JP2013132692A - Drilling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the degree of a hole position in deep hole working to a desired precision in a short period of time.SOLUTION: During drilling using a gun drill, the quantity of displacement of a wall surface of a hole already formed in a workpiece caused by receiving a load placed on the wall surface from the gun drill is predicted. Then curvature correction measures for hole working based upon the predicted quantity of displacement of the wall surface of the hole are included in a product design stage (S10). The work for which the measures are taken is actually drilled using the gun drill (S40, ...) to secure the desired degree of the hole position without repeating trial working and equipment manufacturing/adjustment like a prior art. Consequently, man-hours for repetition of the trial working (S40) and equipment manufacturing/adjustment (S30) are unnecessary, and the degree of the hole position in the drilling can be enhanced to desired precision in a short period of time.

Description

  The present invention relates to a drilling method.

  Conventionally, a technique using a rotary tool having a cutting blade has been widely used as a machining method for drilling a workpiece. In particular, when a deep hole needs to be processed, a gun drilling method is employed. As illustrated in FIG. 8A, the gun drilling method enables deep hole machining in which the ratio of the length of the hole 10 formed in the workpiece W to the diameter is, for example, about 1:40. It is. Further, the gun drill 12, which is a rotary tool used for this, has a ratio of length to diameter that is greater than or equal to the diameter to length ratio of the hole 10 to be machined. Therefore, in order to suppress the deformation of the gun drill 12 during the processing of the hole 10 as much as possible and increase the position of the hole 10, a guide pad 12a is provided at the distal end portion of the gun drill 12 as shown in FIG. It has been.

  This guide pad 12a is a hole already formed in the workpiece W by the gun drill 12 during drilling of the hole 10 at a position shifted in phase by a predetermined angle in the rotation direction of the gun drill 12 with respect to the cutting edge position of the cutting blade 12b. 10 (cylindrical) wall surface 10a is slidably contacted (see, for example, Patent Documents 1 and 2).

Japanese Patent Laid-Open No. 05-253722 JP 2005-288669 A

By the way, in general, as shown in FIG. 1B, the product manufacturing procedure includes design (S10), product shape determination (S20), equipment production / adjustment (S30), trial machining (S40), accuracy OK ( Confirmation) (S50) and production start (S60) are often followed. However, as described above, in the case of manufacturing a product in which the hole 10 is drilled using the gun drill 12, in practice, it is rare that the accuracy is OK (S50) after one trial process (S40). After the trial machining (S40), the operation of returning to the equipment production / adjustment (S30) is repeated, and the accuracy OK (S50) is reached.
Moreover, in the trial machining (S40), when the position of the hole 10 is measured after the hole 10 is actually drilled in the workpiece W, the probe of the three-dimensional measuring instrument used for measuring the position of the hole 10 is: In the case of a deep hole that does not reach the depth of the hole, the workpiece W needs to be destructively inspected. Therefore, the burden required for so-called trial and error, in which trial machining (S40) and equipment production / adjustment (S30) are repeated, is extremely large.

By the way, as a result of diligent research, the present inventors have come to grasp the factors that reduce the position degree of the hole while repeating the trial and error in the gun drilling method. That is, during drilling, as shown in FIG. 8 (b), a thin portion is applied to the portion of the work W where the load F is applied from the guide pad 12 a of the gun drill 12 to the wall surface 10 a of the hole 10. For example, if there is a part where the rigidity is locally different, the hole wall surface 10a is displaced (deformed) in the thin wall direction. In response to such displacement of the hole wall surface 10a, as shown by the arrow A, the cutting blade 12b advances the drilling so as to escape in the thin wall direction. As a result, the hole 10 is shown by an arrow in FIG. As shown, the workpiece W bends in the thin direction, and the position of the hole 10 is lost.
The present invention has been made in view of the circumstances as described above, and the object of the present invention is to improve the position of the hole when performing deep hole processing to a desired accuracy in a short time, and to perform trial processing and equipment. Trial and error that repeats production and adjustment is made unnecessary.

(Aspect of the Invention)
The following aspects of the present invention exemplify the configuration of the present invention, and will be described separately for easy understanding of various configurations of the present invention. Each section does not limit the technical scope of the present invention, and some of the components of each section are replaced, deleted, or further while referring to the best mode for carrying out the invention. Those to which the above components are added can also be included in the technical scope of the present invention.

