JP2007120641A - Vehicular suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfy a requirement that a change of a spring rate of a vehicular suspension device should be performed by simple work while setting the change of the spring rate to be a fixed value. <P>SOLUTION: A tube body 2a of a shock absorber 2 is slidably mounted in an outer tube 3 along the axial direction. The mounted-in end face of the tube body 2a facing the internal of the outer tube 3 is used as a pressure operating face to form a sealed space 3c through which compressed air is filled in the outer tube 3. An accumulator 7 communicated with the sealed space 3c for adjusting air pressure to be supplied is fixed to the outer tube 3. An air spring whose spring rate can be changed by the adjustment of air pressure is connected in parallel to a coil spring 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle suspension system, and more particularly to a vehicle suspension system including a shock absorber and an elastic system that supports a load applied to a vehicle body and bends according to the magnitude of the load. Vehicle requirements that allow adjustment of stiffness (spring rate) relate to the device.

  A coil spring constituting a vehicle suspension device is disposed between a vehicle body side member and a wheel side member, supports a load applied to the vehicle body, and bends according to the magnitude of the load. It is important as one of the factors that determine driving performance and ride comfort. In particular, in a car race that requires road surface followability suitable for road surface unevenness and curves, the difference in the spring rate of the suspension spring has a great influence on the running.

  As for the ride comfort of the vehicle, the road surface on which the vehicle travels is softly absorbed by the small spring rate for the impact and vibration generated by the small unevenness, and hardly absorbed by the large spring rate for the impact and vibration generated by the large unevenness. A suspension system for automobiles has been proposed in which the spring rate is selectively used by a mechanical configuration (Patent Document 1).

  FIG. 2 shows an automobile suspension system in which the spring rate is automatically used according to the state of the road surface. In the suspension device 61 for an automobile, a joint 64 on one end side of a main body constituting a hydraulic shock absorber 62 is supported on the wheel side, and the joint 65 side of the rod 63 is supported on the vehicle body side. On the main body of the shock absorber 62, a spring joint 68 is externally slidable along the axial direction. A first coil spring 71 is disposed on the inner peripheral side of the spring joint 68, and a second coil spring 72 is disposed on the outer peripheral side. A spring receiving seat 65b is formed on the flange portion 65a of the joint 65 on the other end side, and a cover cylinder 67 is fixed to the spring receiving seat 65b.

  An intermediate member 69 is movably disposed along the axial direction on the outer peripheral portion on the other end side of the spring joint 68, and a locking piece 69 a on one end side in the axial direction of the intermediate member 69 is engaged with the other end side of the spring joint 68. The stop piece 68b is movable along the axial direction to a position where it is locked via the intermediate rubber 70.

  The first coil spring 71 is disposed between the spring seat 65 b and the spring seat 68 a of the spring joint 68, and the second coil spring 72 is fixed to the locking piece 69 a of the intermediate member 69 and the body of the shock absorber 62. The spring receiving member 73 is disposed between them. Reference numerals 66 and 74 denote stopper rubbers.

  While a vehicle equipped with the above-described vehicle suspension 61 is running, the shock absorber 62 and the rod 63 slide in the axial direction by reaction force due to road surface irregularities and the like, and absorb and attenuate shock and vibration. In the case of relatively small vibration in which the rod 63 moves relative to the range of the region a between the shock absorber 62 and the rod 63, vibration is generated at a spring rate due to the series connection of the first coil spring 71 and the second coil spring 72. Absorb.

  When the relative movement further proceeds beyond the position where the contact piece 69b of the intermediate member 69 contacts the spring seat 65b (region b), the further movement of the spring joint 68 is restricted and the first coil spring 71 is controlled. The second function is disabled, and only the second coil spring 72 functions.

