JP2011193641A - Linear motor and method for manufacturing reciprocating rod - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear motor for easily assembling a reciprocating rod using a solid permanent magnet and to provide a method for manufacturing the reciprocating rod. <P>SOLUTION: A plurality of solid permanent magnets 18 are inserted into a pipe 13 where a projected shaft 14 is fixed to one end part and a circular member 15 is fixed to the other end part from a magnet guide hole 41 of an assembly tool 40. A screw shaft member 16 is inserted into the circular member 15 against magnetic repulsion by an insertion tool 44, and the screw shaft member 16 is screw-coupled to the circular member 15 with rotation of the insertion tool 44. The plurality of permanent magnets 18 are fasted to the magnet assembly 17 in a state where end faces abut each other. Thus, the reciprocating rod 11 of the linear motor is assembled. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a linear motor in which a reciprocating rod reciprocates in an axial direction and a method for manufacturing the reciprocating rod.

  Since a linear motor can be driven at high speed and has high positioning accuracy, the linear motor is used as a driving source for a positioning device, a conveying device, etc. in an industrial product production line or assembly line. A shaft type linear motor includes a magnet assembly formed by arranging a plurality of permanent magnets in a linear direction, and a coil assembly formed by arranging a plurality of cylindrical coils in a linear direction so as to surround the magnet assembly. Have. The plurality of permanent magnets are arranged with their end faces having the same polarity facing each other, and the end faces are abutted against each other to form a magnet assembly. By energizing each coil of the coil assembly, the magnet assembly and the coil assembly are relatively driven in a linear direction by the electromagnetic force between the magnet assembly and the coil assembly.

  For example, Patent Document 1 describes a rod-type linear motor in which a magnet assembly is attached to a reciprocating rod on the mover side, and a coil assembly is mounted on a housing case on the stator side. Patent Documents 2 and 3 describe a table type linear motor in which a magnet assembly is attached to a fixed rod on the stator side, and a coil assembly is mounted on a reciprocating table on the mover side.

JP 2008-86144 A Japanese Patent Laid-Open No. 10-313566 JP 2007-174803 A

  By the way, in the linear motor described in Patent Document 2, the fixed rod is assembled by the following process. First, one end portion of the center shaft disposed in the pipe is screwed to the bracket, and each permanent magnet is inserted into the pipe through a plurality of cylindrical permanent magnets from the other end side of the center shaft. Subsequently, a nut is screwed to the other end of the center shaft, and a plurality of permanent magnets are tightened between the nut and the bracket, so that the end faces of the same polarity of the plurality of permanent magnets protrude against the magnetic repulsion force. A magnet assembly is formed in the pipe by being applied.

  Moreover, in the linear motor described in Patent Document 3, first, each permanent magnet is inserted into the pipe through a plurality of cylindrical permanent magnets on the center shaft arranged in the pipe, and end caps are respectively provided on both ends thereof. insert. Subsequently, nuts are screwed to both ends of the center shaft, and a plurality of permanent magnets are clamped via end caps between a pair of nuts, thereby preventing the magnetic repulsive force from having the same polarity of the plurality of permanent magnets. A magnet assembly is formed in the pipe. Then, after fixing the end caps and the pipes respectively arranged on both ends of the magnet assembly by caulking, the fixing rod is assembled by removing the nut and pulling out the center shaft.

  Thus, when using the center axis | shaft arrange | positioned in a pipe, it is necessary to form each permanent magnet in a cylindrical shape. Since the cylindrical permanent magnet has a smaller magnetic force than the solid permanent magnet, the thrust of the linear motor is reduced as compared with the case where the solid permanent magnet is used. Therefore, as shown in FIG. 5 of Patent Document 3, there is a structure in which a magnet assembly is formed by a plurality of solid permanent magnets without using a center shaft. However, in this case, the end cap and the pipe are fixed by caulking in a state where a plurality of permanent magnets are pressed into the pipe via the end cap, and the assembling work is complicated. That is, since the end cap and the pipe are fixed by caulking while the end cap is pressed inward in the axial direction, the pressing jig and the caulking machine interfere with each other, or the end surfaces of the permanent magnets are reliably abutted against each other. There is a risk of being fixed in a state where there is no.

  An object of the present invention is to facilitate assembly of a reciprocating rod in a linear motor having a reciprocating rod using a solid permanent magnet.

  Another object of the present invention is to prevent the reciprocating rod from falling by restricting the reciprocating rod from moving in the axial direction, and to alleviate the impact of the reciprocating rod at that time.

  Another object of the present invention is to improve the thrust of a linear motor.

  Another object of the present invention is to prevent the reciprocating rod from falling by its own weight when energization of the coil is stopped.

