Rotary tool

Abstract

The present invention enables rotary tools to have an extended operating life, consume less power, and be more compact. This rotary tool is provided with a first urging portion that is in point contact or line contact with a clutch portion and that is capable of urging the clutch portion toward a rear end.

Description

rotary tools

[0001] The present disclosure relates to rotary tools.

[0002] Japanese Patent Application Laid-Open No. 2009-102663 discloses a rotary tool including a drive unit that generates a first rotational driving force, a grip unit that receives an input of a second rotational driving force, a tip unit, a switching unit, and a torque management unit. The switching unit switches between a first mode in which the first rotational driving force is transmitted from the drive unit to the tip unit and a second mode in which the second rotational driving force is transmitted from the grip unit to the tip unit. In the second mode, the torque management unit is interposed in a transmission path of the second rotational driving force and limits transmission of the second rotational driving force to the tip unit when the second rotational driving force exceeds a predetermined magnitude.

[0003] Japanese Patent Publication No. 2021-10958

[0004] a drive unit configured to generate a first rotational driving force for rotating the tip unit; a grip unit configured to receive an input of a second rotational driving force for rotating the tip unit and positioned closer to the rear end than the tip unit; a switching unit configured to switch between a first mode in which the first rotational driving force is transmitted from the drive unit to the tip unit and a second mode in which the second rotational driving force is transmitted from the grip unit to the tip unit; a clutch unit configured to, in the second mode, limit the transmission of the second rotational driving force to the tip unit when the second rotational driving force exceeds a predetermined magnitude; and a first biasing unit configured to be in point contact or line contact with the clutch unit and to bias the clutch unit toward the rear end.

[0005] FIG. 1 is a cross-sectional view showing a schematic configuration of a rotary tool according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view taken along V-V in FIG. 1 of the rotary tool according to an embodiment of the present disclosure. FIG. 3 is an exploded perspective view and a perspective view of a switching unit. FIG. 4 is a view explaining an operation mechanism of the switching unit in a first mode. FIG. 5 is a view explaining an operation mechanism of the switching unit in a second mode. FIG. 6 is a cross-sectional view taken along VI-VI in FIG. 1 of the rotary tool according to an embodiment of the present disclosure. FIG. 7 is a cross-sectional view taken along VII-VII in FIG. 1 of the rotary tool according to an embodiment of the present disclosure. FIG. 8 is a cross-sectional view explaining an operation mechanism of the rotary tool in the first mode. FIG. 9 is a view explaining an operation mechanism of the rotary tool at the time of transition to idling. FIG. 10 is a cross-sectional view of a rotary tool according to another embodiment.

[0006] As disclosed in Patent Document 1, there is a rotary tool that has a first mode in which the tip portion is rotated electrically and a second mode in which the tip portion is rotated manually.

[0007] According to one aspect of the present disclosure, it is possible to achieve a longer life, lower power consumption, and smaller size.

[0008] 1 is a cross-sectional view showing a schematic configuration of a rotary tool 101 according to an embodiment of the present disclosure (hereinafter also referred to as the present embodiment). The cross section of FIG. 1 passes through an axis A and is parallel to the axis A.

[0009] The rotary tool 101 may have a shape extending from the tip to the rear end along the axis A. An example of such a shape is a rod shape. The rotary tool 101 may include a tip portion 1, a drive unit 2, a grip portion 3, a switching portion 4, a clutch portion 5, a first biasing portion 6, a second biasing portion 7, a control member 9, and a housing portion 10. The clutch portion 5 may include a first member 11 and a second member 12. The first biasing portion 6 may include a first contact member 13 and a biasing structure 8. The second biasing portion 7 may include a second contact member 68 and a third member 69. The first contact member 13 may correspond to a contact member described in the claims. The rotary tool 101 may also include a housing 54, and the drive unit 2, the switching portion 4, the clutch portion 5, the first biasing portion 6, the second biasing portion 7, and the control member 9 may be located inside the housing 54.

[0010] The tip portion 1 is located on the tip side. The tip portion 1 is a portion that comes into contact with a screw, for example, when performing an operation of fastening or loosening a screw. The tip portion 1 is rotatable around an axis A. The axis A may be located at the center of the rotary tool 101 when viewed in the longitudinal direction of the rotary tool 101.

[0011] The drive unit 2 generates a first rotational drive force for rotating the tip portion 1. The first rotational drive force may be a mechanical and / or electrical drive force generated by at least one component provided in the drive unit 2. As the at least one component, the drive unit 2 may have a battery cell 51, a motor 52 that operates using the battery cell 51 as a power source, and a gear unit 53 that transmits the force generated by the motor 52.

[0012] The grip portion 3 receives an input of a second rotational driving force for rotating the tip portion 1. The grip portion 3 is located closer to the rear end than the tip portion 1. The grip portion 3 may receive an input of the second rotational driving force from outside the rotary tool 101. The second rotational driving force may be a driving force generated when a user of the rotary tool 101 grips the grip portion 3 and manually turns the rotary tool 101.

