JP2008229791A - Supporting means of workpiece, and machine tool equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supporting means of a workpiece preventing deflection of the workpiece without hindering transfer of the workpiece in relation to a main spindle of the machine tool, and a machine tool equipped with the supporting means of the workpiece. <P>SOLUTION: This supporting means of the workpiece supports the workpiece w made of a bar material inserted into the main spindle 1 of the machine tool via an insertion hole 13a and held integrally with the main spindle 1 to be rotated and driven in the insertion hole 13a. The supporting means is constituted of a moving supporting body arranged to be freely slid and moved in an axial center direction of the main spindle 1 in the insertion hole 13, and an elastic member 18 for elastically positioning the moving supporting body. The supporting means has a structure for permitting advancing of a workpiece receiving part 16a of the workpiece supply means holding a non-machining side end part of the workpiece w or abutting on the end part into the insertion hole 13a or moving of the workpiece receiving part 16a in the insertion hole 13a by moving the moving supporting body by pushing the supporting body from a rear side by the workpiece receiving part 16a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a workpiece support means for supporting a workpiece within the spindle and a machine tool provided with the workpiece support means.

  As is known in the art, an automatic lathe, which is a machine tool, is provided on a main shaft when a workpiece made of a bar is inserted and supplied into the main shaft so as to protrude a predetermined length from the tip (front end) of the main shaft. By gripping with a chuck and rotationally driving the main shaft, the workpiece is rotationally driven integrally with the main shaft to automatically process the protruding portion of the workpiece from the main shaft.

  When the workpiece has a small diameter, particularly a wire rod, the workpiece may have a jump rope-like runout in the main shaft due to integral rotation with the main shaft. Due to the deflection of the workpiece, damage to the workpiece itself, damage to the spindle, damage to surrounding structures, reduction in machining accuracy, and the like occur. For this reason, a work supporting means for supporting a work within the main shaft with respect to the main shaft is known (for example, see Patent Document 1).

  On the other hand, a workpiece supply device that feeds a workpiece to an automatic lathe by inserting a workpiece through the main shaft generally includes a workpiece push rod that advances and retreats along the axis of the main shaft. The workpiece supply device holds a rear end portion which is a non-working side end portion of a workpiece by a finger chuck provided on the front end (front end) side of the push rod, and the workpiece is fed so that the front end side of the workpiece protrudes from the tip end of the main shaft. Extrude and hold.

For this reason, due to the rotational drive of the workpiece integral with the main shaft, the same workpiece shake occurs between the workpiece supply device (finger chuck) and the main shaft. On the other hand, shake prevention means for preventing the above-described shake of the workpiece between the workpiece supply device and the spindle is also known (see, for example, Patent Document 2).
JP 2002-283104 A JP-A-7-136807

  The supply of new workpieces to the automatic lathe is usually done by the push bar protruding toward the tip of the spindle while holding the rear end of the workpiece by the finger chuck, and sliding the workpiece toward the tip of the spindle. Is done by. Once the workpiece supplied to the automatic lathe is started to be processed, a moving operation is performed so that the workpiece is repeatedly projected from the spindle tip as the machining of the protruding portion from the spindle tip ends.

  In the above work movement work, chucking of the work by the chuck is released after finishing the projecting part from the spindle tip, and in the case of a spindle movement type automatic lathe, the spindle is positioned while the work is held by the finger chuck. In the case of a spindle-fixed type automatic lathe by moving it back in a fixed amount or the like, it is performed by projecting a push rod from a state in which a workpiece is held by a finger chuck. In this way, when the workpiece is slid relative to the main shaft tip side, the finger chuck moves relative to the main shaft toward the front end side of the main shaft.

On the other hand, in the case of the support means shown in the above-mentioned Patent Document 1, the rubber or holding member that supports the workpiece becomes an obstacle, and it is difficult to move the finger chuck from the support means to the tip side of the main shaft. When the finger chuck cannot move from the guide means to the tip end side of the main shaft, there is a disadvantage that the work remains as a remaining material in the main shaft for the main shaft length, and the remaining material length becomes longer and the cost is increased.

  On the other hand, the supporting means shown in Patent Document 2 slides in the movement direction of the workpiece with respect to the workpiece, but requires a rail, a chain drive mechanism, etc., and is adopted as a workpiece supporting means in the main shaft. There is a problem that cannot be done.

