JP4816205B2 - Broaching machine - Google Patents

Description

  The present invention relates to a broaching machine that processes an inner surface or an outer surface of a workpiece into a predetermined shape by moving the broach relative to the workpiece.

  Conventionally, in a broaching machine for processing the inner surface or outer surface of a workpiece into a predetermined shape, the workpiece is fixed and machining is performed while moving the broach equipped with a cutting blade for cutting the workpiece. There is a broaching machine that performs broaching and a work-moving broaching machine that performs machining while moving the workpiece (workpiece) while fixing the broaching.

  For example, a workpiece moving type broaching machine has a rectangular disk-shaped base, a rectangular columnar column fixed to the base and vertically erected, and one side of the column facing forward, along this side. One ball screw (drive shaft) provided with the axis line oriented vertically, the rear end side connected to the ball screw, and the front end side extended to the front side (outward side) orthogonal to one side of the column, A substantially disk-shaped ram (table) formed with a through-hole passing therethrough, a broach formed in a substantially cylindrical rod shape and provided with a cutting edge on the outer periphery thereof, and the broach axis inserted through the through-hole of the ram There is a structure including a lifter head that holds the upper end side of the broach and a pull head that is fixed to the base and holds the lower end side of the broach in a state in which the head is directed vertically (see, for example, Patent Document 1). ).

  In the broaching machine configured in this way, the work piece is fixed to the upper surface side of the ram, and the ball screw is connected to the servo motor supported by the column and rotated around the axis line so that the work piece is worked together with the ram. Can be linearly moved in the vertical direction (vertical direction) of the axial direction of the ball screw (axial direction of the broach). The workpiece that moves in this way is cut into a predetermined shape while being in contact with the cutting edge of the broach.

  However, in the above broaching machine, one ball screw is provided on the rear side of the broaching machine with respect to the broach, and the workpiece is moved along with the ram by this ball screw to perform processing. The holding point is supported by the ball screw, and the processing point at which the broach is cut into the workpiece is arranged on the free end side on the tip side of the ram. For this reason, the bending force acts on the ram due to the load generated at the machining point as the workpiece is cut, and the ram is deformed even though it is extremely small. This deformation causes the workpiece placed on the same axis as the axis of the broach. There was a problem that the axis of the workpiece was displaced. In such a case, there arises a problem that the processing accuracy of the workpiece is lowered due to vibrations generated during processing.

  In particular, when a workpiece having a HRC (Rockwell hardness) before quenching of about 20 to 30 is machined at a cutting speed of about 10 m / min, a certain degree of machining accuracy is ensured even in the above broaching machine. On the other hand, when processing a workpiece of about 60 with HRC after quenching at a high cutting speed of 60 m / min or more, it is extremely fine but is accompanied by deformation of the ram. The decrease in accuracy was remarkable.

  On the other hand, as a machine tool for processing a workpiece by relatively moving a work table and a tool spindle, a substantially horizontal direction (lateral direction) is provided via a guide member having a guide surface that slides or rolls on a bed. ) And a ball screw for moving the table main body along the guide surface, and a pair of ball screws provided at a point-symmetrical position about the position of the center of gravity of the table main body. It has been proposed (see, for example, Patent Document 2).

In this machine tool, a pair of ball screws are provided at point-symmetrical positions around the center of gravity of the table body, and when the table body moves in the lateral direction, the center of gravity moves along the axis of the pair of ball screws. It will always be placed on the containing plane. As a result, the table main body is stably supported by the pair of left and right ball screws, enabling high-speed machining of the workpiece while preventing vibration and the like from occurring.
JP 2003-251522 A JP 2003-145374 A

  However, in the machine tool disclosed in Patent Document 2, for example, a pair of left and right ball screws are provided at point-symmetrical positions around the center of gravity of the table body, thereby enabling high-speed machining while suppressing vibrations. However, when the ram is moved in the vertical direction and the shape of the ram is not completely symmetrical with respect to the center as in the broaching machine disclosed in Patent Document 1, the broach cuts the workpiece. The machining point to be moved deviates from the straight line connecting the axis of a pair of pointed ball screws centered on the center of gravity, and the bending force acts on the ram when high-speed machining is performed. There has been a problem that the cutting accuracy of the steel is reduced.