[0013] In the embodiment of the present disclosure, the first rotational driving force is an electric driving force generated by the motor 52 or the like, and the second rotational driving force is a driving force generated by manually rotating the rotary tool 101. Therefore, in the first mode in which the first rotational driving force is transmitted from the drive unit 2 to the tip end portion 1, the tip end portion 1 rotates automatically. In the second mode in which the second rotational driving force is transmitted from the grip unit 3 to the tip end portion 1, the tip end portion 1 rotates manually.

[0014] The switching unit 4 switches between a first mode in which a first rotational driving force is transmitted from the driving unit 2 to the tip portion 1 and a second mode in which a second rotational driving force is transmitted from the gripping unit 3 to the tip portion 1 .

[0015] Fig. 2 is a cross-sectional view of the rotary tool 101 according to the embodiment of the present disclosure taken along line VV in Fig. 1. Fig. 2 is a cross-section perpendicular to the axis A. Fig. 3 is an exploded perspective view and a perspective view of the switching unit 4. In Fig. 3, the exploded perspective view of the switching unit 4 is denoted by reference numeral 1001, and the perspective view of the switching unit 4 is denoted by reference numeral 1002.

[0016] The switching unit 4 has a carrier 64, a lock pin 65, a lock cam 66, and a lock ring 67. The carrier 64 transmits driving force mainly in the first mode. The lock pin 65 is fitted into the carrier 64. The lock cam 66 is fitted into the carrier 64 and transmits driving force mainly in the second mode. The carrier 64 is fitted into the lock ring 67.

[0017] 4 is a diagram illustrating the operation mechanism of the switching unit 4 in the first mode. This operation mechanism has a first stage and a second stage, and the diagram showing the first stage is given the reference numeral 1003, and the diagram showing the second stage is given the reference numeral 1004.

[0018] In the first mode, the switching unit 4 performs the following operation. In the first stage, when the motor 52 rotates, the carrier 64 begins to rotate in direction D1 around the axis A. In the second stage, the carrier 64 and the lock pin 65 come into contact with each other at contact point C1, and at almost the same time, the carrier 64 and the lock cam 66 come into contact with each other at contact point C2. As a result, the positional relationship between the lock pin 65 and the lock cam 66 does not change, and the lock cam 66 rotates around the axis A.

[0019] 5 is a diagram illustrating the operation mechanism of the switching unit 4 in the second mode. This operation mechanism has a first stage, a second stage, and a third stage, and the diagram showing the first stage is given the reference numeral 1005, the diagram showing the second stage is given the reference numeral 1006, and the diagram showing the third stage is given the reference numeral 1007.

[0020] In the second mode, the switching unit 4 performs the following operations. In the first stage, the carrier 64, lock pin 65, lock cam 66, and lock ring 67 rotate in direction D2 around axis A. In the second stage, the carrier 64, lock pin 65, and lock ring 67 continue to rotate in direction D2. Meanwhile, the lock cam 66 is less likely to rotate in direction D2 than the carrier 64, lock pin 65, and lock ring 67 due to, for example, resistance from screw tightening. As a result, the carrier 64 and lock cam 66 come into contact at contact point C3, making it difficult for the carrier 64 to rotate. When the resistance from the lock cam 66 exceeds a certain level, the carrier 64 and lock ring 67 no longer rotate. In the third stage, the lock pin 65 and lock cam 66 interfere with each other at interference points F1 and F2. As a result, the carrier 64, lock pin 65, and lock cam 66 rotate together around axis A or are unable to rotate relative to each other.

[0021] Note that Fig. 10 is a cross-sectional view of a rotary tool according to another embodiment. More specifically, it is a cross-sectional view taken at the same position as the V-V cross section in Fig. 1. In the rotary tool according to the another embodiment, a lock pin 65 is located on each side of each carrier 64. More specifically, two lock pins 65 are arranged adjacent to each other for one carrier 64. For example, in the second stage of the second mode, the rotary tool 101 according to the embodiment of the present disclosure shown in Fig. 4 transmits force by direct contact between the carrier 64 and the lock cam 66 at contact point C3, whereas in the rotary tool according to the another embodiment, the carrier 64 and the lock cam 66 transmit force via the lock pin 65.

[0022] In the rotary tool 101 according to the embodiment of the present disclosure, each lock pin 65 contributes to the transmission of force from the lock ring 67 to the lock cam 66 in the first stage, and contributes to the transmission of force from the lock cam 66 to the carrier 64 in the third stage. In such a case, since each lock pin 65 functions in both the first stage and the third stage, the number of lock pins 65 is reduced compared to the rotary tool according to another embodiment. On the other hand, in the rotary tool according to another embodiment, the lock pin 65 (first lock pin 65A) located adjacent to the carrier 64 on the side opposite to the direction D2 contributes to the transmission of force from the lock ring 67 to the lock cam 66 in the first stage, and the lock pin 65 (second lock pin 65B) located adjacent to the carrier 64 on the side of the direction D2 contributes to the transmission of force from the lock cam 66 to the carrier 64 in the third stage. In such a case, in a rotary tool according to another embodiment, the first lock pin 65A functions in different stages, such as the first stage, and the second lock pin 65B functions in the third stage. Therefore, the movement distance of the lock pin 65 when transitioning to each stage is shorter than in the rotary tool according to this embodiment, and as a result, the efficiency of force transmission via the lock pin 65 is likely to be improved.

