JPS6137567A - Braking hydraulic pressure controller - Google Patents

Abstract

PURPOSE:To make braking force distribution approximate to an ideal, by regulating a boost of confined pressure caused by operating delay of a solenoid valve to be controlled by the desired braking hydraulic pressure set according to rear-wheel load, with a pressure bost sensor valve. CONSTITUTION:A pressure boost sensor valve 22 is set up in a passage 19 between a solenoid valve 21 and an enclosure chamber 57. Since a differential pressure valve body 83 of the said pressure boost sensor valve 22 receives set load of a spring 105 and thereby closes the passage 19, a rise of hydraulic pressure in the enclosure chamber 57 is delayed whereby a boost of inlet hydraulic pressure to be confined is regulated. Therefore, a hydraulic pressure setting device of a microcomputer 115 outputs a desired braking pressure signal Sc on the basis of front and rear-wheel load signals Sp1 and Sp2 out of each of detecting devices 71a and 71b. A comparing device 19 closes the solenoid valve 21 when inlet hydraulic pressure Pm of a hydraulic pressure detecting device 121 is larger than the desired hydraulic pressure. With the confined pressure gulated by the pressure boost sensor valve 22, the 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 fluid pressure control device used in a hydraulic brake system of an automobile.

(b) Technical Background and Problems A conventional two-brake hydraulic pressure i, IJ fil device is described in, for example, Japanese Patent Laid-Open No. 58-211952. This is a so-called non-linkage type port-sensing provisioning valve (non-linkage uLsPV).
), and the actuation start point (split point) of the proportioning valve (P valve) can be changed according to the load m. Therefore, as shown in Fig. 7, the actual brake force distribution between the front wheel brake force and the rear wheel brake force should be approximated to the ideal brake force distribution regardless of the vehicle's light weight depending on the load and vehicle weight m. I can do it.

However, in such conventional devices, the shift of the load toward the front wheels or the rear wheels is not considered (and is not considered).
Even with the same VAan, for example, if the load is biased towards the front wheels, the wheel load on the rear wheels will not correspond to the split point according to the load, causing early locking of the rear wheels and unstable driving. There was a fear of IO<. - (C) Purpose of the Invention This invention was devised in view of the above-mentioned problems, and provides a brake fluid pressure control device that can prevent early locking of the rear wheels even if the load is shifted toward the front or rear of the vehicle. For the purpose of providing.

2) Structure of the Invention In order to achieve the above object, the present invention comprises a master cylinder that generates hydraulic pressure in response to brake pedal force, and a wheel cylinder that operates by the hydraulic pressure generated by this master cylinder, as shown in FIG. and a control valve which is interposed between the master cylinder and the wheel cylinder and controls the pressure reduction of the outlet liquid pressure in response to the inlet liquid pressure, and a control valve which regulates the pressure reduction of the outlet liquid pressure. - a brake fluid pressure control device having a passageway for applying inlet fluid pressure to the brake fluid pressure control device and a freely openable solenoid valve that operates the passageway to contain the inlet fluid pressure; a load detecting means, a hydraulic pressure setting means for calculating a target brake hydraulic pressure according to the rear wheel load, a hydraulic pressure detecting means for detecting the inlet hydraulic pressure;
a comparison means for comparing the target brake fluid pressure and the inlet fluid pressure and issuing an activation signal to the solenoid valve when the latter exceeds the former; The structure includes a pressure increase sensing valve that regulates the pressure increase of the liquid pressure at the inlet to be sealed in the passage according to the activation delay of the solenoid valve. −
(E) Example - Below,
An embodiment of the present invention will be described in detail with reference to FIGS. 2 to 8.

