JPH09137344A - Linear motor for driving knitting needle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear motor for driving a knitting needle by fixing and arranging one of a sensing head or a body to be sensed on a stator assembled body and the other on a needle assembled body and bringing a change of a space between the sensing head and the body to be sensed to be small. SOLUTION: In this linear motor for driving a knitting needle, a needle assembled body 22 is connected with a stator assembled body 20 to be movable in one direction by a connecting means 24 installed with a guide 44 assembled with a stator assembled body 20 and a moving body 48 movably connected to the guide 46 to be capable of relatively moving in the direction of the needle assembled body 22 and a position sensor 28 which detects the position of the needle assembled body 22 against the stator assembled body is installed. The position sensor 26 is installed with a body 54 to be sensed disposed in either of the guide 46 and the needle assembled body 22 and a sensing head 56 which detects the body 54 to be sensed. The linear motor is so constituted to be arranged with a space between a sensing unit in the sensing head 56 in crossing both directions, i.e., the direction of a magnetic force which acts between the stator 28 of a permanent magnet and the needle 40 of an exiting coil arid the direction of moving of the needle assembled body 22. The linear motor is used for driving the knitting needle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor for reciprocating a knitting needle of a knitting machine, and more particularly to a linear motor having a position sensor for detecting the position of a mover assembly with respect to a stator assembly.

[0002]

A flat knitting machine in which each knitting needle, that is, a knitting needle, is moved by a flat plate-shaped or thin linear motor is known.
For example, it is described in JP-B-1-12855. This type of linear motor for knitting needles has a stator assembly in which a plurality of stators are sequentially arranged in one direction on a flat portion of a plate-shaped stator support, and a plurality of movers of a plate-shaped mover support. A mover assembly sequentially arranged in one direction on a flat portion, a coupling means for movably supporting the mover assembly on the stator assembly, and a position sensor for detecting the position of the mover assembly with respect to the stator assembly. With.

In the above linear motor, the position sensor includes a sensed body disposed in either one of the stator assembly and the mover assembly, and the stator assembly and the mover assembly for sensing the sensed body. And a sensing head disposed on the other side of the solid body.

However, in the conventional linear motor for moving the knitting needle, the plate-shaped stator support is bent by the magnetic force acting between the stator and the mover, thermal expansion and contraction of the stator support, and the like. As a result, the distance between the sensing object of the position sensor and the sensing head changes, and the sensing accuracy of the position sensor changes.

In particular, an elongated position detecting magnet having N poles and S poles alternately in the longitudinal direction is used as a sensed object, and a magnetic sensing element for sequentially sensing the N pole and the S pole of the magnet is used as a sensing head. In the case of a magnetic position sensor using a magnetic detector such as a magnet scale, the distance between the magnet and the magnetic sensing element is 0.05 to 0.30.
If it is not maintained within the range of mm, the detection accuracy is significantly reduced. Similarly, in an optical position sensor using an optical detector such as a photo sensor, the detection accuracy is greatly reduced unless the distance between the sensed body and the sensing head is maintained at a predetermined value.

If the position sensing accuracy of the position sensor is low,
The position of the mover assembly relative to the stator assembly and the speed of movement of the mover assembly cannot be precisely controlled. In order to prevent this, when the thickness of the stator support is increased so that the stator support is not bent by the magnetic force acting between the stator and the mover or between the stators facing each other, the linear motor is increased. Since the thickness of the knitting needle becomes large, the number of knitting needles per unit length cannot be increased.

Further, if the distance between the sensed body and the sensing head changes greatly, the sensed body and the sensing head collide and are damaged due to the movement of the mover assembly, and as a result, function as a position sensor. May be lost.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the change in the distance between the sensed body and the sensing head due to the bending of the stator support.

[0009]

A linear motor for driving a knitting needle according to the present invention includes a stator assembly, a mover assembly, and the mover assembly movably coupled to the stator assembly in one direction. It includes a coupling means and a position sensor for sensing the position of the mover assembly with respect to the stator assembly. The coupling means includes a guide that extends in the one direction and is assembled to the stator assembly, and a moving body that is relatively movably coupled to the guide in the moving direction of the mover assembly. And a moving body assembled to the mover assembly. The position sensor is disposed on one of the guide and the mover assembly, and on the other of the guide and the mover assembly to sense the sensed body. And a sensing head.

