JPH04341474A - Control device for hydraulic elevator - Google Patents

Abstract

PURPOSE:To provide a control device for an oil pressure elevator that is quick and comfortable by providing a valve control device which performs current control of an electromagnetic proportional flow rate valve based on a valve current reference from a pattern change-over device. CONSTITUTION:When a starting valve current pattern 11a is outputted from a starting current pattern generating device 11 to lift an elevator, a lifting valve current 5a which is proportional to a valve current reference (Iref) is supplied to an electromagnetic proportional flow rate control valve 2A for lifting, which is closed by a degree proportional to this current 5a. When the oil pressure pump 7 side pressure of a check valve 9 exceeds the oil pressure jack 1 side pressure, oil begins to flow to the oil pressure jack 1 side through the check valve 9. When a flow rate detecting device 14 detects this moment, the valve current reference (Iref) is changed over to a running valve current pattern 15a, which is supplied to the electromagnetic proportional flow rate control valve 2A so as to ensure speed feedback control that is little affected by disturbance.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a control system for a hydraulic elevator.

0002

2. Description of the Related Art Conventionally, a control device for a hydraulic elevator that uses a hydraulic jack to raise and lower an elevator car has a configuration shown in FIG. 5.

[0003] This conventional hydraulic elevator control device has the following features:
An elevator that is raised and lowered by the ascending electromagnetic proportional flow control valve 2A and the descending electromagnetic proportional flow control valve 2B that control the flow rate of oil entering and exiting the hydraulic jack 1 in proportion to the valve current flowing to the electromagnetic solenoid. The valve current reference I is set according to the valve current pattern by inputting the elevator operation command from the car 3 and the outside.
A valve current pattern generator 4 that generates ref and a valve control current 5a for ascending or a valve for descending, respectively, for the electromagnetic proportional flow control valve 2A or 2B based on the valve current reference Iref generated by the valve current pattern generator 4. The valve current controller 5 provides a control current 5b. In addition, in FIG. 5, 6 is an oil tank, 7 is a hydraulic pump, 8 is a pump motor, and 9 is a check valve.

In such a conventional hydraulic elevator control device, first, when the elevator ascends, the oil in the oil tank 6 compressed by the hydraulic pump 7 passes through the ascending electromagnetic proportional flow control valve 2A and returns to the oil tank 6. be returned.

When the valve current reference Iref is output from the valve current pattern generator 4, the valve current controller 5 controls the ascending electromagnetic proportional flow control valve 2A.
The electromagnetic solenoid current is controlled and the valve is closed in proportion to the solenoid current. As a result, the pressure on the hydraulic pump 7 side is reduced to the hydraulic jack 1 before and after the check valve 9.
When the pressure on the hydraulic jack 1 is exceeded, the oil opens the check valve 9 and flows toward the hydraulic jack 1, thereby raising the elevator car 3.

Next, when the elevator is going down, the pump motor 8 does not operate, and therefore, the check valve 9 is closed because the pressure on the pump 7 side of the check valve 9 is low. Therefore, when the valve current reference Iref is output from the valve current pattern generator 4, the valve current control device 5 controls the electromagnetic solenoid current of the downward electromagnetic proportional flow control valve 2B, and the valve opens in proportion to the solenoid current. It will be done. As a result, oil flows from the hydraulic jack 1 through the descending electromagnetic proportional flow control valve 2B to the oil tank 6, and the elevator car 3 descends.

[0007]

[Problems to be Solved by the Invention] However, in such a conventional hydraulic elevator control device, after the valve current pattern generator 4 outputs the valve current reference Iref until the elevator car 3 starts moving, the oil There is a large mechanical delay time until the oil travels from the oil tank 6 through the piping to the hydraulic jack 1 and pushes up the car 3. For this reason, when trying to detect the actual speed of car 3 and perform speed feedback control, the control stability is poor, so the loop gain must be set low, and as a result, when the elevator starts, the valve current There is a problem in that the actual speed lags behind the pattern, causing a start shock, and there is also a problem in that a steady deviation in speed occurs when running at the rated speed. Furthermore, when the elevator is stopped, there is a problem in that the elevator lands on the floor with creep in order to ensure stability, resulting in a longer running time of the elevator.

[0008] Furthermore, if an attempt is made to perform open-loop control regarding the speed in order to avoid this, there is a problem in that the operating characteristics change due to changes in oil temperature and pressure, requiring sophisticated speed correction.

