Cargo box lid device

Abstract

To provide a cargo box canopy device which improves manual rotation operability of a canopy frame, is inexpensive and has high usefulness.SOLUTION: A cargo box canopy device has a bearing member provided on an upper part of a side gate of a cargo box loaded on a vehicle frame, a support shaft pivotally supported by the bearing member, a base end frame connected to the support shaft, and a tip frame which is so provided that a relative position thereof to the base end frame can be changed, and comprises a canopy frame which is manually rotated around the support shaft between an outer side and an inner side of the side gate, and an adjustment part which is engaged with at least one of the base end frame and the tip frame, and energizes or permits movement of the afore-said one. A rotational load in manual rotation around thew support shaft can be reduced.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a canopy device that openably and closably covers the upper opening of a cargo box mounted on a vehicle. [Background Art]

[0002] A cargo box of a vehicle such as a dump truck is provided with a canopy device pivotally supported on the upper portion of a side gate. The canopy device has a configuration in which, for example, a metal canopy frame is pivotally supported by a bearing portion provided at the upper end of the side gate. A sheet or the like is hung on this canopy frame, and the canopy frame is rotated between the outer side and the inner side of the side gate with the pivot support portion as the rotation center. When the canopy frame is rotated to the closed position, most of the upper opening of the cargo box is covered by the sheet or the like, so that scattering of earth and sand loaded in the cargo box can be prevented.

[0003] Among vehicles equipped with such canopy devices, relatively large vehicles that load a large amount of earth and sand or the like have a large weight of the frame constituting the canopy device. Since the rotation of the frame is performed centered on the upper end of the side gate, from below the side gate to above the cargo box so as to straddle the upper end of the side gate, many have high working efficiency through rotation operation using the driving force of an electric motor or the like (for example, Patent Document 1).

[0004] On the other hand, in the case of a relatively small and lightweight vehicle, the weight of the canopy frame is small, and the installation height of the cargo box and the height of the side gate are also low. Therefore, a configuration that simplifies the rotation operation for manually operated canopy frame rotation devices has also been proposed (for example, Patent Document 2). [Prior Art Documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2008-126877 [Patent Document 2] Japanese Patent No. 5832874 [Summary of the Invention] [Problems that the invention aims to solve]

[0006] In order to reduce the load on the manually operated rotation of the canopy frame, as described in Patent Document 2, the canopy frame has a base frame and a tip frame, and the tip frame is foldable relative to the base frame in order to reduce the rotation radius of the canopy frame. However, simply reducing the rotation radius does not allow for further improvement in terms of actual operation. Therefore, the inventor focused on the following points in order to create a canopy device for a cargo box that is inexpensive and highly useful in terms of manual operation.

[0007] First, in the case of a cargo box mounted on a small, lightweight vehicle, if a foldable canopy frame is used, as in the structure described in Patent Document 2, it is necessary to grip the frame near the pivot point and initiate rotation against the weight of the two types of frames: the base frame and the tip frame. When the canopy frame is in the "closed" state (covering the upper space inside the cargo box) at the start of rotation, it is lifted from a position almost the same height as the pivot point, and a large load is placed on it until it reaches the "open" state (rotating beyond the width of the cargo box to the outside). In this respect, when initiating rotation from the "open" state, which is supported by the pivot point on the outside of the cargo box and hanging down, to the "closed" state, the operating load becomes particularly large because the rotation is initiated from a position lower than the pivot point. In particular, the operator who rotates the canopy frame often works at the rear end of the cargo box (towards the rear of the vehicle) due to the ease of rotation. In other words, since the operator grips the end of the canopy frame, which has the vehicle's longitudinal direction as its length, and rotates it, the load during rotation operation is inevitably large.

[0008] Next, in the case of the folding structure described above, the tip frame rotates relative to the base frame, and a long shaft with the vehicle's longitudinal direction is essential for this structural part. This increases the number of parts and thus the cost. Furthermore, compared to the shaft that is provided on the top of the side gate and pivotally supports the base frame, this shaft is more susceptible to the torsional forces at both the front and rear ends of the canopy frame because it is mounted on either the base frame or the tip frame. Therefore, there is a risk that the functionality of the shaft in the rotational operation when folding may be reduced.

