PIPE EXPANSION TOOL

Abstract

A pipe expansion tool (1) expands one end of a synthetic resin fluid tube. The pipe expansion tool (1) has a motor shaft (20a) that is rotated by an electric motor (20). A feed spindle mechanism (25) converts the rotation of the motor shaft (20a) into a back-and-forth motion of an output shaft (27). A wedge (3) is provided at the front of the output shaft (27) and engages a plurality of claws (4). The plurality of claws (4) open radially outward toward each other. A claw rotation mechanism (30) with a shaft (31) is provided. The shaft (31) rotates about an axis in conjunction with the rotation of the motor shaft (20a). The shaft (31) rotates the plurality of claws (4) about an axis. The output shaft (27), the motor shaft (20a) and the shaft (31) of the claw rotary mechanism (30) are arranged parallel to each other and overlap in the front-back direction.

Description

Technical area

[0001] A present embodiment of the present disclosure relates to pipe expansion tools for expanding a diameter of an end of a fluid pipe, such as one made of synthetic resin, so that it can be coupled to a connected body. BACKGROUND

[0002] For example, consider cases where a fluid pipe made of PEX (cross-linked polyethylene) (hereinafter referred to as a PEX pipe) is coupled to a joint body, such as a pipe made of synthetic resin. Pipe expansion tools are conventionally provided to expand an inner diameter of one end of a PEX pipe. The end of the PEX pipe is expanded in diameter using a pipe expansion tool and attached to the joint body. The end of the PEX pipe gradually shrinks in diameter due to elastic deformation to return to its original diameter. This allows the end of the PEX pipe to be tightly coupled to the joint body. The PEX pipe is firmly secured to the joint body using its own elasticity.

[0003] U.S. Patent No. 9,862,137 discloses a pipe expansion tool for expanding a diameter of a PEX pipe using an electric motor as the drive source. The pipe expansion tool is provided with a wedge having a substantially conical front end and a plurality of claws arranged at the front of the wedge in a circumferential direction of the wedge. The wedge is attached to a front end of an output shaft that moves back and forth inside the pipe expansion tool. As the wedge moves forward by means of the output shaft, the plurality of claws are pushed by the wedge and open mutually radially outward from the wedge. One end of the PEX pipe can be expanded by opening the plurality of claws radially outward, with the claws entering an end opening of the PEX pipe.

[0004] For example, if a pipe expansion tool has six jaws, the end of the PEX pipe is subjected to an opening force from each jaw at six equally spaced locations in the circumferential direction radially outward. Therefore, in a single expansion operation, the end of the PEX pipe is expanded into a substantially hexagonal shape. To expand the end of the PEX pipe into a circular shape, expanding operations are repeated alternately with rotating operations in which the plurality of jaws are rotated at a predetermined angle (e.g., 15° to 30°) in the circumferential direction of the wedge. This causes the position at which each claw contacts the inner peripheral surface of the PEX pipe to be shifted by means of the rotating operation. Therefore, the end of the PEX pipe is uniformly expanded to become close to a circular shape.

[0005] For example, a PEX pipe can be installed between two mutually opposite and closely spaced walls (seeFig. 2) be installed. For better workability when expanding the end of a PEX pipe installed in the narrow space, it is preferable that the pipe expansion tool be compact in a front-to-back direction. The pipe expansion tool includes a power conversion mechanism configured to convert a rotary drive of an electric motor into a back-to-forward movement of the output shaft, and a claw rotating mechanism for rotating the claws. As disclosed in U.S. Patent No. 9,862,137, in a conventional pipe expansion tool, the claw rotating mechanism is arranged coaxially with the output shaft. Therefore, it is difficult to provide the pipe expansion tool in a compact manner in the front-to-back direction.

[0006] US Patent Publication No. 2020 / 0261959 also discloses a pipe expansion tool that expands a PEX pipe using a feed screw mechanism driven by an electric motor as a power source. A substantially conical wedge is provided at a front portion of the pipe expansion tool. The substantially conical wedge moves forward and backward with respect to an end of a PEX pipe by the feed screw mechanism. A plurality of claws are arranged at the front of the wedge and in a circumferential direction of the wedge. The plurality of claws are pushed by the advancing wedge and mutually open radially outward from the wedge. The end of the PEX pipe is expanded by opening the plurality of claws radially outward with the claws having entered an end opening of the PEX pipe.During the normal PEX pipe expansion process, the jaw opening motion is typically repeated several times to expand the PEX pipe to a predetermined size. For example, the jaw opening motions required to expand the PEX pipe to a specific size may be 12 to 18 times for a 1-inch diameter PEX pipe.

[0007] With a conventional pipe expansion tool, a single start operation (ON operation of a trigger) results in a single jaw opening movement. Therefore, the user must repeat the start operation of the pipe expansion tool for the required number of jaw opening movements, which places a significant workload on the user. SummaryTechnical problem

[0008] Therefore, there is a clear need for a pipe expansion tool that is compact and designed in a front-to-back direction. Alternatively, there is a clear need for a pipe expansion tool that reduces the workload for a user during a PEX pipe expansion process. Solution to the problem

[0009] One aspect of the present disclosure relates to a pipe expansion tool for expanding an end of a synthetic resin fluid pipe. The pipe expansion tool includes a motor shaft rotated by an electric motor. A power conversion mechanism converts rotation of the motor shaft into back-and-forth movement of the output shaft. A key at a front portion of the output shaft urges a plurality of claws. The plurality of claws mutually open radially outward. A claw rotating mechanism having a shaft is provided. The shaft rotates about an axis in conjunction with the rotation of the motor shaft. The shaft causes a plurality of claws to rotate about an axis. The output shaft, the motor shaft, and the shaft of the claw rotating mechanism are arranged parallel to each other and overlap each other in the front-and-back direction.

[0010] Therefore, a pipe expansion tool can be provided in a compact manner in the front-to-back direction. Furthermore, the output shaft, the motor shaft, and the shaft are arranged parallel to each other. The pipe expansion tool can also be provided in a compact manner in a direction that crosses the front-to-back direction (up-down direction or left-right direction). BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a pipe expansion tool according to an embodiment of the present disclosure. Fig. Figure 2 is a perspective view of the pipe expansion tool for expanding one end of a PEX pipe. Fig. 3 is a front right perspective view of a tool body with a body casing removed. Fig. 4 is an exploded perspective view of the tool body. Fig. 5 is a perspective view of the tool body with the body casing removed, seen from the rear right side. Fig. 6 is a perspective view of the tool body with the body casing removed, seen from the front left side. Fig. Figure 7 is a perspective view of the tool body, seen from the rear left side, with the body housing removed and showing an output shaft in a rear end position. Fig. Figure 8 is a perspective view of the tool body, seen from the rear left side, with the body housing removed and showing the output shaft in a forward end position. Fig. 9 is a rear view of the tool body with the body casing removed. Fig. 10 is an exploded perspective view of an assembly including a rear shaft. Fig. Figure 11 is a perspective view of the assembly including the tool body and rear shaft. Fig. 12 is a cross-sectional view taken along a line XII-XII in Fig. 9. Fig. 13 is a cross-sectional view taken along a line XIII-XIII in Fig. 12. Fig. 14 is a cross-sectional view taken along a line XIV-XIV in Fig. 13, when the output shaft is in the rear end position. Fig. 15 is a cross-sectional view taken along a line XIV-XIV in Fig. 13 when the output shaft is in the front end position. Fig. 16 is a cross-sectional view taken along a line XVI-XVI in Fig. 13, when the output shaft is in the rear end position. Fig. 17 is a cross-sectional view along the line XVI-XVI in Fig. 13 when the output shaft is in the front end position. Fig. 18 is a block diagram of a controller. Fig. 19 is a drawing showing a control flow. Fig. 20 is a drawing showing the control flow. Description of embodiments

[0011] According to another aspect of the present disclosure, a shaft of a claw rotating mechanism and an electric motor are arranged such that 80% or more of their respective axial lengths overlap the output shaft located at a rear end position in the front-to-rear direction. Therefore, the protrusion amount of the shaft of the claw rotating mechanism and the electric motor in the front-to-rear direction relative to the output shaft can be reduced. Specifically, the protrusion amount rearward relative to the output shaft is reduced at the terminal end position. This makes it possible to achieve the pipe expansion tool having greater compactness in the front-to-rear direction.

[0012] According to another aspect of the present disclosure, the shaft of the claw rotating mechanism and the electric motor are arranged to overlap the output shaft located at the rear end position in the front-to-rear direction over their respective entire axial lengths. Therefore, the shaft of the claw rotating mechanism and the electric motor do not protrude in the front-to-rear direction relative to the output shaft located at its rear end position. This further improves the compactness of the pipe expansion tool in the front-to-rear direction.

[0013] According to another aspect of the present disclosure, the pipe expansion tool includes a transmission mechanism that changes a rotational output of the motor shaft. An idle gear is provided between the transmission mechanism and the power conversion mechanism. Therefore, the transmission mechanism can be arranged to overlap with the power conversion mechanism in the axial direction (front-to-back direction). Thus, the electric motor provided near the transmission mechanism can be installed closer to the power conversion mechanism. This configuration makes it possible to provide the pipe expansion tool in a compact manner in the front-to-back direction.

