Flare forming device and flare forming tool

Abstract

To provide an improvement related to a clutch mechanism in a flare forming device.SOLUTION: A clutch mechanism of a flare forming device is housed in a housing and includes a fixed clutch member, a movable clutch member, and a pressing spring. A first engagement part of a main shaft and a second engagement part of the movable clutch member constitute a feed screw mechanism. The movable clutch member is pressed against a cam surface by the biasing force of the pressing spring and is movable in a front-rear direction relative to the fixed clutch member between a first position where it is held substantially non-rotatable relative to the fixed clutch member and a second position where it is separated from the cam surface and rotatable relative to the fixed clutch member. At the second position, the movable clutch member is configured to be freely rotatable relative to the fixed clutch member in a first direction being a rotation direction when the main shaft moves forward, and to restrict rotation in a second direction being a rotation direction when the main shaft moves backward.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to a flare forming device and a flare forming tool including a flare forming device. [Background technology]

[0002] Flare forming devices for forming a flare (a conically expanded portion) on the end of a pipe (tube) are known. A typical flare forming device includes a main shaft that rotates around a drive shaft and moves back and forth along the drive shaft, and a cone that is supported at the front end of the main shaft and is rotatable around an axis eccentric to the drive shaft. As the main shaft rotates and moves forward from an initial position, the cone gradually expands the end of the pipe, thereby forming a flare. After forming the flare, the main shaft moves backward to the initial position.

[0003] For example, the flare forming device disclosed in Patent Document 1 includes a clutch flange housed in a holder and threadedly engaged with a main shaft. When the clutch pin receiving portion of the clutch flange is engaged with the clutch pin biased rearward by a biasing spring, rotation of the clutch flange relative to the holder is inhibited. Therefore, the main shaft is moved in the front-rear direction relative to the holder and clutch flange by the action of the feed screw. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-081043 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-described flare forming device, an opening is formed in the side of the cylindrical holder, and the clutch pin receiving portion of the clutch flange, the clutch pin, and the biasing spring are disposed within this opening. In this configuration, there is a possibility that the lubricant (e.g., grease) disposed inside the holder may leak from the opening. In addition, since the clutch pin and the biasing spring must be held by the holder, there are disadvantages such as an increase in the number of parts and a complex structure.

[0006] One non-limiting object of the present disclosure is to provide an improvement regarding clutch mechanisms in flare forming devices. [Means for solving the problem]

[0007] According to one non-limiting aspect of the present disclosure, there is provided a flare forming device including a housing, a main shaft, a cone, and a clutch mechanism. The main shaft is accommodated in the housing so as to be rotatable about a first axis that defines the front-to-rear direction of the flare forming device and so as to be movable in the front-to-rear direction along the first axis. The main shaft has a first engagement portion. The cone is supported on the front end of the main shaft so as to be rotatable about a second axis eccentric with respect to the first axis and is configured to form a flare on the end of a pipe. The clutch mechanism is accommodated in the housing.

[0008] The clutch mechanism includes a fixed clutch member, a movable clutch member, and a pressure spring. The fixed clutch member has a cam surface. The fixed clutch member is disposed around the main shaft so as to be substantially immovable relative to the housing. The movable clutch member is disposed around the main shaft behind the fixed clutch member. The movable clutch member has a second engagement portion that directly or indirectly engages with the first engagement portion of the main shaft. The pressure spring is configured to bias the movable clutch member forward.

[0009] The first engagement portion of the main shaft and the second engagement portion of the movable clutch member constitute a feed screw mechanism that moves the main shaft and the movable clutch member relatively in the front-to-rear direction. The feed screw mechanism may include, for example, a first engagement portion configured as a male thread portion and a second engagement portion configured as a female thread portion that threadably mates with (directly engages with) the male thread portion. Alternatively, the feed screw mechanism may be a ball screw mechanism configured such that the first engagement portion having a first spiral groove and the second engagement portion having a second spiral groove are engaged with each other via a plurality of balls that are rollably arranged in a track defined by the first spiral groove and the second spiral groove.

[0010] The movable clutch member is movable in the forward and backward directions relative to the fixed clutch member between (i) a first position where it is pressed against the cam surface by the biasing force of a pressing spring and is held substantially non-rotatable relative to the fixed clutch member, and (ii) a second position where it is separated from the cam surface and is rotatable relative to the fixed clutch member. Furthermore, in the second position, the movable clutch member is configured such that (i) it is freely rotatable relative to the fixed clutch member in the first direction, which is the rotation direction when the main shaft is moved forward, and (ii) its rotation in the second direction, which is the rotation direction when the main shaft is moved rearward, is restricted. Note that "restriction" in this aspect does not only include complete prohibition of rotation of the movable clutch member in the second direction, but also includes allowing a certain amount of rotation and prohibiting any further rotation.

[0011] The flare forming device of this embodiment moves the main shaft in the forward and backward directions using a feed screw mechanism, and forms a flare on the end of a pipe using a cone supported on the front end of the main shaft. Specifically, when the main shaft is rotated in the first direction while being movable forward with the movable clutch member in the first position, the feed screw mechanism moves the main shaft forward. After that, when the cone forms a flare on the end of the pipe and the forward movement of the main shaft is inhibited, the feed screw mechanism moves the movable clutch member from the first position to the second position (in other words, the clutch mechanism is activated). When the main shaft continues to rotate in the first direction with the movable clutch member in the second position, the movable clutch member rotates in the first direction integrally with the main shaft while receiving the biasing force of the pressure spring. This improves the finish of the end of the pipe.

[0012] Thereafter, when the main shaft is rotated in the second direction, the reaction force from the pipe and the biasing force of the pressure spring may be balanced, causing the movable clutch member to rotate integrally with the main shaft at the second position. If the movable clutch member and the main shaft continue to rotate integrally in this state, the feed screw mechanism cannot move the main shaft rearward. In contrast, with the clutch mechanism of this aspect, the rotation of the movable clutch member in the second direction is restricted, so the feed screw mechanism can move the main shaft rearward relative to the movable clutch member, reducing the reaction force from the pipe. As a result, the movable clutch member can return to the first position by the biasing force of the pressure spring.

[0013] In the flare forming device of this embodiment, the clutch mechanism employs a fixed clutch member having a cam surface and a movable clutch member that is held against the cam surface by a pressure spring. This simplifies the configuration of the clutch mechanism compared to conventional clutch mechanisms in which the clutch pin and the spring that urges the clutch pin toward the movable clutch flange are held in an opening in the side of a holder. Furthermore, because there is no need to provide an opening in the side of the housing that houses the clutch mechanism, the possibility of lubricant leakage is reduced.

[0014] According to another non-limiting aspect of the present disclosure, there is provided an electric flare forming tool including a tool housing, the flare forming device according to the above aspect, and a motor. The flare forming device is housed in the tool housing. The motor is housed in the tool housing. The motor is operably coupled to a main shaft of the flare forming device and configured to rotate the main shaft.