[0009] This invention has been made in view of these points, and aims to improve the operability of manually rotating the canopy frame and to provide an inexpensive and highly useful canopy device for a cargo box. [Means for solving the problem]

[0010] A "cargo box canopy device" comprising: a bearing member provided on the upper part of the side gate of a cargo box mounted on a vehicle frame; a support shaft pivotally supported by the bearing member; a base frame connected to the support shaft; and a tip frame provided so as to be able to change its relative position to the base frame, the canopy frame being manually rotated between the outer and inner sides of the side gate with the support shaft as the pivot point; and an adjustment part engaged with at least one of the base frame and the tip frame to allow or bias the movement of the one thereof, wherein the adjustment part reduces the rotational load during the manual rotation with the support shaft as the pivot point.

[0011] The adjustment part is preferably provided on the support shaft and has a structure that biases it to rotate relative to the base frame.

[0012] Furthermore, the canopy frame may have a shaft positioned at the rotating end of the base frame, the tip frame being pivotally supported by the shaft and manually rotatable around the shaft relative to the base frame, and the adjustment unit may have a structure that biases rotation between the shaft or the base frame and the tip frame when manually rotated around the shaft.

[0013] Furthermore, in the above-mentioned "cargo box lid device," the lid frame may have a configuration in which the front frame is movable radially relative to the base frame during manual rotation, and the adjustment part may be provided so as to be able to lock the front frame to the base frame according to the radial length of the lid frame. [Effects of the Invention]

[0014] With the configuration of the present invention, the relative position of the tip frame with respect to the base frame can be changed, and the operating load on the canopy frame, which is manually rotated, can be reduced by an adjustment part that biases or allows at least one of the base frame and the tip frame. This effect is particularly significant when it is necessary to operate the canopy frame, which is a long object, at its end (rear end of the cargo box).

[0015] For example, a configuration in which the base frame is biased via an adjustment unit is preferable because it reduces the load, especially at the start of rotation. In a folding canopy frame, the increase in weight load at the gripping position that occurs due to the reduction in the rotation radius caused by folding can be suppressed. Therefore, a synergistic effect can be obtained between this weight load suppression effect and the convenience of being able to easily rotate the frame without having to reach far due to the reduced rotation radius. These effects can be obtained even when the tip frame is biased via an adjustment unit.

[0016] Further, in the configuration in which the distal frame moves relative to the proximal frame via the adjustment section, a configuration that does not include the shaft which is essential in a foldable structure and allows adjustment of the turning radius of the canopy frame can be employed. Accordingly, stable quality can be maintained over a long period of time. [BRIEF DESCRIPTION OF THE DRAWINGS]

[0017] [Figure 1] FIG. 1 is a side view of a vehicle showing a side gate and a canopy device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a side view of the canopy frame according to the first embodiment as seen from the side of the vehicle. [Figure 3] FIG. 3 is an enlarged side view showing the adjustment section of the canopy frame according to the first embodiment. [Figure 4] FIG. 4 is a schematic view of the canopy frame as seen from the rear of the vehicle, showing the turning operation of the canopy frame according to the first embodiment. [Figure 5] FIG. 5 is a schematic view showing the turning operation of the proximal frame according to the first embodiment. [Figure 6] FIG. 6 is a schematic view showing the turning operation of the distal frame according to the first embodiment. [Figure 7] FIG. 7 is a side view of a canopy frame according to a second embodiment as seen from the side of the vehicle. [MODE FOR CARRYING OUT THE INVENTION]

[0018] An example embodiment of the loading platform lifting device according to the present invention will be described with reference to the drawings. (First Embodiment)

[0019] FIG. 1(a) shows a cargo box 10 and a canopy device 20 thereof according to the present embodiment, and is a side view of the vehicle as seen from the left side. For convenience of explanation, the canopy device 20 is shown in a state of standing up along the vertical direction, similarly to the erected side gate 1 in the cargo box 10.

[0020] The cargo box 10 is mounted on a vehicle such as a dump truck (not shown) and is configured to tilt downwards at the rear on the vehicle frame 11 that extends in the longitudinal direction of the vehicle. The cargo box 10 has a bracket 12 at the lower part of the rear end of the vehicle (right end in the figure), and the bracket 12 is pivotally supported to the rear end of the vehicle frame 11 via a pin 13. Although not shown, a tilting device is also positioned between the cargo box 10 and the vehicle frame 11, forward of the bracket 12 (left side in the figure). This tilting device is a well-known device and consists of a hydraulic cylinder that expands and contracts using pressurized oil from a hydraulic pump. One end of the hydraulic cylinder is connected to the vehicle frame 11 and the other end is connected to the cargo box 10. When the hydraulic cylinder is extended, the cargo box 10 tilts around the pin 13, and when the hydraulic cylinder is retracted, the cargo box 10 returns to a horizontal position.