[0014] According to another aspect of the present disclosure, the output shaft and the motor shaft are arranged offset in the up-down direction, which is perpendicular to the front-back direction. The claw rotating mechanism is located between the output shaft and the motor shaft in the up-down direction when viewed in the axial direction of the output shaft. Therefore, the output shaft, the claw rotating mechanism, and the electric motor can be compactly arranged not only in the front-back direction, but also in the up-down direction perpendicular to the front-back direction. This arrangement prevents the pipe expansion tool from being elongated in the up-down direction.

[0015] According to another aspect of the present disclosure, the claw rotation mechanism is arranged offset with respect to an imaginary plane containing both the motor shaft and the output shaft. Therefore, the output shaft, the claw rotation mechanism, and the electric motor can be arranged compactly in the extension direction (up-down direction) of the imaginary plane in which the motor shaft and the output shaft are aligned. This arrangement enables the pipe expansion tool to be provided compactly in the up-down direction.

[0016] According to another aspect of the present disclosure, the claw rotating mechanism includes a one-way clutch. The one-way clutch rotates in conjunction with a first rotation of the shaft to rotate the plurality of claws. On the other hand, the one-way clutch does not rotate in conjunction with a second rotation opposite to the first rotation of the shaft. The shaft of the claw rotating mechanism includes a rear shaft and a front shaft threadably coupled to a front portion of the rear shaft. Thus, the shaft of the claw rotating mechanism is separable into a rear shaft mounted in an assembly for rotating the shaft and a front shaft mounted in the tool body for transmitting the rotational force of the shaft to the plurality of claws.The tool body on the front shaft side and the assembly on the rear shaft side are assembled separately. After assembly, the front shaft and the rear shaft are connected by threaded engagement in the front-to-back direction. This improves the mountability of the shaft.

[0017] According to another aspect of the present disclosure, the front shaft is threadedly coupled to be fixed in a direction of first rotation with respect to the rear shaft. When the front shaft makes the first rotation, torque is transmitted from the front shaft to the plurality of claws via the one-way clutch, and the torque acts in the direction of fixing the rear shaft relative to the front shaft. The fixing force between the rear shaft and the front shaft becomes stronger. On the other hand, when the front shaft makes a second rotation, the torque transmitted from the front shaft to the plurality of claws is small. The front shaft idles and makes the second rotation with almost no resistance.The rear shaft rotates in the direction it is released from the front shaft, but there is no resistance to the front shaft, and therefore it rotates without breaking the fastening force with the front shaft. Thus, the claw rotation mechanism prevents the threaded connection between the front and rear shafts from loosening.

[0018] According to another aspect of the present disclosure, the power conversion mechanism is a feed screw mechanism provided with an external thread provided around an outer periphery of the output shaft and a nut into which the external thread is inserted. Therefore, the power conversion mechanism can be installed around the axis of the output shaft. Thus, the power conversion mechanism can be prevented from protruding from the output shaft in the axial direction (front-to-back direction). This allows the pipe expansion tool to be provided in a compact manner in the front-to-back direction.

[0019] According to another aspect of the present disclosure, the pipe expansion tool includes a handle extending in a direction that intersects the axial direction of the output shaft. At least a portion of the nut of the feed screw mechanism and at least a portion of the electric motor overlap the handle in the front-to-back direction. The nut of the feed screw mechanism and the electric motor can be arranged closer to the center of the support when a user grasps the handle to support the pipe expansion tool. This arrangement allows for good weight distribution of the pipe expansion tool in the front-to-back direction.

[0020] According to another aspect of the present disclosure, an end of a fluid pipe, made of, for example, a synthetic resin, is expanded in diameter by the pipe expansion tool. The pipe expansion tool includes an internally threaded member. The internally threaded member is configured to rotate forward when the electric motor rotates forward and to rotate reversely when the electric motor rotates reversely. A threaded shaft is threadably coupled to the internally threaded member. The threaded shaft is configured to move from an initial position to a final end position in response to forward rotation of the internally threaded member. The threaded shaft is configured to move rearward from the final end position to the initial position in response to reverse rotation of the internally threaded member. A key extends forwardly from the threaded shaft.The wedge pushes the plurality of claws as the wedge moves forward with the threaded shaft. The plurality of claws mutually open radially outward. An actuating component is provided for starting the electric motor. A controller repeatedly rotates the electric motor forward and reverse during actuation of the actuating component to repeatedly open the plurality of claws.

[0021] The jaws are opened multiple times during a single actuation of the actuating component, thus reducing the workload for the user.

[0022] According to another aspect of the present disclosure, at least one of the initial position and the final end position of the threaded shaft is detected by a detection means. Therefore, the reciprocating movement of the threaded shaft can be performed quickly and reliably.

[0023] According to another aspect of the present disclosure, both the initial position and the final end position of the threaded shaft are detected by a detection means. Therefore, the reciprocating movement of the threaded shaft is performed faster and more reliably.

[0024] According to another aspect of the present disclosure, the controller rotates the electric motor in reverse to cause the threaded shaft to return to its initial position after the actuation of the actuating member is released. When the actuation of the actuating member stops, the threaded shaft moves backward and returns to its initial position, ensuring that the jaws are returned to the closed position.

[0025] According to another aspect of the present disclosure, the controller rotates the electric motor in reverse, causing the threaded shaft to return to the initial position when the actuation of the actuating member starts, if the threaded shaft is not in the initial position when the actuation of the actuating member starts. The threaded shaft stops moving forward from an intermediate position. Consequently, the jaw opening movement is not started from a half-open position, but always starts from the closed position.

[0026] According to another aspect of the present disclosure, the controller counts the number of reciprocating movements of the threaded shaft between the initial position and the final end position during actuation of the actuating member. The controller stops the electric motor from rotating when the number of reciprocating movements reaches a predetermined threshold number of times. Thus, even during actuation of the actuating member, the electric motor stops once the jaw opening movements have been performed a predetermined threshold number of times. This ensures rapid execution of a correct diameter expansion process.

[0027] According to another aspect of the present disclosure, the controller calculates a number of reciprocating movements based on the number of revolutions of the electric motor. When the number of revolutions of the electric motor reaches the predetermined threshold number of times, the electric motor automatically stops after the threaded shaft returns to its initial position. This reduces the workload for the user for multiple diameter expansion operations of the claws.

[0028] According to another aspect of the present disclosure, the detection means is a Hall IC sensor. Accordingly, one or both of the initial position and the final end position of the threaded shaft are detected by the Hall IC sensor.

[0029] According to another aspect of the present disclosure, the detecting means is a detecting circuit that detects a position of the threaded shaft based on the number of revolutions of the electric motor. Therefore, one or both of the initial position and the final end position of the threaded shaft are detected by the detecting circuit.

[0030] According to another aspect of the present disclosure, the pipe expansion tool includes a ball screw with a ball between the threaded shaft and the internally threaded component. Therefore, the threaded shaft can be thread-coupled to the internally threaded component smoothly and without rattling. This allows the threaded shaft to reciprocate precisely and smoothly.

[0031] Hereinafter, an embodiment of the present disclosure will be described with reference to Fig. 1 to 20. As described in Fig. 1, a pipe expansion tool 1 according to this embodiment comprises a tool body 10 accommodated in a body casing 11, and a handle 5 extending from a lower portion of the body casing 11. A user grips the handle 5 while positioned substantially behind the pipe expansion tool 1 (on a far left side in Fig. 1). In this description, a side in front of the user is referred to as a back side, and a side opposite the user's side is referred to as a front side. Up-down and left-right directions are determined with respect to the user.

[0032] As in Fig. 1, Fig. 4 and Fig. 12, an annular cap 2 is attached to a front portion of the tool body 10. A columnar discharge shaft 27 extending in a front-to-back direction is provided at a center of the tool body 10. A substantially conical key 3 is attached to a front end of the discharge shaft 27. The key 3 is located radially inside the cap 2. The discharge shaft 27 and the key 3 are arranged on a discharge axis K extending in the front-to-back direction substantially at the center of the tool body 10 in the up-down and left-right directions. The discharge shaft 27 and the key 3 are movable in the front-to-back direction along the discharge axis K between a rear initial position (rear end position) and a front final end position (front end position).A plurality of claws 4 extending in the front-to-back direction are provided radially outward of the wedge 3 and radially inward of the cap 2. The plurality of claws 4 are arranged at equal intervals in a circumferential direction of the wedge 3. The pipe expansion tool 1 may, for example, have six claws 4, and each claw 4 is arranged at a 60-degree interval in the circumferential direction of the wedge 3. The plurality of claws 4 can open and close between a closed position in which they are in close contact with each other in the circumferential direction to cover the wedge 3, and an open position in which they are open to each other radially outward to expose one end of the wedge 3.

[0033] As in Fig. 1 and Fig. 12, a pusher-type operating member (e.g., shift lever) 6 is provided at a front side of the handle 5. The user can operate the operating member 6 by pressing it while gripping the handle 5. A switch body 6a is provided inside the handle 5, which is switched ON and OFF in association with an operation of the operating member 6. The switch body 6a is in an OFF state when the operating member 6 is not pressed, and is in an ON state when the operating member 6 is pressed. A substantially rectangular box-shaped enlarged diameter portion 7 is provided at a lower end of the handle 5, which widens in the front-back direction and in the left-right direction. The controller 9 is housed in the enlarged diameter portion 7.The controller 9 includes a flat, rectangular, box-shaped housing with a bottom and a resin-injected control board housed within the housing. The controller 9 is housed in the enlarged diameter portion 7 with its thickness oriented in the up-down direction (a direction in which a shortest side of the housing extends). The controller 9 primarily controls driving of an electric motor 20, which will be described later.

