JPS61119829A - Hydraulic buffer - Google Patents

Abstract

PURPOSE:To adjust a desired damping force according to the traveling condition or the like of a vehicle by operating a control valve with the rotational displacement of a suspension spring of a hydraulic buffer when the suspension spring is expanded and compressed. CONSTITUTION:A suspension spring 4 is compressed as the upper end of a piston rod 2 descends, and the lower end of the suspension spring will be rotated as it is compressed. A damping force will be adjusted in response to the compressive displacement of the suspension spring 4, and on the basis of a control valve 5 the highest pressure side damping force can be brought about when the suspension spring 4 is compressed to the extremely. Thus, by selecting the shape of the control valve 5 is brought about a high damping force when the suspension spring 4 is extended and compressed to the extremely so that a desired damping force can be adjusted according to the traveling condition of a vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydraulic shock absorber, and particularly to a hydraulic shock absorber whose damping force can be adjusted.

[Conventional technology]

Various types of hydraulic shock absorbers have been proposed so far to be able to adjust damping force.

For example, a hydraulic shock absorber may have a control valve disposed inside it that can adjust the damping force, and may also be configured to operate the control valve by an appropriate means. be.

According to this conventional example, the desired damping force can be adjusted by operating the control valve manually or by energizing a solenoid, motor, etc. as an actuator. There is.

[Problem that the invention seeks to solve]

However, when operating the control valve manually, it is not possible to automatically adjust the damping force according to the driving conditions and road surface conditions while the vehicle is running, which may result in less favorable ride comfort and handling stability. There is an inconvenience that it cannot be done.

In addition, when it is decided to automatically operate an actuator consisting of a solenoid, a motor, etc. according to the driving conditions of the vehicle and the road surface condition, the control valve is thereby operated in the desired manner, and the desired damping force is adjusted. includes a controller that sends an operation signal to the actuator, a detection means such as a vehicle speed detection means for detecting the vehicle speed or a vehicle height detection means for detecting the vehicle height, and arithmetic processing of the output signal from the detection means. This requires the installation of multiple devices such as processing means for outputting the data to the controller, which complicates the overall configuration, increases the number of parts, and increases the cost of the hydraulic shock absorber.

In view of the above-mentioned circumstances, the present invention has been devised to make it possible to automatically adjust the desired damping force according to vehicle driving conditions, road surface conditions, etc., without requiring the installation of multiple devices. The purpose is to provide a new hydraulic shock absorber.

[Means for solving problems]

In order to solve the above problems, the structure of the present invention is such that a predetermined damping force is generated when the piston rod inserted into the cylinder slides, and a control valve is provided to adjust the predetermined damping force. The hydraulic shock absorber has a suspension spring whose upper end is connected to the piston rod side and whose lower end is connected to the cylinder side, and is controlled by the rotational displacement of the upper end or lower end when the suspension spring is expanded or contracted. It is characterized by being formed to operate a valve.

〔Example〕

The present invention will be described below based on illustrated embodiments.

As shown in FIG. 1, the hydraulic shock absorber according to the present invention has a piston portion 3 at the lower end of a piston rod 2 slidably inserted into a cylinder 1, and an upper end located outside the cylinder 1. The piston rod 2 side has a suspension spring 4 whose lower end is connected to the cylinder 1 side. A control valve 5 is disposed inside the lower end of the cylinder 1.

The cylinder 1 has a seal case 10 inside its upper end, and the piston rod 2 is inserted into the central through hole of the seal case 10. A bushing 11 is provided on the inner circumferential surface of the central through hole, and the bushing 11
The piston rod 2 is brought into sliding contact with the piston rod 2. Further, an O-ring 12 is interposed on the surface of the seal case 10 adjacent to the inner circumferential surface of the upper end of the cylinder 1, and an annular dust seal 13 is provided on the inner circumferential edge of the upper end of the central through hole, and an annular dust seal 13 is provided on the inner circumferential side of the upper end of the central hole Each peripheral edge has an annular oil seal 14. Note that a cylinder 1 is provided at the lower end of the seal case 10.
An annular stopper 15 is disposed on the inner periphery of the ring.

