JPS5848298Y2 - elevator elevator - Google Patents

Description

[Detailed description of the invention] This invention relates to a braking start position control device for an elevator, and when stopping one hoisting machine with a constant braking torque, the braking start point 0 position is adjusted according to the magnitude of the load. This allows the robot to stop accurately at the landing position.

To explain this with respect to Figure 1 a and b, for example, if the braking start point a at the maximum hoisting load is applied to the braking start point at the maximum hoisting load, the load itself will promote deceleration during hoisting. Because of this property, the deceleration is large and it stops at time t□ (time t2 is required at the maximum hoisting load).
The stopping distance at the maximum hoisting load, that is, the area of triangle abc, and the stopping distance at the maximum hoisting load, that is, the area of triangle a
Difference between the area of bc (area of triangle acd with a dramatic line)
This results in an implantation error.

The present invention improves the above points and adjusts the braking start position by detecting the magnitude of the load. The brake is decelerated at the braking start point a', which is delayed by a time t3 from the braking start point a when the maximum hoisting load is applied, to reduce the difference between the stopping distance at the maximum hoisting load and the maximum hoisting load, and to reduce the landing error. It is intended to reduce

That is, the difference between the area of triangle abd and the area of trapezoid abc'a' becomes the landing error.

Figures 2a, b, and c are diagrams showing an embodiment of the present invention, in which Figure 2a is a load detection device, Figure 2 is a charging voltage storage device,
FIG. 2C shows a braking start position control device.

In Fig. 2a, IM is an induction motor for an elevator category, 1A is a three-phase AC power source U, V, W.
CT is a current transformer inserted into the primary side of the induction motor IM, R1 is a variable resistor inserted into the secondary side of the current transformer, SEI is a rectifier, M
R is a meter relay for voltage detection.

In Figure 2, R1 is a resistor, C1 is a capacitor,
1a is a switch contact for starting charging.

In Fig. 2C, 2a is a switch contact for detecting the braking start command position, R2t, R3t, and R4 are resistors, ■R2 is a variable resistor for reference voltage, A1%/fPI is an operational amplifier, and MLl
is a relay.

The x and x' terminals of the button in Figure 2 are x and C in Figure 2, respectively.
Connected to x' terminal.

=In a state where a constant voltage is applied, the gradual decrease characteristic of the accelerating current of the induction motor f changes depending on the size of the load.

Fig. 1 clfi is a diagram showing the state, where A is a heavy load and the accelerating current decreases gradually, and B is a light load and the accelerating current decreases rapidly.

Therefore, the time required for the housing to reach a certain acceleration current value IC changes depending on the magnitude of the load.

Therefore. When this accelerating current is taken out by a current transformer CT, a resistor v
It is clear that a voltage is generated across R1 and the voltage obtained through the rectifier SE□ varies as shown at A and B in FIG. 1C.

Therefore, by detecting a certain constant voltage Vc, it is possible to detect the acceleration time j'4+j5 depending on the load.

In FIG. 2a, a meter relay MR is used to detect the voltage Vc, and the acceleration time is detected by a contact that operates when the voltage falls below Vc.

As shown in Figure 2, the meter relay MR closes the charging start switch contact 1a at the same time as the start of startup or at a predetermined time after the start of startup, and detects the constant accelerating current. The capacitor CI is charged by the DC power supply E through the resistor R1 when the capacitor is in operation.

When meter relay MR operates, charging start switch contact 1
a is opened and the charged voltage E1 is stored.

This charging voltage shows a proportional relationship to the elevator load, as shown in FIG. 1d, and has an opposite tendency when the elevator goes up and down.

Therefore, the charging voltage E1 corresponding to this load is set at the braking start position, and after reaching the braking start command position, it is discharged at a constant time constant, and the braking start command control device shown in Fig. 2C is used. When the discharge voltage is compared with a predetermined reference voltage, and if the discharge voltage is lower than the reference voltage, braking is actually started by the relay ML1, which operates via the operational amplifier AMPI, and the braking start position is controlled according to the load. I can do it.

FIG. 1e shows the process of charging the voltage between the x and x' terminals, pressing the memory button, and discharging the voltage.

The voltage E1 charged by the load detection device at the time of the maximum hoisting load is stored up to the braking start command position a', and when the braking start position a' is reached, the braking start position switch contact 2a is closed, and the charging voltage E1 is Start discharging.

The actual start of braking is delayed by the time t6 until the discharged voltage reaches the predetermined reference voltage ES.

As the elevator load changes from the maximum hoisting load to the maximum hoisting load, the charging voltage becomes smaller, so the time from the braking start command position to the actual braking start position is greatest at the maximum hoisting load. The length decreases as the maximum hoisting load is reached, so the braking start position can be controlled according to the load. ), the implantation error can be reduced.

Also, the landing error is UP when the elevator goes up and DOW when it goes down.
N shows the opposite tendency.

[Brief explanation of drawings]

1A to 1F are characteristic curve diagrams showing the principle of the present invention, and FIGS. 2A, 2B, and 2C are circuit diagrams showing embodiments of the present invention. The same symbols in the diagram indicate the same parts. CT is a current transformer, V
Rl is a variable resistor, VH2 is a reference voltage variable resistor, S
El is a rectifier, MR is a meter relay for voltage detection, R1-
R4 is a resistor, C1 is a capacitor, 1a is a switch contact for charging start, 2a is a switch contact for detecting the braking start command position,
AMPI is an operational amplifier, MLl is a relay, and Eo is a DC power supply.

Claims (1)

[Scope of utility model registration request] A current transformer that detects the primary current of the induction motor that drives the elevator, a detection device that detects when the output of the current transformer reaches a predetermined constant current value, and a current transformer that detects the primary current of the induction motor that drives the elevator; A memory that starts charging the capacitor from a predetermined time using a DC power source, charges the capacitor until the detection device detects that the output of the current transformer reaches the constant current value, and stores the charged voltage. and a control device that starts discharging the stored voltage from a braking start command position and delays the actual start of braking when the discharged voltage reaches a predetermined constant voltage value. Features: Elevator 0 braking start position control device.