JP2008302440A - Workpiece mounting tool and machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve machining efficiency by machining a workpiece surface perpendicular to a rotation axis of a spindle of a machine tool. <P>SOLUTION: A drive shaft 21 is mounted on the spindle 17 of the machine tool 11. A workpiece mounting tool 25 with a workpiece W mounted thereto is attachably/detachably mounted on a table 19. A cutter holder 39 for holding a cutter 37 to be movable relatively to the workpiece W fixed to the workpiece mounting tool 25 and rotatable around the rotation axis O2, is further provided on the workpiece mounting tool 25. The drive shaft 21 and the cutter 37 are engaged by arraying the rotation axis O2 of the cutter 37 and a rotation axis O1 of the drive shaft 21 on a straight line and relatively moving the drive shaft 21 and the cutter 37 in a direction in which the spindle 17 and the table 19 approach to each other, and rotation of the drive shaft 21 is transmitted to the cutter 37. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a workpiece fixture for machining a surface of a workpiece perpendicular to a rotation axis of a main shaft, and a machine tool using the workpiece fixture.

  In a differential case for an automobile, a recess for accommodating a gear is formed, and an axial hole for passing a gear shaft connected to the gear is formed in two opposing side walls surrounding the recess. Since the periphery of the shaft hole on the inner surface of the differential case is a flat seat or a spherical seat, it is necessary to perform thrust processing, spherical processing, or the like.

  When processing the inner surface of the side surface of such a recess, it is necessary to process an area wider than the cross section of the shaft hole, but such a tool cannot pass through the shaft hole. Therefore, it is difficult to perform internal machining with a general machine tool. Therefore, in the inner surface machining, a machine dedicated to inner surface machining as described in Patent Document 1 and Patent Document 2 is generally used. In the inner surface processing machine described in Patent Document 1 and Patent Document 2, a cutter holder for rotatably holding a cutter is provided on a base on which a spindle and a processing table are installed, and a concave portion of a workpiece placed on the processing table. After the cutter held in the cutter holder is placed inside, the spindle placed opposite to the rotation axis of the cutter is moved closer to the rotation axis of the cutter, and the cutter is clamped from both sides of the rotation axis by the spindle. Then, the inner surface of the recess is machined by moving the cutter in the direction of the rotation axis while transmitting the rotational force of the spindle to the cutter and rotating the cutter.

Japanese Patent Laid-Open No. 10-277825 JP-A-11-165211

  If a dedicated machine is used to perform the inner surface processing, the dedicated machine is expensive, and thus increases the manufacturing cost. Therefore, it is desirable to allow internal machining using a general-purpose machine tool such as a machining center. Further, in the inner surface machining, since it is necessary to align the workpiece with the cutter and the spindle, it is necessary to measure the position of the workpiece and align the workpiece with the cutter after the workpiece is fixed to the machining table. In the dedicated machine as described above, it is necessary to perform measurement and alignment of the workpiece position on the processing table every time the workpiece is exchanged, and time is required for the setup work on the processing table. For this reason, the machining is stopped during the set-up work, resulting in a problem that the machining efficiency is lowered.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to enable machining of a work surface perpendicular to the rotation axis of the spindle of a machine tool, thereby improving machining efficiency. There is to make it.

  In order to achieve the above-mentioned object, a workpiece fixture used when machining a surface of a workpiece perpendicular to the rotation axis of the spindle of the machine tool, a pallet that is detachably mounted on the table of the machine tool, There is provided a work fixture including a cutter holder that is provided on the pallet and is capable of moving relative to a work fixed on the pallet and rotatable about a rotation axis.

  According to the present invention, there is also provided a machine tool for machining a surface of a workpiece perpendicular to the rotation axis of the main shaft by moving the main shaft to be rotated and a table on which the workpiece is placed, A drive shaft to be mounted, and a work fixture on which a work is attached and detachably attached to the table, are provided so as to be relatively movable with respect to the work fixed to the work fixture and around the rotation axis. A cutter holder that rotatably holds the cutter, wherein the drive shaft and the cutter align the rotation axis of the cutter and the rotation axis of the drive shaft in a straight line and rotate the main shaft and the table. The drive shaft is engaged by being moved relative to each other in the axial direction so that the rotation of the drive shaft can be transmitted to the cutter. There is provided a machine tool in which the surface of the workpiece perpendicular to the rotation axis of the main shaft is processed by the cutter by relatively moving the main shaft and the table in the direction of the rotation axis of the cutter. .

