JP2009270926A - Test device of magnet for motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a test device of a magnet for a motor for easily and inexpensively specifying demagnetization mode of a magnet at a certain instant under an optional condition. <P>SOLUTION: The test device 10 for measuring the demagnetization state of the magnet for the motor comprises a fixture 2 for holding the motor M formed of a stator S and a rotor R that is located in the inside and has the magnet E in an attitude where the stator S and the rotor R form an optional machine angle, a power supply 3 for carrying direct current to a coil C wound on the stator S, and a magnetic flux meter 4 for measuring the demagnetization state of the magnet E. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a test apparatus for measuring a demagnetization state of a magnet for a motor, and in particular, to determine a demagnetization state of a magnet in a desired motor ambient temperature condition, a desired magnet temperature condition, a desired mechanical angle, and an energized state. The present invention relates to a motor magnet testing apparatus that can be easily and accurately specified.

  A test apparatus for measuring the demagnetization state (demagnetization mode) of a permanent magnet that constitutes a conventional vehicle drive motor uses an actual vehicle to drive the motor, for example, thousands or tens of thousands of revolutions, and then from the motor The permanent magnet was taken out and the demagnetization state (such as which part of the permanent magnet is demagnetized) was measured with a magnetometer.

  However, such a conventional test method uses an actual vehicle to rotate a large number of motors in order to measure the demagnetization mode of the permanent magnet, which requires a large apparatus, increases the test cost, and increases the test time. It was time-consuming and the improvement was screamed.

  Further, the demagnetization state of the permanent magnet taken out after the motor is driven only shows the final demagnetization result, and any mechanical angle (based on the state where the N-pole permanent magnet comes in front of a certain tooth) Angle: This is the angle at which this permanent magnet has moved relative to zero degrees, and what demagnetization occurs in which part of the permanent magnet, or what current state (three-phase alternating current at a certain moment) Any condition such as what demagnetization occurs depending on the amount of current of each phase), and what kind of demagnetization occurs in the ambient temperature of the motor or the temperature of the permanent magnet It is impossible to specify the demagnetization mode of the permanent magnet at a certain moment below.

  If it is possible to easily reproduce any condition that correlates the energization condition, temperature condition, mechanical angle condition, etc., and grasp the demagnetization state of the permanent magnet under that condition, as much as possible while ensuring the prescribed torque performance It can be effective basic data for designing an inexpensive permanent magnet. This is because rare earth magnets are generally used as current permanent magnets, and this rare earth magnet has a coercive force by adding dysprosium (Dy) or terbium (Tb), which are elements having high crystal magnetic anisotropy. On the other hand, these elements are rare and expensive, and the addition of dysprosium, etc. to increase the coercive force of permanent magnets directly leads to a rise in the production cost of permanent magnets. Based on the magnetic mode data, it is possible to specify an optimal magnet configuration (how much dysprosium or the like is added to which part of the magnet).

  It should be noted that there are almost no published techniques related to conventional permanent magnet testing devices, and examples thereof include a permanent magnet evaluation device disclosed in Patent Document 1. However, this evaluation device is a device for evaluating the magnetized state of the permanent magnet, and as described above, it cannot identify the demagnetization mode of the permanent magnet at a certain moment under an arbitrary condition.

JP 11-295403 A

  The present invention has been made in view of the above-mentioned problems, and is a test of a motor magnet that can specify a demagnetization mode of a magnet at any moment under an arbitrary condition simply and without cost. An object is to provide an apparatus.

  In order to achieve the above object, a motor magnet test apparatus according to the present invention is a test apparatus for measuring a demagnetization state of a motor magnet, and includes a stator and a rotor having the magnet positioned therein. Measuring the demagnetization state of the magnet, a jig for holding the motor in a posture in which the stator and the rotor have an arbitrary mechanical angle, a power source for supplying a direct current to the coil wound around the stator, and a magnet. And at least a magnetometer.

  The test apparatus of the present invention is not required to use an actual vehicle, and the desired temperature condition, motor angle of the motor (in the IPM motor, rotation angle of any permanent magnet with respect to any tooth), energization condition (in a three-phase AC motor) The current state of each phase of U, V, and W at a certain moment is reproduced, and the demagnetization mode of the magnet (permanent magnet) under that condition (how much demagnetization occurs in which part of the magnet, magnet This is a device that can evaluate the total amount of magnetic flux).

