Full trailer

Abstract

To improve convenience of a full trailer.SOLUTION: A full trailer has a dolly 3 having a draw bar 30 capable of being switched to a bent state in which the full length is relatively short and an extended state in which the full length is relatively long. The draw bar 30 is composed of a first draw bar member 31 and a second draw bar member 32 whose one sides adjacent to each other are connected to each other in a relatively rotatable manner. The second draw bar member 32 includes a support arm 70 which is brought into contact with the first draw bar member 31 and supports the second draw bar member 32, in the extended state.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present invention relates to a full trailer. [Background technology]

[0002] A full trailer is a type of trailer (towed vehicle) that is towed by a tractor (towing vehicle). Full trailers are broadly divided into dolly and center axle types.

[0003] A dolly-type full trailer is equipped with a carriage with a rear axle and a front axle. Therefore, even when the dolly-type full trailer is disconnected from the tractor, it can maintain its position without auxiliary legs. This type of carriage is generally called a "front wheel carriage" or "dolly," but in this specification it will be referred to as a "dolly."

[0004] The dolly has a frame with a front axle that is rotatably connected to the chassis of the full trailer, and a drawbar with a lunette eye to which a pintle hook provided at the rear of the tractor can be hooked (Patent Document 1).

[0005] One conventional drawbar is configured with two or more parts connected to each other so as to be rotatable relative to one another and is bendable (foldable). More specifically, one conventional drawbar is switchable between a retracted state and an extended state. This type of drawbar is in the extended state when a full trailer is connected to a tractor, and is in the retracted state when the full trailer is disconnected from the tractor. By setting the drawbar to the retracted state, loading from the front of the full trailer becomes possible or easy. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 10-316056 Summary of the Invention [Problem to be solved by the invention]

[0007] Due to a labor shortage in the transportation industry, the number of full trailers with high transport capacity is expected to increase. This forecast calls for further improvements in the convenience of full trailers. [Means for solving the problem]

[0008] A full trailer according to one embodiment has a dolly equipped with a drawbar that can be switched between a retracted state and an extended state. The dolly further includes an actuator having a movable part that can move in the fore-and-aft direction of the vehicle, and a roller that is rotatably supported and in contact with the movable part. When the movable part moves toward the front of the vehicle, the roller moves while rotating from a first position on the movable part to a second position, and when the movable part moves toward the rear of the vehicle, the roller moves while rotating from the second position on the movable part to the first position. When the roller moves from the first position to the second position, the drawbar switches from the retracted state to the extended state, and when the roller moves from the second position to the first position, the drawbar switches from the extended state to the retracted state. [Effects of the Invention]

[0009] According to the present invention, the convenience of full trailers is improved. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a side view showing a full trailer and a full tractor to which the full trailer is coupled. [Figure 2] FIG. 2 is a perspective view showing the upper surface (front side) of the chassis and dolly of the full trailer. [Figure 3] FIG. 2 is a perspective view showing the bottom side (rear side) of the chassis and dolly of the full trailer. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 2 is a perspective view showing a drawbar in a bent state. [Figure 8] FIG. 2 is a perspective view showing the drawbar in an extended state. [Figure 9A] FIG. 2 is a plan view showing the actuator. [Figure 9B] FIG. [Figure 10A] FIG. 4 is a schematic diagram illustrating the operation of an airbag. [Figure 10B] 10A and 10B are other schematic diagrams illustrating the operation of the airbag. [Figure 11] FIG. 10 is another perspective view showing the drawbar in a bent state. [Figure 12] FIG. 10 is another perspective view showing the drawbar in the extended state. [Figure 13] FIG. [Figure 14A] FIG. 10 is a plan view showing the locking mechanism in an unlocked state. [Figure 14B] FIG. 10 is a plan view showing the locking mechanism in a locked state. DETAILED DESCRIPTION OF THE INVENTION

[0011] An example of an embodiment of the present invention will be described below with reference to the drawings. In all drawings used to describe the embodiment, the same reference numerals are used for identical or substantially identical configurations and elements. Furthermore, as a general rule, once a configuration or element has been described, it will not be described again.

[0012] <Full trailer overview> FIG. 1 is a side view showing a full trailer 1 according to this embodiment and a full tractor 2 to which the full trailer 1 is connected. The full trailer 1 is connected to the full tractor 2 via a dolly 3. The full trailer 1 has a rear axle mounted on a chassis 4 and a front axle mounted on the dolly 3. In other words, the full trailer 1 is a two-axle vehicle.

