Bodywork for dump trucks

Abstract

To provide a mounted body for a dump truck that is simple, has a small number of components, and has desired fixing strength while securing a storage space for a dump device.SOLUTION: A mounted body for a dump truck includes: a sub-frame provided on a chassis frame; a hinge portion provided at a rear-end part of the sub-frame; a loading box mounted on the sub-frame via the hinge portion; and an interposing portion provided between the chassis frame and the sub-frame. The interposing portion includes an abutting portion that abuts against a lower-surface part of the sub-frame and a connecting portion that is connected to a side-surface part of the sub-frame. The sub-frame is fixed to the chassis frame via the abutting portion and the connecting portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bodywork used in a dump truck from which a load is discharged by dumping. [Background Art]

[0002] A cargo box mounted on a vehicle such as a dump truck is mounted on a sub-frame fixed to a chassis frame, and can be tilted (dumped) rearward downward relative to the chassis frame about a rear hinge of the sub-frame using a well-known dumping device.

[0003] Unlike ordinary trucks, dump trucks require an accommodation space below the cargo box to install a dumping device. Further, generally, a sub-frame is fixed in a laminated state on the chassis frame, and the cargo box is attachable and detachable (can be dumped) on the sub-frame. In large-sized vehicles, the weight of the load is large, so the fixing strength of the sub-frame to the chassis frame is also required to be high, and various means are known (for example, Patent Document 1).

[0004] In addition to such large vehicles, light vehicles and small vehicles that transport relatively light loads with small sizes are often used as dump trucks. In such small dump trucks, due to the small size of the vehicle itself, the requirements for the accommodation space are also strict. There is also known a configuration in which the sub-frame is not in the above-described laminated state relative to the chassis frame, but is fixed to the chassis frame in a spaced-apart state via upright leg portions, and the dumping device is accommodated in the spaced position. [Prior Art Documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2003-327157 [Summary of the Invention] [Problem to be Solved by the Invention]

[0006] However, in the case of structures with upright-shaped legs, such as those found in light vehicles and small vehicles, the number of legs tends to increase in order for the subframe, which is spaced apart from the chassis frame, to have the desired strength. Consequently, the amount of work required to fix the legs to the chassis frame increases, as does the work required to fix the subframe to those legs. Furthermore, the number of fixing points also increases, leading to increased costs and weight.

[0007] Furthermore, in recent years, with the increasing use of various types of drive sources, it may be necessary to increase the distance between the subframe and the chassis frame when using drive sources that differ from conventional standards. In this respect, a configuration that can improve the fixing strength via the legs helps to increase the versatility of the drive sources that are installed.

[0008] This invention has been made in view of these points, and aims to provide a dump truck body that is simple, has few parts, and has the desired fixing strength, while ensuring sufficient space for housing the dumping device. [Means for solving the problem]

[0009] To solve the above problems, the present invention relates to a dump truck body comprising a subframe provided on a chassis frame whose longitudinal direction is the front-rear direction of the vehicle, a hinge portion provided at the rear end of the subframe, a cargo box mounted on the subframe via the hinge portion, and an intervening portion provided between the chassis frame and the subframe, and can adopt a configuration having the following features. Specifically, the intervening portion has a contact portion that abuts against the lower surface portion of the subframe and a connecting portion that is connected to the side portion of the subframe, and the subframe is fixed to the chassis frame via the contact portion and the connecting portion.

[0010] As described above, this invention focuses on a bodywork mounted on the chassis frame of a dump truck. In particular, the configuration of the intervening parts improves the support strength of each intervening part against the subframe. Therefore, since the number of intervening parts is not unnecessarily increased, an increase in the weight of the above-mentioned bodywork can be prevented. Furthermore, by not increasing the number of intervening parts, and especially by reducing the number compared to conventional designs, the man-hours required for fixing the intervening parts to the chassis frame (legs fixed to the chassis frame) can be reduced. In addition, the improvement in the support strength of each intervening part helps to increase the distance between the subframe and the chassis frame. As a result, this bodywork for dump trucks helps to use various types of drive sources for driving and dumping operations, and can contribute to addressing recent environmental issues.

