JPH0510026B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a linear pulse motor applied to, for example, a magnetic head drive system of a floppy disk drive such as a word processor.

<Prior Art> This type of linear pulse motor is described in, for example, Japanese Patent Application Laid-open No. 113652/1983. As shown in FIGS. 4 and 5, the linear pulse motor has a permanent magnet 92 on a back yoke 91,
Four-phase yokes 94a to 94 are mounted on the upper surface of the permanent magnet 92.
d, four-phase magnetic pole teeth 90a to 90d, and a pair of excitation coils 93 arranged on both sides of a yoke 91 to constitute a stator 9, and on this stator 9, a mover having magnetic pole teeth 97 formed on the lower surface. 96 via a bearing member 95.

<Problems to be solved by the invention> However, the above-mentioned conventional linear pulse motor has the following problems:
Back yoke 91, permanent magnet 92, permanent magnet 92
This requires adhesion between the yokes 94a to 94d of the four phases. This back yoke 91, permanent magnet 9
The second and fourth phase yokes 94a to 94d are laminated by adhesive bonding or welding, so even if each part is ground to a highly accurate flatness, the top surface of the four phase yokes 94a to 94d will be uneven. Become. The upper surface of these yokes 94a to 94d has stator magnetic pole teeth 90a.
The upper surface of the yoke is required to have a highly accurate flatness. Usually, the entire upper surface of the yoke after lamination is ground.
In this case, the grinding area is large, and if the yokes 94a to 94d after bonding are in a figure-eight or reverse-figure-eight shape, as shown in FIG. This takes a long time and is one of the causes of increased costs for linear pulse motors. Furthermore, after grinding, the four-phase yokes 94a to 94d are coated over their upper surfaces for rust prevention, and during this coating process, the permanent magnets 92 have already been combined with the yokes 94a to 94d and the base 91. Therefore, it is necessary to carry out the work while preventing damage to the permanent magnet 92, and these steps are a major cause of the increase in the cost of the linear pulse motor.

Therefore, this invention eliminates the adhesive bond between the base, permanent magnet, and yoke, and molds the yoke and permanent magnet onto a synthetic resin base, thereby reducing manufacturing labor and improving accuracy. An object of the present invention is to provide a method for manufacturing a stator in a pulse motor.

<Means for Solving the Problems> To explain the means of the present invention to achieve the above object, the present invention has a yoke, a permanent magnet,
A stator comprising four-phase magnetic pole teeth and an excitation coil, a mover having magnetic pole teeth formed on a surface facing the magnetic pole teeth, and a bearing mechanism forming a predetermined gap between the magnetic pole teeth of the stator and the mover. A method for manufacturing a stator in a linear pulse motor, which comprises: grinding and surface-treating the magnetic pole tooth side of the yoke; and pressing and fixing the yoke and permanent magnet to the flat surface of a molding die. The process of filling a molded cavity with a synthetic resin material and forming a base in which a yoke and a permanent magnet are molded is performed continuously.

<Function> According to the above manufacturing method, high precision can be obtained in the grinding and surface treatment of the yoke, and the yoke and permanent magnet are pressed against the flat surface of the mold and filled with the synthetic resin material of the molding cavity. Since the base can be molded with magnets, mechanical mass production becomes possible compared to conventional work using adhesives or welding.In particular, there is no need to grind the top surface of the yoke after molding, making it suitable for linear pulse motors. This has the effect of achieving significant cost reductions.

<Example> FIG. 1 and FIG. 2 show an example of a linear pulse motor.

The above-mentioned linear pulse motor includes a stator 1 in which permanent magnets 3, four-phase yokes 4a to 4d, magnetic pole teeth 5a to 5d, and excitation coils 6a to 6b are disposed on the upper surface of a base 2, and the magnetic pole teeth 5a to 5d. It consists of a mover 8 having magnetic pole teeth 81 formed on opposing surfaces, and a bearing mechanism 7 that forms a predetermined gap between the stator 1 and the mover 8.

This invention is characterized by the stator 1 and the manufacturing method, and first, in the first step, the yoke 4a
The magnetic pole tooth side of ~4d is ground with high precision, and the entire surface of the magnetic pole tooth is subjected to surface treatment such as plating.

In the second step, as shown in FIG. 3, the permanent magnet 3 and the surfaces on the magnetic pole tooth side of the yokes 4a to 4d forming a pair on both sides are joined to the flat surface of a mold with high precision, and pins etc. After pressing and fixing with a pressure member and joining the other mold, the yokes 4a to 4 are
A molded cavity surrounding the yokes 4a to 4d and the permanent magnet 3 is filled with a strong synthetic resin material such as Ryton, and the base 2 in which the yokes 4a to 4d and the permanent magnet 3 are molded is formed.

Since the yokes 4a to 4d are formed by punching using a press or the like, insert molding is performed while leaving the fractured surfaces on the side surfaces as they are, so that the yokes 4a to 4d and the base 2 can be joined together due to the unevenness of the fractured surfaces. Retained.

Further, at both ends of the base 2, a mounting portion 22 for attaching to a device and a guide rod 23 for engaging and supporting a preload spring on one side are formed integrally with the base.

