JP2014008541A - Cover device and machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cover device capable of preventing the looseness or breakage of a screw fixing an elastic body to a cover even if expansion/contraction is repeated, and a machine tool.SOLUTION: An expansion/contraction cover device 12 of a machine tool is equipped with a structure successively superimposing three cover boxes in a telescopic manner. When the expansion/contraction cover device 12 is expanded, a rear end side of the cover box 41 and a front end side of the cover box 42 are superimposed. An abutting portion 21 of an elastic body 20 fixed to the cover box 41 collides with a stopper plate 30 provided at the front end of the cover box 42. The abutting portion 21 receives stress from the stopper plate 30. A shielding wall 27 is disposed between the abutting portion 21 and a screw 26 fixing the elastic body 20 to the cover box 41. Therefore, the screw 26 is not influenced by the stress which the abutting portion 21 receives, so that even if the expansion/contraction cover device 12 repeats expansion/contraction, the looseness or breakage of the screw 26 can be prevented.

Description

  The present invention relates to a cover device and a machine tool including the cover device.

  The machine tool includes a cover device. The cover device is formed such that a plurality of covers are stacked in a nested manner so that the entire cover device can be expanded and contracted. The cover device covers and protects the feed mechanism. The feed mechanism moves the column or table of the machine tool. Therefore, the machine tool can prevent chips and splashes of the cutting fluid scattered during processing of the workpiece from entering the feed mechanism. The telescopic cover described in Patent Document 1 includes a plurality of cover boxes and a wiper seal. The plurality of cover boxes are slidably engaged with each other, and each has an upper wall, left and right walls, and a rear wall. The wiper seal is formed of an elastic material such as rubber, and includes a central portion, a lip portion, and a buffer portion. The central part is formed in a flat plate shape. The lip portion is formed on the front side of the central portion and abuts against the upper wall of the adjacent cover box. The buffer portion is formed on the rear side of the central portion and has a lower hardness than the other portions. The wiper seal is fixed with a screw passing through the center portion and the front end portion of the cover box, with a contact plate at the center portion. When a plurality of cover boxes that are adjacent to each other are pulled out in one direction, the wiper seal cushion provided on the top end of the upper wall of the rear cover box in the one direction hits the rear wall of the front cover box. Touch. The buffer part alleviates the impact from the rear wall.

Utility Model Registration No. 3086540

  The stress applied to the buffer portion from the rear wall is transmitted to the screw passing through the central portion. When the expansion / contraction cover repeats expansion and contraction many times, the stress applied to the buffer portion is transmitted to the screw many times. Therefore, the screw could gradually loosen or break.

  An object of the present invention is to provide a cover device and a machine tool that can prevent loosening and breakage of a screw that fixes an elastic body to a cover even if the expansion and contraction is repeated.

  The cover device according to claim 1 of the present invention is a cover device for a machine tool that protects a feed mechanism for driving a movable body by superimposing a plurality of covers in a nested manner and forming the cover as a whole so as to be stretchable. The plurality of covers include at least an outer cover and an inner cover that overlaps the inner side of the outer cover, and the plurality of covers face the outer surface of the inner cover in a state where the plurality of covers are stacked in a nested manner. Of the inner surface of the outer cover, when the cover device extends, the movement of the outer cover on the rear end side in the moving direction of the outer cover moves relative to the inner cover. A fixing means is provided for fixing an elastic body, which is opposed to the stopper portion provided on the front end side in the direction and has an abutting portion that abuts against the stopper portion when the cover device is extended, to the cover. The fixing means includes a pressing plate that presses the elastic body against the inner surface of the cover, and a screw that fixes the pressing plate to the inner surface of the cover via the elastic body. Has a through hole into which the screw is inserted on the rear end side in the moving direction with respect to the abutting portion, and the inner surface of the cover is formed between the screw and the abutting portion inside the through hole. An intervening shielding part is provided.

  When the cover device extends, the outer cover moves relative to the inner cover. The contact portion of the elastic body provided on the inner surface of the outer cover collides with the stopper portion provided on the outer surface of the inner cover vigorously. The contact portion receives stress from the stopper portion. The shielding part is interposed between the contact part and the screw. The stress applied to the contact portion is absorbed by the shielding portion and thus does not affect the screw. Therefore, the cover device can prevent the screw from loosening and breaking.

