JPH0790829B2 - Shock absorber with vehicle height adjuster - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a shock absorber with a vehicle height adjusting device, which is used, for example, in a motorcycle, and in particular, miniaturization of a pressure control device for opening and closing a working fluid passage thereof. Regarding Since the present invention is most suitable for a hydraulic shock absorber, the hydraulic shock absorber will be described below as an example.

[Conventional technology]

A shock absorber with a vehicle height adjusting device used in a motorcycle or the like, for example, secures a predetermined vehicle height during normal traveling, and adjusts the vehicle height to a low value so that these operations can be easily performed during boarding and alighting. It is a device that allows the vehicle height to be changed according to the purpose. In such a shock absorber with a vehicle height adjusting device, a pump chamber is formed in the piston rod of the shock absorber, and a plunger fixed to the cylinder is inserted into this pump chamber to form a pump mechanism. It is configured to adjust the vehicle height by using the hydraulic oil pressurized by the pumping action. For adjusting the vehicle height, it is general to provide a pressure control device for controlling the supply and cutoff of the hydraulic oil to the lift chamber by an external signal.

As the above-mentioned pressure control device, the applicant of the present application has provided a so-called spool valve that opens and closes the hydraulic passage by advancing and retracting an adjusting rod that is hermetically sealed by a seal member with respect to the hydraulic passage. See Japanese Patent Application No. 60-77046).

[Problems to be solved by the invention]

By the way, in particular, in a shock absorber for a motorcycle, there are naturally certain restrictions on the arrangement space and the current capacity for the actuator, and it is required to reduce the size and the capacity of the actuator. However, since the pressure control device according to the above application adopts the spool heightening that moves the valve body in the axial direction against the frictional force of the seal member, the force required to drive the valve body increases accordingly. Therefore, the actuator for driving the valve body needs to have a large size and a large current capacity corresponding to the driving force, and it is difficult to meet the demand for the miniaturization and the small capacity.

The present invention has been made in view of the above conventional demands, and an object of the present invention is to provide a shock absorber with a vehicle height adjusting device that can reduce the force required for actuating a valve element to reduce the actuator size and capacity. I am trying.

[Means for solving problems]

The present invention, as conceptually shown in FIG. 1, shows a pressure control valve 62 of a pressure control device 61 in a shock absorber with a vehicle height adjusting device in a closed state in a pressure supply passage 63. A tilt type valve structure in which the valve body 64 arranged to be biased is tilted by the valve body drive device 65 to open and close the passage 63, and the valve body drive device 65 is brought into contact with the shaft portion of the valve body 64. It is characterized by comprising a rotary cam 66 for tilting the valve body 64 and a lever 68 for connecting a cam shaft 66a of the rotary cam 66 and a reciprocating actuator 67.

[Action]

In the shock absorber with the vehicle height adjusting device according to the present invention, the valve body 64 is tilted so that the passage 63 is opened and closed. Therefore, the force required to open and close the passage 63 does not resist the conventional seal resistance. Compared with the spool type valve structure that moves by moving, it can be made smaller because there is no seal resistance. Further, it is further reduced by setting the valve shaft length B longer than the radius A of the valve body 64. Furthermore, by making the lever length D longer than the turning radius C of the rotary cam 66 that tilts the valve body 64, the force required for opening and closing is further reduced, and therefore the actuator 67 is significantly larger than the conventional one. The size is reduced, and the required current value is greatly reduced.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

2 to 8 are views for explaining a shock absorber with a vehicle height adjusting device according to the first embodiment of the present invention, and this embodiment will be described by taking a so-called accumulator type vehicle height adjusting device as an example.

