JP2007043877A - Linear motor cylinder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel compact cylinder exhibiting high driving force transmission efficiency while having the advantage of an electric cylinder, i.e. high controllability. <P>SOLUTION: The linear motor cylinder includes a hollow tubular member 10, and a cylinder rod 30 arranged reciprocatively for the tubular member 10. The tubular member 10 becomes a field flux generation source when it is provided with a spline outer tube 14 for guiding the cylinder rod 30, and a plurality of permanent magnets 17. The cylinder rod 30 is provided with a spline groove 34 at a position on the outer circumferential surface of the rod corresponding to the spline outer tube 14, and applied with a stator coil 32 generating a magnetic field at a position on the outer circumferential surface of the rod corresponding to the plurality of permanent magnets 17. With such an arrangement, the cylinder rod 30 can perform reciprocal linear motion freely for the tubular member 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a linear motor cylinder device, and more particularly to a technique for realizing an unprecedented cylinder device by combining a linear motor and a spline mechanism.

  For example, a hydraulic cylinder is generally used as an actuator for realizing an expansion / contraction operation of a mechanical device such as an injection device of an injection molding machine or a link mechanism of a construction machine. In this hydraulic cylinder, the pressure and flow rate of the pressure oil are changed by changing the capacity of the variable pump that is a pressure oil supply source, and a wide speed range and thrust range are realized while maximizing the output.

  The hydraulic cylinder driven in this way is composed of a hydraulic cylinder body that performs an expansion and contraction operation, and a hydraulic pressure generator that supplies pressure oil to the hydraulic cylinder body. The hydraulic cylinder body is configured to be able to extend and contract by receiving pressure oil supplied from a hydraulic pressure generator including a hydraulic pump and a switching valve. And until now, the hydraulic cylinder main body and the hydraulic pressure generator constituting the hydraulic cylinder are arranged such that the hydraulic cylinder main body and the hydraulic pressure generator are spaced apart from each other, and supply and discharge of pressure oil between the two through the hydraulic piping, A configuration in which a hydraulic cylinder body and a hydraulic pressure generator are integrally formed is provided (for example, see Patent Document 1 below).

  However, since the hydraulic cylinder requires a relatively large hydraulic pressure generator separately from the hydraulic cylinder body as described above, there is a problem that the manufacturing cost and the maintenance / management cost at the time of introduction become high. It was. In addition, the hydraulic cylinder has a high output and can achieve a wide speed range and thrust range, but is not good at fine stop position control within the stroke. Could not be used. Furthermore, they also had environmental problems such as the generation of waste oil.

  Therefore, various techniques have been devised to replace the hydraulic cylinder having such problems with an electric cylinder using a motor that is easy to control and clean. According to such an electric cylinder, advantages that the hydraulic cylinder does not have, for example, in terms of cost and control, installation conditions, environmental problems, and the like can be exhibited (for example, see Patent Documents 2 and 3 below).

Japanese Utility Model Publication No. 63-164603 JP-A-9-271154 JP 2003-184981 A

  However, the electric cylinders provided up to now have a problem that the transmission efficiency of the motor driving force is very poor because a mechanism for converting the rotational motion by the motor or the like into a linear motion is necessarily required. In addition, although the device size has been improved compared to the hydraulic cylinder, there is still room for downsizing due to the need to connect the motor etc. to the conversion mechanism, further minimizing the device size. Was desired.

  The present invention has been made in view of the existence of such problems, and provides a new cylinder device that has the advantage of an electric cylinder of high controllability and is compact and has high transmission efficiency of driving force. It is the purpose.

  A linear motor cylinder device according to the present invention includes a hollow cylindrical cylindrical member, and a cylinder rod installed to be movable forward and backward with respect to the cylindrical member, and the cylindrical member includes the cylinder rod. A spline outer cylinder for guiding and a plurality of permanent magnets provide a field magnetic flux generating source, and the cylinder rod has a spline groove at a position corresponding to the spline outer cylinder on the outer peripheral surface of the rod. A stator coil that generates a magnetic field is wound around a position corresponding to the plurality of permanent magnets on the outer peripheral surface, thereby enabling reciprocal linear movement.

