Flare forming tool

Abstract

To provide a technique that contributes to stabilization of the finish quality of a flare formed by a flare forming tool.SOLUTION: A flare forming tool comprises a motor, a main shaft, a cone, a clutch mechanism, a detection device, and a control device. The main shaft is operatively connected to the motor and configured to move forward along the first axis while rotating about the first axis following the rotation of the motor in the forward direction. The cone is supported so as to be rotatable about the second axis that is eccentric with respect to the first axis at the front end of the main shaft, and is configured to form a flare at the end of a pipe. The clutch mechanism is configured to operate in response to such a state the cone contacts the end of the pipe and the forward movement of the main shaft is hindered. The detection device is configured to detect the operation of the clutch mechanism. The control device is configured to control the rotation of the motor on the basis of the detection result from the detection device.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a flare forming tool.

Background Art

[0002] An electric flare forming tool for forming a flare (an expanded conical portion) at the end of a pipe (tube) is known. A general flare forming tool includes a main shaft that is movable along a drive shaft while rotating around the drive shaft, and a cone that is rotatably supported around a shaft eccentric to the drive shaft at the front end of the main shaft.

[0003] In order to accurately form a flare, it is preferable that the cone advances while rotating, gradually expands the end of the pipe, and then continues to rotate only while pressing the end of the pipe. For example, the electric flare forming tool disclosed in Patent Document 1 includes a clutch flange that operates in response to the start of flare formation and the rotation of the main shaft while the advancement of the main shaft is hindered. The clutch flange moves rearward with respect to the main shaft and rotates with the main shaft while being pressed by a pressurizing spring. Thereby, the cone continues to rotate while being pressed against the end of the pipe without advancing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above flare forming tool, the rotation of the motor, and thus the rotation of the main shaft, is stopped as the forward / reverse switch is operated by the user. Therefore, the timing at which the cone stops rotating while only pressing against the end of the pipe depends on the timing at which the user operates the forward / reverse switch. For this reason, there are variations in the finish (accuracy) of the flare formed.

[0006] One non-limiting object of the present disclosure is to provide a technique that contributes to the stabilization of the finish of a flare formed by a flare forming tool.

Means for Solving the Problem

[0007] According to one non-limiting aspect of the present disclosure, there is provided a flare forming tool including a motor, a main shaft, a cone, a clutch mechanism, a detection device, and a control device. The motor is rotatable in a forward rotation direction and a reverse rotation direction. The main shaft is operably connected to the motor. The main shaft is configured to move forward along the first axis while rotating around the first axis that defines the front-rear direction of the flare forming tool as the motor rotates in the forward rotation direction. The cone is rotatably supported around a second axis eccentric to the first axis at the front end of the main shaft, and is configured to form a flare at the end of the pipe. The clutch mechanism is configured to operate in response to the cone abutting against the end of the pipe and inhibiting the forward movement of the main shaft. The detection device is configured to detect the operation of the clutch mechanism. The control device is configured to control the rotation of the motor based on the detection result of the detection device.

[0008] According to the flare forming tool of this aspect, the control device can control the rotation of the motor according to whether the clutch mechanism has operated or not. Therefore, the finish (accuracy) of the flare formed can be stabilized (uniformized) as compared with the case where the timing of the start and stop of the rotation of the motor depends on the manual operation of the user.

[0009] Note that the types of the clutch mechanism and the detection device for detecting the operation of the clutch mechanism in this aspect are not particularly limited. For example, a friction-type clutch mechanism or an engagement-type clutch mechanism can be adopted for the clutch mechanism. Also, for example, a magnetic-field sensor, an optical sensor, or a mechanical switch can be adopted for the detection device. Further, the control device can be embodied by, for example, at least one processor and a memory, and its function can be realized by executing a program stored in a non-volatile storage device.

[0010] According to another non-limiting aspect of the present disclosure, a flare forming tool is provided, which includes a motor, a main shaft, a cone, a detection device, and a control device. The motor is rotatable in a forward rotation direction and a reverse rotation direction. The main shaft is operably connected to the motor. The main shaft is configured to move forward along the first axis while rotating around the first axis that defines the front-rear direction of the flare forming tool as the motor rotates in the forward rotation direction. The cone is rotatably supported around a second axis eccentric with respect to the first axis at the front end of the main shaft, and is configured to form a flare at the end of a pipe. The detection device is configured to detect the formation of the flare by the cone. The control device is configured to control the rotation of the motor. The control device controls the rotation of the motor such that after the main shaft rotates by a predetermined rotation amount at a substantially same position in the front-rear direction in response to the detection of the formation of the flare by the detection device, the rotation stops.

[0011] In the flare forming tool of this aspect, the rotation control of the main shaft is realized by the rotation control of the motor by the control device. Therefore, compared with the case where the start and stop timings of the motor depend on the manual operation of the user, the finish (accuracy) of the formed flare can be stabilized (uniformized). Further, when the formation of the flare by the cone is detected, the main shaft rotates by a predetermined rotation amount (predetermined rotation angle) in a state where it is substantially in the same position in the front-rear direction and then stops rotating. During this time, the cone can form a flare so as to approach a perfect circle, and the finish of the flare can be improved.

[0012] In addition, in this aspect, the detection device may detect the formation of the flare by the cone by any method. When the flare is formed by the cone, the forward movement of the main shaft is inhibited. Therefore, the detection device may detect, for example, the operation of some member corresponding to this phenomenon, or may detect some physical quantity corresponding to this phenomenon. For example, the flare forming tool includes a clutch mechanism that operates in response to the forward movement of the main shaft being inhibited, and the detection device may detect the operation of this clutch. Also, for example, the detection device may detect the current value of the motor or the load applied to the main shaft.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0014] In a non-limiting embodiment of the present disclosure, the control device may be configured to rotate the motor in the forward rotation direction by a predetermined amount of rotation and then stop the rotation in response to the operation of the clutch being detected by the detection device.

[0015] According to this embodiment, the main shaft continues to rotate while the motor rotates by a predetermined amount of rotation (predetermined rotation angle) in a state where the forward movement is inhibited, that is, in a state where it is substantially in the same position in the front-rear direction, and stops rotating in response to the rotation of the motor being stopped. During this time, the cone forms a flare so as to approach a perfect circle, and the finish of the flare can be improved.

[0016] In addition to or instead of the above embodiment, the predetermined amount of rotation may be changeable. According to this embodiment, when the desired flare finish cannot be obtained with the initial predetermined amount of rotation, it is possible to change the predetermined amount of rotation to obtain the desired flare finish.

[0017] In addition to or instead of the above-described embodiment, the flare forming tool may further include an operation unit configured to be manually operated by a user. The control device may be configured to change a predetermined amount of rotation in response to a manual operation of the operation unit. According to this embodiment, since the user can change the predetermined amount of rotation by manually operating the operation unit, convenience is improved.

[0018] In addition to or instead of the above-described embodiment, the control device may be configured to move the main shaft backward by rotating the motor in the reverse direction after stopping the motor. According to this embodiment, the main shaft can be moved backward and the cone can be separated from the end of the pipe without any manual operation by the user, so convenience is improved.

[0019] In addition to or instead of the above-described embodiment, the motor may be a brushless motor. According to this embodiment, since the motor is a brushless motor whose rotational position is constantly monitored, the control device can easily control the amount of rotation (rotation angle) of the motor.

[0020] In addition to or instead of the above-described embodiment, the clutch mechanism may include a movable clutch member configured to move in response to the forward movement of the main shaft being inhibited. The detection device may be a hall sensor configured to detect a magnet attached to the movable clutch member. According to this embodiment, a general-purpose hall sensor capable of corresponding to a slight movement of the magnet can surely detect the movement of the movable clutch member, that is, the operation of the clutch mechanism.

[0021] In addition to or instead of the above-described embodiment, the magnet may be attached to a non-rotating portion of the movable clutch member. According to this embodiment, the hall sensor can surely detect the magnet regardless of the rotation of the movable clutch member.

[0022] Hereinafter, with reference to the drawings, representative and non-limiting embodiments of the present disclosure will be specifically described.

[0023] <First Embodiment> Hereinafter, with reference to FIGS. 1 to 12, a flare forming tool 1A according to the first embodiment of the present disclosure will be described. The flare forming tool 1A is a power tool used to expand the end of a pipe into a conical shape in order to enable accurate connection of metal (typically copper) pipes for refrigerants.

