JPS5916108B2 - Switching control device for pole switching compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a pole number changing motor for driving a compressor, in which the motor is temporarily stopped when changing the number of poles of the motor, and then restarted, thereby ensuring the changeover in a short time. It is an object of the present invention to provide a switching control device which prevents damage to the compressor and the electric motor in the event of failure of the pole number switching control component.

Conventionally, in a control device for a pole number switching motor that drives a compressor, in order to prevent reverse braking torque that occurs when switching the motor from small pole operation to multi pole operation, there is also a control device for switching the number of poles from multi pole operation to small pole operation. In order to make it easier to switch to operation, a method was considered in which the electric motor was temporarily stopped and restarted after a certain delay, but even if the electric motor stopped, the discharge and suction sides of the compressor If the restart load torque is large and the motor's starting torque is low, the pressure difference between the It would take a very long time to delay the restart until the compressor is fully recovered.For example, if the above compressor is installed in an air conditioner or the like to condition the indoor air, the indoor air will fluctuate greatly. It will be done.

In addition, if the control parts of the control device for switching the number of poles fail, the number of poles will be switched continuously, especially when switching from small-pole operation to multi-pole operation continuously, as shown below. A reverse torque is generated in the electric motor, and a large force is applied to the shaft connected to the compressor, causing damage.

The present invention eliminates the drawbacks of the prior art. Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of an air conditioner controlled by the switching control device of the present invention. Reference numeral 1 denotes a pole switching electric motor that drives a compressor 2 via a shaft 3. In FIG.

The discharge pipe 4 of the compressor 2 includes a condenser 5, a throttle device 6, and an evaporator γ.
, connected to the suction pipe 8 and connected to the compressor 2,
= constitutes a generally known refrigerant circuit.

Also, the discharge pipe 4 of the compressor 2 and the suction pipe 8 are connected by a bypass pipe 10 via a solenoid valve 9, and when the number of poles of the motor 1 is changed, the solenoid valve 9 is opened, and the discharge side and the suction side of the compressor 2 are connected. The refrigerant pressure of the compressor 2 is equalized, the load torque at the time of restarting the compressor 2 is reduced, and the restart is easily and reliably smoothed.

FIG. 2 shows an embodiment of the switching control device of the present invention, in which the pole number switching motor 1 is a three-phase motor.

The windings of each phase are connected in series to form a 4-pole motor, and connected in parallel to form a 2-polar motor.

The electric motor 1 operates with four poles, with the multi-pole terminals 1at1b*1c connected to the power supply P through the contacts 12 of the four-pole switch 11, and the small-pole terminals 1d,
1e and 1f are connected to power supply P to perform two-pole operation.

15 is a control power supply applied between terminals 16 and 11, and terminal 16 is connected to motor switch 19 via power switch 18;
It is connected to the normally open contact 21 of the delay switch 20, the delay element 23 of the delay switch 22, and the pole number changeover switch 24, respectively.

The motor switch 19 is further connected to normally closed contacts 2γ, 28 and normally closed contacts 29° and 30 of a pole number switching switch 26 operated by a coil 25 whose energization is controlled by the pole number switching switch 24.

The normally open contact 2γ of the pole number switching switch 26 is connected to the normally closed contact 33 of the auxiliary switch 32 via a coil 31 that operates the contact 12 of the 4-pole switch 11, and the normally closed contact 29 is connected to the normally closed contact 33 of the auxiliary switch 32. It is connected to the normally open contact 35 of the auxiliary switch 32 via the coil 34 that activates the contact 14 of the two-pole switch 13, and the distribution close contact 29 is made of the bimetal of the delay switch 20. The normally open contact 21 is connected to a heater 36 that heats the normally open contact 21.

Further, the normally open contact 28 of the pole number switching switch 26 is connected to the normally open contact 3γ of the auxiliary switch 32, and the normally closed contact 30 is connected to the normally closed contact 3B of the auxiliary switch 32, so that the auxiliary switch The t-distribution open contact 37 of the device 32 and the normally closed contact 38 are both connected to a coil 39 that operates the solenoid valve 9.

