JP6708904B2 - Metal tube expansion tool - Google Patents

Description

The present invention relates to a pipe expanding tool for a metal pipe such as a thin stainless steel pipe.

When connecting a metal tube such as the thin-walled stainless steel tube to a valve or a joint, the vicinity of the end is plastically deformed from the inside to expand the diameter into a bump or a flange. FIG. 3 shows an example of the joint 6, in which the metal pipe 5 has a bump-like enlarged diameter portion 52 formed at a portion slightly entering from the end portion 51 thereof. Then, as shown on the right side of FIG. 3, the end portion 51 of the metal pipe 5 and the opening portions 59 and 71 of the cap nut 7 are opposed to the opening portion 61 of the joint 6 to form a male screw formed on the outer periphery of the joint 6. By screwing the female screw 72 of the cap nut 7 into the screw 62, the joint 6 and the metal pipe 5 are connected as shown on the left side of FIG. 3.

At the time of the connection, the inclined surface 521 on the rear side of the expanded diameter portion 52 is pressed in the direction of the joint 6 by the guide inclined surface 73 of the cap nut 7, so that the inclined surface 521 is fitted into the inside of the opening 61 of the joint 6 in advance. The front inclined surface 522 is crimped to the packing 8, and the disc spring 9 fitted on the outer circumference of the male screw 62 is provided between the receiving surface 63 of the joint 6 and the tip portion 74 of the cap nut 7 as necessary. The cap nut 7 is crimped and the reaction thereof prevents the cap nut 7 from loosening with respect to the joint 6, and at the same time, fluid leakage from the connecting portion between the metal pipe 5 and the joint 6 is prevented.

Then, in order to realize such a connection structure, Patent Document 1 is proposed as a tool for expanding the metal tube 5. According to the prior art, a metal tube is fitted inside a flange having an enlarged diameter portion corresponding to the portion to be expanded on the inner peripheral surface, and the tube expansion rubber arranged inside the metal tube is pulled by a piston (shaft) and compressed. Then, the metal pipe is bulged in the radial direction, the metal pipe is expanded and plastically deformed.

In order to compress the pipe expanding rubber, to further expand the metal pipe for plastic deformation, a very large force is required to pull the piston (shaft). Therefore, in Patent Document 1, hydraulic pressure is used to drive the piston (shaft). Other electric tools are commercially available.

JP, 2011-194438, A

In the prior art, hydraulic pressure and a motor are used to generate the large force, and there is a problem that the tool is large and the cost is high. Therefore, the conventional technique is suitable for processing a metal pipe, but is not suitable for a metal pipe that does not require a large force for processing.

An object of the present invention is to provide a metal pipe expanding tool that can be made compact and low cost.

The metal pipe expanding tool of the present invention is a tool for expanding the metal pipe by plastically deforming the vicinity of the end portion of the metal pipe from the inside, and a cap provided with a cylindrical base portion and an end plate fitted to one end thereof. The end plate has a recess into which the end of the metal pipe is fitted, the bottom of the recess serves as an abutment surface against which the end face of the metal pipe abuts, and the side surface of the recess is Such an adapter, which has an inclined surface corresponding to the portion to be expanded, and a cylindrical main body having an internal space communicating with the adapter, and a cylindrical body that is inserted into the main body and is prevented from axial displacement and is rotatable. A drive shaft that is supported by the drive shaft and has one end protruding toward the side opposite to the adapter and is driven to rotate, and one end thereof is concentric with the drive shaft on the other end side of the drive shaft and the drive shaft is rotatable. A shaft which is screwed to the other end and is held slidably in the axial direction while preventing rotation around the axis by the main body between the other end and the one end thereof; A pressing ring that is inserted into an opening formed in the bottom of the recess of the plate and is fixed to the other end of the shaft, and the other end is enlarged in diameter, and one end of the pressing ring that is formed annularly And a pipe-expanding rubber that expands the pipe by narrowing the pressure between the bottom of the recess and the expanded end of the pressing ring and expands the expanded portion of the metal pipe. And

According to the above configuration, when connecting a metal pipe such as a thin-walled stainless steel pipe to a valve or a joint, plastically deform the vicinity of the end of the metal pipe from the inside to expand the pipe, and in the vicinity of the end. The internally expanded tube-expanding rubber is axially compressed and elastically deformed to expand the diameter, thereby expanding the diameter-expanded portion of the metal tube. When the expanded rubber is compressed and expanded in diameter, the force of screwing is used for compression to enable manual compression.