[0021] The cargo box 10 is enclosed by a pair of left and right side gates 1 erected on the sides of the vehicle relative to the floor surface 3, a tailgate 2 erected on the rear side of the vehicle, and a front panel (not shown) erected on the front side of the vehicle.

[0022] The tailgate 2 is configured to rotate in the direction of arrow R1 at the rear of the vehicle, centered on a lower hinge 2a provided at the rear end of the floor surface 3. As shown in the figure, the height of the tailgate 2 is set lower than that of the side gate 1, and when viewed from the rear of the vehicle, the cargo box 10 has a rear opening above the tailgate 2. The cargo box 10 according to this embodiment is mounted so that its rear end is approximately aligned with the rear end of the vehicle frame 11, and is a so-called light vehicle (a light vehicle as defined in the enforcement regulations of the Road Transport Vehicle Act). Therefore, the ground clearance to the pin 13, which is the tilting center of the cargo box 10, is relatively low, and by setting the height of the tailgate 2 lower than that of the side gate 1 as described above, it is possible to prevent the upper end 2b from hitting the ground when it is rotated rearward (opens upward) along arrow R1. Side gate 1 is fixed to the floor surface 3.

[0023] The canopy device 20 is pivotally supported at the upper end of the side gate 1 and comprises a canopy frame 200 having a predetermined frame shape, a sheet 22 that is hung on the canopy frame 200, a bearing member 23 that pivotally supports the canopy frame 200 relative to the side gate 1, a locking device 24 that restricts the rotation of the canopy frame 200, and adjustment parts 26 and 27 that bias the rotation of the canopy frame 200. In this canopy device 20, a part of the canopy frame 200 is attached to the side gate 1 via a stopper member 25.

[0024] The canopy frame 200 has a length (length in the vehicle's longitudinal direction) that is approximately the same as that of the side gate 1 along the vehicle's longitudinal direction. Three bearing members 23 are arranged at the upper end of the side gate 1. A support shaft 21a, positioned close to the side gate 1 in the canopy frame 200, is pivotally supported by the bearing members 23, allowing the canopy frame 200 to rotate between the outer side (front side in Figure 1) and the inner side (back side in Figure 1) of the side gate 1. As described above, the canopy frame 200 according to this embodiment is sized to be installed in a cargo box 10 mounted on a light vehicle, and is light enough for a worker to directly grasp and rotate it by hand.

[0025] As shown in the figure, the sheet 22 is draped over the canopy frame 200 on the inside of the cargo box so that the canopy frame 200 is visible from the outside. In this draped state, the sheet 22 is formed of an upper covering portion that covers the top of the cargo box 10 and a rear covering portion. Multiple holes 211a are provided at the end of the upper covering portion along the canopy frame 200. Although not shown in the figure, the sheet 22 is draped over the canopy frame 200 by passing strings through these holes 211a and tying them to the canopy frame 200. With the canopy frame 200 rotated to cover the upper opening of the cargo box 10, the sheet 22 (rear covering portion) is stretched downward so that the rear covering portion of the sheet 22 covers the rear opening of the cargo box 10. The rear covering portion is stretched by attaching rubber 212 etc., which is provided at the end, to hooks (not shown) etc., which are provided at predetermined positions on the tailgate 2. The sheet 22 is placed over the cargo box 10 to prevent soil, dust, and other debris from being scattered from the top and rear openings of the cargo box 10.

[0026] The bearing member 23 is welded to the top plate 23a located at the upper end of the side gate 1. When viewed along the vehicle's longitudinal direction, the top plate 23a has an L-shaped cross-section and is positioned to cover the entire upper surface of the side gate 1. Two connecting shafts 23b are welded to the top plate 23a at a predetermined distance apart along the vehicle's longitudinal direction.

