JPH0355634Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to the improvement of a hydraulic support device used to support the earth pressure of a side gutter in, for example, civil engineering gutter construction.

(Prior Art) This type of hydraulic support device has conventionally been constructed as shown in FIG. is extended from the cylinder 4 to support the earth pressure of a side gutter, for example, and prevent landslides. Reference numeral 5 indicates a beam material, and reference numeral 6 indicates a conduit buried in the side gutter.

A stop valve (not shown) is interposed in the connector part 7 of the cylinder 4, and when this stop valve is manually opened when the piston rod 3 is contracted, the supply fluid pressure in the working pressure chamber 2 is reduced. is opened to the reservoir side (not shown).

By the way, in such a hydraulic support device, the hand pump must be carried along with the cylinder 4 and the like and connected to piping each time it is used, which not only makes handling troublesome, but also makes it difficult to handle the hand pump when not in use.
There was also a concern that dirt, sand, etc. adhering to the cylinder 4 would get mixed into the cylinder 4 during piping and have an adverse effect on the packing and sliding parts.

Therefore, as shown in FIGS. 6 and 7, a hand pump assembled into a cylinder has also been proposed.

Inside the cylinder 10, a liquid reservoir chamber 13 and a piston operating pressure chamber 14 are defined by the casing 12 of the lever-operated hand pump 11, and the piston 15 has a hollow piston rod 16 that is slidably inserted into the cylinder 10. Concatenated.

The hand pump 11 pumps the liquid in the liquid reservoir chamber 13 into the piston operating pressure chamber 14 by the pump action of the plunger 17.
The plunger 17 reciprocates as the lever 18 swings around the fulcrum 19, causing the piston rod 16 to extend.
0, and when the pump chamber 20 expands, the reed valve 21 opens and the liquid reservoir chamber 1 is supplied via the supply passage 22.
3 is sucked into the pump chamber 20, and when the pump chamber 20 contracts, this liquid is sent out to the piston operating pressure chamber 14 via the check valve 23.

In addition, a return passage 24 is formed in the casing 12 of the hand pump 11 to communicate the piston operating pressure chamber 14 and the liquid reservoir chamber 13, and a ball-shaped stop valve 25 (when a bolt 26 is tightened) is provided in the middle of this passage 24. Close the passage 24, and loosen it to open the passage 24)
is interposed.

(Problem to be solved by the invention) By the way, when using a hydraulic support device having such a hand pump integrally, the liquid reservoir chamber 13 can be opened by swinging the lever 18 as described above. The liquid is supplied to the piston operating pressure chamber 14 to cause the piston rod 16 to extend. However, when the hydraulic pressure in the piston operating pressure chamber 14 exceeds the operating force of the lever 18, the lever 18 no longer moves the plunger 17.
Since it becomes impossible to push the liquid in the pump chamber 20 into the piston operating pressure chamber 14,
The lever 18 in the middle of its stroke could not be pushed down to the initial state, and the lever 18 in the upright state sometimes got in the way of construction work.

(Means for solving the problem) In order to solve this problem, this invention
A piston rod is slidably housed in the cylinder, and a liquid reservoir is formed above the cylinder, and hydraulic fluid from the liquid reservoir is fed to the piston working pressure chamber of the cylinder via a check valve. In a hydraulic support device equipped with a hand pump, the hand pump is composed of a plunger that can freely slide into a pump chamber, and a tilting lever that reciprocates the plunger, and the pump chamber of the hand pump and a liquid reservoir chamber are connected to each other. They communicated through a small passage.

(Function) When the piston rod is extended (when the lever of the hand pump is operated), even when the hydraulic pressure in the piston operating pressure chamber exceeds the operating force of the lever, the hydraulic pressure in the pump chamber is transferred to the liquid reservoir chamber through the small passage. Since it gradually escapes to , it becomes possible to push the plunger and gently lower the lever to its initial state.

(Example) In FIG. 1, 30 is a casing of a hand pump 34 which defines a liquid reservoir chamber 32 and a piston operating pressure chamber 33 in a cylinder 31, and 35 is a casing of a lever 36.
A plunger 39 reciprocates to expand and contract the pump chamber 38 in accordance with a swinging operation with 7 as a fulcrum, and a plunger 39 opens when the pump chamber 38 expands to introduce liquid from the liquid reservoir chamber 32 into the pump chamber 38. Reed valve, 40
is a passage connecting the pump chamber 38 and the piston working pressure chamber 33, and a check valve (not shown) is provided in the middle of the passage to allow the working fluid to flow only from the pump chamber 38 to the piston working pressure chamber 33. be. Reference numeral 41 designates a ball-shaped stop valve installed in a return passage 42 that communicates the piston operating pressure chamber 33 and the liquid reservoir chamber 32. As before, this valve closes the passage 42 when a bolt (not shown) is tightened, and closes the passage 42 when loosened. It's starting to open.

