JPH0386405A - Machining device changeable in turning radius of cutting edge - Google Patents

Abstract

PURPOSE:To enlarge the changeable quantity of a turning radius of a cutting edge of a cutting tool mounted on an eccentric rotary shaft by providing a rotation transmitting mechanism for transmitting the rotation of an intermediate rotary shaft relatively rotated to a main rotary shaft to the eccentric rotary shaft. CONSTITUTION:An intermediate rotary shaft 56 is provided separately from an eccentric rotary shaft 68 holding a cutting tool 80, and a rotating device first rotate the shaft 56 relatively to a main rotary shaft 50. The rotation of the shaft 56 is transmitted through a rotation transmitting mechanism to the shaft 68. The rotation transmitting mechanism is formed, for example, of a combination of gears 64, 86, and even if the shaft center of the shaft 68 is greatly eccentric from the shaft center of the shaft 50, the rotation of the shaft 56 can be satisfactorily transmitted to the shaft 68. Thus, when the shaft 68 is rotated, the distance of a cutting edge of the cutting tool 80 from the shaft center of the shaft 50 changes greatly, and a turning radius of the cutting edge therefore changes greatly as the main rotary shaft 50 rotates.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a cutting device capable of changing the turning radius of a cutting edge, and particularly relates to a technique for increasing the amount of change possible.

BACKGROUND OF THE INVENTION An example of a cutting device capable of changing the turning radius of the cutting edge is disclosed in Japanese Utility Model Application No. 62-91221. This consists of (a) a main rotating shaft that rotates around the axis; (b) an eccentric sleeve that is coaxially and rotatably held on the main rotating shaft and whose inner peripheral surface is eccentric from the axis of the main rotating shaft; (c) a cutting tool holding member rotatably fitted to the inner circumferential surface of the eccentric sleeve and prevented from rotating relative to the main rotating shaft; and (d) a cutting tool holding member with a cutting edge attached to the main rotating shaft. The cutting tool is configured to include a cutting tool held at a position offset from the axis; and (e) a rotating device held on the main rotating shaft and rotating the eccentric sleeve relative to the main rotating shaft. Ru. In this cutting device, when the eccentric sleeve is rotated relative to the main rotating shaft by the rotating device, the cutting tool holding member fitted to the eccentric sleeve moves in the radial direction of the rotating shaft,
The radial position of the rotating shaft of the cutting tool changes, changing the turning radius of the cutting edge.

In this way, when holding the cutting tool holding member on the main rotating shaft via an eccentric sleeve, in order to increase the amount of change in the turning radius of the cutting edge, the amount of eccentricity of the eccentric sleeve must be increased. The outer diameter of the shaft becomes large. In addition, the support rigidity of the cutting tool tends to be insufficient, and distortion and vibration due to cutting resistance are likely to occur during cutting, so there is a limit to the improvement of machining accuracy, and it is not suitable for heavy cutting.

Therefore, the inventors of the present invention have developed and filed an application for a cutting device that allows easy change of the position of the cutting edge as described below. Patent application Hei 1-172
This is No. 526. This device has (i) a main rotating shaft that rotates around its axis, and (ii) an eccentric rotating member that is held by the main rotating shaft so as to be rotatable about an axis that is eccentric from the axis of the main rotating shaft. , (ij) a cutting tool that is attached to the eccentric rotating member with its cutting edge positioned away from the axis of the eccentric rotating member and rotates together with the eccentric rotating member; (iv) held on the main rotating shaft; and a rotation device that rotates the eccentric rotation member relative to the rotation shaft, and the eccentric rotation member is rotated by operating the rotation device to rotate the eccentric rotation member relative to the main rotation shaft. By changing the distance of the cutting edge of the cutting tool attached to the blade from the axis of the main rotating shaft, it is possible to change the turning radius of the cutting edge when the main rotating shaft rotates. therefore,
Compared to the conventional device described above, it is possible to increase the amount of change in the turning radius of the cutting edge while avoiding an increase in the outer diameter of the main rotating shaft, and the support rigidity of the cutting tool is increased, which reduces the amount of cutting resistance caused by cutting resistance. Distortion and vibration can be prevented and machining accuracy can be improved.

