JP5821718B2 - Machine Tools - Google Patents

Description

  The present invention relates to a machine tool that processes a workpiece by moving a spindle with a tool attached thereto in a predetermined direction, for example, up and down, left and right, or front and rear.

  In general, a machine tool includes a spindle to which a tool is attached, a spindle head that rotatably supports the spindle, a column that supports the spindle head to be movable, a moving unit that supports the column to be movable in one direction, A base is provided that supports the moving part so as to be movable in a direction orthogonal to the one direction. The column is provided with a Z moving mechanism for moving the main shaft in the vertical direction. The moving unit is provided with a Y moving mechanism for moving the column in the front-rear direction. The base is provided with an X moving mechanism for moving the moving part in the left-right direction. A workpiece holding portion that holds a workpiece is provided in front of the base column (see, for example, Patent Document 1). The machine tool moves the spindle head in a predetermined direction by the X to Z moving mechanism to perform a desired process on the workpiece. The machine tool is surrounded by a box-shaped machine tool cover having a door on the front surface.

  A ball screw mechanism is often used for each moving mechanism. For example, a spindle head is connected to a nut portion, and the spindle head moves by rotation of the ball screw. In order to improve the production efficiency of parts, machine tools move the spindle head and column as fast as possible to process the workpiece. The load is large. Therefore, it is necessary to prevent the ball screw and the nut portion from being damaged by the load, and the ball screw and the nut portion are periodically replaced.

  A cylindrical nut holder having an axial direction in the front-rear direction is provided at the lower part of the column. The nut holder holds the nut portion of the Y moving mechanism. The moving part is provided with a fixing base for fixing the Y moving mechanism. A bearing unit that supports one end portion of the ball screw of the Y moving mechanism is provided on the front side of the fixed base, and a motor that is connected to the other end portion of the ball screw is provided on the rear side of the fixed portion. Both ends of the ball screw are fixed to a fixed base by a bearing unit and a motor. The nut portion that fits into the ball screw is fixed to the nut holder.

  When replacing the ball screw and nut part of the Y moving mechanism, open the door of the machine tool cover, release the fixing of both ends of the ball screw, and release the fixing of the nut part. Thereafter, the ball screw is moved forward, the nut portion is pulled out from the nut holder along the axial direction, and is taken out from the arc-opened door.

JP-A-8-276346

  When the ball screw and the nut part are taken out from the front side, it is necessary to avoid contact with the work holding part, and the ball screw and the nut part cannot be taken out smoothly. In addition, since the workpiece chips accumulate on the workpiece holding portion, the chips adhere to the worker during the take-out operation. Even if the ball screw and the nut portion are to be taken out from the rear side, since the control panel is usually provided on the rear surface of the machine tool cover, the ball screw cannot be moved rearward along the axial direction.

  This invention is made | formed in view of such a situation, and it aims at providing the machine tool which can take out a ball screw and a nut part smoothly, without an operator getting dirty with chips.

A machine tool according to the present invention includes a spindle head capable of moving up and down for machining a workpiece by attaching a tool, a column that movably supports the spindle head, a support portion that supports the column, and a lower side of the support portion And a ball screw mechanism having a nut portion that moves in a uniaxial direction, a cylindrical nut holding portion that holds the nut portion and forms a slit along the axial direction of the nut portion the Ri Oh provided in the lower portion of the support portion, wherein is provided with fixing base for fixing the ball screw mechanism on the lower side of the ball screw mechanism, a recess in a portion opposed to said ball screw mechanism in said fixed table form And a work holding portion for holding a work is provided on one end side of the ball screw mechanism, and at least a part of the bottom surface of the concave portion is provided with the ball screw mechanism for taking out the ball screw mechanism. It characterized that you have lowered inclined to the other end side of the mechanism.

