Linear motors and machine tools

Abstract

A linear motor (100) that is used in a machine tool comprises a magnet plate (10) in which a plurality of magnets (12) are provided arranged in a first direction, and a slider (50) that is configured to be capable of sliding in the first direction relative to the magnet plate (10). The slider (50) includes a slider core (51), a plurality of coils (52) that are provided to the slider core (51) arranged in the first direction, and securing members (58). The slider core (51) has holes formed therein. The holes extend in a second direction that is parallel to the surface of the magnet plate (10) and orthogonal to the first direction. The securing members (58) are inserted into the holes. The securing members (58) have threaded holes formed in a third direction that is orthogonal to both the first direction and the second direction, and the slider core (51) has through-holes formed therein, the through-holes being in communication with the threaded holes in the third direction. The securing members (58) are inserted into the holes in a state of being divided into at least two parts.

Description

[Technical field]

[0001] The present disclosure relates to a linear motor and a machine tool. [Background technology]

[0002] JP 2014-042423 A (Patent Document 1) discloses an invention related to a linear motor. The linear motor includes a field magnet portion that functions as a stator, and an armature that functions as a mover. The armature has a core, teeth, and a coil. The core is a member that forms the main body of the armature, and is made of electromagnetic steel sheet. A plurality of teeth protrude from the lower part of the core toward a permanent magnet. The armature generates a driving force associated with electromagnetic induction by passing a current through the coil, and moves above the field magnet portion.

[0003] A T-slot nut is embedded in the upper surface of the core. A movable stage for mounting a driven object such as a processing device is fixed by screwing a bolt into the T-slot nut. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-042423 A Summary of the Invention [Problem to be solved by the invention]

[0005] Since the core is made of electromagnetic steel sheet, it is difficult to form a screw hole in the core. One method to solve this problem is to provide a fixing member in the core and form a screw hole in the fixing member. In this case, the magnetic flux generated by the coil passes not only through the electromagnetic steel sheet core but also through the fixing member. As a result, iron loss occurs and the efficiency of the linear motor decreases. Therefore, a technology for suppressing iron loss when a fixing member is provided in a linear motor is desired. [Means for solving the problem]

[0006] In one example of the present disclosure, a linear motor for use in a machine tool is provided. The linear motor includes a magnet plate on which a plurality of magnets are arranged in a first direction, and a slider configured to be slidable in the first direction relative to the magnet plate. The slider includes a slider core, a plurality of coils arranged in the first direction and provided on the slider core, and a fixing member. A hole is formed in the slider core. The hole extends in a second direction that is parallel to a surface of the magnet plate and perpendicular to the first direction. The fixing member is inserted into the hole. A screw hole is formed in the fixing member in a third direction perpendicular to both the first direction and the second direction, and a through hole is formed in the slider core in the third direction and communicates with the screw hole. The fixing member is inserted into the hole in a state in which it is divided into at least two pieces.

[0007] In one example of the present disclosure, the number of divisions of the fixing member is the same as the number of the screw holes.

[0008] In one example of the present disclosure, the hole is a through hole penetrating the slider core in the second direction.

[0009] In one example of the present disclosure, the slider includes a plurality of teeth arranged in the first direction. The teeth are provided on the slider so as to face the magnets. The coils are wound around the teeth, respectively. The hole is formed in at least one of the teeth.

[0010] In one example of the present disclosure, the slider includes a cooling pipe arranged on a surface opposite to a surface facing the magnet plate, and the screw hole does not overlap with the cooling pipe when viewed from the third direction.

[0011] In one example of the present disclosure, the fixing member is divided into at least three parts, and the divided parts of the fixing member are located symmetrically with respect to the center of the slider core in the second direction.

[0012] In one example of the present disclosure, the slider has a plurality of through holes formed therein, the through holes penetrating the slider in the second direction, and the plurality of through holes are symmetrically positioned with respect to a center of the slider core in the first direction.

[0013] In one example of the present disclosure, the slider core is made of a laminated steel plate, and the fixing member is made of a material different from the laminated steel plate.

[0014] In another example of the present disclosure, there is provided a machine tool, the machine tool including the linear motor and a spindle for rotatably holding a workpiece or a tool, the linear motor being used to move a position of the spindle.

[0015] In another example of the present disclosure, there is provided a machine tool including the linear motor and a table on which a workpiece is placed, the linear motor being used to drive the table.

[0016] In another example of the present disclosure, a machine tool is provided, the machine tool including a linear motor and a loader for transporting a workpiece, the linear motor being used to drive the loader.

