JP5671746B2 - Rotating connector - Google Patents

Description

  The present invention relates to a rotary connector capable of transmitting an electric signal or the like between a fixed body and a rotary body, and more particularly to a rotary connector capable of reliably cutting a flat cable in an over-rotation state.

  In an automobile or the like, a rotating connector is used for transmitting an electric signal or an optical signal between a fixed body and a rotating body or supplying electric power. Specifically, when an air bag is provided on the steering wheel or a switch for performing operations such as audio is provided, an electrical connection is established between the steering wheel side that is a rotating body and the vehicle side that is a fixed body. It is necessary to perform communication and the like, and a rotary connector is installed here.

  The rotary connector has a fixed housing on the fixed body side and a movable housing on the rotary body side arranged coaxially, and an annular space between the outer cylinder formed on the fixed housing and the inner cylinder formed on the movable housing. The flat cable is wound around and stored in the annular space. Both ends of the flat cable are connected to the fixed housing side and the movable housing side, respectively.When the movable housing rotates with the rotation of the rotating body, the flat cable is tightened or loosened to rotate the rotating body. Regardless, maintain electrical connection with the stationary body.

  In such a rotary connector, it is necessary to accurately arrange the flat cable in the annular space portion in correspondence with the neutral position of the handle at the time of manufacture. If there is a deviation in this arrangement relationship, the flat cable will be wound or loosened in an unexpected shape, leading to a significant reduction in life. Further, in this case, if the handle is rotated to the maximum angle, the rotary connector is over-rotated, and an excessive load is applied to the flat cable, so the life is shortened or broken. There is also a fear.

  Therefore, before assembling the rotating connector to the steering device, the locking member is fixed to the stationary housing and the movable housing in the rotational neutral position so as not to move, and when the rotating connector is assembled to the steering device, the locking member is broken. It is known that a fixed housing and a movable housing can be rotated relative to each other so that an over-rotation state does not occur when the rotary connector is assembled. An example of such a rotary connector is disclosed in Patent Document 1.

JP-A-9-293576

  However, in the conventional rotary connector, work mistakes at the time of assembly of the rotary connector, work mistakes after unlocking, such as dropping the rotary connector unlocked by the operator just before assembling to the automobile steering device, When the rotary connector with the movable housing deviated from the rotation neutral position is assembled to the steering device, there is a possibility that the deviation from the rotation neutral position may occur.

  In this case, in the final inspection of the automobile assembly, when an inspection for confirming whether the handle rotates to the maximum rotation angle is performed, an over-rotation state may occur in the rotary connector, and the flat cable may be damaged. However, this may not always be discovered. Specifically, it is conceivable that the electrical inspection passes as it is, for example, when the conductors are in contact with each other even in a broken state. Therefore, when an over-rotation state that causes an abnormality in the flat cable occurs, it is necessary to securely disconnect the flat cable and detect the abnormality reliably. It is also necessary to prevent cutting with the rotation. Note that the over-rotation state means, for example, the rotation before reaching the original allowable rotation amount in the rotation of the handle in either the left or right direction when the rotary connector is assembled to the steering device without being held in the rotation neutral position. In this state, an excessive rotational force is applied to the flat cable.

  The present invention has been made in view of the above problems, and provides a rotating connector capable of reliably detecting an abnormality by cutting the flat cable when an over-rotation state that causes an abnormality in the flat cable occurs. The purpose is to do.

In order to solve the above problems, a rotary connector according to the present invention includes a fixed housing having an outer cylindrical body, and a movable housing having an inner cylindrical body that is arranged coaxially with the fixed housing and faces the outer cylindrical body. In the rotary connector in which an annular space is formed between the opposed outer cylinder and the inner cylinder, and a flat cable is wound around and stored in the annular space,
The outer cylindrical body has a lead-out portion that leads the flat cable to the annular space in a state where the flat cable is reversed by the reversing portion, and the lead-out portion is located inside the reversal portion of the flat cable. The fixed housing has a breakable part, and the fixed housing is led from the reversing part in the annular space part, and a part of the flat cable wound along the inner wall of the outer cylindrical body is broken at the broken part. Having a holding part to hold
The holding portion is configured to release the holding state of the flat cable when a pulling force having a magnitude exceeding the force at which the flat cable is broken at the breaking portion acts on the flat cable. .