In the present invention, the ball screw can be extracted from the slit formed in the nut holding portion and moved in a direction other than the axial direction.
Further, the ball screw taken out from the nut holding portion is disposed in the concave portion of the fixed base, and the ball screw and the nut portion can be easily moved.
Further, the bottom surface of the recess is inclined downward to the opposite side to the workpiece holding portion, and the ball screw and the nut portion taken out from the slit can be easily moved downward on the opposite side to the workpiece holding portion.

Machine tool according to the present invention, the recess Yes and extending along the axial direction of the ball screw mechanism, at least a part of the side surface along the axial direction of the recess and characterized that you have to ramp down To do.

In the present invention, the side surface of the concave portion along the axial direction has an inclination, the ball screw taken out from the slit, the side surface can be easily overcome Rukoto the only rolling.

A machine tool according to the present invention includes a spindle head capable of moving up and down for machining a workpiece by attaching a tool, a column that movably supports the spindle head, a support portion that supports the column, and a lower side of the support portion And a ball screw mechanism having a nut portion that moves in a uniaxial direction, a cylindrical nut holding portion that holds the nut portion and forms a slit along the axial direction of the nut portion Is provided at a lower portion of the support portion, a fixing base for fixing the ball screw mechanism is provided below the ball screw mechanism, and a concave portion is formed in a portion of the fixing base facing the ball screw mechanism. There Te, the recess Yes and extending along the axial direction of the ball screw mechanism, at least a part of the side surface along the axial direction in the recess, characterized that you have lowered inclined.

In the present invention, the ball screw can be extracted from the slit formed in the nut holding portion and moved in a direction other than the axial direction.
Further, the ball screw taken out from the nut holding portion is disposed in the concave portion of the fixed base, and the ball screw and the nut portion can be easily moved.
Also has inclined side face of the recess along the axial direction, the ball screw taken out from the slit, the side surface can be easily overcome Rukoto the only rolling.

The machine tool according to the present invention is provided with a workpiece holding portion for holding a workpiece on one end side of the ball screw mechanism, and at least a part of the bottom surface of the recess is inclined downward toward the other end side of the ball screw mechanism to have characterized the Rukoto.

In the present invention, the bottom surface of the recess has inclined downward on the opposite side of the workpiece holding portion, the ball screw and a nut portion taken out from the slit can Rukoto moved easily to the opposite side of the lower and the workpiece holding portion .

  In the machine tool according to the present invention, the ball screw can be extracted from the slit formed in the nut holding portion and moved in a direction other than the axial direction. Therefore, it can be taken out by moving the ball screw and the nut portion to the side or rotating them.

1 is a schematic perspective view of a machine tool according to a first embodiment. It is a simplified front view of a machine tool. It is a simplified right side view of a machine tool. FIG. 3 is a schematic perspective view of a machine tool in which a cover for covering the tool changer and the guide rail is omitted. It is a perspective view which shows the cover for machine tools schematically. It is a schematic perspective view of a Y-direction moving device and a fixed base. It is a schematic perspective view of the Y-direction moving device and the fixed base in which the Y-direction moving table is omitted. 1 is a schematic partial longitudinal sectional view of a machine tool. FIG. 4 is a partially enlarged vertical cross-sectional view of a Y-direction moving device and a fixed base. It is a schematic rear view of a nut holder and a recess. It is a perspective view which shows the state which removed the Y direction drive motor from the motor base board. It is a perspective view which shows the state which removed the bearing unit from the unit base and removed the nut part from the nut holder. It is a partial longitudinal cross-sectional view which shows the state which removed the bearing unit from the unit base and removed the nut part from the nut holder. It is a perspective view which shows the state which removed the bearing unit from the unit base and removed the nut part from the nut holder. It is a perspective view which shows the state which rolled the ball screw along the side surface of the recessed part. It is a fragmentary longitudinal cross-sectional view which shows schematically the state which moved the ball screw and the nut part back rear. It is a perspective view showing roughly the state where a ball screw and a nut part were moved back up. It is a schematic perspective view of the Y-direction moving device and the fixed base in which the Y-direction moving table is omitted. 1 is a schematic partial longitudinal sectional view of a machine tool.

