JPS6139846A - Linear motor device - Google Patents

Abstract

PURPOSE:To prevent disturbant motion such as rotary motion by disposing the centroid of a moving portion driven in a linear direction of a linear motor on the line of operating a linear drive force. CONSTITUTION:When a coil 6 is energized, a drive force F is acted in a direction of an imaginary line 100 between a magnetic unit 7 and an actuating member 5. The line of operating the force F is disposed on a guide moving surface, and this line passes a centroid G of a linear motor 1. Assume that the centroid G is disposed at the position different from that described above, a branch force vertical to the moving direction with respect to the centroid is generated at the force F1, the moving portion 50 moves in a disturbant motion like a fluctuation in elevational directions, but the fluctuation can be prevented by disposing the centroid G of the portion 50 on the line of operating the drive force of the linear direction.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to the recording and recording of information in optical disk devices and the like.
The present invention relates to a linear motor device that is advantageously implemented for positioning a head for reproducing, erasing, etc.

BACKGROUND ART In an information recording, reproducing, and erasing device such as an optical disk recording, reproducing, and erasing device, a head that declares recording, reproducing, and erasing of information with an optical disk as a recording medium is used to record, reproduce, and erase information. There is a desire for a function (random access function) that quickly reaches a predetermined position on a disc to be erased and records, reproduces, and erases information. For this reason, a linear motor device is required to drive the head.

In the linear motor drive device in the prior art, the motion of the head includes a component that is a disturbance factor such as rotational motion or vibration. For this reason, for example, in a recording medium such as an optical disk in which the recording track width is extremely narrow, there is a problem in that stable recording, reproducing, and erasing operations are difficult.

Problems to be Solved by the Invention It is an object of the present invention to solve the above-mentioned problems and to provide an improved near motor device that can reliably drive in a linear direction.

Means to solve problems □To engineering 1, -7□1, 1□2,3.

The moving part guided by the moving part is driven in a linear direction, the center of gravity of the moving part is on the line of action of the linear driving force, and the center of the moment generated in relation to the guiding means by the driving force is with the center of gravity. The guiding position of the movable part by the guiding means that coincides with each other and extends parallel to the linear direction is
The linear motor device is located within one virtual plane, and the center of gravity is placed within this one plane.

According to the present invention, the center of gravity of the moving part of the linear motor device driven in a linear direction is placed on the line of action of the driving force in the linear direction, and the center of the moment generated in relation to the guide means by the driving force is is made to coincide with the center of gravity, and the guide position of the movable part by the guide means extending parallel to the linear direction is on one virtual plane, and the center of gravity is placed within this one plane. The parts can move parallel to said linear direction without disturbance factors, such as rotational movements.

Example @II! I is a front view of the linear motor device 1 according to an embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a plan view of FIG. 1. FIG. 4 shows the actuating member 5,
FIG. 5 is an exploded perspective view of a magnetic body 70 consisting of a yoke 25 and a permanent magnet 26, FIG. be. The configuration of the linear motor device 1 will be explained with reference to FIGS. 1 to 3. The head 3 mounted on and fixed to the 6-carriage 2 is
For example, it is an optical head that records, reproduces, and erases information on an information medium such as an optical disk (not shown) using a laser beam or the like.

The lower part of the head 3 in FIG. 1 passes through the carriage 2 and is integrally formed with a casing 4 fixed to the opposite side of the carriage 2 from the head 3. At one end of the carriage 2,
A substantially cylindrical actuating member 5 is provided. A coil 6 is provided at a driving end 5a of the actuating member 5 on the side opposite to the carriage 2, around which the actuating member 5 is wound. This drive end 5a
A magnetic body 7 having a configuration as described later is inserted nearby.