[0034] As in Fig. 1, an operation panel 7b is provided on an upper side of the enlarged diameter portion 7. Various operation buttons are arranged on the operation panel 7b for, for example, specifying a number of opening / closing movements of the claws 4. When the operation button 7c is pressed and held, the operation panel 7b is activated. The activation state is indicated by illumination of the display 7d. By pressing to operate the operation button 7e in the activation state, a tens digit of a predetermined value can be designated. The tens digit is numerically displayed on a display 7f. In this way, by pressing the control button 7g in the activation state, a units digit of the predetermined value can be designated. The units digit is numerically displayed on the display 7h.The user can determine the number of opening / closing movements of the claws 4 by pressing and operating the operating buttons 7e and 7g. During one pressing operation of the operating member 6, the opening / closing movements of the claws 4 are continuously performed for the predetermined number. When the claws 4 continuously open and close for the predetermined number, the electric motor 20 is automatically stopped.

[0035] As in Fig. As shown in Figure 1, a lower side of the enlarged diameter portion 7 is provided with a battery mounting portion 7a to which a rectangular box-shaped battery 8 can be removably attached. The battery 8 can be removed from the battery mounting portion 7a by sliding it forward. The battery 8 can be attached to the battery mounting portion 7a by sliding it rearward from a front side of the battery mounting portion 7a. The battery 8 removed from the battery mounting portion 7a can be repeatedly charged with a charger provided separately for use. The battery 8 can also be used as a power source for other electric power tools. The battery 8 serves as a power source for supplying electric power to the electric motor 20.

[0036] As in Fig. As shown in Figure 2, when using the pipe expansion tool 1, the user grasps the handle 5 and inserts the plurality of claws 4 into an end 51a of a synthetic resin PEX pipe 51 (fluid pipe). By pressing the operating member 6, the plurality of claws 4 open and close in the radial direction. This causes the end 51a of the PEX pipe 51 to expand in diameter. The PEX pipe 51 is laid, for example, between two opposite walls 52. Therefore, it is preferable that the pipe expansion tool 1 has a front-to-back length that allows it to fit into a narrow space between the two walls 52.

[0037] As in Fig. As shown in Figure 4, the tool body 10 accommodates a front mechanism housing 12, a first middle mechanism housing 13, a second middle mechanism housing 14, and a rear mechanism housing 15 in order from the front to the rear. The front mechanism housing 12, the first middle mechanism housing 13, and the second middle mechanism housing 14 are substantially cylindrical in shape, with a hollow channel at a center penetrating in the front-to-rear direction. The rear mechanism housing 15 is plate-shaped, with the front-to-rear direction as a plate thickness direction. The front mechanism housing 12, the first middle mechanism housing 13, the second middle mechanism housing 14, and the rear mechanism housing 15 cooperate to form a mechanism housing. The mechanism housing accommodates a gear shaft 23, an idle gear 24, and a nut 26, which will be described later.

[0038] As in Fig. 3 and Fig. As shown in Figure 4, an external thread 12a is provided on a front outer peripheral surface of the front mechanism housing 12. An internal thread 2b, which is threadably coupled to the external thread 12a, is provided on a rear inner peripheral surface of the cap 2. The cap 2 connects to a front part of the front mechanism housing 12 by screwing the external thread 12a to the internal thread 2b.

[0039] As in Fig. 3 and Fig. As shown in Figure 4, the outer peripheral surface of the front mechanism housing 12 is provided with four substantially cylindrical boss portions 12c projecting radially outward. The boss portions 12c are formed with threaded holes 12d penetrating in the front-to-rear direction. The first middle mechanism housing 13 and the second middle mechanism housing 14 each have four substantially cylindrical boss portions 13g and 14j projecting radially outward. Each of the boss portions 13g, 14j has a through hole 13h, 14k penetrating in the front-to-rear direction. Four corners of the rear mechanism housing 15 have through holes 15b penetrating in the front-to-rear direction. By aligning the boss portions 12c, 13g, 14j and the through holes 15b in the front-to-back direction, the threaded holes 12d and the through holes 13h, 14k, 15b are connected to each other in the front-to-back direction.Four bolts 16 are inserted from the rear to the front through the through holes 15b, 14k, 13h, respectively, and secured in the threaded holes 12d. The front mechanism housing 12, the first mechanism housing 13, the second middle mechanism housing 14, and the rear mechanism housing 15 are then connected in alignment in the front-to-back direction.

[0040] As in Fig. 3 and Fig. 4, the first mechanism housing 13 has a downwardly extending portion 13b having a substantially U-shaped contour extending downward from a cylindrical shape. The second middle mechanism housing 14 has a downwardly extending portion 14b having a substantially U-shaped contour extending downward from a cylindrical shape. The downwardly extending portion 13b and the downwardly extending portion 14b are connected in the front-to-rear direction to have a space for accommodating the gear shaft 23 and the idler gear 24. The downwardly extending portion 13b is provided with two through holes arranged in parallel one above the other and penetrating in the front-to-rear direction. The lower through hole is provided with a recess 13c for supporting the gear shaft 23, as will be described later.A shaft member 24a supporting the idler gear 24 is press-fitted into the upper through-hole 13d. The downwardly extending portion 14b has two through-holes arranged parallel to each other, one above the other, and penetrating in the front-to-rear direction. The lower through-hole has a recess 14c for supporting the gear shaft 23. The shaft member 24a is inserted into the upper through-hole 14d.

[0041] As in Fig. 3 and Fig. As shown in Fig. 12, a substantially columnar electric motor 20 is housed in a lower rear portion of the body case 11. For example, a motor known as a brushless DC motor is used for the electric motor 20. The electric motor 20 is located below the output shaft 27 located at the rear end position and above the handle 5. The electric motor 20 overlaps the output shaft 27 located at the rear end position by more than or equal to 80% of its axial length (front-to-back length). In this embodiment, the entire axial length of the electric motor 20 overlaps with the output shaft 27 located at the rear end position. A motor shaft 20a of the electric motor 20 extends in the front-to-back direction parallel to the output axis K, which penetrates the center of the output shaft 27, along a motor axis J.The motor axis J is aligned with the output axis K on an imaginary plane S parallel, one above the other, extending in the up-down direction (see . Fig. 13). The motor shaft 20a is rotatably supported by the motor axis J through bearings 20e and 20f. The bearing 20e is provided between the electric motor 20 and a planetary reduction mechanism 22, which will be described later. The bearing 20f is supported on an inner wall of a rear side of the body case 11.

[0042] As in Fig. As shown in Figure 12, the electric motor 20 includes a stator 20b non-rotatably supported relative to the body case 11. The stator 20b is disposed radially outward from the motor shaft 20a. A rotor 20c of the electric motor 20 is mounted on the motor shaft 20a so as to be rotatable integrally with the motor shaft 20a on an inner peripheral side of the stator 20b. A rotational speed detection sensor 20d is provided on the front side of the rotor 20c. The rotational speed detection sensor 20d detects the rotational speed of the motor shaft 20a by detecting a rotation angle of the rotor 20c. A fan 21 is integrally mounted on the motor shaft 20a for cooling air flow into the electric motor 20 between the rotor 20c and the rear bearing 20f in the front-to-rear direction. When the fan impeller 21 and the motor shaft 20a rotate, cooling air flows from the front to the back of the electric motor 20.

[0043] As in Fig. As shown in Fig. 12, the planetary reduction mechanism (transmission mechanism) 22 is provided at the front of the electric motor 20 for reducing the output of the motor shaft 20a. The planetary reduction mechanism 22 has a substantially columnar shape centered on the motor axis J and has approximately the same diameter as the electric motor 20. The planetary reduction mechanism 22 is housed in the body case 11, aligned with the electric motor 20 in the front-to-rear direction. A first sun gear 22a of the planetary reduction mechanism 22 is integrally provided with the front end of the motor shaft 20a at the front of the bearing 20e. An annular first internal gear 22b centered on the motor axis J is provided radially outward from the first sun gear 22a. A plurality of first planetary gears 22c mesh between the first sun gear 22a and the first internal gear 22b.The first planetary gear 22c connects to a first carrier 22d at the front of the first sun gear 22a. The rotational drive of the motor shaft 20a is transmitted at a reduced speed to the first carrier 22d via the first sun gear 22a and the first planetary gear 22c.

[0044] As in Fig. As shown in Figure 12, the first carrier 22d is integrally provided with a second sun gear 22e at the front and is rotatable about the motor axis J together with the second sun gear 22e. An annular second internal gear 22f, centered on the motor axis J, is provided radially outward from the second sun gear 22e. A plurality of second planetary gears 22g mesh between the second sun gear 22e and the second internal gear 22f. The second planetary gears 22g are connected to a second carrier 22h disposed at the front of the second sun gear 22e. The second carrier 22h is integrally provided with the rear end of the front transmission shaft 23 and is rotatable about the motor axis J. Therefore, the rotational drive of the first carrier 22d is transmitted at a reduced speed to the gear shaft 23 via the second sun gear 22e, the second planetary gear 22g and the second carrier 22h.Thus, the rotary drive of the motor shaft 20a is transmitted at a reduced speed to the gear shaft 23 via the planetary reduction mechanism 22.

