WO2021245881A1

WO2021245881A1 - Secondary resistance adjusting device for die casting rotor, and method for adjusting secondary resistance of die casting rotor

Info

Publication number: WO2021245881A1
Application number: PCT/JP2020/022124
Authority: WO
Inventors: 晶子新
Original assignee: 三菱電機株式会社
Priority date: 2020-06-04
Filing date: 2020-06-04
Publication date: 2021-12-09
Also published as: JPWO2021245881A1; JP7309068B2

Abstract

In the present invention, the power generated in a stator winding (12b) when voltage is applied to the stator winding (12b) is measured, the resistance value of the stator winding (12b) is measured, and the temperature of an end ring (33) or a rotor bar of a die casting rotor (11) is measured. The present invention comprises: a computation device (18) that, on the basis of these measurement results, calculates a cutting allowance of the end ring (33) for setting the secondary resistance of the die casting rotor (11) to a first value; and a lathe device (19) that cuts the end ring (33) on the basis of the cutting allowance calculated by the computation device (18).

Description

Secondary resistance adjustment device for die-cast rotor and secondary resistance adjustment method for die-cast rotor

The present disclosure relates to a secondary resistance adjusting device for a cage-type die cast rotor and a secondary resistance adjusting method for the die casting rotor.

The cage-shaped die-casting rotor is manufactured by a die-casting method in which molten aluminum is poured into the iron core for the rotor, and the aluminum part is composed of a plurality of rotor bars and an annular end ring in which the end faces of the rotor bars are connected to each other. The combined resistance of the rotor bar and end ring is called the secondary resistance and affects the torque characteristics of the motor.

If the secondary resistance of the die cast rotor can be adjusted, motors with various specifications can be manufactured. For example, Patent Document 1 discloses a method for obtaining a die-cast rotor having a desired secondary resistance by die-casting a conductive material having a resistivity different from that of aluminum together with aluminum.

Japanese Unexamined Patent Publication No. 4-88855

However, in the method of Patent Document 1, it is necessary to prepare a large number of types of conductive materials for adjusting the secondary resistance, and when the conductivity of aluminum itself varies depending on the material lot or the like, the desired secondary resistance is obtained. There is a problem that it does not become.

The present disclosure has been made in view of the above, and a die cast rotor having a desired secondary resistance can be obtained without preparing a conductive material or the like, even if the conductivity of aluminum itself varies depending on the material lot or the like. It is an object of the present invention to obtain a die casting rotor secondary resistance adjusting device and a die casting rotor secondary resistance adjusting method.

In order to solve the above-mentioned problems and achieve the object, in the secondary resistance adjusting device of the die casting rotor of the present disclosure, the rotor core, a plurality of rotor bars arranged around the rotor core, and both ends of the rotor core are provided. Adjust the secondary resistance, which is the combined resistance between the rotor bar and the end ring of a cage-type die casting rotor with an end ring that joins each end of a plurality of rotor bars. The secondary resistance adjusting device includes a stator jig having a stator winding and a stator core into which a diecast rotor is inserted, a fixture for fixing the diecast rotor to the stator jig, and rotation inside the stator jig. An AC voltage source that applies a voltage to generate a magnetic field to the stator windings, and a first measuring instrument that measures the power generated in the stator windings when a voltage is applied to the stator windings by the AC voltage source. A second measuring instrument for measuring the resistance value of the stator winding, a third measuring instrument for measuring the temperature of the end ring or the rotor bar of the diecast rotor, a calculation device, and a lathe device are provided. The arithmetic unit calculates the cutting allowance of the end ring for setting the secondary resistance to the first value based on the measurement results of the first measuring instrument, the second measuring instrument, and the third measuring instrument. The lathe device cuts the end ring based on the cutting allowance calculated by the arithmetic unit.

According to the present disclosure, there is an effect that a die cast rotor having a desired secondary resistance can be obtained even if the conductivity of aluminum itself varies depending on the material lot or the like without preparing a conductive material or the like.

Schematic diagram of the secondary resistance adjusting device of the die casting rotor according to the embodiment. Top view of the die casting rotor to be adjusted for the secondary resistance according to the embodiment. Front view of the die casting rotor to be adjusted for the secondary resistance according to the embodiment. A circuit diagram showing a connection relationship between a stator winding, an AC voltage source, a power meter, and an ohmmeter according to an embodiment. Flow chart showing the procedure of secondary resistance adjustment according to the embodiment

Hereinafter, the secondary resistance adjusting device for the die casting rotor and the secondary resistance adjusting method for the die casting rotor according to the embodiment will be described in detail with reference to the drawings.