  Here, a permanent magnet can be mentioned as the magnet for the motor targeted by the test apparatus of the present invention, a ternary neodymium magnet obtained by adding iron and boron to neodymium, and a binary alloy of samarium and cobalt. Samarium-cobalt magnets composed of the above, ferrite magnets made mainly from iron oxide powder, alnico magnets made from aluminum, nickel, cobalt and the like. The target motor may be either a DC motor or an AC motor, a motor (IPM motor, stepping motor, etc.) having a magnet (permanent magnet) inside the rotor, and a motor having a magnet on the outer periphery of the rotor. Both (SPM motors) are to be tested.

  This test apparatus is provided with a jig for mounting and fixing a motor, and can hold the motor in a stator and rotor posture so as to have an arbitrary mechanical angle.

  Here, it is preferable that the permanent magnet is temporarily fixed in the magnet slot of the rotor constituting the motor to be fixed without being resin-fixed or the like. Since the permanent magnet can be taken out from the rotor immediately after energization, and a separate permanent magnet for testing can be easily inserted into the slot, this leads to improvement in test efficiency when using a large number of permanent magnets. It is.

  Further, in this test apparatus, a direct current is applied to a coil formed around the stator teeth without rotating the rotor, that is, in a stationary posture. There is no need to firmly fix it inside.

  The test apparatus according to the present invention further includes a power source for supplying a direct current to a coil formed around the teeth of the stator, and when a three-phase coil is formed, the U-phase, V-phase, and W-phase are provided. An independent DC power source is provided for each phase. For example, a rotor and a stator set at a desired mechanical angle are fixed with a jig, and only a U-phase coil or a U-phase and a V-phase, for example, of three-phase coils is reproduced in order to reproduce an energized state at a certain moment. A specific direct current is applied only to the U phase, the U phase, the V phase, and the W phase.

  Since any part of the permanent magnet is demagnetized by this energization, the energized permanent magnet is taken out of the rotor, and the demagnetization mode is specified using the magnetometer. Here, examples of the magnetometer used include a Gauss meter suitable for measuring the amount of magnetic flux at a specific point of the permanent magnet, and a flux meter suitable for measuring the total amount of magnetic flux of the permanent magnet.

  A permanent magnet is inserted into the rotor and temporarily fixed, the mechanical angle is set to a desired angle, a direct current is applied in a desired energization pattern, the permanent magnet is taken out of the slot, and its demagnetization mode is detected by a magnetometer. By repeatedly performing the operation of measuring (such as the amount of magnetic flux at an arbitrary part) while changing the condition setting, the magnet demagnetization mode at a certain moment when the motor is driven can be easily reproduced and specified.

  In addition, a preferred embodiment of the motor magnet testing apparatus according to the present invention further includes a thermostatic chamber that houses the motor and places the motor in an arbitrary pseudo-temperature atmosphere.

  In the present embodiment, for example, a temperature condition around a motor mounted in an actual vehicle, a temperature condition at the time of driving an engine in extreme heat, a temperature condition at the time of driving an engine in a cold region, etc. The purpose of this test is to reproduce the conditions and evaluate the demagnetization mode of the motor magnet under this pseudo-temperature atmosphere. As a configuration therefor, the test apparatus further includes a thermostatic chamber capable of reproducing any temperature environment. It is.

  For example, a jig is prepared in the thermostatic bath, the motor is accommodated in the thermostatic bath, the motor is fixed with a jig at a desired mechanical angle, and the desired temperature condition is set in the thermostatic bath. Energize with the energization pattern. By removing the permanent magnet from the rotor after energization and evaluating the demagnetization mode with a magnetometer, it is possible to evaluate the demagnetization mode of the permanent magnet taking into account the temperature environment around the motor, and more accurate evaluation results Can be obtained.

Furthermore, in a preferred embodiment of the motor magnet test apparatus according to the present invention, a heating member for heating only the magnet is directly or indirectly connected to the magnet.
The present embodiment is an apparatus for performing a test by placing only a permanent magnet under a desired temperature condition. In particular, when the permanent magnet is in a high temperature state, heat is applied to bobbins, insulating paper, etc. around the teeth. This embodiment is suitable when only the permanent magnet is desired to be in a high temperature state without being damaged by the above.

