JP2006055945A - Cutting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out highly efficient machining by enhancing supporting rigidity of a tool when performing shaving, slotting and broaching by using a machine tool, and to reduce damage of a spindle of the machine tool. <P>SOLUTION: This cutting device 11 is provided with a spindle head 23 of the machine tool, the spindle 25 rotatably supported by the spindle head 23 around a rotation axis 27, and a cutting attachment 15 mounted on the spindle 25 to support a cutting tool 43. The cutting tool 43 is reciprocatively moved in the rotation axis 27 direction in relation to a workpiece W. In the one stroke, the workpiece W is cut by the cutting tool 43. In the cutting device 11, an end face of the cutting attachment 15 in the rotation axis 27 direction is arranged to abut on an end face of the spindle head 23. A part or all of force of the rotation axis 27 direction applied to the cutting tool 43 at the time of cutting is received by the end face of the spindle head 23 via the cutting attachment 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cutting apparatus that reciprocates a tool or a broach (hereinafter referred to as a tool) with respect to a workpiece and cuts the workpiece with the tool in one stroke.

When machining a keyway, square hole, flat surface, special shape, or curved surface on a workpiece, the tool held via a tool holder on a ram that reciprocates horizontally or vertically is reciprocated with respect to the workpiece. Then, in one of the strokes, shaping, cutting or broaching is performed by cutting the workpiece with a tool. Conventionally, dedicated machines have been used for such processing.
However, when using a dedicated machine, it is necessary to use another machine tool in order to perform processing other than shaping, vertical cutting and broaching on the workpiece, so it is necessary to perform setup change work. Processing time was long.
In view of this, there has been proposed an apparatus for performing cutting by attaching a cutting tool (slotting tool) to a spindle of a machining center and linearly reciprocating the spindle with respect to a workpiece (see Patent Document 1). .

Japanese Utility Model Publication No. 63-20525

  In shaping, sharpening, or broaching, a large force is generated in the direction of movement of the tool during cutting, and particularly when the tool contacts the workpiece, a large force is generated in the direction of movement of the tool. Therefore, when performing machining, tapping, or broaching using a machining center, a large force acts on the spindle of the machining center in the direction of the axis of rotation of the spindle when the tool and workpiece contact. A large burden is placed on the bearing that is rotatably supported by the spindle head.

  However, since the spindle of the machining center is supported on the spindle head by a bearing mainly intended to rotate at high speed, it is not so strong against the force in the direction of the axis of rotation, that is, the thrust load. Therefore, when a machining center is used for shaping, tapping, or broaching that repeatedly applies a thrust load to the bearing, there is a problem that the spindle life of the machining center, particularly the bearing life and machining accuracy are adversely affected. is there.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to increase the support rigidity of a tool when performing shape cutting, vertical cutting, or broaching using a general-purpose machine tool such as a machining center. This is to realize high-efficiency machining and to reduce the damage to the spindle of the machine tool.

  In order to achieve the aforementioned object, according to the present invention, a spindle head of a machine tool, a spindle supported on the spindle head so as to be rotatable around a rotation axis, and a cutting attachment mounted on the spindle and supporting a tool, A cutting device that reciprocates the tool with respect to the workpiece in the direction of the rotation axis, and cuts the workpiece with the tool in one stroke thereof, wherein the end surface of the cutting attachment in the direction of the rotation axis is the end surface of the spindle head There is provided a cutting device that is arranged so as to abut against the tool and that receives all or part of the force in the direction of the rotational axis acting on the tool during cutting at the end face of the spindle head via the cutting attachment.

  A part of or all of the thrust force acting on the tool during cutting, i.e., the thrust load, is received by the end face of the spindle head, which is a stationary part, via the cutting attachment, so the support rigidity of the tool is high and the efficiency is high. Processing can be performed. Further, the force in the direction of the rotation axis acting on the main shaft and its bearing is remarkably reduced, and it is possible to greatly reduce the damage given to the main shaft as the rotating portion.

In the cutting apparatus, a recess and a protrusion that are engaged with each other are formed on the end surface of the cutting attachment and the end surface of the spindle head, respectively, and the end surface of the cutting attachment and the end surface of the spindle head are brought into contact with each other. It is preferable that the cutting attachment is positioned in the rotational axis direction and the radial direction of the main shaft with respect to the main shaft head by fitting a protrusion.
With such a configuration, when the cutting attachment is mounted on the spindle, the position of the tool in the spindle rotation axis direction and the radial direction with respect to the spindle head is always determined at a predetermined position, so that the tool is accurately positioned with respect to the workpiece. And high-precision machining is possible.

