JP2013191437A - Rotary connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive rotary connector capable of preventing circuit destruction and damage of an electronic apparatus due to the inflow of excessive current.SOLUTION: A lead block 11 included in a cable lead-out part of a rotary connector has connection terminals 30, 30a connected to a band-like conductor 19 of a flat cable 4, and an insulative base substance 31 for holding the connection terminals 30, 30a, and the insulative base substance 31 is provided with a gap part 31a for parting the connection terminal 30a and a pair of opening parts 31b for making the connection terminal 30a expose in the vicinity of both ends of the gap part 31a. A circuit protection component 28 having a function for preventing passage of an excessive current is attached to the lead block 11, and in the circuit protection component 28, the body part thereof 28a is arranged at the gap part 31a, and a lead part 28b projecting from both ends of the body part 28a is arranged at the opening parts 31b and is subjected to spot welding to the connection terminal 30a.

Description

  The present invention relates to a rotary connector that is installed in a steering device of an automobile or the like and is used as an electrical connection means for an airbag system or the like, and in particular, a rotary connector that is designed to prevent damage to an electric circuit due to an excessive current. About.

  The rotary connector exists between a fixed side housing having an outer cylindrical portion, a movable side housing having an inner cylindrical portion and rotatably connected to the fixed side housing, and the outer cylindrical portion and the inner cylindrical portion. A flat cable is housed in an annular space so as to be capable of being wound and unwound, and both ends in the longitudinal direction of the flat cable are electrically and mechanically connected to the lead block. The lead block is a connection component in which a connection terminal is held on an insulating base by insert molding or the like, and such a lead block is incorporated in the outer cylinder part of the fixed side housing and the inner cylinder part of the movable side housing, respectively. A flat cable is a long flexible cable formed by covering a strip conductor with an insulating film. One end of the flat cable in the longitudinal direction is led out from the outermost peripheral portion of the annular space to the outer tube portion. It is connected to a predetermined lead block incorporated. Further, the other end portion in the longitudinal direction of the flat cable is led inward from the innermost peripheral portion of the annular space and connected to another lead block incorporated in the inner cylinder portion. Since each of these lead blocks is electrically connected to an external circuit, both ends in the longitudinal direction of the flat cable are electrically connected to the external circuit.

  In the rotary connector provided in the steering device of the automobile, the fixed side housing is fixed to the steering column side, and the movable side housing is connected to the handle (steering wheel) side and rotates integrally. When the movable housing is rotated in either the forward or reverse direction with respect to the fixed housing, the flat cable is wound or unwound in the annular space according to the rotation direction, and both housings are in either state. The electrical connection between them is maintained through the connection terminal of the lead block and the strip conductor of the flat cable. In other words, the electrical circuit on the handle side (airbag system, horn circuit, etc.) is electrically connected to the electronic device on the vehicle body side, power supply circuit, etc. via the rotary connector. There is no hindrance to signal transmission.

  By the way, electronic devices operated by a switch on the steering wheel side (steering switch) tend to increase in recent years, and accordingly, there is an increased risk that an excessive current flows and an electric circuit is broken or an electronic device is damaged. ing. Therefore, conventionally, a protective component having a fuse function is interposed between the end portion of the flat cable in the longitudinal direction and the outer conductor, and this protective component prevents rotation of the electric circuit due to excessive current. A connector has been proposed (see, for example, Patent Document 1). In such a conventional rotary connector, when an excessive current flows into the flat cable, the protective component having a fuse function is blown by the excessive current, so that conduction between the flat cable and the external conductor is interrupted.

  JP-A-10-92541

  However, the conventional rotary connector disclosed in Patent Document 1 is a support body prepared by connecting both ends of a protective component having a fuse function to a separately prepared relay conductor, and bending the melted portion of the protective component separately. It employs a complicated mounting structure in which the protective parts are supported, and it is difficult to easily perform the mounting work of the protective parts. Therefore, there has been a problem that the total cost of the rotary connector is increased.

  The present invention has been made in view of the actual situation of the prior art, and an object of the present invention is to provide an inexpensive rotary connector that can prevent circuit destruction and electronic device damage due to inflow of excessive current. .

  In order to achieve the above object, the present invention provides a stationary housing having an outer cylinder, a movable housing having an inner cylinder and rotatably connected to the stationary housing, and an insulating film. A flat cable having a plurality of coated strip-shaped conductors and wound in an annular space existing between the outer cylinder part and the inner cylinder part, and connected to the longitudinal end of the flat cable. A rotary connector having a plurality of connection terminals connected to the strip conductors of the flat cable, and an insulating base that holds these connection terminals. The insulating base of the lead block has a gap portion for dividing at least one of the plurality of connection terminals, and the at least one connection end on both sides of the gap portion. A body portion of a circuit protection component that prevents passage of excessive current is disposed in the gap portion, and lead portions that protrude from both ends of the body portion are disposed in the opening portion. Thus, the connection terminal is electrically and mechanically connected.

