JPS6013954B2 - hydraulic elevator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic elevator whose descending speed is directly controlled by a pump.

The descending operation of commonly used hydraulic elevators is carried out by using the weight of the car and plunger to lower the elevator, and by controlling the amount of oil discharged from the hydraulic sill with a flow control valve.

In this method, pressure energy is converted into thermal energy at the throttle part of the flow control valve, and not only does the oil temperature rise significantly, but the oil flow passing through the flow control valve becomes a high-speed flow and capitation occurs. There were drawbacks such as the fact that it spread within the Qin basket. As a means to solve the above problems, a method has recently been proposed in which the speed is controlled by applying regenerative braking to the electric motor that drives the pump instead of using the flow rate control valve.

However, in this method, the remote motor is started in response to the opening operation of the switching valve, but since this motor is a three-phase induction motor, the descending speed suddenly rises, that is, it is suddenly accelerated, causing a shock. It had the disadvantage of being large.

Furthermore, during deceleration, since the switching valve was closed after the power to the electric motor was turned off, there was a problem in that the control action of the electric motor was lost, resulting in temporary acceleration, which worsened riding comfort.

A first object of the present invention is to provide a hydraulic elevator that prevents sudden rises during acceleration and provides less shock.

A second object of the present invention is to provide a hydraulic elevator that prevents temporary acceleration during deceleration and has good texture. The first object of the present invention is achieved by opening the switching valve during descent, accelerating the rotation of the pump with pressure oil on the cylinder side, and then starting the electric motor that drives the pump. .

- Means for achieving the second object of the present invention or other objects and means for achieving the same will be made clear in the description of one embodiment shown below. In FIG. 1, a plunger 3 having a Qin cage 5 at its upper end is inserted into a cylinder 1.

The cylinder includes a strainer 9, a main pump 11, a main motor 13, a main line 15, a main hydraulic switching valve 17, a main line 19,
A main hydraulic system consisting of a solenoid valve 21, chokes 23 and 25, a main suction valve 27, and a main relief valve 29, and a strainer 3
1, auxiliary pump 33, auxiliary electric motor 35, auxiliary pipe 37,
Auxiliary hydraulic pressure switching valve 39, auxiliary pipe line 41, solenoid valve 43, chokes 45, 47, auxiliary suction valve 49, auxiliary relief valve 51
An auxiliary hydraulic system consisting of: 53 is an accumulator.

Here, the reason why two large and small main and auxiliary pumps are provided is that in two-speed operation, it is easier to control the operation if the landing operation is performed by a small pump.

Figures 2, 3, and 4 are electrical circuit diagrams for operating the above-mentioned king and auxiliary hydraulic system, with reference numerals 61, 63, and 65.
is a switch that is turned on when the hydraulic elevator is operating.

67 and 69 are thermal relays, and 71 is turned off only in an emergency.
73, 79, 83, 91, 93 are relays, 75, 95, 97 are time relays, 77 is a lower command switch, 81 is a stop command switch, 85 is a deceleration command switch, 87, 89 are lower command switches. When this contactor is energized, the contacts 87a and 8 of the main circuit in Fig.
Turn on 3a. However, when driving the Qin cage downward,
Prior to this, switches 61, 63, and 65 were turned on, and P-emergency switch 71-thermal relay 69,
A circuit of 67-relay 73-N is formed, and the relay 73 is energized to turn on the contact 73a.

Now, when the lowering command switch 77 is turned on, the P-switch 7
A circuit of 7-relay-79-81b-N is formed, and the relay 79 is energized and the contact 79a is turned on. This contact point 79
A self-holding circuit is constructed from the circle in a, and P-
A circuit of relay 83-contact 79a→deceleration command switch 86-N is configured. This circuit configuration excites the relay 83 and turns on the contact 83a. By turning on this contact 83a, P-relay 91-contacts 83a-N and P-relay 95
- A circuit of contacts 83a-N is constructed, and contacts 91 in FIG.
a, 93a is turned on, the solenoid valves 21, 43 are energized, and the pressure oil in the main pipe 19 and the auxiliary pipe 41 is turned on.
It flows through the solenoid valves 21 and 43 to the main and auxiliary hydraulic switching valves, opening these switching valves. As a result, the oil in the cylinder flows out through the main and auxiliary pipes to the main and auxiliary pumps 11 and 33, rotating these pumps and strainers 9 and 3.
1 to tank 7. Therefore, the Qin cage 5 starts a downward operation together with the plunger 3. On the other hand, relay 9
P-time relay 75-contact 91b-N by excitation of 1
However, due to the action of the time relay 75, the contact 75b remains OH for a certain period of time, and turns ON when the time period expires. Therefore, P-magnetic contactor 87-contact 83a
-75b-N and P- Due to the circuit configuration of one contact 83a of the electromagnetic contactor 89 and one contact 75b-N, the contacts 87a and 89a are closed, and the main motor 13 and the auxiliary motor 35 are started.
At this time, due to the excitation of time relays 95 and 97, contact 95a
, 97a are turned on and self-maintained. In this way, after the Qin cage 5 is accelerated downward to a certain constant speed, the electric motor 13
, 35 are started, there is less starting shock compared to the conventional method in which the electric motor is started almost simultaneously with the opening operation of the flap valve. The Qin car 5 is accelerated by starting the electric motors 13 and 35, and when the electric motors 13 and 35 reach their rated speeds, the Qin car 5 is lowered at a constant speed by the rotational braking. Qin Kago 5 is
When the deceleration position is reached, the deceleration command switch 85 is turned off.
Relay 83 is depleted.

