JPH1066328A - Linear motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save much space. SOLUTION: A linear motor 1 is constituted of a secondary side 2 and a primary side 3 which is located at an air gap from the secondary side 2. The primary side 3 is constituted of a core 6, a coil wound around the core 6, and a core supporting member 9. The core 6 is provided with a magnetic pole detector 11 which has a built-in magnetic force sensor 12 and a built-in signal shaping circuit. The magnetic pole detector 11 is located at the side of the secondary side 3 which is outside a permanent magnet 5, with an element face of the magnetic force sensor 12 facing a yoke 4 of the secondary side 2 and being inclined at a specified angle θ against the yoke 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor used for a linear moving mechanism of a rectangular coordinate type robot or the like.

[0002]

2. Description of the Related Art Conventionally, a secondary side as a stator is constructed by laying a plurality of permanent magnets linearly so that polarities are alternately different, and a movable element is provided on the secondary side via an air gap. A linear motor having a primary side opposed to the above is generally known (for example, Japanese Patent Publication No. Hei 7-108086).
No.).

[0003] In this type of linear motor, a magnetic force detection sensor comprising a Hall element or the like is mounted on the primary side, and based on the magnetic force detection of the magnetic force detection sensor, a change in the magnetic pole on the secondary side is detected to control the operation. It is supposed to do. In general, the magnetic force detection sensor is fixedly mounted so as to face the permanent magnet on the secondary side at the front or rear part in the movable direction on the primary side.

[0004]

However, in the conventional linear motor in which the magnetic force detecting sensor is mounted on the front side or the rear side of the primary side as described above, the magnetic force detecting sensor is provided in addition to the electromagnetic structure for generating thrust. The primary side is larger in the movable direction by the amount of. For this reason, in addition to the moving range of the electromagnetic structure portion, an extra space is required before and after the moving direction by the amount of the magnetic force detection sensor, and it is necessary to review this structure in order to save the space of the linear motor.

Therefore, it is conceivable to make the linear motor compact in the movable direction by providing a magnetic force detection sensor on the lower surface of the primary side, or by providing a magnetic force detection sensor on the side of the primary side 3. It is actually difficult to implement the former because it is necessary to provide a constant air gap between the side and the secondary side, and the magnetic force detection sensor does not face the permanent magnet simply by adopting the latter method. Therefore, there is a concern that the magnetic force detection is not properly performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and has as its object to provide a linear motor that can suitably save space.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to a secondary side in which a plurality of permanent magnets having alternately different polarities are laid in a moving direction via a yoke, and opposed to the secondary side via an air gap. In the linear motor configured with the primary side provided, a magnetic force detection sensor for detecting a magnetic pole change is mounted on the primary side, and the magnetic force detection sensor is disposed on the side of the primary side in the movable direction, and It is arranged outside the permanent magnet and opposed to the yoke at a predetermined angle.

[0010] According to this configuration, since the magnetic force detection sensor is provided on the primary side in the movable direction, the linear motor is compact in the movable direction. Moreover, since the magnetic force detection sensor is provided to face the yoke in a state of being inclined at a predetermined angle, it is possible to appropriately detect a change in magnetic pole based on the detection of magnetic flux leaking from the yoke.

[0009]

Embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show an example of a linear motor according to the present invention. As shown in these figures, the linear motor 1 has a secondary side 2 as a stator and this secondary side 2
And a primary side 3 as a mover provided above the air gap via an air gap.

On the secondary side 2, a plurality of permanent magnets 5 having alternately different polarities are arranged in the left-right direction (moving direction of the primary side 3) and laid on a horizontal base via a yoke 4. It is constituted by that.

On the other hand, the primary side 3 includes a core 6 made of a silicon steel material, a coil 8 mounted on the core 6, and a core supporting member 9.

As shown in FIG. 2, the core 6 has a structure in which thin plate-shaped unit cores 6a having the same shape are overlapped in a width direction (a direction orthogonal to the left-right direction on a plane) and integrally joined. ing. As shown in FIG. 1, each unit core 6a has auxiliary teeth 7b on both left and right sides, and has a comb shape having a plurality of true teeth 7a at regular intervals therebetween. The teeth 7b are connected with each other in a state corresponding to the width direction. The coil 8 is mounted on the main teeth 7a of the unit cores 6a superposed in the width direction as described above.

The unit cores 6a are connected by forming through holes in the unit cores 6a at appropriate locations in the width direction, and fastening the unit cores 6a with bolts and nuts using the through holes. ing.

