JP4733534B2 - Rotating body balance adjusting device and machine tool - Google Patents

Description

  The present invention relates to a rotating body balance adjusting device and a machine tool including the rotating body balance adjusting device.

  2. Description of the Related Art Conventionally, there has been known a balance adjusting device that is attached to a main shaft such as a grinding machine that rotates a grindstone and adjusts the rotational balance of a rotating body including the main shaft (for example, see Patent Document 1). In the balance adjusting device described in Patent Document 1, a ring-shaped vibrator made of a piezoelectric element is attached to the outer periphery of the tip portion of the main shaft, and a ring shape for adjusting the rotational balance of the main shaft on the outer peripheral side of the vibrator. The balance ring is provided. In this balance adjusting device, a traveling wave is generated on the outer peripheral surface of the vibrator due to the vibration of the vibrator, and the balance ring rotates to adjust the rotational balance of the main shaft.

  Also, a balance adjusting device that adjusts the rotational balance of the rotating drum of the washing machine is known to prevent vibration and noise in the washing machine (see, for example, Patent Document 2). The balance adjusting device described in Patent Document 2 includes a hollow annular body into which a magnetic fluid is injected, and an electromagnet that controls the movement of the magnetic fluid inside the hollow annular body. In this balance adjusting device, the hollow annular body is fixed to the rotating drum, and the electromagnet is fixed to the main body frame side of the washing machine at a position corresponding to the inner peripheral side of the hollow annular body. And at the time of rotation of the rotating drum, by energizing the winding constituting the electromagnet, by collecting the magnetic fluid on the inner peripheral side of the hollow annular body by the magnetic force generated by the electromagnet, and also stop energization to the winding, The rotational balance of the rotating drum is adjusted by collecting the magnetic fluid on the outer peripheral side of the hollow annular body by the centrifugal force of the rotating drum.

JP-A-4-131540 JP-A-8-229287

  Compared with the balance adjustment device using the vibrator and the balance ring described in Patent Document 1, the balance adjustment device using the magnetic fluid and the electromagnet described in Patent Document 2 is easy to simplify the configuration. As a result, downsizing and cost reduction are easy. However, the balance adjusting device of Patent Document 2 is used for a rotating drum of a washing machine that does not require rotational accuracy. Therefore, the balance adjusting device described in Patent Document 2 cannot be used for adjusting the rotational balance of a rotating body such as a machine tool that requires rotational accuracy. That is, even if the balance adjusting device of Patent Document 2 is used, it is not possible to adjust the rotation balance of a rotating body that requires rotation accuracy.

  Accordingly, an object of the present invention is to provide a balance adjusting device for a rotating body having a configuration capable of using a magnetic fluid for adjusting the rotational balance of the rotating body that requires rotational accuracy, and the balance adjusting device for the rotating body. To provide a machine tool.

In order to solve the above-described problems, the present invention includes a main body member fixed to a rotating body, and in a rotating body balance adjusting device that adjusts the rotating balance of the rotating body, the axial direction of the rotating shaft of the rotating body is deepened. as the direction, it is formed annularly to the body member along the circumferential direction of the rotating body Rutotomoni, a groove in which a plurality of pockets are formed outward in the radial direction of the rotating shaft, to adjust the rotation balance Therefore, the magnetic fluid injected into the groove portion and the portion of the groove portion that advances to the one side along the circumferential direction of the rotating body from the pocket portion , and the portion of the groove portion that is radially inward from the pocket portion A plurality of electromagnets that can control the movement of the magnetic fluid in the groove by generating a magnetic flux that passes at least a portion of the magnetic fluid, and a part of the magnetic fluid is aligned along the circumferential direction by the generation of the magnetic flux. Progress to one side Because of the action of the force when the rotating body is rotated away from the pocket portion that has been stored until then, the magnetic fluid is one side in the circumferential direction with respect to the pocket portion that has been stored so far. It moves to the pocket part which adjoins in, It is characterized by the above-mentioned.

  In the balance adjusting device for a rotating body according to the present invention, a plurality of pocket portions in which magnetic fluid is collected by centrifugal force when the rotating body rotates are formed in the annular groove. The plurality of pocket portions are formed at positions corresponding to the plurality of electromagnets toward the outer side in the radial direction of the rotation shaft. Further, since the magnetic flux generated in the electromagnet passes through at least the radially inner portion of the corresponding pocket portion on the side opposite to the rotation direction opposite to the rotation direction of the rotating body, by turning the electromagnet into an energized state, The magnetic fluid can be collected by the magnetic force at the radially inner portion of the corresponding pocket portion on the counter-rotating direction side.

  Therefore, the magnet collected in the radially inner portion of the pocket portion on the counter-rotation direction side is made by energizing the electromagnet while rotating the rotating body, and then stopping energization to the electromagnet (deactivating the electromagnet). A part of the fluid can be collected in the pocket portion by centrifugal force, and the remaining magnetic fluid can be caused to flow along the groove portion by inertia force and collected in another pocket portion located downstream in the rotation direction of the rotating body. That is, the magnetic fluid for adjusting the rotation balance between the plurality of pocket portions can be moved. Further, since the plurality of pocket portions are formed at positions corresponding to the plurality of electromagnets, the amount of magnetic fluid collected in each pocket portion can be individually adjusted by individually driving the electromagnets. As a result, with the configuration using the magnetic fluid and the electromagnet, it is possible to adjust the rotational balance of the rotating body that requires rotational accuracy.

In order to solve the above problems, the present invention includes a main body member fixed to a rotating body, and in a rotating body balance adjusting device that adjusts the rotating balance of the rotating body, the axial direction of the rotating shaft of the rotating body is changed. as the depth direction, the narrow width portion formed Rutotomoni formed annularly to the body member, to a predetermined width along the circumferential direction of the rotating body, toward the outside in the radial direction of the rotating shaft than the narrow portion And a plurality of widened portions formed so as to increase in width, and a plurality of discontinuous changing portions that are located between the narrowed portion and the widened portion and whose width changes more rapidly than other portions in the circumferential direction. A groove portion, a magnetic fluid injected into the groove portion to adjust the rotation balance, and a discontinuous change portion of the groove portion or a portion that proceeds to one side along the circumferential direction of the rotating body from the discontinuous change portion. At least part of the generated magnetic flux The Rukoto, anda plurality of electromagnets for controlling the movement of the magnetic fluid in the groove, the occurrence of magnetic flux, progress on one side along the circumferential direction a portion of the magnetic fluid toward the discontinuous change section Then, the magnetic fluid is separated from the widened portion that has been stored so far, and the magnetic fluid is moved in the circumferential direction with respect to the widened portion that has been stored so far by the action of the force when the rotating body is rotated after the separation. It moves to the adjacent wide part on the side, It is characterized by the above-mentioned.

  In the rotating body balance adjusting device of the present invention, the annular groove portion extends from the narrow width portion formed in a predetermined width in the rotation direction of the rotation shaft to at least the outer side in the radial direction of the rotation shaft from the narrow width portion. A plurality of discontinuous change portions that discontinuously change into a widened portion formed so as to increase in width. Therefore, the magnetic fluid can be collected on the radially outer portion of the widened portion by the centrifugal force when the rotating body rotates. In addition, the discontinuous change part is formed at a position corresponding to the electromagnet, and the magnetic flux generated in the electromagnet passes through at least the radially inner part of the corresponding discontinuous change part. The magnetic fluid can be collected in the radially inner portion of the corresponding discontinuous change portion by the magnetic force of the electromagnet.

  Therefore, by turning the electromagnet while energizing the rotating body and then de-energizing the electromagnet, a part of the magnetic fluid collected in the radially inner part of the discontinuous change part is discontinuous by centrifugal force. Gather at the radially outer part of the widened part that constitutes the changing part, and flow the remaining magnetic fluid along the groove part by inertial force, to the radially outer part of the other widened part located downstream in the rotational direction of the rotating body. Can be collected. That is, it is possible to move the magnetic fluid for adjusting the rotational balance between the plurality of widened portions. Further, since the plurality of discontinuous change portions are formed at positions corresponding to the plurality of electromagnets, the amount of magnetic fluid collected in the widened portion can be individually adjusted by individually driving the electromagnets. As a result, with the configuration using the magnetic fluid and the electromagnet, it is possible to adjust the rotational balance of the rotating body that requires rotational accuracy.

  Moreover, in the discontinuous change part, it changes discontinuously from the narrow part formed in the predetermined width to the wide part in the rotation direction of the rotating shaft. For this reason, when the rotating body rotates, the magnetic fluid collected on the radially outer side of the widened portion by centrifugal force can be reliably held on the radially outer portion of the widened portion.

In the present invention, the electromagnet includes two windings that generate magnetic flux, two windings wound around each other, and a pair of magnetic poles facing each other through a gap, and a pair of magnetic poles connected to each other to form a magnetic path. An H-type electromagnet including a return yoke to be formed, and a discontinuous change portion of the groove portion or a portion that advances to one side along the circumferential direction of the rotating body from the discontinuous change portion is disposed in the gap. Preferably it is. If comprised in this way, a magnetic fluid can be efficiently collected in the radial inside part of a discontinuous change part.

  In this invention, it is preferable to provide the permanent magnet which hold | maintains a magnetic fluid with a magnetic force between the narrow part and the wide part in the counter rotation direction opposite to a rotation direction, when a rotary body stops. If comprised in this way, it will become possible to maintain the state in which the rotation balance was adjusted also at the time of a stop of a rotary body. That is, when the rotating body is stopped after adjusting the rotation balance, a predetermined amount of magnetic fluid after balance adjustment can be held between the narrow portion and the widened portion in the counter-rotating direction. Is rotated again, a predetermined amount of magnetic fluid can be collected by centrifugal force on the radially outer portion of the corresponding widened portion, and the state in which the rotational balance is adjusted can be reproduced.

In the present invention, in the reverse rotation direction of the rotating direction opposite, it is preferable that the width of the groove toward the widening section has spread gradually outward in the radial direction from the narrow portion. With this configuration, the magnetic fluid can be smoothly moved along the outer peripheral side surface of the groove portion by the centrifugal force during the rotation of the rotating body, and the magnetic fluid can be reliably collected on the radially outer portion of the widened portion. it can.

  In the present invention, the plurality of electromagnets are preferably attached to the main body member. If comprised in this way, it will become possible to unitize a balance adjustment apparatus and the handling of a balance adjustment apparatus will become easy. For example, the balance adjusting device can be easily attached to and detached from the rotating body.

  In this invention, it is preferable that the control board which controls a several electromagnet is attached to the main body member. If comprised in this way, handling of a balance adjustment apparatus will become still easier.

  The balance adjusting device for a rotating body of the present invention can be used for a machine tool including a main shaft to which the balance adjusting device is attached. This machine tool uses a rotating body balance adjustment device that can easily simplify the configuration using a magnetic fluid and an electromagnet, and can be downsized and reduced in cost. Cost can be reduced. In addition, the balance adjustment device for a rotating body according to the present invention can adjust the rotation balance of a rotating body that requires rotational accuracy. Therefore, the spindle that requires rotational accuracy while achieving downsizing and cost reduction. Can be adjusted with high accuracy.

  A machine tool according to the present invention includes a non-contact power generation mechanism that generates power using mutual induction between a primary winding attached to a machine tool body and a secondary winding attached to a body member. It is preferable to generate electricity to be used in the balance adjustment device of the rotating body by the mechanism. If comprised in this way, the wiring between the balance adjustment apparatus rotated with a main axis | shaft and the main body of a machine tool will become unnecessary, and the structure of a machine tool can be simplified.

  As described above, in the rotating body balance adjusting apparatus according to the present invention, it is possible to adjust the rotating balance of the rotating body that requires rotational accuracy by using a magnetic fluid. Further, in the machine tool of the present invention, a rotating body balance adjusting device that can easily simplify the configuration using magnetic fluid and can be reduced in size and cost is used. Cost can be reduced.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

(Schematic configuration of the main part of the machine tool)
FIG. 1 is a side view showing a schematic configuration of a main part of a machine tool 1 according to an embodiment of the present invention. FIG. 2 is a diagram showing the power generation substrate 9 from the XX direction of FIG.

  The machine tool 1 according to this embodiment is a lathe that performs surface cutting, threading, or drilling of a predetermined workpiece (workpiece) 2. In particular, the machine tool 1 of the present embodiment is a lathe for cutting a small-sized and small workpiece 2 such as a stainless steel pipe having an inner diameter of 40 μm and an outer diameter of 100 μm, or a metal bar having a diameter of 60 μm. It is a small lathe that can be installed on a table.

  As shown in FIG. 1, the machine tool 1 includes a rotating shaft (main shaft) 4 to which a processing tool 3 that contacts and works on a workpiece 2 is fixed, and bearings 5 and 5 that rotatably support the main shaft 4. A main body frame 6 in which a rotation drive mechanism for the main shaft 4 including the main body 4 is housed, and a balance adjustment device 7 for rotating body (hereinafter referred to as a balance adjustment device 7) for adjusting the rotation balance of the rotation body 13 including the main shaft 4. And a power generation substrate 9 constituting a power generation mechanism 8 for generating electricity used in the balance adjusting device 7. In this embodiment, a rotating body 13 whose rotational balance is adjusted by the balance adjusting device 7 is constituted by the processing tool 3, the main shaft 4, and the like.

  In addition to the configuration described above, the machine tool 1 has a chucking device (not shown) that holds the workpiece 2 during processing, and a chucking device drive that moves the chucking device in the left-right direction, the vertical direction, and the vertical direction in FIG. A mechanism (not shown), a main body drive mechanism (not shown) that moves the main body frame 6 in the left-right direction and the vertical direction in FIG. 1, a balance sensor (not shown) for measuring the rotational balance of the rotating body 13, and the like It has. Note that the chucking device may include a rotation mechanism for rotating the workpiece 2 during processing. Further, the main body drive mechanism may include a configuration for moving the main body frame 6 in the vertical direction of FIG.