  Further, the rotary connector according to the present invention is characterized in that the holding portion is a columnar body erected on the fixed housing so as to be positioned between the inverted portion and the fracture portion of the flat cable. Has been.

Further, in the rotary connector according to the present invention, the guide portion forms a guide path that guides the flat cable so that the lead-out portion extends along the circumferential direction of the annular space portion, and the fracture portion is formed at the end portion of the guide path on the annular space portion side. Part is formed,
The flat cable led out to the annular space portion is configured to be reversed at the position of the breaking portion and to face the breaking portion.

  Furthermore, the rotary connector according to the present invention is characterized in that the holding portion holds a state in which the flat cable is bent a plurality of times.

  According to the rotary connector of the present invention, the outer cylinder has a lead-out portion that leads the flat cable to the annular space, and the lead-out portion is located inside the inversion portion of the flat cable and is capable of breaking the flat cable. The fixed housing is a holding portion that holds the flat cable so that a portion of the flat cable that is led out from the inversion portion in the annular space portion and wound along the inner wall of the outer cylindrical body is not broken at the breaking portion. The holding part releases the holding state of the flat cable when a pulling force that exceeds the breaking force at the breaking part is applied to the flat cable. Since it can be cut by touching, if an over-rotation state that causes an abnormality in the flat cable occurs, the flat cable is surely cut and abnormal Detectable and then, while it is possible not to perform the cutting while maintaining the holding state of the flat cable in the holding section as long as the force at which no abnormal.

  Further, according to the rotary connector according to the present invention, the holding portion is a columnar body that is erected on the fixed housing so as to be positioned between the inverted portion and the fracture portion of the flat cable. When a force larger than the holding release force at the holding portion is applied, the cut is reliably performed at the broken portion, so that the flat cable can be cut reliably when an abnormality occurs with a simple configuration. .

  Further, according to the rotary connector of the present invention, the lead-out portion forms a guide path for leading the flat cable along the circumferential direction of the annular space portion, and a fracture portion is formed at the end portion of the guide path on the annular space portion side. The flat cable led to the annular space is reversed at the position of the breakage portion and faces the breakage portion, so that the flat cable is not cut in a normal state and is cut only at the occurrence of an abnormality. Can be arranged.

  Furthermore, according to the rotary connector according to the present invention, the holding portion can easily form a holding shape by holding a state where the flat cable is bent a plurality of times.

  According to the rotary connector of the present invention, the holding portion is provided between the guide wall portion facing the peripheral surface of the outer cylindrical body, and between the guide wall portion and the peripheral surface of the outer cylindrical body, and the flat cable is bent. By having the holding wall portion that holds the portion, the holding portion can be configured with a simple structure, and the setting of the holding release force can be facilitated.

It is a disassembled perspective view of the rotation connector in this embodiment. It is a top view showing the arrangement state of each gear. It is the perspective view which looked at the planetary gear from one side. It is the perspective view which looked at the planetary gear from the other side. It is an enlarged plan view showing the meshing state with the sun gear and the internal gear in a state where the planetary gear is deformed. It is sectional drawing of the side in which the planetary gear is located among the longitudinal cross-sectional views of a rotation connector. It is a disassembled perspective view of a movable housing and a sun gear. It is a perspective view of the upper case which comprises a fixed housing. FIG. 9 is an enlarged view of the vicinity of the derivation unit in FIG. 8. FIG. 10 is a perspective view of a state where the flat cable is led out to the annular space from the state of FIG. 9. It is an expansion perspective view of the state where a strong pulling force was applied to the flat cable and the cable was cut.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an exploded perspective view of the rotary connector in the present embodiment. FIG. 6 is a cross-sectional view of the rotary connector on the side where the planetary gear is located. The rotary connector of the present embodiment has a fixed housing 1 fixed to a steering column portion of an automobile, and a movable housing 2 through which a steering shaft that rotates together with a handle is inserted and rotates. The connecting flat cable 3 is wound and housed in an annular space 5 (FIG. 6) formed between the fixed housing 1 and the movable housing 2.