A magnetic pole detecting device 11 is attached to the side of the core 6 (the left side in FIG. 2). As shown in FIG. 1, the magnetic pole detection device 11 includes a plurality of magnetic force detection sensors 12 (3 in this embodiment) each including a Hall element and the like mounted at regular intervals on a printed circuit board that is elongated left and right.
Two magnetic force detection sensors 12) and a signal shaping circuit that performs predetermined processing on data detected by these magnetic force detection sensors 12 and outputs the processed data to a controller or the like (not shown). The data obtained as a sine waveform by each magnetic force detection sensor 12 is converted into rectangular waveform data in a signal shaping circuit and then output to a controller or the like.

The magnetic pole detecting device 11 is mounted on the core 6 via a mounting member 10 mounted on the auxiliary teeth 7b of the core 6.
It is fixed to.

As shown in FIGS. 2 and 3, the mounting member 10 has an L-shape having a vertical portion 10a along the side surface of the core 6 and a mounting portion 10b projecting laterally at the lower end. And a bolt 1 for connecting the unit cores 6a in a state where the vertical portion 10a is superimposed on the side surface of the core 6.
3a and nut 13b are fastened together to the core 6.
The magnetic pole detection device 11 is attached to the core 6 by fastening the left and right ends of the magnetic pole detection device 11 to the lower surface of the attachment portion 10b with bolts 14a and nuts 14b with the magnetic force detection sensor 12 facing the yoke 4.

Here, the mounting portion 10b of the mounting bracket 10
3 is appropriately inclined with respect to the horizontal plane as shown in FIG. 3, whereby the element surface of the magnetic force detection sensor 12 is inclined with respect to the yoke 4 by an angle θ, and in this embodiment, by about 20 °. Installed in. That is, by attaching the magnetic force detection sensor 12 to the core 6 in such a state that the magnetic force detection sensor 12 is tilted, it is possible to accurately detect a magnetic pole change as described later.

The core supporting member 9 is mounted on the core 6 configured as described above to support the core 6. For example, the core supporting member 9 is provided on the upper part of the core supporting member 9 for work. Are mounted.

According to the linear motor 1 configured as described above, since the magnetic force detection sensor 12 is attached to the side portion of the primary side 3 as described above, the magnetic force detection sensor is moved forward in the primary movement direction. Alternatively, the space saving of the linear motor 1 can be suitably achieved as compared with a conventional linear motor 1 of this type mounted on the rear side.

That is, in the conventional linear motor in which the magnetic force detection sensors are attached to the front and rear of the moving direction, the magnetic force detection sensors are provided so as to protrude to the front and rear of the core via mounting hardware and the like, so that thrust is generated. In addition to the range of movement of the electromagnetic structure such as the core, extra space is required in the moving direction by the amount of the magnetic force detection sensor, in other words, if the installation space of the linear motor is limited, the magnetic force detection The moving distance of the electromagnetic structure portion such as the core has to be set shorter by the amount of the protruding sensor.

However, according to the linear motor 1, since the magnetic force detecting sensor 12 is attached to the side of the primary side 3, there is no extra protruding portion before and after the electromagnetic structural portion such as the core 6, so that the conventional motor is not used. There is no such disadvantage of the linear motor. Accordingly, the linear motor 1 can be installed in a smaller space, and the space can be more effectively utilized when the linear motor 1 is applied.

When the magnetic force detecting sensor 12 is provided on the side of the primary side 3 as in the linear motor 1, the magnetic force detecting sensor 12 is located outside the permanent magnet 5 as shown in FIG. There is concern that changes cannot be detected accurately. However, even when the magnetic force detection sensor 12 is located outside the permanent magnet 5, it is possible to detect a change in the magnetic pole by detecting the leakage magnetic flux from the core 6 to the yoke 4. 4
When the magnetic force detection sensor 12 is installed at an angle with respect to, accurate change in the magnetic pole can be detected.

FIG. 5 shows the results of detection of the magnetic force by the magnetic force detection sensor 12 when the magnetic force detection sensor 12 is arranged at each position shown in FIG. 4A shows the case where the magnetic force detection sensor 12 is arranged facing the permanent magnet 5, and FIG. 4B shows the case where the magnetic force detection sensor 12 is arranged outside the permanent magnet 5 in parallel with the yoke 4. , (C)
3B shows a case where the magnetic force detection sensor 12 is disposed at an angle θ with respect to the yoke 4.

As shown in these figures, when the magnetic force detection sensor 12 is arranged at an angle θ (open circles in FIG. 5), the magnetic force detection sensor 12 is arranged to face the yoke 4 in parallel ( A larger detection value is obtained as compared to the black triangle in FIG. 5, and a result substantially equivalent to the case where the magnetic force detection sensor 12 is arranged to face the permanent magnet 5 (the black circle in FIG. 5) is obtained. Therefore, it can be considered that the change of the magnetic pole can be accurately detected by inclining the magnetic force detection sensor 12 by the angle θ. In FIG. 5, the magnetic force detection sensor 12
The direction of the magnetic flux to be detected by the magnetic force detection sensor 12 differs between the case where the magnetic force detection sensor 12 is arranged outside the permanent magnet 5 and the case where the magnetic force detection sensor 12 is arranged to face the permanent magnet 5, so that the detection values are reversed. ing.