  As described above, in the machine tool 1 of the present embodiment, the machine tool 1 is required to have high rotational accuracy because the machine tool 1 performs cutting on the small-diameter and small workpiece 2. For example, in the machine tool 1, it is necessary to suppress the rotational runout of the rotating body 13 to be less than 0.1 μm. By adjusting the rotational balance of the rotating body 13 with the balance adjusting device 7, the rotational runout of the rotating body 13 is reduced. Suppressed below the value.

  As shown in FIG. 1, the main shaft 4 is disposed between a support portion 4a supported by two bearings 5 and 5, a tip portion 4b to which the processing tool 3 is fixed, and a support portion 4a and the tip portion 4b. And a flange portion 4c having a diameter larger than that of the support portion 4a and the tip portion 4b. As described above, since the machine tool 1 according to the present embodiment performs cutting on the small-diameter and small workpiece 2, the diameter of the main shaft 4 is also thin. For example, the diameter of the tip 4b of the main shaft 4 is 20 mm.

  The tip portion 4b includes a chucking mechanism (not shown) for fixing the processing tool 3 at the tip. Further, on the outer peripheral side of the distal end portion 4b, a male screw to which a fixing nut 10 described later for fixing the balance adjusting device 7 to the main shaft 4 is screwed is formed.

  A left end (not shown) of the support portion 4a in FIG. 1 is connected to an output shaft of a drive motor (not shown) that rotationally drives the main shaft 4 via a coupling (not shown) or the like. These drive motors, couplings, and the like constitute a rotational drive mechanism of the main shaft 4 and are accommodated in the main body frame 6. The main shaft 4 of this embodiment is configured to rotate at a high speed by a rotation drive mechanism. For example, the main shaft 4 rotates at 50000 rpm.

  The balance adjusting device 7 is formed in a substantially cylindrical shape (see FIGS. 3 and 4), and is fixed to the main shaft 4 in a state where the tip end portion 4b of the main shaft 4 is inserted into the inner peripheral side thereof. Specifically, as shown in FIG. 1, the distal end portion 4b is inserted into the inner peripheral side of the balance adjusting device 7, and one end surface (left end surface in FIG. 1) is in contact with the flange portion 4c. The balance adjusting device 7 is fixed to the main shaft 4 by screwing the fixing nut 10 into the male screw formed on 4b. As described above, the machine tool 1 according to the present embodiment cuts the small-diameter and small workpiece 2, and therefore the outer diameter of the balance adjusting device 7 is small and the axial length is also short. ing. For example, the balance adjusting device 7 has an outer diameter of 60 mm and an axial length of 30 mm. The balance adjusting device 7 may be fixed to the main shaft 4 by shrink fitting the tip end portion 4b. The detailed configuration of the balance adjusting device 7 will be described later.

  As shown in FIGS. 1 and 2, the power generation substrate 9 is formed with a through hole 9 a through which the tip portion 4 b of the main shaft 4 is inserted. The power generation substrate 9 is attached to the main body frame 6 via an attachment member 11 fixed to the main body frame 6. Specifically, the axial direction of the balance adjusting device 7 and the main shaft 4 is more on the front end side (right side in FIG. 1) of the main shaft 4 than the balance adjusting device 7 with the front end portion 4b inserted through the through hole 9a. The power generation substrate 9 is fixed to the attachment member 11 so as to face each other.

  In addition, the power generation board 9 cooperates with a later-described secondary winding 28 of the balance adjusting device 7, for example, an annular primary winding 12 for generating electricity used in the balance adjusting device 7. Has been implemented. That is, as shown in FIG. 1, the primary winding 12 is mounted on the power generation substrate 9 so as to face the secondary winding 28 in the axial direction of the main shaft 4. The primary winding 12 is wound in a spiral shape. Further, an alternating current (alternating current) that changes at a predetermined frequency is supplied to the primary winding 12, thereby generating power using mutual induction between the primary winding 12 and the secondary winding 28. . As described above, in the present embodiment, the primary winding 12 and the secondary winding 28 mounted on the power generation substrate 9 generate electricity used by an electromagnet 17 (to be described later) constituting the balance adjusting device 7. A contact-type power generation mechanism 8 is configured. In FIG. 1, for convenience, the primary winding 12 is shown protruding greatly from the power generation board 9 in the left direction in the figure. However, the actual primary winding 12 almost protrudes from the power generation board 9. It is implemented in a state without.

  In this embodiment, the frequency of the alternating current supplied to the primary winding 12 is higher than the rotation frequency of the rotating body 13 so that the rotation of the rotating body 13 is not adversely affected (that is, in order to prevent the occurrence of cogging). Is also very high. For example, the rotational frequency of the rotating body 13 is about 833 Hz (= 50000 rpm / 60 sec), whereas the frequency of the alternating current supplied to the primary winding 12 is about 1 MHz.

(Configuration of balance adjustment device)
FIG. 3 is a cross-sectional view showing a cross section in the axial direction of the balance adjusting device 7 shown in FIG. 4 is a view showing a state in which the first case body 18 and the seal member 22 are removed from the YY direction of FIG. FIG. 5 is an enlarged view showing a Z portion in FIG. 3 in an enlarged manner. 6A and 6B are diagrams for explaining the movement of the magnetic fluid M when the rotating body 13 shown in FIG. 1 is rotated. FIG. 6A shows a state in which the electromagnet 17 is in a non-energized state, and FIG. 17 shows a state in which the power is on. Note that FIG. 3 illustrates a cross section of the balance adjusting device 7 as viewed from the WW direction in FIG. 4. Further, in FIG. 6, the V portion of FIG. 4 is shown enlarged.

  As shown in FIGS. 3 and 4, the balance adjusting device 7 includes a main body member 16 fixed to the main shaft 4, three electromagnets 17 attached to the main body member 16, and a control board 21 that controls the electromagnet 17. It has. In the present embodiment, the three electromagnets 17 can be individually driven by the control board 21.

  In the following description of the balance adjusting device 7, the axial direction of the main shaft 4 (left and right direction in FIG. 3) is “axial direction”, the radial direction of the main shaft 4 is “radial direction”, and the circumferential direction of the main shaft 4 is “ It is written as “circumferential direction”. Further, the main body frame 6 side in the axial direction (left side in FIG. 3) is referred to as “main body side” and the processing tool 3 side in the axial direction (right side in FIG. 3) is referred to as “tip side”. Furthermore, in this embodiment, the spindle 4 when machining the workpiece 2 rotates only in the counterclockwise direction (direction indicated by the arrow R) in FIG. Therefore, the direction indicated by the arrow R is referred to as “rotation direction”, and the clockwise direction opposite to the rotation direction is referred to as “counter rotation direction”.

