JPS58211952A - Deceleration sensing type hydraulic control valve - Google Patents

Abstract

PURPOSE:To optimize the cirtical hydraulic pressure during sudden braking when a car is idled and loaded by providing piston that receives the force of large and small two springs in an enclosure room that receives the pressure corresponding to a loaded load. CONSTITUTION:A solenoid 31 is operated by a deceleration sensor 35 and encloses the pressure that corresponds to a loaded load in an enclosure room 22 and a stepped room 9 by permitting a plunger 30 to close a path 1j. A piston 21 is provided in the enclosure room 22 and receives the force of a relatively weak spring 25 and then engages with a relatively strong spring 27 by its regression. A hydraulic control plunger 2 controls the hydraluic pressure of a rear wheel brake 41 by the pressure of the stepped room 9 and a rear wheel brake 40 interlocks with the rear wheel brake 41 through a valve 4. Since the piston 21 that receives spring force in the enclosure room 2 like this, optimum hydraulic pressure control can be performed without varying the critical hydraulic pressure during sudden braking.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is used in hydraulic brake systems of automobiles, etc., and is used to increase outlet hydraulic pressure (master cylinder hydraulic pressure) in response to an increase in inlet hydraulic pressure (master cylinder hydraulic pressure).
This is a hydraulic pressure control valve for restricting the increase in rear wheel brake fluid pressure, especially a deceleration-sensing hydraulic pressure control valve whose method of restriction changes to the optimum value (for each vehicle weight). be.

A car's hydraulic braking system brakes all five front and rear wheels at the same time, but if the rear wheels lock at the same time, the car skids, causing the car to tremble. This is more dangerous than if the front wheels locked up first.

Therefore, considering the fact that the rear wheels are more likely to lock up than the front wheels, since the weight of the rear wheels decreases as the vehicle load moves forward during braking, the front wheel brake fluid pressure (master cylinder fluid pressure) is increased. On the other hand, a hydraulic pressure control valve that limits the increase in rear wheel brake fluid pressure is inserted into the rear wheel brake system.

This hydraulic pressure control valve can be used as a global portioning valve, a limiting valve, etc., which responds to the inlet hydraulic pressure and controls the outlet hydraulic pressure while limiting the inlet hydraulic pressure. These valves are known as the hydraulic pressure (critical hydraulic pressure) when any valve starts to limit the increase in rear wheel brake fluid pressure.
remains unchanged, and the front and rear wheel brake force distribution characteristics are constant. However.

The ideal front and rear wheel brake force distribution characteristics that allow the front and rear wheels to lock simultaneously change as the vehicle weight changes, and the critical hydraulic pressure needs to be increased as the vehicle weight increases. In this sense, the above-mentioned valve is unsuitable for trucks and the like where the vehicle weight changes greatly between when the vehicle is empty and when it is loaded.

For this reason, when the deceleration exceeds a certain level, a valve (usually a G valve and a closed valve) compresses the spring via a piston using a containment pressure corresponding to the certain deceleration (which increases as the weight of the vehicle increases) at the reaction port. ) has been proposed in combination with the above-mentioned valve, thereby making it possible to increase the above-mentioned critical hydraulic pressure in accordance with an increase in vehicle weight.

This type of hydraulic pressure control valve has front and rear wheel brake force (hydraulic pressure) distribution characteristics as shown in a-b-c in Fig. 2 when the car is empty, and as shown in a-d-e in the figure when the car is loaded. The idea was to control the rear wheel brake fluid pressure so that the distribution of brake force between the front and rear wheels would be close to ideal under any vehicle weight. When braking is performed by rapidly stepping on the brake pedal, the occurrence of vehicle deceleration tends to be delayed.The G valve that responds to this deceleration also has a delay in response, so the stabilization pressure does not correspond to the vehicle iiiilliMIit and becomes high. Pass. Therefore, in such an empty state, the piston does not move, and the critical fluid pressure rises to point f, where the critical fluid pressure P6□ should originally be generated at the point determined by the set load of the spring. First, the front and rear wheel brake force distribution characteristics are close to ideal, and from a-b-c to a'
-f-g.

