JP2558275Y2 - Hydraulic pilot valve - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a hydraulic pilot for switching an operation valve for supplying pressure oil to a working machine cylinder which operates a working machine mounted on a construction machine such as a power shovel, a wheel loader, a dump truck, a bulldozer, and the like. About the valve.

[0002]

2. Description of the Related Art As an operation valve for supplying pressure oil to a working machine cylinder of a construction machine, a spool is slidably provided on a valve body between a neutral position and a pressure oil supply position, and the spool is neutralized by a spring. A pilot-operated operating valve that is held at a position and slides to a pressure oil supply position with pressure oil supplied to the pressure-receiving portion is known. Pressure oil. The applicant of the present invention has previously applied for such a hydraulic pilot valve as shown in FIG. That is, the valve body 1
, A piston 3 that operates the pressure reducing unit 2,
There is known a hydraulic pilot valve provided with a member 4 for pushing the piston 3 and a swingable operation lever 5, and by swinging the operation lever 5, the piston 3 is pushed by the pushing member 4 to supply a pressurized oil. I have.

[0003]

The push member 4 of such a hydraulic pilot valve is connected to a shaft 8 supported on a bearing housing 7 integrally provided on a mounting plate 6 as shown in FIG. Is projected from the cover 9 to connect the operation lever 5, so that the size of the bearing housing 7 is limited by the cover 9, and the diameter of the shaft bearing hole 7a of the bearing housing 7 cannot be increased. And the mounting plate 6 and the bearing housing 7 are integral with each other, so that when integrally manufactured by aluminum die-casting or the like, the projected area becomes large and the manufacturing cost increases. There is a gap between the dust and the like, so that the dust and the like easily enter the inside.
May enter the abutting portion and cause malfunction.

Therefore, an object of the present invention is to provide a hydraulic pilot valve capable of solving the above-mentioned problems.

[0005]

An operating member for pressing a piston is provided on a shaft rotated by an operating lever, and the shaft is supported in a hydraulic pilot valve in which a pressure reducing unit is supplied with pressurized oil by pressing the piston. The bearing housing is provided integrally with the cover, and the cover is mounted on the upper surface of the mounting plate mounted on the valve body.

[0006]

[Operation] Even if the bearing housing is made compact, the rigidity can be increased by the cover, so that the strength against impact load and excessive load can be increased. Also, the projected area of the cover is small, and the cover can be manufactured at low cost using aluminum die casting. It is mounted in close contact with the mounting plate, so that dust and the like do not enter the cover.

[0007]

[Embodiment] As shown in FIGS. 3 and 4, the valve body 10 is provided with, for example, four decompression portions 11 and four pistons 12, and the decompression portions 11 are provided with an inlet port 13 and an outlet port 1.
4 is held in a blocking position by a spring 16, and the spool 15 is pushed by a piston 12 so as to be in a communicating position so that an inlet port 13 is connected to the outlet port 14.
Pressure oil is supplied. A mounting plate 17 is mounted on the upper part of the valve body 10, and a cover 18 is mounted on the upper surface of the mounting plate 17. The cover 18 is formed in a box shape having an upper wall 18a and a rectangular peripheral wall 18b with a downward opening. A bearing housing 19 is integrally formed downward at the left and right central portions of the upper wall 18a.
b, the pistons 12 face each other on both left and right sides of the bearing housing 19, and the holes 21 and 21 of the left and right peripheral walls 18a of the cover 18 and the holes 22 of the bearing housing 19 have First and second shafts 23, 24
Are rotatably supported by bearings 25, and a first operating member 26 is provided on a first shaft 23 to push two pistons 12, and a second operating member 27 is provided on the second shaft 24. Then, the remaining two pistons 12 are pushed. Swing plates 28 are fixed to the ends of the first shaft 23 and the second shaft 24, respectively, and operation levers 29 are attached to the swing plates 28, respectively. As shown in FIGS. 6 and 7, a pair of projecting pieces 30,
A screw rod 31 serving as a stopper is screwed into the mounting plate 17 mounted on the upper surface of the valve body 10, that is, the upper surface of the valve body 10, and fixed with a lock nut 32.

Next, the operation will be described. When the first shaft 23 is rotated in one direction with the operation lever 29, the first operating member 26
Swings and pushes one piston 12 to push down the spool 15 of the pressure reducing unit 11 to bring the pressure oil supply state. At the same time, the projecting piece 30 comes into contact with the screw rod 31 and the operation lever 29
Is the operation stroke end position, and the operation rod end position can be adjusted by tightening and loosening the screw rod 31 and moving it up and down.
The pressure output from one pressure reducing unit 11 by making the operation stroke end position when operating the operation bar 29 in one direction different from the operation stroke end position when operating the operation bar 29 in the other direction by making the vertical position of 1 different. The maximum pressure of the oil and the maximum pressure of the pressure oil output from the other pressure reducing unit 11 can be made different.

[0009]

Since the bearing housing 19 is integrally provided on the cover 18, the rigidity of the bearing housing 19 is increased, and even if the bearing housing 19 is compact, the impact resistance and the strength against an excessive load can be improved. Since the cover 18 is a separate member, the projected area of the cover 18 is small, so that the manufacturing cost can be reduced even if the cover 18 is integrally manufactured by die casting or the like. In addition, the peripheral wall 18b of the cover 18 is closely adhered to the upper surface of the mounting plate 17 without any gap. Thus, dust and the like do not enter the inside of the cover 18.

[Brief description of the drawings]

FIG. 1 is a sectional view of a conventional hydraulic pilot valve.

FIG. 2 is a perspective view of a cover and a mounting plate.

FIG. 3 is a sectional view of the hydraulic pilot valve of the present invention.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a perspective view of a cover and a mounting plate.

FIG. 6 is a front view of the hydraulic pilot valve.

FIG. 7 is a plan view of a hydraulic pilot valve.

[Description of Signs] 10: valve body, 11: decompression section, 12: piston, 17 ...
Mounting plate, 18 cover, 19 bearing housing, 23 first shaft, 24 second shaft, 26 first operating member, 27 second operating member, 28 swing plate, 29
Operation lever, 30 ... Projection piece.

Claims (1)

(57) [Scope of request for utility model registration] 1. A valve body has a pair of pressure reducing portions, a pair of pistons for operating spools of the pressure reducing portions, and an operating member which rotates together with a shaft to push one of the pistons. A hydraulic pilot valve that connects the shaft to the operating lever 29 and operates the operating lever 29 to rotate the shaft and press the one piston 12 by the operating member to supply hydraulic oil; Attach the mounting plate 17 to
An upper wall 18a and a peripheral wall 1
8b, a cover 18 covering the operating member is attached in a box shape opened below the upper wall 18 of the cover 18.
1. A hydraulic pilot valve, wherein a bearing housing 19 for supporting the shaft is provided integrally with a.