  The linear motor of the present invention is a linear motor that reciprocates in the axial direction by projecting a reciprocating rod that is reciprocally attached to the housing case from one end of the housing case, and surrounds the reciprocating rod. The housing case is provided with a coil assembly including a plurality of coils, a pipe having a protruding shaft portion fixed to one end, an annular member fixed to the other end of the pipe, and an assembly disposed on the pipe. A plurality of solid permanent magnets are inserted into the pipe from the magnet guide holes provided in the jig with the end faces of the same polarity facing each other, against the magnetic repulsive force by the insertion tool. The screw shaft member is inserted into the annular member and is screwed to the annular member by rotation of the insertion tool and fastens the plurality of permanent magnets to a magnet assembly in a state where the end faces are abutted against each other. The dynamic rod is formed, by an electromagnetic force between the coil assembly and the magnet assembly, characterized by reciprocating the reciprocating rod axially.

  The linear motor according to the present invention is characterized in that the coil is formed to have a half axial length of the permanent magnet.

  The linear motor of the present invention is provided with a stopper in the housing case that faces the one end face of the annular member with a gap when the reciprocating rod moves to the projecting limit position, and the reciprocating rod reaches the retreat limit position. A cover is provided on the other end portion of the housing case so as to face the other end surface of the annular member with a gap when moved.

  The linear motor of the present invention is characterized in that a buffer member is provided on each end face of the annular member.

  In the linear motor of the present invention, a sealing material is attached to the annular member to form a piston that slides in the housing case, and the reciprocating rod is moved toward the projecting limit position by being supplied with pressure fluid. A forward fluid chamber is formed between the piston and the cover, and a backward fluid chamber that is supplied with pressure fluid and moves the reciprocating rod toward the backward limit position is formed between the piston and the stopper. It is characterized by forming between.

  The linear motor of the present invention is characterized in that the reciprocating rod is reciprocated in the axial direction by an electromagnetic force of the magnet assembly and the coil assembly and a thrust applied to the piston by a pressure fluid. .

  In the linear motor of the present invention, when the reciprocating rod reciprocates in the vertical direction, the thrust applied to the piston by the pressure fluid and the weight of the reciprocating rod or the thrust applied to the piston by the pressure fluid Pressure fluid is supplied to each of the fluid chambers so that the weight of the reciprocating rod and the load applied to the reciprocating rod are in an equilibrium state.

  The method of manufacturing a reciprocating rod according to the present invention includes a pipe having a protruding shaft portion fixed to one end portion, an annular member fixed to the other end portion of the pipe, and a screw shaft member screwed to the annular member. A plurality of solid permanent magnets having opposite end faces of the same polarity facing each other in the pipe from a magnet guide hole provided in an assembly jig arranged in the pipe. Inserting the screw shaft member into the annular member against a magnetic repulsive force by an insertion tool, and screwing the screw shaft member to the annular member by rotating the insertion tool, A step of fastening the permanent magnet to a magnet assembly in which the end faces are abutted against each other.

  According to the present invention, with a plurality of solid permanent magnets inserted into the pipe from the magnet guide hole of the assembly jig, the screw shaft member is inserted into the annular member against the magnetic repulsion force by the insertion tool. By screw coupling, a plurality of permanent magnets are fastened to the magnet assembly in a state where the end surfaces of the magnets are abutted against each other. Therefore, reciprocating rods using solid permanent magnets can be easily assembled. It becomes possible.

  According to the present invention, since the stopper and the cover in which the end faces of the annular member are opposed to each other at both ends of the stroke of the reciprocating rod are provided, the load applied to the reciprocating rod is reduced when the energization to each coil is stopped. When the load is too large or an abnormal load is applied to the reciprocating rod, the end surface of the annular member is brought into contact with the stopper or the cover to restrict the movement of the reciprocating rod in the axial direction. Therefore, it is possible to prevent the reciprocating rod from falling from the housing case and the workpiece driven by the reciprocating rod from falling from the work table. Furthermore, since the buffer members are provided on both end faces of the annular member, the impact of the reciprocating rod when the end face of the annular member comes into contact with the stopper or the cover is alleviated.

  According to the present invention, since the reciprocating rod is reciprocated in the axial direction by the electromagnetic force of the magnet assembly and the coil assembly and the thrust applied to the piston by the pressure fluid, the thrust of the linear motor is improved. Can be made.

  According to the present invention, when the reciprocating rod reciprocates in the vertical direction, the thrust applied to the piston by the pressure fluid and the self-weight of the reciprocating rod, or the thrust applied to the piston by the pressure fluid and the self-weight of the reciprocating rod and Since pressure fluid is supplied to each fluid chamber so that the load applied to the reciprocating rod is in an equilibrium state, the self-weight of the reciprocating rod and the driven member connected thereto can be canceled, It is possible to prevent the reciprocating rod from falling due to its own weight during a power failure.

It is sectional drawing of the linear motor which is one embodiment of this invention. It is a top view of the linear motor shown in FIG. It is a bottom view of the linear motor shown in FIG. It is a left view of the linear motor shown in FIG. It is a right view of the linear motor shown in FIG. It is explanatory drawing which shows the assembly process of a reciprocating rod. It is sectional drawing corresponding to FIG. 1 which shows the modification of a reciprocating rod. It is explanatory drawing corresponding to FIG. 6 which shows the other assembly method of a reciprocating rod. It is sectional drawing of the linear motor which is other embodiment of this invention. It is sectional drawing corresponding to FIG. 9 which shows the modification of a pneumatic circuit.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the motor 10 is a rod-type linear motor that reciprocates a reciprocating rod 11 with a constant stroke in its axial direction, that is, in a linear direction. The motor 10 has a reciprocating rod 11 as a mover extending in the axial direction, and a housing case 12 as a stator on which the reciprocating rod 11 is reciprocally mounted.

