JPH053658A - Linear motor - Google Patents

Abstract

PURPOSE:To stabilize contact of brush with a power supply board. CONSTITUTION:A brush 5, having a contact 51 fit in a through-hole 55a and an L-shaped conductive board 52 fit in a recess 55b and a through-hole 55c, is fixed to an insulating member 41 secured to the outside of the facing piece 4b of an electromagnet 4. At that time, the contact 51 of the brush 5 is urged by a coil spring flexible in the direction perpendicular to one face 3a of a power supply board 3 and the end face 51a thereof abuts on the one face 3a with a predetermined contact pressure. Consequently, the contact 51 does not hook on the copper foil at the positive/negative voltage conductive part formed on one face 3a of the power supply board 3 when the contact 51 rides over the copper foil resulting in suppression of electric noise and abrasion of sliding face. Furthermore, the brush 5 can contact stably with the power supply board in the center thereof even when the sliding face is abraded.

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 opening and closing curtains and conveying articles.

[0002]

2. Description of the Related Art Conventionally, as a linear motor of this kind, the following one provided with a stator block and a mover block is usually used.

The stator block includes a cylindrical guide rail, a plate-shaped permanent magnet magnetized in the plate thickness direction so that the longitudinal direction is alternately different poles at regular intervals, and one side has a positive and negative voltage conductivity. And a power feeding board provided with a portion, and the permanent magnet and the power feeding board are fixedly formed along the longitudinal direction of the inner wall of the guide rail.

The mover block has substantially U-shaped iron cores in which coils are wound in opposite directions on opposite pieces, and the permanent magnet is interposed between the opposite pieces in the plate thickness direction. The electromagnet device includes a plurality of electromagnets arranged in a row, and a brush connected to the coil.

The operation is performed by connecting the brush to the mover block by slidingly contacting the one surface of the power supply board and alternately applying positive and negative voltages to the coil to move the mover block in the longitudinal direction of the guide rail. It is designed to open and close curtains and convey articles.

Further, the structure of the brush will be described in detail with reference to FIG. The brush 11 has a conductive leaf spring 11a having both end pieces 11c and 11d parallel to each other at both ends of the inclined piece 11b.
A contact point 11e made of carbon is fixed to the one end piece 11c, and the other end piece 11d is screwed and supported by an insulating member 12b fixed to an iron core 12a of the electromagnet 12. And
The contact point 11e is spring-biased by the leaf spring 11a so as to be brought into sliding contact with a contact pressure on the one surface 13a of the power supply board 13 having a positive and negative voltage conductive portion formed of copper foil, and the other end piece 11d of the leaf spring 11a.
The coil of the electromagnet 12 is connected to.

[0007]

In the conventional linear motor described above, the brush 11 has the leaf spring 11a and the inclined piece 11a.
It is formed by having both end pieces 11c, 11d parallel to each other at both ends of b, and one end piece 11c is fixed with a contact 11e which is in sliding contact with one surface 13a of the power supply board 13 with a contact pressure, and the other end piece. Since 11d is fixedly supported, the contact point 11e and the other end piece 11d are connected to each other by the inclined piece 11b of the leaf spring 11a.
Since the brush 11 is positioned so as to be inclined with respect to the one surface 13a, the contact state of the brush 11 with the power supply substrate 13 may become unstable as described below.

That is, as shown by the arrow in FIG.
When the brush 11 moves in the direction of the one end piece 11c of the leaf spring 11a, the moving angle between the moving direction and the extending direction of the inclined piece 11b of the leaf spring 11a becomes an acute angle. One side surface 13a is likely to be caught by friction or the like that occurs when passing over the copper foil of the positive and negative voltage conductive parts and jumps, causing electrical noise or sliding contact. The surface is easily worn. Then, when the sliding contact surface is worn out, the other end piece 11d of the leaf spring 11a is fixedly supported, so that the moving angle is gradually increased and the sliding contact surface slides on the one surface 13a of the power supply board 13. The contact point of the contact point 11e that comes into contact moves to the side of the other end piece 11d, and the timing at which positive and negative voltages are alternately applied to the coil may deviate, and the mover block may not move smoothly. is there.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a linear motor capable of stabilizing the contact state of the brush with the power supply substrate.

