Pipe diameter expanding tool

Abstract

To provide a pipe diameter expanding tool that is able to expand a diameter of an end part of a pipe while preventing damage or the like to the end part of the pipe by a plurality of jaws.SOLUTION: A pipe diameter expanding tool 1 for expanding a diameter of an end part of a pipe has a moving mechanism 25 that moves a wedge 3 back and forth. The pipe diameter expanding tool 1 has a plurality of jaws 4 mutually opening outward in a radial direction due to the push by the advanced wedge 3. The pipe diameter expanding device 1 has a switch 6a that generates an ON signal by being operated. The pipe diameter expanding tool 1 has a controller. Upon receiving the ON signal from the switch 6a, the controller advances the wedge 3 to a first advanced position to open the plurality of jaws 4 at a first opening degree. The controller retracts the wedge 3 to close the plurality of jaws 4. The controller advances the wedge 3 to a second advance position before the first advance position to open the plurality of jaws 4 at a second opening degree larger than the first opening degree. The controller retracts the wedge 3 to close the plurality of jaws 4.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present disclosure relates to a pipe expanding tool that expands the diameter of, for example, an end of a pipe to connect to a connected body. [Background technology]

[0002] For example, in order to connect copper tubes through which a fluid flows, a tool for expanding the diameter of one copper tube has been used in the past. The end of one copper tube, which is not expanded, is inserted into the end of the other copper tube, which has been expanded, and the two tubes are brazed together. This allows the copper tubes to be connected. Conventional tube expansion tools manually expand the diameter of the tube ends. The multiple jaws of the tube expansion tool are inserted into the end of the copper tube, and a lever is manually operated to advance a wedge. The multiple jaws arranged in front of the wedge are pushed open by the wedge. This expands the diameter of the end of the copper tube into which the multiple jaws are inserted. For example, depending on the thickness of the copper tube, a very strong force is required to expand the end of the copper tube.

[0003] Instead of a manual pipe expanding tool, it is possible to use, for example, an electric pipe expanding tool that uses a motor as a drive source to open multiple jaws. Patent Document 1 describes an electric pipe expanding tool that expands a PEX (Cross-linked polyethylene) pipe made of PEX. An electric pipe expanding tool for copper pipes is provided based on an electric pipe expanding tool for PEX pipes. The end of the copper pipe can be easily expanded by advancing a wedge with the motor output to open multiple jaws.

[0004] When expanding the end of an elastically deformable PEX pipe, the jaws are repeatedly opened and closed to gradually expand the end of the PEX pipe. At the beginning of the expansion, only a portion of the tip of the jaws is inserted into the PEX pipe. As the end of the PEX pipe is expanded, the jaws are inserted longer into the PEX pipe. The jaws rotate a predetermined angle (e.g., 15°) in the circumferential direction with each closing operation.

[0005] On the other hand, copper tubes are plastically deformed, so for example they open all at once with a large force. The multiple jaws are inserted into the copper tube close to the base before expanding in order to expand the diameter all at once. When the multiple jaws start to open, each jaw is not yet receiving load from the copper tube. Therefore, the motor rotates at high speed, and the inertial force of the wedge pushing the multiple jaws is large. Therefore, when the multiple jaws start to open, they expand the end of the copper tube with the largest force. The momentum when the largest force acts on the end of the copper tube is used to expand the end of the copper tube all at once.

[0006] The multiple jaws are divided into six in the circumferential direction, for example. When the end of the copper tube is opened at once, each jaw tries to expand the diameter of the end of the copper tube, and no force in the expanding direction acts on the end of the copper tube in the area between the jaws. Therefore, the end of the copper tube is expanded into a hexagonal shape. That is, the end of the copper tube has a mixture of expanded and almost unexpanded parts, and the radial extension is not uniform. Therefore, cracks may occur in the end of the copper tube. Therefore, it is desired to improve the operation of the wedge and the multiple jaws in a pipe expanding tool that expands the end of a copper tube, for example. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] US Patent No. 20230256498 Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, there is a need for a pipe expanding tool that has multiple jaws that can expand the end of a pipe while suppressing damage to the end of the pipe. [Means for solving the problem]

[0009] According to one feature of the present disclosure, a pipe expanding tool for expanding an end of a pipe has a moving mechanism for moving a wedge back and forth. The pipe expanding tool has a plurality of jaws that open radially outward relative to one another when pushed by the advanced wedge. The pipe expanding tool has a switch that generates an ON signal when operated. The pipe expanding tool has a controller. Upon receiving the ON signal from the switch, the controller advances the wedge to a first advanced position to open the plurality of jaws at a first opening degree. The controller retracts the wedge to close the plurality of jaws. The controller advances the wedge to a second advanced position forward of the first advanced position to open the plurality of jaws at a second opening degree greater than the first opening degree. The controller retracts the wedge to close the plurality of jaws.

[0010] Therefore, when the switch is turned on, the wedge first advances to a first forward position. The multiple jaws expand the diameter of the end of the tube to a first opening degree. Next, the wedge retracts and the multiple jaws close, and then the wedge advances to a second forward position. The multiple jaws expand the diameter of the end of the tube to a second opening degree that is larger than the first opening degree. In this way, the opening degree of the multiple jaws can be changed by changing the forward position of the wedge. This allows the end of the tube to be expanded in stages. By expanding the end of the tube in stages, the end of the tube can be expanded to a target diameter while suppressing damage such as cracks that occur to the end of the tube during expansion. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a perspective view of the tube expanding tool of the present embodiment with multiple jaws in a closed position. [Diagram 2] FIG. 2 is a perspective view of a tube expansion tool with the jaws at their maximum opening. [Diagram 3] FIG. 1 is a right side view of the tube expansion tool with the jaws fully open. [Figure 4] FIG. [Diagram 5] FIG. 2 is a perspective view of the tool body with the outer case removed, as viewed from the rear right side. [Figure 6] FIG. 11 is a perspective view of the tool body from the rear left side with the outer case removed when the screw shaft is in the initial position. [Figure 7]FIG. 4 is a left side view of the tool body with the outer case removed when the screw shaft is in the initial position. [Figure 8] FIG. 13 is a left side view of the tool body with the outer case removed when the screw shaft is at the end position. [Figure 9] 1 is a vertical cross-sectional view of the tool body seen from the right when the wedge and the screw shaft are in their initial positions. FIG. [Figure 10] 11 is a vertical cross-sectional view of the tool body seen from the right when the wedge and the screw shaft are in their terminal positions. FIG. [Figure 11] 10 is a cross-sectional view taken along line XI-XI in FIG. 9. [Figure 12] 12 is a cross-sectional view taken along line XII-XII in FIG. 11. [Figure 13] 12 is a cross-sectional view taken along line XII-XII in FIG. 11 when the wedge and the screw shaft are at their terminal positions. [Figure 14] FIG. 13 is a top view of a rotating gear, a receiving cam, and multiple jaws. [Figure 15] FIG. 2 is a block diagram showing electrical components of a tube expanding tool. [Figure 16] 11 is a flowchart illustrating a first example of the operation of the wedge and multiple jaws. [Figure 17] 11 is a flowchart illustrating a second example of the operation of the wedge and the multiple jaws. [Figure 18] 13 is a flowchart illustrating a third example of the operation of the wedge and the multiple jaws. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] According to another feature of the present disclosure, the tube expanding tool has a rotation mechanism that rotates the multiple jaws around the axis of the wedge in conjunction with the retreat of the wedge. Therefore, the position of the multiple jaws changes around the axis of the wedge every time they are closed. Therefore, the point of contact of each jaw with the inner circumferential surface of the end of the tube changes around the axis of the wedge every time an expansion operation is performed. Therefore, by performing the expansion operation multiple times, the opening shape of the end of the expanded tube can be made closer to a perfect circle. This allows the end of the tube to be expanded evenly and prevents damage such as cracks from occurring at the end of the tube.

[0013] According to another feature of the present disclosure, the controller advances the wedge from an initial position to a first advanced position. The controller retracts the wedge from the first advanced position to the initial position. The controller advances the wedge from the initial position to a second advanced position. The controller retracts the wedge from the second advanced position to the initial position. Thus, every time the wedge is retracted to the initial position, the multiple jaws reliably close to the closed position. Therefore, the multiple jaws are prevented from coming into contact with the end of the tube when closing while rotating around the axis of the wedge. This prevents the multiple jaws from biting into the end of the tube, allowing the multiple jaws to be opened and closed smoothly.

