JP3923333B2 - Cutting tool and cutting method - Google Patents

Description

[0001]
[Background of the invention]
Field of Invention:
The present invention relates to a cutting tool and a cutting method used in the continuous water construction method.
[0002]
Conventional technology:
In recent years, a cutting method has been proposed in which a groove-shaped cutting is performed on an existing pipe under constant water. In order to perform such cutting, a dedicated cutting tool is required. Therefore, the present applicant has already applied for a cutting tool suitable for such a cutting tool and a cutting method. However, since the iron pipe has a cylindrical shape, there has been a problem that the cutting tool is shaken during cutting. If such blurring occurs, the tool or machine may be damaged quickly, or the shape and width of the cut groove may be irregular.
Therefore, this invention is providing the cutting tool and cutting method which can prevent the blurring of a cutting tool.
[0003]
SUMMARY OF THE INVENTION
In order to solve the above-mentioned problems, a cutting tool according to the present invention is a cutting tool suitable for cutting a pipe, wherein a chip is removably fixed at a plurality of locations in the circumferential direction of the tool body, A milling tool that forms a surface cutting blade and a center drill that protrudes from the tip surface of the tool body are fixed to the tool body.
[0004]
Delete [0005]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are for illustration and description only. The scope of the present invention is defined based on the claims. In the accompanying drawings, the same part numbers in a plurality of drawings indicate the same or corresponding parts.
[0006]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 5 show a first embodiment.
Sealed case 2
As shown in FIGS. 1A and 2A, the sealed case 2 includes first and second divided cases 21 and 22 that are divided into two in the circumferential direction R of the existing pipe 1. The sealed case 2 is rotatable in the circumferential direction R. Rubber between the sealed case 2 and the existing pipe 1 shown in FIGS. 2A and 2B and between the first divided case 21 and the second divided case 22 shown in FIG. Sealed with packing 26. The first split case 21 is a case that covers the existing pipe 1 from below, and the second split case 22 is a case that covers the existing pipe 1 from above. As shown in FIG. 2A, a pair of first protrusions 51 are integrally formed on the right and left sides, into which the rubber packing 26 is fitted, in the sealing case 2. The first protrusion 51 protrudes inward in the tube diameter direction C on the inner surface of the sealed case 2.
[0007]
As shown in FIG. 1A, the second split case 22 is integrally formed with a branch portion 27 and a discharge hole 25. The branched portion 27 projects in a branched shape above the radial direction C of the existing pipe 1. A cutter case 31 </ b> A of the cutting machine 3 is fixed to the branch portion 27 via a work gate valve 70. A cutting tool insertion hole 28 is formed in the branched portion 27. The cutting tool insertion hole 28 is suitable for inserting a cutting tool 4 described later in the radial direction C of the existing pipe 1 and has a smaller inner diameter than the pipe inner diameter of the existing pipe 1. A rubber ring (not shown) is sealed between the branch portion 27 and the work gate valve 70 and between the work gate valve 70 and the cutter case 31A. The branched portion 27 has a female screw portion 27a for screwing a plug (not shown) inside.
[0008]
The said discharge hole 25 is for discharging | emitting the chip produced | generated when cutting the existing pipe | tube 1 with water. The discharge hole 25 is provided at a position close to the cutting tool insertion hole 28. The discharge hole 25 is provided at a position separated from the cutting tool insertion hole 28 by an angle smaller than 90 ° in a direction (first direction) R1 in which the sealing case 2 is rotated in a feeding process described later.
The discharge hole 25 may be provided with a slight displacement in the tube axis direction L with respect to the cutting tool insertion hole 28.
[0009]
Cutting machine 3
Next, an example of a preferable cutting machine 3 will be described with reference to FIG.
In the cutting machine 3 of FIG. 3, the cutter case 31 </ b> A is fixed to the work gate valve 70 (FIG. 1) via the attachment 34. A long cutter shaft 32 is inserted into the cutter case 31A and the gear case 31B. The cutter shaft 32 is rotatably supported around the axis C1 through a first bearing 36A and a bearing (not shown) in the cutter case 31A and the gear case 31B. The axis C <b> 1 of the cutter shaft 32 is set in the radial direction C of the existing pipe 1 when the cutting machine 3 is attached to the sealed case 2. The cutter shaft 32 is rotated by a reduction gear or a bevel gear (not shown) by the power of an electric motor (an example of a prime mover) 35.
