JPS5824006Y2 - Quick return hydraulic cylinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a single-push hydraulic cylinder in which the ram or piston of the hydraulic cylinder returns quickly.

As shown in Fig. 1, a conventional single-push hydraulic cylinder presses pressure oil into a cylinder 1 through a hose 4 that connects a ram or piston 2 to an oil supply/drain port 3 at one end of the cylinder 1, and then returns the ram 2. When the pressure oil is pressed against the spring 5 and the pressurized oil is stopped, the ram 2 stops at an equilibrium position between the pressure oil and the spring, and when the pressure of the pressure oil is lowered from the hose 4, the ram 2 is pressed against the spring 5. pushed back.

In addition, in the reciprocating hydraulic cylinder shown in Fig. 2, pressure oil is supplied from pipes 4 and 6 connected to both ends of the cylinder 1, and the hydraulic pressure on one side of the ram 2 in the cylinder is made higher or lower than that on the other side. Ram 2 can be moved.

In the single-push hydraulic cylinder shown in FIG. 1, the return of the ram is due solely to the force of the spring, and is therefore relatively slow.

In addition, in the reciprocating hydraulic cylinder shown in Figure 2, the hose is
It's expensive because it requires books.

The present invention is a quick-return hydraulic cylinder connected to a hydraulic pump including a drain oil amount adjusting device for sucking back oil out of the return spring in order to further increase the return speed of the ram.

This will be explained with reference to FIGS. 3, 4, and 5.

In Figures 3 to 5, the same symbols as in Figure 1 indicate the same parts, 7 is the oil tank and its oil passage, 8 is the pressure gauge, 9 is the manual 4
direction switching valve, 10 is a high pressure oil passage, 11 is a return oil passage, 12
is a check valve, 13 is a pressure setting safety valve, 14 is an oil tank, 1
5 is an oil tank and its oil passage; 16 is a high-pressure oil passage on the pump side; 17 is a high-pressure oil pump; 18 is a low-pressure oil pump; 19 is a drive machine that simultaneously drives the pumps, such as an electric motor or gas engine; and 20 is an oil Quantity adjustment device, 21 is an oil tank,
22 and 23 are oil soakers, and 24 is a high pressure suction side passage.

The four-way switching valve 9 is moved in the axial direction by manually pushing or pulling the handle 25, and in the A position, oil is supplied to the cylinder 1 and the ram 2 is pushed up against the spring 5.
At position B, stop the oil supply and stop ram 2 at any position! At position C, the oil in the cylinder 2 is sucked back and the ram 2 is quickly returned to its original position.

FIG. 3 shows the flow of oil when the four-way switching valve 9 is in the A position, and the oil in the tank 21 is supplied through the oil soaker 23 by the high-pressure oil pump 17 rotated by the drive machine 19. The high pressure oil becomes oil passage 16, check valve 12, oil passage 10. A port 5 oil passage 4, cylinder oil supply and oil drain port 3
It enters cylinder 1 from above and pushes ram 2 up against spring 5.

The above-mentioned pushing up force can be used in various ways.

A' port at A position is oil passage, oil tank 7, oil passage 1
1. The oil in the tank 7 is discharged into the tank 15 by rotating the suction side of the low-pressure pump which is rotated by the driving machine 19.

Figure 4 shows the flow of oil when the four-way switching valve 9 is in the B position.The oil supply and drain passages for the oil pushing up the ram 2 in the cylinder 1 are cut off, so the ram 2 is in the cylinder. 1, stop at any position and maintain that pressure.

Although the high pressure pump 11 and the low pressure pump 18 are operating,
The high pressure oil sucked up from the tank 21 by the high pressure pump 17 is passed through the oil passage 16° and the check valve 12. Oil passage 10. B port,
B' port communicating with this, oil passage 11. Low pressure pump 1
8 is discharged to the tank 15.

The low-pressure oil sucked up from the tank 22 by the low-pressure pump 18 through the oil filter 22 is discharged into the tank 15 through the oil amount adjusting device 20.

FIG. 5 shows the oil flow when the four-way switching valve 9 is in the C position. Since ports C and C' intersect, the oil pushing up the ram 2 of the cylinder 1 is the oil flow. Passage 4. Bo) C', oil passage 11. The oil is sucked up from the tank 21 by the low pressure pump 18 from the suction side of the low pressure pump 18 and discharged to the tank 15 together with the oil.

The oil that is pushing up the ram 2 due to this oil flow is sucked back by the low-pressure pump 18, so the sucking back force is added to the force of the spring 5, and the ram 2 descends more quickly than when only the spring 5 is used. It returns to its original position.

On the other hand, the oil sucked up from the tank 21 by the high pressure pump 17 is transferred to the oil passage 16. Check valve 12. The oil is discharged to the tank 7 from the oil passage 10C port.

Note that if the ram 2 reaches the lowest position in the cylinder 1 and there is no more oil to return, a phenomenon called cavitation (bubbles will occur) may occur in the pump, potentially destroying the low-pressure pump 18, so do not use a small amount of oil. An oil amount adjusting device 20 is provided to suck oil from the tank 21 into the low pressure pump 18, and a small amount of oil is sucked in by appropriately adjusting the throttle to prevent the occurrence of cavitation.

The quick return hydraulic cylinder of the present invention connects a refueling pump and a drain oil suction pump to the oil supply/drain port of a single-push hydraulic cylinder through a four-way switching valve, and further connects the suction side of the drain oil suction pump to the oil supply/drain port of the single-push hydraulic cylinder. It is connected to an oil tank through a regulating device, and the four-way switching valve operates to refuel, stop refueling, and suck back drained oil.The drained oil quickly returns the ram in the cylinder, and the oil is drained by adjusting the oil amount regulating device. Since cavitation is prevented from occurring in the pump, the ram in the cylinder can be quickly returned easily and reliably, and the oil drain pump can be prevented from being destroyed by cavitation.

[Brief explanation of drawings]

Fig. 1 is a conventional single-push cylinder, Fig. 2 is a perspective view of a conventional double-push cylinder, and Figs. 3, 4, and 5 show the quick-return hydraulic cylinder of the present invention and its oil passage. be. 1 is a hydraulic cylinder, 2 is a ram, 3 is an oil supply/drain port, 5
is a one-sided spring inside the cylinder, 9 is a four-way switching valve,
15 is an oil passage and an oil tank, 16 is a high pressure pump for oil supply, 1
7 is a low pressure pump for draining oil. 19 is a pump drive device, 20 is an oil amount adjustment device, and 21 is an oil tank.

Claims (1)

[Scope of utility model registration request] A refueling pump and a drain oil suction pump are connected to the oil supply/drain port of the single-push hydraulic cylinder via a four-way switching valve, and the suction side of the drain oil suction pump is further connected to an oil tank through an oil volume adjustment device. , refueling by the operation of the four-way switching valve,
A quick-return hydraulic cylinder that stops oil supply, sucks back drained oil, uses the drained oil to quickly return the ram in the cylinder, and prevents cavitation in the drained oil suck-back pump by adjusting an oil amount adjustment device.