Cargo platform device for transport vehicles

Abstract

To provide a transportation vehicle load-carrying platform device that has simple configuration, and exhibits dump operation function and slide operation function while reducing operation burden.SOLUTION: A load-carrying platform device for a semi-trailer truck A, that exhibits dump operation function and slide operation function, comprises: a load-carrying dump slide mechanism 50 that has a chassis frame 20 which is suspended on a trailer rear wheel 21 via an air suspension 70, a load-carrying platform 30 located at an upper surface position of the chassis frame 20, a swing arm 51 which connects the chassis frame 20 and the load-carrying platform 30, and a hoist cylinder 52 which connects the chassis frame 20 and the swing arm 51, and that performs dump / slide operations of a load-carrying platform front position by telescopic motion of the hoist cylinder 52; and a load-carrying support mechanism 60 which is located at a load-carrying platform rear position of the chassis frame 20, and supports the load-carrying platform 30 rotatably and slidably with respect to the chassis frame 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a platform device for a transport vehicle. [Background technology]

[0002] Known loading platform devices for transport vehicles that perform dumping and sliding functions include a chassis frame, a tilting frame, and a loading platform (see, for example, Patent Documents 1 to 4). The prior art devices have a hoist cylinder that lifts the loading platform between the chassis frame and the tilting frame, and a slide cylinder that slides the loading platform between the tilting frame and the loading platform, thereby performing the dumping and sliding functions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-192671 [Patent Document 2] Japanese Patent Application Publication No. 10-129518 [Patent Document 3] Japanese Patent Application Laid-Open No. 2016-94056 [Patent Document 4] Japanese Patent Application Publication No. 2020-55439 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned prior art device requires a three-component configuration consisting of a chassis frame, a tilting frame, and a loading platform, and also requires the use of at least two types of cylinders: a hoist cylinder and a slide cylinder. This results in a large number of parts, making the device configuration complex and increasing the risk of breakdowns and costs. Furthermore, the loading platform dump operation and the loading platform slide operation must be performed independently, increasing the operational burden.

[0005] The present invention has been made in response to the above-mentioned problems, and aims to provide a loading platform device for a transport vehicle that has a simple device configuration, reduces the operational burden, and performs dumping and sliding functions. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the present invention provides a loading platform device for a transport vehicle that performs dumping and sliding functions, and includes a chassis frame suspended from wheels via suspensions, a loading platform positioned on the upper surface of the chassis frame, a swing arm connecting the chassis frame and the loading platform, and a hoist cylinder connecting the chassis frame and the swing arm, a loading platform dump slide mechanism that dumps / slides the front position of the loading platform by extending and retracting the hoist cylinder, and a loading platform support mechanism that is positioned at the rear loading platform position of the chassis frame and supports the loading platform rotatably and slidably relative to the chassis frame. The loading platform support mechanism comprises a pair of support plates arranged on either side of the loading platform center line that divides the loading platform width in half, and tiltable relative to the chassis frame by a support shaft in the loading platform width direction; a pair of guide rails arranged parallel to the underside of the loading platform, with the sliding surfaces of the pair of support plates fitting together to slide in the loading platform fore-and-aft direction; and a slide pad provided on the sliding surface of one of the pair of guide rails and the pair of support plates. [Effects of the Invention]

[0007] By employing the above means, it is possible to provide a bed device for a transport vehicle that has a simple device configuration, reduces the operational burden, and performs dumping and sliding functions. Furthermore, in addition to ensuring the durability and reliability of the loading platform support mechanism, the reduction in slide resistance allows for smoother slide movement and prevents abnormal noise and noise caused by metal contact. [Brief explanation of the drawings]