When the above relative movement further proceeds beyond the position where the spring seat 68a of the spring joint 68 contacts the stopper rubber 74 (region c), the first coil spring 71 and the second coil spring 72 are connected in parallel. In this case, the spring rate is the highest.
JP 56-83633 A

  In the conventional vehicle suspension system described above, the spring rate is automatically changed between the a region, the b region, and the c region according to the road surface condition on which the vehicle travels, but at that time, it is displaced linearly. The relationship between the load applied to the suspension and the stroke changes abruptly when the spring rate is changed.

  The conventional suspension system for a vehicle having such a function of automatically changing the spring rate has an excellent characteristic that it can cope with a road surface condition from a paved road to a bad road, but depending on the driver's preference, the spring rate is high. There is a desire to select a state and a state with a small spring rate according to the driver's own intention.

  An object of the present invention is to provide a vehicle suspension system of a spring rate adjustment type in which the spring rate can be adjusted by an external operation.

  The structure of the suspension system for a vehicle that realizes the object of the present invention includes a shock absorber having a tube body that is slidably mounted along the axial direction, and an internal end surface of the tube body that serves as a pressurizing surface for gas pressure inside. An outer tube in which a sealed space to be filled is formed, an accumulator that allows adjustment of a gas pressure that is communicated and supplied to the sealed space, and a coil spring disposed between the shock absorber and the outer tube. And is arranged between the vehicle body side and the wheel side.

  In the configuration described above, it is possible to provide a flow rate adjusting means that adjustably adjusts the moving flow rate of the gas filled between the accumulator and the sealed space in the outer tube.

  The vehicle suspension device of the present invention is not a combination of two types of suspension devices, that is, an air spring type suspension device and a suspension device having a coil spring, but is constructed by filling one suspension device with, for example, air as a gas. The air spring and the coil spring are coaxially provided in the vertical direction so that the air spring and the coil spring can be connected in parallel without increasing the size of the vehicle suspension system. The spring rate can be changed simply by adjusting the supplied air pressure.

  In addition, by adjusting the moving flow rate of the gas filled between the accumulator and the sealed space in the outer tube, the action of reaching a desired spring rate works late, so that as a kind of shock absorber It is also possible to have a function.

  FIG. 1 is a diagram showing an embodiment of a vehicle suspension device according to the present invention.

  FIG. 1A is a view along the longitudinal direction of a suspension device for a vehicle such as a passenger car comprising a combination of a shock absorber and a coil spring. The upper half shows an external view, and the lower half shows a sectional view. (A) is an AA arrow view of (a), (c) is a perspective view showing the valve body of the flow rate regulating valve of (a).

  The vehicle suspension device 1 of the present embodiment has a hydraulic shock absorber 2 disposed in an outer tube 3, and a body tube 2 a of the shock absorber 2 is slidably disposed with respect to the outer tube 3. The tip of the rod 2 b of the absorber 2 is fixed to the inner bottom of the outer tube 3. Moreover, the front end side of the main body tube 2a slidable with respect to the outer tube 3 is attached to the vehicle body side, and the front end side of the outer tube 3 is attached to the wheel side. The body tube 2a of the shock absorber 2 is attached to the outer tube 3 so as to be airtight. Specifically, the sliding portion 3a is disposed at two locations along the inner peripheral surface of the outer tube 3 in the axial direction. The outer peripheral surface of the main body tube 2a is slid on the inner peripheral surface of the two sliding portions 3a while maintaining airtightness.

  A screw portion 3b is formed on the outer peripheral surface of the outer tube 3, and a nut member 4 forming a screw receiving member is attached by screw connection. An upper end spring receiving member 5 is fixed to the tip of the main body tube 2 a of the shock absorber 2. A coil spring 6 is disposed between the nut member 4 and the upper end spring receiving member 5.

  Here, since the main tube 2a of the shock absorber 2 is slidable with respect to the outer tube 3, when the space 3c in the outer tube 3 is a sealed space, the end surface of the main tube 2a facing the space 3c On the other hand, the gas pressure (air pressure) in the space 3c acts. That is, the space 3c of the outer tube 3 functions as a gas (air) spring.

