JPS6137563A - Braking hydraulic pressure controller - Google Patents

Abstract

PURPOSE:To make braking force distribution approximate to an ideal in spite of operation delay of a solenoid valve, by regulating a pressure boost in inlet hydraulic pressure to be confined in a passage according to the operation delay of the solenoid valve to an inlet hydraulic pressure velocity, with a pressure boost sensor valve. CONSTITUTION:A pressure boost sensor valve 22 is set up in a passage 19 between a solenois valve 21 and an enclosure chamber 57. Since a pressure differential valve body 83 of this pressure sensor valve 22 receives set load of a spring 105 and closes the passage 19, the rising of hydraulic pressure in the enclosure chamber 57 is delayed whereby a pressure boost of inlet hydraulic pressure to be confined is thus regulated. Therefore, in the case where a microcomputer 115 has the solenois valve 21 closed up when a deceleration signal Sp of a deceleration detecting device 113 becomes large than a desired deceleration signal Sc of a deceleration setting device 117, even if there is closing motion delay in the said valve 21, a pressure boost of confined pressure of the enclosure chamber 57 is regulated by the said pressure boost sensor valve 22 so that set load of a spring 70 is set to a proper value.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a brake hydraulic pressure control device used in a hydraulic brake system of an automobile.

(b) Technical background and problems As a conventional pre-pressure hydraulic control device, for example,
The one described in Japanese Patent No. 8-211952 has been proposed. This brake fluid pressure control device uses a deceleration detection sensor to detect when vehicle deceleration exceeds a certain value.
This detection activates the solenoid valve and determines the split point (the point at which the blotting valve starts operating), and the actual brake force distribution between the front wheel brake fluid pressure and the rear wheel brake fluid pressure is adjusted between As shown in Figure 5, both when loading the vehicle and when loading the vehicle.

It is possible to approximate the ideal brake force distribution.

However, in such conventional devices, the delay in operation from the detection by the deceleration detection sensor to the turning on of the solenoid valve is not taken into consideration at all, and the inlet fluid pressure of the provisioning valve increases at a high rate during sudden braking, etc. In this case, the split point may not correspond to the weight of the vehicle and may become too high. For this reason, the above-mentioned approximation characteristic to the ideal brake force distribution deteriorates, which may lead to early rear wheel locking. - (c) Purpose of the Invention The present invention was devised in view of the above-mentioned problems, and its purpose is to provide a brake fluid pressure control device that can improve the approximation characteristics to the ideal brake force distribution regardless of the delay in the activation of the solenoid valve. shall be.

(d) Structure of the Invention In order to achieve the above object, the present invention, as shown in FIG. a control valve that is interposed between the master cylinder and the wheel cylinder and that controls the pressure reduction of the outlet liquid pressure in response to the inlet liquid pressure; and a control valve that regulates the pressure reduction control of the outlet liquid pressure in response to the inlet liquid pressure. In a brake fluid pressure control device that has a passage for applying inlet hydraulic pressure and a solenoid valve that can be opened and closed to close this passage and seal off the inlet hydraulic pressure, a deceleration detection system that detects vehicle deceleration is used. means for setting a target deceleration in advance; and comparison means for comparing the target deceleration and the vehicle deceleration and issuing an activation signal to the solenoid valve when the latter exceeds the former. ,
a pressure increase control valve that is stacked in the passage and regulates the increase in the liquid pressure at the inlet to be confined in the passage in accordance with the activation delay of the two front solenoid valves with respect to the rate of increase in the inlet liquid pressure; And so.

(E) Example Hereinafter, an example of the present invention will be described in detail based on FIGS. 2 to 5.

FIG. 2 shows a brake fluid pressure control device for an automobile, in which a master cylinder 1 is connected to a brake pedal 3,
The first hydraulic pressure chamber 5 and the second hydraulic pressure v7 are arranged so that the same hydraulic pressure is generated in both chambers 5 and 7 as the brake pedal 3 is operated. The first hydraulic pressure chamber 5 is connected to a front wheel cylinder 9 of the front brake, and the second hydraulic pressure chamber 7 is connected to a rear brake V-wheel cylinder 11 via a blow-up valve (P valve) 13. There is. This P valve 13 has a control valve 17, a passage 19, a solenoid valve 21, and a pressure increase sensing valve 22 in a valve body 15.