For this reason, conventionally, an orifice is provided in the passage for the hydraulic pressure (usually master cylinder hydraulic pressure) that goes to the G valve and is the source of the confinement pressure. Efforts were made to prevent this from happening, but
In this case, during sudden braking with a loaded vehicle, the orifice prevents the containment pressure from passing through and increasing the potash 2 pressure, and during this time the G valve closes in response to vehicle deceleration, so the containment pressure does not correspond to the weight of the vehicle. , too low. Therefore, in this case, the movement ItL of the piston (the amount of compression of the spring) is insufficient,
Normally, critical fluid pressure "sst" should be generated at point d, but critical fluid pressure is generated at point d, and the front and rear wheel brake force distribution characteristics change from a-de-e, which is close to the ideal, to a-h-1. It will fade.

The present invention provides a piston that responds to containment hydraulic pressure, and constantly presses the piston with a spring having a relatively low spring constant.
At the same time, when the piston is pressed by a predetermined amount or more by the containment liquid pressure, it engages with a spring having a relatively high spring constant and is also pressed by the spring, so that the containment effect is such that the inlet liquid pressure is cut off. By moving the hydraulic pressure control two plunger to the valve-closing direction and increasing the containment hydraulic pressure after the piston is operated, the piston can be operated when the vehicle is empty without using the orifice. By controlling only the spring with a relatively low spring constant, it is possible to prevent the critical fluid pressure from becoming too high even during sudden braking, and when driving sideways, the piston can be controlled by the spring with a relatively high spring constant. By controlling both the above-mentioned spring with a relatively low spring constant, the critical hydraulic pressure is low even during sudden braking, and it is possible to prevent excessive rotation, making it suitable for any vehicle! [From the viewpoint that the rear wheel brake fluid pressure can be controlled so as to obtain close to ideal front and rear brake force distribution characteristics under any braking speed and any braking speed, the above problem can be solved. It is an object of the present invention to provide a deceleration sensing type hydraulic control valve that embodies the ideal. By giving 'e, a difference corresponding to the above set 07i' is created between the critical hydraulic pressure when the vehicle is empty and the critical hydraulic pressure when the vehicle is sideways, increasing the rear wheel brake fluid pressure when the vehicle is ramming, and further The present invention aims to provide a deceleration sensing type hydraulic pressure control valve that can obtain characteristics that more closely match front and rear wheel brake force distribution characteristics that are close to ideal for a vehicle.

Hereinafter, the present invention will be described in detail based on the illustrated embodiments. Figure 1 shows an example configuration in which the deceleration sensing type hydraulic pressure control valve of the present invention is configured for use in two systems. A stepped through hole consisting of a hole 1a, a medium diameter hole 1c+, and a large diameter hole 1c, and a stepped through hole consisting of a small diameter hole 1 (1) and a large diameter hole le at a position approximately parallel to the stepped through hole. A hole is formed.

(1) The langeer 2 is slidably fitted into the medium diameter hole lb of the stepped through hole, and the valve holder 4 is also slidably fitted into the hole lc. room 6 between
Define.

In addition, the part of 1 langier 2 that fits into the small diameter hole la is
This small diameter portion 2a is formed in a small diameter portion 2a, and this small diameter portion 2a is slidably fitted into the inner peripheral surface of a ring 8 whose outer periphery is fitted into the small diameter hole 1a. A stepped chamber 9 is defined between lb and lb.

ifc, the H port end 2 of the hole 1a and the open end of the hole IC are each closed by a plug 7.8, and the plug 7 and the plunger 2 are closed.
A chamber 5 is defined therebetween.

A through hole 2b extending from the end surface of the plunger 2 facing the chamber 5 to the end surface 1 of the plunger 2 facing the chamber 6 side is provided. The poppet valve l is biased towards valve closing by screw 10.
l'5: The valve seat 12 for this valve body 11 is placed in the chamber 5.
It fits onto the end face of the two-runger 2 facing the front.

The end of the valve body 11 far from the valve stem lla is slidably fitted into the lug 7 to guide the valve body 11, and a spring 18 is compressed between the plug 7 and the valve seat 12. do.

