JP2003103411A - Burring drill and pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a burring drill capable of easily forming a burring part projecting into the internal space of a plate material and to provide a pipe with the burring part formed by the burring drill. SOLUTION: The burring drill comprises, from the end part side of the drill, a drill cutting edge domain 100, a burring forming domain 200, a burring shaping domain 300 and a shank domain 400. A helical tooth is provided on the outer periphery surface of the drill cutting edge domain 100. A taper face is formed on the burring forming domain 200, the outside diameter gradually increasing from the drill cutting edge domain 200 to the burring shaping domain 300. The burring shaping domain 300 includes shaping surfaces 300a and 300b which are curved surfaces and provided at a first distance L1 from an axial center, and flank domains 301 and 302 which are linear and provided at a second distance L2 shorter than the first distance L1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burring drill and a pipe, and more particularly, it is possible to easily form a burring portion on a plate material such as a pipe having an internal space made of a thin member. The present invention relates to a burring drill and a pipe having a burring portion formed by using the burring drill.

[0002]

2. Description of the Related Art In recent years, a pipe has been used as a frame for a large precision machine such as a copying machine, and a female screw hole is provided in the pipe for fixing the device to the pipe. However, in recent years, from the viewpoint of cost reduction, it has been required to use a pipe having a thin plate material.

Since a conventional pipe uses a plate material having a wall thickness of 1.6 mm or more, a thread ridge capable of obtaining a sufficient tightening torque can be formed in the female screw hole. However, in the case of a thin pipe, it is required to use a plate material having a thickness of 1.0 mm to 1.2 mm, and a plate material having a thickness of 1.0 mm to 1.2 mm. When the female screw hole is formed in the screw hole, there arises a problem that the screw thread that can obtain a sufficient tightening torque cannot be formed.

Therefore, it is conceivable to partially increase the thickness of the plate material by forming a burring portion at the portion of the pipe where the female screw hole is to be formed.

Here, a method of forming the burring portion on the plate material will be described with reference to FIGS. 18 and 19.
With reference to FIG. 18, a plate material 10 having a prepared hole 10a is provided in advance with a die 20 provided with a predetermined opening 20a.
It is positioned and placed at a predetermined position. Then, referring to FIG. 19, the upper die 30 is lowered from above to form the cylindrical burring portion 10 b on the plate member 10.

[0006]

However, in the above-mentioned method of forming the burring portion on the plate material, a lower hole is provided at a predetermined position on the side surface of the pipe, and the lower mold is arranged in the internal space of the pipe so that the upper mold is formed. It is necessary to form a burring portion that protrudes toward the inner space side of the pipe by driving, but since a long object is generally used for a pipe used as a frame, it is necessary to insert it into the inner space of the pipe. The shape of the die should be long. As a result, it is difficult to position the die, the workability for inserting the die into the internal space of the pipe is lowered, and the workability of the burring process on the pipe as a whole is significantly lowered.

On the other hand, the plate material of the pipe facing the area where the burring portion is formed is provided with a through hole, and the die is arranged by utilizing this through hole, thereby avoiding the lengthening of the die. It is also possible to realize easy positioning of the die and easy workability for inserting the die into the internal space of the pipe. However, according to this method, the provision of the holes in the pipe results in another problem that the strength of the pipe is reduced.

Therefore, the present invention has been made to solve the above-mentioned problems, and does not require the insertion of a die into the internal space of the pipe, and allows the plate material of the pipe having the internal space to face the internal space. An object of the present invention is to provide a burring drill capable of easily forming a protruding burring portion and a pipe having a burring portion formed by using the burring drill.

[0009]

To achieve the above object, in a burring drill according to the present invention, a burring portion protruding toward the inner space side is formed in a plate material bent to have an inner space. The burring drill, in order to make a hole in the plate material of the pipe, is provided with a twisting blade on the outer peripheral surface, a drill blade region extending in the axial direction, and at the rear end side of the drill blade region, of the drill blade region. A burring forming region formed of a region protruding outward from the outer diameter and a burring shaping region extending in the axial direction from the outer peripheral end of the burring forming region toward the rear end side are provided.

