JPH05304760A - Linear motor - Google Patents

Abstract

PURPOSE:To provide a linear motor which lessens unevenness in thrust so that it can smooth driving When a plurality of needle blocks are coupled. CONSTITUTION:Needle blocks 7 and 7 are coupled by a coupling 14 which shifts the positional relations to the permanent magnets of corresponding yokes 11 and 11, of each needle block 7 and 7 and the positional relations to the conductive parts of corresponding brushes 13 and 13 by specified quantities in shifting direction.

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 transportation, and more particularly to a linear motor which connects a plurality of mover blocks.

[0002]

2. Description of the Related Art In recent years, long linear motors have been used to convey curtains and the like. A linear motor of that type has a stator block in which a stator case elongated in a cylindrical shape is housed and arranged with a power supply board provided with permanent magnets having different poles alternately in the longitudinal direction and conductive portions of positive and negative voltages. A coil is wound around a movable base that is movably guided by the stator case, and a plurality of U-shaped yokes are arranged side by side in the longitudinal direction with opposing leg pieces facing the permanent magnets and connecting pieces. And a movable element block having brushes that are arranged to be in contact with each other and are in sliding contact with the conductive portion of the power supply board to supply power to each coil.

This mover block A is of a three-phase type, for example, as shown in FIG. 6, one movable block B for each phase is provided with a yoke D wound with a coil C, and a brush is provided. E is provided and the front and rear movable bases B and B are rotatably connected to each other so as to have a predetermined positional relationship with a permanent magnet (not shown) of the stator block. If the mover block is dedicated to linear drive, the number of movable blocks may be one, even if it is 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 repulsion (electromagnetic torque) between this and the coil and yoke of the mover block, that is, the electromagnet. , If you want to make it larger, connect a plurality of mover blocks A.

[0004]

By the way, the detent force generated between the permanent magnets of the stator block and the yoke of the mover block becomes thrust and causes thrust unevenness. In other words, the thrust characteristics of one mover block, for example, one with a three-phase type, have a detent force that changes with an electrical angle of 60 ° (1 pitch of the N pole and S pole of the permanent magnet is 360 ° electrical angle). It changes under the influence, and as the mover blocks are connected, the thrust unevenness further increases and it becomes difficult to drive smoothly.

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 in which thrust unevenness is reduced so that smooth driving can be performed when a plurality of mover blocks are connected. It is in.

[0006]

In order to solve such a problem, a linear motor according to the present invention has a stator case elongated in a cylindrical shape, and a permanent magnet having different poles alternately present in the longitudinal direction thereof and a meander vertically. The stator block that accommodates and arranges the power supply board with the positive and negative voltage conductive parts sandwiching the insulating part, and the movable base guided movably in the stator case, the coil is wound to face the permanent magnet. A linear motor having a plurality of yokes arranged side by side in the longitudinal direction and having brushes for slidingly contacting a conductive portion of a power supply board to supply power to each coil, and connecting a plurality of mover blocks. , A movable body block is moved by a connecting body that shifts the positional relationship between the corresponding yoke of each movable block and the permanent magnet and the relative position of the corresponding brush to the conductive portion by a predetermined amount in the moving direction. It is constituted of concatenating click. The predetermined amount by which the positional relationship should be shifted is determined by the number of connected mover blocks.

[0007]

According to this structure, the detent force generated in each mover block is canceled to reduce the fluctuation thereof, and as a result, the uneven thrust force as a whole is also reduced.

[0008]

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

The stator block 1 includes a stator case 2 elongated in a cylindrical shape, a permanent magnet 3 having different poles alternately present in the longitudinal direction thereof, and power supply units 5 and 6 for positive and negative voltages. The substrate 4 is accommodated and arranged.

As shown in FIG. 2, the stator case 2 is formed by extrusion molding of aluminum or the like, the upper part of which is a yoke accommodating portion of the mover block, and the lower part of which is a roller accommodating part of the mover block. Has an opening 2a through which the transported object support penetrates, and roller guides 2b and 2b are provided on both sides thereof. Further, an I-shaped support portion 2c for disposing the permanent magnet 3 is provided on the upper surface, and L-shaped support portions 2d, 2d for disposing the power supply board 4 are provided on one side surface.

The permanent magnet 3 is a support portion 2c of the stator case 2.
As shown in FIG. 3, different poles are alternately present in the longitudinal direction at a constant pitch. Since the permanent magnet 3 is magnetized in the direction orthogonal to the longitudinal direction, that is, in the thickness direction, it is in a state viewed from one side with the above-mentioned alternate different poles. Now, let 1 pitch consisting of N pole and S pole be L.

The power supply board 4 is preferably made of a flexible insulating board, and as shown in FIG. 4, there is an insulating part 4a meandering vertically at regular intervals in the central part, that is, the insulating part 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 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 formed insulatively with respect to the conductive portions 5 and 6.