[0008] [Figure 1] 1A and 1B are side views of a semi-trailer truck to which the loading platform device of the first embodiment is applied, showing a side view of the loading platform in a horizontal configuration and a side view of the loading platform in a slide dump configuration. [Figure 2] 1A, 1B, 1C, and 1D are views of a trailer to which the loading platform device of the first embodiment is applied, showing a side view (a), a plan view (b), a front view (c), and a rear view (d). [Figure 3] 1 is a plan view showing a loading platform dump slide mechanism in the loading platform device of the first embodiment. FIG. [Figure 4]1 is a side view showing a loading platform dump slide mechanism in the loading platform device of the first embodiment. FIG. [Figure 5] 3 is a side view showing the loading platform support mechanism in the loading platform device of the first embodiment. FIG. [Figure 6] 3 is a cross-sectional view showing a loading platform support mechanism in the loading platform device of the first embodiment. FIG. [Figure 7] 2 is a schematic diagram showing a hydraulic control unit in the carrier device of the first embodiment. FIG. [Figure 8] FIG. 10 is an explanatory view showing the rear part of the loading platform before the loading platform is slid and dumped. [Figure 9] FIG. 10 is an explanatory view showing the front part of the loading platform after the loading platform has been slid and dumped. [Figure 10] FIG. 10 is an explanatory diagram showing the sliding dumped loading platform and the open rear gate plate. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A mode for carrying out a platform device for a transporter vehicle according to the present invention will be described below with reference to a first embodiment shown in the drawings. [Example]

[0010] The loading platform device in the first embodiment is applied to a semi-trailer truck (an example of a transport vehicle) used to transport heavy machinery (construction machinery), vehicles, heavy materials, etc. The "overall configuration of the semi-trailer truck" and "detailed configuration of the loading platform device" of the first embodiment will be described below.

[0011] [Overall configuration of semi-trailer truck (Fig. 1, Fig. 2)] As shown in Figure 1, the semi-trailer truck A includes a tractor head 1 and a trailer 2 towed by the tractor head 1. The tractor head 1 and the trailer 2 can be connected and disconnected by a connecting mechanism 3 having a vertical pin shaft PA.

[0012] As shown in Fig. 1, the tractor head 1 has a tractor cabin 10, a tractor frame 11, front tractor wheels 12, and rear tractor wheels 13. In addition to a driving source such as an engine for traveling, the tractor head 1 is also equipped with a generator, a battery, an oil tank, an air pressure unit, and the like.

[0013] As shown in FIGS. 1 and 2, the trailer 2 has a chassis frame 20, a bed 30, a rear tailgate 40, a bed dump slide mechanism 50, a bed support mechanism 60, and an air suspension 70.

[0014] The chassis frame 20 is suspended via the trailer rear wheels 21 and air suspension 70, which allows the rear side of the frame of the chassis frame 20 to be adjusted for height. The trailer rear wheels 21 are configured with two consecutive double tires (a total of eight tires). The left and right rear trailer wheels 21 are connected by a rear axle (not shown) covered by a rear axle case 22. The front side of the frame of the chassis frame 20 is supported and braced against the ground G by the extension of a pair of outrigger cylinders 23, which are arranged on both the left and right sides in the width direction of the loading platform.

[0015] As shown in FIG. 2(b), the loading platform 30 is rectangular and elongated in the fore-and-aft direction, and is positioned on top of the chassis frame 20. The front side of the loading platform 30 is connected to the chassis frame 20 by a loading platform dump slide mechanism 50 (see FIGS. 3 and 4) to enable linked loading platform lifting / lowering movement and loading platform sliding movement. The rear side of the loading platform 30 is supported by a loading platform support mechanism 60 (see FIGS. 5 and 6) to enable both loading platform rotation and loading platform tilt sliding relative to the chassis frame 20. Here, as shown in FIG. 2(b), the loading platform 30 has a front end plate 31, a connecting plate 32, an inclined plate 33, a loading platform flat plate 34, and pole holes 35. Three pole holes 35 are formed on each side of the loading platform flat plate 34, and as shown in FIG. 2(a), poles 36 are detachably mounted by inserting and removing them. Furthermore, a hydraulic winch (not shown) is attached to the loading platform 30 to pull construction machinery, vehicles, and materials that cannot move by themselves onto the loading platform 30 with a wire.

[0016] The rear gate plate 40 is provided at the rear end position of the bed 30 so as to be able to open and close, and has a hydraulic cylinder 41 (hydraulic actuator) that performs the opening and closing operation. As shown in FIG. 1(b), when the bed 30 is slid and dumped by the bed dump slide mechanism 50 and the rear gate plate 40 is opened by the hydraulic cylinder 41, the rear gate plate 40 is approximately flush with the bed plate 34. Therefore, in the open state, the rear gate plate 40 is used as a runway (scaffolding board) when loading or unloading cargo such as construction machinery onto or from the bed 30.