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,
It has a first hydraulic pressure chamber 5 and a second hydraulic pressure chamber 7, and is configured so that equal hydraulic pressure is generated in both chambers 5 and 7 when the brake pedal 3 is operated. The first hydraulic pressure chamber 5 is connected to a front wheel cylinder 9 of a front wheel brake, and the second hydraulic pressure chamber 5 is connected to a rear wheel cylinder 11 of a multi-wheel brake via a proportioning valve (P valve) 13. There is. This P valve 13 has a control valve 17, a passage 19, and a solenoid valve 21 in the valve body 15.
and a pressure increase sensing valve 22.

The control valve 15 is configured to reduce the outlet hydraulic pressure pr in response to the inlet hydraulic pressure PH1, and has a plunger 23. The large diameter part of this plunge 1; 23 is the plug 2
1 is slidably fitted to a valve bore 27 having an inner diameter cross-sectional area A1 formed in 5, and the small diameter portion on the other end side of the plunger ν23 is a retainer 2 having an inner diameter cross-section 1t'iA2 smaller than the cross-sectional area A1.
9, and a first chamber 31 is formed. A valve body storage chamber 33 is formed in the axial center portion of the large diameter portion of the plunger 23, and a valve seat 35 is fitted into the opening side of the valve body storage chamber 33, and is connected to the back side of the valve chamber 27. A second chamber 3g is formed which communicates with an outlet boat 37 formed between the plugs 25. Further, a poppet valve body 41 is stored in the valve body storage chamber 33, and the poppet valve body 41 and the plunger 2
A first spring 43 is interposed between the poppet valve body 41 and the valve chamber 27, and is biased so that the poppet valve body 41 comes into contact with the inner side of the valve chamber 27. The valve body storage chamber 33 communicates with the first through hole 31 through a first through hole 45 formed on the small diameter side of the plunger 23, and communicates with the surroundings of the plug 25 through a hole 47 formed at the tip of the plug. The third chamber 49 is formed in the third chamber 49. This third chamber 49 is communicated with the hero box 1-55 via a first communication hole 51 and a second communication hole 53.

The passage 19 is connected to the inlet hydraulic pressure PI so as to control the pressure reduction of the outlet hydraulic pressure PR by the control valve 17.
One end is connected to the inlet boat 55 via the pressure increase sensing valve 22, and the Il! ! It has a containment chamber 57 on the end side. A containment cavity 57 is formed in the plug 59 and is exposed to one end of the response piston 61. The response piston 61 is similarly supported by the plug 59 so as to be movable by 1M, and the other end of the response piston 61 is exposed into a spring storage chamber 63 formed in the valve body 15. A spring receiving plate 65 that is in contact with the response piston 61 is slidably fitted into this spring housing v63, and a second spring 67 is interposed between this spring receiving plate 65 and the valve body 15. There is. On the other hand, the small diameter portion on the other end side of the flange 23 of the control valve 17 is also exposed into the spring storage chamber 63, and a frame 69 is attached to the spring receiver, and between the spring receiver U frame 69 and the spring receiver plate 65, A third spring 70 is interposed to apply a set load to the plunger +723.

The solenoid valve 21 operates to close the passage 19 to confine the inlet hydraulic pressure pm in the containment chamber 51 and comes into contact with the valve seat 71 formed in one passage. ! It has a valve body 73 that can be rotated in one direction, and a solenoid 75 that drives the valve body 73.

The back pressure sensing valve 22 is interposed in the passage 19 between the solenoid valve 21 and the containment chamber 57, and is sealed in the passage 19 according to the activation delay of the solenoid valve 21 with respect to the pressure increase rate vp of the inlet hydraulic pressure pm. Should inlet fluid pressure p
It regulates the increase in pressure of m, and consists of a differential pressure valve part 77 and seven sensing parts.

The differential pressure valve portion 77 is a differential pressure valve body 8 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.
It has 3. 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 9-1 made of an elastic material is attached within the recess 89 to restrict the flow from the fourth portion 89 to the second through hole 87.

