JP4490127B2 - Back door assist device and back door - Google Patents

Description

  The present invention relates to a back door assist device that supports a back door opening / closing operation and a back door using the assist device.

JP 7-179182 A

Conventionally, as a back door that closes an opening at the rear of a vehicle body such as a wagon car or a one-box vehicle, a back door such as a lift gate or a rear hatch that pivots upward about the upper part of the vehicle body opening, and left and right of the vehicle body opening. There are known open door type back doors that rotate by turning either side to the right or left, and double doors that open by turning the left and right sides of the vehicle body opening to the left and right. . In these cases, by opening the back door fully, the opening of the vehicle body is opened, and it is easy to take out the luggage stored in the rear part of the vehicle from the outside. For this reason, either type of backdoor for most vehicles is used.
However, automobiles are used for various purposes by various people, and other forms of backdoors are also found depending on the applications. For example, as shown in Patent Document 1, a lift gate that rotates upward and a tail gate that rotates downward, and when the back door is opened, the tail gate is located between the floor surface and the road surface in the vehicle. What is used as a slope is known. This can facilitate the transportation of wheelchairs, carts, bicycles, and the like, and is suitably used for the transportation thereof.

  On the other hand, an assist device that supports opening and closing of the back door that opens upward is provided. As this assist device, a cylinder (such as a gas stay) using air pressure or hydraulic pressure is known. As a result, the lifting force when opening the back door and the supporting force when closing the back door can be reduced. In addition to supporting the opening and closing of the back door, it is an actuator type that operates the slide mechanism or worm gear mechanism consisting of the channel connected to the back door and the rack bar with a drive device such as an electric motor. Things are known. However, these have to be arranged together as a unit and lack the layout in the vehicle. In particular, wagon cars, one-box cars, and the like are designed so that the interior of the car can be used widely, and therefore, an assist device with high layout is required.

  An object of the present invention is to provide a back door assist device that can easily open and close the back door without damaging the interior space of the vehicle. Furthermore, it aims at providing the back door which can use a space outside a vehicle effectively in a camping etc.

Backdoor assist device of the present invention is an assisting apparatus that supports the opening and closing of the flap gate pivotally mounted to the bottom of the rear part of the vehicle body, and a cable having one end attached to the flap gate, before Symbol cable A drum that winds up the other end; a spiral spring that constantly urges the drum in a direction of winding the cable; and a bracket that houses the drum and the spiral spring and is attached to the vehicle body, A latch that engages with the flap gate and the drum is provided at both ends, and a stopper is provided in the vicinity of the end on the drum side. The bracket includes a plate-like base bracket and the base bracket. Attached to one side of the drum bracket that covers the drum and the other side of the base bracket And a spring case that covers the spiral spring, and has a stopper bracket around the cable outlet of the bracket. The cable is provided at the rear part of the vehicle body from the cable outlet of the bracket and toward the flap gate side. A taper-shaped guide extending upward and downward at an angle of about 30 degrees is continuous to the flap gate via a locking portion provided on the inner surface, and supports the cable between the bracket and the locking portion. A conduit is attached, and when the flap gate becomes horizontal, the stopper supplied from the drum is locked to the stopper bracket, and the flap gate is held substantially horizontal .
In such a back door assist device, it is preferable that the spiral spring has a cable pull-out amount of 200 to 400 mm at the maximum, and a spiral spring force of 10 to 20 N when the cable pull-out amount is 200 mm.

Backdoor of the present invention is directed to a flap gate pivotally mounted to the lower portion of the body member, in that it consists of a back door assist device of the present invention is characterized.
Such a back door is preferably provided with a hinge lock on the flap gate so that the flap gate does not rotate substantially horizontally. In addition, it is preferable that the flap gate is provided with a leg for supporting the flap gate which is substantially horizontal. Furthermore, it is preferable that the flap gate and the back lid that is attached to the rear of the vehicle body so as to be able to rotate freely are closed . The flap gate is preferably expandable and contractible in a direction connecting the rotation center and the tip thereof .