[0017] [Detailed configuration of the loading platform device (Fig. 3 to Fig. 7)] 3 to 7, the bed device of the trailer 2 includes a bed dump slide mechanism 50, a bed support mechanism 60, an air suspension 70, and a hydraulic control unit 80. Each component will be described in detail below.

[0018] The bed dump slide mechanism 50 has a swing arm 51 that connects the chassis frame 20 and the bed 30, and a hoist cylinder 52 that connects the chassis frame 20 and the swing arm 51, and dumps / slides the front position of the bed by extending and retracting the hoist cylinder 52.

[0019] One end (frame-side lower end) of the swing arm 51 is connected to a first frame connection point P1 of the chassis frame 20 at the front position of the loading platform, and the other end (load platform-side upper end) is connected to a loading platform connection point P2 of the loading platform 30 that is further forward of the loading platform than the first frame connection point P1. Specifically, as shown in Fig. 3, the swing arm 51 is configured in an H-shape and has a first swing arm portion 51a and a second swing arm portion 51b that are arranged as a pair on either side of a horizontal loading platform center line CL that divides the loading platform width in half, and a connecting arm portion 51c that connects the first swing arm portion 51a and the second swing arm portion 51b in the loading platform width direction.

[0020] One end (frame-side lower end) of the hoist cylinder 52 is connected to a second frame connection point P3 of the chassis frame 20, which is located closer to the loading platform than the loading platform connection point P2, and the other end (arm-side upper end) is connected to an arm connection point P4 of the swing arm 51 between the first frame connection point P1 and the loading platform connection point P2. Specifically, as shown in FIG. 3, only one hoist cylinder 52 is disposed at a position on the loading platform center line CL, which divides the loading platform width in half, and the connection point to the connecting arm 51c is the arm connection point P4. As shown in FIG. 4, when the hoist cylinder 52 is retracted, the loading platform 30 is placed parallel to and overlaps the upper surface of the chassis frame 20, and when the hoist cylinder 52 is fully extended, the desired loading platform dump distance D and horizontal loading platform slide distance S are obtained. That is, when the hoist cylinder 52 is extended from the retracted state to the maximum extended state, as shown in Fig. 4, the swing arm 51 swings about the first frame connection point P1 as a center point, causing the platform connection point P2 shown in Fig. 4 to move along an arc to the position of the platform connection point P2'. Therefore, the vertical movement distance from the platform connection point P2 to the platform connection point P2' is the platform dump amount D, and the horizontal movement distance from the platform connection point P2 to the platform connection point P2' is the platform slide amount S. In other words, the platform dump amount D and the platform slide amount S are determined by the setting of the extension / retraction amount of the hoist cylinder 52 and the settings of the four connection points P1, P2, P3, and P4 of the swing arm 51 and the hoist cylinder 52 that make up the link mechanism. Furthermore, if the horizontal bed slide amount S is converted to the inclined bed slide amount S' when the bed 30 is dumped, the relationship becomes the inclined bed slide amount S' (> horizontal bed slide amount S).

[0021] The bed support mechanism 60 is disposed at the rear of the bed on the chassis frame 20, and supports the bed 30 rotatably and slidably relative to the chassis frame 20. As shown in FIG. 6, a pair of bed support mechanisms 60 are disposed on either side of a vertical bed center line CL' that divides the width of the bed in half. As shown in FIG. 5, each bed support mechanism 60 has a support plate 62 tiltably mounted on the chassis frame 20 by a support shaft 61 in the bed width direction, a pair of guide rails 63 that are disposed parallel to the underside of the bed 30 and into which slide surfaces 62a of the pair of support plates 62 are fitted so as to be slidable in the fore-and-aft direction of the bed, and slide pads 64 that are provided on the slide surfaces 62a of the pair of support plates 62.