[0015] According to this aspect, an electric flare forming tool with excellent usability is realized in which the main shaft is driven by the motor. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram showing the overall configuration of a flare forming tool according to a first embodiment. FIG. [Figure 2] 1, showing a cross-sectional view of the flare forming device when the main shaft is in an initial position. [Figure 3] FIG. 3 is a partially enlarged view of FIG. 2. [Figure 4] FIG. 2 is a left side view of the second sleeve, the movable flange, the adjustment flange, and the rotation stopper of the clutch mechanism. [Figure 5] FIG. 10 is a rear perspective view of the second sleeve, movable flange, adjustment flange, and rotation stopper of the clutch mechanism. [Figure 6] FIG. 4 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7]7 is a cross-sectional view corresponding to FIG. 6, showing the rotation stopper abutting against the protrusion. [Figure 8] 1 is a cross-sectional view of the flare forming device when the main shaft is in a forward blocking position and the movable sleeve is in a connected position. FIG. [Figure 9] 1 is a cross-sectional view of the flare forming device when the main shaft is in a forward blocking position and the movable sleeve is in a blocking position. FIG. [Figure 10] FIG. 6 is a cross-sectional view showing the overall configuration of a flare forming tool according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] In one non-limiting embodiment of the present disclosure, the clutch mechanism may include a rotation stopper formed separately from the movable clutch member. The rotation stopper may be configured to (i) allow rotation of the movable clutch member in a first direction and (ii) restrict rotation in a second direction. This embodiment allows the movable clutch member and the rotation stopper to have optimal structures.

[0018] In addition to or instead of the above embodiment, the rotation stopper may be an at least partially elastically deformable member. The rotation stopper may be configured to (i) allow rotation of the movable clutch member in a first direction by elastic deformation, and (ii) restrict rotation of the movable clutch member in a second direction by being locked to prevent rotation with respect to the housing. According to this embodiment, the elastic deformation of the rotation stopper can be used to appropriately allow or restrict rotation of the movable clutch member.

[0019] In addition to or instead of the above embodiment, the rotation stopper may be configured to limit rotation of the movable clutch member in the second direction by being directly engaged with the housing. This embodiment is advantageous because it does not require a structure for engaging the rotation stopper separately from the housing. Note that the rotation stopper may be directly engaged with the housing by, for example, abutting against a protrusion provided on the inner surface of the housing.

[0020] In addition to or instead of the above embodiment, the rotation stopper may be a flat spring member. According to this embodiment, the dimension of the rotation stopper in the first axial direction can be minimized.

[0021] In addition to or instead of the above embodiment, the rotation stopper may have at least one arm portion extending in a circumferential direction about the first axis. The at least one arm portion may be configured to (i) allow rotation of the movable clutch member in a first direction by bending, and (ii) limit rotation of the movable clutch member in a second direction by directly locking a tip of the arm portion with the housing. According to this embodiment, the rotation of the movable clutch member can be appropriately allowed or limited by utilizing elastic deformation of the at least one arm portion.

[0022] In addition to or instead of the above embodiment, the at least one arm portion may include a plurality of arm portions arranged at equal intervals in the circumferential direction. According to this embodiment, the plurality of arm portions arranged in a balanced manner in the circumferential direction can more reliably limit rotation of the movable clutch member in the second direction.

[0023] In addition to or instead of the above embodiment, the flare forming device may further include a thrust bearing disposed between the movable clutch member and the pressure spring in the front-to-rear direction. A portion of the rotation stopper may be disposed between the thrust bearing and the movable clutch member. According to this embodiment, the thrust bearing can decouple the pressure spring from the rotation of the rotation stopper and the movable clutch member.

[0024] In addition to or instead of the above embodiment, the flare forming device may be configured as an attachment that can be selectively attached to a power tool configured to rotate a final output shaft. According to this embodiment, a user can attach the flare forming device to a power tool (e.g., a drilling tool or a fastening tool) configured to rotate a final output shaft and use it only when necessary. This increases the number of tasks that the power tool can be used for, improving convenience.

[0025] Representative and non-limiting embodiments of the present disclosure will be specifically described below with reference to the drawings.

[0026] First Embodiment A flare forming tool 1A according to a first embodiment of the present disclosure will be described below with reference to Figures 1 to 9. The flare forming tool 1A is an electric tool used to expand the end of a metal (typically copper) pipe (tube) for a refrigerant into a conical shape to enable accurate connection of the pipe.

[0027] First, the general configuration of the flare forming tool 1A will be described.

[0028] As shown in FIG. 1, the outer shell of the flare forming tool 1A is formed by a tool housing 11 and a handle portion 15.

[0029] The tool housing 11 extends along the drive axis DX of the flare forming device 3A. The tool housing 11 accommodates an electric motor 21, a speed reduction mechanism 23 operably connected to the motor 21, and the flare forming device 3A operably connected to the speed reduction mechanism 23. An opening 111 is formed at one end of the tool housing 11. A clamp attachment portion 41 at the tip of the flare forming device 3A protrudes outside the opening 111. Although detailed illustration is omitted because this is well-known technology, a pipe clamp device can be attached to the clamp attachment portion 41.

[0030] The handle portion 15 protrudes from the tool housing 11 in a direction intersecting the drive axis DX (more specifically, in a direction substantially perpendicular to the drive axis DX). The handle portion 15 includes a grip portion 150 configured to be gripped by a user. The grip portion 150 extends in a direction intersecting the drive axis DX and has a trigger 151 configured to be pressed by a user. The handle portion 15 also contains a switch 153 and a controller 20. The switch 153 is normally off and is configured to be turned on in response to pressing of the trigger 151. The controller 20 is a control device configured to control the operation of the flare forming tool 1A.

[0031] A battery mounting portion 17 is provided at the free end of the handle portion 15. The flare forming tool 1A operates on power supplied from a battery 19 that is removably attached to the battery mounting portion 17. However, the flare forming tool 1A may also be configured to operate on power supplied from an external AC power source via a power cord.

[0032] After the clamp device clamping the pipe is attached to clamp attachment portion 41 of flare forming device 3A, the user presses trigger 151 to turn on switch 153, causing controller 20 to drive motor 21. As motor 21 is driven, flare forming device 3A is driven via speed reduction mechanism 23, and a flare (a conically expanded portion) is formed at the end of the pipe. Note that hereinafter, the work of forming a flare will also be referred to simply as the flaring work.

[0033] The detailed configuration of the flare forming tool 1A will be described below. For ease of explanation, the direction in which the drive axis DX extends will be defined as the front-rear direction of the flare forming tool 1A. In the front-rear direction, the side where the tip end (clamp mounting portion 41) of the flare forming device 3A is located will be defined as the front side, and the opposite side will be defined as the rear side. Furthermore, the direction perpendicular to the drive axis DX and corresponding to the longitudinal direction of the gripping portion 150 will be defined as the up-down direction of the flare forming tool 1A. In the up-down direction, the side where the free end of the handle portion 15 is located will be defined as the lower side, and the opposite side will be defined as the upper side. Furthermore, the direction perpendicular to the front-rear direction and the up-down direction will be defined as the left-right direction of the flare forming tool 1A.

[0034] The configurations of the tool housing 11 and the handle portion 15 will be described.

[0035] 1, in this embodiment, the tool housing 11 is integrally formed with the handle portion 15. More specifically, two half bodies (a left shell and a right shell), each including a portion forming the tool housing 11 and a portion forming the handle portion 15, are connected and fixed to each other in the left-right direction to form the integrated housing. However, the tool housing 11 and the handle portion 15 may also be formed separately and then connected and fixed to each other.