(Embodiment 1)
Hereinafter, the present invention will be described in detail with reference to the drawings showing a machine tool according to a first embodiment. In the following description, up and down, left and right, and front and rear indicated by arrows in the figure are used. The operator operates the machine tool in front and attaches / detaches the workpiece. 1 is a schematic perspective view of a machine tool, FIG. 2 is a schematic front view of the machine tool, FIG. 3 is a schematic right side view of the machine tool, and FIG. 4 is a cover that covers a tool changer and a guide rail. It is a schematic perspective view of a machine tool in which etc. are omitted.

  The machine tool 100 includes a base 20, a fixed base 21, a Y-direction moving device 22, an X-direction moving device 26, a column 28, a Z-direction moving device 30, a spindle head 32, a tool changer 10, and the like. The base 20 is fixed on the floor surface. The fixed base 21 has a rectangular box shape that is long in the front-rear direction, and is provided on the base 20. The fixed base 21 fixes the Y-direction moving device 22.

  An X-direction moving device 26 is provided on the Y-direction moving device 22. A column 28 is provided on the X-direction moving device 26. The X-direction moving device 26 and the Y-direction moving device 22 support the column 28 so as to be movable in the X direction (left-right direction) and the Y direction (front-back direction).

  The column 28 supports the spindle head 32 through the Z-direction moving device 30 so as to be movable in the Z direction (vertical direction). The tool changer 10 changes a tool attached to a spindle (not shown) that is rotatably supported by the spindle head 32.

  As shown in FIG. 4, the Y-direction moving device 22 includes a pair of guide rails 22a and 22a parallel to each other, a plurality of blocks 22b, 22b, ..., 22b, a Y-direction moving table 22c, and the like. The guide rails 22a and 22a extend in the front-rear direction on the upper surface of the fixed base 21 with an appropriate interval in the left-right direction. The blocks 22b, 22b, ..., 22b are fitted to the guide rails 22a, 22a so as to be movable in the front-rear direction. The Y-direction moving base 22c is fixed on the blocks 22b, 22b,. The Y-direction moving base 22c moves in the front-rear direction by driving a Y-direction drive motor 22d described later. The detailed configuration of the Y-direction moving device 22 will be described later.

  The X-direction moving device 26 includes a pair of guide rails 26a, 26a parallel to each other, a plurality of blocks 26b, 26b,..., 26b, a column base 26c, and an X-direction drive motor (not shown). The guide rails 26a, 26a extend in the left-right direction on the upper surface of the Y-direction moving table 22c with an appropriate interval in the front-rear direction. The blocks 26b, 26b, ..., 26b are fitted to the guide rails 26a, 26a so as to be movable in the left-right direction. The column base 26c is fixed on the blocks 26b, 26b,. The column 28 moves in the left-right direction by driving the X-direction drive motor. The column 28 is fixed on the column base 26c. The column 28 is moved in the Y direction and the X direction by the Y direction moving device 22 and the X direction moving device 26. The column base 26c and the column 28 are integrally formed.

  The Z-direction moving device 30 includes a pair of guide rails 30a, 30a parallel to each other, a plurality of blocks 30b, 30b,..., 30b, a spindle head base 30c, and a Z-direction drive motor (not shown). The guide rails 30a and 30a are extended in the vertical direction on the front surface of the column 28 with an appropriate interval in the horizontal direction. The plurality of blocks 30b, 30b, ..., 30b are fitted to the guide rails 30a, 30a so as to be movable in the vertical direction. The spindle head base 30c is fixed to the front surfaces of the blocks 30b, 30b, ..., 30b. The spindle head base 30c moves in the vertical direction by driving the Z-direction drive motor.