[0022] As shown in FIG. 6, the support plate 62 is tiltably mounted via a support shaft 61 on the chassis-side bracket 24 fixed to the rear axle case 22. The support plate 62 is formed by welding one top plate and two side plate members into a U-shaped cross section that opens downward, and the rectangular flat surface of the top plate member serves as the slide sliding surface 62a. The support area for the loading platform 30 provided by the slide sliding surface 62a is ensured by the area of ​​the rectangular flat surface of the top plate member. As shown in FIG. 6, the guide rail 63 is formed by extending the plate member that constitutes the loading platform flat plate 34 downward and bending the lower end of the extended plate member outward from the loading platform. The inner surface of the guide rail 63 serves as the slide sliding surface 63a, and the length L of the guide rail 63 is set to be longer than the loading platform sliding distance S', as shown in FIG. 5.

[0023] The slide pad 64 is arranged to cover the opposing slide sliding surfaces 62a and 63a in three directions (up and down, left and right), and is made of a friction-resistant and wear-resistant engineering plastic. Examples of engineering plastics that can be used include plastic materials such as monomer cast nylon (registered trademark: "MC nylon") and phenolic resin (Bakelite), and fiber-reinforced plastic materials made by adding carbon fiber to plastic materials.

[0024] As shown in FIG. 5 , the air suspension 70 has a suspension bracket 71, a first suspension link 72, a second suspension link 73, and an airbag 74. The suspension bracket 71 is fixed to the chassis frame 20, and the first suspension link 72 is swingably supported at its lower end. The second suspension link 73 connects an intermediate position of the first suspension link 72 to the rear axle case 22. The airbag 74 is interposed between the tip of the first suspension link 72 and the chassis frame 20. Therefore, by adjusting the air pressure supplied to the airbag 74 to control its height, the rear side of the frame of the chassis frame 20 is supported so that the vehicle height can be adjusted. Note that air pressure to the airbag 74 is supplied from an air pressure unit or the like mounted on the tractor head 1.

[0025] As shown in FIG. 7, the hydraulic control unit 80 is a unit that controls the operating hydraulic pressure of the hoist cylinder 52, the hydraulic cylinder 41, and the pair of outrigger cylinders 23, and is disposed in an empty space below the chassis frame 20.

[0026] The hydraulic control unit 80 includes, as a hydraulic power source unit, a pump motor 82 connected to a battery 81, a hydraulic pump 84 that pumps hydraulic oil from an oil tank 83, a cooling motor fan 85 connected to the battery 81, and a temperature sensor 86. The hydraulic control unit 80 also includes, as solenoid valves, a hoist cylinder solenoid valve 87, a hydraulic cylinder solenoid valve 88, and an outrigger cylinder solenoid valve 89. Furthermore, the hydraulic control unit 80 includes, as an electronic control unit, a hydraulic controller 90 and a communication device 91. Furthermore, the hydraulic control unit 80 includes a tablet terminal 92 that allows an operator to operate the hydraulic control unit 80 via external radio control.

[0027] The hydraulic controller 90 operates a tablet terminal 92, and when it receives cylinder operation input from the tablet terminal 92 via a communication device 91, it outputs control commands to each solenoid valve 87, 88, 89 in accordance with the received input. The hydraulic pressure of each cylinder 52, 41, 23 is controlled by radio-controlled operation of this tablet terminal 92. The battery 81 is automatically charged by a generator or the like mounted on the tractor head 1.

[0028] The hydraulic controller 90 inputs a temperature sensor value from a temperature sensor 86 provided in the independently cooled hydraulic power source unit. If the temperature sensor value exceeds a threshold value when the hydraulic pump 84 is operated by the pump motor 82, the hydraulic controller 90 performs temperature management control to suppress temperature increases in the hydraulic power source unit by operating a cooling motor fan 85. If, for example, a 24V DC motor is used as the pump motor 82, the DC motor does not have a cooling mechanism, and therefore there is a risk of the pump motor 82 burning out if operated for a long period of time. In response to this, performing temperature management control can increase the durability of the pump motor 82 and ensure long-term operation of the pump motor 82.

[0029] Next, the "background art of the loading platform device" will be described. Then, the "dumping / sliding action of the loading platform", "rotating / sliding support action of the loading platform", and "adjusting vehicle height at the rear of the loading platform" in the first embodiment will be described.

