JP5236562B2 - Drill and drilling method - Google Patents

Description

  The present invention relates to a drill and a hole drilling method.

  Conventionally, a drill for forming a through hole in a workpiece is known, and Patent Document 1 below shows an example of such a drill.

  Specifically, in the drill disclosed in Patent Document 1, a drill blade for drilling a workpiece to form a through hole is provided at the distal end portion thereof, and the proximal end side of the drill blade. Are continuously provided with an outer diameter blade for cutting the inner surface of the through hole to define the inner diameter of the through hole. Further, a chamfering blade for chamfering the end portion of the through hole is provided on the proximal end side of the outer diameter blade. And in patent document 1, after forming a through-hole in a to-be-processed object with the drill blade and outer diameter blade, rotating this drill around an axis | shaft, it is made to revolve while rotating a drill around an axis | shaft continuously. The one end portion of the through hole located on the traveling direction side of the drill is chamfered with a chamfering blade.

JP 2000-288813 A

  By the way, the inner surface of the through hole formed by the drill as described above is in a state in which many fine scratches are formed by being cut by the outer diameter blade of the drill. For this reason, it is necessary to perform the finishing process which grind | polishes smoothly the inner surface of the through-hole. However, in this case, a through hole must be formed in the workpiece by a drill, and after chamfering the end of the through hole, the drill must be replaced with a polishing tool to polish the inner surface of the through hole. Therefore, a complicated operation of replacing the drill with a polishing tool is performed.

  The present invention has been made in order to solve the above-described problems, and its purpose is to prevent formation of a work process while forming a through hole, chamfering and penetrating an end portion of the through hole. It is to be able to perform a finishing process that smoothly finishes the inner surface of the hole.

In order to achieve the above object, a drill according to the present invention is a drill for forming a through-hole in a workpiece made of a ductile metal material, and is provided at the tip of the drill. A through-hole having a cutting blade capable of being perforated, and a proximal end side of the perforated part, and by being pressed against the inner surface of the through-hole formed by the perforated part while rotating, A push-in portion that can be smoothed by pushing the inner surface, and provided continuously to at least one of the front end side and the base end side of the push-up portion, and in the axial direction of the through hole A chamfered portion capable of chamfering the end by being pressed against the corresponding end while rotating , the push-in portion has a blade portion pressed against the inner surface of the through-hole, The blade is Having a distal end surface that forms an arc over a radius 0.1mm in a plane perpendicular to the axial direction of the tooth portion if pressing the.

  The drill includes a perforated portion capable of perforating a workpiece, and a smoothing portion capable of smoothing the inner surface of a through hole formed in the workpiece by the perforated portion. Since the through hole is formed in the workpiece by the same drill, the inner surface of the through hole is pushed and further penetrated The end of the hole can be chamfered. That is, a series of steps including formation of a through hole, chamfering of the end of the through hole, and finishing of the inner surface of the through hole can be performed without performing a complicated operation of replacing the drill with a polishing tool or the like. Therefore, in this drill, while preventing the work process from becoming complicated, it is possible to perform formation of the through hole, chamfering of the end portion of the through hole, and finishing to smoothly finish the inner surface of the through hole.

Further, in this drill, the chamfered portion is continuously provided on at least one of the distal end side and the proximal end side of the push-in portion, so that the push-in portion is pressed against the inner surface of the through-hole. It is also possible to press the chamfered portion against the corresponding end portion in the axial direction of the through hole and chamfer the end portion at the same time. Thereby, a process can also be simplified compared with the case where the finishing process which pushes the inner surface of a through-hole, and the chamfering process which chamfers at least one edge part of a through-hole are performed separately. Also, with this drill configuration, the tip surface of the blade portion of the push-in portion can be appropriately rounded, and the tip surface of the blade portion can be pushed well without cutting the inner surface of the through hole. Can do.

The drill according to the present invention is a drill for forming a through-hole in a workpiece made of a ductile metal material, and is provided at a tip portion of the drill so that the workpiece can be drilled. A perforated portion having a cutting blade and a base end side of the perforated portion, the inner surface of the through hole being pushed by being rotated and pressed against the inner surface of the through hole formed by the perforated portion. A smoothing pusher that is continuously provided on at least one of the pusher and the distal end side and the proximal end of the pusher and rotated to a corresponding end in the axial direction of the through hole. A chamfered portion that can be chamfered by being pressed, and the leveling portion has a blade portion that is pressed against the inner surface of the through hole, and the blade portion is Of the push-in part To have a front end surface capable pressed at less than 20 ° angle with respect to the inner surface of the through hole in the plane perpendicular to the direction.