[0010]

In order to solve the above-mentioned problems, the linear motor of the present invention is mounted in the plate thickness direction such that the cylindrical guide rail and the longitudinal direction alternately have different poles at regular intervals. A permanent magnet in the form of a magnetized plate, and a power supply board having a conductive portion for positive and negative voltages provided on one surface, and fixed by fixing the permanent magnet and the power supply board along the longitudinal direction of the inner wall of the guide rail. A plurality of electromagnets each having a child block and a substantially U-shaped iron core in which coils are wound in opposite directions to each other, and a permanent magnet is interposed between the opposing pieces of the iron core in the plate thickness direction. A mover block having an electromagnet device arranged in a row and a brush connected to the coil is provided, and the brush slides into contact with the one surface of the power supply substrate while being biased, and positive and negative voltages are alternately applied to the coil. Is applied to move the mover block In the linear motor to move in longitudinal direction, wherein the brush has a biased comprising structure by a spring to flex in a direction perpendicular to the one surface of the power feeding substrate.

[0011]

According to the linear motor of the present invention, since the brush is biased by the spring that bends in the direction orthogonal to the one surface of the power feeding board, when the brush slides on the one surface, The urging direction of the coil spring is always orthogonal to each other, so that the brush is caught as in the conventional example when passing over the copper foil of the conductive portion of the positive and negative voltages formed on one surface of the power supply board and passing through. It is unlikely that an unstable state will occur, electrical noise will be less likely to occur, and wear on the sliding contact surface will be reduced. Even if the sliding contact surface wears, the contact point is always in the center of the sliding contact surface and is stable. Since the contacts can be made at positions, the mover block can be moved smoothly without causing a difference in the timing of alternately applying positive and negative voltages to the coils as in the conventional example.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

This linear motor comprises a stator block A and a mover block B and is constructed as follows.

First, the stator block A is a guide rail.
It consists of 1, a permanent magnet 2 and a power supply board 3.

The guide rail 1 is made of a metal material such as aluminum and has both ends opened, and as shown in FIG. 3, a guide groove 1a is provided in the center of the lower side to form a tubular shape having a substantially rectangular cross section.
Further, the inside of the rectangle is divided into upper and lower two-stage spaces by a partition wall 1b having an opening in part.

The permanent magnet 2 is formed in a flat plate shape, and one end face of the plate thickness is fixed to the center portion of the inner wall of the upper side of the guide rail 1 along the longitudinal direction. Then, as shown in FIG. 2, the longitudinal direction is magnetized in the plate thickness direction so as to have different poles alternately at regular intervals. Here, the length of one set of magnet pieces consisting of N poles and S poles in the longitudinal direction is L.

As shown in FIG. 4, the power supply board 3 includes a positive voltage conductive part 3b and a negative voltage conductive part 3c formed on the one surface 3a of the plate-like substrate at right angles in the vertical direction at regular intervals. It is formed of copper foil so as to be separated into upper and lower parts by the insulating part 3d meandering in the direction. Here, the width of the insulating portion 3d in the longitudinal direction is L
/ 6, the widths of the conductive portions 3b and 3c in the longitudinal direction are formed to be L / 3, respectively. And this power supply board 3 has one side
Guide rail 1 so that 3a faces the pole face of permanent magnet 2.
It is fixed to the inner wall on one side.

Next, the mover block B is composed of three electromagnets.
It consists of an electromagnet device consisting of 4 and a brush 5.

The electromagnet 4 is a facing piece 4 of a substantially U-shaped iron core 4a.
Coils 4d are formed on b and 4c by winding them in opposite directions via a coil frame (not shown). In the mover block B, the three electromagnets 4 are connected to the facing pieces 4b, 4c.
Are integrally fixed to the row body 4e so as to be lined up in a straight line, and one end of each coil 4d is connected to the brush 5 as will be described later and the other end thereof is commonly connected. It is configured as an electromagnet device. At this time, the length of each electromagnet 4 in the row direction is set so as not to exceed L / 3, and the distance between each brush 5 is L /.
It is set to 3.