In the cutting apparatus, the cutting attachment is provided with a main body that contacts the end face of the spindle head, a head that is rotatably supported by the main body and that holds a tool, and is rotatably provided within the main body. A transmission body mounted on the main shaft and connected to the head so that the other end does not rotate relative to the head, and the tool is linked to the main shaft via the transmission body and the head. It is preferable to rotate around the rotation axis.
With such a configuration, the tool can be rotated around the rotation axis in conjunction with the main axis, so that the direction of the tool around the C axis or the rotation axis can be controlled, and the direction of the workpiece can be changed. However, when a groove or the like in various directions is machined or the feed in the rotation axis direction of the tool is synchronized with the C axis, the spiral groove can be machined.

  As described above, according to the present invention, a general-purpose machine tool such as a machining center is used to perform machining equivalent to or higher than that of a dedicated machine for shaping, standing, and broaching while increasing the support rigidity of the tool and suppressing damage to the spindle. Can be performed. Therefore, even if the workpiece is subjected to other machining in addition to shaping, tapping or broaching, it is not necessary to change the setup from the dedicated machine to the machining center, coupled with the high support rigidity of the tool. Shortening, that is, highly efficient machining can be realized.

  The best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a main part showing a preferred embodiment of the cutting apparatus of the present invention, FIG. 2 shows a main spindle head and a front end of the main spindle of the cutting apparatus shown in FIG. FIG. 3 is a front view seen from the direction of the rotation axis, FIG. 3B is a side view, and FIG. 3 is a schematic view of a machining center to which a cutting attachment is attached. In the following description, “front” refers to the machining area side or the cutting tip side of the cutting attachment in the rotation axis direction of the main shaft, and “rear” refers to the back side of the machining center in the rotation axis direction of the main shaft. To do.

  A cutting apparatus 11 shown in FIG. 1 is obtained by attaching a cutting attachment 15 to a spindle 25 of a machining center 13 which is an example of a machine tool. As shown in FIG. 3, the machining center 13 includes a bed 17, a table 19 that can move on the bed 17 in the Z-axis direction and on which a workpiece is placed, and a Z-axis on the bed 17. A column 21 movable in the vertical X-axis direction, a spindle head 23 supported by the column 21 so as to be movable in the Y-axis direction perpendicular to the X-axis and the Z-axis, and a rotation axis 27 parallel to the Z-axis. The main shaft 25 is supported by the main shaft head 23 as possible. In addition, a tapered hole 29 that engages with a tapered portion such as a tool holder or various machining attachments is formed at the tip of the main shaft 25. In the cutting device 11 of the present invention, the workpiece W on the table 19 and the cutting attachment 15 attached to the main shaft 25 can be moved relative to three orthogonal axes of the X axis, the Y axis, and the Z axis. The configuration of the machining center 13 is not limited to the above configuration.

The cutting attachment 15 includes a main body 31, a head 35 rotatably supported on a front side portion of the main body 31, and a rear side portion of the main body 31 so as to be rotatable about the rotation axis 27 and movable in the direction of the rotation axis 27. And a cutting tool holder 41 for holding a cutting tool 43 for cutting the workpiece W.
The head 35 is supported by the main body 31 so as to be rotatable with respect to the main body 31 by interposing a bearing 33 between the head 35 and the main body 31. Since the force in the direction of the rotational axis 27 received by the cutting tool 43 held by the cutting tool holder 41 during processing, that is, the thrust load, acts on the bearing 33 via the head 35, the bearing 33 can receive the thrust load. Need to use one. In the embodiment shown in FIG. 1, as the bearing 33, two types of angular ball bearings that can receive loads in the opposite directions in the direction of the rotation axis 27 are used in combination.

