JP2003319633A - Voice coil type motor, and work head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a voice coil type motor which is small and light weight and can generate high thrust, and a work head which uses this voice coil type motor. <P>SOLUTION: In the voice coil type motor 30 which is used to give pressure to a bonding tool of an electronic part mounter via a rotary shaft 31, two magnets 39A and 39B are fixed in series to a yoke 35, and two layers of coils (inner coils 38A and 38C and outer coils 38B and 38D) are respectively mounted sandwiching the two magnets 39A and 39B on a shifting member 33 coupled with the rotary shaft 31, thus constituting a mobile part. Hereby, high thrust can be obtained without incurring an increase in the size and the weight of the voice coil type motor. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice coil type motor for generating thrust in a linear direction and a working head using the voice coil type motor.

[0002]

2. Description of the Related Art A mounting head for mounting an electronic component on a substrate is equipped with a load generating means for generating a pressing load for pressing the electronic component against the substrate. As the load generating means, a movable coil and a fixed magnet are provided. A method of using a voice coil type motor by combination is known. In this method, a movable coil is coupled to an electronic component holding tool that is held in contact with an electronic component via a shaft member, and the movable coil is energized in the magnetic field created by the fixed magnet to thereby cause a gap between the electronic component holding tool and the fixed magnet. The generated electromagnetic force is transmitted to the electronic component via the electronic component holding tool.

[0003]

With the diversification of types of electronic parts in recent years, there has been a demand for a high-coil voice coil type motor for mounting a large chip. However, in the conventional voice coil type motor, in order to increase the thrust, it is inevitable that the size and weight of the entire motor increase due to the increase in size of the magnet and coil, which is against the demand for a compact device and the increase in head weight. However, there is a problem in that the mounting operation tact is delayed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a voice coil type motor which is compact and lightweight and can generate a high thrust, and a working head using the voice coil type motor.

[0005]

A voice coil type motor according to claim 1 has a shaft, a bearing portion for supporting the shaft, and a through hole through which the shaft penetrates in a central portion, and the voice coil type motor is parallel to the shaft. A first magnetic member having an outer wall surface, and a second magnetic member that surrounds the first magnetic member and has an inner wall surface that faces the outer wall surface of the first magnetic member at a distance and is parallel to the shaft. At least two magnets that are arranged in series along the longitudinal direction of the shaft in a space sandwiched between the outer wall surface and the inner wall surface and are magnetized in the radial direction, and between the inner wall surface and the magnet. At least two outer coils wound in a space and arranged in series along the longitudinal direction of the shaft corresponding to the magnet, and wound in a space between the outer wall surface and the magnet, Corresponding to the coil At least two inner coils arranged in series along the longitudinal direction of the shaft, a drive circuit for supplying a current to the outer coil and the inner coil, and the outer coil and the inner coil integrated with the shaft Of the bearing, the first magnetic member, the second magnetic member, and the magnet are integrally mounted as a fixed part, and the polarities of the adjacent magnets are reversed. At the same time, the direction of the current flowing through the adjacent outer coil is opposite, and the direction of the current flowing through the inner coil corresponding to the outer coil is the same as that of the outer coil.

A voice coil type motor according to a second aspect is
The voice coil motor according to claim 1, wherein the bearing portion is mounted in a through hole of the first magnetic member.

A voice coil type motor according to a third aspect is
The voice coil motor according to claim 2, wherein a non-magnetic body is provided between the bearing portion and the first magnetic member.

A voice coil type motor according to claim 4 is
The voice coil motor according to claim 3, wherein the bearing, the first magnetic member, the second magnetic member, and the magnet are attached to the non-magnetic body to form the fixed portion.

A voice coil type motor according to a fifth aspect is
The voice coil type motor according to any one of claims 1 to 4, comprising two each of the magnet, the outer coil, and the inner coil.