[0024] First, the schematic configuration of the flare forming tool 1A will be described.

[0025] As shown in FIG. 1, the outer contour of the flare forming tool 1A is formed by a tool housing 11 and a handle portion 15.

[0026] The tool housing 11 extends along the drive shaft DX of the flare forming device 3A. The tool housing 11 houses an electric motor 21, a speed reduction mechanism 23 operably connected to the motor 21, a flare forming device 3A operably connected to the speed reduction mechanism 23, and a detection device 81. 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 it is a well-known technique, a pipe clamp device can be attached to the clamp attachment portion 41.

[0027] The handle portion 15 protrudes from the tool housing 11 in a direction intersecting the drive shaft DX (specifically, a direction substantially perpendicular). 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 shaft DX and has a trigger 151 configured to be pressed by the user. Also, inside the handle portion 15, a switch 153 and a controller 20 are housed. The switch 153 is normally off and is configured to be turned on in response to the pressing of the trigger 151. The controller 20 is a control device configured to control the operation of the flare forming tool 1A.

[0028] Also, at the end of the free end side of the handle portion 15, a battery attachment portion 17 and an operation portion 25 are provided. The flare forming tool 1A operates by electric power supplied from a battery 19 removably attached to the battery attachment portion 17. However, the flare forming tool 1A may be configured to operate by electric power supplied from an external AC power source via a power cord. The operation portion 25 is an input device for a user to input information by manual operation.

[0029] After a clamping device in a state of clamping a pipe is attached to the clamp attachment portion 41 of the flare forming device 3A, when the switch 153 is turned on in response to the user pressing the trigger 151, the motor 21 is driven. With the driving of the motor 21, the flare forming device 3A is driven via a speed reduction mechanism 23, and a flare (an expanded portion in a conical shape) is formed at the end of the pipe. Hereinafter, the operation of forming a flare is also simply referred to as a flare operation.

[0030] The detailed configuration of the flare forming tool 1A will be described below. For convenience of explanation, the extending direction of the drive shaft DX is defined as the front-rear direction of the flare forming tool 1A. In the front-rear direction, the side where the tip (clamp attachment portion 41) of the flare forming device 3A is located is defined as the front side, and the opposite side is defined as the rear side. Also, the direction orthogonal to the drive shaft DX and corresponding to the major axis direction of the grip portion 150 is defined as the vertical direction of the flare forming tool 1A. In the vertical direction, the side where the free end of the handle portion 15 is located is defined as the lower side, and the opposite side is defined as the upper side. Further, the direction orthogonal to the front-rear direction and the vertical direction is defined as the left-right direction of the flare forming tool 1A.

[0031] Hereinafter, the configuration of the tool housing 11 and the elements (structures) arranged inside the tool housing 11 will be described.

[0032] As shown in FIG. 1, in the present embodiment, the tool housing 11 is integrally formed with the handle portion 15. More specifically, two half bodies (left shell and 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, thereby forming an integral housing. However, the tool housing 11 and the handle portion 15 may be formed separately and connected and fixed to each other.

[0033] The light emitting portion 18 is held on the front wall portion of the tool housing 11. The light emitting portion 18 is configured to illuminate the front region of the clamp attachment portion 41 (that is, the region where the end of the pipe is arranged). The light emitting portion 18 includes, for example, LED illumination. The light emitting portion 18 is electrically connected to the controller 20 and is turned on / off by the controller 20 according to the on / off of the switch 153.

[0034] The motor 21 is housed in the front half of the lower portion of the tool housing 11. The rotation axis of the output shaft (not shown) of the motor 21 extends parallel to the drive shaft DX below the drive shaft DX. The motor 21 of the present embodiment is a brushless motor. The motor 21 is electrically connected to the controller 20 and is controlled by the controller 20.

[0035] The speed reduction mechanism 23 is housed in the rear half of the lower part of the tool housing 11 behind the motor 21. The speed reduction mechanism 23 is operably connected to the output shaft (not shown) of the motor 21 and the main shaft 5 of the flare forming device 3A described later. The speed reduction mechanism 23 is configured to reduce the rotational speed of the output shaft of the motor 21 and output it to the flare forming device 3A. Although detailed illustration is omitted, the speed reduction mechanism 23 of the present embodiment is a gear reduction mechanism including a plurality of gears. The output gear 233 of the speed reduction mechanism 23 is operably connected to the flare forming device 3A.

[0036] Hereinafter, the flare forming device 3A will be described.

[0037] As shown in FIG. 1, the flare forming device 3A is disposed above the motor 21 within the tool housing 11. The flare forming device 3A includes a housing 40, a transmission shaft 43, a main shaft 5, a cone 55, and a clutch mechanism 7. The transmission shaft 43, the main shaft 5, the cone 55, and the clutch mechanism 7 are housed in the housing 40. Note that the flare forming device 3A of the present embodiment is configured as one assembly in which these elements are connected to each other.

[0038] The housing 40 is generally a long stepped cylindrical body. Note that the housing 40 of the present embodiment is made of aluminum or an aluminum alloy (hereinafter simply referred to as aluminum) in consideration of weight reduction.

[0039] The housing 40 is arranged to extend in the front-rear direction along the drive shaft DX. Although detailed illustration is omitted, the housing 40 is held within the tool housing 11 by the tool housing 11 in a state of being positioned with respect to the tool housing 11. In the case where the tool housing 11 is formed of two split bodies split left and right as in the present embodiment, the housing 40 (flare forming device 3A as an assembly) may be held in a state of being sandwiched between the split bodies. Note that the tool housing 11 is the outer housing of the flare forming tool 1A, and it can also be said that the housing 40 is the inner housing of the flare forming tool 1A or the drive mechanism housing.

[0040] The front end portion of the housing 40 projects forward of the tool housing 11 through the opening 111 of the tool housing 11. The front end portion of the housing 40 is configured as a clamp attachment portion 41. Note that the clamp attachment portion 41 only needs to be configured to removably hold an arbitrary known pipe clamping device (not shown), and its holding structure is not particularly limited.

[0041] The transmission shaft 43 is operably connected to the output gear 233 of the speed 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 so as to be rotatable around the drive shaft DX by two ball bearings 431 and 432 arranged in the rear end portion of the housing 40. Although detailed illustration is omitted, the rear end portion of the transmission shaft 43 is connected to the output gear 233 coaxially with the output gear 233, and the transmission shaft 43 rotates integrally with the output gear 233 as the motor 21 is driven.

[0042] Hereinafter, the main shaft 5 will be described.

[0043] As shown in Fig. 2, the main shaft 5 is an elongated member that defines the drive shaft DX and can also be referred to as a spindle. The main shaft 5 extends in the front-rear direction within the housing 40. Although details will be described later, the main shaft 5 is movable in the front-rear direction along the drive shaft DX while rotating around the drive shaft DX. The front end portion 501 of the main shaft 5 rotatably supports a cone 55 for forming a flare. As the main shaft 5 moves forward, the cone 55 projects forward from the opening 401 at the front end of the housing 40 (clamp mounting portion 41). A support hole 502 for rotatably receiving a part of the cone 55 is formed in the front end portion 501. The support structure of the cone 55 will be described in detail later.

[0044] The main shaft 5 is rotatable integrally with the transmission shaft 43 and is connected to the transmission shaft 43 so as to be movable in the front-rear direction. Specifically, the rear half of the main shaft 5 is formed in a hollow shaft shape and has a connecting hole 507 with a polygonal cross-section (for example, hexagonal shape). The front half of the transmission shaft 43 is formed in a shape corresponding to the connecting hole 507 and is inserted into the connecting hole 507. With such a configuration, the main shaft 5 is rotatable integrally with the transmission shaft 43 and is slidable in the front-rear direction with respect to the transmission shaft 43.

[0045] Note that the connection 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 and movable in the front-rear direction, for example, by the engagement of a key groove and a key or by a spline connection.

[0046] The rear end portion of the main shaft 5 is configured as a male screw portion 508. Although details will be described later, the male screw portion 508 can mesh with the female screw portion 737 of the movable flange 73 of the clutch mechanism 7. The male screw portion 508 and the female screw portion 737 constitute a feed screw mechanism 50 for moving the main shaft 5 in the front-rear direction.

