JPS5815682Y2 - Quick return mechanism of single acting hydraulic cylinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a single-acting hydraulic cylinder with a quick return mechanism.

More specifically, by incorporating a gas bag inside the cylinder,
The piston is quickly returned to the starting position by the expansion action of the gas bag.

Known single-acting cylinders include those shown in FIGS. 1 and 2.

In the case of FIG. 1, it operates only for strokes in one direction.

In this case, when the operation is finished and the fluid is discharged from the cylinder, the piston must be returned to the starting position 1 by some external force.

Such single-acting cylinders were used in applications where return by gravity was possible, such as vertical hoisting.

The case shown in FIG. 2 is a spring return type hydraulic cylinder, and a spring for returning the piston is provided inside the cylinder.

Since this cylinder requires a space to house the spring, it requires more than twice the length of the required stroke, and has the disadvantage that the overall length of the cylinder is significantly longer.

The present invention improves the shortcomings of the known single-acting cylinders as described above, by providing a middle cylinder in the screw I/N, inserting a strong and pre-inflated gas bag into the middle cylinder, and pressing the button. The idea is to store a portion of the hydraulic energy when the piston is pressurized and use this energy to return the piston quickly.

This invention, which was devised in response to the problem of monarchy, has the following structure.

In other words, there is an outer cylinder and a piston that moves up and down within this outer cylinder.
This piston is integrally provided with a middle cylinder having a smaller diameter than the outer cylinder, and communicates with the inside of the outer cylinder through an opening.

A strong gas bag that is inflated in advance is built into the middle cylinder, and when pressurized oil is supplied from the lower chamber of the piston, the piston rises, and at this time, the oil inside the outer cylinder flows into the middle cylinder. However, as the volume of the inner chamber of the outer cylinder decreases, the pressure increases, which compresses the gas bag and stores energy.

When the lower chamber of the piston is opened, the compression energy within the gas bag acts on the piston, causing the piston to return quickly.

A preferred embodiment of the above configuration will be described below with reference to the drawings.

Figures 3 and 4 show one embodiment of the present invention.

That is, 1 is an outer cylinder in which a piston reciprocates up and down.

3 is a middle cylinder that is integrally attached above the piston 2.

A gas bag 4 is built into the C chamber in the middle cylinder 3, and the upper part is sealed with a stopper 5.

The outer surface of the gas bag 4 is covered with an elastic and tough skin.

Reference numeral 6 denotes a sealing lid on the top of the outer cylinder 1, which is sealed with a seal 7 against the inner cylinder 3.

8 is an O-ring that seals the piston 2 and the outer cylinder.

A hydraulic pump 9 applies pressure to the lower chamber A of the outer cylinder 1 from the inlet pipe 1C.

Reference numeral 11 denotes an opening provided in the lower part of the middle cylinder 3, through which the inner and outer chambers (chamber B and chamber C) of the middle cylinder 3 located above the piston 2 communicate with each other and are filled with oil.

12 is a stopper provided on the middle cylinder 3.

Now, drive the hydraulic pump 9 to remove the lower chamber A of the piston 2.
When pressure oil is supplied to the lower chamber A and the pressure in the lower chamber A becomes Pl (P
'i, > El) and the piston 2 rises (Fig. 4), the volume of the C chamber of the middle cylinder 3 is constant, but the middle cylinder 3
The volume of chamber B between the outer cylinder 1 and the outer cylinder 1 decreases.

As a result, the sum of the volumes of chambers C and B decreases, and the internal pressure increases.

This volume reduction is compensated for by deflation of the gas bag 4.

As a natural result, the pressure within the gas bag 4 increases.

When the button is pressed on the cylinder in the above state, oil supply from the inlet pipe 10 is stopped, and the cylinder is released, the piston 2 descends.

At this time, the gas bag 4 inside the middle cylinder 2 expands, and the expansion pressure becomes B,
The piston 2 is compressed through the oil in the C chamber, and the piston 2 is returned quickly.

According to the present invention, which is constructed and operates as described above, unlike the conventional quick return mechanism, a relatively long member such as a coil spring is not built into the cylinder, so that the overall length of the cylinder can be made very short.

Therefore, it has the effect of being able to achieve the desired purpose even in a narrow space.

[Brief explanation of drawings]

FIG. 1 shows a known single-acting oil cylinder, and FIG. 2 shows a known spring return type oil cylinder. FIG. 3 shows a quick return mechanism of a single-acting hydraulic cylinder according to the present invention, and FIG. 4 shows a state in which hydraulic pressure is applied to the state shown in FIG. 3. As shown in the figure, 1...outer cylinder, 2...piston, 3...
・Middle tube, 4... Gas bag, 5... Plug at the top of the middle tube, 6.
...Airtight lid of outer cylinder, T...Seal 8...O ring, 9...Hydraulic pump, 10...Inlet pipe, 11...
Opening hole, 12...Stopper at the bottom of the middle cylinder.

Claims (1)

[Scope of utility model registration request] An inlet pipe 1 leading to a sealing lid 6 at the top and a hydraulic pump 9 at the bottom
0 and a piston 2 fitted into the outer cylinder 1.
, a middle cylinder 3 provided above the piston and sealed with a stopper 5, a gas bag 4 provided independently in the middle cylinder 3, and an opening provided at the bottom of the middle cylinder 3. 11, and a quick return mechanism for a single-acting hydraulic cylinder, characterized by comprising oil sealed inside the inner cylinder 3 and the inner side of the outer cylinder 1.