Due to this demagnetization of the relay 83, all contacts 83a are turned off, and the relay 91, which does not have self-holding, becomes magnetized. This relay 9
1, the contact 91a becomes OH, the solenoid valve 21 is demagnetized, and the main hydraulic switching valve 17 is opened. At the same time, the time relay 95 is demagnetized after a certain time limit, the contact 95a is turned off, the self-holding of the electromagnetic contactor 87 is released, and the magnetic contactor 87 is demagnetized. Due to this extinction of the contactor 87, the contact point 87a is turned off, and the main motor 1
3 stops. Since the main electric motor 13 stops after the main oil pressure switching valve 17 closes in this manner, it is possible to decelerate the motor without causing the instantaneous acceleration phenomenon that conventionally occurs when the motors operate almost simultaneously. After the main hydraulic switching valve 17 is closed, only the auxiliary hydraulic system operates, and the Qin car runs at the rated landing speed.

When the Qin basket comes close to the stop position, the stop command switch 8
1 is activated, the relay 79 is demagnetized, and the contact 79a is opened.
ff. As a result, the relay 93 is first demagnetized, the contact 93 is turned off, and the solenoid valve 43 is demagnetized. This solenoid valve 4
3 closes the auxiliary hydraulic shutoff valve 39, and then the time relay 97 is demagnetized, releasing the self-holding of the electromagnetic contactor 89, demagnetizing the contactor 89, and turning off the contact 89a. . Therefore, the auxiliary electric motor 35 stops. The reason why the auxiliary electric motor 35 is stopped after the hydraulic switching valve is closed, like the main electric motor described above, is for the same purpose. Incidentally, since the electric motor is stopped after the hydraulic switching valve is closed, the pipe lines 15 and 37 tend to become vacuum, but this is prevented by supplying oil through the suction valves 27 and 49.

The above is a description of one embodiment of the present invention, and since the objective of this example was descending operation control, only the descending operation control was described, and the explanation regarding the ascending operation was omitted.

In addition, although we have described two-stage control using two large and small pumps, it is not necessary to use two large and small pumps, and the same problem will occur even with one pump, and the present invention can also solve this problem. . According to the present invention, since the acceleration time during descending operation can be lengthened, it is possible to provide an elevator with less shock to passengers.

In addition, we were able to provide an elevator with good ride comfort that does not cause passengers to feel uneasy because there is little instantaneous acceleration during deceleration.

[Brief explanation of the drawing]

FIG. 1 is a hydraulic circuit diagram of a hydraulic elevator according to an embodiment of the present invention, FIG. 2 is a main electrical circuit diagram, and FIGS. 3 and 4 are electrical operation circuit diagrams. Explanation of symbols, 1...Cylinder, 5...
Vegetable basket, 11... Main pump, 13...
Main electric motor, 17... Main hydraulic switching valve, 21...
...Solenoid valve, 33...Auxiliary pump, 35...
... Auxiliary electric motor, 39 ... Auxiliary hydraulic switching valve, 43 ... Solenoid valve. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. The pump is rotated by an electric motor, and the oil in the tank is supplied to the cylinder via the switching valve to raise the car, while the oil in the cylinder is pumped into the tank via the switching valve and the pump. In a hydraulic elevator configured to return the car and lower the car, a device is provided that opens the switching valve in response to a start command during the car lowering operation, and after a predetermined period of time has elapsed after the opening of the switching valve. A hydraulic elevator comprising a device that operates to start the electric motor for driving the pump. 2 The pump is rotated by an electric motor, and the oil in the tank is supplied to the cylinder via the switching valve to raise the car, while the oil in the cylinder is returned to the tank via the switching valve and pump to lower the car. In the hydraulic elevator, a device is provided for opening the switching valve in response to a start command during the car lowering operation, and a device for driving the pump that is activated after a predetermined period of time has elapsed after the opening operation of the switching valve. A device is provided to start the electric motor, a device is further provided to detect when the switching valve starts to close during downward deceleration, and a device is provided to stop the electric motor after a predetermined period of time in response to a command from the detection device. A hydraulic elevator featuring: