JP2004064874A - High acceleration type linear motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high acceleration type linear motor which can prevent a thermal deformation of a linear guide by canceling a magnetic attraction force of the motor, can prevent an error of a positional accuracy of a movable element, and can obtain good high acceleration and deceleration performances. <P>SOLUTION: The high acceleration type linear motor includes a gate-like frame 3 provided along a longitudinal direction on a fixed base 1, the linear guide 2 provided in parallel with both sides on the base 1 in a longitudinal direction, the movable element supported on the guide 2 and having a field permanent magnet 4 fixed to a flat plate-like magnet holder 5, and a pair of armatures 6 having armature coils mounted so as to be opposed to two parallel surfaces of the magnet 4. One of the pair of the armatures 6 is fixed to the frame 3, the other is fixed to the base 1, and the movable element is moved along the guide rail 2. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
INDUSTRIAL APPLICABILITY The present invention is used for high-speed positioning feed of a machine tool, an electronic component assembling apparatus, a semiconductor manufacturing apparatus, or the like. The present invention relates to a high acceleration linear motor having a moving magnet structure arranged.
[0002]
[Prior art]
Conventionally, a moving magnet structure that is used for high-speed positioning feed of machine tools, electronic component assembling equipment, semiconductor manufacturing equipment, etc., and has a field permanent magnet on the mover side and an armature on the stator side. Is as shown in FIG.
FIG. 3 is a front sectional view of a conventional linear motor, and FIG. 4 is a side view of the conventional linear motor. 3 is taken along the line AA of FIG. 4, and FIG. 4 is viewed from the direction of arrow B in FIG. In the conventional example, a gap-facing structure in which an armature faces one side of a field permanent magnet will be described as an example.
In the drawing, 1 is a fixed base, 2 is a linear guide, 2a is a guide rail, 2b is a slider, 11 is a field permanent magnet, 12 is a field yoke, 13 is an armature, 14 is a table, 15 is a linear scale, 16 Is a scale head, and 17 is a scale holder.
Here, the mover includes a smooth field yoke 12 made of a ferromagnetic material that passes a magnetic flux, and a smooth field permanent magnet 11 attached to the field yoke 12.
The stator is composed of a field permanent magnet 11 and an armature 13 opposed to each other with a magnetic gap therebetween. The armature 13 is obtained by winding an armature coil around an armature core. .
Further, a linear scale 15 for control is arranged on the stator base 1, and a scale head 16 for detection is arranged on a table 14 serving as a mover via a scale holder 17. Note that a linear scale lead wire (not shown) is drawn from the scale head 16 toward the upper portion of the table 14.
Such a mover is supported by a pair of linear guides 2 each composed of a guide rail 2a and a slider 2b provided on the fixed base 1 in parallel to both sides and in the longitudinal direction, and a field permanent magnet 11 A table 14 attached to the upper part of the armature 13 generates a thrust along the longitudinal direction of the armature 13 (perpendicular to the plane of the drawing), and makes a smooth linear movement.
[0003]
[Problems to be solved by the invention]
2. Description of the Related Art In general, for a wire bonder for which a high-speed positioning feed is strongly required in the field of an electronic component assembling apparatus or the like, there is an increasing need for a linear motor having high acceleration / deceleration performance from the required operation.
For example, when the above-described conventional linear motor structure is applied to an application requiring high acceleration / deceleration performance, such as a wire bonder (not shown), a mover having a field permanent magnet 11 and a stator having an armature 13 In the meantime, a magnetic attraction force expressed by the following equation (1) acts, and a force such as a radial load or a moment load is applied to the linear guide 2, and there is a problem that the life of the linear guide 2 is shortened. Was.
F∝B ² × Sg (N) (1)
Here, the magnetic attraction force is F, the gap magnetic flux density is B, and the gap surface area is Sg.
[0004]
Further, when the acceleration specification and the effective thrust of the linear motor increase, the heat generation of the armature coil increases, and when the cooling is insufficient, the heat of the armature 13 is transmitted to the linear guide 2 via the fixed base 1. In addition, the guide rail 2a may cause thermal deformation or adversely affect the linear scale 15 attached to the fixed base 1, resulting in an error in the positioning accuracy of the mover.