The control valve 15 controls the pressure reduction of the outlet hydraulic pressure pr in response to the inlet hydraulic pressure pn+, and has a plunge p23. The large diameter part of this plunger 23 is the plug 25
The plunger 2.3 is slidably fitted into a valve chamber 27 having an inner diameter glim product A1 formed in the inner diameter Glim product A1, and the small diameter portion on the other end of the plunger 2.3 is slidably fitted into a retainer 29 having an inner diameter cross-sectional area A2 smaller than the cross-sectional area A1. It is supported and a first chamber 31 is formed. A valve body housing holder 33 is formed in the axial center of the large diameter portion of the plunger 23, and a valve seat 35 is fitted into the opening side of this valve/body housing chamber 33, and is connected to the east side of the valve chamber 27. Three second chambers are formed therebetween which communicate with an outlet boat 37 formed in the plug 25. In addition, - is a poppet valve body 41 in the valve body storage chamber 33.
A first spring 43 is interposed between the poppet valve body 41 and the plunger 23 to urge the poppet valve body 41 to come into contact with the inner side of the valve chamber 27. The valve body storage chamber 33 communicates with the first chamber 31 through a first through hole 45 formed on the small diameter side of the plunger 23, and communicates with the plug 25 through a groove 47 formed at the tip of the plug. It communicates with a third chamber 49 formed around it.

This third palm 49 is communicated with the inlet port 55 via the first communication hole 51 and the second communication hole 53.

The passage 19 is used to apply the inlet-hydraulic pressure pi so as to regulate the pressure reduction control of the outlet hydraulic pressure P by the control valve 17, and one end communicates with the inlet boat 55 via the pressure increase sensing valve 22, and the other end communicates with the inlet boat 55 through the pressure increase sensing valve 22. It has a containment chamber 57 at its end.The containment chamber 57 is formed in a plug 59 and is exposed to one end of a response piston 61.The response piston 61 is also slidably supported by the plug 59. The II!! end of the response piston 61 is exposed into a spring storage chamber 63 formed in the valve body 15. Inside this spring storage chamber 63 is a spring receiving plate that is in contact with the response piston 61. 65 is slidably fitted, and a second spring 67- is interposed between the spring receiving plate 65 and the valve body 15.

On the other hand, the small diameter portion of the other end of the plunger 23 of the control valve 17 is also exposed in the spring storage chamber 63, and a frame 69 is attached to the spring receiver, and the spring receiver is provided between the frame 69 and the spring receiver plate 65. , a third spring 70 is interposed to apply a set load to the plunger lν23.

The solenoid valve 21 operates to close the passage 19 and confine the inlet hydraulic pressure pm in the containment chamber 51. It has a solenoid 75 that drives the.

The pressure increase sensing valve 22 is interposed in one passage between the solenoid valve 21 and the containment chamber 57, and the solenoid valve 21 responds to the pressure increase rate Vp of the inlet liquid pressure PIll.
It regulates the increase in the inlet liquid pressure pn+ to be sealed in the passage 19 in accordance with the delay in the operation of vJ, and is composed of a differential pressure valve section 77 and a sensing section 79.

The differential pressure valve portion 77 is a differential pressure valve body 83 whose large diameter portion is fitted into a differential pressure valve chamber 81 with a cross-sectional area A3 formed in the middle of the passage 19.
have. An axial groove 85 is formed on the outer periphery of the large diameter portion of the differential pressure valve body 83, and communicates with a recess 89 formed at one end of the differential pressure valve body 83 via a second through hole 87. An inversion seal 91 made of an elastic material is attached within the recess 89 to restrict the flow from the recess 89 to the second through hole 87 .

