JP4889162B2 - Thrusting method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a technique for performing roughing work by feeding a rotary cutting tool having an outer peripheral bottom blade in the axial direction in order to manufacture a product such as a die from a solid material such as a forged product.
[0002]
[Prior art]
Conventionally, for example, when manufacturing a product such as a die from a solid material such as a forged product, as shown in FIG. 8, a technique for performing contour line processing using an NC processing machine, Japanese Patent No. 2884835, and Japanese Patent No. After rotating and cutting the rotary cutting tool in the axial direction as in No. 2993224, the tool is retracted in the axial direction, and then the contour is formed by repeating the thrusting while moving the tool at a constant pitch in the lateral direction. A technique for cutting is known, and in the contour cutting by such thrusting, usually, when the machining area is partitioned in a matrix, the tool is thrust while moving the tool at a constant pitch along the row direction, When reaching the end portion in the row direction, a processing method is generally used in which the next row is moved at a constant pitch, and the piercing is repeated while moving again at a constant pitch along the row direction.
[0003]
[Problems to be solved by the invention]
However, the technology using the NC processing machine such as the former, especially when processing hard solid materials such as forged products, the cutting tool becomes beaten as the engraving depth etc. becomes deep, and the cutting speed is reduced. Therefore, there is a problem that the processing time becomes extremely long.
Also, in the latter case, in the technique of cutting the contour by moving the rotary cutting tool in the axial direction while moving it at an equal pitch, for example, the tool has a bottom blade only on the outer periphery and no bottom blade in the center. When machining a workpiece with a complicated contour surface shape, depending on the relationship between the width of the bottom blade and the movement pitch, it may not be possible to machine at a depth that exceeds the previously machined depth. In such a place, there is a problem that if machining is performed while correcting the tool while moving the tool in a constant direction at an equal pitch, the amount of uncut material increases and the burden on the subsequent process increases.
[0004]
Therefore, when cutting a hard solid material such as a forged product with a tool having an outer peripheral bottom edge, the present invention is efficient for a part having a complicated shape that is processed at a depth exceeding the depth processed so far. The purpose is to enable good machining, and to reduce the amount of uncut residue and reduce the burden of machining in the next process.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a rotary cutting tool having an outer peripheral bottom blade is processed and fed in the axial direction to a machining end point, and then the rotary cutting tool is retracted in the axial direction. Is moved at a constant pitch along the row direction of the matrix, and the operation of feeding again to the axial direction and pushing to the end point of machining is repeated. In a thrusting method in which the contour is cut to a shape larger than the product shape by sequentially repeating the operations of moving to the next column and then performing a thrusting process at a constant pitch along the row direction of the next column. When moving the tool at a constant pitch along the row direction, the machining end point of the rotary cutting tool at the destination machining position exceeds the machining end point of the rotary cutting tool corresponding to the same position in the previous row. In this case, the machining position is passed as an unmachined state, and machining is started from a position where the machining end point of the rotary cutting tool at the subsequent machining position in the row direction is less than the machining end point of the rotary cutting tool corresponding to the same position in the previous row. We started the process at a fine pitch while returning to the direction opposite to the direction of travel.
[0006]
In other words, as a thrust tool that sharpens the contour by repeating the operation of machining and feeding in the tool axis direction while moving the rotary cutting tool having the bottom blade at a constant pitch, there is a blade in the entire diameter direction of the bottom surface, It is divided into those with blades only on the outer periphery, and those with blades in the entire area can be processed while moving at a large pitch, but if the work material is hard, the burden on the tool is heavy, and torque is normal in a normal machining center Since it is insufficient, it cannot be applied to forging materials such as dies.
For this reason, it is necessary to use a tool having a bottom blade only on the outer periphery for processing a forging material which is a hard material.
[0007]
On the other hand, when the material is viewed from the axial direction of the rotary cutting tool and the machining area is partitioned in a matrix, the rotary cutting tool is butt-machined while moving at a constant pitch along the matrix row direction from the machining start point. When machining is completed to the end, the rotary cutting tool is moved to the next row and the same procedure is repeated to adopt a machining method that completes machining of the entire machining area. If a tool with a bottom edge only on the outer circumference is used, it may be necessary to process at a depth that exceeds the depth processed in the front row at a complicated part of the contour shape. In such a case, if machining is performed in the same direction while maintaining a constant pitch while correcting to the same height as the front row, the uncut amount increases.