  The reciprocating rod 11 includes a pipe 13 formed of a nonmagnetic material such as austenitic stainless steel. The pipe 13 has a thin cylindrical shape extending in the axial direction of the reciprocating rod 11 and is formed to be open at both ends thereof. A protruding shaft portion 14 made of a nonmagnetic material such as duralumin is fixed to one end portion of the pipe 13. The projecting shaft portion 14 formed in a substantially cylindrical shape is fixed to one end portion of the pipe 13 by caulking with the other end side being incorporated in the pipe 13, and one end side of the pipe 13 is closed by the projecting shaft portion 14. ing. A connecting hole 14 a for connecting a driven member (not shown) to the reciprocating rod 11 is formed on one end surface of the protruding shaft portion 14. A driven member is connected to the reciprocating rod 11 by a screw member fastened to the connecting hole 14 a, and the driven member is reciprocated in the axial direction together with the reciprocating rod 11.

  An annular member 15 made of a non-magnetic material such as austenitic stainless steel is fixed to the other end of the pipe 13 by welding. The annular member 15 has an outer diameter that is larger than the outer diameter of the pipe 13 and an inner diameter that is slightly larger than the inner diameter of the pipe 13, and the pipe 13 is connected to the other end via the annular member 15. Open to the side. A female screw portion 15 a is formed on the inner peripheral surface of the annular member 15.

  A screw shaft member 16 is screwed to the other end of the pipe 13 via an annular member 15. The screw shaft member 16 is made of a non-magnetic material such as an aluminum alloy, and has a male screw portion 16a screwed to the female screw portion 15a of the annular member 15, and a pressing portion 16b extending from the male screw portion 16a to one end side of the pipe 13. And has a stepped cylindrical shape. The screw shaft member 16 is inserted into the annular member 15 and screwed to the annular member 15, and the pressing portion 16 b of the screw shaft member 16 is inserted into the pipe 13. A through-hole 16c penetrating in the axial direction is formed in the axial center of the screw shaft member 16, and an engaging groove 16d extending in the radial direction is formed in the other end surface of the screw shaft member 16.

  A magnet assembly 17 is provided inside the pipe 13 so as to be positioned between the protruding shaft portion 14 and the screw shaft member 16. The magnet assembly 17 includes a plurality of solid (cylindrical) permanent magnets 18 that are magnetized in the axial direction, and the plurality of permanent magnets 18 whose magnetic poles are opposite to each other are alternately axially arranged. Are arranged side by side. The plurality of permanent magnets 18 are clamped between the projecting shaft portion 14 and the screw shaft member 16 against the magnetic repulsive force acting on the end surfaces of the plurality of permanent magnets 18 having the same polarity facing each other. As a result, the magnet end surfaces are brought into contact with each other to form the magnet assembly 17. That is, the plurality of permanent magnets 18 formed to have the same axial length are fastened with the magnet end surfaces having the same polarity against the magnetic repulsive force being brought into contact with each other to form the magnet assembly 17. ing. As a result, the magnetic flux concentrates in the radial direction in the vicinity of the end surfaces of the permanent magnets 18 abutted against each other, and a high magnetic flux density (radially concentrated magnetic flux) is generated in the radial direction. Since the magnet assembly 17 is formed by a plurality of solid permanent magnets 18 as described above, the magnet assembly 17 is formed in comparison with a case where a magnet assembly is formed by a plurality of cylindrical permanent magnets. The generated magnetic flux density can be increased, and the thrust of the motor 10 is improved.

  On the other hand, the housing case 12 made of a non-magnetic material such as an aluminum alloy has a cylindrical shape with a substantially rectangular cross section extending in the axial direction of the reciprocating rod 11, and a stepped coil penetrating in the axial direction in the axial center. An accommodation hole 20 is formed. A coil assembly 21 is provided on the inner peripheral surface of the coil housing hole 20 so as to be positioned on one end side of the housing case 12. The coil assembly 21 includes a plurality of cylindrical coils 22 formed in an axial length that is substantially half the length of each permanent magnet 18, and the coils of the plurality of coils 22 are interposed via nonmagnetic spacers 23. The end surfaces are abutted against each other and are arranged in the axial direction. Each coil 22 is wound around the outer peripheral surface of a thin cylindrical bobbin 24 made of non-magnetic material, and the inner peripheral surface of the bobbin 24 faces the pipe 13 through a slight gap on the outer peripheral surface of the pipe 13. Yes. That is, each coil 22 of the coil assembly 21 is disposed so as to surround the magnet assembly 17 provided on the reciprocating rod 11. In addition, an outer shield 25 made of a ferromagnetic material such as iron is provided on the outer peripheral side of the coil assembly 21. The outer shield 25 shields the magnetic flux formed in each coil 22 from leaking out of the housing case 12.

  Each coil 22 of the coil assembly 21 is electrically connected to a connector 28 provided in the housing case 12. By energizing each coil 22 of the coil assembly 21 through the connector 28, magnetic poles are formed in each coil 22 so that the coil end faces adjacent to each other have the same polarity. As a result, the magnetic flux concentrates in the radial direction in the vicinity of the coil end faces adjacent to each other of the coils 22, and a high magnetic flux density (radially concentrated magnetic flux) is generated in the radial direction. The reciprocating rod 11 protrudes from one end of the housing case 12 and reciprocates in the axial direction by the electromagnetic force of the magnet assembly 17 and the coil assembly 21.

  The stroke of the reciprocating rod 11 is set by the relationship between the axial length of the magnet assembly 17 and the axial length of the coil assembly 21, and when the reciprocating rod 11 moves in the axial direction, The axial range where the coil assembly 21 faces is the stroke of the reciprocating rod 11. That is, the stroke of the reciprocating rod 11 is set by the difference between the axial length of the magnet assembly 17 and the axial length of the coil assembly 21.

  Resin bearings 29 and 30 are provided on the inner peripheral surface of the coil housing hole 20 so as to be positioned at both ends of the coil assembly 21. The bearings 29 and 30 are respectively fixed to bearing housings 29a and 30a formed of a nonmagnetic material such as an aluminum alloy. The bearing housings 29 a and 30 a and the bobbin 24 are inwardly connected to an annular fastening member 31 that is screwed to one end of the coil housing hole 20 and through which the reciprocating rod 11 passes, and an inner peripheral surface of the coil housing hole 20. It is fixed between the protruding stopper 32. The bearings 29 and 30 are in sliding contact with the outer peripheral surface of the pipe 13, and the reciprocating rod 11 is supported by the housing case 12 through the bearings 29 and 30 so as to be reciprocally movable.

  Further, a guide hole 33 is formed on the inner peripheral surface of the coil housing hole 20 so as to be positioned on the other end side of the housing case 12. The diameter of the guide hole 33 is formed larger than the outer diameter of the annular member 15, and the annular member 15 reciprocates in the guide hole 33 as the reciprocating rod 11 reciprocates. The guide hole 33 is formed between the cover 34 provided at the other end portion of the coil housing hole 20 and closing the other end side of the coil housing hole 20 and the stopper 32. The length is slightly larger than the stroke of the reciprocating rod 11. That is, when the reciprocating rod 11 moves to the projecting limit position, one end surface of the annular member 15 is opposed to the stopper 32 with a predetermined gap. When the reciprocating rod 11 moves to the retreat limit position, the other end surface of the annular member 15 faces the cover 34 with a predetermined gap. With this stopper structure, when energization to each coil 22 is stopped, or when the load applied to the reciprocating rod 11 is too large or an abnormal load is applied to the reciprocating rod 11, the annular member 15 The end face comes into contact with the stopper 32 or the cover 34, and the movement of the reciprocating rod 11 in the axial direction is restricted. Therefore, it is possible to prevent the reciprocating rod 11 from falling from the housing case 12 and the workpiece driven by the reciprocating rod 11 from falling from the work table.

  A plurality of mounting holes are formed on the outer peripheral surface of the housing case 12, and the motor 10 is mounted on a conveying device (not shown) by a screw member inserted into the mounting holes. A sensor groove 12a is formed on the outer peripheral surface of the housing case 12 along the axial direction of the housing case 12, and a sensor (not shown) for detecting the position of the reciprocating rod 11 can be attached to the sensor groove 12a. It has become.

  Further, a cable groove 12b is formed on the outer peripheral surface of the housing case 12 along the axial direction of the housing case 12, and the cable 35 electrically connected to the connector 28 is inserted into the cable groove 12b. It has become. In addition, a heat radiating portion 12 c that is uneven in the direction orthogonal to the axial direction is formed along the axial direction on the outer peripheral surface of the housing case 12, and heat generated by energization of the coil 22 is generated in the housing case 12. The heat dissipation when releasing to the outside is improved.

  Next, a method for manufacturing the reciprocating rod 11 will be described. FIG. 6 is an explanatory view showing the assembly process of the reciprocating rod. When assembling the reciprocating rod 11, the assembling work is performed with the opening side of the pipe 13, that is, the side opposite to the protruding shaft portion 14 facing upward.

  The pipe 13 has a projecting shaft portion 14 fixed to one end thereof, and one end side of the pipe 13 is closed, an annular member 15 is fixed to the other end portion, and the other end side of the pipe 13 is opened via the annular member 15. ing. When the reciprocating rod 11 is assembled, an assembly jig 40 made of a nonmagnetic material is disposed on the other end side of the pipe 13. The assembly jig 40 has a cylindrical shape with a magnet guide hole 41 penetrating the shaft center, and the diameter of the magnet guide hole 41 is slightly smaller than the outer diameter of the permanent magnet 18 and the external thread portion 16a of the screw shaft member 16. It is greatly formed. The assembly jig 40 and the pipe 13 are annular between a step portion 41 a formed on the inner peripheral surface of the magnet guide hole 41 and an annular fastener 42 screwed to one end of the assembly jig 40. The member 15 is detachably mounted by being tightened. The magnet guide hole 41 of the assembly jig 40 is communicated with the inside of the pipe 13.