Problems to be Solved by the Invention However, in the above cutting device, since the eccentric rotating member is directly rotated by the rotating device,
There is a limit to the amount of eccentricity of the eccentric rotating member with respect to the main rotating shaft.
The amount of change in the turning radius of the cutting edge is still not sufficient. In other words, it is not possible to cut the inner surface of stepped workpieces with greatly different diameters or to cut the end face of a wide area.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a cutting device that can increase the changeable amount of the turning radius of the cutting edge compared to conventional cutting tools.

Means for Solving the Problems The cutting device according to the present invention includes (a) a main rotating shaft that rotates around the axis, and (b) rotating around an axis that is eccentric from the axis of the main rotating shaft. (C) an eccentric rotating shaft that is held on the main rotating shaft; , a cutting tool that rotates together with the eccentric rotating shaft; (d) an intermediate rotating shaft that is provided concentrically and relatively rotatably within the main rotating shaft; and (e) transmitting the rotation of the intermediate rotating shaft to the eccentric rotating shaft. It is configured to include a rotation transmission mechanism, and (f) a rotation device that is held by the main rotation shaft and rotates the intermediate rotation shaft relative to the main rotation shaft.

Function In the cutting device configured as described above, an intermediate rotating shaft is provided separately from the eccentric rotating shaft that holds the cutting tool.
First, the intermediate rotation shaft is rotated relative to the main rotation shaft by the rotation device, and the rotation is transmitted to the eccentric rotation shaft via the rotation transmission mechanism.

The rotation transmission mechanism is configured, for example, by a combination of gears, and can effectively transmit the rotation of the intermediate rotation shaft to the eccentric rotation shaft even when the axis of the eccentric rotation shaft is largely eccentric from the axis of the main rotation shaft. . Therefore, when the eccentric rotating shaft is rotated, the distance of the cutting edge of the cutting tool from the axis of the main rotating shaft changes greatly, and the turning radius of the cutting edge due to the rotation of the main rotating shaft changes greatly.

Effects of the Invention Therefore, it is possible to cut the inner surface of stepped workpieces having greatly different diameters and to cut the end face of a wide area. Further, end face cutting and inner circumferential face cutting can be combined and performed continuously.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

In FIG. 1, 10 is the main axis. The main shaft 10 has a bearing 12. It is rotatably held in the housing 16 via a seal 14 or the like. As shown in FIG. 3, a V-pulley 18 is attached to the rear end of the main shaft 10 protruding from the housing 16 so as to be non-rotatable. The housing 16 is placed on the slide 20 as shown in FIG.
A plate 24 is attached to the rear of the slide 20 by a plurality of bolts 22 so as to be adjustable in height, and a motor 26 is mounted on the plate 24. A V pulley 28 is fixed to the output shaft of the motor 26, and a V pulley 28 is connected to the V pulley 18 and V boo+J 2 B.
By winding the belt 30, the main shaft 10 is rotated by the motor 26.

The main shaft 10 has a central hole 3 extending in the axial direction as shown in FIG.
2, into which a rod 34 is fitted so as to be movable in the axial direction. The tip of the center hole 32 has a large diameter,
A fitting protrusion 38 of the adapter 36 is fitted here.

A housing 44 is fixed to the end face 40 of the adapter 36 with bolts 42, and the housing 44 is fixed to the end face 46 of the main shaft 10 with six bolts 48 as shown in FIG. constitutes an integral main rotating shaft 50 together with the main shaft 10.

A through hole 52 concentric with the center hole 32 is formed in the adapter 36, and an intermediate rotating ring 56 is rotatably fitted into the through hole 52 via bearings 54 and 55. A female thread member 58 is provided on the end face of the 34 wands of the intermediate rotating shaft 56.
is fixed, and a male threaded portion 60 formed at the tip of the rod 34 is screwed together. The male threaded portion 60 is a multi-thread thread such as a four thread thread, and the lead angle of the thread is set to be large. Further, the intermediate rotating shaft 56 has an axial hole 6.
2 is formed to allow the male threaded portion 60 to enter the interior of the intermediate rotating shaft 56, and a guide bush 6 for guiding the male threaded portion 60 is provided at the open end of the axial hole 62.
3 is provided.

