. The step 204e of the front end 204a is located in an annular reaction force chamber 258 formed between the outer peripheral surface of the front end 204a and the inner peripheral surface of the power piston 205. When a hydraulic pressure is introduced into the reaction force chamber 258, the hydraulic pressure acts on the step 204e to apply a reaction force to the input shaft 204.

Further, the valve mechanism 20 is provided in the housing 202.
8 are provided. The valve mechanism 208 is provided with a valve sleeve 209 which is fitted and fixed in a liquid-tight manner within the housing 202.
And a valve spool 210 slidably fitted in the valve sleeve 209. The cylinder hole in the axial direction of the valve sleeve 209 is provided with a step 209a, and is formed as a stepped hole including a small-diameter cylinder hole 209b at the front end and a large-diameter cylinder hole 209c from the center to the rear end. Further, the first to fifth radial holes 211, 212, 21 are formed in the valve sleeve 209 from the front end side thereof.
3,214,215 are perforated, respectively. In that case, the first radial hole 211 is formed in the small-diameter cylinder hole 209b, and the second to fifth radial holes 212,
213, 214, 215 are all large-diameter cylinder holes 209c
Is formed in the part.

The first radial hole 211 is provided in the housing 202.
Through the passage holes 216, 217, and 218 of the valve booster, the space 219 in the valve sleeve 209 located in front of the valve spool 210 is always in communication with the reservoir. ing. The second radial hole 212 is
Through the passage holes 221 and 222 to the power chamber 206, and further through a passage hole 264 formed in the power piston 205.
Through the reaction chamber 258. In addition, the third radial hole 213 is always connected to the reservoir for the brake booster through the passage hole 218. Further, the fourth radial hole 2
Reference numeral 14 is always connected to an accumulator of a hydraulic pressure source (not shown) through a passage hole 223 and a hydraulic pressure inlet 224 of the housing 202, and the hydraulic pressure accumulated in the accumulator by a pump (not shown) of the hydraulic pressure source is constantly maintained. Has been introduced. Further, the fifth radial hole 215 is
Power chamber 206 and reaction chamber 258 through the second passage hole 222.
And is always connected to

The valve spool 210 has a small-diameter spool portion 210a at the front end and a large-diameter spool portion 2 at the rear end from the center.
10b. In this case, the small-diameter spool portion 210a is fitted in the small-diameter cylinder hole 209b of the valve sleeve 209 in a liquid-tight and slidable manner, and the large-diameter spool portion 210b slides in the large-diameter cylinder hole 209c of the valve sleeve 209. Mated as possible. The valve spool 210 has a first annular groove 225 formed between the small-diameter spool portion 210a and the large-diameter spool portion 210b.
A second annular groove 226 is formed in 10b.

The first annular groove 225 is always connected to the second radial hole 212 and has a valve spool 2
When the valve 10 is not operated, the power chamber 206 is connected to the reservoir for the brake booster by connecting to the third radial hole 213, the hydraulic pressure of the power chamber 206 is set to the atmospheric pressure, and the valve spool 210 is operated forward. Sometimes, the power chamber 206 is shut off from the third radial hole 213 to shut off the power chamber 206 from the brake booster reservoir. These third radial holes 21
3 and the first annular groove 225 constitute a hydraulic pressure discharge valve. On the other hand, the second annular groove 226 has the fifth radial hole 215.
And the valve spool 210
When the valve spool 210 is not operating, the power chamber 206 is shut off from the accumulator of the hydraulic pressure source by shutting off from the fourth radial hole 214, and when the valve spool 210 moves forward, the fourth radial hole 21
4 to connect the power chamber 206 to the accumulator,
The valve mechanism 208 controls and outputs the hydraulic pressure of the accumulator according to the input, and the output hydraulic pressure of the valve mechanism 208 is
06. The fourth radial hole 214 and the second annular groove 226 constitute a hydraulic pressure supply valve.

When the hydraulic pressure discharge valve is closed and the hydraulic pressure supply valve is opened to introduce hydraulic pressure into the power chamber 206 as described later, the hydraulic pressure in the power chamber 206 is reduced to the first annular groove 225.
And the hydraulic pressure of the first annular groove 225 is reduced by the small and large diameter spool portions 210a, 210b having different pressure receiving areas.
, The valve spool 210 is biased rightward, that is, toward the inoperative position.

