JPH0721106Y2 - Linear pulse motor - Google Patents

Description

The present invention relates to a linear pulse motor, and more particularly to a magnetic pole structure of the linear pulse motor.

(Prior Art) Linear pulse motors are extremely easy to control, the linear mechanism can be simplified, the motor itself has a braking function, and it is possible to perform high-precision fine movements.
It has excellent features, and the field of application of pulse motors has recently expanded rapidly as a servomotor or actuator in automation systems, but it is expected that the range of application will continue to expand in the future.

FIG. 7 schematically shows an example of a linear pulse motor. In the figure, reference numeral 1 is a stator called a scale, which is composed of a scale yoke 2 and a magnetic pole structure 3 formed thereon. A large number of magnetic poles having mutually different polarities are alternately magnetized in the magnetic pole structure 3 in the order of N, S, N, S ... Reference numeral 4 denotes a slider called a slider, which is formed by connecting two electromagnet structures 5 and 6 with a non-magnetic body 7. Electromagnet structure 5, 6
Windings 8 and 9 are respectively wound around, and magnetic poles 5-1 and 5-2 and 6-1 and 6-2 are provided so as to face the magnetic pole structure 3. As is well known, the required number of pulse signals are alternately applied to the windings 8 and 9 of the electromagnet structures 5 and 6, and the magnetic poles 5-1 and 5-2 and 6-1 and 6 of the electromagnet structures 5 and 6 are provided. -2 and the magnetic pole of the magnetic pole structure 3 are made to step by the thrust generated. As will be described later, the positioning accuracy of the moving slider is determined by the density of the magnetic poles of the magnetic pole structure 3 facing the magnetic poles 5-1 and 5-2 or 6-1 and 6-2. Therefore, when a high degree of positioning is required, it is necessary to make the arrangement of the magnetic poles of the magnetic pole structure 3 extremely dense.

(Problems to be solved by the invention) In a conventional linear pulse motor, for example, when a straight travel is required over a long distance section such as a one-axis table, when a section to be positioned is predetermined, for example, both ends Even when there is a positioning section only in the position, the magnetic poles of the magnetic pole structure 3 of the scale (stator) 1 are magnetized at the same constant pitch over the entire stroke, that is, the entire length. Therefore, when high-accuracy positioning is required, not only the section where the positioning of the moving element is required, but also the moving element may simply pass and may be rough, but high-speed movement is desirable. Even in the section, high-precision processing is performed to make the pitch of the magnetic poles of the magnetic pole structure 3 of the scale 1 as dense as in the positioning section.
For this reason, the cost becomes high, and the speed of the mover in the moving section cannot be increased so much.

The above description has been made on the case where the two electromagnet structures 5 and 6 coupled by the non-magnetic body 7 are used as the mover 4 and the scale 1 is used as the stator, but in the opposite case, that is, the electromagnet structures 5 and 6 are used.
The same applies to the linear pulse motor in which the coupling body 4 of ( 1) is used as the stator and the scale 1 is used as the moving element. The same applies to the case where the scale having the magnetic pole structure 3 formed on the surface as described above is not used but the scale is made of a magnetic material and a large number of slots are provided on the surface along the longitudinal direction. is there.

Therefore, it is an object of the present invention to eliminate the above-mentioned drawbacks in the conventional linear pulse motor.

(Means for Solving the Problems) In order to solve the above problems, the linear pulse motor of the present invention has a plurality of magnetic poles of different polarities alternately arranged in the longitudinal direction on one surface of the stator and the mover. A linear pulse motor which is provided along with a magnetic pole provided on the other of the stator and the mover so as to face the magnetic pole provided on the surface of one of the stator and the mover,
The magnetic pole pitch on the mover side is formed to be a constant pitch over the entire section, while the magnetic pole pitch on the stator side is set to a constant value determined by the following conditional expression in the section requiring positioning of the mover. It is formed in a dense section, and in a section that does not require positioning, it is formed in a fixed sparse section determined by the following conditional expression.