[0023] The clutch unit 5 is interposed in the transmission path of the second rotational driving force in the second mode. The clutch unit 5 may be interposed in the transmission path of the first rotational driving force in the first mode. The clutch unit 5 limits the transmission of the second rotational driving force to the tip end portion 1 when the second rotational driving force exceeds a predetermined magnitude. The clutch unit 5 may limit the transmission of the first rotational driving force to the tip end portion 1 when the first rotational driving force exceeds a predetermined magnitude.

[0024] In an embodiment of the present disclosure, the first member 11 and the second member 12 may be interposed in a transmission path of the first rotational driving force and / or the second driving force. The first member 11 and the second member 12 may each have a generally disk-shaped bottom and a generally columnar or cylindrical protrusion protruding from the center of the bottom. The first member 11 and the second member 12 are located inside a housing 54 of the rotary tool 101. In an embodiment of the present disclosure, the housing 54 has a grip portion 3 and a case portion 10. The first member 11 and the second member 12 are located in this order from the tip side along the axis A. The tip portion 1 can rotate in conjunction with rotation of the first member 11 and / or the second member 12 about the axis A.

[0025] The first urging portion 6 is in point or line contact with the clutch portion 5. The first urging portion 6 can urge the clutch portion 5 toward the rear end. That is, the first urging portion 6 urges the clutch portion 5 toward the rear end by urging the first member 11 from the tip side in a point or line. The number of points or lines at which the first urging portion 6 contacts the clutch portion 5 is not limited to one and may be two or more. The clutch portion 5 may have a washer 55 located between the first urging portion 6 and the first member 11. In this case, the first urging portion 6 is in point or line contact with the washer 55. In the first urging portion 6, the first contact member 13 may be in point or line contact with the clutch portion 5.

[0026] An example of the first biasing portion 6 that comes into point contact with the clutch portion 5 is one that includes a thrust bearing or at least one steel ball. A first biasing portion 6 that includes a thrust bearing is easier to assemble than a first biasing portion 6 that includes at least one steel ball, because rolling elements such as balls are located in a cage. An example of the first biasing portion 6 that comes into line contact with the clutch portion 5 is one that includes a needle bearing. Because a needle bearing has a shorter length in the direction of extension of the axis A than both a thrust bearing and a steel ball, the length of the first biasing portion 6 that includes a needle bearing can be reduced in the direction of extension of the axis A of the rotary tool 101.

[0027] The "point contact" in this embodiment is not limited to point contact in the strict sense. The "point contact" in this embodiment may be point contact from a macroscopic point of view, and for example, it is sufficient that at least one of the contact portion of the clutch portion 5 with the first biasing portion 6 and the contact portion of the first biasing portion 6 with the clutch portion 5 is a sphere and they are in contact with each other. A slight surface contact from a microscopic point of view caused by deformation due to friction or the like occurring between the clutch portion 5 and the first biasing portion 6 is allowed as the "point contact" in this embodiment.

[0028] Similarly, "line contact" in this embodiment is not limited to line contact in the strict sense. "Line contact" in this embodiment may be line contact from a macroscopic perspective, and for example, it is sufficient that at least one of the contact portion of the clutch portion 5 with the first urging portion 6 and the contact portion of the first urging portion 6 with the clutch portion 5 is cylindrical and they are in contact with each other. Slight surface contact from a microscopic perspective due to deformation caused by friction or the like that occurs between the clutch portion 5 and the first urging portion 6 is permitted as "line contact" in this embodiment.

[0029] The clutch portion 5 may have a guide groove 73 at a portion that makes point or line contact with the first biasing portion 6. The guide groove 73 may guide the first contact member 13. More specifically, the guide groove 73 may guide the movement of the first contact member 13 in the circumferential direction. In an embodiment of the present disclosure, the guide groove 73 is formed circumferentially on a member (washer 55) that contacts the first contact member 13. In such a case, the first contact member 13 can be guided, reducing the risk of the first contact member 13 excessively shifting in the radial direction of a circle centered on the axis A. Furthermore, the radius of curvature of the recess of the guide groove 73 may be larger than the radius of curvature of the first contact member 13. In such a case, the resistance between the clutch portion 5 and the first biasing portion 6 is likely to be small. The radius of curvature of the recess of the guide groove 73 may be measured in a cross section that includes the recess and the axis A and is parallel to the axis A. For the guide groove 73, see also FIG. 9 , which will be described later.

