JPH02234819A - Suspension device with frp arm functioning also as spring - Google Patents

Abstract

PURPOSE:To suppress the swinging angle of a ball joint when an arm is deflecting, by forming the free end of the arm working also as an FRP spring, whose fix end is fixed to a car body side member, in such a fashion as facing upward, and by allowing the ball joint to couple a hub carrier swingably. CONSTITUTION:A front suspension of McFerson type for car is equipped with an FRP type cantilever arm 11 working also as a spring at its suspension mechanism part, wherein the arm 11 extends in the direction across the car width and the fix end is fixed to a car body side member, while a hub carrier 31 is borne at its free end 20. Therein the free end 20 is formed inclined upward at an angle theta1 (approx. 15 deg.). To this free end 20 an end piece 21 is fitted for installation of ball joint, wherein a ball joint mounting part 24 is provided at the tip of supporting wall 23, which is bent into approx. an angle tumpled aside viewed on the side elevation, and the hub carrier 31 is fixed by the ball joint 30 secured to this mounting part 24.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a suspension system used in a vehicle such as an automobile.
In particular, the present invention relates to a suspension system having an FRP arm that also serves as a spring.

[Conventional technology In vehicle suspension systems represented by co-double wishbones and MacPherson struts, the lower end side of a hub carrier is supported by a lower arm. A conventional lower arm is made of metal such as steel, and has a link structure in which its base is pivoted to a member on the vehicle body side via a shaft so as to be movable up and down. A suspension spring such as a coil spring elastically supports a vertical load such as a vehicle body load. However, since the coil spring has a large upward protrusion and a spring seat with a large outer diameter, securing a storage space above the coil spring causes the engine room to become narrow. Furthermore, since a suspension spring and an arm are each required, the number of parts is large and the structure is complicated.

As a structure for solving the above-mentioned point m, the present inventors developed a cantilever type spring FR as shown in FIG.
We proposed Am 1 made of P (fiber-reinforced plastic). This spring arm 1 has a fixed end 2 connected to a member 3 on the vehicle body side.
and a ball joint 5 on the free end 4 side.
A hub carrier 6 is swingably supported via a ball joint 5. The arm 1 functions as a structural member to support the hub carrier 6 in the same way as a conventional lower arm, and also functions as a conventional suspension spring by bending in response to a load in the vertical direction. fulfill. Such an arm structure that also serves as a suspension spring would not be possible if arm 1 were made of steel because the flexure would be too small, but arm 1 could be made of FRP.
This made it possible to greatly reduce the amount of deflection, opening the door to practical application.

[Problems to be Solved by the Invention] However, in putting the arm 1 made of FRP into practical use, it was discovered that there is room for improvement in the mounting portion of the ball joint 5 as described below.

The ball joint 5 is used to connect the arm 1 and the hub carrier 6 to each other in a three-dimensional swingable manner, but there is a limit to the angle at which it can swing (swing angle). However, since the axis 02 (see Fig. 8) of the ball joint connecting portion 7 of the hub carrier 6 is originally inclined at a predetermined angle with respect to the vertical plane, the tire 8 is not in contact with the ground as shown in Fig. 8. When the deflection of the arm 1 is in a neutral state, there is a deviation of an angle α between the axis 01 of the ball joint 5 and the axis 02 of the ball joint connecting portion 7 of the hub carrier 6. Moreover, the cantilever type F
When the RP arm 1 curves in an arch shape in the vertical direction, the bending angle becomes larger toward the free end 4 side. Therefore, when the arm 1 is bent upward as shown in FIG. 9 or when the arm 1 is bent downward as shown in FIG. The angle α formed between the two and the two ends becomes extremely large depending on the direction of the deflection. For this reason, it was found that normal ball joints lacked the swing angle and were unusable.

Therefore, an object of the present invention is to provide a suspension device that can suppress the swing angle of the ball joint from becoming excessive when the FRP arm that also serves as a spring is bent upward or downward.

[Means for Solving the Problems] The present invention was developed to achieve the above object. The suspension device has a pair of left and right cantilever type FRP arms that can be elastically bent in the vertical direction, and a hub carrier is swingably connected to the free end side of the arm. A ball joint is provided at the free end side of the arm, and the axis of the ball joint and the axis of the ball joint connecting portion of the hub carrier are aligned with each other, or the angle between the two axes is small. It is characterized by being formed into an angled shape.