[0011] Regarding the above-mentioned dump truck bodywork, a support portion may be provided erected on the upper surface of the chassis frame, the contact portion may be interposed between the support portion and the lower surface of the subframe, and the connecting portion may be fastened to the support portion using a fastening portion. This increases the contact area between the interposed portion and the support portion, thereby increasing the support strength provided by each of these parts.

[0012] Furthermore, it is preferable that the intervening portion has a configuration in which the contact portion and the connecting portion are connected. This allows the lower and side portions to be integrally supported by the subframe, further increasing its support strength. In addition, it is possible to effectively transmit the load from the subframe to the support portion provided on the chassis frame.

[0013] Multiple intervening portions are provided along the vehicle's longitudinal direction, and at least one of the intervening portions has the contact portion. Having the intervening portions helps to reduce the number of work steps and weight compared to conventional designs. Naturally, these effects increase as the number of intervening portions increases, which is preferable. Furthermore, even if the intervening portion has the above-described connecting portion, it can be used at the rear end of the subframe (near the dump hinge) as long as interference with the dump hinge can be avoided. [Effects of the Invention]

[0014] The dump truck bodywork according to the present invention uses an intervening portion having a contact portion that abuts against the lower surface of the subframe and a connecting portion that connects to the side surface of the subframe, thereby fixing the subframe to the chassis frame. The connecting portion fixes the subframe to the chassis frame at its side, preventing lateral displacement of the subframe. At the same time, the presence of the contact portion prevents the concentration of load on the subframe. Therefore, by providing a simple and high-strength intervening portion, it is possible to create a configuration that can accommodate the dumping device and reduce the number of intervening portions, resulting in a lightweight bodywork with the desired strength. [Brief explanation of the drawing]

[0015] [Figure 1] This is a side view of a dump truck showing the dumping state in an embodiment of the present invention. [Figure 2] These are a top view of a subframe, a side view showing the means for fixing the subframe, and a rear view according to an embodiment of the present invention. [Figure 3] (a) to (c) are side views, top views, and partially enlarged views as seen from the front of the vehicle, showing each of the fixing means according to the embodiment of the present invention, and (d) is a side view showing the rearmost fixing means according to the same embodiment. [Modes for carrying out the invention]

[0016] An example of an embodiment of the dump truck according to the present invention will be described with reference to the drawings.

[0017] Figure 1 is a side view showing the dump truck DT of this embodiment in the state of dumping the cargo box B mounted on the chassis frame CF. The dump truck DT is a small vehicle specification, and when in the dumping state, the securing member (not shown) of the tailgate TG of the cargo box B is released, and the lower end rotates toward the rear of the vehicle as shown in the figure. Normally (when the vehicle is in motion, etc.), the lower end of the tailgate TG is secured by the securing member.

[0018] The cargo box B has a floor and a side door (front wall, a pair of left and right side gates, and a tailgate) erected on the floor. It is fixed to a pair of left and right chassis frames CF, whose longitudinal direction is in the vehicle's longitudinal direction (left and right direction in the figure), and is mounted on a pair of left and right subframes SF, also whose longitudinal direction is in the vehicle's longitudinal direction. The cargo box B is also equipped with a dumping device 1 that tilts downwards and backwards relative to the chassis frame CF around a dump hinge DH provided at the rear end of the subframe SF. The dumping device 1 is a well-known device and is composed of actuators such as hydraulic cylinders that extend and retract using pressurized oil from a hydraulic pump. Based on the extension and retraction of these hydraulic cylinders, the cargo box B changes its posture to the dumped state or horizontal state shown in the figure.