As a configuration for that purpose, a heating member such as a heating wire leading to a heating source is attached to the permanent magnet to heat only the permanent magnet to a desired temperature, and then the coil is energized to evaluate the demagnetization mode.
Here, the heating member is constituted by an endless part surrounding the permanent magnet and an overhanging part protruding from the endless part, and the endless part is fixed to the magnet provided on the side of the magnet insertion slot. It is more preferable that the heating wire that is accommodated in the resin filling portion for use and that leads to the heating power source is attached to the overhang portion.

  According to the heating member of this form, a permanent magnet having a magnetic field generated by the heating wire by effectively using the resin filling portion formed in the magnet slot from the beginning and attaching the heating wire to the overhanging portion away from the permanent magnet. Can be effectively eliminated.

  By using the motor magnet testing apparatus according to the present invention described above, permanent magnet demagnetization under certain moment conditions (mechanical angle, energized state, permanent magnet temperature, motor outer periphery temperature, etc.) during motor driving. It becomes possible to accurately evaluate and specify the mode. Furthermore, the heat resistance of the magnet can be evaluated by giving a desired temperature change. By changing the setting conditions in various ways, specifying the demagnetization mode for each condition and accumulating the specified data, it is possible to optimize the permanent magnet design (the material corresponding to the required coercive force that differs for each part of the permanent magnet) (Some parts are composed of neodymium magnets, some parts are composed of samarium cobalt magnets, or some parts are mixed with dysprosium and some parts are mixed)) Can be basic data.

  As can be understood from the above description, according to the motor magnet test apparatus of the present invention, the desired conditions can be accurately reproduced by a simple method without incurring costs, and under the reproduced conditions. The demagnetization mode of the permanent magnet in the rotor can be evaluated and specified. This can serve as basic data for designing a permanent magnet that is as inexpensive as possible while ensuring the desired torque performance, and in particular, hybrid vehicles and electric vehicles whose production continues to expand. This contributes to the optimum design of permanent magnets used in the drive motors.

  Embodiments of the present invention will be described below with reference to the drawings. In the illustrated example, a permanent magnet used in a three-phase AC IPM motor is a test object. However, any type of motor including a DC motor and a permanent magnet used in the permanent magnet are used as a test object. Of course you can do it.

  FIG. 1 is a schematic diagram illustrating a test apparatus according to the present invention. The test apparatus 10 can form a desired pseudo-temperature environment, and is a thermostat 1 that houses the motor M, a rotor jig 22 that is provided in the thermostat 1 and supports the rotor R that constitutes the motor M, and a stator. Stator jig 23 for supporting S is erected on common base 21, and each of U phase coil, V phase coil, and W phase coil formed around each tooth of stator S DC power source 3 capable of supplying independent DC currents to U-phase electric wire 31, V-phase electric wire 32, and W-phase electric wire 33, and magnetic flux for measuring the demagnetization mode of the permanent magnet after energization The total is composed of a total of four.

  The inside of the thermostatic chamber 1 is loaded with an actual motor desired by the tester when evaluating the demagnetization mode of the permanent magnet, such as the temperature condition when the engine is driven in a severe heat and the temperature condition when the engine is driven in a cold region. The ambient temperature can be reproduced.

  Further, the rotor jig 22 and the stator jig 23 can be adjusted to each other so that the angle (mechanical angle) between the permanent magnet and the stator teeth (magnetic pole) can be set to an angle desired by the tester. It has become.

  Further, as shown in FIG. 2, after the permanent magnet E is inserted into the magnet slot ES of the rotor R, the resin is filled in the resin filling slot JS for fixing the permanent magnets opened on the side of the magnet slot ES. The permanent magnet E is temporarily fixed without injecting.

  Here, in order to bring only the permanent magnet E into a desired high temperature state, the heating member 5 is attached to the outer periphery of the permanent magnet E, and the permanent magnet E in a posture in which the heating member 5 is attached is inserted into the magnet slot ES. The heating member 5 includes an endless portion 51 made of a heat conductive material that directly surrounds the permanent magnet E, and an overhanging portion 52 that protrudes from one end of the endless portion 51. It fits in the resin filling slot JS.

  An end portion of the heating wire 6 extending from the electric heat source 7 is wound around the overhanging portion 52, and heat from the electric heat source 7 is transmitted only to the permanent magnet E through the overhanging portion 52 and the endless portion 51, and the permanent magnet E can be brought to a desired high temperature state.

  As apparent from the figure, by attaching the heating wire 6 to the overhanging portion 52 located away from the permanent magnet E, the magnetic field generated by the heating wire 6 can be prevented from acting on the permanent magnet.