[0030] The structure 59 and the first contact member 13 may be in point contact or line contact. The structure 59 may be, for example, annular in shape. In such a case, the resistance between the structure 59 and the first contact member 13 is reduced. The structure 59 may be provided with the above-described guide groove 73 at the portion that makes point contact or line contact with the first contact member 13.

[0031] The rotary tool 101 may be used to tighten the screw 102. The screw 102 is not particularly limited as long as it is intended for screwing, but an example of the screw 102 is a screw for fixing a cutting insert to a pocket of a cutting tool.

[0032] When using the rotary tool 101 to tighten the screw 102, the first mode and the second mode may be performed in this order. In the first mode, the tip 1 is rotated according to a first rotational driving force to tighten the screw 102. In the second mode, the tip 1 is rotated according to a second rotational driving force to further tighten the screw 102.

[0033] As the screw 102 is tightened in the second mode, a state in which the screw 102 is tightened to a predetermined tightness is reached. In this state, if the second rotational driving force is small enough that the clutch unit 5 does not restrict the transmission of the second rotational driving force to the tip end portion 1, the screw 102 stops the rotation of the rotary tool 101, preventing the rotary tool 101 from further tightening the screw 102. In this state, if the second rotational driving force is large enough that the clutch unit 5 restricts the transmission of the second rotational driving force to the tip end portion 1, excessive tightening of the screw 102 is avoided, resulting in idling, in which the gripping unit 3 rotates without rotating the tip end portion 1. The predetermined magnitude of the second rotational driving force, which controls whether the clutch unit 5 restricts the transmission of the second rotational driving force to the tip end portion 1, can be said to correspond to the boundary between whether idling occurs and whether idling occurs. The predetermined magnitude of the second rotational driving force may correspond to an inherent torque value of the rotary tool 101, or may correspond to a torque value adjusted by a torque management unit or the like, for example.

[0034] 6 is a cross-sectional view of the rotary tool 101 according to the embodiment of the present disclosure, taken along line VI-VI in FIG. 1. The first member 11 may have a plurality of balls 56 arranged in an annular shape at a position facing the second member 12. In the cross-section taken along line VI-VI in FIG. 1, the plurality of balls 56 may be, for example, six balls 56 arranged at 60° intervals. FIG. 6 is a cross-section perpendicular to the axis A.

[0035] 7 is a cross-sectional view of the rotary tool 101 according to the embodiment of the present disclosure, taken along line VII-VII in FIG. 1. The second member 12 may have a plurality of recesses 57 arranged in an annular shape at a position facing the first member 11. In the cross-section VII-VII in FIG. 1, the plurality of recesses 57 may be, for example, six recesses 57 arranged at 60° intervals. The plurality of balls 56 and the plurality of recesses 57 may be arranged such that one recess 57 faces one ball 56 at a time. The recess 57 may have a conical shape whose inner diameter decreases from the front end side to the rear end side.

[0036] 8 is a cross-sectional view illustrating the operating mechanism of the rotary tool 101 in the first mode. The first rotational driving force is transmitted in the order of the drive unit 2, the clutch unit 5, and the tip unit 1. In the first mode, the rotary tool 101 operates according to the following operating mechanism.

[0037] The ball 56 fits into the recess 57. This allows the first member 11 and the second member 12 to rotate integrally around the axis A; in other words, the second member 12 does not rotate around the axis A relative to the first member 11. Therefore, the clutch portion 5 can transmit the first rotational driving force to the tip end portion 1, which causes the tip end portion 1 to rotate around the axis A and tighten the screw 102.

[0038] In the first mode, whether the first member 11, the second member 12, the third member 69, the washer 55, the ball 56, the first contact member 13, the second contact member 68, the spring 58, and the housing 54 rotate around the axis A as seen by a user of the rotary tool 101 is summarized below. Here, whether the first member 11, the second member 12, the third member 69, the washer 55, the ball 56, the first contact member 13, the second contact member 68, the spring 58, and the housing 54 rotate around the axis A as seen by a user of the rotary tool 101 refers to whether each member rotates around the axis A relatively from the user's viewpoint, and does not necessarily mean that the user can actually confirm whether each member is rotating from outside the rotary tool 101. The same applies to the second mode, which will be described later.

[0039] (In the case of first mode) First member 11: rotates Second member 12: rotates Third member 69: does not rotate Washer 55: rotates Ball 56: rotates First contact member 13: rotates slightly or does not rotate Second contact member 68: rotates slightly or does not rotate Spring 58: does not rotate Housing 54: does not rotate The amount of rotation of the washer 55 may be less than the amount of rotation of the first member 11, or may be more than the amount of rotation of the first contact member 13. The amount of rotation means the number of rotations per unit time.