[0017] The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the invention taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0018] [Figure 1] 1 is a perspective view showing a linear motor according to an embodiment, viewed from an oblique direction; [Diagram 2] FIG. 2 is a diagram showing the slider from the Z-axis direction. [Diagram 3] 3 is a cross-sectional view of the slider taken along line III-III shown in FIG. 2. [Figure 4] FIG. 2 is a diagram showing the slider from the Z-axis direction. [Diagram 5] 5 is a cross-sectional view of the slider taken along line VV shown in FIG. 4. [Figure 6] 6 is a cross-sectional view of the slider taken along line VI-VI shown in FIG. 4. [Figure 7] FIG. 2 is a diagram showing the slider from the Z-axis direction. [Figure 8] 8 is a cross-sectional view of the slider taken along line VIII-VIII shown in FIG. 7. [Figure 9] 11 is a diagram showing the transition of iron loss when a divided fixing member is used in a linear motor, and the transition of iron loss when a non-divided fixing member is used in a linear motor. FIG. [Figure 10] FIG. 1 is a diagram illustrating an example of a device configuration of a machine tool. [Figure 11] FIG. 13 is a diagram showing another example of the device configuration of a machine tool. [Figure 12] FIG. 13 is a diagram showing another example of the device configuration of a machine tool. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, each embodiment according to the present invention will be described with reference to the drawings. In the following description, the same parts and components are given the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated. Note that each embodiment and each modified example described below may be appropriately and selectively combined.

[0020] <A.リニアモータ100> First, an overview of a linear motor 100 will be described with reference to Fig. 1. Fig. 1 is a perspective view showing linear motor 100 according to an embodiment from an oblique direction.

[0021] As shown in FIG. 1, the linear motor 100 includes a magnet plate 10 and a slider 50.

[0022] The magnet plate 10 functions as a stator. A plurality of magnets 12 are arranged on the magnet plate 10. For the sake of convenience of explanation, hereinafter, the direction in which the magnets 12 are arranged is also referred to as the X-axis direction (first direction). The direction parallel to the surface of the magnet plate 10 and orthogonal to the X-axis direction is also referred to as the Y-axis direction (second direction). The direction orthogonal to both the X-axis direction and the Y-axis direction is also referred to as the Z-axis direction (third direction).

[0023] Each of the plurality of magnets 12 is arranged on the magnet plate 10 with a predetermined interval in the X-axis direction. Each of the magnets 12 is a permanent magnet. Each of the magnets 12 is provided on the magnet plate 10 so that the polarity is opposite to that of the adjacent magnet 12. As an example, assume that the surface of one magnet 12 is the N pole and the back surface of the one magnet 12 is the S pole. In this case, for the magnet 12 arranged next to the one magnet 12, the surface is the S pole and the back surface is the N pole.

[0024] The slider 50 functions as a mover. The slider 50 has a plurality of coils 52. The plurality of coils 52 are arranged in the X-axis direction and provided on the slider 50. Each of the coils 52 is wound in an oval shape around teeth 53 (see FIG. 5) formed on the slider 50, which will be described later.

[0025] The plurality of coils 52 are provided on the slider 50 so as to face the plurality of magnets 12. In other words, the plurality of coils 52 are provided on the slider 50 so as to overlap the plurality of magnets 12 when viewed from the Z-axis direction.

[0026] The slider 50 receives a thrust by causing a magnetic field generated by applying an alternating current to the plurality of coils 52 to act on the plurality of magnets 12, and slides on the magnet plate 10 in the X-axis direction. The alternating current is supplied, for example, from a power source (not shown) electrically connected to the coils 52.

[0027] <B. Fixing member 58> Next, the fixing member 58 provided inside the slider 50 will be described with reference to Figures 2 and 3. Figure 2 is a view showing the slider 50 from the Z-axis direction. Figure 3 is a cross-sectional view of the slider 50 taken along line III-III shown in Figure 2.

[0028] The slider 50 described above includes a slider core 51 and fixing members 58A to 58D. For ease of explanation, in the following, when there is no particular distinction between the fixing members 58A to 58D, any one of the fixing members 58A to 58D will also be referred to as fixing member 58.

[0029] The slider core 51 is a member that forms the main body of the slider 50. The slider core 51 is made of electromagnetic steel plates so that magnetic flux can easily pass through it. Typically, the slider core 51 is a laminated steel plate in which thin electromagnetic steel plates are stacked. By making the slider core 51 out of laminated steel plates, it is possible to reduce eddy currents that cause iron loss.

