JPS5932550A - Two-system fluid pressure control valve moving in response to deceleration - Google Patents

Abstract

PURPOSE:To enable the proportional control starting pressure to be appropriately controlled in response to the loading of a vehicle by providing an inclinable traveling member which gives a preliminary load between two-system fluid pressure control valves equipped with a deceleration responding valve on one of them. CONSTITUTION:One system 2 of a two-system fluid pressure control mechanism is formed by a piston 8 and a valve 19, while the other system 3 is formed by a piston 8', valve 19' and a control piston 23, which receives fluid pressure controlled by means of a deceleration responding valve 44 and pushes the piston 8' rightward. Then, a traveling member 29, giving a preliminary load to both pistons, is slanted with a point A as a fulcrum and receives the preliminary load of a spring 34 along with that of a spring 56. Force of the second preliminary load spring 56 can be received through its adaption to the slant of the traveling member 29, therefore, the proportional control starting pressure at the time of high load can be elevated, the control being made correctly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a deceleration-responsive two-system hydraulic pressure control valve used in a brake device for a vehicle or the like.

Conventionally, as a control unit of this type, it is possible to control the pressure on the wheel cylinder side to be smaller than the master cylinder side pressure by opening and closing a valve placed between the master cylinder and the wheel cylinder. are arranged in parallel, and the biasing force of a load device having at least one preload spring is applied to both control parts so that the valve opens through one movable floating member disposed opposite to both control parts. At the same time, the biasing force of the load device is changed according to the reference pressure obtained from one control section via a deceleration response valve that closes when the deceleration occurring in the vehicle reaches a predetermined value. death,
It is known that the predetermined pressure can be changed.

However, in these conventional systems, when changing the predetermined pressure, it is changed in linear proportion to the reference pressure, so when the total weight of the vehicle is large, it is difficult to set the appropriate predetermined pressure. If the total weight is small, the predetermined pressure is too high; if the total weight is small, if the appropriate predetermined pressure is obtained, the total weight is large. There is a problem that the predetermined pressure is too low.

The present invention has been made in view of the above-mentioned problems, and aims to provide a deceleration-responsive two-system hydraulic pressure control valve that can appropriately change a predetermined pressure. The floating member is made tiltable in accordance with the floating member, and when the tilt of the floating member exceeds a predetermined range, the biasing force of the second load device to open the valve is applied to the control unit via the floating member. It is designed to work on.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, a deceleration-responsive two-system hydraulic control valve is designated as a whole by the reference numeral 1, and the control valve 1 has a valve body 4 in which cylinder holes 2 and 3 are arranged in parallel.

Now, to explain the cylinder hole 2, one end side of the cylinder hole 2 is closed, and the other end side is open to the end surface 5 of the valve body 4. The cylinder hole 2 is a stepped hole having a small diameter hole 6 on the closed end side and a large diameter hole 7 on the open end side, and the stepped piston 8 can freely slide its large diameter portion 9 into the small diameter hole 6. It is inserted with a tight fit. The piston 8 divides the inside of the cylinder hole 2 into an inlet chamber 10 and an outlet chamber 11, and a sealing member 13 and a lid member 14 supporting the same are provided between the small diameter portion 12 and the large diameter hole 7 of the cylinder hole 2. is secured by a retaining ring 15, and is slidable relative to the sealing member 13 and the lid member 14, and the tip of the small diameter portion 12 protrudes outside the cylinder hole 2.

The piston 8 is provided with a passage 16 that communicates between the inlet chamber 10 and the outlet chamber 11, and this passage 16 is connected to a valve 1 disposed inside.
7 allows for communication or disconnection. This valve 1
Numeral 7 constitutes a control section of one brake system together with the piston 8, and includes a hollow seat member 18 which is caulked to the right end of the piston 8, and a stem which passes through this seat member 18 and comes into contact with the closed end of the cylinder hole 2. a valve element 20 comprising 19;
The valve element 20 is biased into seating by a valve spring 21 located within the passageway 16.

