JP2009127782A - Spring type torque limiter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spring type torque limiter with a function of a clutch added thereto, using one type of coil spring to perform both a function of the torque limiter and a function of the clutch while saving energy. <P>SOLUTION: In the torque limiter, part of a coil portion 24 of the coil spring 15 is tightly fastened to an input member 12 and the other part of the coil portion 24 is engaged with an output member 13, and a predetermined torque value is set at the coil portion 24 tightly fastened to the input member 12 so that driving torque is input to the input member 12 in the rotating direction of increasing the tightly fastening force of the coil portion 24. A control member 14 is combined with the input member 12 and the output member 13 in a relatively rotatable and coaxial condition. The control member 14 establishes a freely rotating condition or a rotation constraining condition with external control. A control hook 25 is provided at the end of part of the coil portion 24 tightly fastened to the input member 12. The control hook 25 is engaged with the control member 14. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a spring type torque limiter used in a paper feeding mechanism of an office machine, and more particularly to a spring type torque limiter having a clutch function.

  In order to avoid the inconvenience of the step-out of the drive motor in the paper feed mechanism of office machines such as printers, copiers, etc., when the paper jam is overloaded, a torque limiter is used for the drive unit, A safety mechanism for reducing the load may be provided. The torque limiter used in this case is, for example, a spring type torque limiter as shown in FIGS. 15 and 16 (Patent Document 1).

  In the torque limiter, the input member 1 and the output member 2 are combined in a concentric state and relatively rotatable with the input member 1 as the inner diameter side, and a coil spring 3 is provided on the outer diameter surface of the trunk portion of the input member 1. Bound. Both ends of the coil spring 3 intersect, and hooks 4 and 4 having a certain opening angle are provided at the intersecting tip. The hooks 4, 4 are attracted in a direction approaching each other, and the hooks 4, 4 are provided on the inner diameter surface of the output member 2 in a state where the diameter of the coil portion is larger than the natural state. The coil portion is engaged with the slit 5 and is wound around the body portion of the input member 1 with a constant binding force. A constant set torque value is determined by the binding force of the coil portion.

  Torque is transmitted from the input member 1 to the output member 2 via the coil spring 3, but if the load torque exceeds a set torque value due to the occurrence of a jam or the like, slippage occurs in the coil portion, and torque is transmitted to the load. By interrupting, the influence on the drive motor is avoided.

There is also known a torque limiter having a clutch function in which a clutch function is added to the torque limiter, the clutch is operated as necessary, and torque transmission to a load is cut off (Patent Literature). 2).
JP 2002-174272 A JP 2002-89592 A

  In a safety mechanism using a spring-type torque limiter as described in Patent Document 1, in order to save energy, when a paper feeding action is in a paused state, a latching claw is put on the output side of the torque limiter. The rotation is forcibly stopped by the means and idling is performed at the torque limiter portion. The transmission of the drive torque is interrupted by the idling of the torque limiter, and the load is disconnected from the drive motor, thereby reducing the load on the drive motor and contributing to energy saving.

  However, in the above torque cutoff state, there is an energy loss due to the generation of frictional heat because the coil spring is idling due to the friction that generates the set torque value. Today, energy saving in office machines is an important issue, and such energy loss cannot be ignored.

In the case of Patent Document 2, a coil spring type torque limiter and a coil spring type clutch are combined in series, and two types of coil springs are required, resulting in a high cost.

  Therefore, the present invention reduces the friction at the time of interruption of torque transmission in the spring type torque limiter, thereby saving energy of the spring type torque limiter and using only one type of coil spring. It is an object to achieve cost reduction and space saving by enabling both functions of the clutch.

  In order to solve the above-described problems, the present invention is configured such that the input member 12 and the output member 13 are rotatable and combined in a coaxial state, and a part of the coil spring 15 is tightly bound to the input member 12 and the coil spring 15 is combined. The other portion is engaged with the output member 13, the tightening torque of the coil spring 15 that is bound to the input member 12 is set to a predetermined torque value, and the binding force of the coil spring 15 is applied to the input member 12. In a spring-type torque limiter that inputs driving torque in an increasing rotational direction, the input member 12 and the output member 13 are relatively rotatable, and the control member 14 is combined in a coaxial state. The rotation of the coil spring 15 can be in a free state and constrained state, and the portion of the coil spring 15 bound to the input member 12 can be controlled. Control hook 25 is provided in the part, and configured to control the hook 25 is engaged with the control member 14.

