JPH09221014A - Load responding type hydraulic pressure control valve device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load responding type hydraulic pressure control valve device of good braking efficiency capable of making it approach an ideal hydraulic pressure characteristic without causing any change in a starting point of the hydraulic pressure control even if a nose driving phenomenon takes place at the time of applying brakes. SOLUTION: This device, which stores a piston 2 inside a housing 1 in a freely slidable manner, is equipped with a first valve mechanism D, which varies the hydraulic pressure characteristic in accordance with the pressing force given to the piston 2, and a transmitting member C which gives pressing force to the first valve mechanism D. The device also includes a stepped plunger 1, which is stored inside the housing 1 facing the piston 2 is series and its small diameter portion 1a side abutting upon a transmitting member C and adjusting springs S, S are compressively provided between the large diameter portion side of the stepped plunger 1 and the piston 2, while a second valve mechanism E for controlling by inertia a communication passage 28 between a liquid chamber B, which is formed between the small diameter portion 1a and the large diameter portion 15c of the stepped plunger 15, and an input liquid chamber A or an output liquid chamber for the first valve mechanism D is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load-responsive hydraulic control valve device (load sensing proportioning valve: LSPV) which changes a control hydraulic pressure of a braking device in accordance with a change in a rear wheel load of a vehicle, and more particularly, The present invention relates to an LSPV in which dynamic break points are not affected by load transfer.

[0002]

2. Description of the Related Art As a conventional technique of this kind, for example, there is a load sensing proportioning valve described in Japanese Patent Publication No. 7-84165.

[0003]

In the conventional LSPV, the structure for preventing the load movement from affecting the dynamic break point has the following problems. (A) Since the number of parts is large and press parts are also used, the structure is such that variations due to stacking of parts accuracy naturally increase, and the accuracy of hydraulic characteristics becomes low. (B) Since there are many so-called sliding friction parts such as rotary sliding parts, durability is poor, and there is a risk of deterioration of hydraulic characteristics due to wear. (C) Since parts such as levers and solenoids are exposed to the outside from the LSPV main body, only the LSPV main body side of the dust boot is shown in a cutaway view to cover these parts, but the boot shape ensures reliable waterproofing. Is expected to be extremely complex. Also, the dust boots may be damaged by flying stones or handling during assembly. (D) Since a solenoid is used, wiring is required, which complicates the assembly work and raises the cost.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, in the present invention, a housing mounted on one of a suspension sprung portion and an unsprung portion of a vehicle, and a piston sliding in the housing. A first valve mechanism that is freely accommodated and changes its hydraulic characteristics in accordance with the pressing force applied to this piston; one end pivotally supported by the housing and the other end the sprung portion; It is attached to either the unsprung portion or the other, and detects the relative displacement amount of the sprung portion and the unsprung portion in accordance with the load of the vehicle,
In a load-responsive hydraulic control valve device including a transmission member that applies a pressing force to a valve mechanism, a stepped member that is housed in the housing so as to face the piston in series, and a small-diameter side contacts the transmission member. A plunger is provided, and an adjusting spring is contracted between the large diameter side of the stepped plunger and the piston, and the liquid chamber formed between the small diameter part and the large diameter part of the stepped plunger and the first valve mechanism. A load-responsive hydraulic control valve device is configured by providing a second valve mechanism that controls a communication path between the input liquid chamber or the output liquid chamber by inertia.

Further, according to the present invention, a housing mounted on either one of the suspension upper spring portion and the lower spring portion of the vehicle, and the piston slidably accommodated in the housing, the pressing force applied to the piston. A first valve mechanism for changing the hydraulic pressure characteristic according to the above, one end of which is pivotally supported by the housing and the other end of which is attached to the other of the sprung portion and the unsprung portion. A load-responsive hydraulic control valve device comprising: a transmission member that detects a relative displacement amount between the sprung portion and the unsprung portion according to the loaded load, and applies a pressing force to the first valve mechanism, It has a stepped plunger that is housed in the housing so as to face the piston in series, and the small diameter side contacts the transmission member, and an adjusting spring is contracted between the large diameter side of the stepped plunger and the piston. Then A second passage for controlling the communication passage between the liquid chamber formed between the small diameter portion and the large diameter portion of the stepped plunger and the input liquid chamber or the output liquid chamber of the first valve mechanism by the input hydraulic pressure or the output hydraulic pressure. A load-responsive hydraulic control valve device is provided by providing a valve mechanism.