As a specific structure therefor, a cap-shaped adapter is provided, and a concave portion into which the end portion of the metal pipe is fitted from the outside is formed in the end plate portion of the adapter, while the main body to which the adapter is set. The one end of the retaining ring, which is inserted through the opening formed in the bottom of the recess, is fixed to the shaft that moves forward and backward, and the one end is covered with the pipe expanding rubber before the insertion of the opening. Then, the tube-expanding rubber is sandwiched between the diameter-expanded other end of the holding ring and the bottom of the recess, and the tube-expanding rubber is compressed/released by advancing and retracting the shaft.

Then, the shaft is projected and retracted by rotation of a drive shaft that is connected to one end of the shaft and is rotatable with respect to the main body and is prevented from being displaced in the axial direction. One end of the drive shaft, which is opposite to the side connected to the shaft, projects from the main body and is rotatably driven, and the shaft has one end screwed to the drive shaft and the other end. An intermediate portion between and is held by the main body so as to be slidable in the axial direction while being prevented from rotating about the axis.

Therefore, since the force of screwing the drive shaft into the shaft is used for compressing the expanded rubber, it is possible to manually compress the expanded rubber by rotating one end of the drive shaft with a tool such as a ratchet wrench. You can As a result, the tool does not require a power supply, the tool is small and lightweight and easy to carry, and cost reduction of the tool can be expected.

Further, in the metal pipe expanding tool of the present invention, the adapter, the pipe expanding rubber, and the pressing ring are detachable from the main body, so that they can correspond to the diameter of the metal pipe.

According to the above configuration, by simply replacing at least the adapter, the pressing ring and the tube expanding rubber, it is possible to cope with a plurality of kinds of metal tube diameters such as nominal 1/2B, 3/4B and 1B. ..

As a result, when dealing with the diameters of a plurality of types of metal pipes, it is possible to share the parts other than those parts and further reduce the cost and space of the tool.

Furthermore, in the metal tube expanding tool of the present invention, a rod-shaped grip extending in the radial direction is attached to the main body, and a rod-shaped handle extending in the radial direction is attached to one end of the drive shaft. A person grips the grip and rotates the handle to slide the shaft.

According to the above configuration, in the case of a thin-walled stainless steel pipe of about 0.3 t, which is easily plastically deformed, that is, when the deformation force is small, the main body is provided with a grip that is gripped by an operator while preventing rotation. At one end of the shaft, there is a handle that can be rotated with a small force by the principle of leverage.

Therefore, a tool for rotating the drive shaft, such as the ratchet wrench described above, is not required, and it becomes easier to carry.

Further, in the metal pipe expanding tool of the present invention, a needle-shaped roller that rotatably supports while preventing displacement in the axial direction is interposed between the main body and the drive shaft, and the main body and the drive shaft. And a drive bush that rotatably supports the drive shaft while preventing the displacement of the drive shaft in the radial direction.

According to the above configuration, a needle roller is used to support the drive shaft so that the drive shaft is not displaced in the axial direction, and a drive bush (cylindrical oil-free bearing) is used to support the drive shaft so that the drive shaft is not displaced in the radial direction. Friction (necessary force) between the drive shaft and the main body can be reduced, and manual work can be further facilitated.

Furthermore, in the metal pipe expanding tool of the present invention, one of the other end of the drive shaft and the one end of the shaft is an outer cylinder, and the other is an inner cylinder that is screwed into the outer cylinder, and A spiral groove for forming a length corresponding to the crushing margin of the pipe expanding rubber, or one outer cylinder side is formed hollow for a length corresponding to the crushing margin of the pipe expanding rubber, Is characterized by being formed solid.

