JPS6134204Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to power steering devices for various vehicles, and the steering box doubles as an oil tank, eliminating the need for a special oil tank.
The hydraulic oil stored in the steering box lubricates the engaging parts of the sector gear, etc.
Furthermore, in the case of the integral type, the piping can be significantly shortened.

Power steering devices are becoming widely adopted as steering devices for various vehicles, but in conventional power steering devices, an oil tank was installed at an appropriate location on the vehicle body to store hydraulic oil, so special It was necessary to manufacture an oil tank and to secure space for the equipment.

The present invention aims to solve these conventional problems, and its feature is that the steering box on the vehicle body rotates a sector shaft that has a sector gear inside the steering box. The box is provided with a hydraulic cylinder actuated by a control valve linked to a handle, a piston having a rack that engages with the sector gear is provided in the hydraulic cylinder, and a hydraulic cylinder is provided in the box. The hydraulic oil for cylinder operation is stored up to the area where the sector gear and rack engage.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment. The drawings illustrate an integral power steering system adopted for an agricultural tractor. In FIG. 1, 1 is a tractor body, an engine 2, a transmission case 3 etc. are constructed as a structure. 4 is a radiator, and 5 is a bonnet. Reference numeral 6 denotes a front axle bearing stand, which is attached to the front lower part of the engine 2, and a front axle 8 is swingably supported on the front axle bearing stand 6 by a center pin 7. Front wheels 9 are attached to both ends of the front axle 8 so that they can be steered around a king pin, and each of the front wheels 9 is interlocked with the left and right sides via a knuckle arm 10, a tie rod 11, etc., and one of the knuckle arms 10 A drag link 12 in the longitudinal direction passing along the side of the engine 2 is connected to the engine 2 . 1
3 is a handle, and 14 is a steering box, and this steering box 14 is constructed as shown in FIGS. 2 to 4. That is, the steering box 14 includes a box main body 15 and a pair of left and right side covers 16, the box main body 15 is fastened onto the transmission case 3 with bolts 17, etc., and each side cover 16 is attached to the box main body 15. It is mounted on both sides in an oil-tight manner via packings 18 and the like, and is fastened with bolts 19. The steering box 14 has a hollow shape, and is configured to store hydraulic oil 20 for the steering box inside and also serve as an oil tank. Reference numeral 21 denotes a sector shaft, which is rotatably supported by the steering box 14 via appropriate bearings 22 around a horizontal axis, and is located within the steering box 14 and includes a sector gear 23.
Further, a Pitman arm 24 connected to the drag ring 12 is fixed to the lateral projecting end. Reference numeral 25 denotes a hydraulic cylinder, which is of an integral type and is therefore integrally provided in the steering box 14 together with a control valve 26. Hydraulic cylinder 2
5 is a cylinder body 27 integrated with the box body 15
, a piston 28 fitted inside the piston 28 so as to be slidable in the axial direction, and cylinder chambers 29 and 30 formed above and below the piston 28.
8 is screwed onto a worm 32 connected to the handle shaft 31 via a torsion bar (not shown), and has a rack 33 on a part of its outer periphery. The rack 33 corresponds to a notch 34 formed between the box body 15 and the cylinder body 27, and is engaged with the sector gear 23 through this notch 34. The worm 32 is integrally provided with a rotary of the control valve 26 so as to be fitted onto the torsion bar. The control valve 26 is for controlling and supplying the hydraulic oil 20 discharged from the hydraulic pump 36 to each cylinder chamber 29, 30 of the hydraulic cylinder 25, and as shown in FIG.
It is connected to each cylinder chamber 29, 30 via 38. The body-side drain port 39 of the control valve 26 is formed to open directly into the steering box 14 from the cylinder body 27. 40 is a breather, and 41 is a suction pipe of the hydraulic pump 36, which is connected to the outlet 42 of the steering box 14. 43 is a discharge pipe of the hydraulic pump 36, which is connected to an input port formed on the body side of the control valve 26.

In the above configuration, since the hydraulic pump 36 is in operation while the engine 2 is operating, the hydraulic oil in the steering box 14 is constantly circulated through the hydraulic pump 36 and the control valve 26. Therefore, when the handle 13 is rotated left and right, the control valve 26 is switched and the oil passage 37 or 38 is switched.
to the cylinder chamber 29 or 3 of the hydraulic cylinder 25.
0 is supplied with hydraulic oil 20, and the piston 28 moves up and down, so the rack 33, sector gear 23,
The Pitman arm 24 rotates in the longitudinal direction via the sector shaft 21, causing the front wheels 9 to perform a predetermined steering operation.

As described above, in the present invention, the steering box 14 is also used as an oil tank, and the hydraulic oil 20 for steering is stored therein, so there is no need to equip a separate oil tank, which reduces manufacturing costs and equipment space. It is very advantageous in this respect. Also, in the steering box 14, there are a sector gear 23 of the sector shaft 21 and a rack 3 of the piston 28.
Since the hydraulic oil 20 is stored up to the interlocking part with the rack 33 and the sector gear 23, the hydraulic oil 20 can sufficiently lubricate the interlocking part in the steering box 14 (for example, the interlocking part between the rack 33 and the sector gear 23), thereby preventing wear. The occurrence of such problems can be suppressed to a minimum. Furthermore, in the case of an integral type, the oil tank, hydraulic cylinder, and control valve are integrated in close proximity, so the piping is shortened and the occurrence of oil leakage is also reduced. For example, in the conventional case, as shown in FIG.
and a hydraulic cylinder (including a control valve) 46, a pipe 47 connecting the hydraulic cylinder 46 and the oil tank 44, respectively.
48 and 49, the piping becomes very long, which increases the likelihood of oil leakage, etc. However, according to the present invention, such problems can be solved.

[Brief explanation of the drawing]

Figure 1 is a side view showing one embodiment of the present invention;
The figure is an enlarged sectional view of the main part, and Figure 3 is A of Figure 2.
4 is a front view of the essential parts, FIG. 5 is a schematic configuration diagram of the same, and FIG. 6 is a configuration diagram showing a conventional example. 1... Tractor body, 13... Handle, 14
... Steering box, 20 ... Hydraulic oil, 2
3...Sector gear, 25...Hydraulic cylinder,
26...Control valve.

Claims (1)

[Scope of utility model registration request] A sector shaft 21 having a sector gear 23 inside the steering box 15 on the vehicle body 1 is rotatably supported, and a control valve 26 interlocked with the steering wheel 13 is mounted on the box 15.
A hydraulic cylinder 25 is provided which is operated by a piston 28 having a rack 33 that engages with the sector gear 23, and an operating shaft 20 for operating the hydraulic cylinder 25 is disposed within the box 15. sector gear 2
3. A power steering device characterized in that the power is stored up to the occlusal part between the rack 33 and the rack 33.