The sensing portion 79 connects the first communication hole 51 and the second communication hole 53.
It has a sensing body 95 that is slidably fitted into a sensing chamber 93 formed between. By this sensing body 95, the sensing chamber 93 is connected to the first sensing chamber 97 on the side of the first communication hole 51.
and a second sensing chamber 99 on the second communication hole 53 side. In addition, the sensing body 95 includes a first sensing chamber 97 and a second sensing chamber 9.
9 is formed, and a bimetal 103 is arranged on the first sensing chamber side of this orifice 101. This bimetal 103 is configured to narrow the exit side opening of the orifice 101 in response to a rise in temperature. Small diameter portions 95a and 95b are formed at both ends of the sensing body 95 in the axial direction. One small diameter portion 95a is fitted into the differential pressure valve chamber 81, and a gap between the small diameter portion 95a and the differential pressure valve body 83 is
A fourth sublink 105 is interposed to apply a set load to. The other small diameter portion 95b is slidably fitted into a support hole 109 formed in the plug 107 and communicating with the passage 19. A through hole 111 is formed in the axis of the sensing body 95 to allow the differential pressure valve chamber 81 and the support hole 109 to communicate with each other.

On the other hand, the vehicle detects the vehicle deceleration 9 and outputs a deceleration signal So.
A deceleration detecting means 113 is attached to output the deceleration.

The output signal So of this deceleration detection means 113 is configured to be input to the microcomputer 115.

This microcomputer 115 has deceleration setting means 1.
17 and comparison means 119 are incorporated.

2. The deceleration setting means 117 is for setting a control target for deceleration occurring in the vehicle, that is, a target deceleration G, and outputting a target deceleration signal SC. - This is done for the purpose of proportionally changing the necessary brake fluid pressure in accordance with the above-mentioned loading when the mountain loading amount changes.

The comparison means 119 compares the vehicle deceleration g and the target deceleration G from the deceleration signal Sρ and the target deceleration signal 3c,
When the former exceeds the latter, the actuation signal Suj is input to the drive circuit 123 based on the actuation signal SQ. The drive circuit 123 is connected to the solenoid 75.

Next, the operation of the above embodiment will be described. As the brake pedal 3 is operated, this brake fluid pressure control device operates according to the flowchart shown in FIG. First, step S1 is executed to read the vehicle deceleration g. This vehicle deceleration σ is detected by the deceleration detection means 113 and inputted to the microcomputer 115 as the deceleration signal Sp.

In step S2, the target deceleration G is read. This target deceleration FIG is read by taking in the target deceleration signal 3c from the deceleration setting means 117. .

In step S3, the comparison means 119 decelerates the vehicle [f
A comparison means is made between g and the target deceleration G. When the brake pedal 3 is first depressed, the vehicle decelerates. Once 9 is low, it is determined that the vehicle deceleration g is lower than the target deceleration G.
In step S4, the activation signal SG to the solenoid 75 is
cannot be emitted. Therefore, in step S5, the solenoid valve 21 is kept OFF, and the passage 19 is in a communicating state. Therefore, when the brake pedal 3 is depressed, the hydraulic pressure generated in the master cylinder 1 is reduced to the first hydraulic pressure chamber 5.
is supplied to the front wheel cylinder 9 from
From the second hydraulic chamber 7 to the inlet boat 55 of the P valve 13, the second
Communication hole 53, second sensing chamber 99, orifice 101, first
Sensing chamber 97, first communication hole 51, third chamber 49, full 47. It is supplied to the rear wheel cylinder 11 through the first through hole 4 - 5 , the valve body storage chamber 43 , between the poppet valve body 41 and the valve seat 35 , through the 12 seedlings 39 and the outlet boat 37 . Therefore, the outlet hydraulic pressure pr as the rear wheel brake hydraulic pressure of one car is initially equal to the master cylinder hydraulic pressure (front wheel brake hydraulic pressure) Pa, and depending on the loading amount, the outlet hydraulic pressure pr is shown in a-b (when empty) or a- It rises with the characteristics shown by d (when loaded), etc. During this time, the inlet hydraulic pressure pm as the master cylinder hydraulic pressure also reaches the containment chamber 57 via the passage 19.

