JP2005246500A - Cutting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting method for efficiently forming holes with different diameters in a short time when applying precision machining to cut objects. <P>SOLUTION: A cutting tool with a cutting edge for cutting is mounted to a rotatable spindle provided at a cutting device for cutting the cut object, and after fixing the cut object into a predetermined position of the cutting device, the rotating speed of the spindle of the cutting device is regulated. The cutting tool is thereby alienated by flexure from a mounting shaft, and the cutting tool is elastically and flexurally deformed based on centrifugal force following the rotation of the spindle. The cut object is cut in a state of changing the diameter of a rotation body described by the cutting edge of the cutting tool, and the outer diameter of the cut object or the inner diameter of a cylinder hole formed in the cut object is formed in a desired size. The diameter is changed by changing the rotating speed of the spindle. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The present invention relates to a cutting method when a workpiece is cut using a cutting apparatus.

  To perform precise drilling on metal workpieces, etc., after roughing, the inner surface of the hole is finished with a reamer or the like. In this case, since the diameter of the hole is determined by the size of the reamer used for finishing, the reamer is selected in order to obtain a desired hole diameter. In addition, in order to form a plurality of holes having different hole diameters, a blade tool dedicated to each hole diameter is used, or contouring is performed. Further, when there is a part with a different diameter in the middle of the depth direction of the hole, a recess cutter is used.

  A boring bar may be used for boring a metal workpiece. This boring bar has a bar body attached to a holder of a machine tool and the like, a tip part provided at the tip of the bar body, and a cutting edge provided at the tip part. The bar body is made of a cemented carbide with high rigidity and prevents deflection and chatter.

  However, every time a different hole is formed, the blade must be exchanged to use a blade dedicated to each hole diameter, which takes time, leading to an increase in cost. Further, when contouring is performed, a roundness is likely to occur due to mechanical problems. Further, when using a recess cutter, two processes are required because the first process and the second process are performed, which also leads to an increase in cost. Therefore, there has been a demand for a cutting method that can be performed in a short time when holes having different diameters are to be machined into a workpiece.

  Therefore, an object of the present invention is to provide a cutting method capable of forming holes having different diameters or cylinders having different outer diameters in a short time when precision machining is performed on a workpiece. is there.

Means for Solving the Problems and Effects of the Invention

In order to solve the above problems, the cutting method of the present invention is:
A cutting tool for cutting is attached to a rotatable main shaft provided in a cutting apparatus for cutting a workpiece,
After fixing the workpiece to a predetermined position on the cutting device,
By adjusting the number of revolutions of the main shaft of the cutting device, the cutting tool is separated from the mounting shaft by bending, and the cutting tool is elastically bent and deformed based on the centrifugal force accompanying the rotation of the main shaft. The workpiece is cut while the diameter of the rotating body to be drawn is changed, and the outer diameter of the workpiece or the inner diameter of the cylindrical hole formed in the workpiece is set to a desired size.

  A cutting tool having a blade portion for cutting is attached to the main shaft of the cutting apparatus, and the workpiece is fixed. By rotating the main shaft, the main body of the cutting tool is elastically bent and deformed by centrifugal force. That is, the length from the rotation center to the blade edge of the blade can be changed depending on the number of rotations. The length from the center of rotation to the cutting edge of the cutting tool is greatly changed by increasing the number of rotations of the main shaft, that is, by increasing the rotation speed in order to use the bending deformation caused by the centrifugal force. And since the change of the diameter of the rotary body which a blade edge | tip draws by the change of the rotation speed of a main axis | shaft, the cylinder of a desired diameter can be produced by adjusting rotation speed.

  And as a cutting tool, it is good to cut using a boring bar. The boring bar has a rod-shaped main body portion and a blade portion at the tip thereof. The main body part opposite to the tip having the blade part is attached to the main shaft by a holder, and the boring bar is rotated to perform cutting. By rotating the boring bar as the main shaft rotates, the main body of the boring bar is bent and deformed by centrifugal force. This deformation varies depending on the shape and material of the boring bar. In order to change the amount of bending deformation, a weight or the like may be attached to the main body.

  As an application example of the cutting method for producing a desired diameter by changing the rotation speed of the main shaft, the rotation speed is changed after the rotation speed of the main shaft is adjusted to form a hole with a desired diameter. Thus, there is a processing method for forming holes of different diameters in the workpiece. Conventionally, in order to produce a plurality of holes having different diameters in a single workpiece, they have been replaced with different cutting tools. However, according to the method of the present invention, the diameter can be changed only by changing the number of rotations, so that a plurality of holes having different diameters can be formed in a short time. For example, after a hole having a diameter a is formed in a workpiece at a certain rotation speed R, a hole having a diameter b is formed by setting the rotation speed to R ′. Subsequently, the rotation speed can be returned to R, and a hole having a diameter a can be formed. During this time, it is not necessary to replace the cutting tool, and the control unit of the cutting apparatus may change the number of rotations of the main shaft and perform cutting, and processing can be performed in a short time.