  As shown in FIG. 3, the main body member 16 is injected into first to third case bodies 18, 19, 20 made of a nonmagnetic material and a groove 19 e described later formed in the second case body 19. And a sealing member 22 for preventing leakage of the magnetic fluid M (see FIG. 6). The first case body 18, the seal member 22, the second case body 19, and the third case body 20 are fixed in a state in which those adjacent to each other in this order from the main body side to the distal end side are in contact with each other. Specifically, in a state of being positioned on three positioning knock pins 23 arranged in the axial direction at a pitch of 120 ° with respect to the rotation center of the main shaft 4 (hereinafter referred to as the rotation center). The first case body 18, the seal member 22, the second case body 19, and the third case body are also fixed by three fixing screws 24 arranged at 120 ° pitch with respect to the rotation center and in the axial direction. 20 is fixed. The knock pin 23 is disposed on the radially inner side than the screw 24. In the circumferential direction, the knock pin 23 and the screw 24 are arranged at substantially the same angle with respect to the rotation center.

  As shown in FIG. 3, the first case body 18 is formed in a thick cylindrical shape having a large radial thickness. The first case body 18 includes three round through holes 18a through which the knock pins 23 are inserted and three round through holes 18b through which the screws 24 are inserted in the axial direction at a pitch of 120 ° with respect to the rotation center. It is formed so as to penetrate through. Further, as shown in FIG. 3, three rectangular holes 18c in which a part of the electromagnet 17 is disposed are formed in the surface of the first case body 18 on the front end side so as to be recessed in the axial direction. ing. Specifically, the three square holes 18c are formed at a 120 ° pitch at positions shifted by about 60 ° in the circumferential direction from the through holes 18a and 18b.

  As shown in FIG. 3, the second case body 19 is formed in a thick cylindrical shape having a large radial thickness. 3 and 4, the second case body 19 is rotated by three round through holes 19a through which the knock pins 23 are inserted and three round through holes 19b through which the screws 24 are inserted. It is formed so as to penetrate in the axial direction at a pitch of 120 ° with respect to the center. In addition, three rectangular holes 19c in which a part of the electromagnet 17 is disposed are formed in the surface on the distal end side of the second case body 19 so as to be recessed in the axial direction. The three square holes 19c are formed at a pitch of 120 ° in the circumferential direction at positions shifted by about 60 ° from the through holes 19a and 19b. Further, the second case body 19 is formed with a pair of through holes 19d and 19d penetrating from the bottoms at both ends in the radial direction of the respective square holes 19c to the surface on the main body side. That is, in the second case body 19, three U-shaped holes composed of a square hole 19c and a pair of through holes 19d, 19d are formed at a 120 ° pitch with respect to the rotation center.

  Further, as shown in FIG. 4, an annular groove 19 e whose axial direction is the depth direction is formed on the surface of the second case body 19 on the main body side. In the groove 19e, a magnetic fluid for adjusting the rotational balance of the rotating body 13 (a very fine ferromagnetic material is uniformly dispersed in an oily or water-soluble liquid to which a surfactant or the like is added). M is injected. Specifically, the groove portion 19e is formed in a substantially annular shape in the circumferential direction, and in the radial direction, between the pair of through holes 19d and 19d and between the through hole 19a and the through hole 19b. Is formed. Moreover, as shown in FIGS. 3 and 5, the cross section in the axial direction of the groove 19e is rectangular. Furthermore, as shown in FIG. 4, the wall surface on the inner peripheral side of the groove portion 19e is formed to have a circular shape substantially concentric with the center of rotation when viewed from the axial direction. Furthermore, the depth of the groove 19e is substantially constant.

  As shown in FIGS. 4 and 6, the groove 19e has three narrow portions 19f having a narrow width (radial width), and the width expands outward in the radial direction from the narrow portion 19f. And a discontinuous change portion 19h that changes discontinuously (abruptly) from the narrow width portion 19f to the wide width portion 19g in the rotation direction (in the direction of the arrow R). It is provided at three locations. The three discontinuous change portions 19h are respectively disposed between the pair of through holes 19d and 19d. In the present embodiment, for example, the width of the widened portion 19g is 2.5 times the width of the narrow-width portion 19f, and in the discontinuous change portion 19h, the width of the groove portion 19e is 2.5 times larger in the rotational direction. In this embodiment, as shown in FIG. 6 (A), the portion of the groove portion 19e corresponding to the widened portion 19g (specifically, the widened portion 19g and a predetermined range from the widened portion 19g in the rotational direction) A pocket portion 19j is formed in which the magnetic fluid is collected by the centrifugal force F1 when the rotating body 13 rotates.

  In this embodiment, as shown in FIG. 4, the width of the groove portion 19e gradually increases outward in the radial direction from the narrow width portion 19f toward the wide width portion 19g in the counter-rotating direction. That is, the portion from the narrow width portion 19f toward the widening portion 19g on the counter-rotation direction side is a gradually widening portion in which the width of the groove portion 19e gradually expands outward in the radial direction. Specifically, as shown in FIG. 4, the wall surface on the outer peripheral side of the groove portion 19e has a radius with respect to the center of rotation from the narrow portion 19f toward the wide portion 19g in the counter-rotating direction when viewed from the axial direction. Is formed in an arc shape that gradually increases.

  Further, as shown in FIG. 4, three circular round holes 19 k that are recessed in the axial direction are formed on the surface of the second case body 19 on the front end side (not shown in FIG. 3). The three round holes 19k are formed at a pitch of 120 ° in the circumferential direction at a position shifted by about 30 ° from the square hole 19c in the rotation direction, and are positioned below the annular groove 19e in the radial direction. Is formed. That is, the three round holes 19k are formed at a position relatively close to the widened portion 19g between the narrowed portion 19f and the widened portion 19g in the counter-rotating direction.

  In each of the three round holes 19k, a cylindrical permanent magnet 25 is inserted and fixed from the front end side of the second case body 19. The three permanent magnets 25 function to hold the magnetic fluid M with a magnetic force when the rotating body 13 is stopped between the narrow portion 19f and the wide portion 19g in the counter-rotating direction.

  As shown in FIG. 3, the third case body 20 has a flange portion 20 a formed at the end on the main body side, and an inner side that is formed in a thin cylindrical shape with a small radial thickness and is arranged on the radial inner side. It includes a cylindrical portion 20b and an outer cylindrical portion 20c that is formed in a thin cylindrical shape having a small radial thickness and is disposed on the radially outer side. In the flange portion 20a, three round holes 20d into which the knock pins 23 are inserted and three screw holes 20e into which the screws 24 are screwed are formed at a pitch of 120 ° with respect to the rotation center. The distal end portion 4b of the main shaft 4 is inserted through the inner peripheral side of the inner cylindrical portion 20b. A fixing member 27 (to be described later) for fixing the control board 21 to the third case body 20 is fitted on the outer periphery of the outer cylindrical portion 20c.

  The seal member 22 is formed in a disk shape with an elastic material such as rubber, and a through hole through which the tip end portion 4b of the main shaft 4 is inserted is formed in the center portion. As shown in FIG. 3, the seal member 22 has three round through holes 22 a through which the knock pins 23 are inserted and three through holes 22 b through which the screws 24 are inserted. It is formed at a pitch. Further, as shown in FIG. 5, the seal member 22 is formed with a pair of through holes 22 c and 22 c in the second case body 19 through which a part of a first yoke 34 described later constituting the electromagnet 17 is inserted. Three positions are formed at positions corresponding to the pair of through holes 19d and 19d. The seal member 22 is sandwiched between the first case body 18 and the second case body 19 with a predetermined force, and prevents leakage of the magnetic fluid M injected into the groove portion 19e.