  The work support means of the present invention for solving the above-mentioned problems is inserted into the main spindle 1 of the machine tool by the work supply means through the insertion hole 13a, and is rotated by being gripped integrally with the main spindle 1 side. In a work support means for supporting a work w made of a bar to be driven in the insertion hole 13a while allowing movement of the main spindle 1 in the axial direction, the support means is disposed in the insertion hole 13 in the main shaft 1. And a resilient support 18 that elastically positions the movable support, and holds or abuts the non-working side end of the workpiece. The workpiece receiving portion 16a of the workpiece supply means in contact presses the moving support member from the rear, and moves the moving support member toward the front end side of the main shaft 1 against the urging force of the elastic member 18, thereby receiving the workpiece receiving member. Part 16a That it has a structure that allows movement in the entrance or in the insertion hole 13a into the hole 13a is set to the first feature.

  Second, a plurality of movable supports are provided, and an elastic member 18 is interposed between the movable supports 17b and 17c.

  Third, a fixed support 17a that is fixedly positioned with respect to the main shaft 1 and supports the workpiece w is provided in front of the movable support, and the fixed support 17a is disposed so as to be positioned in the main shaft 1. The elastic member 18 is provided between the fixed support 17a and the adjacent movable support.

  Fourthly, the fixed support 17a is arranged in the vicinity of the rear side of the gripping means for the workpiece w provided on the front end side of the main shaft 1.

  Fifth, it is characterized in that adjacent supports are accommodated so as to partially overlap each other by sliding movement of the moving support.

  Sixth, the moving support 17c with which the workpiece receiving portion 16a contacts is provided with a receiving portion 28 into which a part or all of the workpiece receiving portion 16a is inserted and received.

  Seventh, the insertion hole 13a is characterized by comprising a through-hole penetrating in the axial direction of the cylindrical inner insertion tube 13 inserted into the main shaft 1.

  Eighth, the support and the elastic member 18 are integrally incorporated in the inner intubation 13.

  Ninth, the inner tube 13 is fixed in the main shaft 1 so as to rotate integrally with the main shaft 1.

  Tenth, the insertion hole 13a includes a cylindrical sleeve or a through-hole penetrating in the axial direction of the draw bar constituting the opening / closing mechanism of the grip means for the workpiece w provided on the front end side of the main shaft 1. Yes.

On the other hand, the machine tool of the present invention is characterized in that it integrally includes workpiece support means having at least one of the first to tenth features.

  According to the structure of the workpiece supporting means of the present invention configured as described above, the spindle during rotation driving is supported even when a workpiece having a small diameter such as a wire rod is supported by the moving support in the insertion hole. There is an effect that the jumping-like runout of the workpiece can be prevented and damage to the workpiece itself, damage to the main shaft, damage to surrounding structures, reduction in machining accuracy, and the like can be prevented.

  At this time, during the sliding movement of the workpiece with respect to the spindle of the workpiece, the workpiece receiving portion that holds the non-working side end portion of the workpiece or abuts against the end portion presses the movement support body from the rear, and elastically moves the movement support body. By moving to the front end side of the main shaft against the urging force of the member, the work receiving portion is allowed to enter the insertion hole or move in the insertion hole.

  For this reason, even if the work moves relative to the main shaft relative to the front end side of the main shaft, the movable support follows the movement of the work and moves into the insertion hole or moves through the insertion hole to stably support the work. Continue to prevent jumping of the workpiece. In addition, the workpiece receiving portion enters or moves through the insertion hole, so that the workpiece protrudes from the tip of the spindle while entering the spindle. The length of the remaining material can be shortened.

  Furthermore, the size of the workpiece receiving portion can be made larger than the workpiece within a range where insertion into the insertion hole is allowed, and the workpiece holding portion and the contact with the workpiece can be stably performed. it can. Since the moving support moves against the urging force of the elastic member, the moved moving support can be returned to the initial position by the urging force of the elastic member, and the return mechanism of the moving support is simply configured. can do.

  In particular, by providing a plurality of moving supports, the support interval of the work in the insertion hole can be shortened, and the above-mentioned jumping-like runout can be stably prevented, and the rotation speed of the work (spindle) during machining can be reduced. The workpiece machining efficiency can be improved.