[0036] The elements (structure) arranged inside the tool housing 11 and the handle portion 15 will be described below.

[0037] 1, the motor 21 is accommodated in the front half of the lower part of the tool housing 11. The rotation axis of the output shaft (not shown) of the motor 21 extends below and parallel to the drive shaft DX. The motor 21 is electrically connected to and controlled by the controller 20.

[0038] The reduction mechanism 23 is housed in the rear half of the lower part of the tool housing 11, behind the motor 21. The reduction mechanism 23 is operably connected to an output shaft (not shown) of the motor 21 and a main shaft 5 of the flare forming device 3A, which will be described later. The reduction mechanism 23 is configured to reduce the rotational speed of the output shaft of the motor 21 and output the reduced rotational speed to the flare forming device 3A. Although detailed illustration is omitted, the reduction mechanism 23 in this embodiment is a gear reduction mechanism including a plurality of gears. An output gear 233 of the reduction mechanism 23 is operably connected to the flare forming device 3A.

[0039] The flare forming device 3A is disposed above the motor 21 within the tool housing 11. The flare forming device 3A will be described in detail later.

[0040] The controller 20 is disposed within the lower portion of the handle portion 15, below the switch 153 housed in the upper portion of the handle portion 15. The controller 20 includes at least one processor (e.g., a CPU) or processing circuit, and is electrically connected to the motor 21 and the switch 153. In this embodiment, the controller 20 rotates the motor 21 in the forward direction while the trigger 151 is pressed and the switch 153 is turned on. Furthermore, when the trigger 151 is released and the switch 153 is turned off, the controller 20 stops the rotation of the motor 21 and further rotates the motor 21 in the reverse direction.

[0041] The flare forming device 3A will be described in detail below.

[0042] 1 and 2, the flare forming device 3A includes a housing 40, a transmission shaft 43, a main shaft 5, a cone 57, and a clutch mechanism 7. The transmission shaft 43, the main shaft 5, the cone 57, and the clutch mechanism 7 are housed in the housing 40. The flare forming device 3A of this embodiment is configured as a single assembly in which these elements are connected to each other.

[0043] The housing 40 is an elongated, stepped cylindrical member as a whole. The housing 40 is disposed so as to extend in the front-rear direction along the drive axis DX. Although detailed illustration is omitted, the housing 40 is held within the tool housing 11 by the tool housing 11 while being positioned relative to the tool housing 11. Note that, when the tool housing 11 is formed of two half bodies divided into left and right halves as in this embodiment, the housing 40 (the flare forming device 3A as an assembly) may be held in a sandwiched state between the half bodies. Note that the tool housing 11 is the outer housing of the flare forming tool 1A, and the housing 40 can also be said to be the inner housing of the flare forming tool 1A or the drive mechanism housing.

[0044] The front end of housing 40 protrudes forward of tool housing 11 through opening 111 of tool housing 11. The front end of housing 40 is configured as a clamp mounting portion 41. Note that clamp mounting portion 41 may be configured to removably hold any known pipe clamp device (not shown), and the holding structure is not particularly limited.

[0045] The transmission shaft 43 is operably connected to the output gear 233 of the reduction mechanism 23, and is configured to transmit the rotation of the output gear 233 to the main shaft 5. More specifically, the transmission shaft 43 is supported by the housing 40 by two bearings 431, 432 disposed in the rear end portion of the housing 40 so as to be rotatable about the drive axis DX. Although detailed illustration is omitted, the rear end portion of the transmission shaft 43 is coaxially connected to the output gear 233, and the transmission shaft 43 rotates integrally with the output gear 233 as the motor 21 is driven.

[0046] As shown in FIG. 2, the main shaft 5 is an elongated member that defines the drive axis DX and may also be referred to as a spindle. The main shaft 5 extends in the front-rear direction within the housing 40. As will be described in detail later, the main shaft 5 is movable in the front-rear direction along the drive axis DX while rotating around it. A front end 52 of the main shaft 5 rotatably supports a cone 57 for forming a flare. As the main shaft 5 moves forward, the cone 57 protrudes forward from an opening 401 at the front end of the housing 40 (clamp mounting portion 41).

[0047] The main shaft 5 includes a cylindrical slide portion 51 and a shaft portion 55 extending rearward from the rear end of the slide portion 51.

[0048] The slide portion 51 constitutes the front half of the main shaft 5. The front end of the slide portion 51, i.e., the front end portion 52 of the main shaft 5, rotatably supports a cone 57 for forming a flare. The front end portion 52 is supported by a bearing 510 disposed inside a portion of the housing 40 immediately rearward of the clamp mounting portion 41 so as to be rotatable about the drive axis DX and slidable in the front-rear direction. The rear end portion 53 of the slide portion 51 has a larger diameter than the other portions of the slide portion 51. In other words, the rear end portion 53 is configured as a flange portion. As will be described in detail later, the rear end portion 53 is slidable along the inner surface of a fixed sleeve 71 (specifically, a first sleeve 711) disposed inside the housing 40.

[0049] The shaft portion 55 has a smaller diameter than the slide portion 51, extends rearward from the center of the slide portion 51, and constitutes the rear half of the main shaft 5. The shaft portion 55 is hollow and has a connecting hole 551 with a polygonal (e.g., hexagonal) cross section. The front half of the transmission shaft 43 is formed into a shape corresponding to the connecting hole 551 and is inserted into the connecting hole 551. With this configuration, the main shaft 5 is rotatable integrally with the transmission shaft 43 and is slidable in the front-rear direction relative to the transmission shaft 43. Note that the connecting structure between the main shaft 5 and the transmission shaft 43 is not limited to this example. The main shaft 5 may be connected to the transmission shaft 43 so as to be rotatable integrally with the transmission shaft 43 and to be movable in the front-rear direction relative to the transmission shaft 43, for example, by engagement between a key groove and a key or by spline connection.

[0050] The rear end of shaft portion 55 (i.e., the rear end of main shaft 5) is configured as male thread portion 56. As will be described in detail later, male thread portion 56 can be threadably engaged with female thread portion 737 of movable flange 73 of clutch mechanism 7.

[0051] 2, the cone 57 includes a conical portion 571 and a cylindrical shaft portion 573. The shaft portion 573 extends rearward from the center of the circular rear end surface of the conical portion 571 coaxially with the conical portion 571. A ball holding hole 574 is formed at the rear end of the shaft portion 573. The bottom of the ball holding hole 574 is a conical hole.

[0052] The cone 57 is supported on the front end 52 of the main shaft 5 so as to be rotatable around an axis AX that is eccentric with respect to the axis of the main shaft 5 (i.e., the drive axis DX). More specifically, a support hole 521 is formed in the front end 52. The support hole 521 extends along the axis AX and is configured to receive a shaft portion 573 of the cone 57. In this embodiment, the axis AX is inclined at a predetermined angle with respect to the drive axis DX. The support hole 521 is a stepped, bottomed hole that opens to the front end surface of the front end 52 and includes a large-diameter portion on the opening side, a small-diameter portion on the bottom side, and a bottom. The large-diameter portion and the small-diameter portion of the support hole 521 each have a substantially uniform diameter. Meanwhile, the bottom portion of the support hole 521 is a conical hole whose diameter decreases toward the rear.