[0019] The subframe SF is fixed to the chassis frame CF at a vertical distance of H1. In dump trucks DT, which use light vehicles or small vehicles, the chassis frame CF is located relatively close to the ground (low ground clearance) and its girder height is small, and similarly, a subframe SF with a small girder height is used. As a result, the dump truck DT can have a low vehicle height and a low weight. In such a dump truck DT, the space for housing the dumping device 1 is secured by positioning the subframe SF at a distance of H1 from the chassis frame CF as described above.

[0020] The subframe SF is fixed to the chassis frame CF via four fixing means 2 serving as legs provided along the longitudinal direction of the vehicle. These fixing means 2 are also similarly provided on the opposite chassis frame CF.

[0021] The fixing means 2 will be described with reference to FIG. 2. FIG. 2(a) is a top view of the subframe SF, where the left side in the figure is the front side of the vehicle and the right side in the figure is the rear side of the vehicle. Between the pair of left and right subframes SF, five connecting frames 3a to 3e whose longitudinal direction is the vehicle width direction are provided.

[0022] For each subframe SF, the fixing means 2 includes first fixing means 21, 22, 23 respectively provided at a position on the front side of the vehicle, a position near the central portion in the longitudinal direction of the vehicle, a position closer to the rear side of the vehicle from the vicinity of the central portion, and a second fixing means 24 provided at a position of the rear end portion of the vehicle. The lower portions of the first fixing means 21, 22, 23 can be appropriately changed.

[0023] The first fixing means 21, 22, 23 have the same configuration, and the first fixing means 21 will be described as a representative. As shown in FIG. 2(b), which is a side view of FIG. 2(a), the first fixing means 21 is provided such that the subframe SF is in a fixed state while being spaced apart from the chassis frame C by a vertical height distance H1. The first fixing means 21 includes a leg 211 fixed to the chassis frame CF, an interposing part 212 interposed between the subframe SF fixed to the subframe SF and the leg 211, and a fastening part 213 that fastens the interposing part 212 to the leg 211.

[0024] The leg portion 211 is fixed to the chassis frame CF by welding and has a leg body portion 211a fixed to the upper surface portion CF1 and side portion CF2 of the chassis frame CF, a front leg support portion 211b that supports the front side of the upper surface portion CF1 and leg body portion 211a in the vehicle longitudinal direction, and a rear leg support portion 211c that supports the rear side of the upper surface portion CF1 and leg body portion 211a in the vehicle longitudinal direction. As shown in the figure, the leg portion 211 is erected on the chassis frame CF in order to connect with the intervening portion 212 and to secure the aforementioned separation distance H1. The leg body portion 211a is a unit body in which one metal plate material that covers the upper opening of a cylindrical body is assembled with four metal plate materials whose longitudinal direction is vertical. Regarding its configuration, two of the four metal plates are welded to the side portions CF2 (outer and inner sides of the vehicle) of the chassis frame CF in an opposing position, while the remaining two metal plates are welded to the upper surface CF1 of the chassis frame CF in an opposing position. All four of these plates are also welded to adjacent metal plates. The metal plate covering the upper opening has an overhanging portion that extends outward from the cylindrical body. On the outside of the vehicle, the front leg support portion 211b is a unit made of three metal plates assembled in a roughly U-shape when viewed from vertically above, opening to the rear of the vehicle, and the rear leg support portion 211c is a unit made in a similar manner, opening to the front of the vehicle.

[0025] The intervening portion 212 has a horizontal contact portion 212a that abuts against the lower surface portion SF1 of the subframe SF, and a connecting portion 212b that is connected to the outer side portion SF2 of the subframe SF and is bent into a substantially concave shape. In this embodiment, the contact portion 212a and the connecting portion 212b are made from the same single metal plate material, but they may also be made from different metal plate materials joined together by welding. It is preferable that the contact portion 212a and the connecting portion 212b are integrated with each other, but they may also be provided slightly separated from each other in the horizontal direction.

[0026] The fastening portion 213 consists of a known bolt and nut, and the bolt is inserted into the insertion hole provided in the upper surface of the leg body portion 211 (specifically the protruding portion described above) and the lower surface of the connecting portion 212b, and the nut is screwed in to fasten it. This fastening state is also used in the other first fixing means 22 and 23.