  Further, a fixed support body that is fixedly positioned with respect to the main shaft and supports the workpiece is provided in front of the movable support body, the fixed support body is disposed so as to be positioned in the main shaft, and the elastic member is connected to the fixed support body. By providing it between adjacent moving supports, when the workpiece receiving part comes into contact with the moving support located at the rearmost position, the other moving supports move toward the fixed support side while approaching each other via the elastic member. Can support the workpiece stably.

  By placing the fixed support in the vicinity of the rear side of the work gripping means provided on the front end side of the main shaft, the work receiving portion can be moved to the vicinity of the rear side of the gripping means to move the work, The length of the remaining material can be further shortened.

  In particular, adjacent supports are configured so that they are accommodated by overlapping each other by sliding movement of the moving support, or a part or all of the work receiving part is inserted into the moving support in contact with the work receiving part. By providing the accommodating portion to be accommodated, it is possible to shorten the total length of the support means in a state where the respective support bodies are closest to each other, and it is possible to further shorten the length of the remaining material.

  On the other hand, the support body and the elastic member can be integrated into the inner intubation tube by forming the insertion hole as a through hole penetrating in the axial direction of the cylindrical inner intubation tube inserted into the main shaft. Accordingly, the support means can be exchanged integrally with the internal intubation corresponding to the change in the diameter of the work, and the support means having a size suitable for the work of various diameters can be easily exchanged and used. .

  Also, by fixing the inner intubation in the main shaft so as to rotate integrally with the main shaft, the work can be supported while rotating the support means integrally with the work, and the number of rotations of the work during processing can be further increased. Can be increased.

  Even when the insertion hole is formed from a cylindrical sleeve or a through-hole penetrating in the axial direction of the drawbar constituting the opening / closing mechanism of the workpiece gripping means provided on the front end side of the main shaft, the support means is easily incorporated. be able to.

  A machine tool equipped with a workpiece support means having the above characteristics can machine a small-diameter workpiece such as a wire rod with high accuracy while preventing jumping-like runout in addition to a normal workpiece as described above. And the remaining material can be reduced.

  FIG. 1 is a sectional side view of a main part of a main spindle portion of an automatic lathe provided with a workpiece supporting means of the present invention. As shown in FIG. 1, the main shaft 1 is rotatably supported by the main shaft base 2. The main shaft 1 is concentric and has a hollow shape with an inner hole 1a formed therethrough. The inner hole 1 a is open at both end faces of the main shaft 1. Between the main shaft 1 and the head stock 2, a motor 3 is configured in which the main shaft 1 forms a rotating shaft. The main shaft 1 is driven to rotate about the axis by the drive of the motor 3.

  A chuck sleeve 4 that rotates integrally with the main shaft 1 and slides in the axial direction of the main shaft 1 is inserted into the front end side of the inner hole 1 a of the main shaft 1. A collet chuck 6 is inserted into the chuck sleeve 4. The collet chuck 6 is biased by a spring 7 so that the front end side is pressed against the inner surface of the front end of the main shaft 1.

  An intermediate sleeve 8 is inserted into the inner hole 1 a of the main shaft 1 behind the chuck sleeve 4. The intermediate sleeve 8 is slidably contacted with the inner hole 1a. The front end surface of the intermediate sleeve 8 is in contact with the rear end side of the chuck sleeve 4.

  The spindle stock 2 accommodates an air piston mechanism 9 at a position behind the spindle 1. The air piston mechanism 9 includes a piston 9a and a piston rod 9b. The piston rod 9b has a hollow cylindrical shape. The piston rod 9b protrudes before and after the piston 9a. The air piston mechanism 9 urges the piston 9a forward by a spring 9c.

  The piston rod 9b is slidably in contact with the inner hole 1a of the main shaft 1. The front end side of the piston rod 9b and the rear end side of the intermediate sleeve 8 are engaged. The intermediate sleeve 8 and the piston rod 9b are locked to the main shaft 1 in a state in which sliding in the axial direction of the main shaft 1 is allowed by a radial pin 11 inserted into the main shaft 1.

