JPS641331Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Description of Technical Field] The present invention relates to an improvement of a control device for a hydraulic elevator, and more particularly to a starting control technique for a three-phase induction motor that drives a hydraulic pump.

[Technical background of the invention and its problems]

Generally, in the control of a hydraulic elevator, the raising operation of a car is performed by sending oil discharged from a hydraulic pump driven by a three-phase induction motor to a hydraulic jack, and using the resulting lifting force of a hydraulic cylinder.

Figure 1 shows a starting circuit for a three-phase induction motor for driving a hydraulic pump, where 1 is a three-phase power supply, and 2 is a circuit disconnector that is turned on during normal operation. Also, circuits such as overload detection are omitted. 3a is a normally open contact of a starting contactor, and 4 is a three-phase induction motor.When the normally open contact 3a of the starting contactor is closed, the three-phase induction motor 4 is started.

Fig. 2 is a conventional startup control circuit diagram, where 5 is a control power supply, 6 is an upward level correction switch when landing on the floor, and 7 is a control power supply.
is an upward level correction relay that compensates for the upward level when the car sinks by a certain amount or more in response to car sinking due to oil contraction caused by oil temperature changes or car sinking caused by changes in load. switch 6
is closed, and the ascending direction level correction relay 7 is energized.

8a is a normally open contact of an upward direction call registration relay (not shown), 9 is an upward operation relay, and 7a is a normally open contact of an upward direction level correction relay 7. Due to these, the upward direction operation relay 9 is energized during upward operation. On the other hand, 10 is an oil temperature detection switch installed in the oil tank, and 11 is an oil temperature control relay.In order to maintain stable performance, the oil temperature is detected when the oil temperature in the oil tank falls below a certain temperature of around 30℃. The switch 10 closes, energizes the oil temperature control relay 11, and starts the three-phase induction motor 4. However, this only allows the oil in the oil tank to be circulated within the hydraulic unit by the hydraulic pump to control the oil temperature. In order to raise the temperature, the hydraulic valve of the hydraulic unit is actuated only by the upward operation relay 9 (not shown) to discharge pressure oil to the hydraulic jack, and even if the oil temperature control relay 11 is energized, the pressure is No oil is discharged and the basket does not move. Further, 7b is a normally closed contact of the level correction relay 7 in the ascending direction, 8b is a normally closed contact of the call registration relay, and 11b is a normally closed contact of the oil temperature control relay 11. Priority is given between the direction level correction operation and the oil temperature control operation, and when a call registration in the ascending direction occurs, the normally closed contact 8b of the call registration relay is opened and the oil temperature control relay 11 is energized. Instead, priority is given to level correction in the ascending direction, and when level correction is completed or there is no level difference, operation is performed based on call registration, and if there is no call registration, priority is given to level correction operation and oil temperature control operation, whichever operates earlier. It's summery. These are intended to improve service for call registration.

9a is a normally open contact of the upward direction operation relay 9, 1
1a is a normally open contact of the oil temperature control relay 11, and 3 is a starting contactor.

In this way, the starting contactor 3 is energized in any of the upward level correction operation, the upward call registration operation, and the oil temperature control operation.

However, if call registration occurs during oil temperature control operation or immediately after level correction operation,
If two operating modes occur or overlap within a short period of time, the starting contactor is energized-released-energized within a short period of time, i.e. the three-phase induction motor 4 is activated within a short period of time. It was rebooted in between. On the other hand, as a general characteristic of the three-phase induction motor 4, when it is restarted within a short period of time, an inrush current that is considerably larger than a normal steady current flows through the three-phase induction motor 4.

The inrush current at this time not only has an adverse effect on the three-phase induction motor 4, but also requires more performance than necessary on the circuit, disconnector 2, and starting contactor 3 that protect the three-phase induction motor 4. This made it difficult to select equipment.

[Purpose of invention]

The present invention has been developed in view of the above points, and is designed to prevent the three-phase induction motor that drives the hydraulic pump from restarting within a short period of time, and to reduce the inrush current of the three-phase induction motor that occurs when restarting within a short period of time. By preventing the occurrence of 3-phase induction motors and constantly starting the 3-phase induction motors, the circuit breaker and starting contactor that protect the 3-phase induction motors can be used without adversely affecting the 3-phase induction motors. To provide a control device for a hydraulic elevator that does not require excessive performance.