  As described above, if the insulating base of the lead block is provided with a gap and an opening for the circuit protection component in advance, it is easy to mount the circuit protection component on the lead block and connect it electrically and mechanically. This eliminates the need for separately preparing mounting parts. For this reason, it is possible to provide an inexpensive rotary connector that can suppress an increase in cost of the rotary connector due to the addition of the circuit protection component and can prevent circuit breakage and electronic device damage due to the inflow of excessive current. Further, since the main body portion of the circuit protection component is disposed in the gap portion of the lead block, even if an excessive current flows and the main body portion becomes high temperature, there is no possibility that the surrounding insulating substrate is softened or melted.

  In the above rotary connector, when the inclined base surface for guiding the lead portion to the opening portion is formed on the insulating base, the circuit protection component can be easily disposed at a predetermined position of the lead block during the mounting operation. Therefore, the mounting operation can be performed more easily.

  In the rotary connector, it is preferable that the lead portion is connected to the connection terminal exposed at the opening portion by spot welding because the connection terminal and the lead portion can be connected very easily.

  Further, in the above rotary connector, the circuit protection component may be an electrical component with a fuse function, but the circuit protection component is a resistor whose resistance value increases as the temperature rises due to self-heating. It is preferable that an excessive current can be prevented from passing without fusing parts.

  In the rotary connector of the present invention, since the gap and opening for the circuit protection component are provided in advance in the insulating base of the lead block, the circuit protection component is mounted on the lead block and electrically and mechanically connected. The mounting operation can be easily performed, and there is no need to separately prepare mounting parts. Further, since the main body portion of the circuit protection component is disposed in the gap portion of the lead block, even if an excessive current flows and the main body portion becomes high temperature, there is no possibility that the surrounding insulating substrate is softened or melted. Therefore, the cost increase of the rotary connector due to the addition of the circuit protection component can be suppressed to an extremely low level, and the effects of preventing the circuit breakage and the electronic device damage due to the inflow of excessive current can be obtained.

1 is an external view of a rotary connector according to an embodiment of the present invention. It is a disassembled perspective view of the rotation connector shown in FIG. It is a bottom view of the rotation connector shown in FIG. It is sectional drawing which follows the IV-IV line of FIG. It is a bottom view which abbreviate | omits a baseplate member etc. from FIG. 3, and shows an internal structure. It is principal part sectional drawing which shows the cable derivation | leading-out part of the stationary side housing with which the rotation connector shown in FIG. 1 is equipped. It is explanatory drawing which shows the connection state of the lead block incorporated in the rotation connector shown in FIG. 1, and a flat cable. FIG. 8 is an exploded perspective view corresponding to FIG. 7. It is explanatory drawing which shows the other connection state of a lead block and a flat cable. It is sectional drawing of the X section of FIG. It is explanatory drawing which shows the state before the cutting process of a flat cable. It is the front view which looked at the lead block at one side. It is the rear view which looked at the other surface side of the lead block. It is explanatory drawing which shows the internal structure of a lead block. It is a rear view of the upper rotor which shows the cable derivation | leading-out part of the movable side housing with which a rotation connector is equipped. It is a perspective view which shows the lead block with a circuit protection component integrated in a rotation connector. FIG. 17 is a cross-sectional view of the lead block along the line XVII-XVII in FIG. 16. FIG. 17 is an exploded perspective view corresponding to FIG. 16. It is explanatory drawing which shows the connection state of three lead blocks and four flat cables integrated in the cable derivation | leading-out part of FIG. It is a side view which shows the cut | notch part of each flat cable shown in FIG.

  Hereinafter, embodiments of the invention will be described with reference to the drawings. As shown in FIGS. 1 to 5, a rotary connector according to an embodiment of the present invention includes a fixed housing 1, a movable housing 2 rotatably connected to the fixed housing 1, and both the housings. Flat cable 3, flat cable 4, flat cable 5 (first flat cable), flat cable 6 (second flat cable) wound and housed in an annular space S defined between 1 and 2, and these The first to third lead blocks 10 to 12 and the fourth to sixth lead blocks 20 to 22 connected to both ends of the flat cables 3 to 6 and the housings 1 and 2 are rotatably arranged. The holder 7 is mainly constituted. This rotary connector is used by being assembled in a steering device of an automobile, and electricity between a stationary housing 1 installed on a steering column (not shown) and a movable housing 2 connected to a handle (not shown). Connection is performed by the flat cables 3 to 6.

