JPH0227263B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a control device for a hydraulic elevator,
In particular, the present invention relates to a control device for a hydraulic elevator that controls a flow rate in accordance with a pattern signal to cause a car to travel.

[Prior art] In a system in which a hydraulic elevator is controlled by changing the pump discharge amount depending on the pattern and the car is run (e.g., electric motor control method, variable discharge amount pump control method, etc.), shock and vibration at startup are prevented. Therefore, the bias pattern is divided into a bias pattern that supplies a low flow rate to compensate for leakage at startup, and a running pattern, and both are switched or superimposed with an adder to obtain a pattern signal, and this pattern signal is used to adjust the pump discharge flow rate. A method for controlling this has been proposed.

However, when starting up a bias pattern generation circuit that gives a low flow rate in advance to compensate for this leakage, depending on the startup degree, load, and oil temperature, large shocks and vibrations may occur, or conversely, shocks may occur. If you start up very slowly to avoid this problem, the start-up delay will become very large, making it difficult to adjust.

[Summary of the invention]

This invention was made to eliminate such drawbacks, and the control piston is installed in the flow valve provided between the hydraulic cylinder that drives the car and the hydraulic pump that delivers or discharges pressure oil to the hydraulic cylinder. A dead zone that does not allow pressure oil to flow even when the piston moves, and an opening detection device for the control piston are provided, and the signal from the opening detection device is used to make the slope of the rise of the bias pattern gentle through the inflection point. The present invention proposes a control device for a hydraulic elevator that is capable of suppressing sudden pressure changes and subsequently generating a running pattern to suppress the starting shock.

[Embodiments of the invention]

Examples of this invention are shown in FIGS. 1 to 11.
In the figure, 1 is a hoistway, 2 is a cylinder buried in a pit of this hoistway 1, 3 is a pressure oil filled with this cylinder, 4 is a plunger supported by this pressure oil, and 5 is a plunger of this plunger 4. The car is placed on the top, 5a is the car floor, 7 is the landing floor, 8 is a cam attached to the car 5, 9 is a deceleration command switch for decelerating the moving car 5, and 10 is a stop for the car 5. A stop command switch 11 is a flow valve, 11a is a pipe connected between the cylinder 2 and the flow valve 11 and transmits and receives pressure oil, 12 is reversible and is connected to the flow valve 11 via the pipe 12a. 12b is a hydraulic pump that sends and receives pressure oil, and 12b is a flow valve 11 and an oil tank 1.
5, 13 is a three-phase induction motor that drives this hydraulic pump 12, 14 is a speed generator that detects the rotation speed of this three-phase induction motor 13, and 15 is connected to hydraulic pump 12 via pipe 15a. An oil tank that sends and receives pressure oil. RST is a three-phase AC power supply, 21 is a rectifier circuit that converts three-phase AC into DC, 22 is a capacitor that smoothes this DC, and 23 is an inverter that controls the pulse width of DC to generate three-phase AC with variable voltage and variable frequency. , 24 is a regenerative inverter that returns DC to the three-phase AC power supply RST, 25 is a speed generator 1
4 speed signal 14a, deceleration command signal 9a, the operation command signal generated by the normally open contact 30Tc that is closed from the time the start command is issued until the stop command is issued, and the normally closed contact 30e of the operation contactor. This is a speed control device into which a signal from the inverter and a signal 35Aa are respectively input, and outputs a signal 25a to control the inverter 23. 30a to 30c are normally open contacts of the operating contactor 30 shown in FIG. 3, which connect the three-phase induction motor 13 to the inverter 23.

