JP2000136071A - Control device for hydraulic elevator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an elevator passenger from being kept waiting due to oil temperature raising operation. SOLUTION: This device is provided with an oil temperature detecting device 4 detecting an oil temperature within a hydraulic cylinder 2A and a means 6 for lowering a car 1 to a lowermost floor when the oil temperature of the hydraulic cylinder 2A detected by the oil temperature detecting device 4 in a state that the car 1 is stopped on standby on a floor except the lowermost floor is lower than an oil temperature raising operation starting temperature T0 by a prescribed value or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a hydraulic elevator, and more particularly to a control device for maintaining a hydraulic elevator at an appropriate oil temperature.

[0002]

2. Description of the Related Art Generally, in a hydraulic elevator, when the oil temperature changes, the viscosity changes, and when the oil temperature decreases, the viscosity increases. This affects the performance of the flow control valve in the hydraulic circuit, so that even if an operation command is given to the flow control valve, the time required for flow control becomes longer. As a result, the deceleration becomes smaller, and thus the distance required for deceleration becomes longer, and the vehicle stops at an excessively far position. For this reason, a device that raises the oil temperature when the oil temperature is low has conventionally been invented. For example, it is described in JP-A-3-23166 and JP-A-57-81266.

[0003]

In a conventional hydraulic elevator, an oil temperature detector is provided in an oil tank, and when the oil temperature becomes lower than a predetermined value, the car stops on a position other than the lowest floor and waits. The car is lowered to the lowest floor, and when it reaches the lowest floor, the oil temperature rise operation is performed to keep the oil temperature at an appropriate temperature, but the car stops at the top floor or middle floor In this case, the oil temperature in the hydraulic cylinder becomes lower than the oil temperature in the oil tank. Therefore, when lowered to meet the floor call on the lowest floor, the oil temperature in the oil tank becomes lower than the oil temperature rise operation start temperature, the oil temperature rise operation is started, and elevator users on the lowest floor are Will make you wait.
In addition, when the temperature of the oil in the oil tank is about the same as the oil temperature rise operation start temperature, and the car descends to the lowest floor from the state where the car is stopped or waiting on the top floor, the oil temperature rise operation Becomes longer.

[0004] It is an object of the present invention to provide a hydraulic elevator control device that does not require an elevator user to wait for an oil temperature increase operation.

[0005]

The object of the present invention is to provide a hydraulic jack for raising and lowering a car and a car, a hydraulic pump for supplying hydraulic oil to a hydraulic cylinder of the hydraulic jack,
A hydraulic unit having a plurality of valves for controlling the supply and discharge of oil to and from a hydraulic cylinder, an oil tank for storing oil, and an oil when the oil temperature in the oil tank drops to a preset oil temperature rising operation start temperature. In a control device for a hydraulic elevator having an oil temperature raising operation means for performing a temperature raising operation, a cylinder oil temperature detector for measuring oil temperature in a hydraulic cylinder and a car stop on floors other than the lowest floor. Means for lowering the car to the lowest floor when the oil temperature detected by the oil temperature detector in the cylinder is lower than the oil temperature increase operation start temperature and the difference is equal to or more than a predetermined value in the state where This is achieved by providing the provided functions.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a flowchart of one embodiment, and FIG.
FIG. 5 is a schematic diagram for explaining an oil temperature increasing operation. The hydraulic elevator includes a car 1, a hydraulic cylinder 2A, a hydraulic jack 2 including a plunger 2B that moves up and down in the hydraulic cylinder 2A, an oil tank 3A, an oil pump 3B, a control valve 3C for controlling oil supply and discharge, and a safety valve. The control device includes a valve such as a relief valve (not shown), a hydraulic unit 3 having an oil temperature detector 3D for detecting an oil temperature in the oil tank 3A, and a control device 5. An oil temperature detector 4 is provided near the oil inlet / outlet of the hydraulic cylinder 2A, and the oil temperature detected by the oil temperature detector 4 in a state where the car 1 is stopped or on standby on a floor other than the lowest floor. Tx is the oil temperature increasing operation (heating operation) starting temperature T below ₀ and their difference (T ₀
Means 6 to lower the car 1 to the lowest floor when .about.Tx) is equal to or greater than a predetermined value is provided. Now, the operation will be described for the case where the elevator user uses the fifth floor and there is no customer thereafter, and the car 1 is stopped and kept on standby at the fifth floor.

(1) It is determined whether or not the oil temperature detected by the oil temperature detector 3D of the oil tank 3A is just before the oil temperature rise operation start temperature T ₀ to the oil temperature rise operation end temperature T ₁ (step 1). .

(2) If the decision result in the step 1 is YES, it is decided whether or not the car 1 is stopped at the lowest floor (step 2). In this case, because it is stopped on the 5th floor,
It becomes O.

[0010] (3) if step 2 of the determination is NO, the next oil temperature detector 4 oil temperature detected by the in the hydraulic cylinder 2A is (lower than T ₀₎ increasing operation starts Tx oil temperature It is determined whether the difference from the temperature T ₀ (T _{0 to} Tx) is equal to or greater than a predetermined value Tb (step 3).

(4) If the result of the determination in step 3 is YES, that is, if the temperature difference T _{0 to} Tx is equal to or less than the predetermined value Tb, the oil temperature in the oil tank 3A will remain even if the car 1 descends to the lowest floor not even the oil temperature increasing operation start temperature T ₀ or less and lowered, there is no need for oil temperature increasing operation, it's the end,
Car 1 continues to be stopped on the fifth floor. When the determination result is NO, the car 1 is lowered to the lowest floor, the oil temperature raising operation is started, and the oil temperature is raised to the oil temperature raising operation end temperature T _1.
Is reached, the operation is stopped. In the oil temperature increasing operation, the oil temperature is raised by operating the lily valve or the safety valve to suck oil from the oil tank 3A by the hydraulic pump 3B and returning the oil to the oil tank 3A again as shown in FIG. That means.

[0012]

As described above, according to the present invention, it is possible to provide a hydraulic elevator control apparatus which does not require an elevator user to wait for an oil temperature increase operation.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a schematic configuration of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Riding car 2 Hydraulic jack 2A Hydraulic cylinder 3A Oil tank 3 Oil temperature detector in oil tank 4 Oil temperature detector in hydraulic cylinder 6 Lowering operation means to the lowest floor by oil temperature in cylinder

Claims (2)

[Claims] 1. A hydraulic jack for raising and lowering a car and a car, a hydraulic pump for supplying hydraulic oil to a hydraulic cylinder of the hydraulic jack, a plurality of valves for controlling supply and discharge of oil to and from the hydraulic cylinder, and oil. Elevator having a hydraulic unit having an oil tank or the like for storing oil and an oil temperature increasing operation means for performing an oil temperature increasing operation when the oil temperature in the oil tank falls to a preset oil temperature increasing operation start temperature. In the control device, the oil temperature detected by the cylinder oil temperature detector when the car is stopped on a floor other than the lowest floor and the cylinder oil temperature detector that measures the oil temperature in the hydraulic cylinder, Means for lowering the car to the lowest floor when the difference is lower than the oil temperature increasing operation start temperature and the difference is equal to or more than a predetermined value. apparatus. 2. The hydraulic elevator control device according to claim 1, wherein the car is moved to the lowest floor, and then the oil temperature increasing operation is started.