JP2006102891A - Grinder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinder, suitably controlling the depth of cut of a grinding wheel. <P>SOLUTION: This grinder 10 includes: a support cylinder 20; a main rotor 21 rotating around the main axis 28; and a grinding wheel 38 moved in rotation around the main axis 28 with the above rotation and rotated around the spindle axis 39 parallel to the main axis 28. Further, the grinder 10 includes a moving member 30 disposed in the main rotor 21 and reciprocated parallel to the main axis 28; and a cutting mechanism for causing the spindle axis 39 to approach to and separate from the main axis 28 by the above reciprocating motion. The moving mechanism includes: a rotating shaft 56 driven in rotation around the rotation axis parallel to the main axis 28 provided on the support cylinder 20 and spaced at a predetermined distance; a ball screw 57 for converting the rotation of the rotating shaft 56 to the reciprocation parallel to the main axis 28; and a transmission means for transmitting the converted reciprocating motion to the moving member 30 in the main rotor 21. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a grinding machine that precisely grinds an end portion, a hole, or the like of an irregularly shaped workpiece by a rotating grindstone.

  Conventionally, in a so-called jig grinder that grinds irregularly shaped workpieces such as jigs and dies with high precision, the spindle unit itself with a grindstone is rotated and revolved (revolved) by the main rotating body while drilling. And processing the edges. At this time, the cutting amount of the grindstone mounted on the spindle is adjusted by shifting the position of the spindle unit with respect to the main axis, which is the rotation axis of the main rotating body, in the radial direction of the main rotating body. It is designed to grind holes in tools, grind ends, or grind holes with different diameters. An example of a structure in which another axis is shifted with respect to such a predetermined axis is a machine tool described in Patent Document 1, for example. In addition, although this patent document 1 is not related with a grinding machine regarding a machine tool, the thing of the following structures was common also in the jig grinding machine.

  FIG. 9 is a cross-sectional view showing the main part of such a conventional jig grinding machine. In the following description, the upper side of the figure is the upper side and the right side is the right side. As shown in FIG. 9, a control cam 102 with a spring 103 attached to the tip is inserted into a main rotating body 101 that rotates about a main axis 100 extending in the vertical direction. The rotating body 101 is biased upward. A slope 102 a that obliquely intersects the main axis 100 is formed at the lower end of the control cam 102.

  At the upper end of the motor mounting base 104 provided at the lower end of the main rotating body 101, a vertically long wedge-shaped lever 105 with a sharp upper end is rotatably provided on a horizontal rotation shaft 106. A protrusion 105a that engages with the inclined surface 102a is formed on the upper end of the lever 105, and a slide part 107 that extends in the left-right direction is attached to the lower end of the lever 105 so as to be capable of linear movement by being regulated by a bearing. A spring 108 configured as a compression coil spring is disposed on the left side of the slide portion 107, and urges the slide portion 107 to be constantly pressed to the right side.

  A spindle unit 110 is connected to a lower end portion of the motor mounting base 104 via a slide portion 107 and a slide plate 109. A spindle (not shown) is built in the spindle unit 110, and a spindle 110a that rotates about a spindle axis 111 parallel to the main axis 100 by the motor projects from the lower end of the motor. A grindstone 112 is attached, and the workpiece 113 is ground by the grindstone 112.

  A slide bar 114 extending in a direction perpendicular to the main axis 100 is provided at the upper end portion of the control cam 102, and both ends of the slide bar 114 protrude to the outside of the main rotating body 101. A cylindrical cut feed moving nut 116 is provided on the outer surface of the main rotating body 101 via a bearing 115. The bearing 115 is located at the lower end of the cutting feed moving nut 116, and both ends of the slide bar 114 are joined to the inner ring of the bearing 115. A thread groove 116 a of a triangular screw is formed on the inner peripheral surface from the center portion to the upper end portion of the cut feed moving nut 116. A cylindrical control screw 117 fixed to an external case (not shown) is provided on the outer surface of the main rotor 101 above the cut feed moving nut 116, and the influence of the rotation of the main rotor 101 by the bearing 118 is provided. Not to receive. On the outer peripheral surface of the lower end portion of the control screw 117, a thread 117a of a triangular screw is formed. The thread 117a and the thread groove 116a of the cutting feed moving nut 116 are screwed together. The control screw 117 and the cut feed moving nut 116 are arranged so that the main axis 100 becomes the central axis so that a rotational moment that is a force not parallel to the main axis 100 does not occur in the control cam 102 or the like. Since the main rotating body 101 rotates around the main axis 100, the control screw 117 and the cut feed moving nut 116 need to be arranged so as to avoid the main rotating body 101. Therefore, the control screw 117 and the cut feed moving nut 116 are large members so as to surround the main rotating body 101.