Embodiment.
FIG. 1 is a schematic view of a secondary resistance adjusting device for a die cast rotor according to an embodiment. The adjustment target of the secondary resistance adjusting device is the cage type die casting rotor 11. FIG. 2 is a plan view of the die casting rotor 11 to be adjusted for the secondary resistance according to the embodiment. FIG. 3 is a front view of the die casting rotor 11.

In FIGS. 1 to 3, the cage-shaped die-casting rotor 11 is manufactured by a die-casting method in which molten aluminum is poured into a rotor core 31 which is an iron core for a rotor. The die-cast rotor 11 is composed of a rotor core 31 formed of a laminated iron core in which electromagnetic steel sheets are laminated, a plurality of rotor bars 32 made of aluminum, and a pair of end rings 33 made of aluminum. A plurality of grooves extending in the axial direction at a certain angle are formed on the outer periphery of the rotor core 31, and a plurality of rotor bars 32 are embedded in these grooves. End rings 33 are provided at both ends of the rotor core 31 in the axial direction. The end ring 33 joins each end face of the plurality of rotor bars 32. The end ring 33 has an annular shape. The die cast rotor 11 is inserted inside the stator jig 12 and is fixed so as not to rotate by being pressed from above and below by the fixing pin 13. By cutting the end ring 33 by an appropriate amount, the secondary resistance, which is the combined resistance between the rotor bar 32 and the end ring 33, is adjusted. As the fixing tool for fixing the die casting rotor 11 to the stator jig 12, a method other than the fixing pin 13 may be adopted.

The stator jig 12 has a stator core 12a and a stator winding 12b. The stator core 12a is formed of a laminated core in which electromagnetic steel sheets are laminated. The stator winding 12b is wound around the stator core 12a. An AC voltage source 14, a power meter 15, and an ohmmeter 16 are connected to the stator winding 12b. The AC voltage source 14 can be selected from either single-phase or three-phase according to the form of the stator winding 12b so that a rotating magnetic field can be generated inside the stator jig 12. When single-phase is selected, it is necessary to make it two-phase via a capacitor or the like. The power meter 15 as the first measuring instrument can measure voltage and current, and has a function of calculating electric power from the measured voltage and current.

The resistance meter 16 as the second measuring instrument measures the resistance value of the stator winding 12b. The temperature sensor 17 as a third measuring instrument is in contact with the end ring 33 of the die casting rotor 11 in order to measure the temperature of the aluminum portion of the die casting rotor 11. Regarding the temperature sensor 17, if the temperature of the rotor bar 32 or the end ring 33, which is an aluminum portion, can be measured, this form does not apply.

The arithmetic unit 18 receives the measurement results of the power meter 15, the resistance meter 16, and the temperature sensor 17, and calculates the cutting allowance of the end ring 33 required to set the secondary resistance to the desired first value. It has a function.

The lathe device 19 includes a transport device 19a for gripping and transporting the die-cast rotor 11 and a cutting tool 19b for cutting the end ring 33 of the die-cast rotor 11. The lathe device 19 has a function of cutting the end ring 33 based on the calculation result of the calculation device 18.

FIG. 4 is a circuit diagram showing a connection relationship between the stator winding 12b, the AC voltage source 14, the power meter 15, and the resistance meter 16 according to the embodiment, and shows a three-phase mode as an example. The stator winding 12b is formed of three phases of U-phase 21a, V-phase 21b, and W-phase 21c so as to generate a rotating magnetic field, and the ends of the windings of U-phase 21a, V-phase 21b, and W-phase 21c are connected to each other. Is short-circuited. The AC voltage source 14 is connected to the beginning of each volume of the U phase 21a, the V phase 21b, and the W phase 21c so that a voltage can be applied to the U phase 21a, the V phase 21b, and the W phase 21c. The power meter 15 applies the voltage applied between the U phase 21a and the V phase 21b, the V phase 21b and the W phase 21c, the W phase 21c and the U phase 21a, and the U phase 21a, the V phase 21b, and the W phase 21c. It is connected so that the flowing current can be measured and the electric power of the U phase 21a, the V phase 21b, and the W phase 21c in the stator winding 12b can be calculated. The resistance meter 16 can measure the resistance between the U phase 21a and the V phase 21b, the V phase 21b and the W phase 21c, and the W phase 21c and the U phase 21a so that the U phase 21a, the V phase 21b, and the W phase 21c can be measured. It is connected to the beginning of each volume. The voltage application switches 22a, 22b, 22c and the

resistance measurement switches

23a, 23b, 23c can change the current path so that the voltage application and the resistance measurement are not performed at the same time and the resistance meter 16 is not damaged. It is connected.