  In the cover device according to claim 2 of the present invention, in addition to the configuration of the invention according to claim 1, the elastic body is located at a position opposite to the contact portion with the through hole in the center. A sliding portion that slides on the outer surface of the inner cover when the cover device expands and contracts may be provided, and the shielding portion may be formed in a cylindrical shape that surrounds the screw inside the through hole. The shielding part surrounds the screw. Therefore, the shielding portion can protect the screw not only from the stress from the contact portion but also from the stress applied to the sliding portion when the sliding portion slides on the outer surface of the inner cover.

  According to a third aspect of the present invention, in addition to the configuration of the first or second aspect of the invention, the elastic body is formed in a concave shape at a position where the pressing plate is pressed, and the pressing plate is disposed inside. In the state where the pressing plate is pressed against the inner side of the concave portion and fixed to the inner surface of the cover with the screw, and the inner surface of the concave portion on the contact portion side, and the pressing plate A predetermined gap may be provided between the end portion facing the contact portion side. The inner surface of the concave portion on the contact portion side and the end portion facing the contact portion side of the pressing plate are separated from each other by a predetermined gap. Therefore, the stress applied to the contact portion when the contact portion collides with the stopper portion is not transmitted to the holding plate. Therefore, the cover device can prevent the stress applied to the contact portion from affecting the screw via the pressing plate.

  A machine tool according to a fourth aspect of the present invention includes the cover device according to any one of the first to third aspects. Therefore, the machine tool can obtain the effects of the invention according to any one of claims 1 to 3.

1 is a perspective view of a machine tool 1. The perspective view of the expansion-contraction cover apparatus 12. FIG. The top view of the part with which the cover boxes 41 and 42 overlap. The expanded perspective view of the part with which the cover boxes 41 and 42 overlap. The perspective view of the elastic body 20. FIG. Sectional drawing of the elastic body 20. FIG. Sectional drawing of the part with which the cover boxes 41 and 42 overlap. The enlarged view of the area | region enclosed by W1 of FIG.

  A machine tool 1 according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the left diagonally downward, right diagonally upward, right diagonally downward, and left diagonally upward in FIG. 1 are the front, rear, right, and left of the machine tool 1, respectively. The left-right direction, the front-rear direction, and the up-down direction of the machine tool 1 are defined as an X-axis direction, a Y-axis direction, and a Z-axis direction of the machine tool 1, respectively.

  The structure of the machine tool 1 will be briefly described with reference to FIG. The machine tool 1 includes a base portion 2, a column 5, a spindle head 6, a spindle (not shown), a table 7, an automatic tool changer (hereinafter referred to as “ATC”) 10, and the like. The base 2 is an iron member that is long in the Y-axis direction. The base 2 is provided with legs 3 at the lower four corners. The base portion 2 includes a pedestal portion 4 at the rear of the upper surface. The column 5 is erected on the upper surface of the pedestal 4. The column 5 is a columnar iron member. The column 5 is provided with a storage portion (not shown) in the lower front portion. The storage portion is an opening for storing a Y-axis rear cover 15 described later. The spindle head 6 is provided on the front surface of the column 5 so as to be movable in the Z-axis direction. The spindle is provided at the lower part of the spindle head 6 and is equipped with a tool and rotates at high speed. The ATC 10 is provided in front of the spindle head 6 and automatically replaces a tool mounted on the spindle with another tool.

  The table 7 is provided in the center of the upper surface of the base part 2. A work piece can be arranged on the upper surface of the table 7. The base unit 2 includes a feeding mechanism at the center of the upper surface. The feed mechanism moves the table 7 in the X-axis direction and the Y-axis direction. The feed mechanism includes a Y-axis feed mechanism, a carrier 8, and an X-axis feed mechanism. The Y-axis feed mechanism is provided on the upper surface of the base unit 2. The Y-axis feed mechanism moves the carrier 8 in the Y-axis direction. The Y-axis feed mechanism includes a pair of Y-axis rails (not shown), a Y-axis ball screw (not shown), and a Y-axis motor (not shown). The Y-axis rail and the Y-axis ball screw extend in the Y-axis direction. The Y-axis ball screw is provided between the pair of Y-axis rails. The carrier 8 is movable along the Y-axis rail. The carrier 8 is a rectangular parallelepiped metal casing. The carrier 8 includes a nut (not shown) on the lower surface. The nut is screwed onto the Y-axis ball screw. The Y-axis motor rotates the Y-axis ball screw and moves the carrier 8 along with the nut in the Y-axis direction.