Further, if the heat generated by the armature 13 itself cannot be removed, the heat generated by the armature 13 transfers to the field side via the gap, and increases the temperature rise and thermal deformation on the field permanent magnet 11 side, This has an effect on the mechanical gap length between the field permanent magnet 11 and the armature 13 and causes an error in the positioning accuracy of the mover.
In the prior art, since the linear scale 15 is fixedly arranged on the stator side and the scale head 16 is fixedly arranged on the mover side, a linear scale lead (not shown) on the scale head 16 side is dragged on the mover side. This would cause deterioration of the high acceleration / deceleration performance of the linear motor.
[0005]
The present invention has been made in order to solve the above-described problem, and it is possible to prevent a linear guide from being thermally deformed by offsetting a magnetic attraction force of a linear motor and to prevent an error in positioning accuracy of a mover. It is an object of the present invention to provide a high-acceleration linear motor capable of achieving high acceleration / deceleration performance.
[0006]
[Means for Solving the Problems]
In order to solve the above problem, a high-acceleration linear motor according to claim 1 of the present invention includes a fixed base, a gate-shaped frame provided along a longitudinal direction on the fixed base, A pair of linear guides each comprising a guide rail portion and a slider portion provided in parallel with the both sides and in the longitudinal direction, and a flat magnet supported by the linear guides and mounted in parallel with the slider portions. A mover comprising a holder and a field permanent magnet fixed to the magnet holder; and a movable element arranged via the magnetic gap between the field permanent magnet and two parallel surfaces of the field permanent magnet. And a stator consisting of a pair of armatures having armature coils attached to face each other, fixing one of the pair of armatures to the frame and the other Is fixed at over scan, in which said movable member adapted to move along the guide rail unit.
[0007]
According to a second aspect of the present invention, in the high-acceleration linear motor according to the first aspect, a linear scale for control is arranged on the mover side, and a scale head for detection is arranged on the stator side. .
[0008]
According to a third aspect of the present invention, in the high acceleration linear motor according to the first aspect, a cooling jacket is provided on the frame and the fixed base.
[0009]
According to a fourth aspect of the present invention, in the high acceleration linear motor according to the first aspect, the magnet holder has a non-magnetic permeability of 1.0 to 1.05 and a specific gravity of 2.8 g / cm ³ or less. It is made of material.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front sectional view of a high acceleration linear motor showing an embodiment of the present invention, and FIG. 2 is a side view of the high acceleration linear motor of the present invention. 1 is taken along the line AA of FIG. 2, and FIG. 2 is viewed from the direction of arrow B in FIG. The components of the present invention that are the same as those in the related art are denoted by the same reference numerals, and the description thereof will be omitted.
In the figure, 3 is a frame, 4 is a field permanent magnet, 5 is a magnet holder, 5a is a hole, 6 is an armature, 7 is a cooling jacket, 7a and 7b are refrigerant holes, 8 is a linear scale, and 9 is a scale head. , 9a are linear scale lead wires, and 10 is a scale holder.
The differences between the present invention and the prior art are as follows.
That is, the mover is supported by the linear guide 2 and has a plate-shaped magnet holder 5 attached in parallel with the slider portion 2b, and a field inserted and fixed in a hole 5a provided inside the magnet holder 5. It is composed of a magnetic permanent magnet 4. The magnet holder 5 is a non-magnetic material having a non-magnetic permeability of 1.0 to 1.05 and a specific gravity of 2.8 g / cm ³ or less, and is designed to be lightweight.
In addition, the stator is a pair of armatures 6 that are arranged with the field permanent magnet 4 through the magnetic gap and that are attached so as to face each of two parallel surfaces of the field permanent magnet 4. The armature 6 is obtained by winding an armature coil around an armature core. This pair of armatures 6 includes an upper armature 6a and a lower armature 6b, and one armature 6a is a gate-shaped frame 3 provided on the fixed base 1 along the longitudinal direction. , And the other armature 6 b is fixed to the fixed base 1.