The lower end of the cylinder 1 has a bracket 16 that allows the hydraulic shock absorber to be attached to the axle side of a vehicle. The control valve 5 is disposed at the upper end of the bracket 16, and an operating mechanism 6 for operating the control valve 5 is formed in the bracket 16.

The piston rod 2 is formed to have an eye 20 at its upper end to allow attachment of the hydraulic shock absorber to the vehicle body side. An annular flange portion 21 is formed below the eye 20, and a thick annular bump rubber 22 is disposed on the lower surface of the flange portion 21, and the suspension spring is attached to the flange portion 21. 4 is adapted to be locked at the upper end.

The piston section 3 divides the inside of the cylinder 1 into a rod-side oil chamber A and a piston-side oil chamber B, and generates a predetermined damping force when sliding, that is, when the piston rod 2 slides. It has a valve 30. The damping valve 30 is designed to generate damping forces in both directions: a rebound damping force during the extension stroke when the piston section 3 moves up within the cylinder 1, and a compression damping force during the compression stroke when the piston section 3 descends within the cylinder 1. In this embodiment, it is formed of a variable throttle, and is formed so that the damping force in both directions can be adjusted by the piston portion. The piston portion 3 includes a relief valve 31 that relieves the oil in the rod-side oil chamber A to the piston-side oil chamber B, and a relief valve 3 that relieves the oil in the piston-side oil chamber B to the rod-side oil chamber A.
2 are arranged.

The suspension spring 4 has its upper end engaged with an annular upper guide 40 fixed to the outer periphery of the annular 7-rank portion 21 of the piston rod 2, and its lower end rotatably interposed on the lower end outer periphery of the cylinder 1. equipped annular lower guide 4
1 is locked. That is, the upper end of the suspension spring 4 is fixedly connected to the piston rod 2 side via the upper guide 40, while the lower end rotates around the outer periphery of the cylinder 1 via the lower guide 41. It is connected to the cylinder 1 side as shown in FIG.

The control valve 5 adjusts the compression side damping force generated by the piston portion 3, and in this embodiment, it is disposed inside the lower end of the cylinder 1 at a portion corresponding to the upper end of the bracket 16. It is housed in a block 50 provided therein. Then, the block 50
As shown in FIG. The amount of oil passing through the housing 51 is adjusted by rotational displacement.

That is, as shown in FIG. 2, the rotary valve 52 is formed by cutting out a part of the main body that is sealed in the housing 51 in a crescent shape in plan view.
The rotary valve 52 moves clockwise or toward the half-hour hand in the figure.
When the block 50 rotates, the degree of opening with respect to the oil passage 50α bored in the lower surface of the block 50 is changed.

Note that the oil passage 50α is communicated with an oil passage 16α bored in the lower bracket 16, and the oil passage 16
(It is communicated with the inside of the external accumulator Q via the inside of the external hose H, which is connected with Z.

Further, in the block 50, the accumulator Q
Although it is possible for oil to flow into the piston side oil chamber B from the side,
A check valve 53 is provided to prevent oil from flowing from the piston side oil chamber B to the 7th cumulator Q side, and in this embodiment, a steel ball 53α and a spring that energizes the steel ball 53cL are provided. 536 and a snap ring 53C that locks the rear end of the spring 536
It consists of. Note that a variable throttle ○ may be disposed in the hose H to control the flow rate when oil flows between the hose H and the accumulator Q, thereby adjusting the damping force.

An operating mechanism 6 for operating the control valve 5 includes a rotary rod 60 connected to the rotary valve 52.
By rotating the rotary rod 60.

The rotary valve 52 is formed to be rotatable.

