JP7489735B1 - Bed tilt movement mechanism and freight vehicle - Google Patents

Abstract

[Problem] To provide a bed tilt movement mechanism for a truck that can lower the entire bed to the ground substantially horizontally for loading and unloading luggage, and that reduces manufacturing and maintenance costs. [Solution] The bed tilt movement mechanism includes a guide rail 10 rotatably supported by a tilt base shaft 5 provided on a chassis 3, an idle frame 20 that moves in the fore-and-aft direction of the vehicle along the guide rail 10, a bed support movement fitting 30 that moves along the idle frame 20, a hydraulic cylinder 40 that reciprocates the idle frame 20, and a bed 50 connected to the bed support movement fitting 50. The idle frame 20 has a pulley 22 with a chain 60 wound around it at its rear end, and a pulley 21 with a chain 62 wound around it at its front end, and one end of each of the chains 60 and 62 is connected to the bed support movement fitting 30, and the other end is connected to a fixed frame 15. [Selected Figure] Figure 1

Description

Application of Article 30, Paragraph 2 of the Patent Act Hanamidai Motor Co., Ltd. exhibited the "Freight vehicle equipped with a cargo bed tilting and moving mechanism" invented by Nojo Kenji and Nojo Mikiya at the Japan Truck Show 2022, and distributed and released a catalog featuring the "Freight vehicle equipped with a cargo bed tilting and moving mechanism."

The present invention relates to a platform tilting mechanism and a freight vehicle, for example, a platform tilting mechanism for a freight vehicle that can lower the platform to a substantially horizontal position on the ground to allow loading and unloading of cargo.

Freight vehicles that can lower the entire loading platform to a substantially horizontal position on the ground for loading and unloading cargo have been used for some time now, and a freight vehicle equipped with such a function is disclosed, for example, in Patent Document 1.

The freight vehicle described in Patent Document 1 has a vehicle body consisting of a chassis frame and a subframe, a lift frame mounted on the vehicle body so as to be tiltable, and a cargo bed (body) mounted on the lift frame so as to be slidable and which can be raised and lowered by sliding along the lift frame.
A lift arm, one end of which is pivotally attached to the underside of the subframe, has the other end pivotally attached to the front end of the lift frame, and a lift cylinder, one end of which is pivotally attached to the subframe, has the other end pivotally attached to the center of the lift arm. By operating the lift cylinder, the lift frame slides rearward, and the rear end can be tilted downward.

The truck described in Cited Document 1 employs a mechanism for sliding the platform relative to the lift frame tilted by the lift arms and lift cylinders to lower the platform to the ground and return the platform from the ground to the lift frame, the mechanism comprising a hydraulic motor, a drive shaft driven by the hydraulic motor, a sprocket fixed to the drive shaft, and a chain wound around the sprocket. One end of the chain is fixed to the front end of the lift frame, and the other end is fixed to the rear end of the lift frame. The hydraulic motor drives the sprocket to operate the chain, allowing the platform to slide across the entire lift frame.

The applicant also manufactures and sells a "weight-based platform tilting mechanism for freight vehicles" that can lower the platform to a nearly horizontal position on the ground. This platform tilting mechanism includes a guide rail that is pivotally supported by a tilting axis at the rear of the chassis, a platform that is slidably supported on the guide rail, and a hydraulic cylinder that moves the platform back and forth along the guide rail in the fore-and-aft direction of the vehicle.
In this platform tilt movement mechanism, when the "guide rail and platform" are placed horizontally on the chassis and the platform is to be moved rearward, the hydraulic cylinder of the platform tilt movement mechanism is extended and a load is applied to the platform toward the rear of the vehicle. This causes the platform to move horizontally rearward along the guide rail. Note that the guide rail itself is connected to the tilt base shaft and does not move horizontally. When the platform moves rearward a certain distance, the weight of the platform itself causes the guide rail to tilt rearward, and the platform moves rearward along the guide rail while tilting together with the guide rail. In other words, when the moment acting rearward from the tilt base shaft, centered on the tilt base shaft, reaches a certain value, the platform moves rearward while tilting.