  The X-axis feed mechanism is provided on the upper surface of the carrier 8. The X-axis feed mechanism moves the table 7 in the X-axis direction. The X-axis feed mechanism includes a pair of X-axis rails (not shown), an X-axis ball screw (not shown), an X-axis motor (not shown), and the like. The X-axis rail and the X-axis ball screw extend in the X-axis direction. The X-axis ball screw is disposed between a pair of X-axis rails. The table 7 is movable along the X axis rail. The table 7 includes a nut (not shown) on the lower surface. The nut is screwed into the X-axis ball screw. The X-axis motor rotates the X-axis ball screw and moves the table 7 together with the nut in the X-axis direction. The table 7 moves in the Y-axis direction via the carrier 8. That is, the table 7 can be moved in the X-axis direction and the Y-axis direction by the X-axis feed mechanism, the Y-axis feed mechanism, and the carrier 8. The machine tool 1 can cut the workpiece by relative movement of the workpiece placed on the table 7 and the tool.

  The table 7 includes an extendable cover device 12 on the right side and an extendable cover device 13 on the left side. The telescopic cover device 12 covers the X-axis drive mechanism exposed to the outside from the right side to the right side of the table 7. The telescopic cover device 12 has a structure in which three cover boxes 41 to 43 are sequentially stacked in a nested manner. The cover boxes 41 to 43 each have an upper wall, a right side wall, and a left side wall and are slidably engaged with each other. The cover box 41 is the largest, and the cover boxes 42 and 43 become smaller in this order.

  The cover box 41 is fixed to the right side of the table 7. Therefore, when the table 7 moves rightward, the cover boxes 41 and 42 are sequentially pushed rightward. Since the cover boxes 41 to 43 overlap in a nested manner, the entire stretchable cover device 12 contracts. When the table 7 moves leftward, the cover boxes 41 and 42 are pulled out. The entire telescopic cover device 12 extends.

  The telescopic cover device 13 covers the X-axis feed mechanism exposed to the outside from the left side to the left side from the table 7. The telescopic cover device 13 has the same structure as the telescopic cover device 12, and expands and contracts following the movement of the table 7 in the X-axis direction. The transport body 8 includes a telescopic cover device 14 on the front side and a Y-axis rear cover 15 on the rear side. The telescopic cover device 14 expands and contracts following the movement of the transport body 8 (table 7) in the Y-axis direction. The Y-axis rear cover 15 is a sheet metal having a mountain-shaped cross section. The Y-axis rear cover 15 moves in the Y-axis direction together with the carrier 8 (table 7). When the Y-axis rear cover 15 moves to the column 5 side, it can be stored in the storage portion of the column 5.

  With reference to FIG. 2, the structure of the expansion-contraction cover apparatus 12 is demonstrated concretely. In FIG. 2, the left side, the right side, the lower right side, the lower left side, the upper side, the upper side, and the lower side are defined as the front, rear, right side, left side, upper side, and lower side, respectively. The stretchable cover devices 13 and 14 have the same structure as the stretchable cover device 12 and will not be described. The telescopic cover device 12 has a structure in which three cover boxes 41 to 43 are sequentially stacked in a nested manner.

  The cover box 41 includes an upper wall 51, a right side wall 52, and a left side wall 53, and the whole has a substantially inverted U-shaped cross section. The right wall 52 includes a lower right wall 54 at the bottom. The lower right wall 54 is provided so as to be folded at a substantially right angle from the lower part of the right wall 52 to the left. The left side wall 53 includes a lower left wall 55 at the bottom. The lower left wall 55 is provided by being folded at a substantially right angle from the bottom of the left wall 53 to the right. The elastic body 20 is fixed by a pressing plate 25 (see FIGS. 7 and 8) along the rear end of the inner surface of the upper wall 51. The shape and fixing structure of the elastic body 20 and the shape of the pressing plate 25 will be described later. The fixing plate 56 is provided at the front end of the cover box 41. The fixing plate 56 is fixed to the right side portion of the table 7. Therefore, the cover box 41 can move together with the table 7.