  The stationary housing 1 is roughly constituted by a synthetic resin outer cylinder body 8 and a bottom plate member 9, and the substantially cylindrical outer cylinder body 8 is integrated with the outer peripheral edge of the substantially annular bottom plate member 9 by snap coupling. Has been. An upper connection portion 8a is attached to a predetermined portion on the outer peripheral surface side of the outer cylindrical body 8, and a lower connection portion 9a combined with the upper connection portion 8a is integrally formed at a predetermined position on the outer peripheral side of the bottom plate member 9. Yes. As shown in FIGS. 2 and 4, the combination of the upper connecting portion 8a, the cylindrical case 8b, and the lower connecting portion 9a constitutes a fixed side connecting portion 50 that incorporates the first to third lead blocks 10-12. doing. In addition, the 3rd lead block 12 in the fixed side connection part 50 is connected to the 2nd connection part 27 via the wire harness 26 so that it may mention later, and the 2nd connection part 27 is connected with the fixed side connection part 50. ing.

  The movable housing 2 includes an upper rotor 13 made of synthetic resin, an intermediate rotor 14, and a lower rotor 15. The intermediate rotor 14 and the lower rotor 15 are integrated with the upper rotor 13 by snap coupling. The upper rotor 13 has an annular top plate portion 13a facing the bottom plate member 9, and an inner cylinder portion 13b depending from the center of the top plate portion 13a. The inner diameter of the inner cylinder portion 13b is the steering shaft. (Not shown) is set to a dimension allowing insertion.

  As shown in FIG. 1, the top plate portion 13a of the upper rotor 13 is integrally formed with third and fourth connection portions 13c, 13d and harness extraction portions 13e, 13f. As shown in FIG. 15, on the back side of the upper rotor 13, the third and fourth connection portions 13 c and 13 d and the harness extraction portions 13 e and 13 f constitute a movable side connection portion. The other end part of the flat cable 3 in the longitudinal direction is connected to the fourth lead block 20 incorporated in the third connection part 13c and the harness extraction part 13e, and the fifth lead incorporated in the fourth connection part 13d. The other end of the flat cable 4 in the longitudinal direction is connected to the block 21. In addition, the other end portions of the first and second flat cables 5 and 6 in the longitudinal direction are connected to the sixth lead block 22 incorporated in the harness extraction portion 13f. As shown in FIG. 2, on the top plate portion 13a, a lock member incorporating portion 13g for incorporating a lock member 17 for maintaining the neutral position of the rotary connector, and a handle (not shown) at the neutral position of the rotary connector. And a shaft portion 13h on which the connecting portion 16 is connected.

  The intermediate rotor 14 is for holding the fourth to sixth lead blocks 20 to 22 incorporated in the upper rotor 13 from the back side. As shown in FIG. 4, the intermediate rotor 14 is the back side of the upper rotor 13. Are snap-joined. The lower rotor 15 is formed in a substantially cylindrical shape through which the steering shaft can be inserted. The lower rotor 15 is snap-coupled to the inner cylinder portion 13 b of the upper rotor 13. Then, the lower housing 15 is slidably engaged with the inner peripheral edge of the bottom plate member 9 so that the movable housing 2 is rotatably connected to the fixed housing 1.

  As shown in FIG. 18, each flat cable 3-6 is a long flexible cable carrying a strip-shaped conductor 19 on an insulating film 18 made of PET (polyethylene terephthalate) or the like. Except for both ends in the direction, the strip-shaped conductor 19 is covered with an insulating film 18. These flat cables 3 to 6 are accommodated in an annular space S (see FIG. 4) existing between the outer cylindrical body 8 and the inner cylindrical portion 13b so as to be wound and unwound. The flat cables 3 to 6 have their winding directions reversed in the middle (see FIG. 2). Further, one end of each flat cable 3-6 in the longitudinal direction is electrically and mechanically connected to the first to third lead blocks 10-12 attached to the fixed-side housing 1, and the other end in the longitudinal direction. The portion is electrically and mechanically connected to fourth to sixth lead blocks 20 to 22 attached to the movable housing 2.