Before&! The sensing portion 79 is located between the first communication hole 51 and the 231st! It has a sensing body 95 that is slidably fitted into a sensing portion 93 formed between the through hole 53 and the sensing portion 93 . And this sensor 9
5, the sensing chamber 93 is divided into a first sensing chamber 97 on the first communication hole 51 side and a second sensing chamber 99 on the second communication hole 53 side. Also, sensing (4j 95 has a first sensing chamber 97
An orifice 101 is formed that communicates between the first sensing chamber 99 and the second sensing chamber 99 . l III
A bimetal 103 is arranged. This bimetal 103 has an orifice 10 depending on the fg U Jm field.
It is configured to narrow the exit side opening of No. 1. Small diameter portions 95a, 9 are provided at both axial ends of the sensing body 95.
5b is formed. One of the small diameter portions 95a is fitted into the differential pressure valve chamber 81, and a fourth spring 105 is interposed between the small diameter portion 95a and the differential pressure valve body 83, which can change the load set on the differential pressure valve body 83. It is set up. The other small diameter portion 95b is fitted into a support hole 109 formed in the plug 107 and communicating with the passage 19 so as to be movable by 1'8. A through hole 111 is formed in the core of the sensing body 95 to communicate the differential pressure valve chamber 81 with the support hole 109.

On the other hand, a wheel load detection means 113 is attached to the vehicle, and this wheel load detection means 113 is attached to the front wheel load detection means 1.
13a, contact wheel load detection means 113b, and the like. The front wheel load detection means 113a detects the front wheel load aWa and sends a front wheel load signal St)+ to the microcomputer 115.
It has been superacidized so as to output
13b is configured to detect the rear wheel load Wb and similarly output a rear wheel load signal 3112 to the microcomputer 115. This microcomputer 115 incorporates a hydraulic pressure setting means 117 and a comparison means 119. The microphone 0 computer 115 is also configured to receive an inlet hydraulic pressure signal SG from a liquid juice detecting means 121 which detects and outputs the inlet hydraulic pressure Pl.

The hydraulic pressure setting means 117 is connected to the third line segment P or the fourth line segment P in the figure.
The target brake hydraulic pressure Pi is calculated based on a fixed functional relationship shown by the line segment Q in the figure, and a target brake hydraulic pressure signal 3c is output. The functional relationship represented by the line segment P in FIG. 3 is set according to the vehicle-picture weight W depending on the loading condition. The functional relationship represented by the line segment Q in Figure 4 is
(It is set according to W b. This applies to the case of front loading where the same medium vehicle q1W has the load b shifted to the front wheel side, as shown in Figure 5, and the case of reverse loading. This is because the front wheel cart Wa and the rear wheel direction IWb change.Also, a plurality of line segments Q in Fig. 4 are set for each vehicle weight, for example, line segment Q1 is for light vehicle weight, and line segment 02 is for heavy vehicle weight. This shows the case of weight.This shows that even if the rear wheels are the same?niΦWb,
This is because if the vehicle weight is heavy, there may be no rear loading r:. The comparison means 119 compares the target brake fluid pressure signal 3
．． Target brake fluid rc p from c and inlet fluid pressure signal SG
+ and the inlet hydraulic pressure Pm, and when the latter exceeds the former, an actuation SQ is issued, and this actuation signal SG is input to the drive circuit -123. 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 1 [
The controller operates according to the flow rate shown in FIG. First, step Sr is executed and 1) r1 heavy load W
a and rear wheel load wb are read. This reading is performed by the front wheel load detecting means 113a and the rear wheel load detecting means 113b.
This is performed based on the front wheel load signal SD+ and the rear wheel load signal 5D-2, which are input to the front wheel load signal SD+ and the rear wheel load signal 5D-2.

In step S2, the vehicle weight W is calculated from the front wheel load Wa and rear wheel load wb read in step S1.

