JPS591059B2 - linear pulse motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a linear pulse motor in which a movable part moves linearly.

FIG. 1 is an explanatory diagram of the configuration of a conventionally known linear pulse motor, in which A is a longitudinal sectional view, B is a BB sectional view in FIG. A, and C is a CC sectional view in FIG.

In the figure, 1 is a running path (stator) made of magnetic material.
, 2 is a movable part that faces the running path 1 with a slight gap therebetween, and here it is composed of two U-shaped field cores 21 and 22 that are connected to each other via a permanent magnet 20.

In the U-shaped field cores 21 and 22 of the movable part 2, the distance between the ends (teeth) of the protrusions (teeth) 1 provided on the running path 1 is
It is shifted by P/2 with respect to the interval P between 1 and 12,
Further, the respective U-shaped field cores 21 and 22 are connected to each other so as to be offset by P/4.

A field winding 31,32 is wound around each U-shaped field core 21,22, and the magnetic flux from the permanent magnet 20 is controlled by selectively applying current to the field winding 31,32.

In this device, when an excitation current is first applied to the field winding 32 as shown by the solid arrow, the magnetic flux passing through the tooth O decreases and the magnetic flux passing through the tooth increases.

For this reason, the movable part 2 is held at the position shown in the figure by attracting the teeth 16 on the traveling path 1 side.

Next, when an exciting current is applied to the field winding 31 as shown by the broken line arrow, the magnetic flux passing through the tooth @ increases, the tooth @ and the tooth 14 are attracted to each other, and the movable part 2 moves to the left by P/4. Stop.

Next, an exciting current is applied to the field winding 32 in the direction opposite to the solid arrow to draw the teeth 17 together, thereby moving the movable part 2 further to the left by P/4.

In this way, by alternately passing excitation current through the excitation windings 31 and 32 and changing the flow direction, the movable part 2 can be moved along the travel path 1 by pinching P/4.

By the way, in the device configured in this way, the movable part 2
The minimum amount of movement is 1 p, and in order to move it more finely, it is necessary to reduce the pitch of the teeth provided on the traveling path 1 side, but there is a limit to this.

Therefore, conventionally, in order to improve the resolution of the amount of movement, a method has been adopted in which the excitation current flowing through the field winding 3L32 is controlled in an analog manner as shown in FIG.

However, this method requires a high-output DC amplifier and a digital control element, and has the disadvantage of complicating the device.

Here, the present invention aims to realize a small and highly efficient linear pulse motor that can obtain high resolution with a simple configuration.

FIG. 3 is a configuration diagram showing one embodiment of the present invention, where A is a longitudinal sectional view, B is a BB sectional view in Figure A, C is a CC sectional view in Figure A, and D is a D in Figure A. -D sectional view.

In the device of the present invention, the movable part 2 includes a pair of iron cores 2L22 having a plurality of legs (in this embodiment, five legs ① to ②);
A permanent magnet 20 which is interposed between the pair of iron cores 21 and 220 and has the role of supplying bias magnetic flux, and the pair of iron cores 2
1.22 mutually adjacent legs ■1, ■2 (01~@2.
It is composed of a plurality of excitation windings (5 in this case, 31 to 35) wound over the windings 01 to 02...).

Moreover, at the end facing the running path 1 of each leg ■ to ■, there are a plurality of teeth (in this example, three teeth of a teeth) are provided.

Here, each leg of iron cores 21 and 22 (N+f
l) P (N: integer, m: number of legs, m n: an integer such that m>n; in this embodiment, the cores 21 and 22 are arranged with a deviation from each other, and the iron cores 21 and 22 are It is deviated by P.

In the device configured in this way, the permanent magnet 20 is
Assuming that they are magnetized as shown in Figure B, there is a bias between the movable part 2 and the running path 1 in the direction of the iron core 21, the running path 1, and the iron core 22, as shown by the solid line in the figure. Magnetic flux exists.

Now, when an excitation current is passed through the excitation windings 31 wound around the legs (1) and (2), a magnetic flux is generated by this excitation current as shown by the broken line, and this adds weight to the bias magnetic flux.

Therefore, the magnetic flux between the leg 1 on the iron core 21 side and the running path 1 increases, and the magnetic flux between the leg 2 on the iron core 22 side and the running path 1 decreases.

As a result, the leg 1 of the movable part 2 and the running path 1 attract each other, and the movable part 2 is held at the position shown in FIG. 3A, where the reluctance of the gap is the smallest.

