JPS6112480B2 - - Google Patents

Description

[Detailed Description of the Invention] [Detailed Description of the Invention] The present invention starts the motor by switching the capacitance of the operation capacitor of the pole number switching motor by connecting or disconnecting the auxiliary operation capacitor during steady operation, regardless of whether the pole number switching motor is a multi-pole motor or a small pole motor. The purpose of this is to increase torque and enable efficient constant operation.

Conventionally, pole number switching motors have often been used in devices with low load torque at startup, and even pole number switching motors with low starting torque can be used. However, when used in equipment such as a refrigeration compressor that has a high load torque at startup, it is conceivable that the motor will not start due to insufficient starting torque of the pole switching motor. In this case, it is possible to increase the capacity of the operating capacitor at startup to increase the starting torque, but if the number of poles is switched, the switching method for switching the capacitor capacity during steady operation at startup becomes a problem. It is.
In other words, in a single-pole motor, the operating capacitor capacity was switched by a starting relay activated by the auxiliary coil voltage, but in a pole-switching motor, the starting relay must be controlled because the voltage of the auxiliary coil changes according to the switching of the number of poles. The problem was the circuit. Furthermore, when switching the number of poles of a pole number switching motor, if the auxiliary coil is connected in series or parallel by opening and closing the contacts of the switch that switches the number of poles, the auxiliary coil voltage may not be detected properly. The present invention solves the above problem and provides a control device that constantly switches the operating capacitance of a pole number switching motor during startup and steady operation, regardless of whether the pole number switching motor is a multi-pole motor or a few pole motor. It is.

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

1 is a pole number switching motor, and an electromagnetic switch 2 is provided to switch the number of poles of the motor 1 between two and four poles. 3 is a power plug, one end of which is connected to the operating switch 4. The operating switch 4 is provided with a motor switch 5 and a coil switch 6 in parallel. 7, 8, 9 and 10 are a first main coil, a second main coil, a first auxiliary coil, and a second auxiliary coil of the pole number switching motor 1, respectively. One end of the motor switch 5 is connected to the power plug 3, and the other end is connected to a connection point between the first main coil 7 and the first auxiliary coil 9. The coil switch 6 has one end connected to one end of the power plug 3 and the other end connected to the other end of the power plug 3 via a coil 11 that drives the electromagnetic switch 2 .

When the coil 11 is energized, the contacts 12, 13, 14, and 15 of the electromagnetic switch 2 are closed, and the first main coil 7 and the second main coil 8 of the pole number switching motor 1 are connected in parallel, and the first auxiliary coil 7 and the second main coil 8 are connected in parallel. Coil 9 and 2nd
Auxiliary coil 10 is connected in parallel. 16 is an operating capacitor, one end of which is connected to the connection point of the first main coil 7 and second main coil 8 through a contact 12 during two-pole operation, and the other end is connected to the first auxiliary coil through a contact 14. It is connected to the connection point between the coil 9 and the second auxiliary coil 10. The operating capacitor 16 has one end connected to one end of the second main coil 8 through a contact 17 and the other end connected to one end of the second auxiliary coil 10 through a contact 18 during four-pole operation. Note that when the coil 11 is not energized, the contacts 17 and 18 are closed. The first main coil 7 and the second main coil 8 are connected in series, the first auxiliary coil 9 and the second auxiliary coil 10 are connected in series, and the pole number switching motor 1 is connected during four-pole operation. Reference numeral 19 denotes an auxiliary operating capacitor 19 having a discharge resistor 20 provided in parallel, and is connected in parallel to the operating capacitor 16 via a contact 21 . Note that contact point 21
is a contact point of a starting relay 22 connected in parallel to the first auxiliary coil 9 of the pole number switching motor 1, and is opened by excitation of the electromagnetic coil 23. A contact 24 is connected to a terminal 25 provided at an appropriate position of the electromagnetic coil 23 during four-pole operation, and is connected in parallel with the coil 26 of the electromagnetic coil 23. The coils 27 except the coil 26 are connected in parallel to the first auxiliary coil 9.

Next, the operation during four-pole operation will be explained along the circuits shown in FIGS. 1 and 2.