[0030] The slider core 51 has holes H formed therein, which extend in the Y-axis direction. The number of holes H formed in the slider core 51 is arbitrary. In the example of FIG. 3, four holes HA to HD are formed in the slider core 51. For ease of explanation, in the following, when there is no particular distinction between the holes HA to HD, any one of the holes HA to HD will also be referred to as hole H.

[0031] The shape of the hole H is arbitrary. The hole H may be a rectangular parallelepiped hole, a cylindrical hole, or any other shape.

[0032] In addition, the hole H may be a through hole penetrating the slider core 51 in the Y-axis direction, or may be a hole that is divided by being partitioned. In the example of Fig. 2 and Fig. 3, the hole H is shown as a through hole.

[0033] Fixing members 58 are inserted into holes H. The number of fixing members 58 is set to match the number of holes H formed in slider core 51. In the example of Figs. 2 and 3, fixing member 58A is inserted into hole HA. Fixing member 58B is inserted into hole HB. Fixing member 58C is inserted into hole HC. Fixing member 58D is inserted into hole HD.

[0034] The fixing member 58 has a screw hole formed in the Z-axis direction, and the slider core 51 has a through hole formed in the Z-axis direction that communicates with the screw hole.

[0035] 2 and 3, a screw hole 59A is formed in the fixing member 58A, and a through hole 51A is formed in the slider core 51. The screw hole 59A communicates with the through hole 51A. In other words, the screw hole 59A overlaps with the through hole 51A when viewed from the Z-axis direction.

[0036] Further, a screw hole 59B is formed in the fixing member 58B, and a through hole 51B is formed in the slider core 51. The screw hole 59B communicates with the through hole 51B. In other words, the screw hole 59B overlaps with the through hole 51B when viewed from the Z-axis direction.

[0037] A screw hole 59C is formed in the fixing member 58C, and a through hole 51C is formed in the slider core 51. The screw hole 59C communicates with the through hole 51C. In other words, the screw hole 59C overlaps with the through hole 51C when viewed from the Z-axis direction.

[0038] A screw hole 59D is formed in the fixing member 58D, and a through hole 51D is formed in the slider core 51. The screw hole 59D communicates with the through hole 51D. In other words, the screw hole 59D overlaps with the through hole 51D when viewed from the Z-axis direction.

[0039] Any type of screw may be fitted into the screw holes 59A to 59D. As an example, bolts are fitted into the screw holes 59A to 59D. The bolts are passed through a component to be driven and fitted into the screw holes 59A to 59D, thereby fixing the component to be driven to the slider 50. In other words, the screw holes 59A to 59D are used to fix the component to be driven to the linear motor 100. Examples of the component to be driven will be described later.

[0040] Fixing member 58 is divided into at least two pieces and inserted into hole H. This reduces eddy currents generated in fixing member 58, suppressing iron loss. As a result, motor efficiency is improved.

[0041] The number of divisions of the fixing member 58 is arbitrary. In the example of Fig. 2, each of the fixing members 58A to 58D is divided into three.

[0042] Preferably, the number of divisions of fixing member 58 is the same as the number of screw holes formed in fixing member 58. This makes it possible to suppress iron loss while maintaining the fixing strength of fixing member 58.

[0043] In the example of Fig. 2 and Fig. 3, fixing member 58A is divided into three, while fixing member 58A has the same number of three screw holes 59A formed therein. Fixing member 58B is divided into three, while fixing member 58B has the same number of three screw holes 59B formed therein. Fixing member 58C is divided into three, while fixing member 58C has the same number of three screw holes 59C formed therein. Fixing member 58D is divided into three, while fixing member 58D has the same number of three screw holes 59D formed therein.

[0044] The fixing member 58 is made of a different type of material from the slider core 51. Typically, the iron loss when the magnetic flux generated by the coil 52 passes through the fixing member 58 is larger than the iron loss when the magnetic flux passes through the slider core 51. As an example, while the slider core 51 is made of a laminated steel plate, the fixing member 58 is made of a metal other than the laminated steel plate. The fixing member 58 may be made of iron, for example, or may be made of another type of metal.

[0045] The shape of the fixing member 58 is arbitrary. For example, the shape of the fixing member 58 may be a rectangular parallelepiped timber, a cylindrical shape, or another shape. Typically, the shape of the fixing member 58 is the same as the shape of the hole H.

[0046] <C.スライダ50> Next, the above-mentioned slider 50 will be described in more detail with reference to Fig. 4 to Fig. 6. Fig. 4 is a view showing the slider 50 from the Z-axis direction. Fig. 5 is a cross-sectional view of the slider 50 taken along line VV shown in Fig. 4. Fig. 6 is a cross-sectional view of the slider 50 taken along line VI-VI shown in Fig. 4.