Rollers 15, 16, which are rotatably mounted on support shafts 12, 13, 14 having an axis perpendicular to the carriage 2, along guide shafts 10, 11 fixed respectively to mutually parallel guide rails 8, 9; 17 rotates. This guides the carriage 2. Here the support shaft 13.14
One end of the support shaft 15 is fixed to the carriage 2, and one end of the support shaft 15 is fixed to the pressing plate 18. One end of the pressing plate 18 is supported by one pivot shaft that is fixed to the carriage 2 and has an axis parallel to the support shaft 12 so as to be angularly displaceable.

A locking protrusion 20 is provided at the other end of the pressing plate 18 .

One end of a spring 21 is locked to the locking protrusion 20, and the spring 2
The force of No. □f of the spring 21, the other end of which is applied to the locking protrusion 22 provided at one end of the carriage 2, causes the pressing plate 18 to angularly displace in the clockwise direction around the pivot 19. It will be done like this. In this way, the row 215 is pressed against the guide shaft 11. Here, the virtual line A is the line of action of the driving force generated by the magnetic body 7 and the coil 6 as described later,
The imaginary line 101 represents the guiding movement plane of the rollers i s, 'i '6, 17, which will be described later.

Point G is the center of gravity of the entire moving part including the carriage 2, head 3, casing 4, actuating member 5, etc. Point P is
Loaf 16. This is the center point of the moment at which the sum of the moments related to the force acting between -17 and the guide shaft 10 and the force acting between the cooler 15 and the guide shaft 11 becomes zero. The guide rails 8, 9 and the guide shaft 10.11 here constitute a guide means.

Referring to FIGS. 4 and 5, the magnetic body 7 is fixed to a bottomed cylindrical yoke 25 having an opening at one end in the axial direction, and is fixed over the entire inner peripheral surface of the yoke 25, and is fixed to the yoke 25 in the radial direction. and a permanent magnet 26 magnetized to. York 25
The cross section of the plane including the -diameter is approximately E-shaped as shown in FIG. 5, and the outer yoke 27 and the inner yoke 3. -ri28
including.

The actuating member 5 is connected to the inner yoke 2 of the magnetic body 7 as shown in the fourth figure.
! is inserted into a magnetic gap 29 which forms a force with the permanent magnetic door 26. By energizing the coil 6 of the actuating member 5 inserted in this way, the movable part 50 including the actuating member 5
A driving force is generated along the imaginary line 100 in FIGS. 1 and 2.

Referring to FIG. 6, the support shaft 13 of the row 216 is fixed to the carriage 2. As shown in FIG. Between the support shaft 13 and the wheel 30 is a pair of sliding members 3-, such as ball bearings.
1.32 are provided opposite each other. Sliding member 31.
32 is a rolling element 31a.

32a, inner rings 31b, 32b, outer rings 31c, 32c
including. A threaded hole coaxial with the support shaft 13 is formed at the end of the support shaft 13 on the side opposite to the carriage 2 . screw 3
3 inserts the push plate 34 and the spring washer 35 in this order, and is screwed into the screw hole, so that the sliding member 32 becomes the sixth member.
It is pressed upward in the figure to eliminate the vertical gap between the sliding members 31 and 32 in #&5 in the figure.

The wheel 30 of the roller 16 is provided in its circumferential direction with a groove portion 36 having an arc-shaped cross section parallel to the axis.

An annular recess 37 along the axial center line of this groove 36
is provided. The radius of curvature of 1ills36 is the guide shaft 10
The radius of curvature is slightly larger than that of . 6th
As shown in the figure, the guide shaft 10 fitted into the groove 36 is moved into the annular recess 37 by the curved portion of the groove 36, that is, the groove 3
6 to the center position in the vertical direction in FIG.

The construction of the remaining rollers 14,15 is basically similar to the roller 16 shown in FIG.

The annular recess 37 of each roller 14, 15, 16 (the annular recess of the rows 214, 15 is not shown), etc. are arranged on the -virtual plane. □This imaginary plane is made to coincide with the guiding movement plane obtained by moving each annular recess 37 in the left-right direction in FIG.

1 to 3, the center of gravity G of the moving portion 50 of the linear motor device 1 having the above-described configuration.

Each component of the linear motor device 1 is configured so that the centers P of the moments described above coincide with each other.