According to a sixth aspect of the present invention, there is provided a work head including a shaft which is moved by a voice coil type motor, and a work tool which is attached to one end of the shaft, and a bearing portion which supports the shaft. A first magnetic member having a through hole through which the shaft penetrates in a central portion and having an outer wall surface coaxial with and parallel to the shaft; and an outer wall surface of the first magnetic member surrounding the first magnetic member. A second magnetic member having an inner wall surface that is coaxial and parallel to and is opposed to the shaft, and is serially arranged along the longitudinal direction of the shaft in a substantially cylindrical space sandwiched between the outer wall surface and the inner wall surface. And magnetized in the radial direction, and wound in the space between the inner wall surface and the magnet coaxially with the shaft, and corresponding to the magnet. At least two outer coils arranged in series along the hand direction, and wound in the space between the outer wall surface and the magnet coaxially with the shaft, and corresponding to the outer coils, the longitudinal direction of the shaft. At least two inner coils arranged in series along the outer coil, a drive circuit for supplying a current to the outer coil and the inner coil, and the outer coil and the inner coil are integrally mounted on the shaft. As a movable part, the bearing part, the first magnetic member, the second magnetic member, and the magnet are integrally attached to form a fixed part, and the polarities of the adjacent magnets are reversed, and the adjacent outer parts. The voice coil type motor is configured such that the direction of current flowing through the coil is opposite and the direction of current flowing through the inner coil corresponding to the outer coil is the same as that of the outer coil. At the other end of the shaft, a rotating body integrally rotating with the shaft about the axis and slidably coupled in the longitudinal direction, a driving means for rotating the rotating body, the driving circuit, and the driving means are provided. The control means for controlling was provided.

A working head according to a seventh aspect is the working head according to the sixth aspect, wherein the bearing portion is mounted in the through hole of the first magnetic member.

The working head according to claim 8 is the working head according to claim 7, wherein a non-magnetic body is provided between the bearing portion and the first magnetic member.

A working head according to a ninth aspect is the working head according to the eighth aspect, wherein the bearing portion, the first magnetic member, the second magnetic member, and the magnet are mounted on the non-magnetic body. The fixed portion was used.

According to a tenth aspect of the present invention, there is provided the work head of the sixth aspect.
The work head according to claim 9, wherein each of the magnets, the outer coils, and the inner coils is provided two by two.

According to the present invention, by arranging two magnets having different magnetizing directions in series in the thrust generating direction and arranging coils of two layers inside and outside with each magnet sandwiched therebetween,
High thrust can be obtained without increasing the size and weight of the entire voice coil motor.

[0016]

1 is a front view of an electronic component mounting apparatus according to a first embodiment of the present invention, and FIG. 2 is a perspective view of the electronic component mounting apparatus according to a first embodiment of the present invention. 3 is a sectional view of a mounting head of an electronic component mounting apparatus according to a first embodiment of the present invention, FIG. 4 is a sectional view of a voice coil type motor according to a first embodiment of the present invention, and FIG. It is an explanatory view of the operation of the voice coil type motor of mode 1.

First, the structure of the electronic component mounting apparatus will be described with reference to FIGS. In FIG. 1, the electronic component mounting apparatus 1 is composed of a substrate holding unit 3, a component supply unit 6, and a mounting unit 10 arranged on a base 2. The substrate holding unit 3 includes a holding stage 4, and a substrate 5 that is an electronic component mounting target is held on the holding stage 4.
A large number of electronic components 8 are stored in the component tray 7 placed on the component supply unit 6.

As shown in FIG. 2, the mounting portion 10 has a structure in which a mounting head 12, which is a working head for mounting electronic components, is movably disposed on a moving table 11.
A bonding tool 13, which is a working tool and an electronic component holding tool, is attached to the lower end of the mounting head 12. The bonding tool 13 is provided with a horizontal horizontally long horn 13a, and the horn 13a has a holding portion 1a.
It is connected to the lower end of the mounting head 12 by 3b. A joining action portion 13c is provided on the lower surface of the horn 13a so as to project. The joining action portion 13c abuts and holds the upper surface of the electronic component 8 by suction, and presses the electronic component 8 against the substrate 5 to generate an electronic component. The component 8 is mounted on the substrate 5.