  A spline shaft 119 extending in parallel with the main axis 100 is provided on the side of the cut feed moving nut 116, and an outer cylinder 120 is provided on the outer surface of the spline shaft 119. A ball as a rolling element (not shown) is incorporated between the outer cylinder 120 and the spline shaft 119, and a so-called ball spline is formed by the spline shaft 119, the outer cylinder 120 and the ball. A gear 121 is provided on the outer peripheral surface of the outer cylinder 120, and the gear 121 and the cut feed moving nut 116 are engaged with each other. A gear 122 is provided on the upper end portion of the spline shaft 119 via a rotation shaft of the spline shaft 119. A motor 123 is disposed above the gear 122, and a gear 124 is provided at the lower end of the motor 123 via a rotation shaft of the motor 123. The gear 124 and the gear 122 are meshed with each other.

  Next, the operation when changing the cutting depth will be described. First, the main rotating body 101 slowly rotates (revolves) in a predetermined direction along the main axis 111. At this time, the inner ring of the control cam 102, the slide rod 114 disposed on the upper portion of the control cam 102, and the bearing 115 fixed to the slide rod 114 also revolves as the main rotor 101 rotates. On the other hand, since this revolution is not transmitted to the outer ring of the bearing 115, the outer ring of the bearing 115 and the cut feed moving nut 116 fixed thereto do not revolve. Further, since the control screw 117 is also fixed to an external case (not shown), it does not revolve.

  From this state, when the motor 123 is rotated clockwise in plan view in order to change the cut amount, the spline shaft 119 is rotated via the gear 124 and the gear 122, and the outer cylinder 120 and the gear 121 are rotated along with this rotation. It is rotated. When the gear 121 is rotated, the cut feed moving nut 116 is rotated. The screw groove 116a of the cut feed moving nut 116 and the screw thread 117a of the control screw 117 are relatively moved downward. At this time, since the control screw 117 is fixed to an external case (not shown), the cut feed moving nut 116 moves downward. At this time, the height of the gear 121 is regulated with respect to the cut feed movement nut 116, and moves on the spline shaft 119 together with the outer cylinder 120 as the cut movement feed nut 116 moves downward. Therefore, even if the cutting movement feed nut 116 moves downward, the cutting feed movement nut 116 and the gear 121 are not disengaged. As the cut feed movement nut 116 moves downward, the outer ring of the bearing 115 moves downward, and the revolving movement of the inner ring of the bearing 115 is transmitted. The rotating inner ring of the bearing 115 moves the control cam 102 downward via the slide bar 114.

  When the control cam 102 is pushed downward against the urging force of the spring 103, the projection 105a is pushed obliquely downward to the right by the inclined surface 102a, and the lever 105 rotates clockwise in the figure around the rotation shaft 106. Is rotated (oscillated). Thereby, since the lower end of the lever 105 is connected to the slide part 107 by a nut (not shown), the rotational movement of the lower end of the lever 105 is a linear movement that horizontally moves the slide part 107 to the left side via the nut. After being converted, the slide portion 107 is slid to the left against the urging force of the spring 108. As the slide unit 107 is slid, the spindle unit 110 is slid through the slide plate 109, the spindle axis 111 is slid to the left, and the spindle axis 111 is bored away from the main axis 100. For example, the cutting amount of the grindstone 112 is increased. If the motor 123 is rotated counterclockwise in plan view, the spindle axis 111 is close to the main axis 100, and the cutting amount of the grindstone 112 is reduced.

Therefore, in this jig grinding machine, first, as shown in FIG. 10A, the main axis 100 and the spindle axis 111 coincide with each other (the cutting change amount of the grindstone 112, that is, the revolution of the grindstone is zero). Then, the control cam 102 is pushed downward. Then, as shown in FIG. 10B, the slide plate 109 moves to the left side, and the position of the spindle axis 111 can be shifted in the radial direction of the main rotating body 101 with respect to the main axis 100. As a result, the spindle axis 111 is revolved around the main axis 100 as the main rotating body 101 rotates about the main axis 100. At this time, a change in the distance A between the main axis 100 and the spindle axis 111 becomes a change in the cutting amount of the grindstone 112. As described above, the motor 123 is rotated from the outside of the main rotating body 101 according to a desired cutting amount, and thereby the cutting feed moving nut 116 is moved up and down to control the control cam 102 in the main rotating body 101 via the bearing 115. Move up and down. By changing the cutting amount in accordance with the revolution of the main rotating body 101 by the reciprocating motion of the control cam 102, it is possible to precisely grind jigs and dies having complicated shapes according to their shapes. it can.
JP-A-5-277811

  By the way, in the case of the conventional jig grinding machine, in order to change the cutting amount, the thread 117a of the triangular screw of the control screw 117 provided around the main rotating body 101 and the large cutting provided around the screw thread 117a. The moving member 102 is reciprocated up and down by using a screw pair with the thread groove 116a of the feed moving nut 116.

