KR100335982B1 - Vapor compensation method of hydraulic elevator - Google Patents

Abstract

The present invention relates to a pressure compensation method of an elevator, and in the related art, a pressure sensor incorrectly detects a pressure due to an incorrect offset measurement or an increase in the temperature of oil in a power unit, causing vibration and shock when the car stops during a descent operation. There was this. Accordingly, the present invention provides a first process of detecting pressure automatic compensation by comparing a difference between a pump side pressure during load compensation and a pump side pressure during lowering when a car starting command occurs; A second step of detecting a pressure compensation value by a difference between a pump pressure during load compensation operation and a pump pressure value when stopping and starting the car when the pressure compensation mode is detected in the first step; By performing the third process of correcting the pump pressure by adding the pressure compensation value of the second process to the pump pressure at the time of starting the motor, automatically correcting the fluctuation of the pressure sensor according to the creeping of the offset value and the change of temperature during installation By reducing the vibration and shock of the elevator there is an effect that can improve the riding comfort.

Description

Pressure correction method of hydraulic elevator {VAPOR COMPENSATION METHOD OF HYDRAULIC ELEVATOR}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure correction method of a hydraulic elevator, and more particularly, to detect a shock caused by various environmental changes of a pressure sensor and misfeeding of an offset value, and to automatically compensate for this and improve a ride comfort. A pressure correction method.

In general, the hydraulic elevator is a phenomenon such as the deviation of the running speed and the delay of the operation time due to the change in the characteristics of the flow control valve according to the load change of the carrier, the phenomenon of vibration or shock when starting and landing, such a conventional hydraulic elevator It will be described in detail with reference to the accompanying drawings.

1 is a schematic view showing a configuration of a general hydraulic elevator, in which an inverter 2 receiving a three-phase 380 V 60 Hz power source 1 and a control panel 3 controlling the inverter 2 are connected to each other by a signal line. In and out of the inverter (2), the power line is connected to the hydraulic motor in the power unit (4), the two power lines are hydraulic pressure through the HALL-CT (5) for the current control of the inverter (2) It is connected to the motor (7).

About two thirds of the oil is filled in the power unit 4, and the hydraulic motor 7 shaft and the hydraulic pump 8 are connected to the oil to rotate.

In addition, a hydraulic motor side rotary encoder 6 is mounted behind the hydraulic motor 7 so that rotation of the hydraulic motor 7 can be detected, and the hydraulic motor 7 and the hydraulic pump 8 have a power unit 4. ) It is fixed to the floor and cannot move.

The upper portion of the hydraulic pump 8 is connected to the check valve 10 fixed to the upper portion of the power unit 4 by a metal tube and pressure sensors 9 and 11 on both sides of the check valve 10. Can be connected one by one to sense the pressure on both sides of the pipe.

A hydraulic hose 12 is connected between the check valve 10 and the cylinder 14 so that oil can flow through the hydraulic hose 12.

The cylinder 14 has a jack 15 so that the oil is introduced into the cylinder 14, the jack 15 is moved up and down, the jack side pulley 13 is fixed to the upper portion of the jack 15 Jack side pulley 13 is a rope 19 is connected, one end of the rope 19 is fixed to the ground and the other is suspended from the car 16.

On the opposite side of the car 16, the governor rope 20 is fixed, and the upper and lower parts of the governor rope 20 have pulleys, so when the car 16 moves, the governor rope 20 also moves. I can move it.

The lower end of the rope 19 has a governor 18 and the car side rotary encoder 17 is attached to the governor 18 to detect the movement of the car.

Here, the operation of the conventional apparatus configured as described above will be described.

First, when the car 16 rises, the three-phase 380V is converted into a DC power source from the inverter 2 and converted back to a desired AC power source.

At this time, the converted AC power is applied to the hydraulic motor 7 in the power unit 4 to rotate the hydraulic motor 7 gradually, thereby rotating the hydraulic pump 8 to increase the pressure of the metal pipe. .

Therefore, the cylinder 14 side pressure value is detected by the cylinder side pressure sensor 11, and accordingly the hydraulic motor 7 is driven by the control panel 2, so that the cylinder side pressure and the pump side pressure sensors 9, 11 are reduced. Control so that the detected pressure value is the same.

At this time, when the cylinder-side pressure and the pump-side pressure are the same, the check valve 10 is opened and the hydraulic motor 7 is further accelerated to push oil into the hose. This series of processes is referred to as load compensation operation.