That is, the rotary rod Go is attached to the bracket 1.
An adjustment gear 61 rotatably housed within the bracket 16 is connected to the lower end of the rotary rod 6o. The bracket 16 is attached to the adjustment gear 61.
An internal gear 62 rotatably disposed on the outer periphery of the pin 63α is engaged with the dust cover 63 fixed to the lower guide 41 that locks the lower end of the suspension spring 4. connected by. Further, an annular seal case 64 is disposed on the inner periphery of the upper end of the dust cover 63, and an annular dust seal 64α is interposed on the upper inner periphery of the seal case 64. An annular transfer plate 6 is provided on the bottom surface of the case 64.
5 is attached.

Furthermore, an annular thrust bearing 66 is in contact with the lower surface of the transfer plate 65, and an annular fixed plate 67 is in contact with the lower surface of the thrust bearing 66. The fixing plate 67 includes an annular flange portion 161 extending horizontally from the intermediate body portion of the bracket 16.
! It is supported on the top surface of I. Note that the adjustment gear 61 has a spring 61 interposed between it and a wear prevention plate 61α disposed in contact with the bracket 16.
J is energized and fixed in a predetermined position.

The operation of the hydraulic shock absorber according to the present invention configured as above will be briefly explained.

First, one end of the suspension spring 4 (upper end in the embodiment shown in FIG. 1) is held as a fixed end, and the other end (lower end in the embodiment shown in FIG. 1) of the suspension spring 4 is held as a fixed end. When held as a free end so that it can rotate freely around the axis,
When a compressive force P that compresses the suspension spring 4 is applied in the axial direction of the suspension spring 4, the other free end rotates by an angle θ shown by the following formula (1) or (2). .

θ-P-v/C1+v)-8rLD2/Cd,'
−sin, 2a ---(1) θ=apeν/(1+
v ) @1/KD -5in2a --- (2) where: Poisson's ratio of the material G: Transverse elastic modulus of the material d: Wire diameter D: Suspension spring diameter n + 1 effective number of turns α: Pitch angle: Spring constant It is.

As is clear from the above (11 or (2)), the rotation angle θ
is proportional to the load P, and the load P is proportional to the compressive displacement δ. Therefore, the rotation angle θ is proportional to the pressure M displacement δ.

Therefore, the present invention attempts to operate the control valve 5 at a rotation angle θ that matches the load P, that is, the compression displacement δ, based on the relationship among the rotation angle θ, the compression displacement δ, and the load P. In other words, the suspension spring 4 is the control valve 5.
This is an actuator for operating the .

Therefore, from the state shown in Figure i1, when a load from the vehicle body side of the vehicle acts on the upper end of the piston rod 2 and the piston part 3 enters a pressure stroke in which it descends within the cylinder 1, the inside of the piston side oil chamber B The oil flows into the rod-side oil chamber A through the damping valve 3o of the piston part 3 and generates a predetermined pressure-side damping force, and from the piston-side oil chamber B corresponds to the entering volume of the piston rod 2. The oil will flow out to the accumulator Q side via the control valve 5.

At this time, as the upper end of the piston rod 2 descends, the suspension spring 4 is compressed, and as the suspension spring 4 is compressed,
The lower end will rotate. That is, suspension spring 4
When the lower guide 41 that locks the lower end of the seal case 64 is rotated, the seal case 64 is rotated via the lower dust cover 63. When the seal case 64 is rotated, the lower transfer plate 65 is rolled. That is, the transfer plate 65 can freely rotate relative to the fixed plate 67 by the lower thrust bearing 66.

On the other hand, the rotation of the dust cover 63 rotates the internal gear 62 connected to the dust cover 63 by a pin 63α, and the rotation of the internal gear 620 rotates the adjustment gear 61 meshing therewith. The rotation of the adjustment gear 61 rotates the rotary rod 60, and the rotary valve 52 of the control valve 5 connected to the rotary rod 60 rotates within the housing 51.

