KR100205770B1 - Hydrolic elevater - Google Patents

Abstract

The hydraulic elevator of the present invention detects the displacement and acceleration of the cage, and the cylinder which raises and lowers the cage of the hydraulic elevator is controlled by the feedback signal of the displacement and acceleration of the cage.

Description

Hydraulic elevator

1 is a block diagram showing the configuration of one embodiment of a fluid pressure elevator of the present invention.

FIG. 2A is a characteristic diagram of the elevator of FIG. 1 at the time of boarding. FIG.

FIG. 2B is a characteristic diagram of the elevator of FIG. 1 at the time of getting off.

Figure 3 is a block diagram showing the configuration of a position correction device according to an embodiment of the present invention.

Fig. 4A is a characteristic diagram of the fluid pressure elevator in Fig. 3 using position correction by displacement feedback control at the time of boarding.

4B is a characteristic diagram of the fluid pressure elevator in FIG. 3 using position correction by displacement feedback control at the time of getting off.

5 is a block diagram showing the configuration of a control circuit of the position correction device of the present invention.

6A is a control characteristic diagram when there is no correction of this invention.

6b is a control characteristic diagram of the present invention.

7 is a block diagram showing the configuration of another embodiment of a position correction device according to the present invention.

8A, 8B, and 8C are block diagrams illustrating the arrangement of the position correction device, respectively.

9 is a block diagram showing the configuration of another embodiment of a position correction device according to the present invention.

Figure 10a is a control characteristic diagram of the overlap valve (over lap valve) used in the position correction device of the present invention.

FIG. 10B is a characteristic diagram between the control command and the flow rate in the characteristic shown in FIG. 10A. FIG.

Fig. 11A is a control characteristic diagram of an overlap valve when the overlap valve used in the position correction device of the present invention is uneven in the amount of overlap.

FIG. 11B is a characteristic diagram between the control command and the flow rate in the characteristics shown in FIG. 11A. FIG.

Fig. 12A is a control characteristic diagram of an overlap valve when the overlap valve used in the position correction device of the present invention is severely uneven in the amount of overlap.

FIG. 12B is a characteristic diagram between a control command and a flow rate in the characteristic shown in FIG. 12A. FIG.

13A is a control characteristic diagram of an overlap valve when the unstable region due to non-uniformity of the overlap valve used in the position correction device of the present invention is reduced.

FIG. 13B is a characteristic diagram between the control command and the flow rate in the characteristics shown in FIG. 13A. FIG.

Fig. 14A is a control characteristic diagram of an overlap valve when the unstable region due to non-uniformity of the overlap valve used in the position correction device of the present invention is corrected by a dither signal.

14B is a characteristic diagram between a control command and a flow rate in the characteristic shown in FIG. 14A.

Fig. 15A is a control characteristic diagram of an overlap valve when the unstable region due to non-uniformity of the overlap valve used in the position correction device of the present invention is reduced by using a dither signal.

FIG. 15B is a characteristic diagram between the control command and the flow rate in the characteristic shown in FIG. 15A. FIG.

16A, 16B, and 16C are different characteristic diagrams of a fluid pressure elevator, each illustrating another position correction method of the present invention.

* Explanation of symbols for main parts of the drawings

1: fluid pressure cylinder 2: control valve

3: position correction device 10: cage

30a, 30b: control valve 31a: pump

31b: motor 35: accumulator

36: pressure switch 60: main fluid pressure unit

TECHNICAL FIELD The present invention relates to a fluid pressure elevator including a means for correcting the rise and fall of a cage at rest.

When the hydraulic elevator stops, the cage sinks or floats due to the lifting and lowering of the passengers.

In order to compensate for the injuries or settlements of the cages, when the cages are injured or settled for a certain amount, the main fluid pressure unit that drives the elevator is operated at low speed, or the ON-OFF valve is operated to supply or discharge the pressurized oil. In addition, the position of the cage was mechanically detected and fed back to configure and correct the servo mechanically and hydraulically.

Moreover, as a proposal regarding the position correction means of this kind of elevator, it is as follows.

