JPH0344566Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a suspension used in a vehicle such as an automobile, and particularly relates to a damping force switching device thereof.

Conventionally, various vehicle suspension devices incorporating shock absorbers have been developed.

However, conventional suspension devices use damping force switching devices such as solenoid valves that use electromagnetic force, but this solenoid valve has the problem that the torque it generates is extremely small, and the device is heavy and large. A solenoid valve that generates torque has the disadvantage that the device itself is large-scale and consumes a large amount of power.

The present invention attempts to solve these problems by using an air cylinder that can be operated with compressed air as the prime mover for damping force switching, and by transmitting the movement of the air cylinder directly to the rotary mechanism for damping force switching. This damping force switching mechanism for a vehicle suspension is configured such that a large torque can be easily obtained, it is highly durable, and the rotary mechanism for damping force switching can be reliably operated by the operation of the air cylinder. The purpose is to provide equipment.

In order to achieve the above object, the damping force switching device for a vehicle suspension of the present invention includes an eccentric cam mechanism in the vehicle suspension that reciprocates and rotates the damping force switching rotation mechanism of the shock absorber. In addition, the eccentric cam mechanism
It consists of a knob provided at an eccentric position of the damping force switching rotation mechanism, and a movable arm that is engaged with the knob through a long hole formed at one end, while the other end of the movable arm is A piston rod is connected to the piston rod, and an air cylinder is provided to drive and control the movable arm via the piston rod, and a return spring for the piston rod is loaded inside the air cylinder.

Hereinafter, a damping force switching device for a vehicle suspension as an embodiment of the present invention will be explained with reference to the drawings. FIG. 1 is a plan view thereof, FIG. 2 is an elevational view thereof, and FIG. - Arrow sectional view, 4th
The figure is a sectional view showing the shock absorber.
, , and in Figures a and b are respectively a cross-sectional view taken in the direction of - arrows, a cross-sectional view in the direction of - arrows, and a cross-sectional view in the direction of - arrows in Fig. 4, and Fig. 6 is a partially enlarged view of Fig. 4.

As shown in Figures 1 and 2, an air suspension unit S is attached to each wheel of an automobile, and an actuator for changing the damping force and an actuator for changing the spring constant are installed on the upper part of the air suspension unit S. An air cylinder 1 is also attached.

This air cylinder 1 has its piston rod 8
Compressed air is generated by engaging the elongated hole 3 drilled in the movable arm 2 at the tip with the upper protrusion (knob) 5 provided at the eccentric position of the drive pin 4 that constitutes the rotary mechanism for switching the damping force. Compressed air is supplied from an air compressor as a device to its piston 10 via a dryer and a reserve tank through an air inlet 6.
The drive pin 4 is rotated by being received by the drive pin 4.

This air cylinder 1 is provided with a bent part 11a bent at 90 degrees in its passage 11, and the air cylinder 1 is housed in the upper cover 12 of the air suspension unit S by the mounting bracket 9. The entire structure is compact.

FIG. 3 also shows a state in which the piston 10 is biased to the left in the figure by the return spring 7 when it is not receiving compressed air from the air compressor, that is, a soft state (high damping force). ing.

Furthermore, the Air Suspension Unit S has
As shown in Figures 4 and 5, it is equipped with a strut-type damping force switching type shock absorber.

That is, as shown in FIG. 4, the strut type damping force switching type shock absorber 20 includes a cylinder 21 attached to the front wheel or rear wheel side,
The piston 14 is slidably inserted into the cylinder 21.

The piston 14 also includes orifice passage portions 14a, 14b, 14 that are communicatively connected to each other.
An orifice passage 14d consisting of an orifice passage 14d is formed, and the first and second chambers 2 separated by the piston 14 are
2 and 23 can be communicated.

Furthermore, the piston 14 includes a piston rod 1.
3 are connected, and this piston rod 13
extends upward and passes through the first chamber 22 in a fluid-tight manner, and the upper end of the piston rod is supported by the body frame 29 via a bearing 26 and a mount rubber 27. This support is performed using bolts or the like, and is fixed at several locations.

Note that although the vertical movement of the piston rod 13 is restricted by a nut or the like, rotation is permitted by a bearing 26.