[0045] As in Fig. As shown in Figure 12, the gear shaft 23 is rotatably supported around the motor axis J by bearings 23b and 23c. The front bearing 23b is press-fitted into the recess 13c formed in the lower part of the first middle mechanism housing 13. The rear bearing 23c is press-fitted into the recess 14c formed in the lower part of the second middle mechanism housing 14. The gear shaft 23 has a drive-side gear 23a between the bearings 23b and 23c in the front-to-rear direction. The drive-side gear 23a rotates integrally around the motor axis J with the gear shaft 23.

[0046] As in Fig. As shown in Figure 12, the idle gear 24 is provided between the transmission shaft 23 and the output shaft 27 in the up-down direction. The idle gear 24 is rotatably supported about an axis of the shaft member 24a by a columnar shaft member 24a extending in the front-back direction. The shaft member 24a is inserted into the through hole 13d provided in the downwardly extending portion 13b of the first middle mechanism housing 13 and into the through hole 14d provided in the downwardly extending portion 14b of the second middle mechanism housing 14. The axis of the shaft member 24a is located on an imaginary plane S including the motor axis J and the output axis K (see Fig. 9). A radial bearing 24b is arranged between the shaft member 24a and the idler gear 24 in the radial direction. The idler gear 24 meshes with the lower drive-side gear 23a and an upper driven-side gear 26a.

[0047] As in Fig. As shown in Fig. 12, the tool body 10 is provided with a feed screw mechanism (power conversion mechanism) 25, which is also referred to as a ball screw mechanism. The feed screw mechanism 25 includes an output shaft 27 and a nut 26. An external thread 27a is provided on an outer peripheral surface of the output shaft 27. Therefore, the output shaft 27 corresponds to a threaded shaft of the ball screw mechanism. The nut 26 is formed in a substantially cylindrical shape circumferentially covering the output shaft 27. An internal thread 26b is provided on an inner peripheral surface of the nut 26. The internal thread 26b is in threaded engagement with the external thread 27a of the output shaft 27 via a plurality of balls 27b interposed therebetween. The output-side gear 26a is provided on an outer circumference of the nut 26, which projects radially outward and meshes with the idle gear 24.The drive-side gear 23a meshes with the idle gear 24 and the idle gear 24 meshes with the driven-side gear 26a, whereby the rotary drive of the gear shaft 23 is transmitted to the nut 26 at a reduced speed.

[0048] As in Fig. As shown in FIG. 12, the nut 26 is rotatably supported around the output axis K by bearings 26c and 26d housed in the tool body 10. The front bearing 26c is press-fitted into the inner peripheral surface 13a of the first middle mechanism housing 13. The rear bearing 26d is press-fitted into the inner peripheral surface 14a of the second middle mechanism housing 14. A thrust bearing 26e for receiving an axial load for pressing the nut 26 forward is provided between a rear side of the nut 26 and a front side 15a of the rear mechanism housing 15.

[0049] As in Fig. 3 and Fig. 5, a discharge shaft guide 28 is attached to a rear side of the discharge shaft 27 to prevent the discharge shaft 27 from rotating and to guide the back-and-forth movement of the discharge shaft 27. The discharge shaft guide 28 includes a roller shaft 28a connecting to the rear end of the discharge shaft 27 and extending in the left-right direction. The discharge shaft guide 28 includes a pair of rollers 28b at both the left and right ends of the roller shaft 28a. A pair of loop-shaped rails 28c extending in the front-and-back direction are mounted on the left and right sides of the second middle mechanism case 14. The rollers 28b are engaged with the rails 28c and are movable in the front-and-back direction along the rails 28c. The output shaft 27 is guided by the rollers 28b and moves in the front-to-back direction together with the output shaft guide 28.

[0050] As in Fig. 6 and Fig. As shown in Figure 12, the tool body 10 includes a claw rotating mechanism 30 for rotating the plurality of claws 4. The plurality of claws 4 rotate around the output axis K. The claw rotating mechanism 30 includes a push plate 34 that moves back and forth in conjunction with rotation of the motor shaft 20a, and a shaft 31 that rotates in conjunction with the forward and backward movement of the push plate 34. The shaft 31 is arranged on a shaft axis L extending in the front-to-back direction. The shaft 31 rotates around the shaft axis L. The shaft axis L is located below the output axis K and above the motor axis J in the up-down direction. The shaft axis L is offset to the left side in the left-right direction from the imaginary plane S including the output axis K and the motor axis J (see Fig. 13). The shaft 31 of the claw rotating mechanism 30 partially overlaps the idle gear 24 in the up-down direction. The shaft 31 overlaps the output shaft 27, which is in the rear end position, by more than or equal to 80% of its axial length (front-to-back length). In this embodiment, the shaft 31 overlaps the entire axial length with respect to the output shaft 27, which is in the rear end position.

[0051] As in Fig. 5 and Fig. As shown in FIG. 14, the claw rotating mechanism 30 includes a ball retainer 36 mounted on the shaft 31. The ball retainer 36 is movable in the front-to-back direction along the shaft axis L. A guide shaft 41 extending parallel to the shaft 31 is provided on the right side of the shaft 31. The second middle mechanism housing 14 includes a guide shaft support 14e below the output shaft 27 and above the planetary reduction mechanism 22. The guide shaft support 14e has a through hole 14f penetrating in the front-to-back direction. The guide shaft 41 is press-fitted into the through hole 14f and secured to the second middle mechanism housing 14.

[0052] As in Fig. 5 and Fig. As shown in Figure 10, the ball retainer 36 includes a substantially cylindrical sleeve attachment portion 36a and a laterally extending portion 36e extending to the right side of the sleeve attachment portion 36a. A shaft insertion hole 36c penetrating in the front-to-back direction is provided at a center of the sleeve attachment portion 36a. The shaft 31 is slidably inserted into the shaft insertion hole 36c with respect to the ball retainer 36. The laterally extending portion 36e is provided with a through hole 36f penetrating in the front-to-back direction. The guide shaft 41 is slidably inserted into the through hole 36f with respect to the ball retainer 36. Thus, the ball retainer 36 is guided by the shaft 31 and the guide shaft 41 such that it is slidable in the front-to-back direction and is restricted from rotating about the axis of the shaft 31.

[0053] As in Fig. 5 and Fig. As shown in Figure 14, the claw rotating mechanism 30 includes the push plate 34 that pushes the ball retainer 36 from the rear side. The plate-shaped push plate 34 is integrally mounted on the roller shaft 28a in a position where the plate thickness direction is defined as a front-to-rear direction. The push plate 34 extends downward from the roller shaft 28a and is located rearward of the sleeve attachment portion 36a. The push plate 34 has a through hole 34a penetrating in the front-to-rear direction. The shaft 31, which projects rearward from the sleeve attachment portion 36a, can penetrate the through hole 34a. The push plate 34 pushes the rear side of the ball retainer 36 forward as it moves forward with the output shaft 27. The push plate 34 moves away from the ball retainer 36 as it moves rearward with the output shaft 27. Therefore, the force of the push plate 34 to move the ball retainer 36 is not exerted.

[0054] As in Fig. 10 and Fig. As shown in Fig. 14, the sleeve attachment portion 36a is provided with a ball retaining hole 36b penetrating in the up-down direction to communicate with the shaft insertion hole 36c. A ball 39 is inserted into the pair of ball retaining holes 36b located above and below the shaft insertion hole 36c, respectively. A sleeve 37 covering the ball retaining holes 36b from the radial outside is mounted on the sleeve attachment portion 36a. The sleeve 37 is attached to the sleeve attachment portion 36a such that the ball 39 is retained in the ball retaining hole 36c. A recessed groove 36d extending in the circumferential direction is provided at a front portion of the sleeve attachment portion 36a. An O-ring 38 is mounted in the recessed groove 36d to prevent the sleeve 37 from falling out of the sleeve mounting portion 36a.

[0055] As in Fig. 14 and Fig. As shown in Figure 15, the shaft 31 is formed by assembling a front shaft 32 and a rear shaft 33 in the front-to-rear direction. The front shaft 32 is supported by the first middle mechanism housing 13 and the second middle mechanism housing 14 so as to be rotatable about the axis. The rear shaft 33 is supported by the second middle mechanism housing 14 so as to be rotatable about the axis. The rear shaft 33 is inserted into the ball retainer 36. An external thread 33a is provided at a front end of the rear shaft 33. The front shaft 32 is provided with an internal thread 32a that is thread-coupled with the external thread 33a. The external thread 33a is thread-coupled with the internal thread 32a such that the rear shaft 33 is integrally attached to the front shaft 32. By rotating the rear shaft 33 in a clockwise direction (in a direction of a first rotation R1, which is Fig. 8), when viewed from the rear with respect to the front shaft 32, the external thread 33a and the internal thread 32a are fastened. By rotating the rear shaft 33 in the counterclockwise direction (in a direction of a second rotation R2 shown in Fig. 7), when viewed from the rear with respect to the front shaft 32, the external thread 33a and the internal thread 32a are disengaged from each other.

[0056] As in Fig. 10, Fig. 14 and Fig. As shown in Fig. 15, a pair of ball grooves 33b are provided on the outer peripheral surface of the rear shaft 33. The ball grooves 33b extend substantially in the longitudinal direction of the rear shaft 33 and in the circumferential direction like thread grooves from the rear to the front. The ball grooves 33b extend in the direction of the first rotation R1 (see Fig. 8) from a rear part 33c to a front part 33e. The pair of ball grooves 33b are arranged in a point-symmetric positional relationship with respect to the axial center of the rear shaft 33. A ball 39 protrudes radially inward from the ball retaining hole 36b of the ball retainer 36 into the shaft insertion hole 36c and engages with the ball groove 33b.