[0013] A loading platform C1 is mounted (installed) on the full trailer 1. As shown in the figure, by connecting the full trailer 1 equipped with the loading platform C1 to a full tractor 2 equipped with another loading platform C2, it is possible to transport two loading platforms' worth of cargo at the same time.

[0014] However, a loading platform (for example, a box-shaped body) different from the loading platform C1 can be mounted on the full trailer 1. Also, the full trailer 1 can be coupled to a tractor different from the full tractor 2.

[0015] <Chassis> Fig. 2 is a perspective view showing the top side (front side) of the chassis 4 and dolly 3 of the full trailer 1. Fig. 3 is a perspective view showing the bottom side (back side) of the chassis 4 and dolly 3 of the full trailer 1.

[0016] The chassis 4 is composed of two main rails 10 extending in the length direction of the full trailer 1 (front-to-rear direction of the vehicle) and multiple cross members 11 extending in the width direction of the full trailer 1 (width direction of the vehicle). These main rails 10 and cross members 11 are formed from steel material having a predetermined cross-sectional shape.

[0017] In the following description, the width direction of the full trailer 1 (the width direction of the vehicle) may be referred to as the "left-right direction."

[0018] Each cross member 11 is suspended between two main rails 10. Furthermore, one end of each cross member 11 is fixed to one of the main rails 10, and the other end of each cross member 11 is fixed to the other main rail 10.

[0019] 1 is mounted on the chassis 4 having the above-described structure. In other words, the chassis 4 forms a frame that supports the cargo bed C1.

[0020] A rear bumper 12 is attached to the rear end of the chassis 4, and side guards 13 (FIG. 1) are attached to both sides of the chassis 4. The chassis 4 also has a plurality of air tanks 14 that store compressed air to be supplied to predetermined pneumatic equipment. The compressed air stored in the air tanks 14 is supplied to, for example, the air brakes for the rear wheels.

[0021] Although not shown, the chassis 4 is provided with a suspension device that supports the axle (rear axle).

[0022] <Dolly> Fig. 4 is a plan view of the dolly 3, and Fig. 5 is a bottom view of the dolly 3. Fig. 6 is an exploded perspective view of the dolly 3.

[0023] The dolly 3 is rotatably connected to the chassis 4 shown in Figures 2 and 3. More specifically, the dolly 3 includes a frame 20 and a drawbar 30, and the frame 20 is connected to the front portion of the chassis 4 via a turntable 21. The turntable 21 has a rotating ring 21a fixed to the frame 20 of the dolly 3 and a rotating ring 21b fixed to the chassis 4, which are rotatably fitted together.

[0024] As described above, the chassis 4 is a frame that supports the loading platform C1. Therefore, in the following description, to avoid confusion, the frame 20 of the dolly 3 may be referred to as the "dolly frame 20."

[0025] 2, the front portion of the chassis 4 to which the dolly frame 20 is connected is thinner than the other portions. From another perspective, the height of the tip portion of the main rail 10 forming the front portion of the chassis 4 is lower than the other portions.

[0026] The dolly frame 20 is disposed below the front portion of the chassis 4, which is thinner than the other portions, and overlaps the front portion of the chassis 4. As a result, the height from the bottom surface of the dolly frame 20 to the top surface of the front portion of the chassis 4 is approximately the same as the height of the other portions of the chassis 4.

[0027] Although not shown, the dolly 3 (dolly frame 20) is provided with a suspension device that supports the axle (front axle).

[0028] <Dolly Frame> 4 and 5, the dolly frame 20 has substantially the same structure as the chassis 4. Specifically, the dolly frame 20 is composed of two main rails 22 extending in the longitudinal direction of the vehicle and a plurality of cross members 23 extending in the width direction of the vehicle. The main rails 22 and the cross members 23 are formed from steel material having a predetermined cross-sectional shape.

[0029] However, the main rails 22 that make up the dolly frame 20 are shorter than the main rails 10 that make up the chassis 4. On the other hand, the cross members 23 that make up the dolly frame 20 have the same or approximately the same length as the cross members 11 that make up the chassis 4.

[0030] A connection part 24 extending parallel to the cross member 23 is provided on one end (front side) of the dolly frame 20. The connection part 24 is integrally formed with the main rails 22 and connects the ends of the main rails 22. The connection part 24 also has a plurality of round holes 25 formed therein for passing wiring and piping.

[0031] An air tank 26 that stores compressed air to be supplied to predetermined pneumatic equipment is mounted on the other end (rear side) of the dolly frame 20. The compressed air stored in the air tank 26 is supplied to, for example, the air brakes for the front wheels.