The drill includes a perforated portion capable of perforating a workpiece, and a smoothing portion capable of smoothing the inner surface of a through hole formed in the workpiece by the perforated portion. Since the through hole is formed in the workpiece by the same drill, the inner surface of the through hole is pushed and further penetrated The end of the hole can be chamfered. That is, a series of steps including formation of a through hole, chamfering of the end of the through hole, and finishing of the inner surface of the through hole can be performed without performing a complicated operation of replacing the drill with a polishing tool or the like. Therefore, in this drill, while preventing the work process from becoming complicated, it is possible to perform formation of the through hole, chamfering of the end portion of the through hole, and finishing to smoothly finish the inner surface of the through hole. In addition, when the tip of the blade of the push-in portion is standing at an acute angle with respect to the inner surface of the through hole, when the push-in portion is pressed against the inner surface of the through hole while rotating, There is a possibility that the inner surface of the through hole may be cut at the tip surface of the blade portion of the push-in portion. On the other hand, like the drill of this invention, the front end surface of the blade part of a push-in part is 20 degrees or less with respect to the inner surface of a through-hole in the surface perpendicular | vertical with respect to the axial direction of a push-in part. If it lies down to such an extent that it can be pressed at an angle, the inner surface of the through hole can be prevented from being cut by the tip surface of the blade portion, and the inner surface of the through hole can be pushed well.

  In the drill, the chamfered portion is continuously provided on both the distal end side and the proximal end side of the push-in portion, and the push-out portion is inserted into the through-hole in the distal end side. It is preferable that the chamfered portion and the chamfered portion on the proximal end side have an axial length that allows the corresponding end portions of the through hole to be simultaneously brought into contact with each other.

  With this configuration, when the push-in portion is pressed against the inner surface of the through hole to push the inner surface of the through-hole, the chamfered portion on the distal end side of the push-through portion and the proximal end side of the push-out portion are arranged. The chamfered portions can be pressed against the corresponding end portions of the through-holes to chamfer both end portions at the same time. For this reason, a process process can be simplified more compared with the case where it is necessary to chamfer each both ends in the axial direction of a through-hole separately.

  Further, the hole drilling method according to the present invention is applied to a workpiece made of a metal material having ductility using a drill in which a chamfered portion is continuously provided on at least one of the distal end side and the proximal end side of the leveling portion. A hole drilling method for forming a through hole, wherein the drill is moved in the axial direction while rotating the drill, and a drilling step for forming a through hole in a workpiece by the drilling portion of the drill, and after the drilling step, By revolving while rotating the drill, by pressing the pressing portion against the inner surface of the through hole and pressing the inner surface of the through hole, and revolving while rotating the drill, A chamfering step of chamfering the end portion by pressing the chamfered portion against a corresponding end portion in the axial direction of the through hole.

  In this drilling method, similar to the operation described for the above drill, after the through hole is formed in the workpiece by the same drill, the inner surface of the through hole is pushed, and the end of the through hole is chamfered. It can be performed. Therefore, in this hole processing method, it is possible to perform formation of the through hole, chamfering of the end of the through hole, and finishing to smoothly finish the inner surface of the through hole while preventing the work process from being complicated.

  In the hole drilling method, the chamfering step is preferably performed simultaneously with the push-in step.

  In this configuration, the leveling process of pressing the leveling portion of the drill against the inner surface of the through hole and pressing the inner surface of the through hole, and pressing the chamfered portion of the drill against the corresponding end in the axial direction of the through hole Since the chamfering process for chamfering the end portion is performed at the same time, the finishing process for pushing the inner surface of the through hole and the chamfering process for chamfering at least one end portion of the through hole are performed in comparison with the machining process. Can be simplified.

  Further, the hole drilling method according to the present invention is applied to a workpiece made of a metal material having ductility using a drill in which chamfered portions are continuously provided on both the distal end side and the proximal end side of the leveling portion. A hole drilling method for forming a through hole, wherein the drill is moved in the axial direction while rotating the drill, and a drilling step for forming a through hole in a workpiece by the drilling portion of the drill, and after the drilling step, By revolving the drill while rotating, the normalizing step of pressing the normalizing portion against the inner surface of the through-hole and pressing the inner surface of the through-hole, and the normalizing step are performed simultaneously, A chamfering step in which the chamfered portion on the distal end side of the push-in portion and the chamfered portion on the proximal end side are simultaneously pressed against the corresponding end portions in the axial direction of the through-hole to simultaneously chamfer the end portions. Preparation There.