According to the above configuration, when the pipe expanding rubber is crushed by a specified amount and therefore the metal pipe is expanded by the amount corresponding to the expanded diameter portion of the tubular portion, the shaft penetrates the drive shaft most deeply and is integrated. Since the rotation of the shaft about the axis is blocked, the rotation of the drive shaft is also blocked.

As a result, it is possible to prevent the tubular rubber from being crushed (expanded) excessively and the tubular portion from being damaged.

INDUSTRIAL APPLICABILITY As described above, the metal pipe expanding tool of the present invention is configured such that the pipe expanding rubber internally fitted near the end of the metal pipe is axially compressed and elastically deformed to expand the diameter of the metal pipe. The force of screwing is used for the compression of, and compression by human power is possible.

Therefore, compared to the conventional case where hydraulic pressure or a motor is used, a power source is not required for the tool, the tool is small and lightweight and easy to carry, and cost reduction of the tool can be expected.

It is sectional drawing of the metal-tube expanding tool which concerns on one Embodiment of this invention. It is sectional drawing which shows the mode of the final processing of the metal pipe expanded by the said expansion tool. FIG. 4 is a cross-sectional view of the vicinity of a joint between a metal pipe and a joint.

FIG. 1 is a sectional view of a metal pipe expanding tool 1 according to an embodiment of the present invention. This pipe expanding tool 1 also compresses/releases the annular pipe expanding rubber 21 in the axial direction to deform it, and plastically deforms the vicinity of the end 51 of the metal pipe 5 such as SUS from the inside to expand the pipe. This is the same as the reference 1. The pipe expanding tool 1 of the present embodiment includes the pipe expanding rubber 21, a main body 22, an adapter 23, a drive shaft 24, a shaft 25, a holding ring 26, and a dry bush (cylindrical oil-free bearing) 27, 28. A needle roller 30, a grip 33, and a handle 34.

In this embodiment, the adapter 23 corresponding to the diameter of the metal tube 5, such as nominal 1/2B, 3/4B, and 1B, is selectively attached to the main body 22. There is. The adapter 23 is formed in a cap shape including a cylindrical base portion 232 and an end plate 231 that closes one end of the base portion 232. The end plate 231 has a recess 233 into which the end 51 of the metal tube 5 is fitted from the outside. The bottom portion 236 of the recess 233 is an abutting surface with which the end surface 55 of the metal tube 5 abuts, and the side surface 234 is a surface corresponding to the portion for expanding the pipe. In the example of FIG. 1, the side surface 234 is formed in a tapered shape whose inner diameter increases toward the opening end 235. The end plate 231 has an opening 237 at the center of the bottom 236 of the recess 233.

The main body 22 is configured to include a small diameter portion 221 on the adapter 23 side, a large diameter portion 222 that is continuous with the small diameter portion 221, and an end plate 224 that covers the open end 223 of the large diameter portion 222, and the internal space 225 of the main body 22 is It communicates with the internal space 238 of the cap-shaped adapter 23. The tubular portion 2321 of the base portion 232 of the adapter 23 is fixed to the tip portion 2211 of the small diameter portion 221. In the example of FIG. 1, the tubular portion 2321 is fitted on the outside of the tubular tip portion 2211, but the internal and external relationships thereof may be reversed. As described above, the adapter 23 can be exchanged from the main body 22 according to the diameter of the metal tube 5, so that the distal end portion 2211 and the cylindrical portion 2321 are coupled by screwing or separately. It suffices that it can be exchanged by being coupled with a screw or the like.

