JP2914084B2 - 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.

[0002]

2. Description of the Related Art As a linear motor of this type, a stator block having a substantially long cylindrical stator case on which permanent magnets and a power supply board are disposed, and a plurality of electromagnets and brushes are moved to the stator block. There is a movable block provided with a movable block supported in a possible state. Then, a transported object support for transporting is connected to the mover block.
The mover block may be provided with a plurality of electromagnets on one mover block, or may be separately formed and connected for each electromagnet.

In this power supply substrate, positive and negative conductive portions and insulating portions are formed at predetermined intervals in the longitudinal direction. More specifically, as shown in FIG. 6, the power supply board 4 has an insulating portion 4c disposed in the longitudinal direction and the direction perpendicular thereto to separate the positive and negative conductive portions 4a and 4b. Thereby, the portion where the brush is in sliding contact with in the longitudinal direction is positive conductive portion 4a → insulating portion 4c → negative conductive portion 4b → insulating portion 4c.
→ Positions are arranged in the order of the positive conductive portion 4a──, and positive and negative voltages are supplied to the coil of the electromagnet via the brush.
4d is a land portion, which is separated from the positive and negative conductive portions 4a, 4b but has the same thickness pattern and a constant gap A, in order to eliminate a step formed between the positive and negative conductive portions 4a, 4b and the insulating portion 4c. It is formed with B interposed. When the brush slides on the power supply board 4, the land 4d maintains the sliding surface at a constant height, so that the mechanical wear of the brush can be greatly reduced.

[0004]

In the above-described linear motor, the mechanical abrasion of the brush can be greatly reduced by forming the land portion 4d on the power supply board 5, but the brush is located near the gap A or B. When the mover block is stopped in a state where the brush and the positive conductive portion 4a or the negative conductive portion 4b are stopped.
In some cases, sparks may be generated between the two and accelerate electrical wear. This phenomenon will be described in detail below.

In this type of linear motor, the mover block is driven by electromagnetic attraction and repulsion between a permanent magnet of the stator block and a plurality of electromagnets of the mover block. Therefore, the electromagnet, that is, the mover block, also receives a force due to the suction repulsion in a direction orthogonal to the traveling direction. As a result, microscopically, the traveling direction and the direction orthogonal thereto,
In other words, it also moves back and forth in the running direction and up and down. This movement is remarkable in a type in which the mover block is formed separately for each electromagnet and connected to each other. When the length of the pair of N poles and S poles of the permanent magnet is L, the travel of the mover block is L / L. It occurs almost regularly every time it becomes 2.

FIGS. 7 and 8 show the movement of the mover block.
It will be described based on. FIG. 7 shows one of the electromagnets separated and formed.
This shows a state in which each of the mover blocks 5 is viewed from the side, 6 is a movable base, 7 is an electromagnet, 8 is an iron core, 9 is a coil, and 10 is a brush. The iron core 8 has a substantially U-shape formed by both side pieces and a connecting piece, and both side pieces face the permanent magnet of the stator block so as to sandwich the permanent magnet. In FIG. 7, one side piece is visible. FIG. 8 is an explanatory diagram for explaining the movement of the brush 10 on the power supply board 4.

Now, when the mover block 5 is traveling from right to left on the power supply board 4 shown in FIG. 6 and the brush 10 is located, for example, in the positive conductive portion 4a immediately before reaching the gap A, it is excited. The electromagnet 7 receives a force in the direction of arrow F in FIG.
Next, when the brush 10 passes through the gap A and reaches the land portion 4d of the insulating portion 4c, the electromagnet 7 is in a non-excited state and no longer receives a force, and is in a direction opposite to the direction of the arrow F in FIG. Will be returned.
As a result, the brush 10 comes into contact with the positive conductive portion 4a again as shown in FIG. 8 (a) and receives the force in the direction of arrow F in FIG. 7 (a). And vibrate.
In this case, although a cogging force actually exists, it is negligible because the cogging force is much smaller than the force received by the attraction and repulsion between the electromagnet 7 and the permanent magnet.

The mover block 5 is running on the power supply board 4 shown in FIG.
When the electromagnet 7 is in the land portion 4d immediately before the state, the electromagnet 7 is not excited because it is in a non-excited state. Next, the brush 10
When passing through A and reaching, for example, the positive conductive portion 4a, the electromagnet 7 is excited and receives a force in the direction of the arrow F in FIG. 7B. In this case, as shown in FIG. 8B, the brush 10 only displaces on the positive conductive portion 4a, so that the above-described vibration does not occur.