[0047] As shown in FIGS. 2 and 3, in this embodiment, the main shaft 5 is composed of a plurality of members connected to each other. More specifically, the main shaft 5 includes a first member 51 and a second member 52 connected to the rear end portion of the first member 51 and extending rearward. Note that the main shaft 5 (the first member 51 and the second member 52) of this embodiment is made of iron or an iron alloy (hereinafter simply referred to as iron) in order to ensure sufficient strength.

[0048] The first member 51 is generally a stepped cylindrical member as a whole. The front half portion of the first member 51 is a large-diameter portion 511, which constitutes the front end portion 501 of the main shaft 5. The rear half portion of the first member is a small-diameter portion 516 having a smaller diameter than the front half portion, and extends rearward from the central portion of the rear end surface of the front half portion.

[0049] The second member 52 is generally a stepped cylindrical member as a whole. The front end portion of the second member 52 is configured as a large-diameter portion 521. Among the second member 52, the portion extending rearward from the large-diameter portion 521 is configured as a small-diameter portion 526 having a smaller diameter than the large-diameter portion 521. The large-diameter portion 521 is press-fitted and fixed to the outer circumference of the small-diameter portion 516 of the first member 51, whereby the second member 52 is integrated with the first member 51. The outer diameter of the large-diameter portion 521 is smaller than the outer diameter of the large-diameter portion 511 of the first member 51. A flange portion 522 is provided at the rear end of the large-diameter portion 521. The small-diameter portion 526 is a portion having the above-described connection hole 507, and may be referred to as a hollow shaft portion.

[0050] A slide sleeve 58 is disposed around the large-diameter portion 521 of the second member 52. The slide sleeve 58 is a cylindrical member. The slide sleeve 58 of this embodiment is also made of iron, like the main shaft 5.

[0051] The slide sleeve 58 is fitted around the large-diameter portion 521 of the second member 52. More specifically, when assembling the flare forming device 3A, after the slide sleeve 58 is fitted into the large-diameter portion 521 of the second member 52, the small-diameter portion 516 of the first member 51 is fixed to the large-diameter portion 521 of the second member 52. As a result, the inner peripheral portion of the slide sleeve 58 is held in a state of being fitted between the rear end of the first member 51 and the front end surface of the flange portion 522 in the front-rear direction. With such an engagement structure, the slide sleeve 58 is immovable in the front-rear direction with respect to the main shaft 5 and moves integrally with the main shaft 5 in the front-rear direction.

[0052] As shown in FIG. 2, the slide sleeve 58 is disposed within a fixed sleeve 71 (specifically, the first sleeve 711) described later. The outer diameter of the slide sleeve 58 is larger than the outer diameter of the front end portion 501 of the main shaft 5 and slightly smaller than the inner diameter of the fixed sleeve 71.

[0053] In the radial direction of the main shaft 5 (the direction orthogonal to the drive shaft DX), a seal member 61 is disposed between the second member 52 (main shaft 5) and the slide sleeve 58, and the seal member 61 closes the gap between the second member 52 and the slide sleeve 58. More specifically, the seal member 61 is an annular elastic member and is mounted in an annular groove formed on the outer peripheral surface of the second member 52. Similarly, a seal member 62 is disposed between the slide sleeve 58 and the fixed sleeve 71, and closes the gap between the slide sleeve 58 and the fixed sleeve 71. The seal member 62 is also an annular elastic member and is mounted in an annular groove formed on the outer peripheral surface of the slide sleeve 58.

[0054] The seal members 61 and 62 both prevent foreign matter (e.g., metal chips, dust) from entering the space 405 behind the seal members 61 and 62 when the foreign matter enters the internal space of the housing 40 through the opening 401 at the front end of the housing 40. Although details will be described later, a feed screw mechanism 50 (male screw portion 508 and female screw portion 737) and a clutch mechanism 7 for moving the main shaft 5 in the front-rear direction are arranged in the space 405 behind the seal members 61 and 62. The seal members 61 and 62 can prevent foreign matter from entering the space 405 and reduce the possibility of malfunction of the feed screw mechanism 50 and the clutch mechanism 7. Also, a lubricant is put in the space 405 for lubrication of these mechanisms. The seal members 61 and 62 can prevent the lubricant from leaking forward from the space 405.

[0055] In the present embodiment, O-rings made of rubber are adopted for the seal member 61 and the seal member 62. The crushing allowance of the seal member 62 is set larger than the crushing allowance of the seal member 61. For this reason, the frictional force by the seal member 62 is larger than the frictional force by the seal member 61. More specifically, the crushing allowances of the seal member 61 and the seal member 62 are set to allow the rotation of the second member 52 (main shaft 5) with respect to the slide sleeve 58 while restricting the rotation of the slide sleeve 58 with respect to the fixed sleeve 71. On the other hand, the seal member 62 allows the slide sleeve 58 engaged with the main shaft 5 to move integrally with the main shaft 5 in the front-rear direction with respect to the fixed sleeve 71.

[0056] Hereinafter, the cone 55 and the support structure of the cone 55 will be described.

[0057] As shown in FIGS. 3 and 4, the cone 55 is a single iron member and includes a conical conical portion 551 and a cylindrical shaft portion 553. The shaft portion 553 extends rearward coaxially with the conical portion 551 from the central portion of the circular rear end face of the conical portion 551. A ball holding hole 555 is formed at the rear end of the shaft portion 553. The bottom of the ball holding hole 555 decreases in diameter toward the front and is defined by a conical surface 556 having a vertex on the axis of the cone 55. Further, an annular groove 558 is formed on the outer peripheral surface of the portion of the shaft portion 553 in front of the ball holding hole 555.

[0058] The cone 55 is rotatably supported at the front end portion 501 about an axis AX eccentric with respect to the axis of the main shaft 5 (that is, the drive shaft DX). More specifically, a support hole 502 is formed in the front end portion 501 of the main shaft 5. The support hole 502 extends along the axis AX and is configured to receive the shaft portion 553 of the cone 55. In the present embodiment, the axis AX is inclined at a predetermined angle with respect to the drive shaft DX.

[0059] The support hole 502 is a stepped bottomed hole that opens to the front end face of the front end portion 501 and includes a large diameter portion on the opening side, a small diameter portion on the bottom side, and a bottom portion. The large diameter portion and the small diameter portion of the support hole 502 each have a substantially uniform diameter. On the other hand, the bottom of the support hole 502 decreases in diameter toward the rear and is defined by a conical surface 504 having a vertex on the axis AX.

[0060] A ball bearing 561 is fitted into the large-diameter portion of the support hole 502. The ball bearing 561 includes balls (rolling elements) disposed between an inner ring and an outer ring, and a cage for holding the balls, and is a radial bearing configured to receive a radial load. The front half of the shaft portion 553 is fitted into the ball bearing 561 and is rotatably supported around the axis AX. In this embodiment, the cone 55 is arranged such that its apex is always located on the drive shaft DX, but the apex of the cone 55 may be offset from the drive shaft DX. By always positioning the apex of the cone 55 on the drive shaft DX as in this embodiment, a flare can be formed at the end of a thinner pipe rather than offsetting the apex of the cone 55 from the drive shaft DX.

[0061] The portion of the shaft portion 553 that extends rearward of the ball bearing 561 is disposed within the small-diameter portion of the support hole 502. The conical surface 556 of the ball holding hole 555 of the shaft portion 553 and the conical surface 504 of the support hole 502 face each other in the extending direction of the axis AX. A ball 563 is rotatably disposed between the conical surface 556 and the conical surface 504. The ball 563 of this embodiment is made of iron (steel).

[0062] The ball 563 is in contact with the conical surface 556 of the rear end portion 554 of the cone 55 and the conical surface 504 of the front end portion 501 of the main shaft 5. More specifically, the ball 563 and the conical surface 556 of the cone 55 are in line contact along the circumference of a circle centered on the axis AX (specifically, a circle defined by the conical surface 556 on a plane perpendicular to the axis AX). Also, the ball 563 and the conical surface 504 of the front end portion 501 of the main shaft 5 are in line contact along the circumference of a circle centered on the axis AX (specifically, a circle defined by the conical surface 504 on a plane perpendicular to the axis AX). With such a configuration, the ball 563 can function as a thrust bearing that receives a thrust load and also as a radial bearing that receives a radial load.

[0063] With such a support structure, while the cone 55 rotates around the axis AX while being pressed against the end of the pipe, the rear end portion 554 of the cone 55 receives a thrust load via the ball 563. Thus, it is possible to suppress a thrust load from being applied to the ball bearing 561 disposed around the shaft portion 553, and to stabilize the rotational support of the cone 55.