FIG. 2 shows details of the speed control device 25 shown in FIG. 1, 36 is a comparator, 41U is an upward running pattern generation circuit, and as shown in FIG. When issued, the speed decreases to a constant low speed, and then becomes zero when a stop command is issued. 41D is a descending traveling pattern generating circuit which outputs the same traveling pattern signal in the opposite direction to that of the ascending traveling pattern generating circuit 41U. 41Ua is an upper contact that remains closed during the upward operation; 41Da and 41Db are lower contacts that remain closed during the downward operation; 37 is a 45a
This is a known sample-and-hold circuit that holds the signal according to a command. 45 is a bias pattern generation circuit which issues a command to rotate at a low speed when the normally open contact 30Tc is closed, and becomes zero when the command signal 30e is closed. 46 is an adder that adds the output of the running pattern generation circuit 41U or 41D and the output of the sample hold circuit 37 and outputs a pattern signal; 47 is a conversion circuit that converts the speed signal 14a to the same voltage level as the pattern signal; 48 is a subtracter that takes the difference between the output of the adder 46 and the output of the conversion circuit 47; 49 is this subtracter 48;
a transmission circuit for transmitting the output of 50 at a predetermined amplification degree;
51 is an adder that adds the output of the transmission circuit 49 and the output of the conversion circuit 47 to output the frequency command signal ω ₀ , and 51 is the frequency command signal ω ₀ of the adder 50
A function generating circuit 52 outputs a signal 25a so that a sinusoidal three-phase alternating current is output from the inverter 23 based on the frequency command signal ω ₀ and the voltage command signal V. This is a reference sine wave generation circuit.

Figure 3 shows the control circuit connection diagram, (+), (-)
28 is a control power supply, 28 is a start command circuit that is closed by a call signal, a door closed detection signal, etc., 30T is a control power supply (+) at one end via the start command circuit 28, and a control power supply (-) at the other end. The operation command time relay 30Ta connected to the operation command time relay 30T is the normally closed contact of this time relay 30T, and one end is the normally closed contact 1 of the stop command switch 10.
The other end is connected to the control power supply (+) via 0b, and the other end is connected to one end of the time relay 30T. 30Tb is the normally open contact of the timed relay 30T, 30Tc,
30Td is the normally open contact of the time relay 30T,
Reference numeral 30 denotes an operating contactor controlled by a normally open contact 30Tb, which includes normally open contacts 30a and 30 shown in FIGS. 1 to 3.
b, 30c and the normally closed contact 30e are opened and closed. Reference numeral 11b denotes a descending electromagnetic coil within the flow valve 11, which opens the flow valve 11 by being energized during descending. 90a is a signal that excites the lowering electromagnetic coil 11b.

FIG. 4 is a detailed circuit example of the bias pattern generation circuit 45, in which is a low voltage power supply, 91, 92, 93 are resistors, 94 is a transistor, 95 is a capacitor,
45a is an output signal, the normally open contact 30Tc is closed, and the normally closed contact 30e is opened when the signal 36a is "H".
-30Tc-92-95-The voltage gradually rises at GROUND, and when the signal 36a becomes "L", the resistor 91 is inserted and the rise becomes gradual, and it drops to zero by opening the normally open contact 30Tc and closing the normally closed contact 30e. .

FIG. 5 is a detailed circuit of the running pattern generation circuit 41U, where power supplies 97, 98, and 99 are resistors, and 100
is a capacitor, 101 is a Zener diode, 9
6, 102, 103 are transistors, 104 is
It is a NOT gate, and the transistor 96 is turned on by the "H" signal of the signal 36b, and the voltage rises, gradually decreases by the "H" signal of the signal 9a, and is held at a potential clipped by the Zener diode 101.
NOT gate 104 is opened by opening the normally open contact 30Tc.
The output of becomes “H” and transistor 103 turns on.
to lower the output voltage to zero.

FIG. 6 is a detailed diagram of the comparator 36, 35
Aa is a valve movement detection signal, 36a and 36b are output signals, 70 and 71 are operational amplifiers, and 72 is NOT
Gate, 76 is a diode, 77 is a transistor, 80 to 88 are resistors, 90 is an electromagnetic relay, V ₁ ,
V ₂ is a set voltage, and when the movement amount detection signal 35Aa becomes larger than the set voltage V ₁ , the operational amplifier 7
0 outputs an "H" signal, which drives transistor 77 and energizes electromagnetic relay 90. When the movement amount detection signal 35Aa further increases, the arithmetic amplifier 71 outputs "H" and the signal 36
b outputs an output “H”.

