JPH0321290Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a four-link suspension device for a vehicle that connects an axle housing and a vehicle body frame with a plurality of link rods, and supports the vehicle body on the axle housing with a coil spring. In particular, it relates to its vibration transmission prevention structure.

[Prior art]

Various vibrations occur in the axle housing when the vehicle is running or when the vehicle accelerates or decelerates, and these vibrations are input to the vehicle body frame through the lower and upper control arms or lateral rods that serve as the link rods that connect the axle housing and the vehicle body frame. , causing muffled sounds, etc.

In order to prevent the transmission of these vibrations, especially bending vibrations that are applied to the link rod, conventionally, a damper weight of a predetermined weight is provided at the intermediate position of the link rod or at the joint with the vehicle body frame to reduce the resonance frequency of the link rod. It is shifted from the frequency that is the problem.

[Problem that the invention attempts to solve]

However, it is undesirable to provide a damper weight in the middle of the link rod because excessive stress is generated on the link rod when large-amplitude vibrations are input, and if the damper weight is provided at the pivot joint, its weight is quite large. This is incompatible with reducing the weight of vehicles.

[Means for solving problems]

In view of the above-mentioned problems, the present invention aims to provide a four-link suspension device that does not generate excessive stress on the link rods and can effectively prevent vibration transmission using a relatively lightweight damper weight. do.

Therefore, in the four-link suspension device of the present invention, the base end of the link rod connecting the axle housing and the vehicle body frame is rigidly directly connected to the pivot joint portion on the vehicle body frame side. It has a structure in which a rigid support rod that vibrates integrally is provided, and a damper weight is provided at the tip of the rigid support rod.

[Effect]

If the length of the support rod and the weight of the damper weight are appropriately selected, the node of the bending vibration that is the problem will be shifted to coincide with the pivot point of the link rod on the vehicle body frame side. As a result, the vibration of the pivot joint becomes extremely small, and transmission of vibration to the vehicle body frame is prevented.

〔Example〕

In FIG. 1, an upper control arm 11 and a lower control arm 12, which are link rods, are provided at both ends of the axle housing H, one end of which is rotatably pivoted thereto. The other ends of the control arms 11, 12 are pivotally connected to the vehicle body frame F, and the base ends are rigidly connected to the pivot joints 111, 121 in the direction of extension of the control arms 11, 12 from the respective pivot joints 111, 121. A support rod 2 of a predetermined length that is directly connected and has high rigidity is extended. A damper weight 3 of a predetermined weight is provided at the tip of the support rod 2. Similarly, the lateral rod 13 as a link rod has a support rod 2 extending in the direction of extension of the rod 13 from a pivot portion 131 on the body frame side, and has a damper weight 3 at its tip. (Figure 2). In the figure, 132 is an axle housing side pivot joint.

Now, taking the above lateral rod 13 as an example,
Bending vibrations as shown by broken lines in FIGS. 1 and 2 are input to this. Fig. 3 1 shows a one-node bending vibration, and Fig. 3 2 shows a two-node bending vibration. In both cases, the pivot joint 1
31 vibrates at the center of the vibration, and the vibration is transmitted to the vehicle body frame F (FIG. 2).

Here, in the structure of the present invention, the pivot portion 13
Support rod 2 and damper weight 3 extending from 1
vibrates integrally with the lateral rod 13, and by adjusting the length of the support rod 2 and the weight of the damper weight 3 provided at its tip, the
As shown in FIG. 2, the vibration nodes can be brought into alignment with the pivot portion 131, thereby making it possible to significantly reduce the transmission of vibrations to the vehicle body frame F. In this case, the longer the support rod 2 is, the lighter the damper weight 3 is.

According to the inventors' experiments, the wall thickness is 3.2 mm and the diameter
In the metal pipe lateral rod 13 with a diameter of 21.7 mm and a length (l ₁ in Fig. 2) of 900 mm, a weight of 290 g is applied to the tip of the support rod 2 with a length of 65 mm (l _{2 in Fig. 2} ) with sufficient rigidity.
When the damper weight 3 is provided, as shown in FIG. 5, the noise in the high speed muffled sound range of 120 to 140 Hz can be effectively reduced. Note that the line x in the figure shows the device of the present invention, and the line y shows the conventional device. In this case, the weight of the damper weight is 1/1 compared to the case where it is provided at the pivot joint 131 of the lateral rod 13.
It only costs 2 to 1/3.

In the above embodiment, the support rod 2 does not necessarily have to extend in the direction of extension of the link rod, and may, for example, extend in the orthogonal direction.

Further, the support rod 2 may have a diameter necessary to support the damper weight 3 with rigidity, and is usually thinner and lighter than the link rod. of course,
The link rod itself may be extended to serve as a support rod.

[Effect of idea]

As described above, the four-link suspension device of the present invention has a rigid support rod whose base end is rigidly directly connected to the pivot point on the vehicle frame side of each link rod constituting the device and which vibrates integrally with the link rod. It has a structure in which a damper weight is attached to the tip of the
This system effectively prevents vibration from being transmitted to the vehicle frame without creating excessive stress on the link rod, and by using a relatively lightweight damper weight, resulting in a significant reduction in muffled noise. be.

[Brief explanation of the drawing]

Figure 1 is an overall perspective view of the suspension device of the present invention, Figure 2 is a front view of the lateral rod, Figure 3 is a diagram showing the vibration mode of the conventional lateral rod, and Figure 4 is the vibration mode of the lateral rod of the present invention. FIG. 5 is a diagram comparing the muffled sound when using the suspension device according to the present invention with a conventional device. F...Body frame, H...Axle housing, 11...Upper control arm (link rod), 12...Lower control arm (link rod), 13...Lateral rod (link rod), 11
1,121,131... Pivot joint, 2... Support rod,
3...Dumper weight.

Claims (1)

[Scope of utility model registration request] In a four-link suspension device in which a vehicle axle housing and a vehicle body frame are connected by a plurality of link rods whose both ends are rotatably pivotally connected thereto, a pivot portion of each link rod on the vehicle body frame side includes: A four-link suspension device comprising: a rigid support rod whose base end is rigidly directly connected to the pivot portion so as to vibrate integrally with the link rod; and a damper weight provided at the tip of the rigid support rod.