  The fixed housing 1 is formed by connecting and integrating an upper case 20 having an outer cylindrical body 21 and a lower case 25 having a bottom plate portion 26 by snap coupling or the like. The upper case 20 is formed with a ring portion 22 having a substantially ring shape that protrudes inward from the upper end of the outer cylinder 21, and pulls out the flat cable 3 that protrudes outward from the outer periphery of the outer cylinder 21. The fixed-side upper connection portion 23 for electrical connection is integrally provided.

  The lower case 25 includes a wall portion 25a erected from the outer edge portion of the bottom plate portion 26, and the internal gear 12 is formed on the inner peripheral wall thereof. A planetary gear 11 meshes with the internal gear 12, and the planetary gear 11 meshes with a sun gear 10 provided in the movable housing 2. The configuration of each gear will be described in detail later. The lower case 25 has an opening 27 through which the steering shaft is inserted. The planetary gear 11 rotates and revolves on the inner surface of the bottom plate portion 26.

  The lower case 25 is formed with a fixed-side lower connection portion 28 that is integrated with the fixed-side upper connection portion 23 on the outer peripheral side when integrated with the upper case 20. The fixed side lower connecting portion 28 is provided with a connector (not shown) for electrically connecting the flat cable 3 drawn out to the fixed side to the vehicle side.

  The movable housing 2 includes an upper rotor 30 and a lower rotor 35. The movable housing 2 includes a ring-shaped top plate portion 31 positioned above the annular space portion 5 and an inner cylinder projecting from the inner edge portion of the top plate portion 31 toward the bottom plate portion 26 side of the lower case 25. 32. The inner cylinder 32 is disposed coaxially with the outer cylinder 21 and faces the inner peripheral surface of the outer cylinder 21 via the annular space 5. On the other hand, the lower rotor 35 has a ring-shaped ring portion 36 and a cylindrical portion 37 erected from the inner edge portion of the ring portion 36.

  On the top plate portion 31 of the movable housing 2, a movable side connection portion 33 is formed for pulling out the flat cable 3 and electrically connecting it. That is, the movable side connection portion 33 accommodates a lead block (not shown) connected to the inner end portion of the flat cable 3. An external connector (not shown) derived from an air bag system on the steering unit side, a horn switch circuit, or the like is connected to the lead block. Further, the cylindrical portion 37 of the lower rotor 35 inserted from the opening 27 of the lower case 25 is connected to the inner cylindrical body 32 of the upper rotor 30 inserted into the fixed housing 1 by snap coupling. In this way, by connecting the upper rotor 30 and the lower rotor 35, the ring portion 36 of the lower rotor 35 is rotatable in contact with the lower surface of the bottom plate portion 26 of the lower case 25, and the movable housing 2. Is held rotatably with respect to the fixed housing 1.

  The flat cable 3 includes a plurality of conductive paths extending in the longitudinal direction in the inside thereof, and is formed by being covered with a flexible resin material. In the present embodiment, two flat cables 3 are accommodated: a first flat cable 3a and a second flat cable 3b. The first flat cable 3a is wound in the annular space portion 5 and the winding direction is reversed via the first reversing portion 3c. The second flat cable 3b is also wound in the annular space portion 5 and the winding direction is reversed via the second reversing portion 3d. The first inversion portion 3c and the second inversion portion 3d are formed at different positions in the circumferential direction.

  Each flat cable 3 is fixed to the movable housing 2 at the wound inner peripheral end, and fixed to the fixed housing at the outer peripheral end. Therefore, when the movable housing 2 is rotated with respect to the fixed housing 1, each flat cable 3 winds the flat cable 3 from the first and second reversing portions 3 c and 3 d to the outer peripheral surface side of the inner cylindrical body 32, or Driven from the surface side. For this reason, in the flat cable 3, the inverted shape is maintained regardless of the rotational position of the movable housing 2.