[0040] The operating mechanism of the rotary tool 101 in the second mode will be described. The second rotational driving force is transmitted in this order to the gripping portion 3, the gear unit 53, the clutch portion 5, and the tip portion 1. In the second mode, the rotary tool 101 operates according to the following operating mechanism.

[0041] In the second mode where no freewheeling occurs, the balls 56 remain fitted in the recesses 57, and the second member 12 does not rotate around the axis A relative to the first member 11. Therefore, the clutch portion 5 can transmit the second rotational driving force to the tip portion 1.

[0042] In the second mode where no freewheeling occurs, whether or not the rotary tool 101 rotates around the axis A as seen by the user is summarized below for each member.

[0043] (In the second mode where no freewheeling occurs) First member 11: rotates Second member 12: rotates Third member 69: rotates Washer 55: rotates Ball 56: rotates First contact member 13: rotates Second contact member 68: rotates Spring 58: rotates Housing 54: rotates The first member 11, second member 12, third member 69, washer 55, ball 56, first contact member 13, second contact member 68, spring 58, and housing 54 may rotate together.

[0044] Figure 9 is a diagram illustrating the operating mechanism of the rotary tool 101 during transition to idling. Figure 9 shows four cross sections taken along line VIII-VIII in Figure 6: a free state indicated by reference numeral 1008, a torque transmission state indicated by reference numeral 1009, a clutch actuation start state indicated by reference numeral 1010, and a transition state to the next clutch hole indicated by reference numeral 1011. From the start of transition to idling, the process progresses in the order of the free state, torque transmission state, clutch actuation start state, and the transition state to the next clutch hole, until the transition to idling is completed. Figure 9 is a cross section parallel to axis A.

[0045] When the second mode is selected and freewheeling occurs, the force that tends to rotate the second member 12 about the axis A relative to the first member 11 causes the ball 56 to come out of the recess 57, causing the second member 12 to rotate about the axis A relative to the first member 11. Therefore, it is difficult for the clutch portion 5 to transmit the second rotational driving force to the tip portion 1. The second biasing portion 7, the biasing structure 8, and the second member 12 rotate together with the gripping portion 3.

[0046] In the second mode in which idling occurs, whether or not the rotating tool 101 rotates around the axis A as seen by the user of the rotating tool 101 is summarized below for each member.

[0047] (When the rotary tool 101 is in the second mode and freewheeling occurs) First member 11: Does not rotate Second member 12: Rotates Third member 69: Rotates Washer 55: Does not rotate Ball 56: Does not rotate First contact member 13: Rotates slightly or does not rotate Second contact member 68: Rotates Spring 58: Rotates Housing 54: Rotates From the above, it can be seen that in the rotary tool 101, when freewheeling occurs, the second member 12 rotates around axis A relative to the first member 11 in response to the input of the second rotational driving force.

[0048] In both the first mode and the second mode, the first biasing portion 6 is in point contact or line contact with the clutch portion 5, and therefore the frictional force generated in the first biasing portion 6 is small.

[0049] According to the rotary tool 101, the contact area between the clutch portion 5 and the first biasing portion 6 is small, so that the frictional force generated in the first biasing portion 6 can be reduced, and the deterioration rate of the first biasing portion 6 can be slowed, thereby enabling a longer life. In addition, as the frictional force is reduced, the loss of the first rotational driving force in the first biasing portion 6 is small, so that the tip portion 1 can be sufficiently rotated with a small first rotational driving force, thereby enabling low power consumption of the rotary tool 101 and, in particular, miniaturization of the drive portion 2.

[0050] The second urging portion 7 is in point contact or line contact with the clutch portion 5. The second urging portion 7 is capable of urging the clutch portion 5 toward the tip. The number of points or lines at which the second urging portion 7 contacts the clutch portion 5 is not limited to one, and may be two or more. In the second urging portion 7, the second contact member 68 may play a role in making point contact or line contact with the clutch portion 5.

[0051] An example of the second urging portion 7 that comes into point contact with the clutch portion 5 is one that includes a thrust bearing or at least one steel ball. A second urging portion 7 that includes a thrust bearing is easier to assemble than a second urging portion 7 that includes at least one steel ball, because rolling elements such as balls are located in a cage. An example of the second urging portion 7 that comes into line contact with the clutch portion 5 is one that includes a needle bearing. Because a needle bearing has a shorter length in the direction of extension of the axis A than both a thrust bearing and a steel ball, the length of the first urging portion 6 that includes a needle bearing can be reduced in the direction of extension of the axis A of the rotary tool 101.

[0052] In both the first mode and the second mode, the second biasing portion 7 is in point contact or line contact with the clutch portion 5, and therefore the frictional force generated in the second biasing portion 7 is small.

[0053] According to the rotary tool 101, the contact area between the clutch portion 5 and the second urging portion 7 is small, so that the frictional force generated in the second urging portion 7 can be reduced, and the deterioration rate of the second urging portion 7 can be slowed, thereby enabling a longer life. In addition, as the frictional force is reduced, the loss of the first rotational driving force in the second urging portion 7 is small, so that the tip portion 1 can be sufficiently rotated with a small first rotational driving force, thereby enabling low power consumption of the rotary tool 101 and, in particular, miniaturization of the drive portion 2.