  As shown in FIG. 2, in a rotor R in which one magnetic pole is formed from V-shaped permanent magnets E, E opened on the stator side, a heating member 5 is attached to each permanent magnet E as shown in FIG. When it is desired to evaluate the demagnetization mode of the permanent magnet E in a desired high temperature state, the test is performed with only the permanent magnet E being in a high temperature state. In this test, an arbitrary temperature state, mechanical angle state, and energized state are taken out, and the demagnetization mode of the permanent magnet in the instantaneous state is evaluated and specified. Both stators S are fixed in a posture that maintains a certain mechanical angle.

  The permanent magnet E is set to a desired temperature condition, the outer periphery of the motor M is set to a desired temperature atmosphere in the thermostat 1, and the rotor R and the stator S of the motor M are mounted and fixed at a desired mechanical angle. In this state, a desired energization pattern (applying a desired current only to the U-phase coil, applying a specific current to each of the V-phase coil and the W-phase coil, the U-phase coil, the V-phase coil, DC current is applied to all of the W-phase coils.

  When a current is applied, an arbitrary demagnetization occurs in a certain part of the permanent magnet under the test conditions. This is measured by a magnetometer 4 (Gauss meter or flux meter) shown in FIG. 1, and measurement data is accumulated in a computer (not shown).

  The temperature condition of the permanent magnet, the temperature condition in the thermostat, the mechanical angle condition, and the energization condition are variously changed, the demagnetization mode of the permanent magnet in various condition patterns is specified, and the data is accumulated.

  The illustrated test apparatus 10 performs a test by temporarily fixing a permanent magnet E in a magnet slot ES. Therefore, it is possible to take out the permanent magnet from the slot immediately after the momentary energization, insert the permanent magnet for the next test into the slot, temporarily fix it, and perform the test under other conditions. Many of the tests below can be performed very efficiently.

  In addition, since the test apparatus 10 of the present invention includes all of the constituent devices such as the DC power source 3, the thermostat 1, the magnetometer 4 and the like, the manufacturing cost of the apparatus is not expensive.

  Further, for example, it is not necessary to use an actual vehicle, and the test apparatus 10 is extremely compact, so that the test can be sufficiently performed even in a small place.

  By using this test apparatus 10 to evaluate, identify and store the permanent magnet demagnetization mode under various setting conditions, the optimum design (desired torque) of the permanent magnet is based on the accumulated data. It is possible to execute a permanent magnet that is as cheap as possible while ensuring performance and coercive force. Furthermore, the heat resistance of the magnet can be evaluated by giving a desired temperature change.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

It is the schematic diagram explaining the testing apparatus of this invention. It is a figure explaining the heating member which heats a permanent magnet.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Constant temperature bath, 2 ... Jig, 21 ... Base, 22 ... Rotor jig, 23 ... Stator jig, 3 ... DC power supply, 31 ... U-phase electric wire, 32 ... V-phase electric wire, 33 ... W Phase wire, 4 ... magnetometer, 5 ... heating member, 51 ... endless part, 52 ... overhang, 6 ... heating wire, 7 ... heating source, 10 ... test device, R ... rotor, S ... stator, M ... Motor, C ... Coil, E ... Permanent magnet, ES ... Magnet slot, JS ... Resin filled slot

Claims (5)

A test apparatus for measuring the demagnetization state of a motor magnet,
A jig for holding a motor composed of a stator and a rotor having the magnet located inside the stator in a posture in which the stator and the rotor have an arbitrary mechanical angle;
A power source for applying a direct current to a coil wound around the stator;
A magnet test apparatus for a motor comprising at least a magnetometer for measuring a demagnetization state of the magnet.   The motor magnet testing apparatus according to claim 1, further comprising a thermostatic chamber that houses the motor and places the motor in an arbitrary pseudo-temperature atmosphere.   The motor magnet test apparatus according to claim 1, wherein a heating member that heats only the magnet is directly or indirectly connected to the magnet.   The heating member includes an endless portion surrounding the permanent magnet, and an overhang portion protruding from the endless portion, and the endless portion is filled with a resin for fixing a magnet provided on the side of the magnet insertion slot. The motor magnet test apparatus according to claim 3, wherein a heating wire that is housed in a portion and is connected to a heating power source is attached to the overhang portion.   The stator of the motor is formed with U-phase, V-phase, and W-phase three-phase coils, and any one direct current or two or more phases can be energized. The motor magnet testing device according to claim 1.

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