JPH0232750A - Pulse motor - Google Patents

Abstract

PURPOSE:To produce a large thrust by constructing a primary flux generating section with a splitted core group and permanent magnets and coils arranged between the cores. CONSTITUTION:A linear pulse motor comprises a fixed scale 21 and a slider 22 supported movably in the longitudinal direction (shown by an arrow M) of the scale 21 by a supporting mechanism such as a roller. Tooth sections 21a are formed with a pitch P on the inner face of the scale 21 and tooth sections 21b shifted by P/2 pitches are also formed. A slider 22 is constructed with phase A and B blocks 23, 33 coupled through a coupling member. The phase A block 23 comprises four core sections 24a-24d splitted in the moving direction M and permanent magnets 25a-25c and a wound coil 26 arranged between the splitted cores 24a-24d. The phase B block 33 is constructed similarly. When current is fed through the coils 26, 36 in a predetermined direction, flux flows from the secondary scale 21 through one end section of any one of the splitted cores 24, 34 thus forming a main flux loop.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention is a pulse generator suitable for use in F'A (factory automation) equipment that requires relatively large thrust, such as industrial robots, for example. This is about motors.

``Prior Art'' As is well known, a linear pulse motor moves a slider or a secondary scale (hereinafter simply referred to as scale) in steps based on pulse signals supplied to the slider. The configuration of the magnetic circuit is as shown in FIG. In this figure, l is a scale composed of a long plate-like magnetic material, and on its top surface,
The uneven tooth portions 1 a, 1 a, . . . are formed at equal intervals along the longitudinal direction (left-right direction in the drawing). A slider 2 is placed on the upper surface of the scale 1 so as to be movable in the longitudinal direction of the scale 1 by a support mechanism including rollers (not shown). The slider 2 has a U-shaped A phase core 4, a B phase core 5, and an A phase core 4 of the A phase core 4.
Coils 6a and 6b wound around the phase magnetic pole 4a and the incoming phase magnetic pole 4b, respectively, and the B-phase magnetic poles 5a and B of the B-phase iron core 5.
Coils 7a and 7b each wound around the phase magnetic pole 5b;
It consists of permanent magnets 8 and 9 attached to the top surfaces of iron cores 4 and 5 with the polarities shown in the figure, and a back plate 10 made of a plate-shaped magnetic body attached to the top surfaces of permanent magnets 8 and 9. . Three pole teeth 14a having the same pitch as the pitch P of the teeth 1a of the scale l are formed on the lower surface of the magnetic pole 4a, and the magnetic poles 4b,
Pole teeth 14b are also provided on the lower surfaces of each of 5a and 6b.

15a and 15b are formed respectively. Further, these pole teeth 15b, 14b, 15a are arranged sequentially shifted by P/4 with respect to the pole tooth 14a, and the pole teeth 14a, l
A predetermined gap G is formed between each of the lower surfaces of the teeth 4b, 15a, and 15b and the upper surface of the toothed portion 1a.

And coils 6a, 6b, 7a, 7b
A predetermined pulse signal is sequentially supplied to the coils 6a and 6b.

The magnetic flux generated by the permanent magnets 7a, 7b and the magnetic flux generated by the permanent magnets 8, 9 are connected to each magnetic pole 4a, 4b, 5a,
5b, the magnetic stability position of the slider 2 relative to the scale 1 is sequentially moved. , whereby the slider 2 moves lO in the longitudinal direction of the scale l.

Here, two sets of coils 6a, 6b and 7a, 7
An example will be explained in which the slider 2 is driven by a two-phase excitation force type that always supplies 1i current to b.

■As shown in Fig. 6(a), a predetermined current is passed through the coils 6a and 6b from the terminals 6c to 6(1), and
By passing a predetermined current through the coils 7a and 7b from the terminals 7d to 7c, the magnetic flux generated by the coil 6a and the magnetic flux generated by the permanent magnet 8 are added to each other at the A-phase magnetic pole 4a, and the in-phase magnetic pole 4b, the magnetic flux generated by the coil 7a and the magnetic flux generated by the permanent magnet 9 add to each other at the B-phase magnetic pole 5a, and cancel each other at the hue magnetic pole 5b, so the solid line φ is shown in the figure.
A main magnetic flux is generated, and as a result, the position where each mfa14a and +5a of the A-phase magnetic pole 4a and the B-phase magnetic pole 5a and the tooth portion 1a of the scale 1 are vertically opposed becomes a magnetically stable position. .