  The spindle head 32 is fixed to the spindle head base 30c. By driving and controlling the X direction drive motor, the Y direction drive motor 22d, and the Z direction drive motor, the spindle head 32 moves back and forth, left and right, and up and down.

  The main shaft is connected to a main shaft motor 35 provided at the upper end of the main shaft head 32. The spindle rotates around the axis by driving the spindle motor 35. The spindle can be rotated with respect to the workpiece fixed to the workpiece holder 120 by rotating around the axis with a tool holder (not shown) attached to the lower end.

  FIG. 5 is a perspective view schematically showing the machine tool cover 1. As shown in FIG. 5, the machine tool cover 1 is provided on the upper side of the base 20. The machine tool cover 1 extends in the vertical direction, and includes a rectangular front wall 50, a left wall 60, a right wall 70, and a rear wall 80 that respectively cover the front, rear, left, and right sides of the machine tool 100. The machine tool cover 1 covers the upper side of the machine tool 100 and includes a rectangular ceiling 90 parallel to the left-right direction and the front-rear direction.

  The right wall 70 is provided with two removable panels 71 and 71 at the center thereof. The panels 71, 71 cover an opening (not shown) provided in the central portion of the right wall 70. The operator removes the panels 71 and 71 as necessary, puts his hand through the opening, or enters the machine tool cover 1 through the opening to perform maintenance management of the machine tool 100. The left wall 60 is provided with the same opening as the right wall 70 and two panels. The rear wall 80 is provided with a control board 81 having a control board for controlling the operation of the machine tool 100 and amplifiers for supplying electric power to the motors. The central portion of the ceiling 90 protrudes upward in order to avoid contact with the main shaft and the column 28 and the like.

  A vertically long rectangular opening 51 is provided at the center of the front wall 50, and an operation panel 54 for an operator to input a command is provided to the right of the opening 51. A vertically long rectangular right door 52 and left door 53 are juxtaposed in the opening 51 so as to be movable in the left-right direction.

  The right door 52 is disposed behind the left door 53. A handle 52 a is provided on the front surface of the right door 52. When the operator holds the handle 52a and pulls it to the left side, the right door 52 and the left door 53 sequentially move to the left side and open.

  Next, the configuration of the Y-direction moving device 22 and the fixed base 21 will be described in detail. 6 is a schematic perspective view of the Y-direction moving device 22 and the fixed base 21, FIG. 7 is a schematic perspective view of the Y-direction moving device 22 and the fixed base 21 with the Y-direction moving table 22c omitted, and FIG. 9 is a schematic partial vertical sectional view, FIG. 9 is a schematic partial enlarged vertical sectional view of the Y-direction moving device 22 and the fixed base 21, and FIG. 10 is a schematic rear view of the nut holder 220 and the recess 21a.

  As shown in FIGS. 6 to 9, a concave portion 21 a is formed in the rear portion of the upper surface of the fixed base 21 from the central portion in the front-rear direction to the rear edge portion. As shown in FIGS. 8 and 9, the bottom surface 21b of the recess 21a is inclined downward toward the rear. As shown in FIG. 10, the side surface 21c of the recess 21a is inclined downward toward the bottom surface 21b. As shown in FIGS. 6 and 7, two unit bases 121 for fixing a bearing unit 22 p to be described later are arranged side by side at the front corner of the fixing base 21. The unit base 121 has an L shape, and its inner corner faces the front corner of the fixed base 21. The unit base 121 is integral with the fixed base 21.

  As shown in FIGS. 6 and 7, two motor base plates 210 perpendicular to the left-right direction protrude rearward from the rear surface of the fixed base 21. The motor base plate 210 is integral with the fixed base 21. The motor base plate 210 is adjacent to the left and right of the recess 21a (see FIG. 10). A screw hole 210a (see FIG. 12 described later) in which an internal thread is formed is provided in the upper edge portion of the motor base plate 210. An accommodation box 211 that accommodates the coupling 22k is fixed to the motor base plate 210.