  In the linear motor cylinder device according to the present invention, each of the plurality of permanent magnets is formed as an annular member having a hole through which the cylinder rod can be conducted, and is stacked and fixed in the axial direction of the cylindrical member. Furthermore, it can be arranged so that the polarities appearing on the inner surfaces of the holes of adjacent permanent magnets are different.

  Moreover, the linear motor cylinder apparatus which concerns on this invention WHEREIN: The said stator coil and the said spline groove | channel can be installed so that it may not overlap in the circumferential direction of a rod.

  Further, in the linear motor cylinder device according to the present invention, the plurality of permanent magnets are installed so as to surround a circumferential direction of the spline outer cylinder with a certain gap, and the stator coil includes the plurality of stator coils. It can be configured such that the gap formed between the permanent magnet and the spline outer cylinder can be moved forward and backward.

  Furthermore, in the linear motor cylinder device according to the present invention, the power cord for supplying current to the stator coil may be wound around the outer periphery of the cylinder rod.

  Furthermore, in the linear motor cylinder device according to the present invention, the power cord that supplies current to the stator coil is a linear body that can be pulled out and wound up according to the reciprocating linear motion of the cylinder rod. It can be assumed that a drive mechanism is installed.

  Moreover, the linear motor cylinder apparatus which concerns on this invention WHEREIN: The said stator coil can be set by being wound around the core iron core protruded and installed in the outer peripheral surface of the said cylinder rod.

  Furthermore, the linear motor cylinder device according to the present invention may be provided with position detecting means for detecting the position of the cylinder rod and controlling the reciprocating linear motion of the cylinder rod.

  The summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

  According to the present invention, as a driving source of the cylinder device, a configuration capable of exerting a driving force called a linear motor by linear motion is adopted, so that the transmission efficiency is very high and the controllability is equal to or better than that of an electric cylinder. Can be provided. In addition, the use of a linear motor can provide a cylinder device that achieves a compactness that cannot be achieved by a conventional electric cylinder.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the 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]
The linear motor cylinder device according to the first embodiment will be described with reference to FIGS. 1, 2, and 3. Here, FIG. 1 is an external perspective view showing the entire configuration of the linear motor cylinder device according to the first embodiment, and a part of the outer constituent member is shown by a broken line for explanation of the internal structure. FIG. 2 is a longitudinal sectional side view of the linear motor cylinder device according to the first embodiment, and FIG. 3 is a sectional view taken along the line AA in FIG.

  The linear motor cylinder device according to the first embodiment includes a cylindrical member 10 having a hollow cylindrical shape and a cylinder rod 30 that is installed so as to be movable forward and backward with respect to the cylindrical member.

  The cylindrical member 10 constituting the outline of the linear motor cylinder device includes a spline outer cylinder 14 for guiding the cylinder rod 30 and a plurality of permanent magnets 17 to serve as a field magnetic flux generation source.

  The spline outer cylinder 14 is a member fixedly installed on one end side of the cylindrical member 10 having a hollow cylindrical shape, or a member having an integral structure, and is used for fixing and installing the linear motor cylinder device according to the first embodiment. A member provided with a flange 13. The spline outer cylinder 14 has rolling grooves corresponding to the spline grooves 34 of the cylinder rod 30, and a plurality of protrusions extending in the direction in which the spline grooves 34 extend are formed in these rolling grooves. Yes. Then, a load rolling path is formed between the rolling groove formed in the spline outer cylinder 14 and the spline groove 34 formed in the cylinder rod 30, and the load rolling path is released from the load next to the load rolling path. A no-load return path through which the ball 15 is moved is formed. The spline outer cylinder 14 incorporates a cage 16 that aligns and holds a plurality of balls 15 in a circuit shape. A plurality of balls 15 are installed so as to roll freely between the rolling groove of the spline outer cylinder 14 and the spline groove 34 of the cylinder rod 30 so as to circulate infinitely through the no-load return passage. Thus, stable reciprocating linear motion of the cylinder rod 30 with respect to the spline outer cylinder 14 (that is, the cylindrical member 10) is realized.