  In this drilling method, similarly to the drilling method described above, after the through hole is formed in the workpiece by the same drill, the inner surface of the through hole is pushed, and the end of the through hole is chamfered. Therefore, it is possible to form the through hole, chamfer the end of the through hole, and finish the inner surface of the through hole smoothly while preventing the work process from becoming complicated.

  Further, in this hole drilling method, in the chamfering step performed simultaneously with the push-in step, the chamfered portion on the distal end side of the push-in portion and the chamfered portion on the proximal end side of the push-in portion are connected to the corresponding ends of the through holes. It is possible to chamfer both end portions by pressing against each other at the same time. For this reason, a process process can be simplified more compared with the case where it is necessary to chamfer each both ends in the axial direction of a through-hole separately.

  As described above, according to the present invention, the formation of the through hole, the chamfering process at the end of the through hole, and the finishing process for smoothly finishing the inner surface of the through hole are performed while preventing the work process from becoming complicated. Can do.

1 is a front view of a drill according to a first embodiment of the present invention. It is the figure which showed typically the part used for formation of a through-hole among the drills by 1st Embodiment of this invention. It is sectional drawing along the III-III line in FIG. 2 of the drill by 1st Embodiment of this invention. It is sectional drawing along the IV-IV line in FIG. 2 of the drill by 1st Embodiment of this invention. It is the figure which showed the condition at the time of the blade part of the leveling part of a drill by 1st Embodiment pushing the inner surface of a through-hole. It is a figure which shows the motion of the drill in the hole drilling method by 1st Embodiment of this invention. It is sectional drawing which shows the positional relationship of the drill after a drilling process, and a to-be-processed object in the hole drilling method by 1st Embodiment of this invention. It is sectional drawing which shows the positional relationship of a drill and a workpiece at the time of a regularization process and a chamfering process being started in the hole drilling method by 1st Embodiment of this invention. FIG. 8 is a cross-sectional view showing a positional relationship between the drill and the workpiece when the drill revolves half a round from the state at the start of the leveling process and chamfering process shown in FIG. 7. FIG. 9 is a cross-sectional view showing a positional relationship between the drill and the workpiece when the drill further revolves half a round from the state shown in FIG. 8 and the push-in step and the chamfering step are completed. It is sectional drawing which shows the positional relationship of a drill and a workpiece | work before the process of a through-hole is complete | finished in the hole drilling method by 1st Embodiment of this invention, and a drill is evacuated. It is the figure which showed typically the part used for formation of a through-hole among the drills by 2nd Embodiment of this invention. It is a figure which shows the motion of the drill in the hole drilling method by 2nd Embodiment of this invention. It is sectional drawing which shows the positional relationship of a drill and a to-be-processed object in the chamfering process of the upper end part of a through-hole after a drilling process in the hole drilling method by 2nd Embodiment of this invention. In the drilling method according to the second embodiment of the present invention, after the chamfering process of the upper end portion of the through hole, the positional relationship between the drill and the work piece during the transition to the leveling process and the chamfering process of the lower end portion of the through hole. FIG. It is sectional drawing which shows the positional relationship of a drill and a to-be-processed workpiece at the time of a normalizing process and the chamfering process of the lower end part of a through-hole in the hole processing method by 2nd Embodiment of this invention. It is sectional drawing which shows the positional relationship of a drill and a workpiece at the time of a drill revolving half a round from the state at the time of a start process shown in FIG. 16, and the chamfering process of the lower end part of a through-hole. FIG. 18 is a cross-sectional view showing a positional relationship between the drill and the workpiece when the drill further revolves half a round from the state shown in FIG. 17 and the push-in step and the chamfering step at the lower end of the through hole are completed. It is sectional drawing which shows the positional relationship of the drill and workpiece | work before evacuating a drill after the process of a through-hole is complete | finished in the hole drilling method by 2nd Embodiment of this invention. It is the figure which showed the condition at the time of the blade part of the leveling part of a drill by the 1st modification of 1st Embodiment of this invention pushing the inner surface of a through-hole. It is the figure which showed typically the part used for formation of a through-hole among the drills by the 2nd modification of 1st Embodiment of this invention. It is the figure which showed typically the part used for formation of a through-hole among the drills by the modification of 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
First, with reference to FIGS. 1-5 and FIG. 7, the structure of the drill by 1st Embodiment of this invention is demonstrated.

  The drill according to the first embodiment is for forming a through hole 50 (see FIG. 7) in a workpiece W such as a plate or tube made of a ductile metal material. As shown in FIG. 1, this drill includes a perforated portion 2, a push-in portion 4, a first chamfered portion 6, a second chamfered portion 8, and a base 10. The push-out portion 4, the first chamfered portion 6, the second chamfered portion 8, and the base portion 10 are arranged coaxially.