  The storage box 211 includes a rectangular tube portion 211a whose axial direction is the front-rear direction for storing the coupling 22k, and flange portions 211b that extend from the lower left and right side surfaces of the rectangular tube portion 211a. Through holes 211e and 211f are provided before and after the rectangular tube portion 211a. A lid 211c that can be opened and closed is provided on the top of the rectangular tube portion 211a. The flange portion 211b is provided with an insertion hole 211d for inserting a bolt. The flange portion 211b is disposed on the motor base plate 210 so that the insertion hole 211d and the screw hole 210a of the motor base plate 210 are positioned coaxially. The bolt is inserted into the insertion hole 211 d and screwed into the screw hole 210 a, and the storage box 211 is fixed on the motor base plate 210.

  The Y-direction drive motor 22d includes a rectangular tube-shaped casing that is long in the front-rear direction for housing the motor. Plate-shaped flange pieces 22f perpendicular to the front-rear direction are provided at the four corners of the front part of the housing. The flange piece 22f is provided with an insertion hole 122f for inserting a bolt. The rotation shaft of the Y-direction drive motor 22d protrudes forward from the housing, and a coupling 22k is connected to the rotation shaft. The rotation shaft is inserted into the rectangular tube portion 211a through the rear through hole 211f, and the coupling 22k is located in the rectangular tube portion 211a. The bolt is inserted into the insertion hole 122f of the flange piece 22f, and is screwed into screw holes (not shown) formed at the four corners of the rear end surface of the rectangular tube portion 211a. The Y-direction drive motor 22d is fixed to the rectangular tube portion 211a by screwing the bolts.

  A bearing 22n is fitted in the through hole 211e on the front side of the rectangular tube portion 211a. An annular stopper 22m that restricts movement of a nut portion 22h described later is provided coaxially with the through hole 211d on the front surface of the rectangular tube portion 211a. The stopper 22m is provided with an insertion hole 122m for inserting a bolt. The stopper 22m is made of a flexible member such as a urethane member, and absorbs an impact when the nut portion 22h comes into contact. The bolt is inserted into the insertion hole 122m of the stopper 22m, and is screwed into a screw hole (not shown) formed in the front end surface of the rectangular tube portion 211a. The stopper 22m is fixed to the rectangular tube portion 211a by screwing the bolt.

  In the stopper 22m and the bearing 22n, one end of a ball screw 22g (ball screw mechanism) is fitted from the front side. The operator opens the lid 211c provided on the upper surface of the rectangular tube portion 211a, rotates the coupling 22k, and tightens the ball screw 22g and the rotation shaft of the Y-direction drive motor 22d.

  A bearing unit 22p is provided at the other end of the ball screw 22g. The bearing unit 22p includes a housing cylinder 22q that houses the bearing, and two flange portions 22r and 22r that protrude in the radial direction from both sides of the outer peripheral surface of the housing cylinder 22q. As shown in FIG. 9, two bearings 22s and 22s are coaxially fitted in the accommodating cylinder 22q. A fixing ring 22t for fixing the outer ring of the bearing 22s is fitted into the rear end portion of the housing cylinder 22q, and the fixing ring 22t is fixed to the housing cylinder 22q. An annular stopper 22u for restricting movement of a nut portion 22h described later is provided on the rear end surface of the fixing ring 22t. Two insertion holes 122u and 122u for inserting bolts are respectively provided on the left and right sides of the stopper 22u. The bolt is inserted into the insertion hole 122u of the stopper 22u and is screwed into a screw hole (not shown) formed in the front end surface of the fixing ring 22t. The stopper 22u is fixed to the fixing ring 22t by screwing the bolt. The housing cylinder 22q, the bearing 22s, the fixing ring 22t, and the stopper 22u are integrated to form a bearing unit 22p. The other end of the ball screw 22g is fitted and fixed from the rear side to the stopper 22u, the fixing ring 22t, and the bearing 22s.