[0032] <Drawbar> The drawbar 30 is composed of a first drawbar member 31 and a second drawbar member 32. Adjacent sides of the first drawbar member 31 and the second drawbar member 32 are connected to each other so as to be able to rotate relative to each other. More specifically, the front part of the first drawbar member 31 and the rear part of the second drawbar member 32 are connected to each other so as to be able to rotate relative to each other.

[0033] Furthermore, the other side of the first drawbar member 31 is connected to the dolly frame 20 so as to be able to rotate relatively thereto. More specifically, the rear part of the first drawbar member 31 is connected to the front part of the dolly frame 20 so as to be able to rotate relatively thereto.

[0034] The above-described connection structure allows the drawbar 30 to be switched between a bent state and an extended state. Fig. 7 is a perspective view showing the drawbar 30 in the bent state, and Fig. 8 is a perspective view showing the drawbar 30 in the extended state. The bent state and extended state of the drawbar 30 will be described later.

[0035] <First drawbar member> Referring to Figure 6, first drawbar member 31 has a pair of long sides 41, 42 extending in the width direction of the vehicle and a pair of short sides 43, 44 extending in the front-rear direction of the vehicle, and has a generally rectangular appearance in a plan view in the extended state (Figure 8).

[0036] The long side portion 41 is provided at both ends with rear coupling portions 45 that are rotatably coupled to the dolly frame 20. The long side portion 42 is provided at both ends with front coupling portions 46 that are rotatably coupled to the second drawbar member 32.

[0037] Each rear connecting portion 45 is rotatably connected to a drawbar connecting portion 27 provided at the front of the dolly frame 20 by a connecting pin (not shown). More specifically, a through hole is provided in each of the rear connecting portion 45 and the drawbar connecting portion 27. A first connecting pin is inserted into and straddles the through hole of the rear connecting portion 45 and the through hole of the drawbar connecting portion 27, which are connected to each other.

[0038] As a result, the first drawbar member 31 is rotatable relative to the dolly frame 20 around the first connecting pin as a rotation axis. From another perspective, the first drawbar member 31 is rotatable relative to the dolly frame 20 around the imaginary line R1 shown in FIGS. 7 and 8 as a rotation axis. The imaginary line R1 shown in FIGS. 7 and 8 is a line that coincides with the central axis of the first connecting pin. In the following description, the imaginary line R1 may be referred to as the "rotation axis R1."

[0039] <Second drawbar member> Referring again to Figure 6, second drawbar member 32 has a base portion 51 extending in the width direction of the vehicle and a pair of oblique sides 52, 53 extending in the front-rear direction of the vehicle, and has a generally triangular appearance in plan view in the bent state (Figure 7) and the extended state (Figure 8).

[0040] Both ends of the base portion 51 are provided with rear connecting portions 54 that are rotatably connected to the first drawbar member 31. Annular connecting portions 55 are provided at the tips of the oblique side portions 52 and 53. The connecting portions 55 are lug eyes that can engage with a pintle hook provided on the full tractor 2 shown in FIG. 1 or other tractors.

[0041] Each rear connecting portion 54 is rotatably connected by a connecting pin (not shown) to a front connecting portion 46 provided in the front portion of the first drawbar member 31. More specifically, a through hole is provided in each of the rear connecting portion 54 of the second drawbar member 32 and the front connecting portion 46 of the first drawbar member 31. A second connecting pin is inserted into and straddles the through hole of the rear connecting portion 54 and the through hole of the front connecting portion 46, which are in communication with each other.

[0042] As a result, the second drawbar member 32 is rotatable relative to the first drawbar member 31 around the second connecting pin as a rotation axis. From another perspective, the second drawbar member 32 is rotatable relative to the first drawbar member 31 around the imaginary line R2 shown in FIGS. 7 and 8 as a rotation axis. The imaginary line R2 shown in FIGS. 7 and 8 is a line that coincides with the central axis of the second connecting pin. In the following description, the imaginary line R2 may be referred to as the "rotation axis R2."

[0043] As described above, the dolly 3 has two rotation axes (rotation axes R1 and R2). In other words, the dolly 3 has two joints. One of the joints is provided between the dolly frame 20 and the first drawbar member 31, and the other joint is provided between the first drawbar member 31 and the second drawbar member 32. As a result, the drawbar 30 is foldable. More specifically, the drawbar 30 is switchable between a bent state shown in FIG. 7 and an extended state shown in FIG. 8.

