JP4094856B2 - Machining method of arc groove - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a groove machining method in which a machine tool is used to relatively move a tool and a workpiece, and a groove whose bottom surface forms an arcuate concave curved surface is machined into the workpiece.
[0002]
[Prior art]
Conventionally, a typical groove 50 (hereinafter referred to as an arc groove) 51 is formed on the inner surface of a concave portion of a workpiece 50 having a semicylindrical concave portion as shown in FIGS. 9 and 10. Examples of the processing method include electric discharge machining using a discharge electrode.
[0003]
In this processing method, a discharge electrode having a discharge portion having a shape matching the circular arc groove 51 as a processing shape is used, and this electrode and the workpiece 50 are immersed in an insulating processing liquid, and the electrode and the workpiece 50 are separated. By applying a voltage between the two and discharging them with a small gap between them, the discharge part of the work 50 is melted, and the arc groove 51 having the same shape as the discharge part of the electrode is formed in the work 50. It is to do.
[0004]
[Problems to be solved by the invention]
However, the electric discharge machining method using the discharge electrode is to cause a discharge between the discharge electrode and the workpiece 50 to melt the discharge portion of the workpiece 50 to form the arc groove 51. Since the processing speed is slow, there is a problem that productivity is poor and processing cost is high. In addition, since a dedicated electrode corresponding to the processing shape is required, the processing cost also increases in this respect.
[0005]
The present invention has been made in view of the above circumstances, and provides a groove machining method capable of efficiently performing this at a low cost when machining a groove whose bottom surface forms an arcuate concave curved surface on a workpiece. For that purpose.
[0006]
[Means for solving the problems and effects thereof]
To achieve the above object, the invention described in claim 1 of the present invention is
Comprising a main shaft for holding the tool, the spindle and workpiece relatively movable in the orthogonal biaxial directions, before Symbol spindle or the workpiece to be swung into the orthogonal biaxial directions perpendicular to the swing center axis, said spindle Is a method of machining a groove having a concave curved surface with a bottom surface formed in an arc shape on the inner surface of the concave portion of the workpiece having a semi-cylindrical concave portion using a machine tool configured to be indexable by rotating the axis about the axis. And
The tool is provided with one cutting edge having a rake face and a flank face, and a grooving tool held on the spindle in a state inclined with respect to the axis of the spindle ,
The workpiece is arranged so that the central axis of the groove forming the arc-shaped concave curved surface to be formed and the oscillation central axis are parallel to each other,
Subsequently, the cutting edge of the byte, and positioned so as to have a predetermined depth of cut with respect to the workpiece,
A swing operation for oscillating the bytes or workpiece to the swing center axis, the combined operation of the linear movement operations for linearly moving the byte and work on the orthogonal two axial directions, the cutting edge of the byte, the One end along the arc groove to be further finished so as to be in contact with the arc-shaped machining trajectory virtually set according to the cut amount and to move along the machining trajectory. The tool is moved relative to the workpiece in a non-rotating manner so that the tool moves to the center position of the arc .
Next, after indexing by rotating the spindle about the axis so that the bite is inverted 180 degrees,
In the same manner as when the cutting edge of the cutting tool is moved from one end of the arc groove to the center position, the cutting edge of the cutting tool is moved from the other end along the arc groove to the center position of the arc. Move the tool relative to the workpiece without rotating,
According to another aspect of the present invention, there is provided a method of machining an arc groove, wherein a groove having a bottom surface forming an arc-shaped concave curved surface is formed on the workpiece.
[0007]
According to the present invention, a workpiece having a semicylindrical concave portion is arranged such that the central axis of the groove forming the arc-shaped concave curved surface to be formed and the oscillation central axis are parallel to each other, and the cutting edge is located with respect to the workpiece. Are positioned so as to have a predetermined cut amount, and then the cutting edge comes into contact with an arc-shaped processing locus virtually set according to the cutting amount with a predetermined rake angle and to the processing locus. The bite is moved relative to the workpiece in a non-rotating manner so as to move from one end along the arc groove to be finished to the center position of the arc . This relative movement is performed by a combined operation of a swinging motion that swings the tool or the workpiece about the center axis of swinging and a linear movement operation that linearly moves the tool and the workpiece in two orthogonal axes. As a result, the workpiece is scraped off along the arc-shaped machining locus drawn by the cutting edge with respect to the workpiece, and an arc-shaped groove is formed in the workpiece from one end of the arc along the machining locus to the center position.