  The main body 31 is configured such that when the cutting attachment 15 is attached to the main shaft 25 of the machining center 13, the rear end surface in the direction of the rotation axis 27 abuts the front end surface of the main shaft head 23 around the main shaft 25. In particular, in the embodiment shown in FIG. 1, a plurality of recesses 45 are provided at equal intervals in the circumferential direction so as to surround the main shaft 25 on the front end surface of the main shaft head 23 as shown in detail in FIG. On the other hand, a plurality of protrusions 47 are provided at equal intervals in the circumferential direction on the rear end surface of the main body 31 of the cutting attachment 15 so as to correspond to the recess 45, and when the cutting attachment 15 is attached to the main shaft 25, the cutting attachment is provided. The projection 47 on the rear end surface of the main body 31 can be fitted into the recess 45 on the front end surface of the spindle head 23. Needless to say, a recess may be provided on the rear end surface of the main body 31 and a protrusion may be provided on the front end surface of the spindle head 23. Moreover, it is preferable that the number of the recessed parts 45 and the protrusions 47 is three or more. In this way, the recess 45 and the projection 47 formed on the front end surface of the spindle head 23 and the rear end surface of the cutting attachment 15 are fitted to each other, thereby positioning the cutting attachment 15 in the radial direction and the rotation axis 27 direction with respect to the spindle head 23. The position of the cutting tool 43 when the cutting attachment 15 is mounted on the main shaft 25 can be accurately defined.

Further, the main body 31 has a substantially cylindrical chamber in which a transmission body 39 is accommodated so as to be movable in the direction of the rotation axis 27, and a shoulder portion projects inward in the radial direction on the inner wall of the chamber. An annular protrusion 49 is provided.
On the other hand, the transmission body 39 accommodated in the chamber has a substantially cylindrical shape, and a tapered portion 39 a that engages with the tapered hole 29 of the main shaft 25 is formed at the rear end portion thereof. The transmission 39 has a small diameter so that it can pass through the opening surrounded by the annular protrusion 49 of the chamber, and a small diameter portion 51 located adjacent to the tapered portion 39a, and larger than the small diameter portion 51. The shoulder portion formed between the small-diameter portion 51 and the small-diameter portion 51 includes a shoulder portion formed by the annular protrusion 49 and a large-diameter portion 53 configured to face the direction of the rotation axis 27. Yes.

  A thrust ball bearing is provided in the annular space formed between the inner wall of the chamber of the main body 31 and the outer peripheral surface of the small-diameter portion 51 of the transmission 39 between the shoulder of the annular protrusion 49 and the shoulder of the transmission 39. 37, and the outer ring of the thrust ball bearing 37 (the left raceway ring in FIG. 1) is fixed to the front side surface in the direction of the rotation axis 27 of the shoulder formed by the annular protrusion 49 of the chamber. 37 is fixed to the shoulder of the transmission 39 that faces the shoulder of the annular protrusion 49 in the direction of the rotation axis 27 via a leaf spring 55. Thus, the thrust ball bearing 37 is interposed between the inner wall of the chamber of the main body 31 and the transmission body 39, so that the transmission body 39 can rotate around the rotation axis 27 with respect to the main body 31.

  Furthermore, the head 35 and the transmission body 39 allow relative movement of the transmission body 39 in the direction of the rotation axis 27 with respect to the head 35, and the head 35 rotates in conjunction with the transmission body 39 without rotating relative to the transmission body 39. Are connected to each other. For example, as in the embodiment shown in FIG. 1, an extension portion 35 a having a polygonal cross section extending toward the transmission body 39 is formed at the rear end portion of the head 35, and the extension portion is formed at the front end portion of the transmission body 39. A receiving hole 39b having a cross section complementary to the cross section is formed, and the extension 35a of the head 35 is slidably inserted into the receiving hole 39b of the transmission body 39 in the main body 31, thereby rotating the transmission body 39 relative to the head 35. The head 35 and the transmission body 39 can be connected such that relative movement in the direction of the axis 27 is allowed and the head 35 rotates in conjunction with the transmission body 39.