Attach the valve stem ll of the poppet valve body 11 to the valve holder 4.
a to move the valve body 11 to the open position 7Z.The free piston 14 is slidably fitted to define i15, and a blind hole 4a opening into this chamber is formed in the valve holder 4.

Inside the straight hole 4a is a spring 10. Place the poppet valve body 11 and the valve seat 12 and the poppet valve body lx' and the valve seat 12' of the spring I O', and the valve stem l of the poppet valve body 11'.
1a against the end face of the free piston 14 far from the valve body 11 to set the valve body 11' to the open position O. Fit the small diameter end 4b of the valve holder 4, which is close to the plug 8, into the plug 8 so that it can slide freely. A hole 4c is formed in the valve holder 4 to define a chamber 16, and the bottom of the blind hole 4a communicates with this chamber.
Provided for.

The plug 8 further includes a liquid press port 1 communicating with the chamber 16.
7"fr: formed, the valve body 1 further includes a hydraulic inlet port) 18 communicating with the chamber 5 via a passage xf, a hydraulic outlet port ) 19 communicating with the chamber 15, and a hydraulic outlet port communicating with the chamber 6. 20
to form.

Insert the piston 21 into the small diameter hole xd on the stepped hole side.
is slidably fitted to form the chamber 22, and the washer 28 is fitted to the stepped part 210 formed by making the shaft part 21a of the piston 21 exposed in the large diameter hole le into the small diameter part 21b. A relatively weak spring 25 is installed between the plug 24 that closes the open end of the large diameter hole 1e and the washer 28, and a washer 25 is installed between the two lug 24 and the bottom of the large diameter hole 1e. 26 and a relatively strong spring 27
The movement of the piston 21 toward the plug 24 side is constantly restricted by a relatively weak spring 25, and when the piston moves more than a predetermined amount, a washer 26 is attached to the stepped portion 21d between the piston 21 and the shaft portion 21a. The movement of the piston 21 is also controlled by the relatively strong spring 27. Therefore, the confinement pressure P. The relationship between this and the splash load F is shown in Fig. 8, where the 〇 chamber 22, which has the characteristics of op-q-r-s, is communicated with the stepped chamber 9 through the passage 11, and the passage wJlf is connected through one passage lj. Connect to the middle part of. Another hole lk is opened in the middle part, and the solenoid plunger 30 is inserted into the hole lk, and when the solenoid plunger 80 protrudes by the solenoid coil 81, the passage h tj is cut off from the passage Mlf. It shall be possible.

Then, the solenoid coil 31 is connected to %LLaB5 through the normally open contact 82a of the relay 32, and the relay 32
The coil 82bk of the transistor 84 is connected to the power supply 88 through the collector emitter path. Further, the base of the transistor 34 is connected to a power source 88 via a deceleration detection sensor 85 that detects vehicle deceleration and closes.

The deceleration sensing type hydraulic pressure control valve of the present invention having the above-mentioned configuration, the inlet boat 17 is connected to one hydraulic outlet of the tandem master cylinder 88 together with the wheel cylinder 37 of the left front wheel, and the inlet boat 18 is connected to the wheel cylinder of the right front wheel. 89 and the other hydraulic pressure outlet of the tandem master cylinder 88, the outlet boat 19 is connected to the wheel cylinder 40 of the right rear wheel, and the outlet port 20 is connected to the wheel cylinder 41 of the left rear wheel. is practical and works as follows.

Normally, the deceleration detection sensor 85 is kept open, and the voltage of the power supply 88 is not applied to the base of the transistor 84.
Transistor 84 is in the off state I! and relay coil 8
2b is not energized and relay contact 82a is open. Therefore, the solenoid coil 31 is energized only once.
Often, the solenoid two plunger 30 is in the retracted position,
Connecting HL to 1 If.