  In the torque limiter having the above-described configuration, a predetermined set torque value can be obtained at a portion where the coil spring 15 is bound to the input member 12. When the control member 14 is in a free state, when driving torque is input to the input member 12, the driving torque is transmitted to the output member 13 via the coil spring 15. When the load torque exceeds the set torque value, idling occurs in the binding portion and transmission of the drive torque is interrupted.

  In the torque limiter, if the control member 14 is restrained by an external action when the paper feeding action is in a resting state, the rotation of the coil spring 15 engaged with the control member 14 by the control hook 25 is stopped. Since the input member 12 continues to rotate, the binding force of the coil spring 15 is loosened, the input member 12 is idled, and torque transmission is interrupted. Since the binding force is reduced in the coil portion of the coil spring 15, the friction is reduced.

  As described above, according to the present invention, when the torque transmission is unnecessary, the diameter of the coil portion in the tightly bound state can be forcibly expanded by restraining the control member. Energy saving can be achieved. Further, since the torque limiter and the spring clutch can be operated by using one type of coil spring, the cost can be reduced and the space can be saved by reducing the number of parts.

  The best mode of the present invention will be described below based on examples.

  The torque limiter of the first embodiment shown in FIGS. 1 and 2 includes an input member 12, an output member 13, a control member 14, and a coil spring 15 that are rotatably fitted on a fixed shaft 11. The input member 12, the output member 13 and the control member 14 are each formed in an annular shape, and an input gear 16, an output gear 17 and a control gear 18 are provided on the outer diameter surface. The gears 16, 17, and 18 are provided on the outer diameter surfaces of the members 12, 13, and 14, respectively, in the same manner in the other embodiments described later.

  The input member 12 and the output member 13 are disposed to face each other, and an input side body portion 19 and an output side body portion 20 having the same outer diameter are provided concentrically on the respective opposing surfaces. The body parts 19 and 20 face each other with a slight axial gap. Further, stepped portions 21 and 22 having larger diameters and the same diameter as the input side body portion 19 and the output side body portion 20 are provided on the opposing surfaces of the input member 12 and the output member 13, respectively.

  The control member 14 is rotatably supported at both inner diameter surfaces by the step portions 21 and 22 and positioned in the axial direction. A control claw 23 composed of a solenoid or the like faces the radially outer side of the control gear 18 formed on the outer diameter surface of the control member 14 so as to advance and retract in the radial direction, and is controlled by advancing according to a command from an external control device. It engages with the gear 18 (see the one-dot chain line in FIG. 1) and restrains the control member 14. Further, the control member 14 is released and freed by retreating.

  The coil portion 24 of the coil spring 15 is bound to the input side body portion 19 and the output side body portion 20 with elasticity in the diameter reducing direction. The coil spring 15 is formed of a wire having a square cross section, and a control hook 25 that is radially outward is provided at the end of the coil portion 24 on the input member 12 side (see FIG. 2). The control hook 25 is inserted into the radial engagement hole 26 provided in the control member 14 from the inner diameter side. In the illustrated case, the winding direction of the coil spring 15 is left-handed.

  At least a portion of the coil portion 24 that is bound to the input side body portion 19 is adjusted in the binding force by the number of windings, the material of the wire and the input side body portion 19 (steel or synthetic resin, etc.), and the application of the lubricant. A predetermined set torque value is determined by adjusting the friction coefficient by means of, for example, and when a load exceeding the set torque value is applied, idling occurs and a torque limiter that cuts off torque transmission is performed.

  In FIG. 1, reference numerals 27 and 28 denote retaining rings for the input member 12 and the output member 13, respectively.

  The torque limiter of the first embodiment has the above configuration, and the operation thereof will be described next. In the normal torque transmission state, the control claw 23 is in the retracted position indicated by the solid line, and the control member 14 is in the free state.

In this state, as shown in FIG. 2, the opposite direction is input side barrel portion 19 of the integral input member 12 and a hand winding direction of the coil spring 15 with respect to the fixed shaft 11, i.e., X ₁ in FIG. 1 -X Rotate rightward in the direction of arrow ₁ (see arrow A in FIG. 2). In FIG. 1, the input of the driving torque to the input member 12 is indicated by a white arrow facing the inner diameter direction (the same applies to the following embodiments).

