JP2013138592A - Linear motor including magnet member and manufacturing method of magnet member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear motor including a magnet member which is easily manufactured without needing the adhesion of component members using an adhesive, reduces the used amount of permanent magnets without performing highly accurate processing to the permanent magnets and pole shoes, and reduces the manufacturing costs while maintaining the magnetic flux density, and to provide a manufacturing method of the magnet member.SOLUTION: In a linear motor including a magnet member and a coil which moves relative to the magnet member, the magnet member includes a compact formed by arranging magnets along a longitudinal direction and casting the magnets with a rare earth bond magnet.

Description

  The present invention relates to a linear motor including a magnet member and a method of manufacturing the magnet member, and more specifically, a linear motor including a magnet member in which a permanent magnet and a pole shoe are laminated on each other in the axial direction, and the magnet member, respectively. It relates to the manufacturing method.

  2. Description of the Related Art Conventionally, linear motors are known in which a stator and a mover of a motor are linearly arranged to convert electric energy into thrust for linear motion. This linear motor includes, for example, a magnet member having magnets arranged on a flat back yoke and an armature disposed opposite to the magnet member with a predetermined gap therebetween, or a permanent magnet on a stainless steel pipe or the like. And a magnet member formed by laminating a plurality of pole shoes, and a housing in which a cylindrical coil is combined with a center so as to be loosely fitted to the magnet member.

  In such a linear motor, a magnetic field is generated by passing an electric current through the coil, and a thrust that linearly moves the magnet member is generated by the interaction between the magnetic field of the coil and the magnetic field of the permanent magnet.

International Publication No. 2007/046161

  However, according to the conventional magnet member and the linear motor incorporating the same, the permanent magnet and the pole shoe are fixed to each other in the back yoke and the stainless steel pipe, so that the adhesive is solidified when the magnet member is manufactured. In addition, there is a problem that it is necessary to fix the permanent magnet with a jig or the like, and the manufacturing time cannot be shortened.

  In addition, it is necessary to process the permanent magnet and pole shoe with high precision in order to suppress the gap between the permanent magnet and pole shoe and the stainless steel pipe, the overall length of the magnet member, and to set the magnetic flux density to an ideal state. There is a problem that it is difficult to control the manufacturing cost.

  In addition, since permanent magnets are made of neodymium sintered magnets, it is difficult to control production costs due to the rising price of neodymium sintered magnets. When it is downsized or formed into a cylindrical shape whose inside is processed into a cavity, there is a problem that the magnetic flux density is lowered and the performance of the linear motor cannot be maintained.

  The present invention has been made in order to solve the above-described problems, and can be easily manufactured without using an adhesive to bond the constituent members, and the permanent magnet and the pole shoe are processed with high accuracy. It aims at providing the linear motor provided with the magnetic member which can suppress the usage-amount of a permanent magnet, and can suppress manufacturing cost, maintaining a magnetic flux density, and the manufacturing method of this magnet member.

  The linear motor according to the present invention is a linear motor including a magnet member and a coil movable relative to the magnet member. The magnet member includes magnets arranged along a longitudinal direction, and the magnet. It is characterized by comprising a molded body formed by casting with a rare earth bonded magnet.

  The magnet member manufacturing method according to the present invention includes an assembling step of arranging magnets along a longitudinal direction, a molding step of casting a side surface of the magnet with a rare earth bonded magnet to obtain a molded body, and the molded body. And a magnetizing step for magnetizing.

  According to the present invention, since the magnet is cast with the rare earth bonded magnet, there is no need to bond the magnet with an adhesive, and the magnet member is cast with the rare earth bonded magnet to maintain the magnetic flux density. Since high-precision processing can be performed without polishing, the manufacturing time can be shortened and the manufacturing cost can be reduced.

