JPH09238460A - Linear motor for driving knitting needle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the contact between a stator and a movable body by forming a hole in a movable body supporter and passing a spacer through the hole so as to allow a movable body assembly to move. SOLUTION: Each linear motor 16 includes a spacer 66 located between both stator supporters 30 to prevent the deformation of the stator supporters 30. The spacer 66, being formed integrally with a bent section 64 formed in one of the stator supporter 30, is passed through a hole 68 formed in a movable body supporter 4 and is abutted against the other stator supporter 30. The hole 68 is a long one extending in the movement direction of a movable body assembly 22. The spacer 66 is so passed through the hole 68 as not to prevent the movement of the movable body assembly 22. The spacer 66 could be connected to the other stator supporter 30 by a spring member.

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]

2. Description of the Related Art 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 described in, for example, Japanese Patent Publication No. 1-12855. This type of knitting needle linear motor is a stator in which a plurality of plate-shaped stators (hereinafter referred to as “stators”) that are magnetic force generating means are sequentially arranged in one direction on a flat portion of a plate-shaped stator support. An assembly and a plurality of plate-shaped movers (hereinafter,
It is called "Movable child". ) Sequentially arranged in one direction on a flat portion of a plate-shaped mover support, a coupling means for movably supporting the mover assembly on the stator assembly, and a movable member for the stator assembly. A position sensor for detecting the position of the child assembly.

However, in a conventional linear motor for moving a knitting needle, a plate-shaped stator support causes a magnetic force acting between the stator and a mover, and a gap between the opposing stators of both stator assemblies. It is bent by the magnetic force that acts, and as a result, the stator and the mover come into contact with each other, and the movement of the mover becomes unstable.

In order to prevent this, 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 opposing stators. However, the thickness of the linear motor becomes large, and the number of knitting needles per unit length cannot be increased. If the gap between the stator and the mover is increased by reducing the thickness of the stator or mover without increasing the thickness of the linear motor, the efficiency of the motor will deteriorate and power consumption will decrease. Will increase.

[0005]

An object of the present invention is to eliminate contact between the stator and the mover due to the curvature of the stator support.

[0006]

A linear motor for driving a knitting needle according to the present invention includes a stator assembly in which a plurality of stators, which are magnetic force generating means, are arranged on a plate-shaped stator support, and a stator assembly. A plurality of movable members which are magnetic force generating means and which are plate-shaped members connected at intervals and are arranged between the plate-shaped members and the stator assembly so as to be movable in one direction. A mover assembly in which a child is arranged on a plate-shaped mover support, a coupling means for assembling the mover assembly to the stator assembly so as to be movable in one direction, the stator assembly and the plate-like member. A spacer disposed between the body and the body. The mover support has a hole and the spacer extends through the hole to allow movement of the mover assembly.

The mover assembly reciprocates in one direction with respect to the stator assembly. At this time, the spacer only changes its position in the hole and does not hinder the reciprocating movement of the mover assembly. Further, a magnetic force that changes the relative position between the stator assembly and the mover support acts between the stator and the mover or between the stator assembly and the plate-like body.

However, the change in the relative position between the stator assembly and the plate-like body due to such magnetic force is prevented by the spacer, and the stator assembly and the mover assembly are maintained at a predetermined distance. . As a result, the bending of the stator support due to the magnetic force is prevented, and the contact between the stator and the mover is prevented.

According to the present invention, since the spacer penetrating the hole of the mover support is arranged between the stator assembly and the plate-like body, the spacer is movable at a predetermined position within the moving range of the mover assembly. It is possible to prevent deformation of the mover support and prevent contact between the stator and the mover without hindering movement of the child assembly.

The plate-shaped body is preferably a second stator assembly in which a plurality of stators are arranged on a plate-shaped stator support. When the mover assembly is arranged between the pair of stator assemblies in this way, the moving force acting on the mover assembly is greater than when the plate-shaped body is not the stator assembly. In this case, both stator assemblies can be arranged so that the stators of both stator assemblies face each other with the mover assembly in between.

Furthermore, a pair of second spacers, which are arranged outside the range of movement of the mover assembly in the moving direction of the mover assembly and are opposed to each other via the stator, are the stator support. It is preferable to include a second spacer that abuts the body and the plate-shaped body. Thereby, contact between the stator and the mover can be prevented more reliably.

It further includes a position sensor for sensing the position of the mover assembly relative to the stator assembly, the position sensor and the spacer being located on opposite sides of the coupling means. Alternatively, the spacer may be disposed on one of the stator assemblies, extend through the hole toward the other stator assembly, and contact the stator support of the other stator assembly. However, the spacer may be formed integrally with one of the stator assemblies.