By the way, a drive pin 4 is provided inside the piston rod 13, and this drive pin 4 extends in the longitudinal direction of the piston rod 13 and is provided so as to be rotatable relative to the piston rod 13. There is.

Further, the lower end of the drive pin 4 extends into a space forming a part of the orifice passage 14d in the piston 14, and a shutter 4a as a control valve body is attached to the lower end of the drive pin 4. As shown in FIG.
orifice passage portion 14 by aligning or not aligning with holes 14a', 14a' of
A can be opened and closed.

Further, the upper end of the drive pin 4 extends further upward than the upper end of the piston rod 13, and a movable arm 2 as a drive mechanism is connected to a knob 5 provided at the upper end of the drive pin 4. There is.

Incidentally, a main air spring chamber 28 is disposed in the upper part of the shock absorber 20 coaxially with the piston rod 13.

Further, a sub air spring chamber 30 is disposed coaxially with the piston rod 13 directly above the main air spring chamber 28 .

Also, these air springs 28, 30. The drive pin 4 and the piston rod 13 are connected to each other via a communication passage 17 bored through the drive pin 4 and the piston rod 13, and an on-off valve 15 is interposed in the communication passage 17.

This on-off valve 15 has a first valve portion 15a and a second valve portion 15a.
The valve portion 15b is configured to include a valve portion 15b.

As shown in FIGS. 5a and 5b, the first valve portion 15a has a passage 16a formed in the piston rod 13 and communicating with the auxiliary air spring chamber 30, and a communication passage 17 formed in the drive pin 4. A wide passage 16b communicating with the auxiliary air spring chamber 30 is configured to control opening and closing of the valve by aligning or not aligning with the rotation of the drive pin 4. Communication with the passage 17 can be cut off.

The second valve portion 15b also has a passage 18a formed in the piston rod 13 and communicating with the main air spring chamber 28, as shown in FIGS. 5a and 5b.
and a wide passage 18b formed in the drive pin 4 and communicating with the communication passage 17. Similarly, the rotation of the drive pin 4 causes the valve opening/closing control to be performed by aligning or partially aligning the wide passage 18b that is bored in the drive pin 4 and communicating with the communication passage 17. The main air spring chamber 28 and the communication passage 17 can be disconnected from each other.

Note that the open and close states of the valve portions 15a and 15b are as follows:
It's exactly the same. That is, when the first valve section 15a is open, the second valve section 15b is also open, and conversely, when the first valve section 15a is closed, the second valve section 15b is also closed. In addition, the reference numeral 31 in the figure represents a bellows, 32 represents a coil spring, and 33 represents a spring receiver.

With the above-described configuration, in order for the air cylinder 1 to transition from the soft state to the hard state, compressed air is supplied from the reserve tank to the air inlet 6 through the piping, joint, and air cylinder driving solenoid valve. and drive pin 4
is rotated clockwise to a predetermined position, the projection 5 is rotated to the position indicated by the two-dot chain line in FIG. 1, and the shutter 4a of the drive pin 4 is moved to the fifth
The state shown in Figure b is reached, and the hole 4 of the shutter 4a
a' is the hole 1 of the piston 14 in the shock absorber
Facing 4a', the orifice passage is blocked (closed)
state. That is, the orifice passage uses the orifice passage as an effective flow path to reduce the effective circulation area through which the hydraulic oil flows and to increase the damping force.

In addition, in order to shift the cylinder 1 from the hard state to the soft state shown in FIGS. 1 and 3, the solenoid valve is closed to stop the supply of compressed air to the air inlet 6, and the return spring 7 is If the drive pin 4 is rotated counterclockwise to a predetermined position by the biasing force, the shutter 4a can be moved, and at this time the shutter 4a is in the state shown in FIG.
The hole 4a' of a is the inner piston 1 of the shock absorber.
The orifice passage portion 14a faces the hole 14a' of No. 4 and is in a communicating (open) state. That is, the orifice passage uses the orifice passage as an effective flow path to increase the effective circulation area through which the hydraulic oil flows and to reduce the damping force.

Note that one solenoid valve for driving the air cylinder is provided for each of the front wheel suspension and the rear wheel suspension.

Note that the air cylinder 1 is normally open to the atmosphere.