  Each flange portion 22r is provided with two insertion holes 122r for inserting bolts. The bolt is inserted into the insertion hole 122r of the flange portion 22r and is screwed into a screw hole 121a (see FIG. 12 described later) formed on the upper surface of the unit base 121. The flange portion 22r is fixed to the unit base 121 by screwing the bolts.

  As shown in FIG. 9, a nut portion 22h (ball screw mechanism) is screwed into the ball screw 22g via a rolling element (not shown). The nut portion 22h includes a cylindrical portion 22i and a flange portion 22j projecting radially outward from the outer periphery of the rear end portion of the cylindrical portion 22i. Four insertion holes 122j, 122j, 122j, 122j for inserting bolts are juxtaposed in the circumferential direction in the flange portion 22j (see FIG. 11 described later). A nut holder 220 for holding the nut portion 22h is provided at the rear end portion of the lower surface of the Y-direction moving base 22c.

  As shown in FIG. 10, the nut holder 220 has a cylindrical shape, and a slit 221 along the axial direction of the nut portion 22h is formed on the lower end surface thereof. The left-right width of the slit 221 is substantially the same as or larger than the diameter of the cylindrical portion 22i. Four screw holes 222, 222, 222, 222 corresponding to the insertion holes 122j of the flange portion 22j are provided on the rear surface of the nut holder 220. A female screw is formed in the screw hole 222. The nut portion 22h has a cylindrical portion 22i inserted into the slit 221 so that the flange portion 22j is positioned on the rear side of the nut holder 220. The bolt is inserted into the insertion hole 122j of the flange portion 22j and is screwed into the screw hole 222 of the nut holder 220. The flange portion 22j is fixed to the nut holder 220 by screwing the bolts. A part of the cylindrical portion 22i is located in the nut holder 220, and the nut holder 220 holds the nut portion 22h.

  By driving the Y-direction drive motor 22d, the ball screw 22g rotates, and the nut portion 22h moves in the axial direction (front-rear direction) of the ball screw 22g. The nut holder 220 moves in the front-rear direction by the movement of the nut portion 22h, and the Y-direction moving base 22c moves in the front-rear direction.

  Next, a method for removing the ball screw 22g and the nut portion 22h will be described. The ball screw 22g and the nut portion 22h are periodically replaced to prevent breakage. FIG. 11 is a perspective view schematically showing a state in which the Y-direction drive motor 22d is detached from the motor base plate 210. FIG. An operator removes the panel 71 of the right wall 70 and puts his hand through the opening to perform work, or enters the machine tool cover 1 through the opening and performs work. The operator opens the lid 211c provided on the upper surface of the storage box 211, loosens the coupling 22k that fastens the rotating shaft of the Y-direction drive motor 22d and one end of the ball screw 22g, and releases the connection therebetween. Next, the bolt is removed from the flange piece 22f of the housing of the Y-direction drive motor 22d, and the bolt is removed from the stopper 22m. Thereafter, the bolt is removed from the flange portion 211b, and the Y-direction moving motor 21 is removed from the motor base plate 210. As shown in FIG. 11, when the Y-direction moving motor 21 is removed, the nut portion 22h is held by the nut holder 220, and the ball screw 22g is fixed to the Y-direction moving base 22c.

  12 is a perspective view schematically showing a state in which the bearing unit 22p is removed from the unit base 121 and the nut portion 22h is removed from the nut holder 220. FIG. 13 is a perspective view of the bearing unit 22p removed from the unit base 121, and the nut portion 22h is removed from the nut holder 220. FIG. 14 is a perspective view schematically showing a state in which the bearing unit 22p is removed from the unit base 121 and the nut portion 22h is removed from the nut holder 220. In FIG. 12, the Y-direction moving base 22c is not shown for easy understanding.