In step S3, the vehicle weight W calculated in step S2 and the rear wheel direction read in step S1! Based on the relationship with Wb, it is determined whether the load is skewed according to the preset relationship shown in Figure 5, and if it is detected that the load is not skewed, the map shown by the line segment P in Figure 3 is read. If the vehicle is off-center, the map shown by line segments Q+, 02, etc. in FIG. 4 is read in accordance with the weight of the vehicle.

In step S4, a target brake fluid pressure Pi for starting the operation of the control valve 17 is calculated. The calculation in step S4 is performed by the hydraulic pressure setting means 117.
When the map of the line segment P in Figure 3 is read in step S3, the intersection point PiI or P on the side 1h in Figure 3 is determined according to the vehicle weights W1 and W2 calculated in step $2. :2'8. Step S
3, if the maps of line segments Q+, 02, etc. in FIG. 4 are read, the intersection points Pi3, Pi on the horizontal axis in FIG. 4? 19 as 7. Therefore, in the case of the map shown in line segment 1 in Fig. 3, the target brake fluid pressure Pi is obtained according to the vehicle weight W, and in the case of the map shown in line segments Q+ and Q2 in Fig. A corresponding target brake fluid pressure Pi can be obtained. In addition, in the case of the map of line segments Q+ and Q2 in Figure 4, the same - rear wheel load wb
Even if the vehicle is heavy (Φ) and heavy (W2), the target brake fluid pressure P13 will be lower than that for the light vehicle weight (W1), and even if the vehicle has the same - medium and heavy weight (ΔW), the rear wheel - (M) weight (Wl) will be lower than that for the light vehicle weight (W1). If it is lower, f[t
The target brake fluid pressure Pi1 is set to 17. The target play 1 hydraulic pressure PI calculated by the hydraulic pressure setting means 117 is sent to the comparing means 119 as a target brake hydraulic pressure signal 3c.

Next, in step S5, the inlet hydraulic pressure Pm is read from the inlet hydraulic pressure signal SG detected and input by the hydraulic pressure detection means 121. .

In step So, the comparison means 119 compares the target brake fluid pressure Pi and the inlet fluid pressure Pm. Since the inlet hydraulic pressure Pn+ is low at the beginning of depression of the brake pedal 5, it is determined that the inlet hydraulic pressure PI11 is lower than the target brake hydraulic pressure Pi, and the activation signal SQ to the Truenor door 5 is not issued in step S7.1. Therefore, in step S8, the solenoid valve 21 is kept OFF,
One passage is in communication. Therefore, when the brake pedal 3 is depressed, the hydraulic pressure generated in the master cylinder 1 is supplied from the first hydraulic pressure point 5 to the front wheel cylinder 9, and from the second a pressure point 7 to the inlet boat 55 of the P valve 13, Second communication hole 53,': J2 sensing chamber 99, orifice 101, first sensing chamber 97, first communication hole 51,
Third chamber 49, groove 47, first passage 45, valve body storage chamber 43,
Between the poppet valve body 41 and the valve seat 35, the valve is supplied to the A7 wheel cylinder 11 through the second chamber 39 and the outlet port 37. , so Clll11 stage wheel play-1 outlet as hydraulic pressure; 112 pressure pr is initially master cylinder liquid J
According to the reading of the above map, if there is no bias in the circulation, either a-b (light weight ωW1) or a-d (light weight ωW1) or a-d (light weight W
2) It rises with the characteristics shown in etc. , when the cargo is on one side, it rises with 31 characteristics as shown by (, 1, Figure 8 a-1) (front ramming) or a-d (back ramming), etc. During this time, Mask Schilling liquid j as King The inlet hydraulic pressure pm also reaches the containment chamber 57 via the passage 111.

