JP3086895B2 - Linear motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor used for conveyance, and more particularly, to a linear motor for connecting a plurality of mover blocks.

[0002]

2. Description of the Related Art In recent years, long linear motors have been used for conveying curtains and the like. This type of linear motor is a stator block that houses and arranges a power supply board provided with a permanent magnet and a conductive part having positive and negative voltages alternately arranged in a longitudinal direction in a stator case that is elongated in a cylindrical shape. A coil is wound around a movable base movably guided by a stator case, and a plurality of U-shaped yokes are arranged side by side in the longitudinal direction with opposing leg pieces and connecting pieces facing the permanent magnet. And a mover block having a brush for supplying power to each coil by slidingly contacting the conductive portion of the power supply board.

As shown in FIG. 6, one armature block A has a yoke D on which a coil C is wound on a movable base B for each phase, and has a brush. E is provided, and the front and rear movable bases B, B are rotatably connected so as to have a predetermined positional relationship with a permanent magnet (not shown) of the stator block. In addition, when the mover block is dedicated to linear drive, a single movable base may be used even if the mover block is of a three-phase type. The thrust of the linear motor is obtained by the magnetic force (detent force or detent torque) of the permanent magnet of the stator block and the magnetic attraction and repulsion (electromagnetic torque) of this with the coil and yoke of the mover block, that is, the electromagnet. When it is desired to increase the size, a plurality of the mover blocks A are connected.

[0004]

By the way, the detent force generated between the permanent magnet of the stator block and the yoke of the mover block becomes a thrust and also causes a non-uniform thrust. In other words, the thrust characteristics of a single mover block, for example, of a three-phase type, have a detent force that varies in a cycle of 60 electrical degrees (one pitch of the N pole and S pole of the permanent magnet is 360 electrical degrees). It changes under the influence, and as the mover blocks are connected, unevenness of the thrust further increases, and smooth driving becomes difficult.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a linear motor having reduced thrust unevenness so that smooth driving can be achieved when a plurality of mover blocks are connected. It is in.

[0006]

SUMMARY OF THE INVENTION In order to solve this problem, a linear motor according to the present invention comprises a stator case having a long cylindrical shape and a permanent magnet alternately having a different polarity in the longitudinal direction of the stator case. A stator block that houses and arranges a power supply board with conductive parts of positive and negative voltages sandwiching the insulating part to be sandwiched, and a coil wound around a movable base that is movably guided by the stator case and faces the permanent magnet Motor that has a plurality of yokes that are arranged side by side in the longitudinal direction and that has a brush that has a brush that slidably contacts the conductive portion of the power supply board and supplies power to each coil. In the above, the mover block is formed by a connecting member that shifts a positional relationship of the corresponding yoke of each mover block with respect to the permanent magnet and a positional relationship of the corresponding brush with the conductive portion by a predetermined amount in the moving direction. It is constituted of concatenating click. The predetermined amount of the positional relationship to be shifted is determined by the number of connected mover blocks.

[0007]

According to this structure, the detent force generated for each mover block is canceled out to reduce the fluctuation, and as a result, the thrust unevenness of the whole becomes small.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. This linear motor has a stator block
One, a plurality of mover blocks 7 and a connector 14 are basic constituent members.

The stator block 1 has a stator case 2 extending in a cylindrical shape, a permanent magnet 3 having different poles alternately in the longitudinal direction thereof, and a power supply provided with conductive portions 5 and 6 of positive and negative voltages. The board 4 is accommodated and arranged.

As shown in FIG. 2, the stator case 2 is formed by extruding aluminum or the like, and the upper part is used as the yoke accommodating part of the mover block, and the lower part is used as the roller accommodating part of the mover block. Has an opening 2a through which the conveyed object support penetrates, and has roller guides 2b, 2b on both sides thereof. The upper surface has an I-shaped support portion 2c on which a permanent magnet 3 is disposed, and the one side surface has L-shaped support portions 2d, 2d on which a power supply board 4 is disposed.

The permanent magnet 3 is supported by a support 2 c of the stator case 2.
As shown in FIG. 3, different poles are present alternately at a constant pitch in the longitudinal direction. Since the permanent magnet 3 is magnetized in a direction perpendicular to the longitudinal direction, that is, in the thickness direction, the above-mentioned alternate different poles refer to a state viewed from one side. Now, let one pitch consisting of the north pole and the south pole be L.