  Therefore, the coil spring 6 and the air spring are connected in parallel between the lower wheel side of the outer tube 3 to which the suspension device of the present embodiment is attached and the vehicle body side of the upper body tube 2a of the shock absorber 2. It is designed to support the load under the condition.

  Since the volume in the space 3c is small, if the air spring is constituted only by the space 3c, the stroke of the air spring becomes small. Therefore, in this embodiment, the accumulator (accumulator) 7 is connected to the space 3c, the volume of the air spring is increased to increase the stroke of the air spring, and the air pressure injected into the accumulator 7 is adjusted to adjust the air pressure. It becomes possible to change the spring rate of the spring.

  In the present embodiment, the accumulator 7 is formed in a cylindrical sealed container and is fixed to the outer tube 3 via the connection pipe 8, and the inside of the accumulator 7 and the space 3 c in the outer tube 3 communicate with each other via the connection pipe 8. is doing.

  A valve 7a for injecting compressed air is attached to the upper end side of the accumulator 7, and the gas pressure injected into the accumulator 7 through this valve 7a can be arbitrarily adjusted. On the lower end side of the accumulator 7, a valve body 7c for adjusting the flow rate is provided so as to be rotatable about an axis in a container main body portion 7b formed in an outer cylindrical shape. A circular hole 7d is formed in the connection portion of the connecting pipe 8 on the peripheral wall of the container body 7b, and a hole 7e having the same diameter is formed in the valve body 7c corresponding to the hole 7d ( (Refer FIG.1 (c)). An operation shaft 7f protrudes along the axial direction from the other end of the valve body 7c, and an operation dial 9 is attached to the operation shaft 7f outside the accumulator 7.

  When the operation dial 9 is operated to rotate the flow rate adjusting valve body 7c about its axis, the area where the hole portion 7d of the container body portion 7b and the hole portion 7e of the valve body 7c overlap changes, and the space 3c When moving the compressed air to and from the accumulator 7, it plays a role of adjusting the moving flow rate of the compressed air. For this reason, it has the characteristic that the spring rate of an air spring changes gradually.

  As described above, the vehicle suspension apparatus according to the present embodiment causes the air spring to act on the shock absorber 2 mounted in the outer tube 3 so as to be slidable in the axial direction, and is applied to the accumulator 7 constituting the air spring. By adjusting the gas pressure to be injected, the spring rate in a state where the coil spring 6 disposed between the outer tube 3 and the body tube 2a of the shock absorber 2 and the air spring are connected in parallel can be changed. It becomes possible. At that time, the gas pressure in the air spring can be adjusted by a simple operation of connecting a compressed air supply hose extending from the compressor to the valve 7 a of the accumulator 7.

Sectional drawing of the suspension apparatus for vehicles which shows the Example of this invention. Sectional drawing of the conventional vehicle suspension apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle suspension apparatus 2 Shock absorber 2a Main body tube 2b Rod 3 Outer tube 3a Sliding part 3b Screw part 3c Space 4 Nut member 5 Upper end spring receiving member 6 Coil spring 7 Accumulator 7a Valve 7b Container main body part 7c Valve body 7d, 7e Hole 7f Operation shaft 8 Connection tube 9 Dial

Claims (2)

  An outer tube in which a tube body of a shock absorber is slidably mounted along an axial direction, and an inner end surface of the tube body is used as a pressure acting surface to form a sealed space filled with gas pressure; It has an accumulator that can adjust the gas pressure that is communicated and supplied to the space, and a coil spring disposed between the shock absorber and the outer tube, and is disposed between the vehicle body side and the wheel side. The suspension system for vehicles characterized by the above-mentioned.   The suspension system for a vehicle according to claim 1, further comprising a flow rate adjusting unit that adjustably adjusts a moving flow rate of a gas filled between the accumulator and the sealed space in the outer tube.

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