JPS6321511Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to an improvement of a front suspension device for a tilt cab vehicle.

(Prior Art) In cab-over type lightweight vehicles such as trucks and tractors, the engine is located below the cab, so the cab can be tilted forward to perform maintenance.

Some of these vehicles have a front suspension and a rear suspension interposed between the body frame and the cab in order to improve riding comfort.

Among these, the front suspension is configured as shown in FIG. 1, for example.

That is, a hinge bracket 3 formed on the front member 2 of the cab 1 and a support bracket 5 provided on the vehicle body frame 4 are connected by a U-shaped spring 6 and a buffer 7, and the cab 1 and the frame 4 are connected to an arm 8. are connected via node 9.

The movement of the frame 4 is relaxed by the U-shaped spring 6 and the shock absorber 7 and transmitted to the cab 1, and the arm 8 provides lateral rigidity, but when the cab 1 is tilted, the hinge bracket 3 Since the tilt is performed at the position, arm 8
is made to correspond to the change in the actual length even at the node 9.

(Problem to be solved by the invention) By the way, in order to improve the ride comfort in such a cab suspension device, it is better to reduce the spring constant of the U-shaped spring 6. Increasing the length or reducing the thickness of the moment arm may reduce its lateral stiffness and roll stiffness. On the other hand, the arm 8 having one node 9 also causes a decrease in lateral rigidity due to that node. Due to these circumstances, the spring constant of the spring 6 cannot actually be made very small.

Furthermore, due to the structure in which the U-shaped spring 6 is interposed between the frame 4 and the cab 1, the frame 4
It is necessary to ensure a large space between the cab 1 and the cab 1, and there is also the problem that the cab position becomes high.

Furthermore, as disclosed in Utility Model Application No. 56-11129, there are some that use leaf springs that take up relatively little space, but in this case as well, just using leaf springs does not necessarily provide sufficient lateral rigidity. It was not sufficient, and it was necessary to strengthen the rigidity in some way.

This invention aims to solve these conventional problems.

(Means for Solving the Problems) In order to achieve the above object, this invention assumes that the front suspension device of a tilt cab vehicle supports the cab together with the rear suspension on the vehicle body frame, and the base end of the leaf spring is attached to the vehicle body. It is fixed to the support bracket of the frame to ensure rigidity against lateral loads, while its free end is rotatably connected to the hinge bracket of the cab and supported on the body frame via the radius arm. The leaf springs are rigidly coupled to each other at their free ends via a transbar, and the radius arm has one end rigidly coupled to the transbar and the other end rotatably coupled to a support bracket. .

(Example) Hereinafter, an example of this invention will be described based on FIGS. 2 to 5.

A base end 8a of the leaf spring 8 is supported by a support bracket 5 of the vehicle body frame 4 in a cantilevered manner.

In this case, the base end 8a of the leaf spring 8 is wrapped around the pin 9 of the support bracket 5 or fixed with a U bolt 20 as shown in FIG. 5 to strengthen the spring force and provide rigidity against lateral loads. is ensured.

The leaf spring 8 is supported by a bolt 11 or a U-bolt 20 on the horizontal seat surface 10 of the support bracket 5, but when using the bolt 11,
In order to give the leaf spring 8 some play in the longitudinal direction, the hole 12 for the bolt 11 is formed vertically.

On the other hand, a bracket 14 is provided at the free end of the leaf spring 8 to freely connect the hinge bracket 3 of the cab 1 around a pin 13.

The bracket 14 is fastened with a U-bolt 19 via a base portion 14b that connects opposing pieces 14a, each having a substantially U-shaped cross section, between opposing pieces 14a in which an insertion hole for a pin 13 is formed.

Note that a support piece 14c for holding the leaf spring 8 is formed on the bottom surface of the base portion 14b on the opposite side from the U-bolt 19.

By the way, the leaf springs 8 mentioned above are respectively attached to the left and right sides of the vehicle body, and the leaf springs 8 and 8 are rigidly connected to the transbar 15 via the bracket 14 to ensure rigidity in the lateral direction of the vehicle body. It's becoming like that. By the way, when the left and right leaf springs 8 are rigidly connected to each other by the trans bar 15 in this way, a part of the torsional torque and vertical displacement generated due to the deformation of one leaf spring 8 is transferred to the other leaf spring 8 via the trans bar 15. Since the rotation is transmitted to the leaf spring 8, an anti-roll effect is generated, which also functions to stabilize the attitude of the cab 1.

In this embodiment, in order to improve ride comfort, the leaf spring 8 is thick enough to have sufficient rigidity at the base end 8a side that is cantilevered by the support bracket 5, while the free end is It is formed so that its thickness becomes thinner as it approaches .