[0027] The second fixing means 24 is provided near the dump hinge DH as shown in the figure. The second fixing means 24 has the same configuration as the first fixing means 21, 22, and 23 in that it has a leg portion 241 fixed to the chassis frame CF, an intervening portion 242 fixed to the subframe SF and interposed between the subframe SF and the leg portion 241, and a fastening portion 243 that fastens the intervening portion 242 to the leg portion 241. However, it has a different configuration from the first fixing means 21, 22, and 23 in the following respects.

[0028] The intervening portion 242 is fixed to the lower surface portion SF1 of the subframe SF to avoid interference with the dump hinge, but there is no portion that contacts the side portion SF2. Also, as shown in the figure, unlike the other intervening portions 212, the vertical length of the intervening portion 242 is set to be longer than the vertical length (erect height) of the leg portion 241. However, the distance between the subframe SF and the chassis frame CF is the same as the height H1 as for the other parts.

[0029] Specifically, as shown in Figure 2(c), in the second fixing means 24, the leg portion 241 is made of a roughly U-shaped metal plate material with both left and right sides in the vehicle width direction bent vertically downward, and is fixed by welding to the metal rear panel RP which is installed between the rear surfaces of a pair of left and right chassis frames CF, and to the upper surface portion CF1 of the chassis frame CF. In addition, the intervening portion 242 is made of a roughly U-shaped metal plate material with both upper and lower sides in the vertical direction bent towards the rear in the vehicle front-rear direction. A metal vertical plate material is also fixed in an upright position to the bent upper and lower portions and the front portion which is connected to the upper and lower portions of this roughly U-shaped portion by welding. The upper surface portion of the intervening portion 242 is fixed by welding to the lower surface portion SF1 of the subframe SF. The upper surface portion of the leg portion 241 and the lower surface portion of the intervening portion are fixed via fastening means in the same way as the first fixing means.

[0030] In the dump truck DT according to this embodiment, the legs 211, 221, 231 of the first fixing means 21, 22, 23 (legs 221, 231 are not shown in the figure) and the leg 241 of the second fixing means 24 are provided to the chassis frame CF, allowing for easy fixing using fastening means 213, 223, 233 (fastening means 223, 233 are not shown in the figure) and fastening means 243. In particular, the configuration of intervening parts 212, 222, 232 (intervening parts 222, 232 are not shown in the figure) in the first fixing means 21, 22, 23 provides each of the first fixing means 21, 22, 23 with high strength. As a result, there is no need to unnecessarily increase the number of first fixing means 21, 22, 23, preventing an increase in the weight of the vehicle, and also preventing an increase in the number of locations where fastening means 213, 22, 233 are used, thus preventing an increase in the man-hours of the mounting work. Thus, in this embodiment, the mounting structure (a subframe SF, a hinge portion DH provided at its rear end, a cargo box B, and intervening portions 212, 222, 232, 242) can be mounted to the chassis frame CF with efficient work efficiency, and this also contributes significantly to reducing the vehicle weight.

[0031] The high strength of the intervening parts 212, 222, and 232, as described above, will be explained using Figure 3, which shows the intervening part 212 as a representative example. As shown in Figure 3(a), which is a side view, and Figure 3(b), which is a front view from the front of the vehicle, the lower surfaces of the contact part 212a and the connecting part 212b are both at the same height, and both lower surfaces are substantially flush. Furthermore, both lower surfaces can be in contact with the upper surface of the leg part 211. Therefore, the intervening part 212, which is fixed to the subframe SF that supports the cargo box B, can transmit loads such as loads and impacts from the cargo box B and the subframe SF to the chassis frame CF via the contact part 212a, which has a predetermined area and is in contact with the lower surface SF1 of the subframe SF. Because the contact portion 212a is configured to make surface contact with the lower surface portion SF1 of the subframe SF over a predetermined area via its main surface, stress concentration due to the above load can be avoided compared to a configuration where contact is localized, and high strength can be stably maintained over time.