In the case of using the burring drill having the above-mentioned structure, first, the burring drill is advanced while rotating without rotating the burring drill in the plate material portion so that the plate material portion of the pipe is drilled by the drill blade area. Can be applied. After that, by continuing to rotate the burring drill and advancing the burring forming region into the prepared hole processing region, the burring forming region abuts the pipe plate material and gradually extrudes the plate material toward the internal space side. To form a burring portion. After that, by further advancing while rotating the burring drill, the burring shaping region enters the burring portion, so that the shape of the burring portion can be adjusted.

As described above, only by advancing the burring drill while rotating it, it is possible to form the burring portion projecting toward the inner space side on the plate member bent to have the inner space. As a result, it becomes unnecessary to perform the pilot hole processing and the die arrangement in the internal space of the pipe, which are required for the conventional burring processing, and the burring processing process can be simplified. Further, since the burring process is completed only by the descending operation of the rotating burring drill, the workability of the burring process on the pipe is improved, and the cost can be reduced.

Further, even in the case of a thin plate material, the burring process can be easily performed as described above, and as a result, the plate thickness in the burring process portion becomes thicker, so that a sufficient tightening torque can be obtained. It becomes possible to form mountains.

Further, in the above invention, preferably, the burring forming region has a tapered surface whose outer diameter gradually increases from the drill blade region side toward the burring shaping region side. By having the tapered surface in this way, when the plate material is raised while the burring formation region is in contact with the plate material, the resistance from the plate material is dispersed and the plate material is gradually generated, so that it is added to the burring drill. It is possible to disperse the processing resistance and prevent the plate material from being broken due to the rapid bending of the plate material.

Further, in the above invention, preferably, the burring shaping region extends in the axial direction from the outer peripheral end of the burring forming region toward the rear end side and is provided at a first distance from the axis. A shaping surface area and a flank surface area provided at a position of a second distance shorter than the first distance are included. Further, in the above invention, more preferably, two or more shaping surface regions are provided on an outer peripheral surface of the burring shaping region, and the flank surface regions are provided between the shaping surface regions.

When the burring shaping region has a uniform cylindrical shape, it is experimental that a projection is formed on the surface of the plate material such as a pipe opposite to the area where the burring portion is formed, that is, the surface side of the plate material. Confirmed. The formation of the protrusions causes the device or the like to come into contact with the front surface side of the pipe, and therefore the presence of the protrusions causes a problem that the device cannot be attached to the plate material such as the pipe without a gap.

Therefore, by providing the shaping surface region and the flank surface region as described above, the plate material pushed by the shaping surface region can flow to the flank surface region during shaping of the burring portion. Will be sequentially fed in the direction of movement of the burring drill, and it will be possible to avoid the formation of protrusions on the surface side of the plate material.

In a preferred form, the plate material is
By virtue of the pipe having the internal space, it is possible to obtain the advantageous effects of the present invention.

In order to achieve the above object, a pipe according to the present invention is a pipe having a closed internal space, which is formed by using the above-mentioned burring drill and which projects toward the internal space. It is characterized by having.

In the pipe having this structure, even if the pipe is made of a thin plate material, the plate thickness at the burring portion becomes thicker, so that a sufficient screw thread can be obtained. Can be formed.

In the above invention, preferably, the plate material of the pipe has a wall thickness of 0.6 mm to 1.2 mm. Further, in the above invention, preferably, the pipe is a round pipe having an outer diameter of 20 mm to 30 mm. Further, in the above invention, preferably, the pipe is a square pipe having one side of the outer circumference of 20 mm to 30 mm.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION A burring drill according to an embodiment of the present invention and a pipe in which a burring portion is formed using this burring drill will be described below with reference to the drawings. In each figure,
In order to facilitate understanding of the shape of each region, the ratio is shown differently from the actual ratio.

(Structure of Burring Drill) First, the structure of the burring drill 1 in the present embodiment will be described with reference to FIGS. 1 and 2. 1 is a side view showing the entire structure of the burring drill 1 in the present embodiment, and FIG. 2 is a view taken in the direction of the line II-II in FIG.

First, referring to FIG. 1, the burring drill 1 is a burring drill for forming a burring portion projecting toward the inner space side on a plate material of a pipe having an inner space. From the part side, a drill blade region 100, a burring forming region 200, a burring shaping region 300, and a shank region 400 are provided.