  In this embodiment, the flat cable 3 is for transmitting electrical signals such as an airbag system and a horn circuit, and both longitudinal ends thereof are connected to the first lead block 10 and the fourth lead block 20, respectively. Has been. The flat cable 4 is for transmitting electrical signals of various steering switches, and both ends in the longitudinal direction are connected to the second lead block 11 and the fifth lead block 21, respectively. These flat cables 3 and 4 are general flat cables carrying a plurality of strip conductors 19 (see FIG. 18). On the other hand, the first and second flat cables 5 and 6 are for energizing a steering heater that requires a relatively large current. As shown in FIGS. 8 and 11, these first and second flat cables are used. Nos. 5 and 6 have only one strip-shaped conductor 19 supported in a wide width in order to reduce the wiring resistance. One end of the first and second flat cables 5, 6 in the longitudinal direction is connected to the third lead block 12, and the other end in the longitudinal direction is connected to the sixth lead block 22. Further, as will be described later, both the lead blocks 12 and 22 are constituted by a common component made of the same insulating base 31.

  The holder 7 includes an annular flat plate portion 7a that is rotatably mounted on the bottom plate member 9 in the annular space S, and a plurality of support shafts 7b and guide wall portions 7c provided upright on the annular flat plate portion 7a. It is a molded product of synthetic resin. A roller 23 is rotatably supported on each support shaft 7b, and each flat cable 3-6 is wound around a predetermined roller 23 and passed between the opposing guide wall portions 7c. The winding direction of the flat cables 3 to 6 is reversed halfway.

  Each of the first to third lead blocks 10 to 12 and the fourth to sixth lead blocks 20 to 22 is a component in which the connection terminal 30 is held by insert molding on an insulating base. A plurality of strip-shaped conductors 19 carried by the flat cable 3 are spot welded to corresponding connection terminals 30 of the first lead block 10 and the fourth lead block 20 at both ends in the longitudinal direction. Similarly, a plurality of strip-shaped conductors 19 carried by the flat cable 4 are spot welded to corresponding connection terminals 30 of the second lead block 11 and the fifth lead block 21 at both ends in the longitudinal direction. Further, as will be described later, the strip-shaped conductor 19 (see FIG. 8) carried by the first and second flat cables 5 and 6 has both ends in the longitudinal direction thereof connected to the third lead block 12 and the sixth conductor 6. It is spot welded to the corresponding connection terminal 30 of the lead block 22. Thus, the electrical connection between the fixed housing 1 and the movable housing 2 is established via the connection terminals 30 of the lead blocks 10 to 12 and 20 to 22 and the strip conductors 19 of the flat cables 3 to 6. To be maintained.

  As shown in FIGS. 1 and 15, of the fourth to sixth lead blocks 20 to 22 incorporated in the top plate portion 13 a of the upper rotor 13 constituting the movable housing 2, the first connected to the flat cable 3. The 4-lead block 20 is fitted at a position straddling the third connection portion 13c and the harness extraction portion 13e. And, via an external connector (not shown) connected to the third connection portion 13c and a wire harness 24 led out from the harness extraction portion 13e, an electric circuit such as an airbag system or a horn circuit, The flat cable 3 connected to the fourth lead block 20 is electrically connected. Further, the fifth lead block 21 connected to the flat cable 4 is fitted in the fourth connection portion 13d, and various kinds are provided via an external connector (not shown) connected to the fourth connection portion 13d. The electric circuit of the steering switch and the flat cable 4 connected to the fifth lead block 21 are electrically connected. The sixth lead block 22 connected to the first and second flat cables 5 and 6 is fitted in the harness extraction portion 13f, and the wire harness 25 led out from the harness extraction portion 13f Thus, the electric circuit of the steering heater is electrically connected to the first and second flat cables 5 and 6 connected to the sixth lead block 22.

  On the other hand, the first to third lead blocks 10 to 12 incorporated in the fixed-side housing 1 are fitted into the fixed-side connecting portion 50 in a state of being integrated as shown in FIG. The flat cables 3 and 4 are electrically connected to an electronic device, a power supply circuit, and the like on the vehicle body side via external connectors (not shown) connected to the first and second lead blocks 10 and 11. It has become. The third lead block 12 is connected to the second connection portion 27 via the wire harness 26 (see FIG. 1). For this reason, the first and second flat cables 5 and 6 connected to the third lead block 12 are connected to the second connection portion 27 via an external connector (not shown) and the like on the power circuit on the vehicle body side. And is electrically connected.

  As shown in FIGS. 16 and 17, a circuit protection component 28 is attached to the connection terminal 30 a among the plurality of connection terminals 30 supported by the second lead block 11 connected to the flat cable 4. . The circuit protection component 28 includes a main body portion 28a that is a resistor, for example, and a pair of lead portions 28b that protrude from both end faces of the main body portion 28a. Then, among the connection terminal 30 group of the second lead block 11, a predetermined connection terminal 30 a having a risk of excessive current flowing is cut in advance, and each of the cut portions and a pair of lead portions of the circuit protection component 28 are cut. 28b is connected. In the present embodiment, the lead portion 28b is spot-welded to the connection terminal 30a at those cut points, but the connection terminal 30a and the lead portion 28b can be connected by soldering or the like. Since the circuit protection component 28 can prevent the passage of an excessive current, it is possible to protect a steering switch-related electric circuit from an excessive current and prevent a circuit breakdown or the like. Here, a fuse or the like can be used as the circuit protection component 28. Of course, a plurality of connection terminals 30a may be provided in accordance with a circuit in which an excessive current may flow.