  One hollow cylindrical insertion tube 13 extending from the rear of the through hole 12 to the substantially front end of the intermediate sleeve 8 is inserted into the through hole 12 of the piston rod 9b and the through hole 8a of the intermediate sleeve 8. The through hole 13a of the inner tube 13 and the inner hole 1a of the main shaft 1 are concentric. The inner intubation 13 is integrally fixed to the headstock 2 via the support member 14.

  When the main shaft 1 is rotated by the motor 3 with the above structure, the collet chuck 6, the chuck sleeve 4, the intermediate sleeve 8, the piston 9a, and the piston rod 9b rotate integrally with the main shaft 1. Since the inner tube 13 is fixed to the headstock 2 side, it does not rotate integrally with the main shaft 1.

The inner surface on the front end side of the collet chuck 6 constitutes a gripping surface for chucking (gripping) the workpiece w. Due to the elastic forward projection of the piston rod 9b by the spring 9c, the chuck operating surface 4a of the chuck sleeve 4 presses the tapered surface 6a of the collet chuck 6 via the intermediate sleeve 8, and the collet chuck 6 is in a closed state. Become.

  On the other hand, when air is supplied to the air piston mechanism 9 and the piston 9a is moved backward against the urging force of the spring 9c, the pressing of the tapered surface 6a of the collet chuck 6 by the chuck operating surface 4a of the chuck sleeve 4 is released. The collet chuck 6 is opened by the urging force of the spring 7.

  A workpiece w made of a bar is supplied to the spindle 1 by a bar feeder which is a workpiece supply means (not shown). The bar feeder projects a rod-like pusher 16 provided with a cylindrical finger chuck portion 16 a that is externally fitted to the rear end portion of the workpiece w toward the front end of the main shaft 1 as is conventionally known. The workpiece w is transferred toward the front end side of the main shaft 1 by the protrusion of the pusher 16, and a new workpiece is inserted into the through hole 13 a of the inner intubation tube 13 from behind.

  The workpiece w inserted from the rear into the through hole 13a passes through the open collet chuck 6 and protrudes from the front end of the main shaft 1. By releasing the air supply to the air piston mechanism 9 from this state and closing the collet chuck 6, the workpiece w protrudes a predetermined length from the front end of the main shaft 1 and is gripped integrally with the main shaft 1 by the collet chuck 6. Is done.

  The axis of the workpiece w substantially coincides with the axis of the main shaft 1 in the gripped state. When the main shaft 1 is rotationally driven as described above in a state where the work w is gripped, the work w rotates concentrically with the main shaft 1 integrally. The automatic lathe processes the workpiece w that rotates integrally with the main spindle 1 by a rotary tool of the main spindle 1 with a tool mounted on the tool rest.

  After the machining of the projecting portion of the workpiece w from the spindle 1 is completed, air is supplied to the air piston mechanism 9 for the next machining, and the collet chuck 6 is opened to hold the workpiece w by the collet chuck 6. For example, when the automatic lathe is a spindle movement type, the spindle stock 2 is moved backward integrally with the spindle 1 until the workpiece w protrudes from the front end of a predetermined length, and the workpiece w is relatively moved to the spindle 1. It moves toward the front end side.

  When the automatic lathe is a spindle fixed type, the pusher 16 is moved forward until the workpiece w protrudes from the front end of a predetermined length, and the workpiece w is transferred toward the front end side of the spindle 1. In any case, the transfer of the workpiece w by the bar feeder is performed while the rear end portion which is the non-working side end portion of the workpiece w is held by the finger chuck portion 16a.

  Thereafter, when the workpiece w protrudes from the front end of the main shaft 1 for a predetermined length, the collet chuck 6 is closed, the workpiece w is attached to the main shaft 1 integrally, and the processing of the workpiece w is resumed. The projecting work of the workpiece w from the front end of the main shaft 1 is sequentially repeated until the processing of the entire workpiece accommodated in the main shaft 1 is completed. As described above, the collet chuck 6 is a gripping means capable of integrally fixing and releasing the workpiece w with respect to the main shaft 1. On the other hand, the chuck sleeve 4, the intermediate sleeve 8, the spring 7, the air piston mechanism 9 and the like constitute an opening / closing mechanism for the collet chuck 6.