  The operator removes the bolt from the flange portion 22r of the bearing unit 22p and removes the bolt from the flange portion 22j of the nut portion 22h. Thereafter, the nut portion 22h is extracted from the slit 221. At this time, the fixing of the ball screw 22g to the Y-direction moving base 22c is released. The operator moves the ball screw 22g backward and places it on the fixed base 21. The dimension between the upper surface (excluding the recess 21a) of the fixed base 21 and the lower surface (excluding the nut holder 220) of the Y-direction moving base 22c is set to be larger than the vertical and horizontal dimensions of the bearing unit 22p. It is.

  As shown in FIG. 13, the rear portion of the ball screw 22 g is disposed in the concave portion 21 a of the fixed base 21. As described above, the bottom surface 21b of the recess 21a is inclined downward toward the rear. The inclination angle of the bottom surface 21b is set so that the bearing unit located at the front end of the ball screw 22g does not contact the Y-direction moving base 22c even when the ball screw 22g is placed on the bottom surface 21b.

FIG. 15 is a perspective view schematically showing a state in which the ball screw 22g is rolled along the side surface 21c of the recess 21a. As shown by the arrow in FIG. 15, the operator rolls the ball screw 22g in the right direction along the side surface 21c of the recess 21a. As described above, the side surface 21c of the recess 21a is inclined downward toward the bottom surface 21b. Therefore, compared with the case where the side surface 21c is perpendicular to the bottom surface 21b, the ball screw 22g easily rises on the side surface 21c of the recess 21a while rolling. The ball screw 22g passes between the lower right end portion of the nut holder 220 and the upper end portion of the motor base plate 210 located on the right side.
As shown in FIG. 10, a supply portion that supplies lubricating oil to the nut portion 22h is provided at the lower left end portion of the nut holder 220. Therefore, it is difficult for the ball screw 22g to pass between the lower left end of the nut holder 220 and the upper end of the motor base plate 210 located on the left side. When the supply unit is provided in another part of the nut holder 220, the operator can pass the ball screw 22g between the lower left end of the nut holder 220 and the upper end of the motor base plate 210 located on the left side. Good.

  FIG. 16 is a partial longitudinal sectional view schematically showing a state where the ball screw 22g and the nut portion 22h are moved rearward and upward, and FIG. 17 is a perspective view schematically showing a state where the ball screw 22g and the nut portion 22h are moved rearward and upward. FIG. As shown in FIGS. 16 and 17, the operator presses the Y-direction moving base 22 c forward and moves it forward from the bearing unit 22 p. Since the ball screw 22g is rolled and moved in the right direction, the bearing unit 22p is located on the right side of the nut holder 220. Therefore, even if the Y-direction moving base 22c is moved forward, the nut holder 220 does not contact the bearing unit 22p. The operator pulls the ball screw 22g upward and takes it out from the opening of the right wall 70. As shown in FIG. 16, since the ball screw 22g does not move linearly rearward, it does not contact the rear wall.

  The machine tool according to Embodiment 1 can extract the ball screw 22g from the slit 221 formed at the lower end of the nut holder 220 and move it downward. Therefore, the ball screw 22g and the nut portion 22h can be taken out by moving sideward or rearward without moving forward. Further, the ball screw 22g taken out from the nut holder 220 is disposed in the recess 21a of the fixing base 21, and the ball screw 22g and the nut portion 22h can be easily moved. Further, the bottom surface 21b of the recess 21a is inclined downward to the opposite side (rear side) to the workpiece holding part 120, and the ball screw 22g and the nut part 22h taken out from the slit 221 can be easily moved rearward and downward. Further, the side surface 21c of the recess 21a is inclined, and the ball screw 22g taken out from the slit 221 can easily get over the side surface 21c only by rolling.