If the load compensation movement is not performed as described above, the pressure difference between the pump side and the cylinder side is large at the moment of opening the check valve 10, and the car 16 is severely shaken to shock the passenger.

After performing the load compensation operation as described above, the hydraulic motor 7 continues to drive to the rated speed, in which the oil is introduced into the cylinder 14 through the hose 12 and the oil introduced into the cylinder 14. The jack 15 is pushed out and the pulley 13 on the top of the jack 15 is pushed up to push the rope 19, and the car 16 is moved upward.

On the contrary, when the car 16 is lowered, the hydraulic motor 7 is rotated as in the case of ascending, so that the pressure in the pump is made equal to the pressure on the cylinder side, and then the check valve 10 is opened and the pump pressure When the rotational speed of the hydraulic motor 7 is gradually reduced so as to decrease the oil, the oil in the cylinder 14 flows into the power unit 4 through the hydraulic pump 8 due to the pressure difference, so that the jack on the cylinder 14 When 15 falls and the jack 15 descends, the pulley 13 descends and the car 16 descends.

Here, the pressure sensor (9), 11 of the hydraulic elevator as described above is composed of the current type, when the current of 4mA is output from the pressure sensor (9), 11, '0 bar', '100 bar '20 mA is output, the speed control unit of the control panel 3 receives the values detected by the pressure sensors 9, 11 to control the rotation of the hydraulic motor 7 accordingly.

At this time, the pressure sensors (9) and (11) have a new output value, and the resistance value and the value of the condenser are different when detected. In order to correct this, the pressure sensor (9) in the case of '0 bar', The value of (11) is detected in advance and stored in the ROM, and the offset value stored in the ROM is subtracted from the values of the pressure sensors 9 and 11 read when the pressure is detected to calculate the pressure from the subtracted value.

However, when the oil temperature in the power unit 4 rises, the temperature of the check valve 10 rises, so that the temperature of the pressure sensors 9 and 11 attached to the check valve 10 also rises.

Accordingly, an error in pressure occurs according to a temperature change around the pressure sensors 9 and 11, and when the load is compensated with a pressure value including the error, vibration occurs.

In other words, the prior art operating as described above has a problem in that the pressure sensor incorrectly detects the pressure due to the wrong offset measurement or the temperature of the oil in the power unit rises, causing vibration and shock when the car is stopped during the descent operation.

Accordingly, the present invention devised in view of the above-mentioned problems provides a pressure correction method of a hydraulic elevator that can automatically detect and correct shock caused by various environmental changes and misfeeds in an offset value of a pressure sensor. Its purpose is to provide.

1 is a schematic view showing the configuration of a general hydraulic elevator.

Figure 2 is a hydraulic control system applied pressure compensation method of the present invention hydraulic elevator.

Figure 3 is a block diagram showing the configuration of a control device to which the pressure correction method of the present invention hydraulic elevator is applied.

Figure 4 is a flow chart of the operation of the pressure correction detection method of the pressure correction method of the hydraulic elevator of the present invention.

5 is an operation flowchart of the pressure correction value detection method of the pressure correction method of the hydraulic elevator of the present invention.

Figure 6 is a flow chart of the operation of the pressure correction value applying method of the pressure correction method of the hydraulic elevator of the present invention.

Figure 7 is a waveform diagram of the pressure correction method of the hydraulic elevator of the present invention.

***** Description of the symbols for the main parts of the drawings *****

1: hydraulic cylinder 2: rupture valve

3: hose 4: shut off valve

5: damper 6: hydraulic pump

7: hydraulic motor 8: encoder

9: oil tank 10: oil gauge

11: level switch 12: first temperature sensor

13: second temperature sensor 14: oil cooler

15: hand pump 16: pressure gauge

17 gauge shutoff valve 18 cylinder pressure sensor

19: Tank side pressure sensor 20: Pressure drop for manual lowering

21: Manual / Automatic Lowering Valve 22: Closed Control Valve

23: emergency control valve 24: open solenoid valve

25: closed solenoid valve 26: check valve

27: relief valve 28,30: pilot relief valve

29: oil temperature control valve 31: anti-cavitation valve

The present invention for achieving the above object comprises the first step of detecting the pressure automatic compensation by comparing the difference between the pump side pressure at the time of the load compensation and the pump side pressure when the car start command occurs; A second step of detecting a pressure compensation value by a difference between a pump pressure during load compensation operation and a pump pressure value when stopping and starting the car when the pressure compensation mode is detected in the first step; And performing a third process of correcting the pump pressure by adding the pressure compensation value of the second process to the pump pressure at the time of starting the motor.