Backdoor assist equipment of the present invention includes a cable attached to the flap gate, a drum for winding the cable, since a spiral spring for rotating the drum, at least a portion of the weight of the flap gate The cable supports and the user can easily open and close the flap gate. Therefore, the flap gate can be opened slowly and safely.
In addition, when the back door is closed, the cable is wound around the drum, so that the cable is prevented from being loosened, thereby preventing the cable from being entangled and saving space. Therefore, the interior space can be used effectively, and it is less expensive than conventional cylinder type assist devices.
Further, since the flap gate is provided with means for maintaining it substantially horizontal with respect to the ground, it can be protruded horizontally from the vehicle body by the area of the flap gate. Therefore, a vertically long floor connected to the interior of the vehicle can be formed. As a result, this increased area can be effectively used according to the purpose of outdoor use such as camping. For example, the protruding flap gate can be used as a chair, or can be used as a bed by laying a mattress or the like in the vehicle.

Since the means for maintaining the cable horizontally and the cable stopper that restrains the unwinding of the cable are used , the cable supports both the support for opening and closing the back door and the means for maintaining the cable horizontally. Other means such as are unnecessary. Further, since the cable is stopped when the cable is sent out for a certain length, the user can open and close the flap gate without being aware of the open / closed state of the flap gate. That is, by attaching the cable length to be sent in advance is adjusted to the flap gate, Ru can be held substantially horizontally flap gate to the ground.
Furthermore, since the driving device is a spiral spring for urging the drum in the winding direction of the cable, since the spiral spring torque to the restoration with the deformation increases, the cable tension to support the flap gate with delivery cable length Becomes larger. That is, when opening and closing the flap gate, the torque of the flap gate but increases with the slope, the tension for supporting the flap gate is also increased, the user Ru can be opened and closed operations efficiently flap gate.
Furthermore, the cable is provided at the rear part of the vehicle body from the cable outlet of the bracket, and has a locking part provided on the inner surface with a guide that is tapered at an angle of about 30 degrees up and down toward the flap gate side. Since the conduit that supports the cable is attached between the bracket and the engaging portion, the cable does not bend or shake up and down.
In the back door assist device according to the present invention, when the means for maintaining the substantially horizontal position can support a weight of 200 kg when the flap gate is positioned substantially horizontally, a plurality of persons can dislodged from the vehicle body flap gate also is working aboard the above, it is not the name that or fall.

Backdoor of the present invention, since it has a flap gate pivotally mounted to the bottom of the rear portion of the vehicle body, and a back door assist device of the present invention, it is possible to obtain a back door having an action as described above .
Further, in such a back door, when the opening of the rear part of the vehicle body is closed by the flap gate and the back lid rotatably attached to the upper part of the rear part of the vehicle body, the height of the flap gate is the same as the height of the back lid. The thickness can be lowered. Therefore, Ru can open a back door without having to worry about the flap gate to the body, such as one-box cars coming fall from above the high automobile.

When the flap gate is extendable in the direction of the rotation axis, the flap gate can be opened after the flap gate is contracted to a safe height. Also, place the flap gate in a substantially horizontal position, by extending the flap gate, it is possible to obtain a vehicle floor area to taste.

  Next, the back door of the present invention will be described with reference to the drawings. 1a is a perspective view showing a vehicle body using one embodiment of the back door of the present invention, FIG. 1b is a perspective view showing a state in which the back door of FIG. 1a is opened, and FIG. 2a is a back view of the present invention used in FIG. FIG. 2b is a sectional side view of the assist device, FIG. 2c is a left side view of the stopper bracket used in FIG. 2a, FIG. 2d is a right side view of the stopper bracket used in FIG. 2a, and FIG. Fig. 3b is a front sectional view of the drum used in Fig. 2a, Fig. 4b is a side view of Fig. 4a, and Fig. 4c is Fig. 4a. FIG. 5a, FIG. 5b and FIG. 5c are side views showing the relationship of gravity, cable tension and drag of the flap gate acting on the flap gate of FIG. 1, and FIG. 6a is the back door of the present invention. Other embodiments FIG. 6b is a perspective view showing a state where the back door of FIG. 6a is opened, FIG. 7a is a perspective view showing a rear part of the vehicle body using still another embodiment of the back door of the present invention, FIG. 7b is a perspective view showing a state in which the back door of FIG. 7a is opened.

