JPH044826B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an initial setting method for a linear pulse motor suitable for use in, for example, feeding the head of a floppy disk device.

[Prior Art] In recent years, office automation (OA) has become popular, and floppy disk devices are widely used as storage devices. Linear pulse motors are often used to drive the heads of these floppy disk devices, and there is a strong demand for smaller, cheaper, and thinner motors. Therefore, the present applicant previously proposed a linear pulse motor that satisfies the above requirements in Japanese Patent Laid-Open No. 59-47863.

5 and 6 are perspective views showing a configuration example of a linear pulse motor similar to the linear pulse motor according to the above proposal. In these figures, 1 is a mover made of mild steel or the like, 2 is a stator, and the lower surface of this mover 1 is formed with comb-shaped mover teeth 1a.

On the other hand, the stator 2 sequentially attracts the mover teeth 1a by sequentially switching magnetic poles with increasing magnetic flux through the interaction between the permanent magnet 3 and the electromagnet, thereby causing the mover 1 to reciprocate in a stepwise manner. , consists of the following structure.

First, on the lower side of the mover 1, opposite to this,
A slit plate 4 is arranged, and below the slit plate 4, a yoke 6 to which electromagnetic coils 5a and 5b are fixed, and a permanent magnet 3 having an H-shape in plan view are fixed in this order. A cross-shaped groove is formed in the center of the yoke 6, which allows the four magnetic poles 6a, 6b,
6c and 6d are formed. Moreover, the magnetic pole 6a,
At the position on the slit plate 4 directly above the comb-shaped pole teeth 4a, 4b, 6b, 6c, 6d,
4c and 4d are formed, and the mover teeth 1a of the mover 1
They are facing each other with a very short distance between them.

This gap is formed by a pair of linear bearings 7, 7 placed on both sides of the slit plate 4, and the slider 1 is placed on the linear bearing 7.
The linear bearing 7 and the slider 1 are fitted so as to be movable in the longitudinal direction along a guide path formed by the slit plate 4 and the guides 8 and 9.

FIG. 7 is a perspective view showing the configuration of the linear bearing 7. As shown in the figure, the linear bearing 7 includes a pair of rollers 11, 11, balls 12,
12 and a retainer 13 that holds them.The rollers 11, 11 are connected to the openings 14, 14.
The balls 12, 12 are rotatably fitted into the recesses 15, 15, respectively. Further, in FIG. 6, 16 is a stopper that is bent upward to restrict movement of the linear bearing 7, and 18 is a back plate that shields the permanent magnet 3.

According to the above configuration, both sides of the lower surface of the slider 1 come into contact with the rollers 11, 11 of the linear bearing 7,
Further, both side edges of the mover 1 abut against the balls 12, 12. Then, the movable tooth 1a and the pole teeth 4a, 4
b, 4c, and 4d face each other with a slight distance between them. In this state, when a predetermined pulsed current is supplied to the coils 5a and 5b, the mover 1 moves stepwise and linearly on the stator 2. In this case, the linear bearing 7 of the mover 1 is connected to the stopper 1.
Its movement is restricted at the position where it contacts 6. Note that the retainer 13 does not need to be provided with the pair of rollers 11, 11 and the balls 12, 12 separately, and may be provided with a pair of balls that have both of these functions.

[Problems to be Solved by the Invention] Although the above-described linear pulse motor is extremely superior in that it can be constructed in a small size, low cost, and thin shape, it still has the following problems. That is, in the linear pulse motor described above, when the mover 1 moves, the retainer 13 also moves accordingly. The amount of movement of this retainer 13 is theoretically 1/2 of the amount of movement of the mover 1. However, during actual operation, the rollers 11, 11
The flatness of the surface that comes into contact with the surface, the quality of the machining accuracy such as the roughness of the surface, or the dust that adheres to the same surface,
Disturbances caused by dust, scratches, etc. cause a difference in the amount of movement back and forth. Therefore, when the operation is performed for a long time, the difference in the reciprocation described above accumulates, and the position of the retainer 13 gradually deviates from its original position.
It becomes impossible to secure the movement stroke of mover 1,
In the worst case, the mover 1 may become unable to move.