Note that the attraction force between the traveling path 1 and the movable part 2 is equal to 2 of the magnetic flux density.
increases in proportion to the power of

Next, when an excitation current is passed through the excitation winding 32 wound around the leg @1, the magnetic flux between the leg @1 and the traveling path 1 increases, and the two attract each other. The movable part 2 moves to the right.

Here, the amount of movement of the movable part 2 is JP since there is a shift of 1p between the legs ■ and the legs @.

Similarly, the excitation windings 33, 34, 35°31...
If the excitation current is applied in sequence, the movable part 2 will sequentially move to the right with lp as the minimum movement amount.

Furthermore, when the excitation current is applied to the excitation windings 35, 34, and 33 in this order, the movable portion 2 moves to the left.

On the other hand, if the flow direction of the excitation current flowing through the excitation windings 31 to 35 is reversed from the above case, the magnetic flux between the leg 2 and the running path 1 increases in FIG. 3B, and the two attract each other. becomes.

Therefore, if an excitation current is sequentially passed through the excitation windings 32, 33, 34, . . . in the opposite direction to the above case, the movable part 2 similarly moves to the right with 1P as the minimum movement amount.

Moreover, if a current is applied in the opposite direction to the above case in the order of the excitation windings 35, 34, 33, 32, etc., the movable part 2 moves to the left with the IP as a pinch.

Here, since the pair of iron cores 21 and 22 of the movable part 2 are arranged offset by lp, there are two cases in which the direction of excitation current flowing through the excitation winding is a positive direction, and a negative direction (in the opposite direction). direction)
In this case, the stop positions of the movable parts 2 do not overlap with each other and are shifted by 9P.

FIG. 4 is a vector diagram showing the amount of movement of one pinch of the movable part 2 in 360 degrees, where the solid line indicates the case where the excitation current flows in the positive direction, and the broken line indicates the case where the direction of flow of the exciting current is in the negative direction.

As is clear from this vector diagram, the excitation current is applied to the excitation winding 31 in the forward direction → to the excitation winding 34 in the reverse direction → to the excitation winding 3
When the flow is sequentially switched as follows: 2, forward direction → excitation winding 35 in the reverse direction → excitation winding 33 in the forward direction, etc., the movable part 2 sequentially moves to the right with lp as the minimum movement amount.

Also, the excitation current is applied to the excitation winding 31 in the positive direction → the excitation winding 33
When the flow is sequentially switched in the reverse direction, the forward direction to the excitation winding 35, the forward direction to the excitation winding 34, etc., the movable part 2 sequentially moves to the left with the minimum movement amount.

According to the apparatus configured in this way, the minimum amount of movement of the movable part 2 becomes IP, and the resolution can be improved.

Furthermore, power consumption can be reduced by partially utilizing the magnetic flux from the permanent magnet.

Note that in the above explanation, the excitation current is sequentially switched to flow through only one excitation winding, but if the excitation current is simultaneously switched and applied to several excitation windings in sequence, the torque can be increased. can be increased.

FIG. 5 shows the excitation windings 31, 32 in the positive direction, and the excitation windings 33.
This is a vector diagram when a negative excitation current is simultaneously applied to the excitation winding 34, and shows that it is possible to obtain approximately three times as much torque as when the excitation current is applied only to the excitation winding 31.

In the embodiment shown in FIG. 5, a pair of iron cores 21 and 22 constituting the movable part 2 are provided respectively and arranged so that the teeth are shifted by HP, but as shown in FIG. 6A, A pair of iron cores 21.2 constituting the movable part 2
2 is arranged so that the teeth provided on this are lined up in the same phase,
Instead, the running path 1 is connected to a pair of iron cores 1 as shown in FIG. 6B.
1.12, each of these iron cores 11
．． The teeth provided at 12 may be arranged so as to be offset by IP.

In the embodiment shown in FIG. 3, a permanent magnet 20 is interposed between the pair of iron cores 21 and 22 constituting the movable part 2 to apply a bias magnetic field, but as shown in FIG. A bias magnetic field may be obtained by winding the winding 30 in the magnetic path between the iron core 21 and the iron core 22.

Also, the excitation windings 31, 32, . . . are wound across a pair of legs (for example, ■1 and @), as shown in FIG.

(2) The windings 311 and 312 may be separately wound around 2 and connected in series, or the excitation current may be passed through them separately.

FIGS. 9 and 10 are configuration diagrams showing other embodiments of the apparatus of the present invention.

In FIG. 9, A is a sectional view of the movable part 2, and B is a BB sectional view in FIG.

