JPS6316317Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement in a power/weak switching operation circuit for a plurality of electric motors.

Figure ₁ shows a conventional power/weak _switching operation circuit for n electric motors.
M _o is each electric motor, each strong notch wire, 1M ₁ , 1
M ₂ ,...1M _o is the strong contact 2 of the strong/weak switch 2
a, and each weak notch line 3M ₁ , 3M ₂ ,...3
M _o is the weak contact 2b of the strength changeover switch 2,
They are connected to each other. S is a power source, and the electric motor
It is arranged between the common line 4 of M ₁ , M ₂ , . . . M _o and the strength changeover switch 2 . C ₁ , C ₂ ,…
C _o is a starting capacitor for the electric motors M ₁ , M ₂ , . . . M _o , and is connected to the starting winding of the built-in starting device.

Conventionally, a strength switching operation circuit for n electric motors is configured as described above. For example, when the strength changeover switch 2 is switched to the strong contact 2a side, the power source S is turned on to the electric motors M ₁ , M ₂ , . . . M _o. Each strong notch line 1
It is supplied to a circuit formed by M ₁ , 1M ₂ , . . . 1M _o and the common line 4. Next, when the strength changeover switch 2 is switched to the weak contact 2b side, the power source S is connected to each of the weak notch wires 3M ₁ , 3 of the motors M ₁ , M ₂ , . . . _Mo
It is supplied to the circuit formed by M ₂ , . . . 3M _o and the common line 4.

Note that the electric motors M ₁ , M ₂ , . _. .

However, in the above circuit configuration, each of the weak notch lines 3M ₁ , 3 of each of the electric motors M ₁ , M ₂ , . . . , _Mo
Since M ₂ ,..., 3M _o are connected to each other, when a voltage is applied to the strong notched wires 1M ₁ , 1M ₂ ,..., 1M _o , the load condition of the electric motors M ₁ , M ₂ ,..., M _o The strong notch lines 1M ₁ , 1M ₂ ,
..., 1M _o and the weak notch line 3M ₁ , 3M ₂ , ..., 3
Circulating currents occur in the coils of the motors M ₁ , M ₂ , ..., _Mo between the motors _{M 1 ,} M _{2 , ...} , Mo
..., is a major factor in causing _fire damage accidents.

In order to prevent such a burnout accident, in the prior art, for example, as shown in FIG. 2, an n-pole double-throw switch 5 is used in place of the strength changeover switch 2 shown in FIG. 1, and the strong notch wires 1M ₁ , 1M ₂ ,…, 1M _o
When a voltage is applied to the weak notched wire 3M ₁ ,
The current situation is to configure a circuit in which 3M _{2 .} . . , 3M _o are separated from each other. However, even in this case, the wiring between the n-pole double-throw switch 5 and the n electric motors M ₁ , M _{2 ,} . Therefore, there were problems such as being very inconvenient when performing centralized control.

This idea was created by focusing on the above points, and between the electric motor and the strength changeover switch, a 3 circuit 3 contact relay, that is, 3 switching circuits,
By providing a relay with three contacts: a normally closed contact, a normally open contact, and a common contact for each switching circuit, the above drawbacks can be eliminated and efficient centralized control can be performed for multiple electric motors. The purpose of this is to obtain a strong/weak switching operation circuit.

An embodiment of this invention will be described below with reference to FIG.

Note that the same components as those of the above-mentioned prior art shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed explanation thereof will be omitted.

FIG. 3 shows a strong/weak switching operation circuit using two electric motors M ₁ and M ₂ . R1 is the electric motor
This is a 3-circuit, 3-contact relay provided between M ₁ , M ₂ and the strength changeover switch 2, and the switching circuits L ₁ , L ₂ , L ₃ of the relay have normally closed contacts NC ₁ , respectively.
It is equipped with three contacts: NC ₂ , NC ₃ , normally open contacts NO ₁ , NO ₂ , NO ₃ , and common contacts COM ₁ , COM ₂ , COM ₃ , and near each of the above-mentioned normally open contacts NO ₁ , NO ₂ , NO ₃ . is equipped with a common excitation coil _K1 . Said switching circuit _L1
The normally closed contact NC ₁ and the normally open contact NO ₁ of the motor
The normally closed contact NC ₂ and the normally open contact NO ₂ of the switching circuit L ₂ are connected to the strong notched wire 1M _{1 and} the weak notched wire 3M ₁ of the motor M ₁ , respectively _. , are connected to weak notch wire 3M ₂ respectively. Moreover, each of the switching circuits L ₁ , L ₂ , L ₃ ,
By connecting the common contacts COM ₁ , COM ₂ , COM ₃ , to each other, the strong contact 2 of the strength changeover switch 2
Connected to a. On the other hand, the weak contact 2b of the strong/weak changeover switch 2 is connected to the normally open contact _NO3 of the switching circuit _L3 , and is connected to the power supply S via the coil _K1 of the relay R1, and the electric motors _M1 , M It is connected to the common line 4 of ₂ .

Two electric motors M ₁ and M ₂ configured as above
In the strength switching operation circuit, when the strength changeover switch 2 is turned on to the strong contact 2a side, the power source S switches between the normally closed contacts of the switching circuits L ₁ and L ₂ of the relay R1.
It is supplied to the strong notch wires 1M ₁ and 1M ₂ of the electric motors M ₁ and M ₂ through NC ₁ and NC ₂ . At this time, the weak notch wires 3M ₁ and 3M ₂ of the electric motors M ₁ and M ₂ are separated from each other. Therefore, even if the strength changeover switch 2 is now connected to either of the contacts 2a, _2b and the load conditions of the electric motors _{M1 , M2} change, the strong notch lines _1M1 , Since no circulating current is generated in the coils between 1M ₂ and the weak notched wires 3M ₁ and 3M ₂ , it is possible to prevent burnout of the electric motors M ₁ and M ₂ .

When the strong/weak changeover switch 2 is switched to the weak contact 2b side, a current flows through the coil _K1 of the relay R1, causing an excitation effect on the coil _K1 , and as a result, the switching circuits _L1 , _L2 , L ₃ is a normally closed contact
Normally open contacts NO ₁ , NO ₂ , NO ₃ from NC ₁ , NC ₂ , NC ₃
The power supply S is switched to the normally open contact NO ₁ ,
The NO ₂ is supplied to the weak notch wires 3M ₁ and 3M ₂ of the electric motors M ₁ and M ₂ . At this time, the strong notched wires 1M ₁ and 1M ₂ of the electric motors M ₁ and M ₂ are separated from each other.

Therefore, in this case as well, as described above, no circulating current is generated, and it is possible to prevent the electric motors M ₁ and M ₂ from burning out.

Although the above embodiment deals with two electric motors, the same applies generally to n electric motors.

FIG. 4 shows an embodiment in which two sets of the embodiment shown in FIG. 3 are combined as one unit, and include two electric motors M ₁ and M ₂ and a three-circuit, three-contact relay. A motor group circuit consisting of two electric motors M ₃ and M ₄ and one three-circuit three-contact relay is provided in parallel with the electric motor group circuit consisting of one electric motor group. Note that the same reference numerals in the drawings are the same as in the conventional example and the above-mentioned embodiment, and the explanation thereof will be omitted.

In FIG. 4, this invention uses one strength changeover switch 2 to switch the electric motors M ₁ , M ₂ , M ₃ ,
It is configured to centrally control the strength switching operation of _M4 . In this case, the electric motor M ₁ ,
Even if the loads on M ₂ , M ₃ , and M ₄ fluctuate, no circulating current is generated as in the previous embodiment. Therefore, burnout accidents of the electric motors M ₁ , M ₂ , M ₃ , and M ₄ can be prevented. Note that the above embodiment can be applied to a plurality of groups of n electric motors.