  A one-box car (vehicle body) 10 in FIG. 1a is provided with a back door of the present invention. The back door 11 is a back lid 12 rotatably attached to the upper part of the rear part of the vehicle body, and is rotated to the lower part of the rear part of the vehicle body. It consists of a flap gate 13 that is movably attached and a back door assist device 14 that supports opening and closing of the flap gate 13.

  The back lid 12 is gently curved, and is rotatably attached to the upper portion 15 of the vehicle body by a hinge extending in the width direction of the upper portion 15 of the rear portion of the vehicle body, and gas stays 16 are provided on both sides. (See FIG. 1b). The center is provided with a window made of glass. As a result, the back lid 12 is constantly receiving force from the gas stay 16 in the opening direction. That is, the opening and closing of the back lid is supported by the gas stay 16. This back lid is a conventionally known one.

  The flap gate 13 has a rectangular shape and is rotatably attached to the lower portion 17 of the vehicle body by a hinge extending in the width direction of the lower portion 17 of the rear portion of the vehicle body. Further, one end of the cable 20 of the back door assist device 14 to be described later is locked at a position on both sides of 1: 2 to 1: 1 with respect to the length connecting the rotation center of the flap gate and the tip thereof. . The boundary between the flap gate 13 and the back lid 12 is such that the back lid 12 overlaps the flap gate 13. Therefore, the flap gate can be opened and closed only when the back lid is opened. In such a vehicle, it is possible to take out luggage or the like from the rear of the vehicle with the back lid 12 opened and the flap gate 13 closed. Such a flap gate is preferably one having a weight of 5 to 15 kg. Further, the overlapping order of the flap gate and the back lid may be reversed, or the connecting plate may be interposed in the middle without overlapping.

  The back door assist device 14 is attached to the left and right side walls in the vehicle. As shown in FIGS. 2a and 2b, the cable 20 attached to the flap gate 13, the drum 21 that can store the cable, and the drum The spiral spring 22 that constantly urges the cable in the direction of winding the cable, and the drum 21 and a bracket 23 that houses the spiral spring 22. FIGS. 2a and 2b show a state where the flap gate is kept horizontal as will be described later. The back door assist device 14 may be attached to only one side wall of the vehicle as long as the back door assist device 14 is attached to one side wall of the vehicle to sufficiently assist the opening and closing of the flap gate.

The cable 20 is provided with an inner cable 20a and both ends of the inner cable, and includes a flap gate 13 and locking members 22a and 22b that engage with the drum 21, and a bracket 23 described later and the vicinity of the rear part of the vehicle body. Guided by a conduit 26 mounted in between (see FIG. 3a).
The inner cable 20a is formed by twisting a plurality of steel wires and is conventionally known. Moreover, what is not cut even if it pulls with the force of 200 kg is used.
The drum-side locking tool 22 b is obtained by covering a cable end with a cylindrical metal fitting, and the metal fitting is crimped. The flap gate-side locking tool 22 a is a cylindrical metal fitting having a ring-shaped locking part 24. 24a is attached to the end of the cable and the metal fitting is crimped. A stopper 25 is provided in the vicinity of the end of the inner cable on the drum side. The stopper 25 is formed by attaching a cylindrical metal piece to the inner cable 20a and caulking from above. Thereby, the part 20b of the cable main body 20a covered with this stopper becomes larger in diameter than other parts. The locking tools 22a and 22b may be formed by casting.

