JP4070474B2 - Shock absorber for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The invention of the present application is a shock absorber equipped in a motorcycle or a four-wheeled vehicle, a vehicle, etc., in which a piston connected to a piston rod is fitted in a cylinder filled with hydraulic oil, and the cylinder is partitioned by the piston The present invention relates to a shock absorber for a vehicle in which a control valve for controlling the flow of oil according to vehicle running conditions is provided in a portion communicating with a chamber.
[0002]
[Prior art]
FIG. 9 shows a control valve used in a conventional vehicle shock absorber. In the valve main body 101, a valve chamber 102, an inlet port 103, and an outlet port 105 are formed. A spool 110 disposed in the valve chamber 102 is fitted in a spool fitting hole 111 formed in the valve body 101 through a seal 112 so as to be movable in the spool axis direction.
[0003]
A solenoid 113 for sliding the spool is provided on the outer surface of the valve body 101. A moving iron core 114 of the solenoid 113 is integrally formed with the spool 110, and the spool 110 is moved in the axial direction of the spool by turning on and off the solenoid 113. It has become.
[0004]
A notch passage 116 is formed on the outer periphery of the spool 110, while an annular valve seat 118 on which the cylindrical outer peripheral surface of the spool 110 can be fitted is formed on the inner wall of the valve chamber 102.
[0005]
When the spool 110 is in the open position as shown in FIG. 9, the compression side hydraulic oil chamber 120 and the cylinder side communicate with each other via the inlet port 103, the notch passage 116, the valve chamber 102 and the outlet port 105, When the spool moves in the arrow S direction and the cylindrical outer peripheral surface of the spool 110 is fitted to the annular valve seat 118, the control valve is closed.
[0006]
[Problems to be solved by the invention]
The shock absorber having the control valve as shown in FIG. 5 has the following problems.
(1) Since one end of the spool 110 is supported in a cantilever manner and the spool 110 is moved in the spool axis direction, the dimensions must be determined in consideration of the stroke of the spool 110 in the axis direction. The dimension in the axial direction increases.
[0007]
(2) Since the spool 110 is supported in a cantilevered manner, the spool itself may fluctuate (vibrate) due to the hydraulic pressure, and the stability of the oil pressure may not be obtained, and the sealing performance is also affected. is there.
[0008]
(3) If the notch passage 116 is formed on the outer periphery of the spool 110, the edge 116a of the notch passage 116 may be caught by the annular valve seat 118 when the spool 110 is moved upward and closed. The smooth movement of the spool 110 is hindered.
[0009]
(4) In the structure in which the notch passage 116 is formed on the outer periphery of the spool 110 and the annular valve seat 118 that can be fitted to the cylindrical outer peripheral portion of the spool 110 is formed on the valve body 101 side, it takes time and labor for processing and assembly. Cause cost increase.
[0010]
OBJECT OF THE INVENTION
An object of the present invention is to provide a shock absorber for a vehicle that is provided with an on-off valve that is compact, maintains sealing properties, and is easy to process and assemble.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a cylinder in which hydraulic oil is sealed, and a piston connected to a piston rod is fitted, and oil is circulated in a portion communicating with a cylinder chamber defined by the piston depending on vehicle running conditions. A shock absorber for a vehicle provided with a control valve for controlling the above has the following characteristics.
[0012]
In the first aspect of the invention, the valve body of the control valve includes a spool fitting hole, an outlet port communicating with the cylinder chamber, and an inlet port communicating with another chamber. Is coupled to the rotation drive device and rotatably fitted with a spool having an oil passage so that both side portions in the axial direction of the spool are supported by the spool fitting holes via seal members , The rotation of the spool opens and closes between the inlet port and the outlet port .
[0013]
In this way, the spool of the control valve is rotated by the rotation drive device , and both sides in the axial direction of the spool are supported by the spool fitting holes via the seal members, so that the conventional cantilever support is provided. Compared with the sliding type spool, the dimension in the spool axis direction can be made compact, the sealing performance can be maintained by a simple seal, and the fluctuation of the spool due to the hydraulic pressure can be prevented.
[0014]
According to a second aspect of the present invention, a sub tank having a compression side hydraulic oil chamber is integrally connected to the cylinder by a connecting portion, and the compression side hydraulic oil chamber and one of the cylinders are connected to the connecting portion together with the control valve. And a compression side damping force adjusting valve communicating with the chamber so that the damping force can be adjusted.