  The piercing portion 2 is a portion that can pierce the workpiece W when it is pressed against the workpiece W while rotating the drill around its axis to form the through hole 50, and is provided at the tip of the drill. ing. The perforating part 2 has two cutting blades 2a capable of perforating the workpiece W. The two cutting blades 2a are formed symmetrically with respect to the axis of the drill and are formed in a spiral shape along the axis of the drill. And the front-end | tip part of each cutting blade 2a becomes an acute angle as shown in FIG. 3, and when drilling to the workpiece W, the inner surface of the through-hole 50 is cut by this cutting blade 2a. .

  The push-in portion 4 is a portion that can be pushed and smoothed by being pressed against the inner surface of the through-hole 50 formed by the perforated portion 2 while rotating. The push-in portion 4 is disposed away from the piercing portion 2 toward the base end side, and the outermost diameter of the push-out portion 4 is smaller than the outermost diameter of the piercing portion 2. .

  The push-in portion 4 has two blade portions 4a that are pressed against the inner surface of the through hole 50 to push the inner surface. The two blade portions 4a are formed symmetrically with respect to the axis of the drill. Each blade portion 4a is formed in a series of spirals together with the cutting blade 2a of the perforated portion 2, the chamfering blade 6a of the first chamfered portion 6 described later, and the chamfered blade 8a of the second chamfered portion 8 described later. As shown in FIG. 4, each blade portion 4a has a rounded tip surface 4b, and the tip surface 4b of each blade portion 4a is pressed against the inner surface of the through hole 50 as shown in FIG. Smooth the inner surface. The front end surface 4b of the blade portion 4a forms an arc having a radius of 0.1 mm or more on a surface perpendicular to the axial direction of the push-in portion 4 (axial direction of the drill).

  In the step of smoothing the inner surface of the through-hole 50, the amount of pushing d on the inner surface of the through-hole 50 by the tip surface 4b of the blade portion 4a every time the smoothing portion 4 makes one rotation is about 20 μm. Shall. In this case, the radius of the circular arc of the tip surface 4b of the blade portion 4a is such that the pushing amount d per rotation of the push-in portion 4 is 1/5 or less of the radius of the arc of the tip surface 4b of the blade portion 4a. It becomes a value like this. Therefore, chips are not generated when the inner surface of the through hole 50 is pushed by the tip surface 4b of the blade portion 4a.

  Further, the push-in portion 4 includes a first chamfered portion 6 (described later) located on the distal end side of the through-hole 50 and a second chamfered portion 8 (described later) positioned on the proximal end side thereof. It has an axial length L (see FIG. 2) that can simultaneously contact 50 corresponding ends. Specifically, in the state where the push-in portion 4 is inserted through the through hole 50, the position of the end portion (lower end portion) on the front end side of the first chamfered portion 6 matches the position of the lower end portion of the through hole 50. In addition, the second chamfered portion 8 has an axial length such that the position of the end portion (upper end portion) on the proximal end side coincides with the position of the upper end portion of the through hole 50. Therefore, the axial length L of the push-in portion 4 is determined according to the axial length of the through hole 50 to be formed, that is, the thickness of the workpiece W.

  After the through hole 50 is formed in the workpiece W by the perforated part 2, the first chamfered part 6 is pressed against the end of the through hole 50 on the side in which the drill proceeds, thereby rotating the end of the first chamfered part 6. It is a part that can be chamfered. The first chamfered portion 6 is provided between the perforated portion 2 and the push-in portion 4. That is, the first chamfered portion 6 is continuously provided on the front end side of the push-in portion 4. The outermost diameter of the first chamfered portion 6 gradually decreases from the perforated portion 2 side toward the push-in portion 4 side. And the 1st chamfering part 6 has the two chamfering blades 6a (refer FIG. 1) pressed against the edge part of the through-hole 50, and chamfering the edge part. The two chamfering blades 6a are formed symmetrically with respect to the axis of the drill. Each chamfering blade 6 a is provided continuously between the cutting blade 2 a and the blade portion 4 a between the cutting blade 2 a of the punching portion 2 and the blade portion 4 a of the push-in portion 4.

  The second chamfered portion 8 can be chamfered at its end by being pressed against the end of the through hole 50 opposite to the end chamfered by the first chamfered portion 6 while rotating. Part. The second chamfered portion 8 is continuously provided on the proximal end side of the push-in portion 4. The outermost diameter of the second chamfered portion 8 gradually increases from the leveling portion 4 side toward the base end side of the drill. And the 2nd chamfering part 8 has two chamfering blades 8a (refer FIG. 1) pressed against the edge part of the through-hole 50, and chamfering the edge part. The two chamfering blades 8a are formed symmetrically with respect to the axis of the drill. Each chamfering blade 8 a is provided continuously with the blade portion 4 a of the push-in portion 4.

