JPS6279191A - Hydraulic elevator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a hydraulic elevator in which a car is raised and lowered by a hydraulic jack, and particularly to a safety device in this hydraulic elevator.

[Technical costs of inventions and their problems]

As shown in FIG. 3, this kind of hydraulic elevator that has already been proposed has a car 2 mounted on a hydraulic jack 1 that can be raised and lowered freely, and the hydraulic jack 1 is controlled by a control circuit using hydraulic pressure from a hydraulic pump 3. 4, and is configured to control the elevation via 4.

That is, in FIG. 3, when the hydraulic pump 3 is driven when the car 2 in the hydraulic elevator is raised, the pressure oil discharged from the hydraulic pump 3 first flows through the hydraulic circuit 5 connected to the hydraulic pump 3. The rise valve 6 of the rise control circuit 7
The valve is opened by the action of , and the water flows back to the ura tank 8.

Next, when the rise valve 6 gradually closes due to the action of the rise control circuit 7, the hydraulic pump 3
The discharge pressure of the hydraulic jack increases, and the resulting pressure oil flows out to the hydraulic jack 1 through the check valve 9 of the hydraulic circuit 5, increases the oil pressure of the hydraulic jack 1, and raises the car 2. do.

When the east car 2 reaches a predetermined height, the upper boundary valve 6 is gradually opened by the action of the rise control circuit 7, whereby the pressure oil from the hydraulic pump 3 is released. At the same time as the water is returned to the tank 8, the ascent of the car 2 is stopped, and at the same time, the operation of the hydraulic pump 3 is stopped.

On the other hand, when the car 2 is lowered, when a lowering command for the car 2 is issued, the lowering valve 10 provided in the hydraulic circuit 5 gradually responds by the action of the lowering control circuit 11, and as a result, The pressure oil from the above hydraulic jack 1 is transferred to the oil tank 8.
The water is returned to the tank and the car 2 is lowered. When the car 2 reaches a predetermined setting position, the descending valve 10 is gradually closed by the action of the descending control circuit 11, and the car 2 is gradually decelerated. When the descending valve 10 is completely closed, the car 2 stops at a predetermined position.

In this way, the hydraulic circuit 5 in the hydraulic elevator is
The piping is made of steel pipes, and hydraulic control equipment such as an ascending valve 6, a descending valve 10, an ascending control circuit 7, a descending control circuit 11, etc. provided in this hydraulic circuit 5 is installed by each joint, and a hydraulic jack -1 and the above hydraulic circuit 5
is equipped with a filter and a stop valve (none of which are shown) to remove dust, and is also equipped with a muffler to eliminate pulsations in the discharge pressure of the hydraulic pump 3. Above, the hydraulic circuit 5 uses various types of joints such as a large number of threaded joints, welded joints, flange joints, etc., and these joints are susceptible to leakage of pressure oil for some reason. There is a risk that the raising and lowering operation of the car 2 is problematic in terms of safety and reliability.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and is designed to prevent sudden lifting and lowering of a car due to oil leakage when an oil leakage accident occurs due to some cause in the hydraulic circuit using a hydraulic jack. The purpose of the present invention is to provide a hydraulic elevator which aims to suppress the above-mentioned problems and also to safely stop a car that is raised and lowered by a hydraulic jack.

[Summary of the invention]

The present invention provides a hydraulic elevator equipped with a car that is raised and lowered by a hydraulic jack and an outflow control circuit that hydraulically controls the hydraulic jack, in which a spool valve is provided in the hydraulic circuit of the hydraulic jack, and a back pressure side A normally closed first electromagnetic switching valve is provided between the spool valve and the oil tank, and a normally open second electromagnetic switching valve is provided between the back pressure side of the spool valve and the oil tank. The system is designed to safely stop the car in the event of an oil leak.

[Embodiments of the invention]

Hereinafter, the present invention will be described with reference to an illustrated embodiment. Note that the present invention will be described with the same reference numerals assigned to the same constituent members as in the above-described specific example.

In FIGS. 1 and 2, reference numeral 1 indicates a hydraulic jack.
The hydraulic jack 1 is provided with a car 2 that can be raised and lowered freely, and the hydraulic jack 1 is connected to a hydraulic pump 3 via a hydraulic circuit 5 equipped with a check valve 9. ing. Further, the hydraulic circuit 5 is provided with an outflow control circuit 4, and this flow rate control circuit 4 includes an upper limit control circuit 7 that operates the ascending valve 6 and a descending control circuit 11 that operates the descending valve 10. It consists of

Therefore, when the hydraulic pump 3 is driven when the car 2 is raised, the pressure oil of the hydraulic pump 3 first opens the upper boundary valve 6 by the action of the rise control circuit 7 and returns to the oil tank 8. ,
Thereafter, when the rising valve 6 is closed by the action of the upper limit control circuit 7, the discharge pressure of the hydraulic pump 3 increases and the hydraulic circuit 5
The hydraulic jack 1 is operated through the check valve 5 to lift the car 2 to a predetermined height. When the car 2 reaches a predetermined height, the rise valve 6 is gradually opened by the action of the rise control circuit 7, whereby the pressure oil of the hydraulic pump 3 flows back to the oil tank 8, and the above-mentioned The lifting of the car 2 is stopped, and at the same time, the operation of the hydraulic pump 3 is stopped.

On the other hand, when the car 2 is lowered, when a lowering command for the car 2 is issued, the lowering valve 10 gradually opens under the action of the lowering control circuit 11, thereby transferring the pressure oil from the hydraulic jack 1 to the oil tank 8. When the car 2 descends to a predetermined position, the lowering valve 1
0 is gradually closed by the action of the lower control circuit 11, and the east car 2 is gradually decelerated, and then the lowering valve 10 is closed.
When the valve is completely closed, the car 2 will stop at a predetermined position.