The end plate 224 has an opening 226 which covers the opening end 223 at the rear end of the main body 22 and into which the drive shaft 24 described later is inserted. The end plate 224 is provided to prevent the drive shaft 24 and the shaft 25 from falling off the main body 22. Since the end plate 224 is lightweight corresponding to the small-diameter metal tube 5, the end plate 224 is It is realized by a simple structure called a C-shaped ring that fits into a groove 227 formed on the inner periphery of the opening end 223 side. However, the end plate 224 may be fixed to the open end 223 of the main body 22 by screwing, brazing, bonding, screwing, or the like.

Inside the large-diameter portion 222 of the main body 22, there are formed recessed grooves and step portions for appropriately positioning and accommodating the dry bushes 27, 28 and the needle rollers 30. The dry bushes 27, 28 are smaller than the ball bearings, are cheaper in cost, and rotatably support the drive shaft 24 while preventing the drive shaft 24 from being displaced in the radial direction. The needle roller 30 is also smaller than the thrust roller bearing, has a low cost, and rotatably supports the drive shaft 24 while preventing the drive shaft 24 from being displaced in the axial direction. A washer 31 is interposed between the needle roller 30 and the large diameter portion 222 of the main body 22. After the drive shaft 24 is fitted into the main body 22 in a state where the dry bushes 27 and 28 are attached to the large diameter portion 222, the needle roller 30 is attached to the drive shaft 24, and the washer 31 is fitted, the end plate 224 is Be fitted.

One end 241 of the drive shaft 24 projects from the opening 226 of the end plate 224 as described above, and is formed in the shape of a hexagonal nut in this embodiment. The shape of the one end 241 may be a shape such that a tool such as a ratchet wrench that rotates the drive shaft 24 can be driven without slipping. The other end 242 of the drive shaft 24 is formed in a tubular shape, and a spiral female screw is formed inside.

A male screw formed on the outer peripheral surface of the one end 251 of the shaft 25 is screwed into the female screw of the other end 242. The relationship between the male and female screws of the other end 242 of the drive shaft 24 and the one end 251 of the shaft 25 may be opposite. In the shaft 25, an intermediate portion 253 between the one end portion 251 and the other end portion 252 is formed in a polygonal shape, for example, a square shape, and is inserted through the opening 227 of the small diameter portion 221. As a result, the shaft 25 is held by the main body 22 so as to be slidable in the axial direction while being prevented from rotating about its axis. Further, the drive shaft 24 and the shaft 25 are concentric with each other, and the drive shaft 24 is rotatably engaged with the shaft 25.

One end 262 of the pressing ring 26 is fixed to the other end 252 of the shaft 25 by screwing. In the present embodiment, the tip 261 of the pressing ring 26 is formed in the shape of a hexagonal nut, the one end 262 is formed with a male screw on its outer peripheral surface, and the inner peripheral surface of the tubular other end 252 of the shaft 25 is formed. It is screwed into the female screw formed on the. The central portion 263 of the pressing ring 26 is inserted through the opening 237 formed in the bottom portion 236 of the recess 233 of the end plate 231, and the pipe expanding rubber 21 is fitted on the outer peripheral surface thereof. The other end 264 of the presser ring 26 which is continuous with the central portion 263 has an enlarged diameter and forms a step with the central portion 263. Therefore, the tube expansion rubber 21 can be sandwiched between the bottom portion 236 of the recess 233 of the end plate 231 and the other end portion 264 of the pressing ring 26.

According to the pipe expanding tool 1 configured as described above, the pipe expanding rubber 21 fitted in the vicinity of the end 51 of the thin metal pipe 5 is axially compressed and elastically deformed to expand its diameter. When the vicinity of the end 51 is plastically deformed from the inside to expand the pipe, the force of screwing the drive shaft 24 into the shaft 25 is used to compress the expanded rubber 21, so that the hexagonal portion of the one end 241 of the drive shaft 24 is used. By rotating the tool with a tool such as a ratchet wrench, it is possible to compress it manually. Then, by making the angle of the thread of the connecting portion between the shaft 25 and the drive shaft 24 shallow, the drive shaft 24 must be rotated a little more to move the shaft 25 forward and backward, but the thick metal pipe 5 Can also be plastically deformed. In this way, a pipe expanding tool that does not require a power supply, is small and lightweight, easy to carry, and is expected to reduce tool costs compared to the conventional case of using hydraulic pressure or motor is realized. can do.