(2) As shown in FIG. 6(b), a predetermined current is passed through the coils 6a and 6b in the same direction as (2), and the coil 7a.

By passing a predetermined current through 7b in the opposite direction to ■, a main magnetic flux shown by the solid line φ is generated in the figure, and as a result, each pole tooth 1
The position where the teeth 4a and 15b and the tooth portion La vertically face each other is a magnetically stable position.

■As shown in FIG. 6(c), a predetermined current is passed through the coils 6a and 6b in the opposite direction to ■, and the coils 7a and 17
By passing a predetermined current through b in the same direction as ■, a main magnetic flux shown by the solid line φ3 in the figure is generated, and as a result, each pole tooth 14
The position where b and 15b and the tooth portion 1a are vertically opposed is a magnetically stable position.

■As shown in Figure 6(d), a predetermined current is passed through the coils 6a and 6b in the same direction as ■, and the coils 7a and 7b are fed with ■.
By flowing a predetermined current in the opposite direction, the solid line φ is shown in the figure.
A main magnetic flux indicated by 4 is generated, and as a result, the positions where each of the pole teeth 14b and 15a and the tooth portion 1a are vertically opposed become magnetically stable positions.

By repeating the pulse excitation in the order of the above excitation modes ■-■-■-■, the slider 2 moves to the right in the drawing, that is, in the direction from the magnet ti 4a to 5b, and
・By repeating pulse excitation in the order of each excitation mode of ■−■=■, the slider 2 moves toward the left in the drawing, that is, r
It moves in the direction from the a-pole 5b to 4a. The same applies to the case where the slider 2 is fixed and the scale 1 is moved.

``Problem to be solved by the invention'' By the way, linear pulse motors are generally used for driving carriages of printers in OA (office automation) equipment because they are capable of highly accurate positioning in an oven loop. Because it cannot obtain thrust, it is difficult to apply it to two FA aircraft that require relatively large thrust, such as industrial robots. That is, in the linear pulse smoke mentioned above,
As shown in FIGS. 6(a) to 6(d), one A-phase magnetic pole 4
Coil 6a or 7 in a or B phase magnetic pole 5a
During the period when the magnetic flux generated by a and the magnetic flux generated by the permanent magnet 8.9 are combined to generate thrust, the other in-phase magnetic pole 4
In the magnetic pole b or hue magnetic pole 5b, the magnetic flux generated by the coil 6b or 7b and the magnetic flux generated by the permanent magnet 8.9 cancel each other out, so that no thrust is generated. On the other hand, during the period when thrust is generated in the phase input magnetic pole 4b or the hue magnetic pole 5b, no thrust is generated in the A-phase magnetic pole 4a or the B-phase magnetic pole 5a. Therefore, the thrust generation area that actually contributes to thrust generation is the area of each magnetic pole 4 facing the scale l.
Of the total area of a, 4 b, 5 a, 5 b, 50
%, and expanding this thrust generating area has become an important issue when trying to improve thrust.

This invention was made in view of the above-mentioned circumstances, and aims to provide a pulse motor that can obtain a large thrust by effectively utilizing the total area of each magnetic pole facing the scale for thrust generation. There is.

"Means for Solving the Problems" The present invention includes a secondary scale in which tooth portions are formed at equal intervals along a specific direction, and a secondary scale that is supported movably in the specific direction with respect to the secondary scale. and a primary side magnetic flux generating section, and by sequentially generating magnetic flux in each gap formed between each magnetic pole of the primary side magnetic flux generating section and each tooth portion of the secondary side scale described in 11 [■, In the pulse motor that moves the primary side magnetic flux generation part relative to the secondary side scale, the primary side magnetic flux generation part is divided into a plurality of parts in the specific direction corresponding to the formation interval of the tooth part, and both ends are separated. a group of divided iron cores whose magnetic poles face the teeth, permanent magnets inserted between each of these divided cores so that their polarities are opposite to each other, and permanent magnets that are wound around the group of divided iron cores. It is characterized by being composed of a coil.