Furthermore, FIG. 5 shows another embodiment of this invention, and is a circuit diagram in which two electric motors M ₁ and M ₂ are operated in three stages: strong, medium, and weak. This embodiment uses 3 circuit 3 contact relays R1, R2,
A three-stage switch 2A of high, medium, and low power is provided to centrally control the electric motors M ₁ and M ₂ , and the same components are indicated by the same reference numerals in the figure.

R1 and R2 are three-circuit, three-contact relays that have the same configuration as relay R1 in Figure 3, and are switching circuits.
L ₁ , L ₂ , L ₃ and T ₁ , T ₂ , T ₃ and the coil K ₁ ,
K ₂ is provided in parallel with the electric motors M ₁ and M ₂ respectively.

The electric motors M ₁ , M ₂ have strong notched wires 1M ₁ , 1
M ₂ , medium notched lines 6M ₁ , 6M ₂ and weak notched lines 3M ₁ , 3M ₂ , and the strong notched lines 1M ₁ , 1M _{2 .}
The notched wires 6M ₁ and 6M ₂ are connected to the normally closed contacts NCT 1 and _6M of the switching circuits T ₁ and T ₂ of the relay R2, respectively.
NCT ₂ and the normally open contacts NOT ₁ and NOT ₂ , respectively, and the weak notch wires 3M ₁ and 3M ₂ are connected to the relay R.
It is connected to normally open contacts NO ₁ and NO ₂ of switching circuits L ₁ and L ₂ of No. 1, respectively.

2A is a strong/medium/weak switch, with strong contact 2
Aa, a middle contact 2Ac, and a weak contact 2Ab. First, the strong contact 2Aa is connected to the switching circuits L ₁ , L ₂ of the relay R1,
The common contact of L ₃ is connected to the contact J on the common line of COM ₁ , COM ₂ , COM ₃ , and the middle contact 2Ac is connected to the relay R.
2 to the normally open contact NOT ₃ in the switching circuit T ₃ of the motor M ₁ , via the coil K ₂ .
Connected to common line 4 of _M2 . The weak contact 2Ab is connected to the normally open contact _NO3 of the switching circuit _L3 of the relay R1, and further connected to the common line 4 of the motors _M1 and _M2 via the coil _K1 . Now, when the strong/medium/weak changeover switch 2A is switched to the strong contact 2Aa side, the power supply S passes through the normally closed contacts NC ₁ and NC ₂ of the switching circuits L ₁ and L ₂ provided in the relay R1. It is supplied to the strong notch wires 1M ₁ and 1M ₂ of the electric motors M ₁ and M ₂ . Now, when the changeover switch 2A is switched to the middle contact 2Ac side, current flows through the coil _K2 of the relay R2, and as a result,
Due to the excitation effect produced in the coil _K2 , the relay R
2 switching circuits T ₁ , T ₂ , T ₃ normally closed contacts NCT ₁ ,
Normally open contacts NOT ₁ , NOT ₂ , from NCT ₂ , NCT ₃ ,
NOT ₃ respectively, and the power supply S is the normally open contact of the switching circuit T ₃ of the middle contact 2Ac and relay R2.
NOT ₃ , further passes through contact J, passes through switching circuits L ₁ and L ₂ of relay R1, and then switches to switching circuit T ₁ of relay R2,
Enter T ₂ , power supply M ₁ , M ₂ middle notch wire 6M ₁ , 6
_M2 is supplied respectively. Also, when the changeover switch 2A is switched to the weak contact 2Ab side, the relay R
A current flows through the coil K ₁ of the coil K 1 , and as a result, the excitation effect generated in the coil K ₁ causes the switching circuit L ₁ ,
L ₂ , L ₃ are normally closed contacts NC ₁ , NC ₂ , NC ₃ are normally open contacts
Since the switches are switched to NO ₁ , NO ₂ , and NO ₃ respectively, the power source S is connected to the weak notch wires 3M ₁ , 3 of the motors M ₁ , M ₂ .
supplied to _M2 . Therefore, like the previous embodiments, this embodiment has a structure in which no circulating current is generated, and burnout accidents of the electric motors M ₁ and M ₂ can be prevented. Note that this embodiment can also be configured for n electric motors.