In other words, the normally open contacts 27, 2 of the E pole number switching switch 26
B. The connections between the normally closed contacts 29, 30, the normally closed contacts 33 to 38, and the normally open contacts 35, 37 of the auxiliary switch 32 are as follows: coil 31 of the 4-pole switch 11 and 1: the 2-pole switch The relationship is such that the connection of the coil 34 of the valve 13 to the control power source 15 and the connection of the coil 39 of the solenoid valve 9 to the control power source 15 are switched.

Further, the normally closed contact 33 and the normally open contact 35 of the auxiliary switch 32 are both connected to a normally open contact 40 which is delayed by the delay element 23 of the delay switch 22.

Specifically, the delay element 23 is, for example, a heater, and is heated by the heater to close a contact made of, for example, bimetal, and the contact made of bimetal is the normally open contact 40. be.

The delay element 23 is connected to the motor switch 19, one distribution junction 28 of the pole number switching switch 26, the normally closed contact 30, one distribution junction 3γ of the auxiliary switch 32, and the normally closed contact 38. The coil 3 of the solenoid valve 9 is connected in parallel.
9 is connected in series.

The normally open contact 21 of the delay switch 20 is connected to a coil 41 that actuates the auxiliary switch 32.

Normally open contact 40 of the above delay switch 22, coil 39 of solenoid valve 9, coil 41 of auxiliary switch 32, delay switch 2
0 heater 36 and the coil 25 of the pole number switching switch 26
is connected to terminal 1γ.

Next, the operation of the above configuration will be described.

1) When the power switch 1B and the motor switch 19 are turned on at two-pole startup, the heater 36 of the delay switch 20 is energized via the normally closed contact 29 of the pole number switching switch 26, heating the normally open contact 21, Normally closed contact 30 and normally closed contact 3 of auxiliary switch 32
The coil 39 of the solenoid valve 9 is energized through B, and the solenoid valve 9
opens, and the pressures on the discharge side and suction side of the compressor 2 are balanced.

After energizing the heater 36 for a certain period of time, the normally open contact 21 is closed and the coil 41 of the auxiliary switch 32 is energized, and the normally closed contacts 33 and 3B of the auxiliary switch 32 are opened and the normally open contact 35
, 3γ are closed.

Therefore, the coil 39 of the solenoid valve 9 is energized by the motor switch 19, the normally closed contact 30 of the pole number switch 26, and the auxiliary switch 3.
2 normally closed contact 3B, but the delay switch 2
The current is applied through the second delay element 23.

However, since the coil 39 is connected in series with the delay element 23, the voltage applied to the coil 39 decreases, and magnetic force sufficient to keep the solenoid valve 9 open is not generated.
will be closed.

However, since a sufficient current flows through the delay element 23, the delay element 23 generates heat and the diaphragm opening contact 40 closes after a certain delay, and the coil 34 of the bipolar switch 13 is energized and the contact 14 is activated. The electric motor 1 is energized and becomes two-pole operation.

That is, the delay element 23 of the delay switch 22 detects that the coil 39 of the solenoid valve 9 is not disconnected, the solenoid valve 9 is activated, and the pressures on the discharge side and suction side of the compressor 2 are balanced, and the two-pole operation is started. This is the start of the process.

2) When switching from 2-pole operation to 4-pole operation When the motor 1 is in 2-pole operation, if the pole number changeover switch 24 is turned on, the coil 25 of the pole number changeover switch 26 is energized and the normally closed contact 29 is opened. Energization to the coil 34 of the pole switch 12 is stopped, and the motor 1 is stopped.

- The universal normally closed contact 30 is opened, and the normally open contacts 27, 2
8 is closed.

The above-mentioned normally closed contact 29 is opened and power supply to the shift heater 36 is stopped, but the contact 21 that had been heated until then remains closed, and the normally open contacts 35 and 31 of the auxiliary switch 32 are closed. , the normally closed contacts 33 and 38 are open.

Therefore, the coil 39 is energized via the normally open contact 28 and normally closed contact 3T, and the solenoid valve 9 is opened to balance the refrigerant pressures on the discharge side and suction side of the compressor.

On the other hand, since the coil 39 is energized from the normally open contacts 2B and 3T as described above, the delay element 23 of the delay switch 22 is not energized, but the normally open contact 40 is connected to the delay element 23 until then. It could not be opened because it was too hot.

On the other hand, the normally open contact 21 of the delay switch 20 is gradually cooled and opened, and the current to the coil 41 is stopped and the auxiliary switch 3
The normally open contacts 35, 3γ of No. 2 are opened, and the normally closed contacts 33.
38 is closed.