First, in FIG. 8 showing a schematic structure of the device of the present embodiment and FIG. 7 showing a shock absorber, 2 is a shock absorber, a cylinder 1 of which has a vehicle body supporting portion 1a formed at an upper end thereof, and a lower end thereof at an end. Board
Blocked at 1b. A piston 9 is slidably inserted into the working chamber 3 of the cylinder 1 at the upper end thereof and a vehicle body supporting portion 4 is formed at the lower end thereof.
Furthermore, a lift case 6 having a larger diameter and forming a lift chamber 13 is slidably fitted and attached to the cylinder 1, and the first spring receiver formed in the lift case 6 is mounted.
A buffer spring 8 is inserted between 6c and the second spring receiver 7 of the piston rod 5. This is the main spring 8a and the auxiliary spring 8
A movable spring support 19 is located between the two and is mounted on the cylinder 1 slidably. Reference numeral 10 is a sub tank for replenishing the working oil in the working chamber 3.

A pump chamber 11 is formed in the piston rod 5, and a plunger 12 is slidably inserted in the pump chamber 11 and the plunger 12 is fixed to the cylinder 1. The lift chamber 13, the pump chamber 11, and the working chamber 3 are respectively provided with a main passage 25, and first and second branches branched from the main passage 25.
The first hydraulic passage 1 is communicated with the second hydraulic passages 14 and 15.
A pressure accumulator 17 is connected to 4. Furthermore, the pump chamber 11 and the working chamber 3 are connected by a third hydraulic passage 16.

The hydraulic control device 18 of the present embodiment is provided at the branch portions of the first and second hydraulic passages 14 and 15.
Reference numeral 18 denotes a pressure control valve 19 for switching and communicating one of the first and second hydraulic passages 14 and 15 with the main passage 25, as shown equivalently to FIG. The present embodiment is characterized by the structure of the hydraulic control device 18.

21a and 21b are check valves for accumulating and increasing the vehicle height, 22a and 22b are throttle valves for adjusting ascending speed and descending speed, and 23 is an unload valve for canceling the pumping action when the accumulated pressure exceeds a predetermined value. , 24 are relief valves for safety when the unload valve fails.

Next, the hydraulic control device 18, particularly, will be described in detail with reference to FIGS. 2 to 7 showing a structure embodying FIG.

As shown in FIG. 2, a plug member screwed and fixed to the vehicle body supporting portion 1a at a branch portion between the main passage 25 of the vehicle body supporting portion 1a of the cylinder 1 and the first and second hydraulic passages 14 and 15. A cam accommodating portion 29 that forms a cam chamber with 32 is formed.
A first valve 30 and a second valve 31 are arranged in the first and second hydraulic passages 14 and 15 so as to be axially biased by a biasing spring so as to be compressed to a valve seat. The first and second valves 30 and 31 are circular valve plates 30a and 31a, respectively.
The valve shafts 30b and 31b are integrally formed on the valve shafts 30b and 31b.
Protrudes into the cam accommodating portion 29. The rotary cam 26 is rotatably arranged in the cam accommodating portion 29. The rotary cam 26 is formed by fixing a cam shaft 28 to a cam plate 27, and the first and second valve shafts 30b and 31b are located in the first and second recesses 27a and 27b formed in the cam plate 27. (See FIG. 3).

The cam shaft 28 penetrates the plug member 32 and projects outward, and the central portion of the lever 33 is fixed to the projection by a pin. An output shaft 35 of a solenoid valve 34, which is a reciprocating actuator, is connected to one end of the lever 33 (see FIGS. 4 to 6). The solenoid valve 34 is a bistable latch type that is stable in these two positions after the energization is stopped after the solenoid valve 34 is in the extended state or the contracted state. An external signal from an adjustment switch, a vehicle speed detection sensor (not shown), or the like switches to either state. The solenoid valve 34 is bolted and fixed to a bracket 36 fixed to the vehicle body supporting portion 1a.