[0057] As in Fig. 14 and Fig. 15, the ball 39 moves in the ball groove 33b along an extending direction of the ball groove 33b. When the ball retainer 36 holds the ball 39, rotation about the shaft axis L is restricted. When the ball retainer 36 moves forward with respect to the rear shaft 33, the ball 39 moves from the rear part 33c to the front part 33e of the ball groove 33b. The rear shaft 33 therefore rotates in the direction of the second rotation R2 (see Fig. 7) with respect to the ball retainer 36. When the ball retainer 36 moves rearward with respect to the rear shaft 33, the ball 39 moves from the front part 33e to the rear part 33c of the ball groove 33b. The rear shaft 33 therefore rotates in the direction of the first rotation R1 (see Fig. 8) in relation to the ball mount 36.

[0058] As in Fig. 14 and Fig. As shown in Figure 15, the second middle mechanism housing 14 includes a shaft support 14h that supports the threadedly coupled portion of the front shaft 32 and the rear shaft 33. The shaft support 14h has a ribbed spring receiving portion 14g projecting in the radial direction and a through hole 14i for inserting the shaft 31 in the front-to-rear direction. A compression spring 40 is interposed between the spring receiving portion 14g and the ball retainer 36 in the front-to-rear direction. The rear shaft 33 is inserted through a center of the compression spring 40. The compression spring 40 biases the ball retainer 36 rearward.

[0059] As in Fig. 14 and Fig. As shown in Figure 15, the first middle mechanism housing 13 includes a shaft support 13e that supports the front shaft 32. A through hole 13f is provided in the center of the shaft support 13e, through which the front shaft 32 can be inserted in the front-to-back direction.

[0060] As in Fig. 14 and Fig. 15, the claw rotating mechanism 30 includes a cylindrical one-way clutch 42 and a drive-side gear 43. The one-way clutch 42 and the drive-side gear 43 are mounted on the front part of the front shaft 32 at the front side of the shaft support 13e. The one-way clutch 42 is provided between the front shaft 32 and the drive-side gear 43 in the radial direction. The one-way clutch 42 may have a structure referred to, for example, as a sprag structure and transmits only one-way rotation on the radial inner peripheral side to the radial outer peripheral side. The one-way clutch 42 transmits the first rotation R1 (see Fig. 8) of the front shaft 32 to the drive-side gear 43. The one-way clutch 42 does not transmit the second rotation R2 (see Fig. 7) of the front shaft 32 to the drive-side gear 43 and allows the front shaft 32 to rotate freely.

[0061] As in Fig. As shown in Figure 11, the rear shaft 33, the ball retainer 36, the ball 39, and the sleeve 37 can be integrally assembled as an assembly 35. The assembly 35 can be mounted on the tool body 10 by screwing the external thread 33a of the rear shaft 33 to the internal thread 32a of the front shaft 32. When the assembly 35 is mounted on the tool body 10, the compression spring 40 is compressed by the assembly 35 to be mounted.

[0062] As in Fig. 7, Fig. 8 and Fig. As shown in Fig. 11, the rear part of the front shaft 32 is provided with two-sided flat portions 32b having a pair of planes extending parallel to each other in the front-rear direction. The two-sided flat portions 32b are exposed to the outside of the mechanism case between the first middle mechanism case 13 and the second middle mechanism case 14. The rear end of the rear shaft 33 is provided with two-sided flat portions 33f having a pair of planes extending parallel to each other in the front-rear direction. While the two-sided flat portions 32b are held with a wrench or the like to prevent the front shaft 32 from rotating, the rear shaft 33 is rotated in the first rotation direction R1 by holding the two-sided flat portions 33f with a wrench or the like.Accordingly, the rear shaft 33 is threadably coupled to the front shaft 32. Thus, the assembly 35 including the rear shaft 33 can be integrally mounted to the tool body 10 supporting the front shaft 32.

[0063] As in Fig. 4, Fig. 12, Fig. 16 and Fig. As shown in Fig. 17, the claw rotating mechanism 30 includes a substantially cylindrical rotary drive ring 44 and a substantially cylindrical link 45. The rotary drive ring 44 and the link 45 are supported on the radially inner side of the inner peripheral surface 12b of the front mechanism housing 12 and are axially rotatable about the output axis K. An O-ring 45d is provided between the link 45 and the front mechanism housing 12 in the radial direction. An insertion hole 44b is provided in the center of the rotary drive ring 44 through which the output shaft 27 can be inserted in the front-to-rear direction. A driven-side gear 44a is provided on the outer peripheral surface of the rotary drive ring 44 and projects radially outward. The output-side gear 44a meshes with the drive-side gear 43. The rotational power of the drive-side gear 43 is transmitted to the output-side gear 44a at a reduced speed.A plurality of engagement projections 44c projecting forward and aligned in the circumferential direction are provided at the front end of the rotary drive ring 44.

[0064] As in Fig. 4, Fig. 16 and Fig. As shown in Fig. 17, an insertion hole 45a is provided in the center of the connecting piece 45, through which the output shaft 27 can be inserted in the front-to-back direction. At the rear end of the connecting piece 45, a plurality of engaging recesses 45b are provided, which engage with a plurality of engaging projections 44c of the rotation drive ring 44. The engaging projections 44c are fitted into the engaging recesses 45b to cause the connecting piece 45 to rotate integrally with the rotation drive ring 44. A plurality of engaging projections 45c, which protrude forward and are aligned in the circumferential direction, are provided at the front end of the connecting piece 45.

[0065] As in Fig. 4, Fig. 16 and Fig. As shown in Fig. 17, the rear end of the claws 4 is provided with an engaging recess 4b that engages with the plurality of engaging projections 45c of the link 45. The plurality of engaging projections 45c are fitted into the engaging recess 4b of each claw 4 to cause the claws 4 to rotate about the output axis K integrally with the link 45. An arcuate ring receiving groove 4a in cross section is provided on the radially outer periphery of the rear part of the claws 4. The ring receiving grooves 4a of the plurality of claws 4 are circumferentially connected to form an annular groove. The plurality of claws 4 are circumferentially connected by a ring 4c that is inserted into the ring receiving groove 4a and is elastically stretchable. Claw support grooves 2a extending radially outward and in the circumferential direction are provided on the inner peripheral surface of the cap 2 for receiving the ring 4c.The claw support grooves 2a allow the ring 4c to move in the radial direction, but restrict the ring 4c from moving in the front-to-back direction. The plurality of claws 4 open and close radially around the ring 4c, which is supported by the claw support grooves 2a.

[0066] As in Fig. 14 and Fig. As shown in Figure 15, a magnet 46 is mounted on an upper part of the roller shaft 28a. An initial position sensor (rear end position sensor) 47 and a final end position sensor (front end position sensor) 48 are provided on the upper inner peripheral surface of the body case 11. The initial position sensor 47 and the final end position sensor 48 are sensors that detect magnetic fields and are called Hall ICs. The initial position sensor 47 is arranged directly above the magnet 46 when the output shaft 27 is in the rear end position (initial position), as shown in Figure 15. Fig. 14. When the front-to-back position of the magnet 46 reaches the position corresponding to the initial position sensor 47, the initial position sensor 47 generates a signal. Specifically, the initial position sensor 47 detects the rear end position (initial position) of the output shaft 27 and sends a signal to the controller 9 (see Fig. 1). The final end position sensor 48 is arranged directly above the magnet 46 when the output shaft 27 is in the front end position, as shown in Fig. 15. When the front-to-back position of the magnet 46 reaches a position corresponding to the final end position sensor 48, the final end position sensor 48 generates a signal. Specifically, the final end position sensor 48 detects the front end position (final end position) of the output shaft 27 and sends a signal to the controller 9.

[0067] The following describes the driving of the feed screw mechanism 25 and the claw rotating mechanism 30. As in Fig. As shown in Figure 12, the actuating member 6 is first pressed, causing the motor shaft 20a and the electric motor 20 to rotate. The rotational drive of the motor shaft 20a is reduced by the planetary reduction mechanism 22 and transmitted to the transmission shaft 23. When the transmission shaft 23 rotates, the idle gear 24, which meshes with the drive-side gear 23a, rotates. Furthermore, the nut 26 rotates around the output axis K together with the driven-side gear 26a, which meshes with the idle gear 24. While the nut 26 rotates, the internal thread 26b is thread-coupled with the external thread 26a, and the output shaft guide 28 prevents the output shaft 27 from rotating, thereby causing the output shaft 27 to move in the front-to-back direction, as shown in Figure 12. Fig. 7 and Fig. 8. As shown in Fig. 16 and Fig. As shown in Figure 17, when the output shaft 27 moves forward, the wedge 3 attached to the front end of the output shaft 27 pushes the plurality of claws 4 and the ring 4c to move to the radially outer opening position. When the output shaft 27 moves rearward, the pushing force of the wedge 3 is released, causing the ring 4c to contract and the plurality of claws 4 to return to the radially inner closed position. For example, the plurality of claws 4 move from the mutually separated position shown in Figure 17 to the Fig. 15, to the mutually closed or touching position shown in Fig. 14 is shown.