  According to the present invention, since the cutter holder for supporting the cutter is provided on the work fixture, the general purpose is to attach the drive shaft to the spindle of the machine tool and attach the workpiece fixture to which the workpiece is attached to the table. It is possible to machine the surface of the workpiece perpendicular to the rotation axis of the main shaft, such as the inner surface of a box-shaped workpiece, using this machine tool. In addition, since the cutter holder that supports the cutter is provided on the workpiece fixture, the workpiece and cutter can be aligned before the workpiece fixture is attached to the table, and the workpiece has been set up. The cutter and the work can be arranged on the table in a predetermined positional relationship simply by mounting the tool on the table. Therefore, the setup work on the table can be reduced and the machining stop time can be shortened. Further, when the machining of the workpiece is completed, the cutter is also exchanged together with the workpiece fixture, so that it is not necessary to stop machining for exchanging the cutter.

  The workpiece has a substantially box shape with a recess formed therein, the cutter is disposed in the recess of the workpiece, and the drive shaft is disposed in the recess through a shaft hole formed in a side wall of the recess. It is preferable to engage with.

  The cutter holder preferably includes a horizontal movement mechanism that moves the cutter in the direction of the rotation axis of the cutter, and a vertical movement mechanism that moves the cutter in a direction perpendicular to the rotation axis of the cutter.

  According to the present invention, since the cutter holder for holding the cutter is provided on the work fixture, it is possible to process the surface of the work perpendicular to the rotation axis of the main spindle using a general-purpose machine tool. In addition, since the workpiece and cutter can be aligned before the workpiece fixture is attached to the table, setup work on the table can be reduced, machining stop time can be shortened, and machining efficiency can be improved. It becomes possible to make it. Furthermore, since the cutter is also replaced together with the workpiece fixture, it is not necessary to stop the processing for replacing the cutter due to the wear of the cutter, and the processing efficiency can be improved.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of a machine tool for machining a surface of a workpiece perpendicular to the rotation axis of a main shaft according to the present invention, and FIG. 2 is a diagram of a cutter holder provided on a workpiece fixture of the machine tool shown in FIG. 3 to 6 are diagrams for explaining a procedure for machining the inner surface of the workpiece by the machine tool of the present invention, and FIG. 3 shows a state in which the cutter is disposed in the concave portion of the workpiece. 4 shows a state in which the drive shaft is engaged with the cutter, FIG. 5 shows a state in which the cutter is pressed against the inner surface of the workpiece, and FIG. The state which removed from the inside of a recessed part is shown.

  Referring to FIG. 1, a machine tool 11 for machining a surface (for example, the inner surface of a workpiece) perpendicular to the rotation axis O1 of the main shaft 17 is shown. The machine tool 11 includes a bed 13 installed on a floor surface, a column 15 provided on the bed 13 so as to be movable in the X-axis direction, and a spindle 17 supported on the column 15 so as to be movable in the Y-axis direction. And a table 19 provided on the bed 13 so as to be movable in the Z-axis direction. Here, the X axis indicates the direction of the axis extending perpendicular to the paper surface in FIG. 1, the Y axis indicates the direction of the axis extending in the vertical direction in FIG. 1, and the Z axis indicates the direction of the axis extending in the horizontal direction in FIG. . In the embodiment shown in FIG. 1, the main shaft 17 moves in the X-axis and Y-axis directions with respect to the bed 13, while the table 19 moves in the Z-axis direction with respect to the bed 13. However, it is sufficient that the main shaft 17 and the table 19 are relatively movable in the three orthogonal directions of the X axis, the Y axis, and the Z axis. For example, the main shaft 17 may be moved in three axial directions of the X axis, the Y axis, and the Z axis.