When the guide is displaced due to the deformation of the stator assembly due to magnetic force, thermal expansion and contraction, the mover assembly is also displaced accordingly, so that the sensed body and the sensing head are similarly displaced, and The relative position of the sensor and the sensor head does not change. As a result, the distance between the sensed part of the sensed body and the sensing part of the sensing head does not change.

According to the present invention, one of the sensed body and the sensing head is arranged in the guide assembled to the stator assembly, and the other of the sensed body and the sensing head is assembled to the mover assembly. Since it is arranged in the guide, the change in the distance between the sensed body and the sensing head due to the curvature of the stator support is small.

In a preferred embodiment, the sensed portion of the sensed body and the sensed portion of the sensing head are the direction of the magnetic force acting between the stator and the mover, and the mover assembly. Spaces are provided in a direction intersecting with the moving direction.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 4, a thin plate-shaped motor assembly 10 is provided with four motors 10 for independently reciprocating a jack 14 connected to a knitting needle 12 when attached to a flat knitting machine. A linear motor 16 is included. The four linear motors 16 form one motor assembly 10 by using some members in common.

In FIG. 1, one motor assembly 10 is provided.
And four linear motors 16 constituting the motor assembly.
And is only shown. However, since the flat knitting machine comprises a large number of knitting needles 12 arranged parallel to its needle bed, in practice a flat knitting machine is
Preferably, linear motors equal to or more than the number of knitting needles to be reciprocated by power are required. Therefore, the number of motor assemblies corresponding to the number of the arranged knitting needles is arranged in the flat knitting machine in a state of being sequentially stacked in the arrangement direction of the jacks 14.

Each linear motor 16 has a pair of flat plate-shaped stator assemblies 20 facing each other in the thickness direction of the linear motors with a gap therebetween, and the jack 1 is provided between both stator assemblies 20.
4, a flat plate-shaped mover assembly 22 arranged so as to be capable of reciprocating in the longitudinal direction, a coupling means 24 for movably supporting the mover assembly on one of the stator assemblies 20, and a stator assembly. A position sensor 26 for detecting the position of the mover assembly 22 with respect to 20. Elongated flat jack 14
Connects the mover assembly 22 to the corresponding knitting needle 12.

A plurality of stators 28 of each stator assembly 20.
Are sequentially arranged at a predetermined pitch in the moving direction of the mover assembly 22 on one surface, that is, a flat portion of the flat frame, that is, the stator support 30. In the illustrated example, each stator 28 is a plate-shaped permanent magnet magnetized in the thickness direction. As the plate-shaped permanent magnet, it is possible to use a ferrite magnet, a rare earth magnet, a magnet obtained by molding a powdered magnet material with a synthetic resin or the like into a plate shape, or the like.

Both stator assemblies 20 of the linear motor 16
Are combined in a substantially parallel state by a plurality of screws (not shown) so that the stators, which are one of the magnetic force generating means disposed in the two stator assemblies 20, that is, the permanent magnets 28 face each other in a one-to-one manner. There is. The stator support 30 and the spacer 32 are commonly used by the four linear motors 16. In addition to the spacer 32, a member having such a spacer function may be provided between the two stator support members 30 at a position that does not hinder the movement of the mover assembly 22.

Both stator assemblies 20 of the linear motor 16
In addition, the tongue piece 34 formed on each of the plurality of spacers 32 provided on the one stator support body 30 is fitted into the hole 36 formed on the other stator support body 30 so that the fitting is performed. Relative movement in a direction perpendicular to the direction is prevented, and both the stator assemblies 20 are screwed in a state where the spacer 32 is in contact with the stator support 30. Maintained at.

Each stator support 30 has a plurality of protruding portions 38 formed at intervals on a flat portion on which the magnet 28 is to be arranged.
(See FIG. 4). The protrusion 38 is used for the stator support 3
It is formed by stamping out a predetermined portion of the flat portion of 0 on one side by embossing or the like. The protrusions 38 jointly define the areas in which the magnets 28 should be placed and prevent the magnets 28 from moving relative to the stator assembly 28.

