JP4377397B2 - Overload torque cutoff device - Google Patents

Description

  The present invention relates to an overload torque interrupt device provided in a joint portion between a drive shaft and a driven shaft for transmitting rotational force to various rotating machines.

  In a rotating machine such as a machine tool that uses rotational force, if an overload torque occurs due to a tool biting into the workpiece, which is the product to be processed, or a failure of machine parts or lack of maintenance management, a major accident will occur. There is a possibility. Therefore, if an overload occurs on the driven shaft side during the operation of the machine, it is necessary to immediately stop the torque transmission and stop the operation.

  Conventionally, various torque limiters have been proposed as the overload torque interrupting device as described above. For example, Patent Document 1 (Japanese Utility Model Laid-Open No. 5-62742) includes a driving-side rotating member and a driven-side rotating member that faces the rotating member and can be retracted in the axial direction. By providing a magnet on one side so that it can be magnetically attracted, and forming a counterbore recess into which one of the rotating members fits a ball and a part of the ball into the other, and the ball fits into the recess and engages When the rotation of the driving side rotating member is transmitted to the driven side rotating member and the normal machine is operated, and the overload occurs on the driven side, the driven side rotating member causes the magnetic attractive force of the magnet to When the ball is separated from the counterbore, the torque transmission is cut off.

  In this case, since the ball rotates idly in contact with the opposing surface of the free road side member, the ball enters and leaves the counterbore recess, and noise is generated. In addition, the ball and the periphery of the spot facing recess are easily damaged by the impact of the ball coming in and out, and there is a problem in durability. Further, since the engagement between the ball and the counterbore recess transmits the same torque in both forward and reverse rotations, it is not easy to remove the cause of overload by reverse rotation.

  Also in Patent Document 2 (Japanese Utility Model Laid-Open No. 5-8063), similarly to the above, a counterbore recess in which a ball is fitted on one of the opposed surfaces of the driving side member and the driven side member and a part of the ball is fitted on the other side. , And the rotation of the driving side member is transmitted to the driven side member by the meshing of the ball and the counterbore recess, and the normal machine is operated. In the case of this proposal, when an overload occurs on the driven side, the driven-side member is pulled away from the spot facing recess by pulling the driven-side member away from the driving-side member by the magnetic attractive force of the electromagnet. Is idle.

In this case, it is necessary to accurately detect the overload state, and there are problems such as a complicated structure and a delayed reaction because of the use of electrical means.
Japanese Utility Model Publication No. 5-62742 Japanese Utility Model Publication No. 5-8063

  The present invention has been made in view of the above. Although the structure is simple, when an overload of a certain level or more occurs, the torque transmission provided on the opposing surfaces of the driven member and the driving member is provided. Overload torque shut-off device that can instantly release the engagement state by the joint and the engagement recess, and can easily and reliably shut off torque transmission, and overload torque shut-off device that can also easily release the overload state by reverse rotation In particular, an overload torque interrupting device capable of interrupting torque transmission without causing noise due to idling in the contact state of the engagement element or damage near the engagement element or the engagement recess, The present invention provides an overload torque cutoff device capable of reliably blocking torque transmission while braking the driven member immediately when an overload occurs.