The stator magnetic pole teeth 5 have vertical and horizontal slits 51, 5.
2 and divided into four phases, each having the same pitch and having a phase shifted by 1/4 pitch.
5d.

The excitation coils 6a, 6b are formed by fitting a spool 62 to an iron core 61 and attaching the coils 6a, 6b to the outer periphery of the spool.
is wound around the yokes 4a to 4d and arranged and fixed on both the left and right sides of the yokes 4a to 4d.

The bearing mechanism 7 has a vertical wall 73 on one side of the horizontal wall 72.
For the L-shaped retainer 71, a hole 74 is provided in the horizontal wall to engage the roller shaft 75, and a hole or notch 76 is provided at an appropriate location in the vertical wall 73 to hold the spherical body 7.
7 is engaged and held. The bearing mechanism 7 is arranged on both sides of the stator magnetic pole teeth 5 to support both sides of the slider 8, and the roller shaft 75 supports the stator 1 and the slider 8.
A magnetic gap is set, and the sphere 77 connects the side surface of the slider 8, the traveling reference guide 11, and the preload guide 12.
The side surface of the mover 8 is vertically supported.

Next, the operation of the linear pulse motor will be explained.

In FIGS. 1 and 2, the excitation coil 6a
When a current is applied to the stator magnetic pole teeth 5a, the bias magnetic flux generated by the permanent magnet 3 is strengthened, and the stator magnetic pole teeth 5b generate magnetic flux in a direction that weakens each other. Stable when they are facing each other.

Next, when the current in the coil 6a is cut off and the current is applied to the coil 6b, the permanent magnet 3 is inserted into the stator magnetic pole tooth 5c.
Magnetic flux is generated in the stator magnetic pole tooth 5d in a direction that strengthens the bias magnetic flux and weakens each other, and the magnetic pole tooth 81 of the mover 8 and the stator magnetic pole tooth 5c face each other and are stabilized.
Similarly, by passing a current in the opposite direction to the coil 6a, the magnetic pole teeth 81 of the mover 8 and the stator magnetic pole teeth 5b are stabilized as they face each other. 81 and the stator magnetic pole tooth 5d are opposed to each other for stability. Here, stator magnetic pole teeth 5a, 5
In b, 5c, and 5d, the magnetic pole teeth 5a and 5b and 5c and 5d are 1/2 of the pitch of the magnetic pole tooth row, and the magnetic pole teeth 5
Since a and 5c are out of phase by 1/4 pitch, the above operation causes the mover 8 to move in the A direction by 1/4 pitch.

<Effects of the Invention> As described above, the present invention includes a yoke, a permanent magnet,
A stator comprising phase magnetic pole teeth and an excitation coil, a mover having magnetic pole teeth formed on a surface facing the magnetic pole teeth, and a bearing mechanism forming a predetermined gap between the magnetic pole teeth of the stator and the mover. A method for manufacturing a stator in a linear pulse motor, which includes the steps of grinding the magnetic pole tooth side of the yoke and subjecting it to surface treatment, and pressing and fixing the yoke and permanent magnets to the flat surface of a molding die, followed by molding. The process of filling the cavity with synthetic resin material and forming the base with the yoke and permanent magnet molded was performed in succession to form the stator, and then the process of joining the yoke, permanent magnet, and base with adhesive. is omitted, and the cost of the linear pulse motor can be reduced. Moreover, the surface of the yoke on the magnetic pole tooth side is ground with high precision, and the base is integrally formed by injection molding by pressing it against the flat surface of the molding die, so the surface of the yoke on the magnetic pole tooth side after the base is combined , a highly accurate flat surface can be obtained over the entire surface of the yoke, and the process of grinding the top surface of the yoke can be omitted, thus achieving the object of the invention.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a linear pulse motor according to an embodiment of the present invention, FIG. 2 is an exploded perspective view, and FIG.
The figure is a sectional view showing a molding situation, FIGS. 4 and 5 are views showing a conventional example, and FIG. 6 is an explanatory diagram showing a conventional processing situation. 1... Stator, 2... Base, 3... Permanent magnet, 4a to 4d... Yoke, 5a to 5d... Magnetic pole teeth, 6a, 6b... Excitation coil, 7... Bearing mechanism, 8... Movement Child.

Claims (1)

[Claims] 1. A stator comprising a yoke, a permanent magnet, four-phase magnetic pole teeth, and an excitation coil, a mover having magnetic pole teeth formed on a surface facing the magnetic pole teeth, and magnetic poles of the stator and the mover. A method of manufacturing a stator for a linear pulse motor comprising a bearing mechanism forming a predetermined gap between teeth, the method comprising: grinding and surface treating the magnetic pole tooth side of the yoke; and removing the yoke and permanent magnets. A stator in a linear pulse motor, characterized in that, after being press-fixed to a flat surface of a molding die, a process of filling a molding cavity with a synthetic resin material and forming a base in which a yoke and a permanent magnet are molded is performed continuously. manufacturing method. 2. The method of manufacturing a stator in a linear pulse motor according to claim 1, wherein the base is integrally formed with a guide shaft for engaging and supporting a mounting portion to a device and a preload spring.