JPS63206195A - Inverter power source drive motor - Google Patents

Abstract

PURPOSE:To raise the rotating speed control limit with the output fixed, either by allowing the primary winding to be switched from star to delta connection or by connecting it to an inverter power source as an intermediate tap drawer type. CONSTITUTION:The primary winding 15 of a motor 14 is used in star connection in low speed region. In high speed region an ON-OFF switch 16 is set to 'OFF' and an ON-OFF switch 17 is switched to 'ON' to make the primary winding 15 in delta connection. The winding impedance of star connection will thereby be three times as much as that of delta connection, so that without changing the capacity of an inverter power source 3 the rotating speed can be switched for control between high speed region and low speed which is one third the high speed with the output fixed in applying the same current to the motor 14.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides an inverter power drive motor used in machine tools, etc., in which the rotational speed control range with constant output can be increased without increasing the size of the inverter power supply. About what has been made possible.

[Conventional technology]

When controlling the rotation speed of an inverter-powered motor used in machine tools with a constant output, it is generally 1:4 (for example, the base rotation speed is 1500 rpm and the maximum rotation speed is 6).
For example, as shown in Fig.
If you want to be able to control it within the range of It is necessary to lower the voltage and increase the current. In such a case, an inverter power supply would require three times the capacity and become more expensive, so generally, as shown in Figure 4, a motor whose rotational speed can be controlled within a 1:4 range is used and an appropriate motor is used. The rotational speed was switched and controlled using a gear reduction device 1 having several stages. FIG. 4 shows a spindle device for rotationally driving the chuck 2, in which a rotating shaft 4a of a motor 4, which is rotationally driven by an inverter power supply 3 while controlling the speed in a 1:4 range, is connected to a belt 5, 6 and a gear reduction gear r! It is connected to the spindle door to which the chuck 2 is attached via L1. If the motor 4 is driven to rotate without being decelerated by the speed reducer t1i, the output will be constant, for example from 1500 rpm to 600 Or
The chuck 2 can be rotated in the range up to pm, and if this is reduced to 1/3 by the speed reducer 1, the rotation speed will be 500 rpm.
The rotational speed can be controlled within a total range of 1:12, from pm to 200 rpm.

[Problem that the invention seeks to solve]

The above structure not only generates noise from the gear section, but also requires a lot of effort to replenish lubricant to prevent wear of the gears, and furthermore, the speed reducer 1 is expensive.

In order to eliminate the above-mentioned drawbacks, this invention provides an inverter power supply drive system that enables the rotational speed control range with a constant output to be widened without using a gear reduction device or increasing the size of the inverter power supply. The purpose is to provide motors.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention enables the primary winding 15 of the motor 14 to be switched between human and delta connections, or connects the inverter power supply 3 to the inverter power supply 3 by making the intermediate tap 26 pull-out type. It was designed to connect.

[Effect]

If the connection of the secondary winding 15 is made in the low speed range and in the high speed range by using an appropriate intermediate tap winding so that the winding impedance in the low speed range is three times that in the high speed range, the conventional example can be changed. motor 1 without changing the capacity of the inverter power supply 3 described above.
Apply the same voltage and current to 4 to keep the output constant and 1/
The rotation speed can be controlled at a low speed of 3.

〔Example〕

FIG. 1 shows an embodiment of the present invention, and the same parts as in FIG. 4 are denoted by the same reference numerals. This diagram shows motor 14
The state shown is that the primary winding 15 is connected to a large wire and used in a low speed range, and when used in a high speed range, the on/off switch 16 is opened and the on/off switch 17 is switched to a closed state to open the primary winding 15. Use Δ connection. According to this embodiment, the winding impedance of the large connection is three times that of the Δ connection, so
By applying the same voltage and the same current to the motor 14 without changing the capacity of the inverter power source 3, the output can be kept constant and the rotational speed can be switched and controlled between a high speed range and a low speed 1/3 of the high speed range.

In FIG. 2 showing another embodiment, the primary winding 2 of each phase
An intermediate tap 26 is drawn out from 5.

This figure shows a state in which the primary winding 25 is connected to a large wire and all tap windings are connected to the inverter power supply 3 for use in a low speed range.When used in a high speed range, the on/off switch 16 is opened and opened/closed. Switch the switch 17 to the closed state [Connect the intermediate tap winding to the impark power supply 3]. If the impedance of the all-tap winding is made, for example, three times that of the middle tap winding and the same as that of the large-connection primary winding 15 explained in FIG. The rotational speed can be switched and controlled at a low speed of 1/3 of that speed. In the embodiment described above, the case where the primary winding 15 is a large connection is described, but the present invention can also be implemented in a case where the primary winding 15 is a Δ connection.

〔Effect of the invention〕

According to this invention, since it is connected to the inverter power supply drive motor or to the inverter power supply as an intermediate tap pull-out type, the output is constant with an inexpensive structure without using a gear reduction device or increasing the size of the inverter power supply. The effect of increasing the rotational speed control range is obtained.

[Brief explanation of the drawing]

Figure 1 is a connection diagram of an embodiment of this invention, Figure 2 is a connection diagram of another embodiment of this invention, Figure 3 is a curve diagram showing the relationship between output and rotational speed, and Figure 4 is a diagram of a conventional example. It is a schematic block diagram. 3... Inverter power supply, 14... Motor, 15.2
5... - next winding, 26... intermediate tap. Figure 1 Figure 3

Claims (1)

[Claims] 1) Connect the primary winding of the motor driven by the inverter power supply to ■(
An inverter-powered drive motor characterized by having a star)-Δ (delta) connection switchable or an intermediate tap pull-out type to widen the rotational speed control range with a constant output.