[0064] The ball 563 is disposed between the conical surface 504 and the conical surface 556 that face each other on the axis AX, and is in line contact with each of the conical surface 504 and the conical surface 556 as described above. Thus, while accurately aligning the axis of the cone 55 with the axis AX, it is possible to stably receive a thrust load. Further, among the balls 563, the portions that are in line contact with the conical surface 504 and the conical surface 556 vary as the balls 563 roll, so that local wear of the balls 563 can be suppressed.

[0065] Furthermore, even if there is only one ball bearing 561 disposed around the shaft portion 553, the ball 563 can receive not only a thrust load but also a radial load. Thereby, compared with a structure in which two ball bearings 561 are disposed around the cone 55, while shortening the overall length of the cone 55, stable rotational support for receiving a radial load at two locations is achieved. Also, by adopting the ball bearing 561 as a radial bearing, the overall length of the cone 55 can be shortened compared with a structure in which a needle bearing is disposed around the cone 55.

[0066] As shown in FIGS. 3 to 5, the cone 55 is held at a predetermined position by a retaining pin 565 that engages with the cone 55 and the main shaft 5 so as not to come off from the front end portion 501. More specifically, in the extending direction of the axis AX, a pin hole 512 is formed in a portion of the front end portion 501 of the main shaft 5 between the ball bearing 561 and the ball 563. The pin hole 512 penetrates the front end portion 501 in parallel with an axis orthogonal to the axis AX at a position corresponding to the annular groove 558 of the shaft portion 553 of the cone 55. In this embodiment, the pin hole 512 is arranged to be orthogonal to the drive shaft DX. The pin hole 512 communicates with the inside of the support hole 502 (small diameter portion).

[0067] The retaining pin 565 is inserted into the pin hole 512 and engages with the annular groove 558 of the shaft portion 553 in the support hole 502. The annular groove 558 is configured so as not to inhibit the rotation of the cone 55 in a state where the retaining pin 565 engages with the annular groove 558.

[0068] Furthermore, an annular groove 513 is formed on the outer peripheral surface of the front end portion 501 of the main shaft 5. The annular groove 513 is located at a position corresponding to the opening of the pin hole 512 in the axial direction of the cone 55 (the extending direction of the axis AX). An annular elastic member 566 is mounted in the annular groove 513. The elastic member 566 prevents the retaining pin 565 from coming out of the pin hole 512 by covering the opening of the pin hole 512 from the outside. The elastic member 566 is, for example, a rubber O-ring.

[0069] With such a configuration, a retaining structure for the cone 55 that facilitates the assembly of the cone 55 to the main shaft 5 is realized. Also, since the retaining pin 565 can be easily removed from the cone 55 and the main shaft 5, for example, when it is necessary to replace the cone 55 due to wear, the replacement work is easy.

[0070] Hereinafter, the clutch mechanism 7 will be described.

[0071] As shown in FIG. 2, the clutch mechanism 7 includes a fixed sleeve 71, a movable flange 73 movable relative to the fixed sleeve 71, and a pressing spring 78 configured to press the movable flange 73.

[0072] The fixed sleeve 71 is fitted into the front half of the housing 40 and is held in a state in which its movement is restricted relative to the housing 40. Note that 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-rear direction.

[0073] The first sleeve 711 is a portion that accommodates a part of the main shaft 5 and the slide sleeve 58 within the housing 40, and occupies most of the fixed sleeve 71. Note that the first sleeve 711 in this embodiment is made of aluminum, like the housing 40.

[0074] The outer diameter of the first sleeve 711 is substantially uniform and is slightly smaller than the inner diameter of the housing 40. A flange portion 712 that protrudes radially inward is provided at the front end of the first sleeve 711. The inner diameter of the first sleeve 711 other than the flange portion 712 is substantially uniform.

[0075] In the radial direction of the main shaft 5, three seal members 63 are disposed between the first sleeve 711 and the housing 40 to close the gap between the first sleeve 711 and the housing 40. More specifically, the seal members 63 are all annular elastic members, and are respectively mounted in three annular grooves formed on the outer circumferential surface of the first sleeve 711. In this embodiment, the three seal members 63 are rubber O-rings of the same configuration. The squeeze of the seal members 63 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 63 is permitted.

[0076] Similar to the above-described seal members 61 and 62, when foreign matter enters the internal space of the housing 40 through the opening 401 at the front end of the housing 40, the seal member 63 prevents the foreign matter from entering behind the seal member 63. There is the above-described space 405 behind the first sleeve 711, and the feed screw mechanism 50 and the clutch mechanism 7 are arranged therein. Similar to the seal members 61 and 62, the seal member 63 can prevent foreign matter from entering the space 405 and also prevent the lubricant from leaking forward of the seal member 63.

[0077] As shown in FIGS. 2 and 6, the second sleeve 715 is a cylindrical shape shorter than the first sleeve 711 and has substantially the same inner diameter and outer diameter as the first sleeve 711. The second sleeve 715 is non-rotatably connected to the rear end of the first sleeve 711 with respect to the first sleeve 711. More specifically, a plurality of rectangular protrusions (not shown) are provided at the rear end of the first sleeve 711. A plurality of rectangular recesses 716 that fit into these protrusions are formed at the front end of the second sleeve 715. The first sleeve 711 and the second sleeve 715 are integrated by the engagement of the protrusions and the recesses 716 and are non-rotatable with respect to each other.

[0078] The second sleeve 715 has a cam surface 717 for moving the movable flange 73 in the front-rear direction. The cam surface 717 is provided over the entire circumference of the rear end of the second sleeve 715 (that is, the rear end of the fixed sleeve 71) and includes recesses and protrusions alternately arranged in the circumferential direction.

[0079] Since the cam surface 717 receives a high 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 made of aluminum for weight reduction and is connected to the first sleeve 711. However, instead of this example, the entire fixed sleeve 71 may be formed as a single (non-separable) member of one material.

[0080] The movable flange 73 is a cylindrical member with a flange (flange sleeve). The movable flange 73 is made of iron. The movable flange 73 is arranged around the rear half of the main shaft 5 (the small-diameter portion 526 which is a hollow shaft portion) behind the fixed sleeve 71. The movable flange 73 includes a large-diameter portion 731 (flange portion) to which the clutch pins 734 are fixed, and a small-diameter portion 736 having an outer diameter smaller than that of the large-diameter portion 731 and extending rearward from the large-diameter portion 731.

[0081] The large-diameter portion 731 has an inner diameter larger than that of the rear half of the main shaft 5 and an outer diameter slightly smaller than the inner diameter of the fixed sleeve 71 (the second sleeve 715). A plurality of clutch pins 734 are fixed to the large-diameter portion 731 and extend radially. The number of the clutch pins 734 is the same as the number of the recesses on the cam surface 717. Incidentally, the clutch pins 734 are made of iron. A part of the clutch pins 734 protrudes radially outside the large-diameter portion 731 and is always in contact with the cam surface 717 of the second sleeve 715. The front end portion of the large-diameter portion 731 is arranged inside the second sleeve 715.

[0082] The front half of the small-diameter portion 736 is configured as a female screw portion 737 that can be screwed with the male screw portion 508 at the rear end of the main shaft 5. As described above, the male screw portion 508 and the female screw portion 737 constitute a feed screw mechanism 50 that moves the main shaft 5 in the front-rear direction.

[0083] As shown in FIG. 2, an auxiliary spring 44 is arranged between the rear end of the main shaft 5 and a washer arranged in front of the ball bearing 431 inside the rear end portion of the housing 40. The auxiliary spring 44 in the present embodiment is a compression coil spring and is arranged around the transmission shaft 43. The auxiliary spring 44 biases the main shaft 5 forward with respect to the housing 40. The auxiliary spring 44 is configured to hold the male screw portion 508 at a position where it can be screwed with the female screw portion 737 when the male screw portion 508 is disengaged from the female screw portion 737 due to the rearward movement of the main shaft 5. The biasing force of the auxiliary spring 44 is set to be significantly weaker than the pressing spring 78 described later.

[0084] The pressing spring 78 is configured to bias the movable flange 73 forward with respect to the fixed sleeve 71 and thus the housing 40. More specifically, the pressing spring 78 of the present embodiment is a compression coil spring and is disposed around the small-diameter portion 736 of the movable flange 73. Between the large-diameter portion 731 of the movable flange 73 and the pressing spring 78, a thrust needle bearing 791 is configured with a needle pin sandwiched from the front and rear by two washers 793 and 794. The front end of the pressing spring 78 abuts against the rear washer 794, and the rear end of the pressing spring 78 abuts against the shoulder portion of the housing 40. Note that the rear washer 794 has an outer diameter larger than that of the front washer 793.

