JPS6239037Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a hydraulic jack, and in particular, a pressure relief valve and a pump are arranged in parallel in a direction perpendicular to the axis of the jack body, and the pump lever is operated beyond its pumping operation range to reduce pressure. This relates to a hydraulic jack that lowers the ram by opening the release valve.

Normally, in this type of jack, as shown in Fig. 1, during the reciprocating movement of the pump lever 1 within ∠α, the pump 4 is actuated via the relay frame 3 with the shaft 2 as a fulcrum due to its restraint, and the tank 5, the suction valve 7 is opened through the suction passage 6, and oil is sucked into the pump chamber 4a. Then, by downward movement of the lever 1, the discharge valve 9 is opened through the discharge passage 8, and oil is forced into the ram chamber 10. , a hydraulic jack that is designed to raise the ram 11 is well known, and in order to drain the oil in the ram chamber 10, the pressure relief valve 12 is moved by moving the pump lever 1 beyond ∠α to ∠β. ball valve 12
b is pressed open via the valve rod 13, and the oil is refluxed into the tank 5 through the communication passage 14 communicating with the discharge passage and the reflux passage 15 communicating with the tank 5.
1.

In this case, the snap spring 16 is used as a stopper to restrict the opening movement range of the discharge valve 9.
However, the smaller the diameter of the passage 8, the shallower the mounting groove 17 for the snap spring 16 becomes, which not only lacks reliability but also extremely poor workability and requires a great deal of effort.

Furthermore, as shown in FIG. 2, there is a system in which a tubular member 18 having a notch 18a is press-fitted and held in the discharge passage 8 as a stopper for the discharge valve 9, but in this case, it is difficult to maintain the tubular member 18 during long-term use. There was a drawback that the position could be moved and the communication passage 14 could be blocked.

Furthermore, a relief valve 19 and a tank 5 are provided in the jack body 20 in which the suction passage 6 and the discharge passage 8 are arranged in parallel.
Since relief passages 21 leading to the discharge valve 9 are provided, when the overall size is made smaller, the diameters of these passages are also reduced, which requires a great deal of effort, especially when installing the discharge valve 9. Ta.

In view of the above-mentioned current situation, the present invention proposes a hydraulic jack having a discharge valve structure that securely holds the discharge valve, has a simple structure, and is highly workable.

Therefore, in the present invention, a protruding passage is formed at the tip of the pressure relief valve 12 in the communication passage 14 between the discharge passage 8 and the pressure relief valve 12, and this is inserted into the communication passage 14, and the tip of the protrusion passage is connected to the discharge passage. The invention is characterized in that it protrudes into the inside of the discharge valve 8 and also serves as a stopper for the discharge valve 9.The gist of the present invention will be explained below based on the embodiment shown in the drawings.

FIG. 3 is an enlarged sectional view of the discharge valve portion showing an embodiment of the hydraulic jack of the present invention, and the other structure is the same as the conventional product shown in FIG. 1.

In the drawing, the pressure relief valve 12 is a case 12a.
, the ball valve 12b, and the ball valve 12b on the valve seat 1.
2c, a spring 12e for press-fitting the valve rod 13, and a tubular member 22 fitted to the tip of the case 12a to form a protruding passage 12f, so that the protruding passage 12f protrudes into the discharge passage 8. In particular, as described above, it is designed to serve as a stopper for the discharge valve 9.

In the hydraulic jack of the present invention equipped with such a discharge valve mechanism, it is possible to eliminate the work and assembly effort required for fitting the snap spring 16 in the prior art, and at the same time, the press-fit tubular member 18
Instead of a stopper that is inferior in durability, a protruding passage 12f is provided at the tip of the pressure relief valve 12 itself, and the stopper is formed at the same time as the pressure relief valve 12 is attached to the jack body 20, improving workability. is outstanding and is integrated with the pressure relief valve 12, so
It is extremely robust and has excellent features that can reliably eliminate the defects of conventional products mentioned at the beginning.
The practical benefits are significant.

[Brief explanation of the drawing]

Fig. 1 is a partially longitudinal side view showing an example of a conventional hydraulic jack, Fig. 2 is a sectional view of a discharge valve portion showing another embodiment of the conventional product, and Fig. 3 is a discharge valve of the hydraulic jack of the present invention. FIG. 2 is an enlarged sectional view of main parts showing a valve and a pressure relief valve. 1... Pump lever, 2... Shaft, 3... Relay frame, 4... Pump, 4a... Pump chamber, 5... Tank, 6... Suction passage, 7... Suction valve, 8... Discharge passage , 9...discharge valve, 10...ram chamber, 11...
...Ram, 12...Pressure relief valve, 13...Valve rod, 14...
...Communication passageway, 15...Return path, 16...Snap spring as a stopper, 17...Mounting groove, 18
... Tubular member, 18a ... Notch, 19 ... Relief valve, 20 ... Jack body, 21 ... Relief passage.

Claims (1)

[Scope of utility model registration request] In a hydraulic jack in which a pressure relief valve perpendicular to the axis of the jack body and a pump are arranged in parallel and the pressure relief valve is opened by operating the pump lever beyond the pumping operation range, the communication passage between the discharge passage and the pressure relief valve. A hydraulic jack characterized in that a protruding passage provided at the tip of the pressure relief valve is inserted into the pressure relief valve, and the tip of the protruding passage projects into the discharge passage so as to double as a stopper for the discharge valve.