"Operation" According to the configuration described in (1) above, when a current is passed through the coil in a certain direction, the magnetic flux flowing from the secondary scale to the magnetic pole at one end of a specific split core is transmitted through the permanent magnet to the adjacent split core. A main magnetic flux loop is formed that flows into the core and from the magnetic poles at the other end of the split core to the secondary scale, so the total area of each magnetic pole facing the secondary scale is used effectively for thrust generation. It can be used to generate large thrust.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a magnetic circuit of a linear pulse motor according to a first embodiment of the present invention.

In this figure, 21 is a fixed scale, and 22 is a slider supported movably in the longitudinal direction of the scale 21 (in the direction of arrow M shown in the figure) by a support mechanism such as a roller (not shown). The inner surface of the scale 21 is provided with teeth 21a, 21a, . . . at intervals of a pitch P along its longitudinal direction.
are formed, and tooth portions 21b are similarly formed at intervals of pitch P on the surface opposite to the surface on which these tooth portions 21a are formed.
, 21b, . . . are formed. In this case, tooth 2
1a and 21b are formed to be shifted by P/2 from each other.

On the other hand, the slider 22 includes an A-phase block 23 and a B-phase block 33 that are connected to each other by a connecting member (not shown). The A-phase block 23 has divided iron cores 24a to 24d divided into four in the moving direction M, and permanent magnets 25a to 25a inserted between the divided iron cores 24a to 24d so that their polarities are opposite to each other. 25c, and the coil 2 wound around the divided cores 24a to 24d.
It consists of 6. In this case, each split core 2'4
a to 24 [i are divided at intervals corresponding to the pitch P at which the tooth portions 21a and 21b are formed, and one end facing the tooth portion 21a becomes A...magnetic% 27 a to 27d, and the tooth portion 21b The other end portions facing the A-phase magnetic poles 28a to 28d become the phase-in magnetic poles 28a to 28d, so that when the A-phase magnetic poles 27a and 27c are facing the toothed portion 21a, the phase-in magnetic poles 28b and 28d are in the toothed portion. The positional relationship is such that it faces 21b.

Also, like the A-phase block 23, the B-phase block 24 includes divided iron cores 34a to 34d, and each of these divided iron cores 34a.
Permanent magnets 35a to 35 inserted between 34d and 34d, respectively.
c, and a coil 36 wound around each of the divided cores 34'a to 34d.
4d is divided at intervals corresponding to the pitch P, one end facing the tooth 21a becomes the A-phase magnetic poles 37a to 37d, and the other end facing the tooth 21b becomes the in-phase magnet I+\! 38
a to 38d.

The B-phase block 24 is connected to the A-phase block 23 with a shift of P/4.
The positional relationships between the A-phase magnetic poles 37a to 37d and the tooth portion 21a1 and the phase-in magnetic poles 38a to 38d and the tooth portion 21b are as shown in the figure.

In the above configuration, when no current is supplied to the coils 26 and 36, as shown by the dotted line in FIG.
A magnetic flux loop around the scale 21 is formed only by the magnetic flux generated by the permanent magnets 25a to 25c and 35a to 35c, and the scale remains stationary in this state.

Here, the operation when the slider 22 is driven by the l-phase excitation method in which current is supplied to one of the coils 26 and 36 will be described with reference to FIG.

■As shown in Fig. 2(a), when a predetermined current is passed through the coils 26 of the A phase block 23 in the direction from the phase magnetic pole 2
A magnetomotive force is generated by the coil 26 from 7a to 27d toward the in-phase magnetic poles 28a to 28d, and the magnetic flux accompanying this magnetomotive horn and the magnetic flux generated by the permanent magnets 25a to 25c are A
The phase magnetic poles 27b, 27d and the incoming phase magnetic poles 28a, 28c strengthen each other, and the A-phase magnetic poles 27a, 27c and the negative magnetic poles 28b, 28d cancel each other out, thereby causing the teeth of the scale 21 to increase as shown by the dotted line φ in the figure. The magnetic flux flowing into the A-phase magnetic poles 27b, 27d of the divided iron cores 24b, 24c from the part 21a flows into the adjacent divided iron cores 24a, 24d via the permanent magnets 25a to 25c, and the magnetic flux flows into the magnetic poles 28 to those.
A and 28c form a main magnetic flux loop that flows into the tooth portion 21b of the scale 22. As a result, the Δ phase magnetic pole 27b
, 27d and the tooth portion 21a face each other, and the magnetized poles 28a, 28
The position where c and the tooth portion 21b face each other is a magnetically stable position.