[0014] According to another feature of the present disclosure, the controller advances the wedge from an initial position to a first advanced position. The controller retracts the wedge from the first advanced position to a first retracted position forward of the initial position. The controller advances the wedge from the first retracted position to a second advanced position. Thus, by setting the first retracted position forward of the initial position, the total movement of the wedge can be reduced. This allows the end of the tube to be expanded quickly.

[0015] According to another feature of the present disclosure, while the controller is receiving an ON signal from the switch, the controller moves the wedge back and forth multiple times, each time moving the wedge closer to the end position. After the wedge reaches the end position, the controller returns the wedge to its initial position and stops it. Thus, when the wedge reaches the end position, the multiple jaws expand the end of the tube to its maximum opening. By returning the wedge to its initial position and stopping it after the end of the tube has been expanded, the wedge can be quickly made ready to expand the end of the next tube. This shortens the work time required to expand the ends of multiple tubes, improving workability.

[0016] According to another feature of the present disclosure, while the controller receives an ON signal from the switch, the controller moves the wedge back and forth multiple times, each time moving the wedge closer to the end position. After the wedge reaches the end position, the controller retracts the wedge. The controller again moves the wedge forward to the end position. Thus, when the wedge reaches the end position, the multiple jaws expand the end of the tube to a maximum opening degree. By repeatedly opening and closing the multiple jaws to a maximum opening degree, the opening shape of the end of the tube opened to a maximum opening degree can be made closer to a perfect circle.

[0017] According to another feature of the present disclosure, the tube expanding tool has an input unit for inputting the number of times the wedge moves back and forth. The input unit outputs a signal of the number information to the controller. Therefore, the number of times the wedge moves back and forth can be changed depending on, for example, the diameter, thickness, material, etc. of the tube. This makes it possible to effectively prevent cracks from occurring at the end of the tube during expansion.

[0018] According to another feature of the present disclosure, the controller calculates the first and second forward positions based on the number information. Therefore, the controller can calculate the first and second forward positions to efficiently move the wedge, thereby improving work efficiency.

[0019] According to another feature of the present disclosure, the tube expanding tool has an initial position sensor that detects an initial position of the wedge and transmits a signal to the controller. The tube expanding tool has an end position sensor that detects an end position of the wedge and transmits a signal to the controller. The tube expanding tool has a motor that drives a moving mechanism. The tube expanding tool has a rotation speed detection sensor that detects the number of rotations of the motor. The controller calculates the position of the wedge based on a signal from the rotation speed detection sensor. Therefore, by detecting the number of rotations of the motor, the position of the wedge relative to the initial position or the end position can be quickly detected. This allows the movement of the wedge and the opening and closing of the multiple jaws to be performed smoothly.

[0020] According to another feature of the present disclosure, the moving mechanism has a threaded shaft provided on the wedge. The moving mechanism has a female threaded member into which the threaded shaft is screwed and which rotates around the axis of the threaded shaft to move the threaded shaft back and forth. Therefore, even in a pipe expanding tool that converts the rotation of the female threaded member into the back and forth movement of the threaded shaft and the wedge, the wedge can be moved to multiple forward positions to open multiple jaws at different opening degrees. This makes it possible to expand the end of the pipe while suppressing the occurrence of damage such as cracks.

[0021] Next, one embodiment of the present disclosure will be described with reference to Figures 1 to 18. As shown in Figure 1, the pipe expanding tool 1 of this embodiment has a tool body 10 housed in a main body housing 11, and a grip 5 extending downward from the lower part of the main body housing 11. A user is positioned approximately at the rear of the pipe expanding tool 1 (the far left side in Figure 1) and holds the grip 5. In the following description, the side in front of the user is referred to as the rear, and the side opposite to the side in front of the user is referred to as the front. The up, down, left and right directions are based on the user.

[0022] As shown in Figs. 1, 9 and 10, a ring-shaped cap 2 is attached to the front of the tool body 10. A cylindrical screw shaft 27 extending in the front-rear direction is provided in the center of the tool body 10. A roughly conical wedge 3 is attached to the front end of the screw shaft 27. The wedge 3 is located radially inward of the cap 2. The screw shaft 27 and the wedge 3 are disposed on a screw shaft axis K extending in the front-rear direction in the center of the tool body 10. The wedge 3 is movable in the front-rear direction along the screw shaft axis K integrally with the screw shaft 27. The wedge 3 is movable in the front-rear direction within a range from an initial position P1 as its rear end to a terminal position P2 as its front end.

[0023] As shown in Figs. 2, 3, 9, and 10, a plurality of jaws 4 extending in the front-rear direction are provided radially outward from the wedge 3 and radially inward from the cap 2. The jaws 4 are arranged at equal intervals in the circumferential direction of the wedge 3. The tube expanding tool 1 has, for example, six jaws 4, and the jaws 4 are arranged at 60° intervals in the circumferential direction of the wedge 3. The jaws 4 are inserted into the end 60b of a cylindrical tube 60. The tube 60 is made of, for example, copper, and is provided with a substantially constant diameter and a substantially constant wall thickness in the longitudinal direction. The jaws 4 can be opened and closed in the radial direction between a closed position in which they are in close contact with each other in the circumferential direction to cover the wedge 3, and a maximum opening degree in which they open radially outward from each other to expose the tip of the wedge 3. The outer circumferential surface of the jaws 4 is cylindrical with a closed diameter D1 when in the closed position. The closed diameter D1 is slightly smaller than the diameter of the inner circumferential surface 60a of the tube 60 that is not expanded. The outer circumferential surface of each of the jaws 4 is cylindrical with a maximum opening diameter D2 when the jaws 4 are at the maximum opening position. The outer circumferential surface of each of the jaws 4 extends substantially straight with almost no inclination in the front-to-rear direction in both the closed position and at the maximum opening position.

[0024] 3, the maximum opening diameter D2 is the diameter of the inner circumferential surface 60a when the end 60b of the tube 60 is expanded, and is, for example, slightly larger than the outer diameter of the end 60b of another tube 60. The end 60b of the expanded tube 60 is inserted into and brazed to the end 60b of another tube 60. In this way, the ends 60b of the two tubes 60 are connected.

[0025] As shown in Figs. 1 and 2, a trigger 6 is provided on the front of the grip 5. A user can pull the trigger 6 while holding the grip 5. A switch 6a is provided inside the grip 5, which can be switched on and off in conjunction with the operation of the trigger 6. The switch 6a is in an off state when the trigger 6 is not pulled, and is in an on state when the trigger 6 is pulled. When the switch 6a is in an on state, it transmits an on signal to a controller 9, which will be described later. When the switch 6a is in an off state, it stops transmitting an on signal to the controller 9. When using the tube expanding tool 1, a user holds the grip 5 and inserts the multiple jaws 4 into the end 60b of the tube 60 (see Fig. 3). Pulling the trigger 6 opens and closes the multiple jaws 4 in the radial direction. Finally, the inner circumferential surface 60a of the end 60b of the tube 60 is expanded to the maximum opening diameter D2.

[0026] As shown in Figs. 1, 2 and 11, a bulging portion 7 having a substantially rectangular box shape that is wider than the grip 5 in the front-rear and left-right directions is provided at the lower end of the grip 5. The bulging portion 7 accommodates a controller 9. The controller 9 has a shallow rectangular box-shaped case and a control board that is housed in the case and resin-molded. The controller 9 is housed in the bulging portion 7 with its thickness direction (the direction in which the shortest side of the case extends) aligned with the up-down direction. The controller 9 mainly controls the driving of a motor 20, which will be described later. An input unit 18 is provided on the upper surface of the bulging portion 7. The input unit 18 includes, for example, an operation unit that can be pressed and a display unit whose display is changed by operating the operation unit. A signal inputted by the input unit 18 is transmitted to the controller 9.

[0027] As shown in Figs. 1, 2 and 11, a battery mounting section 7a is provided on the underside of the bulge 7, to which a rectangular box-shaped battery 8 can be removably attached. The battery 8 can be removed from the battery mounting section 7a by sliding it forward. The battery 8 can be attached to the battery mounting section 7a by sliding it from the front to the rear of the battery mounting section 7a. The battery 8 can be removed from the battery mounting section 7a and repeatedly charged and used with a separately prepared charger. The battery 8 can be used as a power source for other power tools. The battery 8 operates as a power source that supplies power to the motor 20, etc.