The present invention for solving the above-mentioned problems is an overload torque interrupting device provided in a joint portion between a drive shaft and a driven shaft arranged on the same axis, and is fixed to an end portion of the drive shaft. A driven side member, a driven side member that is spline-fitted to an end portion of the driven shaft so as to be slidable in the axial direction, and is provided so as to be close to and away from the driven side member; and the driven side member; Spring means for pressing and urging toward the opposite side of the drive side member, and the drive side member and the driven side member have a convex shape protruding from the opposite surface to one of the opposite surfaces. An engagement recess into which the engagement element can be fitted is provided on the other side, and the engagement element and the engagement recess have inclined surfaces whose opposite ends correspond to each other in the rotation direction. While maintaining the contact engagement state in which the inclined surfaces on the front side can transmit torque, When an overload on the dynamic shaft side occurs, the engaging element is detached from the engaging recess along the inclined surface, and the driven member is moved in the axial direction against the spring means to be separated from the driving member. The overload torque cutoff device is provided so as to be obtained , and further includes the following configuration .
A braking disk having a braking surface formed on the outer periphery is fixed to the opposite side of the driven member to the side facing the driving side member. The disk is opposed to the outside of the disk with the disk interposed therebetween. A pair of brakes with an operating handle having a braking portion is pivotally supported on a support bracket that supports the driven shaft in a pivotal manner, and a tension spring means that connects the brakes to the outer periphery of the disk. A braking surface is provided so as to be sandwiched between the braking portions, and the braking surface of the disc forms a reverse taper that gradually increases in diameter from the fixed side to the driven member, and the braking portion of the braking element is the disc. An inclined surface corresponding to the reverse taper of the outer peripheral braking surface is formed, and the driven shaft is movable in the axial direction following the driven member and from the driving side member of the driven member. When not separated A braking restriction ring is provided at a position where the opposing sides of the two brake elements abut against each other and holds the two brake elements in a non-braking state against the tension spring means. When the driven side member is separated from the driving side member by a certain distance or more, the brake regulating ring is detached from the brake element, and the braking portion of the brake element is pressed against the braking surface to perform a braking action. It is .

  According to the overload torque interrupt device, during normal operation, the engagement element provided on one facing surface of the driving side member and the driven side member facing each other in the axial direction has the other facing surface. Of the inclined surfaces at both ends in the rotation direction of the engagement element, the inclined surface on the front side in the rotation direction is in contact with the inclined surface of the corresponding engagement recess, and is held in the engaged state. The rotation of the driving side member is transmitted to the driven side member via the engagement element, and the driven side member rotates together with the driving side member. At this time, the driven side member is pressed and biased to the side facing the driving side member by a spring means, and the driven side member is held in contact with the driving side member by the pressing biasing force. Yes.

  When an overload occurs on the driven shaft side, the engagement element acts so as to be disengaged along the inclination of the inclined surface on the front side in the rotation direction. As a result, the driven member is pressed by the spring means. The engaging element moves in the axial direction against this, and at the same time, the engaging element is detached from the engaging recess. As a result, the drive-side member is idled with respect to the driven-side member, and torque transmission is reliably interrupted.

In the case of the present invention, simultaneously with the movement of the driven member due to the occurrence of an overload, the brake restricting link is disengaged from the pair of brake elements, so that the two brake elements face the drive side member of the driven member. The braking action is performed on the braking disk fixed on the side opposite to the side, the rotation of the driven shaft is immediately stopped, and the progress of the overload state such as biting is suppressed.

In other words, during normal operation, the brake element abuts against the braking restriction ring and is held in an unbraking state, whereas when an overload occurs on the driven shaft side, the driven side member is in contact with the drive side member. The braking restriction ring moves following the separation, and when the driven side member is separated from the driving side member by a certain distance or more, the braking restriction ring is detached from the braking element. The braking portions of the both brake elements are pressed against the braking surface on the outer periphery of the disk by the tension spring means to perform the braking action as described above.

In addition, the braking surface of the braking disk forms a reverse taper that gradually increases in diameter from the side fixed to the driven member, and the braking portion that presses against the braking surface of the brake element is a brake on the outer periphery of the disk. Since the surface has an inclination corresponding to the reverse taper, the driven member is displaced in the direction of pulling away from the driving member by the braking action by the press contact of the brake against the disk . As a result, even if the rotation of the driving side member continues, the engaging element on one of the driven side member and the driving side member abuts against the facing surface facing the engaging member or against the engaging recess. Therefore, the torque transmission can be interrupted without generating noise due to idling in the contact state of the engagement element, and damage to the vicinity of the engagement element or the engagement recess can be prevented. Also become.

Then, when releasing the braking action, it is only necessary to open the two brake elements by holding the operation handle, whereby the driven side member moves to the side opposite to the driving side member by the pressing biasing force of the spring means. Following this, the brake restriction ring also moves and can be returned to the original brake restriction state.