  As described above, the through hole 13a of the inner tube 13 constitutes an insertion hole through which the workpiece w to be processed is inserted. As shown in FIGS. 1 and 2, a plurality (three in this embodiment) of guide pipes 17a, 17b, and 17c are inserted into the through-hole 13a in a sliding contact state. Between each guide pipe 17a, 17b, 17c, the compression spring 18 which is an elastic member is provided in the through-hole 13a. The two compression springs 18 are the same type of spring.

  The foremost guide pipe 17 a is disposed at a substantially front end position of the inner intubation tube 13 in the vicinity of the rear of the collet chuck 6. The guide pipe 17 a is restricted from moving forward by a ring 19 provided in the inner intubation 13. The guide pipe 17c at the last position is restricted from coming off from the rear end side of the inner intubation tube 13 by a ring 21 provided at a substantially rear end of the inner intubation tube 13. The guide pipe 17b at the intermediate position is freely slidable back and forth in the axial direction of the main shaft 1 within the inner tube 13.

  The three guide pipes 17a, 17b, and 17c are arranged such that the guide pipe 17a contacts the ring 19 and the guide pipe 17c contacts the ring 21, and the guide pipe 17b is positioned at an intermediate position between the guide pipes 17a and 17c. The initial positions are respectively positioned by the compression springs 18. In the initial position, the two guide pipes 17 a and 17 b on the front side are disposed in the main shaft 1.

  Each guide pipe 17a, 17b, 17c is provided with a work insertion hole 22 into which a work w is slidably inserted. The workpiece w is in sliding contact with the workpiece insertion hole 22 and passes through the guide pipes 17a, 17b, and 17c. Portions of the workpiece w passing through the guide pipes 17a, 17b, and 17c are supported by the inner tube 13 by the guide pipes 17a, 17b, and 17c.

  Each of the guide pipes 17a, 17b, 17c includes large-diameter large-diameter portions 24a, 24b, 24c having a contact surface 23 in contact with the inner peripheral surface of the through-hole 13a of the internal intubation tube 13, and the large-diameter portions 24a, 24b, It has small diameter portions 26a, 26b, 26c smaller in diameter than 24c. The small diameter parts 24a, 24b, 24c are arranged in front of the large diameter parts 24a, 24b, 24c. Each guide pipe 17a, 17b, 17c is formed in a step shape by large diameter portions 24a, 24b, 24c and small diameter portions 26a, 26b, 26c so that the compression spring 18 can be inserted.

  The guide pipe 17a at the foremost position adjacent to each other, the guide pipe 17b at the intermediate position, and the guide pipe 17b at the intermediate position and the guide pipe 17c at the last position are the large diameter portion 24a of the guide pipe 17a on the front side and the guide on the rear side. The small-diameter portion 26b of the pipe 17b faces the large-diameter portion 24b of the guide pipe 17b at the intermediate position and the small-diameter portion 26c of the guide pipe 17c on the rear side.

  Large diameter portions 24a, 24b of the guide pipes 17a, 17b on the front side facing the small diameter portions 26b, 26c of the guide pipes 17b, 17c on the rear side of the adjacent guide pipes 17a, 17b and the adjacent guide pipes 17b, 17c, respectively. The small-diameter portion insertion holes 27 a and 27 b into which the corresponding small-diameter portions 26 b and 26 c can be inserted are formed so as to sit on the rear side of the workpiece insertion hole 22.

  In the guide pipes 17a and 17b, the workpiece insertion hole 22 and the small diameter portion insertion holes 27a and 27b are continuous to form concentric step holes. Thus, when the guide pipes 17b and 17c are moved forward against the urging force of the compression spring 18, as shown in FIG. 3, the guide pipes 17b and 17c are positioned in the middle in the large diameter portion 24a of the foremost guide pipe 17a. The small diameter part 26b of the guide pipe 17b can be inserted, and the small diameter part 26c of the guide pipe 17c at the last position can be inserted into the large diameter part 24b of the guide pipe 17b located in the middle.

  As described above, the guide pipe 17b at the intermediate position and the guide pipe 17c at the final position can be freely slid forward in the axial direction of the main shaft 1 as described above, and initial when the moving force to move forward is released. The moving support body is configured to be freely slidable backward to the position. The guide pipe 17a at the foremost position constitutes a fixed support that is fixedly positioned with respect to the main shaft 1 at the above position without sliding.