  First, as shown in FIG. 6A, a plurality of solid permanent magnets 18 are inserted into the pipe 13 from the magnet guide holes 41 of the assembly jig 40. The permanent magnets 18 are inserted with magnet end faces of the same polarity facing each other, and are arranged at predetermined intervals by a magnetic repulsive force acting on the facing magnet end faces. As a result, the permanent magnets 18 are arranged at substantially equal intervals from the pipe 13 to the magnet guide hole 41 of the assembly jig 40. Next, the screw shaft member 16 is inserted into the magnet guide hole 41 of the assembly jig 40 so as to be positioned on the other end side with respect to the plurality of permanent magnets 18.

  Further, after inserting the plurality of permanent magnets 18 and the screw shaft member 16 into the pipe 13 and the magnet guide hole 41 of the assembly jig 40, the cover 43 is screwed to the other end of the assembly jig 40, and the magnet The other end side of the guide hole 41 is closed by the cover 43. An insertion tool 44 extending in the axial direction of the reciprocating rod 11 is supported on the cover 43 so as to be movable in the axial direction. One end side of the insertion tool 44 is inserted into the magnet guide hole 41 of the assembly jig 40, and an engagement portion 44 a extending in the radial direction is provided at one end portion of the insertion tool 44.

  Subsequently, as shown in FIG. 6B, the insertion tool 44 is pushed into the magnet guide hole 41 of the assembly jig 40 and one end of the insertion tool 44 is inserted into the through hole 16 c of the screw shaft member 16. At the same time, the engaging portion 44a of the insertion tool 44 and the engaging groove 16d of the screw shaft member 16 are engaged. As a result, when the insertion tool 44 is further pushed into the magnet guide hole 41 of the assembly jig 40, the screw shaft member 16 is moved to the one end side along the magnet guide hole 41 together with the insertion tool 44. The pressing portion 16b of the screw shaft member 16 is abutted against the permanent magnet 18 so that the plurality of permanent magnets 18 are pushed into the pipe 13 from the magnet guide hole 41 against the magnetic repulsive force.

  As shown in FIG. 6C, when the insertion tool 44 is pushed in until the male screw portion 16a of the screw shaft member 16 contacts the female screw portion 15a of the annular member 15, the pressing portion 16b of the screw shaft member 16 becomes the annular member. 15 is inserted into the pipe 13, and its tip is projected into the pipe 13. Each permanent magnet 18 is pressed against one end side by the screw shaft member 16 and is arranged in the pipe 13 with a slight gap formed by a magnetic repulsive force acting on the magnet end surface.

  From this state, the insertion tool 44 is rotated, and the screw shaft member 16 is rotated integrally by the engagement between the engagement portion 44a of the insertion tool 44 and the engagement groove 16d of the screw shaft member 16, so that the screw shaft member 16 is rotated. The male screw portion 16 a is screwed to the female screw portion 15 a of the annular member 15. As shown in FIG. 6D, when the screw shaft member 16 is screwed to the annular member 15, each permanent magnet 18 is further pressed to one end side by the screw shaft member 16. As a result, the end surfaces of the permanent magnets 18 are abutted against each other against the magnetic repulsive force, and the magnet assembly 17 is formed in the pipe 13. That is, the permanent magnets 18 are fastened in a state where the end surfaces of the magnets are abutted against each other by the screw shaft member 16, thereby forming the magnet assembly 17. Finally, by removing the assembly jig 40 from the pipe 13, the assembly operation of the reciprocating rod 11 is completed.

  Thus, in the state where the plurality of solid permanent magnets 18 are inserted into the pipe 13 from the magnet guide hole 41 of the assembling jig 40, the screw shaft member 16 is made to be an annular member against the magnetic repulsive force by the insertion tool 44. Since the plurality of permanent magnets 18 are fastened to the magnet assembly 17 in a state where the end surfaces of the magnets are abutted with each other by being inserted into the screw 15 and screwed together, reciprocation using the solid permanent magnet 18 is performed. The moving rod 11 can be easily assembled.

  That is, there is a possibility that the pressing jig and the caulking machine interfere with each other as in the conventional technique in which the end cap and the pipe are fixed by caulking in a state where a plurality of permanent magnets are pressed into the pipe via the end cap. Therefore, the assembly workability of the reciprocating rod 11 can be improved. Further, since the screw shaft member 16 is screwed to the annular member 15, the magnet end surfaces of the plurality of permanent magnets 18 are pressed against each other and the plurality of permanent magnets 18 are fastened. Can be fixed in a state in which they are reliably abutted against each other.