Further, one end of a lever 227 is attached to the lever support portion 205a of the power piston 205 by the first support pin 2a.
28 swingably supported. This lever 2
The other end of 27 is swingably supported by a valve operating member 229 by a second support pin 230.

The input shaft 204 has a retainer 262.
Are slidably fitted, and two first and second return springs 231a, 231b are used between the retainer portion 262 and the input piston 203. In that case, the first return spring 231
a is constantly contracted between the input piston 203 and the retainer 262, and the return spring 231a connects the input piston 203 and the input shaft 204 to the retainer 26.
2 is constantly biased backward. The second return spring 231b has a free length without contacting the retainer 262 when the input piston 203 is not operated. However, the second return spring 231b contacts the retainer 262 when the input piston 203 has a predetermined stroke, and thereafter the first return spring 231b. 231a. When the input shaft 3 shown in the drawing is not operated, the flange portion 204b of the input shaft 204 contacts the retainer portion 262, and the retreat limit of the input shaft 204 is defined.

The retainer portion 262 has an elongated hole 26 in the vertical direction.
2a is drilled, and the lever 2 is inserted into the long hole 262a.
An engagement pin 227a protruding inwardly from 27 is fitted so as to be engageable in the front-rear direction (left-right direction in the drawing) and slidable in the up-down direction. The distance between the first support pin 228 and the engagement pin 227a is determined by the brake booster H
Regardless of the operation or non-operation of the BB, it is set to be always smaller than the distance between the engagement pin 227a and the second support pin 230. The valve operating member 229 is fitted and fixed to the valve spool 210.
Is constantly urged rearward by a spool return spring 232, and when not in operation, the valve operating member 229 and the valve spool 210 are set to a non-operating position where the rear end of the illustrated valve spool 210 abuts the housing 202. ing.

A solenoid SOL is provided on the housing 202 coaxially with the valve spool 210.
When the solenoid SOL is excited, the movable plunger 280 pushes the valve spool 210 in a non-operation direction.

Next, the master cylinder will be described. As shown in FIGS.
Y includes a cylindrical master cylinder housing 234 having a rear end opening. A sleeve 235 is provided inside the master cylinder housing 234, and the sleeve 235 is connected to the master cylinder housing 234. Cylindrical cap 2 axially supported between
36 is screwed to the master cylinder housing 234 in a liquid-tight manner. The cap 236 is fitted and fixed to the brake booster housing 202 in a liquid-tight manner. Master cylinder MCY includes primary piston 237 and secondary piston 2 having the same effective pressure receiving area set to each other.
38 as a tandem master cylinder.

The primary piston 237 is disposed in the power chamber 206 in the brake booster housing 202 and in each hole of the cap 236 and the sleeve 235. This primary piston 237 has a cap 236
And a second cup seal 240 provided between the sleeve 235 and the cap 236 and provided on the inner peripheral surface of the hole of the cap 236. And slidably provided. The second cup seal 240 prevents the flow of the liquid from the front side to the rear side and allows the reverse flow. Further, the primary piston 237 is attached to the third booster seal 241 by the hydraulic booster housing 202.
The primary piston 237 has a rear end facing the power chamber 206.

The secondary piston 238 is connected to the sleeve 23
5 and in the master cylinder housing 234. The secondary piston 238 is provided between the fourth cup seal 242 provided on the inner peripheral surface of the hole of the sleeve 235 and the master cylinder housing 234 and the sleeve 235, and is provided on the inner peripheral surface of the hole of the master cylinder housing 234. Are provided in a liquid-tight and slidable manner by a fifth cup seal 243 provided at the bottom. The fifth cup seal 243 prevents the flow of the liquid from the front side to the rear side and allows the reverse flow of the liquid.