■As shown in Fig. 2(b), when a predetermined current is passed through the coil 36 of the B-phase block 33 in the direction from the X mark shown in the figure to the - mark, the main magnetic flux shown by the dotted line φ in the figure increases. As a result, the B-phase magnetic poles 37b and 37d and the tooth portion 21a face each other,
A position where the zero magnetic poles 38a, 38c and the tooth portion 21b face each other is a magnetically stable position.

■As shown in FIG. 2(c), when a predetermined current is passed through the coil 26 in the opposite direction to ■, a main magnetic flux is generated as indicated by the dotted line φ3 in the figure, and as a result, the A-phase magnetic poles 27a, 27C and the teeth The position where the portion 21a faces, and the magnetized poles 28b, 28d and the southern part 21b face are magnetically stable positions.

■As shown in FIG. 2(d), when a predetermined current is passed through the coil 36 in the opposite direction to ■, a main magnetic flux is generated as indicated by the dotted line φ4 in the figure, and as a result, the B-phase magnetic poles 37a, 37C and the teeth A magnetically stable position is a position where the portion 21a faces the n magnetic poles 38b, 38d and the tooth portion 21b.

By repeating the pulse excitation in the order of the above excitation modes ■−■−■−■, the slider 22 moves toward the right in the drawing.
That is, by moving in the direction from the A-phase block 23 toward the B-phase block 33 and repeating pulse excitation in the order of each excitation mode of ■-■-■→■, the slider 22 moves toward the left in the drawing, i.e., toward the B-phase block 33. It moves in the direction toward the A-phase block 23.

Here, when the slider 22 is driven by a two-phase excitation method that constantly supplies current to the coil 26 of the A-phase block 23 and the coil 36 of the B-phase block 33, the third
In the 1Mi order shown in Figures (a) to (d), the coils 26 and 36
To do this, a predetermined current may be passed in the direction from the X mark shown in the figure to the * mark.

Next, refer to FIG. 4 for a second embodiment of the present invention.
I will explain. In this second embodiment, the first
The difference from the embodiment is that the slider 52 has an opening-shaped A phase block 43 and an opening-shaped B phase block connected by a spacer 60.
The point is that it is constituted by a phase block 53. That is, the A-phase block 43 is constructed by superimposing split iron cores 44a to 44d formed in the shape of an opening and permanent magnets 45a to 45c, and then winding a coil 46, and The B-phase block 53 includes a split iron core 54 . a to 54d and permanent magnets 55a to 55c
It is constructed by overlapping the coils 56 and winding the coils 56. As a result, split cores 44a to 44
Both ends of d and both ends of the split cores 54a to 54d are the teeth 1a, 1a of the scale 1.

They are facing each other with a gap between them. In such a configuration, as in the first embodiment described above, by supplying current to each coil 46, 56, the slider 52 changes the scale l.
move above.

Note that the present invention is not limited to the embodiments described above, and various modifications listed below are possible.

■It is not limited to a linear pulse motor, but may also be a rotary pulse motor. In this case, as can be easily deduced from the second embodiment, both the slider 52 on the negative side and the scale l on the secondary side may be configured to have a cylindrical shape.

(2) Although the above-mentioned embodiment has been described as a two-phase motor, by changing the arrangement pitch and number of blocks 23, 33 (43, 53), it can be easily made into a multi-phase motor. In this case, for example, if it is a 3-phase motor, the number of blocks is 3n (where n is an integer) and the array bits are each ! /3 pitches at a time.

■Since the magnetic pole pitch is relative, it is sufficient to shift either the negative side or the secondary side. For example, in the first embodiment described above, the A phase and the input phase (B river and hue) can be shifted. The teeth 21a and 21b were made to be in phase and shifted by half a pitch on the scale 21 on the secondary side. It may be configured to shift the phase and input phase or the hue by half a pitch.