  In view of the above circumstances, an object of the present invention is to provide a broaching machine capable of processing a workpiece with high accuracy even when processing at high speed.

  In order to achieve the above object, the present invention provides the following means.

The broaching machine of the present invention comprises a broach formed in a substantially cylindrical bar shape and provided with a cutting edge on the outer periphery thereof, and a table for holding a workpiece, and the broach and the table are relatively aligned along the axis of the broach. In a broaching machine that cuts the workpiece with the cutting edge by moving the workpiece, the point of symmetry about a machining point at which the cutting edge of the broach and the workpiece are in contact with each other and the workpiece is cut A pair of drive shafts for moving the broach and the table relative to each other along the axis of the broach are provided at a position , and a linear direction connecting the pair of drive shafts when viewed from the axial direction of the broach A pair of vertical frame portions extending in the vertical direction provided outside each of the pair of drive shafts, and a horizontal frame portion connecting at least the upper end sides of the pair of vertical frame portions, and the broach and the table A frame formed so as to surround the pair of drive shafts is provided, and the table is outwardly viewed from the table main body portion and a pair of left and right side ends of the table main body portion when viewed from the upper surface side. A pair of left and right support portions that project in a substantially rectangular shape projecting toward the left and right to have a symmetrical shape, and the pair of vertical frame portions of the frame have a U-shaped cross section on each facing inner surface side. And the pair of support portions of the table are respectively engaged in the pair of engagement grooves formed in the vertical frame portion of the frame. In addition, the pair of drive shafts are inserted through the pair of support portions of the table, respectively, to support the table .

  Further, the broaching machine of the present invention is provided with a lifter head for holding the broach so as to be able to advance and retreat in its axial direction. The lifter head has an axis of the lifter head arranged coaxially with the axis of the broach. It is more desirable that it is provided.

  According to the broaching machine of the present invention, a pair of drive shafts for relatively moving the broach and the table is provided at a point-symmetrical position about the processing point where the cutting edge of the broach cuts the workpiece. Therefore, the table can be supported on both sides of a point-symmetrical position about the machining point, and the load acting on the machining point as the workpiece is cut is evenly distributed to the pair of drive shafts. Therefore, the table can be prevented from being deformed to an extremely small extent by the bending force accompanying the load. As a result, even when high-speed machining is performed, vibration or the like is not generated during machining, and the workpiece can be machined with high accuracy, and the production efficiency of the workpiece can be improved. Become.

  In the broaching machine according to the present invention, the broaching machine, the table, and the pair of drive shafts are surrounded by a frame including a pair of vertical and horizontal frame parts, thereby increasing the rigidity of the entire broaching machine. It becomes possible. Thereby, for example, the axis of the rotation main shaft of the driving means such as a motor for driving the driving shaft and the axis of the driving shaft can be arranged on the coaxial line, and the driving means can be supported by the horizontal frame portion and installed. The pair of drive shafts are driven in synchronization with high accuracy, and the broach and the table can be reliably moved along the axis of the broach. Therefore, it becomes possible to process the workpiece with higher accuracy.

  Furthermore, in the broaching machine of the present invention, the lifter head that holds the broach so as to be able to advance and retreat is provided with its axis line coaxially with the axis of the broach, so that the broach is distorted in its axis. Therefore, it is possible to extend and hold it straight. Thereby, it becomes possible to process the workpiece with higher accuracy.

  Hereinafter, a broaching machine according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. One embodiment of the present invention relates to a broaching machine for processing an inner surface of a workpiece into a predetermined shape, and in particular, while moving a workpiece while fixing a broach provided with a cutting blade for cutting the workpiece. The present invention relates to a workpiece moving broaching machine that performs cutting.

  The broaching machine A according to the present embodiment has a substantially cylindrical bar shape provided with the axis O1 direction in the vertical direction (up and down direction) and used for cutting the inner surface of the workpiece W as shown in FIGS. A broach 1, a substantially plate-like table 2 that holds a workpiece W while having a through-hole 2 a that penetrates from the upper surface to the lower surface and through which the broach 1 is inserted, and moves the table 2 up and down along the axis O <b> 1 of the broach 1. A main component is a pair of ball screws (a pair of drive shafts) 3 that can be supported, a broach 1, a table 2, and a frame 4 having a substantially rectangular frame formed so as to surround the pair of ball screws 3. .