7a, b, and c are explanatory diagrams of the flow valve 11, and 6
0A, 60B are flow valve bodies, 60C, 60D
61A and 61B are check valves, 61A and 61B are pistons, and 35A is a flow rate valve movement detection device, which is composed of, for example, a Hall element, etc. When the piston 61A moves slightly, the output 35Aa is a voltage signal larger than the above set voltage V ₁ . becomes. 62 is a spring; 63 and 64 are flow rate restricting valves; 11a, 12a, 12b, and 65 are pipes; 11
b is a lowering electromagnetic coil, and its excitation causes the back oil in the piston 61B to return to the oil tank 15 through the pipes 65 and 12b, so the piston 61B rises upward and is Oil flows into the oil tank 15 through the pipe 12a.

Next, the effect will be explained.

Now, when there is a call in the upward direction, the start command circuit 28 becomes conductive, the time relay 30T is energized at time _t0 in FIG. 10, and the normally open contact 30Tc in FIG. 4 is closed.
As a result, the bias pattern 4 shown in FIG.
5a starts to rise, the time relay 30 is energized and the normally open contacts 30a to 30c start the motor 1.
Since power is supplied to pump 3 and it starts to rotate, hydraulic pump 12
discharges oil from the oil tank 15.

However, there is a leak in the hydraulic pump 12 and the pressure in the pipe line 12a does not rise, so the piston 61A
does not move immediately (see Figure 8a). As the bias pattern 45a gradually rises, the discharge amount gradually becomes larger than the leakage amount of the hydraulic pump 12,
The pressure in the pipe line 12a gradually rises.

Here, the spring force when fully closed is converted into pressure.
P _B , pressure in cylinder 2 on car 5 side is P _J , pump 1
If the pressure on the second side is P _P , then P _P = P _B + P _J will be exceeded and the piston 61A will begin to move slightly, as shown in Figure 9.
When the flow valve movement amount detecting device 35A starts to generate voltage when it moves by X ₀ , and when the movement reaches a minute amount by X ₁ ,
The output 35Aa of the detection device 35A becomes V ₁₁ ,
Since the set voltage exceeds V ₁ , the operational amplifier 7 in Fig. 6 is used.
0 generates an "H" output, and 36a becomes an "L" output, which causes the resistor 91 in FIG. 4 to be inserted.
The bias pattern 45a has a longer time constant and a gentler slope. At this time, the piston 61A is moving;
There is a dead zone like this, and the flow rate does not flow. This pattern causes the bias to rise and push up the piston 61A to the point where the flow starts flowing;
In other words, when it reaches X ₂ in Figure 9, the output 35Aa is
V ₁₂ , which exceeds the set voltage V ₂ , the operational amplifier 71 outputs "H", thereby increasing the signal 36.
b becomes "H", and the sample and hold circuit 37 holds the bias pattern signal 45a and outputs and holds it as 37a. At the same time, the transistor 96 is turned on at 36b "H" according to FIG. 5, and the running pattern signal gradually rises with the time constant of the resistor 97 and capacitor 100 (see FIG. 10g), and the two are added by the adder 48. The electric motor 19 is controlled according to the signal shown in FIG. 10h, and the flow rate is further increased according to this pattern, so the piston 61A moves further to provide the flow rate and the car 5 runs (see FIG. 10i).

At this time, the electromagnetic relay 90 shown in FIG. 3 is energized, but since the contact 41Db is open, the lowering electromagnetic coil 11b is not energized and the lowering circuit does not work.

When the running pattern voltage is saturated, it becomes a constant voltage, and the car 5 becomes at a constant speed. When the car 5 further rises and reaches the deceleration point, the cam 8 engages the switch 9, and the switch 9a outputs an "H" signal. At time _t3 , the transistor 102 in FIG. 5 turns on and the Zener diode 101 The running pattern decreases to a value limited by , and becomes constant at the limit voltage of the Zener diode 101 . After traveling further and reaching the stop command point, the normally closed contact 10b opens at time _t5 and the time relay 30T is demagnetized, so the output of the NOT gate 104 in FIG. 5 becomes "H" due to the opening of the normally open contact 30Tc.
Then, the transistor 103 turns on, and the resistor 97,
99, the voltage drops to zero (time t ₆ ). At this time, the pattern voltage of the electric motor 13 is only the voltage held by 37a, and this pattern voltage is the motor rotation speed for correcting the leakage, and the car 5 remains stopped without running.