Further, in the present invention, in the load-responsive hydraulic control valve device of the first and second inventions, the liquid chamber formed between the small diameter portion and the large diameter portion of the stepped plunger and the first valve. An orifice is provided in the communication passage between the mechanism and the input liquid chamber or the output liquid chamber to form a load-responsive hydraulic pressure control valve device.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. In the drawing, reference numeral 1 denotes a housing of a load-responsive hydraulic control valve device, which is attached to either a suspension sprung portion or a sprung portion of a vehicle. 2 is a piston slidably provided in the right half of the housing 1, 2a is a small diameter portion on the left end side in the drawing, 2b is a small diameter portion 2
A small-diameter piston portion 2c having a diameter slightly larger than a and a cross-sectional area of A ₁ is a body portion 2c having a larger diameter than the small-diameter piston portion 2b.
d is a flange portion having a diameter larger than that of the body portion 2c, 2e is a lip seal facing portion having a diameter smaller than that of the collar portion 2d, 2f is a groove portion having a diameter smaller than this lip seal facing portion 2e, 2g is a diameter larger than the small diameter piston portion 2b and A ₂ A large-diameter piston portion 2h having a cross-sectional area of 2h is a body portion on the right end side in the drawing formed to have a smaller diameter than the large-diameter piston portion 2g.

In the right half of the housing 1, a hole 3 for enclosing the small diameter portion 2a of the piston 2 to the groove portion 2f is provided, and is fitted with the large diameter piston portion 2g of the piston 2 with a slight gap. At the same time, a hole 4 for enclosing the body portion 2h is formed so as to communicate with the hole 3. The hole 4 communicates with an outlet 5 for the output hydraulic pressure P _R provided in the housing 1 through a flow path 6 which also serves as an output liquid chamber. A lip seal 7 is provided on the stepped portion on the right side of the hole 3 in the drawing, and faces the lip seal facing portion 2e.

Further, a sleeve 8 slidably fitted to the small-diameter piston portion 2b of the piston 2 is tightly fitted in the hole 3 through a seal 9, and between the sleeve 8 and the flange portion 2d of the piston 2. Insert the inner spring S ₁ . In the figure, 10 is a retainer, 11 is a seal between the small-diameter piston portion 2b and the sleeve 8, 12 is a retaining ring of the sleeve 8, and the space between the sleeve 8 and the large-diameter piston portion 2g is the input liquid chamber A. It communicates with the inlet 14 of the input hydraulic pressure P _M provided in the housing 1 via the flow path 13.

Further, a stepped plunger 15 facing the piston 2 is slidably provided in the housing 1 on the left side of FIGS. 15a is a small diameter portion having a cross-sectional area A ₄ in diameter to form the left side in FIG stepped plunger 15, 16 O-ring provided in a groove of the small diameter portion 15a, 17 denotes a seal. Further, 15b is a neck portion having a smaller diameter than the small diameter portion 15a, 15c is a large diameter portion having a larger diameter than the small diameter portion 15a and having a sectional area A ₃ , 15d is a flange portion having a diameter larger than the large diameter portion 15c, and 15e is this flange portion 15d. It has a smaller diameter body.

Further, the housing 1 is provided with a hole 18 for enclosing the collar portion 15d so as to communicate with the hole 3, and a preload spring S _{2 is provided} between the stepped surface of the hole 3 and the collar portion 15d. Is provided. In addition, a cap-shaped holder 19 is applied to the left end of the piston 2 in the drawing,
Between the holder 19 and the flange portion 15d, adjustment spring S ₃ and set spring S ₄ is are interposed in series via the retainer 20 as the adjustment spring. Reference numeral 21 is an O-ring provided between the left and right housings 1, 1. The housing 1 is divided into the left and right sides by the holes, flow paths,
In order to facilitate the processing of the liquid chamber and the like, the division location and the division number may be changed as necessary. Further, an O-ring for sealing the dividing surface may be appropriately added. B is a liquid chamber provided on the left side of the large-diameter portion 15c of the stepped plunger 15 in the drawing, and communicates with the bleed screw 23 via the flow path 22. Reference numeral 24 is a seal fitted to the neck portion 15b of the stepped plunger 15.

Further, a bracket 1a is provided on the left end of the housing 1 in the figure, and the lever 2 is attached to the bracket 1a.
The base portion of the lever 5 is pivotally supported by the support shaft 26, and the recess 25a provided in the intermediate portion of the lever 25 abuts the outer end 15f of the stepped plunger 15, and the free end portion 2 of the lever 25
5b is connected via a sensor spring S ₅ to either the suspension sprung or unsprung part of the vehicle. 2
Reference numeral 7 denotes a dust cover which covers a pivotal support portion of the lever 25 and an abutting portion between the lever 25 and the stepped plunger 15.