In addition, in the above-mentioned "weight-based platform tilt movement mechanism for freight vehicles," the tip of the hydraulic cylinder's piston rod is connected to the platform, which moves the platform in the fore-and-aft direction; however, the distance the platform can be moved in the fore-and-aft direction is limited by the stroke length of the hydraulic cylinder, and the hydraulic cylinder alone cannot ensure the distance required to lower the entire platform approximately horizontally to the ground. For this reason, the above-mentioned platform tilt movement mechanism is provided with a mechanism (rear guide frame movement mechanism) at the rear end of the chassis that causes the rear guide frame to slide in the fore-and-aft direction of the vehicle, and when the platform tilt movement mechanism slides the platform backwards, the rear guide frame movement mechanism moves the rear guide frame forward, allowing the entire platform to be lowered approximately horizontally to the ground.

Patent Publication No. 2672394

However, a configuration in which the loading platform is slid in the fore-and-aft direction of the vehicle using a mechanism equipped with "a hydraulic motor, a drive shaft, a sprocket and a chain" as in the truck described in the above-mentioned Patent Document 1 has the problem that the load-bearing capacity of the mechanism is low, which means that maintenance work, such as replacing parts that make up the mechanism, such as the chain, is time-consuming and costly.
In addition, devices that have a rear guide frame moving mechanism on the chassis, such as the "weight-based bed tilt movement mechanism for freight vehicles" sold by the applicant of the present application, have the problem that they require a large number of parts and have a complex structure, resulting in high manufacturing costs.

The present invention was made in consideration of the above problems, and its purpose is to provide a platform tilt movement mechanism that can lower the entire platform of a freight vehicle to the ground substantially horizontally for loading and unloading cargo, and that reduces the number of parts, thereby reducing manufacturing costs, and also reduces maintenance costs. Another purpose of the present invention is to provide a freight vehicle equipped with the platform tilt movement mechanism.

The present invention, which has been made to solve the above problems, is a platform tilt movement mechanism for moving a platform in the fore-and-aft direction of a truck along guide rails provided on the chassis of the truck, thereby lowering the entire platform to a substantially horizontal position on the ground surface or arranging the platform in a horizontal state on the chassis, the mechanism comprising: a pair of guide rails rotatably supported by a tilting base shaft provided on the rear side of the chassis; an idler frame that moves in the fore-and-aft direction of the vehicle along the inner side surfaces of the guide rails; a platform support movement fitting that is slidably supported on the idler frame and moves in the fore-and-aft direction of the vehicle along the idler frame; a hydraulic cylinder that reciprocates the idler frame in the fore-and-aft direction of the vehicle; a fixed frame fixed to the pair of guide rails; and the platform that is connected to the platform support movement fittings and is slidable on the guide rails. The idler frame is provided with a platform push pulley around which a push chain is wound at its rear end, and a platform retraction pulley around which a retraction chain is wound at its front end , one end of the push chain is connected to the platform support moving fitting and is wound around the platform push pulley provided at the rear end of the idler frame, and the other end is connected to the fixed frame fixed to the guide rail, one end of the retraction chain is connected to the platform support moving fitting and is wound around the platform retraction pulley provided at the front end of the idler frame, and the other end is connected to the fixed frame fixed to the guide rail, and when the guide rail is parallel to the ground surface, the platform support moving fitting is disposed in front of the idler frame, In this state, by extending the hydraulic cylinder, the idler frame moves toward the rear of the vehicle, so that the rear end of the idler frame protrudes from the rear end of the guide rail toward the rear of the vehicle, and the loading platform support moving fittings move toward the rear of the vehicle together with the idler frame, and the idler frame moves from the front end to the rear end by the pushing chain. When the loading platform moves to a certain extent toward the rear of the vehicle together with the loading platform support moving fittings due to these operations, the guide rail tilts toward the rear due to the weight of the loading platform itself, and the loading platform moves toward the rear of the vehicle while tilting together with the loading platform support moving fittings, so that the entire loading platform is lowered to the ground surface. When the guide rail is tilted toward the rear, the loading platform support moving fittings move toward the rear of the vehicle. A movable fitting is arranged at the rear end of the play frame, and in this state, by contracting the hydraulic cylinder, the play frame protruding from the rear end of the guide rail toward the rear of the vehicle moves toward the front of the vehicle , and the loading platform support movable fitting moves toward the front of the vehicle together with the play frame and is moved from the rear end to the front end of the play frame by the pulling chain, and when these operations cause the loading platform to move to a certain extent toward the front of the vehicle together with the loading platform support movable fitting, the weight of the loading platform itself causes the inclined guide rail to become horizontal, and the loading platform moves toward the front of the vehicle together with the loading platform support movable fitting while becoming horizontal, so that the loading platform is positioned horizontally on the chassis .