  The coil portion 24 of the coil spring 15 is in a reduced diameter state, and the driving torque is transmitted to the output side by being bound to the input side body portion 19 and the output side body portion 20 with elasticity in the diameter reducing direction. The driving torque output from the output member 13 to the load side is indicated by a white arrow pointing in the outer diameter direction (the same applies to the following embodiments). The control member 14 in the free state also rotates right together with the input member 12 and the output member 13 via the control hook 25.

  In the above torque transmission state, for example, when a load exceeding a set torque value is applied due to a paper jam or the like, idling occurs between the input side body portion 19 and the coil portion 24 tightly bound thereto, and torque is transmitted. Is shut off and the rotation of the output member 13 is stopped. Since the rotation of the coil spring 15 is stopped, the rotation of the control member 14 is also stopped.

On the other hand, in the torque transmission state, when the torque transmission is temporarily interrupted when the paper feeding operation is stopped from the viewpoint of energy saving or the like, the control claw 23 is advanced by external control and engaged with the control gear 18. As a result, the control member 14 is restrained. Since the input member 12 continues to rotate to the right, a part or all of the coil portion 24 that is bound to the input-side body portion 19 near the control hook 25 that has stopped rotating is forcibly expanded in diameter to transmit torque. Is cut off. As the diameter of the coil portion 24 is increased, the friction between the input side body portion 19 and the coil portion 24 is reduced, and the idling torque is reduced as much as possible. Therefore, energy loss is suppressed.

  The torque limiter of the second embodiment shown in FIGS. 3 and 4 is arranged in the order of the control member 14, the input member 12, and the output member 13 from the left in FIG. The control member 14 has a control body 29 on the inner end surface, and the fixed shaft 11 penetrates the control member 14 and the control body 29 so as to be relatively rotatable. On the inner end surface of the control member 14, a step portion 30 is provided in a portion having a larger diameter than the control body portion 29, and one end inner diameter surface of the annular input member 12 is rotatably supported by the step portion 30.

  An output member 13 having the same inner and outer diameters is arranged with a slight gap in the axial direction from the input member 12. The output member 13 has a boss portion 31 at the outer end portion, and the boss portion 31 is rotatably fitted to the outer diameter surface of the control body portion 29. An inner diameter surface of the input member 12 is an input side body portion 19, and an inner diameter surface of the output member 13 is an output side body portion 20.

  The coil spring 15 is tightly bound with elasticity in the diameter-expanding direction with the coil portion 24 extending over the input-side body portion 19 and the output-side body portion 20. A radially inward control hook 25 is provided at an end of the coil portion 24 on the input side body portion 19 side.

  On the inner end face of the control member 14, a small diameter step portion 32 is provided between the control body 29 and the step portion 30, and a slit 33 is formed in the small diameter step portion 32. The control hook 25 is engaged with the slit 33 (see FIG. 4). In this case, the winding direction of the coil spring 15 is left-handed.

  At least a portion of the coil portion 24 wound around the input side body portion 19 is set with a predetermined set torque value in the same manner as in the first embodiment, and when a load exceeding the set torque value is applied. It causes idling and acts as a torque limiter that blocks torque transmission.

  A retaining ring 27 ′ is attached between the front end surface of the control body 29 and the fixed shaft 11.

  The torque limiter according to the second embodiment has the above configuration, and the operation thereof will be described next. In the normal torque transmission state, the control claw 23 is in the retracted position indicated by the solid line, and the control member 14 is in the free state.

In this state, as shown in FIG. 4, the input member 12 is in the same direction as the winding of the coil spring 15 with respect to the fixed shaft 11, that is, in the left direction as viewed in the direction of the arrow X ₂ -X _{2 in} FIG. It is rotated (see arrow B in FIG. 4).

  A driving torque is transmitted to the output side by the coil portion 24 of the coil spring 15 being elastically bound to the input side barrel portion 19 and the output side barrel portion 20 in the diameter increasing direction. The control member 14 in the free state rotates counterclockwise together with the input member 12 and the output member 13 via the control hook 25.

  During the torque transmission described above, when a load exceeding the set torque value is applied due to, for example, a paper feeding jam, idling occurs between the input side body portion 19 and the coil portion 24 tightly bound thereto, and torque transmission is performed. Is shut off and the rotation of the output member 13 is stopped. At the same time, the rotation of the coil spring 15 and the control member 14 is also stopped.

