JPH04341626A - Suspension system for vehicle - Google Patents

Abstract

PURPOSE:To check any propagation of a surge vibration to a shock absorber and a cab boise by slackening a spring seat slidably installed in the axial direction of a cylinder at a time when the surge vibration is produced in a coil spring, and damping the vibration with a damping means. CONSTITUTION:Each of vertical arms 102a, 102b of a wheel support member 102 supporting wheels 101 is connected to a car body 10 via each of arms 13, 14. In addition, the upper part of a piston rod 17 in a shock absorber 5 is supported on the car body 10 via two insulators 21a, 21b, and the lower part of a cylinder 8 is supported by the arm 13 or the like. Moreover, a coil spring 9 is interposed between a spring seat 1 of the cylinder 8 and the car body 10. In this case, this spring seat 1 is constituted to be slidably in the axial direction of the cylinder 8. In succession, a disc spring 41 is pressed by dint of a sliding motion of the spring seat 1, while this sliding motion is damped by a damping means 90.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension device for a vehicle.

0002

[Prior Art] In a conventional suspension device,
By interposing springs and shock absorbers between the vehicle body and wheels, the vertical motion of the wheels is absorbed so as not to be directly transmitted to the vehicle body, and furthermore, minute vibrations transmitted to the vehicle body through the springs and shock absorbers themselves are absorbed. In addition, insulators were interposed between the spring and the vehicle body, and between the shock absorber and the vehicle body.

For example, as in the suspension device disclosed in Japanese Utility Model Application Publication No. 58-32002, if the insulator interposed between the spring and the vehicle body and the insulator interposed between the shock absorber and the vehicle body are separated, Since the weight of the vehicle is supported by the spring, the rigidity of the insulator interposed between the shock absorber and the vehicle body can be set low. Therefore, vibrations transmitted to the vehicle body via the upper part of the piston rod can be reduced.

[0004] In particular, it has been said that the transmission of small-amplitude vibration inputs that give a rough feeling to the vehicle body can be reduced, resulting in good ride comfort.

[0005]

[Problems to be Solved by the Invention] However, in conventional suspension devices, when vibrations in the high frequency range that are road noise are input and surge vibrations occur in the springs, the springs themselves do not have a damping function.
Furthermore, in a high frequency range, the shock absorber is in a stuck state and cannot obtain a damping effect, so it is not possible to damp the surge vibration of the spring.

FIG. 9 shows a schematic diagram of a conventional suspension device. That is, the surge vibration is transmitted from the upper end of the coil spring 9 to the vehicle body 10, and the shock absorber 5 is in a stuck state, and the shock absorber 5 is transmitted to the vehicle body 10.
Since the rigidity of the insulator 21 interposed in the support portion for the shock absorber 5 is low, the entire shock absorber 5 vibrates up and down. Therefore, vertical vibrations are input to the attachment portion between the lower end of the shock absorber 5 and the lower control arm 13. The vibration in the vertical direction is input as a moment to the attachment portion between the lower control arm 13 and the wheel support member 102, and becomes a rotational movement of the wheel support member 102 with an axis in the longitudinal direction of the vehicle body.

The rotational movement causes the upper control arm 14 and lower control arm 13 supported by the wheel support member 102 to vibrate in the left-right direction of the vehicle body, and vibrations caused by the surge vibration are transmitted to the vehicle body 10.

[0008] Therefore, in the high frequency range, there is a problem in that the surge vibration of the coil spring 9 worsens the input to the vehicle body, thereby worsening the noise inside the vehicle.

Furthermore, if the rigidity of the insulator 21 interposed between the shock absorber 5 and the vehicle body 10 is increased in order to suppress the vertical movement of the shock absorber, it can be expected to reduce the small amplitude vibration input, which was an original advantage. Moreover, the surge vibration of the coil spring 9 itself could not be suppressed, and no effect could be expected.