[0008]
Therefore, in the present invention, when the machining end point of the rotary cutting tool at the machining position to which the tool is moved exceeds the machining end point of the rotary cutting tool corresponding to the same position in the front row, the machining position is passed as an unmachined state. Starting from the position where the processing end point of the rotary cutting tool at the subsequent processing position in the row direction is less than the processing end point of the rotary cutting tool corresponding to the same position in the previous row, while returning to the direction opposite to the traveling direction Processing is done at a fine pitch.
[0009]
And if you start machining from the position of the machining end point higher than the machining end point corresponding to the same position in the front row and machine it with a fine pitch while returning to the direction opposite to the traveling direction, you can reduce the remaining amount of machining Can be processed smoothly.
It should be noted that during the machining while returning to the direction opposite to the traveling direction, if the machining end point is lower than that in the previous row, the machining will not be realized.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the accompanying drawings.
Here, FIG. 1 is a flowchart of a piercing method according to the present invention, FIG. 2 is an explanatory diagram for explaining the outline of the piercing method, and FIG. 3 is an explanatory diagram showing an example of a process of contour cutting by the piercing method. 4 is an explanatory diagram of a rotary cutting tool, FIG. 5 is an explanatory diagram showing a processing range of the rotary cutting tool, FIG. 6 is a matrix diagram for explaining a moving pitch of the rotary cutting tool, and FIG. It is explanatory drawing explaining the detail of the thrusting method which concerns.
[0011]
The piercing method according to the present invention is a complicated method in which a hard forging material such as a die is cut with a tool having an outer peripheral bottom blade, and it is necessary to perform deep processing beyond the previously processed region. The shape portion can be processed efficiently, and the amount of uncut material is reduced to reduce the processing load in the next process.
[0012]
Here, an outline of a general thrusting method will be described with reference to FIGS. 2 and 3. As shown in FIG. 2B, the rotary cutting tool 1 having the bottom blade 2 is machined downward along the tool axis direction. After feeding to the machining end point s by feeding, the workpiece is returned upward, and then the rotary cutting tool 1 is moved by a constant pitch along the X direction in FIG. To the machining end point s, and this is repeated.
[0013]
When the rotary cutting tool 1 reaches the workpiece end in the X direction, the rotary cutting tool 1 is returned to the workpiece end opposite to the progress in the X direction, moved at a constant pitch in the Y direction, and again fixed in the X direction. By repeating the thrusting process while moving the pitch, the workpiece W is contoured into a shape as shown by a broken line in FIG. 2B, for example.
[0014]
An example of the shape change of the workpiece W to be contoured by the piercing method as described above is as shown in FIG. 3, and from FIG. 3 (a) which is an initial stage of machining, to FIG. 3 (b) which is an intermediate stage. Then, as shown in FIG. 3C, which is the latter half of the stage, the surface of the workpiece W that has been subjected to such rough processing is gradually finished by contour processing or the like in post-processing.
[0015]
Next, a specific thrusting method in the present embodiment will be described.
First, as shown in FIG. 4, the rotary cutting tool 1 used in the present invention is a square end mill-shaped tool, and includes a plurality of outer peripheral bottom blades 2. The tool diameter a is φ80 mm, and the blade length b of the outer peripheral bottom blade 2 is about 17 mm.
[0016]
For this reason, when machining with this rotary cutting tool 1, the machining area is a hatched annular portion with a diameter a of 80 mm and a width b of about 17 mm as shown in FIG. If it hits W, it will lead to tool breakage and machine breakage. Therefore, when machining with such a rotary cutting tool 1, it is necessary to prevent the portion without the bottom blade 2 from coming into contact with the workpiece W by grinding up from a deep processing depth to a shallow processing depth. There is.
[0017]
The moving position, moving order, etc. of the rotary cutting tool 1 will be described with reference to FIG. 6 when the rotary cutting tool 1 is moved in the axial direction while being moved in the horizontal direction for cutting.
As shown in FIG. 6, the machining area is partitioned in a matrix in the X and Y directions, the X direction is a row direction in which machining is performed while the rotary cutting tool 1 is moved at a constant pitch, and the Y direction is the rotary cutting tool 1. Is the column direction to be moved to the next column step by step when it reaches the end in the X direction (row direction).