  As shown in FIG. 6, in the annular space portion 5 between the outer cylinder body 21 and the inner cylinder body 32, a rotating ring 4 as an inversion maintaining portion is rotatably disposed on the inner surface of the bottom plate portion 26. A planetary gear 11 is rotatably disposed on the rotating ring 4, and the rotating ring 4 also rotates as the planetary gear 11 rotates and revolves. The rotating ring 4 includes a ring-shaped main body portion 40, and a first inversion maintaining portion 41 through which the first inversion portion 3c of the first flat cable 3a is inserted at a different position in the circumferential direction, and a second inversion of the second flat cable 3b. And a second inversion maintaining unit 42 through which the 2 inversion unit 3d is inserted. In addition to the rotating ring body 4, a columnar body or a cylindrical body or a rotatable roller that protrudes from the planetary gear 1 can be applied to the inversion maintaining unit.

  As shown in FIG. 6, the sun gear 10 is fixed to a first facing surface 32 a that faces the bottom plate portion 26 of the lower case 25 in the inner cylinder 32 of the movable housing 2. FIG. 7 shows an exploded perspective view of the movable housing 2 and the sun gear 10. As shown in FIG. 7, the sun gear 10 is formed by integrally forming an inner base portion 10 b and an outer base portion 10 c that are coaxially arranged in a ring shape with a plurality of connecting portions 10 d, and an outer peripheral surface of the outer base portion 10 c. The teeth 10a are formed over the entire circumference. When the movable housing 2 is disposed so as to be rotatable with respect to the fixed housing 1, the sun gear 10 faces the internal gear 12 of the fixed housing 1 coaxially.

  In FIG. 2, the top view showing the arrangement | positioning state of each gearwheel is shown. As shown in this figure, in the state where each gear is arranged, the sun gear 10 and the internal gear 12 are arranged coaxially, so that they are opposed to each other with a certain interval in the circumferential direction. A planetary gear 11 is disposed, and the planetary gear 11 meshes with both the sun gear 10 and the internal gear 12. The sun gear 10 rotates as the movable housing 2 rotates, and the planetary gear 11 meshed with the sun gear 10 revolves along the circumferential direction while rotating along with the rotation of the sun gear 10. Due to the revolution of the planetary gear 11, the rotating ring 4 also rotates on the inner surface of the bottom plate portion 26.

  The configuration of the planetary gear 11 will be described in more detail. 3 is a perspective view of the planetary gear 11 as viewed from one side, and FIG. 4 is a perspective view of the planetary gear 11 as viewed from the other side. As shown in FIG. 3, the planetary gear 11 is configured by integrating a ring-shaped inner base portion 11b and an outer base portion 11c, which are coaxially arranged, with a connecting portion 11d extending in the radial direction. Three connecting portions 11d are provided at an equal angle in the circumferential direction, and regions between these connecting portions 11d are gap portions 11e. Teeth 11a are formed on the outer peripheral surface of the outer base portion 11c over the entire circumference.

  A linkage portion 11f is projected from the inner base portion 11b. The linking portion 11f is attached to the linking recess 44 of the rotating ring 4 so as to be rotatable, and the planetary gear 11 is allowed to rotate, and the rotating ring 4 is rotated in the annular space 5 in accordance with the revolution operation. .

  Further, an elastic arm portion 11g extending toward the inside of the gap portion 11e is formed from the outer peripheral surface of the inner peripheral base portion 11b. The elastic arm portion 11g extends in the radial direction from the outer peripheral surface of the inner base portion 11b, bends in the middle, and extends along the circumferential direction. As shown in FIG. 4, on the bottom surface side of the elastic arm portion 11g, a protruding portion 11h is formed at the tip portion so as to protrude downward in the drawing, that is, toward the bottom plate portion 26. The elastic arm portion 11g is formed thinner than other parts of the planetary gear 11 and is cantilevered, so that it can be elastically deformed. In FIG. 6, the planetary gear 11 is arranged in a state where the elastic arm portion 11 g (not shown) is bent and deformed, and the projection portion 11 h receives a drag (reaction force) from the inner surface of the bottom plate portion 26. An elastic biasing force directed upward in the direction can be generated.

  Since the planetary gear 11 has a plurality of gaps 11e along the circumferential direction inside the teeth 11a formed on the outer circumference, the planetary gear 11 has elasticity in the plane direction and can be slightly deformed. It is. Further, as shown in FIG. 2, the sun gear 10 also has elasticity in the plane direction because a plurality of gaps 10e are formed along the circumferential direction between the connecting portions 10d inside the teeth 10a. Have.