The present invention has been developed in consideration of these points, and its purpose is to absorb the surge vibration when a surge vibration occurs in the coil spring, and to transfer the surge vibration to the shock absorber from the attachment part between the shock absorber and the coil spring. The goal is to prevent it from being transmitted.

[0011]

[Means for Solving the Problems] A wheel support member that rotatably supports a wheel, an arm that attaches the wheel support member to the vehicle body so as to be able to swing vertically, and an upper portion of a piston rod that is attached to the vehicle body through an insulator. A suspension device in which a piston-cylinder shock absorber supports a lower part of the cylinder on a wheel support member or the arm, and a coil spring is interposed between a spring support member provided on the cylinder and the vehicle body, wherein the spring support member is The cylinder is slidable in the axial direction,
A suspension device for a vehicle, comprising a disc spring pressed by the sliding movement of the spring support member and a damping means for damping the sliding movement.

0012

[Operation] When surge vibration occurs in the coil spring,
The surge vibration causes a spring support member that is slidable in the axial direction of the cylinder to vibrate. The disc spring is bent by the vibration, and the vibration is damped by the damping means, thereby suppressing transmission of the vibration to the shock absorber.

[0013]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings.

1 to 6 show a first embodiment of the present invention.

FIG. 1 is a front view showing the entire suspension device to which the present invention is applied. That is, one end of a lower control arm (arm) 13 is connected to an arm 102a extending below the vehicle body of a wheel support member 102 that rotatably supports a wheel 101, and the other end of the lower control arm 13 is connected to the vehicle body 10. On the other hand, one end of the upper control arm 14 is connected to the arm 102b of the wheel support member 102 extending above the vehicle body.
The other end is connected to the vehicle body 10.

Further, the upper end of the coil spring 9 and the upper end of the piston rod 7 are supported on the vehicle body 10, and a lower spring seat (spring support member) 1 is provided in the cylinder 8, and the lower end of the coil spring 9 is sandwiched between the lower spring seat 1. . The lower spring seat 1 is slidable in the axial direction of the shock absorber 5, and a damping means 90 is provided at the bottom of the lower spring seat 1 to damp the sliding movement.
has been established. A mounting member 113 is attached to the lower end of the cylinder 8.
One end of the mounting member 113 is fixed, and the other end of the mounting member 113 is pivoted to the outer end of the lower control arm 13.

FIG. 2 shows a sectional view of the shock absorber 5 and coil spring 9 of the suspension device shown in FIG. 1. A bumper rubber 20 is fixed to the piston rod 7 slidably inserted in the axial direction of the cylinder 8, and shock absorber insulators (insulators) 21a and 21b are installed on the upper end of the piston rod 7 so as to be vertically arranged on the upper part of the bumper rubber 20. It is fixed with a nut 24. The inner peripheral part of the mounting member 25, which has a substantially mortar shape and whose outer peripheral part is fixed to the vehicle body 10 with bolts (not shown), is fitted between the shock absorber insulators 21a and 21b. Further, a coil spring insulator 27 is provided at the lower part of the outer periphery of the mounting member 25, and an upper spring seat 29 is fixed to the lower part of the coil spring insulator 27. The rigidity of the shock absorber insulator 21 is lower than that of the coil spring insulator 27.

Further, the damping means 90 provided in the cylinder 8 has a substantially donut-shaped outer cylinder 30 having a fluid chamber 50 with a substantially rectangular cross section in which lubricating oil 48 is sealed. A disc spring 41 that supports the lower part of the lower spring seat 1 slidably inserted into the outer cylinder 30 is provided within the outer cylinder 30.

FIG. 3 shows an enlarged sectional view of the lower spring seat 1 and damping means 90 shown in FIG. 2. The lower spring seat 1 includes a first member 61, which has an upper end of the cylindrical portion 61b aligned with the inner periphery of the dish-shaped portion 61a in which the coil spring 9 is sandwiched, and a first member 61 that is fitted onto the inner periphery of the cylindrical portion 61b. It consists of a cylindrical part 62c and a second member 62 in which the lower end of the cylindrical part 62c and the inner peripheral part of the disc-shaped part 62d are matched. A sealing material 37 is provided on the outer periphery of the disc-shaped portion 62d to seal between it and the inner wall of the outer cylinder 30.