  2 to 4, the cover box 42 is slightly smaller than the cover box 41 and has the same shape, and includes an upper wall 61, a right side wall 62, a left side wall 63, a right lower wall 64, and a left lower wall 65. The stopper plate 30 is provided at the front end portion of the upper wall 61. As shown in FIG. 4, the stopper plate 30 is a metal member having a substantially rectangular shape when viewed from the front. The stopper plate 30 is provided with a mountain-shaped notch 31 at the center in the left-right direction at the lower end. When the cover box 42 moves, the notch 31 avoids interference with the X-axis feed mechanism. The buffer portions 29 are provided on the front surface of the stopper plate 30 and on both the left and right sides. The buffer part 29 is, for example, rubber or resin. When the telescopic cover device 12 contracts, the pair of buffer portions 29 abut against the back surface of the fixing plate 56 of the cover box 41, respectively. The buffer part 29 reduces the impact when the cover boxes 41 and 42 collide. As shown in FIG. 4, the upper end portion of the stopper plate 30 protrudes slightly above the upper surface of the upper wall 61. Therefore, the elastic body 20 of the cover box 41 can come into contact with the upper end portion of the stopper plate 30 of the cover box 42. As shown in FIG. 2, the elastic body 20 is fixed along the rear end of the inner surface of the upper wall 61.

  The cover box 43 is slightly smaller than the cover box 42 and has the same shape, and includes an upper wall 71, a right side wall 72, a left side wall 73, a right lower wall 74, and a left lower wall 75. Prepare for. The back wall 76 closes the opening on the rear end side of the cover box 43. The stopper plate 30 is also provided at the front end portion of the upper wall 71. The stopper plate 30 of the cover box 43 is also provided with the above-described buffer portion (not shown). The stopper plate 30 of the cover box 43 can be locked to the elastic body 20 of the cover box 42.

  The lower surfaces of the lower right wall 64 and the lower left wall 65 of the cover box 42 slide on the upper surfaces of the lower right wall 54 and the lower left wall 55 of the cover box 41. The lower surfaces of the lower right wall 74 and the lower left wall 75 of the cover box 43 slide on the upper surfaces of the lower right wall 64 and the lower left wall 65 of the cover box 42. Therefore, the stretchable cover device 12 can be stretched on a straight line.

  The shape of the elastic body 20 will be described with reference to FIGS. The elastic body 20 extends in the left-right direction of the telescopic cover device 12 (see FIG. 4) and is formed in a substantially rectangular shape that is elongated in plan view. The elastic body 20 is, for example, rubber or resin, and any material having elasticity may be used. The elastic body 20 includes a contact portion 21, a sliding portion 22, a through hole 23, and a concave portion 24. Five contact portions 21 are provided at predetermined intervals at the front end of the elastic body 20. The contact part 21 protrudes in a convex shape toward the front, and the apex part is formed flat (see FIG. 3). Therefore, the front end portion of the elastic body 20 has a planar wave shape. When the telescopic cover device 12 extends, the five contact portions 21 contact the stopper plate 30.

  The sliding portion 22 is provided along the rear end portion of the elastic body 20. The sliding portion 22 has a shape that extends obliquely downward with respect to the rear and that the vertical width gradually decreases. Therefore, the tip of the sliding portion 22 can slide on the upper surface of the cover box 42 (43). The through holes 23 are provided so as to correspond to the five contact portions 21 respectively. The through hole 23 is a long hole that penetrates in the thickness direction of the elastic body 20 and has a long diameter in the left-right direction of the elastic body 20. The recess 24 is provided on the lower surface 20 </ b> B of the elastic body 20. The recess 24 is provided along the left-right direction of the elastic body 20 at the center in the front-rear direction of the lower surface 20B. Each through hole 23 corresponds to the position of the recess 24. As shown in FIG. 6, the recess 24 includes a bottom surface 24A and inner surfaces 24B and 24C. The inner side surface 24B is located on the front end side of the elastic body 20, and the inner side surface 24C is located on the rear end side of the elastic body 20, and faces each other.