By the way, the containment room 5 is reached through the artificial hydraulic pressure 'pmm passage 19.
7, the differential pressure valve body 83
Since the passage 19 is closed while receiving the set load F, the rise of the hydraulic pressure in the containment chamber 57, indicated by R in Fig. 3, is delayed by the time indicated by T+ or T2 in Fig. 3, and the containment is completed. Inlet hydraulic pressure pa to be contained in chamber 57
+ voltage increase is regulated. At time T1, the brake pedal 3 is suddenly depressed and the pressure increase rate ■p of the inlet hydraulic pressure PnI is the third
In the case of a rapid pressure increase shown by line segment P in the figure, it corresponds to Vl)+, and T2 is 15 times smaller than Vl)2 in the case of a relatively moderate pressure rise. In other words, in the case of sudden pressure increase, the differential pressure valve body 83
Due to the action of the orifice 101, the pressure difference between the first sensing chamber 97 and the second sensing chamber 99 increases, the differential pressure valve body 83 slides toward the first sensing chamber 97, and the fourth spring 95 is compressed. Therefore, the set load mF to the differential pressure valve body 83 is increased. Then, when time T1 or T2 elapses and the inlet hydraulic pressure Pm rises to the differential pressure of the differential pressure valve body 83 determined by the set load IF of the fourth spring 105, the differential pressure valve body 83 resists the fourth spring 105 and 1, the inlet hydraulic pressure PI reaches the containment chamber 57 via the groove 85, the differential pressure valve chamber 81, the through hole 111, the support hole 109, and the passage 19.

Then, the inlet hydraulic pressure Pm comes to act on both end surfaces of the differential pressure valve body 83, and the differential pressure valve body 83 directly contacts the fourth spring 10.
5, it is returned to the open position. The repetition of this kind of action
Due to the return, the containment chamber 57 has a hydraulic pressure PI expressed by the following formula.
+ is supplied.

PIll+ = Pm -L As is clear from this equation, the hydraulic pressure Pm+ supplied to the containment chamber 57 has a value lower than the inlet hydraulic pressure pm depending on the set load F of the fourth spring 105. This relationship is the third
Looking at the figure, the inlet liquid pressure Pm has a pressure increase rate as shown by the line segment P with the rapid pressure increase rate VD+, and the inlet liquid pressure PIll has the same pressure increase rate with respect to the line segment Q with the slow pressure increase rate Vl)2. , the pressure rises at a speed as shown by line segment R. Next, the pedal force on the brake pedal 3 increases, and the state valve S
If it is determined in step 3 that the vehicle depreciation degree g exceeds the target depreciation degree G, the activation signal SQ of the esolenoid 75 is output to the drive circuit 123 in step 84. Then, the solenoid 75 of the solenoid valve 21 is energized by the drive circuit 123, and the solenoid valve 21 is turned on in step S5. Therefore, the valve 73 of the solenoid valve 21 is seated on the valve seat 71, and the passage 19 is closed. When passageway 19 is opened, containment room 5
The hydraulic pressure Pm+- acting on the spring 7 is contained as a containment liquid pressure l)a, and this containment liquid pressure PG compresses the second spring 63 and the third spring 70 via the response piston 61 and the spring receiving plate 65. , determine the set load of the third spring 70. In this case, there is a response delay of time t from when the actuation signal SQ is issued to the solenoid valve 21 until the solenoid valve 21 is turned ON, as shown in FIG. However, as described above, since the pressure increase sensing valve 22 regulates the increase in fluid pressure in the containment chamber 57 according to the rate of increase in the inlet fluid pressure PIl, the containment fluid pressure PG when the solenoid valve 21 is turned ON is Regardless of the change in the pressure increase rate vp, it is possible to make it approximately match the target brake fluid pressure Pi corresponding to the target deceleration G. In this way, after the containment hydraulic pressure PG that almost matches the target brake hydraulic pressure Pi is contained in the containment chamber 57, when the inlet hydraulic pressure pm further increases, the area difference A1 and A of the plunger 23 portion increase.
Based on 2, plunge 1!23 moves 1 to the left in Figure 1 so as to resist the third spring! This plunger 23
By sliding, the poppet valve body 41 is seated on the valve seat 35,
The communication between the inlet boat 55'''' and the exit robot 1-37 is cut off. At this time, the inlet hydraulic pressure pm continues to be supplied to the first chamber 31, and the hydraulic pressure in the first chamber 31 becomes high and the plunger 23
is again slid to the right in FIG. 1, the valve seat 35 is separated from the poppet valve body 41, and the supply of hydraulic pressure to the rear wheel cylinder 11 is resumed. By repeating the above action,
The rear wheel brake hydraulic pressure pr to the wheel cylinder 11 is determined by the split point Pi which is determined by the target deceleration G according to the loading amount, and the master cylinder hydraulic pressure PI is determined according to the loading amount in Figure 4 b-C. (When the vehicle is empty), d-e (When the vehicle is loaded) etc., it is raised under control, and the front and rear wheel brake force distribution characteristics are a-b-c (when the vehicle is empty), a-d-8.
The ideal brake force distribution can be approximated as follows.

