Coupling, screwdriver device and laser processor

Abstract

To provide a coupling that can be restored to a position in which an axis center of a drive shaft and an axis center of an output shaft coincide with each other upon release of a locked state with respect to the output shaft irrespective of the posture of the coupling.SOLUTION: A coupling 10 comprises: a drive-side bush 1 that grips a drive shaft 20a of a drive source 20 and has a columnar protrusion 1c to guide sliding in a first direction on a first plane perpendicular to a center axis; an output-side bush 4 that has columnar protrusions 4c, 4d to guide sliding on the first plane in a second direction orthogonal to the first direction, and that grips a rotary tool 30; a first outer ring member 2 having a groove for guiding the columnar protrusion 1c and a groove for guiding the columnar protrusions 4c, 4d; a second outer ring member 3; an elastic body 6 having the same elastic force throughout in a direction about the center axis; and an elastic body 7 having the same elastic force throughout in a direction around the center axis.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a coupling, a screw driving device, and a laser processing machine. [Background technology]

[0002] When using a screwdriver, in order to achieve accurate tightening, it is necessary to align the axial center between the hexagon socket bolt on the workpiece and the output shaft on the screwdriver to which the hexagon wrench or the like is connected. Due to variations in the assembly accuracy of the workpiece and the accuracy of the parts, it is necessary to align the axial center for each workpiece, which places a large burden on the worker.

[0003] Therefore, in Patent Document 1, a coupling member is disposed between the drive shaft and the output shaft, making it possible to transmit driving force even when the axes of the two shafts do not coincide. The coupling member is configured by arranging an upper base member provided on the drive shaft, a lower base member provided on the output shaft, and an intermediate base member disposed between the two base members in parallel, and by arranging a sliding member that allows sliding only in one axial direction at a position perpendicular to the upper and lower faces of the intermediate base member and arranging an aligning mechanism in parallel with the sliding member, thereby forming a mechanism that transmits driving force when the axes of the drive shaft and the output shaft do not coincide, and automatically returns the axes to a position where they coincide when the lock on the output shaft is released. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 07-103248 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, two springs that expand and contract in two perpendicular directions are used to obtain the restoring force of the alignment mechanism, so if the axial direction of the coupling is tilted relative to the vertical direction, the relative angle between the direction of its own weight and the spring force changes according to the rotation angle of the drive shaft, and the direction and magnitude of the restoring force change, so the drive shaft and the output shaft cannot be aligned. Therefore, Patent Document 1 has the problem that its use is limited to cases where the axial direction of the coupling is vertical.

[0006] The present disclosure has been made in consideration of the above, and aims to obtain a coupling that can return to a position where the axis of the drive shaft and the axis of the output shaft coincide when the locked state with respect to the output shaft is released, regardless of the posture of the coupling. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the coupling of the present disclosure includes a first member, a second member, a third member, a first elastic body, and a second elastic body. The first member holds the drive shaft of the drive source at one end, and a first guide portion that guides sliding in a first direction in a first plane perpendicular to the central axis is provided at the other end. The second member holds the output shaft at the other end, and a second guide portion that guides sliding in a second direction perpendicular to the first direction in the first plane is provided at one end. The third member is provided with a third guide portion that guides the first guide portion and a fourth guide portion that guides the second guide portion, and fixes the first member and the second member. The first elastic body is provided between the first member and the third member, and has the same elastic force in all directions around the central axis. The second elastic body is provided between the second member and the third member, and has the same elastic force in all directions around the central axis. Effect of the Invention

[0008] According to the coupling of the present disclosure, it is possible to achieve the effect that, regardless of the attitude of the coupling, when the locked state with respect to the output shaft is released, the coupling can return to a position where the axis of the drive shaft and the axis of the output shaft are aligned. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing configurations of a coupling, a screw driving device, and a laser processing machine according to a first embodiment; [Diagram 2] FIG. 1 is a cross-sectional view showing a configuration of a coupling and a screw driving device according to a first embodiment. [Diagram 3] FIG. 1 is a perspective view showing a shape of a drive-side bush of a coupling according to a first embodiment; [Figure 4] FIG. 1 is a perspective view showing a shape of an output side bush of a coupling according to a first embodiment; [Diagram 5] FIG. 1 is a perspective view showing a shape of a first outer ring member of a coupling according to a first embodiment; [Figure 6] FIG. 11 is a perspective view showing a shape of a second outer ring member of the coupling according to the first embodiment; [Figure 7] FIG. 1 is a perspective view showing a state of a coupling when the axis of a drive shaft and the axis of a screw do not coincide with each other in the screw driving device according to the first embodiment; [Figure 8] FIG. 1 is a cross-sectional view showing a state of a coupling when the axis of a drive shaft and the axis of a screw do not coincide with each other in the screw driving device according to the first embodiment; [Figure 9] FIG. 13 is a perspective view showing a configuration of a modified example of the coupling and the screw driving device according to the first embodiment; [Figure 10] FIG. 11 is a cross-sectional view showing a partial configuration of a coupling according to a second embodiment. [Figure 11] FIG. 11 is a cross-sectional view showing a partial configuration of a modified example of the coupling according to the second embodiment. [Figure 12] FIG. 11 is a cross-sectional view showing a partial configuration of a modified example of the coupling according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A coupling, a screw driving device, and a laser processing machine according to embodiments will be described in detail below with reference to the drawings.