When the mover block 5 is running from right to left on the power supply board 4 shown in FIG.
When the electromagnet 7 is in the land portion 4d immediately before the state, the electromagnet 7 is not excited because it is in a non-excited state. Next, the brush 10
When passing through B and reaching, for example, the negative conductive portion 4b, the electromagnet 7 is excited and receives a force in the direction of arrow F in FIG. 7 (c). In this case, as shown in FIG. 8C, the brush 10 only displaces on the negative conductive portion 4b, so that the above-described vibration does not occur.

Next, the mover block 5 travels from left to right on the power supply board 4 shown in FIG.
7, the excited electromagnet 7 receives a force in the direction of arrow F in FIG. 7D. Next, the brush 10 passes through the gap B and passes through the land 4d of the insulating portion 4c.
, The electromagnet 7 is de-energized and no longer receives a force, and is returned in the direction opposite to the direction of arrow F in FIG. 7D. As a result, the brush 10 comes into contact with the negative conductive portion 4b again as shown in FIG. 8 (d), and receives the force in the direction of arrow F in FIG. 7 (d). And vibrate.

Such vibration of the electromagnet promotes electrical wear of the brush due to sparks, and also causes a problem that controllability when the linear motor is driven by a switching power supply or the like is reduced. That is, when driven by a controller such as a switching power supply, the on / off and speed control of the switching power supply are performed by capturing the change in current generated when the brush passes through the gap A or B. This is also because a change in current occurs. That is, a change in current due to the vibration of the electromagnet causes a speed different from the actual speed to be detected, or a trouble such as a power-off command not being issued is caused. In an extreme case, the coil of the electromagnet may be disconnected .

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 high safety and capable of reducing brush abrasion.

[0013]

According to a first aspect of the present invention, there is provided a linear motor having a substantially cylindrical tubular stator case and magnetized with different poles in a thickness direction. The permanent magnets are magnetized so that different poles are present alternately at regular intervals in the longitudinal direction and are disposed in the stator case, and the positive and negative conductive portions and insulating portions are formed and fixed at predetermined longitudinal intervals. A stator block having a power supply board 4 disposed in a slave case, and a coil wound around an iron core that has a substantially U-shape with both side pieces and a connecting piece, and the two side pieces face each other with a permanent magnet therebetween. An electromagnet supported by the stator case in a movable state, a brush for supplying a positive and negative voltage of the power supply board to the coil, and a mover block having
, The power supply board has a configuration in which the end faces of the positive and negative conductive portions located on both sides in the longitudinal direction of the insulating portion are formed non-parallel.

Further, a linear motor according to a second aspect is configured such that a land portion having a thickness equivalent to that of the positive and negative conductive portions is formed on the insulating portion of the power supply substrate according to the first aspect.

[0015]

According to the structure of the first aspect, there is a movement of the brush caused by the movement of the electromagnet due to the electromagnetic attraction and repulsion between the permanent magnet of the stator block and the electromagnet of the mover block. However, since the end surfaces of the positive and negative conductive portions located on both sides in the longitudinal direction of the insulating portion are non-parallel, vibrations reciprocating between the positive and negative conductive portions and the insulating portion can be prevented.

According to the second aspect of the present invention, the sliding surface of the brush consisting of the positive and negative conductive portions and the insulating portion can be maintained at a constant height, and the mechanical wear of the brush can be reduced.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In the present invention, the main part is in the configuration of the power supply board, and members and parts having the same basic functions are denoted by the same reference numerals as in the conventional example.

Reference numeral 1 denotes a stator block, and a stator case 2
, A permanent magnet 3, and a power supply board 4. Stator case
2 is provided with a permanent magnet 3 and a power supply board 4 and has a cross-sectional shape as shown in FIG. 2 by extrusion molding of aluminum or the like in order to support a movable block described later in a movable state. It is formed in a substantially elongated cylindrical shape. The stator case 2 includes upper and lower walls 2a, 2b and left and right walls.
A substantially long cylindrical shape is formed by 2c and 2d, and an upper part inside the movable block is an electromagnet housing chamber and a lower inner part is a roller housing chamber. Accordingly, an I-shaped support 2e for supporting the permanent magnet 3 on the inner surface of the upper wall 2a, a substantially L-shaped support 2f, 2f for supporting the power supply board 4 on the right wall 2d, and an opening 2g in the center of the lower wall 2b. Roller guides 2h, 2h are formed on both inner surfaces of the opening 2g. 2j, 2j are mounting portions for mounting the stator case 2 on a ceiling surface or the like.