  FIG. 5 is an enlarged plan view schematically showing the meshing state with the sun gear 10 and the internal gear 12 in a state where the planetary gear 11 is deformed. This figure shows a state where the distance between the sun gear 10 and the internal gear 12 is narrowed. FIG. 5 shows the change in the meshing state with emphasis from the actual state.

  The meshing state of the planetary gear 11 with respect to the sun gear 10 and the internal gear 12 changes due to a dimensional error of each related member including those gears, or expansion or contraction deformation of the gear due to a temperature change. Even in such a case, in general, the backlash between the gears (clearance: a gap set between the pitch circles of the meshing gears) is appropriately set so that the gears mesh smoothly. The planetary gear 11 according to the present embodiment has an air gap portion 11e and can be elastically deformed, and the sun gear 10 also has an air gap portion 10e and can be elastically deformed. And even if each backlash between the internal gear 12 and the internal gear 12 is set to almost zero, the meshing operation can be realized smoothly. As a result, even if the vehicle vibrates during traveling, each gear can realize a smooth meshing operation without rattling in the planar direction, and can prevent rattling noise. Even if foreign matter enters between the planetary gear 11 and the sun gear 10 and the internal gear 12, if the foreign matter has a certain size, each of the gears is caused by elastic deformation of the planetary gear 11 and the sun gear 10. It is possible to avoid troubles in the meshing and rotation. In this embodiment, both the planetary gear 11 and the sun gear 10 are formed with a plurality of gaps 11e and 10e along the circumferential direction so as to be elastically deformable. However, a gap is formed in either one of them. You may do it.

  Further, the planetary gear 11 pushes up the rotating ring 4 by the elastic biasing force generated in the axial direction of the planetary gear 11 that is generated by the elastic arm portion 11g even when the vehicle vibrates during traveling. Even in the vertical direction, stable operation can be performed without rattling. Details will be described later.

  The structure in the rotary connector will be further described. As shown in FIG. 6, an annular space 5 is formed between the outer cylinder 21 of the fixed housing 1 and the inner cylinder 32 of the movable housing 2, and the rotating ring 4 is arranged in the annular space 5. In addition, the flat cable 3 is wound around the inner peripheral side and the outer peripheral side of the rotating ring 4.

  The planetary gear 11 is formed with a linking portion 11f protruding upward, and the rotating ring 4 is formed with a linking recess 44 corresponding thereto. The planetary gear 11 is rotatably attached to the rotating ring 4 by fitting the linkage portion 11 f of the planetary gear 11 into the linkage recess 44.

  The rotating ring 4 has a flange portion 43 protruding outward at the lower end portion. The flange portion 43 is in elastic contact with the second opposing surface 32b formed on the radially outer side of the first opposing surface 32a of the inner cylindrical body 32. That is, the planetary gear 11 pushes up the rotating ring 4 with an elastic urging force that is generated by an elastic arm portion 11g (not shown) in a deformed state and acts on the planetary gear 11 in the axial direction. It is in elastic contact with the second facing surface 32b.

  As described above, the planetary gear 11 has the backlash between the sun gear 10 and the internal gear 12 set to almost zero, is urged upward in the axial direction by the elastic arm portion 11g, and is movable. Since it is sandwiched between the movable housing 2 and the fixed housing 1 via the rotating ring 4, even if the vehicle vibrates during traveling, it does not rattle in the vertical direction and can perform stable rotation and revolution operations. Can be made.

  Next, the fixing structure of the sun gear 10 will be described. As described with reference to FIG. 1, the sun gear 10 is fixed to the first facing surface 32a (FIG. 6) of the inner cylinder 32 (movable housing 2). For this purpose, as shown in FIG. 7, the sun gear 10 has a pin-like convex portion 10f formed on the inner base portion 10b. The convex portions 10f are formed at three locations in the circumferential direction of the sun gear 10 and protrude so as to extend along the axial direction of the sun gear 10 and the inner cylindrical body 32, respectively. Concave portions 34 are formed at three locations in the circumferential direction on the bottom surface of the movable housing 2, and the convex portions 10f and the concave portions 34 are fitted.