(1) A drilling method for drilling a workpiece using a rotary tool having a cutting blade, wherein a load applied to a hole wall surface already formed in the workpiece from the rotary tool during drilling by the rotary tool. A step of predicting the amount of displacement of the hole wall surface that is received and a predetermined measure for canceling the displacement generated in the hole wall surface with respect to the workpiece based on the predicted amount of displacement of the hole wall surface A drilling method including a step and a step of drilling a workpiece subjected to the countermeasure using the rotary tool (Claim 1).
The drilling method described in this section is applied to the hole wall surface already formed in the workpiece from the rotary tool during drilling with the rotary tool in the stage before actually drilling the workpiece using the rotary tool having a cutting blade. The amount of displacement of the hole wall surface caused by the applied load is predicted. Then, based on the predicted amount of displacement of the hole wall surface, a predetermined measure is taken to cancel the displacement generated on the hole wall surface with respect to the workpiece. That is, a countermeasure for correcting the bending of the hole processing based on the predicted amount of displacement of the hole wall surface is incorporated in the product design stage or the processing condition setting stage. Then, the desired position degree of the hole is ensured by repeating the trial machining and the production / adjustment of the equipment by actually drilling the work to which measures have been taken using a rotating tool.

(2) In the above paragraph (1), in the step of predicting the amount of displacement of the hole wall surface using a rotary tool including a guide pad as the rotating tool, the position where the guide pad contacts the hole wall surface; A drilling method for predicting an amount of displacement generated in the hole wall surface corresponding to a position where the cutting edge of the cutting blade comes into contact with the hole wall surface (Claim 2).
In the drilling method described in this section, when predicting the amount of displacement of the hole wall surface, the position where the guide pad contacts the hole wall surface (in the circumferential direction of the hole) and the cutting edge of the cutting blade contact the hole wall surface. Predict the amount of displacement that occurs in the hole wall surface corresponding to the position (in the circumferential direction of the hole), and take predetermined measures to counteract the displacement that occurs in the hole wall surface for the workpiece based on each displacement amount Is.

(3) In the step of predicting the amount of displacement of the hole wall surface in the above item (2), the cutting blade of the hole wall surface caused by the displacement generated in the hole wall surface when the guide pad comes into contact with the hole wall surface In consideration of the displacement at the position where the contact is made, the bending tendency of the hole is obtained, and in the step of taking a measure for canceling the displacement with respect to the workpiece based on the predicted amount of displacement of the hole wall surface, A drilling method in which predetermined measures are taken to eliminate the obtained tendency of bending of the holes (Claim 3).
In the drilling method described in this section, when predicting the amount of displacement of the hole wall surface, the guide pad is brought into contact with the hole wall surface and caused by the displacement generated in the hole wall surface, at the position where the cutting blade of the hole wall surface comes into contact. In consideration of the influence, the bending tendency of the hole (the bending direction of the hole, the amount of bending, and the degree of position) is obtained. And the predetermined countermeasure for eliminating the bending tendency of the hole calculated | required based on the quantity of the estimated displacement of a hole wall surface is given.

(4) A drilling method for changing the shape of the workpiece in the steps of (1) to (3), in which a predetermined measure is taken to cancel the displacement generated in the hole wall surface with respect to the workpiece. (Claim 4).
In the drilling method described in this section, feedback is given to product design when a predetermined measure is taken to cancel the displacement generated in the hole wall surface with respect to the workpiece. For example, if there is bending of a hole due to the presence of a part with different rigidity, such as a thin-walled part, in the part of the workpiece where the hole is to be drilled, It adjusts the meat pressure. Specifically, a design change is performed, such as overlaying for balancing the rigidity of the thin-walled portion, or thinning a portion of the thin-walled portion at a target position on the rigidity balance. This design change is made based on the predicted amount of displacement of the hole wall surface.