  The plurality of permanent magnets 17 installed in the cylindrical member 10 are each formed as an annular member having a hole 17a through which the cylinder rod 30 can be conducted, and are stacked and fixed in the axial direction of the cylindrical member 10. Has been. And the adjacent permanent magnet 17 is installed so that the polarity which appears on the inner surface of the hole 17a may differ. Therefore, the cylindrical member 10 becomes a field magnetic flux generation source by the effect of the plurality of permanent magnets 17 and can exhibit a function as a stator in the linear motor.

  On the other hand, the cylinder rod 30 includes a spline groove 34 at a position corresponding to the spline outer cylinder 14 on the outer peripheral surface of the rod, and at a position on the rod outer peripheral surface corresponding to the plurality of permanent magnets 17 installed in the cylindrical member 10. A stator coil 32 for generating a magnetic field is wound. The cylinder rod 30 is configured to have such a configuration, so that the cylinder rod 30 can reciprocate linearly in the axial direction of the cylindrical member 10.

  The spline groove 34 on the rod outer peripheral surface of the cylinder rod 30 exhibits a function of guiding a stable reciprocating linear motion of the cylinder rod 30 by cooperating with the spline outer cylinder 14 on the cylindrical member 10 side. About this spline groove | channel 34, it is necessary to install so that the stator coil 32 and the spline groove | channel 34 may not overlap in the circumferential direction of a rod on the structure of an apparatus. This is a configuration adopted because it is necessary to avoid contact between the stator coil 32 and the spline outer cylinder 14. Therefore, the length of the cylinder rod 30 according to the first embodiment is required to be at least twice as long as the length of the stator coil 32 installation position that becomes a stroke.

  Examples of the constituent material of the cylinder rod 30 on which the stator coil 32 is installed include stainless steel, ceramics, and high hardness nonmagnetic free-cutting steel. In particular, high-hardness nonmagnetic free-cutting steel has high strength compared to other materials, and is suitable for use as a cylinder rod 30 that serves as a working part and performs work as a cylinder device. As a specific steel type, Hitachi Metals Co., Ltd. HPM75, etc., having a hardness at the time of use of about 40 to 45 in HRC (Rockwell hardness) can be employed.

  The stator coil 32 installed on the cylinder rod 30 is a member configured by winding a coil, and controls the current to the stator coil 32 to generate an N pole and an S pole in the coil. Be able to. Since the plurality of permanent magnets 17 are installed in the cylindrical member 10 so that the polarities appearing on the inner surfaces of the holes 17a of the adjacent permanent magnets 17 are different, N is interposed between the cylinder rod 30 and the stator coil 32. The pulling force of the pole and the S pole and the repulsive force of the N poles and the S poles occur, and the reciprocating linear motion of the cylinder rod 30 is realized.

  Furthermore, since the linear motor cylinder device according to the first embodiment employs a configuration in which the stator coil 32 is installed on the cylinder rod 30, the power cord 35 that supplies current to the stator coil 32 can be connected. It becomes a problem. Thus, in the power cord 35 according to the first embodiment, the power cord 35 is wound around the rod outer periphery of the cylinder rod 30 in a spiral shape, and this spiral shape is always maintained, and the power cord can be expanded and contracted according to the operation of the cylinder rod 30. 35 is adopted. As such a power cord 35, for example, a configuration in which a shape memory material is installed in the coating surrounding the cord or on the coating surface can be adopted.

  Although the operation of the linear motor cylinder device according to the first embodiment is realized by the configuration described above, various improvements can be added to the linear motor cylinder device according to the first embodiment. It is. The power cord 35 used in the linear motor cylinder device according to the first embodiment described above has been described by exemplifying the one wound in a spiral shape on the rod outer peripheral side of the cylinder rod 30. As shown in FIG. 4, the power cord 35 for supplying a current to the child coil 32 is a linear body drive that can freely pull out and wind up the power cord 35 in accordance with the reciprocating linear motion of the cylinder rod 30. It is also possible to employ the mechanism 39.