[0054] The first urging portion 6, the clutch portion 5, and the second urging portion 7 may be aligned on the same straight line substantially parallel to the axis A. This line corresponds to the straight line S shown in FIG. 1 . This reduces the risk of the first urging portion 6, the clutch portion 5, and the second urging portion 7 respectively slipping, thereby reducing the frictional forces associated with the first urging portion 6, the clutch portion 5, and the second urging portion 7. This further extends the life, reduces power consumption, and reduces the size of the rotary tool 101. "Substantially parallel to the axis A" does not necessarily mean being completely parallel to the axis A, but may also be slightly tilted relative to the axis A, specifically by about -5° to +5°, to an extent that the risk of slipping is sufficiently small.

[0055] The first contact member 13 is in point contact or line contact with the clutch portion 5. The biasing structure 8 biases the first contact member 13 from the tip side. The control member 9 is located closer to the rear end than the second biasing portion 7. The control member 9 is a member that can control the biasing force applied to the first contact member 13 by the biasing structure 8.

[0056] The biasing structure 8 may have a spring 58 and a structure 59 located between the first biasing portion 6 and the spring 58 to bias the first biasing portion 6 toward the rear end.

[0057] The control member 9 may have the following configuration. The outer wall of the control member 9 has a male thread portion 60, and the inner wall of the housing 54 (casing 10) has a female thread portion 61. The male thread portion 60 and the female thread portion 61 threadably engage the control member 9 and the housing 54 (casing 10). The control member 9 can be moved toward the distal end or the proximal end depending on the amount of tightening of the male thread portion 60 and the female thread portion 61. When the control member 9 is moved toward the distal end, the control member 9 presses the second biasing portion 7, the clutch portion 5, the first biasing portion 6, and the biasing structure 8 toward the distal end. This causes the spring 58 to compress, and the resulting reaction force increases the biasing force applied from the distal end to the multiple balls 56 fitted in the multiple recesses 57. This makes it difficult for the multiple balls 56 to come out of the multiple recesses 57. The greater the amount of movement of the control member 9 toward the distal end, the greater the second rotational driving force required to cause idling in the second mode.

[0058] The housing 10 is located closer to the tip than the grip 3. The housing 10 engages with the grip 3. In the housing 54, the grip 3 is located closer to the rear end, and the housing 10 is located closer to the tip. The grip 3 and the housing 10 may be screwed together. The housing 54 may be configured so that the male thread 62 of the housing 10 can be screwed into the female thread 63 of the grip 3.

[0059] The clutch portion 5 may be disposed in a transmission path of the first rotational driving force in the first mode. The first member 11 and the second member 12 may be arranged along the axis A.

[0060] In the second mode of this embodiment, the clutch unit 5 may be configured so that the clutch is activated during forward rotation and restricted during reverse rotation. This configuration will be described with reference to FIG.

[0061] 9, the rotation of the second member 12 in direction D3 is defined as forward rotation, and the rotation of the second member 12 in the direction opposite to direction D3 is defined as reverse rotation. In the cross-sectional view taken along line VIII-VIII in FIG. 6, the first member 11 may have a first wall portion 70 and a second wall portion 71 adjacent to the ball 56.

[0062] The first wall portion 70 may be located downstream of the ball 56 in the direction D3. The first wall portion 70 may have a shape that allows the ball 56 to be pushed out of the recess 57, and may be, for example, substantially parallel to the axis A. The second wall portion 71 may be located upstream of the ball 56 in the direction D3. The second wall portion 71 may have a shape that prevents the ball 56 from being pushed out of the recess 57, more specifically, a shape that allows the ball 56 to be held in the recess 57, and may be, for example, curved to fit the surface of the ball 56.

[0063] During forward rotation, the ball 56 comes into contact with the first wall portion 70, and then is pressed against the first wall portion 70, causing the ball 56 to be pushed out of the recess 57 by the first wall portion 70. This allows the rotary tool 101 to spin freely. Therefore, it can be said that the clutch portion 5 operates as a clutch during forward rotation.

[0064] During reverse rotation, after the ball 56 comes into contact with the second wall portion 71, the ball 56 adheres tightly to the second wall portion 71 and can move smoothly along the second wall portion 71, so the ball 56 is not pushed out of the recess 57 by the second wall portion 71. As a result, the rotary tool 101 cannot transition to idling. Therefore, it can be said that the clutch of the clutch portion 5 is restricted during reverse rotation.

[0065] Referring to FIG. 1 , the rotary tool 101 may have a screw 72. In other words, the clutch unit 5 may have the screw 72. The screw 72 may be fixed to the second member 12. When the reverse rotation force is large, the second wall portion 71 may ride up against the ball 56, which may cause the first member 11 to move excessively toward the tip. In order to reduce this risk, at least a portion of the screw 72 may be located closer to the tip than the first member 11. More specifically, the head of the screw 72 may be located closer to the tip than the first member 11.