  In the above embodiment, the magnet assembly 17 is formed by the six permanent magnets 18, but the number of permanent magnets 18 can be arbitrarily changed. For example, the stroke of the reciprocating rod 11 can be increased by increasing the number of permanent magnets 18 forming the magnet assembly 17. Similarly, the coil assembly 21 is formed by the six coils 22, but the number of the coils 22 can be arbitrarily changed. For example, it is possible to increase the electromagnetic force between the magnet assembly 17 and the coil assembly 21 by increasing the number of the coils 22 forming the coil assembly 21 and improve the thrust of the motor 10.

  Further, as shown in FIG. 7, buffer members 46 and 47 made of an elastic material such as rubber may be provided on both end faces of the annular member 15, respectively. As a result, when energization to each coil 22 is stopped, or when the load applied to the reciprocating rod 11 is too large or an abnormal load is applied to the reciprocating rod 11, the end surface of the annular member 15 is It is brought into contact with the stopper 32 or the cover 34 via the buffer members 46 and 47. Therefore, the shock of the reciprocating rod 11 when the end surface of the annular member 15 contacts the stopper 32 or the cover 34 is mitigated by the buffer members 46 and 47.

  Further, as shown in FIG. 7, a sensor magnet 48 may be provided on the annular member 15. Thereby, the axial position of the reciprocating rod 11 can be detected by detecting the magnetism of the sensor magnet 48 by a sensor (not shown) attached to the sensor groove 12 a of the housing case 12. Based on the detection signal from the sensor, the energization of each coil 22 of the coil assembly 21 can be controlled.

  Furthermore, in the embodiment, the through-hole 16c and the engagement groove 16d are formed in the screw shaft member 16, but the shape of the screw shaft member 16 can be arbitrarily changed. For example, as shown in FIG. 8, the screw shaft member 16 may not be provided with the through hole 16c. In that case, the engaging portion 44a provided at one end of the insertion tool 44 is engaged with the engaging groove 16d of the screw shaft member 16, and the reciprocating rod 11 is moved by the same process as shown in FIG. Assembled.

  Furthermore, in the above-described embodiment, the assembly jig 40 and the pipe 13 are detachably mounted by tightening the annular member 15 between the step portion 41a of the assembly jig 40 and the fastener 42. However, it is not limited to this. For example, as shown in FIG. 8, the pipe 13 is inserted into an insertion hole 49 a formed in the fixture 49, and the step portion 41 a of the assembly jig 40 is abutted against the annular member 15. The assembly jig 40 may be arranged on the side.

  FIG. 9 is a cross-sectional view of a linear motor according to another embodiment of the present invention. In FIG. 8, members similar to those described above are given the same reference numerals, and descriptions thereof are omitted.

  The motor 50 is a linear motor having an air cylinder structure as a thrust assist mechanism that assists the thrust of the reciprocating rod 11. Piston packings 51 and 52 slidably in contact with the inner peripheral surface of the coil housing hole 20 are mounted on the outer peripheral surface of the annular member 15, and the annular member 15 slides in the coil housing hole 20 of the housing case 12. Is forming. The piston 53 is driven in the coil housing hole 20 (guide hole 33) in the axial direction, so that the reciprocating rod 11 is reciprocated in the axial direction integrally with the piston 53.

  A sealing material 54 that seals between the outer peripheral surface of the cover 34 and the inner peripheral surface of the coil housing hole 20 is attached, and is sealed between the sealing material 54 of the cover 34 and the piston packing 52 of the piston 53. A forward fluid chamber 55 a is formed in the coil housing hole 20. Further, a rod packing 56 slidably contacting the outer peripheral surface of the pipe 13 is mounted on the inner peripheral surface of the stopper 32, and the retraction is sealed between the rod packing 56 of the stopper 32 and the piston packing 51 of the piston 53. A fluid chamber 55 b is formed in the coil housing hole 20.

  The storage case 12 has a forward supply port 57a for supplying compressed air (pressure fluid) to the forward fluid chamber 55a and a backward supply port 57b for supplying compressed air to the backward fluid chamber 55b. And are provided. When compressed air is supplied from the supply port 57a to the forward fluid chamber 55a, the piston 53 is driven toward the stopper 32, and the reciprocating rod 11 is moved forward together with the piston 53 toward the projecting limit position. On the other hand, when compressed air is supplied from the supply port 57b to the retreating fluid chamber 55b, the piston 53 is driven toward the cover 34, and the reciprocating rod 11 is moved backward toward the retreat limit position together with the piston 53. .

  Next, the pneumatic circuit 60 for supplying compressed air to the supply ports 57a and 57b will be described. The pneumatic circuit 60 includes a forward line 62 a that connects the forward supply port 57 a and the pneumatic source 61, and a backward line 62 b that connects the backward supply port 57 b and the pneumatic source 61. The lines 62a and 62b are provided with pressure reducing valves 63a and 63b with relief holes, and the pressure in the lines 62a and 62b can be arbitrarily set by adjusting the set pressure of the pressure reducing valves 63a and 63b. It is possible.

