JPS6230926B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a suspension system used in a vehicle such as an automobile.

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

However, in any case, such conventional suspension systems have a problem in that either one of ride comfort and handling stability must be sacrificed.

Therefore, as described in JP-A-53-38022, for example, a buffer cylinder is fixed to the vehicle body side with bolts, and two gas spring devices are connected to this buffer cylinder via a fluid flow damping device. Accordingly, suspensions have been proposed in which the spring constant and damping capacity of the shock absorber can be changed depending on the loading conditions and driving conditions of the vehicle.

However, in such conventional suspensions, the buffer cylinder is directly fixed to the car body with bolts, so input and vibration from the wheels are directly transmitted to the car body, causing the car body to vibrate and making the ride uncomfortable. There are problems such as noise and noise.

Therefore, a structure in which this buffer cylinder is fixed to the vehicle body via a rubber mount may be considered, but in this case, a relative displacement would occur between the two gas spring devices and this buffer cylinder, which would cause these gases to The problem is that not only the channels connecting the spring device and the damping cylinder are long, but also that these channels must be made of an elastic material.

The present invention aims to solve these problems by changing the damping force of the shock absorber and the spring constant of the air spring according to the usage situation while maintaining a certain vehicle height, thereby improving ride comfort and handling stability. In addition to improving performance, the structure is simplified by preventing relative displacement between the two spring chambers.
Its purpose is to provide suspension systems for vehicles.

Therefore, the present invention comprises a cylinder attached to the wheel side and a piston rod connected to a piston fitted in the cylinder and whose upper end is supported on the vehicle body side via a bearing and a mount rubber. In a vehicle suspension incorporating a shock absorber, the main air spring chamber is provided above the shock absorber so as to surround the shock absorber, and the main air spring chamber is provided above the main air spring chamber so as to surround the shock absorber. and an on-off valve provided in a passage communicating between the main air spring chamber and the auxiliary air spring chamber, and the main air spring chamber has an upper wall portion attached to the piston rod. and a lower bellows thereof is attached to the upper end of the cylinder, and the piston rod passes through the upper and lower walls of the auxiliary air spring chamber, and the upper wall of the main air spring chamber. and the bearing.

Hereinafter, a suspension system for a vehicle as an embodiment of the present invention will be explained with reference to the drawings. The figure is a cross-sectional view of the main part, and this suspension system incorporates a strut-type damping force switching type shock absorber 1. It is something.

This shock absorber 1 includes a cylinder 1a attached to the front wheel or rear wheel side, and a piston 19 slidably inserted into the cylinder 1a.

The piston 19 also includes orifice passage portions 19a, 19b, 19 that are communicatively connected to each other.
an orifice passage 19d consisting of a
b, 1c can be communicated with each other.

Furthermore, the piston 19 has a piston rod 2.
The piston rod 2 extends upward, passes through the first chamber 1b in a fluid-tight manner, and furthermore, the upper end of the piston rod is connected to a body frame 5 on the vehicle body side via a bearing 3 and a mount rubber 4. is supported by

Incidentally, the vertical movement of the piston rod 2 is restricted by a nut or the like, but rotation is allowed by a bearing 3.

By the way, a control rod 16 is provided inside the piston rod 2, and this control rod 16 extends in the longitudinal direction of the piston rod 2 and is provided so as to be rotatable relative to the piston rod 2. It is being

Further, the lower end of the control rod 16 extends into a space forming a part of the orifice passage 19d in the piston 19, and a shutter 16a as a control valve body is attached to the lower end of the control rod. It is attached so that the passages 19a, 19a can be opened and closed.

Further, the upper end of the control rod 16 extends further upward than the upper end of the piston rod 2, and a driving solenoid mechanism 18 is connected to the upper end of the control rod via a driving gear 17.

Therefore, when the solenoid mechanism 18 is driven, the control rod 1 is
6 rotates, and along with this, the shutter 16a at the lower end of the control rod also rotates, so that the orifice passage 19a can be closed or opened. This makes it possible to change the effective flow area of the orifice passage 19d, making it possible to switch the damping force.