  The base 10 is continuously provided on the base end side of the second chamfered portion 8. The base portion 10 has an outermost diameter equal to the outermost diameter of the perforated portion 2. A range of a predetermined length from the base end portion to the tip end portion of the base portion 10 is a shank 10a that is held by a drill holding portion of a processing device (not shown). The shank 10a is held by the drill holding portion of the processing apparatus and rotated together with the drill holding portion, so that the drill rotates about its axis.

  Next, a hole drilling method using the drill according to the first embodiment will be described with reference to FIGS.

  In this hole drilling method, first, the above-described drill shank 10a is held in a drill holding portion of a machining apparatus (not shown). At this time, the drill is set in the drill holding portion so that the drilled portion 2 of the drill faces downward. Moreover, the workpiece W is installed below the drill. Then, when processing by the processing device is started, the processing device performs a punching process for forming the through hole 50 in the workpiece W. Specifically, the processing apparatus linearly descends along the axial direction of the drill as shown by an arrow S1 in FIG. At this time, a through hole 50 is formed in the workpiece W by the drilling portion 2 of the drill, and the inner surface of the through hole 50 is cut by the cutting blade 2 a of the drilling portion 2. At this time, the inner surface of the through hole 50 is cut by the cutting blade 2a, and a large number of minute scratches are formed. In the drilling step, the processing device is arranged such that the position of the lower end portion of the first chamfered portion 6 is aligned with the position of the lower end portion of the through hole 50 and the position of the upper end portion of the second chamfered portion 8 is the upper end portion of the through hole 50. Lower the drill until it is aligned with the position of.

  Next, the processing apparatus performs a pushing process for pushing the inner surface of the through hole 50 and a chamfering process for chamfering both end portions (upper end portion and lower end portion) of the through hole 50 in the axial direction. At this time, the processing apparatus revolves one revolution as shown by an arrow S3 in FIG. 6 after moving the drill in the direction shown by the arrow S2 in FIG. 6 while rotating the drill. That is, the processing device moves the drill around the inner surface of the through-hole 50 after moving the drill toward the radially outer side of the through-hole 50 while rotating the drill. Thereby, as shown in FIG. 8, the leveling portion 4 of the drill is pressed against the inner surface of the through hole 50, and the first chamfered portion 6 and the second chamfered portion 8 are placed at each corresponding end portion of the through hole 50. After being respectively pressed, in this state, the push-in portion 4 and the double-sided chamfers 6 and 8 move around along the inner surface of the through hole 50 as shown in FIGS. 9 and 10. Along with this circular movement, the inner surface of the through-hole 50 is smoothed by being pushed by the tip surface 4b of the blade portion 4a of the push-in smoothing portion 4. Specifically, since the workpiece W is made of a ductile metal material, the inner surface of the through hole 50 is deformed by pressing the tip surface 4b of the blade portion 4a of the push-in smoothing portion 4, As a result, the inner surface of the through-hole 50 in which a large number of scratches are formed in the drilling step is smoothed to become a smooth surface. Further, the lower end portion of the through hole 50 is cut and chamfered by the chamfering blade 6 a of the first chamfered portion 6 along with the circular movement, and the upper end portion of the through hole 50 is chamfered to the chamfered blade 8 a of the second chamfered portion 8. Is cut and chamfered.

  That is, in the hole drilling method of the first embodiment, the step of smoothing the inner surface of the through hole 50, the step of chamfering the lower end portion of the through hole 50, and the step of chamfering the upper end portion of the through hole 50 are performed simultaneously. .

  Then, when the drill revolves once around the drill, the machining apparatus moves the drill toward the inside in the radial direction of the through hole 50 as indicated by an arrow S4 in FIG. At this time, the processing apparatus moves the drill to the same horizontal position as the drill in the drilling step (position where the axis of the drill coincides with the axis of the through hole 50: see FIG. 11). Thereafter, as shown by an arrow S5 in FIG. 6, the machining apparatus raises the drill along the axial direction and finishes the hole machining on the workpiece W.

