JPH05270392A - Brake control device - Google Patents

Abstract

PURPOSE:To eliminate a need for sealing of brake liquid from working oil in an oil pressure control valve in a brake force control device which feeds working oil from an oil pressure source to a wheel cylinder through an oil pressure control valve controlled according to a tread-power exerted on a brake pedal. CONSTITUTION:A rod 300 is disposed to the end part of an oil pressure control valve 5 and the rod 300 is connected to a brake pedal 1 through a link 405, a cable 401, and springs 402 and 404 located in the cable 401.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake control device for arbitrarily controlling the braking force applied to each wheel.

[0002]

2. Description of the Related Art The present applicant has previously filed Japanese Patent Application No. 2-20201.
No. 0 proposes a brake control device that supports all of the boost control function, ABS function, and TCS function. This braking force control device uses the pressure generated by the master cylinder on the pressure increasing side of the spool, and uses the force from the actuator on the pressure reducing side of the spool to control the hydraulic pressure supplied from an external hydraulic pressure source. The braking hydraulic pressure supplied to the wheel cylinders is controlled.

That is, since the hydraulic oil from the external hydraulic source can be supplied to the wheel cylinder according to the master cylinder pressure,
In addition to realizing a high boosting function, anti-skid (braking slip) control and traction control (driving slip) by electronically controlling the actuator
Control is also possible.

In the brake control device of this prior application, the master cylinder pressure generated in the master cylinder is directly applied to the master cylinder pressure chamber to switch the spool of the hydraulic control valve to the pressure increasing side, and the master cylinder pressure is applied to the spool. Spool pressing force multiplied by the plunger pressure receiving area is applied.

By the way, since this hydraulic control valve uses a spool, hydraulic oil having a viscosity higher than that of the brake fluid is used to reduce leakage. The seal material used for the system from the hydraulic source that uses hydraulic oil to the wheel cylinders via the hydraulic control valve and the seal material used for the system that uses the brake fluid from the master cylinder to the hydraulic control valve are I am using non-erodible ones,
If the liquids mix with each other, the durability against erosion may deteriorate.

Therefore, in the hydraulic control valve of the above-mentioned application, an end face chamber which is formed on the end face of the spool and into which the hydraulic fluid flows, and a master cylinder chamber which is adjacent to the end face chamber and which communicates with the master cylinder and into which the brake fluid flows, are provided. It was sealed with a seal member so that the oil and the hydraulic fluid would not mix.

[0007]

However, since the seal member for separating the brake fluid and the hydraulic oil must be a non-corrosive member for both fluids, the usable material is limited, Further, there is a problem in that it is difficult to provide an optimum sealing member because processing precision and structure for ensuring sufficient sealing property are required.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a brake control device which does not require the provision of a seal member for separating brake fluid and hydraulic oil in a hydraulic control valve. Is.

[0009]

In order to achieve the above object, the invention according to claim 1 is a master cylinder for generating a master cylinder pressure according to a pedaling force applied to a brake pedal, and a wheel for the master cylinder pressure. A wheel cylinder capable of braking each wheel as a cylinder pressure, a hydraulic pressure source, a hydraulic control valve for controlling the output hydraulic pressure of the hydraulic pressure source to a control hydraulic pressure according to the pedaling force, and the wheel cylinder pressure using the control hydraulic pressure. The pressure means for increasing / decreasing and the hydraulic control valve increase / decrease the control hydraulic pressure by switching the oil passage, a spool for applying a force to the spool in a direction to reduce the control hydraulic pressure, and increase the control hydraulic pressure for the spool. And a pressing means for applying a force corresponding to a pedaling force in a direction, in a brake control device separate from the master cylinder. Provided the force generating means for generating a force corresponding to the depression force applied to the Le is the force generated by the force generating means that so as to transmit to said pressing means.

In order to achieve the above object, the invention according to claim 2 is characterized in that the force generating means is an elastic body which expands and contracts according to the stroke of the brake pedal. It is a device.

[0011]

In the brake control device according to the first aspect of the invention, first, when the brake pedal is depressed, master cylinder pressure is generated in the master cylinder, and this becomes the wheel cylinder pressure of the wheel cylinder. The wheel cylinder pressure is set to a higher wheel cylinder pressure by using the control hydraulic pressure from the hydraulic pressure control valve that the pressure means controls and outputs the output hydraulic pressure from the hydraulic pressure source. In the hydraulic control valve, the pressing unit pushes the spool to the pressure increasing side by using the force generated by the force generating unit, and the actuator pushes the spool to the pressure reducing side to control and output the output hydraulic pressure from the hydraulic source. To do.

