JPH10244439A - Cutting method for workpiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a cutting remaining part to a small quantity, and prevent the imposition of an overload on a finishing work tool by dividing an unnecessary part in a work material into upper and lower plural layers in a rough cutting process, and respectively dislocating a starting point of the work tool in its respective layers little by little. SOLUTION: An upper surface of a work material is partitioned into front and rear parts in the same pitch width as a diameter of a work tool, and an unnecessary part is cut and removed a thickness quantity by a thickness quantity of 1/5 of the whole cutting depth by alternately moving the work tool left and right along its passage from a starting point. In this case, the work tool is also lowered by a 1/5 quantity of the whole cutting depth when cutting of respective layer is completed, and its starting point is dislocated forward by a length quantity of 1/5 of a diameter of the work tool. Lastly, a workpiece 24 is obtained by cutting and removing a step-shaped cutting remaining part remaining in the forefront. Next, a small quantity of remaining unnecessary parts 25 are cut and removed by a finishing work tool.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of cutting a workpiece having a predetermined shape by using a cutting device such as a three-axis machine.

[0002]

2. Description of the Related Art Conventionally, when a workpiece having a predetermined shape is formed by cutting, a cutting device that drives a processing tool such as an end mill under computer control to perform a cutting process is used to cut a processing material. Thus, a workpiece is formed.

In such a case, for example, if the workpiece to be obtained is a thick-walled disk-shaped workpiece 2 projecting to the center of the pedestal 1 as shown by a broken line a in FIGS. First, the cutting (unnecessary) part 3 of the processing material is
A plurality of layers are set by dividing the thickness into a thickness that can be cut by the roughing processing tool 4 without any trouble. In FIG. 12, it is divided into five layers.

[0004] Next, cutting and removing the outer portion of the broken line a by reciprocating the processing tool 4 right and left at a predetermined pitch width while shifting the processing tool forward (upward in FIG. 1) is performed from the uppermost layer of the above five layers. By successively repeating the operation toward the lowermost layer, a workpiece 5 in a rough-cut state shown by a solid line b in FIGS. 11 and 12 is obtained.

The above-mentioned pitch width is usually set so that an overlapping portion is formed in the path of the processing tool 4 in order to prevent the uncut portion, but in this case, the pitch width is half the diameter of the processing tool 4. When the center of the processing tool 4 is first moved rightward along the alternate long and short dash line as shown by an arrow A in FIG.
The cutting process is performed in such a manner that the center of the is moved leftward along the thin line.

After finishing the rough cutting with the processing tool 4, the finishing processing tool having a smaller diameter than the processing tool 4 (for example, if the diameter of the rough cutting tool 4 is 3 mm, the diameter of the finishing processing tool is Is used, the unnecessary portion 6 remaining on the peripheral edge of the workpiece 5 in the rough-cut state is used.
By cutting and removing, a workpiece 2 having substantially the same shape as the shape shown by the broken line a can be obtained.

[0007]

However, in the above-described cutting method, when the diameter of the processing tool 4 is larger than the size of the workpiece 2, the unnecessary portion 6 remaining after cutting increases. It must be cut and removed with a small-diameter finishing tool. As a result, there is a problem in that the finishing tool is overloaded, the finishing tool is damaged, and the finishing process takes a long time, thereby lowering the working efficiency.

Further, in order to reduce the unnecessary portion 6 of the uncut portion in the rough cutting step, the pitch width can be set small to increase the overlapping portion in the path of the processing tool 4, but according to this, As the number of reciprocating movements of the processing tool 4 increases, the rough cutting process takes a long time, resulting in a problem that the working efficiency is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to increase the working efficiency of a rough cutting process without lowering the working efficiency, while reducing the remaining amount of unnecessary parts. An object of the present invention is to provide a method for cutting a workpiece, which can prevent an overload from being applied to a finishing tool and can efficiently perform a finishing step.

[0010]

In order to achieve the above object, in the method for cutting a workpiece according to the present invention, first, a layer having a thickness capable of easily cutting unnecessary portions of a processing material with a roughing tool. Into multiple layers.

In such cutting, when the processing tool cuts from the side wall of the processing material toward the center side, the load is not so large, but the processing tool is moved from the upper side to the lower side to perform the processing. When a hole is formed in the upper surface of the material, a relatively large load is applied. Therefore, in this case, the thickness of each layer is set to a value at which the processing tool can easily make a vertical hole.

Then, the starting point of the processing tool in the cutting of each layer is slightly shifted.
As a result, the same result as when the feed pitch width of the processing tool is set small can be obtained without increasing the reciprocating movement of the processing tool in one-layer cutting.