The power supply substrate 4 is preferably made of a flexible insulating substrate. As shown in FIG. 4, there is an insulating portion 4a meandering up and down at regular intervals at the center, that is, the insulating portion 4a. In other words, the conductive parts 5 and 6 of positive and negative voltages are provided above and below the insulating part 4a so as to sandwich the insulating part 4a, and furthermore, the insulating part 4a through which the brush passes has substantially the same height as the conductive parts 5 and 6. The land portion 4b is provided insulated from the conductive portions 5 and 6.

Therefore, the brush of the mover block, which will be described later, has the center of the power supply board 4 in the positive conductive portion 5 → insulating portion 4a (land portion 4b) → negative conductive portion 6 → insulating portion 4a (land portion 4b) → positive conductive portion. Sliding contact with part 5─. The dimensions are L / 3 for the positive and negative conductive parts 5, 6 and L / 6 for the insulating part 4a.

One of the plurality of mover blocks 7, 7,... Is a movable table in which the roller 9 and the article support 10 are substantially integrated.
8, a yoke 11, a coil 12, and a brush 13.

In this embodiment, as shown in FIG. 1, three movable tables 8 made of a synthetic resin such as PBT (polybutylene terephthalate) are rotated by a fastener T such as a tapping screw or a bolt nut. The main parts 8a are movably connected, and each main part 8a has a size capable of disposing the yoke 11 and the coil 12, and is located in the upper accommodating part of the stator case 2 as shown in FIG. More specifically, the main part 8a has two layers in the thickness direction at the front and rear ends in the movement direction in a plan view, and has two layers in the thickness direction. For example, if the front end is the upper layer 8b, the rear end is the lower layer. The portion corresponding to the lower layer on the front end side and the upper layer on the rear end side as 8c is concavely formed in a mountain shape. In the center of the protruding upper layer 8b and lower layer 8c, connecting holes 8d, 8d,.
A hook 8e is attached to the main portion 8a of any of the movable tables 8, and the tip of the hook 8e extends to the roller accommodating portion and is connected to a locking hole 10e of a transported object support 10 for locking a curtain or the like. . In addition, the movable base 8 is made into one, and the main part 8a is
The coil 12 may have such a size that a plurality (for example, three) of the coils 12 can be arranged in the longitudinal direction. A roller shaft 9a penetrates the above-described transported object support 10, and the rollers 9, 9 are rotatable so as to sandwich the transported object support 10.
9a, and a mounting hole (not shown) for mounting a conveyed article is provided near the center. Therefore movable table 8
Are movably guided by the stator case 2. In addition,
If the mover block 7 is dedicated to linear drive,
The connection between 8, 8, and 8 may be fixedly connected.

The yoke 11 is basically composed of opposed leg pieces 11a, 11a.
The connecting piece 11b is formed into a U-shape with a U-shaped laminated core, and the connecting piece 11b is fitted into the movable base 8 and fixed.
Accordingly, the opposing leg pieces 11a, 11a of the yoke 11 face the permanent magnet 3 via the predetermined gap. Opposing piece of yoke 11
It is preferable that a resin cap 11c having a small frictional resistance be provided on the distal ends of the 11a and 11a as well as mechanical protection.

The coil 12 is wound around a coil frame 12a mounted on the opposing pieces 11a, 11a. Such a yoke 11
The coil 12 and the permanent magnet 3 constitute an electromagnet, and three electromagnets are arranged side by side in the longitudinal direction. In this case, one of the terminals of the three coils 12 is connected in common. Further, when the length of the yoke 11 in the longitudinal direction is l1, l1 <L / 3.

The brush 13 has a rectangular parallelepiped shape, and a base end is provided on an insulating plate 13a provided for each electromagnet so that a leading end thereof is in sliding contact with the power supply board 4, and the other end of the three coils 12 is electrically connected to the other end. Connected. The brush 13 has its tip end positioned at an interval of L / 3 in the longitudinal direction.