The end of the intermediate rotating shaft 56 opposite to the open end of the axial hole 62 extends from the through hole 52 of the adapter 36 into the housing 44, and the external gear 64 is attached thereto in a relatively non-rotatable manner. It is being

The tip of the housing 44 is an eccentric cylindrical portion 65 with a small diameter. The eccentric cylindrical portion 65 is formed with an eccentric hole 66 that is eccentric from its axis, that is, the axis of the main rotating shaft 50.
An eccentric rotating shaft 68 is fitted so as to be rotatable but immovable in the axial direction. The tip of the eccentric rotating shaft 68 has a small diameter and projects from the eccentric cylindrical part 65, and a tip holder 72 is attached to this projecting part 70. Chip holder 72
has the same diameter or a slightly smaller diameter than the eccentric cylindrical portion 65 of the housing 44, and is provided with a fitting hole 74 concentrically with the eccentric hole 66. The chip holder 72 has a key 76 shown in FIG.
It is prevented from rotating relative to the eccentric rotation shaft 68 by the nut 78, and is pressed against the stepped portion of the eccentric rotation shaft 68 by the nut 78, and is fixed so as not to be able to move in the axial direction. A tip 80, which is a cutting tool, is attached to this tip holder 72.

The chip 80 is attached to the chip holder 72 as shown in FIG.
is attached to the tip in the radial direction of the workpiece W with the rake face located approximately on a plane including the axis of the main rotating shaft 50, and rotates together with the tip holder 72 to rotate the workpiece W shown by the two-dot chain line in FIG. This is for cutting the end face Wl.

On the other hand, the rear end portion of the eccentric rotating shaft 68 extends into the large diameter portion 82 of the through hole 66 of the housing 44, and an internal gear 84 is attached so as to be non-rotatable. Large diameter part 8
2 communicates with the through hole 52 of the adapter 36, and the external gear 64 attached to the intermediate rotating ring 56 meshes with the internal gear 84, so that the rotation of the external gear 64 is transmitted to the eccentric rotating ring 68. ing. Therefore, when the external gear 64 is rotated by the forward and backward movement of the male threaded portion 60, the rotation is transmitted from the internal gear 84 to the eccentric rotating shaft 68, and the eccentric rotating shaft 68 rotates around the eccentric axis in both forward and reverse directions. can be rotated. That is, in this embodiment, the external gear 64 and the internal gear 84 constitute a rotation transmission mechanism that transmits the rotation of the intermediate rotation shaft 56 to the eccentric rotation ring 68.

Further, a flange 86 is formed on the outer peripheral surface of the eccentric rotating shaft 68. The flange 86 is pressed against the stepped surface of the housing 44 by a ring screw 94 together with a pair of bearings 90 and 92 provided on both sides of the flange 86 in the middle diameter portion 88 of the through hole 66 of the housing 44. Relative movement of the rotary shaft 68 with the housing 44, that is, the main rotary shaft 50 in the axial direction is prevented, and the axial cutting resistance generated when cutting the workpiece W by the tip 80 is transmitted through the eccentric rotary shaft 68. A housing 44 is adapted to receive it.

As shown in FIG. 3, a casing 100 is fixed to the rear end of the V-pulley 18, and the casing 100
Yet another casing 102 has been identified. The outer circumferential surface of the rear end of the rod 34 is chamfered 104 at four locations separated in the diametrical direction, and is fitted into a rectangular through hole 106 formed in the casing 102 in a relatively non-rotatable manner. Rotation of the rod 34 with respect to the main shaft 10 is prevented. The casing 102 is fitted into an arm 108 extending rearward from the housing 16 so as to be relatively rotatable with a fixed casing 110.

An axial hole 112 is formed in the rod 34 from the rear end surface, into which the front end of the screw shaft 114 is fitted. The screw shaft 114 is connected to an output shaft 118 of a motor 116 disposed behind it. On the other hand, a through hole 120 extending in the axial direction is formed in the casing 110, and a moving member 122 is slidably fitted inside the through hole 120. The moving member 122 has an axial hole 12
4, a nut 126 screwed with the screw shaft 114 is fixed to the rear end, and the rod 34 is held rotatably but immovably in the axial direction via bearings 128, 130 at the front end. There is.