[0085] With such a configuration, the pressing spring 78 constantly biases the movable flange 73 forward to press the clutch pin 734 against the second sleeve 715, and the clutch pin 734 is held in the concave portion of the cam surface 717. Thereby, the movable flange 73 is integrated with the fixed sleeve 71 in a substantially non-rotatable manner with respect to the fixed sleeve 71. Hereinafter, the front-rear direction position of the movable flange 73 with respect to the fixed sleeve 71 at this time is referred to as a connection position, and the state of the clutch mechanism 7 is referred to as a connected state. Note that instead of the clutch pin 734, the movable flange 73 may be provided with a convex portion integrally provided on the front end surface of the large-diameter portion 731, and may be configured such that these convex portions directly engage with the concave portion of the cam surface 717 instead of via the clutch pin 734.

[0086] Hereinafter, the operation of the flare forming device 3A when the motor 21 is driven will be described.

[0087] As shown in FIG. 2, in the initial state of the flare forming device 3A, the male screw portion 508 at the rear end of the main shaft 5 is disposed at a position (hereinafter referred to as the initial position) where it can be screwed with the female screw portion 737 of the movable flange 73. The clutch mechanism 7 is in the connected state. When the motor 21 (see FIG. 1) is rotated in the forward rotation direction in this state, the transmission shaft 43 and the main shaft 5 are integrally rotated, and the main shaft 5 moves forward while the male screw portion 508 and the female screw portion 737 are screwed together.

[0088] While the main shaft 5 is moving forward, the slide sleeve 58 disposed around the main shaft 5 (second member 52) slides forward integrally with the main shaft 5 with respect to the first sleeve 711 of the fixed sleeve 71. Further, the main shaft 5 rotates while sliding within the slide sleeve 58. As described above, the first sleeve 711 of the present embodiment is made of aluminum, while the slide sleeve 58 is made of iron. Therefore, the slide sleeve 58 of the present embodiment can suppress the wear of the first sleeve 711 as compared with the case where it slides while rotating with respect to the first sleeve 711.

[0089] When a pipe is clamped by a clamping device (not shown) attached to the clamp attachment portion 41, the cone 55 abuts against the end of the pipe before the main shaft 5 reaches the foremost position within the movable range. As the main shaft 5 rotates while moving forward, the cone 55 revolves around the drive shaft DX while rotating (spinning) around the axis AX, thereby expanding the end of the pipe in a conical shape. When the cone 55 expands the end of the pipe in a conical shape and advances to some extent while forming a flare, the forward movement of the cone 55, and thus the main shaft 5, is obstructed by the pipe before the main shaft 5 reaches the foremost position. FIG. 7 shows the position of the main shaft 5 at this time (hereinafter, also referred to as the forward movement inhibiting position).

[0090] When the main shaft 5 rotates at the forward-inhibiting position, due to the action of the male screw part 508 and the female screw part 737 (feed screw mechanism 50), the movable flange 73 moves backward while rotating with respect to the fixed sleeve 71. As a result, as shown in FIG. 8, the clutch pin 734 separates from the cam surface 717. Hereinafter, the front-rear position of the movable flange 73 with respect to the fixed sleeve 71 at this time is referred to as the blocking position, and the state of the clutch mechanism 7 is referred to as the blocking state. Further, the transition of the clutch mechanism 7 from the connected state to the blocking state (the movement of the movable flange 73 from the connected position to the blocking position) is also referred to as the operation of the clutch mechanism 7. Note that when the main shaft 5 can no longer move forward, since the flare shape has already been formed, it can be said that the clutch mechanism 7 operates in response to the formation of the flare.

[0091] As the movable flange 73 moves backward, the pressing spring 78 is compressed and the biasing force increases. The male screw part 508 and the female screw part 737 are configured such that the frictional force between the male screw part 508 and the female screw part 737 exceeds the biasing force of the pressing spring 78 at this time. Therefore, when the movable flange 73 reaches the blocking position, it starts to rotate integrally with the main shaft 5 at the forward-inhibiting position without further movement. The biasing force of the pressing spring 78 acts on the main shaft 5 via the movable flange 73. The cone 55 supported by the front end portion 501 of the main shaft 5 receives this biasing force and rotates around the axis AX while orbiting around the drive shaft DX while pressing the flare at substantially the same position in the front-rear direction. Hereinafter, this operation of the cone 55 is also referred to as the finishing operation.

[0092] On the other hand, when the motor 21 is rotated in the forward rotation direction with the pipe not disposed in front of the cone 55, the main shaft 5 can move forward more than when there is a pipe. In this case, as shown in FIG. 9, the flange portion 712 of the fixed sleeve 71 abuts against the front end surface of the slide sleeve 58, preventing the main shaft 5 from moving further forward. Thus, the slide sleeve 58 and the flange portion 712 function as stoppers that define the foremost position of the main shaft 5.

[0093] As described above, after the flare is formed on the pipe by the cone 55, when the motor 21 is stopped and rotated in the reverse direction, the movable flange 73 moves forward from the blocking position to the connecting position while rotating with respect to the fixed sleeve 71 due to the biasing force of the compression spring 78 and the action of the male screw portion 508 and the female screw portion 737. That is, the clutch mechanism 7 returns to the connected state. The main shaft 5 moves backward while rotating until the male screw portion 508 disengages from the female screw portion 737, and returns to the initial position shown in FIG. 1.

[0094] The flare forming tool 1A of the present embodiment detects the operation of the clutch mechanism 7 and uses it for driving control of the motor 21. Hereinafter, a detection device 81 for detecting the operation of the clutch mechanism 7 will be described.

[0095] As shown in FIG. 1, the detection device 81 is disposed within the tool housing 11 of the tool housing 11. More specifically, the detection device 81 of the present embodiment is a hall sensor including a hall element. As shown in FIG. 7, the detection device 81 is mounted on a circuit board 82 supported by the tool housing 11 (not shown in FIG. 7) below the flare forming device 3A. The detection device 81 is configured to detect the magnet 85 when the magnet 85 is within a predetermined detection range, turn on, and output a signal indicating the detection result of the magnet 85 as on or off.

[0096] The magnet 85 is arranged to move integrally with the movable flange 73. More specifically, the magnet 85 is attached to a movable member 86 that is supported movably in the front-rear direction at the lower part of the housing 40. The movable member 86 includes an arm 861 disposed below the housing 40 and a protrusion 863 that protrudes into the housing 40 from an opening formed in the lower part of the housing 40. The magnet 85 is fixed to the arm 861. The protrusion 863 is disposed right behind a washer 794 between the large-diameter portion 731 of the movable flange 73 and the pressing spring 78. The movable member 86 is biased forward by a biasing spring 87 disposed between the housing 40 and the movable member 86. For this reason, the protrusion 863 is always held in contact with the rear end face of the washer 794 by the biasing force of the biasing spring 87.

[0097] With such a configuration, as shown in FIG. 7, when the movable flange 73 is in the connection position, the movable member 86 and the magnet 85 are in the foremost position within the movement range. The detection device 81 detects the magnet 85 when the magnet 85 is in the foremost position.

[0098] On the other hand, as shown in FIG. 8, when the clutch mechanism 7 operates and the movable flange 73 moves from the connection position to the disconnection position, the protrusion 863 is pressed by the washer 794, and the movable member 86 moves rearward against the biasing force of the biasing spring 87. Along with this, the magnet 85 moves out of the detection range of the detection device 81. For this reason, when the movable flange 73 is in the disconnection position, the detection device 81 cannot detect the magnet 85. That is, the detection device 81 switches from on to off in response to the operation of the clutch mechanism 7. Although the movement distance of the movable flange 73 from the connection position to the disconnection position is very small, by adopting a hall sensor for the detection device 81, the operation of the clutch mechanism 7 can be reliably detected.

[0099] Further, the washer 794 is a component that moves in the front - rear direction with respect to the housing 40 integrally with the movable flange 73, but does not rotate integrally with the movable flange 73. Therefore, by connecting the washer 794 and the movable member 86 so as to move integrally in the front - rear direction, the movable member 86 can be moved in a state separated from the rotation of the movable flange 73. As a result, the movement of the movable member 86 is stabilized, and the detection accuracy of the magnet 85 by the detection device 81 can be improved.