Level control device of FIG. 1 using an overlap valve equipped with a solenoid valve is included in the "Level maintenance device for fluid pressure elevators" of Japanese Unexamined Patent Publication No. 48 (1973) -27816 of August 25, 1973. Is disclosed. However, since the responsiveness of the solenoid valve itself is insufficient, the device of this patent has a drawback in the responsiveness to compensation of the injury and settlement of the cage.

The "Pneumatic Elevator with Hydraulic Compression Compensation Device" of Japanese Patent Application No. 50 (1975) -6944 of March 19, 1975 discloses a pivot valve for supplying and discharging hydraulic oil to a cylinder. The valve is to supply the hydraulic oil to the cylinder to drive the hydraulic elevator.

The hydraulic elevator of Japanese Patent Application No. 50 (1975) -6944 has a drawback that the oil supply system for driving the hydraulic elevator is complicated. A cylinder oil pressure system for driving a fluid pressure elevator of FIG. 2 is disclosed in Japanese Patent Application Publication No. 51 (1976) -38136 of October 20, 1976. However, this hydraulic oil system also has the drawback that the structure is complicated.

Japanese Patent Application Publication No. 51 (1976) -42826, filed November 18, 1976, discloses a hydraulic pressure system of a cylinder for driving the hydraulic elevator of FIG. However, this device also has the drawback that the system structure is complicated.

Conventional elevators have responsiveness and structural drawbacks as described above.

This invention is made | formed in view of the said situation, and an object of this invention is to provide the fluid pressure elevator of the responsiveness and the correction of a high precision, and a simple structure.

In order to achieve the above object, the present invention corrects the rise and fall of the cage by controlling the amount of pressure fluid supplied to or discharged from the cylinder based on the signal generated according to the rise and fall of the cage when the cage is stopped. Characterized in that.

The signal used as a control signal for the correction of the rise and settle of the cage is the displacement of the cage, the acceleration acting on the cage, the load signal, or the pressure signal of the fluid pressure cylinder for driving the cage.

In addition, it is preferable that the control valve used in the flow rate control device of the pressure fluid applied to the cylinder is an overlap valve.

According to the above arrangement, by combining the fluid pressure source and the control valve of the control device of the present invention mainly composed of the accumulator, a fluid pressure circuit capable of high response and high precision control can be formed. In addition, as a signal for the control command, not only the displacement of the cage, but also the acceleration of the cage, the pressure of the cylinder, or the change of the load of the cage are detected and used as a signal for operating the control valve. Responsiveness and stability are remarkably improved, and the position of the cage can be smoothly corrected.

EMBODIMENT OF THE INVENTION Next, the Example of this invention is described in detail according to drawing.

1 shows a configuration of one embodiment of a fluid pressure elevator that is the subject of the present invention. The flow rate of the high pressure fluid supplied to or discharged from the fluid pressure cylinder 1 is controlled by the opening degree of the control valve 2 or the rotation speed of the fluid pressure pump 6, and the plunger 1a of the fluid pressure cylinder 1 is controlled. ), That is, the rate of rise or fall of the cage 10 (the plunger 1a and the cage 10 of the cylinder 1 are coupled through the pulley 1b and the rope 1c) to the flow rate of the pressure fluid. Controlled by us.

The control valve 2 is composed of a main valve 20, pilot valves 21a, 21b, the pilot valve 21a is used to open the main valve 20, the pilot valve 21b is the main valve ( 20) is used to close. The control valve 2 acts as a check valve when the cage 10 is raised, and acts as a flow control valve when descending, thereby accelerating the position maintenance of the cage 10 and the smooth rise and fall of the cage.

The pump 6 is driven by the motor 7, and the flow rate is controlled by controlling the rotation speed of forward rotation when the cage 10 rises and reverse rotation when the cage 10 rises. The relief valve 4 and the suction valve 5 are safety devices of the fluid pressure circuit. That is, the relief valve 4 is composed of the main valve 40, the pilot relief valve 41, the pilot switching valve 42, the relief pressure is set by the pilot relief valve 41, the mechanical stopper 40d and the pilot The unloading pressure is set by the selector valve 42. In this case, when the fluid temperature is lowered and the viscosity of the fluid is increased, the speed characteristic is lowered and the riding comfort is deteriorated. Therefore, it is necessary to maintain the fluid temperature at a predetermined value in order to prevent the above-mentioned defect. The intake valve 5 is arranged to replenish the fluid from the tank 9 to the pump 6 when the flow path between the control valve 2 and the pump 6 becomes a vacuum. As a result, the flow path becomes a vacuum to generate cavitation, thereby preventing damage to the device due to the cavitation.