The vibrator 1 is provided at one end of the horn 13a.
4 is attached, and by driving the vibrator 14, ultrasonic vibrations are transmitted to the joining action portion 13c via the ultrasonic vibration transmitting horn 13a. As a result, when the bonding tool 13 presses the electronic component 8 against the substrate, ultrasonic vibration is applied to the electronic component 8 via the bonding action portion 13c.

Next, the structures of the moving table 11 and the mounting head 12 will be described with reference to FIG. In FIG. 3, two guide rails 16 are horizontally arranged on the frame 11 a of the moving table 11, and the slider 15 slidably fitted on the guide rail 16 is
The vertical plate 11b is fixed.

The mounting head 12 is the bonding tool 1
Rotating mechanism 20 for rotating 3 and bonding tool 1
3 and a voice coil type motor 30 as a pressing means for applying a pressing load to the upper and lower parts. A holding member 20a that constitutes the main body of the rotation mechanism 20 is coupled to the plate 11b. A motor 21 is vertically arranged on the upper surface of the holding member 20a.
A coupling member 22 pivotally supported by a bearing 23 is coupled to the first output shaft 21a.

A ball spline 24 is attached to the lower portion of the coupling member 22.
A spline shaft portion 31b, which is an upper portion of a vertical rotary shaft 31 (shaft) that penetrates the voice coil type motor 30 via a bearing portion 32, is slidably fitted in the vertical direction 4. The lower end 31a of the rotary shaft 31 is connected to the holding portion 13b of the bonding tool 13 via a connecting member 34 made of a non-magnetic material.

By rotating the motor 21, the rotation is transmitted to the rotary shaft 31 via the ball spline 24 and the spline shaft portion 31b, and the rotary shaft 31 rotates about its axis. At this time, relative vertical displacement of the spline shaft portion 31b with respect to the ball spline 24 is allowed. That is, the coupling member 22 to which the ball spline 24 is mounted and the spline shaft portion 31b are connected to the other end of the rotating shaft 31 and rotate integrally with the rotating shaft 31 about the shaft center in the longitudinal direction. Is a rotating body that slidably moves with respect to the rotating shaft 31. Then, this rotating body is rotationally driven by the output shaft 21a of the motor 21, which is the rotational driving means. The motor 21 is driven by the drive circuit 51, and the drive circuit 51 is controlled by the control means 9 of the electronic component mounting apparatus.

Next, the position detecting means for detecting the vertical position of the rotary shaft 31 will be described. This position detecting means is a linear scale 29 mounted on the rotary shaft 31 by a bracket 28a protruding upward from the left side surface (side surface opposite to the movable table 11) of the dog member 28 mounted on the rotary shaft 31 for detecting the vertical position. , And a reading head 27 mounted on the left side surface of the coupling member 22 by a bracket 26. Linear scale 29
And the reading head 27 are arranged to face each other, and the vertical displacement of the linear scale 29 is read.
By reading at 7, the vertical position of the rotary shaft 31 is detected.

Two optical sensors 25a and 25b are arranged with the dog member 28 interposed therebetween. Optical sensor 25a,
Reference numeral 25b is a transmissive optical sensor that includes a light projecting portion and a light receiving portion, respectively, and detects that the vertical displacement of the rotating shaft 31 has reached a preset upper limit range / lower limit range.

Next, the structure of the voice coil type motor 30 will be described with reference to FIG. In FIG. 4, the holding member 20
A yoke 35 is fixed to the lower surface of a. York 3
Reference numeral 5 is a substantially double-cylindrical member made of magnetic metal such as machine structural steel or martensitic stainless steel, and has an inner tubular portion 35a (first magnetic member) and an outer tubular portion 35d.
(Second magnetic member). The inner tubular portion 35a and the outer tubular portion 35d are connected by an upper connecting portion 35f.