  On the other hand, in the torque transmission state, when the torque transmission is temporarily interrupted when the paper feeding operation is stopped from the viewpoint of energy saving or the like, the control claw 23 is advanced by external control, and this is transferred to the control gear 18. By engaging, the control member 14 is brought into a restrained state. Since the input member 12 continues to rotate counterclockwise with respect to the control hook 25 that has stopped rotating, the coil portion 24 that is bound to the input side body portion 19 near the control hook 25 is forcibly reduced in diameter, and torque transmission is interrupted. Is done. Due to the reduced diameter of the coil portion 24, the friction between the input side body portion 19 and the coil portion 24 is reduced, and the idling torque becomes as small as possible. Therefore, energy loss is suppressed.

  The torque limiter of the third embodiment shown in FIGS. 5 and 6 is the same as that of the second embodiment in that the control member 14, the input member 12, and the output member 13 are arranged in this order from the left in FIG. However, in this case, the coil spring 15 is different from that of the second embodiment in that the coil spring 15 is bound only to the input side body portion 19 formed on the inner diameter surface of the input member 12.

  That is, the output side body 20 is provided at the center of the inner end face of the output member 13, and the output side body 20 penetrates the control member 14 so as to be relatively rotatable. That is, the control member 14 is rotatably fitted to the output side body portion 20. Step portions 30, 30 'having the same diameter are provided on the opposing inner surfaces of the control member 14 and the output member 13, and the input member 12 is rotatably supported between the step portions 30, 30'.

  The coil portion 24 of the coil spring 15 is bound to the inner diameter surface of the input member 12, that is, the input side body portion 19 with elasticity in the diameter increasing direction. A control hook 25 is provided radially inward at the end of the coil portion 24 on the control member 14 side, and an output hook 25 ′ in the same direction is provided at the end of the output member 13 side. As shown in FIG. 6, the winding direction of the coil portion 24 is left-handed.

Hook receiving projection 35 to the smaller diameter portion than the stepped portion 30 in the inner end surface of the control member 14 is provided, the rotation direction of the input member 12 as viewed in the direction of X ₃ -X ₃ taken along line of FIG. 5 (6 The control hook 25 is engaged with the end face 36 on the delay side of the arrow B).

  Further, on the inner end surface of the output member 13, a hook engaging projection 37 is provided on the outer diameter surface of the output side body portion 20, and the output hook 25 ′ is inserted into a slit 38 provided on the hook engaging projection 37. Engaged (see FIG. 6).

  As in the case of each of the embodiments described above, a predetermined set torque value is determined in the coil section 24, and when a load exceeding the set torque value is applied, idling occurs and the torque limiter that cuts off torque transmission is applied. Perform the action.

  The torque limiter of the third embodiment has the above configuration, and the operation thereof will be described next. In the normal torque transmission state, the control claw 23 is in the retracted position indicated by the solid line, and the control member 14 is in the free state.

In this state, as shown in FIG. 6, the input member 12 is in the same direction as the winding of the coil spring 15 with respect to the fixed shaft 11, that is, in the left direction when viewed in the direction of arrows X ₃ -X _{3 in} FIG. It is rotated (see arrow B in FIG. 6). Since the coil portion 24 of the coil spring 15 is tightly bound to the input side body portion 19 in the diameter increasing direction, the control hook 25 is engaged with the control member 14, and the output hook 25 ′ is engaged with the output member 13. These members rotate counterclockwise together with the input member 12, and drive torque is transmitted to the output member 13.

During the torque transmission, when a load exceeding the set torque value is applied due to, for example, a paper feeding jam, idling occurs in the input side body portion 19 and the coil portion 24 tightly bound thereto, and the output member 13 rotates. Is stopped and torque transmission is interrupted. At the same time, the rotation of the coil spring 15 and the control member 14 is also stopped.

  On the other hand, in the torque transmission state, when the torque transmission is temporarily interrupted when the paper feeding operation is stopped from the viewpoint of energy saving or the like, the control claw 23 is advanced by external control, and this is transferred to the control gear 18. By engaging, the control member 14 is brought into a restrained state. Since the input member 12 continues to rotate counterclockwise, the coil portion 24 fastened to the input side body portion 19 in the vicinity of the control hook 25 whose rotation has been stopped is forcibly reduced in diameter, and torque transmission is interrupted. Since the friction between the input-side body portion 19 and the coil portion 24 is reduced by the reduced diameter of the coil portion 24, the idling torque becomes as small as possible. Therefore, energy loss is suppressed.