  In order to attach the circuit protection component 28, the insulating base 31 of the second lead block 11 includes a gap portion 31a that divides the connection terminal 30a, and the front and back sides of the connection terminal 30a in the vicinity of both ends of the gap portion 31a. And a pair of openings 31b for exposing the. The main body 28 a of the circuit protection component 28 is disposed in the gap 31 a, so that the main body 28 a is kept out of contact with the surrounding insulating base 31. Further, since both the lead portions 28b are mounted on the connection terminals 30a in the corresponding openings 31b, spot welding between the lead portions 28b and the connection terminals 30a can be easily performed. The insulating base 31 of the second lead block 11 has an inclined guide surface 31c formed on a part of the inner wall that continues to the opening 31b. When the circuit protection component 28 is attached, the inclined guide surface 31c. Thus, the leading end of the lead portion 28b is guided to the opening portion 31b. Therefore, the circuit protection component 28 can be easily disposed at a predetermined position of the second lead block 11, and the attaching operation can be easily performed.

  Next, when it is necessary to connect the lead blocks so that the longitudinal directions of the first and second flat cables 5 and 6 are different from each other based on FIGS. A description will be given of a configuration example in which the lead block can be used as a common part, instead of being separately prepared and used. The third lead block 12 to be described later is configured on one side surface of the lead block as a common part, and the sixth lead block 22 to be described later is configured on the other side surface. That is, the third lead block 12 and the sixth lead block 22 to which both ends in the longitudinal direction of the first and second flat cables 5 and 6 are connected are common parts constituted by the same insulating base 31. For example, the longitudinal directions of the first and second flat cables 5 and 6 attached to the third lead block 12 and the longitudinal directions of the first and second flat cables 5 and 6 attached to the sixth lead block 22 are orthogonal to each other. Is configured to do. As shown in FIG. 12 and FIG. 13, the third and sixth lead blocks 12 and 22 have different layouts such as connection terminals 30, partition walls 31d and positioning protrusions 31e with respect to the insulating base 31, and are shown in FIG. When the sixth lead block 22 is viewed from the opposite side, the third lead block 12 shown in FIG. 13 is obtained. That is, the third and sixth lead blocks 12 and 22 which are the common parts are connected to the one side surface or the other side surface in accordance with whether the longitudinal ends of the flat cables 5 and 6 are connected. It is designed so that the mounting directions of the flat cables 5 and 6 are substantially orthogonal.

  More specifically, the third and sixth lead blocks 12 and 22 have portions that are attached to the end portions in the longitudinal direction of the first and second flat cables 5 and 6 and are approximately the same size as the end portions in the longitudinal direction. The rectangular plate-like portion 32 is formed. Then, as shown in FIG. 12, a pair of connection terminals 30 are arranged along one long side of the rectangular plate portion 32 on one side surface of the rectangular plate portion 32. As shown in FIG. 8, the strip-shaped conductors 19 of the first and second flat cables 5 and 6 are spot-welded to the connection terminals 30. Thus, on the surface on one side of the rectangular plate-like portion 32, the first and second flat cables 5 and 6 are attached so that the longitudinal ends thereof are along the short side direction of the rectangular plate-like portion 32. In addition, a partition wall 31 d is erected on the insulating base 31 on a straight line separating the pair of connection terminals 30 on the one side surface, and two long sides 2 of the rectangular plate-like portion 32 are provided. A positioning projection 31e is provided at a location, and a pair of regulating walls 31f facing each other with a gap slightly wider than the width dimension of the first and second flat cables 5 and 6 is a rectangular plate portion 32. It is erected along the short side. Therefore, the end portions in the longitudinal direction of the first and second flat cables 5 and 6 can be easily placed at predetermined positions on one side of the rectangular plate-like portion 32 by the partition walls 31d, the positioning protrusions 31e, the restriction walls 31f, and the like. While being able to position, the spot welding of the strip | belt-shaped conductor 19 and the connecting terminal 30 can be performed easily.