Here, we will explain the problems when this linear pulse motor is applied to a floppy disk drive (hereinafter referred to as FDD) as an example.

When the retainer shifts, in the worst case, the retainer cannot ensure a normal stroke. That is, if the retainer has shifted toward the 80 track, the retainer collides with the stopper before the mover reaches the 80 track, and after that, the mover slides on the rollers. Therefore, mechanical loss increases, making it impossible to obtain regular stopping accuracy.

This invention was made in view of the above-mentioned circumstances, and an object thereof is to provide an initial setting method for a linear pulse motor that can prevent the holding member (retainer) from coming off from its original position. There is.

"Means for Solving the Problems" The present invention provides a mover that moves along a guide path formed by a magnetic pole surface of a stator and a guide member attached to the magnetic pole surface, and a mover that moves along a guide path formed by a magnetic pole surface of a stator and a guide member attached to the magnetic pole surface. a rolling element that maintains a constant space between the magnetic pole surface and between the slider and the guide member; and a pair of holders that hold each of the rolling elements between the stator and the slider. and a regulating member that regulates forward and reverse movers of the holding member at predetermined positions, and is used within a range of use that is narrower than a movable range in which the holding member abuts the regulating member. In the linear pulse motor, in order to move the holding member in both forward and reverse directions to the fullest of the movable range, the mover is moved to an extreme position beyond the normal use range, and during this time, the holding member is moved in both forward and reverse directions. The moving element is characterized in that the moving element is moved to a reference position after the displacement of the holding member is corrected by bringing it into contact with one of the regulating members that regulates the movement of the holding member.

"Operation" By moving the mover in the forward direction and causing one end of each holding member to collide with the regulating member on one side,
The holding members that had shifted in the forward direction are corrected to their normal positions, and by moving the mover in the opposite direction and causing the other end of each holding member to collide with the regulating member on the other side, The holding member that has been displaced in the opposite direction is corrected to its normal position.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a linear pulse motor drive circuit to which an initial setting method according to an embodiment of the present invention is applied. In this figure, 2
0 is a pulse distribution circuit that distributes the forward direction input pulse signal CW or reverse direction input pulse signal CCW supplied from the control circuit 21 into four distribution pulse signals S ₁ , S ₂ , S ₃ , and S ₄ ; 22 supplies a positive sequence current 1 or a negative sequence current ₂ to the coil 5a based on the distribution pulse signals S ₁ , S ₂ , S ₃ , S ₄ while supplying a positive sequence current ₃ or a negative sequence current ₄ to the coil 5b _.
This is a switching circuit that supplies A drive circuit 23 is constituted by the pulse distribution circuit 20 and the switching circuit 22. When the power is turned on, the control circuit 21 executes an initial setting operation according to an operation procedure described later.

Here, the initial setting operation will be explained by taking as an example the case where the linear pulse motor having the above-mentioned configuration is used as a head feeding motor of a floppy disk drive (hereinafter referred to as FDD). In this case, a magnetic head for writing and reading magnetic data to and from a floppy disk is configured to be moved in the radial direction of the magnetic disk by a mover 1 of a linear pulse motor. In addition, the floppy disk is provided with a plurality of concentric tracks, and each track is numbered in the order of 00 track Tr.00, 01 track Tr.01...79 track Tr.79 from the outer circumference. . At the time of initial setting, the magnetic head is once positioned on the 00 track, and then positioned on any one of the 00 to 79 tracks (usage range) as required. In this case, in FDD, 00
The relative position of stator 2 and mover 1 during trucking is
It is determined by the origin sensor, etc. The range of use of the FDD is from 00 tracks to 79 tracks, and the mover 1 can be moved from -00 tracks to 80 tracks. Therefore, in FIG. 3A, once the 00 track position is determined, if 80 pulses are applied in this state, the mover 1 will move to the longest stroke position (80 tracks). Conversely, if you give -81 pulses,
It will be the shortest (01 track). And retainer 1
3 is out of alignment, mover 1 and stator 2
Only the relative position of the retainer 13 with respect to the position changes, but the relative positions of the mover 1 and the stator 2 do not change.
Therefore, the states shown in FIG. 3 (b) and (c) are the extreme positions in any case.