[0010]
A cutting screw 37 is provided in the cutter case 31 </ b> A in parallel with the cutter shaft 32. The cutting screw 37 rotates forward and backward via bevel gears 39A and 39B by rotating a handle 38. A female screw formed on the gripping portion 36F is screwed into the cutting screw 37. The gripping portion 36F grips the cutter shaft 32 via the second bearing 36B. Therefore, by rotating the handle 38, the gripping portion 36F moves forward or backward and the cutter shaft 32 moves forward or backward as the cutting screw 37 rotates.
A female screw 32 f for fixing the cutting tool 4 is formed at the tip of the cutter shaft 32.
[0011]
Cutting tool 4
Next, the cutting tool 4 will be described with reference to FIGS.
As shown in FIG. 4B, the cutting tool 4 includes a tool main body 43 and a center drill 49 that is separate from the tool main body 43. The tool body 43 is formed with a substantially cylindrical portion 43b, a female screw portion 43c and a male screw portion 43d. The center drill 49 is screwed into the female screw portion 43 c, whereby the center drill 49 is fixed to the tool body 43. The male screw portion 43d is screwed and fixed to the female screw 32f (FIG. 3) of the cutting machine 3.
[0012]
First and second chips 44 </ b> A and 44 </ b> B are detachably fixed to the substantially cylindrical portion 43 b through male screws 45. That is, when the cutting blade 42 of each chip 44A, 44B is worn, each chip 44A, 44B can be replaced. In the case of this embodiment, the tool body 43 and the chips 44A and 44B constitute a milling tool.
[0013]
As shown in FIG. 4A, each of the chips 44A and 44B is fixed at three locations separated in the circumferential direction R3. As shown in FIGS. 4B and 5, the first tip 44A is fixed to the tip of the substantially cylindrical portion 43b, and the tip surface 40 and the outer peripheral surface 41 of the substantially cylindrical portion 43b are cut. A lathe 42 is formed, and the existing pipe 1 is cut. On the other hand, the second tip 44B constitutes a cutting edge 42 on the outer peripheral surface 41 of the substantially cylindrical portion 43b, and cuts the existing pipe 1.
[0014]
A second notch 43a is formed on the front surface of each of the chips 44A and 44B so that the male screw 45 can be screwed in. The second notch 43a is formed so that the cross section thereof becomes generally smaller as it approaches the proximal end surface 46 from the distal end surface 40 of the tool body 43. The said 2nd notch part 43a comprises the flow path of the water for discharging | emitting the chip | tip produced | generated in the sending process mentioned later with water.
[0015]
The center drill 49 of FIG. 4B protrudes from the tip surface 40 and has a tip portion 49a having a substantially tapered conical shape. The distal end portion 49 a has a substantially V-shaped cutting blade 42, and cuts a small hole in the existing pipe 1. The outer periphery 49b of the center drill 49 is set to be positioned on the outer peripheral side of the substantially cylindrical portion 43b with respect to the inner end 44Aa of the first tip 44A.
When the existing pipe 1 is cut by the tips 44A and 44B, the substantially conical center drill 49 guides the flow of water so that water is smoothly drained from the first notch 43a. Therefore, the chip recovery rate is improved. The “substantially tapered conical shape” means that the center drill 49 may be formed with the first notch 49c of FIG.
[0016]
The cutting tool 4 is suitable for cutting the existing pipe 1 having a mortar lining on the inner surface of the pipe, and the cutting edge 42 on the tip surface 40 and the outer peripheral surface 41 of the tool body 43 is made of a hard metal (Hard metal). It is preferable that the chip is composed of a chip made of The tool body 43 is preferably formed of chrome molybdenum steel.
[0017]
Below, each process of the cutting method of the existing pipe 1 in which this cutting tool 4 suitable for cutting of the existing pipe 1 is used is demonstrated.
Assembly Process First, the sealed case 2 is attached to the existing pipe 1 in a state where the liquid (water) flows in the existing pipe 1 shown in FIG. After this attachment, the operator assembles both split cases 21 and 22 with assembly bolts (not shown). Thereafter, the operator assembles the work gate valve 70 and the cutting machine 3 in the sealed case 2. Thus, the sealed case 2 surrounds a part of the existing pipe 1 in an airtight state.