  As shown in FIG. 1, the broach 1 has a plurality of cutting blades arranged on the outer periphery of a substantially cylindrical rod-shaped broach main body 1a in parallel with a predetermined interval from the lower end side to the upper end side in the axis O1 direction while projecting radially outward. A plurality of rows 1b are provided so as to form a substantially ring shape with a gap in the circumferential direction. Further, the plurality of cutting blades 1b are arranged side by side so that, for example, the cutting blade 1b located on the upper end side from the lower end side of the broach 1 gradually increases in outer diameter, and the lower cutting edge 1b is a rough blade. The upper edge side cutting edge 1b is a finishing edge, and the cutting edge 1b between the rough edge and the finishing edge is an intermediate finishing edge. Further, the upper end side and the lower end side of the broach main body 1a are formed so as to exhibit a multi-stage substantially columnar shape, respectively, and the upper end side is a front grip portion 1c and the lower end side is a rear grip portion 1d. Further, the front gripping portion 1c is provided with a tapered portion whose outer diameter gradually decreases from the lower end side toward the upper end side, and the outer gripping portion 1d also has an outer diameter gradually decreasing from the upper end side toward the lower end side. A tapered portion is provided. The front gripping portion 1c and the rear gripping portion 1d are respectively held by the front gripping portion 1c engaged with a holding hole of a lifter head 5a described later, and the rear gripping portion 1d is also engaged with a holding hole of a pull head 6 described later. Thus, the broach 1 is fixed so that its axis O1 is oriented in the vertical direction.

  As shown in FIGS. 1 and 3, the table 2 includes a table main body 2b having a substantially rectangular shape when viewed from the upper surface side, and a pair of left and right side ends parallel to the table main body 2b. It is comprised from the left-right paired support part 2c which protrudes toward the outward, respectively orthogonally to a side end, and is made into the left-right symmetrical shape. The table main body 2b is provided with a through hole 2a penetrating from the upper surface to the lower surface in the center when viewed from the upper surface side. The through hole 2 a is formed so that its diameter is larger than the maximum outer diameter of the broach 1, and the broach 1 can be inserted therethrough.

  On the other hand, each of the pair of support portions 2c is formed to have a substantially rectangular shape when viewed from the upper surface side, the upper surface is flush with the upper surface of the table main body portion 2b, and the lower surface is lower than the lower surface of the table main body portion 2b. Is also located slightly below. Also, each of the pair of support portions 2c penetrates vertically from the top surface to the bottom surface in the protruding direction (left and right direction when viewed from the front side of the broaching machine A in FIG. 1) and is threaded on the inner surface. A threaded hole 2d is provided. Further, on the lower surface of each of the pair of support portions 2c, an extension portion 2e extending downward while being orthogonal to the lower surface is provided on the table main body portion 2b side from the lower end of the screw hole 2d. One side surface of the extending portion 2e facing the rear side of the broaching machine A is flush with the side surface of the support portion 2c facing the rear side. Further, one side surface of the extending portion 2e facing the rear side and the side surface of the supporting portion 2c are vertically extended from the lower end of the extending portion 2e to the upper end of the supporting portion 2c while being recessed in a direction perpendicular to the side surfaces. In addition, a guide portion 2f having a U-shaped cross section perpendicular to the axis O2 of the table 2 (a straight line extending in the vertical direction through the center of the rectangular table body portion 2b) is provided.

  As shown in FIG. 1, the frame 4 extends in the horizontal direction so as to connect a pair of substantially flat plate-like vertical frame portions 4 a extending in the vertical direction in parallel to each other and the upper ends of the vertical frame portions 4 a. A flat upper horizontal frame portion (horizontal frame portion) 4b and a substantially flat lower horizontal frame portion (base) 4c extending in the horizontal direction so as to connect the lower end portions of the vertical frame portion 4a are provided. It is configured. Here, the vertical length of the pair of vertical frame portions 4a is larger than the horizontal length of the upper horizontal frame portion 4b and the lower horizontal frame portion 4c, and the frame 4 has the longitudinal direction in the vertical direction. It is supposed to present a substantially rectangular frame shape.