At the center of the inner cylindrical portion 35a of the yoke 35,
A through hole 35b is provided so as to penetrate vertically. In the through hole 35b provided at the center of the yoke 35, the rotating shaft 3
1 is rotatably and axially movably supported via a bearing 32. The inner cylinder portion 35a includes an outer wall surface 35c that is coaxial with and parallel to the rotating shaft 31, and the outer wall surface 35c faces the inner wall surface 35e of the outer cylinder portion 35d. That is, the outer cylinder portion 35d includes an inner wall surface 35e that surrounds the inner cylinder portion 35a and faces the outer wall surface 35c with a space therebetween and is coaxial with and parallel to the rotation shaft 31.

A magnet holding portion 35g is provided so as to project downward from the connecting portion 35f in a substantially cylindrical space 37 sandwiched between the outer wall surface 35c and the inner wall surface 35e. Ring-shaped magnets (magnets) 39A and 39B, which are magnetized in the radial direction, are attached to the magnet holder 35g, and the magnets 39A and 39B are arranged in series in the space 37 along the longitudinal direction of the rotating shaft 31. It is arranged.

The inner coil holding portion 33a extending upward from the moving member 33 enters the space between the outer wall surface 35c of the inner tubular portion 35a and the magnets 39A, 39B.
The inner coil holding portion 33a has two inner coils 38A,
38C is installed. Also, the inner wall surface 3 of the outer tubular portion 35d
In the space between the magnet 5e and the magnets 39A and 39B, the outer coil holding portion 33b extending upward from the moving member 33 is provided.
Has entered, and two outer coils 38B and 38D are attached to the outer coil holding portion 33b.

The two inner coils 38A, 38C and the two outer coils 38B, 38D are arranged in series in correspondence with the positions of the magnets 39A, 39B in the axial direction of the rotary shaft 31, respectively, and both the magnets 39A, 3D.
With a winding width B1 shorter than the longitudinal size L1 of 9B,
It is rotated coaxially with the rotating shaft 31. Here, B1 corresponds to the effective coil length related to the thrust of the voice coil motor 30, and L1 is equal to or more than the sum of B1 and the required vertical stroke of the rotary shaft 31.

Outer coils 38B, 38D, inner coil 3
A drive current is supplied to 8A and 38C by the drive circuit 50 (FIG. 3), and the drive circuit 50 is controlled by the control means 9 (FIG. 3). Thereby, the outer coil 38
The magnets 39A and 39B relatively move in the longitudinal direction with respect to B and 38D and the inner coils 38A and 38C, but the outer coils 38B and 38D and the inner coils 38A and 38C are
Since the magnets 39A and 39B are wound with the winding width B1 shorter than the size L1 in the longitudinal direction, the effective coil length is always kept constant in the normal stroke range.

In the above structure, the outer coils 38B, 3
8D, the inner coils 38A, 38C are integrally attached to the rotary shaft 31 via the moving member 33 to form a movable portion that moves in the thrust generation direction (axial direction). Further, the inner tubular portion 35a of the yoke 35, the bearing portion 32, and the outer tubular portion 35d are integrally mounted with the magnets 39A and 39B so that the holding member 20.
It constitutes a fixed part fixed to a.

Referring now to FIG. 5, the magnet 39
The polarities of A and 39B, the winding directions of the outer coils 38B and 38D, and the inner coils 38A and 38C will be described. Figure 5
As shown in FIG. 5, the magnets 39A and 39B are arranged such that the inner side in the radial direction is the S pole and the outer side is the N pole in the magnet 39A, and the inner side in the radial direction is the N pole and the outer side is the S pole in the magnet 39B. It is magnetized in the direction. That is, the magnetizing directions are such that the magnets adjacent to each other in the longitudinal direction of the rotating shaft 31 have opposite polarities.

Of the four coils, the inner coil 38A,
The outer coil 38B has the same winding direction, and the inner coil 38C and the outer coil 38D have the same winding direction. The inner coils 38A and 38C adjacent to each other in the longitudinal direction of the rotating shaft 31 have opposite winding directions, and the outer coils 38B and 38D also have opposite winding directions.