(5) In the above-mentioned steps (1) to (4), in the step of applying a predetermined measure for canceling the displacement generated in the hole wall surface with respect to the workpiece, the displacement of the hole wall surface with respect to the workpiece is suppressed. A perforation method for applying a load for the purpose (claim 5).
The drilling method described in this section applies a load for suppressing displacement of the hole wall surface to the workpiece when a predetermined measure is taken to cancel the displacement generated on the hole wall surface of the workpiece. . For example, when there is bending of a hole due to the presence of a part with different rigidity, such as a thin part, in the part where the hole of the work is drilled, a load is applied to the thin part from the outer wall of the work, and the thin part is deformed. To prevent deformation of the wall surface of the hole. And the position and magnitude | size which provide this load are determined based on the amount of displacement of the estimated hole wall surface.

(6) In the above steps (1) to (5), in the step of taking a predetermined measure for canceling the displacement generated in the hole wall surface with respect to the workpiece, the angle of the rotating tool in the axial direction with respect to the workpiece is A drilling method for setting a holding angle of the workpiece with respect to the rotary tool so that the displacement of the hole wall surface is canceled (Claim 6).
In the drilling method described in this section, when a predetermined measure is taken to cancel the displacement generated in the hole wall surface with respect to the workpiece, the angle of the axial direction of the rotary tool with respect to the workpiece is the direction in which the displacement of the hole wall surface is canceled. In this way, the holding angle of the workpiece with respect to the rotary tool is set. For example, if a hole is bent due to the presence of a part with different rigidity, such as a thin part, in the part where the hole of the work is drilled, the work holding jig is adjusted and the thin part is deformed. An angle between the rotary tool and the workpiece is determined so that drilling proceeds in a non-directional direction, and the workpiece is held. The angle is determined based on the predicted amount of displacement of the hole wall surface.

  Since the present invention is configured in this way, the position of the hole when performing deep hole machining is increased to a desired accuracy in a short time, and trial and error that repeats trial machining and equipment manufacture / adjustment is unnecessary. Is possible.

(A) is a flowchart which shows the drilling method which concerns on embodiment of this invention, (b) is a flowchart which concerns on the conventional drilling method as a comparative example. In the drilling method according to the embodiment of the present invention, the hole occurs on the hole wall surface corresponding to the position where the guide pad of the rotary tool contacts the hole wall surface and the position where the cutting edge of the cutting blade of the rotary tool contacts the hole wall surface. It is explanatory drawing which shows the method of estimating the amount of displacement, (a) is sectional drawing which shows a deformation | transformation of a hole wall surface typically, (b) is a hole in predicting the amount of displacement which arises in a hole wall surface. It is explanatory drawing which shows the coordinate axis set to the surface orthogonal to an axial direction. It is a graph which shows the amount of deformation | transformation of a hole wall surface when a load is provided with respect to each position defined by the coordinate of FIG.2 (b). In the drilling method according to the embodiment of the present invention, the result of predicting the bending tendency of a hole using a simple model is verified, (a) is an overview diagram of the simple model, and (b) is the bending direction of the hole. (C) is a verification diagram of the bending amount of the hole. It is a top view which shows a cylinder head as an example of the workpiece | work which applies the drilling method which concerns on embodiment of this invention. It is the figure which verified the bending tendency of the hole in the cylinder head of FIG. In the drilling method which concerns on embodiment of this invention, the clamp which provides the load for suppressing the displacement of a hole wall surface with respect to a workpiece | work with the sectional view of a cylinder head is shown typically. It explains the conventional drilling method, (a) is a sectional view of the cylinder head, (b) is a sectional view of the hole formed in the cylinder head together with the tip of the gun drill used in the drilling method It is.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. In this description, parts that are the same as or correspond to those in the prior art are assigned the same reference numerals, and detailed descriptions thereof are omitted. Please refer to FIG. 8 related to the prior art as appropriate.
In the drilling method according to the embodiment of the present invention, the hole 10 is drilled in the workpiece W using the gun drill 12, and the design (S10), product is shown in FIG. The steps include shape determination (S20), equipment production / adjustment (S30), trial machining (S40), accuracy OK (confirmation) (S50), and production start (S60). Moreover, the accuracy OK (S50) can be achieved by one trial machining (S40). The specific method will be described below.