[Summary of the idea]

This invention consists of a three-phase induction motor that drives a hydraulic pump, an ascending operation relay that responds to the output of an ascending call registration relay and an ascending level correction relay, and the output of a temperature sensor installed in the oil tank. control of a hydraulic elevator having a starting control circuit comprising an oil temperature control relay that responds to the above, and a starting contactor that connects the three-phase induction motor to a power source in response to the outputs of the upward direction operation relay and the oil temperature control relay. In the apparatus, an off-delay timer excited via a normally open contact of the oil temperature control relay, a normally closed contact of the off-delay timer inserted in series with an excitation circuit of the upward operation relay, and a normally closed contact of the starting contactor. An on-delay timer responds to the normally closed contact, and excitation is started in the excitation circuit of the starting contactor via the normally open contact of the on-delay timer.

and a normally open contact of the starting auxiliary relay, i.e.
Using the normally closed contact of the starting contactor, connect the normally open contact of the starting timer in series with the output of the oil temperature control relay connected in parallel with the on-delay starting timer connected to this and the output of the upward direction operation relay. and a normally open contact of the starting auxiliary relay and a normally open contact of the starting auxiliary relay connected to and energized by these are connected in parallel to a limited time normally open contact of the starting timer so that the starting auxiliary relay is self-maintained, and The starting contactor is energized by the other normally open contact of the starting auxiliary relay, and the auxiliary oil temperature control relay is energized by the normally open contact of the oil temperature control relay, and the excitation coil of the auxiliary oil temperature control relay. An off-delay circuit consisting of a resistor and a capacitor connected in parallel is added to provide a certain period of stop time for the start-stop-start operation mode of the three-phase induction motor, and the inrush of the three-phase induction motor is Prevents generation of current.

[Example of the present invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a starting control circuit diagram of the present invention, in which 11C is a normally open contact of the oil temperature control relay 11, 12 is an auxiliary oil temperature control relay, and 12a is a normally closed contact of the oil temperature control relay 12. Also, 13 is a resistor, and 14 is a capacitor, which constitutes an off-delay circuit for the oil temperature control auxiliary relay 12. First, the oil temperature control relay 11 is energized to circulate the oil in the oil tank, and then When upward direction call registration occurs during operation, the upward direction call registration relay operates and its normally open contact 8a closes.
Further, the normally closed contact 8b opens to release the oil temperature control relay 11, but the oil temperature control auxiliary relay 12 is off-delayed, and its normally closed contact 12a is added to the excitation circuit of the upward operation relay 9. Therefore, the oil temperature control relay 11 is released, but it is possible to prevent the ascending direction operation relay 9 from being energized immediately due to call registration.

Next, 3b is the normally closed contact of the starting contactor 3, 15
is the on-delay start timer, 9b is the normally open contact of the upward operation relay, 11d is the normally open contact of the oil temperature control relay 11, 15a is the normally open contact of the start timer 15, and 16 is the start auxiliary relay 16a, 16b. It is a normally open contact, and first the starting timer 15 is excited and counted by the normally closed contact 3b of the starting contactor 3, thereby setting the release time of the starting contactor 3, that is,
It is possible to measure the stop time of the three-phase induction motor 4,
If it has stopped for more than the time set in startup timer 15,
The start timer 15 counts up, and the normally open contact 15a of the start timer 15 closes. During operation based on upward direction call registration or upward level correction operation, the upward direction operation relay 9 is energized and its normally open contact 9b is closed. On the other hand, during oil temperature rising operation, the oil temperature control relay 11 is energized and its normally open contact 11d is closed, and immediately the starting auxiliary relay 16 is energized and started by the normally open contact 16a of the starting auxiliary relay 16. By energizing the contactor 3, the three-phase induction motor 4 can be started. At this time, the normally closed contact 3b of the starting contactor 3 opens, releasing the starting timer 15, and the normally open contact 3b of the starting contactor 3 opens.
a opens, but the normally open contact 16a of the starting auxiliary relay 16
Since the normally open contact 15a of the starting timer 15 is short-circuited and the starting auxiliary relay 16 can hold itself, the operation can be continued without stopping.