[0020] A lid 30 fitted onto the upper part of the outer cylinder 30.
A sealing material 36a is interposed between the outer cylinder 30 and the cylinder upper part 61b, and a sealing material 36b is interposed between the outer cylinder 30 and the cylinder upper part 62c.

Lubricating oil 48 is sealed in the fluid chamber 50 so that the disk-shaped portion 62d is immersed therein, and an air layer 3 is formed in the upper part.
4 is provided. An orifice 4 is provided in the disc-shaped portion 62d so that the upper and lower lubricating oils 48 flow therethrough. Further, a disc spring 41 is provided between the disk-shaped portion 62d and the fluid chamber 50 at the lower part of the disk-shaped portion 62d.

FIG. 4 shows a view A of the disc spring 41 in FIG.
shows. That is, eight keyhole-shaped grooves 43 are evenly provided on the outer periphery of the disc spring 41.

FIG. 5 is a graph showing the relationship between the amount of displacement of the disc spring 41 and the load. The load applied to the disc spring 41 when the vehicle is stationary is M, and the fluid chamber 50 is configured such that when the disc spring is displaced, it is displaced between X1 and X2.
The characteristics are adjusted to the axial length of the

With the above configuration, when the wheel 101 moves up and down at low frequency, the vibration is absorbed and damped by the coil spring 9 and the shock absorber 5, and the shock interposed between the piston rod 7 and the vehicle body 10 is Since the stiffness of the absorber insulator 21 is low, it is possible to reduce small-amplitude vibrations that give a rugged feeling that are propagated to the vehicle body 10 via the shock absorber 5, thereby improving the ride comfort of the vehicle.

Next, wheel 101 due to minute irregularities on the road surface
When high-frequency vertical vibration, that is, road noise, is input to the coil spring 9 and the shock absorber 5, and surge vibration occurs in the coil spring 9, the coil spring 9
Since the spring constant of the disc spring 41 supporting the lower spring seat 12 whose lower end is sandwiched is low, the lower spring seat 1 vibrates in the vertical direction in response to the surge vibration. The vertical vibration is hardly transmitted to the shock absorber 5 because the spring constant of the disc spring 41 is low.

Due to the vertical vibration of the lower spring seat 1, the lubricating oil in the fluid chambers 50 located above and below the disc-shaped portion 62d flows only through the orifice 48. Due to the flow path resistance generated at this time, the vertical vibration of the lower spring seat 1 is attenuated.

FIG. 6 shows a graph of the vibration frequency of the wheel 101 and the input vibration level to the vehicle body 10 at the connection portion between the upper control arm 14 and the vehicle body 10 of the suspension system using this embodiment. It can be seen that the vibration level at each peak point due to surge vibration was reduced compared to the example.

As explained above, in the suspension device of this embodiment, even if surge vibration occurs in the coil spring 9, it is difficult to be transmitted to the shock absorber 5 and the surge vibration can be attenuated. Vertical vibrations corresponding to vibrations can be suppressed. Therefore, in-vehicle noise caused by surge vibrations can be reduced compared to conventional suspension systems.

Next, a second embodiment to which the present invention is applied is shown in FIG.
Explain using. Since the second embodiment is applied to the same suspension device as the first embodiment, explanations regarding the overall view shown in FIG. 1 and the cross-sectional view of the coil spring and shock absorber shown in FIG. 2 will be omitted. do.

That is, FIG. 7 shows an enlarged sectional view of the lower spring seat 2 and the damping means 91. The damping means 91 provided in the cylinder 8 has a substantially donut-shaped outer cylinder 31 having a fluid chamber 51 with a substantially rectangular cross section in which lubricating oil 48 is sealed, and is slidable on the outer cylinder 31. A disc spring 41 that supports the lower part of the lower spring seat (spring support member) 2 inserted into the outer cylinder 31 is provided within the outer cylinder 31.