[0028] As shown in Figs. 9 and 10, the main body housing 11 includes an exterior case 17 that covers the outer periphery of the tool body 10, and a front mechanism housing 12, a first central mechanism housing 13, a second central mechanism housing 14, and a rear mechanism housing 15 that are connected to each other within the exterior case 17. The front mechanism housing 12, the first central mechanism housing 13, and the second central mechanism housing 14 are substantially cylindrical in shape with a hollow passage penetrating in the front-rear direction at the center. The rear mechanism housing 15 is provided in a plate shape with the plate thickness direction being in the front-rear direction. The front mechanism housing 12, the first central mechanism housing 13, the second central mechanism housing 14, and the rear mechanism housing 15 are connected in the front-rear direction by bolts 16 and cooperate to form a mechanism housing. A gear shaft 23, an idle gear 24, and a female screw member 26, which will be described later, are accommodated in the mechanism housing.

[0029] 4, 9, and 10, a male thread 12a is provided on the front outer peripheral surface of the front mechanism housing 12. A female thread 2b that screws with the male thread 12a is provided on the rear inner peripheral surface of the cap 2. The cap 2 is connected to the front part of the front mechanism housing 12 by screwing the male thread 12a with the female thread 2b.

[0030] As shown in Figs. 4, 9, and 10, the first central mechanism housing 13 has a downward extending portion 13b having a generally U-shaped outer shape extending downward from a cylindrical shape. The second central mechanism housing 14 has a downward extending portion 14b having a generally U-shaped outer shape extending downward from a cylindrical shape. The downward extending portion 13b and the downward extending portion 14b are connected in the front-rear direction to form a space for accommodating a gear shaft 23 and an idle gear 24 described later. The downward extending portion 13b has two through holes that penetrate in the front-rear direction and are arranged in parallel to each other. The lower through hole has a recess 13c for press-fitting a bearing 23b that supports the gear shaft 23. The upper through hole 13d has a shaft member 24a that supports the idle gear 24 press-fitted. The downward extending portion 14b has two through holes that penetrate in the front-rear direction and are arranged in parallel to each other. The lower through hole has a recess 14c for press-fitting a bearing 23c that supports the gear shaft 23. The shaft member 24a is inserted into the upper through hole 14d.

[0031] As shown in Figures 9 and 10, a motor 20 having a generally cylindrical shape is housed in the lower rear portion of the exterior case 17. For example, a motor called a DC brushless motor is used as the motor 20. The motor 20 is located below the screw shaft 27 and above the grip 5. A motor shaft 20a of the motor 20 extends in the front-rear direction along the motor axis J in parallel with the screw shaft axis K passing through the center of the screw shaft 27. The motor shaft 20a is supported by bearings 20e, 20f held in the exterior case 17 so as to be rotatable about the motor axis J.

[0032] As shown in FIGS. 9 and 10, the motor 20 has a stator 20b supported non-rotatably relative to the exterior case 17. The stator 20b is disposed radially outward of the motor shaft 20a. The rotor 20c of the motor 20 is attached to the motor shaft 20a on the inner circumferential side of the stator 20b so as to be rotatable integrally with the motor shaft 20a. A rotation speed detection sensor 20d is provided in front of the rotor 20c. The rotation speed detection sensor 20d detects the rotation angle of the rotor 20c to detect the rotation speed of the motor shaft 20a. A fan 21 is provided between the rotor 20c and the rear bearing 20f in the front-rear direction so as to be rotatable integrally with the motor shaft 20a. When the fan 21 rotates together with the motor shaft 20a, cooling air flows from the front to the rear of the motor 20 to cool the motor 20.

[0033] As shown in Figures 9 and 10, a planetary reduction mechanism 22 for reducing the output of the motor shaft 20a is provided in front of the motor 20. The planetary reduction mechanism 22 is accommodated in the exterior case 17 and aligned with the motor 20 in the front-rear direction. The rotational drive of the motor shaft 20a is reduced in two stages by the planetary reduction mechanism 22 and transmitted to the gear shaft 23. The gear shaft 23 is supported by bearings 23b and 23c so as to be rotatable about the motor axis line J. The gear shaft 23 has a drive gear 23a between the bearings 23b and 23c in the front-rear direction. The drive gear 23a rotates integrally with the gear shaft 23 about the motor axis line J.

[0034] As shown in Figures 9 and 10, an idle gear 24 is provided between the gear shaft 23 and the screw shaft 27 in the vertical direction. The idle gear 24 is supported rotatably around the axis of a cylindrical shaft member 24a extending in the front-rear direction. A radial bearing 24b is provided between the idle gear 24 and the shaft member 24a in the radial direction. The idle gear 24 meshes with the driving gear 23a on the lower side, and also meshes with the driven gear 26a of the female screw member 26 on the upper side.

[0035] As shown in Figs. 9 and 10, the tool body 10 is provided with a moving mechanism 25 of a feed screw mechanism, which is called a ball screw mechanism. The moving mechanism 25 has a screw shaft 27 and a female screw member 26. A male screw 27a is provided on the outer peripheral surface of the screw shaft 27. The female screw member 26 is provided in a substantially cylindrical shape that covers the screw shaft 27 in the circumferential direction. A female screw 26b is provided on the inner peripheral surface of the female screw member 26. The female screw 26b is screwed into the male screw 27a of the screw shaft 27 via a plurality of balls 27b. A driven gear 26a that protrudes radially outward is provided on the outer periphery of the female screw member 26. The rotational drive of the gear shaft 23 is reduced and transmitted to the female screw member 26 by the meshing between the drive gear 23a and the idle gear 24 and the meshing between the idle gear 24 and the driven gear 26a.

[0036] 9 and 10, the female screw member 26 is supported rotatably about the screw shaft axis K by bearings 26c, 26d housed in the tool body 10. The front bearing 26c is press-fitted into the inner circumferential surface 13a of the first central mechanism housing 13. The rear bearing 26d is press-fitted into the inner circumferential surface 14a of the second central mechanism housing 14. A thrust bearing 26e is provided between the rear surface of the female screw member 26 and the front surface of the rear mechanism housing 15 to receive a thrust load that pushes the female screw member 26 rearward. The rear portion of the screw shaft 27 can protrude rearward from a through hole 15a provided in the center of the rear mechanism housing 15.

[0037] As shown in Figs. 4 to 6, a screw shaft guide 28 is attached to the rear of the screw shaft 27 to prevent the rear of the screw shaft 27 from rotating and to guide the forward and backward movement of the screw shaft 27. The screw shaft guide 28 has a roller shaft 28a that is connected to the rear end of the screw shaft 27 and extends in the left and right direction. Rollers 28b are provided on both the left and right ends of the roller shaft 28a. A pair of loop-shaped rails 28c that extend in the front and rear direction are attached to the left and right sides of the second central mechanism housing 14, respectively. The rollers 28b engage with the rails 28c and are movable in the front and rear direction along the rails 28c. The screw shaft 27 moves in the front and rear direction together with the screw shaft guide 28, guided by the rollers 28b and the rails 28c.

[0038] As shown in Figs. 7 to 10, magnets 28d and 28e are provided on the upper part of the roller shaft 28a. The rear magnet 28d and the front magnet 28e are provided with a gap between them. A position sensor 29 for detecting the front-rear position of the screw shaft 27 is provided on the upper inner peripheral surface of the exterior case 17. The position sensor 29 is a sensor for detecting a magnetic field called a Hall IC. The position sensor 29 includes a rear initial position sensor 29a and a front end position sensor 29b. The initial position sensor 29a is disposed so as to be located directly above the magnet 28d when the wedge 3 and the screw shaft 27 are at the initial position P1. The initial position sensor 29a detects the initial position P1 of the wedge 3 when it comes directly below the magnet 28d, and transmits a signal to the controller 9 (see Fig. 1). The end position sensor 29b is disposed so as to be located directly above the magnet 28e when the wedge 3 and the screw shaft 27 are at the end position P2. The end position sensor 29b detects the end position P2 of the wedge 3 when the magnet 28e is directly below it, and transmits a signal to the controller 9.

[0039] 6 to 8, 12 and 13, the tool body 10 has a rotation mechanism 30 that rotates the multiple jaws 4. The multiple jaws 4 are rotated around the screw shaft axis K by the rotation mechanism 30. The rotation mechanism 30 has a push plate 34 that moves back and forth in conjunction with the rotation of the motor shaft 20a, and a shaft 31 that rotates around its axis in conjunction with the back and forth movement of the push plate 34.