For this reason, the gap between the screw thread 117a and the screw groove 116a due to the slip pair is unavoidable, and there is a problem that the accuracy cannot be increased.
Furthermore, the thread 117a and the thread groove 116a were easily worn by friction between the thread 117a and the thread groove 116a. As a result, there is a problem that it becomes difficult to reciprocate the moving member 102 accurately with the use time, which is a major factor that causes a decrease in grinding accuracy.

  Further, since the mass of the cut feed moving nut 116 itself is large, there is a problem that inertia following rotation is large and followability cannot be improved. In particular, it becomes a major obstacle when the direction of rotation constantly changes according to the shape of the workpiece.

  On the other hand, even if it is attempted to increase the accuracy and reduce the play, the control screw 117 and the cut feed moving nut 116 are large-sized screw pairs that surround the periphery of the main rotating body 101, so that the frictional resistance increases. End up. For this reason, there is a problem that the motor 123 is required to have a large capacity, or if the motor 123 has the same capacity, the change rate of the cutting amount becomes slow and the productivity is deteriorated.

  The present invention has been made paying attention to such problems. The purpose is to provide a grinding machine capable of appropriately adjusting the cutting amount of the grindstone.

  In order to achieve the above object, an invention according to claim 1 includes a main body, a main rotor that is rotatably supported by the main body, and rotates about a main axis. A spindle on which a grindstone can be mounted, which is rotated around the main axis along with the rotation and rotated about the spindle axis parallel to the main axis, and reciprocating in parallel with the main axis. A moving member that reciprocates the moving member, and a notch mechanism that moves the spindle axis close to or away from the main axis by the reciprocating movement of the moving member. The drive member is rotated about a rotation axis that is parallel to the main axis provided at the portion and spaced apart by a predetermined distance, and the rotation of the drive member is set to the main axis by using a screw pair of a screw and a nut. Change to parallel reciprocation Converting means for, and summarized in that and a transmitting means for transmitting the converted reciprocating the moving member of the main rotating body.

  According to the above configuration, since the driving member and the converting means are arranged at positions separated from the main axis, there is no need to provide the converting means so as to surround the periphery of the main rotor as in the case of the conventional cutting movement feed nut. The conversion means can be made compact without being affected by the shape of the main rotor.

The gist of the invention described in claim 2 is that, in the invention described in claim 1, a plurality of the conversion means are arranged equiangularly around the main axis.
According to the above configuration, since a plurality of conversion means are arranged equiangularly around the main axis, a rotational moment that is a force not parallel to the main axis from the drive member to the moving member via the conversion means and the transmission means. Is less likely to occur. Therefore, the accuracy of controlling the cut amount is improved.

The invention according to claim 3 is characterized in that, in the invention according to claim 2, the conversion means is disposed at a symmetrical position with the main axis as the symmetry axis.
According to the above configuration, the conversion means is arranged symmetrically with respect to the main axis, so that no rotational moment is generated and the most compact configuration can be achieved.

The gist of the invention described in claim 4 is that, in the invention described in claim 2 or claim 3, the plurality of drive members are driven in synchronization from the same drive source.
According to the above configuration, since the force applied to each converting means is made uniform, a rotational moment due to a difference in driving force does not occur.

The gist of the invention according to claim 5 is that, in the invention according to any one of claims 1 to 4, the conversion means is configured as a ball screw.
Here, the “ball screw” is a screw pair configured by circulating a ball between a male screw and a female screw (nut). According to the above configuration, since the driving resistance is reduced by using the ball screw, the mechanical efficiency is increased to about 95% with the ball screw, while the mechanical efficiency is about 20 to 30% with the normal triangular screw. As a result, the output of the drive source can be reduced. Further, if the same drive source is used, the cutting response is improved and the working efficiency is improved. Furthermore, since the rolling friction is caused by the ball screw, there is no error caused by sliding friction like the triangular screw. Therefore, it becomes possible to perform grinding work accurately and efficiently on the workpiece.

A sixth aspect of the invention is characterized in that, in the invention according to any one of the first to fifth aspects, the driving member is belt-driven.
According to the above configuration, the apparatus can be relatively simplified. In particular, when driving a plurality of driving members, the effect is increased. In addition, since an error caused by gear backlash does not occur, the accuracy can be improved.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein when the moving member is reciprocated, the moving direction of the moving member is relative to the main axis. The gist of the invention is that a guide mechanism for guiding them in parallel is provided between the main body and the transmission means.