In the embodiment of the present invention, in the step of design (S10), an appropriate amount for canceling the displacement generated on the wall surface 10a of the hole 10 with respect to the workpiece W is determined based on the predicted amount of displacement of the wall surface 10a of the hole 10. It includes a process for taking countermeasures.
Further, in the step of product shape determination (S20), during the drilling of the hole 19 by the gun drill 12, the load F applied to the wall surface 10a of the hole 10 already formed in the workpiece W from the gun drill 12 (FIG. 8B). )), And a step of predicting the amount of displacement of the wall surface 10a of the hole 10 is included.

Then, in the step of predicting the amount of displacement of the wall surface 10a of the hole 10 (S20), as shown in FIG. 2A, the guide pad 12a contacts the wall surface 10a of the hole 10 (in the circumferential direction of the hole). ) And the amount of displacement generated on the wall surface of the hole 10 corresponding to the position where the cutting edge of the cutting blade 12a contacts the wall surface 10a of the hole 10 (in the circumferential direction of the hole).
Further, in the step of predicting the amount of displacement of the wall surface 10a of the hole 10 (S20), the cutting blade 12b caused by the displacement generated on the wall surface 10a of the hole 10 by the guide pad 12a coming into contact with the wall surface 10a of the hole 10 is provided. The bending tendency of the hole 10 is obtained in consideration of the displacement of the wall surface 10a at the contact position.

Specifically, as shown in FIG. 2A, the guide pad 12a abuts against the wall surface 10a of the hole 10 and a load is applied to the wall surface 10a, so that the wall surface 10a is indicated by a dotted line in the figure. At the position where the guide pad 12a comes into contact, the guide pad 12a is deformed in the diameter increasing direction (vector A). Then, in response to the deformation at the position where the guide pad 12a abuts, the deformation occurs in the reduced diameter direction (vector B) at the position where the cutting blade 12b abuts. The bending tendency of the hole 10 is obtained in consideration of the influence of the deformation of the wall surface 10a.
In the following description, the positional relationship between the guide pad 12a of the gun drill 12 and the cutting blade 12b is exemplified when there is a phase difference of 90 ° in the circumferential direction with respect to the central axis of the gun drill 12. However, the phase difference between the guide pad 12a of the gun drill 12 and the cutting blade 12b is not limited to 90 °.

Now, the procedure for predicting the amount of displacement generated in the wall surface 10a of the hole 10 is as follows. First, as shown in FIG. 2B, the cross section of the wall surface 10a in the YZ plane perpendicular to the axial direction of the hole 10 is used. A plurality of points (Nos. 1 to 8) are defined at equal intervals (45 ° pitch). The number of points specified here is appropriately determined in consideration of calculation accuracy and calculation time. Then, the amount of displacement of the R component (radial direction) of each point when a radial load is applied to each point is calculated. As a calculation method at this time, an analysis method according to the finite element method can be used. Specifically, it is the procedure for reading necessary data, creating stiffness matrix, processing fixed conditions, calculating load vectors, solving simultaneous linear equations, calculating strain in elements, calculating stress in elements, and outputting results. .

The upper chart of FIG. 3 illustrates the amount of displacement of each point of the wall surface 10a by applying a load to each point, calculated by the above method. In the upper chart of FIG. 3, the deformation of the hole 10 in the diameter increasing direction is indicated by a positive value, and the deformation of the hole 10 in the diameter decreasing direction is indicated by a negative value. For example, No. 2 in FIG. The guide pad 12a is positioned in one direction, and the wall surface 10a No. When a load is applied in one direction, no. Nos. 1 to 3 and 8 are deformed in the diameter increasing direction. At the positions 4 to 7, it is deformed in the diameter reducing direction.
Here, it is considered that the positional relationship between the guide pad 12a of the gun drill 12 and the cutting blade 12b has a phase difference of 90 ° in the circumferential direction with respect to the central axis of the gun drill 12. That is, No. 2 in FIG. When the guide pad 12a is positioned in one direction, no. No. 1 corresponding to the amount of displacement at the position 1 and the position where the cutting blade 12b abuts. The amount of displacement at position 3 is compared.