As explained above, this invention solves problems that could not be prevented with conventional technology by providing one relay with (n+1) circuits and three contacts between n electric motors and one common strength changeover switch. Burnout accidents caused by circulating current in the motor group can be effectively prevented, and wiring connections can be simplified for centralized control of the motor group.

[Brief explanation of the drawing]

Fig. 1 shows a conventional power/weak switching operation circuit for multiple electric motors, Fig. 2 shows a circuit diagram of a conventional technology using an N-pole double-throw changeover switch, and Figs. 3 to 5 show a circuit diagram of this invention. FIG. 3 is a circuit diagram showing each example. 2... Strong/weak changeover switch, 2a... Strong contact of the strong/weak changeover switch 2, 2b... Weak contact of the strong/weak changeover switch 2, 4... Each electric motor M ₁ , M ₂ , ..., M in a group of n electric motors. The common line between _o , R1,
R2...(n+1) circuit 3 contact relay, _Lo ...
...(n+1) The n-th switching circuit of the relay R1 with three contacts in the circuit, NC _o ...(n+1) The normally closed contact provided in the n-th switching circuit of the relay R1 with three contacts in the circuit, NO _o ...(n+1) Circuit 3 contact relay R
a normally open contact provided in the nth switching circuit of 1;
COM _o ...(n+1) circuit Common contact for the n-th switching circuit of relay R1 with 3 contacts, T _o ...
(n+1) The n-th switching circuit of relay R2 with 3 contacts in the circuit, NCT _o ... (n+1) The normally closed contact provided in the n-th switching circuit of relay R2 with 3 contacts in the circuit, NOT _o ... (n+1) circuit 3 contact relay R
a normally open contact provided in the nth switching circuit of 2;
COMT _o ...(n+1) circuit 3 contact relay R2
A common contact for the nth switching circuit.

Claims (1)

[Scope of claim for utility model registration] (1) A motor group consisting of n motors each having a strong notch line, a weak notch line, and a common line, and (n+1)
(n+1) circuit 3-contact relays each having 3 contacts of a normally closed contact, a normally open contact, and a common contact, a strong/weak changeover switch having a strong contact, a weak contact, and a common contact, and a power source, and , the strong notch wire and the weak notch wire of the first motor in the motor group are connected to the normally closed contact and the normally open contact of the corresponding first switching circuit of the relay, and the strong notch wire of the second and subsequent motors The wire and weak notch wire are also connected to the normally closed and normally open contacts of the corresponding second and subsequent switching circuits of the relay, and the common contacts of the (n+1) circuits are connected to each other, and the strong and weak notch wires of the strong and weak changeover switches are connected to each other. The contact and the weak contact are respectively connected to the common contact and the normally open contact of the (n+1)th switching circuit of the relay, the common line of each of the n motors is connected to one end of the power supply, and the strong/weak changeover switch is connected. A common contact is connected to the other end of the power source, and a common excitation coil of the relay is connected between a normally open contact of the (n+1)th switching circuit of the relay and one end of the power source. A power/weak switching operation circuit for multiple electric motors. (2) A request for registration of a utility model characterized in that the strength changeover switch is provided in a circuit consisting of multiple sets of circuits each consisting of a group of motors and a relay connected in parallel, and is configured to switch the motors of each group at the same time. A power/weak switching operation circuit for a plurality of electric motors as described in item 1. (3) Each motor and changeover switch in the motor group is capable of three-stage switching operation of high, medium, and low, and two relays are arranged in a set. A power/weak switching operation circuit for a plurality of electric motors according to the scope 1 or 2.