Like the cylinder hole 2, the cylinder hole 3 has one end connected to the valve body 4.
The inlet chamber 10' has a small diameter hole 6' and a large diameter hole 7' which are the same as the small diameter hole 6 and the large diameter hole 7, and is partitioned by the large diameter part 9' of the piston 8'. The other end is closed by a lid member 22, and the piston 8' and the lid member 22 are closed.
The control piston 23 is slidably fitted tightly between the control piston 23 and the piston 8'. The control piston 23 has an outer diameter larger than the large diameter portion 9' of the piston 8', and defines a control chamber 24 in the cylinder bore 3 together with the lid member 22. Since the piston 8' has the same structure and size as the piston 8, corresponding parts will be designated with the same numbers with a dash 1 and a detailed description will be omitted. Regarding other elements housed in the cylinder hole 3, those corresponding to those in the cylinder hole 2 are also marked with dashes ('
) are given the same numbers.

The inlet chamber 10' communicates with two piping connections 25 (one not shown) provided on the side of the valve body 4, and the outlet chamber 11'.
Similarly, it communicates with the piping connection port 26. entrance chamber 10,
Although not shown, the outlet chambers 11 also communicate with the piping connection ports in the same way. In addition, 27 is a bleeder screw for air bleeding.

The end surface 5 of the valve body 4 where the cylinder holes 2 and 3 open is covered with a cap-shaped fixing member 28, and the pistons 8 and 8' protrude into the space surrounded by both pistons 8 and 8'.
The receiving recess 30 of the floating member 29 has a lever-like protruding end.
, 30'. The fixed member 28 is a floating member 29
The bottom of the cylindrical small diameter part 32, which is fixed to the end face 5 of the valve body 4, has a dish-shaped large diameter part 31 that provides a displacement space (X) of It has a raised bottom spring seat portion 32a and a circumferential groove shaped spring seat portion 32b surrounding the spring seat portion 32a. The floating member 29 has a hole 33 in the middle of the receiving recesses 30 and 30', and the length from the hole 33 to the side end of the receiving recess 30 is a predetermined length longer than the length from the hole 33 to the side end of the receiving recess 30'. It has a longer length and is biased toward the pistons 8, 8' by a preload spring 34 of the first preload device.

In the valve body 4, a stepped cylinder hole 35 parallel to the cylinder holes 2 and 3 is further bored from the end surface 5 side. 36 and a seat member 37 fitted thereto.
8 is press-fitted and fixed, the end surface 5 side is closed with a lid member 39, and the valve seat 38 is divided into a small diameter pressure chamber 40 and a large diameter valve chamber 41. The support member 36 has a central hole 43 having a throttle 42, and a spherical valve element 45 of a deceleration responsive valve 44 is rotatable in the valve chambers 40, 41 and is seated and unseated on the valve seat portion 38. A cylindrical ball guide 46 that can be accommodated in the valve chamber 41 is inserted.
A plurality of holes are inserted into the bottom hole 48 of the valve chamber 41 and fixedly disposed within the valve chamber 41 by fitting the bottom hole circumferential wall into the outer circumferential groove of the valve seat portion 38 and extending in the axial direction between the valve chamber 41 and the inner circumferential surface of the valve chamber 41. In addition to providing a groove defining a book passage 49, a passage 50 communicating with the groove is provided in the valve seat portion 3.
It has a groove 51 defined on the 8 side and for guiding pressure from the passage 50 to the inside. A passage 52 for communicating the pressure chamber 40 with the control chamber 24 is formed in the valve body 4 .

A recess 54 is provided on the outer surface of the lid member 39 which is in the same plane as the end surface 5.
An engaging cylinder 55 is loosely fitted into this recess 54 through the hole 33 of the floating member 29, and the bottom 55a of the engaging cylinder 55 and the raised bottom-shaped spring seat portion 32a of the fixed member 28 are connected to each other.
A preload spring 56 of the second preload device is tensioned over this range. The engagement cylinder 55 has an outer diameter slightly smaller than the diameter of the hole 33 of the floating member 29, and is provided with a flange 57 having a diameter larger than the diameter of the hole 33, and the flange 57 leaves a predetermined gap between it and the floating member 29.ゝThey are facing each other. Note that a lip seal 23a having a check valve function is fitted onto the control piston 23.

The two-system hydraulic pressure control valve 1 having the above configuration is connected to a connection port (not shown) by a pipe, for example, in a so-called X-piping system.