  On the other hand, as shown in FIGS. 9 and 13, on the other surface of the third lead block 12, a pair of connection terminals 30 are juxtaposed along one short side of the rectangular plate portion 32. The strip conductors 19 of the first and second flat cables 5 and 6 are spot-welded to the connection terminal 30. Therefore, as shown in FIG. 9, on the other surface of the rectangular plate-like portion 32, the longitudinal ends of the first and second flat cables 5, 6 are along the long-side direction of the rectangular plate-like portion 32. Attached to. On the other surface, the insulating base 31 is provided with a partition wall 31d upright on a straight line separating the pair of connection terminals 30 and 2 on one short side of the rectangular plate portion 32. A positioning projection 31e is provided at a location, and a pair of regulating walls 31f facing each other with a gap slightly wider than the width dimension of the first and second flat cables 5 and 6 is a rectangular plate portion 32. It is erected along the long side. Also in this case, the end portions in the longitudinal direction of the first and second flat cables 5 and 6 can be easily placed at predetermined positions on the other surface of the rectangular plate portion 32 by the partition wall 31d, the positioning projection 31e, the restriction wall 31f, and the like. In addition, spot welding of the strip conductor 19 and the connection terminal 30 can be easily performed.

  The third lead block 12 exposes a pair of external connection terminals 33 at portions adjacent to the rectangular plate-shaped portion 32, and an external conductor such as a wire harness is electrically and mechanically connected to the external connection terminals 33. Can now be connected. As shown in FIG. 14, the pair of external connection terminals 33 are exposed conductor portions individually led out from the pair of connection terminals 30 on which the strip conductors 19 of the first and second flat cables 5 and 6 are mounted. is there. As shown in FIGS. 12 to 14, the insulating bases 31 of the third and sixth lead blocks 12 and 22 have slit portions 31 g and 31 h that cross a part of the rectangular plate portion 32 in a cross shape. Is formed. Although detailed description will be given later, among the first and second flat cables 5 and 6 to be stacked, the folded end portion 5c provided on the first flat cable 5 on the lower layer side is the first and second flat cables 5 and 6. Depending on the mounting direction with respect to the rectangular plate-shaped part 32, the slit part 31g and the slit part 31h are inserted and locked. 7 and 8, the folded end 5c is inserted and locked into the slit 31h, and in FIG. 9, the folded end 5c is inserted and locked into the slit 31g.

  Next, the mounting structure of the first and second flat cables 5 and 6 with respect to the third and sixth lead blocks 12 and 22 will be described in detail. As shown in FIGS. 7 to 9, the longitudinal ends of the first and second flat cables 5, 6 are cut ends 5 b, 6 b on one side in the width direction, and the distal ends of the remaining narrow portions 5 a, 6 a The strip-shaped conductors 19 are exposed, and the end portions of the strip-shaped conductors 19 are held by an insulating holding film 34. The end portions in the longitudinal direction of the first and second flat cables 5 and 6 are respectively mounted on the third and sixth lead blocks 12 and 22 in a stacked manner, and the width of the first flat cable 5 on the lower layer side is narrow. The portion 5 a and the narrow portion 6 a of the second flat cable 6 on the upper layer side are arranged side by side on the third and sixth lead blocks 12 and 22. That is, the first and second flat cables 5 and 6 are end portions in the longitudinal direction in a positional relationship in which one of the narrow portions 5a (6a) is disposed adjacent to the other cut portion 6b (5b). Neighbors are superimposed. In addition, the strip conductor 19 of the first flat cable 5 protruding from the narrow portion 5a and the strip conductor 19 of the second flat cable 6 protruding from the narrow portion 6a are individually mounted on the pair of connection terminals 30. Thus, each belt-like conductor 19 is spot-welded to the corresponding connection terminal 30.

  As shown in FIG. 11, the narrow portions 5a and 6a of the first and second flat cables 5 and 6 are formed by cutting lines 41 and 42 indicated by a two-dot chain line in FIG. It is formed by cutting. By this cutting operation, the cut surface of the strip-shaped conductor 19 facing the hatched cut portions 5b and 6b in the figure is formed in an L shape at the longitudinal ends of the first and second flat cables 5 and 6. At the same time, in the vicinity of the proximal end portion of the narrow portion 5a in the first flat cable 5, a cut 5d is formed in which the cutting line 42 exceeds the folded end portion 5c, and the first flat cable 5 is folded back using the cut 5d. An end 5c is formed.