[0047] The slider 50 has a housing 60 that defines its exterior. The housing 60 is made of, for example, resin. The housing 60 accommodates a slider core 51, a plurality of coils 52, a cooling pipe 56, and a fixing member 58.

[0048] A plurality of teeth 53 are formed on the slider core 51. Each of the teeth 53 protrudes in the Z-axis direction from the lower surface of the slider core 51 (i.e., the surface closer to the magnet plate 10) and faces the above-mentioned plurality of magnets 12. In other words, the plurality of teeth 53 are formed on the slider core 51 so as to overlap with the plurality of magnets 12 when viewed from the Z-axis direction. Each of the teeth 53 also extends in the Y-axis direction.

[0049] A coil 52 is wound around each of the teeth 53. A hole H for inserting the fixing member 58 is formed in at least one of the teeth 53. In the example of Figs. 5 and 6, a hole HA is formed in the tooth 53A. A hole HB is formed in the tooth 53B. A hole HC is formed in the tooth 53C. A hole HD is formed in the tooth 53D.

[0050] The cooling pipes 56 are provided on the upper surface of the slider core 51 (i.e., the surface away from the magnet plate 10). More specifically, a plurality of grooves are formed on the upper surface of the slider core 51. The grooves are formed at equal intervals and extend in the Y-axis direction. The cooling pipes 56 are arranged in a serpentine manner along the grooves formed on the upper surface of the slider core 51.

[0051] The cooling pipe 56 has a coolant inlet and a coolant outlet. The inlet and the outlet are connected to a cooler (not shown). The coolant flows from the inlet of the cooling pipe 56 to the outlet of the cooling pipe 56, and cools the slider 50. The coolant that reaches the outlet is sent to the cooler and cooled. The cooled coolant is then sent back to the inlet of the cooling pipe 56. In this way, the coolant circulates on the upper surface of the slider core 51 to remove heat from the slider 50. The coolant is a liquid that contains, for example, water.

[0052] The cooling pipe 56 is made of, for example, a metal pipe having good thermal conductivity. As an example, the cooling pipe 56 may be made of a copper pipe, an aluminum pipe, or a stainless steel pipe.

[0053] The cross-sectional shape of the cooling pipe 56 is arbitrary. For example, the cross-sectional shape of the cooling pipe 56 may be circular, rectangular, or another shape.

[0054] The slider core 51 has holes HA-HD extending in the Y-axis direction. The fixing member 58A is inserted into the hole HA. As described above, the fixing member 58A has a screw hole 59A extending in the Z-axis direction, and the slider core 51 has a through hole 51A communicating with the screw hole 59A. The through hole 51A and the screw hole 59A are formed so as not to overlap with the cooling pipe 56 when viewed from the Z-axis direction. This prevents the bolt from coming into contact with the cooling pipe 56 when inserted into the screw hole 59A.

[0055] Similarly, the fixing member 58B is inserted into the hole HB. As described above, the fixing member 58B has a screw hole 59B extending in the Z-axis direction, and the slider core 51 has a through hole 51B communicating with the screw hole 59B. The through hole 51B and the screw hole 59B are formed so as not to overlap with the cooling pipe 56 when viewed from the Z-axis direction. As a result, when a bolt is inserted into the screw hole 59B, the bolt does not come into contact with the cooling pipe 56.

[0056] Similarly, the fixing member 58C is inserted into the hole HC. As described above, the fixing member 58C has a screw hole 59C extending in the Z-axis direction, and the slider core 51 has a through hole 51C communicating with the screw hole 59C. The through hole 51C and the screw hole 59C are formed so as not to overlap with the cooling pipe 56 when viewed from the Z-axis direction. As a result, when a bolt is inserted into the screw hole 59C, the bolt does not come into contact with the cooling pipe 56.

[0057] Similarly, a fixing member 58D is inserted into the hole HD. As described above, a screw hole 59D extending in the Z-axis direction is formed in the fixing member 58D, and a through hole 51D communicating with the screw hole 59D is formed in the slider core 51. The through hole 51D and the screw hole 59D are formed so as not to overlap with the cooling pipe 56 when viewed from the Z-axis direction. As a result, when a bolt is inserted into the screw hole 59D, the bolt does not come into contact with the cooling pipe 56.