  The shape of the pressing plate 25 will be described with reference to FIGS. The holding plate 25 has an elongated rectangular shape in plan view and corresponds to the shape of the concave portion 24 of the elastic body 20. The holding plate 25 is a metal member. The pressing plate 25 includes five fixing holes 25A. Each fixing hole 25 </ b> A corresponds to five through holes 23 provided at predetermined intervals in the left-right direction of the pressing plate 25 and provided in the elastic body 20. The inner peripheral surface of the fixing hole 25A has a tapered shape whose diameter increases from top to bottom. Therefore, the head of a screw 26 described later is locked in the fixing hole 25A. The pressing plate 25 holds the elastic body 20 on the inner surface of the upper wall 51 (61) of the cover box 41 (42) and the inner surface of the upper wall 51 (61) of the cover box 41 (42) with the five screws 26. Fix it.

  The structure for fixing the elastic body 20 in the cover box 41 will be described with reference to FIGS. As shown in FIG. 7, the rear end side of the upper wall 51 of the cover box 41 is inclined obliquely downward with respect to the rear. The upper wall 51 includes five holes 34. The holes 34 are provided at predetermined intervals at the rear end of the upper wall 51. The diameter of the hole 34 is slightly larger than the diameter of the screw 26. The upper wall 51 is provided with a pair of welding holes 35 on the left and right sides of each hole 34. The upper wall 51 includes a cylindrical shielding wall 27 at a position corresponding to each of the five holes 34 on the inner surface. The shielding wall 27 is fixed to the inner surface of the upper wall 51 by, for example, welding. The shielding wall 27 is provided with a screw hole 27A on the inner side. The screw hole 27A and the hole 34 of the upper wall 51 are opposed to each other in the same position.

  As shown in FIG. 8, the upper surface 20 </ b> A of the elastic body 20 is in close contact with the inner wall rear end side of the upper wall 51. The upper surface of the sliding portion 22 of the elastic body 20 is in close contact with the inclined inner surface on the rear end side of the upper wall 51. Therefore, the elastic body 20 does not shift backward from the inclined inner surface on the rear end side of the upper wall 51. Each shielding wall 27 provided in the upper wall 51 is inserted inside the through hole 23 provided in the elastic body 20.

  The pressing plate 25 is disposed inside the concave portion 24 of the elastic body 20 and presses against the inner surface of the upper wall 51. The fixing hole 25A of the pressing plate 25, the screw hole 27A of the shielding wall 27, and the hole 34 of the upper wall 51 are opposed to each other in the same position. The screw 26 is fastened to the screw hole 27A from below the pressing plate 25 through the fixing hole 25A. The flange-shaped head of the screw 26 has a tapered surface that decreases in diameter toward the tip. Therefore, the head of the screw 26 is locked to the taper of the inner peripheral surface of the fixing hole 25A. Since the head of the screw 26 does not protrude outward from the fixing hole 25A, it does not hit the upper surface of the upper wall 61 of the cover box 42. The pressing plate 25 is fixed to the inner surface of the upper wall 51 with the elastic body 20 sandwiched therebetween. Therefore, the elastic body 20 is fixed to the inner surface of the upper wall 51 by the pressing plate 25. Each welding hole 35 performs plug welding. Plug welding is a welding method in which a welding material is poured into each welding hole 35 and solidified. Therefore, the shielding wall 27 can be firmly fixed to the upper wall 51.

  As shown in FIG. 7, the upper surface of the pressing plate 25 contacts the lower end portion of the shielding wall 27 inside the concave portion 24 of the elastic body 20. The front end portion 45 of the pressing plate faces the inner side surface 24B of the concave portion 24 of the elastic body 20. A predetermined gap 33 is formed between the front end 45 and the inner surface 24B. The fixing structure of the elastic body 20 in the cover box 42 is the same as the above structure.

  The expansion / contraction operation of the expansion / contraction cover device 12 having the above configuration will be described. As shown in FIG. 1, the telescopic cover device 12 expands and contracts as the table 7 moves in the X-axis direction. When the table 7 moves to the right, the carrier 8 pushes the cover boxes 41 and 42 sequentially in the right direction. Since the cover boxes 41 to 43 overlap in a nested manner, the entire stretchable cover device 12 contracts.

  When the table 7 moves to the left, the carrier 8 sequentially pulls the cover boxes 41 and 42 outward. The cover box 41 is pulled out from the inside of the cover box 42, and the cover box 42 is pulled out from the inside of the cover box 43. The entire cover boxes 41 to 43 are gradually extended.