[0015]
In invention of Claim 3 , in the shock absorber for vehicles of Claim 1 or 2,
The oil passage is formed inside the spool .
[0016]
Thus, by forming the oil passage inside the spool, it is possible to maintain a smooth movement of the spool as compared with the structure in which the notch passage is formed outside, and to process and assemble the spool and valve body. Becomes easier.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
[Basic structure of shock absorber]
FIG. 1 shows a shock absorber according to the present invention, which shows a pressurized gas-filled rear cushion for a motorcycle, and includes a cylinder 1, a piston 2 slidably fitted in the cylinder 1, A piston rod 3 coupled to the piston 2 and fitted to the cylinder lower end wall via a seal 5 is interposed between an upper spring seat 10 of the cylinder 1 and a lower spring seat 11 of the piston rod 3 so as to be compressible. The mounted cushion spring 12 and the like are provided.
[0018]
At the upper end of the cylinder 1, a gas-filling sub-tank 15 and a pillow ball 16 for connecting the vehicle body are provided, and at the lower end of the piston rod 3, a pillow ball 17 for connecting a swing arm or the like is provided.
[0019]
The hydraulic oil is sealed in the cylinder 1, and although details are omitted in the drawing, as is known (known), the piston 2 is provided with orifice mechanisms 20 and 21 for compression and extension. The hydraulic oil is circulated between the upper cylinder chamber 23 and the lower cylinder chamber 24 of the piston 2 via the corresponding orifice mechanisms 20 and 21 when compressed and extended.
[0020]
The sub tank 15 is integrally cast with the cylinder 1 via a connecting portion 25. The connecting portion 25 is formed with oil passages 30a and 30b from the inlet of the sub tank 15 to the upper cylinder chamber 23, and the oil passage 30a. , 30b, an electronically controlled control valve 32 and a compression side damping force adjusting valve 31 are detachably attached. The lower end of the piston rod 3 is provided with an extension side damping force adjustment adjuster 19 for adjusting the orifice mechanism 21 for extension. The compression-side damping force adjustment valve 31 is disposed so that the valve shaft core is oriented substantially in the horizontal direction, and the control valve 32 is disposed at a lower position and parallel to the compression-side damping force adjustment valve 31.
[0021]
FIG. 2 is an enlarged cross-sectional view taken along the line II-II of FIG. 1, and a rubber plater 35 formed in a bag shape is internally provided in the sub tank 15, and the inside of the plater 35 is a gas chamber 36. Nitrogen gas at a predetermined pressure is injected from the die 37. The outside of the prada 35 is a compression-side hydraulic oil chamber 38, which is filled with hydraulic oil, and that is filled with the hydraulic oil, and through the oil passage 30a, the control valve 32, the compression-side damping force adjustment valve 31, and the oil passage 30b, Communicating with
[0022]
The compression-side damping force adjusting valve 31 has a valve main body 41 screwed to the connecting portion 25. The valve main body 41 includes a preset spring 42 and an adjustment screw 43 for adjusting the spring load of the preset spring 42. It is provided, and by rotating the adjustment screw 43 to increase the set load of the preset spring 42, the resistance of the variable restrictor 44 can be increased to adjust the cushioning property to the hard side, and conversely the set load is decreased. As a result, the resistance of the variable throttle portion 44 can be reduced to adjust the cushioning property to the soft side.
[0023]
The control valve 32 is connected so as to open and close between the outer peripheral annular passage portion 45 of the compression side damping force adjusting valve 31 and the oil passage 30a, and FIG. 3 shows a schematic sectional view thereof. A spool fitting hole 51 having a circular cross section is formed in the valve body 50, and an inlet port 52 and an outlet port 53 are formed at intervals in the spool axis direction. 51, and communicates with the compression side hydraulic oil chamber 38 in the sub tank 15 through the oil passage 30a. The outlet port 53 communicates with the end of the spool fitting hole 51 in the axial direction. The cylinder chamber 23 communicates with the damping force adjusting valve 31 and the oil passage 30b.