A primary chamber 244 is formed between the primary piston 237 and the secondary piston 238, and a primary spring retainer 245 is formed.
The primary return spring 246 of which the maximum length is regulated is contracted. A secondary chamber 247 is formed in a hole between the master cylinder housing 234 and the secondary piston 238, and a secondary return spring 249 whose maximum length is regulated by a secondary spring retainer 248 is contracted. . In this case, the spring force of the secondary return spring 249 is set to be larger than the spring force of the primary return spring 246.

The primary piston 237 has a radial hole 2
50 are drilled. The radial hole 250 is located slightly behind the cup seal 240 in the illustrated inoperative position of the primary piston 237, and the primary chamber 244 has the radial hole 250, the cup seal 2
40, the gap between the rear surface and the cap 236, the cap 2
36, an axial hole 236a formed in
Circumferential groove 2 drilled in cap 236 between 9,240
36b, an inclined hole 236c extending in the axial direction continuously from the circumferential groove 236b, and the master cylinder housing 2
The reservoir 251 is connected to the master cylinder reservoir 251 through the 34 radial holes 234a. Therefore, in this state, no master cylinder pressure is generated in the primary chamber 244. When the primary piston 237 advances and the radial hole 250 is positioned forward of the cup seal 240, the reservoir 25
Since the flow of liquid toward 1 is interrupted, the primary chamber 2
At 44, a master cylinder pressure is generated.

The secondary piston 238 has a radial hole 2
52 are drilled. The radial hole 252 is located slightly behind the cup seal 243 when the secondary piston 238 is in the non-operating position shown in the figure, and in this case, the secondary chamber 247 includes the radial hole 252 and the sleeve 235.
Between the inner peripheral surface of the cylinder and the secondary piston 238, the radial hole 235a formed in the sleeve 235, and the radial hole 234b of the master cylinder housing 234 so as to be connected to the master cylinder reservoir 251. Has become. Therefore, in this state, no master cylinder pressure is generated in the secondary chamber 247. Further, when the radial hole 252 is located forward of the cup seal 243 due to the advance of the secondary piston 238, the flow of the liquid from the secondary chamber 247 to the reservoir 251 is shut off, so that the master cylinder pressure is generated in the secondary chamber 247. It is supposed to.

The primary chamber 244 is connected via a hole 253 formed in the sleeve 235 and a primary output port 254 formed in the master cylinder housing 234.
Wheel cylinder W of one of the brake systems
/ C and the secondary room 247
Is connected to a wheel cylinder W / C of the other of the two brake systems via a secondary output port 255 formed in the master cylinder housing 234. In addition, in the housing 202 of the brake booster HBB,
The chamber 256 accommodating the lever 227 and the like is provided with the passage hole 2
It is always connected to the reservoir for the hydraulic booster through the passage 57 and the passage hole 218 and is always kept at the atmospheric pressure.

The brake booster H configured as described above
In BB, when the brake is not operated, the solenoid SO
L is demagnetized, and the input piston 203 and the input shaft 204 are at the retreat limit position shown in FIG.
Since the valve 27 is also in the non-operation position, the valve mechanism 208 is in the non-operation state shown above, and the hydraulic pressure supply valve is closed and the hydraulic pressure discharge valve is open. The power chamber 206 and the reaction chamber 258 are both shut off from the accumulator and communicate with the reservoir for the hydraulic booster, and the hydraulic pressure from the accumulator is applied to the power chamber 206 and the reaction chamber 25.
8 are not supplied.

Also, the master cylinder MCY does not operate, and the primary piston 237 is in the non-operating position of the retreat limit. At this time, the radial hole 250 of the primary piston 237 is behind the second cup seal 240, and the primary chamber 244 has the radial hole 250, the axial hole 236a,
The master cylinder reservoir 2 is inserted through the circumferential groove 236b, the inclined hole 236c, and the radial hole 234a of the housing 234.
It communicates with 51. Further, the secondary piston 238
Is located behind the fifth cup seal 243, and the secondary chamber 247 is connected to the reservoir 25 via the radial hole 252 and the two radial passage holes 235a and 234b.
It communicates with 1. Therefore, no master cylinder pressure is generated in the primary chamber 244 and the secondary chamber 247.

