JPS6268058A - Voice coil type linear motor - Google Patents

Abstract

PURPOSE:To reduce an occupying space by arranging a movable carriage to the side of a coil bobbin and holding the movable carriage by means of a guide shaft fixed to a side-surface yoke. CONSTITUTION:A coil 12 is wound on a coil bobbin 11, and a center core 21 penetrates the coil 12. A main yoke 22 mounted in parallel with the center core 21 has a permanent magnet 24 oppositely faced to the coil 12 on the inside thereof. A driving section is constituted of a side-surface yoke 23 brought into contact with both end surfaces of the center core 21 and the main yoke 22. A movable carriage 42 is unified with the coil bobbin 11 disposed to the side, and can be slid in parallel with the center core 21 along guide shafts 41 fastened to the side-surface yoke 23.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] When a linear motor that linearly moves a load is incorporated into a device, it is advantageous to have a shorter overall length including the moving table on which the load is attached and the movement range of the moving table.

Therefore, in a voice coil type linear motor (hereinafter referred to as a linear motor), a moving stage for attaching a load is arranged on the side of the coil bobbin to shorten the overall length.

(Industrial Field of Application) The present invention relates to a floppy disk device, and particularly to a linear motor for moving a magnetic head in a track direction.

As floppy disk drives become smaller and thinner, there is a need to reduce the space occupied by the power source that moves the magnetic head in the track direction and to reduce the number of component parts. A small electric motor is generally used as a power source for moving the magnetic head toward the trunk. However, when a small electric motor is used as a power source, a mechanism for converting rotational motion into linear movement is required, and furthermore, it is difficult to reduce the space occupied by the small electric motor.

Therefore, we focused on the fact that the vertebral force required to move the magnetic head is small and the moving distance is small.
Near motors are being considered because they do not require a mechanism to convert into linear motion and can be made smaller and thinner. However, if the overall length including the moving table on which the load is attached and the moving range of the moving table is long, there are many restrictions when incorporating a linear motor into a device. Therefore, the linear motor used in the floppy disk device must have a short overall length.

[Conventional technology]

FIG. 2 is a principle diagram of a linear motor, and FIG. 3 is a perspective view showing an example of a conventional linear motor.

In FIG. 2, the linear motor includes a coil 12 wound around a coil bobbin 11 and a center core 21 passing through the coil 12.
, is provided in parallel with the center core 21 and has the coil 1 inside.
The main yoke 22 has a permanent magnet 24 facing the center core 21, and a side yoke 23 that abuts both ends of the center core 21 and the main yoke 22. It is magnetized so that the outside is the south pole. The magnetic flux 25 emitted from the N pole of the permanent magnet 24 is
As shown in the figure, the gap between the center core 21 and the center core 2
1, returns to the S pole of the permanent magnet 24 via the side yoke 23 and the main yoke 22.

In such a linear motor, when a direct current is applied to the coil 2, the coil 12 moves along with the coil bobbin 1 to the right or left in parallel with the center core 21, depending on the direction in which the current flows.

As shown in FIG. 3, the conventional linear motor includes the above-mentioned driving section, a moving table 3 to which a load is attached, and a connecting shaft 32 that is held by a guide section (not shown) and connects the coil bobbin 11 and the moving table 31. It consists of Therefore, when DC current is applied to the coil 12, the coil 12 moves together with the coil bobbin II, and the moving table 31 also moves to the right or left.

[VJ problem that the invention attempts to solve]

Linear motors can occupy much less space than small electric motors. However, with conventional linear linear motors, the length of the drive unit, the length of the moving base, and the moving distance of the moving base are added together, resulting in a longer overall length and the need for a mechanism (not shown) to guide the moving base or the connecting shaft. , there was a problem that the location where it could be installed was restricted.

[Means for solving problems]

FIG. 1 is a perspective view showing an embodiment of a linear motor according to the present invention. The same objects are represented by the same symbols throughout the plan.