■As for the structure of the motor, if teeth are also formed on the back surface (lower surface) of the scale l of the second embodiment mentioned above, and a slider similar to the slider 53 is placed so as to face this back surface, a double-sided motor can be constructed. This slider 53 can be made into a linear pulse smoke with the f hyperactivity direction of the slider 53 as an axis.
If the scale 1 and the scale l are each formed into a cylindrical shape, a cylindrical linear pulse smoke can be obtained.

■In order to eliminate cogging or improve thrust waveform distortion, a skew structure may be used, or even within the same pole, a slight pitch shift (equivalent skew) may be applied.

(2) In the above embodiment, the number of teeth is relatively small, but by increasing the number of teeth, the motor characteristics can be stabilized.

(2) The permanent magnets 25a to 25c and 35a to 35c do not need to be inserted throughout the entire core, and may be partially inserted as long as sufficient magnetic flux can be obtained.

(2) It is of course possible to provide the primary side slider 22 with a sensor for detecting the relative movement amount with respect to the secondary side scale 21 and drive it as a servo motor.

"Effects of the Invention" As explained above, according to the present invention, the secondary scale is divided into a plurality of parts in the direction of relative movement corresponding to the formation interval of the teeth of the secondary scale, and both ends are connected to the teeth of the secondary scale. a group of split cores serving as magnetic poles facing the section; permanent magnets inserted between each of these core segments so that their polarities are opposite to each other; and a coil wound around the group of split cores. Since the primary side magnetic flux generating section is configured by A main magnetic flux loop is formed which flows into the iron core and flows into the secondary scale from the magnetic poles at the other end of the split core, thereby making the total area of each magnetic pole facing the secondary scale available for thrust generation. The advantage is that it can be used effectively and can obtain twice the thrust of the conventional method, making it possible to apply it to FA equipment that requires a relatively large thrust, such as industrial robots. It will be done.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the magnetic circuit configuration of a linear pulse motor according to a first embodiment of the present invention, and FIGS. 2(a) to (d)
3 is a front view for explaining the operation when the same embodiment is driven by the l-phase excitation method, and FIGS. 3(a) to 3(d) are front views for explaining the operation when the same embodiment is driven by the two-phase excitation force method. 4 is a front view showing the magnetic circuit configuration of a linear pulse motor according to a second embodiment of the present invention; FIG. 5 is a front view showing the magnetic circuit configuration of a conventional linear pulse motor; 6(a) to 6(d) are front views for explaining the operation when the linear pulse motor is driven by a two-phase excitation force type. 7 a~3 8 a~3 Extractor 8d... ・B...Magnetic pole, ・Hue magnetic pole. 1 (Ri...Scale (secondary side scale), 1
a(1a)...Tooth part, 2(52)...Slider (primary side magnetic flux generation part)
, 3 (43)...A phase block, 4 a~24
d (44a to 44 d) -- Split core, 5a to 25c
(45a-45c)...Permanent magnet, 6 (46)
Coils 7a to 27d...A phase magnetic pole, 8a to 28d...Incoming phase magnetic pole, 3, (53)...B phase block, 4 a ~34
d (54a to 54 d)...-divided iron core, 5a to 3
5c (55a-55c)... Permanent magnet, 6 (5
6) Coil, (b) Middle 2 2 Fig. 43 Fig. Φ1 (cl (dl fc) Middle 4

Claims (1)

[Scope of Claims] A secondary scale having teeth formed at regular intervals along a specific direction; and a primary magnetic flux generating section supported movably in the specific direction with respect to the secondary scale. By sequentially generating magnetic flux in each gap formed between each magnetic pole of the primary magnetic flux generating section and each tooth of the secondary scale, the primary magnetic flux generating section is connected to the secondary side. In a pulse motor that moves relative to a scale, the primary side magnetic flux generating section is divided into a plurality of parts in the specific direction corresponding to the formation interval of the teeth, and both ends of the divided iron core are magnetic poles facing the teeth. a permanent magnet inserted between each of these divided core groups so that their polarities are opposite to each other, and a coil wound around the divided core group. motor.