  A finger insertion hole 28 into which the above-described finger chuck portion 16a can be inserted and accommodated is formed in the moving guide pipe 17c at the last position so as to sit behind the workpiece insertion hole 22. The workpiece insertion hole 22 and the finger insertion hole 28 are continuous to form a concentric step hole.

  As described above, in the through hole 13a of the inner insertion tube 13, a support means for the workpiece w including the plurality of guide pipes 17a, 17b, 17c and the compression spring 18 between the guide pipes 17a, 17b, 17c is configured. .

  When the work w is rotated integrally with the main shaft 1 by supporting the work w by the support means, the support pipes 17a, 17b, and 17c support the three places so that the collet chuck 6 and the frontmost guide pipe 17a are In addition, the jumping of the work w between the guide pipes 17a, 17b, 17c can be prevented. As a result, the jumping of the workpiece w in the through-hole 13 including the inside of the spindle 1 is prevented, and the workpiece w is prevented from being damaged, the spindle 1 is damaged, the surrounding structure is damaged, and the like. Is done.

  Since the finger chuck portion 16a is sized to be accommodated in the finger insertion hole 28, the insertion tube 13 is allowed to enter the through hole 13a. For this reason, when the workpiece w is transferred by the above-described pressing body 16, the pressing body 16 has the workpiece insertion hole 22 and the finger insertion hole 28 of the guide pipe 17c at the front end of the finger chuck portion 16a as shown in FIG. It slides freely until it touches the step part.

  In the free movement range of the pusher 16, the support means is positioned at the initial position and supports the workpiece w as shown in FIG. Since both compression springs 18 are the same type of spring, both compression springs 18 have a length of L1, and the moving guide pipe 17b located in the middle is located at the approximate center between the front and rear guide pipes 17a, 17c. . In the initial state, the support means uniformly supports the workpiece w by the three guide pipes 17a, 17b, and 17c.

  On the other hand, the finger chuck portion 16a is inserted and accommodated in the finger insertion hole 28 of the guide pipe 17c at the last position, and the front end of the finger chuck portion 16a abuts on the step portion between the workpiece insertion hole 22 and the finger insertion hole 28 of the guide pipe 17c. Thereafter, as the workpiece w is transferred, the finger chuck portion 16a presses the guide pipe 17c at the last position to the front end side of the main shaft 1 at the stepped portion and moves forward in the through hole 13a while moving integrally. Moving.

  Due to the above movement of the guide pipe 17c at the last position, the guide pipe 17b located in the middle via the compression spring 18 also moves to the front end side of the main shaft 1 against the urging force of the compression spring 18. As a result, the guide pipes 17a, 17b, and 17c approach each other so as to gather toward the frontmost guide pipe 17a.

  Each compression spring 18 contracts as the guide pipes 17b and 17c move. However, since both the compression springs 18 are the same type of spring, as shown in FIG. 5B, both the compression springs 18 have substantially the same length L2. Thereby, the guide pipe 17b located in the middle is always located at the approximate center between the front and rear guide pipes 17a and 17c. As described above, the support means always supports the workpiece w almost uniformly by the three guide pipes 17a, 17b, 17c while the movement guide pipes 17b, 17c move following the transfer of the workpiece w.

Thereby, the support means always supports the workpiece w stably in a balanced manner, and stably prevents the workpiece w from jumping in the main shaft 1. When the guide pipe 17c at the last position is located in the main shaft 1, the support means supports the workpiece w by the three guide pipes 17a, 17b, 17c in the main shaft 1.

  As shown in FIG. 3, the two guide pipes 17b and 17c on the rear side are moved in the through holes 13a of the finger chuck portion 16 to move against the urging force of the compression spring 18 as described above. The pipes 17b and 17c move until the small diameter portions 26b and 26c are inserted into the small diameter portion insertion holes 27a and 27b of the adjacent guide pipes 17a and 17b.

  The workpiece remaining in the support means becomes the remaining material, but as described above, the moving guide pipes 17b and 17c are accommodated partially overlapping the adjacent guide pipes 17a and 17b, and the finger chuck portion 16a is the guide at the last position. Since it is accommodated in the pipe 17c, the overall length of the support means itself is reduced, and the finger chuck portion 16a approaches the collet chuck 6 to shorten the remaining material length.