FIG. 5 shows a magnetic circuit constituted by the magnets 39A and 39B. The magnetic flux crosses the outer coil 38B from the outside (N pole) of the magnet 39A and enters the outer cylinder portion 35d. Then, it crosses the outer coil 38D toward the outside (S pole) of the magnet 39B.
Then, from the inside (N pole) of the magnet 39B, it crosses the inner coil 38C and enters the inner tubular portion 35a, and further, it crosses the inner coil 38A and enters the inside (S pole) of the magnet 39A and closes.

By energizing the outer coils 38B, 38D and the inner coils 38A, 38C in the magnetic field generated by such a magnetic circuit, the outer coils 38B, 38D, the inner coils 38A, 38C and the magnets 39A, 39B are connected to each other. Has a magnitude corresponding to the strength of the current, and a relative force acts in the direction of arrow a or the direction of arrow b depending on the direction of the current. As a result, an axial force corresponding to the current supplied by the drive circuit 50 is transmitted to the rotary shaft that constitutes the movable part together with the magnets 39A and 39B.

The thrust generated in the axial direction is transmitted to the bonding tool 13 via the connecting member 34 connected to the lower end 31a of the rotary shaft 31. This allows
The bonding tool 13 presses the electronic component against the substrate 5 by the bonding action portion 13c. The voice coil type motor 30 having the above-mentioned configuration is composed of a magnet 39 divided into upper and lower parts.
Since A and 39B are sandwiched between the inner and outer two-layer coils, high thrust can be obtained without enlarging these magnets and coils and the yoke 35. Therefore, a compact mounting head is realized while suppressing an increase in the size and weight of the entire voice coil type motor, and high-speed operation is possible.

(Second Embodiment) FIG. 6 is a sectional view of a voice coil type motor according to a second embodiment of the present invention. The voice coil type motor 30A shown in the second embodiment includes the bearing portion 32 via the yoke 35 shown in the first embodiment via a non-magnetic material.
The configuration other than this is the same as that of the voice coil type motor 30 of the first embodiment.

In FIG. 6, a yoke 40 is fixed to the lower surface of the holding member 20a. The yoke 40 is a first magnetic member made of the same magnetic metal as the yoke 35 shown in the first embodiment. A through hole 40a is vertically provided at the center of the yoke 40, and a collar member 41 made of a non-magnetic material such as austenitic stainless steel is fitted in the through hole 40a.

The collar member 41 has a flange portion 41a extending radially upward and a through hole 41b penetrating vertically.
Is provided in the through hole 41b, and a bearing portion 32 that supports the rotating shaft 31 rotatably and axially movable is attached to the through hole 41b. An outer cylinder portion 42, which is made of the same magnetic metal as the yoke 40 and serves as a second magnetic member, is coupled to the flange portion 41a.

The yoke 40 has an outer wall surface 40b which is coaxial with and parallel to the rotating shaft 31, and the outer cylindrical portion 42 has the yoke 40.
And an inner wall surface 42a that is disposed so as to surround the outer wall surface 40b and is opposed to the outer wall surface 40b with a space therebetween and is coaxial and parallel to the rotation shaft 31.

A magnet holding portion 41c is provided so as to project downward from the flange portion 41a in a substantially cylindrical space 47 sandwiched between the outer wall surface 40b and the inner wall surface 42a. Ring-shaped magnets (magnets) 39A and 39B that are magnetized in the radial direction are attached to the magnetic head holding portion 41c. The magnets 39A and 39B are arranged in series in the space 47 along the longitudinal direction of the rotating shaft 31. It is arranged.

Outer wall surface 40b and magnets 39A, 39B
Space between the magnets 39A, 39B and the inner wall surface 42
The inner coil holding portion 33a and the outer coil holding portion 33b, which extend upward from the moving member 33, are respectively inserted into the space between the a and the a. 2 for the inner coil holding portion 33a
The inner coils 38A and 38C are connected to the outer coil holder 3
Outer coils 38B and 38D are attached to 3b, respectively. Regarding the arrangement and polarity of the magnets 39A and 39B, the arrangement and winding direction of the outer coils 38B and 38D, and the inner coils 38A and 38C, the voice coil type motor 30
Is the same as.