[0027] As shown in Figure 1(b) and Figure 1(c) of the AA cross section in Figure 1(b), the connecting shaft 23b is inserted through a cylindrical member 14 provided on the outer surface 1a of the side gate 1. The tip 231b of the connecting shaft 23b protrudes from the cylindrical member 14, and this tip 231b is fixed to the side gate 1 by a stopper member 25. The stopper member 25 consists of a plate 25a with a concave cross-section, and a bolt 25b and nut 25c that fix the tip 231b of the connecting shaft 23b to this plate 25a.

[0028] In other words, as shown in Figure 2(a), the canopy frame 200 is integrally attached to the side gate 1 with the support shaft 21a pivotally supported by the bearing member 23. The canopy frame 200 and other components can be easily removed from the side gate 1 by releasing the stopper member 25 in Figure 1. They can also be easily attached. This mounting structure is not limited to the bolts 25b and nuts 25c described above, but may also be used, such as a pin-shaped member that has a retaining function and can provide support (for example, a pin-shaped member that is inserted horizontally and whose tip can be bent). Next, we will describe the configuration of the canopy frame 200.

[0029] The canopy frame 200 includes a base frame 201 connected to a support shaft 21a, a shaft 202 positioned at the tip of the base frame 201, and a tip frame 203 pivotally supported by the shaft 202. The tip frame 203 is foldable relative to the base frame 201, with the shaft 202 as the pivot point. Furthermore, to reduce the operational load of manual folding, a first adjustment section 26 is provided between the support shaft 21a and the base frame 201, and a second adjustment section 27 is provided between the base frame 201 and the tip frame 203.

[0030] The base frame 201 is composed of a channel material with a roughly U-shaped cross-section that opens outwards from the vehicle (towards the foreground of the paper) in the state shown in Figure 2. It has a first base frame 201a whose longitudinal direction is in the vehicle's longitudinal direction (left-right direction in the figure) and three second base frames 201b whose longitudinal direction is in the vertical direction (up-down direction in the figure).

[0031] The shaft 202 is an extension member whose longitudinal direction is in the vehicle's longitudinal direction and is positioned at the tip of the second base frame 201b. A boss is positioned at the tip of the second base frame 201b, and the shaft 202 is inserted through this boss. The shaft 202 does not have to be an extension that has the same length as the canopy frame 200 along the vehicle's longitudinal direction, but may be an extension that has a length approximately equal to the width of each second base frame 201b.

[0032] The tip frame 203 is connected to a boss covering the circumferential surface of the shaft 202 and is rotatably arranged on the base frame 201 with the shaft 203 as its central axis. The tip frame 203 is made up of pipe-shaped members and has a first tip frame 203a whose longitudinal direction is in the vehicle's front-rear direction and three second tip frames 203b whose longitudinal direction is in the vertical direction, with the second tip frames 203b being connected to the boss mentioned above.

[0033] By assembling the base frame 201, the shaft 202, and the tip frame 203, the canopy frame 200 has a roughly rectangular outer frame and a grid-like inner frame, as shown in the figure. Although the tip frame 203 is connected to the boss, this is not limited to the tip frame 203 as long as it is rotatable relative to the base frame 201; for example, the base frame 201 may be fixed to the boss.

[0034] To fold the canopy frame 200, the front frame 203, as shown in the diagram, is rotated towards the front. The rotated front frame 203 is then housed in a housing section 210 formed on the inner side of the U-shaped cross-section of the base frame 201. By housing the front frame 203 in the housing section 210, the thickness of the canopy frame 200 in the vehicle width direction can be reduced even when the canopy frame 200 is folded and rotated to the outside of the cargo box. As a result, the overall width of the vehicle can also be reduced. A notch is provided at the front end of the first base frame 201a (the left end in the diagram) to avoid interference with the rotated front frame 203, and the front frame 203 is well housed in the aforementioned housing section 210.

[0035] The rotation of the front frame is performed by the operator directly grasping the gripping portion located on the rear side of the canopy frame 200. Specifically, a first gripping portion 204 is provided on the side of the front frame 203, and the operator grasps the first gripping portion 204 to perform a rotational operation (folding the canopy frame 200) around the shaft 202. A pin-shaped member 206 is provided on the first gripping portion 204, and when the canopy frame 200 is folded, the pin-shaped member 206 engages with a catch member 207 fixed to the side of the base frame 201. The catch member 207 has an Ω-shaped engagement portion with a cross-section that can fit into the pin-shaped member 206. The aforementioned pin-shaped member 206 and catch member 207 function as holding members that maintain the folded state of the canopy frame 200. These holding members allow the operator to rotate the canopy frame 200 from the inside to the outside of the side gate 1 while it remains folded. The first gripping portion 204 is not limited to the position shown in the figure and may be provided in other locations. For example, it may be provided on the vehicle rear end side of the first tip frame 203a of the tip frame 203. In this case, the catch member 207 described above is also provided in a position opposite to the first gripping portion 204.