  The lines 62a and 62b are provided with directional control valves 64a and 64b, respectively, located on the supply ports 57a and 57b side of the pressure reducing valves 63a and 63b. The direction control valves 64a and 64b are two-position and three-port solenoid valves, a primary port connected to the pressure reducing valves 63a and 63b, a secondary port connected to the supply ports 57a and 57b, and an exhaust port. And each. When a signal is sent to the directional control valves 64a and 64b, the exhaust position connects the secondary port and the exhaust port. When the signal to the directional control valves 64a and 64b is stopped, the primary port and the secondary port are stopped. The supply position communicates with the side port.

  When each coil 22 of the coil assembly 21 is energized and the reciprocating rod 11 is moved forward toward the projecting limit position by the electromagnetic force of the magnet assembly 17 and the coil assembly 21, the direction control valve 64a. Is the supply position, and the direction control valve 64b is the exhaust position. Then, when compressed air is supplied to the forward fluid chamber 55a, a thrust is applied to the piston 53 toward the stopper 32 side. Similarly, when each coil 22 of the coil assembly 21 is energized and the reciprocating rod 11 is moved backward toward the retreat limit position by the electromagnetic force of the magnet assembly 17 and the coil assembly 21, The control valve 64a is set to the exhaust position, and the direction control valve 64b is set to the supply position. Then, when compressed air is supplied to the retreating fluid chamber 55b, thrust is applied to the piston 53 toward the cover 34 side.

  Thus, since the reciprocating rod 11 is reciprocated in the axial direction by the electromagnetic force of the magnet assembly 17 and the coil assembly 21 and the thrust applied to the piston 53 by the compressed air, the thrust of the motor 10 Can be improved. Also in this motor 50, it is possible to assemble the reciprocating rod 11 by the above process, and it is needless to say that the same effect can be obtained.

  In the above-described embodiment, the pneumatic circuit 60 that assists the thrust of the reciprocating rod 11 with the air cylinder structure is provided. However, the pneumatic circuit 60 is not limited to this and can be arbitrarily changed. For example, when the reciprocating rod 11 is reciprocated in the vertical direction, a pneumatic circuit 70 is provided so as to prevent the reciprocating rod 11 from falling by its own weight when energization of each coil 22 is stopped due to a power failure or the like. Also good. FIG. 10 is a cross-sectional view corresponding to FIG. 9 showing a modified example of the pneumatic circuit. Members similar to those shown in FIG.

  The pneumatic circuit 70 is provided with opening / closing valves 71a and 71b instead of the directional control valves 64a and 64b provided in the pneumatic circuit 60 shown in FIG. The on-off valves 71a and 71b are two-position and two-port solenoid valves, and include a primary port connected to the pressure reducing valves 63a and 63b and a secondary port connected to the supply ports 57a and 57b. . When a signal is sent to the on-off valves 71a and 71b, the primary port and the secondary port are opened, and when the signal to the on-off valves 71a and 71b is stopped, the primary port and the secondary side Closed position that blocks communication with the port.

  When each coil 22 of the coil assembly 21 is energized and the reciprocating rod 11 is reciprocated in the vertical direction by the electromagnetic force between the magnet assembly 17 and the coil assembly 21, the on-off valves 71a and 71b are Open position. Then, by supplying compressed air to the fluid chambers 55a and 55b, a thrust that cancels the weight of the reciprocating rod 11 is applied to the piston 53. That is, the pressure of the compressed air supplied to each fluid chamber 55a, 55b is set so that the thrust applied to the piston 53 by the compressed air and the weight of the reciprocating rod 11 are in an equilibrium state. As a result, even when the energization of each coil 22 is stopped at the time of a power failure and the electromagnetic force between the magnet assembly 17 and the coil assembly 21 does not act, the on-off valves 71a and 71b are in the closed position. The thrust that cancels the weight of the reciprocating rod 11 remains applied to 53.

  As described above, when the reciprocating rod 11 reciprocates in the vertical direction, the fluid chambers 55a and 55b are arranged so that the thrust applied to the piston 53 by the compressed air and the own weight of the reciprocating rod 11 are in an equilibrium state. Since compressed air is supplied, it is possible to prevent the reciprocating rod 11 from falling by its own weight during a power failure. Also in this motor 50, it is possible to assemble the reciprocating rod 11 by the above process, and it is needless to say that the same effect can be obtained. In addition, it goes without saying that the vertical direction is the direction in which the weight of the reciprocating rod 11 acts on itself, and is not limited to the vertical direction but may be an oblique direction.

  In the above embodiment, the pressure of the compressed air supplied to the fluid chambers 55a and 55b is set so that the thrust applied to the piston 53 by the compressed air and the weight of the reciprocating rod 11 are in an equilibrium state. However, it is not limited to this. For example, the pressure of the compressed air supplied to the fluid chambers 55a and 55b so that the thrust applied to the piston 53 by the compressed air and the weight of the reciprocating rod 11 and the load applied to the reciprocating rod 11 are in equilibrium. May be set. Thereby, when the energization to each coil 22 is stopped due to a power failure or the like, it is possible to prevent the weight loss of the reciprocating rod 11 to which a load is applied.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, the protruding shaft portion 14 is fixed to one end portion of the pipe 13 by caulking. However, the present invention is not limited to this, and may be fixed by welding, press-fitting, screw connection, or the like. . Further, the annular member 15 is fixed to the other end of the pipe 13 by welding. However, the present invention is not limited to this, and the annular member 15 may be fixed by caulking or the like.

