JPH0419207A - Suspension for vehicle - Google Patents

Abstract

PURPOSE:To enable reduction in the number of parts and weight, and allow the alignment of wheels to be changed by disposing two arms, oscillated independently in the vertical direction, in the longitudinal direction of a vehicle body, and constructing these arms in such a way as to be deformed differently by vertical force. CONSTITUTION:A suspension arm, disposed being spaced in the longitudinal direction of a vehicle body, is provided with a front arm 18 and a rear arm 20 oscillated independently in the vertical direction, and these arms 18, 20 are constructed in such a way as to be deformed differently by vertical force. An elliptic locus can be described on the tip of the arm 18 and a circular locus can be described on the tip of the arm 20 by changing the degree of the vertical deformation of two arms 18, 20. As a result of these different tip loca of two arms 18, 20 generated by vertical force, each wheel supported by a wheel carrier can be changed in its tow angle and further in its camber angle. The straight line stability and turning performance of a vehicle at the time of travelling on the irregular road surface can be thereby improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a suspension for a vehicle, and more particularly to a suspension that changes the alignment of wheels when a vertical force is applied.

(Prior Art) As a suspension that changes the toe angle and other alignment of wheels by external operation while the vehicle is running, a fluid chamber is defined in an elastic bush disposed at the connection part of a suspension arm with the vehicle body. There is a device that adjusts the flow rate or pressure of fluid into the fluid chamber (Utility Model No. 61-96)
No. 030, Japanese Utility Model Application Publication No. 136209/1983).

In addition, fiber reinforced plastic (FRP) with spring action
When molding the suspension arm, the wheel carrier is attached by making a large notch on the side to create two arm parts spaced apart from each other, and making the central axis of the suspension arm deviate rearward from the center between the two arm parts. It has been proposed that the suspension be
No. 8449).

(Problems to be Solved by the Invention) In a suspension in which a fluid chamber is defined in a bushing, the structure is complicated, and the number of parts and weight are significantly increased. Also,
Sensors, control equipment, etc. for external control are also required, resulting in high costs.

In the suspension made of FRP, the toe angle of the wheel can be changed by lateral force or braking force, or the toe angle or other alignment cannot be changed by vertical force.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a suspension for a vehicle that has a simple structure, reduces the number of parts and weight, and can change the alignment of wheels using vertical force.

(Means for Solving the Problems) The present invention is connected to a vehicle body at a laterally inner portion of the vehicle body,
and a vehicle suspension comprising a suspension arm supporting a wheel carrier at a laterally outer portion, the suspension arm being arranged at intervals in the longitudinal direction of the vehicle body and capable of independently swinging in the vertical direction. It has two arms, and these arms deform differently depending on vertical forces.

(Function and Effect) When a vertical force is applied to a vehicle, one arm deforms to a degree greater than the degree of deformation of the other arm, so the toe angle of the wheel changes and the camber angle also changes. .

The suspension arm is composed of two arms that deform differently depending on the force in the vertical direction, and the structure is simple. In addition, the number of parts can be reduced and the weight can be reduced.

Since alignment can be controlled without external operation, no sensors or control equipment are required, and manufacturing is possible at low cost.

(Embodiment) As shown in FIG. 4, the suspension includes a suspension arm 14 that is connected to the vehicle body 10 at a laterally inner portion of the vehicle body 10 and supports a wheel carrier 12 at a laterally outer portion. The present invention can be practiced whether the wheel carrier 12 supports a steered wheel or a non-steered wheel.

In the illustrated embodiment, the wheel carrier 12 is swingably supported by an upper suspension arm 14 and a lower suspension arm 16, and a double wishbone type suspension is configured. The suspension arm 14 is formed as described below, but the suspension arm 16 may be one commonly used in double wishbone suspensions.

The suspension arm 14 has a front arm 18 and a rear arm 20, which are arranged at intervals in the longitudinal direction of the vehicle body and can swing independently in the vertical direction, and these arms differ depending on the force in the vertical direction. Transform.

As shown in detail in FIG. 2, the arm 18 has an eye 19a on the side for attachment to the vehicle body, and a torsion coil spring 22 extending from the eye 19a to the body.
has a 4-turn helix. The central axis of the helical portion is made to coincide with the central axis of the eye 19a, and the vertical force on the arm 18 is received by winding or unwinding the helical portion of the torsion coil spring 22.

A free end 23 of the coil spring 22 opposite to the eye 19a extends in a direction perpendicular to the arm 18. This freedom @2
3 is the bracket 11 attached to the vehicle body lO (Fig. 4)
Fixed. A hole joint stud 19b is implanted in an end 19b of the arm 18 that is laterally outward of the vehicle body.

The arm 20 has a shape that is substantially symmetrical to the shape of the arm 18 with the torsion coil spring removed. Arm 18
and the arm 20 are connected to the wheel carrier 12 via a hole joint, and each eye 19a is connected to the vehicle body via a rubber bushing so as to be swingable about a horizontal axis.