[0040] As shown in Figs. 5, 7 and 8, the rotation mechanism 30 has a ball retainer 35 attached to the shaft 31. The ball retainer 35 is movable in the front-rear direction along the extension direction of the shaft 31. A guide shaft 41 extending parallel to the shaft 31 is provided to the right of the shaft 31. A cylindrical guide shaft support portion 14e protruding rearward is provided on the downward extension portion 14b of the second central mechanism housing 14. A female screw penetrating in the front-rear direction is provided in the center of the guide shaft support portion 14e. The guide shaft 41 is fixed to the second central mechanism housing 14 by screwing a male screw provided at the tip of the guide shaft 41 into the female screw of the guide shaft support portion 14e.

[0041] 4 and 5, the ball retainer 35 has a generally cylindrical sleeve mounting portion 35a and a side extension portion 35d extending to the right of the sleeve mounting portion 35a. A shaft insertion hole 35c penetrating in the front-rear direction is provided in the center of the sleeve mounting portion 35a. The shaft 31 is inserted into the shaft insertion hole 35c so as to be slidable in the front-rear direction. A through hole 35e penetrating in the front-rear direction is provided in the side extension portion 35d. The guide shaft 41 is inserted into the through hole 35e so as to be slidable in the front-rear direction. Thus, the ball retainer 35 is guided by the shaft 31 and the guide shaft 41 so as to be slidable in the front-rear direction and restricts the rotation of the shaft 31 around its axis.

[0042] As shown in Figs. 4 to 6, the plate-shaped push plate 34 is attached integrally to the roller shaft 28a with the plate thickness direction being the front-rear direction. The push plate 34 extends downward from the roller shaft 28a and is disposed behind the sleeve mounting portion 35a. The push plate 34 has a through hole 34a penetrating in the front-rear direction. The shaft 31 protruding rearward from the sleeve mounting portion 35a is inserted into the through hole 34a. The push plate 34 moves forward and backward integrally with the screw shaft 27. When the screw shaft 27 advances, the push plate 34 presses the rear surface of the ball retainer 35 forward. When the screw shaft 27 retreats, the push plate 34 moves away from the ball retainer 35. Therefore, the push plate 34 exerts a force on the ball retainer 35 only when it advances.

[0043] As shown in FIG. 4, the sleeve mounting portion 35a is provided with a pair of ball retaining holes 35b extending in the radial direction so as to communicate with the shaft insertion hole 35c. A ball 38 is inserted into each of the pair of ball retaining holes 35b. A sleeve 36 is mounted on the sleeve mounting portion 35a, covering the pair of balls 38 and the ball retaining hole 35b from the radial outside. By mounting the sleeve 36 on the sleeve mounting portion 35a, the pair of balls 38 are retained so as not to come off from the ball retaining hole 35b. The pair of balls 38 are disposed at positions that are opposed to each other by 180° around the axis of the shaft 31. The ball retainer 35 is prevented from rotating, so that the pair of balls 38 are restricted from moving around the axis of the shaft 31. A nut 37 for retaining the sleeve 36 is mounted on the front part of the sleeve mounting portion 35a.

[0044] 4, 12, and 13, the shaft 31 is formed by assembling a front shaft 32 and a rear shaft 33 in the front-rear direction. The front shaft 32 is supported by a shaft support portion 13e of the first central mechanism housing 13 so as to be rotatable about its axis. The rear shaft 33 is supported by a shaft support portion 14g of the second central mechanism housing 14 so as to be rotatable about its axis. The rear shaft 33 is inserted into a ball retainer 35. A male thread 33a is provided at the front portion of the rear shaft 33. A female thread 32a that screws into the male thread 33a is provided at the rear portion of the front shaft 32. By screwing the female thread 32a into the male thread 33a, the front shaft 32 and the rear shaft 33 are attached integrally to each other.

[0045] As shown in Figures 4, 12 and 13, a pair of ball grooves 33b is provided on the outer circumferential surface of the rear shaft 33. The ball grooves 33b extend generally in the longitudinal direction of the rear shaft 33 and extend circumferentially from the rear to the front like a screw groove. The ball grooves 33b extend from the rear to the front in the direction of a second rotation R2 (see Figure 6). The pair of ball grooves 33b are arranged in a point-symmetrical positional relationship with respect to the axial center of the rear shaft 33. Balls 38 protruding radially inward from ball retaining holes 35b of the ball retainer 35 to the shaft insertion hole 35c engage with each ball groove 33b.

[0046] As shown in Figs. 6 to 8, when the ball retainer 35 moves back and forth relative to the rear shaft 33, the pair of balls 38 (see Fig. 4) move in the ball groove 33b along the extending direction of the ball groove 33b. Since the pair of balls 38 do not move around the axis of the rear shaft 33, the rear shaft 33 rotates around its axis relative to the ball retainer 35 which moves back and forth. When the ball retainer 35 moves forward, the rear shaft 33 rotates in the direction of a first rotation R1 relative to the ball retainer 35. When the ball retainer 35 moves backward, the rear shaft 33 rotates in the direction of a second rotation R2 relative to the ball retainer 35. The front shaft 32 screwed to the rear shaft 33 rotates around its axis integrally with the rear shaft 33. A flange-shaped spring receiving portion 14f protruding in the radial direction is provided on the shaft support portion 14g of the second central mechanism housing 14. A compression spring 39 is interposed between the spring receiving portion 14f and the ball retainer 35 in the front-rear direction to bias the ball retainer 35 rearward.

[0047] As shown in FIGS. 11 to 13, the rotation mechanism 30 has a cylindrical one-way clutch 42 and a driving side gear 43. The one-way clutch 42 and the driving side gear 43 are attached to the front part of the front shaft 32 in front of the shaft support part 13e. The one-way clutch 42 is provided between the front shaft 32 and the driving side gear 43 in the radial direction. The one-way clutch 42 has a structure called a sprag type, for example, and transmits only one-way rotation from the radial inner peripheral surface side to the radial outer peripheral surface side. The one-way clutch 42 transmits the second rotation R2 (see FIG. 6) of the front shaft 32 to the driving side gear 43. The one-way clutch 42 does not transmit the first rotation R1 (see FIG. 6) of the front shaft 32 to the driving side gear 43, and causes the front shaft 32 to rotate idly.

[0048] As shown in Figs. 4, 12, and 13, the rotation mechanism 30 has a substantially cylindrical rotating gear 50 and a substantially cylindrical receiving cam 51. The rotating gear 50 is disposed in front of the female screw member 26. The receiving cam 51 is disposed in front of the rotating gear 50. The front mechanism housing 12 has a first inner peripheral surface 12b and a second inner peripheral surface 12c which are cylindrical inner peripheral surfaces centered on the screw shaft axis K. The rotating gear 50 is supported by the first inner peripheral surface 12b of the front mechanism housing 12 so as to be rotatable around the screw shaft axis K. The receiving cam 51 is supported by the second inner peripheral surface 12c of the front mechanism housing 12 so as to be rotatable around the screw shaft axis K. The front end of the first inner peripheral surface 12b and the rear end of the second inner peripheral surface 12c are connected by a radially extending surface 12d extending in the radial direction.

[0049] As shown in Figs. 4, 12, and 13, the rotating gear 50 has a cylindrical wall 50b and a driven gear 50a that protrudes radially from the rear of the cylindrical wall 50b. An insertion hole 50c that penetrates in the front-rear direction is provided in the center of the cylindrical wall 50b. The insertion hole 50c is provided with a diameter that allows the wedge 3 and the screw shaft 27 to pass through and move in the front-rear direction. The driven gear 50a meshes with the driving gear 43. The rotational power of the driving gear 43 is reduced and transmitted to the driven gear 50a. When the driving gear 43 rotates in the second rotation R2 (see Fig. 6), the driven gear 50a rotates counterclockwise as viewed from the front. When the driving gear 43 rotates in the first rotation R1 (see Fig. 6), the driven gear 50a rotates clockwise as viewed from the front. The rotating gear 50 has a spring receiving portion 50d extending radially inward from the rear of the cylindrical wall 50b. The inner peripheral surface of the spring receiving portion 50d has a diameter that allows the screw shaft 27 to be inserted therethrough but does not allow the rear end of the wedge 3 to pass through. The rear portion of the coil spring 52, which will be described later, abuts against the front surface of the spring receiving portion 50d.