[0068] As in Fig. As shown in Figure 12, the electric motor 20 is switched to forward or reverse rotation by the controller 9. The output shaft 27 moves forward when the electric motor 20 rotates forward and moves backward when the electric motor 20 rotates backward. The controller 9 switches the electric motor 20 to forward or reverse rotation based on signals transmitted from the initial position sensor 47 and the final end position sensor 48.

[0069] The electric motor 20 is switched to forward rotation and reverse rotation by the controller 9. The output shaft 27 moves forward when the electric motor 20 rotates forward and moves backward when the electric motor 20 rotates backward. The controller 9 switches the electric motor 20 to forward rotation or reverse rotation based on the signals transmitted from the initial position sensor 47 and the final end position sensor 48.

[0070] As in Fig. 7 and Fig. As shown in Figure 8, when the output shaft 27 moves forward, the push plate 34 attached to the roller shaft 28a also moves forward. The push plate 34 pushes the ball retainer 36 forward against the biasing force of the compression spring 40. When the ball retainer 36 moves forward, the ball 39 engages the ball groove 33b, as shown in Figure 8. Fig. 14 and Fig. 15. As shown in Fig. 7 and Fig. As shown in Figure 8, the compression spring 41 prevents the ball retainer 36 from rotating and causes the rear shaft 33 to rotate in the second rotation direction R2. The front shaft 32, to which the rear shaft 33 is threadedly coupled, also rotates in the second rotation direction R2. At the same time, the one-way clutch does not transmit the rotational power of the front shaft 32 to the drive-side gear 43. Therefore, the front shaft 32 rotates in the second rotation direction R2, which releases the threaded connection with the rear shaft 33, but since it rotates idle, the generation of torque for releasing the threaded connection is suppressed. The rotation drive ring 44, which is equipped with the driven-side gear 44a, does not rotate because no rotational power is transmitted from the drive-side gear 43. Therefore, the connecting piece 45 connected to the rotary drive ring 44 and the plurality of claws 4 do not rotate.Thus, the plurality of claws 4 do not rotate about the output axis K and are pushed radially outward by the wedge 3 to open.

[0071] As in Fig. 7 and Fig. As shown in Figure 8, when the output shaft 27 moves rearward, the push plate 34 attached to the roller shaft 28a also moves rearward together. The ball retainer 36 is biased by the compression spring 40 and moves rearward when the pressing force of the push plate 34 is released. When the ball retainer 36 moves rearward, the ball 39 engages the ball groove 33b, as shown in Figure 8. Fig. 14 and Fig. 15. As shown in Fig. 7 and Fig. As shown in Figure 8, the guide shaft 41 prevents the ball retainer 36 from rotating and causes the rear shaft 33 to rotate in the direction of the first rotation R1. The front shaft 32, to which the rear shaft 33 is threadedly coupled, also rotates in the direction of the first rotation R1. At the same time, the one-way clutch 42 transmits the rotational power of the front shaft 32 to the drive-side gear 43. Therefore, the front shaft 32 rotates in the direction of the first rotation R1, which further secures the threaded connection with the rear shaft 33. As shown in Fig. 16 and Fig. 17, the rotary drive ring 44, which is provided with the driven-side gear 44a, rotates in a clockwise direction when viewed from the front due to the transmission of the rotary power from the drive-side gear 43. The link 45 and the plurality of claws 4 also rotate integrally with the rotary drive ring 44. Thus, the plurality of claws 4 move from the position shown in Fig. 17, to the position shown in Fig. 16. That is, the plurality of claws 4 close radially inward while rotating in a clockwise direction as viewed from the front side about the output axis K.

[0072] As described above, the operating member 6 is pressed to start the electric motor 20, causing the claw 4 to open and close and rotate. In this example of the pipe expansion tool 1, while the operating member 6 is operated, the electric motor 20 repeatedly rotates forward and backward, causing the claws 4 to open and close and rotate multiple times in sequence. The control circuit C is provided on the control board 9a of the controller 9 for the repeated forward and reverse rotation of the electric motor 20. The control board 9a includes a power circuit that supplies power from the battery 8 to the electric motor 20.

[0073] As in Fig. As shown in Fig. 18, in addition to the ON operation signal from the operation member 6, the ON signal from the initial position sensor 47 and the ON signal from the final end position sensor 48, the revolution number information from the revolution detection sensor 20d, and the information of the set number of times are input to the control circuit C by the operation of the operation panel 7b. The control board 9a has a detection circuit that detects the revolution number of the electric motor 20 through the revolution detection sensor 20d. The number of opening and closing movements of the plurality of claws 4 (reciprocations of the output shaft 27) is set by the user who operates the operation panel 7b in advance. The information of the set number of movements is stored in the control circuit C as the set number of times P.The set number of times P of opening and closing movements of the claws 4 is appropriately set according to the PEX pipe 51 which is the target of the diameter expansion work.

[0074] Fig. 19 shows a series of operations of the pipe expansion tool 1 controlled by the control circuit C. When the battery 8 is mounted on the battery mounting part 7a, the operation enters a start-up standby state (step 100, hereinafter referred to as ST100). When the operating member 6 is pressed in ST101, the position of the output shaft 27 is detected (ST102). In ST102, the ON / OFF state of the initial position sensor 47 is determined to determine whether the output shaft 27 is in the initial position.

[0075] If it is confirmed in ST102 that the output shaft 27 is not in the initial position (initial position sensor 47 is OFF), the electric motor 20 rotates backward in ST103. This causes the output shaft 27 to initially return to its rear initial position. If it is confirmed in ST102 that the output shaft 27 is in the initial position (initial position sensor 47 is ON), the electric motor 20 rotates forward in ST104. This causes the output shaft 27 to move forward to open the plurality of claws 4.

[0076] While the electric motor 20 is rotating forward, the push operation of the operating member 6 (ON state of the switch body 6a) is confirmed in ST105. When the push operation of the operating member 6 is confirmed, the electric motor 20 continues to rotate forward to open the claws 4. When the output shaft 27 reaches the final end position in ST106, the final end position sensor 48 turns on. Therefore, the plurality of claws 4 fully open.

[0077] If the pushing operation of the operating member 6 is not confirmed in ST105 during the opening movement of the claw 4, it is determined that the user has released the pushing operation of the operating member 6. In this case, the electric motor 20 switches to reverse rotation in ST110. Consequently, the output shaft 27 begins to move backward while moving forward, causing the opening movement of the claws 4 to be interrupted. If the initial position of the output shaft 27 is confirmed in ST111, the electric motor 20 is stopped in ST112. Thus, if the pushing operation of the operating member 6 is released during the opening movement of the claw 4, the electric motor 20 rotates reversely, causing the output shaft 27 to return to its initial position. As a result, the claws 4 are returned to the closed position, and the control flow returns to the standby state of ST100.

[0078] As in Fig. For example, as shown in FIG. 20, when the output shaft 27 reaches the final end position and the jaws 4 have performed the diameter expansion operation, the number of ON times of the final end position sensor 48 (the number of times p of the diameter expansion operation performed) is counted. In ST107, the counted number of times p is compared with the predetermined number of times P. If the number of times p of the opening movement of the jaws 4 is less than the predetermined number of times P (p < P), the electric motor 20 rotates backward (ST108). This causes the output shaft 27 to move backward to close the plurality of jaws 4. During the closing state of the jaws 4, the jaws 4 rotate around the output axis K via the jaw rotating mechanism 30.

[0079] In ST109, the push operation state of the operating member 6 while the electric motor 20 is rotating in reverse is determined. If the push operation of the operating member 6 is not confirmed in ST109, the control flow returns to ST110. Therefore, when the electric motor 20 continues to rotate in reverse and the output shaft 27 returns to the initial position, the electric motor 20 stops. The user operation stops, and the control flow returns to the standby state ST100.

[0080] When the push operation state of the operating member 6 is confirmed in ST109, the control flow returns to ST102. In ST102, the initial position of the output shaft 27 is confirmed by the ON signal of the initial position sensor 47. When the output shaft 27 has reached the initial position and the closed state of the plurality of claws 4 is confirmed, the electric motor 20 is switched to forward rotation again in ST104. This starts the second opening movement of the claws 4. Thereafter, under the condition that the push operation of the operating member 6 is confirmed in ST105, the electric motor 20 is rotated forward until the output shaft 27 reaches the final end position in ST106 to open the claws 4 again. Under the condition that the pushing operation of the operating member 6 is confirmed in ST109, the electric motor 20 rotates reversely until the output shaft 27 reaches the initial position in ST102 to close the claws 4.

[0081] In this way, the opening movements of the plurality of claws 4 are repeated, and the number of executed times p is incremented by one each time. It is confirmed in ST120 that the number of executed times p has reached the specified number of times P (p = P) via ST107. When p = P is confirmed in ST120, the electric motor 20 is switched to reverse rotation to move the output shaft 27 back in ST121. This causes the claws 4 to close while rotating around the output axis K.

[0082] In a state where the electric motor 20 is rotating in reverse (the final stage of the specified number of times P) in ST121, unlike the reverse rotation state in ST108 (intermediate state of the specified number of times P), the pushing operation of the operating member 6 is not confirmed. In the reverse rotation state in ST121, even while the operating member 6 is being operated, the electric motor 20 continues to rotate in reverse to return the output shaft 27 to the initial position, and then the motor 20 is stopped.

[0083] When the initial position of the output shaft 27 is confirmed in ST122 and the closed state of the plurality of claws 4 is confirmed, the electric motor 20 is stopped in ST123. Then, in ST124, the pressing operation of the operating member 6 is released, and the sequence of control operations is terminated.