  The conduit | pipe 26 is attached between the bracket 23 mentioned later and the rear part of a vehicle body. By this conduit 26, the inner cable 20a is supported between the bracket 23 and the vehicle body opening, and is not bent or shaken up and down. Moreover, the layout property of the whole cable can be improved. Reference numeral 26a denotes a cable cap that engages with the bracket 23 when the conduit 26 is attached to the bracket 23, and reference numeral 27 denotes a locking portion that is fixed to the end of the conduit 26 that attaches the conduit 26 to the vehicle body on the flap gate side. This locking portion 27 is an outlet of the inner cable. The locking portion 27 is a prism, and a guide 27a is formed on the inner surface so as to taper toward the flap gate side at an angle of about 30 degrees up and down, and a flange portion 27b having a mounting hole 27c is formed on the side surface. Provided (FIG. 3b). The flange portion 27b is attached to the vehicle body using a locking tool such as a screw and a nut. The locking portion 27 is attached to a position slightly lower than the height of the flap gate so that the angle of the cable with respect to the substantially horizontal flap gate is 15 to 30 degrees. This conduit 26 is particularly effective when the bracket 23 cannot be attached in the vicinity of the locking portion 27 (cable exit) due to a layout problem or the like. However, if the bracket 23 can be attached in the vicinity of the locking portion 27 or directly, the conduit may be omitted. When the locking portion 27 is directly attached to the bracket 23, the locking portion 27 may have a stopper bracket function.

As shown in FIGS. 4 b and 4 c, the drum 21 includes a cylindrical drum portion 30 and a cylindrical rotation shaft portion 31, and the rotation shaft portion 31 is provided at the center of the upper surface of the drum portion 30.
The drum portion 30 includes a body portion 32 and flange portions 33 provided at upper and lower ends thereof, and the inner cable 20a is wound around and stored in the body portion 32 between both flange portions 33. The groove between the flange portions 33 is deep enough to wind the inner cable 20a 2-3 times. The body portion 32 is formed with an engagement portion 35 that engages with the cable locking tool 22b and a stopper storage portion 36 that stores the cable stopper 25. The inner surface of the flange portion 33 is also expanded by the stopper storage portion 36 (see FIG. 4c). The engaging portion 35 includes a hole 35a provided in the axial direction of the drum 21 and a guide groove 35b that connects the outer periphery and the hole. The cable 20 is guided to the hole 35a along the guide groove 35b of the engaging portion 35, the locking tool 22b is fitted into the hole 35a, and the cable 20 and the drum 21 are locked. The reason why there are two engaging portions 35 is that they are shared by the left and right assist devices of the vehicle body. Further, when the inner cable 20 a is wound around the drum 21, the stopper 25 is positioned in the stopper storage portion 36. Thus, when the inner cable 20a is wound around the drum 21, the next cable is smoothly overlapped on the stopper 25, so that the cable can be smoothly wound without being clogged or caught.

The rotating shaft portion 31 is cylindrical and engages with the spiral spring 22. When the rotating shaft portion 31 is engaged with the spiral spring 22, the entire drum 21 is urged with a constant force in one rotation direction.
The spiral spring 22 is a conventionally known one, and the spring force (restoring force) of the spiral spring becomes the tension with respect to the flap gate 13 of the cable. In this spiral spring, the torque to be restored increases with the deformation of the spiral spring itself, that is, the cable tension increases as the cable drawing amount from the drum increases.