[0036] As shown in Figure 3(a), the first adjustment section 26 has a metal spring member 26a wound around the vehicle's front end of the support shaft 21a with the vehicle's longitudinal direction as its axial direction. One end 26b of the spring member 26a is locked to a locking plate 201P that rotates in line with the base frame 201 (specifically, the second base frame 201b), while the other end 26c is locked to a locking holder 1H fixed to the vehicle's front end of the side gate 1. As shown in Figure 3(b), the locking plate 201P fixed to the vehicle's front end of the second base frame 201b is similarly rotatable in conjunction with the rotation of the second base frame 201b. Therefore, as the second base frame 201b (base frame 201) is rotated, one end 26b of the first adjustment unit 26 also rotates, while the other end 26c remains held by the locking holder 1H, thereby allowing the first adjustment unit 26 to be biased against the base frame 201.

[0037] As shown in Figure 3(c), the second adjustment section 27 has a metal spring member 27a that receives and acts upon a tensile load along the longitudinal direction (up and down direction in the figure) of the second tip frame 203b. One end 27b of the spring member 27a is locked to a first tip locking plate 203P fixed to the second tip frame 203b, and the other end 27c is locked to a second tip locking plate 202HP fixed to the circumferential surface of a cylindrical locking section 202H provided at the front end of the shaft 202. As shown in the figure, with respect to the tip frame 203 in the unfolded state, the function of the spring member 27a makes the second adjustment section 27 biasable in the folding direction.

[0038] Next, the opening and closing operation of the canopy frame 200 for the upper opening of the cargo box 10 will be explained using Figure 4. Figure 4 is a schematic diagram of the canopy frame 200 on the left side of the vehicle as seen from the rear of the vehicle. For the sake of explanation, other components visible from the rear have been omitted from the illustration.

[0039] When rotating the canopy frame 200, which is in a nearly straight line and in a closed state (folded down to cover the top of the cargo box 10), to the open state (the state shown by the dashed line in Figure 4(a)) on the outside of the side gate 1, the tip frame 203 is first housed in the housing section 210 of the base frame 201 (see Figure 2) (arrow R3). This rotation operation R3 of the tip frame 203 is performed on the canopy frame 200 in the closed state shown by the solid line (by gripping the first gripping section 204), and can therefore be performed at a relatively low position. Here, since the first gripping section 204 is located on the rotating tip side of the tip frame 203 (farther from the shaft 202 in terms of the rotation radius around the shaft 202), the manual rotation indicated by arrow R3 can be performed without feeling much weight. Furthermore, as shown in the figure, the engagement between the pin-shaped member 206 and the catch member 207 can be performed at a height (height H1) that is approximately the same as the height of the side gate 1, making it easier for the worker to operate.

[0040] Next, when rotating the folded canopy frame 200 to the outside of the side gate to open it (arrows R4, R5), the operator directly grips the second gripping part 205 provided on the base frame 201. The second gripping part 205 is located on the rotating end side of the base frame 201 (far from the pivot shaft 21a in terms of the rotation radius around the pivot shaft 21a). Therefore, the folded canopy frame 200 can be manually rotated as indicated by arrows R4, R5 with relatively little perceived weight. Furthermore, the position where the second gripping part 205 is located is in the middle when the canopy frame 200 is in a nearly straight line, and is at a relatively low height (height H2) for the operator manually rotating the canopy frame 200. Therefore, the canopy frame 200 can be rotated with less force than when gripping a position closer to the pivot shaft 21a, which is the rotation center of the canopy frame 200. This is due to the difference in position between the center of gravity of the second gripping part 205 and the canopy frame 200. If the canopy frame 200 is in a nearly straight line, the center of gravity will be located at a distance equivalent to the distance of the shaft 202 from the pivot shaft 21a, which is the center of rotation. Since the second gripping part 205 is located close to the pivot shaft 21a, the load felt by the operator during the rotation operation indicated by arrow R5 can be reduced. On the other hand, in the rotation operation according to this embodiment, the tip frame 203 is folded against the base frame 201, so the center of gravity of the folded canopy frame 200 is located closer to the pivot shaft 21a than to the second gripping part 205. Therefore, the load felt by the operator during the rotation operation is reduced. Furthermore, even when rotating downwards as indicated by arrow R6, since the center of gravity is located closer to the pivot shaft 21a than to the second gripping part 205, the rotation speed will not suddenly increase, and stable rotation operation can be performed. At the same time, the folding of the canopy frame 200 reduces the turning radius and minimizes the space required outside the vehicle. Furthermore, since the folding state of the canopy frame 200 is maintained by the retaining member, the tip frame 203 does not swing and hang down onto the base frame 201 during manual rotation, thus ensuring safety for the surroundings.