[0018]
Cutting Process After the assembling process, the operator operates the cutting machine 3 to cut the cutting tool to a position where the tip 49a of the center drill 49 is close to the upper surface of the existing pipe 1 as shown in FIG. 4 is lowered. Thereafter, when the operator drives a motor (not shown), the cutting tool 4 rotates together with the cutter shaft 32 and starts a cutting motion for cutting the existing pipe 1. When the operator operates the cutting machine 3 and lowers the cutting tool 4 in the radial direction C while performing the cutting motion, the cutting of the tip 49a is performed as shown in FIG. The cutting blade 42 cuts the existing pipe 1 and pierces the small hole 15 in the existing pipe 1. Subsequently, when the cutting tool 4 is further subjected to cutting motion to cut the cutting tool 4 in the radial direction C of the existing pipe 1, the cutting blade 42 of the first and second tips 44A and 44B is cut. By rotation, a large hole 16 having a diameter larger than that of the small hole 15 is formed as shown in FIG. Thus, as shown in the two-dot chain line of FIG. 1A and FIG. 2A, the tip surface 40 of the cutting tool 4 penetrates a part of the pipe wall 1a of the existing pipe 1 toward the center in the radial direction C. To do. Thereby, the cutting of the existing pipe 1 by the cutting tool 4 is completed.
[0019]
Feeding Step After the cutting step, the operator rotates the sealing case 2 once in the circumferential direction R1 in FIG. 1 while the cutting tool 4 performs the cutting motion. That is, the cutting tool 4 performs a feed motion that rotates in the circumferential direction R1 together with the sealing case 2 while rotating around the cutter shaft 32. Thus, the operator rotates the cutting tool 4 over the entire circumference of the existing pipe 1 in a state where the cutting tool 4 is performing the feeding motion. In this way, chips are generated without generating a section, and the existing pipe 1 is cut over the entire circumference in the circumferential direction R. As shown in FIG. A cutting groove 12 </ b> C cut in the circumferential direction R over the entire circumference is formed. That is, the existing pipe 1 is divided in the pipe axis direction L.
[0020]
Tool extraction step Next, the cutting tool 4 is extracted by the method described below.
First, the operator closes the work gate valve 70 as shown in FIG. 2B after housing the cutting tool 4 in the cutter case 31A. Thereafter, the operator removes the cutting machine 3. Thereafter, the operator performs an operation of closing the cutting tool insertion hole 28 using a known plug insertion device (not shown) or the like.
The female case 65 formed in the sealed case 2 may be screwed with a set screw called a push bolt after the closing operation is completed to fix the sealed case 2 to the existing pipe 1.
[0021]
As shown in FIGS. 7A and 7B, the center drill 49 is such that the outer peripheral end 49b of the cutting blade 42 is positioned on the outer peripheral side with respect to the inner ends of all the chips 44A and 44B. It is preferable to increase the outer diameter. Further, as shown in FIGS. 7A and 7B, the outer peripheral end 49b may be formed to have a diameter slightly smaller than the outer diameter of the chips 44A and 44B.
Thus, the cutting speed can be increased by increasing the diameter of the center drill 49.
[0022]
By the way, as shown in FIGS. 9B and 9C, in the milling cutter 400 that does not have the center drill, at the time of cutting, the tip surface 401 of the milling cutter 400 moves the workpiece (tube wall). Since it pushes toward the center of a pipe | tube, as shown to the dashed-two dotted line of FIG.9 (b) and FIG.9 (c), the cut end 100 remains so that it may peel off toward the center. Therefore, when the milling cutter 400 is rotated in the circumferential direction of the existing pipe 1 and the existing pipe 1 is cut, an annular piece remains.
In contrast, as shown in FIG. 9 (a), when the perforation diameter 2R _S by the center drill 49 is sized close to the borehole diameter 2R _L by milling shaped tool 4A, that is,
In the case of R _L −10 <R _S <R _L (unit: mm), such a piece does not occur.
[0023]
The reason for this is that, as shown in FIG. 9B below, when cutting is performed with a milling cutter 400, bending stress acts on the cut end portion 100, and the cut end portion 100 bends and escapes before cutting, so that the cut end portion 100 remains. On the other hand, as shown in FIG. 9A, when the diameter 2R _S (radius R _S ) of the center drill 49 is large, the moment arm A applied to the cut end portion 100 is reduced, so that the cut end portion 100 is bent. Absent.
[0024]
The center drill 49 shown in FIG. 7B has two cutting blades 42 and two first cutout portions 49c. The two first cutout portions 49 c are arranged such that the second cutout portion 43 a of the tool main body 43 opens toward the tip of the cutting tool 4. By being arranged in this way, when draining during cutting, water flows from the second cutout portion 43a through the first cutout portion 49c, so that even if the center drill 49 is large, the chip recovery rate is increased. .
[0025]
8A and 8B show examples not included in the present invention .