Further, in the tube expanding tool 1 of the present embodiment, the adapter 23 is detachable from the main body 22, and the adapter 23 is prepared with a plurality of recesses 233 having different diameters according to the diameter of the metal tube 5. Corresponding to this, a plurality of types of the pipe expanding rubber 21 and the pressing ring 26 are prepared. Therefore, by simply replacing the adapter 23, the pressing ring 26, and the tube expansion rubber 21, it becomes possible to cope with the diameters of a plurality of types of metal tubes, such as the nominal 1/2B, 3/4B, and 1B. The rest of the main body 22, the drive shaft 24, the shaft 25, the dry bushes 27 and 28, the needle roller 30, and the like are shared to reduce the tool cost.

Furthermore, in the tube expanding tool 1 of the present embodiment, one of the other end 242 of the drive shaft 24 and the one end 251 of the shaft 25 is an outer cylinder, and the other is an inner cylinder that is screwed into the outer cylinder ( In the example of FIG. 1, the drive shaft 24 is an outer cylinder and the shaft 25 is an inner cylinder), and a spiral groove for screwing the same is formed by a length H corresponding to the crushing margin of the pipe expanding rubber 21, or One outer cylinder side is formed hollow by a length H corresponding to the crushing allowance of the expanded rubber 21, and beyond that, it is formed solid (in the example of FIG. 1, it corresponds to the crushing allowance on the outer cylinder (242) side. There is a space for the inner cylinder (251) to enter by the length H). By doing so, when the expanded rubber 21 is crushed by a prescribed amount, and thus the metal pipe 5 is expanded by an amount corresponding to the side surface 234 of the recess 233 of the end plate 231, the shaft 25 penetrates the drive shaft 24 most deeply. Since the shaft 25 is prevented from rotating around the axis, the drive shaft 24 is also prevented from rotating. As a result, it is possible to prevent the tube-expanding rubber 21 from being excessively crushed (expanded) and the tubular portion 231 from being damaged.

Here, FIG. 2 shows a state of final processing of the metal pipe 5 expanded by the pipe expanding tool 1. In the present embodiment, the end portion 51 of the metal tube 5 is expanded from the end surface 55 thereof into a bump 53 shape as shown in FIGS. 2(a) and 2(b). Therefore, the end plate 231 of the adapter 23 is also recessed from the opening end 235 only by the side surface 234 and immediately becomes the bottom surface 236, so that the metal tube 5 cannot be supported from the outside. Therefore, two pipe holding rubber rings 32 are fitted to the outer peripheral surface of the other end 264 of the pressing ring 26 to which the metal tube 5 is fitted, with a gap in the axial direction. As a result, the metal tube 5 can be held without rattling. The end portion 51 of the metal tube 5 is finally formed on the flange 54 by axially crushing the portion of the bump 53 with another jig (not shown), as shown in FIG. It

In the tube expanding tool 1 of the present embodiment, a rod-shaped grip 33 extending in the radial direction is attached to the main body 22 by screwing, and a rod-shaped handle 34 extending in the radial direction is attached to the one end 241 side of the drive shaft 24. Be done. The one end portion 241 of the drive shaft 24 is formed in a hexagonal shape as described above, and the handle 34 is inserted inside the hexagonal portion into a hole 244 formed on one diameter line. Both ends of the handle 34 are crushed by a press machine to prevent them from coming off. Alternatively, both ends of the handle 34 may be prevented from coming off by being screwed with a nut 35 as shown in FIG. 1, and in that case, like the grip 33, the handle 34 may be carried or stored. 34 will also be removable.