The above construction has the bearing 32 and the yoke 40.
A collar member 41 that is a non-magnetic material between the (first magnetic members)
The collar member 41, the bearing portion 32, the yoke 40,
The outer cylinder portion 42 is mounted, the inner coils 38A and 38C are mounted on the outer wall surface 40b of the yoke 40, and the inner wall surface 4 of the outer cylinder portion 42 is mounted.
The outer coil 38B, 38D is attached to the 2a to form a fixed portion.

As described above, by interposing the non-magnetic collar member 41 between the yoke 40 and the bearing portion 32, it is possible to prevent magnetic flux leakage from the magnets 39A and 39B to the rotary shaft 31. Therefore, it is possible to prevent the thrust from being reduced due to the leakage of the magnetic flux, and to bond the bonding tool 1 by the magnetic flux leaked through the rotary shaft 31.
It is possible to prevent the adverse effect on 3.

(Third Embodiment) FIG. 7 is a sectional view of a voice coil type motor according to a third embodiment of the present invention, and FIG. 8 is an operation explanatory view of the voice coil type motor according to the third embodiment of the present invention. Voice coil type motor 30B shown in the third embodiment
In the configuration similar to that of the first embodiment, the arrangement width of the magnet and the coil in the longitudinal direction is changed.

In FIG. 7, the lower surface of the holding member 20a is
The yoke 45 is fixed. The yoke 45 is a substantially double-cylindrical member made of a magnetic metal such as machine structural steel or martensitic stainless steel, and the inner cylindrical portion 4
5a (first magnetic member), outer cylinder portion 45d (second magnetic member)
It is composed of The inner tubular portion 45a and the outer tubular portion 45d are connected by an upper connecting portion 45f.

At the center of the inner cylinder portion 45a of the yoke 45,
A through hole 45b is provided so as to penetrate vertically. In the through hole 45b provided in the central portion of the yoke 45, the rotary shaft 3
1 is rotatably and axially movably supported via a bearing 32. The inner cylindrical portion 45a includes an outer wall surface 45c that is coaxial and parallel to the rotating shaft 31, and the outer wall surface 45c faces the inner wall surface 45e of the outer cylindrical portion 45d. That is, the outer cylinder portion 45d includes an inner wall surface 45e that surrounds the inner cylinder portion 45a and faces the outer wall surface 45c with a space therebetween and is coaxial with and parallel to the rotation shaft 31.

A magnet holding portion 45g is provided so as to project downward from the connecting portion 45f in a substantially cylindrical space 47 sandwiched between the outer wall surface 45c and the inner wall surface 45e. Ring-shaped magnets (magnets) 49A and 49B that are magnetized in the radial direction are attached to the magnetic head holding portion 45g. The magnets 49A and 49B are arranged in series in the space 47 along the longitudinal direction of the rotating shaft 31. It is arranged.

The inner coil holding portion 43a extending upward from the moving member 43 enters the space between the outer wall surface 45c of the inner cylindrical portion 45a and the magnets 49A and 49B.
The inner coil holder 43a has two inner coils 48A,
48C is installed. Further, in the space between the inner wall surface 45e of the outer tubular portion 45d and the magnets 49A and 49B,
Outer coil holding portion 43 extending upward from the moving member 43
b has entered, and two outer coils 48B and 48D are attached to the outer coil holding portion 43b.

The two inner coils 48A and 48C and the two outer coils 48B and 48D are arranged in series corresponding to the positions of the magnets 49A and 49B in the axial direction of the rotary shaft 31, and the magnets 49A and 4B are arranged in series.
The winding width B2 is longer than the longitudinal size L2 of 9B and is wound coaxially with the rotating shaft 31. Here, L2 corresponds to the effective coil length related to the thrust of the voice coil type motor 30B, and B2 is equal to or more than the sum of L2 and the required vertical stroke of the rotary shaft 31.