[0011] Embodiment 1 Fig. 1 is a perspective view showing the configurations of a coupling 10, a screw driving device 100, and a laser processing machine 1000 according to the first embodiment. Fig. 2 is a cross-sectional view showing the configurations of the coupling 10 and the screw driving device 100 according to the first embodiment.

[0012] The laser processing machine 1000 will be described with reference to FIG. 1. The laser processing machine 1000 has a screwdriving device 100, a maintenance target member 200, and a screw 40. A rotating tool 30 is held at the tip of the screwdriving device 100. The screw 40 is attached to the maintenance target member 200. The screwdriving device 100 can automatically tighten and loosen the screw 40 attached to the maintenance target member 200 by the rotating tool 30. This allows the screw 40 that has shifted from its specified position due to vibration or impact during operation of the laser processing machine 1000 to be tightened or loosened, allowing the laser processing machine 1000 to continue continuous operation. The coupling 10 and the screwdriving device 100 can also be applied to equipment and devices other than the laser processing machine 1000.

[0013] The configuration of the screwdriver 100 will be described with reference to FIG. 1 and FIG. 2. The screwdriver 100 has a drive source 20 such as a motor, a drive shaft 20a of the drive source 20, a rotary tool 30 such as a hexagonal wrench fixed to the output shaft, and a coupling 10 that holds the drive shaft 20a and the rotary tool 30. The rotational torque generated by the drive source 20 is transmitted to the rotary tool 30 fixed to the output shaft via the coupling 10. The screw 40 can be rotated by generating a rotational torque of the drive source 20 in a state in which the rotary tool 30 is inserted into a screw 40 such as a hexagonal socket bolt on the work side. In the specification, the central axis direction refers to the central axis direction of the coupling 10. In addition, the direction of gravity is indicated by an arrow g in FIG. 1, but the arrangement direction of the coupling 10 and the direction of gravity g are not limited to this arrangement relationship. In FIG. 1, the drive source 20 is shown in a state where it is not connected to the coupling 10, but when the screwdriver 100 is used, the drive source 20 is connected to the coupling 10.

[0014] The configuration of the coupling 10 will be described with reference to Figs. 1 and 2. The coupling 10 includes a drive bush 1 as a first member, an output bush 4 as a second member, a first outer ring member 2 on the drive side, a second outer ring member 3 on the output side, a plurality of fasteners 5, a drive elastic body 6 as a first elastic body, and an output elastic body 7 as a second elastic body. The first outer ring member 2 on the drive side and the second outer ring member 3 on the output side correspond to the outer ring member as the third member. A drive shaft 20a is attached to the drive bush 1. A rotary tool 30 is attached to the output bush 4. The fastener 5 is, for example, a hexagon socket bolt, and fixes the first outer ring member 2 and the second outer ring member 3. The first outer ring member 2 and the second outer ring member 3 fix the drive bush 1 and the output bush 4 from the outside. When describing the components of the coupling 10, one end side refers to the end close to the driving source 20, and the other end side refers to the end close to the rotating tool 30.

[0015] FIG. 3 is a perspective view showing the shape of the drive-side bush 1 of the coupling 10 according to the first embodiment. The drive-side bush 1 has a drive-side clamp member 1a, an annular projection 1b, a columnar projection 1c, and a columnar projection 1d. The drive-side clamp member 1a holds the drive shaft 20a at one end. Although the illustration of the structure in which the drive-side clamp member 1a holds the drive shaft 20a is omitted, the drive-side clamp member 1a holds the drive shaft 20a by, for example, a set screw and a shaft holder provided with a slit. The annular projection 1b has a larger diameter than the drive-side clamp member 1a and is a flange protruding in the radial direction from the other end side of the drive-side clamp member 1a. As shown in FIG. 2, the annular projection 1b positions the elastic body 6 in the central axis direction. The columnar projection 1c has a rectangular column-shaped projection extending radially outward from the end face on the other end side of the annular projection 1b. The columnar projection 1d has a rectangular columnar shape and extends radially outward from the end face on the other end side of the ring-shaped projection 1b. The extending directions of the columnar projections 1c and 1d are different by 180 degrees and are opposite directions. The columnar projections 1c and 1d function as a first guide portion that guides sliding in the α direction (see FIG. 5), which is a first direction in a first plane perpendicular to the central axis.