  According to the above configuration, the moving member can be moved more strictly in parallel with the main axis by the guide mechanism, so that the cutting accuracy is improved. In particular, when there is only one drive member and conversion means, a rotational moment is likely to occur, but this is effectively suppressed.

  The invention according to an eighth aspect is the invention according to the seventh aspect, wherein the guide mechanism is disposed at a position displaced by 90 degrees in any direction about the main axis with respect to any of the conversion means. It is a summary.

According to the said structure, this is effectively suppressed with respect to the conversion means which produces a rotational moment.
The invention according to claim 9 is the invention according to claim 7, wherein the guide mechanism is disposed at two positions displaced by 90 degrees in both directions around the main axis with respect to any of the converting means. It is a summary.

According to the said structure, this is suppressed more effectively with respect to the conversion means which produces a rotational moment.
The gist of a tenth aspect of the present invention is that, in the seventh aspect of the invention, the guide mechanism is disposed at a position opposed to any one of the conversion means with a main axis as a center. .

According to the said structure, this is effectively suppressed with respect to the conversion means which produces a rotational moment.
The gist of an eleventh aspect of the invention is that, in the invention according to any one of the seventh to tenth aspects, the guide mechanism is configured as a ball spline.

  Here, the “ball spline” refers to a pair in which a ball is circulated between a sleeve (outer cylinder) and a spline shaft, and the outer cylinder moves on the spline shaft by a rolling motion. According to the above configuration, since the guide mechanism is configured as a ball spline, the support rigidity is high, and the accuracy is improved without rattling. In addition, a smooth guide can be provided. Therefore, high-precision grinding is possible without reducing the cutting response.

  ADVANTAGE OF THE INVENTION According to this invention, the grinding machine which can adjust appropriately the cutting amount of a grindstone can be provided.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Embodiments of the invention will be described below with reference to the drawings.
FIG. 1 is a front view of the grinding machine 10, and the front side of the drawing is a front portion of the grinding machine 10 in the following description. As shown in FIG. 1, the grinding machine 10 includes a machine base 11. A processing table 12 that is movable in the front-rear direction and the left-right direction with respect to the machine base 11 is provided at the front upper surface of the machine base 11. A chuck 13 is disposed on the processing table 12, and a work 14 is placed on the chuck 13. A column 15 is erected on the upper rear portion of the machine base 11. A spindle head 16 that is movable in the vertical direction with respect to the column 15 is provided at the front portion of the column 15, and the spindle head 16 is covered with a cover 17.

  As shown in the cross-sectional view of the main part of the grinding machine 10 in FIG. 2, the spindle head 16 includes a support cylinder 20 that constitutes a main body, and a cylindrical shape longer than the support cylinder 20 is formed inside the support cylinder 20. A main rotor 21 is disposed. The upper end portion of the main rotor 21 extends above the upper end of the support cylinder 20, and the lower end portion of the main rotor 21 extends below the lower end of the support cylinder 20.

  A pulley 22 is provided at the upper end of the main rotating body 21, and the pulley 22 is connected to a pulley 24 connected to a rotating shaft of a motor 23 via a belt 25. That is, the rotation of the motor 23 is transmitted to the main rotating body 21 via the pulley 24, the belt 25 and the pulley 22. At this time, the main rotating body 21 is rotated around a main axis 28 that is an axis extending through the center of the main rotating body 21 and extending in the vertical direction. A plurality of first bearings 26 and second bearings 27 are interposed between the support cylinder 20 and the main rotor 21 at the upper end portion and the lower end portion of the support cylinder 20, respectively. The rotation is not transmitted to the support cylinder 20. That is, the main rotating body 21 is rotatably supported by the support cylinder 20.

  A pair of elongated holes 29 penetrating the inside and outside of the main rotator 21 are formed at positions facing each other (perpendicular to the paper surface in FIG. 2) at the center in the vertical direction of the main rotator 21. Inside the main rotor 21, a rod-shaped moving member 30 is disposed so as to reciprocate along the main axis 28. A male screw 31 constituting a ball screw extending downward is disposed at the lower end of the moving member 30.

  A substantially cylindrical sub-rotor 33 that rotates about a sub-axis 32 coaxial with the axis of the male screw 31 is held at the lower end of the main rotor 21 so as to be rotatable with respect to the main rotor 21. . That is, the upper end portion of the sub-rotator 33 enters the lower end portion of the main rotor 21, and between the inner wall of the lower end portion of the main rotor 21 and the outer wall of the upper end portion of the sub-rotator 33, A preloaded bearing 34 is interposed. The minor axis 32 is separated from the main axis 28 by a predetermined distance and extends in parallel to the main axis 28. A nut 35 is fixed to the upper end portion of the sub-rotor 33, and the nut 35 and the male screw 31 are configured and screwed together as a ball screw.