  The torque limiter according to the fourth embodiment shown in FIGS. 7 to 9 has basically the same configuration as that of the third embodiment. However, in this case, the difference is that two coil springs 15 and 15 ′ are used. is doing. These coil springs 15, 15 'are opposite in winding direction. In the illustrated case, the coil spring 15 is counterclockwise (see FIG. 8) and the coil spring 15 'is clockwise (see FIG. 9).

  Each of the coil springs 15 and 15 'has a control hook 25 at one end and an output hook 25' at the other end. Corresponding to these hooks 25, 25 ', the hook receiving projection 35 provided on the control member 14 is formed long enough to approach the inner end face of the output member 13 (see FIG. 7). Similarly, the hook engaging protrusion 37 provided on the output member 13 is also formed long enough to reach the intermediate portion of the input member 12.

The control hook 25 of one coil spring 15 is disposed at the end on the control member 14 side. As shown in FIG. 8, which is a view taken along arrow X ₄ -X ₄ in FIG. 7, the control hook 25 has an end face 36 on the delay side of rotation when the hook receiving protrusion 35 is viewed in the rotation direction B of the input member 12. Is engaged. The output hook 25 ′ at the other end of the coil spring 15 is engaged with the slit 38 of the hook engaging protrusion 37. The coil part 24 is tightly bound to the input side body part 19 with elasticity in the diameter increasing direction.

The control hook 25 of the other coil spring 15 ′ is disposed at the end on the output member 13 side, and the hook receiving projection 35 is viewed in the rotation direction B of the input member 12 (as viewed in the direction of arrows X ₅ -X _{5 in} FIG. 7). 9 is engaged with the end face 36 on the rotation delay side. The output hook 25 ′ is in contact with the output hook 25 ′ in the axial direction and engaged with the slit 38 of the hook engaging protrusion 37.

  Since the other configuration of the fourth embodiment is the same as that of the third embodiment, the description of the overlapping portion is omitted, and the operation thereof will be described next.

In the normal torque transmission state, the control claw 23 is in the retracted position indicated by the solid line, and the control member 14 is in the free state. In this state, as shown in FIGS. 8 and 9, the input member 12 is viewed in the same direction as the winding of the coil spring 15 with respect to the fixed shaft 11, that is, in the direction indicated by arrows X ₄ -X _{4 in} FIG. It is rotated leftward (see arrow B in FIGS. 8 and 9).

  The coil portions 24 and 24 of the coil springs 15 and 15 'are fastened to the input-side body portion 19 in the diameter increasing direction, the control hooks 25 and 25 are engaged with the hook receiving projections 35, and the output hooks 25' and 25 'Is engaged with the hook engaging protrusion 37. For this reason, the output member 13 and the control member 14 rotate counterclockwise together with the input member 12. As a result, the drive torque is transmitted to the output member 13.

During the torque transmission, when a load exceeding the set torque value is applied due to, for example, a paper feeding jam, the input side body portion 19 and the coil portions 24 and 24 of the coil springs 15 and 15 ′ tightly bound thereto are connected. Idling occurs at this time, the rotation of the output member 13 is stopped, and the transmission of torque is interrupted. At the same time, the rotation of the coil springs 15, 15 ′ and the control member 14 is also stopped.

  On the other hand, in the torque transmission state, when the torque transmission is temporarily interrupted when the paper feeding operation is stopped from the viewpoint of energy saving or the like, the control claw 23 is advanced by external control, and this is transferred to the control gear 18. By engaging, the control member 14 is brought into a restrained state.

  Since the input member 12 continues to rotate counterclockwise, the coil portions 24 and 24 that are bound to the input side body portion 19 in the vicinity of the control hooks 25 and 25 of the coil springs 15 and 15 'are reduced in diameter to transmit torque. Blocked. Due to the reduced diameter of the coil portion 24, the friction between the input side body portion 19 and the coil portion 24 is reduced, and the idling torque becomes as small as possible. Therefore, energy loss is suppressed.

  As in the third embodiment, the one using the single coil spring 15 and the one using the two coil springs 15 and 15 'having different winding directions as in the fourth embodiment are effective. The difference will be described next.