When the brake is operated, an input based on the brake depression force is applied to the input piston 203 and the input shaft 204 by depressing the brake pedal BP, and the input piston 203 and the input shaft 204 move forward. At this time,
The retainer portion 262 has its long hole 262a and the engagement pin 227
a is engaged in the front-rear direction.
And, the first return spring 231a does not follow the forward movement of the input shaft 204, and the urging force increases. The increased urging force of the first return spring 231a is transmitted to the lever 227 by the longitudinal engagement between the elongated hole 262a and the engaging pin 227a, and the lever 227 is
Rotates counterclockwise about the first support pin 228.
The counterclockwise rotation of the lever 227 causes the valve operating member 2 to rotate.
The valve spool 210 advances through 29. Then, the first annular groove 225 is shut off from the third radial hole 213 to close the hydraulic pressure discharge valve, and the second annular groove 226 is connected to the fourth radial hole 214 to open the hydraulic pressure supply valve, and the accumulator is opened. Is supplied to the power chamber 206 and the reaction chamber 258.

The hydraulic pressure introduced into the power chamber 206 acts on the rear end face of the primary piston 237, and the primary piston 237 moves forward. The hydraulic pressure in the power chamber 206 is also introduced into the first annular groove 225 through the passage holes 221 and 220 and the second radial hole 212. First annular groove 22
5 is applied to the small-diameter and large-diameter spool portions 210a and 210b having different pressure receiving areas as described above, so that the valve spool 210 moves in the direction in which the hydraulic pressure supply valve is closed and the hydraulic pressure discharge valve is opened. Be energized. Then, the spring force of the first retarder spring 231a, that is, the input piston 20
Input applied to 3 and spool return spring 2
The valve spool 210 is controlled such that the spring force of the valve 32 and the urging force of the valve spool 210 due to the hydraulic pressure of the first annular groove 225 are balanced. By controlling the balance of the valve spool 210 in this manner, the hydraulic pressure in the power chamber 206 becomes a hydraulic pressure according to the input of the input shaft 204, that is, the brake depression force, and the brake booster HBB enters an intermediate load state. Thereby, the brake booster HB
The output of B is the magnitude of the input at this time, that is, the magnitude obtained by boosting the depression force of the brake pedal. That is, the hydraulic pressure of the power chamber 206, that is, the output of the brake booster HBB, is controlled according to the stroke of the input shaft 204, that is, the pedal stroke. Further, the hydraulic pressure in the reaction force chamber 258, which is equal to the hydraulic pressure in the power chamber 206, acts on the front end of the input shaft 204 in the backward direction, and is transmitted as a reaction force to the driver via the brake pedal.

The primary piston 237 advances and its radial hole 250 passes through the second cup seal 240, and a master cylinder pressure is generated in the primary chamber 244. Further, due to the master cylinder pressure generated in the primary chamber 244 and the spring force of the primary return spring 246, the secondary piston 238 advances and its radial hole 252 passes through the fifth cup seal 243, and the secondary chamber 247 also Cylinder pressure occurs. Then, the master cylinder pressure generated in the primary chamber 244 is introduced to both wheel cylinders of one system through the primary output port 254, and the master cylinder pressure generated in the secondary chamber 247 is transmitted from the secondary output port 255 to the other. Introduced to both wheel cylinders of the system, two systems of brakes operate. At this time, the master cylinder pressures of the primary chamber 244 and the secondary chamber 247 are the same, and the hydraulic fluid of the same hydraulic pressure is supplied to each of the two wheel cylinders, and the brake hydraulic pressures of the two systems are equal. Has become. This brake fluid pressure has a magnitude obtained by boosting the depression force of the brake pedal.

When the brake pedal is released to release the brake operation, the input shaft 204 moves backward. Then, the first and second return springs 231a, 231
31b, the lever 227 rotates clockwise around the first support pin 228, and the valve actuating member 22
9 retreats. Thus, the second annular groove 226 is shut off from the fourth radial hole 214 to close the hydraulic pressure supply valve, and the first annular groove 225 is connected to the third radial hole 213 to open the hydraulic pressure discharge valve. For this reason, the hydraulic fluid in the power chamber 206 and the reaction chamber 258 is discharged to the reservoir for the hydraulic booster through the hydraulic pressure discharge valve, and the hydraulic pressure in the power chamber 206 decreases.