[0058] <D. Division Location of the Fixing Member 58> Next, with reference to FIG. 7, the division location in the above-described fixing member 58 will be described. FIG. 7 is a view showing the slider 50 from the Z-axis direction. FIG. 7 is different from FIG. 2 described above in that the center lines CX and CY are added. Other points of FIG. 7 are the same as those of FIG. 2 described above.

[0059] The center line CX represents the center of the slider core 51 in the X-axis direction. More specifically, the center line CX represents the center between one end of the slider core 51 in the X-axis direction and the other end of the slider core 51 in the X-axis direction.

[0060] The center line CY represents the center of the slider core 51 in the Y-axis direction. More specifically, the center line CY represents the center between one end of the slider core 51 in the Y-axis direction and the other end of the slider core 51 in the Y-axis direction.

[0061] As described above, the fixing member 58 is inserted into the hole H of the slider core 51 in a state of being divided into at least two parts. When the fixing member 58 is divided into three or more parts, the division locations of the fixing member 58 are symmetrically located with respect to the center line CY.

[0062] As a more specific example, assume that the fixing member 58 is divided into N parts. N is a natural number of 3 or more. Also, when focusing on the nth division location in the Y-axis direction (n is a natural number), the division location symmetric to the nth division location is the (N - n)th. In this case, the distance from the nth division location to the center line CY is equal to the distance from the (N - n)th division location to the center line CY.

[0063] As an example, the fixing member 58 is divided into three small members (hereinafter also referred to as "first to third small members"), the division location between the first small member and the second small member is referred to as the first division location, and the division location between the second small member and the third small member is referred to as the second division location. In this case, the distance from the first division location to the center line CY is equal to the distance from the second division location to the center line CY.

[0064] As described above, when the split portions of the fixing member 58 are symmetrically positioned with respect to the center line CY, the change in magnetic flux becomes substantially symmetric with respect to the center line CY. As a result, the driving of the linear motor 100 becomes stable.

[0065] In the above description, the symmetry of the split portions of the fixing member 58 has been described, but the same can be said about the positions of the screw holes 59A to 59D formed in the fixing member 58. More specifically, the screw holes 59A to 59D are formed at symmetric positions with respect to the center line CY. Also, the screw holes 59A to 59D are formed at symmetric positions with respect to the center line CX.

[0066] The same can be said about the through holes 51A to 51D formed in the slider core 51. More specifically, the through holes 51A to 51D are formed at symmetric positions with respect to the center line CY. Also, the through holes 51A to 51D are formed at symmetric positions with respect to the center line CX.

[0067] <E. Position of Hole H> Next, with reference to FIG. 8, the position of the hole H formed in the above-described fixing member 58 will be described. FIG. 8 is a cross-sectional view of the slider 50 along line VIII-VIII shown in FIG. 7. FIG. 8 is different from the above-described FIG. 3 in that the center line CX is added. Other points of FIG. 8 are the same as those of the above-described FIG. 3.

[0068] The center line CX represents the center of the slider core 51 in the X-axis direction. More specifically, the center line CX represents the center between one end of the slider core 51 in the X-axis direction and the other end of the slider core 51 in the X-axis direction.

[0069] As described above, a hole H penetrating in the Y-axis direction is formed in the slider core 51. When a plurality of such holes H are formed in the slider core 51, the holes H are symmetrically positioned with respect to the center line CX.

[0070] As a more specific example, assume that N holes H are formed in the slider core 51. Let N be a natural number of 2 or more. Also, when focusing on the n-th hole H in the X-axis direction (where n is a natural number), the hole H at a position symmetric to the n-th hole H is the (N - n + 1)-th one. In this case, the distance from the n-th hole H to the center line CX is equal to the distance from the (N - n + 1)-th hole H to the center line CX.

[0071] As an example, assume that four holes HA to HD are formed in the slider core 51. In this case, the distance from the first hole HA to the center line CX is equal to the distance from the fourth hole HD to the center line CX. Similarly, the distance from the second hole HB to the center line CX is equal to the distance from the third hole HC to the center line CX.

[0072] Thus, when a plurality of holes H are formed to be symmetrically positioned with respect to the center line CX, the change in magnetic flux becomes substantially symmetric with respect to the center line CX. As a result, the driving of the linear motor 100 becomes stable.

[0073] Note that in the above description, the positional relationship of the holes H formed in the slider core 51 has been explained, but the positional relationship of the fixing members 58 is the same as that of the holes H. More specifically, the fixing members 58A to 58D are located at symmetric positions with respect to the center line CX.

[0074] <F. Analysis Results> Next, with reference to FIG. 9, analysis results verifying the effectiveness of dividing the above-described fixing member 58 will be described. FIG. 9 is a diagram showing the transition of iron loss when using the divided fixing member 58 and the transition of iron loss when using the non-divided fixing member 58.

