JPH0356384A - Hydraulic elevator device - Google Patents

Abstract

PURPOSE:To prevent the damage of apparatus and the seizure of sliding parts by providing a chick valve for letting oil flow only to the tank side through a relief valve at an oil passage for communicating a passage between a hydraulic pump and a switching valve with one between a check valve and the relief valve. CONSTITUTION:A switching valve 5 is provided at an oil passage 11 between a hydraulic pump and a tank 6, and an oil passage 11a is communicated with an oil passage 12a provided with a relief valve 7 through an oil passage 13 provided with a check valve 9. Accordingly, when the hydraulic pump is rotated in such a direction as to drive a cage 1 to descend in the fully opened state of the switching valve 5 due to failure, the pressure in the oil passage between the hydraulic pump and the switching valve rises so as not to generate negative pressure in a hydraulic circuit. The relief valve 7 is then actuated to return the oil between the hydraulic pump and the switching valve to the tank, so that the pressure in the oil passage between the hydraulic pump and the switching valve is prevented from rising more than the set pressure of the relief valve, thus preventing the damage of apparatus and the seizure of sliding parts.

Description

[Detailed description of the invention] [Industrial application field]

This invention relates to a hydraulic elevator system with an improved hydraulic circuit.

[Conventional technology]

FIG. 2 shows a hydraulic circuit configuration diagram of a conventional hydraulic elevator system similar to that shown in Japanese Patent Application Laid-Open No. 57-81073. In Figure 2, 1 is a bracket, 2 is a hydraulic jack, and 3 is a ? lJI pressure pump, 4 is an electric motor for driving the hydraulic pump 3, 5 is an on-off valve provided in the oil port #I10 between the hydraulic pump 3 and the hydraulic jack 2, 6 is a tank, 7 is an on-off valve with the hydraulic bonop 3 The oil passage between the valve 5 and the hydraulic bongo 3
This is a relief valve provided in the oil passage 12 that bypasses and communicates with the tank 6. This hydraulic elevator system uses a tank 6 by rotating a hydraulic pump 4 in the forward direction using an electric motor 4 that rotates in forward and reverse directions.
The oil inside is forced into the hydraulic jack 2 through the on-off valve 5,
Move Kako 1 up. Further, by rotating the hydraulic pump 4 in the reverse direction by the electric motor 4, the oil in the hydraulic jack 2 is discharged and returned to the oil tank 6 via the on-off valve 5, and the car 1 is driven downward. During the upward operation, the discharge flow rate of the hydraulic pump 3 is changed to control travel, and during the downward operation, the electric motor 4 drives the hydraulic pump 3 to control the discharge flow rate of the pressure oil in the hydraulic jack z. Furthermore, when the hydraulic pump 3 is rotating forward to raise the car 1, if the pressure in the oil passage between the hydraulic pump 3 and the hydraulic jack 2 increases abnormally, the oil By returning pressure oil from the passage to the tank 6 via the oil passage 12 having the relief valve 7, the pressure in the oil passage between the hydraulic pump 3 and the hydraulic jack 2 does not rise above the set pressure of the relief valve 7. That's what I do.

[Problem M that the invention attempts to solve]

Since the conventional hydraulic elevator system has a hydraulic circuit configured as described above, the on-off valve 5 may fail due to some kind of failure.
In the closed state, the hydraulic pump 4 rotates in the opposite direction to discharge oil from the pump 3 to the tank 6, and the oil passage between the hydraulic pump 3 and the on-off valve 5 becomes under negative pressure. As a result, cavities may occur in the hydraulic pump 3 and its piping route, causing abnormal vibrations that may damage the equipment, or break the oil film on sliding interlocking parts, causing seizure. There was a problem. This invention was made in order to solve the above-mentioned problems, and it is possible to operate this hydraulic pump in a two-stroke manner, including when the hydraulic bonogo rotates in the direction in which the car descends with the on-off valve closed. , Downward No matter which direction it is rotated, cavitation does not occur in the hydraulic valve and its piping route.
Therefore, it is an object of the present invention to provide an inexpensive hydraulic elevator system that can prevent damage to equipment and seizure of sliding parts.

[Means to solve the problem]

In the hydraulic elevator system according to the present invention, an on-off valve is provided in the oil passage between the hydraulic pump and the tank, one end is connected to the oil passage between the hydraulic pump and the hydraulic jack, and the other end is connected to the oil passage between the hydraulic pump and the hydraulic jack. A check valve and a relief valve, through which oil flows only to the tank side, are provided in series in the oil passage communicating with the hydraulic pump, and an oil passage between the hydraulic pump and the on-off valve, the check valve, and the M-F valve. A check valve is provided in the oil passage that communicates with the oil passage between the IJ'J and the oil passage so that the oil flows only to the tank side through the IJ'J first valve.

[Effect]

The hydraulic elevator system according to the present invention is designed to handle the problem when the pressure in the oil passage between the hydraulic pump and the hydraulic jack increases abnormally due to some kind of failure while the hydraulic pump is rotating in the direction of raising the car. In this case, the pressure in the oil passage between the hydraulic pump and the hydraulic jack does not rise above the set pressure of the relief valve by operating the relief valve as in the conventional one. In addition, when the hydraulic pump rotates in the direction of lowering the car with the on-off valve malfunctioning and remaining fully closed, the above-mentioned on-off valve is provided in the oil passage between the hydraulic pump and the tank. Since the oil passage between the hydraulic pump and the on-off valve is communicated with the oil passage having the relief valve by the oil passage with the check valve, the pressure in the oil passage between the hydraulic pump and the on-off valve is reduced. rises and no negative pressure is created in the hydraulic circuit. Then, the relief valve -h operates and the oil between the hydraulic pump and the on-off valve is returned to the tank, so the pressure in the oil passage between the hydraulic pump and the on-off valve becomes higher than the set pressure of the relief valve. There is no sharpness when it rises, which prevents equipment damage and seizure of sliding parts. Also,
By installing two check valves, the hydraulic pump
The pressure on the hydraulic jack side and on-off valve side can be maintained independently. Furthermore, the relief valve can perform both of the above-mentioned operations without increasing the number of parts other than changing the position of the on-off valve from the conventional one and adding two check valves.

【Example】

An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, the same reference numerals as those in FIG. 2 indicate the same or equivalent parts, 8 and 9 are check valves, 10 is an oil passage between the hydraulic bonop 3 and the hydraulic jack 4, and 11 is the hydraulic bonop 3 and the jack 4. 6, and this oil passage 11 is provided with an on-off valve 5. In addition, a check valve 8 and a relief valve 7 are provided in series in an oil passage 12 whose one end is connected to the oil passage GO 0 and whose other end communicates with the tank 6 . Oil passage 1
It is arranged on the 0 side, and the oil is configured to flow only to the cylinder 6 side. -07HH of the oil passage 13 is communicated with the oil passage 11a between the hydraulic pump 3 and the on-off valve 5, which is a part of the oil passage 11,
This oil connoisseur #! The other end of 11.3 communicates with a curved passage 12a between the check valve 8 and the relief valve 7, which is a part of the oil passage 12. A check valve 9 is provided in the oil passage 13, and the check valve 9 is configured to allow oil to flow only to the tank 6 side via the relief valve 7. The configuration and basic operation of this embodiment other than those described above are substantially the same as those of the conventional hydraulic elevator system shown in FIG. In the hydraulic elevator system of this embodiment, when the pressure in the oil passage 10 between the hydraulic pump 3 and the hydraulic jack 2 increases abnormally when the hydraulic pump 3 is rotating in the forward direction, the oil passage @1.
By returning the pressure from 0 to the tank 6 via the oil passage 12 having the check valve 8 and the relief valve 7, the pressure of 0 (it+passage) becomes lower than the set pressure of the relief valve 7, as in the conventional system. It never rises. Also, due to some kind of malfunction,
If the hydraulic pongo 3 rotates in the opposite direction while the on-off valve 5 remains fully open when the car 1 is in downward operation or stopped, this and the on-off valve 5
Oil connoisseur #11. ]. The pressure at a increases and no negative pressure is generated in the hydraulic circuit. And oil passage 1. When the pressure in 1a becomes higher than the set pressure of the relief valve 7, the oil is removed from the passage 11 [I to the oil passage with the check valve 9'' 3, through the part of the oil passage 12 closer to the knob 6 than the check valve 8. As the oil returns to the tank 6, the oil leakage 1 1. The pressure in a does not rise above the set pressure of the relief valve 7. For this reason,
Cavity formation does not occur in the hydraulic bonop 3 and its piping route, and damage to the equipment and seizure of sliding parts can be prevented. Further, by providing the check valves 8 and 9 in the oil passages 12 and 1.3, the pressures on the oil pump 3 on the hydraulic jack 2 side and on the on-off valve 5 side can be maintained independently.