  Moreover, as shown in FIG.1 and FIG.2, the upper horizontal frame part 4b penetrates to the both ends connected to a pair of vertical frame parts 4a in the perpendicular direction from the upper surface to the lower surface, respectively, and is a circle in the opposite view from the upper surface side. A pair of ball screw insertion holes 4d having a shape is provided, and a vertical direction from the upper surface to the lower surface on the central axis O3 (straight line passing through the center of the upper horizontal frame portion 4b) O3 extending in the longitudinal direction (vertical direction) Is provided with a rectangular hole 4e having a rectangular shape when viewed from the upper surface side. On the other hand, as shown in FIG. 3, the pair of vertical frame portions 4a have a U-shaped cross section perpendicular to the central axis O3 at the substantially central portion in the direction orthogonal to the central axis O3 of each of the opposed inner side frames 4. The engaging groove 4f to be exhibited is extended in the vertical direction, and the engaging groove 4f is perpendicular to the inner surface of the vertical frame portion 4a and protrudes toward the central axis O3 (inside the frame 4). Is established and defined. Of the pair of opposing surfaces of the pair of projecting portions 4g that define the engagement groove 4f, one surface (the surface facing the front side of the broaching machine A) is perpendicular to the one surface in the vertical direction. An extended guide rail 4h is projected. The guide rail 4h is engaged with the guide portion 2f formed on the table 2 described above.

  The frame 4 configured as described above has a servo motor (driving means) in which the axis O4 of the rotation main shaft is directed vertically above each of the pair of ball screw insertion holes 4d on both side ends of the upper horizontal frame portion 4b. 7) is supported and installed on the upper horizontal frame portion 4b. Then, one end (upper end) of the ball screw 3 inserted through the ball screw insertion hole 4d of the frame 4 and having the axis O5 in the vertical direction is connected to the rotation main shaft of each servo motor 7. In this way, the pair of ball screws (a pair of drive portions) 3 connected to each servo motor 7 is extended until the other end (lower end) is located slightly above the lower horizontal frame portion 4c, and is rotated around the axis O5. Is rotatably supported.

  At this time, the pair of ball screws 3 are inserted into the pair of screw holes 2d provided in the support portion 2c of the table 2 while being screwed, and the upper surface of the table 2 extends to the axis O5 of the pair of ball screws 3. It is supported so as to be orthogonal. As a result, the servo motor 7 is driven to rotate the pair of ball screws 3 around the axis O5, and the table 2 can be moved up and down in the vertical direction. Further, the table 2 supported by the pair of ball screws 3 so as to be movable up and down has its axis O2 oriented in the vertical direction and coincided with the center axis O3 of the frame 4, and at the same time, the through hole 2a of the table main body 2b is formed. The central axis O3 of the frame 4 is provided. Further, at this time, the pair of support portions 2c of the table 2 are respectively engaged in the pair of engagement grooves 4f defined in the vertical frame portion 4a of the frame 4, and the pair of guide portions 2f are Engaged with the guide rail 4h of the frame portion 4a, the table 2 is guided by the guide rail 4h so that it can slide only in the vertical direction along the central axis O1.

  The pair of ball screws 3 that support the table 2 so as to move up and down as described above are point-symmetrical positions about the processing point H where the workpiece W fixed to the table 2 and the cutting blade 1b of the broach 1 contact each other. Even when the workpiece W moves up and down together with the table 2, the relative positions of the machining point H and the pair of ball screws 3 are not changed.

  On the other hand, as shown in FIGS. 1 and 2, the frame 4 has a rectangular plate that extends vertically above the upper horizontal frame portion 4b at both ends of the rectangular hole 4e of the upper horizontal frame portion 4b located on the servo motor 7 side. A pair of support members 8 are connected to each other, and a pair of guide rail portions 8a extending in the vertical direction while being orthogonal to the inner surfaces project from the opposing inner surfaces of both the support members 8. Moreover, the both supporting members 8 are connected to each other on both upper end sides through a pair of flat connecting members 9. Further, as shown in FIG. 2, a flat plate motor support member 10 is connected to the upper end sides of the inner surfaces of the pair of connection members 9 facing each other so as to connect the pair of connection members 9 to each other. Here, the motor support member 10 is provided with an insertion hole 10a penetrating from the upper surface to the lower surface on the central axis (axis O1 of the broach 1) O3 of the frame 4, and the broach 1 described later is provided in the insertion hole 10a. A ball screw 12 for allowing the lifter head portion 5 holding the head to move forward and backward along the axis O1 of the broach 1 is inserted. A motor 13 for rotating the ball screw 12 about the axis O6 is installed on the upper surface side of the motor support member 10, and the upper end of the ball screw 12 inserted through the insertion hole 10a is the rotation main shaft of the motor 13. It is connected to the same axis and extends downward with the direction of the axis O6 in the vertical direction, and is screwed into the lifter head portion 5 that holds the broach 1.