[0075] The horizontal axis of the graph shown in FIG. 9 represents time. The unit of time is represented by, for example, seconds (S).

[0076] The vertical axis of the graph shown in FIG. 9 represents the degree of iron loss in the fixing member 58. The unit of iron loss is represented by, for example, watts (W).

[0077] In FIG. 9, analysis results R1 and R2 are shown. The analysis result R1 shows the transition of iron loss when the fixing member 58 is not divided. The analysis result R2 shows the transition of iron loss when the fixing member 58 is divided into three parts. In each analysis, the linear motor 100 was driven under the same conditions.

[0078] As shown by the analysis results R1 and R2, the iron loss when the fixing member 58 was divided was less than the iron loss when the fixing member 58 was not divided. Thus, it was confirmed that the iron loss was suppressed by dividing the fixing member 58.

[0079] <G. Application Example of Linear Motor 100> Next, with reference to FIGS. 10 to 12, application examples of the above-described linear motor 100 will be described. The linear motor 100 can be used, for example, to drive various parts in a machine tool.

[0080] The "machine tool" as used herein is a concept encompassing various devices having a function of processing a workpiece. The machine tool 200 may be a horizontal machining center, or may be a vertical machining center. Alternatively, the machine tool 200 may be a lathe, an additional processing machine, or other cutting machines or grinding machines.

[0081] When the linear motor 100 is used in a machine tool, the magnet plate 10 that functions as a stator is attached to a stationary part in the machine tool. On the other hand, the slider 50 that functions as a mover is attached to a part to be driven in the machine tool. In this case, a bolt is passed through the part to be driven, and the bolt is fitted into the above-described screw holes 59A to 59D formed in the slider 50. Thereby, the part to be driven is fixed to the slider 50.

[0082] (G1. Spindle) First, an example in which the linear motor 100 is applied to driving a spindle will be described with reference to Fig. 10. Fig. 10 is a diagram showing an example of the device configuration of a machine tool 200.

[0083] The linear motor 100 is used, for example, to move the position of a spindle 250 for rotatably holding a workpiece or a tool. The spindle 250 may be a work spindle for rotating a workpiece, or a tool spindle for rotating a tool.

[0084] For ease of explanation, hereinafter, a coordinate system based on the main axis 250 will be represented by X'-axis, Y'-axis, and Z'-axis. The X'-axis, Y'-axis, and Z'-axis are mutually orthogonal.

[0085] As shown in FIG. 10, the machine tool 200 includes a control unit 200A, a drive unit 240A, and a spindle 250.

[0086] The control unit 200A is, for example, a CNC (Computer Numerical Control) device. The CNC device is composed of at least one integrated circuit. The integrated circuit is composed of, for example, at least one CPU (Central Processing Unit), at least one MPU (Micro Processing Unit), at least one ASIC (Application Specific Integrated Circuit), at least one FPGA (Field Programmable Gate Array), or a combination thereof. The control unit 200A controls the operation of the drive unit 240A by executing various programs such as a machining program.

[0087] The driving section 240A is a mechanism for driving the spindle 250. The device configuration of the driving section 240A is arbitrary. The driving section 240A may be configured with a single driving unit, or may be configured with a plurality of driving units. In the example of FIG. 10, the driving section 240A is configured with motor drivers 241A to 241C, linear motors 242A to 242C, and encoders 243A to 243C. Each of the linear motors 242A to 242C corresponds to the linear motor 100 described above.

[0088] The motor driver 241A controls the driving in the X'-axis direction of the spindle 250. The motor driver 241A receives an input of a control signal from the control unit 200A, and outputs a current according to the control signal to the linear motor 242A.

[0089] More specifically, the control unit 200A sequentially outputs a control signal including a target position to the motor driver 241A. The motor driver 241A calculates the actual position of the spindle 250 from the feedback signal of the encoder 243A, and outputs a current to the linear motor 242A so that the difference between the actual position and the target position becomes small. In this way, the motor driver 241A moves the spindle 250 to an arbitrary position in the X'-axis direction.

[0090] The motor driver 241B controls driving in the Y'-axis direction of the spindle 250. The motor driver 241B receives an input of a control signal from the control unit 200A, and outputs a current according to the control signal to the linear motor 242B.

[0091] More specifically, the control unit 200A sequentially outputs a control signal including a target position to the motor driver 241B. The motor driver 241B calculates the actual position of the spindle 250 from the feedback signal of the encoder 243B, and outputs a current to the linear motor 242B so that the difference between the actual position and the target position becomes small. In this way, the motor driver 241B moves the spindle 250 to an arbitrary position in the Y'-axis direction.