When the hydraulic pressure in the power chamber 206 decreases, the primary piston 237 moves backward due to the master cylinder pressure in the primary chamber 244 and the spring force of the primary return spring 246. As the power piston 205 retreats, the lever 227 rotates counterclockwise about the second support pin 230. Further, since the master cylinder pressure in the primary chamber 244 decreases due to the retraction of the primary piston 237, the secondary piston 238 also retreats due to the master cylinder pressure in the secondary chamber 247 and the spring force of the secondary return spring 249. These primary piston 237 and secondary piston 23
8, the radial hole 250 and the radial hole 252 pass through the second cup seal 240 and the fifth cup seal 243, respectively, and are again located behind the second cup seal 240 and the fifth cup seal 243. , The primary chamber 244 and the secondary chamber 247 both communicate with the master cylinder reservoir 251 again. Therefore, the pressure fluids of the wheel cylinders of both systems are discharged to the master cylinder reservoir 251 through the primary chamber 244 and the secondary chamber 247, respectively.

When the input of the input piston 203 becomes small and the stroke of the input piston 203 returns to a predetermined amount or less, the second return spring 231b is moved to the retainer 262.
After that, when the input of the input piston 203 is extinguished and the hydraulic pressure in the power chamber 206 becomes the atmospheric pressure, the primary piston 237 is in the non-operation position, and the secondary piston 238 is also in the non-operation position. MCY no longer generates master cylinder pressure. Thereby, the brakes of both brake systems are quickly released.

In the brake booster HBB, the hydraulic pressure in the power chamber 206 can be reduced irrespective of the input by exciting the solenoid SOL in a normal operation state. That is, when the valve spool 210 moves forward during normal brake operation, the valve spool 210 is moved by the movable plunger 28 of the solenoid SOL.
Advance while pressing 0. At this time, the solenoid SOL
Is not excited, the movable plunger 280 advances without resistance. Therefore, during normal brake operation, the brake operation is performed without being affected by the solenoid SOL.

On the other hand, when the above-mentioned braking force reduction request signal is issued during the normal braking operation, the solenoid SOL is excited with a current value corresponding to the magnitude. As a result, the movable plunger 280 of the solenoid SOL operates and presses the valve spool 210 in the non-operation direction.
The valve spool 210 is pushed back in the non-operation direction. Then, since the first annular groove 225 is connected to the third radial hole 213, the hydraulic pressure in the power chamber 206 decreases, and the master cylinder pressure is reduced.

At this time, the above-mentioned hydraulic pressure of the first annular groove 225 acts on the valve spool 210 in the non-operating direction,
The valve spool 210 is controlled so that the resultant force of the spring force of the spool return spring 232 and the electromagnetic force of the solenoid SOL and the spring force of the return spring 231 according to the input stroke of the input shaft 204 are balanced. The hydraulic pressure in the chamber 206 decreases as the electromagnetic force of the solenoid SOL is applied to the valve spool 210 in the non-operation direction. Therefore, the solenoid S
By controlling the supply current to the OL and setting the electromagnetic force in various ways, it is possible to arbitrarily control the pressure reduction of the hydraulic pressure in the power chamber 206 and the master cylinder pressure.

When the pressure reduction control is performed, the spring force of the return spring 231 of the input shaft 204 does not change, so that the input of the input shaft 204 and the input stroke do not change. In this way, even if the pressure reduction control of the hydraulic pressure in the power chamber 206 is performed, there is no effect on the input side. Further, by controlling the supply current to the solenoid SOL, the hydraulic pressure of the power chamber 206 during operation, that is, the master cylinder pressure can be reduced in accordance with the supply current. Thus, the pressure reduction control of the master cylinder pressure can be arbitrarily performed.