Enter the column [1 hydraulic pressure pi passes through the passage 19 and enters the containment palm 5
7, the differential pressure valve body 83
0 set 1 IfW "Since the passage 19 is blocked by 111 while receiving the liquid, the liquid 1 in the containment chamber 57 rises at the time shown in FIG. 3 11 or T2 1) ν."
The inlet liquid pressure pm to be contained in the first containment chamber 57 is regulated. This effect will be explained when the map shown by line segment P in Figure 3 is selected, but in Figure 4, line segment Q
The same applies to the map in which the map indicated by + and Q2 is selected.

The time T1 is Vll+ when the brake pedal 3 is suddenly depressed lυ and the pressure increase rate Vp of the inlet fluid pressure P111 is suddenly increased as shown by the line segment R, and T2 is the relatively mW pressure shown by the line segment R. The case is that of VD2.

That is, in the case of sudden pressure increase, the orifice 1 of the differential pressure valve body 83
Due to the action of 01, the force difference between the first sensing chamber 97 and the second sensing chamber 99 increases, and the differential pressure valve body 83
7 side, and the fourth spring 105 is compressed. Therefore, the set load F applied to the differential pressure valve body 83 is increased. When time T1 or T2 elapses and the inlet hydraulic pressure Pa rises to the operating pressure of the differential pressure valve body 83 determined by the set load fJF of the fourth spring 105, the differential pressure valve body 83 resists the fourth spring 105 and 1 movement to the left in the figure, 8[1
The hydraulic pressure pm reaches the containment chamber 57 through the groove 85, the differential pressure valve palm 81, the through hole 111, the support hole 109, and one passage. 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 applies the fourth spring 105.
%) to return to the closed position. By repeating these actions, a hydraulic pressure pml expressed by the following equation is supplied to the containment 7,557. .

As is clear from this equation, the hydraulic pressure pm1 supplied to the containment chamber 57 becomes a value lower than the inlet hydraulic pressure pm depending on the set I-ΦF of the fourth spring 105. This relationship is the third
In the figure, the inlet hydraulic pressure P1 is 1.0 as shown by the line segment m with respect to the line segment of the rapid back pressure velocity Vll+. Similarly, the artificial fluid pressure pm has a pressure increase rate as shown by the line segment n with respect to the line segment R of the slow pressure velocity VD2.

Next, the depression force on the brake pedal 3 increases, and in step Sa, the inlet hydraulic pressure pm changes to the target play 4 hydraulic pressure Pie (medium amount W
+) or Piz (ΦωW2) once, the size is 117i
Then, the operation signal SO of the solenoid 75 is outputted to the drive circuit 123 in step S9.

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 S9. Therefore, the valve body 73 of the solenoid valve 21 is attached to and removed from the valve seat 71, and the passage 1
9 is closed. When the passage 19 is opened, the hydraulic pressure pn+1 that has been acting on the containment shaft 53 until then is contained as a containment hydraulic pressure PG+ or PO2, etc., and this containment hydraulic pressure PG is applied via the response piston 61 and the spring receiving plate 65. The second spring 63 and the third spring 70 are compressed, and the set load of the third spring 70 is determined. In this case, there is a response delay of time 1 from when the actuation signal SQ is issued to the solenoid valve 21 until the solenoid valve 21 turns ON, as shown in FIG. however,
As described above, the pressure sensing valve 22 regulates the increase in the fluid pressure in the containment chamber 57 according to the back pressure speed of the inlet fluid JT:PIII, so when the solenoid valve 21 is turned on, the containment fluid pressure PGI Or PO2 is the target brake fluid pressure Pi
1 or Piz can be avoided. In this way, after the target brake hydraulic pressure Pi and (↑1 injection hydraulic pressure PG that coincided by 1) are contained in the containment chamber 57, the artificial hydraulic pressure pm increases further by 51? Plunge 23 is the third based on A2.
IS8 to the left in Figure 2 so as to resist the spring. Due to this sliding of the plunge t-23, the poppet valve body 41 is seated on the valve seat 35, and communication between the inlet boat 55 and the outlet boat 37 is cut off. At this time, the inlet hydraulic pressure 1]m continues to be supplied to the first chamber 31, and the hydraulic pressure in the first chamber 31 increases, causing the plunger 1123 to again slide to the right in FIG.
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 V-wheel cylinder 11
The rear wheel brake fluid pressure Pr to the split point Pi1 or Pi which is Iff when the load is not biased.
After 2, Fig. 7 b-c (light/heavy ii! W+) or d-c is applied to the master cylinder hydraulic pressure Pm depending on the vehicle weight W.
(Juju rilW2) etc. as shown < 1111 lit
However, after the split point hPi3 or l) + 4 obtained when the load is biased, depending on the rear wheel load wb, Fig. 8 b-c (front loading) or de As shown in (Last loading), etc., it is lifted up while being controlled. Therefore, the front and rear wheel braking force distribution characteristics are shown in Figure 7a-
b-c (light/heavy fitW+) a-d-e (Ri
The ideal braking force distribution can be approximated to be as follows: (weight/weight ilW2), or a-b-c (front load), or a-d-e (I top load) in FIG. For this reason,
Even if the load is shifted toward the front or rear wheels, the inlet fluid pressure Pm may change depending on the degree of depression of the brake pedal 3.
Even if the pressure increase rate Vp changes, by setting the target brake fluid pressure 1]i, which is the split point, to 1u accordingly, it is possible to prevent early locking of the rear wheels or early locking of the front wheels.