[0016] FIG. 4 is a perspective view showing the shape of the output bush 4 of the coupling 10 according to the first embodiment. The output bush 4 has an output clamp member 4a, an annular projection 4b, a columnar projection 4c, and a columnar projection 4d. The output clamp member 4a holds the rotating tool 30 at the other end. Although the configuration of the output clamp member 4a holding the rotating tool 30 is omitted, the output clamp member 4a holds the rotating tool 30 by, for example, a set screw and a shaft holder provided with a slit. The annular projection 4b has a larger diameter than the output clamp member 4a and is a flange protruding radially from one end side of the output clamp member 4a. As shown in FIG. 2, the annular projection 4b positions the elastic body 7 in the central axis direction. The columnar projection 4c has a rectangular column-shaped projection extending radially outward from the end face on one end side of the annular projection 4b. The columnar projection 4d has a rectangular columnar shape and extends radially outward from one end face of the ring-shaped projection 4b. The columnar projections 4c and 4d extend in opposite directions, differing by 180 degrees. The columnar projections 4c and 4d function as a second guide portion that guides sliding in the β direction (see FIG. 5), which is a second direction perpendicular to the α direction, which is a first direction in a first plane perpendicular to the central axis.

[0017] 5 is a perspective view showing the shape of the first outer race member 2 of the coupling 10 according to the first embodiment. The first outer race member 2 has an annular shape. The drive bush 1 is fixed to the first outer race member 2 so as to be slidable in the α direction, and the output bush 4 is fixed to the first outer race member 2 so as to be slidable in the β direction.

[0018] As shown in FIG. 2, an annular projection 2a protruding radially inward is provided on the inner circumferential side of one end of the first outer ring member 2. The annular projection 2a positions the elastic body 6 in the central axis direction. The first outer ring member 2 is provided with a plurality of screw holes 2h for fixing the fixing device 5. The other end of the first outer ring member 2 is provided with four grooves 2b, 2c, 2d, and 2e extending radially. These four grooves 2b, 2c, 2d, and 2e are rectangular. The grooves 2b, 2c, 2d, and 2e extend radially from the axis of the first outer ring member 2, and the extension directions of adjacent grooves 2b, 2c, 2d, and 2e differ by 90 degrees. That is, the α direction, which is the extension direction of the grooves 2b and 2d, and the β direction, which is the extension direction of the grooves 2c and 2e, are perpendicular to each other. The columnar protrusion 1c of the drive side bushing 1 is gap-fitted into the groove 2b, and the columnar protrusion 1d of the drive side bushing 1 is gap-fitted into the groove 2d. The grooves 2b and 2d function as a third guide portion that guides the columnar protrusions 1c and 1d, which are the first guide portion. The columnar protrusion 4d of the output side bushing 4 is gap-fitted into the groove 2c, and the columnar protrusion 4c of the output side bushing 4 is gap-fitted into the groove 2e. The grooves 2c and 2e function as a fourth guide portion that guides the columnar protrusions 4c and 4d, which are the second guide portion.

[0019] Fig. 6 is a perspective view showing the shape of the second outer race member 3 of the coupling 10 according to the first embodiment. As shown in Fig. 2, an annular projection 3a that protrudes radially inward is provided on the inner peripheral side of the other end of the second outer race member 3. As shown in Fig. 2, the annular projection 3a positions the elastic body 7 in the central axis direction. The second outer race member 3 is provided with a plurality of screw holes 3h for fixing a fixing device 5.

[0020] The elastic body 6 has a circular ring shape and is made of, for example, a rubber material. The elastic body 6 is fitted onto the outer periphery of the driving side clamp member 1a of the driving side bush 1. The elastic body 6 is provided between the outer periphery of the driving side bush 1 and the inner periphery of the first outer ring member 2, and has the same elastic force in all directions (all angles) around the central axis.

[0021] The elastic body 7 has a circular ring shape and is made of, for example, a rubber material. The elastic body 7 is fitted onto the outer periphery of the output side clamp member 4a of the output side bush 4. The elastic body 7 is provided between the outer periphery of the output side bush 4 and the inner periphery of the second outer ring member 3, and has the same elastic force in all directions (all angles) around the central axis.

[0022] In this configuration, the columnar projection 1c of the drive side bush 1 is clearance-fitted into the groove 2b of the first outer ring member 2, and the columnar projection 1d of the drive side bush 1 is clearance-fitted into the groove 2d of the first outer ring member 2, so that the sliding direction between the drive side bush 1 and the first outer ring member 2 is limited to the α direction in Fig. 5, and the rotational torque transmitted from the drive source 20 to the drive side bush 1 is transmitted to the first outer ring member 2. Also, the columnar projection 4d of the output side bush 4 is clearance-fitted into the groove 2c of the first outer ring member 2, and the columnar projection 4c of the output side bush 4 is clearance-fitted into the groove 2e of the first outer ring member 2, so that the rotational torque transmitted to the first outer ring member 2 is transmitted to the output side bush 4, with the sliding direction between the output side bush 4 and the first outer ring member 2 being limited to the β direction in Fig. 5.