  The linear body drive mechanism 39 folds a metal plate or metal wire having a high elastic force in the sheath surrounding the cord at one place, and spirally winds around the folded portion to end the cord. The shape is maintained by pulling out the parts in different directions (see FIG. 4). According to the linear body drive mechanism 39, when the cylinder rod 30 moves in the acting direction (direction to be pushed out) and moves in the direction in which the power cord 35 extends, the cylinder rod 30 is spirally wound against the elastic force of the metal. When the power cord 35 is pulled out and the power cord 35 is pulled out, and the cylinder rod 30 moves in the reaction direction (accommodating direction) and the power cord 35 moves in the contracting direction, it is wound helically by the elastic force of the metal. The power cord 35 is pulled back with the portion thus stored in the winding direction. By adopting such a linear body drive mechanism 39, it is possible to prevent problems caused by entanglement or catching of the power cord 35.

  Further, in order to control the reciprocating linear motion of the cylinder rod 30, it is possible to install a position detecting means for the cylinder rod 30. As this position detecting means, for example, an optical linear scale device provided with a reading sensor that can attach a scale to the rod outer peripheral surface of the cylinder rod 30 and read a scale on the scale, or a reference position of the cylinder rod 30 It is possible to employ a mechanism or the like that provides a sensor that can measure the moving distance from the device. By installing such position detecting means for the cylinder rod 30, it is possible to apply a more suitable driving force to the workpiece.

  The linear motor cylinder device according to the first embodiment has a configuration as described above, so that the transmission efficiency of the motor driving force to the workpiece is very high, and exhibits controllability equal to or higher than that of the electric cylinder. Can do. In addition, by adopting a linear motor, it is possible to achieve a level of compactness that cannot be achieved with a conventional electric cylinder.

[Second Embodiment]
In the first embodiment, the linear motor cylinder device that has achieved a level of compactness that cannot be achieved with a conventional electric cylinder has been described. However, the linear motor cylinder device according to the second embodiment to be described below is further improved. It has a form to achieve compactness. Therefore, a linear motor cylinder device according to the second embodiment will be described with reference to FIGS. 5, 6, and 7. Here, FIG. 5 is an external perspective view showing the entire configuration of the linear motor cylinder device according to the second embodiment, and a part of the outer constituent member is shown by a broken line for explanation of the internal structure. 6 is a longitudinal sectional side view of the linear motor cylinder device according to the second embodiment, and FIG. 7 is a sectional view showing a BB section in FIG. Note that members that are the same as or similar to the members described in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  A characteristic feature of the linear motor cylinder device according to the second embodiment is that a plurality of permanent magnets 17 installed on the cylindrical member 10 surround the circumferential direction of the spline outer cylinder 14 with a certain gap 40 therebetween. On the other hand, the stator coil 63 installed on the cylinder rod 60 is configured to be able to advance and retreat in a gap 40 formed between the plurality of permanent magnets 17 and the spline outer cylinder 14. It is done.

  A specific structure will be described. The cylinder rod 60 according to the second embodiment includes a space 61 that can be stored so as to cover the spline outer cylinder 14, and a stator is provided outside the frame body 62 that constitutes the space 61. A coil 63 is wound. The mover of the linear motor constituted by the frame body 62 and the stator coil 63 is movable forward and backward with respect to the gap 40 formed on the cylindrical member 10 side. The reciprocating linear motion of the cylinder rod 60 is realized by the cooperation of the permanent magnet 17 and the stator coil 63. By adopting such a configuration, the spline outer cylinder 14 (spline groove 64) and the stator coil 63 can be installed redundantly in the circumferential direction of the rod, so that it is axially compared to the first embodiment. It is possible to obtain a linear motor cylinder device with a reduced length.