[0024]
A cylindrical spool 58 is rotatably fitted to the spool fitting hole 51 via a seal 56 and an O-ring 57, and an L-shaped oil passage 60 passing through the spool shaft core is provided inside the spool 58. Is formed. One end of the oil passage 60 in the spool axis direction is always in communication with the outlet port 53, and the other end of the oil passage 60 in the spool axis direction is bent at right angles to the spool axis and opens toward the inlet port 52. The O-ring 57 is disposed in a spool fitting hole portion between the inlet port 52 and the outlet port 53, and the seal 56 is spool-fitted on the side opposite to the O-ring arrangement side (motor 61 side) with respect to the inlet port 52. It is arranged at the hole.
[0025]
The spool 58 is interlocked with a motor shaft of a drive motor 61 such as a step motor fixed to the outer surface of the valve body 50, and is thereby driven to rotate around the spool shaft core. The drive motor 61 is connected to an ECU (Electronic Control Unit) 62, and based on an electronic control signal from the ECU 62, an open position that connects the oil passage 60 to the inlet port 52 as shown in FIG. 4, and an oil passage as shown in FIG. Switching is made between a closed position in which 60 is directed away from the inlet port 52.
[0026]
The ECU 62 shown in FIG. 3 is connected to a manual changeover switch 65 and sensors 66, 67, 68 for detecting various running states of the vehicle, and spools according to various running conditions detected by the sensors 66, 67, 68. 58 is controlled to switch between an open position and a closed position. As the sensors 66, 67, 68, for example, a vehicle speed sensor 66, an acceleration sensor 67, a rear seat load weight sensor 68, and the like are provided.
[0027]
An example of the control will be described. For example, the presence / absence of a passenger on the rear seat is detected by the load weight sensor 68, and when there is a passenger, the valve closing signal is sent from the ECU 62 to the drive motor 61 and the spool 58 is moved to the closed position. Rotates to make the cushioning hard.
[0028]
As another control example, the vehicle speed detected by the vehicle speed sensor 66 and the acceleration detected by the acceleration sensor 67 are input to the ECU 62, and the spool 58 is moved from the closed position to the open position (or within a predetermined range of vehicle speed and acceleration). Control is made to switch from the open position to the closed position.
[0029]
[Action]
In FIG. 1, the shock from the road surface is buffered by the reaction force of the cushion spring 12, the resistance of the hydraulic oil compression orifice mechanism 20, and the gas pressure in the gas chamber 36 of FIG. 2.
[0030]
When the passenger is on the rear seat or loads a heavy load, the loading sensor 68 in FIG. 3 detects this and inputs it to the ECU 62, and sends a valve closing signal from the ECU 62 to the drive motor 61, 58 is rotated to the closed position, and the control valve 32 is closed. This keeps the hard cushioning power. On the other hand, when a passenger is not on the rear seat and does not load a heavy load, the loading sensor 68 detects this and inputs it to the ECU 62, and sends a valve opening signal from the ECU 62 to the drive motor. The spool 58 is rotated to the open position. Thereby, the compression side working chamber 38 and the cylinder chamber 23 of FIG. 3 are communicated, and a soft buffering force is maintained.
[0031]
While the vehicle is running, the vehicle speed and acceleration detected by the vehicle speed sensor 66 and the acceleration sensor 67 of FIG. 3 are input to the ECU 62, and these values are calculated by a predetermined relational expression, and the calculated value is within a predetermined range. In this case, a valve open signal (or valve close signal) is sent to the drive motor 61. Conversely, if the calculated value is not within a predetermined range, a valve close signal (or valve open signal) is sent to the drive motor. .
[0032]
Since the control valve 32 of the embodiment is of an external type, it can be easily assembled, adjusted, maintained and replaced.
[0033]
[Other Embodiments]
(1) FIG. 6 shows another embodiment. For example, the valve body 50 of the control valve 32 is formed integrally with the cylinder 1 and arranged in parallel with the cylinder 1, and a motor 61 is provided at the lower end. As shown in FIG. 7, an oil passage 60 in the spool 58 is formed in an L shape in a plane perpendicular to the spool axis. By rotating the spool 58, the compression side hydraulic oil chamber 38 and the cylinder chamber 23 shown in FIG. 7 are communicated with each other, and an appropriate angle is rotated from the open position to block between the inlet port 52 and the outlet port 53. Switch between the closed position. Of course, the control valve 32 of FIG. 6 is also connected to the ECU 62 in the same manner as the structure described in FIG. The valve body 50 can be configured to be detachable from the connecting portion 25.
[0034]
(2) In the rotary spool structure according to claim 1, in the illustrated embodiment, a motor such as a step motor is provided, and the motor shaft of the motor and the spool are coaxially arranged and connected. In addition, for example, a spool can be configured to rotate using a solenoid and a rack and pinion mechanism.