According to a second aspect of the present invention, in addition to the operation of the first aspect, the brake control device pushes the pressing means by the elastic force of the elastic body that expands and contracts according to the stroke.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is an overall view showing a brake control device of the first embodiment. This brake control device is provided in each of a master cylinder 2 that generates a master cylinder pressure PM in response to depression of a brake pedal 1, and a disc brake device 3 of each wheel from the master cylinder 2 via an oil passage 10. The brake fluid system 100 reaching the wheel cylinders 4, the hydraulic control valve 5 that regulates the accumulator pressure PS from the hydraulic power source 7, and the booster that makes the control pressure PC of the hydraulic control valve 5 a higher wheel cylinder pressure PW. (Pressure means) 12 and a hydraulic oil system 101.

The hydraulic pressure source 7 comprises an oil pump 7a, a check valve 7b and an accumulator 7c,
The hydraulic oil is supplied from an accumulator oil passage 6 to an input port 5a of the hydraulic control valve 5 described later. Further, the TCS pressure PT, which is provided in the branch oil passage 6a of the accumulator oil passage 6 and has the accumulator pressure as a base pressure by opening the valve, transfers the TCS port 5b of the hydraulic control valve 5 described later to An electromagnetic switching valve 8 that operates on the pressure increasing side is provided.

The hydraulic control valve 5 connects and disconnects the accumulator oil passage 6 and the oil passage 9 leading to the booster 12.
A spool 51 that switches between communication and cutoff between the oil passage 9 and the drain 5j, and a proportional solenoid (actuator) that pushes the spool 51 in a direction that allows the oil passage 9 and the drain 5j to communicate with each other, that is, a direction that reduces the control oil pressure PC. ) 5
2 and a rod (pressing means) 300 that acts to push the spool 51 in a direction in which the accumulator oil passage 6 and the oil passage 9 are communicated with each other by depressing the brake pedal 1.

The body 50 forming the hydraulic control valve 5 includes:
An insertion hole 53 is bored in the longitudinal direction, and an input port 5a communicating with the annular groove 53a provided in the insertion hole 53 and a drain port 5d communicating with the annular groove 53d are provided. The output port 5c is provided between the annular grooves 53a and 53d.

The spool 51 is slidably inserted in the axial direction of the insertion hole 53. An annular groove 51a is formed in the center of the spool 51, and lands 51 are formed on both sides of the annular groove 51a.
b, a land 51c is formed. A diaphragm 510 is formed by the land 51b and the annular groove 53a.
By opening and closing, the input port 5a and the output port 5c are connected and disconnected. On the other hand, the land 51c and the annular groove 53d form a diaphragm 511, and the opening and closing of the diaphragm 511 connects and disconnects the output port 5c and the drain port 5d. or,
The land 51c on the right side of the figure has a larger diameter than the land 51b on the left side of the figure, and the insertion hole 53 also has a land 51c.
The diameter is changed according to b and 51c.

In order to close the diaphragm 510 and open the diaphragm 511, that is, to push the spool 51 in the right direction in the drawing,
When a current is applied to the solenoid 52a of the proportional solenoid 52, a plunger 52b, which receives a rightward force in the drawing, is brought into contact with the left end surface of the spool 51 in the drawing.

A spring 66 is press-fitted in an oil chamber 53g formed by the left end surface of the spool 51 in the drawing and the insertion hole 53. The oil chamber 53g is connected to the tank 5j through the drain port 5d.

On the other hand, on the right end surface of the spool 51 in the drawing,
A hole 51d is bored in the axial direction of the spool 51 with the end face closed, and a pilot pin 54 slidable in the axial direction is inserted into the hole 51d. This pilot pin 54
Part of the pedestal 65 protrudes from the hole 51d and is located in the oil chamber 53f formed by the end surface of the spool 51 and the insertion hole 53.
It is slidably fitted in the recess of the. The oil chamber 53f is connected to the tank 5j through the drain port 5d,
A spring 55 that pushes the spool 51 to the left in the drawing is inserted in the oil chamber 53f.