In the overload torque shut-off device, the inclined surfaces at both ends in the rotation direction of the engagement element and the engagement recess have different inclination angles with respect to a plane perpendicular to the rotation direction, and are in contact with and engaged during forward rotation. It is preferable that the inclination angle of the surface is set to be larger than the inclination angle of the inclined surface that contacts and engages during reverse rotation. As a result, it is possible to transmit torques of different magnitudes during forward rotation and reverse rotation, and in particular, a larger torque can be transmitted during reverse rotation. Therefore, after the torque transmission is interrupted as described above due to the occurrence of an overload on the driven shaft side, the cause of the overload state due to the biting on the driven shaft side can be easily canceled by reverse rotation.

  According to the overload torque interrupting device of the present invention, when an overload exceeding a certain level on the driven shaft side occurs, it is provided on the facing surface of the driven side member and the driving side member, although the structure is relatively simple. The engagement state between the engagement element for torque transmission and the engagement recess can be instantaneously released, and torque transmission can be easily and reliably interrupted. Further, by setting the inclination angles of the inclined side surfaces at both ends in the rotational direction of the engagement element and the engagement recess so that a larger torque can be transmitted during the reverse rotation, the overload state can be easily released by the reverse rotation.

For the present invention, in the overload torque shutoff device, by brake shoe for braking the the follower Dogawa member is provided when the driven member is spaced a predetermined or more from the drive-side member, torque transmission Immediately after shutting off, the rotation of the driven member in the overloaded state can be stopped, the progress of the overloaded state can be suppressed, and the damage and damage to the rotating machine due to the overloaded state can be suppressed.

  In particular, when the driven member is further separated from the driving member by the braking action, the driven member can be reliably separated from the driving member when an overload occurs. Torque transmission can be interrupted without causing noise due to idling in the contact state of the joint or damage in the vicinity of the engagement element or the engagement recess.

  Next, embodiments of the present invention will be described based on examples shown in the drawings.

  FIG. 1 is a longitudinal sectional view showing a state in which normal torque can be transmitted, FIG. 2 is a longitudinal sectional view showing a state in which the driven member is separated from the driving member due to the occurrence of an overload, and FIG. FIG. 4 is a plan view of a part of the drive side member, FIG. 5 is a front view from the side of the driven side member facing the drive side member, and FIG. 6 is a view of the drive side member. FIG. 7 is a front view from the braking disk side of the driven member, FIG. 8 is a front view showing the brake element, and FIG. 9 is an enlarged cross section of the engagement element and the engagement recess. It is explanatory drawing.

  In the figure, reference numeral 1 denotes a drive shaft connected to a drive source such as a motor, which is supported on a support bracket 3 via a metal bearing 3a. Reference numeral 2 denotes an output-side driven shaft arranged in series on the same axis as the drive shaft 1, and is supported on a support bracket 4 disposed opposite to the support bracket 3 via a metal bearing 4a. . The support brackets 3 and 4 are connected to each other by fastening members (not shown) such as bolts at fastening portions 3b and 4b at the four corners so as to maintain a fixed distance. An overload torque cutoff device is installed between the support brackets 3 and 4 as described below.

Reference numeral 10 denotes a disk-like drive-side member fixed to the end of the drive shaft 1 with a key, and 20 is spline-fitted to the spline shaft portion 2a at the end of the driven shaft 2 so as to be slidable in the axial direction. The disk-like driven side member that rotates together with the driven shaft 2 is provided so as to be close to and away from the driving side member 10. Reference numeral 5 denotes spring means such as a spring disposed on the outer periphery of the driven shaft 2 between the driven side member 20 and the support bracket 4, and the driven side member 20 is opposed to the drive side member 10. It is provided so as to be pressed and biased. In the case of the figure, between the spring means 5 and the driven member 20, there is provided a spacing collar 6 loosely fitted to the driven shaft 2 so as to be axially displaceable and a brake regulating ring 7 described later. Has been.