Reference numeral 16 denotes a radius arm that supports the free end of the leaf spring 8 on the support bracket 5 of the vehicle body frame 4, and this radius arm 16 has one end attached to a pin fixed to both ends of the transbar 15 so as to protrude laterally. 13 so as not to rotate, while the other end is rotatably connected to the support bracket 5 with a pin 17. In this case, the radius arm 16 can strengthen the rigidity in the lateral direction, and as described above, the torsional reaction force of the transbar 15 can be effectively utilized to further increase the roll rigidity of the cab.

In addition, radius arm 16 and leaf spring 8
If the play provided in the hole 12 of the support bolt 11 of the leaf spring 8 is insufficient due to the relationship with
It is preferable to fit a rubber bushing into a that allows displacement only in the front-back direction. Furthermore, 18 is a rubber mount that restricts the stroke of the leaf spring 8.

With this structure, when vertical vibrations are applied to the cab 1, the leaf springs 8 of the front suspension as well as the rear suspension (not shown) cushion the vibrations and maintain a good ride comfort.

By the way, since the U-shaped spring has a U-shaped curved beam, the vertical spring constant in the direction perpendicular to the beam is higher than that of a leaf spring, which has the same overall length. It is necessary to make it longer, and the lateral rigidity decreases as the length increases. In other words, leaf springs have higher lateral rigidity for the same spring constant. This allows the load from the front, rear, left and right sides of the vehicle to be shared considerably, so the radius arm 16 that supports the free end of the leaf spring 8 on the frame 4 does not have to be as sturdy as the conventional arm 8, and It is easy to strengthen the rigidity since there is no need to prepare it. Further, the configuration of the leaf spring 8 and the radius arm 16 requires less space in the vertical direction than a conventional U-shaped spring.

In addition, in this embodiment, as described above, the leaf spring 8 is formed to be thick on the base end 8a side and gradually become thinner toward the free end to reduce the effective spring constant. As a result, sufficiently soft suspension characteristics can be obtained.

It is more preferable to provide a shock absorber 21 between the leaf spring 8 and the vehicle body frame 4 to absorb vibrations of the cab 1, as shown in FIG.

Further, in this embodiment, the free end of the leaf spring 8 is rigidly connected to the transformer bar 15 via the bracket 14 in order to ensure roll rigidity, but the two may be directly connected by welding, for example, without using the bracket 14. Even if you do this, there is no functional problem.

(Effects of the invention) As described above, according to this invention, the base end of the leaf spring is cantilever-supported on the vehicle body frame, while its free end is connected to the hinge bracket of the cab and supported on the vehicle body frame via the radius arm. The leaf springs on the left and right sides of the vehicle are connected to each other via a transbar, which improves riding comfort. On the other hand, since leaf springs with higher lateral rigidity than U-shaped springs are used, the radius arm has a single link setting similar to a conventional link. It is not necessary to provide the same, and the effect is that the rigidity can be strengthened and the ride comfort can be improved accordingly.

In addition, in this design, as mentioned above, the free ends of the left and right leaf springs and one end of the radius arm are rigidly connected to each other via the transbar, so if one leaf spring deforms, the torsional torque due to the deformation will affect the transbar. is transmitted to the other leaf spring via the leaf spring. For this reason,
Although it has a simple structure, it exhibits an anti-roll effect and contributes to excellent handling stability and ride comfort.

[Brief explanation of the drawing]

Figure 1 is a side view of a conventional front suspension, Figure 2 is a side view showing an embodiment of this invention, Figure 3 is a perspective view, Figure 4 is a front view as seen from the front of the vehicle, and Figure 5 is a side view of a conventional front suspension. The figure is a perspective view showing another embodiment. 1... Cab, 3... Hinge bracket, 4...
...Vehicle frame, 5...Support bracket, 8
...Leaf spring, 13...Pin, 15...
Transbar, 16...radius arm.

Claims (1)

[Scope of utility model registration request] In the front suspension system of a tilt cab vehicle that supports the cab along with the rear suspension on the body frame, the base end of the leaf spring is fixed to the support bracket of the body frame to ensure rigidity against lateral loads, while the free end is fixed to the support bracket of the body frame. It is rotatably connected to the hinge bracket of the cab and supported on the vehicle body frame via a radius arm, and the leaf springs on the left and right sides of the vehicle body are rigidly connected to each other at their free ends via a transbar. A front suspension device for a tilt cab vehicle, characterized in that one end is rigidly connected to a transbar and the other end is rotatably connected to a support bracket.