  In the machine tool according to Embodiment 1, the entire bottom surface 21b of the recess 21a is inclined, but only a part may be inclined. Further, although the Y direction moving device 22 is provided below the X direction moving device 26, the X direction moving device 26 may be provided below the Y direction moving device 22. In this case, if the X-direction moving device 26 has the same configuration as the Y-direction moving device 22 and a concave portion having the same shape as the concave portion 21a described above is formed in the fixed base 21 along the X-axis direction, the same effect as described above. Can produce various effects.

(Embodiment 2)
Hereinafter, the present invention will be described in detail with reference to the drawings showing a machine tool according to a second embodiment. FIG. 18 is a schematic perspective view of the Y-direction moving device and the fixed base 21 in which the Y-direction moving table 22c is omitted, and FIG. 19 is a schematic partial vertical sectional view of the machine tool. As shown in FIG. 18, a recess 21 a is formed on the entire upper surface of the fixed base 21. As shown in FIG. 19, the dimension between the bottom surface 21b of the recess 21a and the lower end of the nut holder 220 is larger than the vertical dimension of the bearing unit 22p. Therefore, even if the nut portion 22h is removed from the nut holder 220 and the bearing unit 22p is disposed in the recess 21a, the nut holder 220 does not contact the bearing unit 22p even if the Y-direction moving base 22c is moved forward. After the Y-direction moving base 22c is moved to the front side of the bearing unit 22p, the ball screw 22g and the nut portion 22h are extracted from the recess 21a and taken out from the opening of the right wall 70.

  Of the configurations according to the second embodiment, configurations similar to those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The embodiment described above is an exemplification of the present invention, and the present invention can be implemented in various modified forms within the scope defined by the matters described in the claims and the description of the claims. it can.

30c Spindle head 34 Spindle 21 Fixed base 21a Recess 21b Bottom face 21c Side face 22 Y-direction moving device 22c Y-direction moving base (supporting part)
22g Ball screw (ball screw mechanism)
22h Nut (ball screw mechanism)
220 Nut holder (nut holding part)
221 Slit 100 Machine tool 120 Workpiece holding part

Claims (4)

A spindle head that can be moved up and down to process a workpiece by attaching a tool, a column that movably supports the spindle head, a support portion that supports the column, and a lower side of the support portion, and is connected in a uniaxial direction In a machine tool comprising a ball screw mechanism having a nut portion that moves to
The retaining nut portion, Ri nut holding portion of the cylindrical shape with a slit along the axial direction of the nut portion Ah provided in the lower portion of the support portion,
A fixing base for fixing the ball screw mechanism is provided below the ball screw mechanism;
A concave portion is formed in a portion of the fixed base facing the ball screw mechanism,
A work holding part for holding a work is provided on one end side of the ball screw mechanism,
At least part of the bottom surface of the recess, in order to take out the ball screw mechanism, machine tool characterized that you have lowered inclined to the other end side of the ball screw mechanism. The recess extends along the axial direction of the ball screw mechanism;
The machine tool according to claim 1 , wherein at least a part of a side surface of the concave portion along the axial direction is inclined downward. A spindle head that can be moved up and down to process a workpiece by attaching a tool, a column that movably supports the spindle head, a support portion that supports the column, and a lower side of the support portion, and is connected in a uniaxial direction In a machine tool comprising a ball screw mechanism having a nut portion that moves to
A cylindrical nut holding part that holds the nut part and forms a slit along the axial direction of the nut part is provided at the lower part of the support part,
A fixing base for fixing the ball screw mechanism is provided below the ball screw mechanism;
Ri the ball screw mechanism recesses on opposite portion forms tear in the fixing stand,
The recess extends along the axial direction of the ball screw mechanism;
At least a portion of the side surface along the axial direction of the recess you characterized that you have lowered inclined machine tools. A work holding part for holding a work is provided on one end side of the ball screw mechanism,
The machine tool according to claim 3 , wherein at least a part of the bottom surface of the recess is inclined downward toward the other end of the ball screw mechanism.

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