JP3048304B2 - Load lifting system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load raising and lowering system for raising and lowering a load such as a parking pallet using a hydraulic cylinder in a multi-story parking device.

[0002]

2. Description of the Related Art Conventionally, in order to be able to park in a restricted site, a parking pallet is raised and lowered between the ground and an upper floor, and one end is pivoted on a parking pit in a semi-underground. There are various proposals for raising and lowering the other end of a pallet and parking two or more vehicles.

[0003] Of these, in the case where a pallet as a load is provided on the parking pit so as to be able to move up and down, a hydraulic cylinder having a rod end mounted on the opposite side of the pallet from the pivot side is widely used. The pallet is raised and lowered so that the pallet has a predetermined inclination by the expansion and contraction of the rod.

Further, in this hydraulic cylinder, the rod is moved up and down by control of supply and discharge of hydraulic oil from a pump driven by a motor, and the supply of hydraulic oil is stopped or the valve is closed in parallel with the supply of hydraulic oil. The amount of expansion and contraction can be held, thereby, for example, holding the position of a pallet on which a vehicle is mounted.

In order to prevent the pallet from lowering due to a natural decrease in hydraulic pressure due to a difference in temperature or temperature, a lock claw member or the like for locking the movement between the cylinder and the rod of the hydraulic cylinder may be used. is there.

[0006]

However, in the pallet lifting / lowering system in which the supply of the hydraulic oil is stopped as described above, and the pallet is held at the set height by the hydraulic cylinder, the natural decrease of the hydraulic pressure occurs as described above. By
When the pallet descends gradually, it may be dangerous if the pallet descends sharply.

In order to prevent the pallet from lowering, when the lowering lock is performed using the lock claw member, the operation of the lock claw member is troublesome. If the operation is to be automated using a plunger or the like, a magnet device with a large operating torque is required, and there has been a problem that the system is large and expensive.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art, and is intended to reduce the load on a parking pallet or the like, regardless of whether the internal pressure of the pipeline is reduced positively or carelessly. It is another object of the present invention to provide a low-cost load raising / lowering system that can safely and reliably maintain a set height by using a stop valve provided in a hydraulic cylinder that raises / lowers this load.

[0009]

In the load elevating system according to the present invention, hydraulic oil is supplied to and discharged from a hydraulic chamber separated by a piston in a cylinder, and the load is raised and lowered via a rod integral with the piston. A hydraulic cylinder, a stop valve provided in a supply / discharge passage for hydraulic oil communicating with the hydraulic chamber, and opening / closing the hydraulic chamber in response to a change in oil pressure in the supply / discharge passage; and an extension mode of the rod. Sometimes, the lifting switch
H, the normally closed limit provided at the upper limit of the rod
Drive the pump through the switch and relay switch
By the hydraulic fluid supplied to the hydraulic oil in the upper SL hydraulic chamber to urge the stop valve, the abnormal decrease in the elongation stopped or conduit pressure of the rod et provided at the upper limit position of the rod
Supply of hydraulic oil by opening the normally closed limit switch
Stopped by closing locking the hydraulic chamber by the return of the stop valve, whereas the rod reduction mode - when de is the elevation
The changeover switch and the relay switch are turned on for a short time.
Ri and briefly allowed driven the pump by the hydraulic fluid supplied to said supply and discharge passage to open the oil pressure chamber by releasing the closing lock of the stop valve, utilizing the load of the load, further on
Normally open limit switch at the lower limit position of the rod
The hydraulic oil is discharged through the switching valve by closing the valve .

[0010]

In the load elevating system according to the present invention, when the hydraulic oil sent to the hydraulic chamber through the supply / discharge passage by the pump stops or the hydraulic oil leaks in the pipeline of the hydraulic circuit, the hydraulic pressure in the supply / discharge passage is reduced. Decrease.

For this reason, the stop valve, which has hitherto opened the hydraulic chamber by receiving the hydraulic pressure of the operating oil in the supply / discharge passage, slides in the supply / discharge passage by receiving a repulsive force such as a spring. Close the hydraulic chamber. For this reason, the hydraulic pressure in the hydraulic chamber is maintained, the extension and contraction position of the rod in the cylinder is locked, and abnormal lowering of the load supported by the rod is reliably prevented.

When the rod is contracted from the extended state, the operating oil is once supplied into the supply / discharge passage to open the stop valve against the spring.
The hydraulic oil in the pressure chamber is discharged under the pressure of the load.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a hydraulic system diagram showing a load elevating system according to the present invention. In FIG. 1, reference numeral 1 denotes a hydraulic cylinder, which slides in a cylinder 2 and separates a hydraulic chamber 3; 4 at one end and the cylinder 2
The cylinder comprises a rod (piston rod) 5 which enters and exits from the inside, and an opening / closing passage 6 for hydraulic oil which is provided at the end of the cylinder 2 and communicates with the hydraulic chamber 3.