[0030] [Background technology for loading platform devices] A known loading platform device for a transport vehicle that performs both dumping and sliding functions includes a chassis frame, a tilting frame, and a loading platform. The loading platform device of the background art has a hoist cylinder interposed between the chassis frame and the tilting frame to lift the loading platform, and a slide cylinder interposed between the tilting frame and the loading platform to slide the loading platform, thereby performing both dumping and sliding functions.

[0031] As described above, the loading platform device of the background art requires a three-component configuration consisting of a chassis frame, a tilting frame, and a loading platform, and also requires the use of at least two types of cylinders: a hoist cylinder and a slide cylinder. This results in a large number of parts, a complex device configuration, and increased malfunctions and costs. Furthermore, the loading platform dump operation and the loading platform slide operation must be performed independently, increasing the operational burden.

[0032] [Dumping / sliding action of the loading platform (Fig. 1, Fig. 8 to Fig. 10)] In response to the above-mentioned background art, there is a demand for reducing the number of parts and the burden of operation. The inventors have noticed that this demand can be met by combining a link mechanism at the front of the bed that adds a sliding movement to the dumping movement and a support mechanism at the rear of the bed that adds a sliding support to the pivoting support.

[0033] Based on this point of view, in Example 1, a loading platform device for a semi-trailer truck A that performs dumping and sliding operations is adopted, and is configured to include a chassis frame 20, a loading platform 30, a rear tailgate 40, a loading platform dump slide mechanism 50, and a loading platform support mechanism 60.

[0034] Before dumping / sliding the loading platform 30, as shown in Figures 1(a) and 8, the hoist cylinder 52 is in the retracted position, so that the loading platform 30 is horizontal and parallel to the chassis frame 20. In addition, the hydraulic cylinder 41 is in the maximum extended position, so that the rear tailgate 40 is vertical to the loading platform 30.

[0035] When hydraulic pressure is supplied to the hoist cylinder 52 from a horizontal position of the loading platform 30 and the hoist cylinder 52 is extended, as shown in FIG. 9, the swing arm 51 swings around the first frame connection point P1 as a center point, and the loading platform connection point P2 moves while tracing an arc to the position of the loading platform connection point P2'. At this time, the rear of the loading platform 30 is rotatably and slidably supported by the loading platform support mechanism 60. Therefore, the support plate 62 of the loading platform support mechanism 60 slides from the position of the guide rail 63 shown in FIG. 8 to the position of the guide rail 63 shown in FIG. 10 while rotating around the support shaft 61. As a result, the loading platform 30 gradually tilts toward the rear of the loading platform due to the combined and linked upward and rearward movement of the front of the loading platform.

[0036] After dumping / sliding the bed 30, as shown in Figures 1(b) and 10, the hoist cylinder 52 is set to the maximum extended position, causing the bed 30 to tilt downward toward the rear. Then, the hydraulic cylinder 41 is set to the retracted position, causing the rear gate plate 40 to open from the vertical position to a position aligned with the bed 30. The opening operation of the rear gate plate 40 from the vertical position to the open position may be performed either before or after the dumping / sliding operation of the bed 30, or simultaneously.

[0037] Therefore, when loading or unloading cargo onto or from the loading platform 30, the rear gate plate 40 can be used as a runway, making it easy to load or unload cargo. When returning the loading platform slide dump configuration shown in Fig. 1(b) to the loading platform horizontal configuration shown in Fig. 1(a), the hoist cylinder 52 is retracted from the maximum extended position and the hydraulic cylinder 41 is extended from the retracted position.

[0038] As described above, the loading platform device of the first embodiment is configured with only two members, the chassis frame 20 and the loading platform 30, eliminating the need for a tilting frame. Furthermore, only the hoist cylinder 52 is used as a cylinder, eliminating the need for a slide cylinder. This reduces the number of parts, simplifies the device configuration, and reduces breakdowns and costs compared to the background art. Furthermore, the dumping / sliding operation of the loading platform 30 can be performed by operating only the hoist cylinder 52, significantly reducing the operational burden compared to the background art.