The control device 12 responds to the call from the cage 10 or the hall or other commands, inputs information from various sensors, and the sensor is connected to a rotary encoder 13 connected to the cage position detecting device 13. 13d), a pressure sensor 15d connected to the outlet pipe 101 of the pump 6, and a pressure sensor 15e connected to the flow path 100 to the cylinder 1. The cage position detecting device 13 is composed of pulleys 13a and 13b and a rope 13c. The controller 12 drives the motor 7 through the inverter 11 and controls the valves 21a, 21b and the pilot switching valve 42.

Reference numeral 9 denotes a tank, and a filter 8 is disposed between the tank 9 and the pump 6.

Next, the operation of the apparatus of FIG. 1 will be described.

(1) Rise:

In response to the command, the control device 12 drives the motor 7, that is, the pump 6, through the inverter 11. When the rotation speed of the pump 6 gradually increases, the flow volume from the pump 6 to the control valve 2 increases, the control valve 2 is pushed open, and the high pressure fluid is supplied to the cylinder 1.

As a result, the cage 10 is accelerated up. When the cage 10 rises and approaches the target floor, the rotation speed of the pump 6 is reduced by the deceleration command to reduce the flow rate to the shutter 1.

As a result, the cage 10 is decelerated, and the cage 10 is also stopped by the pump stop. The opening degree of the control valve 2 also decreases in proportion to the decrease in flow rate, and closes when the pump stops. The position of the cage 10 at this time is monitored by the cage position detection device 13.

(2) descent:

In response to the command, the control device 12 gradually opens the control valve 2 to balance the fluid pressure between the control valve 2 and the pump 6 with the cylinder pressure, and then the motor through the inverter 11. (7) The pump 6 is driven to discharge the high pressure fluid of the cylinder 1, and the cage 10 is accelerated downward. This can alleviate the shock (starting shock) of the acceleration generated in the cage 10 at the start. When the cage 10 approaches the target floor, the rotation speed of the pump 6 is reduced by the deceleration instruction, and the flow volume discharged from the cylinder 1 is reduced.

As a result, the cage 10 is decelerated, and the cage 10 is also stopped by the stop of the pump 6.

After that, the control valve 2 is closed. As with the rise, the position of the cage 10 is monitored by the cage position detection device 13. In order to alleviate the acceleration shock at the start, the pump 6 may be rotated forward at a low speed to balance the fluid pressure between the pump 6 and the control valve 2 to the cylinder pressure, and then open the control valve. . Acceleration, running, etc. after that are performed by control of a pump speed.

When the elevator stops at the target level, the load fluctuates when the passengers are raised and lowered, and the rigidity of the system is lowered, causing the cage 10 to sink or float. This is felt by the passenger as a change in acceleration and at the same time becomes a step between the bottom of the cage and the bottom of the floor. This is not good because it lowers the riding comfort and also lowers the safety.

2A and 2B illustrate this, and show the load change and the displacement of the cage 10. 2A shows the case where the load is increased, the pressure of the fluid pressure cylinder 1 increases, the fluid is compressed, and the extension of the rope and the spring (not shown) is applied, so that the cage 10 sinks. 2b is a case where the load decreases inversely, and the cage 10 rises due to the expansion of the fluid and the compression of the rope and the spring. The settlement and flotation of the cage is proportional to the change in load. At this time, the cage 10 responds with an intrinsic value of 1 to 3 Hz of the system, which is very close to the frequency at which the elevator is to be controlled. Therefore, the settlement of the cage and the correction of the floating amount are difficult with the elevator control method shown in FIG.

FIG. 3 corresponds to a device other than the cylinder 1, the plunger 1a, the pulley 1b, the rope 1c and the cage 10 shown in FIG. 1 to solve this problem. The embodiment of the present invention is shown separately from the main fluid pressure unit 60. The same symbols as in FIG. 1 indicate the same parts or parts with the same functions. The position correction device 3 is a pump 31a, a motor 31b, a filter 31c, a tank 31d, a relief valve 34, a check valve 33, an accumulator 35, and a pressure switch 36. And a control valve 30a for supplying a pressure fluid to the cylinder 1, and a control valve 30b for discharging the pressure fluid from the cylinder 1, and are arranged in parallel with the main fluid pressure unit 60. .