Next, when an upward call registration occurs during oil temperature control operation, normally open contact 1 of the oil temperature control relay 11
1d opens, but due to the off-delay circuit of the oil temperature control auxiliary relay 12, the energization of the upward direction operation relay 9 is slightly delayed, so during this time, the starting auxiliary relay 16 is released, and Start timer 15
The normally open contact 15a is already open at the start of the oil temperature control operation, so even if the normally open contact 9b closes when the upward direction operation relay 9 is energized with a slight delay, the start auxiliary relay 16 will not open immediately. The three-phase induction motor 4 will not be restarted unless it is excited, that is, a certain period of time when the three-phase induction motor 4 is stopped has elapsed. Furthermore, if an upward call is registered during the upward level correction operation or immediately after the operation is completed, the upward operation relay 9 will not be released if the operation is in progress, so the start contactor 3
is not released, and the three-phase induction motor continues to operate without stopping. In the latter case, when the upward operation relay 9 is eventually released and its normally open contact 9b is opened and the starting auxiliary relay 16 is released, the normally open contact 15a of the starting timer 15 is already open. In order to perform the next operation, the three-phase induction motor must be stopped for a period longer than the time set by the start timer 15. In addition, in the case of oil temperature control operation immediately after completion of ascending direction level correction operation or immediately after completion of ascending direction call registration operation, the three-phase induction motor 4 is started to drive the oil pump, so the oil tank is Since the oil temperature rises, there is no possibility of performing oil temperature control operation almost immediately, but in the present invention, when the upward operation relay 9 is released and the starting auxiliary relay 16 is released,
Similarly, if the three-phase induction motor 4 does not stop for a certain period of time, the starting timer 15 will not count up and the starting auxiliary relay 16 will not be re-energized. That is, the three-phase induction motor 4 is not restarted immediately.

[Effects of this invention]

As described above, if the present invention is used, the operation of a three-phase induction motor can be performed even if the operation by oil temperature control operation etc. to maintain the performance of the hydraulic elevator and the call registration operation as the original function are involved within a short time. , it is possible to take a certain period of stop time, and when the three-phase induction motor is restarted, it is always possible to assume a steady starting state, so that the three-phase induction motor can be started without any negative impact. Equipment can be rationalized without unnecessary considerations for circuits, and on the other hand,
It is possible to provide a hydraulic elevator that can maintain stable performance without sacrificing the original service.

[Brief explanation of drawings]

Fig. 1 is a starting circuit diagram of a three-phase induction motor that drives an oil pump, which has been used in the past and to which the present invention is also applied, Fig. 2 is a conventional starting control circuit diagram, and Fig. 3 is a starting control circuit of the present invention. It is a diagram. 3... Starting contactor, 4... Three-phase induction motor, 9
...Up direction operation relay, 11...Oil temperature control relay, 1
2... Off-day timer oil temperature control auxiliary relay, 1
5...Ondelay start timer, 16...Start assist relay.

Claims (1)

[Scope of utility model registration request] A three-phase induction motor that drives the hydraulic pump, an ascending operation relay that responds to the output of the ascending call registration relay and the output of the ascending level correction relay, and an oil motor that responds to the output of the temperature sensor installed in the oil tank. In the control device for a hydraulic elevator, the control device includes a starting control circuit including a temperature control relay and a starting contactor that connects the three-phase induction motor to a power source in response to the outputs of the rising direction operation relay and the oil temperature control relay. an off-delay timer excited via a normally open contact of the oil temperature control relay, a normally closed contact of the off delay timer inserted in series with the excitation circuit of the upward direction operation relay, and a normally closed contact of the starting contactor. A control device for a hydraulic elevator, comprising: an on-delay timer that responds; and a normally open contact of a starting auxiliary relay that starts excitation via a normally open contact of the on-delay timer in an excitation circuit of the starting contactor. .