A chamber 51e formed by the hole 51d and the pilot pin 54, and an annular groove 53b formed in the insertion hole 53.
And a communication hole 51h communicating with the annular groove 53b.
Is provided with a TCS port 5b.

One end of the rod 300 is the pedestal 65.
, And the other end is connected to a rotatable link 405. That is, the end portion of the rod 300 protruding from the hydraulic control valve 5 is provided perpendicularly to the rod 300, and is pivotally supported by one end of a link 405 rotatable at a fulcrum 408 and a connecting portion 407. The connecting portion 406 of the link 405 and the brake pedal 1 are connected by a cable 401 guided by pulleys 409a and 409b.
1, a spring (elastic body, force generating means) 404 is provided on the link 405 side, and a spring (elastic body, force generating means) 402 is provided on the brake pedal 1 side. Spring 40
4 and the spring 402 pass through the hole 403c of the support plate 403a.
04 and the support plate 403a, a stopper 403b having a larger diameter than the hole 403c at a position of a distance d from the support plate 403a.
Is provided.

The booster 12 has the output port 5 on the large diameter side of the step plunger 121 in the body 120.
A control oil pressure chamber 122 communicating with an input port 12a communicating with the oil passage 9 is formed.
A wheel cylinder pressure chamber 123 communicating with the output port 12b is formed on the small diameter side of 1, and the stepped plunger 121 is biased to the left in the drawing by a return spring 124. The wheel cylinder pressure chamber 123 is communicated with the master cylinder 2 by the master cylinder pressure port 12c.

The pilot switching valve 17 provided in the oil passage 10 is provided in the middle of the oil passage connecting the master cylinder pressure oil passage 10 and the master cylinder pressure port 12c, and the oil pressure in the oil passage 9 is changed. As a pilot pressure, the master cylinder 2 and the master cylinder port 12c are connected and disconnected.

Further, in the oil passage 10, the pilot switching valve 17 is provided with the master cylinder 2 and the master cylinder port 1.
The stroke damper 200 is provided in order to prevent the brake pedal 1 from stepping on the board (the state in which the brake pedal 1 does not stroke at all even when a pedaling force is applied) when the brake pedal 2c is disconnected.
Is provided. This is the plunger 2 inside the body 205.
02 is divided into a chamber 201 communicating with the oil passage 10 and a chamber 204 communicating with the atmosphere.
3 is inserted.

The proportional solenoid 52 of the hydraulic control device and the solenoid 81 of the electromagnetic switching valve 8 are drive-controlled by a command from the brake controller 13, and the brake controller 13 has a longitudinal acceleration sensor 14 as a sensor for obtaining input information. The wheel speed sensor 15, the master cylinder pressure sensor 16 and the like are connected.

That is, with the drive control by the brake controller 13, boost control for increasing the master cylinder pressure, ABS control for preventing wheel lock during braking, and TCS control for suppressing drive wheel slip at the time of starting or sudden acceleration. Is done. It is also possible to control the active brake or the like so that a desired yaw rate can be obtained by producing a braking force difference between the left and right wheels.

The operation of the brake control system of the first embodiment having the above construction will be described below.

(A) During non-braking and non-control When the brake pedal 1 is not depressed, the spring force F2 of the spring 55 acting leftward in the figure and the spring force of the spring 66 acting rightward in the figure. The spool 51 is stopped at a position where F1 and the force FS generated by the proportional soleoidoid 52 are in equilibrium.
Is released and the control pressure PC is the drain pressure.

(B) During normal braking When the brake pedal 1 is stepped on, a master cylinder pressure PM is generated in the master cylinder 2 in accordance with the pedaling force applied to the brake pedal 1, and the wheel cylinder 4 is applied to the wheel cylinder 4 via the oil passage 10. Supplied. At the same time, a tension T1 is generated on the cable 401, and this tension T1 is applied to the springs 402 and 4
03 to the connection portion 406 of the link 405. Since the link is rotatably supported by the fulcrum 408, the rod 300 supported by the one end 407 of the link receives a force in the left direction in the drawing. When the above force acts on the spool 51, the spool 51 moves leftward in the drawing to open the throttle 510, and the accumulator pressure PS flows from the input port 5a to the output port 5c. Since the spool 51 is a two-stage spool having a step, a force for moving the spool 51 to the right acts by the control oil pressure PC of the output port 5c. Therefore, when the control pressure PC reaches a predetermined pressure, the throttle 5
Since 10 is closed, the control pressure PC corresponds to the force of the rod 300 pushing the spool 51 to the left in the figure, that is, the pedaling force applied to the brake pedal 1.

