JPS63228954A - Secondary side stator for linear pulse motor - Google Patents

Abstract

PURPOSE:To obtain a stator capable of highly precise positioning with a simple constitution by providing rows of position-sensing teeth at a pitch of resolution to in tau0 in parallel with rows of secondary side driving teeth in a linear pulse motor with resolution tau0. CONSTITUTION:A linear pulse motor 1 is constituted of a secondary side stator 5 fitted on a pedestal 3. Rows of pulse-motor driving teeth 7 and rows of position-sensing teeth 9 are provided on the top surface of said stator 5. A movable element 11 is provided with primary side magnetic poles 13 and supported by rollers 15 along said pedestal 3, and travels perpendicularly to the surface of this paper while maintaining a given gap from the secondary side stator 5. Said movable element 11 is provided with a position sensor 17 in opposition to the rows of position-sensing teeth 9 provided at the secondary side stator 5. If a pitch between said rows of teeth 7 is tau in the dimensional relation between said rows of teeth 7 and those of teeth 9, the number n of teeth in said row of teeth 9 within the pitch tau between said rows of teeth 7 is set in the manner of satisfying the equation. In this manner, highly precise positioning is made possible with a comparatively simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application This invention relates to a linear pulse motor, and more particularly to a secondary stator provided with a tooth row for position detection.

b. Prior Art Linear pulse motors have been widely used for positioning control of moving objects because they can be used in a simple open loop. However, linear pulse motors that are controlled in an open loop have poor acceleration/deceleration characteristics, making it difficult to operate at high speeds, and the stopping position may shift due to the influence of external forces on the moving object. It could not be used for precision positioning control.

For this reason, feedback control using ordinary linear displacement sensors has been used for high-precision positioning control, but since linear displacement sensors are expensive, The way to use is
Developed in recent years.

In this method, a detector for detecting the position of the secondary side protrusion of the pulse motor is installed in the moving body, the position of the moving body is detected by this, and the deviation from the desired position is calculated by the control circuit. It excites and operates the appropriate phase.

C1 Problem to be solved by the invention The amount of movement per step (hereinafter referred to as resolution) τ0 of a linear pulse motor depends on the pitch τ of the secondary tooth row. If τ0−τ
/4. When detecting the position of a moving body driven by this motor using the method described above, the moving body is
With a phase difference of 0, it is necessary to provide four position sensors.

In this case, since the pitch of the teeth in the secondary tooth row is used as a reference for detecting the position, the teeth must be processed with high precision. Also, when the pitch τ is small, for example, if τ is imm, τo will be 0.25 mm, but if the four position sensors are
．． It is not necessarily easy to attach it to a moving body with a phase difference of 25 mm. This becomes even more difficult in the case of polyphase driven motors, and almost impossible in the case of microstep driven motors.

This invention was devised by focusing on these points, and has a relatively simple structure and allows for highly accurate positioning.
The object of the present invention is to provide a secondary stator for a feedback-controlled linear pulse motor.

Means for Solving the d1 Problem In order to achieve the above-mentioned object, the secondary side smoker of the present invention has a linear pulse smoke having a resolution τ0, parallel to its secondary drive tooth row. , is constructed by providing a position detection tooth row with a pitch of resolution τ0.

01 Effect With this configuration, the pitch of the secondary drive tooth row of the linear pulse motor is an integral multiple of the pitch of the position detection tooth row, and the phase relationship between both tooth rows is maintained over the entire length. Precision is maintained. Therefore, feedback control can be performed accurately and easily. Furthermore, since the tooth row for position detection can be created finely for microstepping, feedback control of a high-resolution linear pulse motor is also possible.

f. Example Next, an example of the present invention will be described based on the drawings. Figure 1 shows a linear pulse motor 1 implementing this invention.
In this schematic diagram, a secondary stator 5 of the present invention is mounted on a base 3.
is installed. On the upper surface of the stator 5 is a tooth row 7 for driving a pulse motor. and a tooth row 9 for position detection. The movable element 11 includes a primary magnetic pole 13, is supported by rollers 15 along the base 3, and travels in a direction perpendicular to the plane of the paper while maintaining a constant gap from the secondary stator 5. Mover 11
, a tooth row 9 for position detection provided on the secondary stator 5.
A position sensor 17 is installed opposite to the position sensor 17.

Details of the secondary stator 5 are shown in FIG.

As shown in the figure, a driving tooth row 7 is provided on the upper surface of the secondary stator 5.
A tooth row 9 for position detection is provided parallel to the teeth. Since these tooth rows are created simultaneously using a chemical removal method, etc., the positional relationship is highly accurate.

The dimensional relationship between both tooth rows is as follows: τ is the pitch of the driving tooth row.

If the resolution of the pulse motor is τ0, the number n of teeth in the position detection tooth row between the pitch τ of the drive tooth row is 0-τ/τ0
become. The basic resolution of a 4-phase pulse motor is τ0−τ/
4, so n=4.

This is done by microstep operation to increase the resolution to τ〇−τ/
If it is set to 100, n=100, and the resolution is τ=1
If it is 111 m, it will be 10 μm.

Two position sensors 17 are installed with a phase difference of τo/4 in order to know the direction. As this position sensor, a magnetic type or an optical type is used as appropriate depending on the resolution.

FIG. 2 shows another embodiment. As shown in the figure, a tooth row 9 for position detection is provided on the side surface of the secondary stator 5. In this way, the width of the secondary stator can be shortened, and the pulse motor can also be becomes smaller.

It should be noted that the present invention is not limited to the examples, but can be implemented in 33 different embodiments within the technical scope of the invention.

g1 Effects of the Invention As understood from the above explanation, the present invention has the structure set forth in the claims, and therefore has a relatively simple structure and a food pack control system capable of highly accurate positioning. A secondary stator for a linear pulse motor can be provided.

[Brief explanation of the drawing]

FIG. 1 is a three-dimensional diagram of an embodiment of the invention, FIG. 2 is a three-dimensional diagram of another embodiment, and FIG. 3 is a schematic diagram of a linear pulse motor embodying the invention. Explanation of symbols representing main parts of the drawing 1...Linear pulse motor 5...Secondary side stator 7
...Drive tooth row 9...Position detection tooth row 11...
Mover 13...Primary side pole tooth 17...Position sensor agent Patent attorney Yasuo Miyoshi 2nd ward

Claims (1)

[Claims] A secondary stator of a linear pulse motor having a resolution τ_0, characterized in that a position detection tooth row with a pitch of the resolution τ_0 is provided in parallel to the secondary drive tooth row. .