  The driving-side member 10 and the driven-side member 20 have one of opposing surfaces 11 and 21, for example, the opposing surface 11 of the driving-side member 10 as shown in FIG. Protruding convex engagement elements 12 for torque transmission are provided at a plurality of equiangular intervals (three places in the figure) on a concentric circle with the drive shaft 1 as the center. The engaging element 12 has both inner and outer side surfaces in the radial direction centered on the drive shaft 1 having an arc shape, and both end surfaces in the rotational direction are centered so as to form a trapezoidal shape in a cross section along the rotational direction. The inclined surfaces 12a and 12b are formed by surfaces having the same width in the radial direction. G and H in the figure indicate inclination angles with respect to a radial surface (surface perpendicular to the facing surface 11) perpendicular to the rotational direction of the inclined surfaces 12a and 12b at both ends. The engagement element 12 is formed of a material that is relatively hard and strong in terms of durability. Reference numeral 13 denotes a mounting screw for the engagement element 12.

  On the other hand, the engagement surface 21 of the driven side member 20 has the engagement surface at a plurality of locations (three locations in the figure) corresponding to the engagement elements 12 at equal angular intervals around the driven shaft 2 in the vicinity of the outer peripheral edge. Engagement recesses 22 into which the combination 12 can be inserted and removed are formed. The engaging recess 22 corresponds to the engaging element 12, and both inner and outer side surfaces in the radial direction centered on the driven shaft 2 form an arc shape and are more dimensionally than the engaging element 12 in a cross section along the rotation direction. In order to form a slightly larger trapezoidal shape, both end surfaces in the rotational direction form inclined surfaces 22a and 22b by surfaces having a width in the radial direction. G ′ and H ′ in the figure indicate inclination angles with respect to a radial surface perpendicular to the rotational direction of the inclined surfaces 22a and 22b (surface perpendicular to the facing surface 21). Corresponds to G and H. Accordingly, the rotation of the driving member 10 with the engagement element 12 fitted in the engagement recess 22 causes the inclined surface 12a or 12b on the front side in the rotation direction and the inclined surface 22a or 22b to contact each other in a surface contact state. It comes in contact and engages.

  The inclined angles G, H and G ′, H ′ of the inclined surfaces 12 a, 12 b and 22 a, 22 b at both ends in the rotational direction of the engaging element 12 and the engaging recess 22 are normally transmitted as torque by rotation of the driving side member 10. When the possible contact engagement state is maintained and an overload occurs on the driven shaft 2 side, the engagement element 12 is detached from the engagement recess 22 along the inclined surfaces 22a and 22b. The driven member 20 is set so as to be moved in the axial direction against the magnetic force of the spring means 5 and a magnet, which will be described later, and to be separated from the driving member 10.

  The tilt angles G and H and G ′ and H ′ can be set as appropriate according to a torque limit set as an overload. However, the greater the tilt angle, the smaller the transmitted torque, and the smaller the tilt angle. When the overload occurs, it becomes difficult for the engaging element 12 to be removed from the engaging recess 22 and the overload torque is increased. Therefore, it is more preferable to set the inclination angles G and H and G 'and H' in the range of 10 to 45 degrees. In particular, the inclined surfaces 12a, 12b and 22a, 22b at both ends in the rotational direction of the engaging element 12 and the engaging recess 22 are inclined angles G, H and G ′ with respect to a plane perpendicular to the opposing surfaces 11 and 21. , H ′ are different, and the inclined angles G and G ′ of the inclined surfaces 12 a and 22 a that abut and engage during forward rotation are greater than the inclined angles H and H ′ of the inclined surfaces 12 b and 22 b that contact and engage during reverse rotation. It is preferable to set a large value, for example, about 5 °, in order to cancel the overload state by the reverse rotation because the torque that can be transmitted is large during the reverse rotation.

  Further, in the case of the illustrated embodiment, the driving side member 10 and the driven side member 20 are set to one of the corresponding positions of the opposing surfaces 11 and 21 in the fitted state of the engaging element 12 with respect to the engaging recess 22. The magnet 8 is provided with a magnetic attachment portion 9 made of a magnetic material on which the magnet 8 can be magnetically attached. Thereby, the fitting state of the engagement element 12 with respect to the engagement recess 22 can be held more stably. In the case of the figure, the driven member 20 is provided with a magnet 8, and the driving member 10 is provided with a magnetic attachment 9. The magnet 8 and the magnetic attachment portion 9 may be provided only at one place on the facing surface. However, in practice, the circumferential direction inward of the engaging recess 22 of the facing surfaces 11 and 21, etc. It is desirable to provide them at a plurality of positions at angular intervals, for example, at two positions opposite to each other as shown in the figure. Of course, depending on the pressing and urging force of the spring means 5, the magnet 8 and the magnetic attachment portion 9 are not necessarily required and can be omitted.