Hereinafter, the operation and effect of the pressure correction method of the hydraulic elevator according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a hydraulic control system diagram to which the pressure correction method of the hydraulic elevator of the present invention is applied. As shown in FIG. 2, the hydraulic motor is driven in a vertical direction by the hydraulic fluctuation according to the forward / reverse rotation of the hydraulic motor 7 described below. Hydraulic cylinder (1) to make; A hydraulic pump 6 rotating in the forward direction by the hydraulic motor 7 to pump oil to the hydraulic cylinder 1 side through the hydraulic pipe, or rotating in the reverse direction to discharge the oil; An encoder (8) for detecting the rotational speed of the hydraulic motor; An oil tank (9) in which the hydraulic pump (6), the hydraulic motor (7) and the encoder (8) are installed and the oil is stored; A check valve 26 installed on a hydraulic pipe connecting the hydraulic cylinder 1 and the oil tank 9 to control oil flow from the oil tank 9 to the hydraulic cylinder 1 side or vice versa; ; A closing control valve 22 and an opening solenoid valve 24 installed on a pilot pipe line to control the valve 26 so that oil flows from the oil tank 9 to the hydraulic cylinder 1 side or vice versa as described above. ) And a closed solenoid valve 25; A relief valve 27 for preventing the pressure in the oil pressure line of the oil tank 9 from rising above a predetermined value or adjusting the oil temperature of the oil tank 9; It comprises a pilot relief valve 28, 30 and the oil temperature control valve 29 for controlling the flow of oil in conjunction with the relief valve (27).

4 is an operation flow chart of the pressure correction detection method of the pressure correction method of the hydraulic elevator according to the present invention. As shown in FIG. 4, when the starting command of the car is detected, the load compensation operation is performed until the pump pressure and the cylinder pressure become equal. A first step of doing; A second step of detecting the pump pressure at that time and setting the pre-pressure value when the car descends after the load compensation operation is completed, and then opening the check valve 26; A third step of detecting the pump pressure at the time when the check valve 26 is opened and setting the present pressure value; A fourth step of determining whether the compensation operation is performed by detecting whether the difference between the pre-pressure value and the present-pressure value is greater than or equal to a predetermined value; In the fourth step, if the difference is greater than or equal to a predetermined value, the automatic pressure compensation operation flag is set, and then the speed control operation is executed, and when the car speed command is '0', the fifth step is completed.

Fig. 5 is an operation flowchart of the pressure correction value detection method of the pressure compensation method of the hydraulic elevator of the present invention, and as shown therein, a first step of detecting whether the automatic pressure compensation operation flag is set while there is no car start command; A second step of performing a load compensation operation until the pump pressure and the cylinder pressure are equal if the compensation operation flag is set; Storing a pressure of the pump when the pump pressure and the cylinder pressure are equal to each other as a hold pressure value; A fourth step of detecting a pressure value of the pump at the stop after the raising or lowering operation of the car; And a fifth step of setting the difference between the hold pressure value at the time of waiting for starting the car detected in the third step and the pressure value at the completion of starting detected in the fourth step as a pressure compensation value.

6 is a flowchart illustrating a method of applying a pressure correction value of the pressure correction method of the hydraulic elevator according to the present invention, and as shown therein, a first step of detecting pressure of a cylinder and a pump at the starting point when the motor is started; A second step of adding a pressure compensation value to the detected pump pressure to set a pump correction pressure; Controlling the torque of the motor until the pump correction pressure is equal to the cylinder pressure; A fourth step of driving the car by the set motor torque is made, and this operation of the present invention will be described in parallel with FIG. 3.

First, referring to FIG. 3, a process in which a motor is driven will be described. The input three-phase AC power supply 32 is rectified through the converter 33, and then smoothed by the capacitor C to the input terminal of the inverter 34. The DC voltage is supplied, and the inverter 34 is driven by the pulse width modulation control unit 35 to supply the hydraulic motor 7 with forward or reverse driving AC power, thereby raising or lowering the elevator car 38. Perform the operation.