The lower spring seat 2 includes a dish-shaped part 63a in which the coil spring 9 is sandwiched, a first member 63 in which the upper end of the cylindrical part 63b is aligned with the inner peripheral part of the dish upper part 63a, and the cylindrical part 63a. It consists of a cylindrical part 64c fitted into the inner peripheral part of the part 63b, and a second member 64 in which the inner peripheral part of the disc-shaped part 64d is aligned with the center part of the cylindrical part 64c.

[0032] A lid 31 fitted to the upper part of the outer cylinder 31
A sealing material 36a is interposed between the outer tube 31 and the cylindrical portion 63b, and a sealing material 36b is interposed between the outer cylinder 31 and the cylindrical portion 64c, so that the cylindrical portion 64c A sealing material 36c is interposed between the lower end portion and the outer cylinder 31. Further, a sealing material 37 is provided on the outer periphery of the disc-shaped portion 64d to seal the space between the disc-shaped portion 64d and the inner wall of the outer cylinder 31.

Lubricating oil 48 is sealed in the fluid chamber 51. Further, an air chamber 35 formed by the inner wall of the outer tube 31 and the lower end of the cylindrical portion 64c is provided at the lower part of the outer tube 31, and the air chamber communicates with the atmosphere through the communication hole 34. ing. The disk-shaped portion 64 within the lubricating oil 48
d has an orifice 4 so that the upper and lower lubricating oils 48 communicate with each other.
are provided, and the disc-shaped portion 64d and the disc-shaped portion 64d
Disc springs 41 are provided in the fluid chambers 51 at the upper and lower parts of the housing.

The disc spring 41 is similar to the first embodiment as shown in FIG.
As shown in the figure, eight keyhole-shaped grooves 43 are provided evenly on the outer periphery. Further, its characteristics are shown in FIG. 5 as in the first embodiment.

With the above configuration, when the suspension device in the second embodiment is used, the same functions and effects as those explained in the first embodiment can be obtained, and the graph showing the relationship between the vibration frequency and the vehicle body input is It is similar to that shown in FIG.

Furthermore, in the second embodiment, since the air chamber 35 communicates with the atmosphere, the lower spring seat 2
The air in the air chamber 35 is not compressed even by the vertical vibration of the air chamber 35 . Therefore, compared to the first embodiment, the air itself does not act as an elastic body due to compression and expansion of the air, and does not affect the sliding movement of the lower spring seat 2. Next, a third embodiment to which the present invention is applied will be described using FIG. 8. The third embodiment is applied to the same suspension device as the first embodiment, and therefore the overall sectional view shown in FIG.
Description of the cross-sectional view of the coil spring 9 and shock absorber 5 shown in FIG. 2 will be omitted.

That is, FIG. 8 shows an enlarged sectional view of the lower spring seat 3 and the damping means 92. In cylinder 8,
A cylindrical portion 32a fixed to the cylinder 8, and a cylindrical portion 3
An outer cylinder 32 to which a disk-shaped portion 32b is fixed is provided at the lower end of the outer cylinder 2a. A lower spring seat (spring support member) 3 is slidably provided on the cylindrical portion 32a. The lower spring seat 3 includes a dish-shaped portion 65a in which the coil spring seat 9 is sandwiched, and the dish-shaped portion 65a.
The first member 65 whose upper end of the dish-shaped part 65b is aligned with the inner peripheral part of the
and a cylindrical part 66c that is fitted into the cylindrical part 65b and slides on the cylindrical part 32a at the inner periphery; It consists of two members 66.

[0038] The disk-shaped portion 66d and the disk-shaped portion 32b.
Two disc springs 41, which serve as damping means 92, are provided in a stacked manner between them. The disc springs 41 are stacked in two pieces,
It is assumed that the disc spring 41 has the same characteristics as the disc spring 41 in the first embodiment.