Specifically, as shown in the lower left chart of FIG. As shown in FIG. 2B, the amount of displacement of the wall surface 10a at the positions 1 and 3 is decomposed into components in the Y direction and the Z direction. And the value obtained by adding each YZ component (the value at the bottom of the chart in the lower left of FIG. 3) is at the position of the guide pad 12a (No. 1 on the wall surface 10a) shown in FIG. It is obtained as the YZ component of the displacement amount of the deformation vector A. Further, the displacement amount of the deformation vector B at the position of the blade edge 12b (No. 3 on the wall surface 10a) is also obtained as a YZ component.
Furthermore, by subtracting the YZ component of the displacement amount of the deformation vector B from the YZ component of the displacement amount of the deformation vector A, as shown in the lower right chart of FIG. When the load is applied in one direction, the axial displacement amount of the hole 10 (the displacement amount with respect to the axial center position of the designed hole 10) takes into account the displacement amount at the position of the cutting blade 12b. In the example shown in the figure, it is obtained as Y component: 0.073, Z component: 0.215). In accordance with the above procedure, No. 2 in FIG. The amount of displacement of the wall surface 10a is predicted by obtaining the amount of axial displacement of the hole 10 when the guide pad 12a is positioned in the 2 to 8 directions.

Now, FIG. 4 is generated by receiving a load applied from the gun drill 12 to the wall surface 10a of the hole 10 already formed in the workpiece W during drilling by the gun drill 12, which is obtained by the method according to the embodiment of the present invention. The example which compared the predicted value of the amount of displacement of the wall surface 10a with the amount of displacement which arises in an actual process is shown. Further, here, the bending direction and the bending amount of the hole 10, that is, the bending tendency of the hole 10 are compared.
In this example, as a virtual workpiece W for predicting the amount of displacement generated on the wall surface 10a of the hole 10, a simple model shown in FIG. 4A is used, and the workpiece W for actual machining has the same shape. The hole 10 is processed into the actual product, and a destructive inspection is performed. The workpiece W is formed by forming a groove parallel to one surface of the metal block and forming a hole 10 in a portion sandwiched between the grooves. The diameter of the hole 10 is 8 (mm) in this example as the diameter of the gun drill 12, and the thickness of the left and right sides of the hole 10 is 3 (mm). And the thickness T (mm) above the hole 10 was changed, and the amount of displacement of the wall surface 10a of the hole 110 was compared. As a result, as shown in FIG. 4B, the bending direction of the hole 10 is within a range where there is substantially no problem in the actual machining and the prediction, and it can be determined that they match. Further, as shown in FIG. 4C, the bending amount of the hole 10 is also within the range where the actual machining and the prediction are substantially free from problems regardless of the change in the wall thickness T, and they match. The result was determinable.

Further, as shown in FIG. 5, the same verification was performed when the cylinder head was used as the workpiece W. The workpiece W in this case has a more complicated shape than the simple model of FIG. 4A, but in the example shown in the figure, the length of the guide pad 12a is 35 ( mm), the cross-sectional position for performing the stiffness analysis according to the finite element method was set to a pitch of 35 (mm) along the direction in which the holes extend.
FIG. 6 shows the result of comparing the predicted and actual machining values for the position degree (φ1.4) of the hole 10 on the EX manifold side and the IN manifold side in the cylinder heads of different types of engines. . For all types of cylinder heads, similar to the example of FIG. 4, it was possible to determine that the bending tendency of the hole 10 according to prediction and actual processing was consistent.

Then, in the embodiment of the present invention, from the step of determining the product shape (S20), that is, the displacement of the wall surface of the hole 10, shown in FIG. Returning to the step of taking a predetermined measure for canceling the displacement, the shape of the workpiece is changed.
For example, the pressure of the workpiece W is adjusted so as to balance the rigidity of the portion where the hole 10 is to be drilled. More specifically, a design change is made such as building up for balancing the rigidity of the thin-walled portion, or reducing the thickness of the portion at the target position on the rigidity balance relative to the thin-walled portion. . In addition, for example, a calculation means (such as CAE) that performs product shape determination (S20) and a calculation means (such as CAD) that performs design (S10) are data-linked by appropriate communication means so that the workpiece W can be linked. Thus, the shape change for canceling the displacement generated in the wall surface 10a of the hole 10 can be immediately fed back to the product design.