However, in order to detect such a good change in the magnetic pole, the mounting position and angle of the magnetic force detection sensor 12 or the permanent magnet 5 and the yoke are adjusted so that the magnetic flux detection sensor 12 appropriately detects the leakage magnetic flux. For example, the width of the core 6 on the primary side 3 and the width of the permanent magnet 5 on the secondary side 2 are set to be substantially the same, and the magnetic force detection sensor 12 is disposed above the yoke 4. The mounting position of the magnetic force detecting sensor 12 or the widthwise dimension of the yoke 4 is set so that the magnetic pole change is detected. It is desirable to set the angle.

The linear motor 1 of the above embodiment is
Is an example of the linear motor of the present invention, and its specific configuration can be appropriately changed without departing from the gist of the present invention.

For example, in the linear motor 1 described above, the magnetic pole detection device 11 incorporates the magnetic force detection sensor 12 and the signal shaping circuit integrally.
On the other hand, a signal shaping circuit may be built in an external controller or the like, and data detected by the magnetic force detection sensor 12 may be transmitted to the controller or the like, and then processed by the signal shaping circuit. However, as in the linear motor 1 described above, the magnetic force detection sensor 12 and the signal shaping circuit are integrated into the magnetic pole detection device 11 so that the data obtained as a sine waveform is converted into rectangular waveform data and output to a controller or the like. This has the advantage of being less susceptible to noise and increasing the reliability of the detected data.

In the linear motor 1, the bolt 13a and the nut 13b for integrating the unit cores 6a are integrated.
The mounting bracket 10 is fastened to the core 6 together. For example, a dedicated mounting hole is provided in the core 6 and the core 6 is mounted with a bolt and nut, or the core 6 is mounted on the core 6 using the core support member 9. The metal fitting 10 may be attached. However, on the primary side 3, the mounting of components other than the electromagnetic structure part that generates thrust is suppressed as much as possible, thereby suppressing the enlargement of the primary side 3 to ensure the operation of the primary side 3,
Alternatively, it is advantageous in operation control, and therefore, like the linear motor 1 of the above embodiment, the bolt 13a and the nut 1a
It is preferable that the mounting bracket 10 is mounted using the common 3b. Although omitted in the description of the above embodiment, it is necessary to attach a connector for connecting a power supply wire to each coil 8 to the primary side 3, and therefore, when attaching this connector, for example, As shown in FIG. 6, a mounting bracket 2 for fixing the connector 20 is provided.
By using the bolts 13a and nuts 13b for fixing the mounting bracket 10 and the bolts 22 for mounting the core 6 to the core supporting member 9, the primary side 3 can be effectively prevented from being enlarged. be able to.

[0030]

As described above, according to the present invention, a secondary side in which a plurality of permanent magnets having alternately different polarities are laid in the moving direction via a yoke is opposed to the secondary side via an air gap. In the linear motor composed of the primary side and the primary side, a magnetic force detection sensor for detecting a magnetic pole change is mounted on the primary side, and the magnetic force detection sensor is disposed on the side of the primary side in the movable direction and a permanent magnet is provided. Outside and at a predetermined angle with respect to the yoke, so as to be opposed to each other.
An accurate change in the magnetic pole can be detected based on the detection of the leakage magnetic flux of the magnetic force detection sensor.

[Brief description of the drawings]

FIG. 1 is a side view of a linear motor according to the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is an enlarged view of a main part in FIG. 2 showing an arrangement of a magnetic force detection sensor.

4 (a) to 4 (c) are schematic diagrams corresponding to FIG. 2 showing mounting positions of a magnetic force detection sensor.

FIG. 5 is a diagram showing a detection result of a change in magnetic pole when the magnetic force detection sensors are arranged in (a) to (c) of FIG.

FIG. 6 is a diagram illustrating a mounting structure of a power supply connector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Linear motor 2 Secondary side 3 Primary side 4 Base 5 Permanent magnet 6 Core 7a True tooth part 7b Auxiliary tooth 8 Coil 9 Core support member 10 Mounting bracket 11 Magnetic pole detection device 12 Magnetic force detection sensor

Claims (1)

[Claims] 1. A secondary side in which a plurality of permanent magnets having alternately different polarities are laid in a moving direction via a yoke, and a primary side provided opposite to the secondary side via an air gap. In the linear motor, a magnetic force detection sensor for detecting a magnetic pole change is mounted on the primary side, and the magnetic force detection sensor is disposed on the side of the primary side in the movable direction and is outside the permanent magnet, and A linear motor, wherein the linear motor is arranged to face the yoke at a predetermined angle.