[0041] To close the open canopy frame 200, the above-described operations (arrows R3, R4, R5) should be performed in reverse order. In this case as well, the canopy frame 200 remains folded, thus avoiding manual rotation by reaching high up. Furthermore, as shown in Figure 4(b), the base frame 201 and the tip frame 203 can be rotated together as a single unit while they are extended in a nearly straight line (arrow R6). A plate 208 is fixed to the tip of the base frame 201, on the side facing inward relative to the shaft 202 (right side in the figure). The tip frame 203 is rotatable around the shaft 202, but once it has rotated from the outside to the inside of the cargo box relative to the base frame 201 and is in a nearly straight line with the base frame 201, further rotation inward is restricted by the plate 208. In other words, the plate 208 is positioned to restrict the rotation of the tip frame 203 relative to the base frame 201, so that the canopy frame 200 can maintain a nearly straight line when the canopy frame 200 is in the closed state (the state shown by the dashed line in the figure).

[0042] In addition to the points mentioned above, the adjustment parts 26 and 27 can further enhance the load reduction effect related to the manual rotation of the canopy frame 200.

[0043] The effect of the first adjustment unit 26 will be explained using Figure 5. Figure 5 is a schematic diagram of the cargo box 1 and roof device 20 as seen from the front of the vehicle. For the sake of explanation, the second adjustment unit 27 is omitted in Figure 5.

[0044] As shown in Figure 5(a), the first adjustment part 26 is provided to generate a biasing force in the direction of arrow T1 on the folded and closed canopy frame 200. However, the magnitude of this biasing force is such that it reduces the load on manual rotation operation, and the canopy frame 200 is not set to change its orientation from the illustrated orientation until an operator grasps and attempts to lift it from that orientation. Therefore, the canopy frame 200 is designed not to change orientation unexpectedly, ensuring safety for the surroundings.

[0045] The first adjustment unit 26 is designed so that when the canopy frame 200 is manually rotated from the closed state to the open state, the magnitude of its biasing force becomes zero when it is rotated approximately 135 degrees from the closed state, as shown in Figure 5(b). Therefore, the load on the operator's manual operation is reduced up to the position where the biasing force becomes zero. In particular, this is preferable for lifting operations in the folded state where the weight of both the base frame 201 and the tip frame 203 is directly applied, specifically from the start of the rotation operation until it has been rotated approximately 90 degrees, as the operation is a lifting operation against the weight of the canopy frame 200, and the load is reduced by the biasing force as described above. Furthermore, since the operator needs to grip and operate the canopy frame 200 until it is in the closed state, they often work (manually operate) while positioned at the rear end of the cargo box 10 in order to secure the operating space. In other words, the canopy frame 200, whose longitudinal direction is in the front-rear direction of the vehicle, is manually rotated while positioned at the rear end, so the load reduction effect of the first adjustment unit 26 is very significant.

[0046] As manual operation continues and the canopy frame 200 is moved to a horizontal position as shown in Figure 5(c), the load in the clockwise direction shown decreases due to the added weight of the canopy frame 200. Furthermore, in this horizontal position, a biasing force is generated in the counterclockwise direction on the first adjustment unit 26. In other words, when the gravity of the canopy frame 200 is applied in the direction of its rotation, a braking force begins to be generated on the first adjustment unit 26. Then, as shown in Figure 5(d), when the canopy frame 200 is opened to a hanging position along the side gate 1, an even larger biasing force T3 is generated on the first adjustment unit 26. In other words, in manual operation that requires a large load when the operator lifts the hanging canopy frame 200 to a horizontal position, the large biasing force has the effect of reducing that load.