In the case of four-pole operation, the coil switch 6 of the operating switch 4 is open and only the motor switch 5 is closed.
In this case, the contacts 17 and 18 of the electromagnetic switch 2 are closed,
Contact 24 is also closed. Therefore, the first main coil 7 and the second main coil 8 of the pole number switching motor 1 are connected in series via the contact 17, and the first auxiliary coil 9
and the second auxiliary coil 10 are connected in series to one end of the operating capacitor 16 via a contact 18.
Further, the coil 26 is short-circuited by the contact 24, and the coil 27 of the electromagnetic coil 23 of the starting relay 22 is connected in parallel to the first auxiliary coil 9 via the contact 24. By closing the motor switch 5, the pole number switching motor 1 is energized and started. At startup, the auxiliary operation capacitor 19 is connected in parallel to the operation capacitor 16 via the contact 21, so the system starts with a large capacitance. The starting torque at this time is extremely large. When the rotation of the pole number switching motor 1 increases and the voltage applied to the first auxiliary coil 9 becomes higher than the operating voltage of the electromagnetic coil 23 of the starting relay 22, the contact 21 is opened by excitation of the electromagnetic coil 23.

Therefore, if the pole number switching motor 1 is rotated steadily using only the operating capacitor 16 and the capacity of the operating capacitor 16 is selected to an appropriate value, efficient four-pole operation is possible.

Next, the operation of the two-pole operation will be explained in detail with reference to FIGS. 1 and 3.

When the coil switch 6 of the operation switch 4 is closed and the coil 11 is energized, the contacts 12, 1 of the electromagnetic switch
3, 14 and 15 are closed pole number switching motors 1 and 2.
It becomes a polar motor. That is, a second main coil 8 is connected in parallel with the first main coil 7 via a contact 13, and a first auxiliary coil 9 and a second auxiliary coil 10 are connected.
are connected via contact 15. Further, the first main coil 7 and the second main coil 8 connected in parallel are connected to the power plug 3 via a contact 12. Further, the first auxiliary coil 9 and the second auxiliary coil 10 connected in parallel are connected to the power plug 3 via a contact 14.

Further, the series circuit of the coil 26 and the coil 27 of the electromagnetic coil 23 of the starting relay 22 is connected to the first auxiliary coil 9.
and the second auxiliary coil 10 in parallel. When the motor switch 5 is closed in this state, the pole number switching motor 1 is energized and the auxiliary operation capacitor 1
9 is connected in parallel to the operating capacitor 16, and the motor is started with a high starting torque. Then, the rotation of the pole number switching motor 1 increases, the voltage applied to the first auxiliary coil 9 increases, and the electromagnetic coil 2 of the starting relay 22 increases.
3 is energized and contact 21 opens, operation capacitor 1
6, the pole number switching motor 1 is operated. In this state, the pole number switching motor 1 rotates steadily and can be operated efficiently.

As is clear from the above explanation, starting relay 22
The reason why the electromagnetic coil 23 is connected in parallel to the first auxiliary coil 9 is to solve the following problems. If the first auxiliary coil 9 and the second auxiliary coil 10
When the above-mentioned electromagnetic coil 23 is connected in parallel to the series circuit of There is a possibility that the coil voltage cannot be detected, and in order to prevent this, the connection when switching the number of poles of the pole number switching motor using the contacts of the electromagnetic switch becomes complicated. What should be noted at the time of startup is that when the pole number switching motor 1 is connected to four poles, the first auxiliary coil 9 and the second auxiliary coil 10 are connected in series, so the voltage generated in the first auxiliary coil 9 is It is approximately 1/2 of the auxiliary coil voltage of the pole number switching motor 1, and when the pole number switching motor 1 is connected to two poles, the first auxiliary coil 9 and the second auxiliary coil 10 are connected in parallel, so the first The voltage generated in the auxiliary coil 9 is equal to the auxiliary coil voltage of the pole number switching motor 1. Further, the auxiliary coil voltage of the motor 1 changes somewhat depending on whether the motor is connected with two poles or with four poles. In this way, the voltage generated in the first auxiliary coil 9 differs depending on whether it is a two-pole connection or a four-pole connection, but when it is a two-pole connection, the voltage generated in the first auxiliary coil 9 is different from that in the series circuit of the coil 26 and the coil 27 of the electromagnetic coil 23 of the starting relay 22. An auxiliary coil voltage is applied to the 4-pole connection, and the auxiliary coil voltage is applied only to the coil 27, so that the attraction force of the electromagnetic coil 23 is adjusted to be the same. Therefore, regardless of the two-pole connection or the four-pole connection, the capacitance of the operating capacitor at startup and during steady rotation can be reliably switched, and the efficiency during steady rotation can be maintained optimally.