  As shown in FIGS. 8 and 10, the folded end portion 5 c of the first flat cable 5 is separated from the narrow portion 6 a of the second flat cable 6, which is the upper end of the longitudinal end portion of the first flat cable 5. It is formed by folding back toward the insulating base 31 so as to be inserted and locked in the direction, that is, the slit portion 31h shown in FIG. For example, when the first flat cable 5 is used as the sixth lead block 22 incorporated in the movable housing 2, the longitudinal direction of the first flat cable 5 is set to the rectangular plate-like portion 32 with respect to the sixth lead block 22. Since it is attached in a direction orthogonal to the long side direction (see FIG. 7), the folded end portion 5c is inserted into the slit portion 31h extending along the long side of the rectangular plate portion 32 and locked. On the other hand, when the first flat cable 5 is used as the third lead block 12 incorporated in the fixed-side housing 1, the first flat cable 5 has a rectangular plate-like portion 32 in the longitudinal direction of the first flat cable 5. Therefore, the folded end portion 5c is inserted into the slit portion 31g extending along the short side of the rectangular plate portion 32 and locked. In any case, the folded end portion 5c of the first flat cable 5 is locked in the slit portion 31g or the slit portion 31h in the inserted state, so that one side or the other side of the third or sixth lead blocks 12, 22 Thus, the conductor cut surface of the folded end portion 5c is exposed, and there is no possibility that the folded end portion 5c of the first flat cable 5 and the conductor cut surface of the second flat cable 6 are short-circuited (contacted).

  In addition, since the folding | returning dimension of the folding | returning edge part 5c is prescribed | regulated by the notch 5d formed when the flat cable 40 is cut | disconnected, the folding | returning edge part 5c of a desired magnitude | size can be formed easily. The insulating base 31 of the third and sixth lead blocks 12 and 22 includes a region where the narrow portion 5a of the first flat cable 5 is disposed and a region where the narrow portion 6a of the second flat cable 6 is disposed. Since the partition wall 31d is erected between the narrow walls 5d, the narrow portions 5a and 6a can be easily disposed at predetermined positions sandwiching the partition wall 31d. Can be surely prevented.

  As described above, each of the flat cables 3 to 6 is led out from the annular space S to the fixed-side connection portion 50 (the first connection portion 8c and the second connection portion 27), and the first end portion corresponding to each longitudinal direction corresponds to the first one. The first to third lead blocks 10 to 12 are connected. That is, in the fixed-side connection portion 50, one end portion in the longitudinal direction of the two flat cables 3 and 4 is connected to the first and second lead blocks 10 and 11, respectively. One end in the longitudinal direction of 6 is connected to the third lead block 12. As shown in FIGS. 4, 6, and 19, the flat cables 3 to 6 connected to the first to third lead blocks 10 to 12 are bent at a substantially right angle at the fixed side connection portion 50 to be fixed side connection portions. 50 extends toward the annular space S, is bent again, and is led to the annular space S through the cable lead-out portion G (see FIG. 5). As shown in FIGS. 19 and 20, the insulating film 18 of each of the flat cables 3 to 6 has a cut portion 18a formed in advance on one side edge portion thereof, and the cut portion 18a is fixed to the fixed side connecting portion. It is arranged in the vicinity of 50, that is, between the fixed side connecting portion 50 and the annular space S.

  These cut portions 18a are formed as a cut promoting portion that promotes cutting when a tensile force of a predetermined size or more acts on the flat cables 3 to 6. That is, when the movable housing 2 is not correctly set to the rotation neutral position when the rotary connector is assembled to the steering device, the flat cables 3 to 6 are excessively wound when the handle is rotated in one direction. A situation occurs where the handle is tightened and the handle cannot be rotated any more. In the present embodiment example, as a measure for preventing the handle from being unable to rotate due to such misalignment, the flat cables 3 to 6 are connected to the first to third lead blocks 10 to 12 as necessary. So that it can be easily cut in the vicinity. Therefore, when a situation occurs in which the flat cables 3 to 6 are excessively tightened, the flat cables 3 to 6 are cut in the upper connection portions 8a and 9a on the fixed side so as to be torn apart from the respective cut portions 18a, As a result, the handle can be further rotated.

  In addition, in order to prevent the cut portions from being short-circuited after all the flat cables 3 to 6 are cut in this way, the adjacent flat cables among the flat cables 3 to 6 are located at the positions of the cut portions 18a in the longitudinal direction. It is set so that it may shift along. That is, when all the flat cables 3 to 6 are cut from the cut portion 18a, as shown in FIGS. 19 and 20, the flat cables adjacent to each other in the upper connection portions 8a and 9a (flat cables 3 and 4 are connected to each other). The flat cables 4 and 5 and the flat cables 5 and 6) are separated from each other by the cut portions 18 a so that the cut portions do not come into contact with each other.

  In addition, the notch | incision part 18a is a side edge part of the one side where tensile force acts relatively strongly when the flat cables 3-6 are excessively tightened among a pair of side edge parts along the width direction of the insulating film 18. Only provided. Therefore, it is extremely easy to form the cut portion 18a in each of the flat cables 3 to 6, and the conduction reliability is not affected at all. However, you may provide the cut | notch part 18a in the appropriate location of the both-sides edge along the width direction of the insulating film 18. FIG.