In this way, the damping force switching mechanism D is constituted by the solenoid mechanism 18, the control rod 16, the shutter 16a, etc.

Therefore, in this damping force switching type shock absorber 1, the cylinder 1a on the outside of the body moves up and down with respect to the piston rod 2 in accordance with the up and down movement of the wheel, thereby exerting a damping effect according to the position of the shutter 16a, and thereby improving the shock. can be absorbed effectively.

The solenoid mechanism 18 is automatically controlled by a control means that receives a signal from an acceleration sensor (not shown) and outputs a control signal.

Further, the solenoid mechanism 18 can also be controlled manually.

By the way, a main air spring chamber 6 is provided in the upper part of the shock absorber 1 so as to surround the piston rod 2.
is attached at its upper end to the piston rod 2 and has a bellows 20 at its lower part (this bellows 20 forms part of the main air spring chamber 6).
is attached to the upper end of the cylinder 1.

Further, above the main air spring chamber 6, a sub air spring chamber 10 is provided surrounding the piston rod 2.
is arranged, but this sub air spring chamber 10 is
The piston rod 2 passes through the upper and lower walls of the main air spring chamber 6, and is disposed so as to be sandwiched between the upper wall of the main air spring chamber 6 and the bearing 3.

Furthermore, these air spring chambers 6 and 10 are connected to a passage 11.
are connected to each other through the passage 1.
1 is equipped with an electromagnetic on-off valve 12.

Therefore, by opening and closing the on-off valve 12, the capacity of the spring chamber can be changed, and thereby the spring constant of the suspension can be changed.

The opening/closing control of the opening/closing valve 12 is automatically performed by a control means that outputs an opening/closing control signal in response to a signal from the above-mentioned acceleration sensor or the like.

Further, the opening/closing control of the on-off valve 12 can also be performed manually.

By the way, a coil spring 15 is arranged coaxially with the piston rod 2 so as to surround the main air spring chamber 6 and the on-off valve 12. A spring receiver 1 is supported by the spring receiver 1 and has an upper end formed on the lower surface of the sub air spring chamber 10.
It is supported by 4.

Compressed air for adjusting the vehicle height is supplied to the main air spring chamber 6 through a pipe 8 connected to a compressor (not shown).

This piping 8 is connected to a coil spring 15 that rotates with the rotation of the shock absorber 1 and a sub air spring chamber 1.
Part of the tube is made of flexible tubes so that it can track zero.

Therefore, in order to set the suspension at a predetermined vehicle height position, the vehicle height may be adjusted by first supplying compressed air from the compressor to the main air spring chamber 6 through the pipe 8.

At this time, the on-off valve 12 is left open. As a result, the pressure inside the auxiliary air spring chamber 10 is adjusted to the same pressure as inside the main air spring chamber 6.

When the vehicle height adjustment is completed in this manner, the valve attached to the pipe 8 may be closed to stop the supply of compressed air.

Reference numeral 7 in the figure indicates a bump stopper for preventing damage to the wall surface of the main air spring chamber 6 due to the relative rise of the cylinder portion of the shock absorber 1 on rough roads or the like.

With the above-mentioned configuration, the damping force and spring constant can be adjusted accurately and automatically depending on the usage conditions of the vehicle (normal driving conditions, sudden braking, driving conditions on sharp curves, driving conditions on rough roads, etc.). Since it is possible to perform switching control, it is possible to improve ride comfort and steering stability depending on the time and situation.

Furthermore, since both the damping force and the spring constant can be controlled by switching, by increasing both during sudden braking, sharp curves, or rough roads, it is possible to suppress not only the speed of change in attitude of the vehicle body but also the amount of change in attitude. Furthermore, by reducing both on a road surface having fine irregularities, the natural frequency of the vehicle body is significantly reduced, resulting in an extremely good riding comfort.

Furthermore, since the auxiliary air spring chamber 10 is attached to the piston rod 2 supported by the body frame 5, it is possible to prevent an increase in so-called unsprung weight in the suspension, thereby preventing deterioration of the performance of the suspension. .