[0039] [Pivoting / sliding support for the loading platform] The pivoting / sliding support action of the loading platform 30 by the loading platform support mechanism 60 will be explained in comparison with a comparative example. Here, the loading platform support mechanism of the comparative example is a mechanism that combines a slide guide and a roller. This is because a support mechanism that uses a roller is generally reminiscent of a support mechanism that supports the sliding of two members.

[0040] In the case of the comparative example of the platform support mechanism, the contact between the slide guide and the roller is line contact, and when a heavy object is placed on the platform, the load is concentrated in the narrow contact area due to the line contact, and a large force acts on the roller. If a large force continues to act on one part of the roller, uneven wear occurs on the roller, the roller stops rotating and sliding resistance increases, or the roller becomes damaged and becomes unusable.

[0041] In contrast, the bed support mechanism 60 of the first embodiment is configured with a support plate 62 and a guide rail 63. A slide pad 64 is interposed between the sliding surface 62a of the support plate 62 and the sliding surface 63a of the guide rail 63, providing sliding support through surface contact. Therefore, even if a heavy object is placed on the bed 30, the contact area of ​​the sliding surface 62a of the support plate 62 is ensured, dispersing the load and applying a small force (distributed load). Reducing the force acting on the sliding surface 62a of the support plate 62 reduces sliding resistance. Furthermore, by interposing the slide pad 64 in the sliding portion, sliding resistance can be further reduced, achieving smooth sliding even when a heavy object is loaded. Furthermore, noise and other abnormal sounds due to metal contact can be prevented. Furthermore, reduced sliding resistance ensures the durability and reliability of the bed support mechanism 60.

[0042] [Adjustable vehicle height at rear of loading platform] In the case of the present invention, by adopting the loading platform dump slide mechanism 50, the dump amount D and the slide amount S are set to specified amounts that are linked to each other, so it is not possible to align the tip of the rear tailgate 40 with the position of the ground G by adjusting only the slide amount independently.

[0043] However, this can be compensated for by the vehicle height adjustment function of the airbag 74 of the air suspension 70 installed at the rear of the cargo bed 30, making it possible to align the tip of the rear tailgate 40 with the ground G. For example, as shown in FIG. 10 , when the airbag 74 is inflated to an air pressure state B1, if the ground G is horizontal, the tip of the rear tailgate 40 is aligned with the ground G. At this time, the ground below the rear tailgate 40 is at ground G', which is lower than ground G, and when the airbag 74 is in an air pressure state B1, a gap occurs between the tip of the rear tailgate 40 and the ground G'. At this time, the air pressure of the airbag 74 is reduced, changing from air pressure state B1 to air pressure state B2. By performing this vehicle height adjustment operation using the airbag 74, the gap between the tip of the rear tailgate 40' (imaginary line) and the ground G' can be closed. In this way, by providing a vehicle height adjustment function at the rear of the loading platform 30, it is possible to gradually set the angle of the loading platform 30 and the rear tailgate 40 (road board) relative to the road surface G, and it is also possible to respond to fluctuations in the height of the road surface G.

[0044] As described above, the bed device of the semi-trailer truck A according to the first embodiment can provide the following effects.

[0045] (1) A bed device for a transport vehicle (semi-trailer truck A) that exhibits dumping and sliding functions, comprising a chassis frame 20 suspended from wheels (trailer rear wheels 21) via suspensions (air suspensions 70), a bed 30 located on the top surface of the chassis frame 20, a swing arm 51 connecting the chassis frame 20 to the bed 30, and a hoist cylinder 52 connecting the chassis frame 20 to the swing arm 51, a bed dump slide mechanism 50 that performs dumping / sliding operations on the front position of the bed by extending and retracting the hoist cylinder 52, and a bed support mechanism 60 that is located at the bed rear position of the chassis frame 20 and supports the bed 30 rotatably and slidably relative to the chassis frame 20. This makes it possible to provide a bed device for a transport vehicle (semi-trailer truck A) that exhibits dumping and sliding functions while having a simple device configuration and reducing the operational burden.