That is, the inlet chambers 10 and 10' are respectively connected to two independent brake fluid pressure generating chambers of a tandem master cylinder (not shown), and are also connected to wheel cylinders (not shown) of brake devices provided on the front right wheel and the front left wheel, respectively. The output chambers 11 and 11' are connected to wheel cylinders (not shown) of brake devices provided on the left rear wheel and the right rear wheel, respectively.

Furthermore, when the valve body is attached to the vehicle, the valve element 45 must be attached until a predetermined deceleration occurs when the vehicle is braked.
is attached so that it does not sit on the valve seat portion 38. Specifically, the axis of the cylinder hole 35, in other words, the valve element 4
5 is mounted on the valve seat portion 38 so that the movement axis trace moving within the ball guide 46 has an upward slope of Θ with respect to the road surface, and this angle Θ is set such that the deceleration of the vehicle is 0. A value is selected that causes the deceleration responsive valve 44 to close when the acceleration reaches 3 g (g is the gravitational acceleration). Note that the forward direction of the series is indicated by an arrow on the right side of the figure.

Next, the operation of this control valve 1 will be explained.

When the vehicle is not braked, each member is in the position shown, that is, the pistons 8, 8' receive the preload of the preload spring 34 distributed through the floating member 29, the pistons 8', 8',
The seat member 18' of the piston 8 and the seat member 18 of the piston 8 abut the control piston 23 and the closed end of the cylinder bore 2, respectively, and the control piston 23 abuts the lid member 22 and the valve elements 20, 2.
0' are separated from the seat members 18, 18', respectively, and the valves 19, 1
9' is open, and the inlet chambers 10 and 10 are connected to the outlet chamber 11, respectively.
, 11'.

Now, when the driver operates the tandem master cylinder (not shown) in order to apply the brakes to the vehicle, the brake fluid pressure generation chamber in the tandem master cylinder enters each inlet chamber 10,
10' and the pressure in each inlet chamber 10, 10' begins to increase.

The pressure generated in the inlet chamber 10' is transmitted from the connection port 25 to the wheel cylinder of the right front wheel, and is also transmitted through the passage 16',
The air is transmitted to the rear wheel cylinder through the outlet chamber 11' and the connection port 26 opening into the outlet chamber. at the same time,
The pressure within the inlet chamber 10 is similarly transmitted to the wheel cylinders of the left front wheel and the right rear wheel. In this way, pressure is transmitted to each wheel cylinder, and the vehicle begins to be braked and deceleration occurs.

The pressure generated in the inlet chamber 10' as described above is simultaneously applied to the passages 53, 49, 50 and 51, the ball guide 46,
The pressure is transmitted into the pressure chamber 40 through the control pressure path formed by the center hole 43 and then to the control chamber 24 .

In this state, each piston 8, 8' tries to move against the preload of the preload spring 34 due to the brake fluid pressure acting on each piston, but the pressure in the inlet chambers 10, 10' is low. In some cases, the preloading of the preload spring 34 does not move the valves 19, 19' to the closed position.

At that stage, as the pressure in the inlet chambers 10, 10' increases, the pressure receiving area S of each piston 8, 8' with respect to the outlet chambers 11, 11' becomes larger than the pressure receiving area with respect to the inlet chambers 10, 10'. Due to this, the pistons 8, 8' resist the preload of the preload spring 34 while the total weight of the vehicle is low and against the preload of the preload spring 34 when the total weight of the vehicle is high. 56
The valves 19, 1 begin to move against the sum of the preloads of
9' is closed, the outlet chambers 11, 11' and the inlet chambers 10, 10' are closed.
communication is cut off. Thereafter, the pressure in the outlet chambers 11, 11' is gradually reduced at a predetermined rate in proportion to the rise in pressure in the inlet chambers 10, 10'.

The pressure at which this pressure reduction control is started (the predetermined pressure)
, the so-called breaking point pressure Po will be explained below.

When the brakes of the vehicle begin to apply and the predetermined deceleration occurs, the spherical valve element 45 moves inertia against the inclination Θ, so that the deceleration responsive valve 44 closes and the pressure chamber 4
0, a pressure Pg proportional to the total weight of the vehicle is confined, and this pressure Pg is transmitted to the control room 29.