[0066] On the other hand, when the first member 11 contacts the screw 72, frictional force may be generated between the first member 11 and the screw 72 (more specifically, the head of the screw 72), which may prevent the first member 11 from rotating smoothly. To reduce this risk, the portions of the first member 11 and the screw 72 facing each other may be spaced apart in the direction along the axis A. That is, the rotary tool 101 may have a gap between the portion of the first member 11 facing the screw 72. In this embodiment, the rotary tool 101 has a gap between the portion of the first member 11 on the tip side and the portion of the head of the screw 72 on the rear end side. This may eliminate or reduce frictional force between the first member 11 and the screw 72. Here, the width of the gap may be smaller than the thickness of the first member 11 in the direction along the axis A in order to reduce the risk of the first member 11 slipping toward the tip side. More specifically, the width of the gap may be smaller than the thickness of the first member 11 in the cross section shown in FIG. 9 .

[0067] Instead of the screw 72, a pin provided substantially perpendicular to the axis A may be used.

[0068] In the rotary tool 101, at least one of the first rotational driving force and the second rotational driving force may be transmitted from the grip portion 3 to the housing portion 10 via a light fit. Unlike press-fitting, light fit refers to a case where the shank 74 can be fitted into the hole 64 by hand, for example. In such a case, for example, an operator can attach a different type of tool tip (housing portion 10) to the grip portion 3 as needed. Examples of light fit include (1) a fit using a polygonal prism shank and a hole, and (2) a fit using a protrusion and a notch.

[0069] (1) In the Case of Fitting Using a Polygonal Pillar Shaft and Hole The switching unit 4 may have a polygonal prism-shaped shaft 74 on the grip unit 3 side. Furthermore, a fourth member 75 connecting the switching unit 4 and the second member 12 on the housing 10 side may have a polygonal hole 76 that can fit with the shaft 74. Alternatively, the switching unit 4 may have a polygonal hole 76, and the fourth member 75 may have a polygonal prism-shaped shaft 74 that can fit with the hole 76. While there are no particular limitations on the number of corners on the shaft 74 and the hole 76, a range of 3 to 8 is desirable from the perspective of force transmission. The corners may also be somewhat rounded. Accordingly, as shown in the perspective view of the switching unit 4 in FIG. 3 , the shape of the end face 77 on the tip side of the lock cam 66 may be polygonal, corresponding to the shaft 74 or the hole 76.

[0070] (2) In the Case of Fitting Using a Protrusion and a Cutout The switching unit 4 may have a shaft 74 on the grip unit 3 side. There is no particular limitation on the shape of the shaft 74 and it may be, for example, substantially cylindrical. The shaft 74 may have a protrusion that protrudes in a direction away from the axis A. The fourth member 75 connecting the switching unit 4 and the second member 12 on the housing 10 side may have a hole 76 into which the shaft 74 is inserted. There is no particular limitation on the shape of the hole 76 and it may be, for example, substantially circular. The hole 76 may have a notch at the end on the side where the shaft 74 is inserted and into which the protrusion is inserted. The notch may have a recessed shape recessed from the end on the side where the shaft 74 is inserted. The protrusion may transmit at least one of the first rotational driving force and the second rotational driving force to the housing 10 side via the notch. The switching portion 4 may have a hole 76 with a notch, and the fourth member 75 may have a shaft portion 74 with a protrusion.

[0071] The length in the direction of axis A of the portion where the shaft portion 74 faces the hole portion 76 may be greater than the length in the direction of axis A of the portion where the grip portion 3 and the housing portion 10 are engaged. In such a case, the shaft portion 74 is fitted into the hole portion 76 before the grip portion 3 and the housing portion 10 are engaged, making it easier for an operator to replace the housing portion 10 with respect to the grip portion 3. Furthermore, the length in the direction of axis A of the portion where the shaft portion 74 faces the hole portion 76 may be greater than the length in the direction of axis A of the male screw portion 62, and may be greater than the length in the direction of axis A of the female screw portion 63.

[0072] This means that the connection between the gripping portion 3 side and the housing portion 10 side is loose, and the power transmission unit can be connected between the gripping portion 3 side and the housing portion 10 side without tools, making it easy to attach and detach the housing portion 10 side.

[0073] (Summary) A rotary tool according to aspect 1 of the present disclosure is a rotary tool having a shape extending from a tip to a rear end along an axis, and comprising: a tip portion located on the tip side and rotatable around the axis; a drive portion that generates a first rotational driving force for rotating the tip portion; a grip portion that receives an input of a second rotational driving force for rotating the tip portion and is located on the rear end side of the tip portion; a switch portion that switches between a first mode in which the first rotational driving force is transmitted from the drive portion to the tip portion and a second mode in which the second rotational driving force is transmitted from the grip portion to the tip portion; a clutch portion that is interposed in a transmission path of the second rotational driving force in the second mode and that limits transmission of the second rotational driving force to the tip portion when the second rotational driving force exceeds a predetermined magnitude; and a first biasing portion that is in point contact or line contact with the clutch portion and is capable of biasing the clutch portion toward the rear end.