  The rotary connector configured as described above is assembled in a steering apparatus of an automobile and used as an electrical connection means between an electric circuit on the steering wheel side and an electronic device, a power supply circuit, or the like on the vehicle body side. When the driver rotates the handle, the movable housing 2 of the rotary connector rotates integrally with the handle, and the flat cables 3 to 6 are wound or unwound in the annular space S according to the rotation direction. However, in any state, the electrical connection between the fixed housing 1 and the movable housing 2 is performed by connecting the connection terminals 30 of the lead blocks 10 to 12 and 20 to 22 and the strip conductors 19 of the flat cables 3 to 6. Is to be maintained through.

  When the handle is rotated in the clockwise direction, the flat cables 3 to 6 are drawn out from the inner peripheral wall side of the outer cylindrical body 8 in the annular space S as the movable housing 2 rotates in the clockwise direction. It is wound around the outer peripheral wall of the inner cylinder part 13b. On the other hand, when the handle is rotated counterclockwise, the flat cables 3 to 6 are connected to the outer peripheral wall of the inner cylindrical portion 13b in the annular space S as the movable housing 2 rotates counterclockwise. And is rewound to the inner peripheral wall side of the outer cylindrical body 8.

  As described above, in the rotary connector according to this embodiment, when an excessive current flows into the lead block (second lead block) 11 connected to the end portion in the longitudinal direction of the flat cable 4, the current value is set. A circuit protection component 28 is attached for reduction, and the circuit protection component 28 can prevent damage to the circuit and damage to the electronic equipment due to inflow of excessive current. In addition, since the gap 31a and the opening 31b for attaching the circuit protection component 28 to the insulating base 31 of the lead block 11 are provided in advance, the circuit protection component 28 is mounted on the lead block 11 for electrical and mechanical use. Thus, it is possible to easily perform the connecting operation, and it is not necessary to separately prepare a mounting part, and the cost increase of the rotary connector due to the addition of the circuit protection component 28 is hardly a problem. Further, since the main body portion 28a of the circuit protection component 28 is disposed in the gap portion 31a of the lead block 11, even if an excessive current flows and the main body portion 28a becomes high temperature, the surrounding insulating base 31 is softened. There is no risk of melting.

  In the above embodiment, the circuit protection component 28 is attached to the fixed-side lead block 11. However, the circuit protection component 28 may be attached to the movable-side lead block 21, and there is a concern about the inflow of excessive current. If there is another lead block, the circuit protection component 28 may be attached thereto.

  Further, in the above embodiment example, since a resistor whose resistance value increases as the temperature rises due to self-heating is used as the circuit protection component 28, passage of excessive current is prevented without fusing the circuit protection component 28. However, it is also possible to use an electrical component with a fuse function or the like as a circuit protection component.

DESCRIPTION OF SYMBOLS 1 Fixed side housing 2 Movable side housing 3-6 Flat cable 8 Outer cylinder (outer cylinder part)
DESCRIPTION OF SYMBOLS 11 Lead block 13b Inner cylinder part 18 Insulating film 19 Strip | belt-shaped conductor 28 Circuit protection component 28a Main body part 28b Lead part 30,30a Connection terminal 31 Insulating base | substrate 31a Cavity part 31b Opening part 31c Inclination guide surface S Annular space

Claims (4)

A fixed-side housing having an outer cylindrical portion, a movable-side housing having an inner cylindrical portion and rotatably connected to the fixed-side housing, and a plurality of strip-shaped conductors covered with an insulating film, A flat cable wound in an annular space existing between the outer tube portion and the inner tube portion, and a lead block connected to an end portion in the longitudinal direction of the flat cable, A rotary connector having a plurality of connection terminals connected to the respective strip-shaped conductors of a flat cable, and an insulating base that holds these connection terminals,
A pair of gaps that divide at least one of the plurality of connection terminals on the insulating base of the lead block, and a pair that exposes the at least one connection terminal on both sides of the gap. The circuit board is provided with a body portion of a circuit protection component that prevents passage of an excessive current in the gap portion, and lead portions that project from both ends of the body portion are disposed in the opening portion to connect the connection terminal. A rotary connector characterized in that it is electrically and mechanically connected.   The rotary connector according to claim 1, wherein an inclined guide surface for guiding the lead portion to the opening is formed on the insulating base.   The rotary connector according to claim 1, wherein the lead portion is connected to the connection terminal exposed at the opening by spot welding.   The rotary connector according to any one of claims 1 to 3, wherein the circuit protection component is a resistor whose resistance value increases as the temperature rises due to self-heating.

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