[0053] A bearing 581 is fitted into the large diameter portion of the support hole 521. The bearing 581 is a radial bearing configured to receive a radial load. The front half of the shaft portion 573 of the cone 57 is fitted into the bearing 581 and is supported rotatably around the axis AX. In this embodiment, the cone 57 is disposed so that its apex is always positioned on the drive axis DX. This allows a flare to be formed on the end of a thinner pipe than if the apex of the cone 57 were offset from the drive axis DX.

[0054] A portion of shaft portion 573 that extends rearward beyond bearing 581 is disposed within the small diameter portion of support hole 521. Balls 583 are disposed inside the conical holes of ball retaining hole 574 of shaft portion 573 of cone 57 and the conical holes of support hole 521. With this configuration, balls 583 function as a thrust bearing that receives thrust loads, and can also function as a radial bearing that receives radial loads.

[0055] The clutch mechanism 7 will now be described.

[0056] As shown in FIG. 2, the clutch mechanism 7 includes a fixed sleeve 71 , a movable flange 73 , a pressure spring 75 , and a rotation stopper 77 .

[0057] The fixed sleeve 71 is fitted into the front half of the housing 40 behind the bearing 510 and is held substantially immovable relative to the housing 40. The fixed sleeve 71 in this embodiment is a single cylindrical body formed by connecting a first sleeve 711 and a second sleeve 715 to each other in the front-to-rear direction.

[0058] The first sleeve 711 occupies most of the fixed sleeve 71. The outer diameter of the first sleeve 711 is substantially uniform and slightly smaller than the inner diameter of the housing 40. A flange portion 712 protruding radially inward is provided at the front end of the first sleeve 711. Although not shown in detail, the flange portion 712 functions as a stopper that determines the forward-most position of the main shaft 5 when the main shaft 5 is moved forward with no pipe attached to the flare forming tool 1A. More specifically, the flange portion 712 abuts against the front end of the rear end portion 53 (flange portion) of the slide portion 51 of the main shaft 5, preventing the main shaft 5 from moving further forward. The inner diameter of the first sleeve 711 other than the flange portion 712 is substantially uniform.

[0059] A plurality of seal members 713 are arranged between the first sleeve 711 and the housing 40 in the radial direction of the main shaft 5 (the direction perpendicular to the drive axis DX) and seal the gap between the first sleeve 711 and the housing 40. More specifically, the seal members 713 are all annular elastic members (so-called O-rings) and are respectively fitted in annular grooves formed in the outer peripheral surface of the first sleeve 711. The compression margin of the seal members 713 is set so that the first sleeve 711 is held substantially immovable relative to the housing 40. Note that "substantially immovable" here means that extremely small displacement due to elastic deformation of the seal members 713 is permitted.

[0060] When foreign matter (e.g., metal chips or dust) enters the internal space of the housing 40 through the opening 401, the seal member 713 can prevent the foreign matter from entering the space 405 behind the seal member 713 through the gap between the housing 40 and the first sleeve 711. As will be described in detail later, the lead screw mechanism 6 and clutch mechanism 7 that move the main shaft 5 in the front-rear direction are disposed in the space 405 behind the seal member 713. For this reason, a lubricant is placed in the space 405. The seal member 713 prevents foreign matter from entering the space 405, reducing the possibility of malfunction of the lead screw mechanism 6 or the clutch mechanism 7, and can also prevent the lubricant (e.g., grease) from leaking forward from the space 405.

[0061] As described above, the rear end portion 53 of the sliding portion 51 of the main shaft 5 is slidably disposed within the first sleeve 711. A seal member 513 is disposed between the rear end portion 53 of the sliding portion 51 and the first sleeve 711 in the radial direction of the main shaft 5. The seal member 513 is an annular elastic member (a so-called O-ring), and is fitted into an annular groove formed on the outer peripheral surface of the rear end portion 53 of the sliding portion 51. The squeeze of the seal member 513 is set so that the rear end portion 53 of the sliding portion 51 can slide along the inner surface of the first sleeve 711.

[0062] Similar to the above-described seal member 713, when a foreign object enters the internal space of the housing 40 through the opening 401, the seal member 513 can prevent the foreign object from entering behind the seal member 513 through the gap between the slide portion 51 and the first sleeve 711. Therefore, similar to the seal member 713, the seal member 513 can prevent foreign objects from entering the space 405 and the lubricant from leaking from the space 405.

[0063] The second sleeve 715 is cylindrical and shorter than the first sleeve 711, and has substantially the same inner and outer diameters as the first sleeve 711. The second sleeve 715 is connected to the rear end of the first sleeve 711 so as to be non-rotatable relative to the first sleeve 711.

[0064] 3 to 5, the second sleeve 715 has a cam surface 72. The cam surface 72 is provided around the entire circumference of the second sleeve 715 at the rear end of the second sleeve 715 (i.e., the rear end of the fixed sleeve 71), and includes recessed portions 721 and protruding portions 723 that are alternately arranged in the circumferential direction of the second sleeve 715. In this embodiment, four recessed portions 721 are arranged at equal intervals in the circumferential direction.

[0065] In this embodiment, the first sleeve 711 is made of aluminum to reduce weight. On the other hand, because the cam surface 72 is subjected to a heavy load, the second sleeve 715 is made of iron to ensure sufficient strength. For this reason, the second sleeve 715 is formed as a separate (independent) member from the first sleeve 711, which is made of aluminum to reduce weight, and is connected to the first sleeve 711. However, instead of this example, the entire fixed sleeve 71 may be formed as a single (inseparable) member from a single material.

[0066] Movable flange 73 is a cylindrical member (flange sleeve) with a flange. Movable flange 73 is disposed behind fixed sleeve 71 (more specifically, second sleeve 715) and around shaft portion 55 of main shaft 5. Movable flange 73 includes a large diameter portion 731 (which can also be called a flange portion) to which four clutch pins 734 are fixed, and a small diameter portion 736 that has an outer diameter smaller than that of large diameter portion 731 and extends rearward from large diameter portion 731. Note that movable flange 73 and clutch pins 734 in this embodiment are made of iron.

[0067] The large diameter portion 731 has an inner diameter larger than that of the shaft portion 55 of the main shaft 5 and an outer diameter smaller than the inner diameter of the fixed sleeve 71 (second sleeve 715). The clutch pins 734 are arranged at equal intervals around the circumferential direction of the large diameter portion 731 and extend radially. The number and circumferential positions of the clutch pins 734 correspond to the number and circumferential positions of the recesses 721 on the cam surface 72. A portion of the clutch pin 734 protrudes radially outward from the large diameter portion 731 and is normally in contact with the cam surface 72 of the second sleeve 715. The front end of the large diameter portion 731 is arranged within the second sleeve 715 of the fixed sleeve 71.

[0068] The portion of small diameter portion 736 other than the rear end portion is configured as a female thread portion 737 that can be threadedly engaged with male thread portion 56 of main shaft 5. Male thread portion 56 of main shaft 5 and female thread portion 737 of movable flange 73 configure a feed screw mechanism 6 that moves main shaft 5 and movable flange 73 relatively in the front-to-rear direction. Male thread portion 56 corresponds to the screw shaft of feed screw mechanism 6, and female thread portion 737 corresponds to the nut. Note that feed screw mechanism 6 may be configured as a ball screw mechanism. In this case, multiple balls are rollably disposed within a track defined by a spiral groove formed on the outer circumferential surface of main shaft 5 and a spiral groove formed on the inner circumferential surface of movable flange 73, and main shaft 5 and movable flange 73 engage via the balls.