  As another example, after adjusting the number of rotations of the main shaft to form a hole with a desired diameter, the number of rotations of the main shaft can be changed to form portions with different diameters in the hole. That is, portions having different diameters can be produced in one hole. Such a part can also be produced in two or more places in the hole. For example, a hole having a diameter a is formed in the workpiece by a certain rotation speed R. Then, the rotational speed is set to R ′, and a portion having a larger diameter b is formed in the hole having the diameter a. Thereby, the part of the diameter a and the part of the diameter b can be formed in one hole. Since it is not necessary to replace the blade with a diameter, and only the number of rotations is changed, such a hole can be produced in a short time.

  Using a boring bar with a center of gravity closer to the cutting edge than the center axis of the boring bar body, and increasing the number of revolutions of the main shaft, the finished diameter of the inner diameter of the hole formed in the workpiece is increased, and the main shaft By reducing the rotational speed, the finished diameter of the inner diameter of the hole formed in the workpiece is reduced.

  If a boring bar having a center of gravity closer to the blade side than the center axis of the main body of the boring bar is used, the blade tip side is elastically deformed by centrifugal force in a direction away from the rotation axis by increasing the number of rotations of the main shaft. Therefore, if such a boring bar is used, the diameter of the hole to be manufactured can be increased by increasing the rotation speed. If the number of revolutions is lowered, the amount of elastic deformation is reduced and the diameter of the hole to be produced is reduced. However, the length from the center of rotation to the cutting edge in a stationary state cannot be smaller. If the relationship between the rotational speed and the diameter of the rotating body drawn by the blade edge is grasped in advance, a desired hole can be machined into the workpiece by adjusting the rotational speed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of a vertical type cutting apparatus used in the present invention. The cutting apparatus 1 includes a table 4 that fixes a workpiece 15 and a main body 2 that is connected to the table 4. The main body 2 includes an overarm 3 connected to a main shaft 7 that rotates the shaft. The main shaft 7 is attached to the overarm 3 and is rotated (rotated) around the central axis by a motor built in the main body 2. A holder 8 for fixing the boring bar 71 is attached to the main shaft 7.

  The main body 2 has a controller 5 that controls the rotation of the main shaft 7. By operating the operation panel of the control unit 5, the rotation of the motor can be changed, whereby the rotation of the main shaft 7 can be changed. That is, the rotation of the boring bar 71 mounted integrally with the main shaft 7 by the holder 8 can be changed. The main shaft 7 can be moved in the vertical direction by the operation of the control unit 5. By this movement, the cutting portion 15 can be brought into contact with the blade 15 of the boring bar 71 for cutting. The workpiece 15 is fixed on the table 4, but the table 4 can be moved in the lateral direction, whereby the workpiece can be moved in the lateral direction. Thereby, a hole can be formed in a desired position of the workpiece.

  The boring bar attached to the main shaft and having a cutting blade for cutting will be described with reference to FIG. The boring bar 71 has a main body portion 72 having a front end portion 75, and a blade 73 is attached to the front end portion 75 with a screw 74. The length r (see FIG. 2B) from the central axis 76 of the main body 72 of the boring bar 71 to the tip 77 of the attached blade 73 is shorter than the desired diameter of the hole. Here, the center axis 76 is an axis that becomes a center of rotation when the boring bar 71 is attached to the main shaft 7 of the main body 72, and is an axis that equally divides the horizontal width of the main body into 1/2. (C) is an axis where w1 and w2 are the same. Further, the thickness of the main body is also divided into halves, and w3 and w4 in FIG. 2 (c) are the same.

  The end opposite to the tip 75 of the boring bar 71 is fixed to the main shaft 7 using the holder 8. The length from the center axis 76 of the boring bar 71 to the cutting edge 77 of the blade 73 is thinner than the desired diameter. Subsequently, the workpiece 15 is fixed to the table 4. The workpiece 15 is moved to the horizontal direction by the control unit 5, and the position where the hole is formed is directly below the boring bar 71. Since the main shaft 7 is rotated and moved in the vertical direction by the control unit 5 in the main body unit 2, the control unit 5 is operated to rotate and lower the main shaft to form a hole in the workpiece.