For example, when the unnecessary portion is cut into five layers and the cutting start position in each layer is shifted by a length obtained by dividing the feed pitch width of the working tool by five, unnecessary cutting is performed. The remaining amount of the part becomes five steps from the maximum part (this is the same amount as the conventional example) to the minimum part,
The remaining amount is greatly reduced as compared with the remaining amount in the conventional example.

Moreover, in this case, even if the feed pitch width of the processing tool is set to the maximum (diameter of the processing tool), unnecessary portions can be cut and removed without any problem. In other words, since the starting point is shifted, the uncut portion of the plurality of layers does not occur in the same portion, and even if the uncut portion is generated in the scale, since the thickness is only one layer, it is easily removed in the finishing process. be able to.

As a result, even if the feed pitch width of the processing tool is maximized to reduce the number of reciprocating movements of the processing tool and shorten the time of the rough cutting process, the remaining amount of unnecessary portions is reduced.
The finishing process is simple and there is no overload on the finishing tool. Next, a method for cutting a workpiece according to the present invention will be described in detail with reference to the drawings.

[0016]

FIG. 1 shows an example of a cutting apparatus for cutting a workpiece according to the present invention.
That is, in FIG. 1, an input device 11 receives data such as shape data of a machined surface of a workpiece and information necessary for cutting such as a tool speed, and stores the data in a memory via a connected CPU 12. 13 to be stored.

The CPU 12 operates according to the program stored in the memory 13 while performing arithmetic processing based on various data and information, so as to drive the bar-shaped working tool 15 of the connected cutting section 14. Has become.

The creation of a workpiece according to the present invention using such a cutting device is performed as follows. Here, a work 16 having the same shape as the work 2 of the conventional example as shown in FIGS.
A method obtained by cutting and removing five layers will be described.

First, as shown in FIG.
Is divided into front and rear portions at the same pitch width as the diameter of the processing tool 15 (portion indicated by a thin line), and the processing tool 15 is alternately moved from the starting point C indicated by the arrow along the path to the cutting depth. Unnecessary portions are cut and removed by a thickness of about 1/5 of the entire thickness.

In this case, as shown in the drawing, for a path that does not intersect with the portion corresponding to the workpiece 16, an unnecessary portion corresponding to the entire path is cut and removed, and for a path that intersects the portion corresponding to the workpiece 16, The processing tool 15 rises at a position where the outer peripheral portion of the processing tool 15 and the outer peripheral portion of the portion corresponding to the workpiece 16 are in contact with each other, temporarily stops cutting, and descends at a position passing the portion corresponding to the workpiece 16. The remaining unnecessary parts in the path are cut off. Therefore, the work 1
The left and right ends of the portion in contact with the portion corresponding to the outer periphery of 6 are all semicircular, corresponding to the outer periphery of the processing tool 15.

Then, when the cutting and removal of the unnecessary portion of the uppermost layer is completed, the processing tool 15 is further moved to about 1% of the entire cutting depth.
/ 5 min, and the starting point C is moved to the processing tool 15
5 is shifted forward by the length of 1/5 of the diameter of the above, and the same operation as described above is performed to obtain a state as shown in FIG.

In FIG. 5, a portion surrounded by a dashed line c and a solid line inside the dashed line c indicates an unnecessary portion of the uppermost layer left uncut at the time of the first cutting and a second layer. The portion 18 surrounded by two solid lines and the lower elongated portion 18 ′ in the portion where the unnecessary portions of the two layers have been cut and removed are the portions where the uppermost layer has been cut and removed but the second layer has not been cut and remained. It is.

Therefore, in this state, the elongated portion 1
It has a stepped shape consisting of an outer portion 19 excluding 8 ', a centrally uncut portion 20, and portions 18 and 18' therebetween.

Next, the working tool 15 is further lowered by approximately 1/5 of the entire cutting depth, and its starting point C is further shifted from the starting point C of the second layer by 1/5 in front of the diameter of the working tool 15. ,
By performing the same operation, the unnecessary portion of the third layer as shown in FIG. 6 is cut and removed.

In this case, a portion indicated by a broken line d is a portion which has not been removed by cutting after the second layer cutting process, and the upper two or three layers are removed by this cutting. Part. In this state, the height is gradually increased from the outer portion 21 toward the central portion 22 in four steps.

Next, similarly, the processing tool 15 is further
By lowering the starting point C by about 1/5 of the entire cutting depth, and further shifting the starting point C from the starting point C of the third layer to 1/5 of the diameter of the processing tool 15 and performing the same operation, as shown in FIG. Nana 4
Unnecessary portions of the layer are cut and removed. in this case,
There are five steps in total.

Next, the working tool 15 is further lowered by about 1/5 of the entire cutting depth, and its starting point C is changed to the starting point C of the fourth layer.
Then, by shifting the processing tool 15 forward by 1/5 of the diameter of the processing tool 15 and performing the same operation, unnecessary portions of the fifth layer as shown in FIG. .