[0044] <Reflection and extension> 7, the first drawbar member 31 and the second drawbar member 32 are disposed at different heights. Furthermore, the first drawbar member 31 hangs down from the dolly frame 20 and is perpendicular or nearly perpendicular to the dolly frame 20. On the other hand, the second drawbar member 32 is parallel or nearly parallel to the dolly frame 20 at a position lower than the first drawbar member 31.

[0045] From another perspective, in the bent state, the first drawbar member 31 is perpendicular or approximately perpendicular to the ground, while the second drawbar member 32 is parallel or approximately parallel to the ground at a position lower than the first drawbar member 31.

[0046] From yet another perspective, in the bent state, the dolly frame 20 and the second drawbar member 32 are parallel or approximately parallel to each other, while the first drawbar member 31 is non-parallel to the dolly frame 20 and the second drawbar member 32.

[0047] 8, the first drawbar member 31 and the second drawbar member 32 are disposed at the same height. Furthermore, both the first drawbar member 31 and the second drawbar member 32 are parallel or approximately parallel to the dolly frame 20.

[0048] From another perspective, in the extended state, the first drawbar member 31 and the second drawbar member 32 are parallel or approximately parallel to the ground at the same height.

[0049] From yet another perspective, in the extended state, the dolly frame 20, the first drawbar member 31, and the second drawbar member 32 are parallel or approximately parallel to one another.

[0050] 7 and 8, it can be seen that the total length of the drawbar 30 in the extended state (the length of protrusion relative to the dolly frame 20) is longer than that in the bent state. In other words, it can be seen that the total length of the drawbar 30 in the bent state (the length of protrusion relative to the dolly frame 20) is shorter than that in the extended state.

[0051] When loading the loading platform C1 onto the full trailer 1, the drawbar 30 is bent. As a result, it becomes possible or easy to load the loading platform C1 onto the chassis 4 from the front of the full trailer 1. Similarly, when loading a container or the like onto the full trailer 1, the drawbar 30 is also bent. As a result, it becomes possible or easy to load the container or the like onto the chassis 4 from the front of the full trailer 1.

[0052] On the other hand, when the full trailer 1 is coupled to the full tractor 2, the drawbar 30 is extended. As a result, a necessary and sufficient distance is secured between the full tractor 2 and the full trailer 1.

[0053] <Actuator> The dolly 3 is provided with an actuator 60 for switching the drawbar 30 between a bent state and an extended state. Figure 9A is a plan view showing the actuator 60, and Figure 9B is a front view showing the actuator 60.

[0054] The actuator 60 is made up of an airbag 61, a plate member 62, a guide member 63, etc., and is mounted on the dolly frame 20. As shown in Figure 6 and other figures, a box 64 having opposing side walls 64a, 64b is fixed to the bottom surface of the dolly frame 20. As shown in Figures 9A and 9B, the box 64 further has a top wall 64c, which is bolted to the connection part 24 and the cross member 23 of the dolly frame 20.

[0055] Airbags The airbag 61 is disposed in a box 64 and is bolted to the box 64. For the sake of convenience, the airbag 61 is not shown in FIG.

[0056] The airbag 61 is expandable in the front-to-rear direction of the vehicle. When a predetermined operation is performed, compressed air stored in the air tank 14 (FIGS. 2 and 3) is supplied to the airbag 61, causing the airbag 61 to expand (inflate) in the front-to-rear direction of the vehicle. The operation of the airbag 61 will be described later.

[0057] The air pressure system may be modified so that compressed air stored in another air tank (for example, air tank 26) is supplied to the airbag 61.

[0058] <Plate components> The plate member 62 is a metal plate whose width is wider than the distance between the opposing side walls 64a, 64b of the box 64. The plate member 62 is attached to an end surface of the airbag 61, and both sides of the plate member 62 protrude outside the box 64. More specifically, one side of the plate member 62 protrudes outside the side wall 64a, and the other side of the plate member 62 protrudes outside the side wall 64b.

[0059] The plate member 62 attached to the end surface of the airbag 61 moves in the front-to-rear direction of the vehicle as the airbag 61 expands and contracts. In other words, the plate member 62 is a movable part that can move in the front-to-rear direction of the vehicle.

[0060] <Guide parts> Guide members 63 are attached to side walls 64a, 64b of the box 64. Each guide member 63 is expandable and contractable in response to the expansion and contraction of the airbag 61. More specifically, each guide member 63 includes a retaining cylinder 63a and a rod 63b inserted into the retaining cylinder 63a.