The brush 5 includes a contact 51, a conductive plate 52, and a lead wire.
53, a coil spring 54, and a brush holder 55. The contact point 51 is made of carbon and has a convex shape in cross section, and is formed in a substantially cylindrical shape having a large diameter portion and a small diameter portion.
The conductive plate 52 is formed in an L shape by one piece 52a and the other piece 52b. Both ends of the lead wire 53 are connected to the small-diameter portion of the contact 51 and one piece 52a of the conductive plate 52 so that the contact 51 and the conductive plate 52 are connected.
And are conducting. The coil spring 54 is a compression spring and is fitted between the contact 51 and the one piece 52a of the conductive plate 52 so that one end of the coil spring 54 is fitted into the outer recess of the small diameter portion of the contact 51 to surround the lead wire 53. The brush holder 55 is made of an insulating material and has a convex cross section and is formed into a substantially square shape. A through hole 55a having a diameter slightly larger than the large diameter of the contact 51 is provided at the center thereof, and the brush holder 55 communicates with the through hole 55a. A concave portion 55b and a through hole 55c, which are matched in shape with the L-shaped conductive plate 52, are provided.
A locking piece 55d having a sagittal tip is projected on both sides of 55b.

In the brush 5, the contact 51 is mounted in the through hole 55a of the brush holder 55, and the conductive plate 52 projects the tip of the other piece 52b from the through hole 55c to form the recess 55.
It is attached to b and through hole 55c. On the other hand, a substantially flat plate-shaped insulating member 41 having a locking hole 41a is fixed to the outside of the facing piece 4b of each electromagnet 4, and the locking piece 55d provided on the brush holder 55 is provided in the locking hole 41a. The brush 5 is attached to the electromagnet 4 with one touch by being inserted so that the sagittal tip is locked. At this time, the contact 51 of the brush 5 is biased by the coil spring 54 which is a spring that bends in the direction orthogonal to the one surface 3a of the power supply board 3, and the tip surface 51a of the brush 5 has a predetermined contact pressure. It comes into contact with 3a. The coil 4d is connected to the tip of the other piece 52b of the conductive plate 52 protruding from the through hole 55c of the brush holder 55.

The mover block B constructed as described above has the iron core 4a in the upper space of the guide rail 1.
The permanent magnet 2 is housed in the stator block A by interposing the permanent magnet 2 in the plate thickness direction between the opposing pieces 4b and 4c. Meanwhile, the guide rail
In the lower space of 1, the conveying piece 4f is extended from the row body 4e so as to protrude through the opening of the partition wall 1b and the guide groove 1a, and the conveying piece 4f has a guide rail 1a. The inner wall of the lower side is provided with a roller 4g that rolls in the longitudinal direction. Then, a hole 4h to which an object to be conveyed such as a curtain is connected is provided in a portion protruding to the outside of the conveying piece 4f.

Next, the operation of this linear motor will be described. The contact point 51 of the brush 5 is biased by the coil spring 54, and when the tip surface 51a of the brush 5 is slidably contacted with the one surface 3a, the coil 4d is configured so that a current always flows in any two phases of the three phase coils 4d. A positive and negative voltage will be applied to. For example, when the two electromagnets 4 at both ends are excited and in the state shown in FIG. 4, attraction and repulsion between the facing pieces 4b and 4c of the iron core 4a that are the magnetic poles of the electromagnet 4 and the magnetic pole surface of the permanent magnet 2 are obtained. The moving element block B advances in the direction of the arrow L / 6 by the propulsive force due to the action. Then, this time, the sliding contact position of the brush 5 with respect to the power supply board 3 is changed, the two electromagnets 4 at the rear end are excited, and subsequently the same action further advances by L / 6. After that, the process proceeds continuously L / 6 at a time, advances L / 6 six times, and returns to the state of FIG. In this way, the mover block B advances in the longitudinal direction of the guide rail 1. When moving the mover block B in the reverse direction, the positive and negative voltages of the conductive portions 3b and 3c of the power supply board 3 may be reversed.