FIG. 5 shows a flowchart showing the procedure of secondary resistance adjustment according to this configuration. Hereinafter, the procedure for adjusting the secondary resistance will be described with reference to FIG.

First, in step S1, the die cast rotor 11 is inserted into the stator jig 12.

Next, in step S2, the die cast rotor 11 is fixed so that the die cast rotor 11 does not rotate. In FIG. 1, the die-casting rotor 11 is pressed from above and below with the fixing pin 13 to fix it, but if the die-casting rotor 11 does not rotate even if it receives a rotating magnetic field, another arbitrary fixing method is adopted. May be good.

Next, in step S3, a voltage is applied from the AC voltage source 14 to the stator winding 12b so as to generate a rotating magnetic field inside the stator jig 12. Explaining in the example shown in FIG. 4, the

voltage application switches

22a, 22b, 22c are closed, and voltage is applied to the U phase 21a, the V phase 21b, and the W phase 21c from the AC voltage source 14 to the stator winding 12b. ..

Next, in step S4, the electric power of the U phase 21a, the V phase 21b, and the W phase 21c in the stator winding 12b is calculated. In the example shown in FIG. 4, the voltage applied between the U phase 21a and the V phase 21b, the V phase 21b and the W phase 21c, and the W phase 21c and the U phase 21a and the U phase 21a in the power meter 15 will be described. , The current flowing through the V phase 21b and the W phase 21c is measured, and the power of the U phase 21a, the V phase 21b, and the W phase 21c in the stator winding 12b is calculated.

Next, in step S5, the temperature of the end ring 33 of the die casting rotor 11 is measured by the temperature sensor 17.

Next, in step S6, the voltage application from the AC voltage source 14 is stopped. In the example shown in FIG. 4, the

voltage application switches

22a, 22b, and 22c are opened to stop the voltage application from the AC voltage source 14.

Next, in step S7, the resistance of the stator winding 12b is measured by the resistance meter 16. In the example shown in FIG. 4, the

resistance measurement switches

23a, 23b, and 23c are closed, and the resistance meter 16 is used between the U phase 21a and the V phase 21b, the V phase 21b and the W phase 21c, and the W phase 21c-U phase. Measure the resistance between 21a.

Next, in step S8, the obtained measured values of current, power, temperature, and resistance are transmitted to the arithmetic unit 18.

Next, in step S9, the arithmetic unit 18 calculates the cutting allowance of the end ring 33 required to set the secondary resistance to the desired first value based on the input measured value, and the result is a lathe. It is transmitted to the device 19.

The formula for calculating the cutting allowance of the end ring 33 differs depending on the specifications of the die cast rotor 11 and the stator jig 12. A case where the relationship between the secondary resistance r ₂ and the cutting allowance x of the end ring 33 _{can be expressed by r 2} = a · x + b will be described as an example. a and b are constants. The measured secondary resistance r _{2 'is,} since the secondary resistance when the cutting allowance x = 0, b = r 2 ' becomes. Assuming that the first value, which is the desired value of the secondary resistance, is C, and the cutting allowance for changing the secondary resistance from the state before cutting of the end ring 33 to the first value C is Δx, Δx = (C−). It becomes r ₂ ') / a.

Further, where the in the calculation of the secondary resistance r ₂ is based an equivalent circuit at the time of restraining the test, in a simplified manner, it is assumed that the excitation reactance is much larger than the secondary resistance. When the three-phase connections, such as in FIG. 4 as an example, the temperature correction coefficient of the die cast rotor 11 k _t, U-phase 21a measured by the power meter 15, V-phase 21b, the average value of the current flowing through the W-phase 21c I , The total value of the electric power of the U phase 21a, the V phase 21b, and the W phase 21c calculated by the power meter 15, P, between the U phase 21a and the V phase 21b measured by the resistance meter 16, and between the V phase 21b and the W phase 21c. When the average value of the resistance between the W-phase 21c-U-phase 21a is denoted by R, the secondary resistance _{r 2} is expressed by the following formula (1). By equation (1), the measured secondary resistance r _{2 'are} determined.