The perspective view of the actuator using the magnet member concerning a 1st embodiment of the present invention. The front view of the actuator using the magnet member concerning a 1st embodiment of the present invention. Sectional drawing which shows the linear motor using the magnet member which concerns on the 1st Embodiment of this invention. The partial cross section perspective view which shows the magnet member which concerns on the 1st Embodiment of this invention. The perspective view which shows the modification of the magnet member which concerns on the 1st Embodiment of this invention. The front view of the magnet used for the modification of the magnet member which concerns on the 1st Embodiment of this invention. The layout drawing of the magnet used for the modification of the magnet member which concerns on the 1st Embodiment of this invention. Sectional drawing which shows the linear motor using the magnet member which concerns on the 2nd Embodiment of this invention. The perspective view which shows the molded object of the magnet member which concerns on the 2nd Embodiment of this invention. The figure which shows the internal structure of the molded object of the magnet member which concerns on the 2nd Embodiment of this invention. The exploded view which shows the structure of the molded object of the magnet member which concerns on the 2nd Embodiment of this invention. Sectional drawing which shows the structure of the magnet member which concerns on the 2nd Embodiment of this invention. The graph which shows the experimental result which compared the magnetic flux density of the magnet member which concerns on the 1st Embodiment of this invention, and the conventional magnet member. The graph which shows the experimental result which compared the cogging of the magnet member which concerns on the 1st Embodiment of this invention, and the conventional magnet member. The graph which shows the fluctuation | variation of the motor induced voltage of the modification of the magnet member which concerns on the 1st Embodiment of this invention. The graph which shows the fluctuation | variation of the motor induced voltage of the magnet member which concerns on the 1st Embodiment of this invention. The graph which shows the experimental result which compared the magnetic flux density of the magnet member which concerns on the 2nd Embodiment of this invention, and the conventional magnet member.

  Hereinafter, an embodiment of a magnet member according to the present invention will be described with reference to the drawings. The following embodiments do not limit the invention according to each claim, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. .

[First Embodiment]
FIG. 1 shows an actuator 1 incorporating a linear motor according to the present embodiment. The configuration of the actuator 1 will be described with reference to FIGS. Here, FIG. 1 is a perspective view of the actuator 1 incorporating the magnet member according to the first embodiment. FIG. 2 is a front view of the actuator 1 using the magnet member according to the first embodiment.

  The magnet member 10 incorporated in the actuator 1 has an armature 40 relative to the magnet member 10 having a plurality of plate-like drive magnets 11, 11 having N or S poles magnetized on the surface thereof. It is a flat type linear motor that moves linearly. The armature 40 faces the magnet member 10 through the gap g.

  A plurality of plate-like magnets 11 are arranged in a line in the axial direction on the elongated base 4. The magnet member 10 having the plurality of magnets 11 serves as a stator of the linear motor 1. The base 4 includes a bottom wall portion 4a and a pair of side wall portions 4b provided on both sides in the width direction of the bottom wall portion 4a. Magnet member 10 is attached to the upper surface of bottom wall 4a.

  The magnet member 10 has N and S poles formed on both end faces in a direction (vertical direction in the drawing) orthogonal to the axial direction. The magnets 11 are arranged in a state where the magnetic poles are reversed with respect to a pair of adjacent magnets 11 so that N poles and S poles are alternately formed on the surfaces of the plurality of magnets 11.

  A linear scale 22 is attached to a part of the side surface of the side wall 4 b of the base 5 so that the slits are aligned along the longitudinal direction of the base 5.

  The track rail 8 of the linear guide 9 is attached to the upper surface of the side wall portion 4 b of the base 4. A moving block 7 is slidably assembled to the track rail 8. A plurality of balls are interposed between the track rail 8 and the moving block 7 so as to be able to roll (not shown). The moving block 7 is provided with a circuit-shaped ball circulation path for circulating a plurality of balls. When the moving block 7 slides with respect to the track rail 8, a plurality of balls roll and move between them, and the plurality of balls circulate in the ball circulation path. Thereby, the smooth linear motion of the moving block 7 is attained.

  A bracket 28 is attached to the side surface of one moving block 7. The optical sensor 23 is attached to the bracket 28 so that the linear scale 22 can be read.

  A table 3 is attached to the upper surface of the moving block 7 of the linear guide 9. The table 3 is made of a nonmagnetic material such as aluminum. A moving object is attached to the table 3. An armature 40 that is a mover of the linear motor 1 is suspended from the lower surface of the table 3. As shown in the front view of FIG. 2, a gap is provided between the magnet 11 and the armature 10. The linear guide 9 maintains the gap g even when the armature 40 moves relative to the magnet 11.

  As shown in FIG. 3, in the armature 40, a coil 41 is wound around a plurality of cores 42 formed in a comb shape made of a magnetic material such as silicon steel. The coil 41 constitutes a set of three-phase coils each composed of U, V, and W phases. In this way, when a three-phase current having a phase difference of 120 ° is applied to the three-phase coil 41, a moving magnetic field that moves in the axial direction of the coil 41 is generated. A linear motion synchronized with the speed of the moving magnetic field is realized by obtaining the thrust.