[0023] Next, a method of assembling the coupling 10 will be described. First, the elastic body 6 is fitted onto the outer periphery of the drive-side clamp member 1a of the drive-side bush 1 until it abuts against the ring-shaped protrusion 1b of the drive-side bush 1. The inner diameter of the elastic body 6 is slightly smaller than the outer diameter of the drive-side clamp member 1a. The elastic force of the elastic body 6 fixes the elastic body 6 to the drive-side clamp member 1a. Next, the columnar protrusions 1c and 1d of the drive-side bush 1 into which the elastic body 6 has been fitted are fitted into the grooves 2b and 2d of the first outer ring member 2.

[0024] Next, the elastic body 7 is fitted onto the outer periphery of the output side clamp member 4a of the output side bush 4 until it abuts against the ring-shaped protrusion 4b of the output side bush 4. The inner diameter of the elastic body 7 is slightly smaller than the outer diameter of the output side clamp member 4a. The elastic force of the elastic body 7 fixes the elastic body 7 to the output side clamp member 4a.

[0025] Next, the columnar projections 4c and 4d of the output side bushing 4 are fitted into the grooves 2e and 2c of the first outer race member 2. Finally, the end faces of the second outer race member 3 and the first outer race member 2 are brought into contact with each other, and the second outer race member 3 and the first outer race member 2 are fixed together by a fixing device 5.

[0026] As described above, the columnar projection 1c of the drive side bush 1 and the groove 2b of the first outer ring member 2 are clearance-fitted, and the width of the columnar projection 1c is slightly narrower than the width of the groove 2b of the first outer ring member 2. The columnar projection 1d of the drive side bush 1 and the groove 2d of the first outer ring member 2 are clearance-fitted, and the width of the columnar projection 1d is slightly narrower than the width of the groove 2d of the first outer ring member 2. Similarly, the columnar projection 4c of the output side bush 4 and the groove 2e of the first outer ring member 2 are clearance-fitted, and the width of the columnar projection 4c is slightly narrower than the width of the groove 2e of the first outer ring member 2. The columnar projection 4d of the output side bush 4 and the groove 2c of the first outer ring member are clearance-fitted, and the width of the columnar projection 4d is slightly narrower than the width of the groove 2c of the first outer ring member 2.

[0027] Therefore, the drive side bush 1 and the first outer ring member 2 are slidable in a state limited to the α direction in Fig. 5, and the output side bush 4 and the first outer ring member 2 are slidable in a state limited to the β direction in Fig. 5. The grooves 2b and 2d are perpendicular to the grooves 2c and 2e, so the α direction is perpendicular to the β direction. Therefore, the drive side bush 1 and the output side bush 4 slide within a plane defined by the α direction and the β direction.

[0028] Next, the function of the coupling 10 to transmit rotational torque from the drive source 20 to the rotating tool 30 will be described. The rotational torque generated by the drive source 20 is transmitted to the driving bush 1 by the driving clamp member 1a gripping the drive shaft 20a. The columnar projections 1c and 1d of the driving bush 1 transmit the rotational torque to the first outer ring member 2 via the grooves 2b and 2d of the first outer ring member 2. The grooves 2c and 2e of the first outer ring member 2 transmit the rotational torque to the output bush 4 via the columnar projections 4d and 4c of the output bush 4. This transmits the rotational torque to the rotating tool 30 gripped by the output clamp member 4a.

[0029] Next, an operation of transmitting rotational torque from the drive source 20 to the rotary tool 30 via the coupling 10 in a case where the axis of the drive shaft 20a and the axis of the screw 40 do not coincide with each other will be described.

[0030] Fig. 7 is a perspective view showing a state of the coupling 10 in the screw driving device 100 according to the first embodiment when the axis of the drive shaft 20a does not coincide with the axis of the screw 40. Fig. 8 is a cross-sectional view showing a state of the coupling 10 in the screw driving device 100 according to the first embodiment when the axis of the drive shaft 20a does not coincide with the axis of the screw 40.

[0031] First, a case where the axis of the drive shaft 20a and the axis of the screw 40 are misaligned only in the α direction will be described. When the rotating tool 30 is inserted into the hexagonal hole of the screw 40, the rotating tool 30 receives a force in the α direction from the screw 40. The force that the rotating tool 30 receives from the screw 40 is transmitted to the output side bush 4 via the output side clamp member 4a. This force is transmitted to the first outer ring member 2 via the grooves 2e and 2c of the first outer ring member 2 by the columnar projections 4c and 4d of the output side bush 4. As a result, the first outer ring member 2 moves in the α direction, and the axis of the rotating tool 30 and the axis of the screw 40 coincide with each other. At this time, the elastic body 6 installed between the first outer ring member 2 and the drive side bush 1 elastically deforms, so that the axis of the drive side bush 1 remains aligned with the axis of the drive shaft 20a.