[0069] In this embodiment, an adjustment flange 76 is fixed to movable flange 73. Adjustment flange 76 includes a small diameter portion 761 fixed to the periphery of small diameter portion 736 of movable flange 73, and a flange-shaped large diameter portion 763 that protrudes radially outward from the front end of small diameter portion 761. The outer diameter of large diameter portion 763 is larger than that of large diameter portion 731 of movable flange 73. An annular recess is formed in the front end surface of large diameter portion 763, and the rear end of large diameter portion 731 of movable flange 73 is fixed in a state of fitting into this recess.

[0070] Adjustment flange 76 is provided to appropriately transmit the load of compression spring 75 to movable flange 73, and the outer diameter of large diameter portion 763 is roughly the same as the diameter of compression spring 75. Adjustment flange 76 may be configured as a single member integrated with movable flange 73, or may be omitted as appropriate depending on the dimensions of large diameter portion 763 of movable flange 73 and compression spring 75.

[0071] As shown in FIG. 2, an auxiliary spring 44 is disposed between the rear end of the main shaft 5 and a washer disposed in front of the bearing 431 inside the rear end of the housing 40. The auxiliary spring 44 in this embodiment is a compression coil spring and is disposed around the transmission shaft 43. The auxiliary spring 44 biases the main shaft 5 forward relative to the housing 40. The auxiliary spring 44 is configured to hold the male threaded portion 56 in a position where it can be threaded into the female threaded portion 737 when the male threaded portion 56 comes off the female threaded portion 737 as the main shaft 5 moves rearward. The biasing force (load) of the auxiliary spring 44 is set to be significantly weaker than that of a pressure spring 75, which will be described later.

[0072] As shown in FIGS. 2 and 3 , the pressure spring 75 is configured to bias the movable flange 73 forward toward the fixed sleeve 71. In this embodiment, the pressure spring 75 is a compression coil spring, and is disposed behind the large diameter portion 731 of the movable flange 73 and around the small diameter portion 736 of the movable flange 73 (and the small diameter portion 761 of the adjustment flange 76). The pressure spring 75 normally biases the movable flange 73 forward to press the clutch pin 734 against the cam surface 72 of the second sleeve 715, and the clutch pin 734 is held within the recess 721 of the cam surface 72 (see FIGS. 4 and 5 ). As a result, the movable flange 73 is integrated with the fixed sleeve 71 so as to be substantially unrotatable relative to the fixed sleeve 71. Hereinafter, the longitudinal position of the movable flange 73 relative to the fixed sleeve 71 at this time will be referred to as the connected position.

[0073] As will be described in detail later, movable flange 73 can move rearward relative to fixed sleeve 71 from a connected position to a position where clutch pin 734 is separated from cam surface 72 (hereinafter referred to as a disconnected position; see Figure 9). When movable flange 73 is located in the disconnected position, movable flange 73 can rotate together with main shaft 5 relative to fixed sleeve 71.

[0074] As shown in FIG. 3 , in this embodiment, between the large diameter portion 731 of the movable flange 73 and the front end of the pressure spring 75, in order from the front, there are interposed: the large diameter portion 763 of the adjustment flange 76; a portion of the rotation stopper 77 (more specifically, the base portion 771 described below); a thrust bearing 781; and a washer 785. In this embodiment, the thrust bearing 781 is a thrust needle bearing in which multiple needles are simply held in a cage so that they can roll, and the base portion 771 of the rotation stopper 77 and the washer 785 function as a raceway. The rear end of the pressure spring 75 abuts against the shoulder portion 407 of the housing 40 (see FIG. 2 ). The front end of the pressure spring 75 abuts against the washer 785. Therefore, the pressure spring 75 biases the movable flange 73 forward via the intervening members.

[0075] The rotation stopper 77 is configured to allow free rotation of the movable flange 73 in one direction around the drive axis DX, and to restrict rotation in the opposite direction.

[0076] The rotation stopper 77 of this embodiment is configured as an elastically deformable flat spring member. More specifically, as shown in Figures 5 and 6, the rotation stopper 77 includes a base portion 771 and two arm portions 775 extending from the base portion 771. The base portion 771 and the arm portions 775 are integrally formed by processing a single flat metal plate.

[0077] The base portion 771 is a circular flat plate portion. The two arm portions 775 are arranged symmetrically with respect to the center of the base portion 771 when viewed from the rear of the rotation stopper 77. More specifically, the two arm portions 775 are connected to the base portion 771 at positions facing each other across the center of the base portion 771. Each of the arm portions 775 includes a base end portion 776 that protrudes radially outward from the outer edge of the base portion 771, and an extension portion 777 that extends in an arc shape from the base end portion 776 in one direction around the drive axis DX. More specifically, the extension portion 777 extends counterclockwise from the base end portion 776 when viewed from the rear.

[0078] As shown in FIGS. 3 to 6, the base portion 771 of the rotation stopper 77 is disposed around the small diameter portion 761 of the adjustment flange 76. The front surface of the base portion 771 abuts against the rear surface of the large diameter portion 763 of the adjustment flange 76, and the rear surface abuts against a thrust bearing 781 (more specifically, a needle). The base portion 771 is pressed against the large diameter portion 763 by the biasing force (load) of the pressure spring 75, which causes the rotation stopper 77 to rotate integrally with the adjustment flange 76 and the movable flange 73 around the drive axis DX. Meanwhile, the thrust bearing 781 isolates the pressure spring 75 from the rotation of these components.

[0079] In addition, in the front-rear direction, a base end 776 of the arm portion 775 is located at substantially the same position as the base portion 771. On the other hand, the extension portion 777 of the arm portion 775 extends forward from the base end 776 toward a tip end 778, which is a free end, on the radially outer side of the large diameter portion 763 of the adjustment flange 76, and can bend in the front-rear direction.

[0080] On the other hand, as shown in Figures 3 and 6, two protrusions 42 are provided within the housing 40, which are configured to abut against the rotation stopper 77 and limit the rotation of the rotation stopper 77 in one direction relative to the housing 40.

[0081] More specifically, the two protrusions 42 protrude radially inward (toward the drive shaft DX) from the inner surface of the cylindrical housing 40 at positions facing each other across the drive shaft DX. The tips of the protrusions 42 are located radially inward of the outer edges of the extensions 777 of the arm portions 775. Furthermore, the front-rear position and length of the protrusions 42 are set so that, regardless of the front-rear position of the movable flange 73 relative to the housing 40, (i) the base end 776 of the arm portions 775 of the rotation stopper 77 is located rearward of the rear ends of the protrusions 42, and (ii) the tip 778 of the extension portions 777 of the arm portions 775 is located between the front and rear ends of the protrusions 42.

[0082] Due to the configuration of rotation stopper 77 and protrusion 42 described above, when rotation stopper 77 rotates clockwise as viewed from the rear, regardless of the front-to-rear position of movable flange 73 relative to housing 40, extension portion 777 of arm portion 775 abuts against the rear end of protrusion 42 and bends rearward, thereby being able to overcome protrusion 42. In other words, rotation stopper 77, adjustment flange 76, and movable flange 73 are allowed to rotate clockwise as viewed from the rear relative to housing 40 and fixed sleeve 71.