[0009] The present invention was developed in view of these conventional problems, and has stable speed control characteristics that are not affected by external disturbances such as changes in oil temperature and pressure, and provides a comfortable ride. An object of the present invention is to provide a control device for a hydraulic elevator that can shorten travel time. [Structure of the invention]

0010

[Means for Solving the Problems] A hydraulic elevator control device of the present invention includes an electromagnetic proportional flow control valve having an oil flow control characteristic proportional to the current flowing through an electromagnetic solenoid, and The elevator is controlled by a starting current pattern generator that generates a current pattern from when current starts flowing through the electromagnetic proportional flow control valve until the elevator starts moving, and by detecting the flow rate of oil flowing from the electromagnetic proportional flow control valve to the hydraulic jack. a flow rate detection device that detects the moment when the elevator starts moving; a speed reference generator that generates a speed reference for the elevator after the elevator starts moving; a speed detection device that detects the speed of the elevator; and a speed generated by the speed reference generator. A speed control device that controls the speed based on a reference and a speed feedback signal from a speed detection device, and a starting current pattern generated by the starting current pattern generator and a running current pattern generated by the speed control device are switched to serve as a valve current reference. The apparatus includes a pattern switching device that outputs an output, and a valve current control device that controls the current of the electromagnetic proportional flow control valve based on a valve current reference from the pattern switching device.

[0011]

[Operation] In the hydraulic elevator control device of the present invention, when the elevator is started, the pattern switching device switches to the starting current pattern side, and the valve current control device changes the valve current reference according to the starting current pattern generated by the starting current pattern generator to the valve current control device. The valve current control device supplies the electromagnetic proportional flow control valve with a valve control current that provides a suitable speed pattern when starting the elevator, and controls the elevator car's elevation in an open loop.

Further, after the elevator car starts moving, the pattern switching device switches to the running current pattern side, and the speed control device determines the speed based on the speed reference generated by the speed reference generator and the speed feedback signal from the speed detection device. A valve current reference is provided to a valve current controller so as to provide feedback control to raise and lower the elevator car with a running current pattern corresponding to a predetermined speed reference. Then, the valve current control device applies a valve control current according to this valve current reference to the electromagnetic proportional flow control valve to control the speed of the car.

[0013] In this way, by switching the speed pattern between starting and running and controlling the elevator car's elevation,
Improved ride comfort by reducing starting shock.
In addition, excellent control of speed characteristics can be performed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be explained in detail below with reference to the drawings. FIG. 1 shows an embodiment of the present invention, in which parts common to the conventional hydraulic elevator control system shown in FIG. 5 are denoted by the same reference numerals.

The hydraulic elevator control device of this embodiment uses a starting current that generates a current pattern from when current starts flowing through the electromagnetic proportional flow control valve 2A or 2B when the elevator starts operating until the elevator starts moving. A pattern generator 11, a speed reference generator 12 that generates a speed reference for the elevator after the elevator car 3 starts moving, a speed detector 13 that detects the actual speed of the elevator car 3, and an electromagnetic proportional flow control valve. A flow rate detection device 14 is provided to detect the moment when the elevator starts moving by detecting the flow rate of oil flowing from the hydraulic jack 2A to the hydraulic jack 1 or the flow rate of oil flowing from the hydraulic jack 1 to the electromagnetic proportional flow control valve 2B.

A speed control device 15 inputs the speed reference 12a generated by the speed reference generator 12 and the speed feedback signal 13a from the speed detector 13, performs speed feedback control calculations, and generates a running valve current pattern 15a. and the starting current pattern generator 1
The present invention includes a pattern switching device 16 that switches between a starting current pattern 11a generated by the speed control device 1 and a running current pattern 15a generated by the speed control device 15, and applies one of them to the valve current control device 5 as a valve current reference Iref. .

The valve current control device 5 receives a valve current reference Ir given from the pattern switching device 16.
Electromagnetic proportional flow control valve 2A or 2B based on ef
Current control is performed. Next, the operation of the hydraulic elevator control device configured as described above will be explained.

First, when the elevator is in ascending operation, as shown in FIG.
In the timing chart shown in , the pump motor 8 is started at time t0, and the oil compressed by the hydraulic pump 7 passes through the ascending electromagnetic proportional flow control valve 2A and returns to the oil tank 6.

At time t1, the starting current pattern generator 11
When the starting valve current pattern 11a is output from time t1 to t2, the pattern switching device 16 changes the starting valve current pattern 11a to the valve current reference Ire.
f and is applied to the valve current control device 5. Then, in the valve current control device 5, a rising valve current 5a proportional to this valve current reference Iref is supplied to the rising electromagnetic proportional flow rate control valve 2A, and the rising electromagnetic proportional flow rate is increased by an amount proportional to this rising valve current 5a. Control valve 2A is closed. As a result, when the pressure on the hydraulic pump 7 side of the check valve 9 becomes greater than the pressure on the hydraulic jack 1 side, oil begins to flow from the hydraulic pump 7 side to the hydraulic jack 1 side through the check valve 9.