Note that when the brake pedal 3 is stopped, the inlet fluid pressure 1)i+/fi is lost. Therefore, a pressure difference is generated between the differential pressure valve seedling 81 and the recess 89, and the containment hydraulic pressure PG is increased by the groove 85.
Then, the non-return seal 91 is pushed through the second through hole 87 and expelled to the inlet boat 55 side to prepare for the next operation.

Furthermore, the bimetal 103 of the sensing body 95 reduces the outlet side opening of the orifice 101 as the liquid temperature rises, thereby stabilizing the function of the orifice 101.

(f) Effects of the Invention As is clear from the above, according to the configuration of the present invention, a target deceleration is set in advance, control is performed based on this target deceleration, and the inlet fluid pressure R pressure is controlled by the back pressure sensing valve. The increase in inlet fluid pressure to be contained in the passage is regulated according to the solenoid valve activation delay relative to the speed, so the target deceleration remains constant regardless of changes in the inlet fluid pressure increase rate depending on the brake pedal depression speed. Therefore, a substantially constant brake fluid pressure for starting the control valve can be obtained, and the approximation characteristics to the ideal brake force distribution can be improved.

[Brief explanation of drawings]

FIG. 1 is a reference diagram showing the relationship between drawing elements of this invention, FIG. 2 is an overall diagram showing a 7-rake hydraulic pressure control device according to an embodiment of this invention, and FIG. 3 is a diagram showing control characteristics. FIG. 4 is a flowchart, and FIG. 5 is a brake fluid pressure characteristic diagram. DESCRIPTION OF SYMBOLS 1... Master cylinder, 13... Rear wheel cylinder (wheel cylinder), 17... Control valve, 19... Passage, 21... Solenoid valve,
22... Pressure increase sensing valve, 113... Deceleration detection means,
117...Deceleration setting means, 119...Comparing means.

Claims (1)

[Claims] A master cylinder that generates hydraulic pressure in response to brake pedal force; a wheel cylinder that operates using the hydraulic pressure generated by the master cylinder; a control valve that controls the pressure reduction; a passageway that causes inlet hydraulic pressure to act on the control valve so as to regulate the pressure reduction control of the outlet liquid pressure; and an openable/closable passage that operates to close the passageway to contain the inlet hydraulic pressure. In a brake fluid pressure control device having a solenoid valve, a deceleration detection means for detecting vehicle deceleration, a deceleration setting means for setting a target deceleration in advance, and a comparison between the target deceleration and the vehicle deceleration. and a comparison means for issuing an activation signal to the solenoid valve when the latter exceeds the former, and a comparison means provided in the passage to adjust the inlet liquid pressure to be contained in the passage in accordance with the activation delay of the solenoid valve with respect to the rate of increase in the inlet liquid pressure. A brake fluid pressure control device comprising a pressure increase sensing valve that regulates pressure increase.