D = 1/2 {(n-1) P + P / 2} where D is the distance that the moving element moves in one step, and n is the magnetic pole of the moving element facing one magnetic pole provided on the stator. The number of teeth, P is the pitch of the teeth in one magnetic pole of the mover.

In this case, in place of the above configuration, at least the magnetic pole portion on the stator side is made of a magnetic material, and a large number of slots are provided on the surface along the longitudinal direction, and on the slider side, the slots on the stator side are provided. In a linear pulse motor with magnetic poles facing each other, the magnetic pole pitch on the mover side is set to a constant pitch over the entire section, while the magnetic pole pitch on the stator side determines the positioning of the mover. In the required section, it is formed into a certain dense section determined by the following conditional expression, and
In a section that does not require positioning, it may be formed in a fixed sparse section determined by the following conditional expression.

D = 1/2 {(n-1) P + P / 2} where D is the distance that the mover steps in one step, and n and P are the number of teeth of the mover's magnetic pole and the pitch of the teeth as described above. is there.

Further, in each of the above configurations, it is desirable to provide a section lacking magnetic poles in a section corresponding to the boundary between the dense section and the coarse section of the magnetic pole pitch formed on the stator side.

(Operation) According to the present invention, in the section where the positioning of the moving element is required, the pole pitch of the magnetic pole structure or the pitch of the slots of the slot structure is formed in a predetermined dense section, that is, the section where the positioning is not required, that is, Since the moving element is configured to be formed in a predetermined rough section in the passage section, the moving element can pass through the passage section at a high speed and can be positioned with high accuracy in the positioning section, thereby increasing the speed of the linear pulse motor. At the same time, the manufacturing cost can be reduced.

Also, if a section lacking magnetic poles is provided in the section corresponding to the boundary between the dense section and the coarse section of the magnetic pole pitch formed on the stator side, the moving element moves from high speed to low speed and from low speed to high speed in this area. It is possible to smoothly switch the speed of shifting to.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows only a stator (hereinafter sometimes abbreviated as a scale) 1 when the present invention is applied to the linear pulse motor described in FIG. The mover is the same as the mover 4 in FIG. 7, and is omitted here. In the figure, the parts denoted by the same reference numerals as in FIG. 7 indicate the same or equivalent parts. According to this embodiment, in the positioning sections A and C of the mover (not shown), the alternating arrangement pitch of the magnetic poles in the magnetic pole structure 3 of the scale 1 is closely magnetized to reduce the step amount per step. However, in a section other than the positioning section, that is, in the moving section B where the moving element is desired to pass at a high speed, it is roughly magnetized to increase the step amount per step. Non-magnetized sections D are provided between the positioning section A and the moving section B and between the positioning section C and the moving section B, respectively. The length of the non-magnetized section D is at least longer than the length of the moving element, and the moving element is allowed to travel by inertia in this section. In order to make the transition from one section to the other section smooth in synchronization with the driving of the mover in the positioning section and the moving section, both sections A, B and B
Means 10-1, 10-2, 10-3, and 10-4 for detecting speed and position are provided at predetermined positions near the opposite ends of C and C, respectively. For example, the moving element is now moving from the positioning section A to the moving section B.
Then, for example, the speed at the time when the leading part of the moving element reaches the detecting means 10-1 is detected by the detecting means 10-1 and the position / speed information is transferred to the control circuit 11. When the mover crosses the non-magnetized section due to inertia, and the leading part reaches the detecting means 10-2, the detecting means 10-2 detects the speed at that time and detects the position / position.
The speed information is transferred to the control circuit 11. The control circuit 11 performs pulse control of the moving element after that based on the position / speed information from both detecting means.