As a result, the energization to the coil 39 of the solenoid valve 9 is stopped, and the coil 31 of the 4-pole switch 11 is energized, so that the motor 1 is restarted with 4 poles.

This startup is performed by bypassing the discharge side and suction side of the compressor 2 using the electromagnetic ff9, so there is almost no pressure difference and the starting torque of the motor 1 is very low. In order to increase the pressure, the time during which restart is possible becomes very short, and as described above, the auxiliary switch 32 operates after a certain delay in response to the pole number switching switch 26.
The delay time for the operation is very short, and the number of poles can be switched in a very short time.

3) Switching from 4-pole operation to 2-pole operation During 4-pole operation, if the pole number changeover switch 24 is opened, the current to the coil 25 is stopped, and the normally open contacts 27 and 2B of the pole number changeover switch 26 are closed. It becomes open, and the normally closed contacts 29 and 30 are closed.

Therefore, the energization to the coil 31 of the 4-pole switch 11 is stopped,
Electric motor 1 stops.

On the other hand, the coil 39 is energized via the normally closed contact 30 and the normally closed contact 38 of the auxiliary switch 32, and the solenoid valve 9 is opened, thereby balancing the refrigerant pressures on the discharge side and suction side of the compressor 2.

At this time as well, the power supply to the delay element 23 of the delay switch 22 is stopped, but the normally open contact 40 is not immediately opened.

Also, since the heater of the delay switch 20 is energized via the normally closed contact 29, the diaphragm open contact 21 is closed for a certain period of time in response to the pole number switch 26, and the auxiliary switch 32 is operated. The closed contacts 33, 38 are opened and the normally open contacts 35,
37 is closed, energization to the coil 39 is stopped, and the solenoid valve 9 is closed.
is closed, the coil 34 of the two-pole switch 13 is energized, and the motor 1 is restarted with two poles.

At this time as well, as in the above-mentioned four-pole startup, the time for switching the number of poles is very short, and startup is easily and reliably performed.

4) If the motor switch 19 is opened when stopped, the 4-pole switch 11
Since the energization to the coil 31 or the coil 34 of the two-pole switch 13 is stopped, the energization from the power source P to the electric motor 1 is stopped.

5) At 4-pole startup When the power switch 1B, the motor switch 19, and the number of poles changeover switch 24 are turned on, the coil 25 of the number of poles changeover switch 26 is energized, the normally open contacts 2γ and 28 are closed, and the normally open contacts 29 and 30 will be open.

Therefore, the normally open contact 2γ of the pole number switching switch 26, the coil 31 of the 4-pole switch 11, and the normally closed contact 3 of the auxiliary switch 32.
3 is formed, but since the normally open contact 40 connected in series with it is open, current flows through the delay element 23 and coil 39 of the delay switch 22 via the power switch 18. , the normally open contact 4 by the delay element 23
No. 0 is heated and closed after a certain delay, the No. 1 coil 31 is energized, and the motor 1 operates with four poles.

In 1 above, startup, switching the number of poles, and stopping are performed when each control component of the control device operates normally, but the control device of the present invention can also switch the number of poles even if a part of each control component fails. does not change continuously.

That is, if the pole number changeover switch 24 or the pole number changeover switch 26 fails, the normally open contact 27.2B or the normally closed contact 29.30 of the pole number changeover switch 26 remains closed. , when the normally open contacts 27 and 28 remain closed, the normally closed contacts 29 and 30 open, and the 4-pole switch 1
Only 1 is activated, and only 4-pole operation is performed.

Conversely, if the normally closed contacts 29 and 30 remain closed, the normally open contacts 27 and 28 are opened, the delay switch 20 is activated, and the normally open contacts 35 and 37 of the auxiliary switch 32 are closed, and the normally closed contacts 27 and 28 are opened. 33 and 38 are open and only two-pole operation is performed.

In addition, if the delay switch 20 or the auxiliary switch 32 fails, the normally closed contacts 33, 3B or the normally open contacts 35, 37 of the auxiliary switch 32 remain closed, and the 4-pole There is no case where the number of poles is continuously switched by only operation, only two-pole operation, or only by stopping without energizing the motor 1.