[0061] The retaining cylinder 63a of one guide member 63 is fixed to the outer surface of the side wall 64a, and the retaining cylinder 63a of the other guide member 63 is fixed to the outer surface of the side wall 64b. Furthermore, the tip of the rod 63b of one guide member 63 is connected to one side of the plate member 62 protruding from the side wall 64a, and the tip of the rod 63b of the other guide member 63 is connected to the other side of the plate member 62 protruding from the side wall 64b.

[0062] From another perspective, the end faces of the airbag 61 are connected to the side walls 64a, 64b of the box 64 via the plate member 62 and the guide member 63. As a result, the airbag 61 is prevented from sagging due to its own weight.

[0063] The rods 63b of the guide members 63 are pulled out of the retaining cylinders 63a when the plate members 62 move toward the front of the vehicle as the airbag 61 expands. On the other hand, the rods 63b of the guide members 63 are pulled into the retaining cylinders 63a when the plate members 62 move toward the rear of the vehicle as the airbag 61 contracts.

[0064] <Airbag action / drawbar state change> 10A and 10B are schematic diagrams showing the operation of airbag 61. Roller 47 is attached to long side portion 41 of first drawbar member 31. More specifically, roller 47 is attached to the center of long side portion 41 in the longitudinal direction.

[0065] The roller 47 is rotatably supported and is in contact with a plate member 62 attached to an end surface of the airbag 61. Furthermore, the roller 47 is pressed against the plate member 62 by at least the weight of the first drawbar member 31.

[0066] 10A shows the airbag 61 in a deflated state with the drawbar 30 in a bent state, and FIG. 10B shows the airbag 61 in an expanded state with the drawbar 30 in an extended state.

[0067] <<Bent state → Extended state>> 10A, when compressed air is supplied to the airbag 61, the airbag 61 expands. This causes the plate member 62 to move toward the front of the vehicle, and the roller 47 is pushed in the same direction. As a result, the first drawbar member 31 rotates upward relative to the dolly frame 20. In other words, the first drawbar member 31 rotates so as to protrude from the dolly frame 20. At this time, the roller 47 moves upward on the plate member 62 while rotating. Furthermore, the second drawbar member 32 (not shown) rotates downward relative to the first drawbar member 31.

[0068] 10B, when the roller 47 reaches the position shown in the figure, the first drawbar member 31 and the second drawbar member 32 are positioned at the same height and are parallel or approximately parallel to the dolly frame 20. In other words, the drawbar 30 is in an extended state.

[0069] Thereafter, the draw bar 30 is maintained in the extended state as long as the internal pressure of the air bag 61 is maintained. In other words, the weight of the draw bar 30 in the extended state is supported solely by the air bag 61.

[0070] <Extension state → Flexion state> When the airbag 61 shown in FIG. 10B is released to the atmosphere, the force supporting the weight of the drawbar 30 is lost. Then, the airbag 61 contracts, and the plate member 62 moves toward the rear of the vehicle. As a result, the first drawbar member 31 rotates downward relative to the dolly frame 20. In other words, the first drawbar member 31 rotates so as to hang down from the dolly frame 20. At this time, the roller 47 moves downward on the plate member 62 while rotating. In addition, the second drawbar member 32 (not shown) rotates upward relative to the first drawbar member 31.

[0071] 10A, when the rollers 47 reach the positions shown in the figure, the first drawbar member 31 hangs down from the dolly frame 20, and the second drawbar member 32 becomes parallel or approximately parallel to the dolly frame 20 at a position lower than the first drawbar member 31. In other words, the drawbar 30 becomes bent.

[0072] As described above, roller 47 provided on first drawbar member 31 moves up and down on plate member 62 as plate member 62 moves in the front-to-rear direction of the vehicle.

[0073] Specifically, when the plate member 62 moves horizontally toward the front of the vehicle, the roller 47 moves vertically while rotating from the position shown in Fig. 10A (first position) to the position shown in Fig. 10B (second position). On the other hand, when the plate member 62 moves horizontally toward the rear of the vehicle, the roller 47 moves vertically while rotating from the position shown in Fig. 10B (second position) to the position shown in Fig. 10A (first position).

[0074] When the roller 47 moves (rises) from the first position to the second position, the drawbar 30 is switched from the bent state to the extended state, and when the roller 47 moves (descends) from the second position to the first position, the drawbar 30 is switched from the extended state to the bent state.