Outer coils 48B, 48D, inner coil 4
A driving current is supplied to 8A and 48C by a drive circuit 50 (FIG. 3), and the drive circuit 50 is controlled by the control means 9 (FIG. 3). This allows the outer coil 48
The magnets 49A and 49B move in the longitudinal direction relative to the B and 48D and the inner coils 48A and 48C, but the outer coils 48B and 48D and the inner coils 48A and 48C are
Since the magnets 49A and 49B are wound with the winding width B2 longer than the longitudinal size L2, the effective coil length is always kept constant in the normal stroke range.

Referring now to FIG. 8, magnet 49
The polarities of A and 49B, the winding directions of the outer coils 48B and 48D, and the inner coils 48A and 48C will be described. Figure 8
As shown in FIG. 4, the magnets 49A and 49B are arranged such that the inner side in the radial direction is the S pole and the outer side is the N pole in the magnet 49A, and the inner side in the radial direction is the N pole and the outer side is the S pole in the magnet 49B. It is magnetized in the direction. That is, the magnetizing directions are such that the magnets adjacent to each other in the longitudinal direction of the rotating shaft 31 have opposite polarities.

Of the four coils, the inner coil 48A,
The outer coil 48B has the same winding direction, and the inner coil 48C and the outer coil 48D have the same winding direction. The inner coils 48A and 48C adjacent to each other in the longitudinal direction of the rotary shaft 31 have opposite winding directions, and the outer coils 48B and 48D also have opposite winding directions.

FIG. 8 shows a magnetic circuit composed of the magnets 49A and 49B. The magnetic flux crosses the outer coil 48B from the outside (N pole) of the magnet 49A and enters the outer cylindrical portion 45d. Then, it crosses the outer coil 48D toward the outside (S pole) of the magnet 49B. Then, from the inside (N pole) of the magnet 49B to the inside coil 48
The inner coil part 45a is crossed across C, and the inner coil 4
It crosses 8A and enters the inside (S pole) of magnet 49A and closes.

By energizing the outer coils 48B, 48D and the inner coils 48A, 48C in the magnetic field of such a magnetic circuit, the outer coils 48B, 48D, the inner coils 48A, 48C and the magnets 49A, 49B are connected. Is applied with a relative force in the direction of arrow a or in the direction of arrow b depending on the strength of the current and the direction of the current. As a result, an axial force corresponding to the current supplied by the drive circuit is transmitted to the rotating shaft that constitutes the movable part together with the magnets 49A and 49B.

In the above embodiments, the winding directions of the coils arranged in series in the axial direction are reversed, but the same effect can be obtained even if the winding directions are the same and the connection is changed and a current in the opposite direction is applied. It is clear that it is obtained. In the above embodiments, two magnets, two outer coils and two inner coils are provided, but the thrust may be increased by providing more magnets. It is desirable to have two of each, because it is possible to balance compactness and increase in thrust.

[0058]

According to the present invention, two magnets having different magnetizing directions are arranged in series in the thrust generating direction, and two inner and outer layers of coils are arranged so as to sandwich each magnet. A high thrust can be obtained without increasing the size and weight of the.

[Brief description of drawings]

FIG. 1 is a front view of an electronic component mounting apparatus according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the electronic component mounting apparatus according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a mounting head of the electronic component mounting apparatus according to the first embodiment of the present invention.

FIG. 4 is a sectional view of the voice coil type motor according to the first embodiment of the present invention.

FIG. 5 is an operation explanatory diagram of the voice coil type motor according to the first embodiment of the present invention.

FIG. 6 is a sectional view of a voice coil type motor according to a second embodiment of the present invention.

FIG. 7 is a sectional view of a voice coil type motor according to a third embodiment of the present invention.

FIG. 8 is an operation explanatory diagram of the voice coil motor according to the third embodiment of the present invention.