Further, a control bar 37 is fixed to the lever 33, and the control bar 37 is inserted into a slit 38a of a control rod 38 which is vertically movably inserted into the lift case 6. When the height reaches a predetermined height, the stopper pin 38b reverses the lever 33 to return the solenoid valve 34 to the neutral position.
Furthermore, a manual wire cable 39 is connected to the other end of the lever 33 through an engaging rod 39a, which is connected to a manual vehicle height switching lever (not shown) arranged on a steering handle or the like. It is connected.

Next, the function and effect of the apparatus of this embodiment will be described.

When the cylinder 1 and the piston rod 5 expand and contract due to the traveling of the vehicle, the pump chamber 11 becomes a negative pressure in the extension stroke, and the working oil in the working chamber 3 flows from the check valve of the unload valve 23 to the third hydraulic pressure. The hydraulic oil flows into the pump chamber 11 through the passage 16, and the hydraulic oil is pumped to the pressure accumulating chamber 17 through the discharge check valve 21a in the contraction stroke by the amount of the intrusion of the plunger 12, and the pumping operation is repeated to accumulate the pressure. High-pressure hydraulic oil is stored in the chamber 17. When the pressure in the pressure accumulating chamber 17 reaches the specified pressure, the unload valve 23 becomes conductive in both directions, and the hydraulic oil that has flowed into the pump chamber 11 in the extension stroke returns to the working chamber 3 as it is in the contraction stroke. The function is lost.

First, when increasing the vehicle height, the driving vehicle switches the vehicle height adjustment switch to the rising side. Then, the solenoid valve 34 expands, the lever 33 rotates the rotary cam 26 in the counterclockwise direction in FIG. 3, and the valve shaft 30b of the first valve 30 is pushed by the first recess 27a of the cam plate 27 to move the valve plate 30a. The main passage 25 and the first hydraulic passage 14 communicate with each other by tilting with one end as a fulcrum. As a result, the high-pressure hydraulic oil in the pressure accumulating chamber 17 flows into the lift chamber 13 through the first hydraulic passage 14 and the main passage 25. As a result, the auxiliary spring 8b is compressed to bring the lift case 6 and the movable spring support 19 into contact with each other, the set load and spring constant of the buffer spring 8 increase, and the sinking amount of the shock absorber 2 decreases. Becomes higher. Then, when the vehicle height reaches a predetermined height, the control bar 37 contacts the stopper pin 38b of the control rod 38 and the lever 33 is pushed back to the original neutral position, whereby the first valve 30 is in the original upright state. Then, the first hydraulic passage 14 is closed and the vehicle height is maintained at a predetermined height.

Next, when lowering the vehicle height, the driver switches the vehicle height adjustment switch to the descending side. Then, the solenoid valve 34 contracts, the lever 33 rotates the rotary cam 26 in the clockwise direction, and the valve shaft 31b of the second valve 31 is pushed by the second recess 27b of the cam plate 27 and tilts, so that the main passage 25 and the first passage 25 are connected. 2 Communicates with the hydraulic passage 15. As a result, the working oil in the lift chamber 13 returns to the working chamber 3 through the main passage 25 and the second hydraulic passage 15, which reduces the set load and spring constant of the buffer spring 8 and increases the amount of depression. , As a result, the vehicle height becomes low. In an emergency such as a malfunction of the solenoid valve 34, when the switching lever such as the steering handle is rotated to the lower side, the wire cable 39 causes the lever 33 to rotate to the lower side, which is the same as the case described above. And the vehicle height becomes low.

As described above, in the present embodiment, the vehicle height adjustment hydraulic control device 18
Is a tilt type valve structure that opens and closes the hydraulic passage by tilting the valve element, so the force required for its operation is greater than that of the spool type that moves the valve element axially against the seal resistance. Is small because there is no seal resistance.
Further, the valve shaft length is made longer than the valve plate diameter of the tilt type valve bodies 30 and 31, and the structure in which the valve body is tilted is such that the rotary cam 26 is rotated by the solenoid valve 34 via the lever 33. At the same time, the radius of gyration of the lever 33 is made larger than the radius of gyration of the rotary cam 26, so that the operating force for tilting the valve body can be further reduced. As a result, the solenoid valve 34, which is a vehicle height adjusting actuator, can be downsized, and as a result, the required space can be reduced and the required current capacity can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIGS. 9 to 13.