Therefore, when the screw shaft 114 is rotated by the motor 116, the nut 126 and the moving member 122 move within the through hole 120, and the rod 34 is accordingly moved in the axial direction. When the rod 34 is advanced, the intermediate rotating shaft 56 is rotated, and the external gear 64 is rotated accordingly.
．． The eccentric rotating shaft 68 and the tip holder 72 rotate through the internal gear 84, and the main shaft 10 of the tip 80 (the main rotating wheel 50
) increases in distance from the axis. The tip 80 is farthest from the axis of the main rotation shaft when the eccentric rotation shaft 68 is rotated 180 degrees. At the beginning and end of this 180-degree rotation, the tip of the tip 80 is positioned on one plane that includes the axis of the main shaft lO and the axis of the eccentric rotation shaft 68, and The amount of change in the distance of the tip of the tip 80 from the axis of the main shaft IO is twice the eccentricity of the two wheel centers. Conversely, when the rod 34 is moved backward, the eccentric rotating shaft 68 and the tip holder 72 are rotated in the opposite direction, and the tip 80 is brought closer to the axis of the main shaft 10. That is, in this embodiment, the screw shaft 114. 1 motor 6. Moving member 122. Natsu 126. Rod 34. Female thread member 58. The screw part 60 etc. connects the eccentric rotating shaft 6 to the main shaft 1.
This constitutes a rotating device that rotates relative to zero.

In FIG. 4, the slide 20 on which the housing 16 is mounted is movable on a guide rail 140. As shown in FIG. The guide rail 140 is arranged on a guide stand 144 provided on a base 142 in a direction parallel to the axis of the main shaft IO. A feed screw 152 that is rotationally driven by a motor 150 is screwed into a nut 14B attached to the lower side of the slide 20 by a bracket 146, and the slide 20 moves on the guide table 142 by rotation of the feed screw 152. By being moved, the housing 16
is sent in the axial direction of the main shaft 10. That is, slide 20. Guide rail 140. nut 14
8. Motor 150. The feed screw 152 and the like constitute a moving device that moves the chip 80 together with the main shaft 10 housing 16 and the like in the axial direction of the main shaft IO.

The motors 116 and 150 are connected to the control device 16 shown in FIG.
Controlled by 0. The control device 160 includes a CPU 16
2 Equipped with 164 RAM and 66 ROMI,
Encoders 168 and 170 are connected to a drive circuit 172 for driving the motor 116 and a drive circuit 174 for driving the motor 150. The control device t160 controls the motors 11 through drive circuits 172 and 174 so that the rotation amounts of the motors 116 and 150 detected by the encoders 168 and 170, respectively, are equal to the target rotation amounts.
6. Controls motor 150.

When cutting the end face WI of the workpiece W shown in FIG. 1 using the cutting apparatus configured as described above, data regarding the end face cutting to be performed on the workpiece must be input into the RAM 164 of the control device 160. Accordingly, the motor 116
, 150 are controlled to rotate by a predetermined amount, and the chip 80
is moved in the axial direction and radial direction of the main shaft 10 to perform cutting.

That is, the eccentric rotating shaft 68 is rotated 180 degrees, and the chip 182 is at the position shown by the two-dot chain line in FIG. 1, that is, the main shaft 10.
By gradually rotating the tip 80 from the radially outermost position along the circular locus shown by the dashed line in FIG. If the tip 80 returns to its original position, cutting is completed.

Next, another embodiment of the present invention is shown in FIGS. 6 and 7. Note that the same members as those in the above embodiment are given the same reference numerals and detailed explanations will be omitted.

In the cutting device of this embodiment, the tip holder 18
Two chips 182 and 184 are attached to 0. These chips 182 and 184 are mounted at positions offset from the axis P of the eccentric rotating shaft 68 similar to the previous embodiment, and are rotated together with the chip holder 180. In addition, in the original position shown by the solid line in FIG. 6, the distance from the axis O of the main rotating shaft 50 to the tips of the tips 182 and 184 is the same, and the tips of both tips 182 and 184 are cylindrical. It is designed not to interfere with the inner circumferential surface A1 of A.