  Next, the fixed opening means 6 will be described with reference to FIG. The fixing release means 6 includes a recess 34 formed in the first facing surface 32a (inner cylinder 32), a projection 10f of the sun gear 10, and a notch 10g formed along the circumferential direction of the root of the projection 10f. And is composed of. The notch 10g is formed so as to bite in a direction orthogonal to the axial direction of the sun gear 10, and when a predetermined force is applied to the convex portion 10f in a tilting direction, the convex portion 10f breaks from the root portion. As such, the shape and depth are set. Accordingly, when a torsional load (torque) greater than a predetermined force is applied between the sun gear 10 and the movable housing 2, the convex portion 10f is broken from the root portion, and the fixed state of the sun gear 10 and the movable housing 2 is released. Thus, the movable housing 2 is rotatable independently of the sun gear 10.

  In this way, the sun gear 10 and the movable housing 2 are integrated by the fixing / releasing means 6 that releases the fixed state by a torsional load of a predetermined size or more, so that the sun gear 10 and the like can be brought into contact with foreign matter due to intrusion or the like. Even when locked, the movable housing 2 can be rotated by the fixed opening means 6 and the handle linked to the movable housing 2 can also be rotated. Therefore, the driver encounters when the handle operation is locked. The danger of driving can be avoided.

  The fixed opening means 6 is not limited to the configuration shown in the present embodiment. For example, a convex portion may be formed on the movable housing 2 side and a concave portion may be formed on the sun gear 10 side. Further, the direction of the convex portion and the concave portion is formed so as to extend in the axial direction of the sun gear 10 in the present embodiment, but may be formed so as to extend in the radial direction.

  Next, the cutting structure of the flat cable 3 in the fixed housing 1 will be described. In the planetary gear type rotary connector provided with the planetary gear 11 according to this embodiment, the movable housing 2 is mounted on the handle in a defective state that is not in the rotational neutral position with respect to the fixed housing 1 at the time of manufacture or assembly to an automobile. In such a case, the movable housing 2 will be over-rotated in the subsequent handle operation, and tooth skipping between the planetary gear 11, the sun gear 10, and the internal gear 12, that is, the gears do not mesh with each other. As a result, only the planetary gear 11 may idle, and the movable housing 2 may be rotated. When tooth skip occurs, the state of the rotating connector in a defective state is further deteriorated. In order to make it possible to solve such a problem, the rotary connector according to the present embodiment is provided with a cutting structure that reliably cuts the flat cable 3 so that an abnormality can be reliably detected. FIG. 8 shows a perspective view of the upper case 20 constituting the fixed housing 1.

  The upper case 20 includes the outer cylinder 21 as described above. In order to lead the flat cable 3 from the fixed-side upper connection part 23 side to the annular space part 5, a lead-out part 60 is formed in the outer cylinder 21. The lead-out part 60 forms a guide path 61 through which the flat cable 3 is inserted into the wall surface of the outer cylindrical body 21.

  FIG. 9 shows an enlarged view of the vicinity of the derivation unit 60 in FIG. Of the two opposing walls constituting the guide path 61, the lead-out portion 60 has a break portion 62 formed at the end of the annular space 5 side of one wall where the tip is disposed on the annular space 5 side. ing. The fracture | rupture part 62 is formed in step shape, and the part of the vertical side is a sharp cutter shape.

  A holding portion 63 is formed in the vicinity of the fracture portion 62 on the inner wall constituting the outer cylindrical body 21. The holding part 63 includes a guide wall part 63a formed so as to face the inner wall of the outer cylindrical body 21, a holding wall part 63b extending from the inner wall of the outer cylindrical body 21 so as to protrude toward the guide wall part 63a, and these The insertion wall 63c is formed as a gap between the guide wall 63a and the holding wall 63b.

  FIG. 10 is a perspective view showing a state in which the flat cable 3 is led out to the annular space 5 from the state shown in FIG. As shown in this figure, the flat cable 3 is inserted into the annular space 5 through the guide path 61 extending from the fixed-side upper connecting portion 23 side to the lead-out portion 60, and is inverted there to reverse the inside of the annular space 5 It is wound around. The folded portion 3e, which is an inverted portion of the flat cable 3, is in a state of facing the fracture portion 62 located inside thereof.