Thereafter, when the normally open contact 30Tb opens after a certain period of time, the time relay 30 is demagnetized and the power supply to the motor 13 is cut off, so the pressure in the conduit 12a decreases, the piston 61A closes, and the car 5 stops. keep. When the contact 30e is closed, the bias pattern signal 45a gradually decreases as the voltage of the capacitor 95 is discharged through the resistor 93, and when the piston 61A is opened, the output 35Aa becomes the set voltage V ₁
Since the voltage becomes lower, the output signals of the operational amplifiers 70 and 71 become "L", and the signal 36a becomes "H", the hold of the sample hold circuit 37 is released and the sample mode is entered. As described above, in the rising operation, when oil is discharged from the pump 12, the pressure in the pipe line 12a gradually rises,
When P _P becomes a pressure exceeding P _J +P _B (P _P > P _J +P _B ), the check valve 60C is opened and the piston 61A moves (upper part in the figure), which causes the flow rate valve movement detection device 3 to move.
Since 5A is output, the bias pattern 45a is maintained in a state that is approximately balanced with the amount of leakage.
However, in this state, there is almost no flow. Then, when a running pattern is established, the flow rate increases further and the pressure in the pipe line 12a increases, so that the fluid flows as shown by the solid line in FIG. 7b.

Next, we will discuss the case where there is a downward call. Detection for leakage correction when descending is performed in the same way as when ascending, and bias pattern 45a is detected at the same time as when ascending.
begins to rise, the electric motor 13 rotates in the direction of discharging from the hydraulic pump 12, and the bias pattern 45a starts to rise in order to correct the leakage.

When the flow rate is high enough to correct the leakage and the piston 61A begins to open slightly, the output 35Aa becomes a voltage larger than the set voltage _V1 , and the operational amplifier 70 outputs an "H" signal.
becomes an "L" output, and as a result, the bias pattern 45a gradually increases. Also, the transistor 77 is turned on, the electromagnetic relay 90 is energized, and the lowering electromagnetic coil 11b is energized.
The back pressure of the piston 1B escapes to the oil tank 15 through 65-11b-12b, so the piston 61
B goes up, and the flow valve 11 gradually opens.

When it moves _to
The current value of 5a is held and outputted as 37a, and the running pattern is generated at a voltage opposite to that when rising.
The rotation of the electric motor 13 is lowered by the addition of both. By controlling the flow rate from cylinder 2, the pattern of electric motor 13 is controlled from zero to reverse rotation, so electric motor 13 reaches full speed while performing regenerative braking, and car 5 accordingly changes from acceleration to constant speed. becomes.

When 9a becomes an "H" signal at the deceleration point, the running pattern gradually lowers the rotational speed, decelerates the car 5 while performing regenerative braking, and descends at a constant low speed. When the stop command point is reached, the running pattern drops to zero, and the pattern of the electric motor 13 becomes bias pattern 4.
As we head towards 5a, the rotation shifts from zero to normal rotation,
Car 5 becomes even slower.

In response to the stop command, the lowering electromagnetic coil 11b is demagnetized by opening the contact 30Td, the piston 61B is closed, and the car 5 is stopped when it is fully closed. timed relay 3
After 0T degaussing, the car 5 does not move because the leakage is only corrected in the same way as when the car is raised. Thereafter, the bias pattern 45a also becomes zero after a certain period of time, similar to the rise, and the car 5 remains stopped. As described above, in the lowering operation, the operation until oil is discharged from the pump 12 and the bias pattern is maintained in a state balanced with the amount of leakage is the same as in the ascending operation. When descending, the descending excitation coil 11b is excited in this state, so the back pressure on the pistons 61A and 61B becomes almost zero, and therefore the piston 61B is pushed upward, and the flow rate follows the path 11a-61B-60D-12a. So, it flows.

On the other hand, since the back pressure is released from the piston 61A, it no longer receives pressure, but the check valve 60C
Since the flow to is blocked, the flow path becomes like the solid line shown in FIG. 7c.