  As shown in FIG. 3, the control board 21 is formed in a disc shape having a circular opening 21 a that is fitted on the outer periphery of the inner cylindrical portion 20 b of the third case body 20. The control substrate 21 is fixed to the distal end side of the third case body 20 by a substantially cylindrical fixing member 27 having a substrate restraining portion 27a extending on the inner peripheral side formed on the distal end side. Specifically, the opening 21a is fitted to the distal end side of the inner cylinder part 20b, and the fixing member 27 is fitted to the outer circumference of the outer cylinder part 20c while suppressing the outer circumference of the control board 21 toward the main body side. The control board 21 is fixed to the distal end side of the third case body 20.

  A control element (not shown) for controlling the balance adjusting device 7 is mounted on the surface of the control board 21 on the main body side. That is, the control element is disposed in a space surrounded by the flange portion 20 a, the inner cylinder portion 20 b, the outer cylinder portion 20 c, and the control board 21. The control board 21 of the present embodiment includes, as a control element, for example, a photodiode (light receiving element) that performs on / off control (switching) of energization to two windings 31 and 31 described later that constitute the electromagnet 17. Yes. In this embodiment, a photodiode having a high withstand voltage (for example, one having a withstand voltage of 200 V) is used. Therefore, it is not necessary to provide a step-down circuit for the photodiode, and the circuit configuration of the control board 21 is simplified.

  In addition, for example, an annular secondary winding 28 for generating electricity used in the balance adjusting device 7 is mounted on the control board 21 in cooperation with the primary winding 12 described above. Specifically, as described above, the secondary winding 28 is mounted on the control board 21 so as to face the primary winding 12 in the axial direction. Similar to the primary winding, the secondary winding 28 is also spirally wound. A simple power storage means such as a capacitor for storing electricity generated in the secondary winding 28 by mutual induction may be provided on the control board 21. In FIGS. 1 and 3, for the sake of convenience, the secondary winding 28 is shown to protrude greatly from the control board 21 toward the front end side, but the actual secondary winding 28 almost protrudes from the control board 21. It is implemented in a state without.

  As shown in FIG. 5, the electromagnet 17 includes two windings 31 and 31 that generate magnetic flux, and a pair of magnetic poles 32 that are wound around each other through a gap, 32 and a return yoke 33 that connects the pair of magnetic poles 32 and 32 to form a magnetic path. The electromagnet 17 is provided to adjust the rotational balance of the rotating body 13 by controlling the movement of the magnetic fluid M injected into the groove 19e in the groove 19e.

  The pair of magnetic poles 32 and 32 is formed in a cylindrical shape from a magnetic material, and amplifies the magnetic flux generated by the two windings 31 and 31. As shown in FIG. 5, the pair of magnetic poles 32 and 32 are disposed so as to face each other in the axial direction. In addition, windings 31 and 31 are wound around the outer peripheral sides of the magnetic poles 32 and 32 via cylindrical bobbins (not shown). In this embodiment, when current is supplied to the windings 31, 31, the opposing surfaces of the pair of magnetic poles 32, 32 are magnetized to different polarities, and are formed between the opposing surfaces of the pair of magnetic poles 32, 32. High density magnetic flux is generated in the air gap. That is, in this embodiment, if the opposing surface of one magnetic pole 32 is magnetized to the N pole, the opposing surface of the other magnetic pole 32 is magnetized to the S pole, and a high-density magnetic flux is generated in the air gap.

  As shown in FIG. 5, the return yoke 33 is formed of a first yoke 34 formed by bending a plate-like magnetic material so that the cross section in the axial direction forms a substantially square groove shape, and a flat plate made of the magnetic material. The two second yokes 35, 35 and the third yoke 36 formed in a flat plate shape from a magnetic material are also used. The return yoke 33 suppresses leakage of the magnetic flux amplified by the magnetic poles 32 and 32 to the outside.

  The first yoke 34 includes a bottom surface portion 34a and two side surface portions 34b and 34b. As shown in FIG. 3, the first yoke 34 is formed in the second case 19 in the square hole 19c and the pair of through holes 19d and 19d of the second case body 19 with the winding 31 and the magnetic pole 32 disposed inside. The body 19 is inserted and arranged from the front surface side. Specifically, the winding 31 and the magnetic pole 32 are arranged on the inner side so that the surface on the tip side of the magnetic pole 32 is in contact with the surface on the main body side of the bottom surface portion 34a. The front side portion (the left side portion in FIG. 3) of the two side surface portions 34b, 34b to be connected is disposed in the square hole 19c, and the end portion on the main body side of the two side surface portions 34b, 34b is a pair of through holes 19d, 19d, respectively. Further, the end portions on the main body side of the two side surface portions 34 b and 34 b are respectively inserted into a pair of through holes 22 c and 22 c formed in the seal member 22.

  The two second yokes 35, 35 are arranged in the square hole 18 c of the first case body 18 so as to face each other in the radial direction, and the third yoke 36 faces the bottom surface portion 34 a of the first yoke 34. In addition, the two end faces in the radial direction are arranged in the square holes 18c of the first case body 18 so as to contact the second yokes 35 and 35, respectively. Further, in the space surrounded by the second yoke 35, 35 and the third yoke 36, the winding 31 and the winding 31 are arranged so that the surface on the main body side of the magnetic pole 32 abuts the surface on the tip side of the third yoke 36. A magnetic pole 32 is disposed. In the present embodiment, the second yokes 35 and 35 and the third yoke 36 are separated, but the second yokes 35 and 35 and the third yoke 36 may be formed integrally.

  As shown in FIG. 5, the end of the second yoke 35, 35 on the front end side and the end of the side surface 34b, 34b of the first yoke 34 on the body side are in contact with each other. As described above, a magnetic path that connects the pair of magnetic poles 32 and 32 is formed by the two yokes 35 and 35 and the third yoke 36 (that is, the return yoke 33).

  As shown in FIG. 5, a part of the second case body 19 is disposed in the gap formed between the opposing surfaces of the pair of magnetic poles 32, 32, and the groove formed in the second case body 19. 19e is arranged. Specifically, as shown in FIG. 4, the radially inner portion of the discontinuous change portion 19 h is disposed in the gap formed between the opposing surfaces of the magnetic poles 32 and 32. Therefore, the magnetic flux generated in the electromagnet 17 passes through the radially inner portion of the discontinuous change portion 19h. That is, in the gap formed between the opposing surfaces of the magnetic poles 32 and 32, the radially inner portion of the pocket portion 19j on the counter-rotating direction side is disposed, so that the magnetic flux generated in the electromagnet 17 It passes through the inner portion of 19j in the radial direction on the counter-rotating direction side.