  As shown in FIG. 7, the contact portion 21 of the elastic body 20 fixed to the cover box 41 is provided at the front end of the cover box 42 in a portion where the rear end side of the cover box 41 and the front end side of the cover box 42 overlap. Gradually approach the stopper plate 30. The contact portion 21 of the elastic body 20 collides with the stopper plate 30 vigorously according to the moving speed of the table 7. The contact portion 21 receives stress from the stopper plate 30. The shielding wall 27 is disposed between the contact portion 21 and the screw 26. The shielding wall 27 receives the stress received by the contact portion 21. Since the screw 26 is not in contact with the contact portion 21, it is not affected by the stress received by the contact portion 21.

  Further, in the recess 24 of the elastic body 20, the inner side surface 24 </ b> B and the front end portion of the pressing plate 25 are separated by the gap 33, so that the stress received by the contact portion 21 can be absorbed by the elastic force of the contact portion 21 in the gap 33. . Therefore, the presser plate 25 is not affected by the stress applied to the contact portion 21, and therefore does not affect the screw 26 that fixes the presser plate 25. The screw 26 is not affected by the stress applied to the contact portion 21. Therefore, even if the abutting portion 21 collides with the stopper plate 30 many times vigorously, the screw 26 does not loosen or break, so that the elastic body 20 is firmly attached to the inner surface of the upper wall 51 of the cover box 41. Can be fixed.

  In the above embodiment, the operation of the stopper plate 30 and the elastic body 20 in the portion where the rear end side of the cover box 41 and the front end side of the cover box 42 overlap is described. The same applies to the action of the stopper plate 30 and the elastic body 20 at the portion where the front end side of the elastic plate 20 overlaps.

  In the above description, in the relationship between the cover boxes 41 and 42 shown in FIG. 2, the cover box 41 corresponds to the outer cover of the present invention, and the cover box 42 corresponds to the inner cover of the present invention. In the relationship between the cover boxes 42 and 43, the cover box 42 corresponds to the outer cover of the present invention, and the cover box 43 corresponds to the inner cover of the present invention. The stopper plate 30 shown in FIG. 7 corresponds to the stopper portion of the present invention. The shielding wall 27 corresponds to the shielding part of the present invention.

  As described above, the machine tool 1 of this embodiment includes the telescopic cover device 12. The extendable cover device 12 covers the X-axis feed mechanism. The X-axis feed mechanism is a mechanism that moves the table 7 in the X-axis direction. The telescopic cover device 12 has a structure in which three cover boxes 41 to 43 are sequentially stacked in a nested manner. The cover box 41 is fixed to the right side of the table 7. Therefore, when the table 7 moves rightward, the cover boxes 41 and 42 are sequentially pushed rightward. Since the cover boxes 41 to 43 overlap in a nested manner, the entire stretchable cover device 12 contracts. When the table 7 moves leftward, the cover boxes 41 and 42 are pulled out. The entire telescopic cover device 12 extends.

  When the telescopic cover device 12 is extended, the contact portion 21 of the elastic body 20 fixed to the cover box 41 at the portion where the rear end side of the cover box 41 and the front end side of the cover box 42 overlap is the front end of the cover box 42. It collides with the stopper plate 30 provided in the. The contact portion 21 receives stress from the stopper plate 30. The stress received by the contact portion 21 can be absorbed by the shielding wall 27. The screw 26 inserted into the shielding wall 27 is not affected by the stress applied to the contact portion 21. Therefore, the telescopic cover device 12 can prevent the screw 26 from being loosened and damaged.

  Further, the shielding wall 27 surrounds the screw 26. Therefore, the shielding wall 27 protects the screw 26 not only from the stress from the contact portion 21 but also from the stress applied to the sliding portion 22 when the sliding portion 22 slides on the upper surface of the upper wall 71 of the cover box 43. it can. Further, there is a gap 33 between the front end portion 45 of the pressing plate 25 accommodated in the concave portion 24 of the elastic body 20 and the inner side surface 24B of the concave portion 24. Therefore, the stress applied to the contact portion 21 when the contact portion 21 collides with the stopper plate 30 is not transmitted to the pressing plate 25. Therefore, the expansion / contraction cover device 12 can prevent the stress applied to the contact portion 21 from affecting the screw 26 via the pressing plate 25.