By driving the air cylinder 1 in this way, the damping force can be switched, and the air cylinder 1, the drive pin 4, the shutter 4a, etc. constitute a damping force switching mechanism.

In the above operation, the movement of the piston rod 8 of the air cylinder 1 is directly transmitted through the movable arm 2 and the knob 5 that engages with the elongated hole 3 formed at one end of the movable arm 2, which improves durability. Since the drive pin 4 can be rotated with a large amount of torque, the damping force switching rotation mechanism can be reliably rotated even if the rotational load on the damping force switching rotation mechanism is large.

Therefore, in this damping force switching type shock absorber, the suspension cylinder on the outside of the body moves up and down with respect to the piston rod 13 in accordance with the up and down movement of the wheel, thereby exerting a damping function according to the position of the shutter 4a. It is now able to absorb shots effectively.

Also, due to the reciprocating rotation of the drive pin 4, the valve portion 1
5a is in the open mode, as shown in FIG. 5a, the main air spring chamber 28 and the sub air spring chamber 30
When the valve portion 15a is in the closed mode, the main air spring chamber 2 can be brought into communication with the main air spring chamber 2.
8 and the auxiliary air spring chamber 30 are cut off, and the spring constant can be made large (hard).

That is, by rotating the drive pin 4, the on-off valve 15 can be opened and closed, and by this opening and closing, the spring chamber capacity can be changed.

By changing this spring chamber capacity, the spring constant of the suspension can be changed.

Note that the pressure of compressed air supplied from the reserve tank is approximately 10 kg/cm ² .

The above-mentioned spring constant and damping force switching function allows the spring constant and damping force to be switched simultaneously for the front and rear wheels in two stages, soft state and hard state, and this switching is performed automatically by a computer or the like that drives the solenoid valve. It is done by

As detailed above, according to the damping force switching device for a vehicle suspension of the present invention, the following effects and advantages can be obtained.

(1) The drive pin is directly driven by the compressed air at the required pressure supplied from the compressed air generator to the air cylinder via the movable arm and a knob that engages with an elongated hole formed at one end of the movable arm. Therefore, even if the sliding torque of the drive pin is large, the drive pin can be operated reliably.

(2) Since the drive pin is driven by compressed air supplied from the compressed air generator, its current consumption is lower than when the drive pin is directly controlled by a solenoid.

(3) By using an air cylinder, the entire device can be made smaller and lighter.

(4) Since the engagement between the knob and the movable arm is achieved by the knob engaging with an elongated hole formed at one end of the movable arm, transmission torque is increased and durability is improved. be able to.

[Brief explanation of the drawing]

The figures show a damping force switching device for a vehicle suspension as an embodiment of the present invention; FIG. 1 is a plan view thereof, FIG. 2 is an elevation view thereof, and FIG.
4 is a cross-sectional view showing the shock absorber, and in FIGS. Sectional view, No. 6
The figure is a partially enlarged view of FIG. 4. 1...Air cylinder that doubles as an actuator for switching damping force and an actuator for switching spring constant, 2
...Movable arm, 3...Elongated hole, 4...Drive pin constituting the rotary mechanism for switching damping force, 4a...Shutter, 5...Upper end protrusion (knob), 6...Air inlet, 7... ...Return spring, 8... Piston rod, 9... Mounting bracket, 10... Piston, 11... Passage, 11a... Bent part, 12...
... Cover, 13 ... Piston rod, 14 ... Piston in shock absorber, 15 ... Opening/closing valve,
15a...first valve part, 15b...second valve part, 16a, 16b...passage, 17...communication passage,
18a, 18b... passage, S... air suspension unit.

Claims (1)

[Scope of utility model registration request] A suspension for a vehicle is provided with an eccentric cam mechanism that performs switching by reciprocating a damping force switching rotation mechanism of a shock absorber, and the eccentric cam mechanism is provided at an eccentric position of the damping force switching rotation mechanism. It consists of a knob and a movable arm that is engaged with the knob through an elongated hole formed at one end, while a piston rod is connected to the other end of the movable arm, and the movable arm is connected to the other end of the movable arm. A damping force switching device for a vehicle suspension, characterized in that an air cylinder for controlling the drive of a movable arm is provided, and a return spring for the piston rod is loaded inside the air cylinder.