JPS5970176A - Dc linear motor with encoder - Google Patents

Abstract

PURPOSE:To simplify the structure of a DC linear motor and to facilitate the assembling of the motor by forming a colored part having a reflectively different from a field magnet on the magnet, and providing a light emitting element, a photoconductive converter and a position detector at the armature side opposed to the colored part. CONSTITUTION:Since a light emitting element 9 of a photoreflector 11 emits an encoder forming colored part 12 when a field magnet 6 moves in a running direction, a photoconductive converter 10 alternately receives strong and weak reflected lights through the colored part 12 in a short time interval. A pulse from the converter 10 is processed via a waveform shaper 15 and an F/V converter 16 and applied to a speed controller 17. In this manner, the advancing speed of a moving element made of a field magnet 6 and the like is controlled. A position detector 5 is disposed oppositely to the magnet 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a straight-end linear motor with an encoder.

Conventionally, most of the linear motors found in many products are linear ξ-lux motors. However, is this linear pulse Chiyu a significant amount of blasphemy? : It is expensive, has a heavy container, and cannot move at high speeds, and when you try to move the traveler at high speed, it causes a step-out phenomenon, causing it to stop or malfunction.

However, as the linear motor, a DC linear motor is more desirable.

Also, voice coil type DC linear motors are known, but conventionally, this type of DC linear motor not only generates a counter thrust and cannot obtain strong thrust, but also has a short stroke. .

Furthermore, when installing a propulsion speed detection mechanism in a conventional DC linear motor, a very expensive encoder must be used. It was a motor.

The present invention has been made based on the above-mentioned circumstances, and has a simple configuration by rationally forming the entire encoder and incorporating it.
Moreover, it was designed to provide an i'Pj' style linear motor having an encoder that is easy to assemble and can be mass-produced at low cost.

Hereinafter, with reference to FIGS. 1 to 6, a movable Madai-tsut type surface flow linear motor LM including an encoder according to the first embodiment of the present invention will be described with diameter q shown in FIGS. 7 to 11. A moving coil type DC linear motor LM' for controlling the encoder 2 according to the second embodiment of the invention will be explained.

(First Example) Fig. 1 is a top view of a movable magnet type DC linear motor LM having an encoder, Fig. 2 is a side view of Fig. 1, and Fig.
The figure is a longitudinal cross-sectional view of the one shown in Figs. 1 and 2, viewed from the running direction.Mainly referring to Figs. 1 to 3, the configuration of the movable magnet type DC linear motor LM having an encoder is explain.

A movable magnet type linear motor LM having an encoder according to the first embodiment of the present invention is mounted on a long plate-shaped base 1.
A long magnetic plate 2 narrower than the width of the magnetic plate 2 is fixed, and three groups of rectangular frame-shaped armature coils as shown in FIGS. 1 and 5 are arranged adjacent to each other so as not to overlap each other. A printed circuit board 4 is adhered and fixed thereon to form a stator armature. As shown in FIG. 5, on the printed circuit board 4, a position horizontal element 5 ( For example, one magnetoelectric transducer (such as a Hall element or a Hall IC) is installed by soldering. In the armature coil 3, the opening angle between the conductor parts 3a and 3a contributing to the thrust is approximately 2n-1 (n
is a positive integer greater than or equal to 1) times, in this example, n''=
1, that is, the opening angle 1 is approximately equal to the magnetic pole width of the field magnet 6.
Escape using 1G. A U-shaped running magnetic yoke 7 is provided opposite to the stator armature consisting of the three groups of armature coils, and the running magnetic yoke 7 has a running roller 8 rotatably supported on its side surface. is guided by the side surface of the magnetic plate 2, so that it can run smoothly in the running direction 1c.