[0083] On the other hand, when the rotation stopper 77 rotates counterclockwise as viewed from the rear, as shown in Figure 7, when the tip 778 of the extension portion 777 of the arm portion 775 abuts against the side surface of the protrusion 42, the rotation stopper 77 is prevented from rotating further counterclockwise by the protrusion 42. In other words, the rotation stopper 77, the adjustment flange 76, and the movable flange 73 are restricted from rotating counterclockwise relative to the housing 40 and the fixed sleeve 71 as viewed from the rear.

[0084] The operation of the flare forming device 3A when the motor 21 is driven will be described below.

[0085] As shown in FIG. 2, in the initial state of the flare forming device 3A, the main shaft 5 is disposed in a position (hereinafter referred to as the initial position) where the male thread portion 56 at the rear end can be threadedly engaged with the female thread portion 737 of the movable flange 73. At this time, the movable flange 73 is in the connected position and is substantially immovable relative to the fixed sleeve 71 and the housing 40. The controller 20 (see FIG. 1) starts rotating the motor 21 in the forward direction in response to the switch 153 being turned on. When the motor 21 rotates in the forward direction, the main shaft 5 rotates clockwise as viewed from the rear about the drive axis DX. As the main shaft 5 rotates clockwise as viewed from the rear, the feed screw mechanism 6 moves the main shaft 5 forward. Hereinafter, clockwise rotation as viewed from the rear will be referred to as forward rotation, and counterclockwise rotation as viewed from the rear will be referred to as reverse rotation.

[0086] As shown in FIG. 8, when the pipe P is clamped to a clamp device (not shown) attached to the clamp attachment portion 41, as the main shaft 5 continues to rotate in the forward direction, the cone 57 comes into contact with the end of the pipe P before the main shaft 5 reaches its forward-most position. As the main shaft 5 rotates and moves forward, the cone 57 rotates (spins) about the axis AX and revolves (revolves) around the drive axis DX, thereby expanding the end of the pipe P into a conical shape. When the cone 57 expands the end of the pipe into a conical shape and moves forward to a certain extent while forming a flare, the pipe held by the clamp device prevents the cone 57 and, ultimately, the main shaft 5 from moving forward before the main shaft 5 reaches its forward-most position. FIG. 8 shows the position of the main shaft 5 at this time (hereinafter also referred to as the forward movement inhibiting position).

[0087] When the main shaft 5 continues to rotate forward at the forward movement inhibiting position, the movable flange 73 moves rearward relative to the fixed sleeve 71 against the biasing force of the pressure spring 75 due to the action of the feed screw mechanism 6. As a result, as shown in FIG. 9 , the clutch pin 734 moves away from the cam surface 72 to a disengagement position where it can rotate relative to the fixed sleeve 71. Hereinafter, the movement of the movable flange 73 from the engagement position to the disengagement position will also be referred to as the actuation of the clutch mechanism 7. Note that, because the flare shape has already been formed by the time the main shaft 5 can no longer move forward, it can also be said that the clutch mechanism 7 acts in response to the formation of the flare.

[0088] As movable flange 73 moves rearward, pressure spring 75 is compressed, increasing the biasing force. Feed screw mechanism 6 is configured so that the frictional force between male thread portion 56 and female thread portion 737 exceeds the biasing force of pressure spring 75 at this time. When movable flange 73 reaches the blocking position, it does not move any further and begins to rotate forward integrally with main shaft 5, which is in the forward movement inhibiting position. As described above, extension portion 777 of arm portion 775 (see FIG. 6) can overcome protrusion 42 of housing 40 while flexing in the front-rear direction, so rotation stopper 77 rotates forward integrally with movable flange 73.

[0089] The biasing force of the pressure spring 75 acts on the main shaft 5 via the movable flange 73. The cone 57 supported on the front end 52 of the main shaft 5 receives this biasing force and rotates around the axis AX while orbiting the drive axis DX, pressing against the flare at substantially the same position in the front-to-rear direction. Hereinafter, this movement of the cone 57 is also referred to as the finishing movement.

[0090] As described above, in this embodiment, when the user releases the pressure on trigger 151 and switch 153 is turned off, controller 20 stops motor 21 and then rotates it in the reverse direction. If motor 21 is rotated in the reverse direction while movable flange 73 is in the disconnected position, main shaft 5 rotates in the reverse direction. At this time, if the biasing force (load) applied to movable flange 73 from pressure spring 75 exceeds the reaction force (load) applied to main shaft 5 from pipe P, the main shaft 5 is moved rearward by feed screw mechanism 6 as the main shaft 5 rotates reversely. The biasing force of pressure spring 75 moves movable flange 73 forward and returns to the connected position.

[0091] On the other hand, when the main shaft 5 starts to rotate reversely, the biasing force of the pressure spring 75 may balance out with the reaction force from the pipe P. In this case, the movable flange 73 starts to rotate reversely together with the main shaft 5 at the disconnected position. However, as shown in FIG. 7, when the tip 778 of the arm portion 775 of the rotation stopper 77 abuts against the protrusion 42 of the housing 40, the rotation stopper 77 and the movable flange 73 are prevented from rotating reverse any further, and the feed screw mechanism 6 starts to move the main shaft 5 backward. As a result, the reaction force from the pipe P decreases, and the biasing force of the pressure spring 75 moves the movable flange 73 forward, returning it to the connected position.

[0092] As the main shaft 5 continues to rotate in the reverse direction, the main shaft 5 moves backward while rotating in the reverse direction until the male thread portion 56 disengages from the female thread portion 737, and returns to the initial position shown in FIG. 2. The controller 20 stops the rotation of the motor 21 in the reverse direction as the main shaft 5 returns to its initial position. Note that the controller 20 may stop the motor 21 based on, for example, the detection result of a detection device (not shown) that can detect that the main shaft 5 is at its initial position. This detection device may be, for example, a non-contact sensor (for example, a magnetic field or optical position sensor or proximity sensor), or a contact-type mechanical switch (for example, a microswitch).

[0093] As described above, in the flare forming device 3A of this embodiment, the clutch mechanism 7 employs a fixed sleeve 71 having a cam surface 72 and a movable flange 73 that is pressed against the cam surface 72 by a pressure spring 75. This simplifies the configuration of the clutch mechanism 7 compared to conventional clutch mechanisms in which the clutch pin and the biasing spring that biases the clutch pin toward the movable clutch flange are held in an opening in the side of a holder. Furthermore, because there is no need to provide an opening in the side of the housing 40 that houses the clutch mechanism 7, the possibility of lubricant leaking from the housing 40 can be reduced.

[0094] Furthermore, as described above, limiting the reverse rotation of movable flange 73 prevents movable flange 73 and main shaft 5 from continuing to rotate in the reverse direction together, ensuring that main shaft 5 is returned to its initial position. In this embodiment, a rotation stopper 77 separate from movable flange 73 is used to limit the reverse rotation of movable flange 73, allowing movable flange 73 and rotation stopper 77 to each have an optimal structure. Furthermore, because rotation stopper 77 is a single flat spring member, this has the advantages of reducing manufacturing costs and minimizing the thickness in the direction of the drive axis DX.