As shown in FIG. 8B, the cutting tool 4 </ b> A includes a tool main body (milling tool) 43 and a center drill 49 separate from the tool main body 43. The tool body 43 is formed with a milling portion 43b, a male screw portion 43c, and a center drill insertion hole 43d. A shaft portion 49c of the center drill 49 is inserted through the center drill insertion hole 43d. The shaft portion 49 c of the center drill 49 is fixed to the tool body 43 by a set screw 48. A cutting edge 42 is integrally formed on the tip surface 40 and the outer peripheral surface 41 of the milling portion 43b of the tool body 43. The cutting edge 42 of the outer peripheral surface 41 is formed in a spiral shape. The male screw portion 43d is screwed and fixed to a female screw 32f (FIG. 3) of the cutting machine 3.
[0026]
As shown in FIG. 8 (a), the cutting blades 42 of the surfaces 40 and 41 are provided at six locations apart from each other in the circumferential direction R3.
[0027]
The center drill 49 of FIG. 8B protrudes from the tip surface 40 and has a tip portion 49a having a tapered conical shape. The distal end portion 49 a has a substantially V-shaped cutting blade 42, and cuts a small hole in the existing pipe 1. The outer periphery 49b of the center drill 49 is set to be positioned on the outer peripheral side of the milling portion 43b with respect to the inner end 42a of the cutting edge 42 of the tip surface 40.
[0028]
The cutting tool 4A is suitable for cutting a steel pipe. As the milling tool 43, it is preferable to integrally form a cutting blade 42 with high speed steel or tool steel. better not.
[0029]
When cutting pipes, the time required for cutting with a center drill is short, so the center drill's cutting edge is made of high speed steel or tool steel regardless of the type of pipe. It is preferable to use a blade.
[0030]
In each of the above examples , the method of cutting an existing pipe using the main cutting tool has been described. However, the cutting tool does not limit the method of using the main cutting tool. Therefore, it can be used in various construction methods such as cutting an existing pipe under constant water half a circumference in the circumferential direction or taking out a branch of water.
[0031]
In each of the above examples , the cutting tool is rotated in the circumferential direction of the existing pipe to cause the cutting tool to perform a feeding motion. However, the cutting tool is moved in the pipe axis direction of the existing pipe to perform the feeding motion to the cutting tool. You may let them.
In each of the above examples , a large hole was drilled with a milling tool without generating a section, but in the present invention, when a large hole was drilled with a milling tool, an annular section was generated. May be. That is, the tool body may be formed in a cylindrical shape, and the cutting edge may be provided on the tip and outer periphery of the cylindrical portion.
[0032]
As described above, the preferred embodiments have been described with reference to the drawings. However, those skilled in the art will readily understand various changes and modifications within the obvious scope by looking at the present specification.
For example, the disconnect device may be employed a known drilling machine. In addition, a cutting machine may be attached to the sealed case before surrounding the existing pipe with the sealed case.
The sealed case may be divided into three or four in the circumferential direction.
Further, the sealed case may be divided into a plurality of pieces in the tube axis direction (see, for example, JP-A Nos. 11-28735 and 11-304073), in which case it is not always necessary to rotate the entire sealed case, A part of the sealed case may be rotated.
In addition, the sealed case is composed of a plurality of divided cases that are divided into two or more in the circumferential direction before being assembled to the existing pipe. After assembly, the sealed case is endlessly integrated in the circumferential direction by welding. Also good.
Furthermore, the fluid flowing in the existing pipe in the present invention is included in the scope of the present invention even if it is other fluid such as oil in addition to water.
Accordingly, such changes and modifications are to be construed as within the scope of the present invention.
[0033]
【The invention's effect】
According to the present invention described above, since the centers drill is protruded from the distal end surface of the cutting tool, the cutting tool at the start cutting blurred danger is eliminated. Therefore, since the cutting tool can be cut into the existing pipe in a stable state, damage to the cutting machine and the wear of the cutting edge of the tool are reduced.
In addition, if the tip is fixed, even if the tip is worn due to mortar lining, the sharpness can be obtained by replacing the tip.
Also, by providing a center drill at the tip of the milling tool, the flow of water when discharging chips follows the surface of the center drill, so turbulent flow is unlikely to occur and the flow becomes smooth. , Chip collection rate increases.
[0034]
In addition, if the cutting blades on the outer peripheral surface of the cutting tool are provided at three or more locations separated in the circumferential direction of the cutting tool, since at least one of the cutting blades always contacts the cutting surface, it is further stable. It can be cut into existing pipes in the state.