Arm 18 and arm 20 were obtained by molding FRP. The arm 18 is made by Nittobo Co., Ltd. and has an average diameter of 13 μm, for example.
Glass fiber impregnated with epoxy resin is wound around a predetermined mandrel and molded. Prior to molding, arm 1
The distance from the outer end 19b of the torsion coil spring 22 to the eye 19a is determined, and a mandrel is formed by fixing a core having the inner peripheral shape of the helical portion of the torsion coil spring 22 near the eye 19a. This Mann I. Rel is used.

Since the arm 20 does not have a torsion coil spring, it can be molded using a mandrel without the core.

The direction in which the glass fibers are arranged during molding is determined by taking into account the applied force and the function of the part that receives this force. For example, since the arms 18 and 20 have upper and lower blades, longitudinal forces, and lateral forces, they must have sufficient strength and rigidity to withstand these forces. Therefore, as shown in FIG. 2, various directions are combined, such as a direction 26a that follows the overall shape of the arm 18, and directions 26b and 26c that intersect this direction 26a. On the other hand, in the torsion coil spring 22, the arrangement direction of the glass fibers is aligned in the helical direction 26d in order to take advantage of the features of this type of spring and cope with bending stress.

The cross-sectional shapes of the arms 18 and 20 are H-shaped to increase rigidity, as shown in FIG. It is.

After molding arms 18 and 20, these arms were further compressed using a secondary mold so that the fiber volume percentage of each part was 60%, and heat curing treatment was performed at a temperature of 120°C for 2 hours. .

The arm 18 and the arm 20 are swingably connected to the vehicle body 10 by a bolt passing through each eye 19a,
When the free end 23 of the torsion coil spring 22 of the arm 18 is fixed to the bracket 11, the torsion coil spring 22 functions as a suspension spring. Therefore, there is a shock absorber 28 (FIG. 4) disposed between the lower arm 16 and the vehicle body 10, or at a position away from the shock absorber 28, which is used in the conventional Tuple Witschborn suspension. coil spring,
There is no need to prepare separately.

As a result of the torsion coil spring 22 of the arm 18 functioning as a suspension spring, the torsion coil spring 22 and the support of the arm 18 integrated therewith bear the weight of the vehicle body and the vertical force applied from the wheels. As a result, the arm 18 is slightly bent, and the arm 20 is only slightly bent because it receives almost no vertical force. In this way, arm 18 and arm 20 deform differently depending on the vertical force.

The two arms of the suspension arm 14 can also be configured as shown in FIG. In figure a, arm 3
0 is provided with a torsion coil spring 31, and arm 32 is provided with a torsion coil spring 33, and the arms 30 and 32 are symmetrical in shape.

In the figure, the arm 34 is equipped with a torsion coil spring 35, the arm 36 is equipped with a torsion coil spring 37, and the arm 34 is equipped with a torsion coil spring 35.
4 and arm 36 have symmetrical shapes. However, in the case of the same figure, the arrangement of the torsion coil springs is different from the arrangement of the torsion coil springs in the case of the same figure a. Furthermore, in Figure C, arm 38 is provided with a torsion coil spring 39 and arm 40 is provided with a torsion coil spring 41, or the two arms 38, 40 are asymmetrical. Both are attached to the vehicle body so that the torsion coil spring is at the rear.

In the embodiment shown in FIG. 5, in order to make the vertical deformation of one arm and the other arm different, it is sufficient to change the stiffness of the arms themselves in the northward direction. That is, the physical properties of the material can be changed by changing the cross-sectional shape of the arm, or by changing the type, arrangement direction, volume ratio, etc. of reinforcing fibers even if the cross-section is the same. Another means of making the vertical deformation different is to make the spring constant of the torsion coil spring of one arm different from the spring constant of the torsion coil spring of the other arm.

In the above embodiment, both arms are made of FRP, but instead of this, one arm is made of FRP.
It is also possible to form the torsion coil spring integrally with P, and to form the other arm from a material other than FRP, such as steel or aluminum.

In the embodiment shown in FIG. 6, the wheel carrier 12 is supported by an upper suspension arm 42 and a lower suspension arm 44, forming a tuple wishbone type suspension. However, in this embodiment - the upper suspension arm 42 is the same as that used in conventional double-witschhorn suspensions, whereas the lower suspension arm 44 is designed for vertical deformation. It consists of two arms with different degrees of

Instead of the embodiment shown in FIG. 6, it is also possible to omit the upper suspension arm 42 and the shock absorber 28 while connecting the struts 46 to the wheel carrier 12 to form a strut type suspension.

In the embodiment shown in FIG. 7, the wheel carrier 12 is supported by an upper suspension arm 48 and a lower suspension arm 50, forming a double wishbone suspension. However, in this embodiment, both the upper suspension arm 48 and the lower suspension arm 50 are composed of two arms having different degrees of vertical deformation.