Further, the upper wall portion of the main air spring chamber 6 is attached to the piston rod 2, and the sub air spring chamber 1 is attached to the piston rod 2.
0 is also attached to the piston rod 2 adjacent to the upper wall part of the main air spring chamber 6, and is attached to the auxiliary air spring chamber 10.
is prevented from being displaced with respect to the upper wall of the main air spring chamber, so it is possible to communicate between the two air spring chambers 6 and 10 through an extremely short passage 11, and this passage 11
There is no need to provide particular elasticity to the structure, and the structure can be simplified.

Note that it is of course possible to manually control switching between the damping force and the spring constant.

It is also possible to adjust the vehicle height by changing the amount of compressed air supplied.

Furthermore, since the main air spring chamber 6 and the auxiliary air spring chamber 10 are provided so as to overlap on the upper part of the shock absorber 1, the suspension unit as a whole can be constructed extremely compactly, and the coil spring Since the upper end of the air spring chamber 15 is supported by the spring receiver 14 formed on the lower surface of the auxiliary air spring chamber 10, a more compact assembly can be achieved by using common parts.

As described in detail above, according to the vehicle suspension system of the present invention, the damping force of the shock absorber and the spring constant of the air spring can be changed as appropriate, so that the riding comfort can be improved depending on the situation. , it is possible to improve steering stability, and this has the advantage of providing both comfort and safety.

Furthermore, since both the damping force and the spring constant can be controlled by switching, by increasing both during sudden braking, sharp curves, or rough roads, it is possible to suppress not only the speed of change in attitude of the vehicle body but also the amount of change in attitude. Furthermore, by reducing both on a road surface having fine irregularities, the natural frequency of the vehicle body is significantly reduced, resulting in an extremely good riding comfort. Moreover, the Lord,
Since the auxiliary air spring chamber is built into the upper part of the shock absorber so as to surround the shock absorber, there is an effect that the suspension unit as a whole can be constructed extremely compactly.

Furthermore, since the auxiliary air spring chamber is attached to the piston rod supported on the vehicle body side, it is possible to prevent an increase in so-called unsprung weight in the suspension, thereby preventing deterioration of the performance of the suspension.

Further, the upper wall of the main air spring chamber is attached to the piston rod, and the auxiliary air spring chamber is also attached to the piston rod adjacent to the upper wall of the main air spring chamber, and the upper wall of the main air spring chamber of the auxiliary air spring chamber is attached to the piston rod. Since displacement with respect to the air spring chamber is prevented, it is possible to communicate between the two air spring chambers through an extremely short passage, and there is no need to provide particular elasticity to this passage. This has the effect of simplifying the structure.

[Brief explanation of the drawing]

The figure is a sectional view showing a main part of a vehicle suspension system as an embodiment of the present invention. 1...Shock absorber, 1a...Cylinder, 1b, 1c...Chamber, 2...Piston rod, 3...Bearing, 4...Mount rubber,
5...Body frame, 6...Main air spring chamber, 7
... Bump stopper, 8 ... Piping, 10 ... Sub-air spring chamber, 11 ... Passage, 12 ... Opening/closing valve, 1
3, 14...Spring holder, 15...Coil spring, 16
... Control rod, 16a ... Shutter as control valve body, 17 ... Drive gear, 18 ... Solenoid mechanism, 19 ... Piston, 19a, 19
b, 19c... Orifice passage part, 19d...
Orifice passage, 20... bellows, D... damping force switching mechanism.

Claims (1)

[Claims] 1 Incorporating a shock absorber that has a cylinder attached to the wheel side and a piston rod connected to a piston fitted in the cylinder and whose upper end is supported on the vehicle body side via a bearing and a mount rubber. In a vehicle suspension, a main air spring chamber is provided above the shock absorber to surround the shock absorber, and a sub air spring is provided above the main air spring chamber to surround the shock absorber. and an on-off valve provided in a passage communicating between the main air spring chamber and the auxiliary air spring chamber, the main air spring chamber having an upper wall attached to the piston rod and a bellows at its lower portion. is attached to the upper end of the cylinder, and the sub air spring chamber has its upper wall and lower wall penetrated by the piston rod, and is located between the upper wall of the main air spring chamber and the bearing. A vehicle suspension system characterized by being arranged so as to be sandwiched between.