[0050] 4 and 14, the rotating gear 50 has a generally rectangular guide 50e protruding forward from the front surface of the cylindrical wall 50b. A total of two guides 50e are provided at intervals of 180° in the circumferential direction of the cylindrical wall 50b. The guides 50e guide the receiving cam 51 so as not to rotate relative to the rotating gear 50 and to be movable in the front-rear direction.

[0051] As shown in Figs. 4, 12 to 14, the receiving cam 51 has a cylindrical portion 51a. An insertion hole 51b is provided in the center of the cylindrical portion 51a, penetrating in the front-rear direction. The insertion hole 51b is provided with a diameter that allows the wedge 3 and the screw shaft 27 to be inserted therethrough. A spring receiving portion 51c is provided in the rear of the cylindrical portion 51a, protruding radially outward like a flange. A coil spring 52 is interposed between the spring receiving portion 50d of the rotating gear 50 and the spring receiving portion 51c of the receiving cam 51. The receiving cam 51 is urged forward with respect to the rotating gear 50 by the coil spring 52.

[0052] As shown in Figures 4 and 14, the spring receiving portion 51c is provided with a guide engagement portion 51d that is notched radially inward and penetrates the spring receiving portion 51c in the front-rear direction. A total of two guide engagement portions 51d are provided at 180° intervals in the circumferential direction of the spring receiving portion 51c. Each guide engagement portion 51d engages with a respective guide 50e of the rotating gear 50. As a result, the receiving cam 51 rotates integrally with the rotating gear 50 around the screw shaft axis K (see Figure 12). In addition, the receiving cam 51 is movable relative to the rotating gear 50 in the front-rear direction.

[0053] As shown in Figs. 4 and 14, the receiving cam 51 has a plurality of cam engagement parts 51e protruding forward from a front surface 51f of the cylindrical part 51a. Each cam engagement part 51e is formed in a substantially rectangular shape. A total of six cam engagement parts 51e are provided at intervals of 60° in the circumferential direction of the cylindrical part 51a. A concave jaw engagement part 4b that engages with any one of the plurality of cam engagement parts 51e is provided on the rear surface of the jaw 4. The plurality of jaws 4 rotate integrally with the receiving cam 51 around the axis of the screw shaft axis K by engaging each cam engagement part 51e with the jaw engagement part 4b of each jaw 4. A convex part 4d that is convex backward with respect to the jaw engagement part 4b is formed on both circumferential ends of each jaw engagement part 4b.

[0054] As shown in Figs. 9 and 10, a ring receiving groove 4a having an arc-shaped cross section is provided on the radial outer periphery of the rear part of each jaw 4. The ring receiving grooves 4a of the multiple jaws 4 are connected in the circumferential direction to form an annular groove. The multiple jaws 4 are connected in the circumferential direction by a ring 4c that is inserted into the ring receiving groove 4a and can expand and contract elastically. A jaw support groove 2a that can receive the ring 4c is provided on the inner peripheral surface of the cap 2, extending radially outward and in the circumferential direction. The jaw support groove 2a allows the ring 4c to move in the radial direction but restricts the ring 4c from moving forward and backward. The multiple jaws 4 open and close in the radial direction around the ring 4c supported by the jaw support groove 2a.

[0055] The driving of the moving mechanism 25 and the rotating mechanism 30 will be described with reference to Figs. 6 to 13. First, the motor shaft 20a of the motor 20 rotates. The motor 20 is switched between forward and reverse rotation by the controller 9. The rotation drive of the motor shaft 20a is reduced in speed by the planetary reduction mechanism 22 and transmitted to the gear shaft 23. When the gear shaft 23 rotates, the idle gear 24 meshed with the driving gear 23a rotates. The female screw member 26 meshed with the idle gear 24 by the driven gear 26a rotates around the axis of the screw shaft axis K. When the female screw member 26 rotates, the screw shaft 27, which is prevented from rotating by the screw shaft guide 28, moves back and forth. The screw shaft 27 advances when the motor 20 rotates forward, and retreats when the motor 20 rotates reverse. When the screw shaft 27 advances, the wedge 3 also advances and presses the multiple jaws 4 and the ring 4c so as to open them radially outward. When the screw shaft 27 retreats, the wedge 3 also retreats and the pressing force is released, so that the ring 4c contracts and the jaws 4 close radially inward.

[0056] When the screw shaft 27 advances, the push plate 34 attached to the roller shaft 28a also advances integrally therewith. The push plate 34 presses the ball retainer 35 forward against the biasing force of the compression spring 39. When the ball retainer 35 advances, the shaft 31 rotates in the direction of the first rotation R1. At this time, the one-way clutch 42 does not transmit the rotational power of the shaft 31 to the drive-side gear 43. The rotating gear 50 does not rotate because no rotational power is transmitted from the drive-side gear 43. Therefore, the receiving cam 51 and the multiple jaws 4 connected to the rotating gear 50 do not rotate. Thus, the multiple jaws 4 do not rotate around the axis of the screw shaft axis K, but are pushed by the wedge 3 to open radially outward.

[0057] When the screw shaft 27 moves backward, the push plate 34 attached to the roller shaft 28a also moves backward. When the pressing force of the push plate 34 is released, the ball retainer 35 is biased by the compression spring 39 and moves backward. When the ball retainer 35 moves backward, the shaft 31 rotates in the direction of the second rotation R2. At this time, the one-way clutch 42 transmits the rotational power of the front shaft 32 to the driving side gear 43. The rotating gear 50 rotates in the counterclockwise direction as viewed from the front by transmitting the rotational power from the driving side gear 43. The receiving cam 51 and the multiple jaws 4 also rotate integrally with the rotating gear 50. Thus, the multiple jaws 4 close radially inward while rotating in the counterclockwise direction as viewed from the front about the axis of the screw shaft axis K.

[0058] Next, examples of the movements of the wedge 3 and the multiple jaws 4 in the present disclosure will be described. Note that the position to which the wedge 3 moves, the number of times it moves in the forward and backward directions, the opening degree of the multiple jaws 4, the number of times it opens and closes, etc. are not limited to those shown in the examples.

[0059] As shown in FIG. 15, the controller 9 receives an ON signal from the switch 6a and drives the motor 20. The controller 9 supplies power from the battery 8 to the motor 20 to drive the motor 20. The controller 9 detects that the wedge 3 is located at the initial position P1 based on a signal transmitted from the initial position sensor 29a (see FIG. 9). The controller 9 detects that the wedge 3 is located at the terminal position P2 based on a signal transmitted from the terminal position sensor 29b (see FIG. 10). The controller 9 calculates the movement distance of the wedge 3 from the initial position P1 or the terminal position P2 from the number of rotations of the motor 20 based on a signal transmitted from the rotation speed detection sensor 20d. This calculates the position of the wedge 3 between the initial position P1 and the terminal position P2. The controller 9 calculates the operation of the wedge 3 based on a signal transmitted from the input unit 18. The input unit 18 can input, for example, the number of times to move the wedge 3 back and forth. A signal of number information is transmitted from the input unit 18 to the controller 9.

[0060] A first example of the operation of the wedge 3 and the jaws 4 is shown based on Figures 9, 10, 15, and 16. First, the user pulls the trigger 6 (step 01, hereinafter referred to as ST01). The switch 6a transmits an ON signal to the controller 9 while the trigger 6 is pulled (ST02). The controller 9 drives the motor 20 in the forward direction (ST03). The wedge 3 advances 4 mm from the initial position P1 to a first forward position behind the terminal position P2 by the moving mechanism 25. The jaws 4 are pushed by the wedge 3 and open to a first opening degree that is larger than the closing diameter D1 (ST04). The controller 9 reverses the motor 20. The wedge 3 retreats 4 mm from the first forward position to the initial position P1 by the moving mechanism 25. The jaws 4 close from the first opening degree to the closing position and rotate around the axis of the screw shaft axis K by the rotating mechanism 30 (ST05). The multiple jaws 4 rotate, for example, 15° counterclockwise when viewed from the front.

[0061] The controller 9 rotates the motor 20 in the forward direction. The wedge 3 is advanced by 8 mm from the initial position P1 to a second advanced position, which is forward of the first advanced position and rearward of the terminal position P2, by the moving mechanism 25. The jaws 4 are pushed by the wedge 3 and open to a second opening degree, which is larger in diameter than the first opening degree (ST06). The controller 9 rotates the motor 20 in the reverse direction. The wedge 3 is retreated by 8 mm from the second advanced position to the initial position P1 by the moving mechanism 25. The jaws 4 are closed from the second opening degree to a closed position and rotated around the axis of the screw shaft axis K by the rotating mechanism 30 (ST07). The jaws 4 are rotated, for example, 30° counterclockwise as viewed from the front. The angle by which the jaws 4 rotate when the wedge 3 retreats once is approximately proportional to the distance the wedge 3 retreats.