When the vehicle is empty, the operating time until the deceleration response valve 44 closes is short, so the containment pressure Pg transmitted to the control chamber 24 hardly increases, and the control piston 23
Since the force driving the control piston 23 to the right is small, the control piston 23
does not move substantially, and each piston 8, 8' has a floating member 2.
Since only the biasing force of the preload spring 34 proportionally divided by 9 is applied in the direction to open the valves 19, 19', the above-mentioned corner pressure Po is determined as a function of the biasing force of the preload spring 34.

When the total weight of the vehicle increases due to loading, the operating time of the deceleration response valve 44 becomes longer and the containment pressure Pg increases proportionally, so the control piston 23 moves the piston 8' preload spring 34 received through
It will move to the right against the attached forces (proportionally divided attached forces). When the control piston 23 moves to the right, both the piston 8' and the valve element 20' are pushed to the right, causing the floating member 29 to tilt clockwise about the contact point (A) between the receiving recess 30 and the piston 8 as a fulcrum. Therefore, the amount of compression of the preload spring 34 increases, and the biasing force applied to the pistons 8, 8' in the opening/closing direction increases.

Since the tilting angle of the floating member 29 corresponds to the loading capacity of the vehicle, when the loading capacity exceeds a certain amount, the peripheral edge of the hole 33 of the floating member 29 engages with the engagement tube 55 in a biting manner. The inducer member 29 then drives the engagement tube 55 against the preload of the second preload spring 56, causing the second preload spring 56 to be compressed. Therefore, in addition to the biasing force exerted by the preload spring 34, the floating member 29 is newly loaded with the preload springs 54, 5.
6 comes to act, and the above-mentioned corner pressure P
o is determined as a function of the sum of the applied forces by both preload springs 34 and 56, and the range of change of the above-mentioned corner pressure Po with respect to the range of change of the pressure Pg confined within the control chamber 24 is determined by the first This increases significantly compared to the case of empty loading as a function of the applied force by the preload spring 34.

Note that the pressure in the control chamber 24 does not rise above the pressure in the output chamber 11' because of the presence of the check valve 23a, and therefore, an excessive rise in the corner pressure is prevented.

Next, we will discuss abnormal situations.

For example, no pressure is transmitted to the inlet chamber 10 and the inlet chamber 10'
Suppose that pressure is normally transmitted only to. In this case, the failure to apply brakes on one side of the system causes
Since it takes time for the deceleration responsive valve 44 to close, the pressure sealed within the control chamber 24 becomes extremely large.

Therefore, when the total weight of the vehicle is large, the control piston 23 is driven significantly to the right, and the preload spring 34,
56 and press against the fixing member 28, the valve 19' does not close, and the pressure in the inlet chamber 10' is directly transmitted to the outlet chamber 11', so that the vehicle Sufficient braking force can be obtained even if the total weight is large.

Conversely, when pressure is not transmitted to the inlet chamber 10' and pressure is normally transmitted to the inlet chamber 10, the piston 8 moves to the right as the pressure increases, and the floating member 29
The preload spring 34 is compressed and tilted counterclockwise using the contact point (B) between the piston 8' and the receiving recess 30' as a fulcrum, and the side end of the receiving recess 30 comes into contact with point C of the fixing member 28. come into contact with The stroke of the piston 8 at this time is shorter than the stroke required to close the valve 19, and since the valve 19 is configured not to close, the pressure in the inlet chamber 10 further increases. For this reason, the floating member 29 now begins to tilt clockwise about the point C as a fulcrum, and begins to move away from the piston 8'. Therefore, if the distance between the contact point (A) and the midpoint between the contact points (A) and (B) is taken as l', and the length from the contact point (A) to the side end of the receiving recess 30 is l', then the piston 8 The applied force F in the valve opening direction is F=Fo(l+
l/l')...(1) However, Fo: preload spring 34
Therefore, in the case of this embodiment where l>l', F>2
It becomes Fo. Since the applied force until the floating member 29 engages with the above point C is Fo, the pressure at the turning point after the above engagement that enables pressure reduction control is extremely high, and even if the total weight of the vehicle is large, this Sufficient braking force can be obtained.