  Note that the stator coil 63 according to the second embodiment is wound around a core iron core 66 that is installed so as to protrude from the outer peripheral surface of the cylinder rod 60. This is a configuration that is employed to exert the function of strengthening the magnetic field by the stator coil 63 by the effect of the core core 66. In the second embodiment, the installation capacity of the stator coil 63 inevitably decreases due to the relationship of providing the space 61, so even if the volume of the stator coil 63 is restricted by the installation of the core core 66. It becomes possible to realize a linear motor cylinder device having the same driving force as that of the first embodiment.

  As mentioned above, although preferred embodiment of this invention was described, the technical scope of this invention is not limited to the range as described in said each embodiment. Various modifications or improvements can be added to the above embodiments. 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 is an external perspective view showing an overall configuration of a linear motor cylinder device according to a first embodiment. It is a longitudinal cross-sectional side view of the linear motor cylinder apparatus which concerns on 1st Embodiment. It is sectional drawing which shows the AA cross section in FIG. It is a figure which illustrates the structure of a linear body drive mechanism. It is an external appearance perspective view which shows the whole linear motor cylinder apparatus structure which concerns on 2nd Embodiment. It is a longitudinal cross-sectional side view of the linear motor cylinder apparatus which concerns on 2nd Embodiment. It is sectional drawing which shows the BB cross section in FIG.

Explanation of symbols

  10 cylindrical member, 13 flange, 14 spline outer cylinder, 15 ball, 16 cage, 17 permanent magnet, 17a hole, 30 cylinder rod, 32 stator coil, 34 spline groove, 35 power cord, 39 linear body drive mechanism, 40 linear scale, 41 main scale, 42 reading head, 52 permanent magnet, 53 stator coil, 55 core iron, 60 cylinder rod, 61 space, 62 frame, 63 stator coil, 64 spline groove, 66 core iron.

Claims (8)

A hollow cylindrical tubular member;
A cylinder rod installed to be movable back and forth with respect to the tubular member;
Have
The cylindrical member includes a spline outer cylinder for guiding the cylinder rod, and a field flux generation source by including a plurality of permanent magnets,
The cylinder rod is provided with a spline groove at a position corresponding to the spline outer cylinder on the outer peripheral surface of the rod, and is wound with a stator coil that generates a magnetic field at positions corresponding to the plurality of permanent magnets on the outer peripheral surface of the rod. Thus, the linear motor cylinder device is characterized in that it can freely reciprocate linearly. In the linear motor cylinder device according to claim 1,
Each of the plurality of permanent magnets is formed as an annular member having a hole through which the cylinder rod can be conducted, and is stacked and fixed in the axial direction of the cylindrical member. A linear motor cylinder device, wherein the linear motor cylinder device is installed so as to have different polarities appearing on the inner surface of the hole. In the linear motor cylinder device according to claim 1 or 2,
The linear motor cylinder device, wherein the stator coil and the spline groove are installed so as not to overlap in a circumferential direction of the rod. In the linear motor cylinder device according to claim 1 or 2,
The plurality of permanent magnets are installed so as to surround the circumferential direction of the spline outer cylinder with a certain gap therebetween,
The linear motor cylinder device, wherein the stator coil is configured to be able to advance and retract in the gap formed between the plurality of permanent magnets and the spline outer cylinder. In the linear motor cylinder device according to any one of claims 1 to 4,
The linear motor cylinder device according to claim 1, wherein a power cord for supplying current to the stator coil is wound around an outer peripheral side of the cylinder rod. In the linear motor cylinder device according to any one of claims 1 to 4,
A linear body drive mechanism is provided in which a power source cord for supplying current to the stator coil is provided with a linear body drive mechanism that allows the power cord to be drawn out and wound up in accordance with the reciprocating linear motion of the cylinder rod. Motor cylinder device. In the linear motor cylinder device according to any one of claims 1 to 6,
The linear motor cylinder device according to claim 1, wherein the stator coil is wound and installed on a core core that protrudes from an outer peripheral surface of the cylinder rod. In the linear motor cylinder device according to any one of claims 1 to 7,
A linear motor cylinder apparatus comprising position detecting means for detecting a position of the cylinder rod and controlling a reciprocating linear motion of the cylinder rod.

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