  In addition, the dummy core 43 is attached to the both ends along the longitudinal direction of the armature 40, and it has the structure which suppresses the fall of the magnetic flux density in an edge part and suppresses cogging.

  As shown in FIG. 4, the magnet member 10 according to the present embodiment is formed in a flat plate shape made of a magnetic material such as iron, and a plurality of magnets 11 on the upper surface of a back yoke 50 extending along the longitudinal direction. , 11 are arranged in a line along the moving direction of the armature 40. The magnets 11 and 11 constitute a molded body 30 whose outer surface is cast with a rare-earth bonded magnet 14. The rare earth bonded magnet refers to a flexible and thermoplastic magnet obtained by kneading rare earth magnetic powder into rubber or plastic. Specifically, a neodymium bonded magnet or a samarium bonded magnet is preferably used. The magnet 11 is a neodymium sintered magnet formed in a flat plate shape, and a conventional magnet is formed so that the size of the molded body 30 cast with the rare earth bonded magnet 14 is the same as that of the conventional magnet. Compared to, it is formed in a small size.

  The rare-earth bonded magnet 14 is magnetized so as to coincide with the magnetic poles of the magnet 11 to be cast. The magnetic poles of the adjacent molded body 30 are reversed on the upper surface of the back yoke 50 so that the N pole and the S pole are reversed. It is arranged.

  The magnet member 10 according to the present embodiment is casted by the rare earth bonded magnet 14 after the arranging step in which the magnets 11 and 11 adjacent to each other are arranged on the upper surface of the back yoke 50 while inverting the N pole and the S pole. The molded body 30 may be magnetized in the magnetizing process through a molding process for obtaining the molded body 30, and the molded body 30 in which the plurality of magnets 11 and 11 are individually cast with the rare earth bonded magnet 14 is arranged on the upper surface of the back yoke 50. Then, it may be magnetized in the magnetizing step.

  According to the magnet member 10 and the method for manufacturing the magnet member 10 according to the present embodiment, the magnet 11 is cast with the rare earth bonded magnet 14, so that the molded body 30 after molding needs to be processed with high accuracy by polishing or the like. The manufacturing cost can be reduced. This is because the molding using the rare-earth bonded magnet 14 is injection-molded using a mold, so that the shape of the molded body 30 after molding can be molded with high accuracy.

  In addition, since the molded body 30 is formed by casting the magnet 11 with the rare earth bonded magnet 14, the magnet 11 can be formed smaller than the conventional magnet, and the amount of expensive neodymium sintered magnet used can be reduced. By reducing it, it is possible to reduce the manufacturing cost.

  The linear motor using the magnet member according to the first embodiment described above has been described for the case where the magnets 11 and 11 are formed in a flat plate shape. However, the shape of the magnet is not limited to a flat plate shape, and may be, for example, a polygonal shape in which each corner portion of the flat plate is chamfered. This modification will be described below.

  FIG. 5 is a perspective view showing a modification of the magnet member according to the first embodiment of the present invention, and FIG. 6 shows a magnet used in the modification of the magnet member according to the first embodiment of the present invention. FIG. 7 is a front view, and FIG. 7 is a layout diagram of magnets used in a modification of the magnet member according to the first embodiment of the present invention.

  As shown in FIG. 5, the magnet member 10 ′ according to the present modification is made of a magnetic material such as iron and is formed in a flat plate shape like the magnet member 10 described above, and extends along the longitudinal direction. A plurality of magnets 11 ′ and 11 ′ are arranged in a line along the moving direction of the armature 40 on the upper surface of the armature 40. Further, the magnets 11 ′ and 11 ′ are casted with a rare earth bonded magnet 14 on the outer surface.

  As shown in FIG. 6, the magnet 11 ′ has a polygonal shape in which chamfers C are formed at corners of a rectangular magnet. Thus, by forming the chamfer C at the corner of the magnet 11 ', the amount of sintered magnet used can be greatly reduced. In addition, when the chamfer C is formed at the corner of the magnet, the motor induced voltage waveform becomes a waveform closer to a sine wave compared to the case where the magnet is formed in a rectangular shape, and the thrust ripple can be reduced. In addition, although the thrust of a motor will fall by forming chamfer C, since the influence which the corner | angular part of a magnet has on an induced voltage is comparatively small, when chamfering C is formed in a corner | angular part, Although the amount of use can be reduced by about 20%, the reduction in motor thrust is suppressed to about 5%, and it has been obtained from the analysis results that the effect of reducing magnets is great.