At this time, the accumulator 35 acts as an auxiliary fluid pressure source to the pump 31a, accumulates the high pressure fluid from the pump 31a, and instantaneously supplies a large flow rate. Therefore, a large flow rate can be supplied to the cylinder 1 with a small power supply. The control device 37 always accumulates a pressure fluid of a predetermined pressure or more in the accumulator 35 with a signal from the pressure switch 36, detects the position X and the acceleration α of the cage 10, and sets the amount of settlement of the cage 10. Alternatively, in proportion to the floatation amount, the pressure fluid is supplied to the cylinder 1 by the control valve 30a or the pressure fluid is discharged from the cylinder 1 by the control valve 30b, thereby positioning the position of the cage 10 in each floor. Keep it constant at all times.

Instead of the acceleration α detected from the cage, a physical quantity such as the pressure of the cylinder or the load applied to the cage may be used.

4A and 4B show the state when the servo system is configured by returning the displacement of the cage, and the position of the cage is corrected. 4A and 4B show the operation and cage positions of the control valves 30a and 30b when the passengers board and get off the cage 10, respectively. The broken line shows the case where there is no correction, and the solid line and the two-dot chain line show the case where it corrects. The cage 10 sinks or floats as indicated by the broken line at the time of getting on or off the passenger, and the variation of the cage 10 at this time occurs in a very short time and coincides with the intrinsic value of 1 to 3 Hz. This makes normal feedback control difficult. That is, since the intrinsic value is low, it is difficult to attain both high response control and stable control by returning only the displacement of the cage 10.

In order to realize high response, increasing loop gain is unstable, and oscillation occurs like a two-dot chain line, and stable control results in small loop gain, resulting in lack of responsiveness. There is a characteristic to correct. The improvement of the stability and the increase of the loop gain which are usually performed in such a control system improve the problem slightly, and the settlement of the cage is not enough to compensate for the settlement or the injury, and the cage displacement is large.

5 shows a control circuit of a position correction device according to an embodiment of the present invention, and a comparator 37a for a fluid pressure gauge including a control valve 30a, 30b, a cylinder 1, and a cage 10. And a switch 37c driven by the amplifier 37b and the control device 12. The switch 37c is closed by the " elevator stop signal " output from the control device 12 and opened by the " elevator start signal " so that the cage 10 is stopped with respect to the position correction device 3 only. Operate. In this embodiment, the closed loop for returning the cage displacement is configured and the acceleration is also returned. This ensures both responsiveness and stability.

Instead of the acceleration, a signal of the load or the cylinder pressure applied to the cage may be a valuable signal through the high pass filter 37d.

6a and 6b show the operation and effect of the present embodiment, comparing cage displacement, cage acceleration, load, and cylinder pressure without correction (Fig. 6a) and with correction (Fig. 6b). Indicates. The load changes in a very short time, and the cage displaces later than the occurrence of the load fluctuation due to the inertia of the cage or the like. The cylinder pressure changes similarly to the displacement, but the acceleration becomes a large value at the start and end of the displacement. The load or cylinder pressure is displayed as a broken line through the high pass filter. It is a waveform like acceleration. Therefore, the control signal output from the comparator 37a at the beginning of correcting the position of the cage according to the return of the acceleration becomes a control signal larger than the actual displacement of the cage, and the loop gain of the control system is the same as before and does not impair stability. In addition, the feedback control of the acceleration is faster than the cage displacement. In other respects, while maintaining the loop gain of an appropriate control system, a correction larger than the return transient is predicted and performed, and the response is improved to reduce the maximum displacement.

The same effect can be applied to the case of returning a signal through a high-pass filter of load or cylinder pressure instead of acceleration. Therefore, when proper control is realized by the position correction device, as shown by the solid line in FIG. 6B, the cage which starts to settle or float is immediately returned to the stop position on the target floor.

That is, when the cage is settled, the control valve 30a instantly replenishes the cylinder 1 with the high pressure fluid, and when the passenger gets off and the cage 10 rises, the cylinder with the control valve 30b similarly. It discharges high pressure fluid of and returns to stop position quickly.