The above problem is solved at least in the coil bobbin 11 shown in FIG.
a main yoke 22 that has a coil 12 wound around it, a center core 21 that passes through it, and a permanent magnet 24 that is provided in parallel with the center core 21 and faces the coil 12 inside.
, and a drive section composed of a side yoke 23 that abuts both sides of the center core 21 and the main cork 22, and a guide shaft 41 that is integrated with the coil bobbin 11 disposed on the side and fixed to the side yoke 23. along the center core 21
This problem is solved by the linear motor of the present invention, which comprises a movable table 42 that can be slid in parallel with the linear motor.

[Effect]

In Fig. 1, the overall length of the linear motor is shortened by arranging the moving platform to the side of the coil bobbin, and the width of the linear motor is increased because the moving platform is held by a guide shaft fixed to the side cork. Therefore, restrictions on the location where it is installed are reduced, and the space it occupies can be made much smaller than that of conventional linear motors.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to FIG.

In the figure, a coil bobbin 11 is integrally molded with a moving table which will be described later, and a coil 12 is wound around the outer periphery of the coil bobbin 11. Although the coil bobbin and the moving table are integrally molded in this embodiment, they may be molded separately and then integrated by bonding or the like. Further, the coil bobbin 11 is provided with a through hole, through which the center core 21 is allowed to slide.

A main yoke 22 is provided on the outside of the coil bobbin H in parallel with the center core 21, and a permanent grinding stone 24 facing the coil 12 is mounted inside the main yoke 22.

In this example, a main yoke with a U-shaped cross section is used, and permanent magnets are attached to the three inside surfaces. It is possible to operate even if the side surface of the main yoke and the permanent magnet attached to the side surface are omitted.

Side yokes 23 are brought into contact with both sides of the center core 21 and main yoke 22, and the magnetic flux 25 emitted from the N pole of the permanent grinding stone 24 is transmitted through the gap between the center core 21, the center core 21, and the side yokes 23. , and a magnetic circuit that returns to the S pole of the permanent magnet 24 via the main yoke 22.

The coil hobbin 1 is arranged on the side of the coil hobbin 11.
1 is integrally molded with the guide shaft 4 provided parallel to the center core 21 and fixed to the side yoke 23.
1, it is held in a movable state. Therefore, when DC current is applied to the coil 12, the coil 12 moves together with the coil bobbin 11, and the moving table 42 also moves to the right or left.

As mentioned above, the linear motor shown in this example has the moving base placed on the side of the coil bobbin, so the overall length is short, and the width is extremely short because the moving base is held by the guide shaft fixed to the side yoke. It can be suppressed slightly. Therefore, restrictions on the position where it is inserted are reduced, and the space it occupies can be made much smaller than the conventional linear motor.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a linear motor that has a short overall length including a moving table on which a load is attached and a moving range of the moving table, and has fewer restrictions on the position where it is installed.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of a linear motor according to the present invention, FIG. 2 is a principle diagram of a linear motor, and FIG. 3 is a perspective view showing an example of a conventional linear motor. In the figure, 11 is a coil bobbin, 12 is a coil, 21 is a center core, 22 is a main yoke, 23 is a side yoke, 24 is a permanent magnet, 41 is a guide shaft,
42 represents a moving table. Perspective view showing the implementation row of the 1-liter amotor of the present invention 1ζ 1st diagram = principle diagram of demo-9

Claims (1)

[Claims] At least a coil (
12), a center core (21) passing through it, a main yoke (22) provided in parallel with the center core (21), and having a permanent magnet (24) facing the coil (12) inside; A driving section is formed of a side yoke (23) that abuts both sides of the center core (21) and the main yoke (22), and is integrated with the coil bobbin (11) arranged on the side. A voice coil type linear characterized by comprising a movable base (42) movable in parallel with the center core (21) along a guide shaft (41) fixed to a side yoke (23). motor.