[0046] (2) One end of the swing arm 51 is connected to a first frame connection point P1 on the chassis frame 20 at the front position of the loading platform, and the other end is connected to a loading platform connection point P2 on the loading platform 30 that is further forward of the loading platform than the first frame connection point P1, and the hoist cylinder 52 is connected to a second frame connection point P3 on the chassis frame 20 that is further forward of the loading platform than the loading platform connection point P2, and the other end is connected to an arm connection point P4 of the swing arm 51 between the first frame connection point P1 and the loading platform connection point P2. Therefore, the front position of the loading platform 30 can be dumped / slid relative to the chassis frame 20 using a simple mechanism consisting of two parts, the swing arm 51 and the hoist cylinder 52.

[0047] (3) The swing arm 51 is configured to include a first swing arm portion 51a and a second swing arm portion 51b that are arranged as a pair on either side of the bed center line CL that divides the width of the bed in half, and a connecting arm portion 51c that connects the first swing arm portion 51a and the second swing arm portion 51b in the bed width direction, and the hoist cylinder 52 is arranged at the position of the bed center line CL, with the arm connecting point P4 serving as the connecting portion to the connecting arm portion 51c, and is configured so that the bed 30 is placed on top of the chassis frame 20 when the cylinder is in a retracted state, and the desired bed dump amount D and bed slide amount S are obtained in the maximum extended state when the cylinder is extended from the retracted state. Therefore, even when one hoist cylinder 52 is used, the pair of swing arms 51a, 51b that are arranged on either side of the bed center line CL can stably dump / slide the front position of the bed 30 relative to the chassis frame 20.

[0048] (4) The bed support mechanism 60 includes a pair of support plates 62 arranged on either side of the bed center line CL that divides the width of the bed in half, and tiltably mounted on the chassis frame 20 by a support shaft 61 in the bed width direction, a pair of guide rails 63 that are arranged parallel to the underside of the bed 30 and into which slide surfaces 62a of the pair of support plates 62 are fitted so as to be slidable in the fore-and-aft direction of the bed, and a slide pad 64 that is provided on the slide surface 62a of one of the pair of guide rails 63 and the pair of support plates 62. This not only ensures the durability and reliability of the bed support mechanism 60, but also realizes smooth slide movement by reducing slide resistance and prevents abnormal noise and noise caused by metal contact.

[0049] (5) The loading platform 30 has a rear gate 40 at its rear end position that can be opened and closed, and the rear gate 40 has a hydraulic actuator (hydraulic cylinder 41) that performs the opening and closing operation, and when opened by the hydraulic actuator, it is used as a ramp when loading or unloading cargo onto or from the loading platform 30. Therefore, the rear gate 40 can be opened and closed by operating the hydraulic actuator (hydraulic cylinder 41), and the rear gate 40 in the open state can be used as a ramp.

[0050] (6) The suspension is an air suspension 70 having an air bag 74 mounted between the chassis frame 20 and the rear axle case 22 that houses the rear axle that connects the left and right rear wheels (left and right trailer rear wheels 21) in the width direction of the loading platform. Therefore, if there is a misalignment between the tip of the rear tailgate 40 and the ground G, the air bag 74 can be used to adjust the height of the rear part of the loading platform of the chassis frame 20, thereby aligning the tip of the rear tailgate 40 with the ground G.

[0051] The loading platform device for a transport vehicle of the present invention has been described above based on Example 1, but the specific configuration is not limited to Example 1, and design changes and additions are permitted as long as they do not deviate from the gist of the invention according to each claim in the scope of the claims.

[0052] In the first embodiment, the slide pads 64 are provided on the slide sliding surfaces 62a of the pair of support plates 62. However, the slide pads may be provided on the slide sliding surfaces of the pair of guide rails.

[0053] In the first embodiment, an example is shown in which the plate material constituting the loading platform 30 is used as the guide rail 63 and is extended downward. However, the guide rail may be fixed to the underside of the loading platform by welding or the like.

[0054] In the first embodiment, a configuration example of the bed dump slide mechanism 50 is shown, which is a combination of an H-shaped swing arm 51 and a hoist cylinder 52. However, the bed dump slide mechanism is not limited to the configuration example of the first embodiment, and may be any mechanism that performs dumping / sliding operations on the front part of the bed.