Reference numeral 7 denotes a hydraulic oil supply / discharge passage provided at the lower end of the cylinder 2 so as to communicate with the opening / closing passage 6. The opening / closing passage 6 is opened and closed in the supply / discharge passage 7. A slide stop valve 8 is provided. The stop valve 8 is urged by a spring 9 at a set pressure in a direction opposite to a supply direction of the hydraulic oil.

On the other hand, in the hydraulic system, 11 is a motor, 12 is a pump driven by the motor 11, 13 is a check valve, and the pump 12 supplies and discharges the operating oil in the tank 14 through the check valve 13. It can be supplied to the passage 7. 15 is a relief valve, 16
Reference numeral denotes a switching valve for switching and returning the working oil returned from the supply / discharge passage 7 to the tank 14.

A power supply 17 such as a battery is connected to the motor 11 via a relay switch 18. A movable contact piece 19a of a lift switch 19 is connected to the power supply 17.

On the other hand, the opening and closing control of the relay switch 18 to the ascending contact 19b which is connected to the movable contact piece 19a via a normally closed limit switch 20 provided at the upper limit position of the rod 5 is performed. One end of the relay coil 21 is connected, and the other end of the relay coil 21 is grounded.

The relay 17 is connected to the power supply 17 via a movable contact 19a of a lift switch 19, a contact 19c for lowering, a switch 22 and a backflow prevention diode 23.
The one end of the coil 21 is connected. Further, the contact 19c is provided at a lower limit position of the switch 5 and the rod 5 which are interlocked with the switch 22.
Via the normally open limit switch 25, the switching valve 1
The solenoid 26 for driving 6 is connected.

FIG. 2 shows a parking device showing an example of use of the hydraulic cylinder 1. In the drawing, reference numeral 31 denotes an inclined parking pit formed by partially excavating the ground, and 32 denotes a driving pit which is formed in the parking pit 31. Concrete.

Reference numeral 33 denotes a column established at the opening edge of the parking pit 31 on the ground side, and reference numeral 34 denotes a parking pallet supported by a hinge 35 at the upper end of the column 33. The front end 34a of the parking pallet 34 can contact and separate from the ground of the entrance / exit 36.

Reference numeral 37 denotes a handrail provided on the parking pallet 34, and 1 denotes a front of the hinge 35,
A hydraulic cylinder as shown in FIG. 1 is interposed between the opening edge on the ground side and the parking pallet 34, and the rod 5 end of the hydraulic cylinder 1 is pivotally supported by the parking pallet 34. . Note that R is a hydraulic circuit including the above-described hydraulic means.

Next, the operation of the load elevating system having such a configuration will be described. First, a case where the parking pallet 34 is lifted using the hydraulic cylinder 1 will be described.

First, the movable contact piece 19a of the lift switch 19 is switched to the contact point 19b for lifting. For this reason, the power supply 17 is provided at the upper limit position of the rod 5.
A current flows through the relay coil 21 via the normally-closed limit switch 20, and the relay coil 21 is energized to release the relay.
The switch 18 turns on.

When the relay switch 18 is turned on, a voltage is applied to the motor 11 from the power supply 17, and the motor 11 drives the pump 12. Therefore, this pump 1
Numeral 2 pumps up the operating oil in the tank 14 and is guided into the supply / discharge passage 7 below the cylinder 2 via the check valve 13.

Therefore, the hydraulic pressure in the supply / discharge passage 7 increases, and the stop valve 8 slides in the supply / discharge passage 7 while compressing the spring 9. As a result, the opening / closing passage 6 is opened, hydraulic oil is pressure-fed to the hydraulic chamber 3 in the cylinder 2, the piston 4 is pushed upward, and the rod 5 extends out of the cylinder 2.

As a result, by the extension of the rod 5,
The parking pallet 34 as a load is also pushed up and pivots around the hinge 35 to open the entrance / exit at the tip.

When the rod 5 is fully extended and the parking pallet 34 reaches the uppermost position, the upper limit of the rod 5
Since the normally closed limit switch 20 provided at the position is opened, the relay coil 21 is deenergized and the relay switch 1 is turned off.
8 is also opened, and the motor 11 stops.

For this reason, the driving of the pump 12 is also stopped,
A large oil pressure does not act in the supply / discharge passage 7, and the stop valve 8 returns by receiving the repulsive force of the spring 9 to close the opening / closing passage 6. As a result, the parking pallet 34 can be kept in the raised state safely and can prevent accidents such as natural fall.