According to the apparatus constructed as described above, the relative displacement amount between the sprung portion and the unsprung portion according to the load of the vehicle is converted into the force of the sensor spring S ₅ , and the lever 25 is moved.
A pressure adjusting mechanism that abuts against the outer end 15f of the stepped plunger 15 to apply a pressing force to the piston 2 via a transmission member C such as the above. A hydraulic pressure adjusting mechanism is configured to change the hydraulic pressure characteristic of the output hydraulic pressure P _{R with} respect to the input hydraulic pressure P _M according to the pressing force of the spring.
The first valve mechanism D is configured by

1 and 2 show a first embodiment of the present invention. In this embodiment, a communication passage 28 between the liquid chamber B and the input liquid chamber A of the first valve mechanism D is shown. A second valve mechanism E controlled by inertia is provided therein.

That is, a void 29 for accommodating the G ball 30 is provided in the middle of the communication passage 28, and the bottom surface 29a of this void 29 is inclined by θ with respect to the horizontal line L shown in FIG. When the deceleration does not act on the G ball 30 inserted in the void 29, the G ball 30 is positioned on the right side of the drawing. 31 is a communication passage 2 on the left side of the G ball 30
8 is a valve seat provided in the opening, 32 is a G ball 30
Flow plate for G ball support provided on the right side of the, 33
Is a seal and 29b is a flow path engraved on the inner peripheral surface of the void 29.

FIG. 3 shows a second embodiment of the present invention. In this embodiment, an input is made in the communication passage 28 between the liquid chamber B and the input liquid chamber A of the first valve mechanism D. A second valve mechanism F controlled by the hydraulic pressure P _M is provided. Depending on the output hydraulic pressure P _R ,
The second valve mechanism F may be controlled.

That is, a bottomed stepped cavity 34 communicating with the communication passage 28 is provided in the housing 1 on the left side in FIG. 3, and a ring is placed in the second cavity from the left of the stepped cavity 34 in FIG. In addition to providing a ring-shaped seal 35, a ring-shaped second valve seat 36 is provided in the fourth space from the left. 3
7 is an O-ring.

Numeral 38 is a space provided in the housing 1 on the right side of FIG. 3 so as to communicate with the communication passage 28 at a position facing the second valve seat 36, and 39 is loosely fitted in the space 38. A disk-shaped head portion 39a, a rectangular tubular sliding portion 39b penetrating the second valve seat 36, and a small diameter shaft portion 39 penetrating the seal 35.
It is the 2nd plunger which consists of c. In addition, 39d is a second valve seal provided on the head portion 39a, and 40 is between the rectangular tubular sliding portion 39b of the second plunger 39 and the spring seat 41 applied to the step in the space 34. It is an inserted spring.

Although the above-mentioned first valve mechanism D is a lip seal type, it may be a poppet valve type. Also, the transmission member C described above is one in which the lever 25 and the sensor spring S ₅ separately, which rod spring, and those together with the leaf spring, the sensor spring S ₅ of the tension spring Alternatively, a compression spring, a leaf spring, a torsion spring, a bar spring, etc. may be used.

Next, the operation of the device of the present invention configured as described above will be described. The relationship between the sectional areas A _{1 to} A ₄ of the piston 2 and the stepped plunger 15 described above is as follows. _{A 1 <A 2 A 3> A} 4

The relationship of the set loads of the above-mentioned springs S _{1 to} S ₄ is as follows. S ₁ > S ₄ S ₃ ≦ S ₄ (however, = indicates light load) However, the spring constant is S ₃ > S _4, and S ₃ is S
_The retainer 20 supporting ₄ is hardly bent until the end surface on the small diameter side comes into contact with the flange portion 15d of the plunger 15.
The role of the set spring S ₄ is to reduce the variation in the hydraulic pressure control start point during light loading by providing a gap between the retainer 20 and the flange portion 15d of the stepped plunger 15. The role of the preload spring S ₂ is to apply it to the output hydraulic pressure characteristics required by the vehicle by changing only the springs S ₂ and S ₃ .