A pump chamber 38 is provided on the inner surface of the reed valve 39.
A notch groove 44 is formed for releasing the liquid pressure to the liquid reservoir chamber 32 side via the supply passage 43. The passage area of the notched groove 44 is set to such an extent that it does not interfere with the pumping action of the plunger 35. Reference numeral 45 indicates a stopper for regulating the maximum opening degree of the reed valve 39.

Therefore, when this hydraulic support device is in use, by swinging the lever 36 of the hand pump 34, the liquid in the liquid reservoir chamber 32 is supplied to the piston operating pressure chamber 33 by the pumping action of the plunger 35 as before. This hydraulic pressure causes a piston rod (not shown) to extend, and the piston operating pressure chamber 33
When the hydraulic pressure exceeds the operating force of the lever 36, the supply of hydraulic pressure from the pump chamber 38 to the piston operating pressure chamber 33 is blocked, and in this state, the cylinder 31 and the piston rod are activated, for example, under the earth pressure of a side gutter during civil engineering gutter construction. support. Even in that case, when the plunger 35 is pushed in, the hydraulic pressure in the pump chamber 38 gradually escapes to the liquid reservoir chamber 32 side through the notch groove 44, so the lever 36 in the middle of its stroke returns to its initial position where it does not interfere with construction work. It becomes possible to push it back gently. Note that the backflow of the hydraulic oil from the piston working chamber 33 is prevented by a non-return valve (not shown) provided in the flow path 40, so that even if the hydraulic pressure in the pump chamber 38 decreases, the piston rod will not contract.

Instead of the notched groove 44, a throttle hole 44A may be formed in the reed valve 39 as shown in FIG. 2, or a pump chamber 38 may be formed in the plunger 35 as shown in FIG.
A throttle hole 44B communicating with the liquid reservoir chamber 32 may be formed, and as shown in FIG.
A spring 48 is provided that biases 9 in the opening direction,
A small gap 44C may be formed between the reed valve 39 and the seat surface when the pressure inside the pump chamber 38 is low.

(Effects of the invention) In summary, according to this invention, a piston rod is housed in a cylinder so as to be able to slide freely, a liquid reservoir is formed above the piston rod, and a liquid reservoir is formed in the piston operating pressure chamber of the cylinder. In a hydraulic support device equipped with a hand pump that pumps hydraulic fluid from the pump through a check valve, the hand pump is composed of a plunger that can freely slide into the pump chamber, and a tilting lever that reciprocates the plunger. At the same time, we have installed an orifice to release the hydraulic pressure in the pump chamber of the hand pump from upstream of the check valve to the liquid reservoir chamber, so that, for example, after the piston rod is extended during civil engineering gutter construction, the lever of the hand pump can be used to prevent construction work from getting in the way. This has the effect that it becomes possible to push it back to the initial position where it does not become.

[Brief explanation of drawings]

Figure 1 is a sectional view of the main parts of an embodiment of this invention, and Figure 2
Figures 4 to 4 are sectional views of main parts showing other embodiments,
Fig. 5 is a usage state diagram showing the prior art, Fig. 6 is an overall sectional configuration diagram showing the prior art, and Fig. 7 is its A-
It is an A sectional view. 31...Cylinder, 32...Liquid storage chamber, 33...
Piston operating pressure chamber, 34...Hand pump, 36
... lever, 38 ... pump chamber, 39 ... reed valve, 40 ... check valve, 44 ... notch groove.

Claims (1)

[Scope of utility model registration request] A piston rod is slidably housed in the cylinder, and a liquid reservoir is formed above the piston rod, and the hydraulic fluid from the liquid reservoir is supplied to the piston working pressure chamber of the cylinder through a check valve. In a hydraulic support device equipped with a hand pump for pressure feeding, the hand pump is composed of a plunger that is slidable into a pump chamber, and a tilting lever that reciprocates the plunger, and the hand pump is configured to have a pump chamber and a liquid reservoir chamber of the hand pump. A hydraulic support device characterized in that the and are connected via a small flow path.