On the other hand, when lowering the parking pallet 34, the movable contact piece 19a of the lift switch 19 is switched to the lower contact 19c. As a result, the relay coil 2 is again switched through the switch 22 and the diode 23.
A short period of time, about 1 to 2 seconds, flows through the switch 1, which is energized and the relay switch 18 is turned on.

For this reason, the motor 11 is driven, the pump 12 is operated, and the hydraulic oil in the tank 14 is fed to the supply / discharge passage 7 by pressure. The stop valve 8 is pushed in against the spring 9 for the short time, the opening / closing passage 6 is opened, and the rod 5 is urged downward under the load of the parking pallet or the vehicle. The working oil in the chamber 3 is pushed out by the piston 4.

[0031] Also, this time, the switch 24 and Rimi
Tsu switching from the power source 17 through the door switch 25 valve 16
Current flows through the solenoid 26 of the switching valve 1
6 is switched to the drain side, and the hydraulic oil pushed out from the hydraulic chamber 3 to the supply / discharge passage 7 is returned to the tank 14.

The rod 5 of the hydraulic cylinder 1
That is, when the parking pallet 34 reaches the lower limit position, the hydraulic pressure in the supply / discharge passage 7 is greatly reduced, and the spring 9
, The stop valve 8 closes the opening / closing passage 6.

On the other hand, when the rod 5 lifts the parking pallet 34, oil leakage may occur from the pipeline of the hydraulic system for some reason.
At this time, the stop valve 8 moves by receiving the repulsive force of the spring 9 due to the abnormal decrease in the oil pressure in the supply / discharge passage 7, and closes the opening / closing passage 6.

Therefore, the rod 5 does not descend any more, and the accidental fall of the parking pallet and the accompanying accident of falling of the vehicle can be avoided beforehand and reliably.

[0035]

As described above, according to the present invention, the stop valve for opening and closing the hydraulic chamber according to the change of the oil pressure in the supply / discharge passage is provided in the supply / discharge passage of the hydraulic oil communicating with the hydraulic chamber. When the rod is in the extension mode, the stop valve is urged by the limit switch and the relay switch to supply the hydraulic oil to the hydraulic chamber separated from the cylinder by the piston. When the hydraulic pressure in the pipeline is abnormally low, the stop valve is closed to lock the hydraulic chamber by returning the stop valve. On the other hand, when the rod is in the contraction mode, the stop lock is released by supplying hydraulic oil to the supply / discharge passage. to open the oil pressure chamber Te, since it is configured so as to discharge the hydraulic oil by using a load of load, the load such as a palette for parking, actively, also the pressure drop of inadvertent conduits Regardless, using the stop valve provided in the hydraulic cylinder for raising and lowering the load, there is an effect that can be obtained which can be held safely and securely to a set height.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram showing a load elevating system according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a parking device provided with a hydraulic cylinder in FIG.

[Explanation of symbols]

 Reference Signs List 1 hydraulic cylinder 2 cylinder 3 hydraulic chamber 4 piston 5 rod 7 supply / discharge passage 8 stop valve R hydraulic circuit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Sho 54-16995 (JP, U) Japanese Utility Model Sho 62-20781 (JP, Y2) Japanese Utility Model Sho 49-22940 (JP, Y1) (58) Field (Int.Cl. ⁷ , DB name) E04H 6/06 F15B 15/14 305

Claims (1)

(57) [Claims] 1. A hydraulic cylinder which supplies and discharges hydraulic oil to and from a hydraulic chamber separated in a cylinder by a piston and raises and lowers a load via a rod integral with the piston, and a hydraulic cylinder which communicates with the hydraulic chamber. A stop valve provided in the supply / discharge passage for opening and closing the hydraulic chamber in response to a change in hydraulic pressure in the supply / discharge passage; and a lifting / lowering switching switch in the extension mode of the rod.
H, the normally closed limit provided at the upper limit of the rod
Drive the pump through the switch and relay switch
By the hydraulic fluid supplied to the hydraulic oil in the upper SL hydraulic chamber to urge the stop valve, the abnormal decrease in the elongation stopped or conduit pressure of the rod et provided at the upper limit position of the rod
Supply of hydraulic oil by opening the normally closed limit switch
Stopped by closing locking the hydraulic chamber by the return of the stop valve, whereas the rod reduction mode - when de is the elevation
The changeover switch and the relay switch are turned on for a short time.
The pump is driven for a short time to operate the supply / discharge passage.
Release the stop lock of the stop valve by oil supply, open the hydraulic chamber, use the load of the load , and
Normally open limit switch at the lower limit position of the rod
A load elevating system for discharging hydraulic oil via a switching valve by closing the valve .