  On the opposite side of the driven side member 20 from the side facing the driving side member 10, a braking disk 23 having a braking surface 24 on the outer periphery having a cylindrical shape is fixed by a fastening screw 25 or the like. A brake element 40 having a braking portion 41 that can be pressed against the braking surface 24 on the outer periphery of the disk 23 is provided outside the disk 23, and the driven member 20 is driven by the occurrence of an overload. The driven member 20 can be braked when the driven member 20 is separated from the side member 10 by a certain distance or more.

In particular, as in the illustrated embodiment, a pair of operation with handles brake shoe 40, 40 is outwardly having an arcuate damping part 41, 41 facing each other across the disk 23 of the disk 23 for the brake However, the brake parts 41 and 41 are supported by the support bracket 4 that supports the driven shaft 2 so as to be pivotably pivotable, and the brake parts 41 and 41 are connected by the tension spring means 42 that connects the brake elements 40 and 40. A braking surface 24 on the outer periphery of the disk 23 is provided so as to be sandwiched. Reference numerals 43 and 43 denote shaft support portions, and reference numerals 44 and 44 denote operation handle portions.

When the normal torque is transmitted, both the brake members 40, 40 are provided with engaging projections 45, 45 provided so as to protrude on the opposite sides as shown in FIG. The brake portions 41, 41 are spaced from the brake surface 24 against the tension spring means 42 by abutting against the outer periphery of the brake regulating ring 7 provided so as to be movable in the axial direction. is held in a non-braking state you possess, also, overload occurs on the driven side, when the driven-side member 20 is spaced a predetermined or more from the drive-side member 10, the brake regulating ring 7 by following the this By moving and disengaging from the engaging protrusions 45, 45, the two brake elements 40, 40 are pulled toward each other by the tensile force of the tension spring means 42, and the braking portions 41, 41 are moved to the braking surface. Press against 24 It is configured to perform the action.

Therefore, the brake regulating ring 7 is configured to transmit both the engagement torque and the engagement recess 12 in the normal torque transmission , that is, when the driven member 20 is not separated from the driving member 10. When the engagement element 12 is disengaged from the engagement recess 22 due to the occurrence of an overload on the driven side, the engagement protrusion 45 is located at a position where it abuts against the engagement protrusion 45 , 45 on the opposite side of the brake element 40, 40. , 45 is set so as to be separated from the position of the driven side member 20 so as to deviate from the position of 45, and the distance 6 is held by the collar 6. In some cases, the brake regulating ring 7 is formed integrally with the collar 6.

  Further, the braking surface 24 of the braking disk 23 forms a reverse taper that gradually increases in diameter from the side fixed to the driven member 20 and is pressed against the braking surface 34 at the brake elements 40 and 40. The braking portions 41, 41 form an inclined surface corresponding to the reverse taper of the braking surface 24 on the outer periphery of the disk, and the driven member 20 is simultaneously displaced and moved away from the driving member 10 by the braking action. It is configured to work.

The braking surface 24 of the disk 23 and the braking portion 41 of the braking element 40 are usually formed by adhering braking lining materials 26 and 46 having good friction durability. Further, the outer portions (upper and lower parts in FIG. 1) of the brake elements 40, 40 in the support bracket 4 extend toward the other support bracket 4 and have end portions inward. Guide portions 47, 47 that are bent into a shape are projected, and both the brake elements 40, 40 are held inside the guide portions 47, 47 so that lateral vibration during braking action is restricted. It can be supported with good stability.

  In the above-described embodiment, the elastic force of the spring means 5 that presses the driven side member 20 to the side facing the drive side member 10, the elastic force of the spring means 42 for braking action, etc. It is set appropriately according to the magnitude of torque to be transmitted, the magnitude of torque limit, and the like.

