JPS6112301Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention is applicable to a type of car body structure in which the cab is assembled to the chassis frame via a suspension (hereinafter referred to as a cab suspension car), such as a cab over truck. This invention relates to a front cab suspension device used.

The general structure of a cab suspension vehicle is as follows:
As shown in FIG. 1, a pair of left and right cab frames 2 forming the bones of a cab 1 are connected at their front and rear ends via a front cab suspension device 3 and a cab suspension device 4, respectively. left,
It is assembled to the right chassis frame 5, and the suspension system of each device 3 and 4 is equipped with a suspension spring, a suspension damper, etc.
This serves to attenuate the vertical vibration of the vehicle body transmitted to the cab 1, thereby making the cab 1 more comfortable to ride.

By the way, with conventional front cab suspension devices, when excessive vertical vibration occurs in the vehicle body when driving on a rough road, or when excessive roll tilt occurs in the vehicle body due to a sharp curve, etc., the suspension is suspended. Overstroke tends to occur in suspension springs and the like, and this is because so-called weak springs with a low spring constant are used in the suspension system in order to improve the riding comfort of the cab 1.

However, when an overstroke occurs, metal touches occur between the metal members of the system, resulting in a problem that causes damage to the device.

In addition, in a vibration damping device for a movable driver's cab, as shown in Japanese Patent Publication No. 44-16968,
A buffer structure for a movable base of the driver's seat that moves vertically using these members is shown, which includes a spring, a shock absorber, etc., but in this structure, when the movable base moves downward, the downward Since there is no means to restrict the stroke of the movable base, there is a risk that the movable base will overstroke downward, causing metal members supporting the movable base to touch each other, resulting in damage to the device.

The present invention was devised to solve the above-mentioned problems.In other words, the purpose of the present invention is to prevent excessive vertical vibrations or rolls in the vehicle body.
To provide a front cab suspension device in which the device is not damaged.

Hereinafter, the present invention will be explained based on an illustrated embodiment.

As shown in FIG. 2, the suspension device of the embodiment includes a bracket 6 consisting of a pair of vertical plates erected on both sides of the chassis frame 5, and an arm support shaft 7 horizontally suspended between the vertical plates. , a lower arm 8 whose front end is pivotally connected to the support shaft 7 and whose middle part has a U-shaped cross section; a box-shaped bracket 9 which is fixed and protrudes downward from the cab frame 2; An upper arm 10 is welded to the lower surface and has a U-shaped cross section with the rear half folded diagonally downward, and both arms 8 and 10 are pivotally connected by a hinge shaft 11. Further, a suspension spring 13 made of a weakly elastic coil spring is interposed between the middle part of the upper arm 10 and the middle part of the lower arm 8.

In addition, a shock absorber 22 is stretched between the arm support shaft 7 and a shaft 12 that is suspended horizontally on the front edge of the bracket 9.

Furthermore, in the suspension device of this embodiment,
A dish-shaped spring receiver 14 is interposed between the lower end of the spring 13 and the floor surface of the lower arm 8, and
The upper end of a shaft 16 suspended on the center line of the spring 13 is pivotally supported on the horizontal shaft 15 of the upper arm 10.

Therefore, the lower half of the shaft 16 has a threaded portion 1.
The threaded portion 16a penetrates the spring receiver 14 and the floor surface 8a of the lower arm 8, and above and below the penetrating portion of the threaded portion 16a,
The core metals of an upper stopper 17 and a lower stopper 18, each made of a washer-like rubber damper, are screwed together.
9 is fixed to the shaft 16.

In addition, a plurality of locations on the floating outer circumference of the spring receiver 14 are supported by the upper end of an adjusting screw 20 that is screwed into a screw hole of the lower arm 8 and projects upward, and the screw 20 is supported by a fixing nut 21. It is fixed to the lower arm 8.

Next, the operation of the suspension device of the embodiment configured as described above will be described.

Similar to the operation of a general front cab suspension device, the gravity load applied to the front end of the cab frame 2 is carried by the chassis frame 5 via the spring 13 and the lower arm 8.
The vertical vibration force transmitted from the vehicle body to the cab 1 is attenuated by the absorption action of the spring 13 and the absorber 22 working together, thereby making the cab 1 more comfortable to ride.

By the way, if excessive stress is applied to the suspension system due to the above-mentioned abnormal running, the spring 1
3 tries to expand and contract significantly, but before the overstroke condition occurs, either stopper 1
7 and 18 contact the floor surface 8a of the arm 8, and the stoppers 17 and 18 act as dampers, so overstroke is suppressed without causing any impact, thereby preventing metal touching of the structural members. , there will be no damage to any parts.

Since the installation height of the stoppers 17 and 18 can be adjusted extremely easily by tightening or loosening the nuts 19, it is possible to set the restraint stroke according to the road conditions in the driving area and the load weight at that time. Therefore, overstroke can be effectively suppressed.

In addition, the preload force of the spring 13 can be adjusted by changing the height of the spring receiver 14 by operating the adjustment screw 20, so the spring 13 can be weakened (or If set (strongly), the occurrence of overstroke will be reduced from this point as well, resulting in safer and more comfortable driving.

As described above, according to the front cab suspension device according to the present invention, a stopper consisting of two upper and lower rubber dampers is provided on the shaft arranged on the center line of the suspension spring. The structure is designed to prevent the overstroke of the spring, so there is no risk of damage to the suspension system even during abnormal driving, and comfortable driving is always possible depending on road conditions and loading conditions. That is, it has the effect of improving safety and feeling during driving.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the front part of a cab suspension vehicle, and FIG. 2 is a schematic diagram of a front cab suspension device showing an embodiment of the present invention. 1...Kiyab, 2...Kiyab frame, 3...
Front cab suspension device, 5... Chassis frame, 8... Lower arm, 10... Atsupa arm, 13... Suspension spring, 1
6...Shaft, 17, 18...Upper and lower stoppers.

Claims (1)

[Claim for Utility Model Registration] Between the lower arm that is pivotally connected to the front end of the chassis frame and the atsupa arm that is fixed to the front end of the cab frame and whose rear end is pivotally connected to the rear end of the lower arm. In a front cab suspension device in which a front suspension spring made of a coil spring is mounted on a shaft, the shaft is disposed on the center line of the front suspension spring, and the upper end of the shaft is pivotally supported on an atsupa arm. a shaft whose lower end passes through the lower arm; a rubber upper stopper which is attached above the penetration part of the shaft and whose vertical position can be adjusted; A rubber lower stopper is installed below the penetration part and is installed so that its vertical position can be adjusted.When the suspension spring attempts to overstroke, the upper stopper or the lower stopper is installed so that its vertical position can be adjusted. A front cab suspension device characterized in that one of the stoppers is formed so as to abut against a lower arm.