When the flow rate detection device 14 detects this time point t2 from the flow rate flowing into the hydraulic jack 1, the pattern switching device 16 starts the valve current reference Iref from the traveling valve current pattern 11a to the traveling valve current pattern 15.
Switch to a.

This traveling valve current pattern 15a is based on the speed reference 12a generated by the speed reference generator 12.
This is a current pattern output as a result of speed feedback control calculation performed by the speed control device 15 so that the deviation between the feedback signal 13a and the actual speed of the car 3 detected by the speed detection device 13 becomes 0. . Then, between times t2 and t3, this current pattern is selected as the valve current reference Iref and given to the valve current control device 5, and the valve current control device 5 electromagnetically controls the rising valve current 5a proportional to this valve current reference Iref. It is supplied to the proportional flow rate control valve 2A, and speed feedback control is performed that is less susceptible to disturbances such as changes in oil temperature and pressure.

Conversely, in the case of descending operation, the starting valve current pattern 11a is set as the valve current reference Iref until the descending electromagnetic proportional flow control valve 2B starts to open, and thereafter, the running valve current pattern 15a is set as the valve current reference Iref. The descending operation is controlled by using the current reference Iref and controlling the oil flow rate in the same way as the ascending operation.

In this way, by switching the running pattern between the time of starting and the time of rated running, the starting valve current pattern 11 is maintained for a while at the time of starting.
By controlling the electromagnetic proportional control valve 2A or 2B in accordance with the valve current reference Iref according to a, starting operation control with less start shock can be performed, and once the car starts moving, speed feedback control can be performed. By doing this, you will be able to drive with good responsiveness.

FIG. 3 shows a more specific embodiment of the present invention. In this embodiment, 17 is a contactor for starting and stopping the pump motor 8, and 18 is a contactor for starting and stopping the pump motor 8. A flow rate sensor 19 detects the flow rate of oil flowing out, a roller guide 2 for raising and lowering the elevator car 3 along the guide rail 20;
A pulse generator 1 rotates together with the rollers of the roller guide 19 and generates a number of pulses proportional to the travel distance of the elevator car 3.

Further, 22 is an A/D converter that converts the analog signal from the flow rate sensor 18 into a digital signal, and 23
is a pulse counter that detects the car position or car speed by counting the pulses generated by the pulse generator 21. 24 is a microcomputer that performs various necessary control calculation processes such as switching of the starting valve current pattern, running valve current pattern, feedback control calculation, and calculation of the valve current reference Iref; 25 is a digital computer output from the microcomputer 24; A D/A converter 26 is an output interface for outputting the signal from the microcomputer 24 to the outside.

The signal 27 outputted from the output interface 26 is a rise/fall switching signal for switching the output of the valve current control device 5 depending on the operating direction of the elevator, and the signal 28 is a contactor-on signal for turning on the contactor 17. . Next, the operation of the hydraulic elevator control device configured as described above will be explained.

As shown in the flowchart of FIG. 4, first, during upward operation, the microcomputer 24 outputs a command 28 to turn on the contactor 17, turning on the contactor 17 and starting the pump motor 8 (step S
1, S2). In addition, a rising switching signal 27 is output,
The output of the valve current control device 5 is switched to the ascending electromagnetic proportional control valve 2A side (step S3).

Next, the microcomputer 24 outputs the starting current pattern, which is converted into an analog signal by the D/A converter 25 to become the valve current reference Iref, which is output to the valve current control device 5 (step S
6).

In response to this, the valve current control device 5:
A starting current is applied to the ascending electromagnetic proportional flow control valve A, and the valve is closed in proportion to this current. Therefore, when the pressure on the hydraulic pump 7 side of the check valve 9 exceeds the pressure on the hydraulic jack 1 side, oil begins to flow from the hydraulic pump 7 side through the check valve 9 to the hydraulic jack 1 side. Then, the flow rate sensor 18
detects the flow rate of this oil and inputs the detected amount to the microcomputer 24 through the A/D converter 22.

When the microcomputer 24 receives the flow rate detection signal (step S8), the microcomputer 24 calculates a speed standard, counts the pulses generated by the pulse generator 21 rotating in conjunction with the roller guide 19 with the pulse counter 23, and obtains the result. A speed feedback control calculation is executed for the speed determined, and a running valve current pattern is output (steps S8 to S11).

