JPH0533430Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a brake fluid pressure control device, and in particular a load sensing type brake fluid pressure control device in which the fluid pressure supplied from a master cylinder to a wheel cylinder is reduced in accordance with the wheel load of a vehicle. The present invention relates to a brake fluid pressure control device.

BACKGROUND OF THE INVENTION Devices for controlling brake pressure in response to vehicle wheel loads are already known. British patent 1449095
The device described in the specification of No. 1 is one example.
In this device, a wheel load is detected using a stacked leaf spring disposed between a sprung member and an unsprung member. The stacked leaf spring is
Movement in the width direction is regulated by a regulating member fixed to the sprung member near the longitudinal end, and a roller (or ball) is placed at the tip.
It is becoming increasingly popular. The roller is held by a housing fixed to the sprung member,
As the wheel load increases, it is pushed into the housing and compresses the elastic body disposed within the housing. The elastic body transmits part of the applied load to the housing and the rest to the piston that is slidably fitted to the housing, and as the piston is moved accordingly, the valve installed in the housing is Opening and closing are controlled, and the brake pressure is adjusted to a level corresponding to the load.

Problems to be Solved by the Invention However, in the above device, the movement of the stacked leaf spring in the width direction is restricted by a regulating member near its tip, and the tip is supported by a roller. Therefore, there was a problem that the structure was complicated.

Means for Solving the Problems In order to solve the above-mentioned problems, the load-sensing brake fluid pressure control device according to the present invention has the following features: (b) a suspension spring disposed between the valve body and having one longitudinal end connected to the sprung member via a support shaft so as to be relatively movable and rotatable in the vertical direction; (c) a pressure reducing valve that includes a valve piston and is attached to the sprung member and reduces the brake fluid pressure supplied from the brake master cylinder to the wheel cylinder of the wheel; and (c) a pair of side walls that are respectively suspended from both ends of the bottom wall. The suspension spring has a groove shape and is attached to the support shaft such that the opening faces downward and the connection portion of the suspension spring to the support shaft is housed inside so that the suspension spring can rotate relative to the support shaft. and (d) a pair of side walls respectively hanging from both ends of the bottom wall, forming a groove shape, fixed to the sprung member, and accommodating the input piston so as to be relatively movable in the vertical direction. And,
A cylinder for vertically movably guiding the support shaft, an output piston fitted in the center of the bottom wall of the cylinder so as to be movable vertically relative to the cylinder, and disposed between the cylinder and the input piston, It includes an elastic body that transmits the load received by the input piston to the cylinder and the output piston, and includes force component means that transmits a part of the load received by the input piston to the sprung member and the rest to the valve piston. It is configured as follows.

Functions and Effects In the device configured as described above, the input piston that receives the load of the suspension spring is attached to the support shaft that connects the suspension spring to the sprung member. Since the load is transmitted at one location, the structure can be simplified.

Furthermore, since the input piston and cylinder are groove-shaped, it is easy to avoid interference with the suspension spring, which is shaped like a strip, and it is easy to attach them to the support shaft.

One end of the suspension spring is fitted inside a groove-shaped input piston and is rotatably connected by a support shaft, and the input piston is fitted into a groove-shaped cylinder as well, allowing the support shaft to move up and down relative to the cylinder. By guiding one end of the suspension spring can be connected to the sprung member via the cylinder and input piston. In this way, by making the input piston and cylinder, which are the components of the load sensing device, also serve as the components of the connection device to the sprung member of the suspension spring, the structure can be simplified, and the cost and weight can be reduced. can be achieved.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 3 is a diagram showing the entirety of a load-sensing brake fluid pressure control device which is an embodiment of the present invention. In the figure, numeral 10 is a frame which is a sprung member. This frame 10 and a rear axle housing which is an unsprung member. A stacked leaf spring 14 as a suspension spring is disposed between the spring 12 and the spring 12. The stacked leaf spring 14 is made by stacking a plurality of strip-shaped leaf springs 16, one longitudinal end of which is attached to the frame 10 via a shackle 18, and the other end attached to a support shaft. It is connected to a pair of reinforcing plates 22 (only one of which is shown in the figure) fixed to the frame 10 by bolts 20 such that they can move relative to each other in the vertical direction.

As shown in FIG. 1, the frame 10 has a square cross-sectional shape, and the reinforcing plates 22 are fixed to both sides of the frame in the left-right direction of the vehicle. The cylindrical member 24 is fixed with its center line extending in the left-right direction of the vehicle, and a promotion valve 26 is accommodated within the cylindrical member 24. An L-shaped lever 30 is mounted within the cylindrical member 24 so as to be rotatable around a shaft 32 extending in the longitudinal direction of the vehicle. ,
A plate 40 and a compression coil spring 42 are interposed. As a result, the valve body 34 is biased toward the inside of the vehicle, and the snap spring 44
is prevented from coming off from the cylindrical member 24. 46 is a cap that covers the opening of the cylindrical member 28.