When this control pressure PC is generated, the control oil pressure P
Pilot switching valve 17 with C as pilot pressure is oil passage 1
By switching to the side that shuts off 0, the control oil pressure PC
Is supplied to the booster 12, and the step plunger 121 is moved rightward in the drawing. When the step plunger 121 moves to the right in the figure, the wheel cylinder pressure chamber 123 is pressurized, so that the wheel cylinder pressure PW is equal to the step plunger 121.
The area ratio (A5 / A6: A5 is the cross-sectional area of the large diameter portion and A6 is the cross-sectional area of the small diameter portion) is applied, and the wheel cylinder pressure becomes higher.

The above operation will be described below by using equations.

Since the springs 402 and 404 are extended by the tension T1 generated in the cable 401, the displacement of the cable 401 is x and the spring constant of the spring 402 is k.
1, the displacement is x1, the spring constant of the spring 404 is k2,
Assuming that the displacement is x2, T1 = k1 * x1, T1 = k2 * x2, and x = x1 + x2, so T1 = [k1 * k2 / (k1 + k2)] x. The displacement x of the cable 401 is
Only the tension T1 is transmitted to the connecting portion 406 in the link 405 because it is absorbed by the elongation of 2,404. This connection 4
If the force transmitted to 06 is T2, then x2 <d, then T2 =
It is T1.

The force FTH transmitted from the link 405 to the spool 51 via the rod 300 is the fulcrum 40 of the link 405.
8 is L1 and the distance between the fulcrum 408 and the pivot 407 of the rod 300 is L2, FTH = (L1 / L2) T2 = (L1 / L2) [k1.k2
/ (K1 + k2)] x. This FTH can be adjusted by the link ratio L1 / L2 so that it is approximately equal to the thrust generated by the proportional solenoid 52.

As described above, this force FTH causes the spool 51
Is pressed to the left in the figure, the diaphragm 510 opens and the spool 5
Since 1 is a two-stage spool having a step, a control hydraulic pressure PC of the output port 5c exerts a force to move the spool 51 to the right. The force at that time is A
1 and the cross-sectional area of the small diameter portion is A2, it is (A1-A2) .PC.

At this time, the balance of the spool 51 is (A1-A2) .multidot.PC = FTH + F2-F1.

Therefore, the control oil pressure PC is proportional to the pedal effort,
The spring force (F2-F1) is added.

Next, when a current is applied to the solenoid 52a,
A force FS proportional to the current is generated in the plunger 52b and pushes the spool 51 to the right in the figure. Spool 5 at this time
The balance of 1 is (A1−A2) · PC = FTH + F2−F1−FS, and the control oil pressure P depends on the current to the solenoid 52a.
C will be controlled to increase or decrease.

When the pressure applied by the booster 12 is further added, the wheel cylinder pressure PW is controlled by the following equation.

PW = {A5. (FTH + F2-F1-FS)
)} / {A6. (A1-A2)} Further, when the stopper 403b and the support plate 403a come into contact with each other when the brake pedal 1 is depressed, the FTH does not increase even if the brake pedal 1 is further depressed, so the link 406 The strength of the members from the spool to the spool 51 can be secured.

When this is illustrated, the characteristics shown in FIG.
When the solenoid current is zero, the pressure increase ratio becomes the largest, and the characteristic shown in FIG. When the solenoid current is increased, the wheel cylinder pressure PW is reduced in proportion to the solenoid current, resulting in the characteristic (b).

Therefore, the wheel cylinder pressure characteristic with respect to the master cylinder pressure is set in the brake controller 13 according to the vehicle state by a function or a map, and based on the information indicating the vehicle state and the information from the master cylinder pressure sensor 16. By controlling the solenoid current, the wheel cylinder pressure can be obtained with an arbitrary boosting characteristic according to the vehicle state. That is, a boost control function having a high degree of freedom is exerted instead of a unique boost ratio.