  In the present embodiment, when the rotating body 13 is rotating while the electromagnet 17 is not energized, the magnetic fluid M collects in the pocket portion 19j by the centrifugal force F1, as shown in FIG. 6A. That is, the magnetic fluid M collects in the radially outer portion of the widened portion 19g.

  Further, when the electromagnet 17 is energized in this state, as shown in FIG. 6B, the magnetic fluid M collects in the radially inner portion of the pocket portion 19j on the counter-rotating direction side by the magnetic force of the electromagnet 17. . That is, when the electromagnet 17 is energized, the magnetic fluid M collects in the radially inner portion of the discontinuous change portion 19 h by the magnetic force of the electromagnet 17.

  Then, when the energization to the electromagnet 17 is stopped again, as shown in FIG. 6A, a part of the magnetic fluid M collected in the radially inner portion of the pocket portion 19j on the counter-rotating direction side is caused by the centrifugal force F1. The remaining magnetic fluid M gathers in the pocket portion 19j and flows to the downstream side in the rotational direction along the groove portion 19e by the inertial force F2 (see the two-dot chain line in FIG. 6A) and is located downstream in the rotational direction. Collect in the other pocket 19j. That is, a part of the magnetic fluid M collected at the radially inner portion of the discontinuous change portion 19h gathers at the radially outer portion of the widened portion 19g constituting the discontinuous change portion 19h by the centrifugal force F1, and the remaining magnetic fluid M flows along the groove portion 19e by the inertial force F2, and gathers at the radially outer portion of the other widened portion 19g located downstream in the rotational direction. Therefore, the magnetic fluid M can be moved between the three pocket portions 19j (between the three widened portions 19g) by turning the electromagnet 17 on and off. That is, the ratio of the magnetic fluid M (of the three widened portions 19g) in the three pocket portions 19j can be changed by turning on and off the electromagnet 17. The three pocket portions 19j (three discontinuous change portions 19h) are formed at positions corresponding to the three electromagnets 17, respectively. Therefore, by individually driving the electromagnet 17, the amount of the magnetic fluid M collected in each pocket portion 19j (in each widened portion 19g) can be individually adjusted.

  When the rotating body 13 is stopped, the magnetic fluid M is held by the magnetic force of the permanent magnet 25 at a position corresponding to the permanent magnet 25 of the groove 19e.

(Rotation balance adjustment method)
FIG. 7 is a flowchart showing a procedure for adjusting the rotational balance of the rotating body 13 of the machine tool 1 shown in FIG.

  In the machine tool 1 configured as described above, the rotation balance of the rotating body 13 is adjusted as follows.

  In this embodiment, adjustment of the rotation balance of the rotating body 13 is performed in a state where the main shaft 4 is rotated. That is, first, the main shaft 4 is rotated (step S1). When the main shaft 4 rotates, the magnetic fluid M collects in the pocket portion 19j (see FIG. 6A). In this state, the rotation balance of the rotating body 13 is measured by a balance sensor (not shown) (step S2), and it is determined whether or not adjustment of the rotation balance is necessary (step S3). In this embodiment, since the rotation balance of the rotating body 13 is adjusted while the main shaft 4 is rotated, the rotation balance can be adjusted while measuring the rotation balance. Therefore, it is easy to adjust the rotation balance.

  If it is determined in step S3 that adjustment of the rotation balance is not necessary, the rotation of the spindle 4 is stopped (step S9), and the adjustment of the rotation balance of the rotating body 13 is ended. On the other hand, when it is determined that the rotation balance needs to be adjusted, the power generation mechanism 8 generates power and generates electricity necessary for driving the electromagnet 17 (step S4). Specifically, the primary winding 12 is supplied with alternating current of a predetermined frequency to generate power. Note that power generation by the power generation device 8 may be performed after step S1.

  Thereafter, the electromagnet 17 is turned on (step S5). That is, based on the measurement result of the rotation balance, electricity is supplied from the control board 21 to the electromagnet 17 corresponding to the pocket portion 19j where the amount of the magnetic fluid M is to be reduced. When the electromagnet 17 is energized, the magnetic fluid M collects in the radially inner portion of the pocket portion 19j where the amount of the magnetic fluid M is desired to be reduced on the counter-rotating direction side (see FIG. 6B).

  Thereafter, energization to the electromagnet 17 is stopped (step S6). When the electromagnet 17 is in a non-energized state, part of the magnetic fluid M collected in the radially inner portion of the corresponding pocket portion 19j on the counter-rotating direction side gathers in the pocket portion 19j by the centrifugal force F1, and the remaining magnetic fluid M flows to the downstream side in the rotational direction along the groove portion 19e by the inertial force F2, and gathers in another pocket portion 19j located on the downstream side in the rotational direction.

  Thereafter, the rotational balance of the rotating body 13 is again measured (step S7), and it is determined whether or not the rotational balance needs to be adjusted (step S8). When the adjustment of the rotation balance is not necessary, the rotation of the main shaft 4 is stopped (step S9), and the adjustment of the rotation balance of the rotating body 13 is ended. On the other hand, when it is necessary to adjust the rotation balance, the process returns to step S5 until the rotation balance of the rotating body 13 becomes appropriate (that is, the rotational shake of the rotating body 13 is equal to or less than a predetermined value or less than a predetermined value). Until the rotation balance is adjusted.

(Main effects of this form)
As described above, in this embodiment, the electromagnet 17 is energized while rotating the rotating body 13, and then the energization to the electromagnet 17 is stopped. The magnetic fluid M for adjusting the rotational balance can be moved (between the parts 19g). In addition, by individually driving the three electromagnets 17, the amount of the magnetic fluid M collected in each pocket portion 19j (the radially outer portion of each widened portion 19g) can be individually adjusted. As a result, with the configuration using the magnetic fluid M and the electromagnet 17, it is possible to adjust the rotational balance of the spindle 4 that requires rotational accuracy.

  That is, in the machine tool 1 of the present embodiment, the balance adjusting device 7 that can easily simplify the configuration using the magnetic fluid M and the electromagnet 17 and can be reduced in size and cost is used. 1 can be reduced in size and cost. In addition, the rotation balance of the spindle 4 that requires rotational accuracy can be accurately adjusted without stopping the rotation of the rotating body 13 while reducing the size and cost.

  Further, the groove portion 19e of the present embodiment includes a discontinuous change portion 19h. In the discontinuous change portion 19h, the width of the groove portion 19e is discontinuous in the rotation direction from the narrow width portion 19h to the wide width portion 19g (abruptly). To) change. Therefore, when the rotating body 13 rotates, the magnetic fluid M collected in the pocket portion 19j (outward in the radial direction of the widened portion 19g) by the centrifugal force F1 is prevented from flowing out to the downstream side in the rotational direction, and the magnetic fluid M is allowed to flow into the pocket portion. 19j (in the radially outer portion of the widened portion 19g) can be securely held.