[0047] In this embodiment, as described above, the first adjustment unit 26 is provided so that the biasing force becomes zero in the state shown in Figure 5(b). Therefore, the biasing forces T1 and T3 generated in the posture shown in Figure 5(a) and the posture shown in Figure 5(d) are set to be approximately the same size. However, their size can be appropriately changed according to the vehicle specifications and the needs of the operator.

[0048] Next, the effects of the second adjustment section 27 will be explained using Figure 6, which is a schematic diagram of the cargo box 1 and the roof device 20 as seen from the front of the vehicle. In Figure 6, as in Figure 5, the first adjustment section 26 is omitted for the sake of explanation. As shown in Figure 6(a), it is provided so as to generate a biasing force in the direction of arrow T11 on the front frame 203 in the unfolded state before it is folded. When manually rotating the roof frame 200 from the unfolded state to the folded state (manually rotating the front frame 203), a biasing force is generated on the second adjustment section 27 as shown by arrow T11, so, as with the first adjustment section 26, the operating load on the worker who is working (manually operating) while positioned at the rear end of the cargo box 10 can be reduced.

[0049] When manually rotating the tip frame 203 from the deployed state to the folded state, the second adjustment unit 27 exerts a biasing force equivalent to the tensile force T12, albeit in a downward direction, even when rotated approximately 90 degrees from the closed state, as shown in Figure 6(b). When the manual operation continues and the tip frame 203 is moved to a horizontal position, as shown in Figure 6(c), the load in the clockwise direction shown decreases due to the added weight of the tip frame 203. Furthermore, in this horizontal position, the second adjustment unit 27 exerts a biasing force equivalent to the tensile force T13 in the direction inward of the cargo box (to the left in the figure). In other words, when operating the folded tip frame 203 to the deployed state, the tensile force of the second adjustment unit 27 acts as a biasing force, reducing the load when lifting the tip frame 203. Therefore, the second adjustment unit 27 is configured to provide the operator with the same biasing force at both the start of folding and the start of deploying the tip frame 203. In particular, it is preferable because, based on a simple configuration related to the folding operation, it can provide a load-reducing effect for both unfolding and folding operations.

[0050] In this embodiment, the first adjustment unit 26 and the second adjustment unit 27 are provided on the front side of the vehicle so as not to interfere with the operation of workers mainly working at the rear end of the cargo box 10. However, they may be provided on the rear side of the vehicle, or on both the front and rear sides, as long as they do not hinder the worker's operability. Furthermore, although the structures that generate the biasing force are provided differently for the first adjustment unit 26 and the second adjustment unit 27, the design can be appropriately modified according to the structure of the vehicle or the canopy frame 200 or the needs of the workers. (Second embodiment)

[0051] Unlike the first embodiment, this embodiment has a configuration that allows the rotation radius of the canopy frame to be reduced by sliding the tip frame toward the base frame. The differences from the first embodiment will be explained using Figure 7.

[0052] The base frame 201 is constructed of pipe material in a comb-like shape as shown in Figure 7(a). In this embodiment, there is a first base frame 301a whose longitudinal direction is in the vehicle's front-rear direction (left-right direction in the figure), and three second base frames 301b whose longitudinal direction is in the vertical direction (up-down direction in the figure).

[0053] The front frame 302 is also made of comb-shaped pipe material and has a first front frame 302a whose longitudinal direction is in the vehicle's longitudinal direction, three second front frames 302b whose longitudinal direction is in the vertical direction, and a connecting frame 302c which is installed between the second front frames 302b and whose longitudinal direction is in the vehicle's longitudinal direction. As shown in the figure, the second front frame 302b is provided in a position opposite to the second front frame 301b, and its inner diameter is set to be larger than the outer diameter of the second front frame 301b.

[0054] Next, although not shown in the diagram, fixing members are provided at the F1, F2, and F3 points indicated by the dashed lines to secure the second end frame 302b to the second base frame 301b. The fixing members are configured using known methods such as bolts and nuts or pin-shaped members, depending on the material, strength, or weight of the base frame 301 and the end frame 302.