Each magnet 28 has a quadrangular (rectangular shape in the illustrated example) shape. The magnet 28 is used in the mover assembly 22.
In the state where the end faces of the same length of the adjacent magnets 28 are in contact with each other so that the magnetization directions of the adjacent magnets 28 are opposite to each other in the moving direction, the stators are supported in a line in the moving direction of the mover assembly 22. It is located on the body 30. However, a plurality of magnets 28
May be arranged in a plurality of rows on the stator support 30.

The stator support 30 is made of a ferromagnetic material such as steel, and each magnet 28 has one of its magnetic pole faces directly or indirectly brought into contact with the flat portion of the stator support 30.
For this reason, each magnet 28 is attracted to the flat portion of the stator support 30 by its own magnetic force, and thus is prevented from coming off the stator support 30. Only the region of the stator support 30 where the magnet 28 is arranged may be made of a ferromagnetic material.

A mover assembly 2 which forms the other side of the magnetic force generating means.
The plurality of movers 40 of the two mover assemblies 2 are arranged in the same direction as the arrangement direction of the magnets 28 on the frame, ie, the mover support 42, at the same pitch as the arrangement pitch of the magnets 28 or at another predetermined pitch.
They are sequentially arranged in two moving directions. Mover assembly 22
Are arranged between the two stator assemblies 20, with the mover support 42 extending parallel to the stator supports 30 of both stator assemblies 20 and the mover 40 facing the magnets 28. .

In the illustrated example, each mover 40 is an exciting coil that is energized in the forward direction and the reverse direction at an appropriate timing, and is formed in a flat plate shape. Each mover, that is, the coil 40, has an opening formed in the mover support 42 such that the direction of the magnetic field generated by the coil (direction of the central axis of the coil) is in the thickness direction of the mover support 42. 44 (see FIGS. 2 and 4) is immovably arranged. It is preferable to coat the coil 40 with a synthetic resin made of a non-magnetic material.

Each mover assembly 22 includes, for example, a plurality (three in the illustrated example) of coils 4 formed in the shape of a flat plate.
0 is fixed to one surface of a flexible sheet-like member with a space, and then the sheet-like member is supported by a mover so that the coils 40 are housed in the opening 44 of the mover support 42. It can be assembled by attaching it to the body 42. The sheet-shaped member may be a sheet-shaped wiring board having a plurality of conductors for energizing the coil 40 formed by a printed wiring technique.

Each mover assembly 22 has an end opposite to the coupling means 24 with respect to the position of the coil 40.
It is connected to the stator assembly 20 by a guide means (not shown) having a large play. However, this guiding means is not always necessary.

The coupling means 24 is provided with a guide 46 which is long in the moving direction of the mover assembly 22, and a bearing or a moving body 48 which is fitted in the guide so as to be relatively movable in the longitudinal direction of the guide, that is, a so-called moving body. It is a linear bearing.
The guide 46 is a linear guide having a U-shaped cross-section so as to form a groove that slidably receives the moving body 48, and the groove extends in the moving direction of the mover assembly 22 and supports the mover. It is non-movably attached to one stator support 30 at the bottom so as to open to the side of the body 42.

The moving body 48 has an elongated shape extending along the guide 46. The mover support 42 is a moving body 48.
Has a deformed portion deformed into a substantially U-shaped cross-sectional shape having a width dimension larger than the width dimension. The moving body 48 is arranged in the recess of the U-shaped deforming portion, and the moving body support 4
2 through the hole 50 (see FIG. 2) formed in the screw hole 52
The movable element support body 42 is assembled with a plurality of screw members screwed together (see FIG. 3). In this way, the mover assembly 22 and the stator assembly 20 are movably coupled by the coupling means 24 while maintaining a predetermined distance.

In the illustrated example, the guide 46 is provided for each linear motor 16, but one guide 46 that is long in the moving direction of the mover assembly 22 is adjacent to the linear motor 16 in the moving direction of the mover assembly 22. May be used in common. Further, an elongated moving body having a U-shaped cross section having a groove is attached to the mover assembly 22 so that the groove opens to the side of the one stator assembly 20, and is fitted into the groove of the moving body. A guide may be attached to one stator assembly 20.

The position sensor 26 includes an elongated sensed body 54 arranged on the mover assembly 22 so as to extend in the moving direction thereof, and one stator assembly 2 for sensing the sensed body.
Sensing head 56 arranged at 0. In the illustrated example, the position sensor 26 includes a position detection magnet in which the sensed body 54 has N poles and S poles alternately in the longitudinal direction,
In addition, the sensing head 56 is a magnetic position sensor having a magnetic sensing element that senses the N pole and the S pole, that is, a so-called magnescale.

As shown in FIGS. 3 and 4, the sensing head 56 sequentially senses the N pole and S pole of the position sensing magnet, that is, the sensed body 54, as the mover assembly 22 moves. , S to output electrical signals corresponding to the brackets 58, the brackets 58 are attached to the lateral sides of the guide 46 by a plurality of screw members (not shown).

As shown in FIGS. 2 and 4, the sensed body 54 is in a state in which it is passed from one side of the mover support body 42 to the other side through a cutout hole 60 formed in the mover support body 42. Then, it is attached to the mover support 42 by a plurality of screw members 62. Preferably, the sensed body 54 is slightly moved from the sensing head 56 in a direction intersecting or orthogonal to both the direction of the magnetic force acting between the stator 28 and the mover 40 and the moving direction of the mover assembly 22. Separated.
The sensed part of the sensed body 54 and the sensed part of the sensing head 56 face each other. The cutout hole 60 is for the sensed body 5.
4 is formed at a position where the sensed portion 4 and the sensing portion of the sensing head 56 can be visually observed.

In the illustrated example, the position sensor 26 is arranged on the side opposite to the magnetic force generating means 28, 40 with respect to the coupling means 24. However, the position sensor 26 is connected to the coupling means 24.
May be arranged on the magnetic force generating means 28, 40 side. In this case, another cutout hole 60 needs to be provided between the coupling means 24 and the coil 40.

The elongated plate-shaped jack 14 is removably assembled to the mover support body 42 by a plurality of screw members at one end, and corresponds to the other end after the motor assembly 10 is incorporated in the knitting machine. It is connected to the knitting needle 12. In the illustrated example, the jack 14 has magnetic force generating means 28, with respect to the coupling means 24 and the position sensor 26.
It is located on the side opposite to 40. But Jack 1
4 may be arranged on the side of the magnetic force generating means 28, 40 with respect to the coupling means 24 and the position sensor 26.

In the state where the motor assembly 10 is assembled in the knitting machine, since the mover support body 42 is in the vertical state, the own weight of the mover assembly 22 acts right above the connecting means 24. Therefore, the moment that rotates the mover assembly 22 about the coupling means 24 does not act on the mover assembly 22, and the mover assembly 22 is maintained in the vertical state. However, when there is a possibility that the mover assembly 22 may be rotationally displaced, it is preferable that each mover assembly 22 is coupled to the stator assembly 20 by coupling means at two locations above and below the mover 42. .

When an appropriate current is supplied to each coil 40, the mover assembly 22 is linearly moved with respect to the stator assembly 20 while maintaining the vertical state. As a result, the predetermined knitting needle 12 is moved. Stator assembly 2
The movement of the mover assembly 22 with respect to
Is sensed by

In the linear motor 16 described above, the magnet 2
8 and the coil 40, or when a magnetic force is applied between the magnets 28 facing each other, or when the stator support 30 undergoes thermal expansion and contraction, both stator supports 30 are coupled to each other by the coupling means 24.
Bend so as to approach each other around the arrangement position of.

However, in the linear motor 16, since the sensing head 56 is attached to the guide 46, when the stator support 30 is curved as described above, the guide 46, the moving body 48, and the mover assembly are matched accordingly. Since 22 is displaced, the sensed body 54 and the sensing head 56 are similarly displaced, and the relative positions of the sensed body 54 and the sensing head 56 do not change. As a result, the distance between the sensed portion of the sensed body 54 and the sensing portion of the sensing head 56 does not change. The guide 46 is displaced accordingly, and the distance between the sensed portion of the movable body assembly sensed body 54 and the sensing portion of the sensing head 56 does not change significantly.