It is important that the control valves 30a and 30b can control a sufficient flow rate necessary for correction, and that it is a high response, and the control device 37 may impart the function to the control device 12.

7 shows another embodiment, in which the same symbols as in FIGS. 1 and 3 indicate the same parts or parts with the same functions. The difference from FIG. 3 is that the position correction device is a pressure-increasing type position correction device 3A that accumulates high pressure fluid in the accumulator 35 by the operation of the main unit as indicated by 3A. That is, the pressure intensifier 32 boosts the outlet pressure of the pump 6 to a set magnification and supplies it to the accumulator 35.

When the pump 6 is at rest, the piston of the booster 32 is returned to its original position by the spring 32a via the check valve 32b to supply the fluid to the outlet of the booster. Therefore, the high pressure fluid is automatically supplied to the accumulator 35 by the operation of the pump 6. When the elevator stops and operation of the position correction device 3A is required, the accumulator 35 is always in the standby state.

If the pressure of the accumulator 35 maintains a prescribed value, the pressure intensifier 32 does not operate. Therefore, even if there is no pressure switch or a relief valve, the accumulator pressure does not become beyond a prescribed value, and stability is maintained.

(2), (4), (6), (7), (9) and (11) in FIG. 7 correspond to the main fluid pressure unit 60 shown in FIG. As described above, in the present embodiment, since the pressure is increased by the pressure intensifier 32 automatically by the operation of the pump 6 and accumulates in the accumulator 35, a pressure switch or the like is unnecessary.

8A, 8B, and 8C show the arrangement of the main fluid pressure unit 60, the fluid pressure cylinder 1, and the cage 10, and the main fluid pressure unit 60 is placed in the machine room 70, The fluid pressure cylinder 1 is disposed in the hoistway 71.

FIG. 8A shows a case where the position correction device 3 is disposed in the machine room in parallel with the main fluid pressure unit 60, joined to the main flow path 15 by the flow path 15a, and joined with the cylinder 1 in the hoistway.

However, since the oil supply passage 15 which normally couples the unit 60 and the cylinder 1 is long, a delay in pressure transfer occurs and the responsiveness in control decreases.

8B divides the position correction device 3 into a pump, a motor, a booster, a pressure switch, a filter, a relief valve, a fluid pressure source part 3B of a check valve, an accumulator, and a control part 3C of a control valve, The base part 3B is arranged in the machine room 70, the control part 3C is provided in the hoistway 71, the both are couple | bonded with the flow path 15b, and the control part 3C is connected to the oil path 15 by the flow path 15a. To join. By dividing the position correction device 3 in this way, it is necessary to arrange the flow path 15b between the machine room 70 and the hoistway 71, but the flow path length between the controller 3C and the cylinder 1 is increased. It is shortened, the response is improved, and the positional correction performance is drastically improved. FIG. 8C is an embodiment in which the position correction device 3 is installed in the hoistway 71 and coupled to the oil passage 15 by the flow path 15a. As in FIG. 8B, responsiveness and position correction performance can be improved.

Another embodiment is shown in FIG. The same symbol as in FIG. 3 indicates the same component or the same functional component. This embodiment is basically the same as the embodiment of FIG. 3, and the configuration, operation, and effect as the position correction device are the same as the embodiment of FIG. The difference is that the filter 62 and the flow path 62a for recovering the fluid leaked from the packing of the cylinder 1, the level gauge 63, and the switching valve 61 and the flow path 64 on the discharge side of the pump 31a. ) And the discharge fluid is switched to either the accumulator 35 or the main fluid pressure unit 60. That is, normally, it functions as the position correcting apparatus 3 shown in FIG. 9 similarly to the embodiment of FIG. When the liquid level meter 63 detects that the liquid level of the tank 31d has risen by accumulating the leakage fluid from the packing of the cylinder 1, the switching valve 61 is switched to switch the main fluid pressure unit 60 via the flow path 64. To the fluid. Due to this, the conventionally used device is not a high-precision control valve such as a servo valve for low cost, but a low-cost control valve such as a proportional solenoid valve, while a low-precision control valve increases the nonuniformity of the overlap amount of each control valve. .

