JPS6030141Y2 - Power steering device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a power steering device, and particularly to a power steering device suitable for use in large vehicles such as trucks.

Conventionally, in large vehicles such as trucks, the main shaft of the steering bundle is arranged in a nearly vertical direction, and the mounting position of the engine and steering wheels with respect to the chassis frame has caused the ball screw type power steering system to be used. The device is used,
It was installed on the chassis frame with its axial direction substantially perpendicular.

However, when the axial direction is vertical, the driver's seat must be placed at a high position due to its axial length, and the ball screw type power steering device itself is complicated and expensive. However, there was a problem in that the steering rigidity was low due to play between a large number of component parts and elastic deformation of each component.

Incidentally, small vehicles using a rack and pinion type power steering device are known.

This rack and pinion type power steering device has the advantage that it can be manufactured at low cost because it has fewer parts compared to the above-mentioned ball screw type power steering device, and can increase steering rigidity, but due to its structure, it Since it is disposed in a direction perpendicular to the direction of travel, it has conventionally been considered difficult to secure mounting space for large vehicles.

In view of the above-mentioned points, the present invention replaces the drag link section of the conventional steering device with a rack and pinion type power steering device and arranges it in the longitudinal direction of the vehicle. This makes it extremely easy to install a power steering system.

The present invention will be described below with reference to the illustrated embodiment. In the figure, 1 is a chassis frame of a large vehicle such as a truck, 2 is a driver's seat, and 3 is a steering wheel.

Conventionally known rack and pinion power steering device (hereinafter referred to as RP
It is written as PS.

) 4 is disposed so that its axial direction, that is, the axial direction of the rack shaft 5, substantially follows the rear direction of the vehicle, and the front end portion of its main body 6 is pivotally supported on the chassis frame 1.

The rack shaft 5 slidably protrudes from the rear end of the main body 6 and is linked to the steering wheel 3 via a pole stud and a knuckle arm 7 (not shown).

In addition, within the main body 6, an input shaft 8 that is interlocked with the rack shaft 5 through a pinion (not shown) that meshes with rack teeth cut into the rack shaft 5 is connected to a pair of universal joints 9 and It is linked to a main shaft 12 connected to a steering handle 11 via a spline fitting part 10 between the joints.

The connecting means 13 consisting of the pair of universal joints 9 and the spline fitting part 10 is conventionally well known, and is generally used in large vehicles in which the two areas around the driver's seat are of a so-called tilt cabin type. Since it is a connecting means, the connecting means can be used as is.

It should be noted that this connecting means 13 may have another structure, and although not shown, it goes without saying that the left and right steering wheels 3 are interlocked with each other by a tie rod arm and a tie rod.

Furthermore, it goes without saying that the RPPS 4 is connected to a hydraulic circuit.

With the above configuration, when the steering handle 11 is steered, the rotation thereof is transmitted to the input shaft 8 via the main shaft 12 and the connecting means 13, and as is clear from the operation of the conventionally known RPPS 4, the rotation of the steering handle 11 is transmitted to the input shaft 8. The hydraulic circuit is switched depending on the direction of rotation of the main body 6, and high pressure oil is introduced into a power cylinder (not shown) inside the main body 6.

Then, the rack shaft 5 is displaced in the axial direction with respect to the main body 6 by the acting force from the pinion of the input shaft 8 and the hydraulic pressure.
This operation of the rack shaft 5 is transmitted to the steering wheel 3 via the pole stud and the knuckle arm 7 to deflect it.

RPPS caused by deflection of the steering wheel 3 and relative displacement between the steering wheel 3 and the chassis frame 1 when the vehicle is running.
4. Displacement of the main body 6 with respect to the chassis frame 1 is absorbed by the pivot between the main body 6 and the chassis frame 1 and the connecting means 13, and is not transmitted to the steering handle 11.

As described above, in the present invention, the rack and pinion type power steering device is disposed almost in the longitudinal direction of the vehicle, so compared to the case where it is disposed in the orthogonal direction, especially in large vehicles such as trucks. This makes it extremely easy to install and saves space, and by arranging it in this way, it has the excellent effect of allowing the driver's seat to be installed at a lower position than before. .

Further, by using the rack and pinion type power steering device, there is an advantage that the steering device can be manufactured at low cost and the steering rigidity can be increased.

In particular, according to the present invention, in a device that uses the conventionally widely used pole nut type power steering device, by applying a rack and pinion type power steering device that constitutes the unsprung load of the vehicle in place of the drag link part. It has the advantage of excellent versatility in that it can easily be used as a low-floor steering mechanism.

[Brief explanation of the drawing]

The figure is a schematic side view showing one embodiment of the present invention. 1... Chassis frame, 4... Rack and pinion type power steering device, 5... Rack shaft, 6
...Body, 8...Input shaft, 11...
・・・Steering handle, 13・Curving・Connection means.

Claims (1)

[Scope of utility model registration request] A rack and pinion type power steering device is disposed approximately in the longitudinal direction of the vehicle, and its main body is pivotally supported on the chassis frame of the vehicle as the vehicle's unsprung load, and the rack shaft is linked to the steering wheels, and the rack and pinion type power steering device is A power steering device characterized in that an input shaft of the steering device and a steering bundle are interlocked via a coupling means capable of absorbing displacement of the main body with respect to a chassis frame.