Finally, the work 24 as shown in FIGS. 9 and 10 is obtained by cutting and removing the stepped uncut portion 23 remaining at the forefront. In FIG. 10, a broken line e represents the shape of the workpiece 16 to be obtained, and a portion indicated by a dashed line f starts cutting from the same point without shifting the starting point of the processing tool 15 as in the conventional example. The uncut portion of the case is shown.

When the rough cutting step is completed as described above, the processing tool 15 is replaced with a finishing tool, and the remaining unnecessary portion 25 is cut and removed. As a result, a workpiece 16 as shown in FIGS. 2 and 3 is obtained. In this finishing step, since the amount of the remaining unnecessary portion 25 is small, it is possible to prevent an overload from being applied to the finishing tool and to shorten the required time, thereby greatly improving work efficiency. I will be.

It should be noted that in the above-mentioned rough cutting step, a slight uncut portion is left at the bottom of the fifth layer to be cut, and this surface is finely finished in the finishing step. Also,
After the rough cutting process, there is a portion where the unnecessary portion 25 for five layers remains, but the amount is small, and the cutting direction in the finishing process is a direction from the side wall side to the horizontal direction. Even fine finishing tools can be cut without any problems.

[0031]

As described above, in the method for processing a workpiece according to the present invention, in the roughing step, unnecessary portions in the processing material are divided into upper and lower layers, and the starting point of the processing tool in each layer is slightly shifted. Like that.
As a result, the uncut portion is greatly reduced, and the same result can be obtained as when the feed pitch width of the processing tool is set small and the number of reciprocating movements of the processing tool is increased. Become.

As a result, the time required for both the roughing step and the finishing step can be reduced, and the finishing tool can be prevented from being overloaded, and the finishing tool can be prevented from being damaged. Also, by setting the shift width of the starting point to a length that divides the pitch width of the processing tool into equal parts, the uncut portion becomes a step with the same interval as the shift width, so that the finishing process will not be overloaded. Suitable finishing can be performed.

Furthermore, even if the feed pitch width of the processing tool is set to the maximum diameter of the processing tool, it is possible to perform satisfactory cutting and removal of unnecessary portions without any problem. This makes it possible to further reduce the number of reciprocating movements of the processing tool.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a cutting device used in an example of the present invention.

FIG. 2 is a plan view of a workpiece.

FIG. 3 is a front view of a workpiece.

FIG. 4 is an explanatory view showing a state in which an unnecessary portion of an uppermost layer of a processing material is cut and removed.

FIG. 5 is an explanatory view showing a state in which an unnecessary portion of a second layer of the processing material is cut and removed.

FIG. 6 is an explanatory view showing a state in which an unnecessary portion of a third layer of the processing material is cut and removed.

FIG. 7 is an explanatory diagram showing a state in which an unnecessary portion of a fourth layer of the processing material is cut and removed.

FIG. 8 is an explanatory view showing a state where an unnecessary portion of a lowermost layer of a processing material is cut and removed.

FIG. 9 is a plan view showing a state where an unnecessary portion of a lowermost layer of the processing material is cut and removed.

FIG. 10 is a sectional view taken along line B-B 'of FIG.

FIG. 11 is an explanatory view showing a state in which an unnecessary portion of a processing material according to a conventional example is cut and removed.

12 is a sectional view taken along line A-A 'of FIG.

[Explanation of symbols]

 14 ··· Cutting part 15 ··· Processing tool 16 ··· Workpiece 17 ··· Material for processing 25 ··· Unnecessary part C ··· Starting point

Claims (4)

[Claims] 1. A method for cutting a workpiece to obtain a predetermined workpiece by cutting and removing an unnecessary portion of the processing material by reciprocating the processing tool for roughing back and forth with a predetermined pitch width back and forth while moving the tool back and forth. In addition, the unnecessary portion is cut and removed in a plurality of layers from the surface layer side to the deep layer side, and the starting point of the roughing tool in the cutting of the plurality of layers is set to a pitch smaller than the fixed pitch width by the pitch. A method for cutting a workpiece, wherein each layer is cut at a constant pitch while being shifted in a direction. 2. The method for cutting a workpiece according to claim 1, wherein the shift width of the starting point of the roughing tool is set to a value obtained by dividing a pitch width of the roughing tool by the number of layers. 3. The method for cutting a working tool according to claim 1, wherein the pitch width of the working tool for rough cutting is set to the same length as the diameter of the working tool for rough cutting. 4. The finishing is performed by cutting and removing unnecessary portions with a roughing tool, and then cutting and removing a small amount of unnecessary portions remaining on the periphery of the workpiece with a finishing tool. 3. The method for cutting a workpiece according to claim 1.