Incidentally, it is desirable to be able to obtain a DC linear motor LM with smooth thrust (torque) by allowing the position sensing element 5 to remain in the above position, and the position sensing element 5
It has the advantage of being convenient in mass production because it can be easily placed in a suitable position. The inner surface of the magnetic yoke 7 has a fourth
A field magnet 6 shown in the figure is fixedly installed, and the armature
The stator armature consists of six groups of coils. In addition, the magnetoelectric conversion element 5, which is a position detection element, is opposed to the i[l11 surface part of the field magnet 6, and outputs an appropriate signal to the semiconductor rectifier (drive circuit) 13 by turning the N or S magnetic pole to O. Output. At such a position @ electric conversion element 5f
: This arrangement is possible because the width of the field magnet 6 can be narrowed by the width of the conductor portion 3b that does not contribute to the thrust of the armature coil 3. Therefore, a space is created in which the field converting element 5 can be disposed on the stator's side facing the side surface of the field magnet 6. Similarly, a photoreflector 11 consisting of a light emitting element 9 and a photoconductive conversion element 10 can be disposed on the stator armature side, facing the side surface of the field magnet 6. As shown in FIG. 4, on the 11111 surface portion of the field magnet 6,
Colored parts 6a and 6b having different reflectances are alternately formed at a fine pitch. This colored portion is an encoder forming portion, and the encoder forming colored portion 12 and the photoreflector 11 form an encoder.

Therefore, if the movable magnet type DC linear motor LM is powered on and b, then \theta armature f:'! s
As shown in FIG. 6, a torrential current flows in the direction of the arrow 7 through the group of armature coils 3, producing thrust in the direction of the arrow 7, and the field magnet 6 moves in the direction of the arrow. Both terminals of each group of armature coils 3 are connected to the semiconductor rectifier 13, and both output terminals of the magnetoelectric conversion element 5 as the position detection element 5 are connected to the semiconductor rectifier #13. 14-1, 14-
2 are the Shirasu'1 source terminal and the negative power supply terminal of the semiconductor rectifier e13, respectively. As is clear from FIG. 6, the armature coils 3 are approximately equal to the magnetic pole width of the field magnet 6, and each group of armature coils 3 is arranged so as to overlap each other. ing. When the field magnet 6 moves in the traveling direction as described above, the photoreflector 1
Since the light emitting element 9 of No. 1 irradiates the encoder forming colored portion 12 (colored portions 6a and 6b with different reflectances), strong reflected light and weak reflected light are alternately transmitted through the colored portion 12 for a short period of time. The photoconductive conversion element 10 receives light at intervals. This element 10 generates a pulse every time a strongly reflected light (or weakly reflected light may be used) is detected. After the waveform is shaped by the pulse gold waveform shaping circuit 15, the frequency pulse is converted into voltage by the F (frequency)-V (voltage) conversion circuit 16, and this voltage is output to the speed control circuit 17. The control signal by the semiconductor rectifier 7
By outputting to 113, the propulsion speed of the mover made of the field magnet 6 and the like can be controlled.

In the above embodiment, since the moving range of the mover is limited, two or more photoreflectors 11 may be arranged at appropriate intervals in the longitudinal direction.

(Second Embodiment) Fig. 7 is a top view of a moving coil type DC linear motor LM' having an encoder, Fig. 8 is a side view of Fig. 7, and Fig. 9 is the same as Fig. 7 and Fig. 8. FIG. 10 is a perspective view of the field magnet 6 having a colored portion 12' for forming an encoder, and FIG. 11 is a developed view of the field magnet 6 and three groups of armature coils. .

The movable coil type DC linear motor LM' having the encoder 2 according to the second embodiment of the present invention has almost the same structure as the DC linear motor LM according to the first embodiment, and has four t4a child coils on the running magnetic yoke 7 side. A field magnet 6 having long (N, S) magnetic poles alternately is fixed on the magnetic plate 2, and an armature consisting of three groups of armature coils is fixed in the running direction. ((It is made to move.Position sensing element 5
61 is the same as the first embodiment. One photoreflector 11 consisting of a light emitting element 9 and a photoconductive conversion element 10 is placed in a cavity within the frame of an arbitrary armature coil 3. As shown in FIG. 1O, the field magnet is formed with an encoder-forming colored portion 1z having colored portions 6a and 6b having different reflectances alternately in fine steps. Since the developed view of FIG. 11 is the same as the principle shown in FIG. 6, the explanation thereof will be omitted. The same applies to other components and operations.

In the case of this moving coil type linear motor LM', it can be driven more easily than the moving magnet type linear motor LM, and only one first reflector 11 is required, so it has all the advantages of being mass-produced at low cost.