  A spindle unit 36 is connected to the lower end of the auxiliary rotating body 33, and a spindle 37 projects from the lower end of the spindle unit 36. In addition to a motor as a power source for the spindle 37, the spindle unit 36 includes a transmission mechanism for transmitting the rotation of the motor to the spindle 37, a nozzle for supplying air and grinding oil to the workpiece during grinding, and the like. A disc-shaped grindstone 38 is mounted on the tip of the spindle 37 so as to be rotated about the spindle axis 39. The spindle axis 39 is separated from the auxiliary axis 32 by a predetermined distance, and is positioned in parallel with the auxiliary axis 32. Accordingly, the main axis 28, the sub axis 32, and the spindle axis 39 are parallel to each other. At this time, the distance between the main axis 28 and the sub axis 32 and the distance between the sub axis 32 and the spindle axis 39 are equal as shown in FIG.

  Hereinafter, a mechanism for raising and lowering the moving member 30 along FIG. 4 will be described with reference to FIG. 3 is an enlarged view of a main part of FIG. 2, and FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. As shown in FIG. 4, a slide bar 40 extending in a direction (horizontal direction) orthogonal to the main axis 28 is provided at the upper end of the moving member 30 that rotates together with the main rotating body 21 (see FIG. 3). The slide bar 40 is rotated together with the moving member 30. Both ends of the slide bar 40 are inserted through a pair of long holes 29 (FIG. 3), and both ends of the slide bar 40 protrude to the outside of the main rotating body 21. An annular elevating member 41 is provided on the outer surface of the main rotating body 21 so as to surround the main rotating body 21, and a predetermined interval is provided between the main rotating body 21 and the elevating member 41. A pair of elevating bearings 42 arranged in parallel are interposed. Therefore, the rotation of the main rotating body 21 is not transmitted to the elevating member 41.

  Both ends of the slide bar 40 projecting to the outside of the main rotating body 21 (in the direction perpendicular to the paper surface in FIG. 3) are sandwiched and fixed by the inner rings 43 of a pair of lift bearings 42 indicated by two-dot chain lines, and are integrated with the inner ring 43. It is designed to rotate. At this time, the length of the slide bar 40 is longer than the outer diameter of the inner ring 43 of the elevating bearing 42 and shorter than the inner diameter of the outer ring 44 of the elevating bearing 42 as shown in FIG. Therefore, the inner ring 43, the slide rod 40, and the moving member 30 rotate together with the main rotating body 21, but the rotation of the main rotating body 21 is not transmitted to other parts.

  Long holes 45 (FIG. 3) extending in the vertical direction are respectively formed on both sides of the support cylinder 20 facing each other with the main rotating body 21 therebetween. A pair of arms 46 extending outward are formed at the upper end of the elevating member 41, and the distal end of each arm 46 extends through the long hole 45 to the outside of the support cylinder 20. Nuts 47 constituting ball screws as conversion means are provided at the tips of the respective arms 46, and male nuts 48 (see FIG. 3) constituting ball screws as conversion means extending vertically. Are respectively screwed via rolling balls (not shown). At this time, the ball screw 57 composed of the nut 47 and the external thread 48 is disposed at symmetrical positions with the main axis 28 as the symmetry axis. In other words, each ball screw 57 is disposed equiangularly around the main axis 28.

  As shown in FIG. 2, pulleys 49 are provided at the upper ends of the respective male screws 48 via respective rotation shafts 56 as drive members that are parallel to the main axis 28 provided on the support cylinder 20 and spaced apart by a predetermined distance. Each pulley 49 is separately connected via a pulley 51 and two belts 52 connected to the rotation shaft of the same motor 50 as a drive source. Therefore, the rotation of the motor 50 is belt-driven by the rotation shafts 56 via the pulleys 51, the belts 52, and the pulleys 49, and this driving force is transmitted to the male screws 48. That is, by rotating one motor 50, each rotation shaft 56, that is, each male screw 48 is rotated in synchronization.

  In the present embodiment, the drive member is configured by the rotation shaft 56. Further, the conversion means is constituted by a ball screw 57 constituted by a nut 47, a male screw 48, a ball (not shown) and the like. The nut 47, each arm 46, the elevating member 41, the elevating bearing 42, and the slide bar 40 constitute a transmission means. The drive member, conversion means, and transmission means constitute a moving mechanism.