  Thus, since magnet member 10 'concerning this modification forms chamfering C in the corner of a magnet with little influence on thrust, the amount of sintered magnet used while minimizing thrust drop Therefore, further cost reduction can be achieved. Further, by forming the chamfer C, the motor induced voltage becomes a waveform closer to a sine wave, and the thrust ripple can be reduced.

  Further, as shown in FIG. 7, the magnet 11 ′ having the chamfered C has the same effective lengths and magnet pitches of various magnet members such as (a) to (d) in FIG. It can be realized using ', and in the case of developing a lineup of linear motors, it is possible to reduce costs by using a common magnet.

[Second Embodiment]
The linear motor using the magnet member according to the first embodiment described above has been described for the case where the magnet member is applied to a flat type linear motor. The magnet member according to the second embodiment to be described next will be described in the case where the magnet member is applied to a so-called rod type linear motor. Note that members that are the same as or similar to those in the first embodiment described above are given the same reference numerals, and descriptions thereof are omitted.

  FIG. 8 is a cross-sectional view showing a linear motor using a magnet member according to the second embodiment of the present invention, and FIG. 9 is a perspective view showing a molded body of the magnet member according to the second embodiment of the present invention. FIG. 10 is a diagram showing an internal structure of a molded body of a magnet member according to the second embodiment of the present invention, and FIG. 11 is a diagram of molding of the magnet member according to the second embodiment of the present invention. FIG. 12 is an exploded view showing the structure of the body, and FIG. 12 is a cross-sectional view showing the structure of the magnet member according to the second embodiment of the present invention.

  As shown in FIG. 8, the magnet member according to the present embodiment is configured as a magnet rod 10a used in a rod-type linear motor 1a. The magnet rod 10a is movably inserted in a housing 40a that includes a coil 41a in which the magnet rod 10a is loosely fitted.

  The magnet rod 10a is arranged such that the magnets face each other between the N poles and the S poles, and a pole shoe 13 is interposed between the N poles and the S poles. The coil 41a constitutes a set of three-phase coils composed of U, V, and W phases. As described above, when a three-phase current having a phase difference of 120 ° is applied to the coil 41a configured in three phases, a moving magnetic field that moves in the axial direction of the coil 41a is generated. Therefore, the housing 40a is thrust by the moving magnetic field. Thus, the linear motion of the magnet rod 10a synchronized with the speed of the moving magnetic field is realized.

  Further, the magnet rod 10a according to the present embodiment is provided with a spline mechanism (not shown) that regulates the rotational movement of the magnet rod 10a in the circumferential direction via an end cap 20 attached to the end portion.

  Furthermore, the magnet rod 10a according to the present embodiment is configured by connecting a molded body 30a in which a magnet 11a is cast with a rare earth bonded magnet so as to have pole shoes 13 at both ends. Here, the rare earth bonded magnet refers to a magnet having flexibility and thermoplasticity in which rare earth magnetic powder is kneaded into rubber or plastic.

  As shown in FIGS. 9 and 10, the molded body 30 a is arranged at a cylindrical magnet 11 a having a through hole 12 formed in the axial direction and both ends of the magnet 11 a in the axial direction. Pole shoe 13 having substantially the same cross-sectional shape, and the through hole 12, the side surface of the magnet 11a, and the pole shoe 13 are integrally formed by casting with a rare-earth bonded magnet 14a. Further, a connecting hole 14b for inserting a connecting means 21 described later is formed on the axial end surface of the molded body 30a.

  Next, a specific structure of the molded body 30a will be described with reference to FIG. The magnet 11a is comprised from the division bodies 11b and 11b divided | segmented into the axial direction. The divided bodies 11b and 11b and the pole shoes 13 and 13 are assembled to a cylindrical bobbin 15.

  The divided bodies 11b and 11b are composed of neodymium sintered magnets, and the axial cross-sectional shape is formed in an arc shape so as to form a cylindrical magnet 11a by combining the divided bodies 11b and 11b. .

  The pole shoe 13 is made of a magnetic material such as iron, and is formed in a substantially annular shape having a through hole 16 so that the cross-sectional shape in the axial direction of the magnet 11a is substantially the same. Formed grooves 13 a are formed radially from the center on the end face of the pole shoe 13 in the axial direction.