According to the configuration of the present invention, the platform can be moved a distance twice as long as the length of the extension and retraction action of the hydraulic cylinder, and the movement distance required to lower the entire platform to a substantially horizontal position on the ground can be secured. Therefore, according to the present invention, it is not necessary to provide a rear guide frame movement mechanism that moves the rear guide frame back and forth, such as the "self-weight type platform tilt movement mechanism for freight vehicles" sold by the applicant of the present application, and the number of parts can be reduced, and the structure can be simplified, resulting in a significant reduction in manufacturing costs.
In addition, the configuration of the present invention is more durable than a mechanism that slides the cargo bed using a "hydraulic motor, drive shaft, sprockets and chain" as described in the above-mentioned Patent Document 1, and therefore can reduce maintenance costs compared to the cargo truck described in Patent Document 1.

The push chain and the pull chain are both disposed within the frame of the idler frame, and when the hydraulic cylinder is extended, the idler frame is pushed by the hydraulic cylinder and moves toward the rear of the vehicle, and when the idler frame moves toward the rear of the vehicle, the platform support moving fitting supported by the idler frame moves toward the rear of the vehicle together with the idler frame, and while the idler frame is moving toward the rear of the vehicle, the push chain wound around the platform push pulley on the rear end side of the idler frame operates in a first rotation direction and pulls the platform support moving fitting connected to one end thereof toward the rear of the vehicle, and the platform support moving fitting moves toward the rear of the vehicle relative to the idler frame. It is desirable that, when the hydraulic cylinder is contracted, the idler frame is pulled by the hydraulic cylinder and moves toward the front of the vehicle, and when the idler frame moves toward the front of the vehicle, the cargo bed support moving fitting supported by the idler frame moves toward the front of the vehicle together with the idler frame, and while the idler frame is moving toward the front of the vehicle, the retracting chain wound around the cargo bed retracting pulley on the front end side of the idler frame operates in a second rotational direction opposite to the first rotational direction to pull the cargo bed support moving fitting connected to one end thereof toward the front of the vehicle, causing the cargo bed support moving fitting to move toward the front of the vehicle relative to the idler frame.