  As shown in FIG. 4, outer cylinders 54 are fixed to the elevating member 41 via arms 53 on both side walls facing each other with the elevating member 41 interposed therebetween. A hole is bored in the outer cylinder 54 in parallel with the main axis 28. A spline shaft 55 extending in the vertical direction is inserted into each outer cylinder 54, and the spline shaft 55 is fixed to the support cylinder 20 in parallel with the main axis 28. Between each outer cylinder 54 and each spline shaft 55, balls that are rolling elements (not shown) are respectively incorporated. A ball spline 58 as a guide mechanism is formed by the outer cylinder 54, the spline shaft 55, and a ball (not shown). The outer cylinder 54 is guided by the spline shaft 55 and is configured to move accurately and smoothly in the vertical direction. Each ball spline 58 is disposed between the main body including the support cylinder 20 and the transmission means (in this embodiment, the support cylinder 20 outside the main rotor 21). In this case, each ball spline 58 is disposed at a position (two locations) that is displaced by 90 degrees in both directions around the main axis 28 with respect to any one of the ball screws 57.

  Therefore, when each male screw 48 is rotated by the motor 50, each nut 47 is moved upward or downward, and the moving member 30 is reciprocated through each arm 46 and the elevating member 41 with this movement, The male screw 31 is moved upward or downward. At this time, the outer cylinder 54 is reciprocated up and down along the spline shaft 55 with the reciprocation of the moving member 30. That is, the reciprocating motion of the moving member 30 is guided by the ball spline 58 so as to be parallel to the main axis 28 so that the force received from each arm 46 does not cause an inclination due to the rotational moment. It has become. The reciprocating motion of the moving member 30 is converted into a rotational motion of the nut 35 about the auxiliary axis 32 using a screw pair of the male screw 31 and the nut 35. Accordingly, the auxiliary rotating body 33 is rotated about the auxiliary axis 32 along with the rotational movement of the nut 35.

  Therefore, when the main rotating body 21 rotates (rotates) around the main axis 28, the auxiliary axis 32 revolves (rotates) around the main axis 28. Further, by rotating the auxiliary rotating body 33 around the auxiliary axis 32, the spindle unit 36 is revolved around the auxiliary axis 32 so that the spindle axis 39 approaches or separates from the main axis 28. It has become. FIG. 2 shows a state in which the main axis 28 and the spindle axis 39 coincide.

  Thus, the moving member 30 constitutes the moving member of the present invention. The male screw 31 moved up and down by the moving member 30, the nut 35 constituting the male screw 31 and the ball screw, the sub-rotor 33 rotated by the nut 35, and the spindle axis 39 by the rotation of the sub-rotator 33 The cutting mechanism is constituted by a spindle unit 36 that holds a spindle 37 that is brought close to or away from the main axis 28.

Next, the operation of the grinding machine 10 configured as described above will be described with reference to FIGS.
When the workpiece 14 is ground by the grinding machine 10, when the main rotating body 21 rotates (rotates) around the main axis 28, the moving member 30, the sub-rotating body 33, and the spindle unit 36 are also driven by the rotation. Rotated about line 28. Further, the grindstone 38 is rotated around the spindle axis 39 by the spindle unit 36. At this time, as shown in FIGS. 2 and 5A, the main axis 28 and the spindle axis 39 are in a state of being coincident (the change in the cutting amount of the grindstone 38 is zero). In order to increase the cutting amount of the grindstone 38 from this state, when each rotating shaft 56 is rotated in the forward direction by the motor 50, due to the screw pair of each male screw 48 and each nut 47 constituting the ball screw, While being guided by each ball spline 58, the elevating member 41 and the moving member 30 are accurately moved upward, and the male screw 31 is also accurately moved upward.

  Then, as shown in FIG. 5B, the auxiliary rotating body 33 moves the auxiliary axis 32 through the nut 35 (FIG. 2) in a state where the main axis 28, the auxiliary axis 32, and the spindle axis 39 are maintained in a parallel state. Rotated to the center. As a result, the spindle axis 39 is revolved around the auxiliary axis 32, the main axis 28 and the spindle axis 39 are separated by a distance B, and the spindle axis 39 is revolved around the main axis 28. For this reason, the cutting amount of the grindstone 38 is increased by the distance B. Conversely, in order to reduce the cutting depth of the grindstone 38 from this state, when each pivot shaft 56 is rotated in the opposite direction, each ball spline 58 is caused by a screw pair between each male screw 48 and each nut 47. While being guided, the elevating member 41 and the moving member 30 are accurately moved downward, and the male screw 31 is also accurately moved downward. As a result, the distance B between the main axis 28 and the spindle axis 39 is reduced.

According to the embodiment detailed above, the following effects are exhibited.
Since the male screw 48 and the nut 47 constituting the rotating shaft 56 and the ball screw 57 are arranged at positions separated from the main axis 28, the grinding machine 10 is compact without being affected by the shape of the main rotating body 21. There is an effect that it can be made a simple configuration.