  The bobbin 15 includes a cylindrical bobbin main body 18 and a pair of flanges 17 and 17 extending in the radial direction. The divided bodies 11b and 11b are combined with the bobbin main body 18 and the pole shoe 13 is attached to the flange 17. Are assembled so as to contact each other. A plurality of forming grooves 15 a are formed at the radial end of the flange 17. The bobbin 15 is composed of a neodibond sintered magnet, and the bobbin main body 18 and the flanges 17 and 17 are integrally configured.

  The molded body 30a is formed by casting a magnet 11a, a bobbin 15 and a pole shoe 13 together with a rare earth bonded magnet 14a. Specifically, a neodymium bonded magnet is preferably used as the rare earth bonded magnet 14a. At this time, since the molding grooves 13a and 15a are formed on the axial end faces of the flange 17 of the bobbin 15 and the pole shoe 13, respectively, the rare earth bonded magnet 14a is filled in the molding grooves 13a and 15a, so that the outside of the magnet 11a. The surface, the inside of the through hole 12, the bobbin 15 and the pole shoe 13 can be integrally formed by casting with a rare-earth bonded magnet 14a.

  The molded body 30a formed in this way is combined as a magnet rod 10a as shown in FIG. The magnet rod 10a is laminated in a cylindrical tube member 19 formed of a nonmagnetic material such as stainless steel so that the N poles and the S poles face each other. Further, end caps 20 are respectively assembled to both ends of the magnet rod 10a by assembling means such as caulking.

  Further, the molded bodies 30 a are assembled with each other via the connecting means 21. The connection means 21 is a pin-shaped member, and the molded bodies 30a are combined with each other by being press-fitted into a connection hole 14b formed at an axial end of the molded body 30a.

  Next, the manufacturing method of the magnet rod 10a which concerns on this embodiment is demonstrated. The magnet rod 10a according to the present embodiment has a magnet 11a formed by combining the divided bodies 11b and 11b so that the magnet rod 10a has a cylindrical shape with the through holes 12 formed in the axial direction, and the magnet 11a and the axial cross-sectional shape thereof. An assembly step of assembling the pole shoe 13 formed in the same manner to the bobbin 15 is provided.

  In the assembling process, the divided bodies 11b and 11b are assembled to the bobbin body 18 from the radial direction, and the pole shoe 13 is assembled to the flange 17 along the axial direction.

  Moreover, the manufacturing method of the magnet rod 10a which concerns on this embodiment attaches each member assembled at the assembly process to a metal mold | die, and insert-molds it by the rare earth bond magnet 14a, and casts each member into a cast-in molded object A molding step for obtaining 30a is provided.

  Furthermore, the manufacturing method of the magnet rod 10a which concerns on this embodiment is equipped with the magnetization process which magnetizes the molded object 30a obtained at the formation process. The molded body 30a is magnetized by this magnetization step, and the function as the magnet rod 10a can be achieved by setting one side of the molded body 30a to the N pole and the other side to the S pole.

  Moreover, the manufacturing method of the magnet rod 10a which concerns on this embodiment is a lamination process which arrange | positions the magnetized molded object 30a in the cylinder member 19 with S poles and N poles facing each other, and molded object 30a. Connection means connected to each other by the connection means 21 is provided.

  According to the magnet rod 10a and the method of manufacturing the magnet rod 10a according to the present embodiment, the magnet 11a and the pole shoe 13 are cast with the rare earth bonded magnet 14a. Since it is not necessary to process with high accuracy, the manufacturing cost can be reduced.

  Moreover, since the magnet 11a is formed in the cylindrical shape which has the through-hole 12, it can aim at suppression of manufacturing cost by reducing the usage-amount of an expensive neodymium sintered magnet. Furthermore, since the molded bodies 30a are connected to each other by the connecting means 21, it is possible to reduce the manufacturing time without considering the time for solidifying the adhesive and eliminating the need for a jig or the like. Manufacturing costs can be reduced.

  Furthermore, since the magnet 11a is constituted by the divided bodies 11b and 11b obtained by dividing the magnet 11a in the axial direction, it can be easily assembled to the bobbin 15 on which the flange 17 is formed.

[Example]
Next, a comparison of magnetic flux density and cogging between the magnet member according to the first and second embodiments and the conventional magnet member will be described with reference to FIGS.