The drill blade region 100 is provided with a twisting blade on the outer peripheral surface in order to make a hole in the plate material of the pipe as the burring drill 1 advances in the axial direction. The burring formation region 200 is a region that projects outward from the outer diameter of the drill blade region 100 on the rear end side of the drill blade region 100, and in the present embodiment, the burring shaping region 300 is formed from the drill blade region 100 side. The tapered surface is formed so that the outer diameter gradually increases toward the side.

The reason why it is preferable to provide a tapered surface as the burring formation region 200 is that the burring formation region 2 is formed.
When 00 abuts the plate material of the pipe and raises the plate material to the inner space side, the resistance from the plate material is dispersed and the plate material is gradually generated, so that the machining resistance applied to the burring drill 1 is dispersed. This is because it is possible to prevent the plate material from being broken due to the plate material being rapidly bent. Therefore, if such a phenomenon does not pose a problem, it is not necessary to provide a tapered surface, and, for example, as shown in FIG. 3, a burring forming region having a surface orthogonal to the axial direction of the burring drill 1 is formed. Two
It is also possible to adopt 00.

The burring shaping region 300 is provided so as to extend in the axial direction from the outer peripheral end portion of the burring forming region 200 toward the rear end side, and the burring shaping region 300 has a curved shape with the distance from the axis being the first distance L1. Surface areas 300a and 300b,
Linear flank area (D cut area) 301, 302 provided at a position of a second distance shorter than the first distance L1
And (the shortest distance L2). Further, as shown in the drawing, a flank surface region 301 and a flank surface region 302 are provided between the shaping surface region 300a and the shaping surface region 300b. The functions of the shaping surface areas 300a and 300b and the flank surface areas 301 and 302 will be described later.

Drill blade area 10 of burring drill 1
0, burring forming area 200, burring shaping area 3
00 and the outer diameter dimension relationship of the outer peripheral surface of the shank region 400, as shown in FIG. 2, the drill blade region 100 has the smallest diameter φL1, and then the burring shaping region 30.
The 0 shaped surface region has a diameter φL2, and then the shank region 400 has a diameter φL3. Here, the burring formation region 200 has the same diameter φL1 as the front end portion and the burring shaping region 30 at the rear end portion.
It has the same diameter φL2 as 0. In addition, the flank area 30
The mutual interval of 1,302 is W1.

For example, the specific dimensions of the burring drill 1 for drilling a hole having an opening diameter of φ3.5 mm in a pipe are: φL1 = φ3.0 mm, φL2 = φ3.5 mm, φ
L3 = φ4.0 mm and W1 = 3.0 mm. Also,
The axial length is 5.0 mm for the drill blade region 100, 2.0 mm for the burring region 200, 5.0 mm for the burring shaping region 300, and 25.0 mm for the shank region 400.

Further, the surfaces of the drill blade region 100, the burring forming region 200, the burring shaping region 300, and the shank region 400 of the burring drill 1 are subjected to a surface treatment that is excellent in lubricity and is resistant to seizure. A preferable example is surface treatment such as diamond coating.

(Process for Burring Pipe) Next,
A burring process for a pipe using the burring drill 1 shown in FIG. 1 will be described with reference to FIGS. 4 to 7. The case where a hole of φ3.5 mm is formed in the pipe will be described. 4 to 7 are sectional process diagrams showing a burring process for a pipe using the burring drill 1.

First, referring to FIG. 4, a square pipe 600
The burring drill 1 is lowered to one side while being rotated. The pipe 600 has a side of 20 mm and a plate thickness of 1.
It is a 2 mm square pipe and has a closed internal space. The rotation speed of the burring drill 1 is 1
000 rpm to 1200 rpm, descending speed is 80
It is about mm / min to 160 mm / min.

Next, referring to FIG. 5, the drill blade region 10
By 0, a pilot hole is formed on one side of the pipe 600. After that, the burring drill 1 is continuously rotated and lowered. Next, referring to FIG. 6, the burring forming region 20 is formed.
While 0 is in contact with the plate material of the pipe 600, the pipe 600
Gradually raise the plate material toward the inner space side.