As shown in FIG. 3, the permanent magnets 3 are magnetized with different polarities in the thickness direction and magnetized so that different poles are present alternately at regular intervals in the longitudinal direction. The case 2 has a supporting concave portion 3e corresponding to the supporting portion 2e. In the permanent magnet 3, by fixing the supporting concave portion 3e and the supporting portion 2e by appropriate means such as press-fitting or bonding, different poles are present alternately over almost the entire length of the stator case 2.

The power supply substrate 4 has positive and negative conductive portions 4a, 4b and an insulating portion 4c formed at predetermined intervals in the longitudinal direction, and is fixedly disposed on the support portions 2f, 2f of the stator case 2. It will be described later.

Reference numeral 5 denotes a mover block, which includes an electromagnet 7 and a brush.
10 is a main component, and has a roller 11 that is structurally integrated with the movable base 6 and is connected to the movable base 6 so as to be movable. Further, the linear motor of the embodiment has three electromagnets for three-phase driving. Further, as shown in FIG. 4, the mover block 5 is of a type that is separately formed into three for each electromagnet and is connected and connected. This type is suitable for curve running.

Each movable base 6 has a slightly larger planar shape than the electromagnet 7 so that each electromagnet 7 can be disposed, and has a connecting portion 6a at both ends in the longitudinal direction for rotatably connecting each other. . The movable table 6 is accommodated in the electromagnet accommodating chamber of the stator case 2, and at least one of the movable tables is provided with a hook 12 extending to the roller accommodating chamber.

Each electromagnet 7 is composed of a laminated iron core 8 and a coil 9 wound therearound. Iron core 8 is a piece 8a, 8a on both sides
The connecting piece 8b is embedded and fixed in the movable base 6 such that the connecting piece 8b is substantially U-shaped, and the side pieces 8a, 8a face each other so as to sandwich the permanent magnet 3. At the tip of these two pieces 8a, 8a,
It is desirable to cover the protective caps 8c, 8c made of resin with low frictional resistance while also providing mechanical protection. The coil 9 is wound around coil frames 9a, 9a mounted on both side pieces 8a, 8a.

The three electromagnets 7, 7, 7 are connected to and connected to the three movable bases 6, 6, 6, so that the stator case 2
Are arranged side by side in the longitudinal direction. In this case, the length of each electromagnet 7 in the longitudinal direction is expressed by the length of a pair of N pole and S pole of the permanent magnet 3 as L.
Is set so as not to exceed L / 3. Therefore, the length in the longitudinal direction of the iron core 8 is L / L in consideration of the dimensions of the coil 9.
Set sufficiently smaller than 3. In addition, the three coils 9, 9, 9 arranged side by side connect one of the terminals in common,
The other is separately connected to three brushes 10.

Each brush 10 has a rectangular parallelepiped shape,
The base end is fixed to the front end of a conductive spring 10a fixed to the movable table 6 so as to slide on the base 4. The brush 10 is connected to the power supply board 4
In order to supply the positive and negative voltages of
And is electrically connected to the other terminal of each coil 9 via. In addition, each brush 10 is set so that the interval is L / 3. A capacitor 13 has one end connected to the terminal of each coil 9 and the other end connected in common in order to reduce electric noise generated when the mover block 5 travels.

Reference numeral 14 denotes a conveyed object support, which is formed in a substantially rectangular parallelepiped shape, and which is engaged with a tip end of a hook 12 extending from the movable table 6.
14a, and the support shaft 11a of the rollers 11, 11 penetrates. As described above, the movable block 6 and the rollers 11, 11 are connected to each other, so that the movable block 5 can move within the stator case 2, that is, can move. That is, the transported article supporter 14 also functions as a roller support member of the mover block 5. 14b is a mounting hole for mounting a transported object such as a curtain.

Next, the power supply board 4 will be described. The power supply substrate 4 is provided with positive and negative conductive portions 4a and 4b by forming a conductive pattern having a constant thickness on one surface of the insulating substrate.
The insulating portion 4c is formed such that a portion where no conductive pattern is present eventually separates the positive and negative conductive portions 4a and 4b. The positive and negative conductive portions 4a and 4b and the insulating portion 4c are formed at predetermined intervals in the longitudinal direction so that the above-mentioned brush 10 can slide. When the brush 10 is in contact with the positive conductive portion 4a, a positive voltage is applied to the coil 9, and when the brush 10 is in contact with the negative conductive portion 4b, a negative voltage is applied to the coil 9.