  -Since the external thread 48 rotated by the rotating shaft 56 has an extremely small mass compared to the conventional cutting feed moving nut 116, the inertia accompanying the rotation is small. Therefore, the controllability of cutting is improved, and there is an effect that cutting accuracy and followability can be improved.

  Since the ball screw 57 is disposed at a symmetrical position with the main axis 28 as the axis of symmetry, the main axis 28 with respect to the moving member 30 from the rotating shaft 56 via the transmission means such as the ball screw 57 and the lifting member 41. It is possible to make it difficult to generate a rotational moment that is a force that is not parallel to the rotation. Therefore, there is an effect that the accuracy of controlling the cutting amount of the grindstone 38 can be improved.

  Since the two rotating shafts 56 are driven in synchronization by one motor 50, the force applied to each male screw 48 is made uniform, and no rotational moment due to the difference in driving force is generated. Therefore, there is an effect that the accuracy of controlling the cutting amount of the grindstone 38 can be improved.

  -Since the drive resistance is reduced by using the ball screw 57 as the conversion means, the mechanical efficiency is increased to about 95% with this ball screw 57, compared to about 20 to 30% with the normal triangular screw. Can do. Therefore, the output of the motor 50 can be reduced. In the case of the same motor 50, the ball screw 57 has a better cut response than the case where a triangular screw is employed, and the work efficiency can be improved. Furthermore, since the ball screw 57 functions by rolling friction, there is no error caused by sliding friction like a triangular screw. Therefore, there is an effect that the workpiece 14 can be accurately and efficiently ground.

  -Since the rotation shaft 56 is driven by a belt, the apparatus can be relatively simplified. In particular, when driving a plurality of rotating shafts 56, the effect is increased. In addition, since an error caused by gear backlash does not occur, accuracy can be improved.

  Since the moving member 30 can be moved more strictly in parallel with the main axis 28 by the ball spline 58, the cutting accuracy of the grindstone 38 can be improved. In particular, when there is one rotating shaft 56 and one ball screw 57, a rotational moment is likely to occur, but this can be effectively suppressed.

  Since two ball splines 58 are disposed at positions displaced by 90 degrees in both directions around the main axis 28 with respect to any of the ball screws 57, the ball spline 58 is further layered against the ball screw 57 that generates a rotational moment. This can be effectively suppressed.

  -Since the guide mechanism is configured as the ball spline 58, the support rigidity is high, and the accuracy can be improved without rattling. In addition, the moving member 30 can be smoothly guided. Therefore, high-precision grinding can be performed without reducing the cutting response of the grindstone 38.

(Example of change)
In addition, the said embodiment can also be changed and actualized as follows.
-As shown to Fig.6 (a), it cannot be overemphasized that the ball screw 57 as a conversion means does not necessarily need to be provided with two or more, and only one may be arrange | positioned. In this case, since a rotational moment which is a cantilever and is not parallel to the main axis 28 is generated, it is preferable to dispose the ball spline 58 as a guide mechanism regardless of the position so that the moving member 30 does not tilt.

  In addition, when a single ball screw 57 is disposed, for example, as shown in FIG. 6B, one ball spline 58 is disposed at a position facing the main axis 28 as a center, As shown in FIG. 6C, two of the ball screws 57 may be disposed at positions where the angle is displaced 90 degrees in either direction around the main axis 28. Further, as shown in FIG. 6 (d), it may be arranged at any of the above positions to have three locations.

  On the other hand, as shown in FIGS. 7A and 7B, three or four or more ball screws 57 may be arranged around the main axis 28. In this case, it is desirable to arrange them equiangularly around the main axis 28 so that no rotational moment is generated. Further, when there are three ball screws, it is convenient that the elevating member 41 has a triangular shape in plan view as shown in FIG.

  Of course, as shown in FIGS. 8A to 8D, the number and position of the ball screw 57 and the ball spline 58 are not limited to these, and the required accuracy, rigidity, size, Various aspects can be taken from the viewpoint of cost and the like.

The guide mechanism is not limited to a ball spline, and may be a sliding pair or a rolling pair using rollers or the like.
The cutting mechanism that moves the moving member 30 back and forth to bring the spindle 37 close to or away from the main axis 28 preferably has the configuration shown in the embodiment in terms of accuracy. However, the present invention is not limited to this configuration, and instead of this configuration, a conventional configuration may be used, and another configuration may be used.

-You may drive each rotating shaft 56 using a gearwheel. Alternatively, each rotation shaft 56 may be manually rotated.
-You may comprise the conversion means with screws, such as a triangular screw, a square screw, and a round screw, and a nut which can be screwed together.

