JPH0626055Y2 - Pole number conversion motor conversion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a converter for a pole-changing electric motor, which omits a main circuit switching board and switches the main circuit by directly connecting a power cable. It is a thing.

[Conventional technology]

FIG. 6 is a circuit diagram showing a circuit configuration of a converter for a conventional pole-changing motor, in which six windings are provided by one winding and the number of poles is changed externally by switching the wiring. Switching, so-called single-winding pole-changing motors (eg Conseq
It is a typical control circuit example of uent Pole and PAM (Pole Amplitude Modulation).

In the figure, 1 is a motor winding, 2 is a terminal box attached to the motor, 3 is a low speed side terminal provided in the terminal box, 4 is a high speed side terminal, 5 is a low speed side main circuit closing contactor (circuit breaker), 6. A switching board for accommodating a high-speed side main circuit closing contactor (circuit breaker) 7 and a high-speed side short-circuiting contactor (circuit breaker) 8 is an overcurrent relay.

Next, the operation will be described. FIG. 6 shows an example of constant torque control (double Y connection on the high speed side, Δ connection on the low speed side), but at the time of low speed operation, the main circuit closing contactor (or circuit breaker) for the high speed side 7
When the high-speed side short-circuit contactor 8 is turned off, Δ connection is established, and when the low-speed side main circuit closing contactor (or circuit breaker) 6 is closed, the motor is started and operated at the low-speed side pole number.

When the high speed side main circuit closing contactor 6 is turned off and the high speed side shorting contactor 8 is turned on during high speed operation, a double Y connection is formed. The motor starts and operates with the number of poles on the high speed side.

[Problems to be solved by the invention]

Since the conventional converter for the pole number conversion motor is configured as described above, it is necessary to provide a switching board in the central electric room, but if this switching board becomes a high voltage and large capacity, it must be configured by a circuit breaker. However, it has a drawback that it occupies a large space and is expensive, and the construction cost increases because the power cable needs to be additionally installed as compared with a single-speed electric motor. It also had drawbacks such as.

Therefore, when using a pole-changing motor for the purpose of energy saving and the load that is constantly used, and if there is some time to spare when switching, a worker must manually switch the wiring at the motor terminal. Therefore, a means to minimize these investment amounts can be considered.

However, as described above, when a worker manually switches, there are two methods: (1) short replacement time and easy switching, and (2) prevention of incorrect wiring (Fool Proof). Although the conditions are required, there is a problem that the conventional pole number conversion motor cannot satisfy these conditions.

The present invention was made in order to solve the above problems, and an object thereof is to obtain a converter for a pole-changing electric motor that is easy to connect and does not cause incorrect wiring by a worker in the field. To do.

[Means for solving problems]

A converter for a pole-changing electric motor according to the present invention comprises a plurality of solid terminals for connecting power cables and a plurality of fixed terminals for mutual short circuit between a single fixed winding and a power source, and symmetrically with each other. It is provided with first and second fixed terminal groups arranged. When the power cable and the short-circuit cap are connected to one of these fixed terminal groups, the insulation protection cap is connected to the fixed terminals of the other fixed terminal group. Moreover, these connections are the first
And can be recombined between the second fixed terminal groups.

[Action]

If the power cable is connected and the connection is changed in the first and second fixed terminal groups in this invention, the pole number of the electric motor can be converted without using a conventional switching board. . Since the first and second fixed terminal groups are arranged symmetrically to each other, the connecting work is easy, and the fixed terminals other than the place where the power cable is connected have a short-circuit cap and insulation protection. Since the cap is connected, erroneous wiring can be effectively prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
The figure is a front layout view of a fixed terminal portion of an electric motor, in which 2 is a terminal mounting box and 10 is a connector. 11 is a low speed side fixed terminal, 1
2 is a fixed terminal on the high speed side, 13 is a dummy terminal, 14 is a fixed terminal for short-circuiting during high speed operation, and the fixed terminal group 26 is constituted by the fixed terminal 11 on the low speed side and the dummy terminal 13, and the fixed terminal on the high speed side 12 A second fixed terminal group 27 is constituted by the fixed terminals 14 for short circuit.