What is important in the power supply substrate 4 is that, as shown in FIG. 1, the end faces of the positive and negative conductive portions 4a and 4b located on both sides in the longitudinal direction of the insulating portion 4c are formed in a non-parallel manner. . The end surfaces of the conventional positive and negative conductive portions 4a and 4b are formed so as to be orthogonal to the reference line in the longitudinal direction, but in this embodiment, the positive conductive portion 4a becomes thinner as the width in the longitudinal direction approaches the tip. As a result, each end face of the negative conductive portion 4b is formed so as to be similarly thick. Specifically, it is non-parallel inclined by about 20 ° from a line perpendicular to the reference line in the longitudinal direction.

The longitudinal length W1 at the center of the positive and negative conductive portions 4a, 4b is W1 ≧ L / 3, and the longitudinal length W2 at the center of the insulating portion 4c is W2 ≦ L / 6. As a result, the portion where the brush 10 slides is positioned in the longitudinal direction in the order of the positive conductive part 4a → the insulating part 4c → the negative conductive part 4b → the insulating part 4c → the positive conductive part 4a──, and positive and negative voltages are applied to the brush. The electric power is supplied to the coil 9 of the electromagnet 7 via 10.

Further, the insulating part 4c has positive and negative conductive parts 4a, 4b
Conductive pattern with a thickness equivalent to that of A and B
Is formed to form a land portion 4d. This allows
A step generated between the positive and negative conductive portions 4a, 4b and the insulating portion 4c can be eliminated.

The linear motor has a movable block 5
Brush 1 on at least two of the three coils 9,9,9
The current flows through 0, 10, and 10, and the resulting permanent magnet 3 of the stator block 1 and the electromagnet of the mover block 5
7 and the mover block 5
Are driven in a fixed direction. When the driving (running) direction of the mover block 5 is reversed, the polarity of the voltage supplied to the positive / negative conductive portions 4a and 4b may be reversed.

When the traveling operation of the mover block 5 is viewed microscopically, as described in the description of the conventional example, a force due to suction repulsion is also applied in a direction orthogonal to the traveling direction.
As a result, it also moves in the traveling direction and its orthogonal direction, in other words, in the front-back and up-down directions of the traveling direction. This movement is
This is remarkable in a type in which a mover block is formed separately for each electromagnet and connected to each other. When the length of a pair of N poles and S poles of a permanent magnet is L, the travel of the mover block becomes L / 2. Occur almost regularly.

The relationship between the movement of the brush 10 and the power supply board 4 caused by the movement of the mover block 5 will be described with reference to FIG. The movement of the mover block 5 at each position of the positive and negative conductive portions 4a, 4b and the insulating portion 4c when the brush 10 travels is the same as that of FIG.

Now, when the mover block 5 is traveling from right to left on the power supply board 4 shown in FIG. 1 and the brush 10 is located, for example, in the positive conductive portion 4a immediately before reaching the gap A, it is excited. The electromagnet 7 receives a force in the direction of arrow F in FIG.
Next, when the brush 10 passes through the gap A and reaches the land portion 4d of the insulating portion 4c, the electromagnet 7 is in a non-excited state and no longer receives a force, and is in a direction opposite to the direction of the arrow F in FIG. Will be returned.
In this case, the brush 10 is, as shown in FIG.
Since only displacement occurs on the land portion 4d in 4c, no vibration as in the conventional example occurs.

The mover block 5 is traveling from left to right on the power supply board 4 shown in FIG.
When the electromagnet 7 is in the land portion 4d immediately before the state, the electromagnet 7 is not excited because it is in a non-excited state. Next, the brush 10
When passing through A and reaching, for example, the positive conductive portion 4a, the electromagnet 7 is excited and receives a force in the direction of the arrow F in FIG. 7B. In this case, the brush 10 only displaces on the positive conductive portion 4a as shown in FIG. 5B, so that the vibration does not occur as in the conventional example.