The present invention also relates to a freight vehicle that includes a chassis connected to a cabin and extending in the fore-and-aft direction of the vehicle, and a platform tilting and moving mechanism for moving the platform in the fore-and-aft direction of the vehicle, and that can lower the entire platform to approximately horizontally on the ground surface for loading and unloading luggage, the platform tilting and moving mechanism including a pair of guide rails rotatably supported by a tilting base shaft provided on the rear side of the chassis, an idler frame that moves in the fore-and-aft direction of the vehicle along the inner side surfaces of the guide rails, a platform support moving fitting slidably supported on the idler frame and that moves in the fore-and-aft direction of the vehicle along the idler frame, a hydraulic cylinder that reciprocates the idler frame in the fore-and-aft direction of the vehicle, a fixed frame fixed to the pair of guide rails, and the platform connected to the platform support moving fittings and slidably movable on the guide rails. the play frame is provided with a platform push pulley around which a push chain is wound at its rear end and a platform retraction pulley around which a retraction chain is wound at its front end, one end of the push chain is connected to the platform support moving fitting and is wound around the platform push pulley provided at the rear end of the play frame and the other end is connected to the fixed frame fixed to the guide rail, one end of the retraction chain is connected to the platform support moving fitting and is wound around the platform retraction pulley provided at the front end of the play frame and the other end is connected to the fixed frame fixed to the guide rail, and when the guide rail is parallel to the ground surface, the platform support moving fitting moves in a direction parallel to the play frame's The hydraulic cylinder is extended in this state, whereby the idler frame moves toward the rear of the vehicle, so that the rear end of the idler frame protrudes from the rear end of the guide rail toward the rear of the vehicle, and the loading platform support moving fittings move toward the rear of the vehicle together with the idler frame, and the idler frame moves from the front end to the rear end by the pushing chain. When the loading platform moves to a certain extent toward the rear of the vehicle together with the loading platform support moving fittings due to these operations, the guide rail tilts toward the rear due to the weight of the loading platform itself, and the loading platform moves toward the rear of the vehicle while tilting together with the loading platform support moving fittings, so that the entire loading platform is lowered to the ground surface, and when the guide rail is tilted toward the rear, the loading platform support The movable fitting is arranged at the rear end of the play frame, and in this state, by contracting the hydraulic cylinder, the play frame protruding from the rear end of the guide rail toward the rear of the vehicle moves toward the front of the vehicle , and the loading platform support movable fitting moves toward the front of the vehicle together with the play frame and moves from the rear end to the front end of the play frame by the pulling chain, and when these operations cause the loading platform to move to a certain extent toward the front of the vehicle together with the loading platform support movable fitting, the weight of the loading platform itself causes the inclined guide rail to become horizontal, and the loading platform moves toward the front of the vehicle together with the loading platform support movable fitting while becoming horizontal, so that the loading platform is positioned horizontally on the chassis .

According to the present invention, it is possible to provide a platform tilt movement mechanism for a freight vehicle that can lower the entire platform to the ground substantially horizontally for loading and unloading cargo, and that reduces the number of parts, thereby reducing manufacturing costs, and also reduces maintenance costs. In addition, according to the present invention, it is possible to provide a freight vehicle equipped with the platform tilt movement mechanism.