Further, after the step (S20) of predicting the amount of displacement of the wall surface of the hole 10, the displacement of the wall surface 10a of the hole 10 is suppressed with respect to the workpiece W in the equipment manufacturing / adjustment step (S30) instead of the design change. It is good also as giving the load for.
In this case, as shown in FIG. 7, a load is applied to the thin portion from the outer wall of the workpiece W by the clamp 14 to suppress the deformation of the thin portion so that the wall surface 10a of the hole 10 is not deformed. It is. In addition, for example, a data communication is performed by an appropriate communication means between a calculation means (CAE, etc.) for determining a product shape (S20) and a work holder having an automatic clamp related to equipment manufacture / adjustment (S30). It is also possible to immediately feed back the load application for canceling the displacement generated in the wall surface 10a of the hole 10 with respect to the workpiece W.

Further, after the step of predicting the amount of displacement of the wall surface of the hole 10 (S20), in the equipment manufacturing / adjustment step (S30), the holding jig for the workpiece W is adjusted, and the axial direction of the gun drill 12 with respect to the workpiece W It is good also as setting the holding angle of the workpiece | work W with respect to the gun drill 12 so that it may become the direction which cancels the displacement of the wall surface 10a of the hole 10. In this case, the holding jig for the workpiece W is adjusted, and the workpiece is held by determining the angle between the gun drill 12 and the workpiece W so that the drilling proceeds in a direction in which the thin portion does not deform. In addition, for example, a calculation means (CAE, etc.) for determining the product shape (S20) and a work holder having an automatic angle adjustment means for equipment manufacture / adjustment (S30) are linked by appropriate communication means. Thus, the angle adjustment for canceling the displacement generated on the wall surface 10a of the hole 10 with respect to the workpiece W can be immediately fed back.
Furthermore, the above-mentioned predetermined measures for canceling the displacement with respect to each workpiece W can be used in combination as appropriate.

Now, according to the embodiment of the present invention configured as described above, the following operational effects can be obtained.
The drilling method according to the embodiment of the present invention is a trial machining (S40) shown in FIG. 1A, that is, a step of actually drilling a workpiece W using a gun drill 12 having a cutting blade 12b. A hole generated in response to a load F applied to the wall surface 10a of the hole 10 already formed in the workpiece W from the gun drill 12 during drilling by the gun drill 12 in the stage of product shape determination (S20), which is the previous stage. The amount of displacement of the ten wall surfaces 10a is predicted. Then, based on the predicted amount of displacement of the wall surface 10a of the hole 10, a predetermined measure (S10, S30) for canceling the displacement generated on the wall surface 10a of the hole 10 with respect to the workpiece W is applied. That is, a countermeasure for correcting the bending of the hole processing based on the predicted displacement amount of the wall surface 10a of the hole 10 is incorporated in the product design stage (S10) or the processing condition setting stage (S30). Then, by actually drilling the workpiece W with countermeasures using the gun drill 12 (from S40), as in the prior art (see FIG. 1B), trial machining (S40) and equipment production / adjustment. It is possible to secure a desired position of the hole 10 without repeating (S30).
Therefore, the trial and error man-hours for repeating the trial machining (S40) and the equipment production / adjustment (S30) are required, and the position of the hole 10 when deep hole machining is performed can be increased to a desired accuracy in a short time. It becomes possible.

  Further, in the drilling method according to the embodiment of the present invention, when the amount of displacement of the wall surface 10a of the hole 10 is predicted (S20), as shown in FIG. The amount of displacement that occurs on the wall surface 10a of the hole 10 corresponding to the position that contacts the wall surface 10a and the position where the cutting edge of the cutting blade 12b contacts the hole wall surface 10a is predicted. Thus, a predetermined measure is taken to cancel the displacement generated on the wall surface 10a of the hole 10.

  Further, when the amount of displacement of the wall surface 10a of the hole 10 is predicted (S20), the guide pad 12a is brought into contact with the wall surface 10a of the hole 10 and the cutting blade 12b is brought into contact with the wall 10a. In consideration of this displacement (FIG. 3), the bending tendency of the hole 10 is obtained. Then, by applying a predetermined measure for eliminating the bending tendency of the hole 10 obtained based on the predicted displacement amount of the wall surface 10a of the hole 10 (S10, S30), the wall surface 10a of the hole 10 is applied. It cancels the resulting displacement.