FIG. 13 is different from the embodiment of FIG. 11 in that the output of the brake booster HBB can be increased in the case of a hydraulic brake booster HBB when there is a request signal to increase the braking force. It was made. That is, in the embodiment of FIG. 11, the valve spool 210 is pushed in the non-operation direction by the electromagnetic force of the solenoid SOL. However, in the brake booster HBB of this embodiment, the valve spool 210 is operated by the electromagnetic force of the solenoid SOL. Pull in the direction. Therefore, the movable plunger 280 of the solenoid SOL and the valve spool 2
10 are connected so as to engage with each other in a pulling direction. Other configurations of the brake booster HBB of this embodiment and the master cylinder MCY are the same as those of the embodiment of FIG.

The brake booster H configured as described above
In BB, when the solenoid SOL is excited during the normal braking operation, the movable plunger 280 pulls the valve spool 210 in the operating direction. Therefore, the valve spool 210 moves to the left, so that the output pressure of the valve mechanism 208 increases and the hydraulic pressure of the power chamber 206 increases. Therefore, the master cylinder pressure is increased.

At this time, the above-mentioned hydraulic pressure of the first annular groove 225 acts as a combined force of the acting force for pushing the valve spool 210 in the non-operating direction and the spring force of the spool return spring 232, the electromagnetic force of the solenoid and the input of the input shaft 204. Since the valve spool 210 is controlled such that the resultant force of the return spring 231 in accordance with the stroke is balanced, the hydraulic pressure in the power chamber 206 is controlled by the solenoid SOL.
When the electromagnetic force is applied to the valve spool 210 in the operating direction, the electromagnetic force rises. Therefore, the solenoid S
By controlling the supply current to the OL and setting the electromagnetic force in various ways, it is possible to arbitrarily control the increase in the hydraulic pressure of the power chamber 206 and the master cylinder pressure.

When the pressure increase control is performed, the spring force of the return spring 31 of the input shaft 204 does not change, so that the input of the input shaft 204 and the input stroke do not change. As described above, even if the pressure increase control of the hydraulic pressure in the power chamber 206 is performed, there is no influence on the input side.

[0053]

As described above, according to the present invention, the output of the brake booster can be freely controlled irrespective of the depression force of the brake pedal in response to a request for increasing or decreasing the braking force, and It is possible to obtain an effect that the present invention can be applied to a brake system for a wide range of vehicles including a brake device, an engine brake, an exhaust brake device, or a brake assist device.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a flowchart of a control device ECU shown in FIGS. 1 and 2;

FIG. 4 is a sectional view showing a specific configuration of the first embodiment shown in FIG. 1;

FIG. 5 is an enlarged sectional view of a main part of FIG. 4;

FIG. 6 is a characteristic diagram of the present invention.

FIG. 7 is an enlarged sectional view of a main part showing a third embodiment of the present invention.

FIG. 8 is a sectional view showing an operation state different from that of FIG. 7;

FIG. 9 is a sectional view showing an operation state different from those in FIGS. 7 and 8;

FIG. 10 is a sectional view showing a specific configuration of the second embodiment shown in FIG. 2;

FIG. 11 is an enlarged sectional view of a main part of FIG. 10;

FIG. 12 is an enlarged sectional view of a main part of FIG. 10 different from FIG. 11;

FIG. 13 is an enlarged sectional view of a main part showing a fourth embodiment of the present invention.

[Explanation of symbols]

6, 106 ... valve body 10, 11 ... power piston 15, 115, 208 ... valve mechanism 17, 117, 2
04: Input shaft 42, 142 ... Solenoid plunger 18, 118 ...
Valve plungers 52, 152 Plate plungers 47, 48 Contact members 53, 153 Reaction disc 207 Spring 210 Valve spool 227 Lever VBB Pneumatic brake booster BP Brake pedal HBB Hydraulic brake booster Device ECU… Control device SOL… Solenoid