Here, when the master cylinder 88 is actuated by depressing the brake pedal 42, both hydraulic pressures of the master cylinder (0 force) are simultaneously changed to the same value of the master cylinder hydraulic pressure Pm.
is output. These master cylinder hydraulic pressures Pmtlf
lJ wheel cylinder 87.89 always has 1"1
, and the rear wheel cylinder 4° has an il from the boat 17.
6. Hole 4C%1ii Hole 4a, valve body 11' and valve seat 1
2' gap, the chamber 15 and the boat 19'ft as originally, and the rear wheel cylinder 41 has the boat 1
8 through Mlf, g5, the gap between the valve body 11 and the valve seat 12, the gap between the through hole 2b and the valve stem lla, the chamber 6 and the bow) 20, and is initially supplied with that '1''. The rear wheel brake fluid pressure toward the wheel cylinders 40 and 41 is equal to the initial master cylinder fluid pressure (front wheel brake fluid pressure) Pm, and increases with the characteristics shown by a-b in FIG. 2. By the way, from the boat 18 The master cylinder hydraulic pressure pm reaches the chamber 22 through the passages klf and 1j-X-, and further reaches the stage 9 through the passage -11.

Therefore, the balance equation of the force acting on the plunger 2 at this time is: the cross-sectional area 2A□ of one plunger 2 that fits into the medium-diameter hole 1b of the stepped through-hole, the cross-sectional area of the small diameter portion 2a of the plunger 2 A
2. The spring force of the spring 1δ is expressed by the following equation, assuming that the hydraulic pressure (containment pressure to be described later) in the stepped chamber 9 is Po (Po−Pm in the above state).

PO・(A□−A2)+f>PIN・(A□−A,)・
・・・・・・・・・・・・(1) Even if the master cylinder hydraulic pressure pm increases due to further depression of the brake pedal 42,
In the case of PO-pm, one lancia 2 is positioned upward in the figure by the spring 18.

During the above-mentioned braking, when the vehicle deceleration exceeds a certain value, this is detected and the deceleration detection sensor 85 is closed.
As a result, the base relay coil 32 of the transistor 84
1), relay contact 82a closes. ,,
), t9tsi, 1. E8 □. 1 source, 8 is energized to project solenoid 1 lunge 8o, 1 cup 1j
is cut off from passage xf. Thus, room 221-dori cormorant 1i,
The master cylinder hydraulic pressure when the vehicle deceleration of the above-mentioned constant value occurs is contained in the stepped chamber 9, and this containment pressure po is determined by the force expressed by the pressure receiving area (A, -12) of the 1 langeer 2. Spring 18 moves the plunger 2 upward in FIG.
Trying to move along with it. At the same time, the containment hydraulic pressure p
o acts to push the piston 21 upward as well.

Incidentally, even though the same deceleration occurs, the brake pedal depression force (master cylinder hydraulic pressure Pm) for this purpose increases as the vehicle weight becomes heavier, and therefore corresponds to the above-mentioned containment pressure PoFi vehicle weight.

However, when the vehicle weight is light, such as when the vehicle is empty, the interior
The confinement pressure inside the piston 21F is relatively strong.
How many times F(
), and the stepped portion 2 of the shaft portion 21a of the piston 21
The washer 28 seated on the washer 11 is placed at a position slightly apart from the washer 26.

From this point on, when the brake pedal 42 is further depressed and the master cylinder hydraulic pressure Pm increases, the value of the eclipse in the equation (1) increases, and as it moves forward, the spring 1
3, the valve body 11 moves downward in the figure, and finally the valve body 11 touches the valve seat 12.
Self-closes by sitting on.

This downward movement of the two plunger 2 in the figure acts to compress the liquid in the stepped chamber 9, sends the containment liquid in the stepped chamber 9 to the chamber 22 through the passage 1, and moves the piston 21 upward. (0'-pI-q/-rI-6 indicated by am in Figure 8)
1 shows the spring load characteristic 2 when the plunger is activated) is the spring 2 that presses the stepped portion 21C of the shaft portion 21a of the piston 21.
5 uses one with a relatively low spring constant, so it is
Since the second load fiF rises only by a portion corresponding to the difference between F and -1i'□, it can be said that it almost rises.