Therefore, according to the linear motor 16,
Even if the thickness of the stator support 30 is small, the sensed body 54 and the sensing head 56 due to the bending of the stator support 30
The position sensor 2
Since the position sensing accuracy of 6 is high, the position of the mover assembly 22 with respect to the stator assembly 20 and the moving speed of the mover assembly 22 can be precisely controlled.

According to the linear motor 16, the sensed portion of the sensed body 54 and the sensed portion of the sensing head 56 can be visually inspected through the cutout hole 60.
The distance between 4 and the sensing head 56 can be easily adjusted to the correct value.

If the stator 28 is a permanent magnet and the mover 40 is an exciting coil as in the above embodiment, the driving force of the linear motor is large. However, the stator 28 may be an exciting coil and the mover 40 may be a permanent magnet. Further, if the stator support 30 is commonly used by a plurality of (in the illustrated example, four) linear motors 16, the assembling work thereof becomes easy. However, the stator support 30 may be provided for each linear motor 16.

In the above embodiment, the sensed body 54 and the sensing head 56 are arranged such that the sensed part and the sensed part of the sensed part and the sensed part act on the direction of the magnetic force acting between the stator 28 and the mover 40.
The movable body assembly 22 is arranged so as to be spaced in a direction intersecting with the moving direction of the movable body assembly 22, but the sensed body 54 and the sensing head 56 have a sensed part and a sensed part, respectively, and a stator. 28 and the mover 40 may be arranged so as to be spaced in the direction of the magnetic force acting on them.

In the above embodiment, the sensing head 56 of the position sensor 26 is arranged on the guide 46 and the sensed body 54 is arranged on the mover assembly 22, but the sensed body 54 is arranged on the guide 46. The sensing head 56 to the mover assembly 22.
It may be placed at. In this case, a long sensed body may be used and the long sensed body may be commonly used by the linear motors adjacent to each other in the moving direction of the mover assembly.

Instead of using a magnetic position sensor as the position sensor, another position sensor such as an optical proper position sensor may be used. As the optical position sensor, it is possible to use a sensor in which an object to be sensed is provided with an optical mark such as a bar code, and a sensing head is provided with an optical detector such as a light transmitter / receiver.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a motor assembly using four linear motors of the present invention.

FIG. 2 is a perspective view showing an example of a mover support of the linear motor shown in FIG.

3 is a perspective view showing an example of a coupling means and a sensing head of the linear motor of FIG.

FIG. 4 is a cross-sectional view showing an example of a coupling means and a position sensor portion of the linear motor of FIG.

[Explanation of symbols]

 10 Motor Assembly 12 Knitting Needle 16 Linear Motor 20 Stator Assembly 22 Mover Assembly 24 Coupling Means 26 Position Sensor 28 Stator (Permanent Magnet) 30 Stator Support 40 Mover (Excitation Coil) 42 Mover Support 46 Guide 48 Moving Object 54 Sensitive Object 56 Sensing Head 58 Sensing Head Bracket 60 Hole

Claims (2)

[Claims] 1. A stator assembly, a mover assembly, coupling means for movably coupling the mover assembly to the stator assembly in one direction, and the mover with respect to the stator assembly. A position sensor for sensing the position of the assembly, wherein the coupling means is a guide extending in the one direction, the guide being attached to the stator assembly, and the guide in the moving direction of the mover assembly. A movable body that is movably coupled to the movable element assembly, and the position sensor is disposed in one of the guide and the movable element assembly. A linear motor for driving a knitting needle, comprising: a sensed body; and a sensing head arranged on the other of the guide and the mover assembly to sense the sensed body. 2. The sensed part of the sensed body and the sensing part of the sensing head are a direction of a magnetic force acting between the stator and the mover and a moving direction of the mover assembly. 2. A space is provided in a direction intersecting with each other.
Linear motor described in.