  The rotation of the boring bar 71 and the diameter of the hole to be formed will be described with reference to FIG. The figure shows the boring bar 71 attached to the main shaft by the holder 8. The length from the central axis 76 of the boring bar 71 to the cutting edge is set as r, and the length twice as long is set as a. The center axis 76 is an axis that serves as the rotation center described in FIG. Then, by rotating the boring bar 71, the boring bar 71 bends due to centrifugal force according to the rotational speed. Let the diameter at this time be b. The diameter b changes depending on the number of rotations of the boring bar 71. By increasing the rotation speed, that is, by increasing the rotation speed, the diameter of the rotating body drawn by the blade edge 77 is increased by the centrifugal force in the boring bar having the center of gravity on the blade edge 77 side with respect to the center axis 76. Therefore, by increasing the number of rotations of the boring bar 71, the diameter of the hole formed in the workpiece 15 can be increased. Therefore, the rotational speed is adjusted so that the diameter b becomes a desired diameter to be formed.

  Next, FIG. 4 shows a horizontal embodiment of the cutting apparatus. The cutting device 31 includes a table 4 for fixing the workpiece 15 and a main body 32 connected to the table 4. The main body 32 includes a main shaft 7 that rotates the shaft, and rotates the shaft by a motor built in the main body 32. The main shaft 7 can move in the vertical direction along the main body portion 32. Thereby, a hole can be formed at a predetermined position of the workpiece 15. A holder 8 for fixing the boring bar 71 is attached to the main shaft 7.

  The workpiece 15 can be fixed on the table 4 by a fixing device. And it can move to the left-right direction of a figure, or a paper surface perpendicular | vertical direction. Thereby, the workpiece 15 can be moved and a hole can be formed in a desired position. Then, similarly to the above-described embodiment, the control unit 5 is operated to move the main shaft 7 in the vertical direction. The rotation speed of the boring bar 71 is adjusted and rotated so that a hole with a predetermined diameter is formed at a desired position of the work piece 15, and the work piece 15 is moved from the left to the right in the figure, thereby boring. A hole is formed by the bar 71. The diameter of the hole formed by changing the rotation speed of the boring bar 71 is the same as in the above-described embodiment.

  FIG. 5 shows an example of holes formed. (A) is sectional drawing of the to-be-cut object 80. FIG. (B) is the top view 80 of a to-be-cut object. The workpiece 80 is formed with a two-step hole 81 having portions with different diameters. That is, the hole 81 has a diameter b2 and a larger diameter b1.

  A method for forming the hole 81 will be described. First, the boring bar 71 is rotated at a rotational speed at which the length of the diameter is b2, and a hole up to a predetermined depth h2 is completed. Then, by further increasing the number of revolutions, the diameter is b1, and processing is performed at a depth of h1. Thus, since the diameter of the hole can be changed by changing the number of revolutions, it is not necessary to replace the boring bar 71, and the time required for processing can be considerably shortened compared to the conventional case. In addition, although the figure showed the case where the diameter of an upper stage is large and the diameter of a lower stage is small, it is not restricted to this. It can be formed in the same manner when the upper diameter is small and the lower diameter is large. Or it is not restricted to a case where the change of the diameter is two steps, and a change of three steps or four steps can be performed.

  FIG. 6 shows a cross-sectional view of an embodiment of a hole 90 having a portion 93 having a different diameter in the middle of the depth direction of the hole. As shown in the figure, the workpiece 90 has a hole 93 having a diameter b1 in the middle of the diameter b2.

  A method for forming such a hole 92 will be described. First, a hole up to a depth h5 is cut at a rotational speed at which the diameter is b2. Subsequently, the number of rotations is increased so that the diameter becomes b1, and cutting is performed from the depth h3 to the depth h4 according to the rotation speed, and a portion 93 having a large diameter is formed in the middle of the hole, thereby forming the shape of the hole 92. Complete. Even when such a cutting process is performed, it is not necessary to replace the cutting tool such as the boring bar 71 in accordance with a desired diameter. Therefore, it is possible to cut many holes having different diameters in a short time.

  FIG. 7 shows an embodiment in which two holes having different diameters are formed. (A) is sectional drawing of the to-be-cut object 100, (b) is the top view. Two holes having different diameters are formed in the workpiece 100. The diameter of the hole 101 is b3, and the diameter of the hole 102 is b4. The case where the diameter b4 is smaller than the diameter b3 is shown.

  A method of forming a plurality of holes having different diameters will be described. First, the rotation speed of the main shaft is adjusted so that the diameter becomes b3, and the hole 101 is cut. Subsequently, the workpiece 100 or the spindle 7 is moved to change the cutting position by the boring bar 71, and the cutting is performed at a reduced rotational speed so that the diameter becomes b4, thereby completing the hole. In the case of forming a plurality of holes having different hole diameters as described above, the holes can be formed only by changing the number of rotations. Similarly, when three or more holes are formed, the holes can be formed in a short time because it is only necessary to change the rotational speed. According to this method, even when the number of holes having different diameters is increased, the formation time is not significantly increased.