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

One of the plurality of mover blocks 7, 7 is a movable table in which the roller 9 and the transported object 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 bases 8 made of synthetic resin such as PBT (polybutylene terephthalate) are rotated by fasteners T such as tapping screws or bolts and nuts. The main parts 8a are movably connected to each other, and each main part 8a has a size capable of disposing the yoke 11 and the coil 12, and is located in the upper housing part of the stator case 2 as shown in FIG. More specifically, the front and rear ends of the main portion 8a in the moving direction in plan view are mountain-shaped, and there are two layers in the thickness direction. For example, if the front end side is the upper layer 8b, the rear end side is the lower layer. 8c, the portions corresponding to the lower layer on the front end side and the upper layer on the rear end side are recessed in a mountain shape. And, in the center of the projecting upper layer 8b and lower layer 8c, connecting holes 8d, 8d, for the fastener T are provided.
Further, a hook 8e is attached to the main part 8a of any one of the movable bases 8, and the tip of the hook 8e extends to the roller accommodating part and is coupled to the locking hole 10e of the transported object support 10 for locking the curtain or the like. .. It should be noted that the number of movable bases 8 is one, and the main part 8a is the yoke 11
The coil 12 may have a size such that a plurality (for example, three) of coils 12 can be arranged in the longitudinal direction. A roller shaft 9a is inserted through the conveyed object support 10 so that the rollers 9 and 9 can be rotated so that the conveyed object support 10 is sandwiched therebetween.
It is supported by 9a, and a mounting hole (not shown) for mounting a conveyed object 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 for linear drive only,
8,8,8 may be fixedly connected.

The yoke 11 is basically composed of opposed leg pieces 11a, 11a.
The connecting piece 11b and the connecting piece 11b form a U-shape with a laminated iron core, and the connecting piece 11b is fitted and fixed to the movable table 8.
Therefore, the facing leg pieces 11a, 11a of the yoke 11 face the permanent magnet 3 with a predetermined gap. Opposing piece of yoke 11
It is desirable to cover the tip portions of 11a, 11a with a resin cap 11c having a small frictional resistance for the purpose of mechanical protection.

The coil 12 is wound around the coil frame 12a mounted on the facing 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 commonly connected. 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 portion thereof is provided on an insulating plate 13a provided for each electromagnet so that a front end portion of the brush 13 is slidably contacted with the power supply board 4, and the other end of the three coils 12 is electrically connected. Connected to each other. The tip of the brush 13 is located at an interval of L / 3 in the longitudinal direction.

As shown in FIG. 5, the connecting body 14 has a movable base 8
Has the same thickness as the main part 8a of the
It has upper layer 14b and lower layer 14c corresponding to 8c, and connecting holes 14d and 14d corresponding to connecting holes 8d and 8d. The connecting body 14 is for connecting two movable element blocks 7, and the distance between the connecting holes 8d, 8d is L / 12.

In order to connect the two mover blocks 7, 7 using this connecting body 14, as shown in FIG. 1, the lower layer 8c of the rear movable table 8 of the front moving piece block 7 and the connecting body 14 are connected. Upper layer 14
b, the upper layer 8b of the movable tip block 8 of the rear mover block 7 and the lower layer 14c of the coupling body 14 are overlapped with each other, and the coupling holes 8d and 14d are coaxially arranged to be rotatably coupled by a fastener T. Also in this case, if the mover blocks 7 and 7 are exclusively for linear drive, they may be fixedly connected.

Basically, this linear motor is always provided with brushes 13 to any two (two-phase) coils (12, 12) of three (three-phase) coils 12 of each mover block 7,7. Let the current flow,
The magnetomotive force generated at that time obtains a propulsive force in a fixed direction to move the mover blocks 7, 7. However, in this embodiment, since the connecting body 14 is interposed between the mover blocks 7 and 7, the corresponding yokes 11 and 11 of the mover blocks 7 and 7 are arranged.
Of the brushes to the permanent magnet 3 and the corresponding brushes 13,1
The positional relationship of 3 to the conductive parts 5 and 6 is L with respect to the moving direction.
It is relatively deviated by / 12 (electrical angle 30 °). In the case where there is one mover block 7 and three phases, the cycle of the detent force is generated every L / 6 (electrical angle of 60 °). Will be canceled out, and the fluctuation of the total detent force will be extremely small. 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, 14d of the connecting body 14, that is, the predetermined amount by which the positional relationship between the corresponding yoke of each movable element block and the permanent magnet and the corresponding positional relationship of the brush to the conductive portion are shifted is 3 In the case of the phase, since the detent force is generated every L / 6, if the number of mover blocks to be connected is N, the relationship is L / 6N. Therefore, when connecting three mover blocks, the connecting hole of the connecting body 14
The distance between 14d and 14d becomes L / 18 (electrical angle 20 °).

The shape of the connecting body or the connecting structure of the mover blocks connected to the connecting body may be appropriately designed. The point is that between the two connecting portions of the connecting body which determines the amount of displacement between the mover blocks. It is sufficient that the dimensions of the above are in accordance with the gist of the present invention.

[0024]

According to the linear motor of the present invention, the detent force generated in each mover block is canceled out, and the fluctuation of the entire detent force becomes extremely small. Therefore, the thrust unevenness is reduced and the mover is reduced. Smooth drive can be achieved when a plurality of blocks are connected.

[Brief description of drawings]

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

FIG. 2 is a vertical 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 connected body.

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 base 9 Roller 10 Transport object support 11 Yoke 12 Coil 13 Brush 14 Coupling body 14d Connection of coupling body Hole

Claims (1)

[Claims] 1. A power supply board provided with a conductive part of positive and negative voltages, with a permanent magnet having alternating poles alternating in the longitudinal direction and an insulating part meandering vertically sandwiched in a stator case elongated in a cylindrical shape. A coil is wound around a stator block that is housed and arranged, and a movable table that is movably guided by the stator case, and a plurality of yokes facing the permanent magnets are arranged side by side in the longitudinal direction and a power supply board is provided. A linear motor having a brush having a brush for slidingly contacting the conductive portion of each of the coils to feed power to each coil, and in a linear motor connecting a plurality of the mover blocks, a positional relationship between a corresponding yoke of each of the mover blocks and a permanent magnet, A linear motor in which a mover block is connected by a connecting body that shifts a positional relationship of a corresponding brush with respect to a conductive portion by a predetermined amount with respect to a moving direction.