Since 15 short-circuits a plurality of adjacent dummy terminals 13 or short-circuit fixed terminals 14 to each other, as shown in FIG.
As shown in FIG. 3, a short-circuit cap 17 in which a bar 16 as a short-circuit member formed of a copper plate or the like is molded inside with an insulating resin is similar in appearance to the short-circuit cap 15, but the bar is molded inside. Not shown is an insulating protection cap, 18 is a power cable, and 19 is a cable mounting seat.

FIG. 4 is an example of circuit connection of this embodiment and corresponds to FIG. 1, and the lead wire of the motor winding 1 is the low speed side fixed terminal 11, the high speed side fixed terminal 12 and the short circuit fixed terminal in the terminal mounting box 2. 14 and not connected to the dummy terminal 13. However, the short-circuit cap 15 is connected to the dummy terminal 13, and the interlock signal 20 is issued from the dummy terminal 13. An insulation protection cap 17 is attached to the high speed side fixed terminal 12 and the short circuit fixed terminal 14 to protect each terminal.

FIG. 5 shows an example of a relay sequence used in the circuit configuration of FIG. 1, and shows an example in which the interlock is taken by the interlock switch LS corresponding to the interlock signal 20. . In the figure, a changeover switch composed of 25 interlocking switches SW1 and SW2,
Illustration is omitted in FIG. Then, when the switches SW1 and SW2 are on the terminals a ₁ and a ₂ side, the green lamp indicating the high speed side is turned on, and when the switches SW1 and SW2 are on the b ₁ and b ₂ side, the red lamp indicating the low speed side is turned on. ing. The interlock switch LS is connected in series to the coil of the relay RY so that the yellow lamp YL is turned on when the coil is excited. still,
PBS1 and PBS2 are a push button switch for starting and a push button switch for stopping, respectively.

Next, the operation will be described. FIG. 1 and FIG. 4 show the low speed side operation. Since the power cable 18 is connected to the low speed side fixed terminal 11 and the dummy terminal 13 is short-circuited by the short circuit cap 15, The lock signal 20 is issued and the interlock switch L
S turns ON. Therefore, the relay RY is operated to turn on the yellow lamp YL, and the changeover switch 25 is set to b ₁ ,
If it is on the b ₂ side, low speed operation will be performed.

At this time, if the changeover switch 25 is erroneously switched to the a ₁ or a ₂ side, the contact of the relay PY on the terminal a ₂ side is opened, and malfunction is prevented. Even if the short-circuit cap 15 is mistakenly connected to the high speed side, the low speed operation is not performed.

Next, when switching to the high speed operation, the stop push button switch PBS2 is pressed to temporarily stop the operation of the electric motor. Then, the power cable 18, the connector 10 attached thereto, and the short-circuit cap 15 are transferred to the high-speed side fixed terminal 12 and the short-circuit fixed terminal 14, respectively, for connection. Also, the high speed side fixed terminal 12 and the short circuit fixed terminal 1
The insulation protection cap connected to 4 is connected to the low speed side fixed terminal 11 and the dummy terminal 13, respectively.

At this time, as described above, the first fixed terminal group 26 and the second fixed terminal group 27 are arranged symmetrically, and the power supply cable 18 and the short-circuit cap 15 are always on the energizing side and the non-energizing side is on the energizing side. Since the insulation protection cap 17 is always connected, the worker can work without looking at the connection diagram.

Since the low speed side fixed terminal 11 and the high speed side fixed terminal 12 are arranged adjacent to each other near the center of the terminal mounting box 2,
It is possible to prevent unreasonable force from being applied to the power cable 18, and it is possible to further facilitate the connection work by the worker.

Thus, when the power cable 18 and the short-circuit element 15 are connected to the high speed side, the limit switch LS is turned off,
High-speed operation is performed by pressing the changeover switch 25 to a _1, a starting push button switch PBS1 in a state where switching has _two side.