[0084] As described above, in this embodiment, the forward and reverse rotation of the electric motor 20 is switched to cause the output shaft 27 to reciprocate between the initial position and the final end position multiple times. This allows the opening and closing movement of the claws 4 to be repeated while the operating member 6 is pressed and held once. Consequently, the workload for the user can be reduced.

[0085] According to the embodiment, the initial position and the final end position of the output shaft 27 (threaded shaft) are detected by the initial position sensor 47 and the final end position sensor 48, respectively. This ensures the fast and reliable execution of the reciprocating movements of the output shaft 27.

[0086] According to the embodiment, the electric motor 20 rotates in reverse (ST110, ST111) to allow the output shaft 27 (threaded shaft) to return to its initial position after the pushing operation of the operating member 6 (operating member) is released. Therefore, when the operation of the operating member 6 is released in the middle of the specified number of times P, the output shaft 27 is returned to the initial position to reliably return the claws 4 to the closed position. This allows the next operation to be performed quickly.

[0087] According to the embodiment, for example, if the output shaft 27 is not in the initial position when the pushing operation of the operating member 6 is started, the electric motor 20 rotates in reverse once to return the output shaft 27 to the initial position. This prevents the output shaft 27 from moving forward from an intermediate position. Consequently, the jaw opening movement is not performed from a half-open position, but is always started from the closed position. Therefore, the diameter expansion operation can be performed efficiently.

[0088] According to the embodiment, the number of reciprocating movements p of the output shaft 27 between the initial position and the final end position is counted during the pushing movement of the operating member 6. When the number of reciprocating movements p reaches the predetermined number of times P, the electric motor 20 stops rotating. Therefore, even during the pushing operation of the operating member 6, the electric motor 20 automatically stops when the opening movements of the claws 4 have been performed for the predetermined number of times P. This allows the correct diameter expansion operation to be performed quickly.

[0089] According to the embodiment, when the number of reciprocating movements of the output shaft 27 reaches the predetermined number of times P (ST120), the electric motor 20 rotates reversely (ST121) to stop the output shaft 27 at its initial position. After the output shaft 27 returns to the initial position (ST122), the electric motor 20 stops (ST123). Thus, after the opening movements of the plurality of claws 4 are performed for the predetermined number of times P, the electric motor 20 automatically stops after the output shaft 27 returns to its initial position. This allows the next diameter-expanding operation to be started quickly.

[0090] According to the embodiment, the initial position and the final end position of the output shaft 27 are detected by Hall IC sensors (initial position sensor 47 and final end position sensor 48). Therefore, the accuracy and compactness of the detection means for detecting the initial position and the final end position of the output shaft 27 are ensured.

[0091] According to the embodiment, the pipe expansion tool 1 includes a feed screw mechanism 25 (ball screw) with balls 27b interposed between the output shaft 27 (threaded shaft) and the nut 26 (internally threaded component). Therefore, the output shaft 27 can be smoothly threadedly coupled to the nut 26 without rattling. Consequently, the output shaft 27 can reciprocate precisely and smoothly.

[0092] As described above, the pipe expansion tool 1 for expanding the end of a fluid pipe made of synthetic resin has a motor shaft 20a driven by an electric motor 20 as shown in Fig. 12. The pipe expansion tool 1 includes a feed screw mechanism (power conversion mechanism) 25 that converts the rotation of the motor shaft 20a into a back-and-forth movement of the output shaft 27. The pipe expansion tool 1 includes a plurality of claws 4 that are pressed by a key 3 provided at the front of the output shaft 27 to mutually open them radially outward. The pipe expansion tool 1 includes a shaft 31 that rotates about an axis in conjunction with the rotation of the motor shaft 20a, and a claw rotating mechanism 30 that rotates the plurality of claws 4 about an axis through the shaft 31. The output shaft 27, the motor shaft 20a, and the shaft 31 of the claw rotating mechanism 30 are arranged parallel to each other and overlap each other in the front-and-back direction.

[0093] Therefore, by arranging the output shaft 27, the motor shaft 20a, and the shaft 31 of the claw rotating mechanism 30 to overlap in the front-back direction, the pipe expansion tool 1 can be provided in a compact manner in the front-back direction. Furthermore, the output shaft 27, the motor shaft 20a, and the shaft 31 are arranged parallel to each other. Therefore, the pipe expansion tool 1 can be provided in a compact manner in the up-down direction or in the left-right direction that intersects the front-back direction.

[0094] As in Fig. 12 and Fig. As shown in Figure 14, the shaft 31 of the claw rotating mechanism 30 and the electric motor 20 are arranged such that 80% or more of their respective axial lengths overlap the output shaft 27 at the rear end position in the front-to-rear direction. Therefore, the protrusion amount of the shaft 31 of the claw rotating mechanism 30 and the electric motor 20 in the front-to-rear direction relative to the output shaft 27 is reduced, especially in the protrusion rearward relative to the output shaft 27 at the rear end position. This enables the pipe expansion tool 1 to achieve greater compactness in the front-to-rear direction.

[0095] As in Fig. 12 and Fig. As shown in Figure 14, the shaft 31 of the claw rotating mechanism 30 and the electric motor 20 are arranged to overlap the output shaft 27 in the rear end position in the front-to-rear direction with their respective total axial lengths. Therefore, the shaft 31 of the claw rotating mechanism 30 and the electric motor 20 do not protrude in the front-to-rear direction relative to the output shaft 27 in the rear end position. This further improves the compactness of the pipe expanding tool 1 in the front-to-rear direction.

[0096] As in Fig. As shown in Figure 12, the pipe expansion tool 1 includes a planetary reduction mechanism (transmission mechanism) 22 that changes the rotational output of the motor shaft 20a. The pipe expansion tool 1 includes the idler gear 24 provided between the planetary reduction mechanism 22 and the feed screw mechanism 25. The planetary reduction mechanism 22 can be arranged to overlap with the feed screw mechanism 25 in the front-to-back direction by interposing the idler gear 24 therebetween. The electric motor 20, which is provided near the planetary reduction mechanism 22, can be installed closer to the feed screw mechanism 25. This arrangement makes it possible to provide the pipe expansion tool 1 in a compact manner in a front-to-back direction.

[0097] As in Fig. As shown in Figure 13, the output shaft 27 and the motor shaft 20a are offset in the up-down direction, which is perpendicular to the front-back direction. The claw rotating mechanism 30 is located between the output shaft 27 and the motor shaft 20a in the up-down direction when viewed in the axial direction of the output shaft 27. The output shaft 27, the claw rotating mechanism 30, and the electric motor 20 can be compactly arranged not only in the front-back direction, but also in the up-down direction perpendicular to the front-back direction. This arrangement prevents the pipe expansion tool 1 from being elongated in the up-down direction.

[0098] As in Fig. As shown in Figure 13, the claw rotating mechanism 30 is arranged offset with respect to an imaginary plane S containing both the motor shaft 20a and the output shaft 27. Therefore, the output shaft 27, the claw rotating mechanism 30, and the electric motor 20 can be arranged compactly in the up-down direction in which the imaginary plane S extends, on which the motor shaft 20a and the output shaft 27 are aligned. This makes it possible to provide the pipe expansion tool 1 in a compact manner in the up-down direction.

[0099] As in Fig. 11 and Fig. 14, the claw rotating mechanism 30 has a one-way clutch 42. The one-way clutch 42 rotates in conjunction with the first rotation R1 (see Fig. 8) of the shaft 31 for rotating the plurality of claws 4, but does not rotate in conjunction with the second rotation R2 (see Fig. 7), which is opposite to the first rotation R1 of the shaft 31. The shaft 31 of the claw rotating mechanism 30 includes a rear shaft 33 and a front shaft 32 threadedly coupled to the front portion of the rear shaft 33. The shaft 31 of the claw rotating mechanism 30 is separable into the rear shaft 33 and the front shaft 32. The rear shaft is mounted in an assembly 35 for rotating the shaft 31. The front shaft 32 is mounted in the tool body 10 for transmitting the rotational drive of the shaft 31 to the plurality of claws 4. The tool body 10 on the front shaft 32 side and the assembly 35 on the rear shaft 33 side are separately assembled. The front shaft 32 and the rear shaft 33 are screwed together to connect in the front-to-back direction. This configuration improves the mountability of shaft 31.

[0100] As in Fig. 14 and Fig. 15, the front shaft 32 is threadedly coupled such that it rotates in the direction of the first rotation R1 (see Fig. 8) with respect to the rear shaft 33. Therefore, when the front shaft 32 performs the first rotation R1, a torque is transmitted from the front shaft 32 to the plurality of claws 4 via the one-way clutch 42, and the torque acts in the direction in which the rear shaft 33 is fixed relative to the front shaft 32. Therefore, the fixing force between the rear shaft 33 and the front shaft 32 becomes stronger. On the other hand, when the front shaft 32 performs the second rotation R2 (see Fig. 7), the torque transmitted from the front shaft 32 to the claws 4 is small. Therefore, the front shaft 32 rotates freely and performs the second rotation R2 largely without resistance. The rear shaft 33 rotates in the direction in which it is loosened with respect to the front shaft 32, but since no resistance is exerted on the front shaft 32, it therefore rotates without releasing the fastening force with the front shaft 32. Thus, the operation of the claw rotating mechanism 30 prevents loosening of the threaded connection of the front shaft 32 and the rear shaft 33.