[0075] Here, the roller 47 is always in contact with the plate member 62, but is not fixed to the plate member 62. Therefore, even if the roller 47 moves up and down as described above, no vertical force is applied to the plate member 62 or the airbag 61 to which the plate member 62 is attached. As a result, the load on the airbag 61 is reduced, allowing the airbag 61 to expand and contract smoothly in the fore-and-aft direction of the vehicle, and extending the life of the airbag 61.

[0076] <Support arm> FIG. 11 is another perspective view showing the drawbar 30 in the bent state, and FIG. 12 is another perspective view showing the drawbar 30 in the extended state.

[0077] The second drawbar member 32 is provided with a support portion that supports itself when in the extended state. In the present embodiment, the second drawbar member 32 is provided with support arms 70 that support itself when in the extended state. The support arms 70 are provided on both longitudinal sides of the bottom portion 51 of the second drawbar member 32.

[0078] Each support arm 70 is a rectangular metal plate that protrudes toward the rear of the vehicle from bottom portion 51 of second drawbar member 32. Furthermore, a fixing portion 71 is provided at the tip of each support arm 70, and a through-hole 72 is formed in fixing portion 71.

[0079] Each fixing portion 71 is a metal block or plate that stands vertically from the support arm 70, and the through-hole 72 penetrates the fixing portion 71 in the thickness direction.

[0080] Meanwhile, the first drawbar member 31 is provided with at least a pair of fixing portions 73a, 73b corresponding to the fixing portion 71. More specifically, a pair of fixing portions 73a, 73b is provided on one longitudinal side of the long side portion 42, and another pair of fixing portions 73a, 73b is provided on the other longitudinal side.

[0081] Each of the fixing portions 73a, 73b is a metal block or plate that protrudes toward the long side portion 41. Each of the fixing portions 73a, 73b has a through hole 74 formed therein that corresponds to the through hole 72.

[0082] The support arms 70 provided on the second drawbar member 32 come into contact with the first drawbar member 31 when the drawbar 30 is in the extended state. More specifically, when the drawbar 30 is in the extended state, each support arm 70 comes into contact with the long side portion 42 of the first drawbar member 31 from below (FIG. 12).

[0083] At this time, one fixing portion 71 is inserted between the pair of fixing portions 73a, 73b, and the other fixing portion 71 is inserted between the other pair of fixing portions 73a, 73b. Furthermore, the through hole 72 of one fixing portion 71 communicates with the through hole 74 of the pair of fixing portions 73a, 73b. Similarly, the through hole 72 of the other fixing portion 71 communicates with the through hole 74 of the other pair of fixing portions 73a, 73b.

[0084] When the support arm 70 abuts against the first drawbar member 31, the weight of the second drawbar member 32 is supported by the first drawbar member 31. In other words, the support arm 70 prevents the second drawbar member 32 from sagging down from the first drawbar member 31.

[0085] At this time, the weight of the first drawbar member 31 is supported by the airbag 61 (FIG. 10B). Therefore, in the extended state, the weight of both the first drawbar member 31 and the second drawbar member 32 is supported by the airbag 61. In other words, in the extended state, the entire drawbar 30 is supported horizontally by the airbag 61.

[0086] The support portion is not limited to the above-described support arm 70. For example, the support portion may be formed by a rear end member of second drawbar member 32 that is extended so as to slip under first drawbar member 31.

[0087] Furthermore, in this embodiment, fixed portion 71 corresponds to the second fixed portion, and through hole 72 corresponds to the second through hole. Furthermore, in this embodiment, fixed portions 73a and 73b correspond to the first fixed portion, and through hole 74 corresponds to the first through hole.

[0088] <Coil springs> On the other hand, when airbag 61 is released to the atmosphere, the force with which airbag 61 supports drawbar 30 is lost, and drawbar 30 enters a bent state, as described above.

[0089] Therefore, the dolly 3 has two coil springs 75 (FIGS. 1, 7, and 8) that hold the second drawbar member 32 when in the bent state. Note that while only the coil spring 75 located on the front side is shown in FIG. 1, a similar coil spring exists behind the coil spring 75 shown in the figure. Also, for the sake of convenience, the coil spring 75 is not shown in the figures other than FIG. 1, 7, and 8.

[0090] One end (base end) of each coil spring 75 is connected to the dolly frame 20, and the other end (tip end) is connected to the second drawbar member 32. More specifically, the base end of each coil spring 75 is connected to a bracket 76 shown in Figures 7 and 8, etc. The bracket 76 is attached to the connection portion 24 of the dolly frame 20.

[0091] 7, 8, etc. The hooks 77 are provided on both ends of the bottom portion 51 of the second drawbar member 32.