  FIG. 13 shows Example 1 of the magnet member 10 according to the first embodiment, Comparative Example 1 of a magnet member using a conventional magnet, and the magnet used in the magnet member 10 according to the first embodiment. It is a graph which shows the experimental result which compared transition of the magnetic flux density of the comparative example 2 of the magnet member using only 11. FIG.

  As is apparent from the measurement results of Comparative Example 2, when the magnet is formed small in order to reduce the amount of neodymium sintered magnet used for the magnet of the conventional magnet member, the magnetic flux density is greatly reduced, which is ideal. It can be seen that the shape is far away from the sinusoidal wave.

  On the other hand, as is clear from the measurement result of Example 1, the magnet member 10 according to the first embodiment reduces the size of the magnet 11 that is a neodymium sintered magnet as in the case of Comparative Example 2. However, since the surface of the magnet 11 is cast with a rare earth bonded magnet, the magnetic flux density is hardly lowered, and it can be seen that a magnetic flux density equivalent to that of a conventional magnet member can be obtained. Moreover, while the location where the magnetic flux density is high exists at both ends of the peak value of Comparative Example 1, the magnetic flux density graph of Example 1 has a shape closer to a sine wave. As can be seen from this result, in the case of Example 1, there is no portion with high magnetic flux density at both ends of the peak value as in Comparative Example 1, and the shape is closer to a sine wave. It can be seen that smooth operation can be performed without causing any trouble.

  Next, FIG. 14 is similar to FIG. 13 in Example 1 of the magnet member 10 according to the first embodiment, Comparative Example 1 of a magnet member using a conventional magnet, and the first embodiment. It is a graph which shows the experimental result which compared the cogging of the comparative example 2 of the magnet member using only the magnet 11 used for the magnet member 10 which concerns.

  As in Comparative Example 2, when the size of the magnet is reduced, the pitch between the magnets also increases, and it can be seen that cogging occurs due to the deterioration of the distribution of magnetic flux density. Moreover, although it is improving also about the comparative example 1 compared with the comparative example 2, it turns out that cogging has arisen not a little.

  On the other hand, the cogging of Example 1 shows a substantially flat value, and it can be seen that the cogging hardly occurs. This is because the magnetic flux density has a more ideal shape, and the magnetic flux density at the corners of the magnet is suppressed by casting the magnet with a rare earth bonded magnet, so there is no unevenness in thrust. It is.

  FIG. 15 is a graph showing the variation of the motor induced voltage in Example 2 of the modified example of the magnet member 10 ′ according to the first embodiment of the present invention, and FIG. 16 shows the variation in the first embodiment of the present invention. It is a graph which shows the fluctuation | variation of the motor induced voltage of Example 1 of the magnet member 10 which concerns.

  Comparing FIG. 15 and FIG. 16, the motor induced voltage of the second embodiment has a shape closer to a sine wave than the waveform of the first embodiment in any of the U, V, and W phase waveforms. Is clear. In addition, the RMS value can be confirmed to be slightly changed in the first embodiment, but the second embodiment shows a substantially flat result.

  As described above, it is understood that the thrust ripple associated with the fluctuation of the induced voltage is reduced in the second embodiment in addition to the reduction in the magnet volume as compared with the first embodiment.

  FIG. 17 shows an example 3 of the magnet rod 10a according to the second embodiment, a comparative example 3 of a conventional magnet rod using a solid columnar magnet, and a magnet of the conventional magnet rod formed in a cylindrical shape. It is a graph which shows the result of having measured transition of magnetic flux density of comparative example 4 of a magnet rod.

  As is apparent from the measurement results of Comparative Example 4, when the magnet is formed in a cylindrical shape in order to reduce the amount of neodymium sintered magnet used for the magnet of the conventional magnet rod, the magnetic flux density is compared with Comparative Example 3. Is about 20% lower.

  On the other hand, as is apparent from the measurement result of Example 3, the magnet rod 10a according to the present embodiment has the through holes 12 and the surfaces of the magnets 11a casted with rare earth bonded magnets, so that the magnetic flux density is almost reduced. It can be seen that a magnetic flux density equivalent to that of a conventional magnet rod can be obtained.

  As described above, the magnet member 10 and the magnet rod 10a according to the present embodiment can reduce the amount of expensive neodymium sintered magnets used while maintaining the performance without reducing the magnetic flux density. Can be suppressed.