When the eccentric rotation shaft 6 is rotated counterclockwise in FIG. 6, the tip of the tip 182 moves away from the axis of the main rotation shaft 50, and the tip of the tip 184 approaches. When the eccentric rotation shaft 68 is rotated 90 degrees counterclockwise, the tip of the tip 182 becomes the farthest from the axis of the main rotation shaft 50, as shown by the two-dot chain line in FIG. The tip of will be closest. The opposite is true when the eccentric rotating shaft 68 is rotated clockwise. As shown in FIG.
82 has a triangular shape, and the end surface A2 and the inner peripheral surface A of the workpiece A,
It is used for cutting. Chip 184 is also chip 18
2, it has a triangular shape, and cuts the end surface A3 and inner peripheral surface A of the workpiece A on the opposite side to the end surface A2.

When cutting a workpiece using the above cutting device,
First, rotate the eccentric rotating wheel 68 90 degrees counterclockwise,
The cutting edge of the tip 182 is placed at the farthest position from the axis of the main rotating shaft 50, and from this state the cutting edge of the tip 182 is returned to its original position, that is, while the cutting edge turning radius is reduced, the main rotating shaft 50 is moved.
is rotated to cut the end face A2. And chip 1
When the turning radius 82 becomes slightly smaller than the inner diameter of the product, the rotation of the eccentric rotating shaft 68 is stopped, the main rotating shaft 50 is advanced in the axial direction, and the tip 182 pushes and polls the inner circumferential surface A1 onto the workpiece. When cutting by the tip 182 is completed and the tip holder 180 penetrates the workpiece A, the eccentric rotating shaft 68 is rotated 90 degrees clockwise to position the tip of the tip 184 radially outward, and the cutting edge is rotated. The end face A is rotated while reducing the radius of the main rotating wheel 50.
Perform 3 cutting. When the turning radius becomes equal to the inner diameter of the product, the rotation of the eccentric rotating wheel 68 is stopped, and the inner circumferential surface A is stopped.

While finishing by pulling and polling, the main rotating shaft 5
When 0 is returned to its original position, the series of cutting ends.

One reciprocation of the main rotating shaft 50 causes both end surfaces Az of the workpiece A.

A3 cutting and rough machining and finishing machining of the inner circumferential surface A can be performed, and machining efficiency can be improved.

Further, as shown in FIG. 8, by attaching the tip 188 to the tip holder 186 in the states shown in (a) to C), end face cutting, push polling, and pull polling can be performed in order. Furthermore, as shown in (d), a relatively thin chip holder 1
If a chip 192 is attached to 90 with two apexes protruding, one chip 192 can touch the shoulder surface B8 of workpiece B.
The inner peripheral surface B2 and the shoulder surface B3 can be cut.

Furthermore, it is also possible to removably attach a main rotating shaft to the main shaft of a machine tool and install a rotating device within the main rotating shaft, or by changing the shape of the tip holder, the tip, or the structure of the rotation transmission mechanism. The present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of drawings]

FIG. 1 is a front sectional view showing the front part of the main part of a cutting device which is an embodiment of the present invention, and FIG. 2 is a side view thereof. FIG. 3 is a front sectional view showing the rear part of the main part of the device, and FIG. 4 is a front view (partially) showing the entire device. FIG. 5 is a block diagram showing the electrical control section of the above device. FIG. 6 is a front view showing another embodiment of the present invention together with a workpiece, and FIG. 7 is a side view thereof. FIGS. 8(a) to 8(d) are partial front views showing examples of chip attachment, which are still other embodiments of the present invention. 34: Rod 50: Main rotating shaft 56: Intermediate rotating shaft 58: Female thread member 60: Male thread portion 64
: External gear 68: Eccentric rotating shaft 80; Chip

Claims (1)

[Scope of Claims] A main rotating shaft that rotates around the axis, an eccentric rotating shaft held by the main rotating shaft so as to be rotatable about an axis eccentric from the axis of the main rotating shaft, and the eccentric rotating shaft. A cutting tool that is attached to a part protruding from the main rotating shaft with the cutting edge located at a position offset from the axis of the eccentric rotating shaft, and that rotates together with the eccentric rotating shaft, and that can rotate concentrically and relative to the main rotating shaft. a rotation transmission mechanism that transmits the rotation of the intermediate rotation shaft to the eccentric rotation shaft; and a rotation transmission mechanism that is held by the main rotation shaft and rotates the intermediate rotation shaft relative to the main rotation shaft. A cutting device capable of changing a cutting edge turning radius, comprising: a rotating device.