(C) During ABS control During sudden braking or when wheel locking is likely to occur on the bottom μ road,
An ABS operation for preventing wheel lock is performed by a control command from the ABS control unit of the brake controller 13 to the proportional solenoid 52.

That is, as the normal boosting characteristic, for example, if the solenoid current is set so as to obtain the characteristic (e), a pressure increase up to the characteristic (a) and a pressure decrease up to the characteristic (b) are performed. The slip ratio of each wheel is calculated from the vehicle speed information obtained by integrating the input signal from the longitudinal acceleration sensor 14 and the wheel speed information obtained from the wheel speed sensor 15, and the slip ratio is the optimum slip ratio. The wheel cylinder pressure PW can be increased, maintained, or reduced as shown in the range.

That is, the ABS for improving the vehicle stability during braking.
The function can be achieved with a sufficient increase or decrease of the wheel cylinder pressure PW.

(D) During TCS control When the drive wheel slip occurs due to sudden accelerator pedal operation during starting or sudden acceleration, the brake controller 1
The TCS operation for suppressing the drive wheel slip is performed by the control command to the proportional solenoid 52 and the ON command to the solenoid 81 from the TCS control unit 3 of FIG.

That is, when the ON command is output to the solenoid 81, the electromagnetic switching valve 8 is opened, so that the accumulator pressure PS becomes the TCS pressure PT and the hydraulic control valve 5 is operated.
Is supplied to the chamber 51e from the TCS port 5b. This T
The CS pressure PT acts on the pilot pin 54 and pushes the pilot pin 54 to the right in the figure. However, since the pilot pin 54 is in contact with the base 65, the spool 51 is moved leftward in the drawing. At this time, the balance of the spool 51 becomes (A1 -A2) .PC = A3 .PT -F1 -FS + F2, where A3 is the cross-sectional area of the pilot pin 54.

Therefore, even though the brake pedal 1 is not depressed, the control oil pressure PC can be arbitrarily set according to the solenoid current from the maximum pressure determined by the TCS pressure PT to the pressure reduced by the force FS proportional to the solenoid current. Can be controlled. The characteristic is the characteristic shown in FIG.

That is, the braking force can be applied to the drive wheels according to the amount of the drive wheel slips, and the TCS function of effectively suppressing the drive wheel slips is exhibited.

(E) When Electronic Control System and Hydraulic System Fail When the electronic control system associated with the brake controller 13 fails, the current to the solenoid 52a is made zero and the electromagnetic on-off valve 8 is closed.

Therefore, since the force acting on the spool 51 is (A1 -A2) .PC = FTH + F2 -F1, the ABS operation and the TCS operation cannot be performed, but the characteristic (a) of FIG. 2 is maintained. That is, the state of maximum capacity of the brake boosting performance is ensured, and the braking action having the boosting function is guaranteed.

Due to a failure of the oil pump 7a or the like, the hydraulic pressure source 7
Therefore, when the hydraulic source pressure fails such that the accumulator pressure PS is not, the control hydraulic pressure PC is not generated by the hydraulic control valve 5. When the control oil pressure PC is not generated in this manner, the pilot switching valve 17 having the control oil pressure PC as the pilot pressure is switched to the communication side as shown in FIG. 1, so that the master cylinder pressure PM is increased. The wheel cylinder pressure PW is directly applied to the wheel cylinder 4 of each wheel.

In the hydraulic control valve 5 used in this embodiment,
Using the cable 401 and springs 402 and 404,
Since the pedaling force applied to the brake pedal 1 is transmitted to the rod 300, it is not necessary to provide a seal member in the hydraulic control valve 5 for separating the brake fluid and the hydraulic oil.

Further, since the cable 401 is used for transmitting the pedaling force applied to the brake pedal 1 from the brake pedal 1 to the rod 300, there is an effect that the layout flexibility when mounted on a vehicle is high.

Next, the second embodiment will be described with reference to FIG.

In the brake control device of this embodiment, the springs 402 and 404 which generate a force by pulling used in the above-described first embodiment are replaced by the springs (elastic body, force generating means) 502 which generate a force by compression. , 504,
The booster 12 and the pilot switching valve 17 are replaced by a hydraulic synthesizer (pressure means) 21 and an electromagnetic switching valve 27, respectively.