  As shown in FIG. 1, the lifter head portion 5 is formed in a substantially cylindrical shape in which an upper lifter drive portion 5b and a lower lifter head 5a are integrated, and the ball screw 12 is attached to the lifter drive portion 5b. Are screwed together, and can be moved forward and backward (movable up and down) in the direction of the axis O6 by the rotation of the ball screw 12 by the motor 13. At this time, the lifter head portion 5 is arranged so that its axis O 7 is coaxial with the axis O 6 of the ball screw 12 and the axis O 1 of the broach 1, the axis O 2 of the table 2, and the center axis O 3 of the frame 4. It is supported. The lifter head portion 5 thus provided is provided with a guide portion 5c extending in the vertical direction on the outer periphery of the lifter drive portion 5b, and this guide portion 5c is the guide rail portion of the pair of support members 8 described above. 8a is engaged to be movable up and down. Thereby, the lifter head unit 5 is configured to move while maintaining the direction of the axis O7 stably at the time of forward / backward movement. In addition, the lower lifter head 5a has a holding hole formed on the axis O7 that opens to the lower end of the lifter head 5a and extends upward in the direction of the axis O7 (lifter drive unit 5b side). The holding hole is formed so that the front grip portion 1c of the broach 1 is engaged and the axis O1 of the broach 1 is maintained in the vertical direction so as to be able to move forward and backward.

  On the other hand, a pull head 6 is fixed to the lower horizontal frame portion 4c of the frame 4 and is engaged with the rear grip portion 1d of the broach 1 on which the front grip portion 1c is held by the lifter head 5a. Yes. The pull head 6 has a holding hole extending toward the lower side in the axis O8 direction (the lower horizontal frame portion 4c side) on the upper surface side, and the holding hole can be engaged with and held by the rear grip portion 1d. It is possible. Thus, the broach 1 in which the front gripping portion 1c and the rear gripping portion 1d are held by the lifter head portion 5 and the pull head 6 is inserted into the through hole 2a of the table 2, and its axis O1 is connected to the center axis O3 of the frame 4 and the lifter. The ball screw 12 to which the head portion 5 is connected is arranged and held on the same axis as the axis O6.

  In the broaching machine A of the present embodiment configured as described above, the pair of vertical frame portions 4a are respectively provided on the outside in the linear direction connecting the pair of ball screws 3, and the upper ends of the pair of vertical frame portions 4a are And the lower ends are connected by the upper horizontal frame portion 4 b and the lower horizontal frame portion 4 c, and the broach 1, the table 2, and the pair of ball screws 3 are disposed so as to be surrounded by the frame 4. Thereby, the broaching machine A of the present embodiment is excellent in rigidity as the entire structure by the frame 4.

  Next, a method of cutting the workpiece W using the broaching machine A having the above-described configuration will be described, and the operation and effect of the broaching machine A of the present embodiment will be described.

  Here, first, by driving a pair of servo motors 7 and rotating a pair of ball screws 3 connected thereto, the table 2 is positioned at the lowermost position with its lower surface close to the upper surface of the pull head 6, Further, it is assumed that the motor 13 is driven and the lifter head 5a is positioned at the uppermost position on the motor 13 side. In this state, the broach 1 is pulled out from the through hole 2 a of the table 2, the rear grip portion 1 d is positioned above the upper surface of the table 2, and a gap is provided between the broach 1 and the table 2. ing.