Next, the usage method and operation | movement of the cutting device 11 of this invention are demonstrated.
When the cutting attachment 15 of the cutting apparatus 11 of the present invention is mounted on the spindle 25 of the machining center 13, the protrusion 47 formed on the rear end surface of the main body 31 of the cutting attachment 15 is a recess formed on the end surface of the spindle head 23 of the machining center 13. The tapered portion 39 a of the transmission 39 of the cutting attachment 15 is inserted into the tapered hole 29 of the main shaft 25 of the machining center 13 while aligning the concave portion 45 and the protrusion 47 in the direction of the rotational axis 27 so as to be received in the shaft 45. And the pull stud (not shown) provided in the rear-end part of the taper part 39a of the transmission body 39 is engaged with the draw bar (not shown) arrange | positioned in the main axis | shaft 25, and the transmission body 39 is a taper hole. Pull it back into 29. Then, the transmission body 39 moves rearward in the chamber of the main body 31, and a force in the rearward direction in the rotational axis acts on the shoulder portion of the main body 31 from the shoulder portion of the transmission body 39 via the leaf spring 55 and the thrust ball bearing 37. Then, the rear end surface of the main body 31 is pressed against the front end surface of the spindle head 23. Thus, the front end surface of the main spindle head 23 and the rear end face of the main body 31 are brought into contact with each other while the recess 45 on the front end face of the main spindle head 23 and the protrusion 47 on the rear end face of the main body 31 are fitted to each other. The cutting attachment 15 is positioned with respect to 25 in the direction of the rotation axis 27 and in the radial direction. Further, since the transmission body 39 and the head 35 are only connected with the extension 35a of the head 35 inserted into the receiving hole 39b of the transmission body 39, only the transmission body 39 moves backward in the direction of the rotation axis 27. In addition, the head 35 does not move backward in the direction of the rotational axis 27, and no backward force acts in the direction of the rotational axis 27 on the head 35. Therefore, when the cutting attachment 15 is mounted on the main shaft 25 of the machining center 13, the cutting tool 43 held by the cutting attachment 15 is always positioned at a predetermined position, and high-precision machining is possible. The cutting attachment 15 can be attached to and detached from the spindle 25 of the machining center 13 using a known automatic tool changer.

  When machining, the workpiece W on the table 19 is attached to the cutting attachment 15 mounted on the spindle 25 of the machining center 13 in a state in which the spindle 25 is locked so that the cutting tool 43 does not rotate around the rotation axis 27. Is relatively moved in the Z-axis direction, that is, in the direction of the rotation axis 27 of the main shaft 25, and the workpiece W is shaped or sharpened by the cutting tool 43 of the cutting attachment 15. When the cutting tool 43 of the cutting attachment 15 approaches and contacts the workpiece W in the direction of the rotation axis 27 of the main shaft 25, a force in the direction of the rotation axis 27 acts on the cutting tool 43 and a thrust load acts on the cutting attachment 15.

  However, as shown in FIG. 1, a gap is opened between the head 35 and the transmission body 39 and between the main body 31 and the transmission body 39 in the direction of the rotation axis 27. Since the force in the direction is not directly transmitted to the transmission body 39, the force in the direction of the rotation axis 27 transmitted from the cutting tool 43 to the head 35 through the cutting tool holder 41 is applied only to the main body 31 through the bearing 33 or the like. The transmission 39 does not receive a force in the direction of the rotation axis 27. Further, since the rear end surface of the main body 31 in the direction of the rotation axis 27 is in contact with the front end surface of the spindle head 23 which is a stationary part of the machining center 13, the force in the direction of the rotation axis 27 acting on the main body 31 of the cutting attachment 15 is the main axis. Transmit to head 23. Therefore, the force in the direction of the rotation axis 27 generated by cutting with the cutting tool 43 is received by the front end surface of the spindle head 23, and the force in the direction of the rotation axis 27 acting on the main shaft 25 as the rotating portion, that is, the thrust load is greatly reduced. Or substantially disappear. As a result, the cutting tool 43 is supported by the spindle head 23, and the rigidity increases and high-efficiency machining can be performed. Further, the bearing (not shown) that rotatably supports the spindle 25 with respect to the spindle head 23 is hardly damaged, and the bearing life of the spindle 25 and the machining accuracy of the machining center 13 can be hardly adversely affected. .

  Further, the transmission body 39 and the head 35 of the cutting attachment 15 are rotatably supported with respect to the main body 31, and the transmission body 39 and the head 35 are connected so as not to rotate relative to each other. If the main shaft 31 mounted with 39 is rotated around the rotation axis 27, the head 35 rotates in conjunction with the rotation of the main shaft 31 via the transmission body 39 and is supported by the head 35 via the bite holder 41. The cutting tool 43 can be rotated around the rotation axis 27. Therefore, by controlling the rotation of the spindle 31, the cutting tool 43 can be easily indexed, and the orientation of the cutting tool 43 relative to the workpiece W can be easily adjusted. Further, by synchronizing the feeding operation in the direction of the rotation axis 27 and the rotating operation of the cutting tool 43, a helical shape can be processed.