[0035]
Further, if the diameter of the cutting hole by the center drill is made close to the diameter of the cutting hole by the milling tool, the feed speed at the time of cutting can be increased, so that the cutting time can be shortened. Moreover, when the tube is cut into an annular shape, there is no possibility that an annular piece will occur.
[0036]
Also, if the first notch part of the center drill is arranged so that the second notch part of the milling tool opens toward the tip of the tool, the drainage flows smoothly from the first notch part to the second notch part. Even if the outer diameter of the center drill is large, a high recovery rate of chips can be maintained.
[0037]
Further, as described above, since the cutting tool is prevented from being shaken at the time of cutting, the shape of the hole formed in the existing pipe when the cutting is completed becomes a shape close to a perfect circle. Therefore, after the hole is formed, if the cutting tool is sent in the circumferential direction or the axial direction of the existing pipe to cut the groove in the existing pipe, the shape of the groove does not become irregular, and a constant groove width tends to be obtained. . Therefore, the water stoppage of a valve or a lid inserted into the groove is improved.
[Brief description of the drawings]
FIG. 1 (a) is a cross-sectional view showing an assembly process of a construction method according to a first embodiment of the present invention, and FIG. 1 (b) is a plan view of a second divided case as viewed from the inside.
FIG. 2A is a longitudinal sectional view showing a cutting process, and FIG. 2B is a longitudinal sectional view showing a tool removing process.
FIG. 3 is a partially broken side view showing a cutting machine.
4A is a transverse sectional view of the cutting tool according to the first embodiment, and FIG. 4B is a longitudinal sectional view thereof.
FIG. 5 is a perspective view of the same.
6 (a) and 6 (b) are cross-sectional views showing a cutting process, respectively.
[7] FIG. 7 (a) cross-sectional view showing a modification of the cutting tool according to the first embodiment, FIG. 7 (b) is a perspective view of the cutting tool.
It is.
FIG. 8A is a cross-sectional view of a cutting tool not included in the present invention , and FIG. 8B is a side view of the same section.
FIG. 9 is a schematic diagram showing a state of cutting at the time of cutting.
[Explanation of symbols]
1: Existing pipe 15: Small hole 16: Large hole 4: Cutting tool 4A: Milling tool 40: Tip surface 41: Outer peripheral surface 42: Cutting blade 43: Tool body 43a: First notch 44A: First tip 44Aa : Inner end 44B: second tip 45: male screw 49: center drill 49a: tapered cone tip 49b: outer periphery of center drill C: radial direction L: axial direction R: circumferential direction R3: circle Circumferential direction

Claims (5)

A cutting tool suitable for cutting pipes,
A milling tool in which a chip is removably fixed at a plurality of locations in the circumferential direction of the tool body, and a cutting edge on the outer peripheral surface is configured by the chip;
A cutting tool provided with a center drill that is separate from the tool main body, protrudes from the tip end surface of the tool main body, and has a plurality of cutting blades integrally formed instead of chips. A cutting tool suitable for cutting pipes,
A milling tool in which a chip is removably fixed at a plurality of locations in the circumferential direction of the tool body, and a cutting edge on the outer peripheral surface is configured by the chip;
A center drill that is separate from the tool body, protrudes from the tip surface of the tool body, and has a plurality of cutting blades integrally formed instead of a chip,
The cutting tool set so that the outer peripheral end of the cutting blade of the center drill is positioned on the outer peripheral side with respect to the inner end of the cutting blade of the tip. In claim 1 or 2,
The tip is made of cemented carbide,
The cutting tool of the center drill is a cutting tool formed integrally with the center drill from high-speed steel or tool steel. A cutting tool suitable for cutting pipes,
A milling tool in which a chip is removably fixed at a plurality of locations in the circumferential direction of the tool body, and a cutting edge on the outer peripheral surface is configured by the chip;
A center drill that is separate from the tool body, protrudes from the tip surface of the tool body, and has a plurality of cutting blades integrally formed instead of a chip,
The hole diameter of the small hole cut by the center drill is smaller than the hole diameter of the large hole cut by the cutting blade of the milling tool, and
Cutting tool in which the radius R _{S of the} small hole is set in the following range with respect to the radius R _{L of the} large hole.
R _L −10 <R _S <R _L (unit: mm) A continuous water cutting method of cutting an existing pipe using the cutting tool according to any one of claims 1 to 4 ,
Drilling a hole in the tube while rotating the cutting tool,
Thereafter, while continuing the rotation of the cutting blade on the outer peripheral surface, the cutting tool is moved in at least one of the circumferential direction or the axial direction of the tube to cause the cutting tool to perform a feeding motion, thereby cutting the tube. Cutting method.

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