Here, as described above, according to the burring drill 1 in the present embodiment, since the burring forming region 200 is provided with the tapered surface, the burring forming region 200 is in contact with the plate material of the pipe. As a result, the resistance from the plate material is dispersed, the processing resistance applied to the burring drill 1 is dispersed, and the plate material can be prevented from being broken due to the rapid bending of the plate material.

Next, referring to FIG. 7, by continuing to lower the burring drill 1 while rotating it, the burring forming region 200 causes the plate material to be raised toward the inner space side by approximately 90 ° to form the burring portion 602. To be done. Then, the shape of the burring portion 602 is shaped by the burring shaping region 300 passing through the burring portion 602 while rotating.

Here, in the burring drill 1 according to the present embodiment, the burring shaping region 300 has shaping face regions 300a and 300b and flank face regions 301 and 3.
02 is provided. For example, when the burring shaping region 300 has a uniform cylindrical shape as shown in the cross-sectional view of FIG. 8, the surface of the plate member 601 of the pipe 600 opposite to the region where the burring portion 602 is formed, That is, it was confirmed that the protrusion S as shown in FIG. 9 was formed on the surface side of the pipe 600. The projection S is formed when the device etc. is mounted on the front surface side of the pipe 600.
There is a problem in that the device cannot be attached to the pipe 600 without a gap due to the existence of.

Therefore, as described above, the shaping surface area 300
By providing a and 300b and flank regions 301 and 302, the plate member 601 pressed by the shaping surface regions 300a and 300b can flow to the flank regions 301 and 302 when shaping the burring portion 602. Therefore, the plate member 601 is sequentially fed in the rotation advancing direction of the burring drill 1, and it is possible to avoid the formation of the projection S on the surface side of the pipe 600.

Therefore, the shape of the burring shaping region 300 is not limited to the shapes shown in FIGS. 1 and 2, and the shaping surface region that contacts the inner surface of the burring portion 602 and the inner surface of the burring portion 602 do not contact. It suffices that the flank surface regions are provided alternately. For example, as shown in the cross-sectional view of the burring shaping region 300 in FIG. 10, the shaping surface regions 300c, 300d, 300 formed of curved surface portions are provided.
e, 300f and linear flank surface regions 303, 304,
A configuration in which 305 and 306 are alternately provided, and FIG.
As shown in the sectional view of the burring shaping region 300 of FIG.
When forming a drill blade region having a twisting blade direction opposite to the twisting blade direction of the drilling blade region 100 and looking at one cross section, a shaping surface region 300 including two curved surface portions.
g, 300h and two linear flank areas 306, 3
It is also possible to adopt a configuration in which 07 and 10 appear alternately.

FIG. 12 shows a cross-sectional shape of the pipe 600 shown in FIGS. 4 to 8, which is formed by the burring process using the burring drill 1 and has a burring portion protruding toward the inner space side. In FIG. 12, W = 25 mm, t1 = 1.2 mm, t2 = 1.7 m
m, φ3 = 3.5 mm.

According to the pipe 600 having this shape,
Even when the pipe 600 is made of a thin plate material, the plate thickness in the burring portion 602 becomes thicker, so that it is possible to form a screw thread capable of obtaining a sufficient tightening torque.

The optimum plate thickness of the pipe when the burring drill 1 in this embodiment is used is as follows.
0.6 mm to 1.2 mm is preferable, and the shape of the pipe is a round pipe having a diameter of 20 mm to 30 mm,
Alternatively, a square pipe having a side length of 20 mm to 30 mm is preferable.

(Operation / Effect) As described above, according to the burring drill and the pipe in the present embodiment, the pipe 60
By making the burring drill 1 rotate while advancing without making a pilot hole in the plate material 601 portion of 0, it becomes possible to perform the pilot hole processing by the drill blade region 100 in the plate material 601 portion of the pipe 600. After that, the burring formation region 200 enters the prepared hole processing region by advancing the burring drill 1 while rotating the burring drill 1 to move the burring formation region 200 into the pipe 6.
The burring portion 602 is formed by projecting the plate material toward the inner space side of the pipe 600 while contacting the plate material 601 of No. 00. After that, by further advancing while rotating the burring drill 1, the burring shaping region 300 enters the inner surface of the burring portion 602,
The shape of the burring portion 602 can be adjusted.