From this point on, the rear wheel brake fluid pressure PR applied to the wheel cylinder 41 is restricted from increasing as shown below.
The hydraulic pressure at this time, that is, the critical hydraulic pressure Ps (see Figure 2), can be expressed as O Here, AH is the master cylinder hydraulic pressure Pm when the poppet valve body 11 self-closes by the cross-sectional area of the piston 21! , in the chamber 5, the force PmA pushes the first lange 2 in the opposite direction, that is, upward in the figure, and the rear wheel brake fluid pressure pr in the chamber 6 exerts a downward force PrA1 on the first lange 2 in the figure. Opposed to O where Pm2Ps
When the brake pedal 42 is further depressed so that □ and 7j are pressed, the force of the master cylinder fluid [EPm, together with the spring force F of the splash 18, etc., causes the 1-lunger 2 to rise in the figure, and the valve body 11 is opened again. As a result, the rear wheel brake fluid pressure pr applied to the wheel cylinder 41 increases as the master cylinder fluid pressure Pm is replenished, but as the valve body 11 opens, the master cylinder fluid pressure Pm again pushes the two plunger 2 downward in the figure. As a result of operation 7, the valve body 11 immediately closes itself (O force) By repeating this action, the rear wheel brake hydraulic pressure PrH increases while being limited with respect to the increase in the master cylinder hydraulic pressure Pm.

During this period, that is, during prn > ps□, the balance equation of the force acting on the 1 plunger 2 is found.As is clear from the above, from this equation, the rear wheel brake fluid pressure toward the wheel cylinder 41 is Pr is expressed by the following formula.

As is clear from this equation, when pm = ps□, the rear wheel cylinder hydraulic pressure Pr has an upward slope l of (a-b in Fig. 2) in this case, as shown by J- in Fig. 2. can.

On the other hand, the opening and closing of the valve body 11 due to the above-mentioned operation of the plunger 2 is transmitted to the valve body 11' via the free piston 14F, and this valve body 11' also opens and closes simultaneously and in the same manner. Therefore, the rear wheel brake fluid pressure Pr toward the wheel cylinder 40
It is also controlled by the rear wheel brake fluid pressure surrounding the wheel cylinder 41.

Therefore, the brake fluid pressure Pr of both rear wheels is controlled by the above-mentioned action so that the front and rear wheel brake force distribution characteristics approximate the ideal characteristics when the car is empty and become a-J- in Fig. 2, so that the rear wheels are placed first. It can prevent the danger of locking.

On the other hand, the weight of the vehicle increases due to the loading of vehicles, and as a result
2. As the confinement pressure in p increases, this confinement pressure moves the piston 21 to gradually compress the relatively strong spring 27, and the spring force F of the spring 25 and 27 increases as the vehicle weight increases. For example, if fluid pressure is confined in the chambers 22 and 9 at F8, then when the valve is closed due to the downward movement of the plunger 2 in the figure, the chamber The sealing liquid in 9 flows into the container 22,
The piston 21 is further pushed upward in the figure to obtain an even higher confinement pressure determined by the splash frame F4 in FIG. The pressure increases further, and a horizontal vehicle state occurs at Ps in Fig. 2.

It is inferior to Ps2 from , and also the above-mentioned (
4) The rear wheel brake fluid pressure pr determined as shown in the equation is controlled as shown by /-m in Figure 2, and the front and rear brake force distribution characteristics in the loaded state are close to ideal characteristics as shown in Figure 2. Middle a-7
- m can be used to prevent the rear wheels from locking first.

In the above-mentioned embodiment, the spring 18 is applied to the plunger 2 in the valve opening direction, but this spring 181'i is simply for positioning the plunger 2. Yes, a very small spring constant and set load is sufficient, and in some cases it may be unnecessary.

Furthermore, in the above embodiment, the configuration of the deceleration detection section is as follows:
Although the explanation was given using a deceleration detection sensor 85, a sphere as seen in Japanese Patent Publication No. 47-46297 was used to isolate the containment chamber from artificial fluid pressure by using this sphere and a valve that closed when the sphere moved. It can also be applied to deceleration sensing type hydraulic control valves with a fixed orifice at the chamber inlet.
In this case, in FIG. 2, the characteristics of a-j- when the car is empty and a-l'-m' when the car is loaded can be obtained. That is, the pressure between points b and co when the car is empty and between points h and z' when the car is loaded is the part where the pressure is increased.