Here, gravity (f1) of the flap gate, force (f2) acting on the flap gate from the cable, and drag (f3) against the flap gate at the rear of the vehicle body act on the flap gate. The user opens the flap gate while supporting the flap gate with a force (F) that resists the sum of gravity (f1), cable tension (f2), and drag (f3) of the flap gate at the tip of the flap gate (see FIG. 5).
The torque in the direction in which the flap gate opens is zero when the flap gate is closed, increases according to the angle at which the flap gate falls, and becomes maximum when the flap gate is in a substantially horizontal state. That is, since the vertical component of the drag (f3) decreases according to the angle at which the flap gate tilts, a vertical force for supporting the flap gate that increases according to the angle at which the flap gate tilts is required at the tip of the flap gate. On the other hand, when the flap gate is closed, the cable tension (f2) is minimized because the amount of the inner cable drawn is minimum. As the flap gate is opened, the amount of the inner cable drawn becomes longer, so that the tension increases and becomes maximum when the flap gate is in a substantially horizontal state.

  Therefore, when the spiral spring is used as a driving device, the user starts to open the flap gate with force (F) against the minimum cable tension at the end of the flap gate (see FIG. 5a). When the angle of the flap gate is between 0 and 90 °, the force required to support the flap gate that increases in accordance with the angle at the tip of the flap gate is reduced by the support of the cable tension (f2) that also increases, The user opens while supporting the flap gate with force (F) (see FIG. 5b). Then, the maximum cable tension (f2) is received as a support just before the flap gate is substantially horizontal (see FIG. 5c). That is, the user can open the flap gate 13 with the minimum force by using the spiral spring. As such a spiral spring, it is preferable that the cable draw amount is 200 to 400 mm at the maximum, and the spiral spring force (cable tension) is 10 to 20 N when the cable draw amount is 200 mm.

Returning to FIG. 2 b, the bracket 23 is a rectangular plate-like base bracket 40, attached to one surface of the base bracket, a drum bracket 41 covering the drum 21, and attached to the other surface of the base bracket. It has a spring case 42 to cover, and has a stopper bracket 43 around the cable outlet of the bracket.
The stopper bracket 43 is a U-shaped metal plate provided at the cable outlet portion of the base bracket 40, and flanges 43 a and 43 b at both ends are provided perpendicular to the base bracket 40. 2c and 2d, a flange 43b far from the drum is attached with a cable cap 26a fixed to the end of the conduit 26, so that a hole 37 slightly larger than the diameter of the cable cap formed at the center thereof is provided. A guide groove 38 is formed to guide the hole (for locking the cable cap), and a U-groove 39 for guiding the cable is formed in the flange 43a near the drum (stopper mechanism). Stop).

  The inner cable 20a is guided from the guide groove 38 of the flange 43b to the hole 37, the cable 20 is passed through the stopper bracket 43, and the cable cap 26a is fitted into the hole 37 of the flange 43b. As a result, the inner cable 20 a is slidable and the conduit 26 is fixed to the bracket 23. As a result, the inner cable 20a is passed and the cable body is locked to lock the stopper 25. That is, when the flap gate 13 starts to be opened and the flap gate 13 becomes horizontal, the stopper 25 is arranged so that the stopper 25 of the cable 20 is locked to the stopper bracket 43, so that the flap gate 13 becomes substantially horizontal. Retained.

The back door assist device 14 configured as described above is used by locking the locking tool 22a at one end of the cable 20 to the flap gate 13. At this time, the tension by the spiral spring 22 is always applied to the cable 20. When the user starts opening the flap gate at the tip of the flap gate, the cable 20 wound around the drum 21 is sent out from the drum 21 as the flap gate 13 rotates. At this time, at the front end of the user's flap gate, the force for supporting the flap gate required together with the opening of the flap gate 13 is partially reduced by the cable tension. Furthermore, since the cable tension increases with the opening of the flap gate, the burden on the user is further reduced. When the flap gate 13 reaches a substantially horizontal position, the cable stopper 25 reaches the stopper bracket 43 (the state shown in FIGS. 2a and 2b). Here, the cable stopper 25 is locked to the cable bracket 43, and the flap gate 13 is also held substantially horizontally without rotating further. At this time, in order to hold the flap gate more stably, a lock may be provided to hold this state. In particular, locking is required when the vertical component of cable tension (F2) is greater than the vertical component of flap gate force (F1).
Even when the flap gate 13 is in an open state, the flap gate 13 is supported by the tension of the cable 20, so that the user can close the flap gate 13 by simply lifting it lightly. When the vertical component of the cable tension (F2) is larger than the vertical component of the flap gate force (F1), the flap gate can be easily closed by unlocking the flap gate. As described above, the back door assist device 14 assists in opening and closing the flap gate 13.