Now, when the power is turned on to the control circuit 21 while the magnetic head is positioned on the 00 track, a forward direction input pulse signal CW for 80 pulses is sent to the pulse distribution circuit 20 as shown in FIG. Supplied. As a result, the slider 1 moves in the direction of arrow A (forward direction) from the state shown in FIG. In this case, if the retainer 13 is slightly displaced in the direction of arrow A, as shown in FIG. , one end of the retainer 13 collides with the stopper 16, whereby the retainer 13 is corrected to its normal position. Next, as shown in FIG. 2, the reverse direction input pulse signal CCW for 81 pulses is supplied to the pulse distribution circuit 20, and the mover 1 moves in the direction of arrow B (reverse direction) from the state shown in FIG. Then, as shown in FIG. 3C, the vehicle exceeds the usage range and is located on the -01 track. In this case, if the retainer 13 were to be displaced in the direction of arrow B, as in the direction of A, the overshoot that would occur when the mover 1 moved 81 tracks and stopped, as shown in FIG. Therefore, the other end of the retainer 13 collides with the stopper 16, whereby the retainer 13 is corrected to its normal position. Furthermore, as shown in FIG. 2, one pulse worth of forward input pulse signal CW is supplied to the pulse distribution circuit 20, and the mover 1 moves in the direction of arrow A from the state shown in FIG. As shown in d, the initial setting operation is completed by positioning on the 00 track.

``Effects of the Invention'' As explained above, according to the present invention, a linear pulse motor based on the general idea that the holding member is used within a range of use narrower than the movable range in which it comes into contact with the regulating member. Since the initial setting method is performed by moving the holding member in the forward and reverse directions beyond the use range and then moving the mover to the reference position, each time such an initial setting operation is performed, , the position of the holding member can be corrected to the normal position, and therefore the holding member can be prevented from coming out of its original position.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a drive circuit for a linear pulse motor to which an embodiment of the present invention is applied, and FIG. FIGS. 3 and 4 are time charts for explaining the forward direction input pulse signal CW and reverse direction input pulse signal CWW supplied to the CW, FIG. 6 is an exploded perspective view showing the structure of the conventional linear pulse motor, and FIG. 7 is a perspective view showing the structure of the linear bearing of the linear pulse motor. 1...Mover, 2...Stator, 5a, 5b...
Coil, 7... Linear bearing, 8, 9... Guide (guiding member), 11... Roller (rolling element), 1
2... Ball (rolling element), 13... Retainer (holding member), 16... Stopper (regulating member), Tr.0
0 to Tr.79... Usage range.

Claims (1)

[Claims] 1 A mover that moves along a guide section formed by a magnetic pole surface of a stator and a guide member attached to this magnetic pole surface, and a space between the mover and the magnetic pole surface and between the mover and the guide. A rolling element that maintains a constant space between the members, a pair of holding members that hold each of the rolling elements between the stator and the slider, and A linear pulse motor is provided with regulating members that regulate movement at predetermined positions, and is used within a range of use that is narrower than a movable range in which the holding member abuts the regulating member. In order to move the mover in both the forward and reverse directions as far as it will go, the mover is moved to an extreme position beyond the normal range of use, and during this time the holding member is brought into contact with one of the regulating members that restricts movement in both the forward and reverse directions. 1. An initial setting method for a linear pulse motor, comprising: correcting a positional deviation of the holding member, and then moving the mover to a reference position.