[0092] When the drawbar 30 is switched from the extended state to the bent state, the second drawbar member 32 drops to a position lower than the first drawbar member 31. This causes the coil spring 75 to stretch. The stretched coil spring 75 generates a force (restoring force) that tries to pull up the second drawbar member 32. As a result, the second drawbar member 32 is held parallel or approximately parallel to the ground without touching the ground.

[0093] <Locking mechanism> The dolly 3 has a locking mechanism 80 shown in Figures 4, 7, etc. The locking mechanism 80 is disposed inside the first drawbar member 31, and restricts relative rotation between the first drawbar member 31 and the second drawbar member 32 when the drawbar 30 is in the extended state.

[0094] 13 is a perspective view showing the locking mechanism 80. The locking mechanism 80 has a pair of locking pins 81a, 81b and an operating unit 82. The operating unit 82 is composed of a handle 83, a rotating member 84, and link members 85a, 85b. Furthermore, the handle 83 includes a grip portion 83a that is held by the operator, and a shaft portion 83b that is interposed between the grip portion 83a and the rotating member 84.

[0095] The operating unit 82 moves the lock pins 81a and 81b between a fixed position and a released position. The fixed position is a position where the lock pins 81a and 81b restrict relative rotation between the first drawbar member 31 and the second drawbar member 32. On the other hand, the released position is a position where the lock pins 81a and 81b allow relative rotation between the first drawbar member 31 and the second drawbar member 32.

[0096] The rotating member 84 is rotatably supported by a support shaft 86 that passes through the center of the rotating member 84. The rotating member 84 is rotatable in a first direction and a second direction opposite to the first direction, with the support shaft 86 as the rotation axis.

[0097] The link member 85a connects a connection end 84a provided on one side of the rotating member 84 to the lock pin 81a. The link member 85b connects a connection end 84b provided on the other side of the rotating member 84 to the lock pin 81b.

[0098] More specifically, one end of link member 85a is pin-connected to connecting end 84a, and the other end of link member 85a is pin-connected to lock pin 81a. One end of link member 85b is pin-connected to connecting end 84b, and the other end of link member 85b is pin-connected to lock pin 81b.

[0099] Furthermore, the tip of the shaft portion 83b of the handle 83 is connected to the connecting end portion 84a via the same pin that connects the connecting end portion 84a and the link member 85a.

[0100] <Operation of the locking mechanism> Next, the operation of locking mechanism 80 will be described, assuming that drawbar 30 is in an extended state. Fig. 14A is a plan view showing locking mechanism 80 in an unlocked state. Fig. 14B is a plan view showing locking mechanism 80 in a locked state. More specifically, locking pins 81a and 81b of locking mechanism 80 shown in Fig. 14A are positioned in the unlocked position. Meanwhile, locking pins 81a and 81b of locking mechanism 80 shown in Fig. 14B are positioned in the locked position.

[0101] As described above, the locking mechanism 80 is provided inside the first drawbar member 31. However, the handle 83 of the locking mechanism 80 penetrates the short side portion 44 of the first drawbar member 31 and extends to the outside of the first drawbar member 31.

[0102] 14A is pushed to one axial side of shaft portion 83b, rotating member 84 rotates in a first direction. For example, when an operator grasps grip portion 83a and pushes handle 83 into first drawbar member 31, rotating member 84 rotates in the first direction.

[0103] Then, the lock pins 81a and 81b are moved from the release position shown in Fig. 14A to the lock position shown in Fig. 14B. At the same time, the lock pins 81a and 81b are inserted into the through holes 72 and 74 (Fig. 11), which are in communication with each other.

[0104] From another perspective, when the handle 83 shown in Fig. 14A is pushed to one side in the axial direction of the shaft portion 83b, the lock pins 81a and 81b move away from each other in the width direction of the vehicle, and as a result, the respective lock pins 81a and 81b move from the release position to the lock position.

[0105] As described above, through-hole 72 is provided in fixed portion 71, and through-hole 74 is provided in fixed portions 73a and 73b. Also, as described above, when drawbar 30 is in the extended state, fixed portion 71 is inserted between fixed portions 73a and 73b, and through-hole 72 and through-hole 74 communicate with each other.

[0106] Lock pins 81a, 81b that have moved to the fixed positions pierce fixing portions 73a, 73b provided on first drawbar member 31 and fixing portion 71 provided on second drawbar member 32. As a result, relative rotation between first drawbar member 31 and second drawbar member 32 is restricted.