[0092] The motor driver 241C controls the driving in the Z'-axis direction of the spindle 250. The motor driver 241C receives an input of a control signal from the control unit 200A, and outputs a current according to the control signal to the linear motor 242C.

[0093] More specifically, the control unit 200A sequentially outputs a control signal including a target position to the motor driver 241C. The motor driver 241C calculates the actual position of the spindle 250 from the feedback signal of the encoder 243C, and outputs a current to the linear motor 242C so that the difference between the actual position and the target position becomes small. In this way, the motor driver 241C moves the spindle 250 to an arbitrary position in the Z'-axis direction.

[0094] (G2.Table) Next, an example in which the linear motor 100 is applied to driving a table will be described with reference to Fig. 11. Fig. 11 is a diagram showing another example of the device configuration of a machine tool 200.

[0095] The linear motor 100 is used, for example, to drive a table 260 provided in a machine tool. The table 260 is a platform on which a workpiece to be machined is placed.

[0096] As shown in FIG. 11, machine tool 200 includes a control unit 200A, a drive unit 240B, and a table 260.

[0097] The driving unit 240B is a mechanism for driving the table 260. The device configuration of the driving unit 240B is arbitrary. The driving unit 240B may be configured with a single driving unit, or may be configured with a plurality of driving units. In the example of FIG. 11, the driving unit 240B is configured with motor drivers 241D, 241E, linear motors 242D, 242E, and encoders 243D, 243E. Each of the linear motors 242D, 242E corresponds to the linear motor 100 described above.

[0098] The motor driver 241D controls driving in the X'-axis direction of the table 260. The motor driver 241D receives an input of a control signal from the control unit 200A, and outputs a current according to the control signal to the linear motor 242D.

[0099] More specifically, the control unit 200A sequentially outputs a control signal including a target position to the motor driver 241D. The motor driver 241D calculates the actual position of the table 260 from the feedback signal of the encoder 243D, and outputs a current to the linear motor 242D so that the difference between the actual position and the target position becomes small. In this way, the motor driver 241D moves the table 260 to an arbitrary position in the X'-axis direction.

[0100] The motor driver 241E controls driving in the Y'-axis direction of the table 260. The motor driver 241E receives an input of a control signal from the control unit 200A, and outputs a current according to the control signal to the linear motor 242E.

[0101] More specifically, the control unit 200A sequentially outputs a control signal including a target position to the motor driver 241E. The motor driver 241E calculates the actual position of the table 260 from the feedback signal of the encoder 243E, and outputs a current to the linear motor 242E so that the difference between the actual position and the target position becomes small. In this way, the motor driver 241E moves the table 260 to an arbitrary position in the Y'-axis direction.

[0102] (G3.Loader) Next, an example in which the linear motor 100 is applied to driving a loader will be described with reference to Fig. 12. Fig. 12 is a diagram showing another example of the device configuration of a machine tool 200.

[0103] The linear motor 100 is used, for example, to drive a loader 270 for transporting a member. The member may be a workpiece before or after machining, or may be a tool.

[0104] As shown in FIG. 12, machine tool 200 includes a control unit 200A, a drive unit 240C, and a loader 270.

[0105] The driving unit 240C is a mechanism for driving the loader 270. The device configuration of the driving unit 240C is arbitrary. The driving unit 240C may be configured with a single driving unit or may be configured with a plurality of driving units. In the example of FIG. 12, the driving unit 240C is configured with motor drivers 241F, 241G, and 241H, linear motors 242F, 242G, and 242H, and encoders 243F, 243G, and 243H. Each of the linear motors 242F, 242G, and 242H corresponds to the linear motor 100 described above.

[0106] The motor driver 241F controls driving in the X'-axis direction of the loader 270. The motor driver 241F receives an input of a control signal from the control unit 200A, and outputs a current according to the control signal to the linear motor 242F.

[0107] More specifically, the control unit 200A sequentially outputs a control signal including a target position to the motor driver 241F. The motor driver 241F calculates the actual position of the loader 270 from the feedback signal of the encoder 243F, and outputs a current to the linear motor 242F so that the difference between the actual position and the target position becomes small. In this way, the motor driver 241F moves the loader 270 to an arbitrary position in the X'-axis direction.

[0108] The motor driver 241G controls driving in the Y'-axis direction of the loader 270. The motor driver 241G receives an input of a control signal from the control unit 200A, and outputs a current according to the control signal to the linear motor 242G.