FIG. 2 is a diagram showing an example of the relationship between the mover 4 and the magnetic pole structure 3 of the scale 1 in the positioning sections A and C of FIG. 1, and FIG. It is a figure. In the figure, the parts denoted by the same reference numerals as in FIG. 7 indicate the same or equivalent parts. In this example, the magnetic poles 5-1, 5-2 and 6-1, 6- of the electromagnet structures 5, 6 are shown.
2 has two teeth 5-1 a, 5-1 b, 5-2.
-A, 5-2b, 6-1-a, 6-1-b, 6-2-
a and 6-2-b are provided as shown. FIG. 4 and FIG. 5 are views showing the stepped state of the mover in FIG. 2 and FIG. 3, respectively, which face one magnetic pole N or S magnetized to the magnetic pole structure 3 of the scale 1 . Mover
When the number of teeth of the magnetic poles of 4 is n, the distance D by which the moving element 4 steps in one step is represented by D = 1/2 {(n-1) P + P / 2}. Here, P is the pitch of the teeth in one magnetic pole of the mover, for example, the point at which one tooth 5-1-a in 5-1 corresponds to the point at which the next tooth 5-1-b corresponds. Is the distance between. Therefore, in the positioning sections A and C shown in FIGS. 2 and 4, one magnetic pole of the magnetic pole structure 3, for example, the N pole 12 is connected to one tooth 5 of the magnetic pole 5-1 of the moving element.
Since it is facing -1-a, n = 1, and in this section, the step distance in one step is 1 / 4P, and the third step
In the moving section B shown in FIGS. 5 and 5, one magnetic pole of the magnetic pole structure 3, for example, the N pole 13 is the two teeth 5 of the magnetic pole 5-1 of the moving element.
Since it faces -1-a and 5-1 -b, n = 2, so the distance to step in this step is 3 / 4P.
Therefore, it is three times as large as the positioning section.

Now, when the mover 4 is in the positioning section A or C, a pulse is applied to the winding 8 of the mover 4 , and the magnetic pole 5-1 moves to S.
Assuming that --2 has just been excited by N and has arrived at the position shown in FIG.
Is not excited, the pulse is applied to the winding 9 and the magnetic pole 6-1
Is magnetized to the N pole and the magnetic pole 6-2 is magnetized to the S pole, and the mover 4 becomes 1/4.
Step forward by P and come to the position shown in Figure 4 (b). In the next step, the winding 9 is not excited and the pulse is applied to the winding 8 to excite the magnetic pole 5-1 to N and 5-2 to S to advance to the position shown in FIG. To do. The same thing is repeated thereafter, and the mover steps forward by 1 / 4P. Also now, the mover 4
Is in the moving section B, a pulse is applied to the winding 8 of the moving element 4 , the magnetic pole 5-1 is excited to S and 5-2 is excited to N,
Assuming that you have arrived at the position shown in Figure (a),
In the next one step, the winding 8 is not excited, and the pulse is applied to the winding 9 so that the magnetic pole 6-1 becomes the N pole and the magnetic pole 6-2 becomes the S pole.
Excited by the pole, the mover 4 steps forward by 3 / 4P and reaches the position shown in Fig. 5 (B). In the next step, winding 9
Is not excited, the pulse is applied to the winding 8 and the magnetic pole 5-1
Is excited by N and 5-2 is excited by S and advances to the position shown in FIG. The same thing is repeated thereafter, and the mover is 3 / 4P.
Step by step.

In the above embodiment, the number n of teeth of the magnetic pole of the moving element 4 facing one magnetic pole N or S magnetized to the magnetic pole structure 3 of the scale 1 is set to 1 in the positioning section and 2 in the moving section. However, the value of n in this embodiment is merely an example,
The present invention is not limited to this, and can be appropriately selected in designing.

In the above example, two 4 that the electromagnetic structure 5,6 bound a non-magnetic material 7 and the mover, has been described that the scale 1 and the stator, if the present invention is the opposite, i.e. The same can be applied to the case where the combined body 4 of the electromagnet structures 5 and 6 is used as a stator and the scale 1 is used as a mover.