When the brake pedal 3 is depressed by 1 step, the inlet fluid pressure pm
disappears. Therefore, a pressure difference is generated between the differential pressure valve chamber 81 and the recess 89, and the containment hydraulic pressure PG is at full 85, and the second through hole 87
through the inlet port 55 while pushing away the check seal 91.
It is removed to the side and prepared for the next operation. Also, sensing rest 95
Bimetal 103 (Yo'&4)
The present invention is not limited to the embodiments described in -1.

It is also possible to perform the control by detecting only W11 of the rear wheels 61.

(F) Effects of the Invention As is clear, according to the configuration of the present invention, the target brake fluid 11 is stopped depending on at least the rear wheel load, and the -C control 21I is performed based on this 11 target brake fluid pressure. Rir. J, -), it is possible to prevent the rear wheels from locking early even if the load is biased towards both front and rear sides. Moreover, the back pressure of the inlet fluid pressure to be contained in the passage is regulated by the field pressure sensing valve according to the activation delay of the solenoid valve with respect to the inlet fluid pressure gal speed, so the ideal brake Approximation characteristics for force distribution can be improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of the present invention, FIG. 2 is an overall diagram of a brake fluid pressure control device according to an embodiment of the present invention, and FIG.
Figure 4 is a control characteristic diagram, Figure 5 is a characteristic diagram that does not show the deviation of the V4 load, Figure 6 is a 70-dipt, Figure 7, 8
The figure is a brake fluid pressure characteristic diagram. 1... Master cylinder 11... 917 Wheel cylinder (wheel cylinder) 17... Control valve 19... Passage 21... Solenoid valve 22... Back pressure sensing valve 113... Wheel tilting Φ detection Means 117... Hydraulic pressure setting means 119... Comparing means 121... Hydraulic pressure detecting means "'=Bt Fig. 7 Fig. 8

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. A brake fluid pressure control device having a solenoid valve comprising at least a wheel load detection means for detecting a rear wheel load, a fluid pressure setting means for calculating a target brake fluid pressure according to the rear wheel load, and the inlet fluid pressure. a hydraulic pressure detecting means for detecting the target brake hydraulic pressure and the inlet hydraulic pressure, and a comparing means for generating an activation signal to the solenoid valve when the latter exceeds the former; A brake fluid pressure control device comprising: a pressure increase sensing valve that regulates the increase in inlet fluid pressure to be confined in a passage in accordance with a delay in activation of the solenoid valve with respect to a fluid pressure increase rate.