[0062] The controller 9 rotates the motor 20 in the forward direction. The wedge 3 advances 12 mm from the initial position P1 to the terminal position P2 by the moving mechanism 25. The jaws 4 are pushed by the wedge 3 and open to the maximum opening degree, which is larger than the second opening degree (ST08). The controller 9 rotates the motor 20 in the reverse direction. The wedge 3 retreats 12 mm from the terminal position P2 to the initial position P1 by the moving mechanism 25. The jaws 4 close from the maximum opening degree to the closed position and rotate around the axis of the screw shaft axis K by the rotating mechanism 30 (ST09). The jaws 4 rotate, for example, 45° counterclockwise as viewed from the front. The controller 9 stops the motor 20, and a series of diameter expanding operations is completed. The first forward position and the second forward position are calculated by the controller 9 based on the signals transmitted from the initial position sensor 29a and the rotation speed detection sensor 20d, respectively.

[0063] Each of the above steps is executed while the user is pulling the trigger 6. For example, when the user stops pulling the trigger 6, the transmission of the ON signal from the switch 6a to the controller 9 is stopped. The controller 9 reverses the motor 20 to move the wedge 3 back to the initial position P1. When the controller 9 detects that the wedge 3 has returned to the initial position P1 by a signal sent from the initial position sensor 29a, it stops the motor 20. The multiple jaws 4 close to the closed position. In this way, even if the user stops pulling the trigger 6 before the series of diameter expanding operations are completed, the position of the wedge 3 and the opening degree of the multiple jaws 4 are returned to the initial state and the motor 20 is stopped.

[0064] When the end 60b of the tube 60 is expanded while changing the stroke amount of the wedge 3 to change the opening degree of the multiple jaws 4 as in the first example, damage to the end 60b of the tube 60 can be suppressed more than when the end 60b of the tube 60 is expanded in a single expanding operation. For example, when a test was conducted in which the end of an annealed copper tube with an outer diameter of 3 / 8 inch and a wall thickness of 0.8 mm, or the end of a work-hardened copper tube with an outer diameter of 1 inch and a wall thickness of 1.5 mm was expanded in a single expanding operation, cracks occurred in both tube ends. For example, by performing an expanding operation in which the stroke amount of the wedge 3 is changed three times as in the first example, the end of the tube can be expanded while suppressing cracks.

[0065] In addition, for example, as in the first example, by expanding the end 60b of the tube 60 by changing the stroke amount of the wedge 3 three times, the output of the motor 20 can be reduced. The end 60b of the tube 60 is expanded by the combined force of the output of the motor 20 and the force of the rotor 20c and other rotating bodies, the screw shaft 27, the wedge 3, etc., moving due to inertia. When expanding the end 60b of the tube 60 by one expansion operation, the expansion can be performed with a large inertial force at the start of the expansion, but the inertial force decreases as the expansion ends. Therefore, it is necessary to increase the output of the motor 20 at the end of the expansion when the force required for expansion is large. Therefore, the peak value of the current flowing through each electrical component also becomes high, and it is necessary to provide electrical components that can withstand the peak value of the current. When expanding the end 60b of the tube 60 by changing the stroke amount of the wedge 3 three times as in the first example, the expansion start operation with a large inertial force is performed three times. Therefore, it is possible to reduce the output of the motor 20 at the end of each operation. This makes it possible to suppress the peak value of the current flowing through each electrical component.

[0066] Next, a second example of the operation of the wedge 3 and the multiple jaws 4 will be shown based on Figs. 9, 10, 15, and 17. In the second example, the operations from ST01 to ST06 are the same as those in the first example. After ST06 is completed, the controller 9 reverses the motor 20. The wedge 3 is moved by the moving mechanism 25 from the second forward position to the first backward position, which is forward of the initial position P1, by 4 mm. The multiple jaws 4 are closed to an opening angle smaller than the second opening angle and larger than the closed position, and rotated around the axis of the screw shaft axis K by the rotating mechanism 30 (ST11). At this time, the opening angle of the multiple jaws 4 is approximately the first opening angle. The multiple jaws 4 are rotated, for example, by 15° in the counterclockwise direction when viewed from the front.

[0067] The controller 9 rotates the motor 20 in the forward direction. The wedge 3 advances 8 mm from the first retreat position to the terminal position P2 by the moving mechanism 25. The jaws 4 are pushed by the wedge 3 and open to the maximum opening degree (ST12). The controller 9 rotates the motor 20 in the reverse direction. The wedge 3 retreats 12 mm from the terminal position P2 to the initial position P1 by the moving mechanism 25. The jaws 4 close from the maximum opening degree to the closed position and rotate around the axis of the screw shaft axis K by the rotating mechanism 30 (ST13). The jaws 4 rotate, for example, 45° counterclockwise as viewed from the front. The controller 9 stops the motor 20 and a series of diameter expanding operations is completed. In the second example, the movement distance of the wedge 3 is shorter than that of the first example by twice the distance between the initial position P1 and the first retreat position in ST11 and ST12. The first forward position, the second forward position, and the first reverse position are calculated by the controller 9 based on signals transmitted from the initial position sensor 29a and the rotation speed detection sensor 20d, respectively.

[0068] The above steps are executed while the user is pulling the trigger 6. For example, when the user stops pulling the trigger 6, the controller 9 stops the motor 20 in a state in which the wedge 3 is returned to the initial position P1 and the multiple jaws 4 are closed to the closed position, similar to the first example.

[0069] Next, a third example of the operation of the wedge 3 and the multiple jaws 4 will be shown with reference to Figures 9, 10, 15, and 18. In the third example, operations from ST01 to ST08 are the same as in the first example. After ST08 is completed, the controller 9 reverses the motor 20. The wedge 3 is moved back 12 mm from the terminal position P2 to the initial position P1 by the moving mechanism 25. The multiple jaws 4 are closed from the maximum opening position to the closed position and rotated around the axis of the screw shaft axis K by the rotating mechanism 30 (ST21). The multiple jaws 4 are rotated, for example, 45° counterclockwise when viewed from the front.

[0070] After ST21, the controller 9 judges whether the trigger 6 is still pulled and continues to receive an ON signal from the switch 6a (ST22). If the controller 9 receives an ON signal from the switch 6a, it rotates the motor 20 in the forward direction. The wedge 3 advances 12 mm from the initial position P1 to the terminal position P2 by the moving mechanism 25. The multiple jaws 4 are pushed by the wedge 3 and open to the maximum opening degree (ST23). Thereafter, ST21 and ST22 are executed again. In this manner, the wedge 3 repeatedly moves back and forth between the initial position P1 and the terminal position P2. The multiple jaws 4 repeatedly open and close between the closed position and the maximum opening degree, and rotate around the axis of the screw shaft axis K when closing. In this manner, a smoothing operation can be performed to adjust the shape of the end 60b (see FIG. 3) of the expanded tube 60 into a cylindrical shape.

[0071] If the controller 9 does not receive an ON signal from the switch 6a at the time of ST22, it stops the motor 20. As a result, the wedge 3 returns to the initial position P1 and the multiple jaws 4 close to the closed position, and the series of diameter expanding operations ends. For example, if the user stops pulling the trigger 6 between ST01 and ST08, the controller 9 stops the motor 20 in a state where the wedge 3 returns to the initial position P1 and the multiple jaws 4 close to the closed position, as in the first example.

[0072] As described above, the pipe expanding tool 1 for expanding the end 60b (see FIG. 3) of the pipe 60 has a moving mechanism 25 for moving the wedge 3 back and forth as shown in FIGS. 9 and 10. The pipe expanding tool 1 has a plurality of jaws 4 that are pushed by the advanced wedge 3 and open radially outward relative to one another. The pipe expanding tool 1 has a switch 6a that generates an ON signal when operated. The pipe expanding tool 1 has a controller 9 (see FIG. 1). When the controller 9 receives an ON signal from the switch 6a, it advances the wedge 3 to a first advanced position to open the plurality of jaws 4 at a first opening degree. The controller 9 retracts the wedge 3 to close the plurality of jaws 4. The controller 9 advances the wedge 3 to a second advanced position forward of the first advanced position to open the plurality of jaws 4 at a second opening degree larger than the first opening degree. The controller 9 retracts the wedge 3 to close the plurality of jaws 4. In the present disclosure, the second forward position also includes a terminal position which is the front end position to which the wedge 3 can move.