Note that the temperature correction coefficient k _t, if the temperature t measured by the temperature sensor 17, when it is to be corrected to 25 ° C. as a room, the temperature coefficient of the aluminum so is 4.2 × 10 -3 ^/ ℃, temperature compensation coefficient _{k t} is expressed by the following equation (2).

Thus, the arithmetic unit 18, the formula (1), based on equation (2), 'seek, above equation, [Delta] x = _{(C-r 2'} secondary resistance _{r 2} based on) / a End The cutting allowance Δx of the ring 33 is obtained.

Next, in step S10, the fixed die-casting rotor 11 is released, and the die-casting rotor 11 is taken out from the stator jig 12 by the transfer device 19a. Further, the die cast rotor 11 is conveyed into the lathe device 19. The lathe device 19 cuts the end ring 33 of the die casting rotor 11 with the cutting tool 19b based on the information of the cutting allowance Δx of the end ring received from the arithmetic unit 18.

As described above, according to the embodiment, since the secondary resistance of the die casting rotor 11 to be adjusted is measured and the end ring 33 is cut based on the value, the conductivity of the aluminum itself varies depending on the material lot or the like. Even if it is, a die cast rotor having a desired secondary resistance can be obtained.

The configuration shown in the above-described embodiment shows an example of the contents of the present disclosure, can be combined with another known technique, and is one of the configurations as long as it does not deviate from the gist of the present disclosure. It is also possible to omit or change the part.

11 die cast rotor, 12 stator jig, 12a stator core, 12b stator winding, 13 fixing pin, 14 AC voltage source, 15 power meter, 16 resistance meter, 17 temperature sensor, 18 arithmetic unit, 19 lathe device, 19a transfer device. , 19b blade, 31 rotor core, 32 rotor bar, 33 end ring.

Claims

A squirrel-cage die-casting rotor having a rotor core, a plurality of rotor bars disposed around the rotor core, and end rings provided at both ends of the rotor core and connecting each end of the plurality of rotor bars. In the secondary resistance adjusting device of the die casting rotor that adjusts the secondary resistance which is the combined resistance with the end ring.
A stator jig having a stator winding and a stator core into which the die-cast rotor is inserted.
A fixture for fixing the die cast rotor to the stator jig, and
An AC voltage source that applies a voltage for generating a rotating magnetic field to the stator windings inside the stator jig,
A first measuring instrument for measuring the electric power generated in the stator winding when the voltage is applied to the stator winding by the AC voltage source.
A second measuring instrument for measuring the resistance value of the stator winding, and
A third measuring instrument for measuring the temperature of the end ring or the rotor bar of the die casting rotor, and
Based on the measurement results of the first measuring instrument, the second measuring instrument, and the third measuring instrument, the cutting allowance of the end ring for setting the secondary resistance to the first value is calculated. Arithmetic logic unit and
A lathe device that cuts the end ring based on the cutting allowance calculated by the arithmetic unit, and
A secondary resistance adjusting device for a die cast rotor, which is characterized by being provided with.
The arithmetic unit obtained and obtained the secondary resistance before cutting the end ring based on the measurement results of the first measuring instrument, the second measuring instrument, and the third measuring instrument. The secondary resistance adjusting device for a die cast rotor according to claim 1, wherein the cutting allowance of the end ring is calculated based on the secondary resistance before cutting and the first value.
The secondary resistance adjusting device for a die cast rotor according to claim 1 or 2, wherein the rotor bar and the end ring are made of aluminum.
Using a stator jig having a stator winding and a stator core into which a die-cast rotor is inserted, a rotor core, a plurality of rotor bars arranged around the rotor core, and both ends of the rotor core are provided. In a method for adjusting secondary resistance of a die casting rotor that adjusts a secondary resistance that is a combined resistance between the rotor bar and the end ring of a cage-type die casting rotor having an end ring that connects each end of the plurality of rotor bars. ,
The process of fixing the die cast rotor so that it does not rotate with respect to the stator jig, and
A step of applying a voltage for generating a rotating magnetic field to the stator jig to the stator winding, and a process of applying the voltage to the stator winding.
A step of measuring the electric power generated in the stator winding when the voltage is applied to the stator winding, and a step of measuring the electric power generated in the stator winding.
The step of measuring the temperature of the end ring or the rotor bar of the die casting rotor, and
The process of measuring the resistance value of the stator winding and
A step of calculating the cutting allowance of the end ring for making the secondary resistance a first value based on the measured power, the measured temperature, and the measured resistance value.
The process of cutting the end ring based on the calculated cutting allowance, and
A method for adjusting the secondary resistance of a die cast rotor, which comprises.