Minimum (1) of nonuniformity in FIG. 11a (X ₀ + ), And max (2) (X ₀ + ), And in this case i ₀ + in accordance with (1) where the nonuniformity is small Shall be. By doing this, in (2) where the nonuniformity is large The region of becomes an insensitive region, but the dead zone can be made sufficiently small as shown in Fig. 11B. The reason for this is as shown in Fig. 12A, in accordance with the large nonuniformity (2). In this case, as shown in FIG. 12B, the overlap characteristic between the control command e and the flow rate Q becomes linear, and in the case of (1) where the nonuniformity is small, Q = ± Elevator system with piston control system- Of + This is because it becomes unstable between them.

13A and 13B show a control method of making the dead band even smaller than those shown in FIGS. 11A and 11B. The relationship between the command e and the control residual i is assumed to be a broken line as indicated by broken lines in Fig. 13A (OFG). In other words, The gradient is large in E and the smaller in others. In this way, if the nonuniformity is large (2) Corresponding to The relationship between the command e and the flow rate Q can be reduced, as indicated by ODE in FIG. 13B. In addition, in (1) where the nonuniformity is small Corresponding to Is 0 and The relationship between the command e and the flow rate Q is also shown in FIG. 13b. No need for a leaking fluid recovery device, which makes it possible to make it smaller, and the tank liquid level of the position correction device is not abnormally lowered. The filter 62 is used to remove foreign matter contained in the leaking fluid.

Since the position correction device 3 requires a large flow rate at the moment of operation, the accumulator 35 is used as an auxiliary fluid pressure source to store fluid pressure energy. At this time, if there is a leak from the control valves 30a and 30b, the energy accumulated so far is wasted, and the accumulated pressure is lowered, so that energy may be insufficient when necessary. For this reason, in the present embodiment, the overlap valve is adopted, and the overlap is taken large to reduce the leakage. In Fig. 9, reference numeral 103 denotes a pressure gauge. In general, when the overlap between the control valves 30a and 30b is large, it becomes nonlinear and the control becomes difficult. However, in the control method of this embodiment shown in FIG. 10A, this can be linearized. In FIG. 10A, the line 102 represents a linear characteristic curve without overlap, and FIG. 10A illustrates a control method of an overlap valve with overlap in the linear characteristic. The overlap of the control valve is X ₀ , the valve displacement X and the flow rate Q are Q = β (X ± Xo), and the control current i and the valve displacement X are proportional (X ∝ i). If the gain of the amplifier 37b shown in FIG. 5 is linear, the command e and the control current i become i (x X) = αe, and only when e ≧ e ₀ , the control valve can control the flow rate Q. Therefore, in this embodiment, the gain of the amplifier is made nonlinear such that the relationship between e and i is _equal to i =? In this way, the control command e and the flow rate Q become proportional as shown in FIG. 10B, and control becomes easy since it becomes control of a normal linear system.

And, in addition, ₀ e2e low flow rate gain. This is convenient when controlling with a control valve and can constitute a control system having good stability and responsiveness.

15A and 15B show a case where there is a nonuniformity in the dead band of the control valve as described above, and in (1) and (2) the lower limit of the nonuniformity ( ) And cap ( ). As described above, the signal is ( ), The control signal e and the flow rate Q are as shown in Fig. 15b, and even when the nonuniformity is large, the deadband - Decreases. Therefore, when the dead zone of the control valve is small, the dead zone at this time (shown in Fig. 15B) can be ignored practically.

16A, 16B, and 16C illustrate a method of correcting the position of the cage 10 using the main fluid pressure unit 60 as in the above-described embodiment. When the cage 10 reaches the target floor and the driving operation of the hydraulic elevator is finished, a command to open the door is issued. In this embodiment, preparation for the position correction operation is started by the door opening prevention instruction. That is, the door opening prevention command starts the motor 7 and the pump 6 in the upward direction, and increases the pressure of the flow path 101 to a value slightly lower than the cylinder pressure. This operation is carried out until the door is opened, the door is opened and the passengers are lifted and the bottom of the cage is settled like the dotted line in FIG. Control is performed as in the solid line of FIG. Or FIG. 16B.