[0073] Therefore, when the switch 6a is turned on, the wedge 3 first advances to a first forward position. The jaws 4 expand the diameter of the end 60b of the tube 60 to a first opening degree. Next, the wedge 3 retreats and the jaws 4 close, and then the wedge 3 advances to a second forward position. The jaws 4 expand the diameter of the end 60b of the tube 60 to a second opening degree that is larger than the first opening degree. In this way, the opening degree of the jaws 4 can be changed by changing the forward position of the wedge 3. This allows the end 60b of the tube 60 to be expanded in a stepwise manner. By expanding the end 60b of the tube 60 in a stepwise manner, the end 60b of the tube 60 can be expanded to a target diameter while suppressing the occurrence of damage such as cracks in the end 60b of the tube 60 during the expansion.

[0074] As shown in Figures 12 and 13, the tube expanding tool 1 has a rotation mechanism 30 that rotates the multiple jaws 4 around the axis of the wedge 3 in conjunction with the retreat of the wedge 3. Therefore, the position of each jaw 4 changes around the axis of the wedge 3 every time it closes. Therefore, the location of each jaw 4 that contacts the inner circumferential surface 60a (see Figure 3) of the end 60b of the tube 60 changes around the axis of the wedge 3 every time the tube expanding operation is performed. Therefore, by performing the expanding operation multiple times, the opening shape of the end 60b of the tube 60 that is expanded in diameter can be made closer to a perfect circle. This allows the end 60b of the tube 60 to be expanded evenly, and prevents the end 60b of the tube 60 from being damaged, such as cracked.

[0075] As shown in FIG. 16, the controller 9 advances the wedge 3 from the initial position P1 to the first forward position. The controller 9 retracts the wedge 3 from the first forward position to the initial position P1. The controller 9 advances the wedge 3 from the initial position P1 to the second forward position. The controller 9 retracts the wedge 3 from the second forward position to the initial position P1. Therefore, every time the wedge 3 is retracted to the initial position P1, the multiple jaws 4 are reliably closed to the closed position. Therefore, when the multiple jaws 4 are closed while rotating around the axis of the wedge 3, contact with the end 60b of the tube 60 (see FIG. 3) is suppressed. This makes it possible to suppress the multiple jaws 4 from biting into the end 60b of the tube 60, and the multiple jaws 4 can be opened and closed smoothly.

[0076] As shown in Fig. 17, the controller 9 advances the wedge 3 from the initial position P1 to the first advanced position. The controller 9 retracts the wedge 3 from the first advanced position to a first retracted position forward of the initial position P1. The controller 9 advances the wedge 3 from the first retracted position to the second advanced position. Therefore, by setting the first retracted position forward of the initial position P1, the total movement amount of the wedge 3 can be suppressed. This allows the end 60b (see Fig. 3) of the pipe 60 to be expanded in diameter quickly.

[0077] As shown in FIG. 16, while the controller 9 receives an ON signal from the switch 6a, the controller 9 moves the wedge 3 back and forth multiple times, bringing the wedge 3 closer to the terminal position P2 each time it advances. After the wedge 3 reaches the terminal position P2, the controller 9 returns the wedge 3 to the initial position P1 and stops it. Therefore, when the wedge 3 reaches the terminal position P2, the multiple jaws 4 expand the end 60b of the tube 60 (see FIG. 3) to the maximum opening degree. By returning the wedge 3 to the initial position P1 and stopping it after completing the expansion of the end 60b of the tube 60, the controller 9 can quickly move to a preparation state for expanding the end 60b of the next tube 60. This shortens the operation time for expanding the ends 60b of the multiple tubes 60, thereby improving the workability.

[0078] As shown in Fig. 18, while receiving an ON signal from the switch 6a, the controller 9 moves the wedge 3 back and forth multiple times, bringing the wedge 3 closer to the terminal position P2 with each advance. After the wedge 3 reaches the terminal position P2, the controller 9 retreats the wedge 3. The controller 9 advances the wedge 3 again to the terminal position P2. Therefore, when the wedge 3 reaches the terminal position P2, the multiple jaws 4 expand the diameter of the end 60b of the tube 60 to the maximum opening degree. By repeatedly opening and closing the multiple jaws 4 to the maximum opening degree, the opening shape of the end 60b of the tube 60 opened to the maximum opening degree can be made closer to a perfect circle.

[0079] As shown in Figure 2, the pipe expansion tool 1 has an input unit 18 for inputting the number of times the wedge 3 moves back and forth. The input unit 18 outputs a signal of the number information to the controller 9. Therefore, the number of times the wedge 3 moves back and forth can be changed depending on, for example, the diameter, thickness, material, etc. of the pipe 60. This makes it possible to effectively prevent damage such as cracks from occurring in the end 60b (see Figure 3) of the pipe 60 during diameter expansion.

[0080] 15 and 16, the controller 9 calculates the first advance position and the second advance position based on the number information. Therefore, the controller 9 can calculate the first advance position and the second advance position and move the wedge 3 efficiently. This can improve the work efficiency.

[0081] As shown in FIG. 15, the pipe expanding tool 1 has an initial position sensor 29a that detects the initial position P1 (see FIG. 9) of the wedge 3 and transmits a signal to the controller 9. The pipe expanding tool 1 has an end position sensor 29b that detects the end position P2 (see FIG. 10) of the wedge 3 and transmits a signal to the controller 9. The pipe expanding tool 1 has a motor 20 that drives the moving mechanism 25. The pipe expanding tool 1 has a rotation speed detection sensor 20d that detects the rotation speed of the motor 20. The controller 9 calculates the position of the wedge 3 based on the signal from the rotation speed detection sensor 20d. Therefore, by detecting the rotation speed of the motor 20, the position of the wedge 3 relative to the initial position P1 or the end position P2 can be quickly detected. Therefore, the movement of the wedge 3 and the opening and closing of the multiple jaws 4 can be smoothly performed.

[0082] 9 and 10, the moving mechanism 25 has a threaded shaft 27 provided on the wedge 3. The moving mechanism 25 has a female threaded member 26 into which the threaded shaft 27 is screwed and which rotates about the axis of the threaded shaft 27 to move the threaded shaft 27 back and forth. Therefore, even in the pipe expanding tool 1 which converts the rotation of the female threaded member 26 into the back and forth movement of the threaded shaft 27 and the wedge 3, the wedge 3 can be moved to multiple forward positions to open multiple jaws 4 at different opening degrees. This makes it possible to expand the end 60b of the pipe 60 while suppressing the occurrence of damage such as cracks.

[0083] Various modifications can be made to the pipe expanding tool 1 of the present embodiment described above. The pipe expanding tool 1 having six jaws 4 has been exemplified. Instead of this, for example, the pipe expanding tool 1 may have five or less jaws 4 or seven or more jaws 4. A plurality of different types of jaws 4 having different closing diameters D1, maximum opening diameters D2, front-to-rear lengths, etc. may be attached to the tool body 10 together with the cap 2 in an exchangeable manner according to the outer diameter, thickness, material, etc. of the end 60b of the pipe 60 to be expanded. The pipe 60 to be expanded is not limited to a copper pipe, and may be, for example, another type of metal pipe or a plastic pipe such as a PEX pipe.

[0084] The rotation mechanism 30 is exemplified as rotating the multiple jaws 4 in a counterclockwise direction as viewed from the front. Alternatively, the multiple jaws 4 may be configured to rotate in a clockwise direction as viewed from the front. In this case, the rotation direction of the front shaft 32 in which the one-way clutch 42 transmits power to the drive side gear 43 is counterclockwise as viewed from the front (the direction of the first rotation R1 shown in FIG. 6).

[0085] The moving mechanism 25 is exemplified as a ball screw mechanism in which a ball 27b is interposed between the male screw 27a of the screw shaft 27 and the female screw 26b of the female screw member 26. Alternatively, for example, a feed screw mechanism in which the male screw 27a and the female screw 26b are mutually configured as trapezoidal screws and directly screwed together may be used. As a mechanism for moving the wedge 3 back and forth, instead of the moving mechanism 25, for example, a cam mechanism in which a cam rotates with the output of the motor 20 may be provided. By switching the rotation direction of the cam of the cam mechanism between forward and reverse, it is possible to gradually change the forward and backward movement of the wedge 3. As a mechanism for moving the wedge 3 back and forth, instead of the moving mechanism 25, for example, a hydraulic mechanism may be provided.