  As described above, in the first embodiment, the drill is capable of drilling the workpiece W, and the inner surface of the through hole 50 formed in the workpiece W by the drilling portion 2. Are provided with a leveling portion 4 that can be smoothed and a first chamfered portion 6 and a second chamfered portion 8 that can chamfer each end of the through hole 50. For this reason, after the through hole 50 is formed in the workpiece W in the drilling process by the same drill, the inner surface of the through hole 50 is pushed in the leveling process, and each end of the through hole 50 is further chamfered in the chamfering process. The part can be chamfered. That is, a series of steps including forming the through hole 50, chamfering the end of the through hole 50, and finishing the inner surface of the through hole 50 is performed without performing a complicated operation of replacing the drill with a polishing tool or the like. Can do. Therefore, in the first embodiment, the through hole 50 is formed, the end portion of the through hole 50 is chamfered, and the finishing process for smoothly finishing the inner surface of the through hole 50 is performed while preventing the work process from being complicated. Can do.

  In the first embodiment, the first chamfered portion 6 is continuously provided on the distal end side of the pusher portion 4, and the second chamfered portion 8 is continuously provided on the proximal end side of the pusher portion 4. Therefore, the first chamfered portion 6 and the second chamfered portion 8 are pushed to the inner surface of the through hole 50 at the same time as the inner surface of the through hole 50 is pressed against the inner surface of the through hole 50. It is possible to chamfer each end by pressing against the corresponding end. That is, since the leveling process and the chamfering process can be performed simultaneously, the finishing process for pressing the inner surface of the through hole 50 and the chamfering process for chamfering the end of the through hole 50 are performed separately. Processing steps can be simplified.

  Moreover, in this 1st Embodiment, the blade part 4a of the leveling part 4 of a drill is a front-end | tip surface which forms circular arc with a radius of 0.1 mm or more in the surface perpendicular | vertical with respect to the axial direction of the said leveling part 4 Since it has 4b, moderate roundness can be given to the front end surface 4b of the said blade part 4a. As a result, the front end surface 4b of the blade portion 4a can be pushed well without cutting the inner surface of the through hole 50.

  In the first embodiment, the leveling portion 4 of the drill is inserted into the through hole 50, and the first chamfered portion 6 and the second chamfered portion 8 are connected to the corresponding end portions of the through hole 50. Since it has an axial length that can be brought into contact with each other at the same time, the first chamfered portion 6 and the second chamfered portion 8 are simultaneously pressed against the corresponding end portions of the through-hole 50 to simultaneously chamfer both end portions. be able to. For this reason, a process process can be simplified more compared with the case where it is necessary to chamfer each both ends in the axial direction of the through-hole 50 separately.

(Second Embodiment)
Next, with reference to FIG. 12, the structure of the drill by 2nd Embodiment of this invention is demonstrated.

  In the drill according to the second embodiment, unlike the first embodiment, the outermost diameter of the base portion 10 is larger than the outermost diameter of the drilled portion 2. The outer diameter of the second chamfered portion 8 gradually increases from the push-in portion 4 toward the base portion 10 side, and increases until it exceeds the outermost diameter of the perforated portion 2 and matches the outermost diameter of the base portion 10. It has become. In the second embodiment, the length L in the axial direction of the push-in portion 4 is larger than the length L in the axial direction of the push-out portion 4 in the first embodiment. That is, in the second embodiment, the axial length L of the push-in portion 4 is set to be chamfered by bringing the first chamfered portion 6 into contact with the lower end portion of the through hole 50 as will be described later. In this case, the length is set such that the second chamfered portion 8 does not contact the upper end portion of the through hole 50.

  Other configurations of the drill according to the second embodiment are the same as those of the drill according to the first embodiment.

  Next, a drilling method using the drill according to the second embodiment will be described with reference to FIGS.

  In the hole machining method according to the second embodiment, the machining device (not shown) first performs a drilling process for forming the through hole 50 in the workpiece W, as in the first embodiment. At this time, the processing apparatus linearly descends along the axial direction of the drill as indicated by an arrow S1 in FIG. 13 while rotating the drill around the axis. Thereby, the through-hole 50 is formed in the workpiece W by the drilling part 2 of the drill. In the second embodiment, the machining apparatus lowers the drill until the second chamfered portion 8 is pressed against the upper end portion of the through hole 50 as shown in FIG. In the second embodiment, since the outer diameter of the second chamfered portion 8 is larger than the outermost diameter of the perforated portion 2, the second chamfered portion 2 can be simply lowered by dropping the drill along its axial direction. The chamfered portion 8 is pressed against the upper end portion of the through hole 50, thereby chamfering the upper end portion of the through hole 50. That is, in this 2nd Embodiment, the chamfering process of the upper end part of the through-hole 50 is performed by dropping a drill continuously from a drilling process.