[0074] The rotary tool according to a second aspect of the present disclosure is the rotary tool of the first aspect, further including a second biasing portion that is in point contact or line contact with the clutch portion and is capable of biasing the clutch portion toward the tip end.

[0075] A rotary tool according to a third aspect of the present disclosure is the rotary tool of the second aspect, wherein the first biasing portion, the clutch portion, and the second biasing portion are aligned on the same straight line that is substantially parallel to the axis.

[0076] A rotary tool according to aspect 4 of the present disclosure is configured such that, in aspect 2 or 3, the first biasing portion has a contact member that makes point contact or line contact with the clutch portion and a biasing structure that biases the contact member from the tip side, and the rotary tool is provided with a control member that is located closer to the rear end than the second biasing portion and controls the biasing force applied to the contact member by the biasing structure.

[0077] A rotary tool according to a fifth aspect of the present disclosure is in any one of the first to fourth aspects, further comprising a housing portion located closer to the tip than the grip portion and engaging with the grip portion.

[0078] The rotary tool according to aspect 6 of the present disclosure is, in aspect 5, capable of transmitting at least one of the first rotational driving force and the second rotational driving force from the gripping portion side to the housing portion side via a light fitting.

[0079] A rotary tool according to a seventh aspect of the present disclosure is the rotary tool of any one of the first to sixth aspects, wherein the clutch portion is interposed in a transmission path of the first rotational driving force in the first mode.

[0080] A rotary tool according to an eighth aspect of the present disclosure is the rotary tool of any one of the first to seventh aspects, wherein the clutch portion has a first member and a second member arranged along the axis.

[0081] The invention according to the present disclosure has been described above based on the drawings and examples. However, the invention according to the present disclosure is not limited to the above-described embodiments. In other words, the invention according to the present disclosure can be modified in various ways within the scope of the present disclosure, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the invention according to the present disclosure. In other words, it should be noted that a person skilled in the art can easily make various modifications or corrections based on the present disclosure. It should also be noted that these modifications or corrections are included in the scope of the present disclosure.

[0082] REFERENCE SIGNS LIST 1 Tip portion 2 Drive portion 3 Grip portion 4 Switching portion 5 Clutch portion 6 First biasing portion 7 Second biasing portion 8 Biasing structure 9 Control member 10 Housing portion 11 First member 12 Second member 13 First contact member 101 Rotary tool 102 Screw A Axis S Straight line

Claims

1. A rotary tool having a shape that extends along the axis from the tip to the rear end, A tip portion located on the side of the aforementioned tip and rotatable around the shaft, A drive unit that generates a first rotational driving force for rotating the tip portion, A gripping portion located on the rear end side of the tip portion receives input of a second rotational driving force to rotate the tip portion, A switching unit that switches between a first mode in which the first rotational driving force is transmitted from the drive unit to the tip, and a second mode in which the second rotational driving force is transmitted from the gripping unit to the tip, In the second mode, a clutch unit interposed in the transmission path of the second rotational driving force is provided, which restricts the transmission of the second rotational driving force to the tip when the second rotational driving force exceeds a predetermined magnitude, A rotary tool comprising a first biasing portion that makes point or line contact with the clutch portion and is capable of biasing the clutch portion toward the rear end.

2. The rotary tool according to claim 1, further comprising a second biasing portion that makes point or line contact with the clutch portion and is capable of biasing the clutch portion toward the tip.

3. The rotary tool according to claim 2, wherein the first biasing portion, the clutch portion, and the second biasing portion are arranged on the same straight line substantially parallel to the shaft.

4. The first biasing portion comprises a contact member that makes point or line contact with the clutch portion, and a biasing structure that biases the contact member from the tip side, The rotary tool according to claim 2, wherein the rotary tool is located on the rear end side of the second biasing portion and includes a control member that controls the biasing force on the contact member by the biasing structure.

5. The rotary tool according to claim 1, wherein the clutch is operated when rotating in the forward direction and restricted when rotating in the reverse direction.

6. The rotary tool according to any one of claims 1 to 5, further comprising a housing portion located on the tip side of the gripping portion and engaging with the gripping portion.

7. The rotary tool according to claim 6, wherein at least one of the first rotational driving force and the second rotational driving force can be transmitted from the gripping portion to the housing portion via a light fitting.

8. The clutch portion is interposed in the transmission path of the first rotational driving force in the first mode, as described in any one of claims 1 to 5.

9. The rotary tool according to any one of claims 1 to 5, wherein the clutch portion has a first member and a second member arranged along the shaft.