[0008]
After that, after the spindle is rotated and indexed so that the bite is inverted 180 degrees, the cutting edge is turned into the arc groove in the same manner as when the cutting edge is moved from one end of the arc groove to the center position. The cutting tool is moved relative to the workpiece in a non-rotating manner so as to move from the other end along the arc to the center position of the arc. As a result, the workpiece is scraped off along the arc-shaped machining locus drawn by the cutting edge with respect to the workpiece, and an arc-shaped groove is formed in the workpiece from the other end of the arc along the machining locus to the center position. Thus, over the entire arc length from one end of the arc along the processing path to the other end the work is cut away, arcuate shape corresponding to the machining path is made form the workpiece.
[0009]
If a circular groove having a finished dimension cannot be formed by a single process, an arc groove having a finished dimension can be formed in the workpiece by repeating the above operation with a predetermined cut amount.
[0010]
Thus, in the present invention, the workpiece is scraped off by rotating the bite and the workpiece relative to each other in a non-rotating manner so that the cutting edge of the bite draws an arc-shaped machining locus with respect to the workpiece, thereby forming an arc-shaped groove. Therefore, a highly accurate processed surface can be obtained. In addition, since the machining speed is higher than that of electric discharge machining and machining can be performed efficiently, productivity can be improved and machining cost can be suppressed. In addition, a dedicated electrode corresponding to the processing shape is not necessary, and the processing cost can also be suppressed in this respect.
[0011]
In addition, a tool for cutting a groove that is held on the spindle while being tilted with respect to the axis of the spindle is used for the tool, and the cutting edge of the tool is moved from one end along the arc groove to be finished to the center position of the arc. Thereafter, the cutting tool is inverted 180 degrees, and thereafter, the cutting edge of the cutting tool is moved from the other end along the arc groove to the center position of the circular arc, so that the moving range of the cutting tool edge in one machining operation is narrowed. Even when the arc length of the arc groove is long, it is possible to prevent inconvenience such as interference between the cutting tool and the workpiece during the relative movement.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a method for processing an arc groove according to a specific embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, a 5-axis control vertical machining center 1 as shown in FIG. 1 is used as a machine tool, and the inner surface of the workpiece 50 having a semicylindrical recess as shown in FIGS. 9 and 10 is used. The arc groove 51 is formed. The arc groove 51 is described as being processed on the workpiece 50 without roughing. However, the present invention is not limited to this, and the arc groove processing method of this example may be applied to finishing after roughing. good.
[0013]
As shown in FIG. 1, the 5-axis control vertical machining center 1 includes a bed 2, a column 3 disposed on the bed 2, a column 3 disposed on the column 3, and moves in the direction of the arrow X-axis. The saddle 4 made possible, the spindle head 5 supported by the saddle 4 and movable in the direction of the arrow Z-axis, and the tool 10 are held and supported by the spindle head 5 to show the arrow C-axis. The main shaft 6 can be rotated and indexed in the direction, and the table 7 is disposed on the bed 2 and can be moved in the arrow Y-axis direction and swingable in the arrow A-axis direction.
[0014]
The 5-axis control vertical machining center 1 includes an X-axis feed mechanism (not shown) that moves the saddle 4 in the direction indicated by the arrow X, and a Z that moves the spindle head 5 in the direction indicated by the arrow Z. An axial feed mechanism (not shown), a Y-axis feed mechanism (not shown) that moves the table 7 in the direction of the arrow Y, and a C-axis rotation that rotates the spindle 6 in the direction of the arrow C Indexing mechanism (not shown), A-axis rotary feed mechanism (not shown) for swinging the table 7 in the direction of the A-axis, X-axis feed mechanism (not shown), Z Controls the operation of a shaft feed mechanism (not shown), a Y-axis feed mechanism (not shown), a C-axis rotation indexing mechanism (not shown), and an A-axis rotation feed mechanism (not shown). A numerical control device (not shown). The table 7 is configured such that the workpiece 50 is placed and fixed thereon.