[0032] At the same time, as shown in Figure 3(c) which is a top view, the side portion SF2 of the subframe SF is also supported by the connecting portion 212b, so the effect of preventing the mounted structure from shifting in the vehicle width direction is also high. Furthermore, as described above, the contact portion 212a and the connecting portion 212b are connected, and the load can be transmitted well to the leg portion 211 that contacts each other from their lower surfaces. Therefore, the load is also transmitted well from the leg portion 211 to the chassis frame CF.

[0033] The configuration of these intervening parts 212, 222, and 232 can be modified as appropriate, as long as the various effects described above can be obtained. For example, with respect to the contact part 212a, the shape of the contact portion with the lower surface part SF1 of the subframe SF can be rectangular, elliptical, or any other shape. Furthermore, the contact part 212a is not limited to a shape that contacts only the lower surface part SF1 of the subframe, but can also be a bent shape that contacts the side surface of the subframe SF on the vehicle side. The connecting part 212b can also be modified as appropriate, and instead of a recessed shape with inclined front and rear ends as shown in Figure 3(a), it can be a recessed shape that stands upright in the vertical direction. Of course, it can also be a recessed shape with the front end inclined towards the rear of the vehicle and the rear end inclined towards the front of the vehicle.

[0034] Regarding the number of first fixing means 21, 22, and 23, if at least one is used, the above-described effect can be achieved in a mounting structure that is spaced apart from the chassis frame CF. Furthermore, regarding the second fixing means 24, if interference with the dump hinge DH can be prevented, the first fixing means may be used as a substitute. Also, in this embodiment, fastening means were used for each fixing means 21 to 24, but welding and other methods of fixing are also applicable. In fixing means 21 to 24, the vertical height of the legs 211 to 241 and the intervening parts 212 to 242 is not limited to those described above. In the first fixing means 21 to 23, the vertical height of the legs 211 to 231 was described as large, but the reverse is also acceptable, or they may be of equivalent size. The same applies to the second fixing means 24. Furthermore, a configuration without legs 211 to 241, where the intervening parts 211 to 241 are directly fixed to the chassis frame CF, is also acceptable.

[0035] With the above configuration, the dump truck bodywork can be modified to achieve the desired support strength even if the distance H1 from the chassis frame CF is appropriately changed. This allows for changes to the type of engine, tanks, and number of tanks installed in the dump truck DT, thereby increasing the versatility of the dump truck DT. Therefore, it can also be applied to mounting various devices that are suitable for environmental issues, taking exhaust emissions into consideration. [Industrial applicability]

[0036] The present invention is useful for a dump truck body that is mounted above and spaced apart from the chassis frame. [Explanation of Symbols]

[0037] DT Dump Truck DH Damp Hinge B Packing box CF Chassis Frame SF subframe 1. Dumping device 2 Fixing means 21, 22, 23 First fixing means 24 Second fixing means 211 Legs 212 Interposition part 212a Contact part 212b Connection part 213 Fastening means

Claims

1. A subframe is provided on the chassis frame, with the vehicle's longitudinal direction being the front-to-rear direction, A hinge portion provided at the rear end of the subframe, A cargo box mounted on the subframe via the hinge portion, An intervening portion provided between the chassis frame and the subframe, Equipped with, The intervening portion has a plate-like portion made from a single plate, The plate-shaped portion has a contact portion that abuts against the lower surface of the subframe, and a connecting portion that is connected to the contact portion and connected to the side surface of the subframe. The subframe is fixed to the chassis frame via the contact portion and the connecting portion. A dump truck body characterized by the following features.

2. A support portion is provided which is erected on the upper surface of the chassis frame. The contact portion is interposed between the support portion and the lower surface portion of the subframe, and the connecting portion is fastened to the support portion using a fastening portion. The dump truck body described in feature 1.

3. Multiple intervening portions are provided along the vehicle's longitudinal direction. At least one of the intervening portions has the contact portion. The dump truck body described in feature 1.

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