  The workpiece W requiring processing is fixed to the table 2 from the gap with respect to the broaching machine A in this state. Here, in the present embodiment, for example, a pilot hole is formed in advance on a hard workpiece W having an HRC (Rockwell hardness) of about 60, and the inner surface of the pilot hole is formed on the broaching machine A of the present embodiment. Is processed into a predetermined shape. The workpiece W is arranged in a state where the central axis O9 of the pilot hole is arranged coaxially with the central axis O2 of the through hole 2a (axis of the table 2) O2 and the pilot hole and the through hole 2a are communicated with each other. It is fixed to the upper surface side.

  When the workpiece W is fixed to the table 2 as described above, the motor 13 is driven and the ball screw 12 connected to the motor 13 is rotated around the axis O6, so that the front gripping portion 1c and the holding hole are engaged. In combination, the lifter head 5a holding the broach 1 is lowered. At this time, since the guide portion 5c of the lifter driving portion 5b is engaged with and guided by the guide rail portion 8a of the support member 8, the lifter head 5a descends while maintaining the direction of the axis O7 with certainty. Then, the rear grip portion 1d of the broach 1 is inserted through the prepared hole of the workpiece W and the through hole 2a of the table 2 in this order, and is engaged with the holding hole of the pull head 6 so that the broach 1 is fixed.

  Next, at the stage where the broach 1 is fixed, the two servo motors 7 are driven in synchronization to rotate the pair of ball screws 3. At the same time, the table 2 and by extension the workpiece W move upward, and the inner surface of the raised hole of the workpiece W is first cut into the rough blade 1b formed on the lower end side of the broach 1. Then, by continuously raising the workpiece W together with the table 2, the inner surface of the prepared hole is cut into the intermediate finishing blade and the finishing blade of the broach 1. When the finishing blade formed on the upper end side of the broach 1 passes through the prepared hole of the workpiece W, the workpiece W is cut to a predetermined shape accuracy and finished.

  Thus, when cutting the workpiece W, in the broaching machine A of the present embodiment, the cutting edge 1b of the broach 1 is in a point-symmetrical position around the processing point H at which the workpiece W is cut. Since the pair of ball screws 3 for moving the table 2 up and down relative to the broach 1 are provided, the cutting load applied to the processing point H when the workpiece W is cut is evenly distributed to each of the pair of ball screws 3. Will be accepted. For this reason, according to the broaching machine A of the present embodiment, even when machining is performed at a cutting speed of 60 m / min or more, for example, the center axis O9 of the prepared hole of the workpiece W is relative to the axis O1 of the broach 1 Therefore, the workpiece W can be machined with high accuracy without causing deformation or deformation of the broach 1 so as to distort the axis O1 or vibration during machining. Therefore, it becomes possible to improve the production efficiency of the workpiece W.

  Further, in the broaching machine A of the present embodiment, since the frame 4 is provided so as to surround the broach 1, the table 2 and the pair of ball screws 3, the rigidity of the entire broaching machine A is increased. Therefore, even when high-speed machining is performed, high-precision machining can be reliably performed.

  Furthermore, the support portion 2c of the moving table 2 is engaged with the engagement groove 4f of the frame 4, and the guide portion 2f of the table 2 is engaged with the guide rail 4h of the frame 4 so as to be movable up and down. The table 2 can be moved in a state in which the center axis O9 of the pilot hole of the workpiece W and the axis O1 of the broach 1 coincide with each other more reliably. In addition, since the servo motor 7 that rotationally drives the pair of ball screws 3 is supported by the frame 4 so that the rotation main shaft and the axis O5 of the ball screw 3 can be coaxial, the pair of ball screws 3 can be reliably rotated in rotation. Thus, the table 2 and thus the workpiece W can be moved up and down reliably while maintaining the axes O2 and O9 and the axis O1 of the broach 1 on the same axis. Therefore, the workpiece W can be more reliably processed with high accuracy.

  Further, in the broaching machine A of the present embodiment, a pair of vertical frame portions 4a provided on the outside of each of the pair of ball screws 3 in the linear direction connecting the pair of ball screws 3 as viewed from the direction of the axis O1 of the broach 1 in particular. The lifter head that holds the broach 1 so as to be able to move forward and backward by comprising the upper horizontal frame portion 4b and the lower horizontal frame portion 4c that connect the upper ends and the lower ends of the pair of vertical frame portions 4a. It is possible to provide the lifter head 5a by arranging the axis O7 of 5a on the same axis as the axis O1 of the broach 1, thereby ensuring that the broach 1 is straight so that the axis O1 is not distorted. It becomes possible to extend and fix and hold. Therefore, the workpiece W can be further reliably processed with high accuracy.