[0100] Hereinafter, the elements (structures) provided in the handle portion 15 of the tool housing 11 will be described.

[0101] As shown in FIG. 1, inside the handle portion 15, a switch 153 and a controller 20 are arranged. Further, an operation portion 25 is provided at the lower end portion of the handle portion 15.

[0102] The controller 20 is electrically connected to the motor 21, the switch 153, the operation portion 25, and the detection device 81 inside the tool housing 11. In the present embodiment, the controller 20 is composed of a microcomputer including a CPU 201, a ROM 202, a RAM 203, etc. However, the controller 20 may be composed of another type of processor / processing circuit (for example, ASIC (Application Specific Integrated Circuits), FPGA (Field Programmable Gate Array)) and a memory.

[0103] Although illustration is omitted because it is a well-known technique, a three-phase inverter and a hall sensor are electrically connected to the controller 20. The controller 20 supplies a pulsed current (pulse) corresponding to a set duty ratio to the motor 21 by switching the six semiconductor switching elements of the three-phase inverter. The controller 20 controls the energization of the motor 21 via the three-phase inverter based on a signal indicating the rotational position (rotation angle) of the motor 21 (specifically, the rotor) input from the hall sensor, thereby controlling the rotational speed of the motor 21. Further, the controller 20 controls the driving of the motor 21 based on signals output from the switch 153, the operation unit 25, and the detection device 81.

[0104] The operation unit 25 of the present embodiment is an input device through which a user can input information regarding the timing (hereinafter referred to as stop timing information) for stopping the driving of the motor 21 after the clutch mechanism 7 has operated. In the present embodiment, as the stop timing information, information for specifying the amount / angle (hereinafter referred to as the target rotation amount) by which the motor 21 rotates between the operation of the clutch mechanism 7 and the stop of the driving of the motor 21 is adopted. In the present embodiment, the controller 20 uses PWM (Pulse Width Modulation) control for driving control of the motor 21, and the target rotation amount is specified by the number of pulses for driving the motor 21. Therefore, the target rotation amount can also be referred to as the target pulse number.

[0105] The operation unit 25 can be embodied, for example, as shown in FIG. 10. In this example, the operation unit 25 includes a mode switching button 251, an increase button 253, a decrease button 254, and a display unit 257. Note that the mode switching button 251, the increase button 253, and the decrease button 254 are push buttons. The display unit 257 includes two 7-segment displays capable of displaying numbers.

[0106] The mode switching button 251 is a button operated to select a mode. The clamp device attached to the clamp attachment part 41 generally corresponds to a plurality of types of pipes with different diameters. In the ROM 202 of the controller 20, mode numbers indicating each of the plurality of types of pipes are stored in association with the initial values of the target pulse numbers set for each pipe. Each time the mode switching button 251 is pressed, the controller 20 sequentially selects the stored mode numbers, specifies the corresponding target pulse numbers, and causes them to be displayed on the 7-segment display of the display unit 257. Note that the mode number indicating the type of the selected pipe may be displayed on the display unit 257.

[0107] Both the increase button 253 and the decrease button 254 are buttons operated to change the target pulse number. The increase button 253 is a button operated to increase the target pulse number from the current set value. The decrease button 254 is a button operated to decrease the target pulse number from the current set value. Each time the increase button 253 or the decrease button 254 is pressed, the controller 20 increases or decreases the currently set target pulse number by a predetermined number. Note that the predetermined number can be arbitrarily set, but in order to enable flexible change of the rotation amount, the pulse number may be changeable, for example, by one pulse at a time.

[0108] Further, the controller 20 causes the digital number indicating the changed target pulse number to be displayed on the 7-segment display of the display unit 257. Therefore, the user can change the target pulse number to a desired value by manually operating the increase button 253 or the decrease button 254 while checking the display unit 257.

[0109] Instead of the example of FIG. 10, the operation unit 25 can be embodied, for example, as shown in FIG. 11. In this example, the operation unit 25 includes a change button 252 and a display unit 258. The change button 252 is a push button. The display unit 258 includes a plurality of indicator lamps.

[0110] The change button 252 is a button that is operated to change the target number of pulses of the motor 21 from the current set value. In the display unit 258, an indicator lamp corresponding to the set target number of pulses is lit. In the initial state, the target number of pulses is set to the initial value, and the indicator lamp in the middle of the display unit 258 is lit. Each time the change button 252 is pressed, the controller 20 increases the currently set number of pulses by a predetermined number, and when the changed number of pulses reaches a predetermined upper limit value, it returns to the lower limit value. The lighting of the indicator lamp is also performed in response to this change.

[0111] Note that the configuration of the operation unit 25 is not limited to the examples in FIGS. 10 and 11 and may be changed as appropriate. For example, the operation unit 25 may be embodied as a rotary dial, a slide lever, or a touch screen instead of a push button.

[0112] Hereinafter, the drive control of the motor 21 by the controller 20 (specifically, the CPU 201) during the flare operation will be described. Note that the motor drive process shown in FIG. 12 is started in response to the pressing operation of the trigger 151 and the switch 153 being turned on. The CPU 201 of the controller 20 executes the motor drive process by, for example, reading and executing a program stored in the ROM 202.

[0113] First, before starting the flare operation using the flare forming tool 1A, the user attaches the clamping device in a state where a pipe of a desired diameter is clamped to the flare forming tool 1A, and appropriately manually operates the operation unit 25 to set the target rotation amount.

[0114] When the flare forming device 3A is provided with the operation unit 25 shown in FIG. 10, the user selects an appropriate mode (pipe type) by manually operating the mode switching button 251. The CPU 201 of the controller 20 reads out the correspondence relationship stored in the ROM 202 and stores the initial value of the target number of pulses corresponding to the selected mode in the RAM 203. Thereafter, when the user presses the increase button 253 or the decrease button 254, the target number of pulses stored in the RAM 203 is changed according to the pressing operation.

[0115] When the flare forming device 3A is provided with the operation unit 25 shown in FIG. 11, the CPU 201 stores the initial value of the target number of pulses, which is preset and stored in the ROM 202, in the RAM 203. Thereafter, when the user presses the change button 252, the target number of pulses stored in the RAM 203 is changed according to the pressing operation.

[0116] Thereafter, when the user presses the trigger 151 and the switch 153 is turned on, the CPU 201 starts the motor drive process shown in FIG. 12. The CPU 201 specifies the target number of pulses stored in the RAM 203 (S101) and starts driving the motor 21 (S103). More specifically, the CPU 201 calculates an appropriate duty ratio and supplies pulses corresponding to the calculated duty ratio to the motor 21. The rotation direction of the motor 21 at this time is the forward rotation direction. By rotating the motor 21 in the forward rotation direction, the main shaft 5 and the cone 55 rotate and move forward as described above, and the cylindrical end portion of the pipe is expanded into a conical shape to form a flare.

[0117] While the motor 21 is rotating in the forward rotation direction, the CPU 201 monitors the signal periodically output from the detection device 81 and determines whether the detection device 81 has been turned off, that is, whether the clutch mechanism 7 has been actuated (S105). While the CPU 201 determines that the clutch mechanism 7 is in the connected state (S105: NO), the drive of the motor 21 is continued (S103).

[0118] When the CPU 201 determines that the clutch mechanism 7 has been actuated (S105: YES), it counts the number of pulses supplied to the motor 21 after the clutch mechanism 7 has been actuated (S107). The CPU 201 determines whether the number of supplied pulses has reached the target number of pulses stored in the RAM 203 (S109). If the number of supplied pulses has not reached the target number of pulses (S109: NO), the CPU 201 returns to counting the number of pulses (S107). That is, the CPU 201 continues to drive the motor 21 until the number of supplied pulses reaches the target number of pulses. While the driving of the motor 21 continues after the clutch mechanism 7 has been actuated, the cone 55 performs a finishing operation.

[0119] When the number of supplied pulses reaches the target number of pulses (S109: YES), the CPU 201 stops driving the motor 21 by stopping the pulse supply to the motor 21 (S113). The CPU 201 further starts rotating the motor 21 in the reverse direction (S115). As a result, the main shaft 5 starts to move backward.