That is, when the bottom of the cage subsides, the speed of the motor 7 is increased by the feedback signal such as the displacement and acceleration of the cage 10, and the high pressure fluid is supplied to the cylinder 1 through the control valve 2. The cage 10 is raised. At this time, the control method is the same as described above, and the control valve 30 can control the B-C close to the proportional straight line 3 at the same time. That is, the dead zone can be made small within the range of nonuniformity, and the command e and the flow rate Q can be approximated to linear.

Figure 14a shows one embodiment of another control method for a control valve having a dead band made of the present invention.

FIG. 14A shows the relationship between the command e and the control residual i and the valve displacement X and the flow rate Q, where e and i (X) are proportional (i = αe) and X (Xi) and Q are deadbands. X ₀ (Xi ₀ ) (Q = β (X ± X ₀ )). The command signal e ₀ corresponds to this dead band X ₀ (#i ₀ ). In the present invention, the control valves 30a and 30b are controlled by superimposing a dither signal having an amplitude e ₀ and a frequency ω on the control command e. That is, for the control command e ₁ = e + e ₀ sinωt, the current becomes i ₁ = i + i ₀ sin ωt = αe ₁ = α (e + e ₀ sin ωt). Therefore, the control valve displacement is X ₁ = X + X ₀ sin ω t (∝ i ₀ ).

e1 is represented by (A), (B) and (C) in the drawing, and i ₁ and X ₁ are represented by (A '), (B') and (C '). To vibrate. Here, (A), (B) and (C) represent the case of e = 0, e = 0, e ₀ , 2e ₀ ,. When e = 0, the displacement X ₁ becomes (A '), and the flow rate Q is zero. At e = 2e ₀ , X ₁ ≥ X ₀ , and as indicated by (C '), X ₁ is always outside the dead zone, its average value is X ₁ , and the average value of the flow rate is Q ₁ . When the control command is in the range of 0e2e ₀ , the control valve displacement continuously changes in the range of 0XX1. Therefore, the flow rate also changes continuously in the range of 0QQ ₁ , and the relationship between e and Q is as if there is no dead band as shown in Fig. 14B.

Just changed from the motor (7). In the case where the cage 10 is injured, inversely to the case of FIGS. 16A and 16B, the feedback signal is detected to exceed a certain value, the lowering control valve 2 is opened, and the motor 7 is proportional to the feedback signal. The pump 6 is driven in the downward direction to discharge the pressure fluid of the cylinder 1. In this case, since the inertia of the motor and the pump is large, a delay occurs in the operation of the position correction, and the amount of displacement of the cage is slightly increased, but it is not necessary to prepare the position correction device as a separate unit, and it can be realized at low cost. FIG. 16C illustrates the state after the passengers are lifted and lifted, and the case where the door is closed and the standby state is indicated by a solid line. However, in an elevator, when a passenger lifts and ends, the door is normally closed, and the lifter immediately starts to move up or down.

In such a case, once the pump is stopped and then restarted, the pressure in the flow path 15a drops to atmospheric pressure and the pressure difference between the outlet and the inlet of the pump increases.

In such a case, it is not preferable that the starting delay increases in the rising operation and the starting shock increases in the falling operation. In the present embodiment, when the elevator continues to operate even after the position correction operation is completed, the motor is continuously operated so that the pressure in the flow path 15a is kept slightly lower than the load pressure. Then, in accordance with the start command, the rotational speed of the motor is controlled in the same manner as the one-dot chain line (rising) or the two-dot chain line (falling). In this way, the above-described start delay and start shock can be reduced, so that a fluid pressure elevator with good riding comfort can be realized.

According to the present invention, not only the cage displacement as the feedback signal, but also the load signal or the pressure signal of the cylinder acting on the cage via the acceleration or bypass filter is fed back. have. The deadband overlap valve eliminates normal fluid leakage, saves energy, and sets nonlinear gain in the amplifier, or superimposes the deserial signal corresponding to the deadband in order to control it without deadband. Like valve, controllability can be improved, so good position compensation control is possible. In addition, when the main fluid pressure unit is controlled as described above, the power supply for position correction can be made unnecessary, and the position correction control can be performed at low cost.