[0095] Second Embodiment A flare forming tool 1B according to a second embodiment of the present disclosure will be described below with reference to Fig. 10. The flare forming tool 1A of the first embodiment (see Fig. 1) is a power tool dedicated to flaring work, in which a flare forming device 3A is incorporated into a tool housing 11 together with a motor 21 and the like. In contrast, the flare forming tool 1B of the second embodiment includes an existing driver drill 9 and a flare forming device 3B removably attached to the driver drill 9. In other words, the flare forming device 3B is an attachment that can be attached to the driver drill 9.

[0096] The driver drill 9 is a well-known power tool (rotary tool) configured to rotate a tool bit (not shown) removably attached to a chuck 94 about a drive axis DX. The driver drill 9 includes a tool housing 90 extending along the drive axis DX, and a handle portion 95 extending from the tool housing 90 in a direction intersecting the drive axis DX.

[0097] The tool housing 90 accommodates a motor 91 and a spindle 93 operatively connected to the motor 91 via a speed reducer 92. The chuck 94 is connected to the spindle 93 so as to rotate integrally therewith.

[0098] The handle 95 includes a grip 950. The grip 950 is provided with a trigger 951 that is pressed by the user, and a forward / reverse switching lever 952 that moves in response to the user's pressing and switches the rotation direction of the motor 91 between forward and reverse. The handle 95 houses a switch 953 that operates in response to manual operation of the trigger 951 and the forward / reverse switching lever 952, and a controller 955 that controls the drive of the motor 91. While the trigger 951 is pressed and the switch 953 is on, the controller 955 rotates the motor 91 in the rotation direction specified by the forward / reverse switching lever 952. A rechargeable battery 19 is removably attached to the lower end of the handle 95.

[0099] Most of the configuration of the flare forming device 3B is substantially the same as that of the flare forming device 3A of the first embodiment. Therefore, in the following description, the substantially same configurations are denoted by the same reference numerals as in the first embodiment, and the description thereof will be omitted.

[0100] In the flare forming device 3B of this embodiment, the main shaft 5 is operatively connected to the spindle 93 of the driver drill 9 and is configured to rotate in response to the rotational drive of the spindle 93. More specifically, a connecting hole 435 is formed in the rear end of the transmission shaft 43 of the flare forming device 3B. The connecting hole 435 is configured to be connected to another member so as to be able to transmit rotation, and extends along the axes of the transmission shaft 43 and the main shaft 5.

[0101] The transmission shaft 43 is operably connected to the chuck 94 of the driver drill 9 via a connecting shaft 98. One axial end of the connecting shaft 98 is formed to be able to fit into a connecting hole 435 of the transmission shaft 43. The opposite end is formed to be able to fit into an insertion hole 941 for a tool bit formed in the chuck 94 of the driver drill 9. Note that the connecting hole 435, the insertion hole 941, and the two ends of the connecting shaft 98 may have polygonal cross sections, for example, similar to the connecting hole 551 of the main shaft 5 and the front half of the transmission shaft 43 in the first embodiment. Furthermore, for example, the connecting shaft 98 may be connected to the chuck 94 and the transmission shaft 43 so as to be able to rotate integrally therewith by engagement between a key groove and a key or by spline connection.

[0102] The rotation of the spindle 93 of the driver drill 9 is transmitted to the transmission shaft 43 via the chuck 94 and the connecting shaft 98. Therefore, when the motor 91 of the driver drill 9 is rotated in the forward direction, the main shaft 5 of the flare forming device 3B moves forward, and the cone 57 forms a flare on the end of the pipe, as described in the first embodiment. On the other hand, when the motor 91 of the driver drill 9 is rotated in the reverse direction, the main shaft 5 moves backward, returning to its initial position.

[0103] As described above, the flare forming device 3B of this embodiment is configured as an attachment that can be selectively attached to the driver drill 9 to perform flaring work. Therefore, the user can attach the flare forming device 3B to the driver drill 9 only when necessary and use it as a flare forming tool 1B. This increases the number of tasks that the driver drill 9 can be used for, improving convenience.

[0104] The flare forming device 3B may be selectively attached to and used not only on the driver drill 9 but also on other rotary tools (for example, drilling tools, fastening tools) via an appropriate connecting shaft. Furthermore, the flare forming device 3B may be selectively attached to and used on a manual tool having a manually rotatable connecting shaft, rather than on a power tool, or may be integrated with such a manual tool to form a manual flare forming tool.

[0105] The correspondence between each component (feature) of the above embodiment and each component (feature) of the present disclosure or invention is shown below. However, each component of the embodiment is merely an example and does not limit each component of the present disclosure or invention.

[0106] Each of the flare forming device 3A of the first embodiment and the flare forming device 3B of the second embodiment is an example of a "flare forming device." The drive shaft DX is an example of a "first shaft." The shaft AX is an example of a "second shaft." The fixed sleeve 71 (more specifically, the second sleeve 715) is an example of a "fixed clutch member." The integrated movable flange 73 and clutch pin 734 are an example of a "movable clutch member." The engaged position and disengaged position of the movable flange 73 are examples of a "first position" and a "second position," respectively. The driver drill 9 of the second embodiment is an example of a "power tool." The spindle 93 is an example of a "final output shaft." The flare forming tool 1A of the first embodiment is an example of a "flare forming tool."

[0107] The flare forming device according to the present disclosure is not limited to the flare forming devices 3A and 3B of the above-described embodiments. For example, the following non-limiting examples are possible. Furthermore, at least one of these modifications may be adopted in combination with the flare forming devices 3A and 3B of the embodiments and at least one of the features described in the claims.

[0108] For example, the configuration of fixed sleeve 71 and / or movable flange 73 of clutch mechanism 7 can be modified as appropriate. For example, movable flange 73 can be configured to include protrusions integrally formed on the front end surface of large diameter portion 731 instead of clutch pin 734, and these protrusions can be configured to directly engage with recesses 721 of cam surface 72 rather than via clutch pin 734. Furthermore, the shapes, number, and positions of recesses 721 and protrusions 723 on cam surface 72, and the shape, number, and position of the corresponding clutch pin 734 (or protrusions), can be modified as appropriate.

[0109] The configuration that allows free forward rotation of movable flange 73 while restricting reverse rotation is not limited to rotation stopper 77. For example, the number and / or position of arm portions 775 of rotation stopper 77 may be changed from that of the example embodiment described above. However, if there are multiple arm portions 775, it is preferable that the arm portions 775 are arranged at equal intervals. The same applies to protrusion 42 of housing 40. Furthermore, protrusion 42 may be disposed within housing 40, rather than on housing 40, and provided on a member that is integrated with housing 40. Furthermore, rotation stopper 77 and protrusion 42 may be modified so that arm portions 775 bend radially inward when rotation stopper 77 allows rotation of movable flange 73.

[0110] Furthermore, instead of a rotation stopper 77 that is separate from movable flange 73, movable flange 73 itself may be provided with a structure that allows movable flange 73 to freely rotate forward while restricting reverse rotation. For example, a spring member corresponding to arm portion 775 of rotation stopper 77 in the above embodiment may be fixed to adjustment flange 76 or movable flange 73.