10 Motor (Linear motor)
DESCRIPTION OF SYMBOLS 11 Reciprocating rod 12 Housing | casing case 12a Sensor groove 12b Cable groove 12c Heat radiation part 13 Pipe 14 Projection shaft part 14a Connection hole 15 Annular member 15a Female thread part 16 Screw shaft member 16a Male thread part 16b Pressing part 16c Through-hole 16d Engaging groove 17 Magnet Assembly 18 Permanent magnet 20 Coil housing hole 21 Coil assembly 22 Coil 23 Spacer 24 Bobbin 25 Outer shield 28 Connector 29, 30 Bearing 29a, 30a Bearing housing 31 Fastening member 32 Stopper 33 Guide hole 34 Cover 35 Cable 40 Assembly jig 41 Magnet guide hole 41a Stepped portion 42 Fastener 43 Cover 44 Insertion tool 44a Engagement portion 46, 47 Buffer member 48 Sensor magnet 49 Fixing tool 49a Insertion hole 50 Motor (linear motor)
51, 52 Piston packing 53 Piston 54 Sealing material 55a Forward fluid chamber 55b Backward fluid chamber 56 Rod packing 57a, 57b Supply port 60 Pneumatic circuit 61 Air pressure source 62a Forward line 62b Retraction lines 63a, 63b Pressure reducing valves 64a, 64b Direction control valve 70 Pneumatic circuit 71a, 71b Open / close valve

Claims (8)

A linear motor that reciprocates in the axial direction by projecting a reciprocating rod that is reciprocally attached to the housing case from one end of the housing case,
A coil assembly comprising a plurality of coils is provided in the housing case so as to surround the reciprocating rod,
A pipe having a protruding shaft portion fixed to one end, an annular member fixed to the other end of the pipe, and a magnet guide hole provided in an assembly jig disposed in the pipe, a plurality of pieces in the pipe. A solid permanent magnet is inserted into the annular member against the magnetic repulsion force by an insertion tool with the end faces of the same polarity facing each other, and the annular tool is rotated by rotation of the insertion tool. The reciprocating rod is formed by a screw shaft member that is screw-coupled to a member and fastens a plurality of the permanent magnets to a magnet assembly in a state where the end faces are abutted against each other.
A linear motor that reciprocates the reciprocating rod in an axial direction by an electromagnetic force between the magnet assembly and the coil assembly.   The linear motor according to claim 1, wherein the coil is formed to have an axial length that is half that of the permanent magnet.   3. The linear motor according to claim 1, wherein when the reciprocating rod moves to a projecting limit position, a stopper is provided in the housing case that faces the one end surface of the annular member with a gap, and the reciprocating rod is A linear motor characterized in that a cover that faces the other end surface of the annular member with a gap when it is moved to the retreat limit position is provided at the other end of the housing case.   4. The linear motor according to claim 3, wherein a buffer member is provided on each end face of the annular member.   5. The linear motor according to claim 3, wherein a sealing material is attached to the annular member to form a piston that slides within the housing case, and pressure fluid is supplied to bring the reciprocating rod to the projecting limit position. A forward fluid chamber is formed between the piston and the cover, and a retreating fluid chamber that is supplied with pressure fluid and moves the reciprocating rod toward the retreat limit position is formed with the piston. A linear motor formed between the stopper and the linear motor.   6. The linear motor according to claim 5, wherein the reciprocating rod is reciprocated in an axial direction by an electromagnetic force between the magnet assembly and the coil assembly and a thrust applied to the piston by a pressure fluid. A linear motor.   6. The linear motor according to claim 5, wherein when the reciprocating rod reciprocates in the vertical direction, thrust applied to the piston by pressure fluid and self-weight of the reciprocating rod, or thrust applied to the piston by pressure fluid. And a pressure fluid is supplied to each fluid chamber so that the weight of the reciprocating rod and the load applied to the reciprocating rod are in an equilibrium state. A method of manufacturing a reciprocating rod having a pipe having a protruding shaft portion fixed to one end, an annular member fixed to the other end of the pipe, and a screw shaft member screwed to the annular member. ,
Inserting a plurality of solid permanent magnets with opposite end faces of the same polarity into the pipe from magnet guide holes provided in an assembly jig disposed in the pipe; and
The screw shaft member is inserted into the annular member against the magnetic repulsive force by an insertion tool, and the screw shaft member is screwed to the annular member by rotation of the insertion tool, so that a plurality of the permanent magnets are connected to each other at the end surfaces. And a step of fastening to the magnet assembly in a state of being abutted against each other.

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