Claims (18)

A fluid pressure elevator comprising a cage driven by a cylinder, and a control valve for raising and lowering the cage by supplying and discharging pressure fluid to and from the cylinder, the means for detecting displacement of the cage and acceleration of the cage. Or based on an output signal from means for detecting all physical quantities corresponding to this acceleration, means for detecting displacement of the cage, and means for detecting the acceleration of the cage or the physical quantity corresponding to this acceleration. And a position correction device for returning the cylinder. The fluid pressure elevator according to claim 1, wherein the means for detecting the physical quantity comprises means for checking the pressure of the cylinder. The fluid pressure elevator according to claim 1, wherein the means for detecting the physical quantity comprises means for detecting a load applied to the cage. The fluid pressure elevator of claim 1, wherein the position correction device has an accumulator for accumulating pressure fluid supplied to the cylinder. A fluid pressure elevator comprising a cage driven by a cylinder, and a control valve for raising and lowering the cage by supplying and discharging pressure fluid to and from the cylinder, the means for detecting displacement of the cage and acceleration of the cage. Or the pressure fluid based on an output signal from means for detecting a physical quantity corresponding to this acceleration, means for detecting displacement of the cage, and means for detecting the acceleration of the cage or the physical quantity corresponding to this acceleration. And a position correction device having an overlap valve for returning the cylinder. 6. The fluid pressure elevator according to claim 5, wherein the means for detecting the physical quantity comprises means for detecting the pressure of the cylinder. 6. The fluid pressure elevator according to claim 5, wherein the means for detecting the physical quantity comprises means for detecting a load applied to the cage. 6. The fluid pressure elevator according to claim 5, wherein the position correction device has an accumulator for accumulating pressure fluid supplied to the cylinder. 6. The overlap valve according to claim 5, wherein the overlap valve corresponds to means for detecting the displacement of the cage, and means for detecting the displacement of the cage through a control device that outputs a DC component signal to the overlap valve based on the output signal. And a means for detecting a physical quantity. The method of claim 5, wherein the overlap valve is a means for detecting the displacement of the cage through a control device for outputting a signal superimposed by the output signal and the dither signal to the overlap valve, the acceleration of the cage Or means for detecting a physical quantity corresponding to this acceleration. The cage driven by the cylinder, the first tank for storing the fluid, the first pump for discharging the fluid in the tank by the first control signal, and the cage by supplying and discharging the pressure fluid from the pump to the cylinder And a first control valve for lowering, the fluid pressure elevator comprising: a second tank for storing fluid and receiving fluid leaked from the cylinder; a second pump for discharging fluid in the second tank; A switching valve for supplying the discharged fluid from the second pump to the first tank when the fluid in the second tank reaches the selected predetermined level; and the fluid in the second tank does not reach the selected predetermined level. And a second control valve for discharging the fluid supplied from the second pump to the cylinder in response to the second control signal. Beiter. 12. The method of claim 11, wherein the first pump comprises a rotary encoder for detecting cage speed and cage position, a pressure sensor for detecting pressure in the cylinder, and a pressure sensor for detecting fluid pressure discharged from the first pump. And a control device for driving said first pump based on an output signal. 12. The fluid control system of claim 11, wherein the second control valve returns the fluid to the cylinder based on an output signal of a means for detecting displacement of the cage and a means for detecting an acceleration of the cage or a physical quantity corresponding to the acceleration. A fluid pressure elevator comprising an overlap valve to. The fluid pressure elevator according to claim 13, wherein the means for detecting the physical quantity comprises means for detecting the pressure of the cylinder. The fluid pressure elevator according to claim 13, wherein the means for detecting the physical quantity comprises means for detecting a load applied to the cage. The fluid pressure elevator of claim 13, wherein the position correction device has an accumulator for accumulating pressure fluid supplied to the cylinder. The method of claim 13. The overlap valve includes means for detecting a displacement of the cage and means for detecting an acceleration of the cage or a physical quantity corresponding to the acceleration through a control device that outputs a DC component signal to the overlap valve based on the output signal. A hydraulic pressure elevator, characterized in that connected to The method of claim 13, wherein the overlap valve is a means for detecting the displacement of the cage, through the control device for outputting a signal superimposed by the output signal and the dither signal to the overlap valve, the acceleration of the cage or the acceleration And means for detecting a physical quantity corresponding to the fluid pressure elevator.