JPH0636905U - Trailing arm type vehicle suspension system - Google Patents

Abstract

(57) [Summary] [Purpose] A vehicle suspension system capable of changing the steering stability of a vehicle in accordance with the traveling situation when the vertical position of the wheel with respect to the vehicle body changes between the left and right wheels such as cornering. Is to provide. [Structure] The suspension device includes two trailing arms 11,
12 and a torsion beam 17 which connects the tips of these two trailing arms to each other. The torsion beam 17 is formed by an outer member 21 and an inner member 22 housed therein. One end of the inner member 21 is connected to the outer member, and the other end of the inner member 21 is engaged with the inner surface of the outer member by an engaging portion 25 provided therein. The distance between the connecting portion and the engaging portion is changed by the driving means 28. When this distance changes, the spring characteristic of the torsion beam 17 changes.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a trailing arm type vehicle suspension device, and more particularly to a trailing arm type vehicle suspension device having a torsion beam for suspending a rear wheel of a vehicle.

[0002]

[Prior art]

 FIG. 1 is a diagram showing an example of a trailing arm type vehicle suspension device for suspending the rear wheels of an automobile. Two trailing arms 11 and 12 are provided on the left and right of an automobile body not shown. The bearings 13 and 14 provided on the base end side are swingably mounted, and the trailing arms 11 and 12 are provided with wheel support shafts 15 at the tip ends thereof. There is.

A torsion beam 17 is connected to the tip ends of the trailing arms 11 and 12, and coil springs 18 and 19 are attached to both ends of the torsion beam 17. In this way, the basic structure of the trailing arm type vehicle suspension system for the rear wheels, that is, the rear suspension is formed.

FIG. 2 is a partially cutaway plan view showing a torsion beam 17 that has been conventionally used in the rear suspension shown in FIG. 1. The torsion beam 17 connected to the tips of the trailing arms 11 and 12 is shown in FIG. The outer member 21 has an opening at the lower end and has a U-shaped cross section, and an inner member 22 accommodated inside the outer member 21. Both ends are fixed to the trailing arms 11 and 12, respectively.

[0005]

[Problems to be solved by the device]

 As described above, in the rear suspension having the torsion beam 17, one of the left and right rear wheels is displaced upward with respect to the vehicle body and the other rear wheel is displaced downward with respect to the vehicle body, such as when cornering the vehicle body. In such a case, the torsion beam 17 is subjected to a load in a twisting direction around the central axis in the longitudinal direction. As a result, the predetermined spring characteristic set by the torsion beam 17 is provided, and steering stability during cornering or the like is achieved.

However, as described above, the conventional torsion beam 17 cannot arbitrarily change the initially set spring characteristics, so that the torsion beam 17 can be used for traveling regardless of the condition of the road surface or the traveling condition. It was impossible to change the conditions. The present invention has been made in view of the above problems of the prior art, and improves the steering stability by making it possible to change the spring characteristics of a torsion beam in a trailing arm type vehicle suspension system having a torsion beam. With the goal.

[0007]

[Means for Solving the Problems]

 The present invention for achieving the above object is provided with two trailing arms which are swingably attached to the left and right sides of a vehicle body at their base end portions, and to which wheels are attached to the front end portions, and these two trailing arms. In a trailing arm type vehicle suspension device having a torsion beam connecting the ends of the outer member, the torsion beam is formed by an outer member and an inner member housed inside the outer member, and one end of the inner member is formed by the outer member. An engaging member that engages with the outer member is provided at the other end of the inner member while being connected to the member, and the engaging member is moved in the axial direction so as to move the one end of the inner member and the engaging member. The trailing arm type vehicle suspension device is characterized in that a driving means for changing the dimension between the and is provided.

[0008]

[Action]

 In the trailing arm type vehicle suspension device configured as described above, when the drive means is actuated, the connecting portion between the inner member and the outer member and the engaging portion provided on the inner member and the outer member are engaged. The distance to the position changes. As a result, the spring characteristics of the torsion beam formed by the outer member and the inner member change, and the vertical position of the wheels with respect to the vehicle body is different between the left and right wheels, such as when the vehicle turns. The steering stability in each case can be adjusted according to the driving situation.