In this embodiment device, one of the pair of iron cores constituting the movable part 2 is further made into two iron cores 211 and 212, and the other iron core 22 is sandwiched between these two iron cores 211 and 212 via a permanent magnet 20, The structure is such that it is symmetrical in the moving direction of the movable part 2.

In addition, each leg has excitation windings 311, 312 and 313, respectively.
．． 3.21, 322, 323, . . . are wound, and excitation current is caused to flow through the excitation windings 311, 321, . . . and 312, 322, .

According to this embodiment, the moving torque of the movable part 2 is
Since it works in the same direction as the direction of travel, efficiency can be improved.

In Figure 10, A is a vertical cross-sectional view, and B is B in Figure A.
-B sectional view.

In the device of this embodiment, teeth are formed on the upper and lower surfaces of the running path 1 at the same pitch, but whose arrangement and HP are shifted from each other.

In addition, the movable part 2 is configured to sandwich the pair of iron cores 21, 21' running path 1 from below.

With such a configuration, the suction force acting between the movable part 2 and the travel path 1 in a direction perpendicular to the direction of movement can be canceled out, so that efficiency can be further improved.

As explained above, according to the present invention, a linear pulse motor that can obtain high resolution with a simple configuration can be realized.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a conventionally known linear pulse motor.
is a vertical sectional view, B is a BB sectional view in Figure A, C is a CC sectional view in Figure A, and Figure 2 shows the excitation current needed to increase the resolution of the amount of movement of the movable part in the device shown in Figure 1. FIG. 3 is a configuration diagram showing one embodiment of the present invention, where A is a vertical cross-sectional view, B is a BB cross-sectional view in figure A, C is a CC cross-sectional view in figure A, and D is a cross-sectional view along line C-C in figure A. DD sectional view in Figure A, Figure 4 is a vector diagram for explaining the operation of the device in Figure 3,
Fig. 5 is a vector diagram illustrating the operation when excitation current is simultaneously applied to a plurality of excitation windings in the apparatus shown in Fig. 3, and Fig. 6 shows other arrangements of teeth provided in the running path and movable part. 7 is a sectional view showing another example of applying a bias magnetic field, FIG. 8 is a sectional view showing another example of excitation winding, and FIGS. 9 and 10 are sectional views showing the structure of another example of applying a bias magnetic field. 9A is a sectional view of the movable part, FIG. 9B is a sectional view taken along line B-B in figure A, and FIG. 10A is a vertical cross-section of the running path and the movable part. Figure 10B is a sectional view taken along the line BB in Figure A. DESCRIPTION OF SYMBOLS 1... Running path, 2... Movable part, 20... Permanent magnet, 21.22... Pair of iron cores, 31-35... Excitation winding, ■1, ■2, @t j @2～■1 ,■
2... Field legs.

Claims (1)

[Scope of Claims] 1. In a linear pulse motor composed of a running path and a movable part having a plurality of field legs that move along the running path, the movable part is provided with teeth of the same pitch P. It consists of a pair of iron cores arranged with a phase difference of ↓P, and means for supplying a bias magnetic flux passing through these pair of iron cores, and a plurality of field magnets provided in the pair of iron cores. The distance between the legs is set to be (N shidan) P (where m is the number of legs, and n is an integer with the relationship m>n) with respect to the pitch P of the teeth provided on this iron core, and A linear pulse motor in which teeth are formed with the same pitch as the teeth provided on the iron core of the movable part. 2 One of the pair of iron cores constituting the movable part is divided into two in a direction perpendicular to the moving direction of the movable part, and the other of the pair of iron cores is placed between the two halves of the core through bias magnetic flux supply means. A linear pulse motor according to claim 1. 3. In a linear pulse motor consisting of a running path and a movable part having a plurality of field legs that move along the running path, the moving parts are formed with teeth having the same pitch and whose phases are different from each other. It consists of a pair of iron cores arranged in the same phase and a means for supplying bias magnetic flux through these pair of iron cores, and a plurality of field legs provided on the pair of iron cores are provided with mutual spacing between them. The tooth pitch P is set to (N) P (where m: the number of field legs, n is an integer with the relationship m > n), and is provided on the iron core of the movable part on the running path. A linear pulse motor in which two types of teeth are arranged at the same pitch as the teeth and shifted from each other by -UP. 4. The linear pulse motor according to claim 3, wherein the running path is constituted by a pair of iron cores each having teeth of the same pitch P and arranged with a phase difference of 1 HP. 5. Teeth are formed on both sides of the running path at the same pitch P and are shifted by 1 or HP from each other, and a pair of iron cores constituting a movable part sandwich the running path. Linear pulse motor described in Section 3