  In addition, since the foremost guide pipe 17a is positioned in the vicinity of the rear of the collet chuck 6, the support means having the shortest overall length is positioned in the vicinity of the rear of the collet chuck 6, and the finger chuck portion 16a is in the collet. The workpiece w can be transferred until it is located in the vicinity of the rear of the chuck 6, and the remaining material length is further shortened.

  When the finger chuck portion 16a is moved rearward with respect to the main shaft 1 for exchanging the workpiece w, the both moving guide pipes 17b and 17c are automatically moved rearward by the urging force of the compression spring 18, and FIG. It automatically returns to the initial position shown in (A). The interlocking movement mechanism and the return mechanism of the guide pipes 17b and 17c are simply configured by the compression spring 18.

  Since the finger chuck portion 16a only needs to be accommodated in the finger insertion hole 28 of the guide pipe 17c at the final position, the diameter of the finger chuck portion 16a can be made larger than the diameter of the workpiece w, and the rear end portion of the workpiece w can be held. Can be performed stably, and the transfer work of the work w by the pusher 16 can be performed more smoothly. Thereby, especially when the diameter of the workpiece w is as small as several millimeters, for example, even when the workpiece is a wire, the workpiece w can be stably held and moved.

  In addition, the support means of this work is integrated in the inner intubation tube 13 as described above. For this reason, the support means (guide pipe) provided with the workpiece insertion hole 22 corresponding to the diameter of the workpiece used for processing can be exchanged integrally with the inner tube 13. Thereby, it is not necessary to replace the support means alone, and the support means can be easily replaced according to the workpiece.

  In the above embodiment, the workpiece w is in contact with the workpiece insertion hole 22 and the large diameter portions 24a, 24b, 24c of the guide pipes 17a, 17b, 17c are in contact with the peripheral surface of the through hole 13a. There may be some backlash between the workpiece insertion hole 22 and the large diameter portions 24a, 24b, 24c of the guide pipes 17a, 17b, 17c and the peripheral surface of the through hole 13a.

  However, since the wobbling prevention effect of the work w is reduced by the amount of play, the play needs to be within the allowable range of wobbling of the work w. On the other hand, in the present embodiment, the elastic member is the compression spring 18, but any member may be used as long as it has a biasing force that biases and returns the movement guide pipes 17 b and 17 c to their initial positions.

  Although both compression springs 18 are of the same type, different types of compression springs can be used. In this case, the guide pipe 17b positioned in the middle is not necessarily positioned substantially at the center between the front and rear guide pipes 17a and 17c, but the effect of supporting the workpiece w by the guide pipes 17a, 17b and 17c (the effect of preventing the workpiece w from swinging). ) Is.

  In this embodiment, two guide pipes serving as the moving support are provided and three guide pipes are provided. However, any number of guide pipes serving as the moving support may be provided as long as the number is one or more. Further, although the fixed support is constituted by the guide pipe 17a, the structure on the main shaft 1 side, for example, the rear end face of the collet chuck 6 can be used as the fixed support. However, the fixed support body needs to be positioned inside the main shaft 1.

  In this embodiment, the push body 16 has a structure in which the work w is transferred by holding the end portion of the work w by the finger chuck portion 16a. It can also be set as the structure which contacts and carries out the transfer operation | work of the workpiece | work w. The contact surface with the finger chuck portion 16a or the workpiece w may be in contact with the rear end surface of the guide pipe 17c at the last position so that the guide pipe 17c is moved forward.

  In the above embodiment, the intubation tube 13 is a fixed type that does not rotate integrally with the main shaft 1. However, the intubation tube is provided integrally with the main shaft 1 in the main shaft 1, and the intubation tube is rotated integrally with the main shaft. It can also be configured. In this case, the supporting means configured in the inner intubation also supports the workpiece w while rotating integrally with the main shaft 1.

  In the present embodiment, the example in which the support means of the present invention is adopted for the spindle 1 of a machine tool (automatic lathe) has been described. However, a rod-shaped workpiece is inserted and fixed integrally by a gripping means such as a collet chuck. Any shaft can be adopted as long as it is a rotationally driven shaft that is integrally rotated.

  And if the said support means is a hole (insertion hole) into which the workpiece | work w is directly inserted, it is the same as this embodiment other than the through-hole 13a of the inner tube 13 by preventing the guide pipes 17a and 17c from coming off. The structure can be provided. For example, an insertion hole can be constituted by a hole of an intermediate sleeve 8 which is a sleeve for opening and closing the collet chuck 6 and a piston rod 9b, and the support means can be accommodated in the insertion hole.