  In particular, in this embodiment, the electromagnet 17 is a so-called H-type electromagnet, and the radially inner portion of the pocket portion 19j in the counter-rotating direction is disposed in a gap formed between the pair of magnetic poles 32 and 32. . Therefore, the magnetic fluid M can be efficiently collected at the radially inner portion of the pocket portion 19j in the counter-rotating direction. That is, since the radially inner portion of the discontinuous change portion 19h is disposed in the gap formed between the magnetic poles 32 and 32, the magnetic fluid M is efficiently disposed on the radially inner portion of the discontinuous change portion 19h. Can be collected.

  In this embodiment, three permanent magnets 25 that hold the magnetic fluid M with magnetic force when the rotating body 13 is stopped are provided between the narrow portion 19f and the wide portion 19g in the counter-rotating direction. Therefore, even when the rotating body 13 is stopped, the state in which the rotation balance is adjusted can be maintained. That is, when the rotating body 13 is stopped after the rotation balance is adjusted, a predetermined amount of magnetic fluid after balance adjustment is provided at the groove portion 19e corresponding to the permanent magnet 25 between the narrow portion 19f and the wide portion 19g. Since M can be held, when the rotating body 13 rotates again, the same amount of magnetic fluid M as before stopping can be collected in the corresponding pocket portion 19j by the centrifugal force F1, and the rotational balance is adjusted. Can be reproduced. In particular, in this embodiment, since the permanent magnet 25 is disposed relatively close to the widened portion 19g between the narrowed portion 19f and the widened portion 19g in the counter-rotating direction, the rotational balance is adjusted. Can be reliably reproduced.

  In this embodiment, in the counter-rotating direction, the width of the groove 19e gradually increases outward in the radial direction from the narrow portion 19f to the wide portion 19g. Therefore, the magnetic fluid M can be smoothly moved along the outer peripheral side surface of the groove 19 by the centrifugal force F <b> 1 during rotation of the rotating body 13. As a result, the magnetic fluid M can be reliably collected in the pocket portion 19j.

  In this embodiment, three electromagnets 17 are attached to the main body member 16. A control board 21 that controls the electromagnet 17 is also attached to the main body member 16. Therefore, the balance adjusting device 7 can be unitized, and the balance adjusting device 7 can be easily handled. For example, the balance adjusting device 7 can be easily attached to and detached from the main shaft 4.

  In this embodiment, electricity used in the balance adjusting device 7 is generated by the non-contact power generation mechanism 8 that uses mutual induction between the primary winding 12 and the secondary winding 28. Therefore, wiring between the balance adjusting device 7 and the main body of the machine tool 1 becomes unnecessary, and the configuration of the machine tool 1 can be simplified.

(Other embodiments)
The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited to this, and various modifications can be made without departing from the scope of the present invention. For example, the balance adjusting device 7 may be configured using the second case body 59 formed with the annular groove portion 59e shown in FIG. 8 instead of the second case body 19 formed with the groove portion 19e described above. . That is, as shown in FIG. 8, a groove portion 59e is formed that includes three pocket portions 59j that are formed in a substantially arc shape so as to expand outward in the radial direction and at a pitch of 120 ° with respect to the rotation center. Alternatively, the balance adjusting device 7 may be configured using the second case body 59.

  In the second case body 59, the inner peripheral wall surface and the outer peripheral wall surface of the groove 59e are formed to have a circular shape substantially concentric with the center of rotation when viewed from the axial direction. The second case body 59 corresponds to the square hole 19c and the pair of through holes 19d and 19d of the above-described form, respectively, and the square hole 59c and the pair of through holes 59d and 59d in which a part of the electromagnet 17 is disposed. Are formed, and three pocket portions 59j are formed so as to correspond to the positions where the square holes 59c and the through holes 59d and 59d are formed. Furthermore, in the gap formed between the opposed surfaces of the pair of magnetic poles 32, 32, the radially inner portion of the pocket portion 59j on the counter-rotating direction side is disposed. Therefore, the magnetic flux generated in the electromagnet 17 passes through the radially inner portion of the pocket portion 59j on the counter-rotating direction side. Further, in the second case body 59, three round holes 59k corresponding to the three round holes 19k described above are formed at positions corresponding to the end portions on the rotational direction side of the pocket portion 59j. The permanent magnet 25 is fixed to the round hole 59k. The three permanent magnets 25 fulfill the function of holding the magnetic fluid M at the rotation direction end of the pocket portion 59j when the rotating body 13 is stopped. Note that through holes corresponding to the above-described through holes 19a and 19b are also formed in the second case body 59, but illustration thereof is omitted in FIG.

  Like the groove part 59e shown in FIG. 8, the groove part formed in a 2nd case body does not necessarily need to be provided with the discontinuous change part corresponded to the discontinuous change part 19h of the form mentioned above. Even in this case, the magnetic fluid M can be moved between the three pocket portions 59j by energizing the electromagnet 17 while rotating the rotating body 13 and then stopping energization of the electromagnet 17. it can. In addition, by individually driving the three electromagnets 17, the amount of the magnetic fluid M collected in each pocket portion 59j can be individually adjusted. As a result, with the configuration using the magnetic fluid M and the electromagnet 17, it is possible to adjust the rotational balance of the spindle 4 that requires rotational accuracy.

  Further, in the above-described form and the other form shown in FIG. 8, the second case body 19, 59 has three pocket portions 19j, 59j, and the second case body 19 has a discontinuous change portion 19h. Three are formed. In addition to this, for example, the number of pocket portions 19j and 59j and the discontinuous change portion 19h formed in the second case bodies 19 and 59 may be two, or may be four or more. Further, as long as the magnetic fluid M can move between the pocket portions 19j and 59j, the grooves 19e and 59e do not necessarily have to be formed in an annular shape.

  Furthermore, in the embodiment described above and the other embodiment shown in FIG. 8, the pair of magnetic poles 32 and 32 are disposed so as to face each other in the axial direction. In addition, for example, the pair of magnetic poles 32 and 32 may be arranged so as to face each other in the radial direction. The electromagnet 17 is not limited to an H-type electromagnet, and may be an electromagnet that does not include the return yoke 33, for example. Furthermore, the electromagnet is not necessarily provided with a pair of magnetic poles, and may have only one magnetic pole.

  Furthermore, in the embodiment described above and the other embodiment shown in FIG. 8, the inside of the pocket portion 19j, 59j in the radial direction on the counter-rotating direction side is formed in the gap formed between the opposing surfaces of the pair of magnetic poles 32, 32. A portion (a radially inner portion of the discontinuous change portion 19h) is disposed. However, even if the inner portion of the pocket portion 19j, 59j in the radial direction on the counter-rotating direction side (the inner portion in the radial direction of the discontinuous change portion 19h) is not disposed in the gap between the magnetic poles 32, 32, If the magnetic flux generated in the electromagnet 17 passes through at least the radially inner portion (the radially inner portion of the discontinuous change portion 19h) of the pocket portions 19j and 59j on the counter-rotation direction side, the above-described effects can be obtained. It becomes possible to obtain.

  Further, in the embodiment described above and the other embodiment shown in FIG. 8, the electromagnet 17 is attached to the second case bodies 19 and 59 constituting the main body member 16. In addition, for example, the electromagnet 17 may be attached to a member different from the main body member 16 and the other member may be fixed to the main shaft 4.