  Next, the processing device slightly raises the drill as indicated by an arrow S2 in FIG. 13 while rotating the drill. At this time, the processing apparatus raises the drill to a position where the position of the lower end portion of the first chamfered portion 6 is aligned with the position of the lower end portion of the through hole 50 as shown in FIG. Thus, in the position where the drill is raised, the second chamfered portion 6 is located above the upper end portion of the through hole 50.

  Thereafter, the processing apparatus performs a leveling process of pressing the inner surface of the through hole 50 and a chamfering process of chamfering the lower end portion of the through hole 50 in the same process as in the first embodiment. That is, the processing apparatus moves the drill toward the radially outer side of the through hole 50 as shown by an arrow S3 in FIG. 13 while rotating the drill, and presses the leveling portion 4 against the inner surface of the through hole 50. At the same time, the first chamfered portion 6 is pressed against the lower end portion of the through hole 50 (see FIG. 16). Thereafter, the processing device revolves one revolution as shown by an arrow S4 in FIG. 13 while rotating the drill. Accordingly, as shown in FIGS. 16 to 18, the push-in portion 4 and the first chamfered portion 6 circulate along the inner surface of the through hole 50, and accordingly, the inner surface of the through hole 50 is smoothed. While pushing, the lower end of the through hole 50 is chamfered. Thereafter, the processing apparatus moves the drill to the same horizontal position as that in the drilling step as shown by an arrow S5 in FIG. 13 (see FIG. 19), and then shows the arrow in FIG. Then, the drill is lifted to finish the drilling.

  As described above, also in the second embodiment, the drill includes the perforated part 2, the push-in part 4, the first chamfered part 6, and the second chamfered part 8. For this reason, a series of processes including the formation of the through hole 50, the chamfering process of the end of the through hole 50, and the finishing process of the inner surface of the through hole 50 can be performed by the same drill. Therefore, also in the second embodiment, as in the first embodiment, the through hole 50 is formed, the end of the through hole 50 is chamfered, and the inner surface of the through hole 50 is formed while preventing the work process from being complicated. Smooth finishing can be performed.

  In the second embodiment, since the first chamfered portion 6 is continuously provided on the front end side of the push-in portion 4, the push-in portion 4 is pressed against the inner surface of the through-hole 50 and the through-hole. The first chamfered portion 6 can be pressed against the lower end portion of the through hole 50 and the lower end portion thereof can be chamfered at the same time as the inner surface of 50 is pushed. That is, since the leveling process and the chamfering process of the lower end portion of the through hole 50 can be performed at the same time, the finishing process of pressing the inner surface of the through hole 50 and the chamfering process of chamfering the lower end part of the through hole 50 are performed. The machining process can be simplified as compared with the case where it is performed separately.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes meanings equivalent to the scope of claims for patent and all modifications within the scope.

  For example, the blade portion 4 a of the push-in portion 4 has a tip surface 4 b that can be pressed at an angle of 20 ° or less with respect to the inner surface of the through hole 50 in a plane perpendicular to the axial direction of the push-in portion 4. You may have. Such a configuration of the first modification of the first embodiment is shown in FIG. Specifically, in the first modified example, the tip surface 4b of the blade portion 4a of the push-in portion 4 is formed into a flat surface, and the tip surface 4b and the through hole 50 against which the tip surface 4b is pressed are formed. The angle α between the inner surface and the inner surface is 20 ° or less. In other words, the tip surface 4b of the blade portion 4a of the push-in portion 4 has an angle of 20 ° or less inward with respect to the tangential direction of the circular locus drawn by the tip of the blade portion 4a as the drill rotates. It is formed to make.

  In the first modification, in the step of smoothing the inner surface of the through hole 50, the amount d of pushing the inner surface of the through hole 50 by the tip surface 4b of the blade portion 4a every time the smoothing portion 4 makes one rotation is , About 10 μm to about 20 μm.

  By the way, when the front end surface of the blade portion of the push-in portion stands up at an acute angle with respect to the inner surface of the through-hole 50, the inner surface of the through-hole 50 while the push-out portion rotates during the push-in process. There is a possibility that the inner surface of the through-hole 50 may be cut at the tip surface of the blade portion of the leveling portion when pressed against. On the other hand, as in the first modification, the tip end surface 4b of the blade portion 4a of the push-in portion 4 is formed on the inner surface of the through hole 50 in a plane perpendicular to the axial direction of the push-out portion 4. If it lies to the extent that it can be pressed at an angle of 20 ° or less, the inner surface of the through hole 50 can be prevented from being cut by the tip surface 4b of the blade portion 4a, and the inner surface of the through hole 50 can be improved. Can be pushed.