[0032] Next, a case where the axis of the screw 40 is misaligned only in the β direction with respect to the axis of the drive shaft 20a will be described. When the rotating tool 30 is inserted into the hexagonal hole of the screw 40, the rotating tool 30 receives a force in the β direction from the screw 40. The force that the rotating tool 30 receives from the screw 40 is transmitted to the output side bush 4 via the output side clamp member 4a. The force transmitted to the output side bush 4 moves the output side bush 4 in the β direction, and the axis of the rotating tool 30 and the axis of the screw 40 coincide with each other. At this time, the elastic body 7 installed between the second outer ring member 3 and the output side bush 4 elastically deforms, so that the axis of the second outer ring member 3, the first outer ring member 2, and the driving side bush 1 are maintained in a state of coinciding with the axis of the drive shaft 20a.

[0033] The direction in which the axis of the drive shaft 20a and the axis of the screw 40 are misaligned exists within a plane formed by the perpendicular α and β directions. Therefore, when the α-direction component of the amount of misalignment between the axis of the drive shaft 20a and the axis of the screw 40 is within the range in which the first outer ring member 2 can slide in the α direction, and the β-direction component of the amount of misalignment between the axis of the drive shaft 20a and the axis of the screw 40 is within the range in which the output bush 4 can slide in the β direction, the axis of the rotating tool 30 and the axis of the screw 40 can be aligned by the sliding of the first outer ring member 2 in the α direction and the sliding of the output bush 4 in the β direction.

[0034] When the driving source 20 is rotated while the axis of the drive shaft 20a and the axis of the screw 40 are misaligned, the ratio of the α-direction component and the β-direction component in the force applied by the screw 40 to the rotating tool 30 changes. In response to this change in ratio, the first outer ring member 2 moves in the α-direction relative to the drive-side bush 1, and the output-side bush 4 moves in the β-direction relative to the first outer ring member 2, so that the axis of the rotating tool 30 and the axis of the screw 40 coincide with each other.

[0035] According to the coupling 10 of the first embodiment, even if the axis of the drive shaft 20a and the axis of the screw 40 do not coincide with each other, the rotational torque can be transmitted from the drive shaft 20a to the rotating tool 30 in the same manner as when the axes of these shafts coincide with each other.

[0036] According to the coupling 10 of the first embodiment, the columnar projections 1c and 1d of the drive bush 1 are rectangular columns, so that the rotation of the first outer ring member 2 around the α direction relative to the drive bush 1 is limited. Furthermore, the columnar projections 4c and 4d of the output bush 4 are rectangular columns, so that the rotation of the output bush 4 around the β direction relative to the first outer ring member 2 is limited. Therefore, the axis of the drive bush 1 of the coupling 10 and the axis of the output bush 4 are kept parallel to each other. That is, the axis of the drive shaft 20a and the axis of the rotating tool 30 are kept parallel to each other via the coupling 10.

[0037] As described above, even if the axis of the drive shaft 20a and the axis of the screw 40 do not coincide, the coupling 10 can align the axis of the screw 40 and the axis of the rotating tool 30 while maintaining the parallelism between the axis of the drive shaft 20a and the axis of the rotating tool 30, thereby transmitting the rotational torque from the drive shaft 20a to the rotating tool 30.

[0038] Here, the function of aligning the axis of the drive shaft 20a of the coupling 10 with the axis of the rotary tool 30 when the rotary tool 30 is not inserted into the screw 40 will be described. When the axis of the drive shaft 20a and the axis of the screw 40 are misaligned only in the α direction, as described above, the first outer ring member 2 moves relative to the drive side bush 1, and the elastic body 6 fitted between the outer periphery of the drive side clamp member 1a and the inner periphery of the first outer ring member 2 is elastically deformed. At this time, the elastic body 6 applies a reaction force to the first outer ring member 2. In this state, when the rotary tool 30 is removed from the screw 40, the reaction force from the elastic body 6 causes the first outer ring member 2 to return to its original position, so that the axis of the drive side bush 1 and the axis of the output side bush 4 are aligned, and the axis of the drive shaft 20a and the axis of the rotary tool 30 are aligned.