Then, by rotating the rotary valve 52, the opening degree of the lower oil passage 50α of the block 50 is adjusted to a smaller value, and oil flows from the piston-side oil chamber B to the 7th cumulator Q corresponding to the volume of entry of the piston rod 2. The amount of outflow is limited, that is, the damping force of the suppression is adjusted to be high.

That is, according to the present invention, the damping force is adjusted according to the compression displacement δ of the suspension spring 4, and when the control valve 5 as shown in FIG. It becomes possible to generate damping force. Therefore, by selecting the shape of the control valve 5, it is possible to freely generate a high damping force when the suspension spring 4 is fully extended and compressed, and to generate a moderate damping force in the middle. . Furthermore, when using the control valve 5 as shown in the figure, the damping force can be adjusted continuously without steps.

Figure 3 shows a hydraulic shock absorber according to another embodiment of the present invention, and instead of the embodiment shown in Figure 1, which is formed into a single cylinder type, the hydraulic shock absorber has a double cylinder shape. It is formed into a cylindrical shape.

That is, an outer shell 17 is disposed outside the cylinder 1, and a reservoir chamber C is formed between the outer shell 17 and the cylinder 1. The reservoir chamber C is communicated with the inside of the piston-side oil chamber B inside the cylinder 1 via a control valve 5 and a base valve 7 arranged inside the lower end of the cylinder 1. A gas chamber is provided above the reservoir chamber C.

Then, the upper end of the cylinder 1, that is, the outer shell 17
A bearing 18 is interposed inside the upper end of the piston rod 2, and the piston rod 2 is slidably inserted into the central through hole of the bearing 18.

The piston portion 3 disposed within the cylinder 1 is formed to generate a damping force on the rebound side, and in this embodiment, a damping valve 3 consisting of a variable throttle
0, and a relief valve 31 whose function is to relieve oil from the rod-side oil chamber A to the piston-side oil chamber B;
It has a check valve 33 that prevents oil from flowing out from the rod side oil chamber A into the piston side oil chamber B.

The base valve 7 is formed as a compression-side damping valve, and has an oil passage 70α formed in a valve case 70 disposed between the block 50 of the control valve 5 and the cylinder 1. The upper end opening has an annular leaf valve 71 disposed with a fixed inner peripheral end, and the upper surface of the leaf valve 71 has a non-return valve 72 disposed so as to close the upper end opening. It becomes. The non-return valve 72 is the valve case 7
It is biased downward by a spring 74 whose rear end is locked to a set pin 73 disposed on the solid shaft core of the leaf valve 71. It has opposing orifices 72α.

Therefore, the oil in the piston side oil chamber B is removed from the non-return valve 7.
At the same time, the outer peripheral end of the lower leaf valve 71 is bent, and the oil flows out into the lower oil passage 70α. Then, when the outer peripheral end of the leaf valve 71 is bent and oil passes through, a predetermined pressure-side damping force is generated. The oil that has flowed into the oil passage 70α also flows into the reservoir chamber C via the lower control valve 5.

Note that the oil flowing out to the reservoir chamber C side via the control valve 5 passes through the lower surface oil passage 50α of the block 5o, and the oil passage 5oα is directly connected to the inside of the reservoir chamber C, and the oil passage 5oα is directly connected to the inside of the reservoir chamber C. Drilling of an oil passage 16α (see Figure 1) in 16 is omitted.

Furthermore, in this embodiment, the piston rod 2
, suspension spring 4, control valve 5 and actuation mechanism 6
The configuration is the same as that of the embodiment shown in FIG.

Figure 4 shows a hydraulic shock absorber according to yet another embodiment of the present invention, and in this embodiment, the control valve 5 is different from the embodiment shown in Figures 1 and 3. The difference is that a control valve 5 is disposed inside the piston rod 2 near the lower end, instead of being disposed at the lower end of the cylinder 1.

The actuation mechanism 8 that operates the control valve 5 is disposed on the piston rod 2 side, and the suspension spring 4 as an actuator has its lower end fixedly connected to the cylinder 1 side. The upper end thereof is rotatably connected to the upper end side of the piston rod 2 so as to be a free end.

Hereinafter, differences from each of the embodiments described above will be briefly explained.

That is, an eye 19 is connected to the lower end of the cylinder 1, allowing the hydraulic shock absorber to be attached to the axle side of a vehicle. Further, a base valve 7 is disposed inside the lower end of the cylinder 1, and the base valve 7 has a pressure side valve 75 consisting of a throttle and allows oil to flow from the first piston side oil chamber B to the reservoir chamber C side. It has a check valve 76 that prevents the piston-side oil chamber B from leaking, and a relief valve 77 that causes the oil in the piston-side oil chamber B to leak into the reservoir chamber C. A damping valve 3 is provided in the piston portion 3.
(See Figure 01'1 and Figure 3) is not provided, and the inside of the cylinder 1 is only divided into a rod-side oil chamber A and a piston-side oil chamber B.

A control valve 5 is disposed inside near the lower end of the piston rod 2, and the control valve 5 is rotatably disposed within a housing 23 formed from the lower end of the piston rod 2 to the inside near the lower end. The rotary valve 54 includes an orifice 54 (Z).

A communication hole 24 is formed in a corresponding portion of the piston rod 2 that the orifice 54α faces, and the degree of opening between the orifice 54α and the communication hole 24 is adjusted by rotating the rotary valve 54. The damping force is variably generated by this. The lower end of a rotary rod 80, which is an element of the actuation mechanism 8, is connected to the rotary valve 54, which is the control valve 5, and the rotary rod 80 has an axial center bored from near the lower end to the upper end of the piston rod. It is rotatably housed in a central through hole formed by Furthermore, a bracket 25 is connected to the upper end of the piston rod 2 to allow the lower end of the hydraulic shock absorber to be attached to the vehicle body side of the vehicle.

The O-ar guide 41 that locks the lower end of the suspension spring 4 is
It is fixedly abutted against an annular stopper 42 fixed to the outer periphery of an outer shell 17 disposed outside the cylinder 1 . An upper guide 40 that locks the upper end of the suspension spring 4 is rotatably connected to the upper end of the piston rod 2 via an actuating mechanism 8 provided on the bracket 25. It is.

The basic structure of the operating mechanism 8 is not different from the operating mechanism 6 shown in FIG. 1 and FIG.
Since the rotary rod 80 is housed in the through hole of the shaft core of the piston rod 2, the bracket 25 is connected between the adjustment gear 81 and the internal gear 82 by a pin 83α.
There is a difference in that an intermediate gear 83 held by the intermediate gear 83 is interposed. Further, the internal gear 82 is connected to a lower dust cover 84 that is in contact with an upper guide 40 that locks the upper end of the suspension spring 4. The lower dust cover 84 is connected to an annular seal case 85 disposed on its inner circumference, and is connected to an annular transfer plate 86 disposed on the upper edge of the inner circumference of the seal case 85. ing.

An annular thrust bearing 87 is disposed on the upper surface of the rolling plate 86.
An annular fixing plate 88 is disposed on the upper surface of 7. Further, the fixing plate 88 is fixed to the bracket 25.

Note that the bump rubber 22 is held on the lower surface of the lower dust cover 84, and the seal case 85 is held on the lower surface of the lower dust cover 84.
A dust seal 85α is disposed on the lower edge of the inner peripheral side. Another dust seal 84c is interposed on the inner periphery of the upper end of the lower dust cover 84, and the internal gear 8 is disposed on the outer periphery of the upper end of the lower dust cover 84.
An upper dust cover 89 formed to cover 2 is disposed. Further, the upper dust cover 89 is fixed to the bracket 25 by a snap ring 89α interposed on the bracket 25.

Furthermore, the adjustment gear 81 is connected to the bracket 25.
It is formed so as to be fixed in a predetermined position by being biased by a spring 81h interposed between the wear prevention plate 81α and the abrasion prevention plate 81α that is in contact with the side.

In the hydraulic shock absorber according to this embodiment configured as described above, rotation due to compression displacement of the suspension spring 4 is generated at the upper end side of the suspension spring 4, and the rotation of the upper end causes the operating mechanism to 8 is operated, and the control valve 5 performs a predetermined operation.

Note that, instead of this, the control valve 5 in this embodiment has a notch 54b formed in the rotary valve 54, as shown in Figure 5 (In) and Figure 58 (B). It may be formed to adjust the degree of opening between the piston rod 2 and the communication hole 24 of the piston rod 2, and it goes without saying that the configuration is arbitrary.

〔Effect of the invention〕

According to the present invention, it is possible to automatically adjust the damping force according to the driving conditions of the vehicle and the road surface condition, and there is an advantage that the riding comfort and steering stability of the vehicle are improved.

Further, according to the present invention, in the operation of the control valve, equipment such as actuators such as solenoids and motors, controllers for driving the actuators, and equipment such as vehicle height or vehicle speed detection means such as sensors, processing means, etc. This has the advantage of eliminating the need for additional equipment, reducing the number of parts, and contributing to lower costs.

Furthermore, by selecting the configuration of the control valve, it is possible to adjust the desired damping force, which has the advantage of improving the versatility of the hydraulic shock absorber.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing a hydraulic shock absorber according to an embodiment of the present invention. Figure t-2 is an enlarged cross-sectional view of the control valve portion indicated by the line ■-■ in Figure 1, and Figures 3 and 4 show hydraulic shock absorbers according to other embodiments of the present invention, similar to those in Figure 1. Figure 5 (a) is an enlarged vertical cross-sectional view showing another embodiment of the control valve, and Figure 5 (0) is a cross-sectional view shown by the middle line of Figure 5 (a). . 1...Cylinder, 2...Piston rod, 3...
Piston part, 4... Suspension spring, 5... Control valve, 6, 8... Operating mechanism, 7... Base valve, 16.25... Bracket, 17.1 Outer shell, 30.75 -... Damping valve, 40... Upper guide, 41-... Lower guide, 52.54... Rotary valve, 60.80... Rotary rod, 61
．． 81...Adjust gear, 62.83...Internal gear, 65.86...Transfer plate, 66, '87...
Thrust bearing, 67.88-・Fist fixing plate, A・・
・Rod side oil chamber, B...Piston side oil chamber, C...Reservoir chamber, D...Gas chamber, H...Hose, 0...
Variable aperture, Q...accumulator.

Claims (7)

[Claims] (1) In a hydraulic shock absorber, a predetermined damping force is generated when a piston rod inserted into a cylinder slides, and the hydraulic shock absorber is configured to have a control valve that adjusts the predetermined damping force. The device has a suspension spring having an upper end connected to the piston rod side and a lower end connected to the cylinder side, and is configured to actuate a control valve by rotational displacement of the upper end or the lower end when the suspension spring is expanded or contracted. A hydraulic shock absorber characterized by: (2) The hydraulic shock absorber according to claim 1, wherein the control valve is disposed inside the lower end of the cylinder. (3) The hydraulic shock absorber according to claim 1, wherein the control valve is disposed inside near the lower end of the piston rod. (4) The hydraulic shock absorber according to claim 1, wherein the control valve is formed so as to be able to adjust the damping force in either the expansion side or the compression side. (5) The hydraulic shock absorber according to claim 1, wherein the control valve is formed so as to be able to adjust the damping force in both the expansion side and the compression side. (6) The hydraulic shock absorber according to claim 1, wherein the hydraulic shock absorber is formed into a single cylinder. (7) The hydraulic shock absorber according to claim 1, wherein the hydraulic shock absorber is formed into a double cylinder.