  The present invention is not limited to the above embodiment, and various modifications can be made. In the above embodiment, as shown in FIG. 8, the screw 26 is directed from the lower side to the upper side with respect to the fixing hole 25 </ b> A of the pressing plate 25, the screw hole 27 </ b> A of the shielding wall 27, and the hole 34 of the upper wall 51 of the cover box 41. Although inserted and fastened, it may be inserted and fastened from above to below. In that case, at least the fixing hole 25A of the pressing plate 25 may be a screw hole, and the hole 34 may be a simple fixing hole without a screw thread.

  Moreover, in the said embodiment, although the shielding wall 27 is provided with 27 A of screw holes, you may make it a simple fixing hole without a screw thread instead, and may make the hole 34 a screw hole.

  Moreover, in the said embodiment, although the hole 34 is a mere fixing hole without a screw thread, the hole 34 may be a screw hole similarly to the shielding wall 27 provided with 27 A of screw holes.

  Moreover, in the said embodiment, although the vertex part of the contact part 21 of the elastic body 20 is formed flat, it is not restricted to this. For example, the apex portion of the contact portion 21 may be formed in a triangular shape and the tip may be sharp.

  Moreover, in the said embodiment, although the expansion-contraction cover apparatus 12 is provided with the three cover boxes 41-43, it should just be provided with at least two cover boxes.

  In the above embodiment, the cover boxes 41 to 43 have a substantially inverted U-shaped cross section. However, the cover boxes 41 to 43 may have other shapes, for example, a mountain shape in which the upper wall is refracted, or a shape in which the upper wall is curved in an arc shape. There may be.

  In the above embodiment, the gap 33 between the inner surface 24B of the recess 24 of the elastic body 20 and the front end portion 45 of the pressing plate 25 may not be present.

  In the above embodiment, the shielding wall 27 is formed in a cylindrical shape and covers the periphery of the screw 26. However, it may be any shape as long as it shields at least the space between the screw 26 and the contact portion 21 (for example, a flat plate shape). .

DESCRIPTION OF SYMBOLS 1 Machine tool 7 Table 8 Carrying body 12 Cover apparatus 20 Elastic body 21 Contact part 22 Sliding part 23 Through hole 24 Recessed part 24B Inner side surface 26 Screw 27 Shielding wall 30 Stopper plate 41-43 Cover box 45 Front end part

Claims (4)

A cover device for a machine tool, which is formed by overlapping a plurality of covers in a nested manner and forming the whole to be stretchable and protecting a feed mechanism for driving a movable body,
The plurality of covers are
Comprising at least an outer cover and an inner cover overlapping the inner side of the outer cover;
When the cover device extends out of the inner surface of the outer cover facing the outer surface of the inner cover with the plurality of covers stacked in a nested manner, the cover device moves relative to the inner cover. On the rear end side in the moving direction of the outer cover,
An elastic body provided with an abutting portion facing a stopper portion provided on the front end side in the moving direction on the outer surface of the inner cover and abutting against the stopper portion when the cover device is extended is fixed to the cover. Fixing means,
The fixing means includes
A pressing plate for pressing the elastic body against the inner surface of the cover;
A screw for fixing the pressing plate to the inner surface of the cover via the elastic body;
The elastic body includes a through hole into which the screw is inserted, on the rear end side in the movement direction with respect to the contact portion,
The cover device according to claim 1, further comprising: a shielding portion interposed between the screw and the contact portion on the inner surface of the cover inside the through hole. The elastic body includes a sliding portion that slides on the outer surface of the inner cover when the cover device expands and contracts at a position opposite to the contact portion with the through hole in the center.
The cover device according to claim 1, wherein the shielding portion is formed in a cylindrical shape surrounding the screw inside the through hole. The elastic body is
In the position where the pressing plate is pressed, a concave portion is formed which is recessed and accommodates the pressing plate inside,
In a state where the pressing plate is pressed inside the recess and fixed to the inner surface of the cover with the screw, the inner surface on the contact portion side of the recess and the contact portion side of the pressing plate The cover device according to claim 1, wherein a predetermined gap is provided between opposite ends.   A machine tool comprising the cover device according to claim 1.

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