The mover block 5 is running from right to left on the power supply board 4 shown in FIG.
When the electromagnet 7 is in the land portion 4d immediately before the state, the electromagnet 7 is not excited because it is in a non-excited state. Next, the brush 10
When passing through B and reaching, for example, the negative conductive portion 4b, the electromagnet 7 is excited and receives a force in the direction of arrow F in FIG. 7 (c). In this case, the brush 10 only displaces on the negative conductive portion 4b as shown in FIG. 5C, so that the vibration does not occur as in the conventional example.

Next, the mover block 5 travels from left to right on the power supply board 4 shown in FIG.
7, the excited electromagnet 7 receives a force in the direction of arrow F in FIG. 7D. Next, the brush 10 passes through the gap B and passes through the land 4d of the insulating portion 4c.
, The electromagnet 7 is de-energized and no longer receives a force, and is returned in the direction opposite to the direction of arrow F in FIG. 7D. In this case, as shown in FIG. 5D, the brush 10 only displaces on the land portion 4d in the insulating portion 4c, so that the vibration does not occur as in the conventional example.

As described above, the linear motor of the present invention
Vibration hardly occurs between the positive and negative conductive portions 4a and 4b and the insulating portion 4c as seen in the conventional example. As a result, controllability of a controller such as a switching power supply is improved, safety is enhanced, and electrical wear of the brush can be reduced.

In this embodiment, the end surfaces of the positive and negative conductive portions 4a and 4b are approximately 20 degrees away from a line perpendicular to the longitudinal reference line.
Non-parallel tilted by °. However, the amount by which the mover block moves due to the electromagnetic attraction and repulsion varies depending on the magnetic force of the permanent magnet and the magnetomotive force of the electromagnet. Therefore, the inclination angles of the end faces of the positive and negative conductive portions 4a and 4b are appropriately set according to these. It is necessary.

[0040]

According to the linear motor of the present invention, the movement of the electromagnet due to the electromagnetic attraction between the permanent magnet of the stator block and the electromagnet of the mover block, that is, the movement of the brush caused by the movement of the mover block is reduced. Even if there are, the end faces of the positive and negative conductive portions located on both sides in the longitudinal direction of the insulating portion are non-parallel, so that reciprocating vibration between the positive and negative conductive portion and the insulating portion can be prevented, and therefore the safety is high, and the brush is high. Electrical abrasion can be reduced.

The linear motor according to the second aspect is the first aspect.
In addition to the effect of the linear motor described above, the sliding surface of the brush composed of the positive and negative conductive portions and the insulating portion can be maintained at a constant height, and the mechanical wear of the brush can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view of a main part showing one embodiment of the present invention.

FIG. 2 is a sectional view showing the entire structure.

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

FIG. 4 is a perspective view of the mover block.

FIGS. 5A to 5D are explanatory views illustrating the movement of the brush on the power supply board.

FIG. 6 is a front view of a main part showing a conventional power supply board.

FIGS. 7A to 7D are explanatory diagrams illustrating the movement of the mover block.

FIGS. 8A to 8D are explanatory views illustrating the movement of the brush on the power supply board.

[Explanation of symbols]

 1 Stator block 2 Stator case 3 Permanent magnet 4 Power supply board 4a Positive conductive part of power supply board 4b Negative conductive part of power supply board 4c Insulation part of power supply board 4d Land in insulating part of power supply board 5 Mover block 6 Movable table 7 Electromagnet 8 Electromagnet core 9 Electromagnet coil 10 Brush 11 Roller 12 Hook 14 Conveyance support

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02K 41/02 H02K 41/035 A47H 5/02

Claims (2)

(57) [Claims] 1. A stator case having a substantially long cylindrical shape, and magnetized with different poles in a thickness direction, and magnetized and fixed so that different poles are present alternately at regular intervals in a longitudinal direction. A stator block having a permanent magnet disposed on the stator case, a power supply substrate disposed on the stator case with the positive and negative conductive portions and insulating portions formed at predetermined intervals in the longitudinal direction, and both side pieces; An electromagnet supported by the stator case in a movable state with a coil wound around an iron core facing each other so as to sandwich a permanent magnet between the connecting pieces, and the positive and negative of the power supply board A brush for supplying a voltage to the coil, and a mover block having a brush, wherein the power supply substrate has non-parallel end faces of positive and negative conductive portions located on both sides in the longitudinal direction of the insulating portion. Linear motor. 2. The linear motor according to claim 1, wherein a land portion having a thickness equal to that of the positive and negative conductive portions is formed on the insulating portion.