With the above configuration, when the wheel 101 moves up and down with low frequency vibration, the same effect as in the first embodiment is achieved.

On the other hand, the wheels 101 due to minute irregularities on the road surface
When the high-frequency vertical motion is input to the coil spring 9 and the shock absorber 5, and surge vibration occurs in the coil spring 9, the lower spring seat 3 moves vertically in response to the surge vibration, similar to the first embodiment. .

Due to the vertical vibration of the lower spring seat 3, the two disc springs 41 stacked one on top of the other slide against each other.
The vertical vibration of the lower spring seat 3 is attenuated by the sliding friction generated at this time.

That is, the damping means is the sliding friction of the disc spring 41, and its operation and effect are similar to those explained in the first embodiment. This is similar to that shown in 6.

Furthermore, in the third embodiment, since the sliding friction of the disc spring 41 is used as a damping means for the lower spring seat 3, the structure is simpler than in the first and second embodiments.

By the way, in the first and second embodiments, the flow path resistance when the lubricating oil passes through the orifice 4 provided in the disk-shaped portion 1d is used as the damping means. Even if a highly viscous fluid is sealed in the disk and a circular member with rod-shaped or plate-shaped members extending radially is provided in place of the disk-shaped portion 62d, a damping effect can be similarly obtained due to the flow resistance.

Further, although a double wishbone type suspension device is used in each of the above embodiments, the present invention can also be applied to a strut type or semi-trailing type suspension device.

[0046]

[Effect] As explained above, in the suspension device according to the present invention, the spring support member supporting the coil spring is made vertically slidable, and the spring support member is supported by a disc spring. Since the damping means is provided, when surge vibration occurs in the coil spring, the spring support member vibrates vertically, and since the vertical vibration of the spring support member can be damped by the damping means, the surge vibration does not occur in the shock absorber. Because it is difficult to transmit and suppresses the shock absorber itself from vertically vibrating in response to surge vibrations,
The vibration input from the arm connecting the wheel support member to the vehicle body, which was caused by the vertical vibration of the shock absorber, can be reduced, and the noise inside the vehicle can be reduced.

[Brief explanation of drawings]

FIG. 1 is a front view of the entire suspension device showing a first embodiment of the present invention.

FIG. 2 is a sectional view of the shock absorber and coil spring in FIG. 1;

FIG. 3 is a sectional view of the lower spring seat and damping means shown in FIG. 2;

FIG. 4 is a view A of the disc spring shown in FIG. 3;

FIG. 5 is a graph showing the relationship between displacement and load of a disc spring.

FIG. 6 is a graph showing the relationship between vibration frequency and vehicle body input vibration level.

FIG. 7 is a sectional view showing a second embodiment of the present invention.

FIG. 8 is a sectional view showing a third embodiment of the present invention.

FIG. 9 is a schematic diagram showing a conventional suspension device.

[Explanation of symbols]

1, 2, 3...lower spring seat (spring support member), 4...orifice, 5...shock absorber, 7...
Piston rod, 8... Cylinder, 9... Coil spring, 10... Vehicle body, 13... Lower control arm (arm), 21... Shock absorber insulator (insulator), 27... Coil spring insulator,
41... disc spring, 90, 91, 92... damping means.

Claims (1)

[Claims] 1. A wheel support member that rotatably supports a wheel, an arm that attaches the wheel support member to the vehicle body so as to be swingable in the vertical direction, an upper portion of a piston rod that is supported on the vehicle body via an insulator, and a cylinder In a suspension device in which a piston-cylinder shock absorber has a lower portion supported on a wheel support member or the arm, and a coil spring is interposed between a spring support member provided on the cylinder and the vehicle body, the spring support member is connected to an axis of the cylinder. 1. A suspension device for a vehicle, comprising: a disc spring that is slidable in a direction and is pressed by the sliding movement of the spring support member; and a damping means that damps the sliding movement.