[0009]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment of the present invention. 3 and 4 are views showing the basic structure of a trailing arm type vehicle suspension system according to an embodiment of the present invention. In FIGS. 3 and 4, the components shown in FIGS. Common members are given the same reference numerals.

As shown in FIG. 3, the two trailing arms 11 and 12 can be swingably attached to a vehicle body (not shown) by bearings 13 and 14 provided at their base ends, respectively. The trailing arms 11 and 12 are provided with shafts 15 and 16 at the tips thereof for supporting wheels. The tip ends of these trailing arms 11 and 12 are connected by a torsion beam 17. The torsion beam 17 has an outer member 21 whose both ends are fixed to the trailing arms 11 and 12 by a fixing means such as welding or screwing, and an inner member 22 accommodated in the outer member 21. There is.

The outer member 21 is formed by bending a steel plate as a spring material, and has a U-shaped cross-section with an open lower end, as shown in FIG. The inner member 22 is formed of a torsion bar made of a steel rod as a spring material. A large number of axially extending grooves are formed on the outer peripheral surface of one end of the inner member 22 to form serrations or splines 23. ing. The serration 23 is connected to a serration hole formed in a bracket portion 24 provided in the outer member 21, so that the inner member 21 can slide in the outer member 21 in the axial direction.

A cam 25 as an engaging member is integrally provided on the tip end side of the inner member 22 with the fixing member such as the pin 20 on the inner member 22, and the tip end of the cam 25 is the outer member 21. Is in contact with the inner surface of the circular arc portion 21a. The radius of curvature of the inner surface of the circular arc portion 21a is set to be smaller than the radius from the central axis O of the inner member 22 to the tip, and at the cam 25, the other end portion of the inner member 22 and the outer member 21. And are engaged. In order to move the inner member 22 in the outer member 21 in the axial direction, a hydraulic cylinder 26 is mounted in the other end of the outer member 21, and the other end of the inner member 22 is mounted in the hydraulic cylinder 26. The installed piston 27 is accommodated, and the hydraulic cylinder 26 and the piston 27 form an actuator 28.

Therefore, the inner member 22 is axially driven in the outer member 21 by supplying hydraulic pressure to either of the left and right oil chambers formed on both sides of the piston 27 in the hydraulic cylinder 26. The distance L between the one end of the bracket portion 24 connecting the member 22 and the outer member 21 and the cam 25 as the engaging member changes. A hydraulic pump (not shown) is connected to the hydraulic cylinder 26. When the driver operates a switch provided in the vehicle compartment, the torsion beam 17 has a spring characteristic around its central axis depending on the distance L. Therefore, the driver can change the spring characteristics according to the road surface condition and the traveling condition to adjust the riding comfort and steering stability. The sectional shape of the outer member 21 may be U-shaped, V-shaped, or trapezoidal in addition to the U-shaped as shown in the drawing. It is desirable to make the shape open.

FIG. 5 is a view showing a modified example of the cam 25 shown in FIGS. 3 and 4. In this case, the radius of curvature of the inner surface of the arc portion 21 a is from the center O of the inner member 22 to the tip of the cam 25. It has the same length as the end. Therefore, in this case, until the tip of the cam 25 is rotated with respect to the outer member 21 together with the inner member 22 to the corner of the arc portion 21a as shown by the chain double-dashed line in FIG. The beam 17 does not apply a spring force to the wheels, and the spring characteristic of the torsion beam 17 becomes a non-linear spring characteristic.