  The stopper bracket 43 is firmly formed and is designed not to be broken even when the cable 20 is pulled with a force of 200 kg. For example, it is preferable to use a steel plate as a material. Further, the cable stopper 25 is designed not to come off from the cable body 20 a even when pulled by the above force, and further, the cable 20 does not come off from the flap gate 13. By designing in this way, when the flap gate 13 is in a substantially horizontal position, the flap gate 13 will not fall even if the user sits on the flap gate 13.

Further, a hinge lock may be provided on the hinge of the flap gate of FIG. 1 so that the flap gate does not rotate from substantially horizontal.
Further, the flap gate may be provided with a leg 45 that pivots to an angle of 90 degrees with respect to the flap gate, with the vicinity of the upper end of the flap gate as an axis, as indicated by imaginary lines in FIGS. 1a and 1b. With the legs 45, the flap gate in the opened state can be maintained horizontally, and the stability of the vehicle body in the state in which the flap gate is opened is further increased. For example, even if a heavy object is placed on the flap gate, there is no risk of the vehicle body tilting. Further, although the folding leg 45 is disclosed in FIG. 1a, it may be detachable.
Further, in the vehicle of FIG. 1, the flap gate 13 and the cable 20 may be locked by a hook or the like so as to be removable. By removing the cable 20 from the flap gate in this manner, the flap gate 13 can be rotated 180 degrees from the state where it is closed in the opening at the rear of the vehicle body, that is, it can be lowered with respect to the bottom of the vehicle body. . As a result, the flap gate itself does not get in the way when carrying luggage in the car.

  In this embodiment, the spiral spring is used as the cable driving device, but a motor may be used. In this case, since the drum is rotated using a motor, winding and feeding of the cable are automated. That is, the opening and closing of the flap gate can be automated. In this case, it can be achieved by directly connecting the motor shaft to the drum shaft or indirectly via a pinion or the like. In this case, it is preferable to provide a limit switch that stops the motor when the flap gate reaches substantially horizontal. As a result, it is possible to prevent the cable from being sent out against the stopper stopped by the stopper bracket.

  The back door 50 in FIG. 6 is such that the opening at the rear of the vehicle body is blocked only by the flap gate 51. The flap gate 51 is extendable and includes a flap gate main body 52 and a window 53 made of glass provided on the flap gate main body 52. The window 53 can be moved up and down and can be stored in the flap gate main body 52. By raising and lowering this window, the height of the flap gate 51 can be lowered and opened, and the flap gate 51 descending from above the vehicle body can be avoided. The other structure is the same as the back door of FIG. 1, and the flap gate 51 is also assisted in opening and closing by the back door assist device 14.

  The back door 55 in FIG. 7a has a flap gate 56 that can be expanded and contracted, and the other configuration is the same as that of the back door in FIG. The flap gate 56 can expand the area outside the vehicle connected to the interior of the vehicle in the horizontal direction by lowering the flap gate 56 substantially horizontally and then expanding the portion 57 folded in two. The extension portion 57 is preferably provided with a leg 58 at the tip. Thereby, the extension part 57 can be stably held in the substantially horizontal direction, and the vehicle body can be prevented from being tilted by placing a heavy object on the extension part 57. Further, the extension portion 57 may be foldable as shown in FIG. 7B and may be accommodated in the flap gate 56.