When driving up, after checking the safety of each part of the system through the safety circuit (not shown) in the normal driving mode, it is confirmed that there is no problem in safety and the call signal is sent by the passenger waiting in the platform or the passenger in the car. When registered, the driving of the hydraulic motor 7 is controlled through the path under the common control of the driving control unit 37 and the speed control unit 36 to drive the car 38 in the up or down direction.

That is, when an ascending call to any floor is registered, the closing control valve 22 is driven by the common control of the operation control unit 37 and the speed control unit 36 to check the valve 26 and the opening solenoid valve 24. ) And the pilot pipe through the closing control valve 22 is opened, and the hydraulic motor 7 is rotated in a predetermined speed pattern by the common control of the operation control unit 37 and the speed control unit 36.

Therefore, the hydraulic pump 6 is driven to raise the hydraulic pressure of the hydraulic pump 6 side pipeline on the hydraulic pipeline so that the check valve 26 is opened, whereby the oil pumped from the oil tank 9 is hydraulic. After the check valve 26 on the pipeline, the damper 5, the shutoff valve 4, and the rupture valve 2 are supplied to the cylinder 1 side to raise the piston, whereby the car 38 is formed on the target floor. Drive up toward.

On the contrary, if the falling call to any floor is registered during the falling operation, the closing control valve 22, the opening solenoid valve 24 and the closing solenoid valve are controlled by the common control of the driving control unit 37 and the speed control unit 36. (25) is driven, the closing control valve 22 and the closing solenoid valve 25 are opened, and the opening solenoid valve 24 is closed. As a result, the pilot pipe through the check solenoid valve 25 from the check valve 26 is opened. At this time, the hydraulic motor (3) has a predetermined speed pattern by the common control of the operation control unit 37 and the speed control unit 36. 7) is reversed.

Accordingly, the piston is lowered while the oil in the cylinder 1 is discharged in the reverse direction, whereby the car 38 is lowered and driven toward the target floor.

In the above description, 'common control between the speed control unit 36 and the operation control unit 37' means more perfection when controlling a control object that greatly affects safe operation, such as the hydraulic motor 7 or each valve. For this purpose, the speed control section 36 and the operation control section 37 issue control commands (control patterns), respectively, so that the hydraulic motor 7 or the corresponding valves are driven only under the condition that the respective control commands coincide with each other. I mean. Of course, at this time, no abnormality should be detected in the safety phase through the safety circuit.

In the present invention, in controlling the operation, the shock sensor due to various environmental changes of the pressure sensors 18 and 19 and misfeeding of offset values are automatically detected and corrected to correct the load compensation operation. This is done in detail.

First, when a car start command is generated, pressure automatic compensation is detected by comparing the difference between the pump side pressure at the time of load compensation and the pump side pressure at the time of falling.

That is, when the start command of the car is detected, the load compensation operation is executed until the pump pressure and the cylinder pressure are equal. When the car is lowered after the load compensation operation is completed, the pump pressure at that time is detected and the pre-pressure value is reached. After setting, save it to ROM.

Then, when the open solenoid valve 24 and the closed solenoid valve 25 are picked up and the check valve is opened, the pump pressure at that time is detected and set to the present-pressure value, and the present-pressure value and the pre- If the difference with the pressure value is higher than the predetermined value (the user sets the proper value by experiment) as shown in the waveform diagram of Fig. 7, set the automatic pressure compensation operation flag and execute the speed control operation and set the speed as '0'. Stops the car.

The pump pressure and the cylinder pressure are values detected by the pressure sensors 18 and 19 and read by an analog / digital converter (not shown), which controls the pressure equally while the check valve 26 is blocked. If the pressure sensor 18, 19 is wrong, the pressure in the two spaces are different.

Thereafter, when the check valve 26 is opened, the pressures of the two spaces are combined to form an equilibrium. In this case, the pump side pressure becomes the same as the cylinder side pressure because the pump side space is small and the cylinder side space is large.

However, the pump pressure value read into the analog / digital converter is different from the pressure value after opening the check valve 26 from the pressure value before opening the check valve 26 because the pressure has changed. If it is fixed, the pressure sensor detection value is wrong and should be compensated.

If it is determined that automatic pressure compensation is necessary in the above, the pressure compensation value is set to the difference between the pump pressure at the time of the load compensation operation and the pump pressure at the stop after the start of the car.