As is clear from the description of the above embodiments, the present invention provides at least one suspension arm that supports the wheel carrier, which is arranged at intervals in the longitudinal direction of the vehicle body and swings independently in the vertical direction. In the above embodiment, at least one of the two arms is made of FRP and is integrally equipped with a torsion coil spring in order to make the deformation of these arms different due to vertical force. It is molded and takes advantage of FRP's high strength and low elasticity properties. However, for longitudinal and lateral forces, both arms preferably have sufficient rigidity to position the wheel.

Various combinations of yuzu oil and fibers can be used to form arms from FRP. For example, as the resin material, in addition to the above-mentioned epoxy, thermosetting resins such as unsaturated polyester, thermoplastic resins such as polyethylene and polypropylene, or various polymer alloys can be used. On the other hand, as the fibrous material, in addition to the above-mentioned glass fibers, carbon fibers, organic fibers, etc., or fibers that are a mixture of these can be used. Desired strength, elastic modulus, heat resistance, and other properties can be obtained by using such fiber materials alone or in combination.

In the case where the arm and helical coil spring are integrated as in the above embodiment, since the arm receives a force in the vertical direction, it is possible to intentionally apply vertical deformation to the arm. Therefore, for example, in the embodiment shown in FIG. 1, by changing the vertical deflection, that is, the degree of deformation, of the two arms 18 and 20, an ellipse A can be formed at the tip of the arm 18, as shown in FIG. , the locus of the circle B can be drawn at the tip of the am 20. As a result of the different trajectories of the tips of the two arms 18.20 due to the vertical force, the wheel 60 supported by the wheel carrier 12 changes its toe angle C as shown in FIG. As shown in FIG. 10, change the camber angle.

This improves straight-line stability and turning performance when the vehicle runs on uneven roads.

The toe change characteristic according to the present invention utilizes the deformation of the arm in response to vertical force, so there is no inflection point in the toe change as shown in E in Figure 11, and the toe change continues continuously from rebound to bounce. Changes to toe-in. On the other hand, the toe change characteristic using the deflection of the conventional bushing is a broken line F,
When the bounce changes to a loose bounce, it passes through an inflection point.

In other words, as the ball moves from bounce to rebound, it changes from toe-in to toe-out.

The straight-line performance of a vehicle during straight-ahead driving decreases when the wheels tend to toe out, and improves when the wheels tend to toe-in. Therefore, in order to achieve stable straight-line performance, braking performance, and steering characteristics, it is preferable that stable toe-in be maintained without significant changes. Further, when a large lateral force is applied during a turn, it is preferable to provide a relatively large toe-in in order to increase the cornering force by causing the outer wheel to tend to toe-in and obtain good turning and braking stability. According to the present invention, such conditions can be satisfied.

According to the above-described embodiment in which the arm integrally provided with the torsion coil spring is obtained by molding FRP, weight reduction can be achieved. In addition, since the torsion coil spring functions as a suspension spring, there is no need to provide a separate coil spring, and the torsion coil spring can be placed in the dead space between the suspension arm and the vehicle body, so it is necessary for the suspension. The amount of space required can be significantly reduced, and that space can be used for other purposes.

[Brief explanation of drawings]

Figure 1 is a plan view of the suspension arm, Figure 2 shows one of the two arms provided on the suspension arm, where a is a plan view, b is a side view, and Figure 3 a is the same as in Figure 2. Along line 3A-3A, and b is 3 in FIG.
4 is a rear view of the suspension according to the present invention, FIGS. 5 a'-c are plan views of another embodiment of the suspension arm, and FIGS. The figure is a rear view of another embodiment of the suspension, Figure 8 is a schematic diagram of the trajectory drawn by the ends of the two arms of the suspension arm as they bounce and rebound, and Figure 9 is a schematic diagram of the trajectory drawn as the tips of the two arms of the suspension arm bounce and rebound. In the plan view showing the change in angle, a shows the standard state, b shows the state after the change, and the first
Figure 0 is a rear view showing changes in camber angle due to bounce and rebound, a shows the standard state, b shows the state after the change, and Figure 11 shows changes in toe angle due to bounce and rebound. FIG. 3 is a characteristic diagram showing characteristics. 12: Wheel carrier, 14: Suspension arm, 18.20.30.32.34.36.38.40: Arm, 22.31.33.35.37.39.41: Torsion coil spring.

Claims (1)

[Claims] A vehicle suspension comprising a suspension arm connected to a vehicle body at a laterally inner portion of the vehicle body and supporting a wheel carrier at a laterally outer portion, the suspension arm being spaced apart from each other in the longitudinal direction of the vehicle body. A suspension for a vehicle that has two arms that are arranged vertically and can swing independently in the vertical direction, and these arms deform differently depending on the vertical force.