  When the single coil spring 15 is used as in the third embodiment (see FIGS. 5 and 6), when the input member 12 and the coil portion 24 are idle and are idle, the idling torque is not zero. Therefore, when the input-side body portion 19 that is rotating with respect to the coil portion 24 in a stopped state is in sliding contact, a thrust force is induced in the coil portion 24. The direction of the thrust force is determined by the rotation direction B of the input member 12 and the winding direction (left-handed) of the coil spring 15. In the illustrated case, the direction is the direction of the output member 13, and the coil spring 15 may move in that direction and come into contact with the output member 13, which may hinder the rotation of the output member 13.

  On the other hand, when two coil springs 15 and 15 ′ having different winding directions are used as in the fourth embodiment, the direction of the thrust force induced in each coil spring 15 and 15 ′ is opposite. , Negotiate and negate each other. For this reason, there is an advantage that smooth rotation can be obtained without causing the above-mentioned troubles.

  The torque limiter of the fifth embodiment shown in FIGS. 10 and 11 is arranged in the order of the control member 14, the output member 13, and the input member 12 in this order from the left in FIG.

  An input side body 19 is provided at the center of the inner surface of the input member 12, and the input side body 19 penetrates the control member 14 so as to be relatively rotatable. That is, the control member 14 is rotatably fitted to the input side body portion 19. Step portions 30, 30 'having the same diameter are provided on the opposing inner surfaces of the control member 14 and the input member 12, and the output member 13 is rotatably supported between the step portions 30, 30'.

  The coil part 24 of the coil spring 15 is bound to the outer diameter surface of the input side body part 19 of the input member 12 with elasticity in the diameter reducing direction. A control hook 25 is provided radially outward at the end of the coil portion 24 on the control member 14 side, and an output hook 25 ′ in the same direction is provided at the end of the input member 12 side. As shown in FIG. 11, the winding direction of the coil portion 24 is left-handed.

A hook receiving projection 35 is provided on the inner end surface of the control member 14 at a portion having a smaller diameter than the stepped portion 30, and the input member 12 and the input integral with the input member 12 when viewed in the direction of arrows X ₆ -X _{6 in} FIG. The control hook 25 is engaged with the end face 36 that is the side of rotation of the side body portion 19, that is, the delay side of the right rotation (see arrow A in FIG. 11).

  Further, a hook engaging projection 37 is provided at an end of the inner diameter surface of the output member 13 on the input member 12 side, and the output hook 25 ′ is engaged with a slit 38 provided in the hook engaging projection 37. The

  A predetermined set torque value is determined between the coil portion 24 and the input side body portion 19 in the same manner as in each of the above embodiments, and when a load exceeding the set torque value is applied, idling occurs. The point that the action of the torque limiter that cuts off the torque transmission is performed is the same as in the case of the above embodiment.

Next, the operation of the fifth embodiment will be described. In the normal torque transmission state, the control claw 23 is in the retracted position indicated by the solid line, and the control member 14 is in the free state. In this state, as shown in FIG. 11, the input member 12 and the input side body 19 integral with the fixed shaft 11 are opposite to the winding of the coil spring 15, that is, X ₆ -X _{6 in} FIG. It is rotated rightward as seen in the direction of the arrow (see arrow A in FIG. 11).

  The coil portion 24 of the coil spring 15 is tightly bound to the input side body portion 19 in the diameter reducing direction, the control hook 25 is engaged with the hook receiving projection 35, and the output hook 25 ′ is engaged with the hook engaging projection 37. Therefore, the output member 13 and the control member 14 rotate clockwise as a unit with the input member 12. As a result, the drive torque is transmitted to the output member 13.

  During the torque transmission, when a load exceeding the set torque value is applied due to, for example, a paper feeding jam, idling occurs between the input side body portion 19 and the coil portion 24 tightly bound thereto, and the output member 13 Is stopped and torque transmission is interrupted. At the same time, the rotation of the coil spring 15 and the control member 14 is also stopped.

  On the other hand, in the torque transmission state, when the torque transmission is temporarily interrupted when the paper feeding operation is stopped from the viewpoint of energy saving or the like, the control claw 23 is advanced by external control, and this is transferred to the control gear 18. By engaging, the control member 14 is brought into a restrained state.

  Since the input member 12 continues to rotate to the right, the coil portion 24 that is bound to the input-side body portion 19 near the control hook 25 that has stopped rotating is forcibly expanded in diameter, and torque transmission is interrupted. As the diameter of the coil portion 24 is increased, the friction between the input side body portion 19 and the coil portion 24 is reduced, and the idling torque is reduced as much as possible. Therefore, energy loss is suppressed.