First, regarding the first embodiment of FIGS. 1 and 2.
explain. Either the sprung part or the sprung part of the vehicle
Connect the housing 1 to one side and the sensor spring to the other
S_FiveSince it is connected to the sensor
Spring S_FiveLoad changes. Figure 1 is for light loading
Kick sensor spring S _FiveIndicates a weak load
Fig. 2 shows the sensor spring S during constant loading._Five
Indicates that the load is strong, and the stepped plunger 15
Moves to the right as the load increases and the plunger 15
The distance δ from the da 19 is narrowed. By the way, the specified hydraulic pressure has been reached
Until the piston 2 of the first valve mechanism D is an inner spring
S₁, Adjust Spring S_ThreeBy the right side of Figures 1 and 2
Is pressed against the bottom of the hole 4 in the housing 1
In a state. At this time, the lip seal facing portion 2e of the piston 2
Since there is a gap between the lip seal 7 and
The fluid chamber A and the outlet 5 communicate with each other. Reaching the prescribed hydraulic pressure
And hydraulic force acting on the small diameter piston part 2b of the piston 2
Is Inner Spring S₁And adjust spring S_Threeof
The first valve mechanism D overcomes the spring force and the poppet operates.
(The input hydraulic pressure P is increased by repeating the opening and closing of the valve._MOut against
Hydraulic pressure P_RActs to reduce the pressure at a constant rate).

Next, the operation of the second valve mechanism E will be described. Since the gap is maintained between the G ball 30 and the valve seat 31 until the set deceleration is reached, the second valve mechanism E is in the inoperative state, and the input liquid chamber A and the containment chamber B communicate with each other. doing. When the set deceleration is reached, the G ball 30 rolls to the left and contacts the valve seat 31.
In other words, the second valve mechanism E is activated, the communication between the input liquid chamber A and the containment chamber B is cut off, the pressure liquid in the containment chamber B is sealed, and the stepped plunger 15 cannot slide. That is, the stepped plunger 15 does not displace from the moment the second valve mechanism E operates, for example, even when the vehicle decelerates to a high degree of deceleration. The relationship between the input / output hydraulic pressures (P _M and P _R ) at this time is as follows. P _R = {(A ₂ −A ₁ ) / A ₂ } × P _M + {(S ₁ + S
₃ ) / A ₂ } As described above, since the position of the stepped plunger 15 remains unchanged after reaching the predetermined deceleration, the spring force of the adjusting spring S ₃ does not change. Therefore, the output hydraulic pressure P
_R is not affected by the front turning of the vehicle that occurs during high deceleration.

[0024] FIG. 3 is a second embodiment of the present invention, which, in place of the second valve mechanism E controlled by the inertia of the G ball 30 of the first embodiment, the input fluid pressure P _M or output fluid Pressure P
Second controlled by second plunger 39 operated by _R
The valve mechanism F is used. That is, in this device, when the hydraulic pressure applied to the small diameter shaft portion 39c of the second plunger 39 reaches the set value and the hydraulic force acting on the second plunger 39 becomes larger than the load of the spring 40, the second plunger 39 moves. Moving to the left in the figure, the second valve seal 39d attached to the head portion 39a of the second plunger 39 causes the second valve seat 36 to move.
The stepped plunger 15 is blocked by closing the communication passage 28 between the liquid chamber B provided on the outer peripheral portion of the small diameter portion 15a of the stepped plunger 15 and the input liquid chamber A of the first valve mechanism D. Block.

Further, in the above-described first and second embodiments of the present invention, the communication passage 28 is provided with orifices 31a and 28a, respectively. This is to detect the slight vibration of the lever 25 caused by the uneven road surface during vehicle braking, and thereby make the response of the stepped plunger 15 a little slower so as not to deteriorate the hydraulic pressure characteristic.

FIG. 4 is a characteristic diagram of the hydraulic pressure in each loading state in which the input hydraulic pressure is plotted on the abscissa and the output hydraulic pressure is plotted on the ordinate.

[0027]

Since the device of the present invention is constructed as described above, the pushing force applied to the piston 2 is maintained even if the force of the sensor spring S ₅ is reduced due to the nose dive phenomenon that the front wheel side sinks during braking. Since the adjustment spring force is always constant due to the containment hydraulic pressure of the second valve mechanism E (or F), there is no decrease in the hydraulic pressure control start point (break point hydraulic pressure),
Further, since the gradient of the hydraulic pressure characteristic line does not decrease, the ideal hydraulic pressure characteristic can be approximated to that extent, and the braking efficiency improves.

Since the hydraulic pressure (containment hydraulic pressure) of the second valve mechanism E (or F) in the device of the present invention is determined by the deceleration (or brake hydraulic pressure) of the vehicle, the precision of the hydraulic pressure characteristic is high, and There is little variation.

Second valve mechanism E (or F) of the device of the present invention
Is stored in the brake fluid flow path of the valve body, and therefore has excellent environmental resistance. Further, since the G ball 30 rolls and the second plunger 39 makes only a slight stroke, there is no concern about wear, and durability for a long period of time is improved.

Since the device of the present invention has a small number of parts and does not need to use electric parts, the assembling work is easy and the cost is low.