Since such a linear motor is constructed as described above, the brush 5 has a coil spring 54 which is a spring in which the contact 51 is bent in a direction orthogonal to the one surface 3a of the power feeding substrate 3.
Since the tip end surface 51a is slidably brought into contact with the one surface 3a while being biased by, and the moving direction and the biasing direction of the coil spring 54 are always orthogonal to each other, the contact point 51 is one surface of the power supply board 3. When passing over the copper foil of the positive and negative voltage conductive parts 3b and 3c formed on 3a, it is unlikely to be in an unstable state like being caught as in the conventional example, and electrical noise or sliding contact surface A certain tip surface 51a is less worn, and even if the sliding contact surface is worn, the contact point is always in the center of the tip surface 51a and can be contacted at a stable position. There is no possibility that the timing at which the voltage is alternately applied to the coil is displaced, and the mover block B can move smoothly.

The brush 5 can be attached to the electromagnet 4 with one touch by inserting the locking piece 55d of the brush holder 55 into the locking hole 41a of the insulating member 41. The installation work can be easily performed without the troublesome work of fixing the device to the insulating member by screwing.

In this embodiment, the contact 51 and the conductive plate
I used the lead wire 53 to connect to the 52
And the coil spring 54 mounted between the conductive plate 52 and the one piece 52a.
Is formed of a copper alloy material having high conductivity and spring property, the contact 51 and the conductive plate 52 are connected via the coil spring 54.
Can be conducted, and the lead wire 53 can be omitted.

[0027]

According to the linear motor of the present invention, since the brush is biased by the spring that bends in the direction orthogonal to the one surface of the power supply board, when the brush is moved in sliding contact with the one surface, The urging direction of the coil spring is always orthogonal to each other, so that the brush is caught as in the conventional example when passing over the copper foil of the conductive portion of the positive and negative voltages formed on one surface of the power supply board and passing through. It is unlikely that an unstable state will occur, electrical noise will be less likely to occur, and wear on the sliding contact surface will be reduced. Even if the sliding contact surface wears, the contact point is always in the center of the sliding contact surface and is stable. Since the contacts can be made at the positions, there is no difference in the timing when positive and negative voltages are alternately applied to the coils as in the conventional example, and the mover block can move smoothly.

[Brief description of drawings]

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

FIG. 2 is a partially cutaway perspective view showing the structure of the above linear motor.

FIG. 3 is a sectional view of the same.

FIG. 4 is an explanatory diagram showing an operation state of the above.

FIG. 5 is a sectional view showing a main part of a conventional example.

[Explanation of symbols]

 A Stator block 1 Guide rail 2 Permanent magnet 3 Power supply board 3a One side 3b Conductive part 3c Conductive part B Movable block 4 Electromagnet 4a Iron core 4b Opposing piece 4c Opposing piece 4d Coil 4e Row assembly 5 Brush 54 Coil spring

Claims (1)

Claim: What is claimed is: 1. A cylindrical guide rail, a plate-shaped permanent magnet magnetized in the plate thickness direction so that the longitudinal direction alternates with different poles at regular intervals, and one side is positive and negative. A power supply board provided with a conductive portion for voltage, and a stator block in which a permanent magnet and a power supply board are fixed along the longitudinal direction of the inner wall of the guide rail, and coils on opposite pieces in mutually opposite directions. An electromagnet device in which a plurality of electromagnets each having a substantially U-shaped iron core wound around and having a permanent magnet interposed in a plate thickness direction between the opposing pieces of the iron core are arranged in a row, and a brush connected to a coil , And a brush is urged to one surface of the power supply board while the brush is urged against one surface of the power supply board, and positive and negative voltages are alternately applied to the coil so that the mover block extends in the longitudinal direction of the guide rail. In a linear motor that moves in the direction, the brush , Linear motor characterized by comprising urged by a spring to flex in a direction perpendicular to the one surface of the power feeding substrate.