Regarding the opening and closing of the flow valve 11, this flow valve 11 is operated at a pressure P _P on the pump side rather than a pressure P _J on the jack side.
It opens when the amount exceeds even a little. Then, movement of the valve is detected in this state where it begins to open. Therefore, the operation of the controller depends on this detection signal 35.
It is shown that the operation of Aa holds the bias pattern value for the flow rate corresponding to the leak and generates the running pattern.

As described above, in this embodiment, the flow valve is provided with a dead stroke so that the control piston does not move within a certain stroke even if it moves, and is also provided with a device that detects the opening of the piston, so that the point at which the piston starts to move and the flow rate are The slope is increased until the point where the flow starts is detected and the pressure gets close to the pressure at which the car starts moving, and then the bias pattern is made to have a gentle slope, which reduces the pressure change when the plunger starts moving. In addition to being able to reduce the shock, it is no longer necessary to lengthen the start-up time to prevent shock by switching the start-up of the bias pattern.

Furthermore, since the bias pattern is maintained and added from running to stop, it is possible to correct for leakage, and to prevent speed fluctuations and stoppage caused by differences in load, oil temperature, and pump leakage coefficient, which are noticeable in hydraulic elevators. Floor error can be reduced.

In this embodiment, the running pattern has a creep speed, but it may be a creepless pattern as described above.

Further, the timing of holding the bias pattern and starting the generation of the running pattern may be any time from the time when the flow valve starts operating until the time when the flow starts flowing.

Furthermore, if shocks due to some load fluctuations are allowed, the running pattern may be generated after a certain period of time, such as at the inflection point of the bias pattern.

Further, in the case of detecting the car speed, it is not necessary to maintain the bias pattern, and it is sufficient to switch the bias pattern when the running pattern is generated.

In addition, a proportional solenoid valve that controls the flow rate without changing the discharge amount of the pump, and which can variably control the flow rate, has the same effect when rising.

〔Effect of the invention〕

As explained above, the present invention provides a flow valve with a dead zone in which pressure oil does not flow even if the control piston moves, and an opening detection device for the control piston, and a signal from the opening detection device is used to bias the flow valve. Since the start-up slope of the pattern is made gentler through the inflection point and a running pattern is generated, start-up shocks due to load and oil temperature fluctuations can be reduced.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing an example of a hydraulic elevator control device according to the present invention, Fig. 2 is a detailed diagram of the speed control device of Fig. 1, Fig. 3 is a control circuit connection diagram, and Fig. 4 is a bias pattern. Detailed diagram of generation circuit, 5th
The figure is a detailed diagram of the running pattern generation circuit, Figure 6 is a detailed diagram of the comparator, Figure 7 a is a detailed diagram of the flow valve, Figures 7 b and c are operation diagrams showing the operation of the flow valve, respectively, and Figure 8 9 is a graph showing the relationship between the amount of movement of the control piston and the output voltage of the flow rate valve movement amount detection device, FIG. 10 is a time chart of each part when the car is raised, and FIG. 11 is a diagram of the operation of the control piston. This is a time chart of each part when the car is lowered. 2: cylinder, 5: cage, 11: flow valve, 11
b: Lowering electromagnetic coil, 12: Hydraulic pump, 1
3: Three-phase induction motor, 15: Oil tank, 25: Speed control device, 28: Starting command circuit, 35A: Flow rate valve movement amount detection device, 36: Comparator, 37:
Sample hold circuit, 41U, 41D: Running pattern generation circuit, 45: Bias pattern generation circuit. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1 A hydraulic cylinder that drives the car, a hydraulic pump that sends or discharges pressure oil to this hydraulic cylinder via a flow valve, a bias pattern generation circuit that generates a bias pattern with a low discharge amount in response to a start command, and a drive pattern that generates a low discharge rate. The car is equipped with a running pattern generation circuit that generates a running pattern, and a controller that switches or superimposes both of the above patterns to obtain a pattern signal, and controls the discharge flow rate of the hydraulic pump based on the pattern signal from the controller to run the car. The flow valve is provided with a dead zone that does not allow pressure oil to flow even if the control piston moves, and an opening detection device for the control piston, and a signal from the opening detection device determines whether the bias pattern starts up. A control device for a hydraulic elevator, characterized in that the inclination is made gentle through an inflection point, and the above travel pattern is generated.