  Further, the magnet member 10 and the magnet rod 10a according to the present embodiment are manufactured with the rare earth bonded magnets 14 and 14a whose outer shapes are injection-molded because the magnets 11 and 11a are cast with the rare earth bonded magnets 14 and 14a. be able to. As a result, it is not necessary to increase the processing accuracy of neodymium magnets that are difficult to process, and the manufacturing cost can be reduced. Moreover, by casting the magnets 11 and 11a with rare earth bonded magnets, the surface treatment for preventing rust of the magnets 11 and 11a is not required, and the manufacturing cost can be further reduced.

  Moreover, although the linear motor 1 which concerns on 1st Embodiment demonstrated the case where the dummy core 43 was provided in the armature 40, if the cogging can be suppressed, it does not need to provide the dummy core 43. FIG.

  Moreover, although the magnet member 10 which concerns on 1st Embodiment demonstrated the case where the flat magnet 11 was arranged in parallel with respect to the longitudinal direction of the back yoke 50, the shape of the magnet 11 rounded the corner | angular part. You may make it a shape and you may employ | adopt the structure of what is called skew arrangement | positioning which has an angle with respect to a longitudinal direction and arranges diagonally.

  Moreover, although the magnet rod 10a which concerns on 2nd Embodiment demonstrated the case where the magnet 11a and the pole shoe 13 were assembled | attached to the bobbin 15, it is sufficient to fix the magnet 11a and the pole shoe 13 within a metal mold | die. If possible, the bobbin 15 may not be used. Further, without using the pole shoe 13, only the magnet 11a or the magnet 11a may be assembled to the bobbin 15 to be laminated in the axial direction to form a magnet rod. Further, the magnet may be formed in a cylindrical shape having a through hole in the axial direction, and the through hole in the axial direction may be embedded with a rare earth bonded magnet to form a molded body.

  Moreover, although the magnet rod 10a which concerns on 2nd Embodiment demonstrated the case where the molded object 30a was connected with the some connection means 21, multiple magnets 11a and pole shoes 13 are arranged in an axial direction, and the rare earth bond magnet 14a. If they are formed integrally with each other, the connection means 21 may not be used for connection.

  Moreover, although the magnet rod 10a which concerns on 2nd Embodiment demonstrated the case where two or more molded objects 30a were assembled | attached in the cylindrical member 19, it connects several molded bodies 30a with the connection means 21 without using the cylindrical member 19. FIG. The outer surface of the molded body 30a may be exposed and used. In this case, since the cylindrical member 19 is not used, the molded body 30a can be formed larger by the thickness of the cylindrical member 19, and the magnetic flux density can be further increased. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  1, 1a linear motor, 10 magnet member, 10a magnet rod, 11, 11a magnet, 11a divided body, 12 through hole, 13 pole shoe, 14, 14a rare earth bonded magnet, 14b connecting hole, 15 bobbin, 19 cylinder member, 21 Connecting means, 40 armature, 40a housing, 41, 41a coil.

Claims (9)

In a linear motor comprising a magnet member and a coil movable relative to the magnet member,
The magnet member includes a molded body in which magnets are arranged along a longitudinal direction, and the magnet is cast with a rare earth bonded magnet. The linear motor according to claim 1,
The magnet is formed in a flat plate shape and arranged at a predetermined interval on a stator extending along a longitudinal direction. The linear motor according to claim 2,
The magnet is formed in a polygonal shape and has a chamfered corner. The linear motor according to claim 1,
The magnet is formed in a cylindrical shape with a through hole formed in the longitudinal direction,
The said rare earth bond magnet casts the through-hole and the side of the said magnet, The linear motor characterized by the above-mentioned. The linear motor according to claim 4,
A linear motor comprising a bobbin inserted through the through hole. In the linear motor according to claim 4 or 5,
2. The linear motor according to claim 1, wherein the magnet is constituted by a divided body divided into at least two parts. The linear motor according to any one of claims 4 to 6,
The molded body includes a connecting hole in an axial end face, and a plurality of the molded bodies are connected to the connecting hole via a connecting means to form a magnet rod. In the linear motor according to any one of claims 4 to 7,
A linear motor characterized in that a plurality of the molded bodies are laminated in a cylindrical tube member. An assembly process of arranging magnets along the longitudinal direction;
A molding step of casting a side surface of the magnet with a rare-earth bonded magnet to obtain a molded body;
A magnet member manufacturing method comprising magnetizing the molded body.

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