[0018]
And NC machining data is prepared in advance from the contour shape of the product, the dimension data of the material before machining, the specifications of the rotary cutting tool 1, etc., and the machining allowance from the material before machining at the fine coordinates on the matrix, That is, the position of the processing end point s at each coordinate is automatically determined.
In addition, the position where the piercing process is started first is the deepest part of the shape, and a hole is drilled in advance with a tool larger than the rotary cutting tool 1 (for example, about φ100 mm), and the depth is gradually increased from there. Processing is performed while moving in a shallow direction.
[0019]
Here, in the case of the example, the movement pitch y in the Y direction can be processed even with a pitch of about 16 mm because the blade length b of the outer peripheral bottom blade 2 is about 17 mm. Because the number of parts to be cut near the center of the steel increases, the cutting speed decreases and the cutting performance deteriorates. As a result, the load on the tool and processing machine increases, leading to processing stoppage. The pitch is set to 10 mm from the viewpoint of results and processing efficiency.
[0020]
In addition, with respect to the movement pitch x in the X direction, the movement pitch y in the Y direction is 10 mm, and the movement pitch x determines the amount of machining substantially. Therefore, from the viewpoint of shortening the machining time, the tool Considering the fact that the diameter is 80 mm, the pitch is set to a large pitch of 70 mm.
[0021]
In the matrix specifications as described above, when the processing of the nth column is finished, the processing of the (n + 1) th row is started, and the position of the tool 1 after the machining is P ₂ , FIG. As shown in a), when the machining end point s at the next movement destination position P ₄ falls below the machining end point s at the position P ₃ corresponding to the same position in the previous row, if the machining is performed as it is, there is no outer peripheral bottom edge 2. Since the portion comes into contact with the workpiece W and leads to tool breakage or machine tool failure, machining cannot be performed.
[0022]
At this time, in the present invention, it is determined whether the position P ₄ is higher or lower than the position P ₅ corresponding to the same position in the previous row as the processing end point s of the position P ₆ of the further movement destination without performing the processing at the position P ₄ . As shown in FIG. 7B, when the processing end point s at the previous position P ₆ is higher than the position P ₅ corresponding to the same position in the previous row, the processing is started from this place, and then at a fine pitch (10 mm). Processing is performed while returning to the opposite direction.
Incidentally, in order to facilitate the explanation in FIG. 7, the pitch (10 mm) of the columns is displayed wider than the actual one.
[0023]
During machining in the opposite direction, if the machining end point s drops below the machining end point s at the same position in the previous row, the machining cannot be performed as it is, so the height of the machining end point s at the same position in the previous row is not reached. Correct and process.
On the other hand, if the machining end point s is corrected to the height of the machining end point s from the first position P ₄ to the front row same position P ₃ and machining is performed at a constant pitch along the traveling direction, the amount of uncut material increases, and the next process is performed. The burden of increases.
[0024]
In the matrix of FIG. 6, when the processing end point s at the previous position P ₆ is lower than the processing end point s at the position P ₅ corresponding to the same position in the previous row, the previous position P ₈ and the previous position at the same position P are further reduced. _It is determined whether the machining end point s is higher or lower than the machining end point s ₇ , and the condition of the machining end point at the subsequent position is determined, and the machining is started from a position satisfying the condition and returned in the reverse direction.
[0025]
In the case of the above embodiments, the flow of a series of processing operations can be summarized as follows.
First, before starting machining, NC machining data is created from the contour shape of the product, the dimension data of the material before machining, the specifications of the rotary cutting tool 1, etc., and the machining allowance at each coordinate sectioned in a matrix is determined. Make it asking. At this time, the coordinates are fine enough to include at least a 10 mm pitch coordinate for each row and column.
Then, with a tool larger than the rotary cutting tool 1, for example, a tool having a diameter of about 100 mm, a hole is drilled at the deepest part of the machining depth, and piercing with the rotary cutting tool 1 is started therefrom.
[0026]
Then, as shown in FIG. 1, when the first cutting process is completed and the rotary cutting tool 1 is moved at a constant pitch (70 mm) in the X direction (row direction), the machining at the position moved by one pitch (70 mm). It is determined whether the end point s is higher than the processing end point s at the same position in the previous row.