FIG. 2 shows another embodiment of the present invention. In this embodiment, the cylinder hole 3' has the same structure as the cylinder hole 2, and the length is shorter than the length of the cylinder hole 3'. A control chamber is provided between the piston 8'' and the control piston 23, and communicates with the pressure chamber 43 through a passage 53. Since the control chamber 24 is located on the inlet chamber 10' side, the cylinder hole 35 is bored from the surface opposite to the end surface 5 of the valve body 4, and an engaging cylinder 55 is formed on the end surface 5.
A recess 54 is formed for loosely fitting. The ball guide 46 has an outer surface recess on the valve member 38 side that defines a passage 50 communicating with the passage 53 between the valve chamber 40 and the inner peripheral surface of the valve chamber 40, and a hole 51 communicating with the passage 50.

Regarding other configurations, the same or equivalent components as those in FIG. 1 are given the same reference numerals.

In the embodiment shown in FIG. 1, the containment pressure Pg transmitted to the control chamber 24 drives the control piston 23 in the valve closing direction of the piston 8', and as the control piston 23 moves, the piston 8' closes the valve. By driving the valve 19' to the right without closing the valve, the biasing force of the preload springs 34 and 56 changes and the corner pressure Po is changed. The confinement pressure Pg transmitted to the control chamber 24 directly acts on the piston 8' in the direction of opening the valve, and at the same time acts on the control piston 23, causing the floating member 29 to tilt. Although it is different from the embodiment shown in FIG. 1 in that the floating member 29 and the engagement tube 55 are engaged, the range of change in the corner pressure Po is greatly increased compared to that before the engagement. The effect is the same. In addition, in an abnormal situation, that is, when pressure is not normally transmitted to the inlet chamber 10' and the total weight of the vehicle is large, the control piston side end of the floating member 29 engages with the fixed member 28, causing the valve 19' to close. The action of preventing the valve from closing, or when pressure is not normally transmitted to the input chamber 10, the floating member 29
The engagement of the fixed member 28 with the side end of the piston 8 changes the range of change in the corner pressure Po with respect to the increment of the pressure transmitted to the input chamber 10 in the same manner as in the embodiment shown in FIG. It will be held on.

As described above, according to the present invention, the first load device always acts as a load device that applies a force in the valve opening direction to the two control units, and the first load device starts acting when the total vehicle weight exceeds a predetermined range. By using the second load device, the change rate of the pressure reduction control start pressure, which is the predetermined pressure, is small in a range where the total vehicle weight is small, and the change rate of the pressure reduction control start pressure is small when the total vehicle weight increases. Therefore, it is possible to prevent the braking force from becoming too large or too small and to obtain an appropriate braking force.

Furthermore, a structure is provided in which a floating member that distributes the energizing force of the load device to the two control units is tiltable, and when the tilt angle of the floating member exceeds a certain range, the second load device starts acting. Therefore, the above effects can be obtained without complicating the internal structure of the load device.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of a deceleration-responsive two-system hydraulic control valve according to the present invention, and FIG. 2 is a longitudinal cross-sectional view of another embodiment of the present invention. 2, 3, 3''...Cylinder hole, 8, 8', 8''...Piston 10, 10'...Inlet chamber 11, 11'...Outlet chamber 19, 19'...Valve 23 ...Control piston 24...Control chamber 28...Fixed member 29...Floating member 34, 56...Preload spring 55...Engaging cylinder.

Claims (1)

[Claims] It has a control section in parallel that can control the wheel cylinder side pressure to a predetermined pressure or higher compared to the mask cylinder side pressure by opening and closing a valve disposed between the mask cylinder and the wheel cylinder, and both control sections The biasing force of a load device having at least one preload spring is distributed to both control parts so that the valve opens through one movable floating member disposed opposite to the control part, and the biasing force of the load device having at least one preload spring is distributed to the two control parts to open the valve. The predetermined pressure can be changed by changing the biasing force of the load device according to the reference pressure obtained from one of the control parts via a deceleration response valve that closes when the generated deceleration reaches a predetermined value. In the deceleration-responsive two-system hydraulic control valve, the floating member is allowed to tilt in response to the reference pressure, and when the tilt of the floating member exceeds a predetermined range, a second load device opens the valve. A deceleration-responsive two-system hydraulic pressure control valve in which a biasing force for valving acts on the control section via the floating member.