  The torque limiter according to the sixth embodiment shown in FIGS. 12 to 14 basically has the same configuration as that of the fifth embodiment. However, in this case, the difference is that two coil springs 15 and 15 ′ are used. is doing. These coil springs 15, 15 'are opposite in winding direction. In the illustrated case, the coil spring 15 is counterclockwise (see FIG. 13) and the coil spring 15 'is clockwise (see FIG. 14).

  Each of the coil springs 15 and 15 'has a control hook 25 at one end and an output hook 25' at the other end. Corresponding to these hooks 25, 25 ', the hook receiving projection 35 provided on the control member 14 is formed long enough to reach the intermediate portion of the output member 13 (see FIG. 12). Similarly, the hook engaging protrusion 37 provided on the inner diameter surface of the output member 13 is also formed to have a length over the entire length of the output member 13.

The control hook 25 of one of the coil springs 15 is disposed at an intermediate portion of the output member 13, and the control hook 25 is connected to the input member 12 and the input side body portion integral with the hook receiving projection 35 as shown in FIG. 19 is engaged with the end face 36 on the delay side when viewed in the rotational direction A. The output hook 25 ′ at the other end of the coil spring 15 is disposed at the end on the control member 14 side and is engaged with the slit 38 of the hook engaging protrusion 37. The coil part 24 is bound to the input side body part 19 with elasticity in the direction of diameter reduction.

  The control hook 25 of the other coil spring 15 ′ also has a delay in rotation when the hook receiving projection 35 is viewed in the rotational direction A of the input member 12 and the input side body 19 integral with the input member 12 at the center of the output member 13. It is engaged with the end face 36 on the side, and is arranged close to or in contact with the control hook 25 of the coil spring 15 in the axial direction. The output hook 25 ′ is disposed at the end of the hook engaging protrusion 37 on the input member 12 side, and is engaged with the slit 38 of the hook engaging protrusion 37.

  Since the other configuration of the sixth embodiment is the same as that of the fifth embodiment, description of overlapping portions is omitted, and the operation thereof will be described next.

In the normal torque transmission state, the control claw 23 is in the retracted position indicated by the solid line, and the control member 14 is in the free state. In this state, as shown in FIG. 13, the input member 12 and the input side body 19 integrated with the fixed shaft 11 are opposite to the winding of the coil spring 15, that is, X ₇ -X _{7 in} FIG. It is rotated to the right as seen in the direction of the arrow (see arrow A in FIG. 13).

  The coil portions 24 and 24 of the coil springs 15 and 15 ′ are fastened to the input-side body portion 19 in the diameter reducing direction, the control hooks 25 and 25 are engaged with the hook receiving projections 35, and the output hooks 25 ′ and 25 Since 'is engaged with the hook engaging protrusion 37, the output member 13 and the control member 14 rotate rightward together with the input member 12. As a result, the drive torque is transmitted to the output member 13.

  During the torque transmission, when a load exceeding the set torque value is applied due to, for example, a paper feeding jam, the input side body portion 19 and the coil portions 24 and 24 of the coil springs 15 and 15 ′ tightly bound thereto are connected. Idling occurs at this time, the rotation of the output member 13 is stopped, and the transmission of torque is interrupted. At the same time, the rotation of the coil springs 15, 15 'and the control member 14 is also stopped.

  On the other hand, in the torque transmission state, when the torque transmission is temporarily interrupted when the paper feeding operation is stopped from the viewpoint of energy saving or the like, the control claw 23 is advanced by external control, and this is transferred to the control gear 18. By engaging, the control member 14 is brought into a restrained state.

  Since the input member 12 continues to rotate to the right, the coil portions 24 and 24, which are bound to the input-side body portion 19 near the control hooks 25 and 25 'that have stopped rotating, are forcibly expanded in diameter to transmit torque. Is cut off. The friction between the input side body portion 19 and the coil portion 24 is reduced by increasing the diameters of the coil portions 24, 24, and the idling torque becomes as small as possible. Therefore, energy loss is suppressed.

  The merit of using the two coil springs 15 and 15 ′ having different winding directions is that, as described in the fourth embodiment, the thrust force induced in the coil portions 24 and 24 is canceled out and smooth rotation can be ensured. It is in that point.

