JPS5924622B2 - Magnetizer for motor permanent magnet pieces - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides that a pole caning is axially fitable over a cylindrical magnetizing core shaft and is worn within a pole casing supporting a magnetizing coil placed in a longitudinal slot. The present invention relates to a magnetizing device for a permanent magnet piece.

When assembling a motor in which permanent magnets are incorporated in the stator, the magnetization ability of the separate permanent magnet pieces is first tested.

Before inserting the magnet piece into the pole casing, it is essential to completely demagnetize the magnet piece again, otherwise the magnetic forces will prevent assembly of the pole casing.

The fully assembled pole casing is then fitted onto the above-mentioned magnetizing upper shaft and the permanent magnet pieces are magnetized.

Testing of the magnetic flux generated by permanent magnets has traditionally only been possible after the final assembly of the armature and pole casing and during the final inspection.

If the magnetic flux does not correspond to the specified value, the motor cannot be used and must be disassembled again to remove defective parts. The purpose is to make it possible to check whether the magnetization is sufficient during magnetization of the pole casing.

The device according to the invention is suitable, for example, for use in mass production and can be achieved at very little additional cost.

According to the invention, this object is achieved by supporting a measuring coil whose upper axis of magnetization is located at least approximately in the vicinity of the pole gap plane.

For magnetizing the pole caning according to the invention, the pole housing is inserted axially onto the magnetizing upper shaft and then pulled out again.

When a measuring coil located near the pole gap plane is installed in the magnetized axis, a voltage is induced in the measuring coil during relative movement between the pole casing and the magnetized core axis, and its time integral is the magnitude of the magnetic flux intensity. is independent of the speed of relative motion.

The measuring coil can simply be connected to an electronic magnetometer or other electronic integrator.

As a result, the strength of the magnetic flux can be measured automatically without any additional work steps, and a pass/fail indication can be given each time.

The device according to the invention is thus particularly advantageous for mass production.

If the required magnetic flux is not obtained, the pole casings can be removed, saving the labor time required for final assembly and the subsequent disassembly time required for conventional conventional measurement methods.

The measuring coil is mounted in the magnetized core shaft, so that the magnetized core retains a cylindrical surface.

It is particularly advantageous in this case to mount the measuring coil at the bottom of the slot of the magnetizing coil, so that the functioning of the magnet arrangement can be better monitored and stray effects are less of a problem.

Furthermore, the measuring coil can be used to detect the maximum value of the magnetic flux impulse during zero magnetization.

The desired magnetization strength is thereby obtained, the maximum value of which must exceed a predetermined limit value.

If this value is not reached, the permanent foundation stone will not be sufficiently magnetized and the specified magnetic flux will not occur.

In this way, the magnetization device itself can also be monitored at the same time.

It is furthermore advantageous to provide the upper magnetization axis with sensors distributed around it in order to detect the course of the magnetic flux density in the circumferential direction.

As a result, peaks and troughs in the magnetic field distribution, which actually lead to noise-prone motors due to non-uniformity of the material, are detected, and these magnet pieces are removed.

These additional sensors can be mounted, for example, in the center of each magnet strip and at the ends of the magnet strip, so that the local magnetic field strength at particularly relevant locations on the magnetic field distribution is monitored.

Static sensors, such as, for example, Hall probes, can be used as well as dynamically operated sensors that require a relative movement between the pole casing and the upper axis of magnetization in order to induce a voltage depending on the area of use.

The dynamically operating sensor, as well as the measuring coil, is connected to an already known integrating element.

Next, the present invention will be explained in detail using examples.

A magnetizing upper shaft 1 made of a thin plate has two mutually opposing slots extending in the axial direction on its cylindrical surface, and according to the known method, a magnetizing coil 2 is accommodated in the slots. There is.

In addition to the magnetizing coil 2, a measuring coil 3 is provided at the bottom of the slot.

The measuring coil is arranged close to the pole gap plane, so that at the same time it responds well to the magnetic field of the magnet pieces 4 and 5 to be magnetized.

Together with the pole casing 6 surrounding the magnet pieces, the magnet pieces shown in dotted lines are fitted axially onto the magnetizing upper shaft, with one magnet piece above the magnetizing upper shaft and the other magnetizing piece above the magnetizing upper shaft. It touches the bottom of the upper shaft.

That is, they are transposed 90 degrees with respect to the magnetizing coil 2 and the measuring coil 3, respectively.

The operating method is described below.

The pole casing 6 has magnet pieces 4 and 5 which are not yet magnetized.
It is also fitted onto the upper magnetization shaft 1.

The magnet pieces 4 and 5 are magnetized by current impulses in the magnetizing coil 2, and the pole casing 6 is pulled out from the magnetizing upper shaft for further assembly.

During this withdrawal movement, the area of the magnet piece surrounded by the measuring coil 3 that is affected by the magnetic field changes, so that a voltage is induced in the measuring coil 3.

The time integral of this voltage is independent of the withdrawal speed of the pole casing and indicates whether the magnetic flux has the desired value.

The causes of insufficient magnetic flux can be due to functional defects of the magnetizing device as well as material defects of the magnet material, and an examination of the magnetic flux can at the same time indicate an accidental deterioration of the functioning of the magnetizing device.

Using electronic fluxmeters or other electronic integrators, it is furthermore possible to automate the necessary zero adjustment of the measuring instruments for each measuring step.

In order to check the overall magnetic flux as well as to know the magnetic flux distribution in the circumferential direction, measuring probes 7 to 12 are mounted in the magnetizing core 1 at the center of the magnet piece and at the end of the magnet piece, respectively.

This measuring probe extends in the longitudinal direction of the upper axis of magnetization.

The measuring probe can be configured, for example, as a hall probe or as a measuring coil connected to an integral voltage measuring device.

In this case, the magnetic flux can be directly measured on the surface of the six axes, and the magnetic flux can be known relatively accurately in a virtually circular range.

If the desired value is not obtained, the defect is indicated by an alarm signal or automatic shutdown of the magnetizing device.

To summarize the advantages of the present invention, the magnetic flux of the magnet system can be measured directly after magnetization without interrupting the production flow and without requiring additional work steps, and further processing of this defective product can be stopped. .

In addition, defects in the magnetization device itself can be detected directly.

[Brief explanation of the drawing]

FIG. 1 shows a sectional view of the magnetized core shaft according to the present invention, and FIG. 2 shows a plan view of the magnetized core shaft according to FIG. 1...Magnetized core shaft, 2...Magnetized coil,
3... Measuring coil, 4.5... Magnet piece, 6... Pole casing, 7, 8, 9, 10, 1
1.12...Sensor.

Claims (1)

[Claims] 1. A permanent magnet piece installed in a pole casing that can be fitted onto a cylindrical magnetization core shaft in the axial direction is magnetized using a magnetization coil installed in a vertical slot of the magnetization upper shaft. A magnetizing device, characterized in that the upper magnetizing axis 1 supports a measuring coil 3 located at least approximately in the vicinity of the pole gap plane. 2. Device according to claim 1, in which the measuring coil 3 is mounted in the magnetized core 1. 3. Device according to claim 1 or 2, in which the measuring coil 3 is arranged at the bottom of the slot of the magnetizing coil 2. 4. Any one of claims 1 to 3, wherein the upper magnetization shaft 1 further has sensors 7 to 12 distributed around it in order to detect the course of magnetic flux density in the circumferential direction. The device according to item 1. 5. Device according to claim 4, in which the sensor is constructed as a whole sensor. 6. Device according to claim 1, in which the measuring coil is connected to an integrating element. 7. The device according to claim 4, wherein the sensor is connected to an integrating element.