According to the device of the present invention, the hydraulic pressure can be changed according to the vehicle specifications.
If you want to change the characteristics, the spring S _TwoAnd S_ThreeChange only
Therefore, it can be easily adapted to various vehicles and is versatile.
No.

In the first embodiment of the device of the present invention, when the sensor spring S ₅ is broken or the front system fails, the G ball 30 does not move until the set deceleration, so that the containment chamber B is Since the hydraulic pressure continues to increase and the stepped plunger 15 moves in the direction to strengthen the adjustment spring force,
The hydraulic pressure control start point can be increased to secure the braking force.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the device of the present invention.

FIG. 2 is an operation explanatory view of FIG. 1;

FIG. 3 is a sectional view showing a second embodiment of the device of the present invention.

FIG. 4 is a characteristic diagram of hydraulic pressure in each loading state.

[Explanation of symbols]

1 Housing 2 Piston 3, 4 Hole 5 Outlet 6 Output Liquid Chamber 7 Lip Seal 8 Sleeve 9 Seal 10 Retainer 11 Seal 12 Stop Ring A Input Liquid Chamber 13 Flow Path 14 Inlet 15 Stepped Plunger 16 O-ring 17 Seal 18 Hole S ₁ Inner spring S ₂ Preload spring S ₃ Adjust spring S ₄ Set spring S ₅ Sensor spring 19 Holder 20 Retainer 21 O-ring 22 Flow path B liquid chamber (containment chamber) 23 Bleed screw 24 Seal 25 Lever 26 Spindle 27 Dust Cover C Transmission member D First valve mechanism 28 Communication passage 28a Orifice E Second valve mechanism 29 Vacancy 30 G ball 31 Valve seat 31a Orifice 32 Flow plate 33 Seal P _M Input hydraulic pressure P _R Output hydraulic pressure F Second valve machine Structure 34 Cavity 35 Seal 36 Second valve seat 37 O-ring 38 Cavity 39 Second plunger 40 Spring 41 Spring seat

Claims (3)

[Claims] 1. A housing mounted to either one of a suspension sprung portion and an unsprung portion of a vehicle, and a piston slidably accommodated in the housing, and a liquid is responsive to a pressing force applied to the piston. First to change pressure characteristics
A valve mechanism, one end of which is swingably supported on the housing and the other end of which is attached to the other of the sprung portion and the unsprung portion, and which has a sprung portion depending on a load of the vehicle. A load-responsive hydraulic control valve device, comprising: a transmission member that detects a relative displacement amount of an unsprung portion and applies a pressing force to the first valve mechanism, wherein the load-responsive hydraulic pressure control valve device is opposed to the piston in series and inside the housing. Has a stepped plunger that is in contact with the transmission member on the small diameter side, and an adjusting spring is contracted between the large diameter side of the stepped plunger and the piston so that the small diameter portion and the large diameter portion of the stepped plunger are large. A load-responsive hydraulic pressure provided with a second valve mechanism for controlling a communication passage between the liquid chamber formed between the radial portions and the input liquid chamber or the output liquid chamber of the first valve mechanism by inertia. Control valve device. 2. A housing mounted to either one of a suspension sprung portion and an unsprung portion of a vehicle, a piston slidably accommodated in the housing, and a liquid depending on a pressing force applied to the piston. First to change pressure characteristics
A valve mechanism, one end of which is swingably supported on the housing and the other end of which is attached to the other of the sprung portion and the unsprung portion, and which has a sprung portion depending on a load of the vehicle. A load-responsive hydraulic control valve device, comprising: a transmission member that detects a relative displacement amount of an unsprung portion and applies a pressing force to the first valve mechanism, wherein the load-responsive hydraulic pressure control valve device is opposed to the piston in series and inside the housing. Has a stepped plunger that is in contact with the transmission member on the small diameter side, and an adjusting spring is contracted between the large diameter side of the stepped plunger and the piston so that the small diameter portion and the large diameter portion of the stepped plunger are large. A second valve mechanism for controlling a communication passage between the liquid chamber formed between the radial portions and the input liquid chamber or the output liquid chamber of the first valve mechanism by the input hydraulic pressure or the output hydraulic pressure. Load-responsive hydraulic control valve device. 3. The load-responsive hydraulic control valve device according to claim 1, wherein the liquid chamber formed between the small diameter portion and the large diameter portion of the stepped plunger and the input liquid chamber of the first valve mechanism. Alternatively, a load-responsive hydraulic pressure control valve device is characterized in that an orifice is provided in a communication passage between the output fluid chamber and the output fluid chamber.