[0120] While the main shaft 5 has not returned to the initial position (S117: NO), the CPU 201 continues to drive the motor 21 (S115). When the main shaft 5 returns to the initial position (S117: YES), the CPU 201 stops driving the motor 21 (S119) and ends the motor drive process. That is, even if the switch 153 is not turned off (even if the pressing of the trigger 151 is not released), the CPU 201 stops the rotation of the motor 21 in the reverse direction in response to the main shaft 5 returning to the initial position. Note that in S117, the CPU 201 can determine whether the main shaft 5 has returned to the initial position based on, for example, the detection result of a detection device (not shown) capable of detecting that the main shaft 5 is in the initial position. This detection device may be, for example, a magnetic or optical sensor or a mechanical switch, similar to the detection device 81 for detecting the actuation of the clutch mechanism 7.

[0121] Note that when the switch 153 is turned off while the controller 20 is rotating the motor 21 in the forward rotation direction, the controller 20 stops the rotation of the motor 21 and further rotates the motor 21 in the reverse rotation direction to return the main shaft 5 to the initial position. Similarly, when the switch 153 is turned off while the motor 21 is rotating in the reverse rotation direction, the controller 20 continues to drive the motor 21 and returns the main shaft 5 to the initial position.

[0122] As described above, in the flare forming device 3A of the present embodiment, the controller 20 rotates the motor 21 by the target rotation amount and then stops the rotation in response to the operation of the clutch mechanism 7. By such control, the finish (accuracy) of the formed flare can be stabilized (uniformized) as compared with the case where the timing of stopping the rotation of the motor 21 depends on the manual operation of the user. Further, after the operation of the clutch mechanism 7, that is, after the flare is formed by the cone 55, the cone 55 performs the finishing operation at substantially the same position in the front-rear direction, so that the flare can be formed to approach a perfect circle and the finish of the flare can be improved.

[0123] Furthermore, in the present embodiment, the user can appropriately change the set target rotation amount by manually operating the operation unit 25. Therefore, for example, when the user determines that the finishing operation is insufficient or an excessive finishing operation has been performed as a result of checking the flare formed by performing the flare operation for trial, the user can change the target rotation amount. Thereby, the finish of the flare can be further improved.

[0124] In addition, after the controller 20 rotates the motor 21 by the target rotation amount and stops the rotation, the controller 20 automatically moves the main shaft 5 backward (without any manual operation of the user) and returns it to the initial position. Thereby, the convenience of the flare forming tool 1A is improved.

[0125] <Second Embodiment> Hereinafter, with reference to FIG. 13, the flare forming tool 1B according to the second embodiment of the present disclosure will be described. The flare forming tool 1A (see FIG. 1) of the first embodiment is an electric tool dedicated to flare work, and the flare forming device 3A is incorporated in the 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 detachably attached to the driver drill 9. That is, the flare forming device 3B is an attachment that can be attached to the driver drill 9.

[0126] The driver drill 9 is a well-known electric tool (rotary tool) configured to rotationally drive a tip tool (not shown) detachably attached to a chuck 94 around a drive shaft DX. The driver drill 9 includes a tool housing 90 extending along the drive shaft DX, and a handle portion 95 extending in a direction intersecting the drive shaft DX from the tool housing 90.

[0127] The tool housing 90 houses a motor 91 and a spindle 93 operably connected to the motor 91 via a speed reduction mechanism 92. The chuck 94 is connected to the spindle 93 so as to rotate integrally with the spindle 93.

[0128] The handle portion 95 includes a grip portion 950. The grip portion 950 is provided with a trigger 951 pressed by a user, and a forward / reverse switching lever 952 that moves in response to the pressing operation of the user and switches the rotation direction of the motor 91 between the forward rotation direction and the reverse rotation direction. Inside the handle portion 95, a switch 953 that operates in response to a manual operation on the trigger 951 and the forward / reverse switching lever 952, and a controller 955 that controls the drive of the motor 91 are housed. The controller 955 drives the motor 91 while the trigger 951 is pressed and the switch 953 is turned on. A rechargeable battery 19 is detachably attached to the lower end portion of the handle portion 95.

[0129] Unlike the flare forming device 3A of the first embodiment, the flare forming device 3B does not include the movable member 86 and the magnet 85. Regarding the other configurations of the flare forming device 3B, they are substantially the same as those of the flare forming device 3A of the first embodiment. Therefore, in the following description, for substantially the same configurations, the same reference numerals as those in the first embodiment are given and their descriptions are omitted.

[0130] In the flare forming device 3B of the present embodiment, the main shaft 5 is operably 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 connection hole 435 is formed at the rear end portion of the transmission shaft 43 of the flare forming device 3B. The connection hole 435 is configured to be rotatably connected to another member and extends along the axes of the transmission shaft 43 and the main shaft 5.

[0131] The transmission shaft 43 is operably connected to the chuck 94 of the driver drill 9 via a connection shaft 98. One end portion in the axial direction of the connection shaft 98 is formed to be fitted into the connection hole 435 of the transmission shaft 43. The opposite end portion is formed to be fitted into the tip tool insertion hole 941 formed in the chuck 94 of the driver drill 9. Note that the connection hole 435, the insertion hole 941, and the two end portions of the connection shaft 98 may have a polygonal cross section, for example, similar to the connection hole 507 and the front half portion of the transmission shaft 43 of the first embodiment. Also, for example, the connection shaft 98 may be integrally rotatably connected to the chuck 94 and the transmission shaft 43 by the engagement of a key groove and a key, or by a spline connection.

[0132] The rotation of the spindle 93 of the driver drill 9 is transmitted to the transmission shaft 43 via the chuck 94 and the connection shaft 98. Therefore, when the motor 91 of the driver drill 9 rotates in the forward rotation direction, as described in the first embodiment, the main shaft 5 of the flare forming device 3B advances and the cone 55 forms a flare at the end of the pipe. Also, when the motor 91 of the driver drill 9 rotates in the reverse rotation direction, the main shaft 5 retreats and returns to the initial position.

[0133] As described above, the flare forming apparatus 3B of the present embodiment is configured as an attachment that can be selectively attached to the driver drill 9 and can perform flare work. Therefore, the user can attach the flare forming apparatus 3B to the driver drill 9 only when necessary and use it as the flare forming tool 1B. Thus, the applicable work of the driver drill 9 can be increased, improving convenience.

[0134] Note that the flare forming apparatus 3B may be selectively attached to and used not only with the driver drill 9 but also with other rotary tools (e.g., drilling tools, fastening tools) via an appropriate connecting shaft. Further, the flare forming apparatus 3B may be selectively attached to and used with a manual instrument having a manually rotatable connecting shaft instead of a power tool, or may be integrated with such a manual instrument to constitute a manual flare forming apparatus.

[0135] 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 the present invention.

[0136] The flare forming tool 1A of the first embodiment is an example of a "flare forming tool". The motor 21, the main shaft 5, the cone 55, and the clutch mechanism 7 are examples of a "motor", a "main shaft", a "cone", and a "clutch mechanism", respectively. The drive shaft DX is an example of a "first shaft". The detection device 81 is an example of a "detection device configured to detect the operation of the clutch mechanism" and a "detection device configured to detect the formation of a flare by the cone". The controller 20 (specifically, the CPU 201) is an example of a "control device". The operation unit 25 is an example of an "operation unit". The movable flange 73 and the clutch pin 734 are examples of a "movable clutch member".

[0137] Note that the flare forming tool according to the present disclosure is not limited to the flare forming tool 1A of the above embodiment. For example, the following non-limiting changes are possible. Further, at least one of these changes can be adopted in combination with at least one of the flare forming tool 1A of the embodiment and the features described in the claims.

[0138] For example, instead of the clutch mechanism 7 described above, any type of clutch mechanism that operates in response to the forward movement of the main shaft 5 being inhibited (in response to the formation of the flare shape) may be adopted. For example, a meshing type or friction type clutch mechanism may be adopted.

[0139] The detection device 81 that detects the operation of the clutch mechanism 7 (formation of the flare) is not limited to a hall sensor, and any other known detection device may be adopted. For example, a mechanical microswitch, an optical sensor, another type of magnetic field sensor, etc. may be adopted.

[0140] In the first embodiment, after the operation of the clutch mechanism 7 is detected, the target pulse number is used to determine whether the motor 21 has rotated by the target rotation amount. Instead of this example, for example, the controller 20 may determine whether the motor 21 has rotated by the target rotation amount based on a signal from a hall sensor that detects the rotational position of the motor 21. Specifically, the controller 20 may specify the rotational position of the motor 21 when the clutch mechanism 7 operates, and then determine whether the motor 21 has reached the rotational position corresponding to the target rotation amount based on the signal from the hall sensor.