  Moreover, you may abbreviate | omit the 2nd chamfering part 8 among drills like the 2nd modification of the said 1st Embodiment shown in FIG.

  Moreover, you may abbreviate | omit the 1st chamfer part 6 among drills like the modification of the said 2nd Embodiment shown in FIG.

  Further, in the first embodiment, the axial length L of the push-in portion 4 is set to be equal to or longer than the axial length of the through-hole 50, and the inner surface of the through-hole 50 by the push-out portion 4 is increased. The push-in step, the chamfering step of the lower end portion of the through hole 50 by the first chamfered portion 6, and the chamfering step of the upper end portion of the through hole 50 by the second chamfered portion 8 may be performed separately.

  Moreover, in the said 2nd Embodiment, although the pressurization process of the inner surface of the through-hole 50 and the chamfering process of the lower end part of the through-hole 50 were performed simultaneously, this press-up process and the chamfering of the lower end part of the through-hole 50 were performed. You may perform a process separately. That is, after the chamfering process of the lower end portion of the through hole 50 by the first chamfered portion 6, the pressurizing portion 4 may perform the pressing process of the inner surface of the through hole 50. After performing the leveling process of the inner surface of the through hole 50 by the ridge portion 4, a chamfering process of the lower end portion of the through hole 50 by the first chamfered portion 6 may be performed.

2 Perforated part 2a Cutting blade 4 Push-in part 4a Blade part 4b Tip surface 6 First chamfered part 8 Second chamfered part 50 Through hole W Workpiece

Claims (6)

A drill for forming a through hole in a workpiece made of a metal material having ductility,
A drilling portion provided at the tip of the drill and having a cutting blade capable of drilling in the workpiece;
If the push is disposed on the base end side of the perforated part and can be smoothed by pushing the inner surface of the through hole while rotating against the inner surface of the through hole formed by the perforated part Shibu and
The end portion is chamfered by being continuously provided on at least one of the front end side and the base end side of the push-in portion and being pressed against the corresponding end portion in the axial direction of the through hole while rotating. And a chamfered portion capable of
The leveling portion has a blade portion pressed against the inner surface of the through hole,
The drill portion has a tip surface that forms an arc having a radius of 0.1 mm or more in a plane perpendicular to the axial direction of the push-in portion .   A drill for forming a through hole in a workpiece made of a metal material having ductility,
  A drilling portion provided at the tip of the drill and having a cutting blade capable of drilling in the workpiece;
  If the push is disposed on the base end side of the perforated part and can be smoothed by pushing the inner surface of the through hole while rotating against the inner surface of the through hole formed by the perforated part Shibu and
  The end portion is chamfered by being continuously provided on at least one of the front end side and the base end side of the push-in portion and being pressed against the corresponding end portion in the axial direction of the through hole while rotating. And a chamfered portion capable of
  The leveling portion has a blade portion pressed against the inner surface of the through hole,
  The drill portion has a tip surface that can be pressed at an angle of 20 ° or less with respect to the inner surface of the through hole in a plane perpendicular to the axial direction of the push-in portion. The chamfered portion is continuously provided on both the distal end side and the proximal end side of the push-in portion,
The push-in portion can simultaneously contact the chamfered portion on the distal end side and the chamfered portion on the proximal end side with each corresponding end portion of the through-hole while being inserted into the through-hole. The drill according to claim 1 or 2 , having an axial length. A drilling method for forming a through hole in a workpiece made of a ductile metal material using the drill according to claim 1 or 2 ,
A drilling step of moving the drill in the axial direction while rotating the drill, and forming a through hole in the workpiece by the drilling portion of the drill;
After the drilling step, by revolving while rotating the drill, the step of pushing the pushing portion against the inner surface of the through hole and pushing the inner surface of the through hole,
A chamfering method comprising: a chamfering step of chamfering the end portion by pressing the chamfer portion against a corresponding end portion in the axial direction of the through hole by revolving the drill while rotating. The hole machining method according to claim 4 , wherein the chamfering step is performed simultaneously with the leveling step. A hole processing method for forming a through hole in a workpiece made of a ductile metal material using the drill according to claim 3 ,
A drilling step of moving the drill in the axial direction while rotating the drill, and forming a through hole in the workpiece by the drilling portion of the drill;
After the drilling step, by revolving while rotating the drill, the step of pushing the pushing portion against the inner surface of the through hole and pushing the inner surface of the through hole,
Simultaneously with the leveling step, the chamfered portion on the distal end side and the chamfered portion on the proximal end side of the leveled portion are simultaneously pressed against the corresponding end portions in the axial direction of the through-holes. A hole drilling method comprising a chamfering step for chamfering an end portion at the same time.

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