  FIG. 8 shows another embodiment of the vertical type of the cutting apparatus of the present invention. The cutting device 41 includes a table 4 for fixing the workpiece 15 and a main body 2 connected to the table 4. Further, the overarm 3 at the upper part of the main body 2 has a main shaft 7. A holder 42 for fixing a boring bar 71 for cutting is attached to the main shaft 7.

  FIG. 9 shows a perspective view of the holder 42. The holder 42 includes a cylindrical portion 43 connected to the main shaft 7, and a grip portion 44 for gripping the boring bar 71, which has a larger rotating diameter than the cylindrical portion 43. The grip portion 44 is formed with a chuck portion for fixing the boring bar 71 to the outer edge portion. The boring bar 71 is fixed to the chuck portion so that the cutting blade 73 of the boring bar 71 faces the rotation axis. Thereby, the outer edge shape of a to-be-cut object can be formed.

  As in the previous embodiment, the rotation of the main shaft 7 can be changed by operating the operation panel of the control unit 5. That is, the rotation of the boring bar 71 can be changed. The main shaft 7 can be moved in the vertical direction by the operation of the control unit 5. Further, the workpiece 15 is fixed on the table 4, but the table 4 can be moved in the lateral direction, whereby the workpiece 15 can be moved in the lateral direction.

  FIG. 10 shows an example of the workpiece to be cut and formed by fixing the boring bar 71 with the holder 42 shown in FIG. (A) is the perspective view of the to-be-cut object 110, (b) is the sectional drawing. As shown in the figure, the workpiece 110 has a narrow-diameter portion 112 that is narrowed in the middle of the side surface of the cylindrical portion 111.

  A method for forming such a workpiece 110 will be described. First, the rotational speed of the boring bar 71 is adjusted so as to have a diameter of b5, and the side surface of the cylindrical portion 111 of the workpiece 110 is cut. Subsequently, the rotation speed is lowered so as to have the diameter of b6, and the narrow diameter portion 112 is formed. Thus, by changing the rotation speed, not only the diameter of the inner circle but also the diameter of the outer circle can be changed.

  As described above, by changing the number of rotations of the spindle and changing the bending due to the centrifugal force of the main body of the cutting tool for cutting, a plurality of holes having different diameters can be formed, or one hole can be formed. It is possible to easily form portions having different diameters or to form portions having different diameters on the side surface of the cylinder. Since it is not necessary to replace the cutting tool as in the prior art, different diameters can be quickly produced.

An example of a vertical cutting device. Example of a boring bar. The figure explaining the diameter of the hole formed by rotation speed. An example of a horizontal cutting device. Examples of workpieces. Example 2 of a workpiece. Example 3 of an object to be cut. Example 2 of a vertical cutting apparatus. The figure explaining a holder. Example 4 of a workpiece.

Explanation of symbols

1 Cutting Device 7 Spindle 15 Workpiece 71 Cutting Tool (Boring Bar)
73 Cutting blade 80, 90, 100, 110 Workpiece

Claims (5)

A cutting tool for cutting is attached to a rotatable main shaft provided in a cutting apparatus for cutting a workpiece,
After fixing the workpiece to a predetermined position of the cutting device,
By adjusting the number of rotations of the main shaft of the cutting device, the blade is separated from the mounting shaft by bending, and the blade is elastically bent and deformed based on the centrifugal force accompanying the rotation of the main shaft, Cutting the workpiece while changing the diameter of the rotating body drawn by the blade tip of the cutting tool, and setting the outer diameter of the workpiece or the inner diameter of the cylindrical hole formed in the workpiece to a desired size The cutting method characterized by making it into.   The cutting method according to claim 1, wherein a boring bar is used as the cutting tool.   The hole having a diameter different from the hole is formed in the workpiece by changing the rotation speed after adjusting the rotation speed of the main shaft to form the hole having a desired diameter. 2. The cutting method according to 2.   3. The cutting process according to claim 1, wherein after adjusting the number of rotations of the main shaft to form the hole having a desired diameter, the number of rotations of the main shaft is changed to form a portion having a different diameter in the hole. Method.   Using the boring bar having a center of gravity closer to the cutting edge than the center axis of the main body of the boring bar, and increasing the rotational speed of the main shaft, the finished diameter of the inner diameter of the hole formed in the workpiece 5. The cutting method according to claim 2, wherein the finish diameter of the inner diameter of the hole formed in the workpiece is reduced by increasing the rotation speed of the spindle and lowering the rotational speed of the spindle.

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