【Effect of the invention】

As explained above, according to the present invention, an on-off valve is provided in the oil passage between the hydraulic pump and the tank, one end of which is connected to the oil passage between the hydraulic pump and the hydraulic jack, and the other end is connected to the oil passage between the hydraulic pump and the hydraulic jack. A check valve and a relief valve through which oil flows only toward the tank are provided in series in an oil passage communicating with the tank, and the oil passage between the hydraulic pump and the on-off valve, the check valve and the relief valve are connected in series. A check valve is provided in the oil passage that communicates with the oil passage between the tank and the tank, so that the oil flows only to the tank side through the relief valve, so that the following effects can be obtained. In other words, when the hydraulic pump is rotating in the direction that raises the car, if the pressure in the oil passage between the hydraulic pump and the hydraulic jack increases abnormally, the relief valve operates like the conventional one. By doing this, this IJ 'J-
The pressure in the oil passage between the hydraulic pump and the hydraulic jack does not rise above the set pressure of the valve. Additionally, when the hydraulic pump rotates in the direction of lowering the car with the on-off valve fully closed, the pressure in the oil δ passage between the hydraulic pump and the on-off valve increases, causing a negative voltage in the hydraulic circuit. If no pressure is generated and the pressure in the oil passage between the hydraulic pump and the on-off valve exceeds the set pressure of the relief valve, the oil in the oil passage between the hydraulic bongo and the on-off valve will flow into this passage. An oil passageway with a relief valve from the oil passageway connected to it? ! Since the oil is returned to the tank through the oil passageway, the pressure in the oil passage between the hydraulic pump and the on-off valve does not rise above the set pressure of the relief valve. Therefore, damage to the equipment or slippage may occur! II! rf! It is possible to prevent burn-in of the ladle while doing JJ. In addition, since there is no increase in the number of parts other than the addition of two inverted double valves, the cost is hardly higher than that of the conventional one, and a hydraulic worker one noveta device having the above-mentioned advantages can be provided at a low cost.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a hydraulic circuit of a hydraulic elevator system according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a hydraulic equivalent of a conventional hydraulic elevator system. 1 Car, 2 Hydraulic jack, 3 Hydraulic mortar, 4 Electric motor, 5 Open/close valve, 6 Tank, 7 Relief valve, 8,
9 Check valve, 10, 11, 12, 13 Oil passage. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] Pressure oil is supplied from the hydraulic pump into the hydraulic jack to operate the car upward, and the pressure oil in the hydraulic jack is discharged to operate the car downward, and during the upward operation, the discharge flow rate of the hydraulic pump is changed. In a hydraulic elevator device that controls traveling, drives the hydraulic pump for descending operation, and controls traveling by controlling the discharge flow rate of pressure oil in the hydraulic jack,
An on-off valve is provided in the oil passage between the hydraulic pump and the tank, one end of which connects to the oil passage between the hydraulic pump and the hydraulic jack, and the other end of which communicates with the tank;
A check valve and a relief valve through which oil flows only toward the tank are provided in series, and an oil passage between the hydraulic pump and the on-off valve is communicated with an oil passage between the check valve and the relief valve. A hydraulic elevator device characterized in that an oil passage is provided with a check valve that allows oil to flow only to the tank side via the relief valve.