[0101] As in Fig. As shown in Figure 12, the power conversion mechanism is a feed screw mechanism 25 equipped with an external thread 27a provided around the outer periphery of the output shaft 27 and a nut 26 into which the external thread 27a is threaded. Therefore, the feed screw mechanism 25 can be installed around the axis of the output shaft 27. This can prevent the feed screw mechanism 25 from protruding from the output shaft 27 in the front-to-back direction. This allows the pipe expansion tool 1 to be provided in a compact manner in the front-to-back direction.

[0102] As in Fig. As shown in Figure 12, the pipe expansion tool 1 includes a handle 5 extending in a direction intersecting an axial direction of the output shaft 27. At least a portion of the nut 26 of the feed screw mechanism 25 and at least a portion of the electric motor 20 overlap with the handle 5 in the front-to-back direction. Therefore, when a user grasps the handle 5 to store the pipe expansion tool 1, the nut 26 of the feed screw mechanism 25 and the electric motor 20 can be positioned near the center of storage. This enables good weight balance of the pipe expansion tool 1 in the front-to-back direction.

[0103] The pipe expansion tool 1 according to the present embodiment described above can be modified in various ways. The pipe expansion tool 1 with six jaws 4 was described as an example. Instead, the pipe expansion tool 1 may have, for example, five or fewer or seven or more jaws 4.

[0104] A configuration has been described as an example in which the shaft 31 of the claw rotating mechanism 30 and the electric motor 20 overlap the output shaft 27 at the rear end position over the entire length in the front-to-back direction. Alternatively, the shaft 31 of the claw rotating mechanism 30 and the electric motor 20 may overlap with respect to the output shaft 27 at the rear end position, for example, by 80% or 90% of the total length in the front-to-back direction. A configuration has been described as an example in which the shaft axis L is offset from the left side of the imaginary plane S including the motor axis J and the output axis K. Instead, the shaft axis L may be offset from the right side of the imaginary plane S including the motor axis J and the output axis K. The imaginary plane S including the motor axis J and the output axis K may extend at an angle with respect to the up-down direction.A configuration has been described as an example in which the motor axis J, the output axis K, and the shaft axis L are parallel to each other. Alternatively, a configuration in which the motor axis J and the output axis K, the output axis K and the shaft axis L, the motor axis J and the shaft axis L, or a combination thereof are inclined to each other may be included. The inclination angle of the mutually inclined axes may be, for example, 5° or less, or 10° or less.

[0105] The claw rotating mechanism 30 for rotating the plurality of claws 4 in a clockwise direction when viewed from the front side has been described as an example. Alternatively, the claw rotating mechanism 30 may be configured to rotate the plurality of claws 4 in a counterclockwise direction when viewed from the front side. In this case, the rotation direction of the front shaft 32, in which the one-way clutch 42 transmits the power to the drive-side gear 43, is the counterclockwise direction (the direction of the second rotation R2 shown in Fig. 7) when viewed from the front. The external thread 33a and the internal thread 32a are provided to fix the rear shaft 33 to the front shaft 32 when the rear shaft 33 rotates in the second rotation direction R2.

[0106] A configuration has been described as an example in which the external thread 33a is provided at the front end of the rear shaft 33, and the internal thread 32a is provided at the rear end of the front shaft 32 so as to be threadably coupled with the external thread 33a. Alternatively, an internal thread 32a may be provided at the rear end of the front shaft 32, and an external thread 33a may be provided at the front end of the rear shaft 33 so as to be threadably coupled with the internal thread 32a.

[0107] A feed screw mechanism 25, referred to as a ball screw mechanism, has been described as an example in which the balls 27b are interposed between the external thread 27a of the output shaft 27 and the internal thread 26b of the nut 26. Instead, for example, it may be a slide screw mechanism in which the external thread 27a and the internal thread 26b are directly thread-coupled to each other without interposing a ball.

[0108] According to one embodiment, both the initial position and the final end position of the output shaft 27 (threaded shaft) are detected by the Hall IC sensor. Alternatively, only one of the initial position and the final end position may be detected by the sensor.

[0109] According to one embodiment, the rotational speed of the electric motor 20 is detected by the rotational speed detection sensor 20d. The initial position and the final end position of the output shaft 27 may be configured to be detected based on the rotational speed of the electric motor 20 detected by the rotational speed detection sensor 20d, as an alternative to the Hall IC sensor. In this case, it may be configured such that one or both of the initial position and the final end position are detected by a rotational speed detection circuit of the electric motor 20. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 9 862 137 [0003, 0005]

Claims

[1] Pipe expansion tool for expanding one end of a fluid pipe made of synthetic resin, with a motor shaft rotated by an electric motor, a power conversion mechanism configured to convert the rotation of the motor shaft into a front-to-back movement of an output shaft, a plurality of claws configured to mutually open radially outward when pressed by a wedge provided at a front portion of the output shaft, and a claw rotating mechanism having a shaft configured to rotate on an axis in conjunction with rotation of the motor shaft, the shaft causing the plurality of claws to rotate on an axis, in which the output shaft, the motor shaft and the shaft of the claw rotating mechanism are arranged parallel to each other and overlap with each other in a front-to-back direction. [2] A pipe expansion tool according to claim 1, wherein the shaft of the claw rotating mechanism and the electric motor are arranged such that, in the front-to-back direction, 80% or more of their respective axial lengths overlap with the output shaft located at a rear end position. [3] A pipe expansion tool according to claim 2, wherein the shaft of the claw rotating mechanism and the electric motor are arranged to overlap, in the front-to-back direction, the output shaft located at a rear end position with their respective entire axial lengths. [4] Pipe expansion tool according to one of claims 1 to 3, further comprising a transmission mechanism configured to change a rotational output of the motor shaft, and an idle gear provided between the transmission mechanism and the power conversion mechanism. [5] Pipe expansion tool according to claim 4, wherein the output shaft and the motor shaft are offset in an up-down direction perpendicular to the front-back direction, and the claw rotating mechanism is located between the output shaft and the motor shaft in the up-down direction when viewed in an axial direction of the output shaft. [6] A pipe expansion tool according to claim 5, wherein the claw rotating mechanism is arranged offset with respect to an imaginary plane including both the motor shaft and the output shaft. [7] Pipe expansion tool according to one of claims 1 to 6, wherein the claw rotating mechanism comprises a one-way clutch, the one-way clutch is configured to rotate in conjunction with a first rotation of the shaft to rotate the plurality of claws, the one-way clutch is configured such that it does not rotate in conjunction with a second rotation opposite to the first rotation of the shaft, and the shaft of the claw rotating mechanism has a rear shaft and a front shaft threadedly coupled to a front portion of the rear shaft. [8] A pipe expansion tool according to claim 7, wherein the front shaft is threadedly coupled to be fixed in a direction of first rotation with respect to the rear shaft. [9] A pipe expansion tool according to any one of claims 1 to 8, wherein the power conversion mechanism is a feed screw mechanism having an external thread provided around an outer periphery of the output shaft and a nut into which the external thread is inserted. [10] The pipe expansion tool according to claim 9, further comprising a handle extending in a direction crossing an axial direction of the output shaft, wherein at least a part of the nut of the feed screw mechanism and at least a part of the electric motor overlap the handle in the front-to-back direction. [11] Pipe expansion tool according to claim 1, wherein the power conversion mechanism has an internally threaded component, the output shaft is a threaded shaft, the internally threaded component is configured to rotate forward in response to forward rotation of the electric motor and to rotate reversely in response to reverse rotation of the electric motor, and the threaded shaft is thread-coupled to the internally threaded member and is configured to move forward from an initial position to a final end position in response to forward rotation of the internally threaded member and to move rearward from the final end position to the initial position in response to reverse rotation of the internally threaded member. [12] Pipe expansion tool according to claim 11, further comprising an actuating component configured to start the electric motor, and a controller configured to allow the electric motor to rotate forward and backward repeatedly during actuation of the actuating member to repeatedly open the plurality of jaws. [13] The pipe expansion tool according to claim 12, further comprising a detecting means configured to detect at least one of the initial position and the final end position of the threaded shaft. [14] The pipe expansion tool of claim 13, further comprising a detecting means configured to detect both the initial position and the final end position. [15] A pipe expansion tool according to any one of claims 12 to 14, wherein the controller is configured to rotate the electric motor reversely after stopping the actuation of the actuating member to return the threaded shaft to the initial position. [16] A pipe expansion tool according to any one of claims 12 to 15, wherein the controller is configured to rotate the electric motor reversely to return the threaded shaft to the initial position when the actuation of the actuating member begins and the threaded shaft is not in the initial position. [17] A pipe expansion tool according to any one of claims 12 to 16, wherein the controller is configured to count a number of reciprocating movements of the threaded shaft between the initial position and the final end position during the actuation of the actuating member, and wherein the controller stops the electric motor from rotating when the number of reciprocating movements reaches a predetermined number of times. [18] The pipe expansion tool of claim 17, wherein the controller is configured to calculate the number of reciprocating movements based on a rotational speed of the electric motor. [19] A pipe expansion tool according to claim 13 or 14, wherein the detecting means is a Hall IC sensor. [20] A pipe expansion tool according to claim 13 or 14, wherein the detecting means is a detecting circuit configured to detect a position of the threaded shaft based on a rotational speed of the electric motor.

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