  According to the torque interrupt device having the above-described configuration, during normal operation, the engagement element 12 provided on one facing surface 11 of the driving side member 10 and the driven side member 20 facing each other in the axial direction is Of the inclined surfaces 12a and 12b at both ends in the rotational direction of the engaging element 12, the inclined surface 12a on the front side in the rotational direction of the engaging concave portion 22 corresponding thereto Abutting on the inclined surface 22 a and being held in an engaged state, the rotation of the driving side member 10 is transmitted to the driven side member 20 via the engaging element 12, and the driven side member 20 rotates together with the driving side member 10. . At this time, the driven member 20 is pressed and biased to the side facing the driving side member 10 by the spring means 5, and is further driven by the magnetic force of the magnet 8 provided on one of the opposing surfaces 11 and 21. The side member 20 is held in a state of being attracted to and in contact with the driving side member 10. At this time, the brake elements 40, 40 are held in the non-braking state against the reference spring means 42, with the engagement protrusions 45, 45 coming into contact with the outer periphery of the brake regulating ring 7. Transmission is made normally.

  When an overload occurs on the driven shaft 2 side due to a tool biting or failure with respect to the workpiece, the engagement element 12 of the drive side member 10 is inclined to the inclined surfaces 12a and 22a on the front side in the rotation direction. The driven side member 20 resists the magnetic force applied by the magnet 8 and the pressing force applied by the spring means 5 as a result. The engaging element 12 is disengaged from the engaging recess 22 at the same time. As a result, the drive side member 10 idles with respect to the driven side member 20, and the torque transmission is interrupted.

  Moreover, the brake regulating ring 7 that moves following the driven member 20 moves from the engagement protrusions 45, 45 of the brake elements 40, 40 substantially simultaneously with the detachment of the engagement element 12 from the engagement recess 22. The braking elements 40 and 40 perform a braking action by the urging force of the tension spring means 42 connecting them, and the braking parts 41 and 41 of the braking elements 40 and 40 are fixed to the driven member 20. Further, it comes into pressure contact with the braking surface 24 of the braking disk 23. As a result, the rotation of the driven member 20 is immediately stopped, and it is possible to suppress the progress of biting or the like that causes an overload state.

  In particular, if the braking surface 24 of the disk 23 and the braking portions 41 and 41 of the brake elements 40 and 40 form an inclined surface with a reverse taper as shown in the figure, the driven member is driven by the braking action. Since 20 is displaced in a direction further away from the driving side member 10, the driven side member 20 is sufficiently separated from the driving side member 10, and the torque can be reliably shut off.

  Therefore, even if the driving side member 10 continues to rotate, the engaging element 12 will idle without contacting the opposing surface 21 facing it or entering / exiting the engaging recess 22. Therefore, torque transmission can be cut off without generating noise due to idling in the contact state of the engagement element 12, and damage to the vicinity of the engagement element 12 and the engagement recess 22 can be prevented.

Then, when the braking action is released after the torque transmission is cut off and the operation is stopped once as described above, the braking which is disengaged from the engaging projections 41, 41 of the brake elements 40, 40 as shown in FIG. Since the restricting ring 7 is engaged with the engaging protrusions 41 and 41 and the movement is restricted, the operation rings 44 and 44 of the brake elements 40 and 40 are held and the both springs are opposed to the tension spring means 42. What is necessary is just to open the brake elements 40, 40, and the brake regulating ring 7 is also moved following the movement of the driven member 20 to the opposite side of the drive member 10 by the spring means 5. The original non-braking state can be restored. Further, the engagement element 12 is fitted into the engagement recess 22 so that torque can be transmitted.

  In this state, for example, the drive-side member 10 is reversely rotated to cancel the cause of the overload state such as biting. At this time, if the reverse rotation can transmit a larger torque, the release The action can be easily performed.

  In the above-described embodiment, the case where the engaging element is provided in the driving side member and the engaging concave portion is provided in the driven side member is shown, but conversely, the same is applied to the driven side member. The engaging member can be implemented by providing the engaging recess in the driving side member. Also, the magnet and the magnetic attachment part can be implemented by providing the magnet on the driving member and the magnetic attachment part on the driven member, contrary to the illustrated embodiment.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used as a torque limiter provided in a joint portion between a drive shaft and a driven shaft for transmitting rotational force to various rotating machines.