[0109] More specifically, the control unit 200A sequentially outputs a control signal including a target position to the motor driver 241G. The motor driver 241G calculates the actual position of the loader 270 from the feedback signal of the encoder 243G, and outputs a current to the linear motor 242G so that the difference between the actual position and the target position becomes small. In this way, the motor driver 241G moves the loader 270 to an arbitrary position in the Y'-axis direction.

[0110] The motor driver 241H controls driving in the Z'-axis direction of the loader 270. The motor driver 241H receives an input of a control signal from the control unit 200A, and outputs a current according to the control signal to the linear motor 242H.

[0111] More specifically, the control unit 200A sequentially outputs a control signal including a target position to the motor driver 241H. The motor driver 241H calculates the actual position of the loader 270 from the feedback signal of the encoder 243H, and outputs a current to the linear motor 242H so that the difference between the actual position and the target position becomes small. In this way, the motor driver 241H moves the loader 270 to an arbitrary position in the Z'-axis direction.

[0112] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0113] 10 magnet plate, 12 magnet, 50 slider, 51 slider core, 51A through hole, 51B through hole, 51C through hole, 51D through hole, 52 coil, 53 teeth, 53A teeth, 53B teeth, 53C teeth, 53D teeth, 56 cooling pipe, 58 fixing member, 58A fixing member, 58B fixing member, 58C fixing member, 58D fixing member, 59A screw hole, 59B screw hole, 59C screw hole, 59D screw hole, 60 housing, 100 linear motor, 200 machine tool, 200A control unit, 240A drive unit, 240B drive unit, 240C drive unit, 241A motor driver, 241B motor driver, 241C motor driver, 241D Motor driver, 241E motor driver, 241F motor driver, 241G motor driver, 241H motor driver, 242A linear motor, 242B linear motor, 242C linear motor, 242D linear motor, 242E linear motor, 242F linear motor, 242G linear motor, 242H linear motor, 243A encoder, 243B encoder, 243C encoder, 243D encoder, 243E encoder, 243F encoder, 243G encoder, 243H encoder, 250 spindle, 260 table, 270 loader.

Claims

1. A linear motor for use in a machine tool, a magnet plate on which a plurality of magnets are arranged in a first direction; a slider configured to be slidable in the first direction relative to the magnet plate, The slider includes: a slider core having a plurality of teeth formed to face the plurality of magnets; A plurality of coils are arranged on the slider core in the first direction; A fixing member, The plurality of teeth are formed on the slider core and aligned in the first direction, The plurality of coils are wound around the plurality of teeth, a hole is formed in the slider core, the hole extends in a second direction parallel to a surface of the magnet plate and perpendicular to the first direction, a portion of the hole overlaps with the coils when viewed from the first direction, and the fixing member is inserted into the hole; a screw hole is formed in the fixing member in a third direction perpendicular to both the first direction and the second direction, and a through hole is formed in the slider core in the third direction and communicating with the screw hole, and a portion of the screw hole overlaps with the plurality of coils when viewed from the first direction, The fixing member is inserted into the hole in a state in which the fixing member is divided into at least two pieces, A linear motor, wherein the fixing member is divided into at least two pieces and is arranged so as to be in contact with each other within the hole.

2. 2. The linear motor according to claim 1, wherein the number of divisions of the fixing member is the same as the number of the screw holes.

3. The linear motor according to claim 1 , wherein the hole is a through hole penetrating the slider core in the second direction.

4. the slider includes a cooling pipe that is arranged on a surface opposite to a surface facing the magnet plate, The linear motor according to claim 1 , wherein the screw hole does not overlap with the cooling pipe when viewed from the third direction.

5. The fixing member is divided into at least three parts, 3. The linear motor according to claim 1, wherein the dividing portions of the fixing member are positioned symmetrically with respect to a center of the slider core in the second direction.

6. a plurality of through holes penetrating the slider in the second direction are formed in the slider, The linear motor according to claim 3 , wherein the through holes are positioned symmetrically with respect to a center of the slider core in the first direction.

7. The slider core is made of laminated steel plates, 3. The linear motor according to claim 1, wherein the fixing member is made of a material different from the laminated steel plates.

8. A linear motor according to claim 1 or 2; a spindle for rotatably holding a workpiece or a tool; The linear motor is used to move the position of the spindle.

9. A linear motor according to claim 1 or 2; A table for placing a workpiece thereon, The linear motor is used to drive the table.

10. A linear motor according to claim 1 or 2; a loader for transporting the member; The linear motor is used to drive the loader.

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