Sectional view of Example 1 _X 1 -X ₁ arrow sectional view of Fig. 1 Sectional drawing of Example 2 _X 2 -X ₂ cross-sectional view taken along FIG. 3 Sectional drawing of Example 3 _X 3 -X ₃ arrow sectional view of Fig. 5 Sectional drawing of Example 4 X ₄ -X ₄ arrow sectional view of FIG. Figure 7 _X 5 -X ₅ cross-sectional view along a line Sectional drawing of Example 5 _X 6 -X ₆ cross-sectional view along a line 10 Sectional drawing of Example 6 _X 7 -X ₇ cross-sectional view along a line 12 _X 8 -X ₈ sectional view taken along line of FIG. 12 Cross section of conventional example _X 9 -X ₉ sectional view taken along line of FIG. 15

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Fixed shaft 12 Input member 13 Output member 14 Control member 15, 15 'Coil spring 16 Input gear 17 Output gear 18 Control gear 19 Input side trunk | drum 20 Output side trunk | drum 21, 22 Step part
23 Control claw 24 Coil part 25 Control hook 25 'Output hook 26 Engagement holes 27, 27' Retaining ring 28 Retaining ring 29 Control body part 30, 30 'Step part 31 Boss part 32 Small diameter step part 33 Slit 35 Hook receiving protrusion 36 End surface 37 Hook engagement protrusion 38 Slit

Claims (7)

  The input member (12) and the output member (13) are rotatable and coaxially combined, and a part of the coil spring (15) is fastened to the input member (12) and the other of the coil spring (15) is connected. The portion is engaged with the output member (13), the tightening torque of the coil spring (15) fastened to the input member (12) is set to a predetermined torque value, and the coil spring is applied to the input member (12). (15) In the spring-type torque limiter for inputting the rotational driving torque in the direction of increasing the binding force, the input member (12) and the output member (13) can be rotated relative to each other, and can be coaxially controlled. (14) are combined, and the control member (14) can be in a state where its rotation is free and constrained by external control, and is bound to the input member (12) of the coil spring (15). Control hook (2 ) Is provided, a spring type torque limiter, characterized in that the control hook (25) is engaged with said control member (14).   The input member (12) and the output member (13) have an input side barrel (19) and an output side barrel (20) facing each other, and a part of the coil spring (15) is the input side barrel. It is bound to the outer diameter surface of the portion (19) with elasticity in the direction of diameter reduction, and the other part of the coil spring (15) is engaged with the output side body portion (20) by binding. Item 2. The spring-type torque limiter according to Item 1.   The input member (12) and the output member (13) have the input side body part (19) and the output side body part (20) on their inner diameter surfaces, and a part of the coil spring (15) is part of the coil spring (15). The input side body (19) is tightly bound to the inner diameter surface of the input side body (19) with elasticity in the diameter increasing direction, and the other part of the coil spring (15) has elasticity in the diameter increasing direction on the inner diameter surface of the output side body (20). The spring-type torque limiter according to claim 1, wherein the spring-type torque limiter is engaged by tightening.   The input member (12) has an input side body (19) on its inner diameter surface, and the coil spring (15) is tightly bound to the inner surface of the input side body (19) with elasticity in the diameter increasing direction, A control hook (25) and an output hook (25 ') provided at both ends of the coil spring (15) are engaged with the control member (14) and the output member (13), respectively. Item 2. The spring-type torque limiter according to Item 1.   The input member (12) has an input side body (19) on its inner diameter surface, and the coil spring (15) is composed of two coil springs (15, 15 ') having different winding directions, A control hook (25) and an output hook (25 ') provided at both ends of each coil spring (15, 15') are tightly bound to the inner diameter surface of the input side body (19) with elasticity in the diameter increasing direction. The spring-type torque limiter according to claim 1, wherein the spring-type torque limiter is engaged with the control member (14) and the output member (13).   The input member (12) has an input side body (19) on the inner end face thereof, and the coil spring (15) is bound to the outer diameter surface of the input side body (19) with elasticity in the direction of diameter reduction. The control hook (25) and the output hook (25 ') provided at both ends of the coil spring (15) are engaged with the control member (14) and the output member (13), respectively. The spring-type torque limiter according to claim 1.   The input member (12) has an input side body (19) on its inner end surface, and the coil spring (15) is composed of two coil springs (15, 15 ') having different winding directions, respectively. A control hook (25) and an output hook (25 ') provided at both ends of each coil spring (15, 15') are bound to the outer diameter surface of the input side body (19) with elasticity in the direction of diameter reduction. The spring-type torque limiter according to claim 1, wherein the spring-type torque limiter is engaged with the control member and the output member.

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