[0141] Alternatively, instead of operating the clutch mechanism 7, the controller 20 may control the timing of stopping the rotation of the motor 21 based on some physical quantity corresponding to the formation of the flare (stopping the forward movement of the main shaft). For example, instead of the detection device 81, a current sensor that detects the current value of the motor 21 or a load sensor that detects the load applied to the main shaft 5 may be employed. In these modified examples, after the detected current value or load exceeds a predetermined threshold value, the controller 20 may rotate the motor 21 by a target rotation amount and then stop the rotation.

[0142] The flare forming tool 1A may include a communication device capable of communicating with an external device (e.g., a personal computer, a portable terminal (e.g., a smartphone, a tablet terminal)). In this modified example, the user can input information regarding the target rotation amount of the motor 21 not only using the operation unit 25 provided on the flare forming tool 1A but also using an external device. The CPU 201 of the flare forming tool 1A can perform drive control of the motor 21 after the operation of the clutch mechanism 7 is detected based on the information transmitted from the external device. Note that in this modified example, the operation unit 25 of the flare forming tool 1A may be omitted.

[0143] In view of the gist of the present invention and the above-described embodiments, the following aspects are constructed. At least one of the following aspects can be adopted in combination with at least one of the features of the embodiments and their modified examples or at least one of the features described in each claim. [Aspect 1] The predetermined rotation amount is set as a target pulse number, which is the number of drive pulses supplied to the motor, and the control device is configured to stop the rotation of the motor when the actual number of pulses supplied to the motor reaches the target pulse number after the operation of the clutch mechanism is detected (after the formation of the flare is detected). [Aspect 2] The flare forming tool further includes a notification unit that notifies information regarding the predetermined rotation amount. Each of the display units 257 and 258 in this aspect is an example of the "notification unit" in this aspect. [Aspect 3] Further provided is a housing that houses the main shaft and the clutch mechanism, The clutch mechanism includes a movable clutch member that is movable in the front-rear direction between a first position immovable with respect to the housing and a second position behind the first position, and a pressing spring that biases the movable clutch member forward, The movable clutch member is configured to move from the first position to the second position in response to the forward movement of the main shaft being inhibited, and to rotate integrally with the main shaft with respect to the housing, The detection device is configured to detect the movement of the movable clutch member from the first position to the second position as the operation of the clutch mechanism. [Aspect 4] The main shaft has a male screw portion, The movable clutch member is disposed around the main shaft and includes a movable flange having a female screw portion that can be screwed into the male screw portion, The movable flange is configured to move from the first position to the second position while rotating by the action of the male screw portion and the female screw portion in response to the forward movement of the main shaft being inhibited. [Aspect 5] The clutch mechanism includes a fixed clutch member disposed around the main shaft substantially immovable with respect to the housing in front of the movable clutch member, The fixed clutch member has a cam surface, The movable clutch member is configured to engage with the cam surface in a non-rotatable manner with respect to the fixed clutch member by the biasing force of the pressing spring when in the first position, and to separate from the cam surface in response to moving while rotating to the second position. The fixed sleeve 71 (second sleeve 715) is an example of the "fixed clutch member" of this aspect.

Explanation of Reference Numerals

[0144] 1A, 1B: Flare forming tools, 11: Tool housing, 111: Opening, 15: Handle part, 150: Gripping part, 151: Trigger, 153: Switch, 17: Battery mounting part, 18: Light emitting part, 19: Battery, 20: Controller, 201: CPU, 202: ROM, 203: RAM, 21: Motor, 23: Reduction mechanism, 233: Output gear, 25: Operation part, 251: Mode switching button, 252: Change button, 253: Increase button, 254: Decrease button, 257: Display part, 258: Display part, 3A, 3B: Flare forming device, 40: Housing, 401: Opening, 405: Space, 41: Clamp mounting part, 43: Transmission shaft, 431: Ball bearing, 432: Ball bearing, 435: Connecting hole, 44: Auxiliary spring, 5: Main shaft, 50: Feed screw mechanism, 501: Front end part, 502: Support hole, 504: Conical surface, 507: Connecting hole, 508: Male screw part, 51: First member, 511: Large diameter part, 512: Pin hole, 513: Annular groove, 516: Small diameter part, 52: Second member, 521: Large diameter part, 522: Flange part, 526: Small diameter part, 55: Cone, 551: Conical part, 553: Shaft part, 554: Rear end part, 555: Ball retaining hole, 556: Conical surface, 558: Annular groove, 561: Ball bearing, 563: Ball, 565: Retaining pin, 566: Elastic member, 58: Slide sleeve, 61: Seal member, 62: Seal member, 63: Seal member, 7: Clutch mechanism, 71: Fixed sleeve, 711: First sleeve, 712: Flange part, 715: Second sleeve, 716: Recess, 717: Cam surface, 73: Movable flange, 731: Large diameter part, 734: Clutch pin, 736: Small diameter part, 737: Female screw part, 78: Compression spring, 791: Thrust needle bearing, 793: Washer, 794: Washer, 81: Detection device, 82: Circuit board, 85: Magnet, 86: Movable member, 861: Arm, 863: Projection, 87: Biasing spring, 9: Driver drill, 90: Tool housing, 91: Motor, 92: Reduction mechanism, 93: Spindle, 94: Chuck, 941: Insertion hole, 95: Handle part, 950: Gripping part, 951: Trigger, 952: Forward and reverse switching lever, 953: Switch, 955: Controller, 98: Connecting shaft, AX: Axis, DX: Drive shaft

Claims

1. A flare forming tool, comprising: a motor rotatable in a forward rotation direction and a reverse rotation direction; a main shaft operably connected to the motor and configured to move forward along the first axis while rotating about the first axis defining the front-rear direction of the flare forming tool as the motor rotates in the forward rotation direction; a cone rotatably supported about a second axis eccentric to the first axis at a front end of the main shaft and configured to form a flare at an end of a pipe; a clutch mechanism configured to operate in response to the cone abutting against the end of the pipe and inhibiting the forward movement of the main shaft; a detection device configured to detect the operation of the clutch mechanism; and a control device configured to control the rotation of the motor based on the detection result of the detection device.

2. The flare forming tool according to claim 1, wherein: the control device is configured to rotate the motor by a predetermined amount of rotation in the forward rotation direction and then stop the rotation in response to the operation of the clutch being detected by the detection device.

3. A flare forming tool, comprising: a motor rotatable in a forward rotation direction and a reverse rotation direction; a main shaft operably connected to the motor and configured to move forward along the first axis while rotating about the first axis defining the front-rear direction of the flare forming tool as the motor rotates in the forward rotation direction; a cone rotatably supported about a second axis eccentric to the first axis at a front end of the main shaft and configured to form a flare at an end of a pipe; a detection device configured to detect the formation of the flare by the cone; and a control device configured to control the rotation of the motor, wherein the control device controls the rotation of the motor such that after the main shaft rotates by a predetermined amount of rotation at substantially the same position in the front-rear direction and the formation of the flare is detected by the detection device, the rotation is stopped.

4. The flare forming tool according to claim 2 or 3, wherein: the predetermined amount of rotation is changeable.

5. The flare forming tool according to claim 4, wherein: further comprising an operation unit configured to be manually operated by a user, wherein the control device is configured to change the predetermined amount of rotation in response to a manual operation of the operation unit, and the flare forming tool is characterized in that. **Claim 6** A flare forming tool according to any one of claims 2 to 5, wherein the control device is configured to move the main shaft rearward by rotating the motor in the reverse direction after stopping the motor, and the flare forming tool is characterized in that. **Claim 7** A flare forming tool according to any one of claims 1 to 6, wherein the motor is a brushless motor, and the flare forming tool is characterized in that. **Claim 8** A flare forming tool according to claim 1 or any one of claims 3 to 7 directly or indirectly dependent on claim 1, wherein the clutch mechanism includes a movable clutch member configured to move in response to inhibition of forward movement of the main shaft, wherein the detection device is a hall sensor configured to detect a magnet attached to the movable clutch member, and the flare forming tool is characterized in that. **Claim 9** A flare forming tool according to claim 8, wherein the magnet is attached to a non-rotating portion of the movable clutch member, and the flare forming tool is characterized in that.

Images