[0055] In this embodiment, by releasing the fixing by the fixing member described above, the tip frame 302 can be slid (moved) toward the base frame 301, as shown in Figure 7(b). At this time, the second base frame 301b is housed inside the second tip frame 302b. Then, at the parts F11, F21, and F31 indicated by the dashed lines, the sliding of the tip frame 302 is restricted using the same fixing member. By holding the tip frame 302 relative to the base frame 301 in the state shown in Figure 7(b), the rotation radius of the canopy frame 300 by manual operation is reduced. Therefore, as in the first embodiment, the operating burden on the worker is reduced.

[0056] In addition, this embodiment has a configuration that allows the rotation radius of the canopy frame 300 to be reduced by simple means (fixing members), resulting in fewer parts and cost reduction effects, including in terms of maintenance. Furthermore, since the rotation radius can be reduced simply by sliding the tip frame 302 in the rotation radius direction (up and down direction as shown in the figure) of the canopy frame 300, there is no need to provide a folding shaft (shaft 202) as in the first embodiment. Regarding the fixing members, they are provided at each part of the second base frame 301b and the second tip frame 302b, but they may be limited to the necessary parts as appropriate. Also, although two fixing members are provided in each rotation radius direction as shown in the figure, the number of installation locations may be increased to increase the options for the rotation radius.

[0057] Although the configuration according to the present invention has been described separately as a first embodiment and a second embodiment, a configuration combining both forms (for example, a configuration in which the first adjustment unit 26 is applied to the second embodiment) is also possible. Furthermore, in the first embodiment, the member used in the canopy frame 200, for example, the member used in the base frame 201, was a channel member, but a pipe-shaped member may be used as in the second embodiment. Although the above-described cargo box 10 is intended to be mounted on a dump truck or the like that is tilted downwards towards the rear, it is also applicable to vehicles that do not have a tilting device or vehicles other than light vehicles that are equipped with a manually operated canopy device. [Industrial applicability]

[0058] This invention is useful for all types of cargo boxes mounted on vehicles. [Explanation of Symbols]

[0059] 1 Side Gate 2 tailgates 3 Floor surface 10 packing boxes 11 Vehicle Frame 20 Canopy device 22 seats 23 Bearing member 24 Locking device 25 Stopper member 26, 27 Adjustment section 200 Canopy Frame 201 Base frame 202 Shaft 203 Tip frame 204 1st grip part 205 Second grip part

Claims

1. A bearing member provided on the upper part of the side gate of a cargo box mounted on a vehicle frame, The support shaft supported by the bearing member, A canopy frame having a base frame connected to the support shaft and a tip frame whose relative position to the base frame can be changed, and which is manually rotated between the outer and inner sides of the side gate with the support shaft as the pivot point, An adjustment unit provided on the support shaft and configured to engage with the base frame and bias rotationally relative to the base frame, It is equipped with, The adjustment unit is configured such that its biasing force acts in an upward direction on the canopy frame, whether the canopy frame is in a closed or open state, thereby reducing the rotational load during manual rotation with the pivot shaft as the pivot point. A cargo box lid device characterized by the following features.

2. A bearing member provided on the upper part of the side gate of a cargo box mounted on a vehicle frame, The support shaft supported by the bearing member, A canopy frame having a base frame connected to the support shaft and a tip frame whose relative position to the base frame can be changed, and which is manually rotated between the outer and inner sides of the side gate with the support shaft as the pivot point, An adjustment unit that engages with the tip frame and biases the rotation of the tip frame, It is equipped with, The canopy frame has a shaft positioned at the rotating end of the base frame, The aforementioned tip frame is pivotally supported on the shaft and is provided to be manually rotatable about the shaft relative to the base frame. The adjustment unit has a configuration that biases rotation between the shaft or the base frame and the tip frame when the shaft is manually rotated around the shaft. A cargo box lid device characterized by the following features.

3. A bearing member provided on the upper part of the side gate of a cargo box mounted on a vehicle frame, The support shaft supported by the bearing member, A canopy frame having a base frame connected to the support shaft and a tip frame whose relative position to the base frame can be changed, and which is manually rotated between the outer and inner sides of the side gate with the support shaft as the pivot point, An adjustment unit that engages with at least one of the base frame and the tip frame to restrict movement, It is equipped with, The canopy frame is such that the front frame is manually rotated relative to the base frame. It has a configuration that allows it to slide in the radial direction, The adjustment section is provided so that the tip frame can be locked to the base frame when the radial length of the canopy frame is extended or contracted. A cargo box lid device characterized by the following features.

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