That is, the rod 3 protruding from the hydraulic control valve 5
00 end is provided perpendicularly to the rod 300, and the fulcrum 5
08 is pivotally supported by one end of a link 505 rotatable and a connecting portion 507, and the connecting portion 506 of the link 505 and the brake pedal 1 are connected to a rod 501c, a spring 504, a rod 501b, a spring 502, and a rod 5.
It is connected by 01a. The rod 501b is the support plate 50.
3a through the hole 503c, and the spring 502
A stopper 503b having a diameter larger than that of the hole 503c is provided at a distance d from the support plate 503a between the support plate 503a and the support plate 503a.

In the hydraulic synthesizer 21, a control hydraulic chamber 212 communicating with the output port 5c and the input port 21a communicating with the oil passage 9 is formed on one side of the plunger 211 in the body 210, and on the opposite side. Master cylinder 2
A wheel cylinder pressure chamber 213 that is communicated with the master cylinder pressure port 21c is formed, and a return spring 214 that biases the plunger 211 to the left in the drawing is provided inside. Since the cross-sectional areas of both ends of the plunger 211 are set to be the same, there is no boosting function.

Further, the electromagnetic switching valve 27 is switched by the command signal from the controller 13 so as to communicate when the master cylinder pressure is zero, and to shut off when the master cylinder pressure is generated and during TCS control.

The other structure is the same as that of the first embodiment, and the description thereof will be omitted.

With the above construction, the brake control system in the second embodiment is such that when the brake pedal 1 is depressed, the rod 5
01a moves leftward in the figure to compress the spring 402. Therefore, the rod 501b moves to the left in the drawing, and compresses the spring 404. The displacement of the rod 501a is absorbed by the springs 502 and 504, and only the force is transmitted to the rod 501c. This force is transmitted to the rod 300 from the connecting portion 507 of the link 505. If the force pushing the rod 300 to the left in the figure is FTH, (A), (B), (C), (D), as in the first embodiment.
The action and effect of (E) can be obtained.

At this time, since the wheel cylinder pressure PW does not have a boosting function by the hydraulic synthesizer 21, it is represented by PW = (FTH + F2-F1-FS) / (A1-A2).

In the present embodiment, when the stroke of the rod 501a due to the depression of the brake pedal 1 is x and the pushing force of the rod 501a is T1, T1 = [k1.k2 / (k1 + k2)] x. Since the stroke x of the rod 501a is absorbed by the contraction of the springs 402 and 404, only the pressing force T1 is transmitted to the connecting portion 506 in the link 505. When the force transmitted to the connecting portion 406 is T2, T2 = T1 when x2 <d.

The force FTH transmitted from the link 505 to the spool 51 via the rod 300 is the fulcrum 40 of the link 405.
8 is L1 and the distance between the fulcrum 408 and the pivot point 407 of the rod 300 is L2, FTH = [L1 / (L1 + L2)] T2 = [L1 / (L1
+ L2)] [k1k2 / (k1 + k2)] x. This FTH can be adjusted by the link ratio L1 / L2 so that it is approximately equal to the thrust generated by the proportional solenoid 52.

When the stopper 503b contacts the support plate 503a when the brake pedal 1 is depressed, the FTH does not increase even when the brake pedal 1 is further depressed.
It is possible to secure the strength of the members up to.

Further, in this embodiment, since the rod 501 is used instead of the cable used in the first embodiment, there is no slack or extension of the cable. Therefore, the response between the brake pedal 1 and the hydraulic control valve 5 is high. Is improved.

Next, a third embodiment of the present invention will be described with reference to FIGS. 4 is an overall view of the brake control device, and FIG. 5 is a view A in FIG.

The brake control system of the present embodiment uses the rod 300, link 405 and cable 401 used in the above-described first embodiment as the rod (pressing means) 302 and the gear group 60.
5 and the cable 601 instead of the booster 12 and the pilot switching valve 17, the hydraulic synthesizer 21 and the electromagnetic switching valve 2
7 is set.

That is, the gear group 6 is provided at the end of the rod 302.
05 meshes with a rack 302a formed on the rod 302, and a cable 601 guided by a pulley 409c is connected so that the gear group 605 rotates in accordance with the stroke of the brake pedal 1.

The gear group 605 is formed integrally with the gear 615b and has a pulley 615a connected to the cable 601.
It comprises a gear 625a which is meshed with the gear 615b and integrally formed with the gear 625b, and a gear 635a which is integrally meshed with the gear 625b and meshed with the rack 302a formed on the rod 302.