  The flat cable 3 on the side of the annular space 5 from the folded portion 3e is wound as it is along the inner wall of the outer cylindrical body 21 and is inserted into the insertion portion 63c constituting the holding portion 63, and beyond that to the guide wall portion 63a. At the same time, it is folded back at the folded portion 3f and is folded back again at the folded portion 3g at a position where it hits the holding wall portion 63b, and the tip is disposed along the inner wall of the outer cylindrical body 21.

  Since the flat cable 3 is held in a state of being folded twice by the holding portion 63 in this way, the vicinity of the lead-out portion 60 of the flat cable 3 is pulled by the force F shown in FIG. In this case, when the force F becomes large and reaches a holding force described later, the folded state of the holding portion 63 is first released, and immediately after that, the folded portion 3e is instantaneously pulled. At that time, the folded portion 3e of the flat cable 3 is instantaneously abutted against the fracture portion 62 and cut. The holding force of the flat cable 3 in the holding portion 63 is the friction force between the flat cable 3 and the inner wall of the outer cylinder 21 and the guide wall portion 63a in the holding portion of the flat cable 3, the friction force between the folded flat cables 3; And, since it is determined by the resistance against deformation when the folded state of the flat cable 3 is released, the holding force can be set by selecting the flat cable 3 and the shape of the holding portion 63.

  FIG. 11 is an enlarged perspective view showing a state where the flat cable 3 is subjected to a force greater than the holding force, the folded state of the holding portion 63 is released, and a strong tensile force is instantaneously applied to the flat cable 3 and the flat cable 3 is cut. Yes. As shown in this figure, the folded state of the holding portion 63 of the flat cable 3 is released when a tensile force of a predetermined level or more is applied to the flat cable 3, and when the flat cable 3 is further pulled, the folded portion 3e is released. Since it is instantaneously pressed against the tip of the breaking portion 62, it is cut by this. When the flat cable 3 is disconnected, the electrical connection is completely disconnected, so that it can be reliably detected as an abnormality at the time of inspection.

In order to reliably cut the flat cable 3 before the over-rotation occurs in the movable housing 2 and the gear skip occurs, it is necessary to set the following force relationship. F ₁ is the force applied to the flat cable 3 when gear tooth skipping occurs, F _{2 is} the force for holding the flat cable 3 in the holding portion 63, and F is the force required to cut the flat cable 3 at the breaking portion 62. _{Assuming 3} , F ₁ > F ₂ > F ₃ is set.

Due to this force relationship, when the force F applied to the flat cable 3 is smaller than the force F ₁ causing the gear tooth skipping and larger than the force F ₂ holding the flat cable 3 in the holding portion 63, the force is reliably held. The holding of the flat cable 3 in the portion 63 is released. In this case, since a force greater than the force F ₃ required to cut the flat cable 3 at the breaking portion 62 is applied to the flat cable 3, the flat cable 3 is surely secured by the breaking portion 62 without causing gear skipping. Is disconnected. If the force F applied to the flat cable 3 is smaller than the force F ₂ for holding the flat cable 3 in the holding portion 63, the holding of the flat cable 3 in the holding portion 63 is maintained, so that the cutting is performed by the breaking portion 62. It will not be done.

Thus, by providing the holding portion 63 in the outer cylindrical body 21 and appropriately setting the above three force relationships, a tensile force greater than the force F ₂ holding the flat cable 3 in the holding portion 63 is applied to the flat cable 3. In the case of acting, when the flat cable 3 is reliably cut without causing gear skipping and a pulling force smaller than the force F ₂ for holding the flat cable 3 in the holding portion 63 is applied to the flat cable 3. The holding state of the flat cable 3 in the holding part 63 can be maintained so that the cutting is not performed. As a result, when there is an abnormality, it can be surely discovered, and in other cases, it is possible to reliably prevent cutting, so that it is possible to prevent the occurrence of problems due to over-rotation.