FIGS. 6 and 7 are views showing a torsion beam of another type of vehicle suspension system according to another embodiment of the present invention. In this figure, members common to those in the above embodiment are designated by the same reference numerals. It is attached. As shown in the figure, the tip of the inner member 22 is fixed to a bracket portion 24 provided on the outer member 21 by a pin 20 or the like. A serration portion 31 is formed at the other end of the inner member 22, and a cam 25 is fitted in the serration portion 31 at a serration hole portion formed in the cam 25. A drive cylinder 32 provided at the tip of an actuator 28 is fixed to the end surface of the cam 25. The drive of the actuator 28 causes the cam 25 to slide in the axial direction, and the tip of the inner member 22 and the cam 25. The distance L between and will change.

FIGS. 8 and 9 are views showing a torsion beam of another type of vehicle suspension system according to another embodiment of the present invention. In this figure as well, the members common to the above-mentioned embodiment are designated by the same reference numerals. As shown in the figure, a cam 25 that contacts the inner front surface of the outer member 21 is fixed to the tip of the inner member 22 by a pin 20 or the like, and the serration 41 formed at the base end of the inner member 22 is It is fitted in a serration hole formed in a bracket portion 24 provided in the outer member 21 so as to be slidable in the axial direction. The actuator 28 is attached to the inner member 22. Therefore, the inner member 22 is slidable in the axial direction by the actuator 28, and the distance L between the cam 25 and the bracket portion 24 is changed. The arcuate portion 21a of the outer member 21 shown in FIGS. 7 and 9 may have the cross-sectional shape shown in FIG. Further, instead of the cam 25 as the engaging member, a bar member is provided on the inner member 22 so as to project outward in the radial direction, and a guide member having a groove with which the tip of the bar member engages is used as the outer member 21. It may be provided on the arc surface. Further, as the actuator 28 forming the driving means, a ball screw driven by an electric motor may be used without using the hydraulic cylinder 26 shown in the figure.

[0017]

[Effect of device]

 As described above, according to the present invention, the spring characteristic of the torsion beam formed by the outer member and the inner member is determined by the engagement between the portion connecting the inner member and the outer member by the driving means and the inner member. Since it can be adjusted by changing the distance between the part where the outer member and the outer member engage, it is possible to adjust the characteristics of the suspension according to the driving situation and improve the steering stability. it can.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall structure of a trailing arm type vehicle suspension device,

FIG. 2 is a partially cutaway plan view showing a conventional torsion beam in the suspension device,

FIG. 3 is a partially cutaway plan view showing a torsion beam of a trailing arm type vehicle suspension system according to an embodiment of the present invention;

FIG. 4 is an enlarged sectional view taken along line 4-4 in FIG.

5 is a sectional view showing a portion corresponding to FIG. 4 in a trailing arm type vehicle suspension device according to another embodiment of the present invention;

FIG. 6 is a partially cutaway plan view showing a torsion beam of a trailing arm type vehicle suspension device according to another embodiment of the present invention;

FIG. 7 is an enlarged sectional view taken along line 7-7 in FIG.

FIG. 8 is a partially cutaway plan view showing a torsion beam of a trailing arm type vehicle suspension system according to still another embodiment of the present invention;

9 is an enlarged cross-sectional view taken along the line 9-9 in FIG.

[Explanation of symbols]

11, 12 ... Trailing arm, 17 ... Torsion beam, 21 ... Outer member, 22 ... Inner member, 25
... cam, 28 ... actuator (driving means).

Claims (1)

[Scope of utility model registration request] 1. Two trailing arms (11, 12) mounted on the left and right sides of a vehicle body so as to be swingable at respective base end portions thereof and having wheels mounted at the front end portions thereof, and these two trailing arm ( In a trailing arm type vehicle suspension system having a torsion beam (17) connecting the ends of (11, 12), the torsion beam (17) is an inner member housed inside the outer member (21) and the outer member (21). A member (22), and one end of the inner member (22) is connected to the outer member (21).
And an engaging member (25) that engages with the outer member (21) is provided at the other end of the inner member (22) and the engaging member (25) is moved in the axial direction. A trailing arm type vehicle suspension device comprising a driving means (28) for changing a dimension (L) between one end of the inner member (22) and the engaging member (25).