[0039] Furthermore, when the axis of the drive shaft 20a and the axis of the screw 40 are misaligned only in the β direction, as described above, the output side bush 4 moves relative to the second outer ring member 3, causing the elastic body 7 fitted between the outer periphery of the output side clamp member 4a and the inner periphery of the second outer ring member 3 to elastically deform. At this time, the elastic body 7 applies a reaction force to the output side bush 4. When the rotating tool 30 is removed from the screw 40 in this state, the reaction force from the elastic body 7 causes the output side bush 4 to return to its original position, so that the axis of the drive side bush 1 and the axis of the output side bush 4 coincide with each other, and the axis of the drive shaft 20a and the axis of the rotating tool 30 coincide with each other.

[0040] As described above, the direction in which the axis of the drive shaft 20a and the axis of the screw 40 are misaligned exists in a plane formed by the orthogonal α and β directions. Therefore, if the α-direction component of the amount of misalignment between the axis of the drive shaft 20a and the axis of the screw 40 is within the range in which the first outer ring member 2 can slide in the α direction, and the β-direction component of the amount of misalignment between the axis of the drive shaft 20a and the axis of the screw 40 is within the range in which the output bush 4 can slide in the β direction, when the rotating tool 30 is removed from the screw 40, the axis of the drive bush 1 and the axis of the output bush 4 will coincide with each other due to the reaction force applied by the elastic body 6 to the first outer ring member 2 and the reaction force applied by the elastic body 7 to the output bush 4, and the axis of the drive shaft 20a and the axis of the rotating tool 30 can be coincided with each other.

[0041] 1, when the central axes of the coupling 10 and the rotating tool 30 are oriented in a direction other than the gravity direction g, the weight of the coupling 10 and the rotating tool 30 causes the axis of the drive side bush 1 and the axis of the output side bush 4 to be misaligned. Even when used in this position, the axis of the drive side bush 1 and the axis of the output side bush 4 are prevented from being misaligned by the reaction force from the elastic body 6 fitted between the outer periphery of the drive side bush 1 and the inner periphery of the first outer ring member 2 and the reaction force from the elastic body 7 fitted between the outer periphery of the output side bush 4 and the inner periphery of the second outer ring member 3. Even if the drive shaft 20a is rotated in this position, the axis of the drive shaft 20a and the axis of the rotating tool 30 are prevented from being misaligned by the reaction force from the elastic body 6 and the reaction force from the elastic body 7.

[0042] Thus, according to the coupling 10 of the first embodiment, the elastic bodies 6, 7 have the same elastic force in all directions around the central axis, so that no matter what posture the coupling 10 is in, the reaction force against the load according to the rotation phase of the drive shaft 20a does not vary, and the axial cores of the drive shaft 20a and the rotating tool 30 can be aligned at fixed positions. Moreover, no matter what posture the coupling 10 is in, when the locked state with the screw 40 is released, the coupling 10 can automatically return to a position where the drive shaft 20a and the rotating tool 30 are aligned.

[0043] In the above description, the driving side bush 1 as the first member is provided with columnar protrusions 1c, 1d as convex portions that function as first guide portions that guide sliding in the α direction, the output side bush 4 as the second member is provided with columnar protrusions 4c, 4d as convex portions that function as second guide portions that guide sliding in the β direction, and the first outer ring member 2 is provided with grooves 2b, 2d as concave portions that function as third guide portions that guide the first guide portions, and grooves 2c, 2e as concave portions that function as fourth guide portions that guide the second guide portions; however, the first guide portion provided in the driving side bush 1 and the second guide portion provided in the output side bush 4 may be concave-shaped, and the third guide portion and fourth guide portion provided in the first outer ring member 2 may be convex-shaped to guide sliding in the α direction and the β direction.

[0044] Although the elastic bodies 6 and 7 are shown as rubber materials having a circular ring shape, multiple springs having the same elastic force that expands and contracts in the radial direction and are installed at equal intervals in the circumferential direction may be used as long as they have the same elastic force in all directions around the central axis. The elastic bodies 6 and 7 are shown as ring-shaped, but are not limited to ring-shaped and may be chain-shaped. The elastic bodies 6 and 7 may have multiple holes at equal intervals in the circumferential direction.

[0045] In addition, the positions of the grooves 2c and 2e of the first outer ring member 2 are shown as positions extending in a radial direction perpendicular to the grooves 2b and 2d, but the positions of the grooves 2c and 2e are not limited to positions extending in a radial direction perpendicular to the grooves 2b and 2d, and may be in any direction other than parallel to the grooves 2b and 2d. In addition, the inner diameter of the elastic body 6 is slightly smaller than the outer diameter of the driving side clamping member 1a, but the inner diameter of the elastic body 6 may be the same as the outer diameter of the driving side clamping member 1a. Similarly, the inner diameter of the elastic body 7 may be the same as the outer diameter of the output side clamping member 4a.