This running valve current pattern becomes the valve current reference Iref of the valve current control device 5 through the D/A converter 25, and the valve current control device 5 converts the valve current proportional to this valve current reference Iref into an electromagnetic proportional The flow rate is supplied to the flow control valve 2A, and the valve is closed by a predetermined amount. As a result, a flow rate of oil proportional to the travel valve current pattern flows into the hydraulic jack 1, raising the elevator car 3 at a predetermined speed.

In the case of downward operation, the ON command 28 for the contactor 17 is not output, and therefore the pump motor 8
is not activated (steps S1, S4). Also, rise,
A descending operation command is output as the descending switching signal 27 (step S5). Then, the valve current control device 5 controls the current of the descending electromagnetic proportional flow control valve 2B based on the procedure of steps S6 to S11 in the same manner as when ascending.
Descending operation control is performed.

In this way, in the absence of a speed feedback signal from when current begins to flow through the electromagnetic proportional flow control valve 2A or 2B until the elevator car 3 begins to move, the speed is controlled according to the open-loop controlled starting valve current pattern. When the car 3 starts moving and a speed feedback signal can be obtained by controlling the electromagnetic proportional flow control valve 2A or 2B, the oil is controlled by switching to speed feedback control and controlling the electromagnetic proportional flow control valve 2A or 2B. This makes it possible to control speed unaffected by disturbances such as temperature and pressure.

Since speed feedback control is not performed during startup when no speed feedback signal is obtained, the loop gain can be set high, steady speed deviation is small, and landing control without creep is achieved. You will also be able to do

In the above embodiment, speed feedback control is performed by a microcomputer using a digital control method, but this can also be performed by an analog circuit. Further, although the actual speed of the car is detected by a pulse generator interlocked with the roller guide, other speed detection methods may also be used. Further, although the starting valve current pattern is shown as a square wave in FIG. 2, it may have another shape. Furthermore, although the starting valve current pattern is open-loop controlled with respect to speed, the control amount may be compensated for using oil temperature, pressure, etc.

[0036]

[Effects of the Invention] As described above, according to the present invention, the speed is controlled in an open loop according to the starting valve current pattern from the time when current starts flowing through the electromagnetic proportional flow control valve until the car starts moving. Since the system switches to speed feedback control after the car has started moving, open-loop control can be used to control the start-up, when the speed deviation becomes large because a speed feedback signal cannot be obtained, and the car can be started without starting shock. Since the machine switches to speed feedback control after it starts moving, there is no speed deviation and a large loop gain can be achieved, making it possible to perform speed control that is less susceptible to disturbances such as changes in oil temperature and pressure. Furthermore, when the elevator reaches the floor, accurate speed control is possible down to low speeds, there is no creep, and the running time can be shortened.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a timing chart showing the operation of the above embodiment.

FIG. 3 is a block diagram of another embodiment of the invention.

FIG. 4 is a flowchart for explaining the operation of the above embodiment.

FIG. 5 is a block diagram of a conventional example.

[Explanation of symbols]

1...Hydraulic jack 3... Car 5...Valve current control device 6...Oil tank 7...Hydraulic pump 8...Pump motor 9...Check valve 11...Starting current pattern generator 11a...Starting valve current pattern 12...Speed reference generator 12a... Traveling valve current pattern 13...Speed detection device 13a...Speed feedback signal 14...Flow rate detection device 15...Speed control device 15a... Traveling valve current pattern 16...Pattern switching device Iref…Valve current reference

Claims (1)

[Claims] 1. An electromagnetic proportional flow control valve having oil flow control characteristics proportional to the current flowing through an electromagnetic solenoid, and an elevator starting to operate after current starts flowing through the electromagnetic proportional flow control valve when the elevator starts operating. A starting current pattern generator generates a current pattern, a flow rate detection device detects the moment when the elevator starts moving by detecting the flow rate of oil flowing from the electromagnetic proportional flow control valve to the hydraulic jack, and the elevator starts moving. a speed reference generator that generates a speed reference for the elevator after the elevator has been moved; a speed detector that detects the speed of the elevator; and a speed feedback control using the speed reference generated by the speed reference generator and a speed feedback signal from the speed detector. a speed control device that switches between a starting current pattern generated by the starting current pattern generator and a running current pattern generated by the speed control device and outputs the same as a valve current reference; A control device for a hydraulic elevator, comprising: a valve current control device that controls the current of the electromagnetic proportional flow control valve based on a valve current reference.