It is a longitudinal cross-sectional view in a state where normal torque transmission is possible. It is a longitudinal cross-sectional view of a state in which the driven member is separated from the driving member due to the occurrence of overload. It is a front view from the opposing surface side with the driven side member of a drive side member. It is the top view which cut down some drive side members. It is a front view from the opposing surface side with the drive side member of a driven side member. It is the top view which cut down some drive side members. It is a front view from the brake disk side of the driven member. It is a front view which shows a brake element part. It is an expanded sectional explanatory view of a portion of an engagement child and an engagement crevice.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Drive shaft, 2 ... Driven shaft, 3, 4 ... Support bracket, 3a, 4a ... Metal bearing, 5 ... Spring means, 6 ... Collar, 7 ... Braking control ring, 8 ... Magnet, 9 ... Magnetic attachment part, 10 DESCRIPTION OF SYMBOLS ... Drive side member, 11 ... Opposing surface, 12 ... Engagement element, 12a, 12b ... Inclined surface of both ends of rotation direction, 13 ... Mounting screw, 20 ... Driven side member, 21 ... Opposing surface, 22 ... Engaging recess, 22a, 22b: Inclined surfaces at both ends in the rotational direction, 23: Braking disk, 24 ... Braking surface, 26 ... Braking lining material, 40 ... Braking element, 41 ... Braking part, 42 ... Tension spring means, 43 ... Shaft support, 44 ... an operation handle part, 45 ... an engagement protrusion, 46 ... a braking lining material, 47 ... a guide part, G, H, G ', H' ... an inclination angle.

Claims (2)

An overload torque interrupting device provided in a joint portion between a drive shaft and a driven shaft arranged on the same axis,
A drive-side member fixed to the end of the drive shaft and a spline fit slidably in the axial direction to the end of the driven shaft so as to be close to and away from the drive-side member. A driven member, and spring means for pressing and urging the driven member toward the driving member.
The drive side member and the driven side member are provided with a convex engagement element projecting from the opposing surface on one of the opposing surfaces, and an engagement concave part into which the engagement element can be fitted on the other. The engaging element and the engaging recess have inclined surfaces in which both end surfaces in the rotation direction correspond to each other, and normally hold the contact engagement state in which the inclined surfaces on the front side in the rotation direction can transmit torque. When overload occurs on the driven shaft side, the engaging element is detached from the engaging recess along the inclined surface, and the driven member is moved in the axial direction against the spring means to be separated from the driving member. In the overload torque cutoff device provided to obtain ,
A braking disk having a braking surface formed on the outer periphery is fixed to the opposite side of the driven member to the side facing the driving side member. The disk is opposed to the outside of the disk with the disk interposed therebetween. A pair of brakes with an operating handle having a braking portion is pivotally supported on a support bracket that supports the driven shaft so as to be pivotable in a vertical manner, and the outer circumference of the disc is connected by a tension spring means that connects the brakes. The braking surface is provided so as to be sandwiched between the braking portions,
The brake surface of the disk forms a reverse taper that gradually increases in diameter from the side fixed to the driven member, and the brake portion of the brake element forms an inclined surface corresponding to the reverse taper of the brake surface on the outer periphery of the disk,
In addition, on the driven shaft, the opposing sides of the two brake elements abut each other when the driven member can move in the axial direction following the driven member, and the driven member is not separated from the driving member. There is provided a brake regulating ring which is in a contact position and holds both brake elements in an unbraking state against the tension spring means, and the driven side member is driven by the drive side member when an overload is generated on the driven shaft side. Overload torque , wherein the brake restricting ring is disengaged from the brake element and the braking portion of the brake element is pressed against the braking surface to perform a braking action when separated from the brake element by a certain distance or more. Shut-off device.   The inclined surfaces at both ends in the rotation direction of the engaging element and the engaging recess have different inclination angles with respect to a surface perpendicular to the rotation direction, and the inclination angle of the inclined surface that abuts and engages during forward rotation is different during reverse rotation. The overload torque interrupt device according to claim 1, wherein the overload torque interrupting device is set to be larger than the inclination angle of the inclined surface that abuts and engages.

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