[0046] Fig. 9 is a perspective view showing the configuration of a modified example of the coupling 10 and the screw driving device 100 according to the first embodiment. In Fig. 9, the columnar projections 1c, 1d of the drive-side bush 1 and the columnar projections 4c, 4d of the output-side bush 4 are triangular prisms. The columnar projections 1c, 1d, 4c, 4d may be in other polygonal prism shapes as long as they can restrict rotation around the α direction and rotation around the β direction.

[0047] Furthermore, the rotating tool 30 is not limited to a hexagonal wrench, but may be a bit or the like. The screw 40 is not limited to a hexagonal socket bolt, but may be a cross head screw or the like. The fastener 5 is not limited to a hexagonal socket bolt, but may be a joining means such as a rivet, a clamp, an adhesive, welding, or soldering.

[0048] Furthermore, although the grooves 2b, 2c, 2d, and 2e are formed in the first outer ring member 2, the grooves 2b, 2c, 2d, and 2e may be formed in the second outer ring member 3.

[0049] In addition, the columnar projections 1c, 1d of the drive-side bush 1 are flush with the outer peripheral surface of the first outer ring member 2, but they do not need to be flush, and the outer diameter of the columnar projections 1c, 1d may be smaller than the outer diameter of the first outer ring member 2, or the outer diameter of the columnar projections 1c, 1d may be larger than the outer diameter of the first outer ring member 2. In addition, the columnar projections 4c, 4d of the output-side bush 4 are flush with the outer peripheral surface of the second outer ring member 3, but they do not need to be flush, and the outer diameter of the columnar projections 4c, 4d may be smaller than the outer diameter of the second outer ring member 3, or the outer diameter of the columnar projections 4c, 4d may be larger than the outer diameter of the first outer ring member 2.

[0050] Embodiment 2 In the first embodiment, the ring-shaped projection 1b of the drive-side bush 1 is provided on the end face of the drive-side clamp member 1a, but it may be provided at any position in the central axis direction of the drive-side clamp member 1a as long as the position can hold the elastic body 6 so as not to come off from the drive-side bush 1. Also, the ring-shaped projection 2a of the first outer race member 2 is provided on the end face of the first outer race member 2, but it may be provided at any position in the central axis direction of the first outer race member 2 as long as the position can hold the elastic body 6 so as not to come off from the first outer race member 2.

[0051] In the first embodiment, the ring-shaped projection 4b of the output bush 4 is provided on the end face of the output clamp member 4a, but it may be provided at any position in the central axis direction of the output clamp member 4a as long as the position can hold the elastic body 7 so as not to come off the output bush 4. Also, the ring-shaped projection 3a of the second outer race member 3 is provided on the end face of the second outer race member 3, but it may be provided at any position in the central axis direction of the second outer race member 3 as long as the position can hold the elastic body 7 so as not to come off the second outer race member 3.

[0052] FIG. 10 is a cross-sectional view showing a part of the configuration of the coupling 10 according to the second embodiment. In FIG. 10, for convenience, the driving bush 1 and the output bush 4 are shown in the same figure, and the first outer ring member 2 and the second outer ring member 3 are shown in the same figure, and only the columnar protrusion 1c is shown. The first outer ring member 2 has an annular protrusion 2a at the end on the rotating tool 30 side, and the driving bush 1 has an annular protrusion 1b at the center part separated by the width of the central axis direction of the elastic body 6 from the end of the driving clamp member 1a on the rotating tool 30 side, and the elastic body 6 is fitted between the annular protrusion 2a and the annular protrusion 1b. The second outer ring member 3 has an annular protrusion 3a at the end on the driving source 20 side, and the output bush 4 has an annular protrusion 4b at the center part separated by the width of the central axis direction of the elastic body 7 from the end of the driving source 20 side of the output clamp member 4a, and the elastic body 7 is fitted between the annular protrusion 3a and the annular protrusion 4b.

[0053] Fig. 11 is a cross-sectional view showing a partial configuration of a modified example of the coupling 10 according to the second embodiment. In Fig. 11, for convenience, the drive bush 1 and the output bush 4 are shown in the same figure, the first outer ring member 2 and the second outer ring member 3 are shown in the same figure, and only the columnar protrusion 1c is shown. In Fig. 11, the first outer ring member 2 and the second outer ring member 3 are not provided with ring-shaped protrusions, and the drive bush 1 is provided with two ring-shaped protrusions 1g, 1f spaced apart by the width of the elastic body 6 in the central axial direction, and the output bush 4 is provided with two ring-shaped protrusions 4g, 4f spaced apart by the width of the elastic body 7 in the central axial direction.