1 is a schematic diagram showing a side view of a truck equipped with a platform tilter movement mechanism according to an embodiment of the present invention. FIG. This is a schematic diagram for explaining the relationship between the guide rails, play frame, hydraulic cylinder, platform support and movement fittings, push chains, and pull-in chains that constitute the platform tilting movement mechanism of an embodiment of the present invention, and is a schematic diagram showing the state in which the platform has been removed from the platform tilting movement mechanism. 2 is a schematic diagram showing a guide rail, an idler frame, and a hydraulic cylinder that constitute a platform tilting movement mechanism according to an embodiment of the present invention, viewed from above. FIG. 1A and 1B are schematic diagrams showing guide rails that constitute a platform tilting movement mechanism according to an embodiment of the present invention, in which FIG. 1A is a schematic diagram showing a plan view of the guide rail, and FIG. 1B is a schematic diagram showing a side view of the guide rail. 1A and 1B are schematic diagrams showing a play frame that constitutes a loading platform tilting movement mechanism of an embodiment of the present invention, in which (a) is a schematic diagram showing a plan view of the play frame, and (b) is a schematic diagram showing a side view of the play frame. 1A is a schematic diagram illustrating the relationship between the guide rails, the play frame, the loading platform support moving fittings, the push chain, the retraction chain, and the fixed frame when the loading platform tilting movement mechanism of an embodiment of the present invention is in a drivable state, where (a) is a schematic diagram illustrating the loading platform tilting movement mechanism viewed from above, (b) is a schematic diagram illustrating the connection relationship between the push chain and the retraction chain that constitute the loading platform tilting movement mechanism, the loading platform support moving fittings, and the fixed frame, and (c) is a schematic diagram illustrating the loading platform tilting movement mechanism viewed from the rear side of the vehicle. 1A is a schematic diagram illustrating the relationship between the guide rails, the play frame, the loading platform support moving fittings, the push chain, the retraction chain, and the fixed frame when the loading platform tilting movement mechanism of an embodiment of the present invention has the loading platform lowered to the ground surface, (a) is a schematic diagram illustrating the loading platform tilting movement mechanism viewed from above, (b) is a schematic diagram illustrating the connection relationship between the push chain and the retraction chain that constitute the loading platform tilting movement mechanism, the loading platform support moving fittings, and the fixed frame, and (c) is a schematic diagram illustrating the loading platform tilting movement mechanism viewed from the rear side of the vehicle. Schematic diagrams for explaining the state of the idle frame, platform support fittings, push chain, and retraction chain when the idle frame of the platform tilting movement mechanism of an embodiment of the present invention is moved, where (a) is a schematic diagram showing the state of the idle frame, push chain, platform push sheave, and fixed frame when the idle frame and platform support moving fittings are positioned on the front side of the vehicle, (b) is a schematic diagram showing the state of the idle frame, push chain, platform push sheave, and fixed frame when the idle frame and platform support moving fittings are positioned on the rear side of the vehicle, (c) is a schematic diagram showing the state of the idle frame, retraction chain, platform retraction sheave, and fixed frame when the idle frame and platform support moving fittings are positioned on the front side of the vehicle, and (d) is a schematic diagram showing the state of the idle frame, retraction chain, platform retraction sheave, and fixed frame when the idle frame and platform support moving fittings are positioned on the rear side of the vehicle. Schematic diagrams for explaining the operation of the loading platform tilting movement mechanism of an embodiment of the present invention, where (a) is a schematic diagram showing the state in which the play frame and loading platform support moving fittings of the loading platform tilting movement mechanism are positioned at the front end of the vehicle, (b) is a schematic diagram showing the arrangement of the play frame and loading platform support moving fittings when the hydraulic cylinder of the loading platform tilting movement mechanism is extended A mm from the state shown in (a), and (c) is a schematic diagram showing the arrangement of the play frame and loading platform support moving fittings when the hydraulic cylinder of the loading platform tilting movement mechanism is extended B mm from the state shown in (b).

Below, a freight vehicle equipped with a platform tilt movement mechanism according to an embodiment of the present invention will be described with reference to the drawings.

First, a schematic configuration of a truck equipped with a platform tilting mechanism according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG.
Here, Fig. 1 is a schematic diagram showing the side of a truck equipped with the platform tilt mechanism of this embodiment, and Fig. 2 is a schematic diagram for explaining the relationship between the guide rail, the play frame, the hydraulic cylinder, the platform support and movement fittings, the push chain, and the pull chain that constitute the platform tilt movement mechanism of this embodiment, and shows the state in which the platform has been removed from the platform tilt movement mechanism.
In addition, Figure 1 shows both a state in which the loading platform 50 is placed horizontally on the chassis 3 and a state in which the loading platform 50 has been moved rearward and lowered to a substantially horizontal position on the ground surface GL.

As shown in FIG. 1, the cargo vehicle W of this embodiment includes a cabin 1, a chassis 3 connected to the cabin 1 and extending in the fore-and-aft direction of the vehicle (X direction), and a loading platform tilt movement mechanism for moving a loading platform 50 in the fore-and-aft direction of the vehicle.
The cargo bed 50 has a rectangular floor 51 in a plan view on which cargo such as vehicles (automobiles) are placed, and a torii section 52 which extends upward at a right angle to the floor 51 at the front end side (cabin 1 side) of the floor 51.