[0015]
As the tool 10, for example, a tool as shown in FIG. 2 is used. The tool 10 includes a grooving tool 20 and a holder 11 for holding and fixing the tool 20 so as to be inclined at about 45 degrees with respect to the axis of the main shaft 6.
[0016]
As shown in FIGS. 3 and 4, the cutting tool 20 includes a shank portion 21 and a blade portion 22, and the blade portion 22 intersects the rake face 23 with an angle (cutlery angle) β with the rake face 23. It comprises a main flank 24 and sub-flank 25 formed on both sides of the rake face 23.
[0017]
The cutting tool 20 is held and fixed to the holder 11 by, for example, being inserted into a mounting hole 11 a formed in the holder 11 and then the shank portion 21 being tightened with a fixing bolt 12.
[0018]
Then, using the 5-axis control vertical machining center 1 and the tool 10 configured as described above, a groove 51 whose bottom surface forms an arc-shaped concave curved surface is processed in the workpiece 50. First, after the work 50 is placed and fixed on the table 7 so that the central axis of the arc groove 51 and the axis of the X axis are parallel, the protruding direction of the cutting tool 20 and the arc groove 51 The main shaft 6 is rotated about its axis by the C-axis rotation indexing mechanism (not shown) so as to be orthogonal to the central axis, and this is indexed, as shown in FIG. 5 (a). The table 7 is swung by the A-axis rotary feed mechanism (not shown), and the work 50 is inclined in the protruding direction of the cutting tool 20.
[0019]
Next, after the blade portion 22 of the tool 10 is positioned so as to have a predetermined cut amount d with respect to the workpiece 50, the blade portion 22 is virtually set according to the cut amount d. In order to move the tool 10 and the workpiece 50 relatively so as to contact the arc-shaped machining locus L, the spindle head 5 and the table 7 are moved to the Z-axis feed mechanism (not shown) and the Y-axis feed mechanism. The table 7 is moved by a part (not shown), and the table 7 is swung by the A-axis rotation feed mechanism part (not shown).
[0020]
Thus, the relative positional relationship between the tool 10 and the workpiece 50 is such that the workpiece 50 is inclined to the right approximately 45 degrees from the horizontal (FIG. 5A), and the workpiece 50 is horizontal (FIG. 5). 5 (b)), the workpiece 50 is changed to a state where the workpiece 50 is inclined to the left by approximately 45 degrees from the horizontal (FIG. 5C), and the blade 22 is moved from one end of the arc along the machining locus L. A first operation of moving to the center position is performed.
[0021]
At this time, the blade portion 22 moves as shown in FIGS. That is, a line D passing through the intersection P between the rake face 23 and the main flank 24 and parallel to the relative movement direction of the blade part 22 with respect to the workpiece 50, and a line orthogonal to the line E as the line E, A rake angle α between the rake face 23 and the line E, a main flank angle γ between the main flank face 24 and the line D, and a sub flank angle F between the sub flank face 25 and the side surface of the groove 51. , G are formed, and the intersecting portion P moves so as to be in contact with the machining locus L. As a result, the workpiece 50 is cut from one end of the arc along the machining locus L to the center position.
[0022]
Then, after completing the first operation, as shown in FIG. 8A, the C-axis rotation indexing mechanism (not shown) with the main shaft 6 as the center of the axis is provided to reverse the tool 10 by 180 degrees. )) To determine this.
[0023]
Next, as in the first operation, the relative positional relationship between the tool 10 and the workpiece 50 is such that the workpiece 50 is sequentially inclined to the left by about 45 degrees from the horizontal (FIG. 8A), The workpiece 50 is changed to a horizontal state (FIG. 8B), and the workpiece 50 is changed to a state inclined to the right by about 45 degrees from the horizontal (FIG. 8C). The tool 10 and the workpiece 50 are relatively moved so as to perform the second operation of moving from the other end of the arc along the locus L to the center position. As a result, the workpiece 50 is cut from the other end of the arc along the machining locus L to the center position.
[0024]
Thus, the workpiece 50 is scraped over the entire arc length from one end of the arc along the machining locus L to the other end, and an arc shape corresponding to the machining locus L is formed in the workpiece 50.
[0025]
Thereafter, by repeating the first operation and the second operation with a predetermined cut amount d, an arc groove 51 having a predetermined finished dimension is formed in the workpiece 50. The cutting depth d is appropriately set according to the material of the workpiece 50, required machining accuracy, and the like.