[0054] Fig. 12 is a cross-sectional view showing a partial configuration of a modified example of the coupling 10 according to the second embodiment. In Fig. 12, for convenience, the drive side bush 1 and the output side bush 4 are shown in the same figure, and the first outer ring member 2 and the second outer ring member 3 are shown in the same figure, and only the columnar protrusion 1c is shown. In Fig. 12, the drive side bush 1 and the output side bush 4 are not provided with ring-shaped protrusions, but the first outer ring member 2 is provided with two ring-shaped protrusions 2g, 2f spaced apart by the width of the elastic body 6 in the central axial direction, and the second outer ring member 3 is provided with two ring-shaped protrusions 3g, 3f spaced apart by the width of the elastic body 7 in the central axial direction.

[0055] The configurations shown in the above embodiments are examples of the contents of the present disclosure, and may be combined with other known technologies, the configurations of each embodiment may be combined as appropriate, and parts of the configurations may be omitted or modified without departing from the gist of the present disclosure. [Explanation of symbols]

[0056] 1 Drive side bush, 1a Drive side clamp member, 1b, 1f, 1g, 2a, 2f, 2g, 3a, 3f, 3g, 4b, 4f, 4g Ring-shaped protrusions, 1c, 1d, 4c, 4d Column-shaped protrusions, 2 First outer ring member, 2b, 2c, 2d, 2e Groove, 2h, 3h Screw hole, 3 Second outer ring member, 4 Output side bush, 4a Output side clamp member, 5 Fixing device, 6, 7 Elastic body, 10 Coupling, 20 Drive source, 20a Drive shaft, 30 Rotating tool, 40 Screw, 100 Screw driving device, 200 Maintained member, 1000 Laser processing machine.

Claims

1. a first member that holds a drive shaft of a drive source at one end and has a first guide portion that guides sliding of the drive shaft in a first direction on a first plane perpendicular to a central axis at the other end; a second member having a first end provided with a second guide portion for guiding sliding in a second direction perpendicular to the first direction on the first plane, and a second member for gripping an output shaft at the other end; a third member that is provided with a third guide portion that guides the first guide portion and a fourth guide portion that guides the second guide portion and that fixes the first member and the second member; a first elastic body provided between the first member and the third member and having the same elastic force in all directions around the central axis; a second elastic body provided between the second member and the third member and having the same elastic force in all directions around the central axis; A coupling characterized by:

2. the first member is a driving side bush having the first guide portion, the second member is an output side bush having the second guide portion, the third member is an outer ring member that has the third guide portion and the fourth guide portion and fixes the drive side bush and the output side bush from outside, the first elastic body is provided between an outer periphery of the drive side bush and an inner periphery of the outer ring member, The second elastic body is provided between an outer periphery of the output side bush and an inner periphery of the outer ring member.

2. The coupling according to claim 1 .

3. The first guide portion and the second guide portion are rectangular prism-shaped protrusions extending in a radial direction, The third guide portion and the fourth guide portion are rectangular grooves extending in a radial direction.

3. The coupling according to claim 2.

4. The first guide portion and the second guide portion are triangular prism-shaped protrusions extending in a radial direction, The third guide portion and the fourth guide portion are triangular grooves extending in a radial direction.

3. The coupling according to claim 2.

5. the first elastic body and the second elastic body are made of annular rubber materials, the first elastic body is disposed between an annular projection provided on an end surface of the drive-side bushing on the output shaft side and an annular projection provided on an end surface of the outer ring member on the drive shaft side, The second elastic body is disposed between a ring-shaped protrusion provided on an end surface of the output bush on the drive shaft side and a ring-shaped protrusion provided on an end surface of the outer ring member on the output shaft side.

3. The coupling according to claim 2.

6. the first elastic body and the second elastic body are made of annular rubber materials, the first elastic body is disposed between an annular projection provided on an end surface of the outer ring member on the output shaft side and an annular projection provided on a central portion of the drive-side bush, The second elastic body is disposed between an annular projection provided on an end surface of the outer ring member on the drive shaft side and an annular projection provided in a central portion of the output side bush.

3. The coupling according to claim 2.

7. the first elastic body and the second elastic body are made of annular rubber materials, the first elastic body is disposed between two annular projections provided at different positions in the central axis direction of the drive-side bush, The second elastic body is disposed between two annular projections provided at different positions in the central axis direction of the output bush.

3. The coupling according to claim 2.

8. The outer ring member has a first outer ring member on the drive shaft side and a second outer ring member on the output shaft side, the first elastic body and the second elastic body are made of annular rubber materials, the first elastic body is disposed between two annular projections provided at different positions in the central axis direction of the first outer ring member, The second elastic body is disposed between two ring-shaped protrusions provided at different positions in the central axis direction of the second outer ring member.

3. The coupling according to claim 2.

9. A coupling according to any one of claims 1 to 7; The drive source having the drive shaft; A rotary tool fixed to the output shaft. A screwdriver device comprising:

10. A screwdriving device according to claim 9; A maintainable member having a screw attached thereto; Equipped with The screw is tightened or loosened by the rotary tool of the screw driving device. A laser processing machine characterized by:

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