  In addition, this invention is not limited to said one Embodiment, In the range which does not deviate from the meaning, it can change suitably. For example, in the present embodiment, the explanation has been given on the assumption that the inner surface of the pilot hole of the workpiece W is finished in a predetermined shape, but the present invention may be applied to process the outer surface of the workpiece W into a predetermined shape. Is. In addition, the pair of drive shafts 3 for moving the table 2 up and down are a pair of ball screws 3, but a cylinder or the like may be used, for example. If possible, a drive shaft composed of another mechanism may be used.

  In the present embodiment, the broach 1 is fixed and the workpiece 2 is held while the table 2 holding the workpiece W is lifted. For example, a lifter head 5 a that holds the broach 1 is attached to a pair of drive shafts 3 via a support member so as to be movable up and down, and the table 2 is connected to, for example, a frame 4 and fixed. It may be a broaching type broaching machine in which the broach 1 is moved downward with respect to W by a pair of drive shafts 3. In this case, similarly to the table moving type broaching machine shown in the present embodiment, the lifter head 5a and thus the broach 1 is connected to the axis O1 by the pair of drive shafts 3 provided at the point-symmetrical positions around the processing point H. Since it moves along the direction, the pair of drive shafts 3 can receive the cutting load evenly, and the bending moment does not act on the table 2 even when high-speed cutting is performed. It is possible to process W with high accuracy. Also, by allowing the both ends of the support member connected to the lifter head 5a to be raised and lowered while being engaged with the engagement groove 4f of the frame 4, the direction of the axis O1 of the broach 1 can be reliably maintained in the vertical direction. It is possible.

  Further, in the present embodiment, the description has been made on the assumption that the workpiece W is processed while raising the table 2 (workpiece W) with respect to the broach 1. However, the broach 1 and the table 2 are relative to each other. For example, the workpiece W may be processed while the table 2 is lowered with respect to the broach 1.

It is a figure which shows the broaching machine which concerns on one Embodiment of this invention. FIG. 2 is a view taken along line XX in FIG. 1. It is a YY line arrow line view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Broach 1b Cutting blade 1c Front grip part 1d Rear grip part 2 Table 2a Through-hole 2f Guide part 3 A pair of ball screw (a pair of drive shafts)
4 Frame 4a Vertical frame 4b Upper horizontal frame (horizontal frame)
4f Engaging groove 5 Lifter head 5a Lifter head 6 Pull head A Broaching machine H Processing point W Workpiece O1 Broach axis

Claims (2)

A broach formed in a substantially cylindrical rod shape and provided with a cutting edge on the outer periphery thereof, and a table for holding a workpiece, the broach and the table are moved relative to each other along the axis of the broach to move the workpiece. In a broaching machine that cuts a workpiece with the cutting blade,
The broach and the table are relatively moved along the axis of the broach at a point-symmetrical position about a processing point where the cutting edge of the broach and the workpiece come into contact with each other and the workpiece is cut. A pair of drive shafts to be moved are provided ,
A pair of vertical frame portions extending in the vertical direction provided outside each of the pair of drive shafts in a linear direction connecting the pair of drive shafts when viewed from the axial direction of the broach, and at least of the pair of vertical frame portions A frame formed so as to surround the broach, the table, and the pair of drive shafts.
The table is composed of a table main body portion and a pair of left and right support portions that project outward from a pair of left and right side end sides of the table main body portion when viewed from the upper surface side. And left and right symmetrical shape,
In the pair of vertical frame portions of the frame, engagement grooves having a U-shaped cross section extend in the vertical direction on the respective inner surfaces facing each other.
The pair of support portions of the table are respectively engaged in a pair of engagement grooves formed in the vertical frame portion of the frame, and the pair of drive shafts are supported by the pair of support portions of the table. A broaching machine, wherein the broaching machine is inserted into each part to support the table . The broaching machine according to claim 1 , wherein
A lifter head is provided for holding the broach so as to be able to advance and retreat in its axial direction, and the lifter head is provided with the axis of the lifter head arranged coaxially with the axis of the broach. Board.

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