As described above, in the present embodiment, the plurality of fixed terminals in the terminal mounting box 2 are separated into the first fixed terminal group 26 and the second fixed terminal group 27, which are arranged in a mutually targeted manner, and the connection concept is considered. Since it has been unified, the worker can surely perform the connecting work without checking the circuit diagram. Further, since the dummy terminal 13 is used as the interlock signal generating means, it is possible to prevent forgetting to attach the short-circuit element 15 and, if necessary, an appropriate limit switch or the like at the lead-in portion of the power cable 18. It can also be installed to prevent connection mistakes in the power supply circuit.

Further, in order to effectively prevent a connection mistake, it is preferable to distinguish the short-circuit cap 15 and the insulation protection cap 17 by color. Further, in FIG. 1, the upper short-circuit fixed terminal 14 and the lower high-speed side fixed terminal 12 are shown.
Two insulation protection caps 17 attached to each
Although the above is shown as a separate structure, it is also possible to connect this at the root portion to form an integrated structure. With such an integrated configuration, more reliable connection mistake prevention and easier connection work can be expected.

In the above embodiment, an example of constant torque connection switching (double Y connection / Δ connection) has been shown, but the same applies to the case of square torque control connection switching (double Y connection / Y connection). It is possible to Of course, in the case of switching the constant output connection (Δ connection / double Y connection), the display on the low speed side and the display on the high speed side are different from those in the above-described embodiment, and the same applies. Further, in the above-described embodiment, the connector 10 is used assuming a high-voltage electric motor, but in the case of a low-voltage electric motor, the electric motor lead wire is used as the power cable, and the first and second fixed terminals are used. The group may be provided on the terminal block.

[Effect of device]

As described above, according to the present invention, by providing the first and second fixed terminal groups, the switching at the time of converting the number of poles can be manually connected, and the short-circuit cap and the insulation protection cap can be effectively used. It is possible to connect the single stator winding to the power supply side in a short time because it is used for
In addition, it is possible to effectively prevent an error in connection at that time.

Therefore, in the case of a pole conversion motor used for applications that do not require frequent switching and allow sufficient working time for switching, an expensive switching panel and additional cables for switching are required. There is no need for installation, and there is an advantage that a more economical advantage can be obtained. In addition, the insulation protection camp has the effect of preventing contamination and corrosion of empty terminals.

[Brief description of drawings]

FIG. 1 is a front view showing the structure in the vicinity of the fixed terminal portion of the pole number conversion motor of FIG. 4, FIGS. 2 and 3 are sectional views showing one component of FIG. 1, and FIG. FIG. 5 is a circuit diagram showing a circuit configuration of a converter for a pole-changing electric motor according to one embodiment, FIG. 5 is a circuit diagram showing an example of a relay sequence used in the circuit configuration of FIG. 1, and FIG. 6 is a conventional pole. It is a circuit diagram which shows the circuit structure of the converter of a number conversion motor. 1 is a motor winding, 11 is a low speed side fixed terminal, 12 is a high speed side fixed terminal, 13 is a dummy terminal, 14 is a fixed terminal for short circuit,
Reference numeral 15 is a short-circuit cap, 17 is an insulation protection cap, 18 is a power cable, 26 is a first fixed terminal group, and 27 is a second fixed terminal group. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Scope of utility model registration request] 1. A pole number conversion motor for converting the number of poles of a stator by changing a connection state of a single stator winding with a power source side, wherein the pole number conversion motor is provided between the single stator winding and a power source. A plurality of fixed terminals for connecting power cables and a plurality of fixed terminals for mutual short-circuiting, which perform pole number conversion, and a first and a first fixed terminal group arranged symmetrically to each other, and fixing any one of them. A pole-changing electric motor comprising: a short-circuit cap having a power cable and a short-circuit member removably attached to the terminal group; and an insulating protection cap removably attached to the other fixed terminal group. Converter. 2. The pole number conversion method according to claim 1, wherein one of the first and second fixed terminal groups has a dummy terminal as a fixed terminal for mutual short circuit. Electric motor conversion device. 3. A utility model using the dummy terminal as an interlock signal generating means for confirming that the power cable, the short-circuit cap and the insulation protection cap are properly connected. A converter for a pole-changing electric motor according to claim 2.