  When the gripping means for the workpiece on the spindle side is a pull-type collet chuck, an insertion hole can be formed by a drawbar hole for opening and closing the collet chuck, and the support means can be accommodated in the insertion hole. However, as in the above embodiment, the support means cannot be replaced integrally with a shaft that can be attached to and detached from the main shaft, and the replacement work may be complicated.

  A work tool, for example, an automatic lathe, can be configured by integrally providing the workpiece supporting means configured as described above. This machine tool (automatic lathe) can prevent jumping-like run-out of the workpiece including the aforementioned small-diameter workpiece in the spindle, and can reduce the remaining material, which is highly economical, In addition, high-precision processing can be performed.

It is principal part sectional drawing of the principal-axis part of an automatic lathe. It is an expanded sectional view of an intubation part. It is principal part sectional drawing which shows the duplication state of a movement guide pipe. It is principal part sectional drawing which shows the relationship between the guide pipe and finger chuck part of the last position. (A) is a principal part sectional side view which shows the support means in the state where each guide pipe has returned to the initial position, (B) is a principal part side sectional view which shows the support means in the state where the movement guide pipe moved. .

Explanation of symbols

1 Main shaft 13 Inner tube 13a Through hole (insertion hole)
16a Finger chuck part (work receiving part)
17a Guide pipe (support)
17b Guide pipe (support)
17c Guide pipe (support)
18 Compression spring (elastic member)
28 Finger insertion hole (holding means accommodating portion)
w Work

Claims (11)

  A workpiece (w) that is inserted into the spindle (1) of the machine tool by the workpiece supply means through the insertion hole (13a) and is integrally gripped on the spindle (1) side and rotationally driven. ) In the insertion hole (13a) while allowing movement of the main shaft (1) in the axial direction, the support means is inserted into the main hole (1) in the insertion hole (13). And a resilient support member (18) for elastically positioning the movable support member, and holds or holds the non-working side end portion of the workpiece. The workpiece receiving portion (16a) of the workpiece supply means that comes into contact with the pressure presses the moving support member from the rear, and the moving support member faces the front end side of the main shaft (1) against the urging force of the elastic member (18). Of the workpiece receiving part (16a) Hole (13a) the support means of the workpiece has a structure that allows movement in entrance or insertion hole (13a) in to the.   The work supporting means according to claim 1, wherein a plurality of moving supports are provided, and an elastic member (18) is interposed between the moving supports (17b) and (17c).   A fixed support (17a) that is fixedly positioned with respect to the main shaft (1) and supports the workpiece (w) is provided in front of the movable support, and the fixed support (17a) is placed in the main shaft (1). The work supporting means according to claim 1 or 2, wherein the elastic member (18) is disposed between the fixed support (17a) and the adjacent moving support.   The work support means according to claim 3, wherein the fixed support (17a) is arranged in the vicinity of the rear side of the grip means of the work (w) provided on the front end side of the main shaft (1).   The workpiece supporting means according to any one of claims 2 to 4, wherein the adjacent supports are configured to be partially overlapped and accommodated by sliding movement of the movable support.   The moving support (17c) with which the work receiving portion (16a) is in contact is provided with a receiving portion (28) into which a part or all of the work receiving portion (16a) is inserted and received. Means for supporting a workpiece as described in 1.   The support of the workpiece according to any one of claims 1 to 6, wherein the insertion hole (13a) is a through-hole penetrating in the axial direction of a cylindrical inner intubation tube (13) inserted into the main shaft (1). means.   The work supporting means according to claim 7, wherein the support and the elastic member (18) are integrally incorporated in the inner intubation (13).   The work supporting means according to claim 8, wherein the inner intubation (13) is fixed in the main shaft (1) so as to rotate integrally with the main shaft (1).   The insertion hole (13a) comprises a cylindrical sleeve or a through-hole penetrating in the axial direction of the drawbar constituting the opening / closing mechanism of the grip means for the workpiece (w) provided on the front end side of the main shaft (1). The work supporting means according to any one of 1 to 6.   A machine tool provided integrally with the workpiece support means according to claim 1.

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