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Michio Kobayashi 2-11-6 Shinmeicho, Higashimatsuyama-shi, Saitama Bosch Brake System Co., Ltd. (72) Hiroshi Osaki 2--11 Shinmeicho, Higashimatsuyama-shi, Saitama No. 6 Inside the Bosch Brake System Co., Ltd. (72) Yoshiho Takasaki 2-11-6 Shinmeicho, Higashimatsuyama-shi, Saitama Prefecture Inside the Bosch Brake System Co., Ltd. (72) Osamu Kanazawa 2, Shinmeicho, Higashimatsuyama-shi, Saitama No. 11-6 Bosch Brake System Co., Ltd. (72) Inventor Hiroyuki Oka 2-11-6 Shinmeicho, Higashi Matsuyama-shi, Saitama Prefecture No. 2 11-6 Bosch Brake System Co., Ltd. (72) Inventor Hiroaki Niino Kariya, Aichi Prefecture 1-1-1 Showacho Denso Co., Ltd. (72) Inventor Kazuya Maki Kariya, Aichi Prefecture Showacho 1-chome 1 address Stock Company in Denso (72) inventor Mamoru Sawada Kariya, Aichi Showacho 1-chome 1 address Stock Company in DENSO

Claims (9)

[Claims] 1. A valve mechanism of a brake booster which is urged by a pedaling force applied to a brake pedal to switch a flow path and generates an output corresponding to the magnitude of the pedaling force, and the valve mechanism is the same as the pedaling force. A solenoid for urging in the direction or in the opposite direction, wherein the solenoid increases or decreases the urging force applied to the valve mechanism in response to a brake force increase request signal or a decrease request signal, and the brake booster A brake system characterized by increasing or decreasing the output of a brake. 2. The biasing force of the solenoid is controlled by a control device, and the control device changes an energizing current value to the solenoid according to a magnitude of a braking force increase request signal or a decrease request signal. The brake system according to claim 1, wherein the brake system calculates and controls the biasing force of the solenoid based on the current value. 3. The brake booster is a pneumatic brake booster, wherein the brake booster is slidably provided in a shell, a power piston provided on the valve body, and a power piston provided on the valve body. A constant-pressure chamber and a variable-pressure chamber formed before and after the piston, the valve mechanism provided in the valve body for switching and controlling the flow path, and a valve plunger interlocking with a brake pedal and constituting the valve mechanism are advanced to move the flow. An input shaft for switching a path, and the solenoid biases a solenoid plunger. The solenoid plunger is slidably movable between a reaction disk of a brake booster and the valve plunger. The brake system according to claim 1 or 2, wherein the brake system is arranged to transmit an urging force to the valve plunger. Temu. 4. A plate plunger is slidably provided between the reaction disc and the solenoid plunger, and at least one of a contact surface between the plate plunger and the solenoid plunger and a contact between the solenoid plunger and the valve plunger. The brake system according to claim 3, wherein at least one of the contact surfaces is a spherical surface. 5. The solenoid plunger includes a contact member at one end thereof for contacting the plate plunger, and a contact member at the other end thereof for contact with the valve plunger. Each of the contact members has the spherical surface formed thereon. The brake system according to claim 4, wherein the brake system is provided. 6. The valve plunger is provided with an input shaft side member connected to an input shaft, and slidably provided with respect to the input shaft side member, wherein a valve seat of the valve mechanism is formed. The valve side member is normally urged to the front side with respect to the input shaft side member and held at the forward end position, and the solenoid plunger moves the valve side member from the forward end position to the rear side. 4. A displacement according to claim 3, wherein
The brake system according to 1. 7. The brake system according to claim 6, wherein the input shaft member slidably penetrates through the solenoid plunger and is linked to a reaction disk of a brake booster. 8. The brake booster is a hydraulic brake booster, wherein the brake booster is provided with an input shaft that is advanced by the depression force of a brake pedal and one end of the brake booster that is swingable. A lever, a valve mechanism interlocked with the other end of the lever and operated by swinging the lever, and a lever mechanism provided between the input shaft and the lever, and swinging the lever in accordance with advancement of the input shaft. An elastic member, and the valve mechanism is characterized in that the sum of the acting force of the output hydraulic pressure of the hydraulic brake booster and the urging force of the solenoid balances the urging force of the elastic member. The brake system according to claim 1, wherein 9. The valve mechanism includes a valve spool, and the lever is interlocked with one end of the valve spool to urge the valve spool to one side, and to exert an output hydraulic pressure acting on a hydraulic brake booster. The valve biases the valve spool to the other, and the solenoid biases the valve spool to the one or the other.
The brake system according to 1.