FIG. 1a is a perspective view showing a vehicle body using an embodiment of the back door of the present invention, and FIG. 1b is a perspective view showing a state in which the back door of FIG. 1a is opened. 2a is a front view showing the back assist device of the present invention used in FIG. 1, FIG. 2b is a sectional side view thereof, FIG. 2c is a left side view of the stopper bracket used in FIG. 2a, and FIG. Is a right side view thereof. 3a is a cross-sectional view of the cable used in FIG. 2, and FIG. 3b is a local cross-sectional view of FIG. 3a. 4a is a front view showing the drum used in FIG. 2, FIG. 4b is a side view thereof, and FIG. 4c is a sectional view taken along line XX of FIG. 4a. 5a, 5b, and 5c are side views showing the relationship between the gravity of the flap gate acting on the tip of the flap gate and the cable tension. FIG. 6a is a perspective view showing a vehicle body using another embodiment of the back door of the present invention, and FIG. 6b is a perspective view showing a state in which the back door of FIG. 6a is opened. 7a is a perspective view showing a rear part of a vehicle body using still another embodiment of the back door of the present invention, and FIG. 7b is a perspective view showing a state in which the back door of FIG. 7a is opened.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 One box car 11 Back door 12 Back lid 13 Flap gate 14 Back door assist device 15 Upper part 16 Gas stay 17 Lower part 20 Cable 21 Drum 22 Spiral spring 22a, 22b Locking tool 23 Bracket 24 Locking part 24a Metal fitting 25 Stopper 26 Conduit 27 Locking portion 27a Guide 27b Flange portion 27c Mounting hole 30 Drum portion 31 Rotating shaft portion 32 Body portion 33 Flange portion 35 Engaging portion 35a Hole 35b Guide groove 36 Stopper storage portion 37 Hole 38 Guide groove 39 Slot 40 Base bracket 41 Drum bracket 42 Spring case 43 Stopper bracket 43a, 43b Flange 45 Leg 50 Back door 51 Flap gate 52 Flap gate body 53 Window 55 Back door 56 Wrap gate 57 extended site 58 leg

Claims (7)

An assist device that supports opening and closing of a flap gate that is pivotally attached to the lower part of the rear part of the vehicle body,
A cable having one end attached to the flap gate;
And a drum for winding up the other end side of the front Symbol cable,
A spiral spring that constantly urges the drum in the direction of winding the cable;
It houses the drum and spiral spring, and has a bracket that can be attached to the car body.
The cable is provided with a latch that engages with the flap gate and the drum at both ends, respectively, and a stopper is provided near the end on the drum side,
The bracket includes a plate-shaped base bracket, a drum bracket attached to one surface of the base bracket and covering the drum, and a spring case attached to the other surface of the base bracket and covering the spiral spring, and a cable outlet of the bracket. It has a stopper bracket around it,
The cable is provided at the rear part of the vehicle body from the cable outlet of the bracket, and through a locking part provided on the inner surface with a guide that is tapered at an angle of about 30 degrees up and down toward the flap gate side. , Continuous to the flap gate,
A conduit for supporting the cable is attached between the bracket and the locking portion,
A back door assist device in which when the flap gate becomes horizontal, a stopper supplied from the drum is locked to the stopper bracket, and the flap gate is held substantially horizontal . The back door assist device according to claim 1, wherein the spiral spring has a maximum cable pull-out amount of 200 to 400 mm, and a spiral spring force of 10 to 20 N when the cable pull-out amount is 200 mm. A flap gate pivotally attached to the lower part of the vehicle body,
A back door comprising the back door assist device according to claim 1. The back door according to claim 3, wherein the flap gate is provided with a hinge lock so that the flap gate does not rotate from substantially horizontal. The back door according to claim 3, wherein the flap gate is provided with a leg that supports the flap gate that is substantially horizontal. The back door according to claim 3, wherein an opening of the rear part of the vehicle body is closed by the flap gate and a back lid rotatably attached to an upper part of the rear part of the vehicle body. The back door according to claim 3, wherein the flap gate is extendable in a direction connecting the rotation center and the tip thereof.