  A drive shaft 21 for rotationally driving a cutter 37 described later is mounted on the main shaft 17 via a tool holder 23. The drive shaft 21 includes a large-diameter cylindrical portion 21a located on the side closer to the main shaft 17 and a small-diameter cylindrical portion 21b located on the side far from the main shaft 17, and a boundary portion between the large-diameter cylindrical portion 21a and the small-diameter cylindrical portion 21b. A shoulder portion 21c is formed at the end. Further, in order to prevent the cutter 37 from rotating with respect to the small-diameter cylindrical portion 21b when engaged with a cutter 37 described later, the small-diameter cylindrical portion 21b is radially outward from the outer peripheral surface of the small-diameter cylindrical portion 21b. A key 21 d that protrudes in the longitudinal direction of the drive shaft 21 is provided.

  On the table 19, a work fixture 25 to which the work W is fixed is detachably attached. The workpiece W has a substantially box shape, and a concave portion 27 is formed in the central portion, a window portion 29 communicating with the outside is formed in the upper portion, and the side wall 31 surrounding the concave portion 27 is opposed to the side. A pair of shaft holes 33 are formed. However, it is not limited to a box-shaped workpiece W as long as it has a surface perpendicular to the rotation axis O1 of the main shaft 17. The workpiece fixture 25 is provided on the pallet 35, which is fixed on the table 19 and is detachably mounted on the table 19, a cutter 37 for processing the workpiece W, and a surface of the workpiece W to be processed. And a cutter holder 39 for holding the cutter 37 around its rotation axis O2 in a rotatable manner. The pallet 35 is of a general type used in the machine tool 11 and is not particularly limited as long as it can be detachably attached to the table 19 by a clamp or the like (not shown).

  As shown in FIG. 2, the cutter 37 has a cutting edge 37a at both ends in the direction of the rotation axis O2, and is a type of machining the surface of the workpiece W perpendicular to the rotation axis O2 by the cutting edge 37a. The cutter holder 39 holds the work fixture 25 so that the rotational axis O2 is parallel to the rotational axis O1 of the main shaft 17 when the work fixture 25 is attached to the table 19.

  In the embodiment of FIG. 1, the cutter 37 is formed with a through hole 37b having a diameter substantially the same as the diameter of the small-diameter cylindrical portion 21b of the drive shaft 21 along the central axis (that is, the rotation axis O2). 17 can be fitted to the small-diameter cylindrical portion 21b of the drive shaft 21 attached to the drive shaft 21. Further, as shown in FIG. 2, the peripheral surface of the through-hole 37 b has a cross-sectional shape corresponding to the cross-section of the key 21 d provided on the small-diameter cylindrical portion 21 b of the drive shaft 21. A key groove 37c extending along the rotation axis O2 is formed (see FIG. 2). With such a configuration, when the small-diameter cylindrical portion 21b of the drive shaft 21 is inserted into the through hole 37b of the cutter 37 and the key 21d of the drive shaft 21 is engaged with the key groove 37c of the through hole 37b of the cutter 37, The cutter 37 is allowed to move in the longitudinal axis direction with respect to the drive shaft 21, while the cutter 37 is prevented from rotating with respect to the drive shaft 21. However, the engagement between the cutter 37 and the drive shaft 21 is not limited as long as the rotational force of the main shaft 17 can be transmitted to the cutter 37 via the drive shaft 21, and the key 21d as in the embodiment of FIG. It is not limited to the configuration using the key groove 37c. For example, splines that engage with each other may be provided on the outer peripheral surface of the drive shaft 21 and the peripheral surface of the through hole 37 b of the cutter 37.

  When the cutter 37 and the drive shaft 21 are engaged, the small-diameter cylindrical portion 21b of the drive shaft 21 is inserted into the through hole 37b of the cutter 37 until the shoulder portion 21c of the drive shaft 21 contacts the end surface of the cutter 37 in the rotation axis O2 direction. To do. Thereby, the relative position of the cutter 37 with respect to the drive shaft 21 in the direction of the rotation axis O1 is determined. If the position of the cutter 37 on the drive shaft 21 in the direction of the rotation axis O1 is regulated, the drive shaft 21 and the cutter 37 do not need to be fixed, and the cutter has its rotation axis with respect to the drive shaft. The drive shaft 21 and the cutter 37 may be fixed to the drive shaft 21 by a nut or the like (not shown) at this position.