The male screw 48 may be changed to a nut, the nut 47 may be changed to a ball screw configured as a male screw, and these may be screwed together.
-You may comprise so that each rotating shaft 56 may be driven by drive sources, such as a separate motor, respectively. In this case, each drive source needs to be adjusted so that each rotation shaft 56 is driven in synchronization.

  -The transmission means may be configured to use magnetic force. For example, the elevating member 41 and the moving member 30 may be provided with magnets that attract each other.

The front view of the grinding machine of embodiment. The principal part sectional view of the grinding machine of an embodiment. The principal part enlarged view of FIG. FIG. 4 is a sectional view taken along line 4-4 of FIG. (A) is a conceptual diagram showing a state in which the main axis of the grinding machine of the embodiment and the spindle axis coincide with each other, (b) is a state when the spindle axis is displaced relative to the main axis from the state of (a). FIG. (A)-(d) The plane simple figure which shows the arrangement | positioning position of the ball screw and ball spline of a modification. (A), (b) Both plane simplified views which show the arrangement | positioning position of the ball screw and ball spline of a modification. (A)-(d) The plane simple figure which shows the arrangement | positioning position of the ball screw and ball spline of a modification. Sectional drawing of the principal part of the conventional grinding machine. (A) is a conceptual diagram showing a state in which a main axis of a conventional grinding machine and a spindle axis coincide with each other, and (b) shows a state when the spindle axis is displaced from the main axis in the state of (a). Conceptual diagram.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Grinding machine, 20 ... Support cylinder which comprises main-body part, 21 ... Main rotating body, 28 ... Main axis, 30 ... Moving member which comprises cutting mechanism, 31 ... Male screw which comprises the ball screw which comprises cutting mechanism , 32 ... auxiliary axis, 33 ... auxiliary rotating body constituting the cutting mechanism, 34 ... bearing, 35 ... nut constituting the cutting mechanism, 37 ... spindle, 38 ... grinding wheel, 39 ... spindle axis, 40 ... constituting transmission means. Slide rod 41 ... Lifting member constituting transmission means, 42 ... Lifting bearing constituting transmission means, 46 ... Arm constituting transmission means, 47 ... Nut constituting ball screw as transmission means and conversion means, 48 ... A male screw constituting a ball screw as a conversion means, 50: a motor as a drive source, 52: a belt, 54: a ball spline as a guide mechanism Outer cylinder 55 ... spline shaft constituting the ball spline as a guide mechanism, 56 ... rotational axis as the drive member, 57 ... ball screw as a conversion means, the ball spline as 58 ... guide mechanism.

Claims (11)

The main body,
A main rotating body that is rotatably supported by the main body and rotates about a main axis;
A spindle on which a grindstone can be mounted, which is rotated around the main axis along with the rotation of the main rotating body and rotated about a spindle axis parallel to the main axis,
A moving member that is disposed in the main rotating body and reciprocates parallel to the main axis, a moving mechanism that reciprocates the moving member, and the spindle axis that is close to the main axis by the reciprocating movement of the moving member. Or a notch mechanism for separating,
The moving mechanism includes a driving member that rotates by being driven about a rotation axis that is parallel to the main axis provided in the main body and spaced apart by a predetermined distance, and a screw pair of a screw and a nut. A grinding machine comprising: conversion means for converting the rotation of the rotation into reciprocation parallel to the main axis; and transmission means for transmitting the converted reciprocation to a moving member in the main rotating body. 2. The grinding machine according to claim 1, wherein a plurality of the converting means are arranged equiangularly around the main axis. 3. The grinding machine according to claim 2, wherein the converting means is disposed at a symmetrical position with the main axis as a symmetry axis. The grinding machine according to claim 2 or 3, wherein the plurality of driving members are driven in synchronization from the same driving source. The grinding machine according to any one of claims 1 to 4, wherein the converting means is configured as a ball screw. The grinding machine according to any one of claims 1 to 5, wherein the driving member is driven by a belt. When the moving member is reciprocated, a guide mechanism that guides the moving direction of the moving member to be parallel to the main axis is provided between the main body and the transmission means. The grinding machine according to any one of claims 1 to 6. The grinding machine according to claim 7, wherein the guide mechanism is disposed at a position displaced 90 degrees in any direction about the main axis with respect to any of the conversion means. The grinding machine according to claim 7, wherein the guide mechanism is disposed at two positions displaced by 90 degrees in both directions around the main axis with respect to any of the conversion means. The grinding machine according to claim 7, wherein the guide mechanism is disposed at a position opposed to any one of the conversion means with a main axis as a center. The grinding machine according to any one of claims 7 to 10, wherein the guide mechanism is configured as a ball spline.

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