Moreover, the position of this coincident point G is on the line of action of the driving force indicated by the virtual $100, and the position of the virtual #1101
The linear motor device 1 is configured so as to be included in the above-mentioned guiding movement plane shown in FIG.

The operating state of the linear motor device 1 having the above configuration will be explained with reference to FIGS. 1 to 3.

When the coil 6 is energized, a driving force F acts between the magnetic force collector 7 and the actuating member 5 in the direction of the imaginary line 100. The line of action of this driving force F is on the guiding movement plane as described above. A line of action like 2 passes through the center of gravity G of the linear motor device 1 as described above. Here, assume a configuration in which the center of gravity G is different from the position described above, for example, G1 is the center of gravity. At this time, the driving force F1 is applied to the center of gravity G1 as shown in the first diagram.
It acts on At this time, the driving force F1 has a component force perpendicular to the moving direction with respect to the center of gravity G1, and the moving portion 50
Disturbances such as rattling will occur in the vertical direction of the figure.

Therefore, by arranging the center of gravity G of the movable portion 50 to be at the above-described position, movements such as the above-mentioned rattling can be prevented.

Further, when the movable portion 50 is moved in this manner, the center P of the moment described above is located at the same position as the center of gravity G. Here, for example, when the moving part 50 is moving to the left in FIG.
Assume a configuration in which the center of the moment associated with the forces F 1 , F 2 , F 3 , such as frictional forces, exerted on the guide shaft 10.11 by the guide shaft 10.11 is at a position P1, which is different from the center of gravity G. Here, point P1, driving force F, force F 1 , F
The distance from each line of action of 2 and F3 is j21,
i! 2, Iz3. The sum M of moments around the moment center point 21 is expressed by the following formula.

M=Izl-F+J23-Fl-(j21+ff12)
・(F 2 + F 3 ) ・
...(1) Here, the sum of moments M is not zero, so
A rotational movement about the moment center P1 will occur.

The sum M1 of moments when the center of the moments is the same point as the center of gravity G is expressed by the following formula.

M1=(Iz1+#3)-Fl-(i!2-F212
・F3), ...(2) Here, the sum of moments M1 is zero. By making the center of moment P and the center of gravity G in this manner, it is possible to prevent disturbance movements such as rotation as described above.

In the above embodiment, there were three rollers, but in the present invention, the number of rows 2 is not limited to three, but may be four or more.

According to the present invention as described above, the center of gravity of the moving part of the linear motor device is made to coincide with the center of the moment generated in relation to the guide means by the driving force that drives the moving part in a linear direction. The center of gravity is located on the line of action of the driving force and within a virtual plane that includes the guiding position of the moving part by the guiding means. Therefore, the movable portion can move along the straight line direction, thereby preventing rattling or the like.

[Brief explanation of the drawing]

FIG. 1 is a front view of a linear motor device 1 according to an embodiment of the present invention, FIG. VI2 is a plan view of FIG. 1, FIG. 3 is a side view of FIG. 1, and FIG. Exploded perspective view of 5th
The figure is a cross-sectional view taken along the section line ■--■ in FIG. 4, and FIG. 6 is a cross-sectional view of the vicinity of the row 216. 1... Linear motor device, 2... Carriage, 5...
... Operating member, 6... Coil, 7... Magnetic body, 8,
9... Guide rail, 10.11... Guide shaft, 15,
16, 17...Roller, 25...Yoke, 26...
・Permanent magnet, 3°...Wheel, 36...Groove, 37.
...Annular Recess Agent Patent Attorney Kei Nishi Part Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] A linear motor device that drives a moving part guided by a guide means in a linear direction, wherein the center of gravity of the moving part is on the line of action of the driving force in the linear direction, and the drive force drives the moving part in a linear direction. The center of a related moment is aligned with the center of gravity, the guiding position of the movable part by the guide means extending parallel to the straight line is within one virtual plane, and the center of gravity is within this one plane. A linear motor device featuring: