JP2014093874A - Permanent magnet, manufacturing method of permanent magnet, tool, motor and robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent magnet having smaller variation in magnetic property, a manufacturing method of the permanent magnet, a tool used in the manufacturing method of the permanent magnet, and a highly reliable motor and robot using the permanent magnet.SOLUTION: A permanent magnet 53 includes a plurality of permanent magnet pieces 54 which are aligned in a prescribed direction, and whose magnetic poles are oriented in a same direction. The plurality of permanent magnet pieces 54 include a first permanent magnet piece 541; a pair of second permanent magnet pieces 542 which are arranged respectively both sides of the first permanent magnet piece 541, and have larger magnetic flux density than the first permanent magnet piece 541; and a pair of third permanent magnet pieces 543 which are arranged between the first permanent magnet piece 541 and respective second permanent magnet pieces 542, and have smaller magnetic flux density than the first permanent magnet piece 541.

Description

  The present invention relates to a permanent magnet, a method for manufacturing a permanent magnet, a jig, a motor, and a robot.

Conventionally, horizontal articulated robots and vertical articulated robots have been used as industrial robots. For example, a horizontal articulated robot has a base, a first arm that can rotate with respect to the base, and a second arm that can rotate with respect to the first arm. 1. The second arm is driven. In recent years, in order to improve the driving performance (for example, speed and low vibration property) of the robot, the robot has been downsized, and the motor has been downsized along with the downsizing.
In a small motor, a rare earth permanent magnet (neodymium magnet, samarium-cobalt magnet) having a high magnetic flux density is used to obtain a high torque. However, since these permanent magnets are sintered magnets formed by solidifying powder, it is difficult to manage the magnetic properties of the finished product, and individual differences are large.

In order to reduce the eddy current generated on the surface of the permanent magnet, the permanent magnet is divided into a plurality of magnet pieces (permanent magnet pieces) in the direction of the rotation axis of the motor, and an insulating sheet is sandwiched between the divided magnet pieces. The structure is known (for example, refer to Patent Documents 1 and 2). In such a configuration, the magnetic flux density when a plurality of magnet pieces are integrated into one permanent magnet affects the performance of the motor. Therefore, the magnetic flux density of the permanent magnet is measured after the magnet pieces are integrated. The product is judged as good or defective.
However, in such a method, since a non-defective product or a defective product is determined only after a plurality of magnet pieces are integrated, there is a large variation in the magnetic characteristics of the completed motor, and the yield is also poor. Therefore, there is a limit to reducing the cost of the motor.

JP 2005-228830 A JP 2006-136130 A

  An object of the present invention is to provide a permanent magnet with little variation in magnetic characteristics, a method of manufacturing the permanent magnet, a jig used in the method of manufacturing the permanent magnet, and a highly reliable motor and robot using the permanent magnet. It is to provide.

Such an object is achieved by the present invention described below.
The permanent magnet of the present invention comprises a plurality of permanent magnet pieces arranged in a predetermined direction and aligned with magnetic poles,
The plurality of permanent magnet pieces are at least a first permanent magnet piece and a pair of second magnets positioned on both sides of the first permanent magnet piece in the predetermined direction and having a larger magnetic flux density than the first permanent magnet piece. A permanent magnet piece, and a pair of third permanent magnet pieces located between the first permanent magnet piece and each of the second permanent magnet pieces and having a magnetic flux density smaller than that of the first permanent magnet piece. It is characterized by that.
Thereby, a permanent magnet with little variation in magnetic characteristics can be obtained. Moreover, it becomes a permanent magnet which has a magnetic flux density substantially equal to a 1st permanent magnet piece as a whole.

In the permanent magnet of the present invention, it is preferable that the second permanent magnet pieces are respectively disposed at both end portions in the predetermined direction.
Thereby, a sufficiently large magnetic flux density can be obtained at both ends of the permanent magnet.
In the permanent magnet of the present invention, when the set magnetic flux density of the permanent magnet is B (Wb / m ² ),
A permanent magnet piece having a magnetic flux density of 0.9B or more and 1.1B or less is preferably used as the first permanent magnet piece.
Thereby, the magnetic flux density of the obtained permanent magnet can be made substantially equal to the set magnetic flux density.

In the permanent magnet of the present invention, it is preferable that the adjacent permanent magnet pieces are joined with an insulating adhesive.
Thereby, generation | occurrence | production of an eddy current at the time of applying a permanent magnet to a motor can be suppressed, for example.
The method for producing a permanent magnet of the present invention is a method for producing a permanent magnet comprising a plurality of permanent magnet pieces arranged in a predetermined direction and aligned with magnetic poles,
As the plurality of permanent magnet pieces, a first permanent magnet piece, a second permanent magnet piece having a larger magnetic flux density than the first permanent magnet piece, and a third having a smaller magnetic flux density than the first permanent magnet piece. A preparation step of preparing a permanent magnet piece;
At least a pair of second permanent magnet pieces are located on both sides of the first permanent magnet piece, and the third permanent magnet piece is located between the first permanent magnet piece and each of the second permanent magnet pieces. And a joining step of arranging the plurality of permanent magnet pieces and joining the adjacent permanent magnet pieces together.
Thereby, a permanent magnet with little variation in magnetic characteristics can be obtained. Moreover, it becomes a permanent magnet which has a magnetic flux density substantially equal to a 1st permanent magnet piece as a whole.

In the permanent magnet manufacturing method of the present invention, in the joining step, the plurality of permanent magnet pieces, which are odd-numbered from one end in the predetermined direction, are held at intervals in the predetermined direction. And holding a plurality of even-numbered permanent magnet pieces spaced apart in the predetermined direction,
The even-numbered permanent magnet piece is inserted between a pair of adjacent odd-numbered permanent magnet pieces, and the odd-numbered permanent magnet piece is inserted between a pair of adjacent even-numbered permanent magnet pieces. It is preferable to arrange the plurality of permanent magnet pieces by making them enter.
Thereby, since the unintentional variation | mutation of the permanent magnet piece by the repulsive force of a permanent magnet piece can be suppressed, a permanent magnet can be manufactured easily and accurately.

In the method of manufacturing a permanent magnet of the present invention, in the joining step, an adhesive is supplied to the side surface of each permanent magnet piece in the middle of the approach, and the adhesive is stretched by sliding between adjacent permanent magnet pieces. It is preferable to spread.
Thereby, adhesion of permanent magnet pieces can be performed easily and reliably.
In the method for manufacturing a permanent magnet according to the present invention, it is preferable that the tip portion of each permanent magnet piece in the entering direction has a tapered shape.
Thereby, supply of an adhesive agent becomes easy.

The jig of the present invention is a jig used in the method for producing a permanent magnet of the present invention,
A first holding part that holds the odd-numbered permanent magnet pieces, a second holding part that holds the even-numbered permanent magnet pieces, and a plurality of holding parts held by the first holding part The odd-numbered permanent magnet pieces are interposed between a first spacer that forms a gap through which the even-numbered permanent magnet pieces enter, and a plurality of permanent magnet pieces held by the second holding portion. And a second spacer that forms a gap through which the magnet piece enters.
Thereby, a permanent magnet can be manufactured easily.

In the jig of the present invention, it is preferable that the first holder and the second holder are each made of a magnetic material and hold the permanent magnet piece by magnetic attraction.
Thereby, a permanent magnet piece can be hold | maintained easily and reliably.
In the jig of the present invention, it is preferable that each of the first spacer and the second spacer is made of a nonmagnetic material.
Thereby, removal of the 1st, 2nd spacer from a permanent magnet piece can be performed easily.
The motor of the present invention includes a rotor in which a plurality of the permanent magnets of the present invention are arranged in the circumferential direction.
As a result, the motor becomes highly reliable.

The robot of the present invention includes a base,
An arm connected to the base and rotatable relative to the base;
And a motor according to the present invention for rotating the arm with respect to the base.
Thereby, a highly reliable robot can be obtained.

It is sectional drawing which shows the motor which concerns on 1st Embodiment of this invention. It is a top view of the rotor with which the motor shown in FIG. 1 is provided. FIG. 3 is a perspective view of the rotor shown in FIG. 2. It is a top view which shows the structure of the permanent magnet with which the rotor shown in FIG. 2 is provided. It is a top view which shows the structure of the permanent magnet with which the rotor shown in FIG. 2 is provided. It is a top view which shows the structure of the permanent magnet with which the rotor shown in FIG. 2 is provided. It is a graph which shows an example of the classification by the magnetic flux density of a permanent magnet. It is a top view for demonstrating arrangement | positioning of a permanent magnet. It is a perspective view which shows the jig | tool used for manufacture of a permanent magnet. It is a perspective view which shows the jig | tool used for manufacture of a permanent magnet. It is a perspective view which shows the jig | tool used for manufacture of a permanent magnet. It is a perspective view of a permanent magnet piece. It is a perspective view explaining the usage method of the jig | tool shown in FIG. It is a top view explaining the usage method of the jig | tool shown in FIG. It is a top view explaining the usage method of the jig | tool shown in FIG. It is a top view explaining the usage method of the jig | tool shown in FIG. It is a top view of a rotor with which a motor concerning a 2nd embodiment of the present invention is provided, and a top view of a permanent magnet with which a rotor is provided. It is a perspective view of the jig | tool used for manufacture of the permanent magnet shown in FIG. It is a perspective view which shows the state which the jig | tool shown in FIG. 18 hold | maintained the permanent magnet piece. It is a perspective view which shows the robot (the robot of this invention) to which the motor of this invention is applied. It is a perspective view which shows the robot (the robot of this invention) to which the motor of this invention is applied.

Hereinafter, a permanent magnet, a manufacturing method of a permanent magnet, a jig, a motor, and a robot of the present invention will be described in detail based on preferred embodiments shown in the drawings.
<First Embodiment>
First, a first embodiment of a permanent magnet, a method of manufacturing a permanent magnet, a jig, and a motor according to the present invention will be described.

  1 is a cross-sectional view showing a motor according to a first embodiment of the present invention, FIG. 2 is a plan view of a rotor included in the motor shown in FIG. 1, FIG. 3 is a perspective view of the rotor shown in FIG. FIG. 5 is a plan view showing a configuration of a permanent magnet included in the rotor shown in FIG. 2, FIG. 5 is a plan view showing a configuration of the permanent magnet included in the rotor shown in FIG. 2, and FIG. 6 is a permanent view provided in the rotor shown in FIG. FIG. 7 is a graph showing an example of classification based on the magnetic flux density of the permanent magnet, FIG. 8 is a plan view for explaining the arrangement of the permanent magnets, and FIGS. FIG. 12 is a perspective view of a permanent magnet piece, FIG. 13 is a perspective view for explaining how to use the jig shown in FIGS. 10 to 12, and FIGS. FIG. 16 shows the use of the jig shown in FIGS. The method is a plan view illustrating a.

1. Motor A motor (motor of the present invention) 1 shown in FIG. 1 has a housing 2, a rotating shaft 3, a stator 4, and a rotor 5. The motor 1 is not particularly limited, and examples thereof include a servo motor and a stepping motor.
Bearings 21 and 22 are provided on the upper wall and the bottom wall of the housing 2. The bearings 21 and 22 are rotatably supported by the rotary shaft 3. A rotor 5 is fixed to the rotary shaft 3 in the housing 2. The rotor 5 includes a cylindrical core 51 and a magnet 52 provided on the outer periphery of the core 51. A stator 4 is disposed around the rotor 5. The stator 4 has a cylindrical shape and has a plurality of coils 41 arranged at predetermined intervals in the circumferential direction.

The magnet 52 has a multipolar structure in which a plurality of magnetic poles are formed in the circumferential direction. As shown in FIG. 2, the magnet 52 is composed of a plurality of permanent magnets 53 arranged in the circumferential direction of the core 51. Although the number of permanent magnets 53 is not particularly limited, six cases will be representatively described below for convenience of explanation.
The six permanent magnets 53 have the same shape. Each permanent magnet 53 has different magnetic poles on the inner peripheral side and the outer peripheral side. The six permanent magnets 53 are arranged so that the magnetic poles of the adjacent permanent magnets 53 are opposite to each other. That is, the six permanent magnets 53 are arranged on the outer peripheral side so that the S poles and the N poles are alternately arranged.

  As shown in FIG. 3, each permanent magnet 53 is formed by joining a plurality of permanent magnet pieces 54 side by side in the axial direction of the magnet 52. Although it does not specifically limit as the number of the permanent magnet pieces 54 which each permanent magnet 53 has, It is preferable that it is about 5-10 pieces, and it is more preferable that it is about 5-7 pieces. By setting it as such a number, the outstanding magnetic field characteristic which is mentioned later can be exhibited, keeping the structure and manufacture of the permanent magnet 53 simple.

  Further, an insulating adhesive 55 is interposed between the adjacent permanent magnet pieces 54, and the adjacent permanent magnet pieces 54 are joined by the adhesive 55. Thereby, peeling of the permanent magnet piece 54 is prevented. Moreover, since each adhesive agent 55 functions also as an insulating layer which insulates the adjacent permanent magnet piece 54, generation | occurrence | production of the eddy current during the drive of the motor 1 can be suppressed effectively.

  Although it does not specifically limit as each permanent magnet piece 54, The rare earth permanent magnet which has a high magnetic flux density is used suitably. Examples of rare earth permanent magnets include Nd—Fe—B permanent magnets (neodymium magnets) and Sm—Co permanent magnets (samarium-cobalt magnets). However, the main elements constituting the permanent magnet piece 54 may be replaced with other elements as necessary. For example, a part of Nd may be replaced with Pr, Dr, Tb, etc., and a part of Fe may be replaced with Co. The adhesive 55 is not particularly limited as long as it has insulating properties. For example, various adhesives such as epoxy, silicone, and acrylic can be used.

  Next, the relationship between the magnetic flux density (surface magnetic flux density) and arrangement of the plurality of permanent magnet pieces 54 included in each permanent magnet 53 will be described. In addition, since each permanent magnet 53 is the same structure, below, it demonstrates on behalf of the one permanent magnet 53, and the description about the other permanent magnet 53 is abbreviate | omitted. Hereinafter, the case where the permanent magnet 53 includes five permanent magnet pieces 54, the case where the permanent magnet 53 includes six permanent magnet pieces 54, and the case where the permanent magnet 53 includes seven permanent magnet pieces 54 will be described as a representative.

1.1 When Five Permanent Magnet Pieces 54 In the permanent magnet 53 shown in FIG. 4, the five permanent magnet pieces 54 are aligned in a row and bonded with an adhesive 55. In the case of such a permanent magnet 53, the magnetic flux density B1 (Wb / m ² ) of one first permanent magnet piece 541 located in the center in the arrangement direction (the axial direction of the magnet 52) is a permanent determined by design. It is substantially equal to the set magnetic flux density B (Wb / m ² ) of the magnet 53. Specifically, the magnetic flux density B1 preferably satisfies the relationship of 0.9B ≦ B1 ≦ 1.1B, and more preferably satisfies the relationship of B1 = B. Thereby, as will be described later, the magnetic flux density of the entire permanent magnet 53 can be made substantially equal to the set magnetic flux density B, and the permanent magnet 53 having predetermined magnetic characteristics is obtained.

Further, the magnetic flux density B2 (Wb / m ² ) of the two second permanent magnet pieces 542 located at both ends in the arrangement direction is larger than the set magnetic flux density B and the magnetic flux density B1, respectively. Specifically, the magnetic flux density B2 preferably satisfies the relationship of B <B2 ≦ 2B and B1 <B2 ≦ 2B1. Thereby, sufficient magnetic flux density can be exhibited at both ends of the permanent magnet 53.

The magnetic flux densities B3 of the two third permanent magnet pieces 543 sandwiched between the first permanent magnet pieces 541 and the second permanent magnet pieces 542 are smaller than the set magnetic flux density B and the magnetic flux density B1, respectively. Specifically, the magnetic flux density B3 preferably satisfies the relationship of 0.5B ≦ B3 <B and 0.5B1 ≦ B3 <B1.
As described above, by arranging the first permanent magnet piece 541 having the magnetic flux density B1 substantially equal to the set magnetic flux density B in the central portion of the permanent magnet 53, the magnetic flux density of the entire permanent magnet 53 is substantially equal to the set magnetic flux density B. can do. That is, the permanent magnet 53 has predetermined magnetic characteristics. Further, by arranging the second permanent magnet piece 542 having the magnetic flux density B2 larger than the set magnetic flux density B at both ends, a sufficient magnetic flux density can be maintained at both ends of the permanent magnet 53. In addition, the second permanent magnet piece 542 having a magnetic flux density larger than the set magnetic flux density B and the magnetic flux smaller than the set magnetic flux density B together with the first permanent magnet piece 541 having a magnetic flux density substantially equal to the set magnetic flux density B. By using the third permanent magnet piece 543 having a density, the material can be effectively used, and the manufacturing cost (material cost) can be reduced. This effect will be described in detail in the description of the method for manufacturing the permanent magnet 53 described later.

1.2-Six Permanent Magnet Pieces 54 In the permanent magnet 53 shown in FIG. 5, the six permanent magnet pieces 54 are aligned in a row and bonded with an adhesive 55. In the case of such a permanent magnet 53, the magnetic flux density B1 (Wb / m ² ) of the ^two first permanent magnet pieces 541 located side by side in the central portion in the arrangement direction is determined by the design. Is substantially equal to the set magnetic flux density B (Wb / m ² ). Specifically, the magnetic flux density B1 preferably satisfies the relationship 0.9B ≦ B1 ≦ 1.1B, and more preferably B1 = B.

Further, the magnetic flux density B2 (Wb / m ² ) of the two second permanent magnet pieces 542 located at both ends in the arrangement direction is larger than the set magnetic flux density B and the magnetic flux density B1, respectively. Specifically, the magnetic flux density B2 preferably satisfies the relationship of B <B2 ≦ 2B and B1 <B2 ≦ 2B1.
Further, the magnetic flux densities B3 of the two third permanent magnet pieces 543 sandwiched between the first permanent magnet pieces 541 and the second permanent magnet pieces 542 are smaller than the set magnetic flux density B and the magnetic flux density B1, respectively. Specifically, the magnetic flux density B3 preferably satisfies the relationship of 0.5B ≦ B3 <B and 0.5B1 ≦ B3 <B1. Even with such a configuration, the same effect as in the case where the number of the permanent magnet pieces 54 described above is five can be exhibited.

1.3 When Seven Permanent Magnet Pieces In the permanent magnet 53 shown in FIG. 6, seven permanent magnet pieces 54 are arranged in a line and bonded with an adhesive 55. In the case of such a permanent magnet 53, the magnetic flux density B1 (Wb / m ² ) of one first permanent magnet piece 541 located at the center in the arrangement direction is a set magnetic flux density B of the permanent magnet 53 determined by design. It is almost equal to (Wb / m ² ). Specifically, the magnetic flux density B1 preferably satisfies the relationship 0.9B ≦ B1 ≦ 1.1B, and more preferably B1 = B.

Further, the magnetic flux density B2 (Wb / m ² ) of the two second permanent magnet pieces 542 located at both ends in the arrangement direction is larger than the set magnetic flux density B and the magnetic flux density B1, respectively. Specifically, the magnetic flux density B2 preferably satisfies the relationship of B <B2 ≦ 2B and B1 <B2 ≦ 2B1.
Further, the magnetic flux density of the four permanent magnet pieces 54 sandwiched between the first permanent magnet piece 541 and the second permanent magnet piece 542, specifically, the first permanent magnet piece 541 side (center side) is located. The magnetic flux density B3 of the two third permanent magnet pieces 543 and the magnetic flux density B4 of the two fourth permanent magnet pieces 544 located on the second permanent magnet piece 542 side (end side) are respectively set magnetic flux density B and magnetic flux. It is smaller than the density B1. Specifically, the magnetic flux densities B3 and B4 preferably satisfy the relationships of 0.5B ≦ B3, B4 <B, 0.5B1 ≦ B3, and B4 <B1. The magnetic flux densities B3 and B4 may be the same or different. If they are different, either B3 or B4 may be larger. Even with such a configuration, the same effect as in the case where the number of the permanent magnet pieces 54 described above is five can be exhibited.
The relationship between the arrangement of the permanent magnet pieces 54 and the magnetic flux density has been described above.

2. Method for manufacturing permanent magnet 53 (method for manufacturing permanent magnet of the present invention)
The manufacturing method of the permanent magnet 53 includes a first step for obtaining a large number of permanent magnet pieces 54, a second step (preparation step) for classifying the obtained permanent magnet pieces 54 according to magnetic flux density, and a classified permanent magnet piece. And a third process (joining process) for selecting, arranging, and joining a plurality of 54 according to the design. In the following, the permanent magnet 53 having five permanent magnet pieces 54 will be described as a representative.

2.1-First Step First, raw materials for the permanent magnet piece 54 are prepared. As a raw material, for example, in the case of a neodymium magnet, Nd: 21 to 30 wt%, Dy: 0.01 to 10 wt%, B: 1 to 2 wt%, and Fe: 60 to 70 wt% can be used. Next, the above materials are dissolved (high frequency induction melting) in vacuum or argon gas. Next, the raw material is pulverized (coarse pulverized, finely pulverized) to obtain a powder having a particle size of about 3 to 5 μm. Next, after the powdery raw material is compression-molded in a magnetic field, sintering and heat treatment (aging treatment) are performed. Next, after performing secondary processing (for example, cutting, polishing, etc.) as necessary, surface treatment (for example, electrodeposition coating, Ni plating, etc.) is performed. And after inspecting a size, the presence or absence of a breakage, etc. as needed, a sintered compact is magnetized so that it may become setting magnetic flux density B. Thereby, the permanent magnet piece 54 is obtained. In this way, a large number of permanent magnet pieces 54 are prepared.
In addition, about the manufacturing method (a raw material is included) of the permanent magnet piece 54, it is not limited to said method, A process may be omitted or added as needed.

2.2-Second Step Here, the permanent magnet piece 54 is manufactured in the first step so as to have a set magnetic flux density B. The magnetic flux density may deviate from the set magnetic flux density B. Therefore, in this process, the permanent magnet pieces 54 are classified based on the magnitude of the magnetic flux density. The classification method is not particularly limited. For example, as shown in FIG. 7, the classification is divided into seven classes A to G in descending order of the magnetic flux density, and the set magnetic flux density B is included in the central class D. . Although it does not specifically limit as a numerical range of class A-G, For example, it can set as follows.

Class G: 0.3B or more and less than 0.5B Class F: 0.5B or more and less than 0.7B Class E: 0.7B or more and less than 0.9B Class D: 0.9B or more 1B or less ・ Class C: over 1.1B, 1.3B or less ・ Class B: over 1.3B, 1.5B or less ・ Class A: over 1.5B, 1.7B or less

2.3-Third Step First, five permanent magnet pieces 54 are selected from the many permanent magnet pieces 54 classified in the second step. Among the five permanent magnet pieces 54, one is a class D permanent magnet piece 54, which is a magnet piece that becomes the first permanent magnet piece 541 located in the center of the permanent magnet 53. Further, two are class A permanent magnet pieces 54, which are second permanent magnet pieces 542 located at both ends of the permanent magnet 53. Further, two are class G permanent magnet pieces 54, which are magnet pieces serving as third permanent magnet pieces 543 located between the first and second permanent magnet pieces 541 and 542. By arranging these five permanent magnet pieces 54 in a line as shown in FIG. 8A and joining them with an adhesive 55, a permanent magnet 53 having a magnetic flux density substantially equal to the set magnetic flux density B as a whole is obtained.

  Other combinations include the following combinations. Among the five permanent magnet pieces 54, one is a class D permanent magnet piece 54, which is a magnet piece that becomes the first permanent magnet piece 541 located in the center of the permanent magnet 53. Further, two are class B permanent magnet pieces 54, which are second permanent magnet pieces 542 located at both ends of the permanent magnet 53. Further, two are class F permanent magnet pieces 54, which are magnet pieces serving as third permanent magnet pieces 543 located between the first and second permanent magnet pieces 541 and 542. By arranging these five permanent magnet pieces 54 in a line as shown in FIG. 8B and joining them with an adhesive 55, a permanent magnet 53 having a magnetic flux density substantially equal to the set magnetic flux density B as a whole is obtained.

  Other combinations include the following combinations. Among the five permanent magnet pieces 54, one is a class D permanent magnet piece 54, which is a magnet piece that becomes the first permanent magnet piece 541 located in the center of the permanent magnet 53. Two are class C permanent magnet pieces 54, which are second permanent magnet pieces 542 located at both ends of the permanent magnet 53. In addition, two are class E permanent magnet pieces 54, which are magnet pieces that become third permanent magnet pieces 543 located between the first and second permanent magnet pieces 541 and 542. By aligning these five permanent magnet pieces 54 in a line as shown in FIG. 8C and joining them with an adhesive 55, a permanent magnet 53 having a magnetic flux density substantially equal to the set magnetic flux density B as a whole is obtained.

  In this way, by selecting and combining the classified permanent magnet pieces 54, the magnetic flux density deviates relatively from the set magnetic flux density B, that is, the permanent magnet pieces 54 that could not be used conventionally, that is, Since the permanent magnet pieces 54 of classes A to C and E to G can be used, almost all the permanent magnet pieces 54 can be used for manufacturing the permanent magnet 53. Therefore, the material can be effectively used, and the manufacturing cost of the permanent magnet 53 can be reduced.

3. Jig (Jig of the present invention)
As described above, in the third step, the plurality of permanent magnet pieces 54 are joined using the adhesive 55. However, since the adjacent permanent magnet pieces 54 repel each other, bonding may be difficult. Therefore, by using the following jig 9 (the jig of the present invention), the permanent magnet piece 54 can be easily and accurately joined.

As shown in FIGS. 9 to 11, the jig 9 has a base 91, a pair of slide plates 92 and 93, a pair of spacers 94 and 95, and a fixture 96.
As shown in FIG. 9, the pedestal 91 includes a plate-shaped main body 911 having a flat upper surface and a guide 912 that protrudes from the upper surface of the main body 911. The guide 912 has a guide surface 912a that is orthogonal to the upper surface of the main body 911 and is a flat surface. The slide plates 92 and 93 and the spacers 94 and 95 can move linearly on the upper surface of the main body 911 by moving along the guide surface 912a.

  The pedestal 91 is preferably made of a soft magnetic material such as iron, an iron-containing alloy (silicon iron, permalloy, sendust), soft ferrite (ceramics containing iron oxide as a main component). Since the permanent magnet piece 54 is magnetically attracted (adhered) to the pedestal 91 by being composed of a soft magnetic material, it is possible to prevent unintentional misalignment and detachment of the permanent magnet piece 54 during work described later. Work can be done easily and accurately.

  Note that a non-adhesive protective film for preventing adhesion between the adhesive 55 and the main body 911 is preferably formed on the upper surface of the main body 911. The protective film preferably further has a function of improving the slidability of the slide plates 92 and 93 (that is, reducing the friction coefficient). Thereby, the operation | work mentioned later can be performed more smoothly. The constituent material of the protective film is not particularly limited as long as the above-described function can be exhibited. For example, a fluororesin such as Teflon (“Teflon” is a registered trademark) can be used.

  The slide plate (first holding tool) 92 is made of a soft magnetic material like the pedestal 91. As shown in FIG. 10, the slide plate 92 has a substantially rectangular plate shape in plan view, and on its side surface, a slide surface 921 that slides with the guide surface 912 a and a plurality of permanent magnet pieces 54. And a holding surface 922 for holding the film by magnetic adsorption. In the present embodiment, the holding surface 922 is inclined with respect to the main surface, but the posture (direction) of the holding surface 922 may be appropriately set depending on the shape of the permanent magnet piece 54 to be held. Since the slide plate (second holder) 93 has the same configuration as the slide plate 92, the description thereof is omitted (see FIG. 11).

  The spacer (first spacer) 94 is a member for arranging a plurality of permanent magnet pieces 54 held on the slide plate 92 at a predetermined interval. As shown in FIG. 10, the spacer 94 includes a main body 941 and a plurality of protrusions 942 protruding from the main body 941. The main body 941 has a plate shape having a substantially rectangular shape in plan view, and on its side surface, a sliding surface 941a that slides with the guide surface 912a, and a contact surface 941b that contacts the holding surface 922 of the slide plate 92, It is included. Further, the upper surface of the main body 941 in FIG. 10 is curved corresponding to the shape of the permanent magnet piece 54.

  The plurality of protrusions 942 are formed along the arrangement direction of the permanent magnet pieces 54. The width of each protrusion 942 (length in the arrangement direction of the protrusion 942) W1 and the distance D between a pair of adjacent protrusions 942 are designed to be equal to the width W2 of the permanent magnet piece 54 (see FIG. 12). Further, the protrusion 942 positioned closest to the sliding surface 941a is spaced from the sliding surface 941a by a distance equal to the width W2 of the permanent magnet piece 54. In such a spacer 94, by disposing the permanent magnet piece 54 in a recess 943 (a recess which is open to the sliding surface 941a on the most sliding surface 941a side) between a pair of adjacent protrusions 942. The permanent magnet pieces 54 can be arranged at a predetermined interval.

  On the other hand, the spacer (second spacer) 95 is a member for arranging a plurality of permanent magnet pieces 54 held on the slide plate 93 at a predetermined interval. As shown in FIG. 11, the spacer 95 has a main body 951 and a plurality of protrusions 952 protruding from the main body 951. Further, the main body 951 has a plate shape having a substantially rectangular shape in plan view, and on its side surface, a sliding surface 951 a that slides with the guide surface 912 a and a contact surface that contacts the holding surface 932 of the slide plate 93. 951b. Further, the upper surface of the main body 951 in FIG. 11 is curved corresponding to the shape of the permanent magnet piece 54.

  The plurality of protrusions 952 are formed along the arrangement direction of the permanent magnet pieces 54. Both the width W1 of each protrusion 952 and the separation distance D between a pair of adjacent protrusions 952 are designed to be equal to the width W2 of the permanent magnet piece 54. In such a spacer 95, the permanent magnet pieces 54 can be arranged at a predetermined interval by arranging the permanent magnet pieces 54 in the recesses 953 sandwiched between a pair of adjacent protrusions 952.

The spacers 94 and 95 are preferably made of a nonmagnetic material such as a metal material such as copper, aluminum or brass, or an alloy such as stainless steel. By using a non-magnetic material, magnetic adsorption of the permanent magnet piece 54 to the spacer 94 is prevented, so that the spacer 94 can be easily detached.
As will be described later, the fixture 96 is a member for preventing displacement due to repulsion of the permanent magnet pieces 54 when the spacers 94 and 95 are removed. Such a fixture 96 can be fixed to the base 91 by means not shown. Note that the fixture 96 is preferably made of a nonmagnetic material like the spacers 94 and 95.

  The configuration of the jig 9 has been described above. Next, a method for manufacturing the permanent magnet 53 using the jig 9 will be described. Here, when using the jig | tool 9, as shown in FIG. 12, it is preferable that the extending direction both ends 54a of each permanent magnet piece 54 are chamfered. In other words, it is preferable that both end portions 54a of each permanent magnet piece 54 have a tapered shape whose width gradually decreases toward the end. Thereby, as described later, the adhesive 55 can be easily applied.

  First, as shown in FIG. 13, the second permanent magnet piece 542, the first permanent magnet piece 541, and the second permanent magnet piece 542 (that is, the permanent magnet pieces positioned odd-numbered from one end in the arrangement direction of the permanent magnet pieces 54). 54) are arranged in this order from the sliding surface 941a to the concave portion 943 of the spacer 94, and these three permanent magnet pieces 54 are magnetically attracted to the holding surface 922 of the slide plate 92. On the other hand, the two third permanent magnet pieces 543 and 543 (that is, the permanent magnet pieces 54 positioned evenly from one end in the arrangement direction of the permanent magnet pieces 54) are arranged in the concave portion 953 of the spacer 95 from the sliding surface 951a side. At the same time, these two permanent magnet pieces 54 are magnetically attracted to the holding surface 932 of the slide plate 93.

  Next, as shown in FIG. 14A, the slide plate 92 and the spacer 94 holding the three permanent magnet pieces 54 are brought into contact with the guide surface 912a so that the slide surfaces 921 and 941a are in contact with the upper surface of the base 91. To place. At this time, the main body 941 of the spacer 94 is positioned above the permanent magnet piece 54. On the other hand, the slide plate 93 and the spacer 95 holding the two permanent magnet pieces 54 are arranged on the upper surface of the pedestal 91 with their sliding surfaces 931 and 951a in contact with the guide surface 912a. At this time, the main body 951 of the spacer 95 is positioned above the permanent magnet piece 54.

  Next, as shown in FIG. 14B, at least one of the slide plates 92 and 93 is linearly moved along the guide surface 912a toward the other side. As a result, the third permanent magnet piece 543 enters between the first permanent magnet piece 541 and each second permanent magnet piece 542. This movement is performed until the first and second permanent magnet pieces 541 and 542 come into contact with the spacer 95 and the third permanent magnet piece 543 comes into contact with the spacer 94. Here, as described above, since both end portions of each permanent magnet piece 54 are tapered, in this state, there is a gap between the end portion of the predetermined permanent magnet piece 54 and the adjacent permanent magnet piece 54. S is formed.

  Next, as shown in FIG. 15A, an adhesive 55 is supplied to each gap S. In this state, the length L ′ of the portion where the adjacent permanent magnet pieces 54 overlap is preferably less than or equal to ½ of the total length L ″ of the permanent magnet pieces 54 and is almost ½. Thereby, as will be described later, the adhesive 55 can be spread over almost the entire region in the extending direction of the permanent magnet piece 54.

  Next, as shown in FIG. 15B, the fixing tool 96 is fixed to the pedestal 91, and all the permanent magnet pieces 54 are sandwiched between the guide 912 and the fixing tool 96. Next, as shown in FIG. 16A, the spacers 94 and 95 are removed from the permanent magnet piece 54. As described above, since the spacers 94 and 95 are made of a nonmagnetic material, this step can be easily performed. In addition, since all the permanent magnet pieces 54 are clamped by the guide 912 and the fixture 96, the displacement of the permanent magnet pieces 54 due to the repulsive force when the spacers 94 and 95 are removed can be suitably prevented.

Next, as shown in FIG. 16B, at least one of the slide plates 92 and 93 is moved linearly along the guide 912 toward the other, and the first and second permanent magnet pieces 541 and 542 are moved. The front end is brought into contact with the holding surface 932 of the slide plate 93 and the front end of the third permanent magnet piece 543 is brought into contact with the holding surface 922 of the slide plate 92. Thereby, all the permanent magnet pieces 54 are arranged in a line. Further, during this movement, the adjacent permanent magnet pieces 54 slide, whereby the adhesive 55 is extended, and the adhesive 55 extends and spreads over a wide area between the adjacent permanent magnet pieces 54. Thereby, the adjacent permanent magnet pieces 54 can be bonded with a stronger bonding strength (a sufficient bonding strength that does not lose the repulsive force). In particular, as described above, by setting L ′ to be equal to or less than ½ of L ″, the adhesive 55 can be spread and spread over almost the entire area in the extending direction of the permanent magnet piece 54, and more firmly bonded. Can do.
Thus, the permanent magnet 53 is obtained. Thus, by using the jig 9, the permanent magnet 53 can be formed easily and accurately.

Second Embodiment
Next, a permanent magnet, a method for manufacturing the permanent magnet, a jig, and a motor according to a second embodiment of the present invention will be described.
17 is a plan view of a rotor provided in a motor according to a second embodiment of the present invention, and a plan view of a permanent magnet provided in the rotor. FIG. 18 is a perspective view of a jig used for manufacturing the permanent magnet shown in FIG. FIG. 19 is a perspective view showing a state in which the jig shown in FIG. 18 holds a permanent magnet piece.

  As shown in FIG. 17A, the magnet 52 of the rotor 5 of the motor 1 of the present embodiment is configured by four permanent magnets 53 provided in the core 51. Each permanent magnet 53 has a plate shape and is arranged in the circumferential direction of the core 51 with an interval. Further, each permanent magnet 53 is magnetized in the thickness direction (the radial direction of the core 51), and one set of permanent magnets 53b opposed via the rotating shaft 3 has an S pole on the outside and an N pole on the inside. The other set of permanent magnets 53a is arranged such that the outer side is an N pole and the inner side is an S pole. Further, as shown in FIG. 17B, each permanent magnet 53 is configured by arranging a plurality of permanent magnet pieces 54 in the axial direction of the rotating shaft 3 and joining them with an adhesive 55. Even with this configuration, the same effects as those of the first embodiment described above can be obtained.

The shape of the permanent magnet 53 of the present embodiment is different from the shape of the permanent magnet 53 of the first embodiment described above. Therefore, the shapes of the slide plates 92 and 93 and the spacers 94 and 95 of the jig 9 (mainly the inclination angles of the holding surfaces 922 and 933 and the shapes of the main bodies 951 and 961) are changed as shown in FIG. . FIG. 19 shows a state where the permanent magnet pieces are held on the slide plates 92 and 93. In addition, since the usage method of the jig | tool 9 is the same as that of 1st Embodiment mentioned above, the description is abbreviate | omitted.
According to the second embodiment as described above, the same effects as those of the first embodiment described above can be obtained.

≪Robot≫
Next, a robot (the robot of the present invention) to which the motor 1 described above is applied will be described.
A robot 7 shown in FIG. 20 is a horizontal articulated robot. Such a robot 7 has a base 71, a first arm 72, a second arm 73, a work head 74, and an end effector 75.

The base 71 is fixed to a floor surface (not shown) with bolts or the like, for example. A first arm 72 is connected to the upper end of the base 71. The first arm 72 is rotatable around a rotation axis along the vertical direction with respect to the base 71. In the base 71, a motor 1 (1A) for rotating the first arm 72 is installed.
A second arm 73 is connected to the tip of the first arm 72. The second arm 73 is rotatable about a rotation axis along the vertical direction with respect to the first arm 72. A second motor 1 (1B) that rotates the second arm 73 is installed in the second arm 73.

  A work head 74 is disposed at the tip of the second arm 73. The working head 74 includes a spline nut 741 and a ball screw nut 742 that are coaxially disposed at the tip of the second arm 73, and a spline shaft 743 inserted through the spline nut 741 and the ball screw nut 742. The spline shaft 743 can rotate about its axis with respect to the second arm 73 and can move (elevate) in the vertical direction.

  In the second arm 73, a motor 1 (1C) and a motor 1 (1D) are arranged. The driving force of the motor 1C is transmitted to the spline nut 741 by a driving force transmission mechanism (not shown). When the spline nut 741 rotates in the forward and reverse directions, the spline shaft 743 rotates in the forward and reverse directions around the rotation axis along the vertical direction. On the other hand, the driving force of the motor 1D is transmitted to the ball screw nut 742 by a driving force transmission mechanism (not shown), and when the ball screw nut 742 rotates forward and backward, the spline shaft 743 moves up and down.

An end effector 75 is connected to the tip (lower end) of the spline shaft 743. The end effector 75 is not particularly limited, and examples thereof include one that grips the object to be conveyed and one that processes the object to be processed.
The robot 8 shown in FIG. 21 is a vertical articulated (six axis) robot. Such a robot 8 includes a base 81, four arms 82, 83, 84, 85, and a wrist 86, which are sequentially connected.

The base 81 is fixed to a floor surface (not shown) with bolts or the like, for example. The arm 82 is connected to the upper end portion of the base 81 in a posture inclined with respect to the horizontal direction, and the arm 82 can rotate about a rotation axis along the vertical direction with respect to the base 81. It has become. In addition, a motor 1 (1E) for rotating the arm 82 is installed in the base 81.
An arm 83 is connected to the distal end portion of the arm 82, and the arm 83 is rotatable about a rotation axis along the horizontal direction with respect to the arm 82. In the arm 83, a motor 1 (1F) that rotates the arm 83 with respect to the arm 82 is provided.

An arm 84 is connected to the tip of the arm 83, and the arm 84 can rotate about a rotation axis along the horizontal direction with respect to the arm 83. Further, in the arm 84, a motor 1 (1G) that rotates the arm 84 with respect to the arm 83 is installed.
An arm 85 is connected to the distal end portion of the arm 84, and the arm 85 can be rotated around a rotation axis along the central axis of the arm 84 with respect to the arm 84. Further, in the arm 85, a motor 1 (1H) that rotates the arm 85 with respect to the arm 84 is installed.

  A wrist 86 is connected to the tip of the arm 85. The wrist 86 includes a ring-shaped support ring 861 connected to the arm 85, and a cylindrical wrist body 862 supported at the tip of the support ring 861. The front end surface of the wrist body 862 is a flat surface, and is, for example, a mounting surface on which a manipulator that holds a precision device such as a wristwatch is mounted.