As described above, the burring portion 602 protruding toward the inner space can be formed on the plate member 601 of the pipe 600 having the inner space only by advancing the burring drill 1 while rotating. . As a result, it becomes unnecessary to perform the pilot hole processing and the die arrangement in the internal space of the pipe, which are required for the conventional burring processing, and the burring processing process can be simplified.

Further, since the burring process is completed only by the descending operation of the rotating burring drill 1, the workability of the burring process on the pipe 600 is improved and the cost can be reduced.

Further, even when the pipe 600 is made of a thin plate material, the burring process can be easily performed as described above, and as a result, the plate thickness in the burring process portion becomes thicker and a sufficient tightening torque can be obtained. It is possible to form threads.

The shape of the burring drill 1 shown in FIG. 1 is merely an example.
To burring drills 1A to 1E as shown in FIG.
Can be adopted. Each of the burring drills 1A to 1E is characterized by the shape of the burring forming region and the burring shaping region.

The shape of the burring forming area 200a of the burring drill 1A shown in FIG. 13 is that a burring surface having an irregular shape is provided along the circumferential direction, and a concave surface that is inclined in the same direction as the torsion blade formed in the drill blade area is formed. Have As the shape of the burring shaping region 300a, the same shape as that shown in FIG. 10 is adopted.

The shape of the burring forming area 200b of the burring drill 1B shown in FIG. 14 is similar to the shape of the burring forming area 200a, but the inclination direction of the concave surface is formed in the drill blade area. The difference is that it is inclined in the opposite direction to the twist blade. The burring shaping region 300b has the same shape as that shown in FIG.

The burring forming area 200c and the burring shaping area 30 of the burring drill 1C shown in FIG.
The shape of 0c is such that four convex members extending in the axial direction are formed at a pitch of 90 ° on the circumference, and the tip end portion of the convex member is inclined in the direction opposite to the twist blade formed in the drill blade region. The burring forming region 200c is formed by being provided in the above, and the burring shaping region 300c is formed in the region of the convex member. The tip of the convex member may be inclined in the same direction as the twisting blade.

The shape of the burring forming region 200d of the burring drill 1D shown in FIG. 16 is provided with two acute-angled convex portions projecting toward the tip side on the circumference. The shape of the burring shaping region 300d is the same as that shown in FIG.

The shape of the burring region 200d of the burring drill 1E shown in FIG. 17 is such that four sloping surfaces are provided on the circumference, the sloping surfaces sloping away from the axis from the tip side toward the rear side. The shape of the burring shaping region 300e is
The same shape as shown in FIG. 10 is adopted.

As described above, various shapes can be adopted in the burring formation area and the burring shaping area, and for example, the shapes shown in the above-described embodiments can be combined appropriately.

Further, in the above-mentioned embodiment, the case where the burring portion is formed in the pipe having the internal space as the plate material has been described, but the plate material is not limited to the pipe, and the U shape, this character shape Even in the case where the burring portion is formed on the plate material having the internal space that is bent in the same manner, it is possible to obtain the same effect as the above.

Therefore, the above-described embodiment disclosed this time is an example in all respects. Therefore, the technical scope of the present invention is defined not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[0054]

As described above, according to the burring drill according to the present invention, it is not necessary to perform the pilot hole processing and the die arrangement in the internal space of the bent plate material, which are required in the conventional burring processing, and the internal space is eliminated. It is possible to simplify the burring process for the plate material that is bent so as to have.

Further, according to the pipe according to the present invention,
Even when the pipe is made of a thin plate material, the plate thickness in the burring portion becomes thicker, so that it is possible to form a screw thread capable of obtaining a sufficient tightening torque.

[Brief description of drawings]

FIG. 1 is a side view showing an entire structure of a burring drill 1 in the present embodiment.

FIG. 2 is a view from the direction of the line II-II in FIG.

FIG. 3 is a side view showing the overall structure of a burring drill 1 having a burring forming region 200 of another form.

FIG. 4 is a first sectional view showing a burring process for a pipe using the burring drill 1 in the present embodiment.