[0027]
If the processing end point s at the position moved by one pitch (70 mm) is lower than the processing end point s at the same position in the previous row, the processing is not performed at that position, and the height of the subsequent processing end point s is temporarily set. Is processed by obtaining a position that is lower than the processing end point s at the same position in the front row, and then processing while gradually returning at a fine pitch (for example, 10 mm).
[0028]
By the processing method as described above, even when a product having a complicated contour shape is processed, it is possible to reduce the amount of uncut material and to process the product smoothly.
[0029]
Incidentally, when the machining end point s at the position moved by one pitch (70 mm) in the row direction is higher than the machining end point s at the same position in the previous row, the current machining end point s is moved by one pitch (70 mm). It is determined whether or not the angle connecting the processing end point s is less than 70 degrees. If the angle is less than 70 degrees, the processing is continued at a pitch of 70 mm, and if it is 70 degrees or more, the processing is changed to a fine 10 mm pitch. Yes.
This is because when the machining end point s is rapidly increased along the row direction, if machining is continued at the same pitch (70 mm), uncut material increases and the post-processing burden increases.
[0030]
The present invention is not limited to the above embodiment. What has substantially the same configuration as the matters described in the claims of the present invention and exhibits the same operational effects belongs to the technical scope of the present invention.
For example, the specific movement pitch amount in the embodiment is an example.
[0031]
【Effect of the invention】
As described above, the piercing method according to the present invention performs an operation of moving the rotary cutting tool in the row direction at a constant pitch and feeding it in the axial direction, and by repeating this operation in the row direction, the contour shape of the product is changed. In a machining method such as machining, when the rotary cutting tool is moved at a constant pitch along the row direction, the machining end point of the rotary cutting tool at the destination machining position is If the machining end point is exceeded, this machining position is passed as an unmachined state, and the machining end point of the rotary cutting tool at the subsequent machining position in the row direction is less than the machining end point of the rotary cutting tool corresponding to the same position in the previous row. Since machining is started from the position where it becomes, and it is made to machine at a fine pitch while returning to the direction opposite to the traveling direction, it is possible to perform efficient machining and at the same time, machining with less uncut material Come as now, it was to be able to reduce the burden of post-process.
[Brief description of the drawings]
FIG. 1 is a flowchart of a piercing method according to the present invention. FIG. 2 is an explanatory diagram for explaining an outline of the piercing method. FIG. 4 is an explanatory diagram of a rotary cutting tool. FIG. 5 is an explanatory diagram showing a machining range of the rotary cutting tool. FIG. 6 is a matrix diagram for explaining a moving pitch of the rotary cutting tool. Explanatory drawing explaining the details of the thrusting method [Fig. 8] Explanatory drawing of a conventional mold machining method [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Tool, 2 ... Outer peripheral bottom blade, S ... End point of a process.

Claims (2)

After the rotary cutting tool having an outer peripheral bottom blade is fed in the axial direction and thrust to the end point, the rotary cutting tool is retracted in the axial direction, and then the rotary cutting tool is fixed along the row direction of the matrix. Repeat the operation of moving at a pitch, feeding again in the axial direction and thrusting to the end point of machining, and when machining to the end in the row direction, move the rotary cutting tool to the next row of the matrix, then A striking method in which contouring is performed to a shape larger than the product shape by sequentially repeating the operation of striking at a constant pitch along the row direction of the column, wherein the rotary cutting tool is moved along the row direction. when moving at a constant pitch, the rotary cutting tool, when the machining end point of the machining feed in the axial direction in the target processing position corresponds to the front row the same position, exceeding the machining end point, Passes the processing position as the raw state, the rotary cutting tool, machining end point of the machining feed in the axial direction of the previous working position in the row direction corresponds to the front row same position, than the machining end point The processing is started at a position where the processing is completed , and processing is performed at a pitch smaller than the predetermined pitch while returning to the direction opposite to the traveling direction along the row direction so that the processing end points are successively lowered. Butting method. In the piercing method according to claim 1, before piercing with the rotary cutting tool having the outer peripheral bottom blade, the deepest part of the product shape is pierced with a tool having a larger diameter than the rotary cutting tool, A thrusting method characterized by starting the thrusting by the rotary cutting tool from a position where the thrusting is performed.

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