This embodiment is an example of a so-called direct type in which the hydraulic oil by the pumping action is directly supplied to the lift chamber, and the same reference numerals as those in FIGS. 2 to 8 indicate the same or corresponding portions.

In the present embodiment, the hydraulic control device 48 is configured so that only the second hydraulic passage 15 that connects the lift chamber 13 and the working chamber 3 can be opened / closed, that is, only the decrease in vehicle height can be controlled. Further, the vehicle height is raised by switching the check valve of the unload valve 43 and the conducting portion by the control bar 57.

The hydraulic control device 48 mainly comprises a hydraulic control valve 49 and a valve body drive device 50. As shown in FIG. 9, the hydraulic control valve 49 is connected to the main passage 25 and the second hydraulic passage 15. Disc 45
Is arranged such that its valve body 45a is axially biased so as to come into pressure contact with the valve seat, and its valve shaft 45b is projected into the cam accommodating chamber 29. And in this cam storage chamber 29, a rotating cam
The cam plate 52 of 51 is rotatably arranged.
Is a disc-shaped member having a notched recess 52a, and the valve shaft 45b is located in the recess 52a (see FIG. 10).
A lever 33 is connected to the cam shaft 53 of the rotary cam 51, and a solenoid valve 34 and a wire cable 39 are connected to the lever 33.

As shown in FIG. 11, the unload valve 43 has a valve chamber 54 formed in the third passage 16 that connects the pump chamber 11 and the working chamber 3, and the sensor member 55 is disposed in the valve chamber 54 outwardly. The valve plate 56 is arranged so as to be able to project and retract freely and to be urged in the axial direction. In addition, 44 is a relief valve.

The outer end of the sensor member 55 is in sliding contact with the control surface 57a of the control bar 57 attached to the flange 6a at the upper end of the lift case 6, and an inclined surface 57b is formed on the control surface 57a. There is. Also this control bar 5
The mounting base 57c of 7 has a pin hole 57d with a predetermined pitch and a guide groove 5d.
7e is formed and inserted in the flange portion 6a so as to be vertically movable. The flange portion 6a is provided in the guide groove 57e.
The detent pin 6b fixed to the above is engaged, and the stopper pin 58 is inserted into the pin hole 57d located on the upper and lower surfaces of the flange portion 6a.

Next, the function and effect of the second embodiment will be described.

In the expansion stroke, the hydraulic oil that has flowed into the pump chamber 11 from the working chamber 3 through the check valve portion of the unload valve 43 of the third hydraulic passage 16 flows through the first hydraulic passage 14 in the contracting stroke to the lift chamber 13
It is pumped into the inside, whereby the set load and the spring constant increase and the amount of subsidence decreases, and as a result, the cylinder 1 rises and the vehicle height increases. When the sensor member 55 of the unload valve 43 comes to the inclined surface 57b of the control bar 57 as the vehicle height rises, the sensor member 55 moves forward and a conduction gap is formed between the valve plate 56 and the sensor member 55. As a result, the check valve function of the unload valve 43 is lost, and as a result, the hydraulic oil flowing from the working chamber 3 into the pump chamber 11 in the expansion stroke returns to its original state in the contraction stroke, and the vehicle height is at that position. Held in.

Then, when it is desired to change the rising height of the vehicle according to the suspension of the driver, the position of the control bar 57 may be changed. To do this, pull out the upper and lower stopper pins 58,
The control bar 57 is moved to a desired position, and the stopper pin 58 is set in this state.