As shown in FIG. 5, the connecting body 14 is
Has the same thickness as the main part 8a, and the upper layer 8b and the lower layer
Upper layer 14b and lower layer 14c corresponding to 8c, and connection holes 14d, 14d corresponding to connection holes 8d, 8d are provided. This connecting member 14 is for connecting two mover blocks 7 and has L / 12 between the connecting holes 8d.

In order to connect the two mover blocks 7, 7 using the connecting member 14, as shown in FIG. 1, the lower layer 8c of the rear end movable base 8 of the front mover block 7 and the connecting member 14 are connected. Upper layer 14
b, the upper layer 8b of the tip movable base 8 of the rear movable block 7 and the lower layer 14c of the connecting body 14 are overlapped, and the connecting holes 8d, 14d are coaxially arranged and rotatably connected by the fastener T. Also in this case, if the mover blocks 7, 7 are dedicated to linear drive, they may be fixedly connected.

Basically, this linear motor is always connected to any two (two-phase) coils of three (three-phase) coils 12, 12, 12 of each mover block 7, 7 via a brush 13. Apply current,
The mover blocks 7, 7 are advanced by obtaining a propulsive force in a certain direction by the magnetomotive force generated at that time. However, in this embodiment, since the connector 14 is interposed between the mover blocks 7, 7, the corresponding yokes 11, 11 of the mover blocks 7, 7 are provided.
Relative to the permanent magnet 3 and the corresponding brushes 13,1
3 with respect to the conductive portions 5, 6
/ 12 (electrical angle 30 °). In the case where there is only one mover block 7 and three phases, the cycle of the detent force is generated every L / 6 (electrical angle 60 °). Are offset, and the fluctuation of the entire detent force becomes extremely small. Then, the timing of the current flowing through the coil 12 via the brush 13 is also shifted by L / 12 to generate a smooth thrust.

The distance between the connecting holes 14d of the connecting body 14, that is, the predetermined amount for shifting the positional relationship between the corresponding yoke of each mover block with respect to the permanent magnet and the positional relationship with respect to the conductive portion of the corresponding brush is 3 In the case of the phase, since the detent force is generated every L / 6, if the number of connected mover blocks is N, the relationship is L / 6N. Therefore, when connecting three mover blocks, the connection holes of the connector 14 are required.
The distance between 14d and 14d is L / 18 (electrical angle 20 °).

The shape of the connecting member or the connecting structure of the mover blocks connected to the connecting member may be appropriately designed. In short, the connection between the two connecting portions of the connecting member that determines the amount of shift between the mover blocks is important. It is sufficient that the size of the satisfies the purpose of the present invention.

[0024]

According to the linear motor of the present invention, the detent force generated for each mover block is canceled out, and the fluctuation of the entire detent force is extremely small. When a plurality of blocks are connected, smooth driving can be performed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view thereof.

FIG. 3 is a partial perspective view of the permanent magnet.

FIG. 4 is a plan view of the power supply board.

FIG. 5 is a perspective view of the connector.

FIG. 6 is a perspective view of a conventional mover block.

[Explanation of symbols]

 1 Stator block 2 Stator case 3 Permanent magnet 4 Power supply board 5,6 Conductive part of power supply board 7 Mover block 8 Movable table 9 Roller 10 Carrier 11 Yoke 12 Coil 13 Brush 14 Linkage 14d Linkage of link Hole

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-48-14976 (JP, A) JP-A-4-79916 (JP, A) JP-A-4-137486 (JP, U) JP-A-63 10782 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H02K 41/02-41/035 B60L 13/03-13/10

Claims (1)

(57) [Claims] 1. A power supply board provided with a conductive part having positive and negative voltages so as to sandwich a permanent magnet having different polarities alternately in a longitudinal direction thereof and an insulating part meandering up and down in a stator case extending in a cylindrical shape. A stator block accommodated and arranged, a coil is wound around a movable base movably guided by a stator case, and a plurality of yokes opposed to the permanent magnets are arranged side by side in the longitudinal direction. And a linear motor that has a brush that feeds power to each coil in sliding contact with the conductive portion of the linear motor. A linear motor in which mover blocks are connected by a connecting body that shifts a positional relationship of a corresponding brush with respect to a conductive portion by a predetermined amount in a moving direction.