In this case, the relationship between the field permanent magnet 4 as the movable part and the armature 6 as the fixed part is such that the length of the movable part is L _m and the movable range (stroke) of the movable part is L as shown in FIG. when the _st, the length _{L a} of the armature 6 as a fixing portion _has a _{L a> L m + L st} .
[0011]
Further, a linear scale 8 for control is arranged on the magnet holder 5 on the mover side, and a scale head 9 for detection is arranged on the frame 3 on the stator side via the scale holder 10. I have. The linear scale lead wire 9a is drawn out from the scale head 9 toward the upper part of the frame 3.
Further, the frame 3 and the fixed base 1 are provided with coolant holes 7a and 7b, respectively, and the cooling jacket 7 is formed in the longitudinal direction of the frame 3 and the fixed base 1 so that the coolant flows inside the cooling jacket 7. The armature 6 is cooled.
[0012]
Next, the operation will be described.
When the armature coil in the stator of the linear motor is excited, a thrust is generated between the mover and the stator, and the mover moves on the guide rail 2 a of the linear guide 2. At this time, an attractive force acts between the mover and the stator of the linear motor, but the pair of armatures 6a and 6b constituting the stator sandwich the field permanent magnet 4 constituting the mover therebetween. The movable element is attached by a magnetic attraction because the field permanent magnet 4 is attached to the flat magnet plate 5 so as to face the vertical direction of the field permanent magnet 4. This force can be canceled out in the system composed of the mover and the stator. When the suction force is canceled, unnecessary force does not act on the mover or the linear guide 2.
[0013]
Therefore, the linear motor according to the embodiment of the present invention includes the fixed base 1, the gate-shaped frame 3 provided along the longitudinal direction on the fixed base 1, the parallel on both sides of the fixed base 1, and A pair of linear guides 2 each having a guide rail 2a and a slider 2b provided in the longitudinal direction; a flat-shaped magnet holder 5 supported by the linear guide 2 and mounted in parallel with the slider 2b; A mover composed of the field permanent magnet 4 fixed to the holder 5 is disposed via the magnetic gap between the field permanent magnet 4 and each of two parallel surfaces of the field permanent magnet 4. And a stator consisting of a pair of armatures 6 having armature coils attached as described above, one of the pair of armatures 6 being fixed to the frame 3 and the other being fixed to the fixed base 1. Since the mover is moved along the guide rail 2, when the linear motor is applied to an application requiring high acceleration / deceleration performance such as a wire bonder, the mover having the field permanent magnet 4 is required. Since the force acting by the magnetic attraction between the stator and the stator having the armature 6 is canceled out in this system, no force such as a radial load or a moment load is applied to the linear guide 2. In addition, it is possible to prevent the life of the linear guide 2 from being shortened.
[0014]
Further, in the present embodiment, the cooling jacket 7 is formed on the fixed base 1 and the frame 3 so that the refrigerant flows along the longitudinal direction of the fixed base 1 and the frame 3, so that the heat generated by the armature coil is generated by the refrigerant. Heat can be exchanged and heat can be efficiently removed to the outside. As a result, thermal deformation of the guide rail 2a due to conduction of heat of the armature 6 to the linear guide 2 via the fixed base 1 or an adverse effect on the linear scale 8 and the like can be eliminated. Of the life of the armature can be prevented, and the positioning accuracy of the mover can be improved.
[0015]
Further, in this embodiment, since the magnet plate of the movable portion is made of a non-magnetic material having a non-magnetic permeability of 1.0 to 1.05 and a specific gravity of 2.8 g / cm ³ or less, the weight of the movable portion is reduced. Therefore, the life of the guide can be extended and the reliability of the mechanism can be improved.
[0016]
Further, in this embodiment, since the control linear scale 8 is fixedly arranged on the mover side and the scale head 9 is fixedly arranged on the stator side, the linear scale lead wire 9a on the scale head 9 side is connected from the stator side. By pulling out, unlike the conventional case, the linear scale lead wire is not dragged around from the mover side, and the high acceleration / deceleration performance of the linear motor can be improved.
[0017]
【The invention's effect】
As described above, the present invention has the following effects.