Further, in the above-mentioned embodiment, as the scale 1 , the one in which the surface of the scale yoke 2 is magnetized to form the magnetic pole structure 3 is used, but the present invention is not limited to this, and the sixth
As shown in the figure, the same application can be made to the case where the scale yoke is made of a magnetic material and a large number of slots are provided on the surface thereof along the longitudinal direction. 6, A and C are positioning sections, B is a moving section, and D'is a section in which a slot is not provided corresponding to the non-magnetized section in FIG.

(Effects of the Invention) With the configuration as described above, the linear pulse motor according to the present invention exhibits the following remarkable effects.

(1) High-precision positioning and high-speed movement are possible with one motor.

(2) The magnetizing pitch or gear cutting pitch may be large in the moving section that does not require positioning, and accuracy is not required so much, so that machining of the magnetic poles on the stator side is easy.

(3) Furthermore, if a section lacking magnetic poles is provided in the section corresponding to the boundary between the dense section and the coarse section of the magnetic pole pitch formed on the stator side, the moving element moves from high speed to low speed at this portion, and The speed can be smoothly switched from low speed to high speed.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a magnetized state of a scale (stator) in a linear pulse motor according to an embodiment of the present invention, and FIG. 2 is a magnetic pole structure of a slider and a scale in a positioning section of FIG. FIG. 3 is a diagram showing an example of the relationship in FIG. 3, FIG. 3 is a diagram showing an example of the same relationship in the movement section B, and FIGS. 4 and 5 show the stepping state of the mover in FIGS. 2 and 3, respectively. 6 and 6 are views for explaining a slot structure of a scale in a linear pulse motor according to another embodiment of the present invention, and FIG. 7 is a schematic view of an example of the linear pulse motor. (Explanation of symbols) 1 ...... Stator 3 ...... Magnetic pole structure 4 ...... Mover 5, 6 ...... Electromagnet structure 8, 9 ...... Winding 5-1, 5-2, 6-1, 6-2 ... ... Magnetic poles 5-1a, 5-1b, 5-2a, 5-1b ...
Magnetic pole teeth 6-1-a, 6-1-b, 6-2-a, 6-1-b ...
Magnetic pole teeth A, C ... Positioning section B ... Moving section D ... Non-magnetized section D '... Non-slot section

Claims (3)

[Scope of utility model registration request] 1. A plurality of magnetic poles having mutually different polarities are alternately provided on one surface of a stator and a mover along the longitudinal direction, and the other of the stator and the mover is provided with the stator and the mover. In a linear pulse motor in which a magnetic pole is provided so as to face a magnetic pole provided on one surface of the child, the magnetic pole pitch on the mover side is formed at a constant pitch over the entire section, while fixed. The magnetic pole pitch on the child side is formed in a constant dense area determined by the following conditional expression in the section where positioning of the moving element is required, and in a section where positioning is not required, a constant dense area determined by the following conditional expression. A linear pulse motor characterized by being formed in a sparse section. D = 1/2 {(n-1) P + P / 2} where D is the distance that the moving element moves in one step, and n is the magnetic pole of the moving element facing one magnetic pole provided on the stator. The number of teeth, P is the pitch of the teeth in one magnetic pole of the mover. 2. A magnetic pole portion on at least the stator side is made of a magnetic material, a plurality of slots are provided on the surface along the longitudinal direction, and the slider side faces the stator side slot. In a linear pulse motor with magnetic poles, the magnetic pole pitch on the mover side is formed to be a constant pitch over the entire section, while the magnetic pole pitch on the stator side is a section that requires positioning of the mover. The linear pulse motor is characterized in that it is formed in a constant dense section defined by the following conditional expression, and is formed in a constant sparse section defined by the following conditional expression in a section that does not require positioning. . D = 1/2 {(n-1) P + P / 2} where D is the distance that the moving element moves in one step, and n is the magnetic pole of the moving element facing one magnetic pole provided on the stator. The number of teeth, P is the pitch of the teeth in one magnetic pole of the mover. 3. The linear pulse motor according to claim 1, wherein a section lacking magnetic poles is provided in a section corresponding to a boundary between a dense section and a coarse section of the magnetic pole pitch formed on the stator side.