  The rotation of the transmission 39 and the head 35 of the cutting attachment 15 is for adjusting the orientation of the cutting tool holder 41 and the cutting tool 43 held by the cutting tool 15 and for rotating at a low speed. It is not necessary to rotate the shaft at a high speed like the main shaft 25 of the machining center 13. For this reason, it is not necessary to use a deep groove ball bearing or the like that is capable of high-speed rotation while being able to rotate the transmission body 39 and the head 35 with respect to the main body 31 while being susceptible to thrust load. However, it is possible to use angular ball bearings or thrust ball bearings that are not suitable for thrust loads, but are resistant to thrust loads, so that they can be used for thrust loads (that is, loads in the direction of the rotation axis 27) that occur during shaping or tapping. Durability can be improved.

The cutting apparatus 11 of the present invention has been described above with reference to the preferred embodiment shown in the drawings, but the present invention is not limited to the illustrated embodiment. For example, broaching can be performed using a broach instead of the cutting tool 43. Moreover, in the said embodiment, although the head 35 is rotatable with respect to the main body 31 in the cutting attachment 15 of the cutting apparatus 11, the cutting tool 43 is indexed with respect to the work W by adjusting the table side or the cutting tool holder 41. In this case, the main body 31 and the head 35 can be integrally formed. Even in this case, in order to obtain a force for pressing the main body 31 against the spindle head 23, the transmission body 39 is movable in the direction of the rotation axis 27 with respect to the main body 31, and has the same configuration as that of the above-described embodiment. It is preferable to be accommodated in
Moreover, although the recessed part 45 and the processus | protrusion 47 are provided in the rear-end surface of the main body 31 of the cutting attachment 15, and the front-end surface of the spindle head 23, these are not essential, The rear-end surface and main axis of the main body 31 of the cutting attachment 15 are provided. It is also possible to form both the front end surfaces of the head 23 flat so that the flat end surfaces come into contact with each other.

It is principal part sectional drawing which shows embodiment of the cutting device of this invention. The spindle head of the cutting apparatus shown by FIG. 1 and the front-end part of a spindle are shown, (a) is the front view seen from the rotating shaft direction of the spindle, (b) is a side view. It is the schematic of the machining center which mounts a cutting attachment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Cutting device 13 Machining center 15 Cutting attachment 23 Spindle head 25 Spindle 27 Rotating axis 31 Main body 35 Head 39 Transmission body 41 Tool holder 43 Tool bit 45 Concave portion 47 Projection

Claims (4)

A spindle of a machine tool, a spindle supported by the spindle head so as to be rotatable around a rotation axis, and a cutting attachment mounted on the spindle and supporting a tool, the tool reciprocating in the direction of the rotation axis with respect to the workpiece. A cutting device that moves and cuts a workpiece with a tool in one of the strokes,
The end face of the spindle head in the rotational axis direction is arranged so as to abut on the end face of the spindle head, and all the forces in the rotational axis direction acting on the tool during cutting work are passed through the cutting attachment to the end face of the spindle head. A cutting device characterized by being configured to receive at. A spindle of a machine tool, a spindle supported by the spindle head so as to be rotatable around a rotation axis, and a cutting attachment mounted on the spindle and supporting a tool, the tool reciprocating in the direction of the rotation axis with respect to the workpiece. A cutting device that moves and cuts a workpiece with a tool in one of the strokes,
The end face of the cutting attachment in the rotational axis direction is disposed so as to abut on the end face of the spindle head, and a part of the force in the rotational axis direction acting on the tool at the time of cutting is passed through the cutting attachment to the spindle head Cutting device characterized by being configured to receive at the end face of the.   The end surface of the cutting attachment and the end surface of the spindle head are respectively formed with a recess and a projection that engage with each other, and the end surface of the cutting attachment and the end surface of the spindle head are brought into contact with each other to fit the recess and the projection. The cutting apparatus according to claim 1 or 2, wherein the cutting attachment is positioned in a rotational axis direction and a radial direction of the spindle relative to the spindle head.   The cutting attachment includes a main body that abuts on an end surface of the spindle head, a head that is rotatably supported by the main body and that holds a tool, and is rotatably provided in the main body. And a transmission body connected to the head so as not to rotate relative to the head, and the tool rotates about the rotation axis in conjunction with the main shaft via the transmission body and the head. The cutting device according to claim 1 or 2, wherein

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