[0107] 14B is pulled toward the other axial side of shaft portion 83b, rotating member 84 rotates in the second direction. For example, when an operator grasps grip portion 83a and pulls handle 83 out from first drawbar member 31, rotating member 84 rotates in the second direction.

[0108] As a result, the lock pins 81a and 81b are moved from the fixed position shown in Fig. 14B to the released position shown in Fig. 14A. At the same time, the lock pins 81a and 81b are withdrawn from the through holes 72 and 74 (Fig. 11). More specifically, the lock pins 81a and 81b are withdrawn from at least the through hole 72 and one of the through holes 74 located outside the through hole 72.

[0109] From another perspective, when handle 83 shown in Fig. 14B is pulled to the other axial side of shaft portion 83b, lock pins 81a and 81b approach each other in the width direction of the vehicle. As a result, each lock pin 81a and 81b moves from the fixed position to the released position, and restriction on relative rotation between first drawbar member 31 and second drawbar member 32 is released.

[0110] Thereafter, when the airbag 61 is opened to the atmosphere, the first drawbar member 31 and the second drawbar member 32 rotate due to their own weight, and the drawbar 30 becomes bent.

[0111] As described above, the locking mechanism 80 can be switched between the locked state and the unlocked state simply by pushing and pulling the handle 83.

[0112] In addition, when the handle 83 is pulled in the axial direction of the shaft portion 83b, the lock pins 81a and 81b move from the release position to the fixed position, and when the handle 83 is pushed in the axial direction of the shaft portion 83b, the lock pins 81a and 81b move from the fixed position to the release position.

[0113] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit and scope of the present invention.

[0114] For example, in another embodiment, when the drawbar 30 is in the extended state, the dolly frame 20, the first drawbar member 31, and the second drawbar member 32 are parallel or approximately parallel to one another, but are disposed at different heights from the first drawbar member 31 and the second drawbar member 32. From another perspective, the extended state of the drawbar 30 is not limited to a state in which the first drawbar member 31 and the second drawbar member 32 are disposed at the same height. [Explanation of symbols]

[0115] DESCRIPTION OF SYMBOLS 1...full trailer, 2...full tractor, 3...dolly, 4...chassis, 10...main rail, 11...cross member, 12...rear bumper, 13...side guard, 14...air tank, 20...frame (dolly frame), 21...turntable, 21a, 21b...rotating ring, 22...main rail, 23...cross member, 24...connection portion, 25...round hole, 26...air tank, 27...drawbar connecting portion, 30...drawbar, 31...first drawbar member, 32...second drawbar member, 41, 42...long side portion, 43, 44...short side portion, 45...rear connecting portion, 46...front connecting portion, 47...roller, 51...bottom portion, 52, 53...oblique side portion, 54...rear Connecting portion, 55...connecting portion, 60...actuator, 61...airbag, 62...plate member, 63...guide member, 63a...retaining tube, 63b...rod, 64...box, 64a, 64b...side wall, 64c...top wall, 70...support arm, 71...fixing portion, 72...through hole, 73a, 73b...fixing portion, 74...through hole, 76...bracket, 77...hook, 80...locking mechanism, 81a, 81b...lock pin, 82...operating portion, 83...handle, 83a...grip portion, 83b...shaft portion, 84...rotating member, 84a, 84b...connecting end portion, 85a, 85b...link member, 86...support shaft, C1, C2...bed, R1, R2...virtual line (rotating axis)

Claims

1. A full trailer having a dolly equipped with a drawbar that can be switched between a bent state having a relatively short overall length and an extended state having a relatively long overall length, The drawbar is composed of a first drawbar member and a second drawbar member, adjacent to each other and connected at one side thereof to be relatively rotatable, the second drawbar member includes a support portion that abuts against the first drawbar member and supports the second drawbar member when the second drawbar member is in the extended state.

2. 2. The full trailer according to claim 1, wherein the dolly has a coil spring that holds the second drawbar member in the bent state.

3. 3. The full trailer according to claim 2, wherein the coil spring holds the second drawbar member so that the second drawbar member does not come into contact with the ground when the coil spring is in the bent state.

4. a first fixing portion having a first through hole is provided on the first drawbar member; The support arm is provided with a second fixing portion having a second through hole, 2. The full trailer according to claim 1, wherein the first through hole and the second through hole communicate with each other when in the extended state, and a lock pin is inserted into the communicated first through hole and the second through hole.

5. At least one pair of the first fixing portions is provided on the first drawbar member, The full trailer according to claim 4 , wherein in the extended state, at least one of the second fixing portions is inserted between a pair of the first fixing portions.

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