[0086] The diameter expanding operation in which the end 60b of the pipe 60 is expanded in three steps has been exemplified. Instead of this, the end 60b of the pipe 60 may be expanded in two or four or more steps. The position at which the wedge 3 is moved forward and backward is not limited to those exemplified in the first to third examples, and may be changed as appropriate. For example, the wedge 3 may first be advanced to the first forward position two or more times, and then the advanced position may be changed to the second forward position. For example, the wedge 3 may be advanced to the second forward position two or more times, and then the advanced position may be changed to a third forward position forward of the second forward position. For example, the first retreated position may be forward or rearward of the first retreated position. For example, in addition to the operation of retreating to the first retreated position, the operation of retreating to the second retreated position forward of the first retreated position may be included.

[0087] The diameter expanding operation is exemplified in which the first forward position, the second forward position, and the terminal position P2 are proportionally arranged at 4 mm, 8 mm, and 12 mm from the initial position P1, respectively. The distance from the initial position P1 to each position is not limited to being proportional or being limited to being a linear function, and may be changed as appropriate. The distance from the initial position P1 to the first forward position, the second forward position, and the terminal position P2, respectively, may be, for example, 6 mm, 9 mm, and 12 mm, or may be, for example, 8 mm, 10 mm, and 12 mm, or may be, for example, 5 mm, 10 mm, and 12 mm. For example, the smoothing operation of the third example may be added to the diameter expanding operation of the second example.

[0088] In the illustrated embodiment, the wedge 3 moves back and forth by continuing to pull the trigger 6, thereby opening and closing the multiple jaws 4. Alternatively, the pipe expanding tool 1 may continue to be driven even if the trigger 6 is stopped being pulled immediately after it is pulled. In this case, once the trigger 6 is pulled and the switch 6a transmits an ON signal to the controller 9, the controller 9 continues to drive the motor 20 until the wedge 3 completes a specified number of back and forth movements. Even if the trigger 6 is stopped being pulled, this does not result in an OFF operation, and the motor 20 continues to be driven until another OFF operation, such as an emergency stop operation, is performed.

[0089] The example shows a trigger 6 that is pulled to turn on the switch 6a and start the pipe expanding tool 1. The operating part for starting the pipe expanding tool 1 is not limited to the trigger 6, and may be, for example, a push button that turns on the switch 6a when pressed. [Explanation of symbols]

[0090] 1…Pipe diameter expansion tool 2...Cap, 2a...Jaw support groove, 2b...Female thread 3…Wedge 4... jaw, 4a... ring receiving groove, 4b... jaw engagement portion, 4c... ring 4d…Convex part 5. Grip 6...Trigger, 6a...Switch 7... bulging portion, 7a... battery mounting portion 8…Battery 9. Controller 10...Tool body 11...Main body housing 12... front mechanism housing, 12a... male thread, 12b... first inner circumferential surface 12c...Second inner peripheral surface, 12d...Radially extending surface 13: first central mechanism housing, 13a: inner circumferential surface, 13b: downward extension, 13c: recess 13d: through hole, 13e: shaft support 14... second central mechanism housing, 14a... inner circumferential surface, 14b... downward extension, 14c... recess 14d: through hole, 14e: guide shaft support portion, 14f: spring receiving portion 14g…Shaft support 15... rear mechanism housing, 15a... through hole 16…Volts 17…Outer case 18...Input section 20...motor, 20a...motor shaft, 20b...stator, 20c...rotor 20d...rotation speed detection sensor, 20e, 20f...bearing 21...Fan 22...Planetary reduction mechanism 23... gear shaft, 23a... driving gear, 23b, 23c... bearings 24... idle gear, 24a... shaft member, 24b... radial bearing 25...Movement mechanism (ball screw mechanism) 26... female screw member, 26a... driven gear, 26b... female screw, 26c, 26d... bearing 26e...Thrust bearing 27...screw shaft, 27a...male screw, 27b...ball 28...screw shaft guide, 28a...roller shaft, 28b...roller, 28c...rail 28d, 28e…Magnet 29...position sensor, 29a...initial position sensor, 29b...end position sensor 30...Rotation mechanism 31...Shaft 32...front shaft, 32a...female thread 33... rear shaft, 33a... male thread, 33b... ball groove 34...push plate, 34a...through hole 35...ball retainer, 35a...sleeve mounting portion, 35b...ball retaining hole 35c... shaft insertion hole, 35d... side extension portion, 35e... through hole 36…Sleeve 37...Nut 38…Ball 39…Compression spring 41...Guide shaft 42…One-way clutch 43...Drive gear 50...rotating gear, 50a...driven gear, 50b...cylindrical wall, 50c...through hole 50d...Spring support, 50e...Guide 51... receiving cam, 51a... cylindrical portion, 51b... insertion hole, 51c... spring receiving portion 51d... guide engagement portion, 51e... cam engagement portion, 51f... front surface 52...Coil spring 60...pipe, 60a...inner surface, 60b...end J: Motor axis K: Screw shaft axis R1: First rotation R2: Second rotation P1…Initial position P2…Terminal position D1…Closing diameter D2: Maximum opening diameter

Claims

1. A pipe enlargement tool for enlarging the end of a pipe, A mechanism for moving the wedge back and forth, Multiple jaws that open radially outward from one another when pushed by the forward-moving wedge, A switch that emits an ON signal when operated, It has a controller, and the controller is When the ON signal is received from the switch, The wedge is advanced to the first forward position and the plurality of jaws are opened to a first degree of opening. The wedge is retracted to close the multiple jaws, The wedge is advanced from the first forward position to a second forward position, and the plurality of jaws are opened to a second opening greater than the first opening. A pipe diameter expanding tool that retracts the wedge to close the plurality of jaws.

2. A pipe diameter expanding tool according to claim 1, A pipe diameter expanding tool having a rotation mechanism that rotates the plurality of jaws around the axis of the wedge in conjunction with the retraction of the wedge.

3. A pipe diameter expanding tool according to claim 1 or 2, The controller advances the wedge from the initial position to the first forward position. The wedge is moved back from the first forward position to the initial position. The wedge is advanced from the initial position to the second advanced position. A pipe diameter expanding tool that retracts the wedge from the second forward position to the initial position.

4. A pipe diameter expanding tool according to claim 1 or 2, The controller advances the wedge from the initial position to the first forward position. The wedge is moved backward from the first forward position to a first retracted position forward of the initial position, A pipe diameter expanding tool that advances the wedge from the first retracted position to the second advanced position.

5. A pipe diameter expanding tool according to claim 1 or 2, While the controller is receiving the ON signal from the switch, The wedge is moved back and forth multiple times, and with each forward movement, the wedge is brought closer to the terminal position. A pipe diameter expanding tool that, after the wedge reaches the terminal position, returns the wedge to its initial position and stops it.

6. A pipe diameter expanding tool according to claim 1 or 2, While the controller is receiving the ON signal from the switch, The wedge is moved back and forth multiple times, and with each forward movement, the wedge is brought closer to the terminal position. After the wedge reaches the terminal position, the wedge is retracted. A pipe diameter expanding tool that advances the wedge again to the terminal position.

7. A pipe diameter expanding tool according to claim 1 or 2, A pipe diameter expanding tool having an input unit for inputting the number of times the wedge moves back and forth, the input unit sending a signal of the number of times to the controller.

8. A pipe diameter expanding tool according to claim 7, The controller is a pipe enlargement tool that calculates the first forward position and the second forward position based on the count information.

9. A pipe diameter expanding tool according to claim 1 or 2, An initial position sensor that detects the initial position of the wedge and transmits a signal to the controller, A terminal position sensor that detects the terminal position of the wedge and transmits a signal to the controller, A motor that drives the aforementioned moving mechanism, A pipe diameter expanding tool having a rotation speed detection sensor for detecting the rotation speed of the motor, wherein the controller calculates the position of the wedge based on the signal from the rotation speed detection sensor.

10. A pipe diameter expanding tool according to claim 1 or 2, The aforementioned moving mechanism is a pipe diameter expanding tool having a screw shaft provided on the wedge and a female screw member into which the screw shaft is screwed and which rotates around the axis of the screw shaft to move the screw shaft back and forth.

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