[0055] In the first embodiment, the rear gate plate 40 is provided at the rear end position of the loading platform 30 so as to be openable and closable by a hydraulic cylinder 41. However, the rear gate plate may be configured so that the opening and closing operation is performed by a hydraulic actuator other than a hydraulic cylinder, or may be configured so that the opening and closing operation is performed manually.

[0056] In the first embodiment, an example of the air suspension 70 is shown as the suspension, which is installed at the rear position of the cargo bed 30, has an airbag 74, and is capable of adjusting the vehicle height. However, a spring-type suspension may also be used as the suspension, and a vehicle height adjustment mechanism may be provided in parallel therewith.

[0057] In the first embodiment, an example is shown in which the loading platform device of the present invention is applied to a semi-trailer truck A equipped with a tractor head 1 and a trailer 2 towed by the tractor head 1. However, the loading platform device of the present invention can be applied to various kinds and types of transport vehicles, such as full trailer trucks and dump trucks, as long as the transport vehicle has a loading platform. [Explanation of symbols]

[0058] A Semi-trailer truck (transport vehicle) 20 Chassis frame 30 Cargo bed 40 Rear tailgate 50 Dump bed slide mechanism 51 Swing arm 52 Hoist cylinder 60 Cargo support mechanism

Claims

1. A bed device for a transport vehicle that exhibits a dump operation function and a slide operation function, a chassis frame suspended from the wheels via a suspension; a loading platform disposed on an upper surface of the chassis frame; a bed dump slide mechanism that includes a swing arm that connects the chassis frame and the bed, and a hoist cylinder that connects the chassis frame and the swing arm, and that performs a dump / slide operation on the front position of the bed by extending and contracting the hoist cylinder; a loading platform support mechanism that is disposed at a loading platform rear position of the chassis frame and that rotatably and slidably supports the loading platform with respect to the chassis frame, The bed support mechanism includes a pair of support plates arranged on either side of a bed center line that divides the width of the bed in half, the support plates being tiltable relative to the chassis frame by a support shaft in the bed width direction, a pair of guide rails that are arranged parallel to the underside of the bed and into which slide sliding surfaces of the pair of support plates are fitted so as to be slidable in the bed front-rear direction, and a slide pad that is provided on the slide sliding surface of one of the pair of guide rails and the pair of support plates. A loading platform device for a transport vehicle.

2. 2. The platform device for a transport vehicle according to claim 1, One end of the swing arm is connected to a first frame connection point of the chassis frame at a front position of the loading platform, and the other end is connected to a loading platform connection point of the loading platform that is located on a loading platform forward side of the first frame connection point, The hoist cylinder has one end connected to a second frame connection point of the chassis frame that is located on the loading platform front side of the loading platform connection point, and the other end connected to an arm connection point of the swing arm between the first frame connection point and the loading platform connection point. A loading platform device for a transport vehicle.

3. 3. The platform device for a transport vehicle according to claim 2, The swing arm is configured to include a first swing arm portion and a second swing arm portion that are arranged as a pair on either side of a center line of the loading platform that divides the width of the loading platform in half, and a connecting arm portion that connects the first swing arm portion and the second swing arm portion in the loading platform width direction, The hoist cylinder is disposed at the center line of the loading platform, the arm connection point is a connection part to the connection arm part, the loading platform is disposed so as to overlap with the upper surface of the chassis frame when the cylinder is in a contracted state, and when the cylinder is extended from the contracted state, the desired loading platform dump amount and loading platform slide amount are obtained in the maximum extension state. A loading platform device for a transport vehicle.

4. A loading platform device for a transport vehicle according to any one of claims 1 to 3, The loading platform is provided with a rear gate plate at a rear end position so as to be able to open and close, The rear gate plate has a hydraulic actuator that performs an opening and closing operation, and when opened by the hydraulic actuator, it is used as a walkway when loading or unloading luggage onto or from the loading platform. A loading platform device for a transport vehicle.

5. In the loading platform device of the transport vehicle described in claim 4, The suspension is an air suspension having an air bag interposed between the chassis frame and a rear axle case that houses a rear axle that connects the left and right rear wheels in the width direction of the loading platform. A loading platform device for a transport vehicle.

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