These are normally open contact 27 and normally closed contact 2 of the above-mentioned pole number switching switch.
This effect is even greater if 9 is a switching contact and the normally closed contact 33 and normally open contact 35 of the auxiliary switch are switching contacts.

The auxiliary switch 32 was operated by the delay switch 20, and the delay switch 20. Of course, the auxiliary switch 32 may also be used.

Further, although the present invention is provided with a solenoid valve 9 that equalizes the refrigerant pressure on the discharge side and suction side of the compressor 2, most failures of the solenoid valve 9 are caused by disconnection of the coil 39.

If the electromagnetic box 9 fails, there is a possibility that the electric motor 1 will be reenergized while there is a differential pressure in the compressor 2, and in that case, the electric motor 1 will burn out, but in the above embodiment, Since the delay element 23 of the delay switch 22 is connected in series with the solenoid valve, if the coil 39 is disconnected, the delay element 23 will not be energized and will not generate heat, and the normally open contact 40 will be open. As a result, the coil 31 of the 4-pole switch 11 and the coil 34 of the 2-pole switch 13 are de-energized and the motor 1 is stopped, so there is no risk of burnout.

In the above embodiments, even if the coil 31 of the 4-pole switch 11 and the coil 34 of the 2-pole switch 13 are replaced, the intent of the present invention does not change.

Further, in the above embodiment, the delay switch 20 is provided to operate the auxiliary switch 32 after a certain delay in response to the pole number switching switch 26, but this is because the compressor 1 In order to equalize the pressure difference between the discharge side and the suction side of the motor, the solenoid valve 9 has time to operate, and a certain delay is performed for the purpose of making it easier to restart the electric motor 1. However, it is obvious that the delay switch 20 may be replaced with a differential pressure switch or the like that detects the pressure difference between the discharge side and the suction side of the compressor, and opens and closes the auxiliary switch.

As described above, the switching control device for a pole number switching compressor of the present invention includes a pole number switching switch that switches the number of poles of a pole number switching motor that drives a compressor, and a pole number switching switch that switches the number of poles of the pole number switching motor that drives the compressor. An auxiliary switch that stops energizing the electric motor and reenergizes it after a predetermined delay time by a delay means from the energization stop, and a solenoid valve that communicates the discharge side and the suction side of the compressor. A means such as a contact that opens a solenoid valve is provided, an element that detects a disconnection of a coil that operates the solenoid valve or a circuit connected to this coil, and a contact that stops energization of the pole number switching motor by this element, etc. When changing the number of poles of the pole number switching motor, the motor is always stopped once, the pressure on the discharge side and the suction side of the compressor are equalized in a short time, and after a certain delay, the starting load torque is reduced. Since it can be restarted in a low state, the number of poles can be changed in a short time, and the restart can be performed easily and reliably, and no reverse braking torque is generated on the motor, ensuring the protection of the compressor and motor. When the coil that operates the solenoid valve or the circuit connected to this coil is disconnected,
The element that detects this disconnection can stop the energization of the pole number switching motor, and due to a failure of the solenoid valve, the motor is reenergized with differential pressure in the compressor when the number of poles of the motor is switched, causing a startup failure. This provides excellent effects such as preventing the electric motor from burning out.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of an air conditioner controlled by the switching control device of the present invention, and FIG. 2 is a circuit diagram of an embodiment of the switching control device of the present invention. 1... Pole switching motor, 2... Compressor, 9... Solenoid valve, 22... Delay switch, 23... Delay element (element), 26...
・Pole number switching switch, 21 to 30...Contact, 32
...Auxiliary switch, 33,35°37.38...
... Contact, 39 ... Coil that operates the solenoid valve, 40 ... Curved normally open contact (contact controlled by delay element).

Claims (1)

[Scope of Claims] 1. A pole number switching switch that switches the number of poles of a pole number switching motor that drives a compressor, and a means for stopping energization of the pole number switching motor by the pole number switching switch and delaying from this energization stop. an auxiliary switch that reenergizes after a certain delay time, a solenoid valve that connects the discharge side and suction side of the compressor, and means such as a contact that opens the solenoid valve before the certain delay time; A pole switching compressor is provided with an element for detecting disconnection of a coil for operating the electromagnetic valve or a circuit connected to the coil, and a means such as a contact for stopping energization of the pole switching motor using this element. Switching control device. −