In the cutting structure, the configuration of the holding portion 63 is not limited to that having two wall portions as in the present embodiment. For example, two pin-shaped protrusions having different radial positions in the fixed housing 1 are formed in the vicinity of the outer cylindrical body 21, and the flat cable 3 is held twice by folding the flat cable 3 by these protrusions. The holding | maintenance part 63 to perform can also be comprised. In this case, the protrusion is configured to be broken when a force of a predetermined F ₂ or more is applied to the flat cable 3 to release the holding state of the flat cable 3.

Further, instead of the configuration of the holding portion 63 shown in FIG. 11, an inversion pin 64 indicated by a chain line between an inversion portion of the flat cable 3 indicated by a chain line in the drawing and a break portion 62 disposed inside the inversion portion. The structure in which the (columnar body) is erected on the bottom plate portion 26, that is, the flat cable 3 (dashed line in the figure) is arranged with the reverse pin 64 erected in the vicinity of the outlet of the lead-out portion 60 on the tip side of the fracture portion 62 inside An inverted configuration can also be employed. In this case, the inverting pin 64 forms the cutting structure of the present invention. The inversion pin 64 may be formed so that a notch is cut into the base end side (bottom plate portion 26 side) so as to be broken by the force of F ₂ . With such a configuration, F ₂ can be easily set with a simple configuration, and when the flat cable is excessively rotated, the flat cable can be surely cut to detect an abnormality.

Further, a protrusion is protruded from the inner wall of the outer cylindrical body 21, a hole portion through which the protrusion is inserted is formed in the flat cable 3, and the flat cable 3 is held by inserting the protrusion into the hole portion. The holding part 63 can also be configured. Also in this case, the protrusion is configured to be broken when a force of a predetermined F ₂ or more is applied to the flat cable 3 to release the holding state of the flat cable 3.

  In addition, although the example of the rotation connector provided with the planetary gear 11 was shown as embodiment of this invention, this invention can also be applied to another structure. For example, a structure in which a rotating ring body with a roller attached is arranged in the annular space portion 5 of the rotary connector, or a plurality of flat cables having reversing portions are wound so that the reversing portions have a predetermined interval. By applying the present invention to such a configuration, when the flat cable is over-rotated, it is needless to say that the flat cable can be surely cut to detect an abnormality.

  Although the embodiment of the present invention has been described above, the application of the present invention is not limited to this embodiment, and can be applied in various ways within the scope of its technical idea.

DESCRIPTION OF SYMBOLS 1 Fixed housing 2 Movable housing 3 Flat cable 4 Rotating ring 5 Annular space 6 Fixed release means 10 Sun gear 10a Teeth 10e Cavity 10f Protrusion 10g Notch 11 Planetary gear 11a Teeth 11e Cavity 12 Internal gear 21 Outer cylinder 26 Bottom plate part 32 Inner cylinder 34 Recessed part 60 Derived part 61 Guide path 62 Breaking part 63 Holding part 63a Guide wall part 63b Holding wall part 63c Insertion part

Claims (4)

A fixed housing having an outer cylindrical body, and a movable housing having an inner cylindrical body that is disposed coaxially with the fixed housing and faces the outer cylindrical body, between the opposed outer cylindrical body and the inner cylindrical body In the rotary connector in which the annular space portion is formed and the flat space is wound around and stored in the annular space portion,
The outer cylindrical body has a lead-out portion that leads the flat cable to the annular space in a state where the flat cable is reversed by the reversing portion, and the lead-out portion is located inside the reversal portion of the flat cable. The fixed housing has a breakable part, and the fixed housing is led from the reversing part in the annular space part, and a part of the flat cable wound along the inner wall of the outer cylindrical body is broken at the broken part. Having a holding part to hold
The rotary connector is characterized in that the holding state of the flat cable is released when a pulling force larger than the force by which the flat cable is broken at the breaking portion acts on the flat cable.   The rotary connector according to claim 1, wherein the holding portion is a columnar body erected on the fixed housing so as to be positioned between the inverted portion of the flat cable and the fracture portion. The lead-out part forms a guide path for leading the flat cable along the circumferential direction of the annular space part, and the fracture part is formed at the annular space part side end of the guide path,
The rotary connector according to claim 1, wherein the flat cable led to the annular space portion is inverted at the position of the fracture portion and faces the fracture portion.   The rotary connector according to claim 1, wherein the holding portion holds a state where the flat cable is bent a plurality of times.

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