FIG. 5 is a second cross-sectional view showing a burring process for a pipe using the burring drill 1 in the present embodiment.

FIG. 6 is a third cross-sectional view showing a burring process for a pipe using the burring drill 1 according to the present embodiment.

FIG. 7 is a fourth cross-sectional view showing a burring process for a pipe using the burring drill 1 in the present embodiment.

FIG. 8 is a cross-sectional view in the case where the burring shaping region 300 has a uniform cylindrical shape.

FIG. 9 is a cross-sectional view when a protrusion S is formed on the front surface side of a pipe 600.

FIG. 10 is a burring shaping region 30 having another form.
It is a 1st sectional view of 0. FIG.

FIG. 11 is a burring shaping region 30 having another form.
It is a 2nd sectional view of 0.

FIG. 12 is a cross-sectional view of a pipe that is formed by a burring process using the burring drill 1 and that includes a burring portion that projects toward the internal space.

FIG. 13 is a side view showing the entire structure of a burring drill 1A according to another embodiment and a view seen from the tip side.

FIG. 14 is a side view showing the entire structure of a burring drill 1B according to another embodiment and a view seen from the tip side.

FIG. 15 is a side view showing the entire structure of a burring drill 1C according to another embodiment and a view seen from the tip side.

FIG. 16 is a side view showing the entire structure of a burring drill 1D according to another embodiment and a view seen from the tip side.

FIG. 17 is a side view showing the entire structure of a burring drill 1E according to another embodiment and a view seen from the tip side.

FIG. 18 is a first cross-sectional view showing a method for forming a burring portion on a conventional plate material.

FIG. 19 is a second cross-sectional view showing a conventional method for forming a burring portion on a plate material.

[Explanation of Codes] 1,1A, 1B, 1C, 1D, 1E Burring Drill, 100 Drill Blade Area, 200, 200A, 200
B, 200C, 200D, 200E Burring forming region, 300, 300A, 300B, 300C, 300
D, 300E burring shaping area, 400 shank area, 300a, 300b, 300c, 300d, 30
0e, 300f, 300g, 300h Shaping surface area, 3
01, 302, 303, 304, 305, 306, 30
7 flank area, 600 pipe, 601 plate material, 60
2 Burling part.

Continued front page    (72) Inventor Masanobu Yoshikawa             1-36 Takebuchi Nishi, Yao City, Osaka Prefecture Stock Association             Company beauty craft F-term (reference) 3C037 EE00

Claims (9)

[Claims] 1. A burring drill for forming a burring portion protruding toward an internal space in a plate material bent to have an internal space, wherein the burring drill is twisted on an outer peripheral surface to form a hole in the plate material. A blade is provided, a drill blade region that extends in the axial direction, and a burring formation region consisting of a region protruding outward from the outer diameter of the drill blade region on the rear end side of the drill blade region, and the burring formation region. A burring shaping region extending in the axial direction from the outer peripheral end toward the rear end,
Burring drill. 2. The burring drill according to claim 1, wherein the burring formation region has a tapered surface whose outer diameter gradually increases from the drill blade region side toward the burring shaping region side. 3. The shaping surface region, wherein the burring shaping region extends in the axial direction from the outer peripheral end of the burring formation region toward the rear end side, and is provided at a first distance from the shaft center, The flaring drill according to claim 1 or 2, further comprising: a flank area provided at a second distance that is shorter than the first distance. 4. The burring drill according to claim 3, wherein two or more shaping surfaces are provided on an outer peripheral surface of the burring shaping area, and the flank surface areas are provided between the shaping surface areas. 5. The burring drill according to claim 1, wherein the plate member is a pipe having an internal space. 6. A pipe having an internal space, characterized by having a burring portion formed by using the burring drill according to any one of claims 1 to 4 and protruding toward the internal space side. ,pipe. 7. The plate material of the pipe has a thickness of 0.6 mm.
7. The pipe of claim 6, which is from 1.2 mm. 8. The pipe according to claim 6, wherein the pipe is a round pipe having an outer diameter of 20 mm to 30 mm. 9. The pipe has a length of one side of an outer periphery of 20.
The pipe according to claim 6 or 7, which is a square pipe of mm to 30 mm.