  Further, in the embodiment described above, one balance adjusting device 7 is attached to the tip end side (right side in FIG. 1) of the main shaft 4. In addition to this, for example, as shown in FIG. 9, a total of two balance adjusting devices 7 may be attached, one on each side of the portion of the main shaft 4 that is supported by bearings 5 and 5. In the case of such a configuration, the rotation balance of the rotating body 13 can be adjusted more appropriately. In FIG. 9, the same components as those shown in FIG. 1 and the components equivalent to those shown in FIG.

  Furthermore, with the form mentioned above, the electricity used by the balance adjusting device 7 is generated by the power generation mechanism 8. In addition to this, for example, a rechargeable battery may be attached to the balance adjusting device 7 and electricity used in the balance adjusting device 7 may be supplied from this battery.

  In the above-described embodiment, the processing tool 3 is fixed to the tip of the main shaft 4. In addition, for example, the workpiece 2 may be fixed to the tip of the main shaft 4. In the above embodiment, a lathe is taken as an example of the machine tool 1 to describe the embodiment of the present invention. However, the machine tool 1 is not limited to a lathe, and is a milling machine, a grinding machine, a machining center, or the like. There may be. Furthermore, the rotation balance of the rotating body may be adjusted by using the balance adjustment 7 of the above-described form by a device other than the machine tool 1 having the rotating body (for example, a motor having a rotor as the rotating body). .

It is a side view which shows schematic structure of the principal part of the machine tool concerning embodiment of this invention. It is a figure which shows the board | substrate for electric power generation from the XX direction of FIG. It is sectional drawing which shows the cross section of the axial direction of the balance adjusting apparatus shown in FIG. It is a figure which shows the state which removed the 1st case body and the sealing member from the YY direction of FIG. It is an enlarged view which expands and shows the Z section of FIG. It is a figure for demonstrating the motion of the magnetic fluid at the time of rotation of the rotary body shown in FIG. 1, (A) shows when the electromagnet is in a non-energized state, and (B) shows when the electromagnet is in an energized state. Show. It is a flowchart which shows the adjustment procedure of the rotation balance of the rotary body of the machine tool shown in FIG. It is a figure which shows the 2nd case body concerning other embodiment of this invention from the YY direction of FIG. It is a side view which shows the periphery of the main axis | shaft of the machine tool concerning other embodiment of this invention.

Explanation of symbols

1 Machine tool 4 Spindle (Rotating shaft)
6 Body frame (body)
7 Rotating body balance adjusting device 8 Power generation mechanism 12 Primary winding 13 Rotating body 16 Main body member 17 Electromagnet 19, 59 Second case body 19e, 59e Groove portion 19f Narrow width portion 19g Widening portion 19h Discontinuous change portion 19j, 59j Pocket Part 21 Control board 25 Permanent magnet 28 Secondary winding 31 Winding 32 Magnetic pole 33 Return yoke F1 Centrifugal force M Magnetic fluid

Claims (9)

In a balance adjustment device for a rotating body that includes a main body member fixed to the rotating body and adjusts the rotation balance of the rotating body,
As the depth direction in the axial direction of the rotation axis of the rotating body, the rotating body along a circumferential direction of an annular shape on the body member Rutotomoni, multiple toward the outside in the radial direction of the rotary shaft pockets A groove part in which the part is formed ,
A magnetic fluid injected into the groove to adjust the rotational balance;
At least a part of the groove portion is a portion that progresses to one side along the circumferential direction of the rotating body from the pocket portion and that is radially inward of the pocket portion of the groove portion. A plurality of electromagnets capable of controlling the movement of the magnetic fluid in the groove by generating magnetic flux ;
Comprising
Due to the generation of the magnetic flux, a part of the magnetic fluid travels to one side along the circumferential direction and leaves the pocket portion that has been stored so far.
The magnetic fluid moves to the adjacent pocket portion on one side in the circumferential direction with respect to the pocket portion that has been stored so far due to the action of force when the rotating body is rotated after the separation. To
The balance adjustment apparatus of the rotary body characterized by the above-mentioned. In a balance adjustment device for a rotating body that includes a main body member fixed to the rotating body and adjusts the rotation balance of the rotating body,
The axial direction of the rotation axis of the rotating body as a depth direction along the circumferential direction of the rotary body is formed annularly on the main body member Rutotomoni, narrow portion formed in a predetermined width, the narrow Than the other portion in the circumferential direction and located between the narrow portion and the widened portion, and the widened portion formed so that the width is wider toward the outside in the radial direction of the rotating shaft than the portion Groove portions each having a plurality of discontinuous change portions whose widths change rapidly ,
A magnetic fluid injected into the groove to adjust the rotational balance;
By generating a magnetic flux in which at least a part passes through the discontinuous change portion of the groove portion or a portion that advances to the one side along the circumferential direction of the rotating body from the discontinuous change portion. A plurality of electromagnets for controlling the movement of the magnetic fluid;
Comprising
Due to the generation of the magnetic flux, a part of the magnetic fluid moves toward the one side along the circumferential direction toward the discontinuous change portion and leaves the widened portion that has been stored so far.
The magnetic fluid moves to the adjacent widened portion on one side in the circumferential direction with respect to the widened portion that has been stored so far due to the action of the force when the rotating body is rotated after the separation. To
The balance adjustment apparatus of the rotary body characterized by the above-mentioned. The electromagnet has two windings for generating magnetic flux, a pair of the two windings wound around each other, and a pair of magnetic poles facing each other through a gap and connecting the pair of magnetic poles to form a magnetic path An H-type electromagnet including a return yoke that
3. The discontinuous change portion of the groove portion or a portion that advances to one side along the circumferential direction of the rotating body from the discontinuous change portion is disposed in the gap. The rotating body balance adjusting device as described.   The permanent magnet which hold | maintains the said magnetic fluid with a magnetic force at the time of the stop of the said rotary body is provided between the said narrow part and the said wide part in the counter rotation direction opposite to the said rotation direction, or characterized by the above-mentioned. 3. The balance adjustment device for a rotating body according to 3. Wherein in a counter rotation direction of the rotating direction opposite, 4 claim 2, characterized in that the width of the groove from the narrow portion toward the wider section has spread gradually on the outside of the front Ki径direction The rotating body balance adjusting device according to claim 1.   The balance adjustment device for a rotating body according to any one of claims 1 to 5, wherein the plurality of electromagnets are attached to the main body member.   The balance adjustment device for a rotating body according to claim 6, wherein a control board that controls the plurality of electromagnets is attached to the main body member.   A machine tool comprising the rotating body balance adjusting device according to claim 1 and a main shaft to which the balance adjusting device is attached. A non-contact power generation mechanism that generates power using mutual induction between a primary winding attached to the main body of the machine tool and a secondary winding attached to the main body member;
9. The machine tool according to claim 8, wherein the power generation mechanism generates electricity used in the balance adjustment device for the rotating body.

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