Further, in a control circuit other than the control circuit of the present invention, the number of contacts of the pole number switching switch increases, resulting in a complicated circuit.

Although the electromagnetic coil 23 is connected in parallel to the first auxiliary coil 9, there is no change in the effect even if the electromagnetic coil 23 is connected in parallel to the second auxiliary coil 10 instead of the first auxiliary coil 9.

As is clear from the above embodiments, the control circuit for the pole number switching motor of the present invention connects the main coil to the first main coil and the first main coil of the single-phase motor in which a series circuit of an auxiliary coil and a capacitor is connected in parallel to the main coil. It is divided into two main coils, and the auxiliary coil is divided into a first auxiliary coil and a second auxiliary coil to form a pole number switching motor, and the first main coil and the second main coil are also divided into the first auxiliary coil. and an electromagnetic switch that connects the second auxiliary coil in series to switch to a multi-pole motor and connects them in parallel to switch to a small-pole motor, and connects the auxiliary coil in parallel to the main coil through contacts of this electromagnetic switch. A series circuit of capacitors is connected, and a starting relay is provided to the capacitor with a contact for connecting or disconnecting the auxiliary capacitor in parallel depending on the startup and steady operation of the pole number switching motor,
The electromagnetic coil of the starting relay is connected in parallel to the first auxiliary coil or the second auxiliary coil, and a part of the electromagnetic coil is opened and closed in response to switching of the number of poles of the pole number switching motor. It is connected in parallel to the contacts of the device, and detects the voltage of either the first auxiliary coil or the second auxiliary coil to detect the difference in auxiliary coil voltage that occurs when the pole number switching motor is in multi-pole operation and when it is in low-pole operation. The voltage is almost the same regardless of the number of poles, and this adjusted voltage can be easily finely adjusted by short-circuiting a part of the electromagnetic coil of the starting relay with the contact of the electromagnetic switch for switching the number of poles. , after the start relay operates reliably and the start is completed, the start relay disconnects the auxiliary operation capacitor from the operation capacitor and enters a highly efficient steady operation state. By connecting it in parallel to one of the second auxiliary coils, even when switching the number of poles, the electromagnetic coil will not be short-circuited by the contacts of the pole number switching switch, and the auxiliary coil voltage can be reliably controlled with a simple configuration. It is something that can be detected. Moreover, the present invention provides an excellent control device for a pole number switching motor that is optimal for a pole number switching motor of a refrigerator, which has a large starting load torque and requires high efficiency during steady operation.

[Brief explanation of the drawing]

Fig. 1 is an electric circuit of a control device for a pole switching motor according to an embodiment of the present invention, Fig. 2 is a schematic circuit diagram of the control device in four-pole operation, and Fig. 3 is a schematic circuit diagram of the control device in two-pole operation. FIG. 1...Pole number switching motor, 2...Electromagnetic switch, 4
...Operation switch, 5...Motor switch, 6...
Coil switch, 7...first main coil, 8...second
Main coil, 9...first auxiliary coil, 10...second
Auxiliary coil, 11... Coil, 12, 13, 1
4, 15, 17, 18, 21, 24...Contact, 1
6... operating capacitor, 19... auxiliary operating capacitor, 22... starting relay, 23... electromagnetic coil, 26, 27... each coil of electromagnetic coil 23.

Claims (1)

[Claims] 1 A series circuit of an auxiliary coil and a capacitor is connected in parallel to the main coil.The main coil of a single-phase motor is divided into a first main coil and a second main coil, and the auxiliary coil is divided into a first auxiliary coil and a second auxiliary coil. The first main coil and the second main coil are connected in series, and the first auxiliary coil and the second auxiliary coil are connected in series to form a multi-pole motor by dividing the coil into a multi-pole motor. A series circuit of the auxiliary coil and a capacitor is connected in parallel to the main coil through the contacts of the electromagnetic switch, and the auxiliary capacitor is connected to the capacitor. A starting relay having contacts that are connected or disconnected in parallel depending on starting and steady operation is provided, and an electromagnetic coil of this starting relay is connected in parallel to one of the first auxiliary coil or the second auxiliary coil, A control device for a pole number switching motor, in which a part of this electromagnetic coil is connected in parallel to the contacts of the electromagnetic switch, which is closed when a multi-pole motor is used and opened when a small-pole motor is used.