The linear motor according to the embodiment of the present invention is provided with a fixed base, a gate-shaped frame provided along the longitudinal direction on the fixed base, and parallel to both sides on the fixed base and in the longitudinal direction. A pair of linear guides each including a guide rail portion and a slider portion, a plate-shaped magnet holder supported by the linear guide and mounted in parallel with the slider portion, and a field permanent magnet fixed to the magnet holder. The armature is composed of a pair of armatures having an armature and an armature coil disposed so as to face each of the two parallel surfaces of the field permanent magnet, the armature being disposed through the magnetic gap with the field permanent magnet. A pair of armatures, one of the pair of armatures is fixed to a frame, the other is fixed to a fixed base, and the mover is moved along the guide rail. Therefore, when this linear motor is applied to an application that requires high acceleration / deceleration performance such as a wire bonder, the force exerted by magnetic attraction between the mover having the field permanent magnet and the stator having the armature is Since the linear guide is canceled in this system, no force such as a radial load or a moment load is applied to the linear guide, and the life of the linear guide can be prevented from being shortened.
[0018]
Further, in the present embodiment, the cooling jacket is formed on the fixed base and the frame, and the refrigerant is caused to flow along the longitudinal direction of the fixed base and the frame. Heat can be removed efficiently. As a result, it is possible to solve the problem that the heat of the armature is conducted to the linear guide via the fixed base and the thermal deformation of the guide rail 2a or the adverse effect on the linear scale 8 and the like can be eliminated. Thus, the life of the linear guide can be prevented from being shortened, and the positioning accuracy of the mover can be improved.
[0019]
In this embodiment, the magnet plate of the movable portion is made of a non-magnetic material having a non-magnetic permeability of 1.0 to 1.05 and a specific gravity of 2.8 g / cm ³ or less, so that the weight of the movable portion is reduced. Thus, the guide life can be extended and the reliability of the mechanism can be improved.
[0020]
Also, in this embodiment, the linear scale for control is arranged on the mover side, and the scale head side is fixedly arranged on the stator side, so that the linear scale lead wire on the scale head side is pulled out from the stator side, Unlike the conventional case, the linear scale lead wire is not dragged from the mover side, and the high acceleration / deceleration performance of the linear motor can be improved.
[Brief description of the drawings]
FIG. 1 is a front sectional view of a high-acceleration linear motor according to an embodiment of the present invention.
FIG. 2 is a side view of the high acceleration linear motor of the present invention.
FIG. 3 is a front sectional view of a conventional linear motor.
FIG. 4 is a side view of a conventional linear motor.
[Explanation of symbols]
1: Fixed base 2: Linear guide 2a: Guide rail 2b: Slider 3: Frame 4: Field permanent magnet 5: Magnet holder 6: Armature 7: Cooling jacket 7a, 7b: Refrigerant hole 8: Linear scale 9: Scale head 9a: Linear scale lead wire 10: Scale holder

Claims (4)

Fixed base,
A gate-shaped frame provided along the longitudinal direction on the fixed base,
A pair of linear guides comprising a guide rail portion and a slider portion provided in parallel with both sides on the fixed base and in the longitudinal direction,
A mover comprising a plate-like magnet holder mounted on the linear guide in parallel with the slider portion and a field permanent magnet fixed to the magnet holder,
A stator comprising a pair of armatures arranged with the field permanent magnet via a magnetic gap and having armature coils attached to each of two parallel surfaces of the field permanent magnet. With
One of the pair of armatures is fixed to the frame, the other is fixed to the base,
A high-acceleration linear motor, wherein the mover is moved along the guide rail portion. The high-acceleration linear motor according to claim 1, wherein a linear scale for control is arranged on the mover side, and a scale head for detection is arranged on the stator side. The high-acceleration linear motor according to claim 1, wherein a cooling jacket is provided on the frame and the fixed base. Said magnet holder, relative magnetic permeability 1.0 to 1.05 and a high acceleration type linear motor according to claim 1, characterized by being configured of a nonmagnetic material serving as a specific gravity of 2.8 g / cm ³ or less.

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