The valve body 34 includes a first port 50 connected to a brake master cylinder (not shown) and a second port 52 connected to a wheel cylinder.
A stepped hole 54 with a bottom and opening at the end surface on the outside of the vehicle is formed. This stepped hole 54 is formed concentrically with the plate 40, and its opening is closed by fitting a plug 56 in a liquid-tight manner and cannot be removed, so that a hydraulic pressure chamber 58 is formed inside the valve body 34. are formed, and the first port 50 and the second port 52 are communicated with the hydraulic pressure chamber 58 through liquid passages 60 and 62, respectively.

A valve piston 64 is fitted within the hydraulic pressure chamber 58 so as to be slidable in the axial direction. The end of the valve piston 64 on the outside of the vehicle is sealed by a cup seal 66 and protrudes to the outside of the valve body 34, but the other end is located inside the hydraulic chamber 58, and a valve is attached to the tip of the valve piston 64. A child 68 is integrally formed. The valve piston 64 is normally kept at the deepest position retracted into the main body 3 by the compression coil spring 70, and in this state, the valve piston 68
is apart from the valve seat member 72. Therefore, the brake fluid supplied from the hydraulic pressure source is supplied to the wheel cylinder as it is. Further, a ball 74 is rotatably held at the end of the valve piston 64 projecting from the main body 34 and is brought into contact with the plate 40 . The ball 74 is brought into contact with the center of the plate 40 by forming the stepped hole 54 concentrically with the plate 40 .

The pair of reinforcing plates 22 are fixed such that their lower ends extend downward from the frame 10,
Each of the extending portions has a long hole 8 extending vertically.
0 is formed, and a cylinder 82 is formed inside.
are fitted. The cylinder 82 has a groove shape with side walls 86 hanging from both ends of a bottom wall 84, and is fixed to the lower surface of the frame 10 at the bottom wall 84. Elongated holes 88 similar to 80 are formed respectively. An input piston 90 is fitted into the cylinder 82 so as to be movable in the vertical direction.
The input piston 90 also has a groove shape with side walls 94 depending from both ends of a bottom wall 92,
A through hole 96 through which the bolt 20 is inserted is formed in each side wall 94, and is attached to the reinforcing plate 22 together with the stacked leaf spring 14.

The reinforcing plate 2 is attached by the bolt 20 of the stacked leaf spring 14.
As shown in FIG. 2, the end of the side to be connected to 2 is curved into a partially cylindrical shape, and inside thereof there are a metal bushing 98 and a rubber bushing 100.
and are fixed by vulcanization adhesive. Then, when the end of the stacked leaf spring 14 is inserted between the reinforcing plates 22, the input piston 90 has its opening facing downward, and the rubber bush 1 is connected to the side wall 94.
00 from both sides in the longitudinal direction.
2, the bolt 20 is inserted into the elongated holes 80, 88, the through hole 96, the bush 98, the through hole 96, the elongated holes 88, 8 from the side of the reinforcing plate 22 on the outside of the vehicle.
0 and is supported by the reinforcing plate 22 by screwing the nuts 102 and 104 together. These nuts 102 and 104 are screwed together with a slight gap between the inner nut 102 and the reinforcing plate 22, and the input piston 90 is supported by the bolt 20 together with the stacked plate spring 14, and A state in which the stacked leaf spring 14 is allowed to move relative to the frame 10 within the range in which the bolt 20 moves within the elongated holes 80 and 88 while receiving the load of the spring 14, and the input piston 90 is allowed to move relative to the cylinder 82. becomes.

A rubber elastic body 110 is disposed between the cylinder 82 and the input piston 90, and an output piston 112 with a circular cross section is movable in the vertical direction at the center of the bottom wall 84 of the cylinder 82. is mated to. The upper end of the output piston 112 penetrates the frame 10 and projects into the interior thereof, and an arm portion 114 on the opposite side of the arm portion 38 that is in contact with the plate 40 of the lever 30 is provided on the upper surface of the output piston 112. being brought into contact. This arm portion 114 is inserted into the frame 10 through elongated holes 116 and 118 formed in the reinforcing plate 22 and the frame 10, respectively. It can be twisted and rotated.