With such a configuration, the operator grips the grip 33 by utilizing the force applied to the small-diameter metal tube 5, that is, the force applied to the plastic deformation of the metal tube 5, and uses the principle of leverage. By rotating the handle 34 with a small force, the shaft 25 can slide and the metal pipe 5 can be plastically deformed. Therefore, a tool for rotating the drive shaft 24, such as the ratchet wrench, is not required, and it becomes easier to carry. Furthermore, since the grip 33 and the handle 34 that project from the main body 22 in the radial direction are detachable, they are easy to carry and store.

1 Pipe Expansion Tool 21 Pipe Expansion Rubber 22 Main Body 2211 Tip Part 221 Small Diameter Part 222 Large Diameter Part 223 Open End 224 End Plate 225 Inner Space 226 Opening 227 Groove 23 Adapter 231 End Plate 232 Base 2321 Cylindrical Part 233 Recess 234 Side 235 Open End 236 Bottom part 237 Opening part 238 Internal space 24 Drive shaft 25 Shaft 251 One end part 252 Other end part 253 Intermediate part 26 Holding ring 261 Tip 262 One end part 263 Central part 264 Other end part 27, 28 Dry bush 30 Needle roller 32 For pipe holding Rubber ring 33 Grip 34 Handle 35 Nut 5 Metal tube 51 End part 52 Expanded part 521,522 Inclined surface 53 Lump 54 Flange 55 End face 59 Opening 61 Opening 62 Male screw 6 Joint 7 Cap nut 71 Opening 72 Female screw 8 Packing 9 Disc spring

Claims (5)

In a tool for expanding the metal tube by plastically deforming the vicinity of the end of the metal tube from the inside,
It is formed in a cap shape having a tubular base and an end plate fitted into one end thereof, and the end plate has a recess into which the end of the metal tube is fitted, and the bottom of the recess is the metal. An end surface of the tube is an abutting surface against which the side surface of the recess is an inclined surface corresponding to the portion to be expanded, and such an adapter,
A tubular body having an internal space communicating with the adapter;
A drive shaft that is inserted into the main body, is rotatably supported while being prevented from being displaced in the axial direction, and has one end protruding in the opposite side to the adapter and rotationally driven.
One end of the drive shaft is concentric with the drive shaft on the other end side of the drive shaft and the drive shaft is rotatably screwed, and a rotation between the other end and the one end thereof is about the axis of the main body. And a shaft that is retained so as to be slidable in the axial direction,
A pressing ring, one end of which is inserted through an opening formed in the bottom of the recess of the end plate and is fixed to the other end of the shaft, and the other end of which is expanded in diameter,
It is formed in an annular shape and covers one end side of the pressing ring, and is expanded by narrowing the pressure between the bottom of the recess and the expanded other end of the pressing ring to expand the diameter of the metal pipe. A pipe expanding tool for a metal pipe, comprising: a pipe expanding rubber for expanding a pipe expanding portion. The pipe expanding tool for a metal pipe according to claim 1, wherein the adapter, the pipe expanding rubber, and the pressing ring are detachable from the main body so as to correspond to the diameter of the metal pipe. A rod-shaped grip extending in the radial direction is attached to the main body,
A rod-shaped handle extending in the radial direction is attached to one end of the drive shaft,
The metal pipe expanding tool according to claim 1 or 2, wherein an operator grips the grip and rotates the handle to slide the shaft. Between the main body and the drive shaft, a needle roller that rotatably supports while preventing displacement in the axial direction is interposed.
4. A metal pipe expanding tool according to claim 3, wherein a drive bush is interposed between the main body and the drive shaft and rotatably supports the drive shaft while preventing the drive shaft from being displaced in the radial direction. .. Of the other end of the drive shaft and one end of the shaft, one is an outer cylinder and the other is an inner cylinder to be screwed into the outer cylinder, and a spiral groove for the screwing is formed by crushing the expanded rubber. The length corresponding to the clearance is formed, or the one outer cylinder side is formed to be hollow for the length corresponding to the crushing margin of the pipe expanding rubber, and further away is formed solid. The expanding tool for a metal tube according to any one of 1 to 4.

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