On the other hand, a spool valve 12 is installed in the hydraulic circuit 5 connected to the hydraulic jack, and this spool valve 12 has a piston type valve body 1 inside a case body 12a.
2b is fitted so that it can be raised and lowered, and the back pressure side 12 of this valve body 12b is
- A stopper 12d is attached to the case body 12a of C. Also, the back pressure side 1 of the spool valve 12
A normally closed first electromagnetic switching valve 13 is provided between J3 and the hydraulic circuit 5, and a normally closed first electromagnetic switching valve 13 is provided between the back pressure side 12c of the spool valve 12 and the oil tank 8. Type 2
An electromagnetic switching valve 14 is attached.

Therefore, since the first electromagnetic switching valve 13 is in a closed state when not energized, the primary side of this spool valve 12 is communicated with the hydraulic circuit 5. Further, since the second electromagnetic switching valve 14 is in a closed state when not energized, the back pressure side 12c communicates with the oil tank 8.

However, in the normal operating state, both the first and second electromagnetic switching valves 13 and 14 are not energized, so as described above, the first electromagnetic switching valve 13 is closed and the first electromagnetic switching valve 13 is closed. 2
The electromagnetic switching valve 14 is open. Also, since the back pressure side 12c of the spool valve 12 is connected to the oil tank 3,
The pressure has become zero. Furthermore, since oil pressure is acting on the hydraulic circuit 5, the primary side of the spool valve 12 is
The valve body 12b is pressed until it comes into contact with the stopper 12d, thereby causing the hydraulic jack 1 to lift up the car 2.

Next, when the car 2 descends for some reason, a part of the car 2 comes into contact with the descent detection switch S1, and the descent detection switch S1 is activated by the first and second electromagnetic switching valves 13. 14 is activated.

Then, the first electromagnetic switching valve 13 opens, and the pressure oil in the hydraulic circuit 5 is transferred to the back pressure side 12 of the spool valve 12.
When the spool valve 12 is closed by pressing down the valve body 12b, the second electromagnetic switching valve 14 is simultaneously closed, thereby blocking the outflow to the oil tank 8. .

The electric circuit shown in FIG. 2 is a power supply circuit I incorporated in the hydraulic elevator of the present invention, and this power supply circuit I includes a door lock switch S2 of the car 2, a control circuit 16, and an abnormal descent stop switch. The circuit 17 is numbered.

Therefore, when the door of the car 2 is opened, the door lock switch S2 is set to OnL, and when the door is opened, the door lock switch S2 is set to OnL.
The door lock switch S2 is set to oH.

Next, when the door is closed and the door switch S2 is turned on, the relay 18 is turned on and the contact A1 is turned on, and the control circuit 16 is energized for normal operation.

Next, when the car 2 starts descending for some reason (for example, due to an oil leak), the descending detection switch S is activated.
1 is turned on, the relay 19 of the abnormal descent stop circuit 17 that operates the first and second electromagnetic switching valves 13 and 14 is energized, thereby turning on the contact C and turning off the door lock switch S2. Since the relay 18 is not energized and the contact A2 is turned on, the abnormal descent stop circuit 17 is energized to control the first and second electromagnetic switching valves 13 and 14. Further, when the door is closed, even if the contact A2 is turned off and the contact C1 is turned on, the abnormal descent stop circuit 17 is not energized, so that normal operation is possible.

Note that the first and second electromagnetic switching valves 1 in the power supply circuit I
3. An alarm will be installed in the circuit that excites 14,
It is free to detect abnormal descent of the car 2.

〔Effect of the invention〕

As described above, according to the present invention, in a hydraulic elevator equipped with a flow control circuit for hydraulically controlling the hydraulic jack 1 of which car 2 is raised and lowered by the hydraulic jack 1, the hydraulic circuit 5 of the hydraulic jack 1 is provided. A spool valve 12 is provided at the back pressure side 12c of the spool valve 12 and the hydraulic circuit 5.
A normally closed eleventh magnetic switching valve 4; 13 is provided between the spool valve 12 and the oil tank 8, and a normally open second electromagnetic switching valve 13 is provided between the back pressure side 12c of the spool valve 12 and the oil tank 8. Therefore, even if the car 2 starts descending for some reason, it can not only be stopped effectively and appropriately, but also abnormal conditions such as oil leakage can be detected and the car 2 can be stopped safely. can.

[Brief explanation of drawings]

FIG. 1 is a diagram of the hydraulic elevator of the present invention, and FIG. 2 is a diagram of the hydraulic elevator of the present invention.
The electric circuit diagram incorporated in the present invention, FIG. 3, is a diagram of a previously proposed hydraulic elevator. 1... Hydraulic jack key 12... Passenger car, 3... Hydraulic pump, 5... Hydraulic circuit, 8... Ura tank, 9...
...Check valve, 12... Spool valve, 13... First electromagnetic switching valve, 14... Second electromagnetic switching valve. Applicant's agent Mr. Sato Figure 3

Claims (1)

[Claims] In a hydraulic elevator equipped with a car that is raised and lowered by a hydraulic jack and a flow control circuit that hydraulically controls the hydraulic jack, a spool valve is provided in the hydraulic circuit of the hydraulic jack, and a spool valve is provided between the back pressure side of the spool valve and the hydraulic circuit. A hydraulic elevator characterized in that a normally closed first electromagnetic switching valve is attached to the spool valve, and a normally open second electromagnetic switching valve is attached between the back pressure side of the spool valve and the pressure oil tank.