[Function] The suspension system configured as described above is designed so that when the arm is in the neutral position of vertical deflection, the axis of the ball joint and the axis of the ball joint connecting portion of the hub carrier almost coincide with each other, that is, the ball joint swings. You can make it come to the neutral point of the angle. Since the arm deflects upward or downward from the neutral point, the ball joint swings depending on the direction of arm deflection from the neutral point. Therefore, even when the arm is bent in either the up or down direction, the swing angle of the ball joint is appropriately distributed to both sides of the neutral point.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

FIG. 2 is a diagram showing a pair of left and right MacPherson type front suspensions in an automobile. Each suspension uses a mutually independent FRP cantilever-type FRP arm 11 that also serves as a spring. This arm 11 is similar to the known FRP spring plate,
The matrix resin and the continuous reinforcing fibers mainly extending in the longitudinal direction are used to form an arched band shape that is slightly upwardly convex in its free state.

The arm 11 extends in the vehicle width direction, and its base end side, that is, the fixed end 12, is fixed to a member 15 on the center side of the vehicle body by means of a bracket 13 and fastening parts 14 such as bolts, as an example of fixing means. Fixed.

The other end of the arm 11, that is, the free end 20 side, is shaped to be inclined upward by an angle θl, as shown in FIG. In the arm 11 made of FRP, θ1 cannot be made very large due to its molding process. θ1
is preferably within about 15°. The reason for attaching the angle θ1 to the free end 20 in this manner will be described later. An end member 21 for attaching a ball joint is attached to this free end 20. This end member 21 is constructed as shown in FIGS. 4 and 5.

The housing 22, which forms the main part of the end member 21, is made by bending a thick metal plate into the following shape. The housing 22 includes a first support wall 23 that is bent into a substantially rectangular shape in a side view (FIG. 4).

That is, the tip side of the first support wall 23 is a ball joint attachment part 24, and this joint attachment part 24 is inclined upward by an angle θ2 with respect to the arm attachment part 25. And the ball joint 30 is attached to the joint mounting part 24.
is fixed, and the hub carrier 31 is supported by the ball joint 30 so as to be able to swing freely in three dimensions.

As shown in FIG. 1, the ball joint 30 includes a spherical portion 32, a shaft portion 33, and a socket 34, as in a normal ball joint 30.
A hub carrier 310 is attached to the shaft portion 33.
The ball joint connecting portion 35 is fixed by a nut 36.

As shown in FIG. 1, when a reference load is applied to the arm 11 in the vertical direction, the axis 01 of the ball joint 30 and the axis 02 of the ball joint connecting portion 35 are aligned, that is, the ball joint 30 is The total angle of θ1 and θ2 is set so as to reach the neutral point of the swing angle. Therefore, if θ1 is within 15°, 01
, 02 can be made equal, θ2 may be set to zero.

An axle and a strut damper 37 are provided on the hub carrier 31. Therefore, the load point is located near the center of the ball joint 30. 38 is a tire.

The first support wall 23 is connected to one side of the arm 11 (lower side in the figure) through a sheet-like liner 40 made of a rubber-like elastic body.
Polymerized into The liner 40 connects the arm 11 and the first support wall 2
3 and fixed with adhesive.

A pair of side walls 41 rising up on both left and right sides of the first support wall 23.
42 faces the side surface of the arm 11. Second support walls 43, 44 connected to the upper ends of these side walls 41, 42 are bent inward so as to face each other. Note that the second support walls 43 and 44 may be connected to each other. Side walls 41, 421, in side view, one end side (
It has a tapered shape such that the height on the other end side is lower than the height on the right side in the figure. For this reason, the second support wall 43.
The height of 44 also gradually decreases from the right side to the left side in the figure.

A metal seat plate 51 made of steel or the like is superimposed on the upper surface side of the arm 11 in the drawing with a sheet-like litchi 50 made of a rubber-like elastic body interposed therebetween. The liner 50 is fixed to the arm 11 and the seat plate 51 with adhesive. The liners 40 and 50 prevent wear of the arm 11 and also serve to equalize the tightening surface pressure applied to the arm 11. Therefore, the liners 40 and 50 have a hardness lower than that of the arm 11, have appropriate elasticity and flexibility, and are made of elastomer fibers, for example, so as not to "sag" even when subjected to repeated loads. It would be better to use something that has been strengthened.

The wedge spring 52 interposed between the seat plate 51 and the second support walls 43 and 44 is made of a strong material with spring elasticity, such as heat-treated steel, and is U-shaped or square-shaped in side view.
It is bent into a slightly open shape. Wedge spring 52
The width is set to be slightly narrower than the distance between the side walls 41 and 42. Opening angle θ3 of wedge spring 52 in free state
is larger than the taper angle θ4 of the side walls 41,42. The wedge spring 52 is driven between the second support wall 43, 44 and the seat plate 51 from the right side in the figure.

The caulking portions 61.62 used as detent means 60 for fixing the wedge spring 52 inwardly recess a portion of the side wall 41.42 after the wedge spring 52 has been driven into the predetermined position. This caulking part 61.62
This prevents the wedge spring 52 from moving in the direction in which it comes off. As the detent means 60, the wedge spring 52 may be fixed to the housing 22 by, for example, welding or brazing instead of the caulking portions 61, 62 described above.

Further, holes 65 are provided in the vicinity of the end of the arm 11, in the seat plate 51, and in the first support wall 23, each passing through in the thickness direction. A bolt 66 is inserted into this hole 65, and by screwing and tightening a nut 67, the arm 11, the first support wall 23, the liners 40, 50, the seat plate 51, etc. are restrained from each other in the thickness direction. . Note that instead of using the bolt 66 and nut 67, a fastening member such as a rivet may be used.

The end member 21 fixed as described above is attached to the arm 11
and the housing 22 are firmly crimped and fixed to each other by the wedge spring 52, and since the litchi 40.50 functions as a buffer material, the arm 11 and the end member 21 are prevented from relative movement such as rubbing against each other in the longitudinal direction. It will no longer occur.

Therefore, problems such as the reinforcing fibers of the arms 11 being cut due to friction do not occur. Further, even if the inner diameter of the hole 65 provided in the arm 11 is small, its function can be sufficiently exhibited, so there is no problem in terms of strength even if the hole 65 is provided.

In the suspension system having the above configuration, when the tire 38 is in contact with the ground and the deflection of the arm 11 is in a neutral state, as shown in FIG.
And hub carrier 31 bo? The axis 02 of the joint connecting portion 35 substantially coincides with the axis 02. In other words, θl and θ2 are set so that the ball joint 30 is at the neutral point when the arm 11 is in the neutral state.

When the free end side of the arm 11 bends upward, as in the case of a so-called full bump, the arm 11 bends upward as shown in FIG.
Due to the displacement of the free end 20 of the two axes 01,0
An angular deviation β1 occurs between (2) and (2). On the other hand, when the free end of the arm 11 bends downward, as in the case of a so-called full rebound, the end member 21 tilts in the opposite direction to the direction of the full bump, as shown in FIG. An angular deviation β2 occurs with respect to Oz. In this way, the swinging angles β1 and β2 of the ball joint 30 can be appropriately distributed on both sides of the neutral point of the ball joint 30, so that the swinging of the ball joint 30 can be prevented from being excessively biased to one side. can be prevented. The ball joint 30 with a small swing angle is structurally strong and has a large degree of freedom in design.

? Alternatively, the arm 11 may have a Taber leaf shape in which the plate thickness gradually decreases from the fixed end 12 to the free end 20, so that a predetermined spring constant can be obtained with a shorter span. However, even if the arm 11 has the same width and thickness in the longitudinal direction, the intended purpose of the present invention can be achieved. Also, when the arm 11 is neutrally bent, both axes o. , o2 do not necessarily have to match perfectly; in short, the axis 0■
．． It is sufficient if the angle θ1 is set so that 02 approaches.

The present invention is not limited to the MacPherson strut type, but can also be applied to, for example, a double wishbone type arm.

[Effects of the Invention] According to the present invention, the maximum swing angle from the neutral point of the ball joint can be reduced when the FRP arm that functions as both a suspension spring and a lower arm is deflected by input in the vertical direction. In order to be able to
It becomes practically possible to connect an FRP arm that also serves as a suspension spring to a hub carrier using a ball joint.

[Brief explanation of the drawing]

FIG. 1 is a front view of a part of the suspension system showing one embodiment of the present invention, FIG. 2 is a front view of almost the entire suspension system shown in FIG. 1, and FIG. 3 is the same as FIG. 4 is a front view of the FRP arm in the suspension shown in FIG. 1, FIG. 5 is a plan view of the ball joint mounting portion in the suspension shown in FIG. 6, and FIG. 7 is a front view showing different operating states of the suspension system shown in FIG. 1, and FIGS. 8 to 10 are front views showing different operating states of the suspension system using a conventional FRP arm. It is a front view. DESCRIPTION OF SYMBOLS 11...FRP arm also used as a spring, 12...Fixed end of the spring, 15...Member on the vehicle body side, 20...Free end of the spring, 21...End member, 22...Housing, 30・
...Ball joint, 31...Hub carrier, 35
...Ball joint connection part. Applicant's Representative Patent Attorney Takehiko Suzue Figure 4 Figure 5 Figure 6 Figure 9 Figure 8 Figure 10

Claims (1)

[Scope of Claims] A pair of left and right pieces provided on the left and right sides of the vehicle body, with fixed ends fixed to the vehicle body side, free ends extending in the width direction of the vehicle body, and capable of elastically bending in the vertical direction. beam type F
The suspension device has an arm made of RP, and the free end of the arm is provided with a ball joint for swingably connecting the hub carrier, and the free end of the arm is connected to the ball joint. The FRP arm also serves as a spring, and is formed in such a shape that the axis of the hub carrier and the axis of the ball joint connecting portion of the hub carrier coincide with each other, or that the angle formed by both axes is small. Suspension system.