The support ring 861 can be rotated around a rotation axis along the horizontal direction with respect to the arm 85. The wrist main body 862 is rotatable about a rotation axis along the central axis of the wrist main body 862 with respect to the support ring 861. In the arm 85, a motor 1 (1I) for rotating the support ring 861 relative to the arm 85 and a motor 1 (1J) for rotating the wrist body 862 relative to the support ring 861 are disposed. Yes. The driving forces of the motors 1I and 1J are transmitted to the support ring 861 and the wrist body 862 by a driving force transmission mechanism (not shown), respectively.
As mentioned above, although the permanent magnet, the manufacturing method of the permanent magnet, the jig, the motor, and the robot have been described based on the illustrated embodiment, the present invention is not limited to this, and the configuration of each part is the same. Any structure having a function can be substituted. In addition, any other component may be added to the present invention.

  DESCRIPTION OF SYMBOLS 1, 1A-1J ... Motor 2 ... Housing 21, 22 ... Bearing 3 ... Rotating shaft 4 ... Stator 41 ... Coil 5 ... Rotor 51 ... Core 52 ... Magnet 53 ... Permanent magnet 54, 541-544 ... Permanent magnet piece 54a ... End 55 ... Adhesive 7 ... Robot 71 ... Base 72 ... Arm 73 ... Arm 74 ... Working head 741 ... Spline nut 742 ... Ball screw nut 743 ... Spline shaft 75 ... End effector 8 ... Robot 81 ... Base 82-85 ... Arm 86 ... List 861 ... Support ring 862 ... Wrist body 9 ... Jig 91 ... Pedestal 911 ... Main body 912 ... Guide 912a ... Guide surface 92 ... Slide plate 921 ... Sliding surface 922 ... Holding surface 93 ... Slide plate 931 ... Sliding Surface 932 ... Holding surface 94 ... Spacer 94 ... Main body 941a ... Sliding surface 941b ... Abutting surface 942 ... Protrusion 943 ... Recessed portion 95 ... Spacer 951 ... Main body 951a ... Sliding surface 951b ... Abutting surface 952 ... Protrusion 953 ... Recessed portion 96 ... Fixing tool B ... Set magnetic flux density B1 to B4 ... Magnetic flux density D ... Separation distance S ... Gap W1, W2 ... Width

Claims (13)

A plurality of permanent magnet pieces arranged in a predetermined direction and aligned with magnetic poles,
The plurality of permanent magnet pieces are at least a first permanent magnet piece and a pair of second magnets positioned on both sides of the first permanent magnet piece in the predetermined direction and having a larger magnetic flux density than the first permanent magnet piece. A permanent magnet piece, and a pair of third permanent magnet pieces located between the first permanent magnet piece and each of the second permanent magnet pieces and having a magnetic flux density smaller than that of the first permanent magnet piece. A permanent magnet characterized by that.   The permanent magnet according to claim 1, wherein the second permanent magnet pieces are arranged at both ends in the predetermined direction, respectively. When the set magnetic flux density of the permanent magnet is B (Wb / m ² ),
The permanent magnet according to claim 1 or 2, wherein a permanent magnet piece having a magnetic flux density of 0.9B or more and 1.1B or less is used as the first permanent magnet piece.   The said permanent magnet piece adjacent is the permanent magnet as described in any one of Claim 1 thru | or 3 joined by the insulating adhesive agent. A method of manufacturing a permanent magnet comprising a plurality of permanent magnet pieces arranged in a predetermined direction and aligned with magnetic poles,
As the plurality of permanent magnet pieces, a first permanent magnet piece, a second permanent magnet piece having a larger magnetic flux density than the first permanent magnet piece, and a third having a smaller magnetic flux density than the first permanent magnet piece. A preparation step of preparing a permanent magnet piece;
At least a pair of second permanent magnet pieces are located on both sides of the first permanent magnet piece, and the third permanent magnet piece is located between the first permanent magnet piece and each of the second permanent magnet pieces. And a joining step of arranging the plurality of permanent magnet pieces and joining the adjacent permanent magnet pieces together. In the joining step, among the plurality of permanent magnet pieces, a plurality of permanent magnet pieces that are odd-numbered from one end in the predetermined direction are held at intervals in the predetermined direction, and a plurality of even-numbered permanent magnet pieces are disposed. Holding the permanent magnet pieces spaced apart in the predetermined direction;
The even-numbered permanent magnet piece is inserted between a pair of adjacent odd-numbered permanent magnet pieces, and the odd-numbered permanent magnet piece is inserted between a pair of adjacent even-numbered permanent magnet pieces. The method for manufacturing a permanent magnet according to claim 5, wherein the plurality of permanent magnet pieces are arranged by being allowed to enter.   The permanent magnet according to claim 6, wherein in the joining step, an adhesive is supplied to a side surface of each permanent magnet piece in the middle of the approach, and the adhesive is stretched and spread by sliding between adjacent permanent magnet pieces. Production method.   The method of manufacturing a permanent magnet piece according to claim 7, wherein a tip end portion of each permanent magnet piece in a direction of entry has a tapered shape. A jig used in the method of manufacturing a permanent magnet according to any one of claims 6 to 8,
A first holding part that holds the odd-numbered permanent magnet pieces, a second holding part that holds the even-numbered permanent magnet pieces, and a plurality of holding parts held by the first holding part The odd-numbered permanent magnet pieces are interposed between a first spacer that forms a gap through which the even-numbered permanent magnet pieces enter, and a plurality of permanent magnet pieces held by the second holding portion. And a second spacer that forms a gap through which the magnet piece enters.   The jig according to claim 9, wherein each of the first holder and the second holder is made of a magnetic material, and holds the permanent magnet piece by magnetic attraction.   The jig according to claim 9 or 10, wherein each of the first spacer and the second spacer is made of a nonmagnetic material.   A motor comprising a rotor in which a plurality of permanent magnets according to any one of claims 1 to 4 are arranged in a circumferential direction. The base,
An arm connected to the base and rotatable relative to the base;
A robot comprising: the motor according to claim 12, wherein the arm is rotated with respect to the base.

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