In a preferred embodiment, the hole is an elongated hole elongated in the moving direction of the mover assembly. Also, the coupling means is a guide extending in the moving direction of the mover assembly and attached to the stator assembly, and a moving member coupled to the guide so as to be relatively movable in the moving direction of the mover assembly. And a movable body assembled to the mover assembly. In this case, one of the sensed body and the sensing head can be attached to the lateral side portion of the guide, and a hole through which the gap between the sensed body and the sensing head can be visually observed can be formed in the mover support.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 3, a thin plate-shaped motor assembly 10 independently reciprocates a jack 14 connected to a knitting needle 12 when attached to a flat knitting machine. It includes four linear motors 16. The four linear motors 16 form one motor assembly 10 by commonly using some members, for example, a stator support body 20 which is a component of the stator assembly.

In FIG. 1, one motor assembly 10 is shown.
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 in parallel to its needle bed, in practice the flat knitting machine is made up of It requires more linear motors than the number. Therefore, in the flat knitting machine, a number of motor assemblies corresponding to the number of the arranged knitting needles are arranged in a state of being superposed in the arrangement direction of the jacks 14.

Each linear motor 16 has a pair of flat plate-shaped stator assemblies 20 opposed to each other at intervals in the thickness direction of the linear motor, and the jack 1 between the 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 flat surface or flat portion of the flat plate-shaped frame, that is, the stator support 30. Each stator 28
In the illustrated example, is a plate-shaped permanent magnet magnetized in the thickness direction. As the plate-shaped permanent magnet, a ferrite magnet,
It is possible to use a rare earth magnet, a magnet obtained by molding a powder magnet material together with a synthetic resin 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 permanent magnets, that is, the stators 28 arranged in both the stator assemblies 20 and acting as one magnetic force generating means face each other in a one-to-one manner. ing. Both the vertical edges of one stator support 30 are attached to the other stator assembly 30.
The bent portion 32 is bent to the side. Both stator supports 30 are commonly used by the four linear motors 16 of the motor assembly 10.

Both stator assemblies 20 of the linear motor 16
In addition, the tongue piece 34 formed in each bent portion 32 of the one stator support body 30 is fitted into the hole 36 formed in the other stator support body 30, so Relative movement in the direction at right angles is prevented, and both stator assemblies 20 are fixed with screws in a state where the bent portion 32 is in contact with the other stator support 30. Maintained at.

Each stator support 30 has a plurality of protruding portions 3 formed at intervals on a flat portion on which the stator 28 is to be arranged.
8 (see FIGS. 2 and 3). The protrusion 38 is formed by stamping a predetermined portion of the flat portion of the stator support 30 to one surface side by embossing or the like. The protrusions 38 cooperate with each other to define the areas in which the stator 28 should be placed and prevent the stator 28 from moving relative to the stator assembly 28.

Each stator 28 has a rectangular shape (in the illustrated example,
(Rectangle) shape. The stator 28 is a mover in a state where end surfaces of adjacent stators 28 having the same length are in contact with each other so that the magnetization directions of the adjacent stators 28 in the moving direction of the mover assembly 22 are opposite. The stator supports 30 are arranged in a line in the moving direction of the assembly 22. However, the plurality of stators 28 may be arranged on the stator support 30 in a plurality of rows.

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

The plurality of movers 40 of the mover assembly 22 are
The stator 2 is attached to the flat frame, that is, the mover support 42.
8 is sequentially arranged in the moving direction of the mover assembly 22 at the same pitch as the arrangement pitch of the stators 28 or at another predetermined pitch. The mover assembly 22 is arranged so that the mover support 42 extends parallel to the stator supports 30 of both stator assemblies 20 and the mover 40 faces the stator 28. It is located in between.

In the illustrated example, each mover 40 acting as the other magnetic force generating means is an exciting coil which is energized in the forward direction and the reverse direction at an appropriate timing, and is formed in a flat plate shape. . Each coil mover, that is, the mover 40, is formed on the mover support 42 so that the direction of the magnetic field generated by the mover (the direction of the central axis of the coil) is in the thickness direction of the mover support 42. It is immovably arranged in the opening 44 (see FIG. 3). It is preferable to coat the mover 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 movers 4 formed in the shape of a flat plate.
0 is fixed to one surface of a flexible sheet-like member at a distance, and then the sheet-like member is moved so that the mover 40 is housed in the opening 44 of the mover support 42. It can be assembled by attaching it to the support 42. The sheet-shaped member may be a sheet-shaped wiring board having a plurality of conductors for energizing the mover 40 formed by a printed wiring technique.

Each mover assembly 22 has an end portion on the side opposite to the coupling means 24 with respect to the position where the mover 40 is arranged.
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 moving body 48 which is fitted to 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 for slidably receiving the moving body 48, and the groove is a mover assembly 22.
Is mounted immovably on one of the stator supports 30 by a mounting means (not shown) so as to extend in the moving direction of and move to the side of the mover support 42. In the example shown,
The guide 46 is formed by extruding the stator support 30.
The bottom is received in a hole 50 (see FIG. 3) formed in the base. The hole 50 is a long hole in the moving direction of the mover assembly 22, and is formed in a portion between the position sensor 26 and the stator 28.

The moving body 48 has an elongated shape extending along the guide 46, and as shown in FIG. 3, a plurality of screws are provided in the recesses of the dish-shaped deformed portion formed in the mover assembly 42. It is assembled by the member 52. Each screw member 52
Passes through the through hole formed in the mover support 42,
It is screwed into a screw hole formed in the moving body 48.

In the illustrated example, a 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 FIG. 3, a plurality of the sensed bodies 54 are provided in a punching hole 58 formed in the mover support body 42 while being passed from one side of the mover support body 42 to the other side. It is attached to the mover support 42 by the screw member 60. 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.

As shown in FIG. 3, the sensing head 56 sequentially senses the N pole and the S pole of the position sensing magnet, that is, the sensed body 54 as the mover assembly 22 moves. It is attached to the bent portion 62 of the stator support 30 by a plurality of screw members (not shown) so as to output corresponding electric signals. The bent portion 62 forms an edge of the hole 50 in the width direction together with the bent portion 64.

The sensed portion of the sensed body 54 and the sensing head 56.
And the sensing portion of the hole 50 are opposed to each other at intervals in the width direction of the hole 50. The punching hole 58 is formed at a position where the sensed portion of the sensed body 54 and the sensed portion of the sensing head 56 can be visually observed.

Each linear motor 16 also includes a spacer 66 disposed between both stator supports 30 to prevent deformation of both stator supports 30. As shown in FIG. 3, the spacer 66 is formed integrally with the bent portion 64 formed in one of the stator supports 30, and also penetrates the hole 68 formed in the mover support 42. And extends to contact the other stator support 30. The hole 68 is an elongated hole that is long in the moving direction of the mover assembly 22, and the spacer 66 extends through the hole 68 so as not to prevent the mover assembly 22 from moving. The spacer 66 may be connected to the other stator support 30 by a screw member.

As shown in FIG. 2, each linear motor 16
Further includes a pair of elongated second spacers 70 and a pair of elongated third spacers 72. The second spacers 70 are arranged outside the moving range of the mover assembly 22 in the moving direction of the mover assembly 22 and facing each other with the stator 28 interposed therebetween. Abut. The third spacers 72 are arranged outside the moving range of the mover assembly 22 in the moving direction of the mover assembly 22 and facing each other via the coupling means 26. Abut.

Each of the second spacers 70 and each of the third spacers 72 are attached to at least one of the stator supports 30 by a plurality of screw members, welding or the like. Since the second and third spacers 70 and 72 are arranged outside the moving range of the mover assembly 22,
It does not hinder the reciprocating movement of the mover assembly 22.

In the illustrated example, the position sensor 26 is arranged on the opposite side of the movable element 46, which is a magnetic force generating means, with respect to the coupling means 24. However, the position sensor 26 is connected to the coupling means 2
4 may be arranged on the magnetic force generating means 28, 40 side.

The elongated plate-shaped jack 14 is detachably attached to the mover support body 42 by a plurality of screw members at one end, and is supported at the other end after the motor assembly 10 is incorporated in the knitting machine. Is connected to the knitting needle 12.

In the illustrated example, the jack 14 has a 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.

The motor assembly 10 is assembled to the knitting machine so that the mover support 42 is vertical, and the own weight of the mover assembly 22 acts right above the coupling 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 mover 40, the mover assembly 22 is moved linearly with respect to the stator assembly 20 while being maintained in the vertical state. As a result, the predetermined knitting needle 12 is moved. Stator assembly 20
The movement of the mover assembly 22 with respect to is sensed by the position sensor 26.

In the linear motor 16 described above, the stator 2 between the stator 28 and the mover 40 or facing each other.
When a magnetic force acts between the two, the two stator supports 30 bend so as to approach each other around the arrangement position of the coupling means 24.

However, in the linear motor 16, the spacer 66 penetrating the mover support body 42 has the two stator support bodies 30.
Since the stator assembly 20 and the mover assembly 22 are disposed between the two, the change in the relative positional relationship between the stator assembly 20 and the mover assembly 22 is prevented within the moving range of the mover assembly 22 in the vicinity of the arrangement position of the stator 28. To be done. As a result, the distance between the stator and the mover does not change significantly. Further, the change in the relative positional relationship between the stator assembly 20 and the mover assembly 22 is also prevented by the second and third spacers 70 and 72.

Therefore, according to the linear motor 16,
Even if the thickness of the stator support 30 is small, the change in the gap between the stator 28 and the mover 40 due to the curvature of the stator support 30 is small or absent. Contact is prevented. Further, since it is not necessary to increase the thickness dimension of the stator support 30, it is not necessary to increase the thickness dimension of the linear motor. Furthermore, the stator 28
Alternatively, since it is not necessary to reduce the thickness of the mover 40, the efficiency of the motor does not decrease and the power consumption does not increase.

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 punched hole 58.
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-described 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.

When the sensed body 54 and the sensing head 56 are arranged as in the latter case, the curvature of the stator support changes the distance between the sensed body of the position sensor and the sensing head, thereby improving the sensing accuracy of the position sensor. It will change. In particular, in the case of a magnetic position sensor using a magnetic detector, the detection accuracy is significantly reduced unless the distance between the magnet and the magnetic sensing element is maintained within the range of 0.05 to 0.30 mm. 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. Also, if the distance between the sensed body and the sensing head changes greatly,
As the mover assembly moves, the sensed body and the sensing head may collide and be damaged, and as a result, the function as the position sensor may be lost.

However, when the spacer 66 and the hole 68 are provided, the bending of the stator support 30 is prevented near the positions where the sensed body 54 and the sensing head 56 are arranged.
The distance between the sensed part of the sensed body 54 and the sensed part of the sensing head 56 does not change significantly. As a result, the position sensing accuracy of the position sensor 26 is high, and therefore 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.

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 magnetic position sensors as position sensors, other position sensors such as optical position sensors 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.

The spacer 66 and the hole 68 are preferably formed as close to the position sensor 26 as possible. Therefore, in the illustrated example, the spacer 66 and the hole 68 are formed between the coupling means 24 and the magnetic force generation means 28, 40. However, the spacer 66 and the hole 68 may be formed between the coupling means 24 and the position sensor 26 or on the side of the coupling means 24 opposite the position sensor 26.

Instead of integrally forming the spacer 66 with the one edge 64, the second and third spacers 70, 7 are provided.
Similar to 2, the spacer may be formed by a member different from the stator support 30, and the spacer may be attached to at least one stator support 30 by means such as a screw member.

In the illustrated example, the hole 68 is defined by the mover assembly 2.
2 is a long hole in the moving direction, but as long as the spacer 66 does not hinder the movement of the mover assembly 22, a circular shape, an elliptical shape, or the like.
It may be a hole having another shape.

[Brief description of 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 an exploded perspective view showing an embodiment of the linear motor shown in FIG.

3 is a sectional view showing an embodiment of the linear motor shown in FIG. 1, and is a sectional view showing a portion of a coupling means and a position sensor.

[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 66 Spacer 68 Hole 70, 72 Second and Third Spacer

Claims (4)

[Claims] 1. A stator assembly in which a plurality of stators, which are magnetic force generating means, are arranged on a plate-shaped stator support, a plate-shaped member connected to the stator assembly at intervals, and A mover assembly movably arranged in one direction between a plate-shaped body and the stator assembly, wherein a plurality of movers serving as magnetic force generating means are arranged on a plate-shaped mover support. A subassembly, a coupling means for assembling the mover assembly to the stator assembly so as to be movable in one direction, and a spacer arranged between the stator assembly and the plate-like body, The knitting needle driving linear motor, wherein the mover support has a hole, and the spacer penetrates the hole to allow the mover assembly to move. 2. The linear motor according to claim 1, wherein the plate-shaped body is a second stator assembly in which a plurality of stators, which are magnetic force generating means, are arranged on a plate-shaped stator support. 3. A pair of second spacers arranged at two positions outside the moving range of the mover assembly in the moving direction of the mover assembly and facing each other with the stator interposed therebetween. The linear motor according to claim 1 or 2, further comprising a second spacer that comes into contact with the stator support and the plate. 4. A position sensor for sensing the position of the mover assembly relative to the stator assembly, the position sensor and the spacer being located on opposite sides of the coupling means. Item 1. The linear motor according to item 1, 2 or 3.