[0036]
(3) In each illustrated embodiment, the oil passage is simply opened and closed (ON / OFF), but an intermediate position may be provided. Further, as shown in FIG. A diameter branch hole 60a, a medium diameter branch hole 60b, and a small diameter branch hole 60c may be formed in the radial direction of the spool 58, and the flow cross-sectional area at the time of opening may be switched to three stages of large, medium, and small. .
[0037]
(4) Although the illustrated embodiment is an example applied to the rear suspension of a motorcycle, it can also be applied to a front suspension, and can also be applied to a four-wheeled vehicle or a construction vehicle or vehicle. Is also possible.
[0038]
【The invention's effect】
As described above, in the present invention, a piston connected to a piston rod is fitted in a cylinder filled with hydraulic oil, and oil is circulated in a portion communicating with a cylinder chamber defined by the piston depending on vehicle running conditions. The shock absorber for a vehicle provided with a control valve for controlling has the following advantages.
[0039]
(1) By making the spool of the on-off valve rotary, the dimensions in the spool axis direction can be made compact and the spool support area is larger compared to the method of sliding in the spool axis direction as shown in FIG. Therefore, high sealing performance can be maintained by a simple seal.
[0040]
(2) By controlling the spool of the control valve so as to be rotatable in the spool fitting hole, the fluctuation of the spool due to the hydraulic pressure can be prevented as compared with the cantilevered sliding type spool as shown in FIG. The hydraulic fluid flow rate can be stabilized.
[0041]
(3) When the oil passage is formed inside the spool of the control valve, the spool is not caught when the spool is operated as compared with the structure in which the notch passage is formed on the outer periphery of the spool as shown in FIG. And can be easily processed and assembled. Further, since the passage resistance can be reduced, the hydraulic oil flow rate is also stabilized.
[Brief description of the drawings]
FIG. 1 is a side view of a rear cushion for a motorcycle to which the present invention is applied.
FIG. 2 is an enlarged cross-sectional view taken along the line II-II in FIG.
FIG. 3 is a schematic enlarged vertical sectional view of an on-off valve.
4 is a cross-sectional view taken along the line IV-IV in FIG. 3 showing a valve open state.
5 is a cross-sectional view corresponding to the IV-IV section of FIG. 3 showing the valve closed state.
FIG. 6 is an upper side view of a rear cushion for an automobile showing another embodiment of the present invention.
7 is an enlarged cross-sectional view taken along the line VII-VII in FIG.
FIG. 8 is a cross-sectional view showing a modified example of the control valve according to the present invention.
FIG. 9 is an enlarged longitudinal sectional view of a conventional control valve.
[Explanation of symbols]
1 cylinder 2 piston 3 piston rod 12 cushion spring 15 sub tank 23 upper cylinder chamber 24 lower cylinder chamber 31 compression side damping force adjustment valve 32 control valve 38 compression side hydraulic oil chamber 51 spool fitting hole 52 inlet port 53 relief hole 56 seal 57 O-ring 58 Spool 61 Motor 62 ECU (electronic control unit)
66, 67, 68 sensors

Claims (3)

Within the sealed hydraulic oil cylinder, fitted with a piston coupled to the piston rod, the portion communicating with the cylinder chamber partitioned by the piston, provided with a control valve for controlling the flow of oil by vehicle running condition vehicle Shock absorber for
The valve body of the control valve includes a spool fitting hole, an outlet port communicating with the cylinder chamber, and an inlet port communicating with another chamber,
The spool fitting hole is connected to a rotation driving device and rotates with a spool having an oil passage so that both side portions of the spool in the axial direction are supported by the spool fitting holes via seal members, respectively. Mating possible,
A shock absorber for a vehicle, wherein the spool opens and closes between the inlet port and the outlet port . The vehicle shock absorber according to claim 1,
A sub tank having a compression side hydraulic oil chamber is integrally connected to the cylinder by a connecting portion ,
A compression side damping force adjustment valve that communicates between the compression side hydraulic oil chamber and one of the cylinder chambers so as to be able to adjust the damping force is provided in the connecting portion together with the control valve. Shock absorber for vehicles. In the vehicle shock absorber according to claim 1 or 2,
The shock absorber for a vehicle , wherein the oil passage is formed inside the spool .

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