[0026]
Therefore, according to this arc groove processing method, the non-rotating tool 10 and the workpiece 50 are relatively moved so that the blade portion 22 of the tool 10 draws an arc-shaped processing locus L with respect to the workpiece 50. By doing so, the workpiece 50 is scraped off and the arc-shaped groove 51 is formed, so that a highly accurate machining surface can be obtained.
[0027]
In addition, since the machining speed is higher than that of electric discharge machining and machining can be performed efficiently, productivity can be improved and machining cost can be suppressed. In addition, a dedicated electrode corresponding to the processing shape is not necessary, and the processing cost can also be suppressed in this respect.
[0028]
Further, in this example in which the arc length of the arc groove 51 is long, the tool 10 and the workpiece 50 are moved when the blade portion 22 is continuously moved from one end of the arc along the machining locus L to the other end. However, the interference can be prevented by dividing the operation into two operations of the first operation and the second operation.
[0029]
As mentioned above, although one Embodiment of this invention was described, the specific aspect which this invention can take is not limited to this at all .
[0030]
In the above-described example, the arc groove machining method using the 5-axis control vertical machining center 1 has been described as an example. However, the method is not limited to this, and for example, a 5-axis control horizontal machining center or B, C This can also be applied to machining using a complex machining lathe having a pivoting function .
[Brief description of the drawings]
FIG. 1 is a perspective view showing a machine tool for carrying out arc grooving according to an embodiment of the present invention.
FIG. 2 is a front view showing a tool used in arc grooving according to the present embodiment.
FIG. 3 is a front view showing a groove machining bit according to the present embodiment.
4 is a side view of the groove machining bit shown in FIG. 3. FIG.
FIG. 5 is an explanatory diagram for explaining relative movement between a tool and a workpiece according to the present embodiment.
6 is an enlarged detailed view of a B portion in FIG. 5. FIG.
7 is a front view in the direction of arrow C in FIG. 6. FIG.
FIG. 8 is an explanatory diagram for explaining relative movement between a tool and a workpiece according to the present embodiment.
FIG. 9 is an explanatory diagram for explaining an example of a workpiece.
10 is a cross-sectional view in the direction of arrows AA in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 5-axis control vertical machining center 2 Bed 3 Column 4 Saddle 5 Spindle head 6 Spindle 7 Table 10 Tool 11 Holder 20 Grooving tool 22 Blade part 23 Rake face 24 Main relief face 50 Work 51 Groove shape

Claims (1)

Comprising a main shaft for holding the tool, the spindle and workpiece relatively movable in the orthogonal biaxial directions, before Symbol spindle or the workpiece to be swung into the orthogonal biaxial directions perpendicular to the swing center axis, said spindle Is a method of machining a groove having a concave curved surface with a bottom surface formed in an arc shape on the inner surface of the concave portion of the workpiece having a semi-cylindrical concave portion using a machine tool configured to be indexable by rotating the axis about the axis. And
The tool is provided with one cutting edge having a rake face and a flank face, and a grooving tool held on the spindle in a state inclined with respect to the axis of the spindle ,
The workpiece is arranged so that the central axis of the groove forming the arc-shaped concave curved surface to be formed and the oscillation central axis are parallel to each other,
Subsequently, the cutting edge of the byte, and positioned so as to have a predetermined depth of cut with respect to the workpiece,
A swing operation for oscillating the bytes or workpiece to the swing center axis, the combined operation of the linear movement operations for linearly moving the byte and work on the orthogonal two axial directions, the cutting edge of the byte, the One end along the arc groove to be further finished so as to be in contact with the arc-shaped machining trajectory virtually set according to the cut amount and to move along the machining trajectory. The tool is moved relative to the workpiece in a non-rotating manner so that the tool moves to the center position of the arc .
Next, after indexing by rotating the spindle about the axis so that the bite is inverted 180 degrees,
In the same manner as when the cutting edge of the cutting tool is moved from one end of the arc groove to the center position, the cutting edge of the cutting tool is moved from the other end along the arc groove to the center position of the arc. Move the tool relative to the workpiece without rotating,
An arc groove machining method, wherein a groove having a bottom surface forming an arcuate concave curved surface is formed on the workpiece.

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