  The cutter holder 39 includes a support column 41 extending in a substantially vertical direction from the work mounting surface of the pallet 35, a horizontal arm 43 extending substantially parallel to the rotation axis O 2 of the cutter 37 from the support column 41, and substantially perpendicular to the rotation axis O 2 of the cutter 37. And a vertical arm 47 depending on a specific direction. A cutter 37 is held at the tip of the vertical arm 47 through a bearing 49 (see FIG. 2) so as to be rotatable around the rotation axis O2.

  The vertical arm 47 preferably includes a vertical movement mechanism for moving the cutter 37 in a direction substantially perpendicular to the rotation axis O <b> 2 of the cutter 37. For example, in the embodiment shown in FIG. 1, a vertical guide 45 that guides the vertical arm 47 to the tip of the horizontal arm 43 so as to be movable in a direction substantially perpendicular to the rotation axis O2 of the cutter 37 is used as the vertical movement mechanism. The vertical arm 47 is vertically moved by a fluid pressure cylinder (not shown) attached to the vertical guide 45. When the fluid pressure cylinder is used in this way, a coupling (not shown) that engages with each other when the pallet 35 is attached to the table 19 is provided at the center of the table 19 and the pallet 35, and this coupling is interposed therebetween. If the working fluid is supplied from the table 19 to the fluid pressure cylinder of the work fixture 25, the vertical movement mechanism can be operated even after the work fixture 25 is attached to the table 19.

  Further, the horizontal arm 43 preferably includes a horizontal movement mechanism for moving the cutter 37 in the direction of the rotation axis O2 of the cutter 37. For example, in the embodiment shown in FIG. 1, the slider 51 and the guide rail 53 are used as the horizontal movement mechanism, and the horizontal arm 43 is provided with the guide rail 53 and is movable along the guide rail 53. A simple slider 51 is attached to the upper end of the support column 41 so that the support column 41 and the horizontal arm 43 can move relative to each other in the direction of the rotational axis O2 of the cutter 37.

  However, the horizontal movement mechanism may be any mechanism that can move the cutter 37 in the direction of the rotation axis O2 of the cutter 37, and the relative movement of the cutter 37 in the direction of the rotation axis O2 between the horizontal arm 43 and the vertical guide 45. May be allowed. For example, a guide rail may be provided on the horizontal arm 43, and the vertical guide 45 may be fixed to a slider that moves along the guide rail.

  When the combination of the slider 51 and the guide rail 53 is used as a horizontal movement mechanism, it is preferable to provide a return spring 55 between the support column 41 and the horizontal arm 43 or between the horizontal arm 43 and the vertical guide 45. If the return spring 55 is provided in this way, the cutter 37 can be moved by applying an external force to the cutter 37 in the direction of the rotation axis O2, but when the external force is not applied, the cutter 37 is automatically set to the origin position. You can go back.

Next, a procedure for machining the inner surface of the workpiece W by the machine tool 11 shown in FIG. 1 will be described with reference to FIGS.
First, as shown in FIG. 3, the cutter 37 held by the cutter holder 39 is placed on the workpiece fixture 25 on the side surface 31 of the workpiece W using a horizontal movement mechanism and a vertical movement mechanism. It moves to the front, and it aligns so that the axis line of a pair of shaft hole 33 provided in the side wall 31 which the workpiece | work W opposes, and the rotating axis O2 of the cutter 37 may align on a straight line. Since the cutter 37 and the workpiece W can be aligned on the workpiece fixture 25, a setup station or the like (not shown) provided outside the machine tool 11 or the like other than the table 19 of the machine tool 11 is used. Just do it. Therefore, it is not necessary to stop the machine tool 11 for the alignment of the cutter 37 and the workpiece W, and the machining efficiency can be improved.