As explained above, in the present invention, a piston is provided that responds to the hydraulic pressure within the containment chamber, and the piston is directed toward the containment chamber with a relatively low spring constant.

At the same time, when the piston is pressed by a predetermined amount or more due to the liquid pressure in the containment chamber, it engages a spring with a relatively high spring constant and is also pressed by the spring, so that the containment chamber is closed to the entrance. After being cut off from the hydraulic pressure, the pressure is increased by moving the containment hydraulic pressure 2 and the hydraulic pressure control 1 plunger in the valve opening direction, so when the piston is empty, the piston can be moved only by a spring with a relatively low spring constant. The piston can be controlled to prevent the critical hydraulic pressure from becoming too high during sudden braking, and the piston can also be controlled by a spring with a relatively high splash constant when the vehicle is sideways, so that the critical hydraulic pressure does not increase during sudden braking. ix, it can prevent it from slipping. Furthermore, in the present invention, by applying a set load to the springs having a relatively high spring constant, the critical hydraulic pressure at the time of loading a vehicle can be made higher.

Therefore, the deceleration-sensing hydraulic pressure control valve of the present invention can accurately perform the above-mentioned action under any braking speed, and the rear wheel brake fluid can be adjusted to provide nearly ideal front and rear brake force distribution characteristics for each vehicle weight. Pressure can be controlled.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional side view showing an example of the deceleration sensing type hydraulic pressure control valve of the present invention configured for two-system distribution, in a state in which it is put into practical use in an X-distribution type hydraulic brake system for an automobile. A diagram showing the fluid pressure control characteristics of the fluid pressure control valve in comparison with the characteristics of a conventional fluid pressure control valve. FIG. 8 is a T diagram showing the relationship between the containment fluid pressure and the spring load in the valve of the present invention. It is. l... Valve body 2... Hydraulic pressure control plunger 4... Valve holder 7.8.21.2
4...1 lug 9...stepped room 10,
10... Splash 11, ill'... Poppet valve body 1
2, 12'...Valve seat 14...Feley piston
17, 18... Entrance boat 19, 20...
Outlet boat 21...Piston 22-=chamber
9.22... Containment chamber 25... Splash 271 with a relatively low spring constant.・Spring 30 with a relatively high spring constant... Solenoid 1 Langeer 31... Solenoid coil 82... Relay 8
8... Power supply 34... Transistor 35... Deceleration detection sensor 80-85... Deceleration detection section 87, 89... Front wheel cylinder 38
...Tandem master cylinders 40, 41...Rear wheel cylinder 42...Brake pedal. Button-1 Figure 2 Figure 3 Date seal (PO)

Claims (1)

[Scope of Claims] L: A hydraulic pressure control gear that responds to the inlet hydraulic pressure and limits the inlet hydraulic pressure while controlling the outlet hydraulic pressure, and a deceleration detection unit that detects a predetermined deceleration of a braked vehicle. and a deceleration sensing type hydraulic control comprising a containment chamber which is arranged to push the plunger in the valve closing direction and is isolated from the inlet hydraulic pressure when the deceleration detection section detects deceleration. The valve is provided with a piston that responds to the hydraulic pressure in the containment chamber, and the piston presses toward the containment chamber with a spring having a relatively low spring constant, and the piston responds to the hydraulic pressure in the containment chamber. When pressed by a predetermined amount or more, the thread is connected to a spring with a relatively high spring constant, and the containment chamber is formed so that it is also pressed by the spring, so that the containment chamber absorbs the containment liquid pressure after the inlet liquid pressure is cut off.
The pressure reduction mechanism is characterized in that the pressure is increased by the movement of the hydraulic pressure side 7/jar in the valve closing direction, and the working hydraulic pressure of the hydraulic pressure control 1 langeer is changed 1 in accordance with the turret loading. Speed sensing type hydraulic pressure control valve 0 Section The deceleration sensing type hydraulic pressure control valve according to claim 1, wherein the spring having a relatively high spring constant is given a predetermined set load.