In the brake fluid pressure control device configured as described above, approximately half of the wheel load is applied to the elastic body 110 via the suspension spring 14, bolt 20, and input piston 90. The elastic body 110 is connected to the cylinder 82 and the output piston 112.
The force applied to the output piston 112 is transmitted to the plate 40 by the lever 30. The upward force transmitted by the output piston 112 is applied to the lever 30.
It is then turned 90 degrees and added to the plate 40. Since the compression coil spring 70 applies a force opposite to the force applied by the lever 30 to the plate 40, the force applied to the plate 40 by the lever 30 acts on the valve piston 64. A force equal to the biasing force of the compression coil spring 70 is applied. A portion of the wheel load is applied to the valve piston 64, and the proportioning valve 26 reduces the pressure when the hydraulic pressure supplied from the master cylinder reaches a predetermined hydraulic pressure corresponding to the wheel load. The hydraulic pressure in the wheel cylinder is controlled to a level corresponding to the wheel load.

In the above embodiment, it is desirable to attach a dust boot to prevent water, dust, etc. from entering between the bolt 20, cylinder 82, input piston 90, etc.

Further, as shown in FIG. 4, a rubber elastic body 124 may be interposed between the input piston 120 and the cylinder 122. This elastic body 124 is connected to the input piston 120 and the cylinder 122.
The input piston 120 and the cylinder 122 have a groove shape having a bottom wall 126 sandwiched between the bottom wall 126 and a pair of side walls 128 depending from both ends of the bottom wall 126 . It is fixed by vulcanization adhesive.
The side wall 128 includes a cylinder 122 and a reinforcing plate 132.
A long hole 138 similar to the long holes 134 and 136 provided in each of the stacked leaf springs 14 and 138 is provided.
0 is allowed to move. Furthermore, the elongated hole 13 of the bolt 142
A roller 144 is rotatably attached to a portion located within 4,136. The rest of the configuration is the same as that of the previous embodiment, and corresponding parts are given the same reference numerals and detailed explanations will be omitted.

In this way, relative movement of the input piston 120 with respect to the cylinder 122 is allowed by elastic deformation of the side wall 128 of the elastic body 124, and sliding between the input piston 120 and the cylinder 122 can be avoided. Furthermore, the roller 144 reduces frictional resistance and wear on the bolt 142 and the inner surfaces of the elongated holes 134 and 136.

In addition, in the above embodiment, the output piston 11
The force applied to the plate 40 can be reduced by appropriately setting the lever ratio of the lever 30 that transmits the force received by the plates 2 and 130 to the plate 40.

Furthermore, if the proportioning valve 26 can be provided in the vertical direction, the lever 30 may be omitted and the output pistons 112, 130 may be brought into direct contact with the plate 40.

Further, in the above embodiment, the case where a proportioning valve is used as the pressure reducing valve has been described, but the same effect can be obtained even when a limit valve is used, and the pressure reducing valve can be attached to an unsprung member. The present invention can also be applied to a load-sensing brake fluid pressure control device.

Although not illustrated in detail, the present invention can be implemented in various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a front cross-sectional view showing the entirety of a load-sensing brake fluid pressure control device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view along the line shown in FIG. 1. FIG. 3 is a side view showing the main parts of the hydraulic pressure control device. FIG. 4 is a front sectional view showing the main parts of a load-sensing brake fluid pressure control device according to another embodiment of the present invention. 10... Frame, 12... Rear axle housing, 14... Layered leaf spring, 20... Bolt,
26... Proportioning valve, 34... Valve body, 64... Valve piston, 82... Cylinder, 84... Bottom wall, 86... Side wall, 90...
Input piston, 92...bottom wall, 94...side wall, 1
10...Elastic body, 112...Output piston, 12
0...Input piston, 122...Cylinder, 12
4...Elastic body, 130...Output piston, 140
...Stacked leaf spring, 142...Bolt, 144...
roller.

Claims (1)

[Claims for Utility Model Registration] A belt plate-like member disposed between a sprung member and an unsprung member, one longitudinal end of which is vertically movable relative to the sprung member via a support shaft. A suspension spring that is rotatably and rotatably connected to each other, and a valve piston that protrudes from the valve body to the outside, is attached to the sprung member, and is configured to apply brake fluid pressure supplied from a brake master cylinder to a wheel cylinder of a wheel. A pressure reducing valve for reducing pressure, and a pair of side walls hanging down from both ends of the bottom wall to form a groove, the opening facing downward to the support shaft, and connecting the suspension spring to the support shaft. The input piston is mounted so as to be relatively rotatable with the suspension spring housed therein, and includes an input piston that receives the load of the suspension spring, and a pair of side walls that are suspended from both ends of the bottom wall, forming a groove shape. A cylinder that is fixed to the upper member, accommodates the input piston so as to be movable relative to the input piston in the vertical direction, and guides the support shaft so as to be movable in the vertical direction; an output piston fitted so as to be movable relative to the input piston; and an elastic body disposed between the cylinder and the input piston to transmit a load received by the input piston to the cylinder and the output piston. a load-sensing brake fluid pressure control device, comprising force component means for transmitting a portion of the applied load to the sprung member and the remainder to the valve piston.