  Next, the work fixture 25 in a state in which the cutter 37 and the workpiece W have been aligned with the rotation axis O2 of the cutter 37 being parallel to the rotation axis O1 of the spindle 11 of the machine tool 11 is placed on the table 19. Attach to and fix. Then, the table 19 and the pallet 35 of the work fixture 25 are brought into engagement with a tapered cone (not shown) provided on the table 19 and a tapered hole (not shown) provided on the bottom surface of the pallet 35. They are arranged in a predetermined positional relationship. After the work fixture 25 is fixed to the table 19, as shown in FIG. 3, the rotation axis of the drive shaft 21 (that is, the rotation axis O1 of the main shaft 17) and the rotation axis O2 of the cutter 37 are in a straight line. The drive shaft 21 mounted on the main shaft 17 is moved on the rotation axis O2 of the cutter 37 so that the cutter 37 and the drive shaft 21 are opposed to each other with the side wall 31 of the workpiece W interposed therebetween.

  Next, the main shaft 17 and the table 19 are moved relative to each other in the Z-axis direction to bring the drive shaft 21 closer to the cutter 37, and as shown in FIG. Then, the drive shaft 21 is passed through, and the small diameter cylindrical portion 21 b of the drive shaft 21 is inserted into the through hole 37 b of the cutter 37. At this time, the key 21d of the drive shaft 21 is engaged with the key groove 37c of the through hole 37b. Accordingly, the cutter 37 is prevented from rotating with respect to the drive shaft 21, and the rotational force of the main shaft 17 is transmitted to the cutter 37 via the drive shaft 21, so that the cutter 37 rotates and the cutter 37 rotates. It becomes possible to process the workpiece W. On the other hand, since the key groove 37c and the key 21d both extend in parallel with the longitudinal axis of the drive shaft 21, the movement of the cutter 37 along the longitudinal axis of the drive shaft 21 is allowed.

  The small diameter cylindrical portion 21b of the drive shaft 21 is inserted into the through hole 37b of the cutter 37 until the shoulder portion 21c of the drive shaft 21 contacts the end surface of the cutter 37 in the rotation axis O2 direction. In this state, the cutter 37 is pressed against the shoulder 21c of the drive shaft 21 by the urging force of the return spring 55 of the horizontal movement mechanism, and the main shaft 17 and the cutter 37 are arranged in a predetermined positional relationship. Processing becomes possible. Next, the workpiece W is further moved toward the main shaft 17 in the Z-axis direction in a state where the cutter 37 is pressed against the shoulder portion 21 c of the drive shaft 21. Then, the cutter 37 is pushed against the shoulder portion 21 c of the drive shaft 21, so that the slider 51 fixed to the support column 41 moves along the guide rail 53 on the horizontal arm 43 against the urging force of the return spring 55. Then, the cutter 37 and the workpiece W move relative to each other, and the end surface of the cutter 37 in the rotation axis O2 direction is pressed against the inner surface of the side wall 31 of the workpiece W far from the main shaft 17 as shown in FIG. . By rotating the main shaft 17 in this state, the inner surface of the workpiece W can be machined by the cutting edge 37a provided on the end surface of the cutter 37 in the rotation axis O2 direction.

  When the machining of one machining surface is completed, as shown in FIG. 6, the spindle 17 and the table 19 are moved relative to each other in the Z-axis direction in a direction away from each other, thereby driving from the through hole 37b of the cutter 37. When the shaft 21 is pulled out and the surface opposite to the processed surface is processed in the same manner, the table 19 is rotated so that the surface to be processed of the workpiece W is arranged on the side far from the main shaft 17, and then the cutter 37 is again formed. The small-diameter cylindrical portion 21b of the drive shaft 21 may be inserted into the through-hole 37b and processed similarly. When the cutter 37 is fixed to the drive shaft 21 with a nut or the like, after the processing of one surface is completed, the main shaft 17 and the table 19 are moved relative to each other in the Z-axis direction so as to face each other. You may process the other of the surfaces.