[Explanation of symbols]

1 Electronic component mounting equipment 5 substrates 8 electronic components 10 Mounting part 11 Moving table 12 Mounting head 13 Bonding tool 20 rotation mechanism 21 motor 30 voice coil type motor 31 rotation axis 38A, 38C, 48A, 48C inner coil 38B, 38D, 48B, 48D outer coil 39A, 39B, 49A, 49B Magnet

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Claims (10)

[Claims] 1. A first magnetic member having a shaft, a bearing for supporting the shaft, a through hole through which the shaft penetrates in a central portion, and an outer wall surface parallel to the shaft, and the first magnetic member. A second magnetic member that surrounds the magnetic member and has an inner wall surface that faces the outer wall surface of the first magnetic member at a distance and is parallel to the shaft; and a second magnetic member in a space sandwiched between the outer wall surface and the inner wall surface. At least two magnets that are arranged in series along the longitudinal direction of the shaft and are magnetized in the radial direction, and are wound in a space between the inner wall surface and the magnet, and correspond to the magnets of the shaft. At least two outer coils arranged in series along the longitudinal direction;
At least two inner coils wound in a space between the outer wall surface and the magnet and arranged in series along the longitudinal direction of the shaft corresponding to the outer coil, the outer coil and the inner coil. A drive circuit for supplying a current to the shaft, wherein the shaft is integrally mounted with the outer coil and the inner coil to form a movable portion, and the bearing portion, the first magnetic member, the second magnetic member, and the magnet. Are integrally mounted to form a fixed part, the polarities of the adjacent magnets are reversed, the direction of the current flowing through the adjacent outer coil is reversed, and the current flowing through the inner coil corresponding to the outer coil is A voice coil type motor characterized in that the direction is the same as that of the outer coil. 2. The voice coil type motor according to claim 1, wherein the bearing portion is mounted in a through hole of the first magnetic member. 3. The voice coil type motor according to claim 2, wherein a non-magnetic material is provided between the bearing portion and the first magnetic member. 4. The voice coil type according to claim 3, wherein the bearing portion, the first magnetic member, the second magnetic member, and the magnet are mounted on the non-magnetic body to form the fixed portion. motor. 5. The magnet, the outer coil, and the inner coil are each provided with two pieces each.
A voice coil type motor according to claim 4. 6. A work head comprising a shaft which is moved by a voice coil type motor and a work tool which is attached to one end of the shaft, the bearing having a shaft for supporting the shaft, and the shaft having the shaft at the center. A first magnetic member having a through hole penetrating therethrough and having an outer wall surface coaxial with and parallel to the shaft; and surrounding the first magnetic member,
A second magnetic member having an inner wall surface that faces the outer wall surface of the magnetic member with a gap and is coaxial and parallel to the shaft; and the length of the shaft in a substantially cylindrical space sandwiched between the outer wall surface and the inner wall surface. Arranged in series along the direction,
At least two magnets that are magnetized in the radial direction, are wound coaxially with the shaft in a space between the inner wall surface and the magnet, and are arranged in series along the longitudinal direction of the shaft corresponding to the magnets. At least two outer coils arranged,
At least two inner coils that are wound coaxially with the shaft in a space between the outer wall surface and the magnet, and are arranged in series along the longitudinal direction of the shaft corresponding to the outer coils; A driving circuit that supplies a current to the coil and the inner coil, and the outer coil and the inner coil are integrally mounted on the shaft to form a movable part,
The bearing portion, the first magnetic member, the second magnetic member,
The magnet and the magnet are integrally attached to form a fixed portion, and the polarities of the adjacent magnets are reversed, and the directions of the currents flowing through the adjacent outer coils are reversed, and the inner coil corresponding to the outer coil is further reversed. A voice coil type motor is constructed with the direction of the electric current flowing in the same direction as the outer coil. The other end of the shaft is integrally rotated with the shaft about the axis and slidably connected in the longitudinal direction. A working head comprising: a rotating body for rotating, a driving means for rotating the rotating body, a control means for controlling the drive circuit, and the driving means. 7. The work head according to claim 6, wherein the bearing portion is mounted in a through hole of the first magnetic member. 8. The work head according to claim 7, wherein a non-magnetic material is provided between the bearing portion and the first magnetic member. 9. The work head according to claim 8, wherein the bearing portion, the first magnetic member, the second magnetic member, and the magnet are mounted on the non-magnetic body to form the fixed portion. 10. The work head according to claim 6, further comprising two each of the magnet, the outer coil, and the inner coil.