That is, it detects whether the automatic pressure compensation operation flag is set while there is no car start command, and if the pressure compensation operation flag is set, load compensation operation is performed until the pump pressure and cylinder pressure are the same.

Then, the pump pressure when the pump pressure is equal to the cylinder pressure is stored in the ROM as a hold pressure value, and the check valve 26 is opened.

If the pump pressure is greater than the cylinder pressure, the moment the car opens the check valve 26, the car rises, and if the pump pressure is less than the cylinder pressure, the car passes the check valve 26 down.

At this time, if the car goes up, the torque current is decreased. If the car goes down, the torque current is increased, and the torque current is adjusted until the car stops and stops.

Then, the difference between the hold pressure value at the time of waiting for starting the car and the pump pressure value at the completion of starting is detected as the pressure compensation value.

Thereafter, the pressure compensation value is added to the pump pressure at the start of the motor 7 to correct the pump pressure.

That is, when the motor 7 is started, the pressures of the cylinder 1 and the pump 6 at the starting point are detected, the pressure compensation value is added to the detected pump pressure, and the pump correction pressure is set. The torque of the motor 7 is controlled until it is equal to the cylinder pressure, and the car is driven by the set motor torque current.

In other words, in the present invention, when the check valve 26 is opened during the descent operation, if the pump pressure or the cylinder pressure is higher than or equal to the predetermined value, it is determined that the pressure detection is abnormal.

At this time, the pressure correction, first check the cylinder 7 and the pump pressure to control the motor (7) and then open the check valve 26 to check whether the car is moving, where the car is further rotated by rotating the motor (7) The rotation speed is increased until the car is not moving, and if the car rises when the check valve 26 is opened, the rotation speed of the motor 7 is decreased until the car is stopped.

Then, when the car stops, remember the pump pressure at that time, close the check valve 26, subtract the pump pressure at the time when the first load compensation is completed from the stored pump pressure value, and store the subtracted value as the pressure compensation value. The pump pressure is corrected by adding the pressure correction value to the pump pressure during the next load compensation operation.

As described in detail above, the present invention has an effect of automatically improving the riding comfort by reducing the vibration and shock of the elevator by automatically correcting the fluctuation of the pressure sensor according to the erroneous entry of the offset value and the change of temperature at the time of installation.

Claims (4)

A first step of detecting pressure automatic compensation by comparing a difference between a pump side pressure during load compensation operation and a pump side pressure during lowering when a car start command occurs; A second step of detecting a pressure compensation value by a difference between a pump pressure during load compensation operation and a pump pressure value when stopping and starting the car when the pressure compensation mode is detected in the first step; And a third process of correcting the pump pressure by adding the pressure compensation value of the second process to the pump pressure during load compensation operation. The method of claim 1, wherein the first step comprises: a first step of performing a load compensation operation until the pump pressure and the cylinder pressure are equal when the starting command of the car is detected; A second step of detecting a pump pressure at that time and setting the pre-pressure value after opening the check valve after the load compensation operation is completed; A third step of detecting the pump pressure at the time when the check valve is opened and setting the present pressure value; A fourth step of determining whether the compensation operation is performed by detecting whether the difference between the pre-pressure value and the present-pressure value is greater than or equal to a predetermined value; And setting the automatic pressure compensation driving flag when the difference value is equal to or greater than the default value in the fourth step, and ending when the car speed command is '0'. The method of claim 1, wherein the second process comprises: a first step of detecting whether an automatic pressure compensation driving flag is set while there is no start command; A second step of performing a load compensation operation until the pump pressure and the cylinder pressure are equal if the compensation operation flag is set; Storing a pressure of the pump when the pump pressure and the cylinder pressure are equal to each other as a hold pressure value; A fourth step of detecting a pressure value of the pump at the stop after the car's raising or lowering operation; And a fifth step of setting the difference between the hold pressure value at the time of waiting for starting the car detected in the third step and the pressure value at the completion of the start detected in the fourth step as a pressure compensation value. . The method of claim 1, wherein the third process comprises: a first step of detecting pressure of a cylinder and a pump at a starting point when the motor is started; A second step of adding a pressure compensation value to the detected pump pressure to set a pump correction pressure; Controlling the torque of the motor until the pump correction pressure is equal to the cylinder pressure; And a fourth step of driving the car by the set motor torque.