When lowering the vehicle height, when the driver sets the selector switch to the down side, the solenoid valve 34 expands and the lever 33 rotates the cam.
53 is rotated clockwise, whereby the valve element 45 is tilted so that the lift chamber 13 and the working chamber 3 communicate with each other, and the working oil in the lift chamber 13 returns to the working chamber 3 and, as a result, the vehicle High becomes low.

As described above, in this embodiment, similar to the first embodiment, the control actuation force is small, the effect of miniaturizing the actuator is obtained, and the height of the vehicle can be freely adjusted at a predetermined interval. effective.

Although the height of the control bar 57 can be adjusted stepwise by the pin hole 57d and the stopper pin 58 in the second embodiment, the mounting base 57 of the control bar 57 can be adjusted.
It is also possible to adjust steplessly by threading c. Further, this concept can be applied to the above-mentioned accumulator type shock absorber. Furthermore, in the first and second embodiments described above, the shock absorbers for motorcycles have been described, but the present invention can be applied to other shock absorbers for vehicles such as automobiles.

〔The invention's effect〕

As described above, according to the vehicle height adjusting device-equipped shock absorber of the present invention, the pressure control valve has a tilt type valve structure, and
Since the valve element is tilted by the actuator via the rotary cam and lever, the actual operating force can be reduced, and the actuator can be downsized to reduce the required installation space and the required current capacity. There is.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram for explaining a main part configuration of the present invention, and FIGS. 2 to 8 are diagrams for explaining a shock absorber with a pressure accumulation type vehicle height adjusting device according to a first embodiment of the present invention. FIG. 2 is a sectional view of the pressure control valve portion, FIG. 3 is a sectional plan view of the rotary cam, and FIGS. 4, 5, and 6 are front, side and plan views of the pressure control device, respectively. FIG. 7 is a sectional front view of the shock absorber, FIG. 8 is a system diagram for explaining a schematic configuration of this embodiment, and FIGS. 9 to 13 are for explaining a second embodiment of the present invention. FIG. 9 is a sectional view of the pressure control valve portion, FIG. 10 is a sectional plan view of the rotating cam, FIG. 11 is a sectional view of the unload valve portion, and FIGS. 12 (a) and 12 (b). Are cross-sectional views taken along line IIa-IIa and line IIb-IIb in Fig. 11, respectively, and Fig. 13 is a system diagram. In the figure, 1 is a cylinder, 3 is a working chamber, 5 is a piston rod, 6 is a lift case, 8 is a buffer spring, 11 is a pump chamber, 12 is a plunger, 13 is a lift chamber, 14, 15 and 16 are the first and the first. First
2,3rd hydraulic passage, 18,48,61 are pressure control devices, 19,49,62 are pressure control valves, 20,50,65 are valve disc drive devices, 30,31,45,64 are valve discs, 30b , 31b and 45b are shaft portions of the valve body, 26, 51 and 66 are rotary cams, 34 and 67 are actuators, and 33 and 68 are levers.

Claims (1)

[Claims] 1. A pumping mechanism formed by inserting a plunger mounted in a working chamber of a cylinder into a pump chamber formed in a piston rod, wherein a cylindrical lift case is slidably mounted on the cylinder. Forming a lift chamber,
A buffer spring is provided between the lift case and the piston rod, the lift chamber, the pump chamber, and the working chamber communicate with each other through the first and second passages, and the pump chamber and the working chamber are connected to the third chamber.
A shock absorber with a vehicle height adjusting device, wherein the pressure control device is provided in at least one of the first and second passages and communicates with the passage, and the pressure control device includes a pressure control valve and a valve body drive device. And a tilt-type valve structure for tilting a valve body disposed in the passage to open and close the passage, and the valve body drive device is applied to a shaft portion of the valve body. A rotary cam that contacts and tilts the rotary cam; a reciprocating actuator that rotationally drives the rotary cam; and a lever that has one end connected to the cam shaft of the rotary cam and the other end connected to the actuator. A characteristic shock absorber with a vehicle height adjustment device.