Example second ability i! The principle of the i example may be applied to the first embodiment, and the principle of the first embodiment may be applied to the second embodiment.
Although the case is shown in which it is formed directly on the field magnet 6, it goes without saying that it is also possible to form it by other means such as an adhesive tape having colored parts 6a and 6b. trench armature coil 3
It goes without saying that the present invention is also applicable to cases where groups overlap.

In addition, the magnetic poles of the field magnet 6 may be skewed 654, or the conductor portion 3a contributing to the thrust of the armature coil 3.
The spirit of the invention is still alive even in things that are skewed.
Naturally, this applies.

(Effects) The DC linear motor having the encoder of the present invention eliminates the drawbacks of the linear and o-smoke motors and the drawbacks of the conventional discoil type DC nif motor as described in 7 above, so almost no reaction thrust is applied. A DC linear motor with an encoder that can provide a strong thrust, high efficiency, and a long stroke.Moreover, the encoder can be built-in with an inexpensive and simple configuration, making it easy to assemble and mass-produced at a low cost. It has the effect of providing the world with the following.

[Brief explanation of drawings]

Figure 1 is a top view of a movable magnet type DC near moke having an encoder according to the first embodiment of the present invention, Figure 2 is a side view of Figure 1, and Figure 3 is the same as Figures 1 and 2. FIG. 4 is a perspective view of a field magnet having an encoder forming part, FIG. 5 is a perspective view showing the durability of the position sensing element and the shape of the armature coil, and FIG. The figure is a developed view of the field magnet and armature coil group, Figure 7 is a top view of a moving coil type DC linear motor that is shouldered with the encoder of the second embodiment of the present invention, and Figure 8 is a side view of Figure 7. 9 is a longitudinal sectional view of the one shown in FIGS. 7 and 8, viewed from the running direction, FIG. It is a developed view of a magnet and an armature. LM...Moving magnet type DC linear motor having an encoder, LM'...Moving coil type DC linear motor having an encoder, 1... Base, 2 ... Magnetic plate, 3... Armature coil, 4... Printed circuit board,
5... Position detection element, 6... Field magnet, 6a
. 6b... Colored part, 7... Traveling magnetic material yoke, 8...
- Running roller, 9... Light emitting element, 10... Photoconductive conversion element, 11... Photoreflector, 12, 12
'... Colored part for forming encoder, 13... Semiconductor rectifier, 14-1... Positive power supply terminal, 14-2...
... Negative power supply terminal, ]5 ... Waveform diagram circuit, 16
... F-V conversion circuit, 17 ... Speed control circuit, 18
···Power cord.

Claims (1)

[Claims] 1. A conductor portion that contributes to thrust by providing a P-pole (P is a positive integer of 3 or more) field magnet having N-pole and S-pole magnetic poles along the traveling direction of the mover. 1J, which consists of a group of armature coils wound with an opening angle width approximately 2n -1 (n is a positive integer of 1 or more) times the magnetic pole width of the field magnet, the armature is relative to the field magnet. Direction [7]
Either the field magnet or the armature is used as a stator, the other is used as a mover, and two or more colored parts with different reflectances are directly or indirectly applied to the field magnet at a fine pitch. An encoder characterized in that a large number of the colored part detection elements are formed and all of the colored part detection elements serve on the armature side facing the colored part. DC linear motor with. 2. A DC linear motor having an encoder as set forth in claim 1, wherein the colored portion of the field magnet is provided on a surface facing the armature. 3. The encoder according to claim 1, wherein the colored portion of the field magnet is provided on a side surface of the field magnet. -Ryu linear mome. 4. The encoder according to claim 2, wherein the light emitting element and the photoconductive conversion element are disposed at a position between the conductor parts contributing to the thrust of the armature coil. DC linear motor with. 5. A DC linear motor having an encoder as set forth in claim 4, wherein the single armature coil is wound into a frame shape. 6. The light emitting element and the photoconductive conversion element are located entirely within the body of the armature coil. , No. 1 [4] of the patent claim characterized in that the light emitting element and the photoconductive conversion element contribute to the 41f force of the armature coil and are provided at a position tA facing the conductor part -1, set of 4, page 3J 8. A DC linear motor having an encoder according to claim 1, wherein the light emitting element and the photoconductive element include a photoreflector as a single element. DC linear motor with encoder.