  When the processing on the workpiece W is completed, the workpiece fixture 25 is removed from the table 19 and another workpiece fixture 25 to which a new workpiece W is attached is attached to the table 19 by a pallet exchanging device (not shown). At this time, the cutter 37 is also exchanged together with the work fixture 25. Therefore, even when the cutter 37 needs to be replaced due to wear, the cutter 37 can be replaced at a place other than on the table 19, and it is not necessary to interrupt the processing for replacing the cutter 37, so that the processing efficiency is improved. It becomes possible to improve. When the workpiece fixture 25 to which the processed workpiece W is attached is transferred to a setup station or the like, the cutter 37 is pulled upward from the concave portion 27 of the workpiece W by the vertical movement mechanism of the cutter holder 39, and the workpiece W is moved to the pallet 35. Removed from. The removal of the cutter 37 from the concave portion 27 of the workpiece W and the removal of the workpiece W from the pallet 35 can be performed at a place other than on the table 19, and in the meantime, the machine tool 11 processes a new workpiece W. Since it can be performed, the processing efficiency is improved.

  While the present invention has been described based on the illustrated embodiment, the present invention is not limited to the illustrated embodiment. For example, in the above embodiment, the horizontal movement mechanism of the cutter holder allows horizontal movement by an external force, but it may be movable by a motor or the like by itself. Further, the vertical mechanism of the vertical arm may use other actuators such as a motor and a ball screw nut mechanism instead of the fluid pressure cylinder.

1 is an overall configuration diagram of a machine tool for machining a surface of a workpiece perpendicular to a rotation axis of a main shaft according to the present invention. It is an enlarged view of the cutter holding part of the cutter holder provided in the workpiece fixture of the machine tool shown in FIG. It is a diagram for demonstrating the procedure which processes the inner surface of the workpiece | work by the machine tool of this invention, and has shown the state which has arrange | positioned the cutter in the recessed part of the workpiece | work. It is a diagram for demonstrating the procedure which processes the inner surface of the workpiece | work by the machine tool of this invention, and has shown the state which engaged the drive shaft with the cutter. It is a diagram for demonstrating the procedure which processes the inner surface of the workpiece | work by the machine tool of this invention, and has shown the state which pressed the cutter against the inner surface of the workpiece | work. It is a diagram for demonstrating the procedure which processes the inner surface of the workpiece | work by the machine tool of this invention, and has shown the state which removed the cutter from the recessed part of a workpiece | work after completion | finish of a process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Machine tool 17 Main shaft 19 Table 21 Drive shaft 25 Work fixture 27 Recessed part 33 Shaft hole 37 Cutter 37b Through-hole 39 Cutter holder

Claims (3)

A work fixture used when machining a surface of a work perpendicular to the rotation axis of the spindle of a machine tool,
A pallet that is detachably mounted on the table of the machine tool;
A cutter holder that is provided on the pallet and is capable of moving relative to a workpiece fixed on the pallet and rotating around a rotation axis;
A workpiece fixture characterized by comprising:   2. The workpiece according to claim 1, wherein the cutter holder includes a horizontal movement mechanism that moves the cutter in a direction of the rotation axis of the cutter, and a vertical movement mechanism that moves the cutter in a direction perpendicular to the rotation axis of the cutter. Mounting tool. A machine tool that processes a surface of a workpiece perpendicular to the rotation axis of the spindle by relatively moving a spindle driven to rotate and a table on which the workpiece is placed,
A drive shaft mounted on the main shaft;
The workpiece is mounted on a workpiece fixture that is detachably mounted on the table, and holds the cutter so as to be movable relative to the workpiece fixed to the workpiece fixture and rotatable about the rotation axis. A cutter holder;
The drive shaft and the cutter are arranged such that the rotation axis of the cutter and the rotation axis of the drive shaft are aligned in a straight line, and the main shaft and the table are relatively moved toward each other in the direction of the rotation axis. And the rotation of the drive shaft can be transmitted to the cutter, and the cutter and the table are moved relative to each other in the direction of the rotation axis of the cutter. A machine tool characterized by machining the surface of the workpiece perpendicular to the rotation axis.

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