Further, the hydraulic synthesizer 21 and the electromagnetic switching valve 27 are the same as those used in the above-mentioned second embodiment, and therefore their explanations are omitted.

The other structure is similar to that of the first embodiment, and the description thereof is omitted.

With the above configuration, the brake control device in the third embodiment is similar to the first embodiment (A) when the force pushing the rod 302 by depressing the brake pedal 1 to the left in the figure is FTH. The actions and effects of (B), (C), (D), and (E) can be obtained. At this time, since the wheel cylinder pressure PW does not have a boosting function by the hydraulic synthesizer 21, it is expressed by PW = (FTH + F2-F1-FS) / (A1-A2).

Further, in the first embodiment, FTH is adjusted by the link ratio L1 / L2 of the link 405, but in the present embodiment, it can be adjusted by the total gear ratio G of the gear group 605. At this time, FTH is represented by FTH = (1 / G) [k1 · k2 / (k1 + k2)] x.

Further, in the present embodiment, the cable 601 is used to transmit the pedaling force applied to the brake pedal 1 from the brake pedal 1 to the rod 302 as in the first embodiment, and therefore the degree of freedom of layout when mounted on a vehicle is high. By using the gear group 605 which is high in size and small in size, the size can be reduced as compared with the links 405 and 505 in the first and second embodiments.

Although the embodiments using the present invention have been described above, the invention is not limited to the above embodiments as long as it is not necessary to seal the brake fluid and the hydraulic oil in the hydraulic control valve. In one embodiment, instead of the rod 300, a proportional solenoid operated by a current signal from the controller 13 may be provided and the spool 51 may be pushed in the pressure increasing direction according to the master cylinder pressure detected by the pressure sensor 16.

Further, a hydraulic pressure is generated by the pedaling force applied to the brake pedal 1, and a piston cylinder different from the master cylinder 2 which uses the same hydraulic oil as that used in the hydraulic pressure source 7 is provided. It is also possible to push 51 to the pressure increasing side.

[0079]

As described above, in the brake device of the present invention, the force generated by the force generating means acts on the spool of the hydraulic control valve in the direction of increasing the control pressure.
The reliability of the brake control device can be improved without using a seal member for separating the brake fluid and the hydraulic oil in the hydraulic control valve.

[Brief description of drawings]

FIG. 1 is an overall view of a brake control device showing a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between a master cylinder pressure and a wheel cylinder pressure of the braking force control device shown in FIG.

FIG. 3 is an overall view of a brake control device showing a second embodiment of the present invention.

FIG. 4 is an overall view of a brake control device showing a third embodiment of the present invention.

5 is a view A in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Brake pedal, 2 ... Master cylinder, 4 ... Wheel cylinder, 5 ... Hydraulic control valve, 7 ... Hydraulic source, 12 ... Booster (pressure means), 21 ... Hydraulic synthesizer (pressure increasing means), 51
... Spool, 52 ... Proportional solenoid (actuator), 300, 302 ... Rod (pressing means), 402,
404, 502, 504 ... Spring (elastic means, force generating means).

Claims (2)

[Claims] 1. A master cylinder for generating a master cylinder pressure according to a pedaling force applied to a brake pedal; a wheel cylinder capable of braking each wheel by using the master cylinder pressure as a wheel cylinder pressure; a hydraulic pressure source; A hydraulic control valve for controlling the output hydraulic pressure of the power source to a control hydraulic pressure according to the pedaling force, a pressure means for increasing and decreasing the wheel cylinder pressure using this control hydraulic pressure, and the hydraulic control valve for controlling the control hydraulic pressure by switching the oil passage. In a brake control device having a spool to be increased / decreased, an actuator that applies a force to the spool in a direction to reduce the control hydraulic pressure, and a pressing unit that applies a force according to a pedaling force to the spool in a direction to increase the control hydraulic pressure, In addition to the master cylinder, a force generating unit that generates a force according to the pedaling force applied to the brake pedal is provided. A braking force control device characterized in that the force generated by the force generating means is transmitted to the pressing means. 2. The brake control device according to claim 1, wherein the force generating means is an elastic body that expands and contracts according to the stroke of the brake pedal.