  In addition, the drilling method according to the embodiment of the present invention feeds back the product design and changes the shape of the workpiece W when a predetermined measure is taken to cancel the displacement of the wall surface 10a of the hole 10 with respect to the workpiece W. (S10). Then, by making this design change based on the predicted amount of displacement of the hole wall surface (S20), it is not necessary to repeat the trial machining (S40) and the equipment manufacturing / adjustment (S30), and deep hole machining is performed. It is possible to increase the position of the hole 10 to a desired accuracy in a short time.

  Further, in the drilling method according to the embodiment of the present invention, the load for suppressing the displacement of the wall surface 10a of the hole 10 with respect to the workpiece W when taking a predetermined measure for canceling the displacement with respect to the workpiece W. (S30). Then, by determining the position and size to which the load is applied based on the predicted amount of displacement (S20) of the wall surface 10a of the hole 10, trial processing (S40) and equipment production / adjustment (S30) are performed. The number of man-hours to be repeated becomes unnecessary, and the degree of positioning of the hole 10 when performing deep hole processing can be increased to a desired accuracy in a short time.

  Furthermore, in the drilling method according to the embodiment of the present invention, when a predetermined measure is taken to cancel the displacement of the wall surface 10a of the hole 10 with respect to the workpiece W, the angle of the gun drill 12 with respect to the workpiece W in the axial direction is The holding angle of the workpiece W with respect to the gun drill 12 may be set so as to cancel the displacement of the wall surface 10a of the hole 10 (S30). Then, by determining this angle based on the predicted displacement (S20) of the wall surface 10a of the hole 10, it is not necessary to repeat the trial machining (S40) and the equipment manufacturing / adjustment (S30). It is possible to increase the degree of position of the hole 10 when performing the hole processing to a desired accuracy in a short time.

10: Hole, 10a: Wall surface, 12: Gun drill, 12a: Guide pad, 12b: Cutting blade, 14: Clamp, W: Workpiece

Claims (6)

A drilling method for drilling a workpiece using a rotary tool having a cutting blade,
Predicting the amount of displacement of the hole wall surface caused by receiving a load applied to the hole wall surface already formed in the workpiece from the rotating tool during drilling by the rotating tool;
Applying predetermined measures for canceling the displacement generated in the hole wall surface with respect to the workpiece based on the predicted amount of displacement of the hole wall surface;
A drilling method, comprising: drilling a workpiece with the countermeasure using the rotary tool. In the step of predicting the amount of displacement of the hole wall surface by using a rotary tool having a guide pad as the rotating tool, the position where the guide pad contacts the hole wall surface, and the cutting edge of the cutting blade on the hole wall surface The drilling method according to claim 1, wherein an amount of displacement generated in the hole wall surface corresponding to a contact position is predicted. In the step of predicting the amount of displacement of the hole wall surface, the displacement of the hole wall surface at the position where the cutting blade contacts due to the displacement generated on the hole wall surface when the guide pad contacts the hole wall surface is considered. The bending tendency of the hole,
Based on the predicted amount of displacement of the hole wall surface, in a step of counteracting the displacement generated in the hole wall surface with respect to the workpiece, a predetermined value for eliminating the obtained bending tendency of the hole 3. The drilling method according to claim 2, wherein measures are taken. The drilling method according to any one of claims 1 to 3, wherein a shape of the workpiece is changed in a step of taking a predetermined measure for canceling a displacement generated in the hole wall surface with respect to the workpiece. . The load for suppressing the displacement of the hole wall surface is applied to the workpiece in the step of taking a predetermined measure for canceling the displacement generated in the hole wall surface of the workpiece. 5. The drilling method according to any one of items 1 to 4. In the step of applying a predetermined measure for canceling the displacement generated in the hole wall surface with respect to the workpiece, the axial angle of the rotary tool with respect to the workpiece is in a direction to cancel the displacement of the hole wall surface. The drilling method according to claim 1, wherein a holding angle of the workpiece with respect to the rotating tool is set.

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