[0111] Furthermore, a one-way clutch disposed between movable flange 73 and housing 40 (or a member integrated with housing 40) may be used instead of rotation stopper 77. In this modification, the one-way clutch may be configured so that (i) it rotates freely when movable flange 73 rotates forward, thereby allowing movable flange 73 to rotate freely relative to housing 40, and (ii) it rotates integrally with housing 40 when movable flange 73 rotates reversely, thereby restricting the rotation of movable flange 73 relative to housing 40.

[0112] In the first embodiment, the controller 20 controls the change in the rotation direction of the motor 21 (and consequently the main shaft 5) and the start and stop of driving based only on the on / off state of the switch 153. However, the controller 20 may also control the change in the rotation direction of the motor 21 and the start and stop of driving in accordance with, for example, the operation of a forward / reverse switch, the position of the main shaft 5 identified using a detection device, the operation of a clutch mechanism detected using a detection device, or the like.

[0113] In view of the spirit of the present invention and the above-described embodiments, the following aspects are constructed, and at least one of the following aspects may be adopted in combination with the features of the embodiments and their variants, or at least one of the features described in each claim. [Aspect 1] The cam surface has at least one recess and at least one protrusion alternately arranged in the circumferential direction of the fixed clutch member, The movable clutch member is configured to engage the at least one recess in the cam surface when in the first position. [Aspect 2] The housing has at least one protrusion disposed therein, The protrusion is configured to abut against the rotation stopper to prevent the rotation stopper from rotating in the second direction. [Aspect 3] the rotation stopper has a flat base portion disposed around the movable clutch member between the movable clutch member and the thrust bearing, The at least one arm portion includes a base end portion that protrudes radially outward from the base portion, and an extension portion that extends in the circumferential direction from the base end portion radially outward of the movable clutch member. [Aspect 4] The rotation stopper is pressed against the movable clutch member by the biasing force of the pressure spring, and rotates integrally with the movable clutch member. [Explanation of symbols]

[0114] 1A, 1B: flare forming tool, 11: tool housing, 111: opening, 15: handle portion, 150: grip portion, 151: trigger, 153: switch, 17: battery mounting portion, 19: battery, 20: controller, 21: motor, 23: reduction mechanism, 233: output gear, 3A, 3B: flare forming device, 40: housing, 401: opening, 405: space, 407: shoulder portion, 41: clamp mounting portion, 42: protrusion, 43: transmission Shaft, 431: bearing, 432: bearing, 435: connecting hole, 44: auxiliary spring, 5: main shaft, 51: slide portion, 510: bearing, 513: seal member, 52: front end portion, 521: support hole, 53: rear end portion, 55: shaft portion, 551: connecting hole, 56: male thread portion, 57: cone, 571: conical portion, 573: shaft portion, 574: ball retaining hole, 581: bearing, 583: ball, 6: feed screw mechanism, 7: clutch mechanism, 71: fixed sleeve, 711: first sleeve, 712: flange portion, 713: seal member, 715: second sleeve, 72: cam surface, 721: recessed portion, 723: protruding portion, 73: movable flange, 731: large diameter portion, 734: clutch pin, 736: small diameter portion, 737: female thread portion, 75: pressure spring, 76: adjustment flange, 761: small diameter portion, 763: large diameter portion, 77: rotation stopper, 771: base portion, 775: arm portion, 776: Base end portion, 777: Extension portion, 778: Tip portion, 781: Thrust bearing, 785: Washer, 9: Driver drill, 90: Tool housing, 91: Motor, 92: Reduction mechanism, 93: Spindle, 94: Chuck, 95: Handle portion, 98: Connecting shaft, 941: Insertion hole, 950: Grip portion, 951: Trigger, 952: Forward / reverse switching lever, 953: Switch, 955: Controller, AX: Shaft, DX: Drive shaft, P: Pipe

Claims

1. A flare forming device, Housing and a main shaft that is accommodated in the housing and is rotatable about a first axis that defines a front-rear direction of the flare forming device and is movable in the front-rear direction along the first axis, the main shaft having a first engagement portion; a cone supported on a front end of the main shaft for rotation about a second axis eccentric to the first axis, the cone configured to form a flare at an end of a pipe; a clutch mechanism accommodated in the housing, The clutch mechanism includes: a fixed clutch member having a cam surface and disposed around the main shaft so as to be substantially immovable relative to the housing; a movable clutch member disposed around the main shaft behind the fixed clutch member and having a second engagement portion that directly or indirectly engages with the first engagement portion of the main shaft; a pressure spring configured to bias the movable clutch member forward, the first engagement portion of the main shaft and the second engagement portion of the movable clutch member constitute a feed screw mechanism that moves the main shaft and the movable clutch member relatively in the front-rear direction, the movable clutch member is movable in the front-rear direction relative to the fixed clutch member between (i) a first position where the movable clutch member is pressed against the cam surface by the biasing force of the pressure spring and is held substantially unrotatable relative to the fixed clutch member, and (ii) a second position where the movable clutch member is separated from the cam surface and is rotatable relative to the fixed clutch member, a movable clutch member configured to, in the second position, (i) freely rotate relative to the fixed clutch member in a first direction, which is a rotation direction when the main shaft is moved forward, and (ii) have limited rotation in a second direction, which is a rotation direction when the main shaft is moved rearward.

2. The flare forming device according to claim 1, the clutch mechanism includes a rotation stopper formed separately from the movable clutch member, The flare forming device, characterized in that the rotation stopper is configured to (i) allow rotation of the movable clutch member in the first direction and (ii) restrict rotation in the second direction.

3. The flare forming device according to claim 2, The rotation stopper is an at least partially elastically deformable member, The rotation stopper is configured to (i) allow rotation of the movable clutch member in the first direction by elastic deformation, and (ii) restrict rotation of the movable clutch member in the second direction by being non-rotatably engaged with the housing.

4. The flare forming device according to claim 3, The flare forming device, wherein the rotation stopper is configured to be directly engaged with the housing to limit rotation of the movable clutch member in the second direction.

5. The flare forming device according to claim 3 or 4, The flare forming device is characterized in that the rotation stopper is a flat spring member.

6. A flare forming device according to claim 5 dependent on claim 3, the rotation stopper has at least one arm portion extending in a circumferential direction around the first axis, The at least one arm portion is configured to (i) flex to allow rotation of the movable clutch member in the first direction, and (ii) limit rotation of the movable clutch member in the second direction by directly engaging a tip of the at least one arm portion with the housing.

7. The flare forming device according to claim 6, The at least one arm portion includes a plurality of arm portions arranged at equal intervals in the circumferential direction.

8. The flare forming device according to any one of claims 2 to 7, a thrust bearing disposed between the movable clutch member and the pressure spring in the front-rear direction, A flare forming device, wherein a portion of the rotation stopper is disposed between the thrust bearing and the movable clutch member.

9. The flare forming device according to any one of claims 1 to 8, The flare forming device is configured as an attachment selectively attachable to a power tool configured to rotatably drive a final output shaft.

10. An electric flare forming tool, A tool housing; a flare forming device according to any one of claims 1 to 8 housed in the tool housing; a motor contained in the tool housing and operably coupled to the main shaft of the flare forming device and configured to rotate the main shaft.

Images