The platform tilt movement mechanism is capable of moving the platform 50 in the fore-and-aft direction of the vehicle (X direction) along guide rails 10 provided on the chassis 3, and can move the platform 50 rearward to lower the entire platform 50 to a substantially horizontal position on the ground surface GL, or to position the platform 50 horizontally on the chassis 3.

As shown in FIG. 2, the platform tilt movement mechanism includes a pair of guide rails 10 supported for rotation by a tilt base shaft 5 (see FIG. 1) provided on the rear side of the chassis 3, a play frame 20 that moves in the fore-and-aft direction of the vehicle (X direction) along the inner side of the guide rails 10, a platform support movement fitting 30 that is slidably supported by the play frame 20 and moves in the fore-and-aft direction of the vehicle along the play frame 20, a hydraulic cylinder 40 that reciprocates the play frame 20 in the fore-and-aft direction of the vehicle, a fixed frame 15 (see FIG. 6(b), FIG. 7(b), FIG. 8) fixed to the guide rails 10, and a platform 50 that is connected to the platform support movement fitting 30 and can slide on the guide rails 10.

In addition, the above-mentioned idle frame 20 is provided with a platform push-out sheave (pulley) 22 around which a push-out chain 60 is wound at its rear end, and a platform retraction sheave (pulley) 21 around which a retraction chain 62 is wound at its front end.
The pushing chain 60 and the pulling chain 62 each have one end connected to the platform support moving fitting 30 and the other end connected to the fixed frame 15 .
The lower end of the front end side (the torii section 52 side) of the loading platform 50 is connected to the loading platform support movement fitting 30 (see FIG. 1). In addition, a cross plate 11 is installed on the front end side of the pair of guide rails 10.

The inclined base shaft 5 that supports the guide rail 10 is axially fixed perpendicular to the longitudinal direction of the guide rail 10 at the rear end side between the left and right frames that make up the chassis 3. An engagement portion 12 is formed at the bottom of the guide rail 10 at a position corresponding to the inclined base shaft 5, and the inclined base shaft 5 is inserted into this engagement portion 12, so that the guide rail 10 is supported by the chassis 3 so that it can rotate freely.

The hydraulic cylinder 40 has a cylinder tube 40a and a piston rod 40b that moves in and out of the cylinder tube 40a. The cylinder tube 40a is fixed to a cross plate 11 that is installed on the front end side of the guide rail 10, and the tip of the cylinder rod 40b is fixed to the rear end side of the play frame 20.

When the hydraulic cylinder 40 extends or retracts the piston rod 40b, the play frame 20 reciprocates along the guide rail 10 in the fore-and-aft direction of the vehicle (X direction).
Specifically, the extension operation of the piston rod 40 of the hydraulic cylinder 40 causes the idler frame 20 to move toward the rear of the vehicle. Also, when the idler frame 20 moves toward the rear of the vehicle, the loading platform support moving fitting 30 moves toward the rear of the vehicle together with the idler frame 20, and the pushing chain 60 operates, so that the loading platform support fitting 30 is pulled toward the rear of the vehicle by the pushing chain 60, and the loading platform support moving fitting 30 moves toward the rear of the vehicle relative to the idler frame 20.
Furthermore, the contraction of the piston rod 40 of the hydraulic cylinder 40 causes the idle frame 20 to move towards the front of the vehicle. Furthermore, when the idle frame 20 moves towards the front of the vehicle, the loading platform support moving fitting 30 moves together with the idle frame 20 towards the front of the vehicle, and the retraction chain 62 operates, pulling the loading platform support moving fitting 30 towards the front of the vehicle by the retraction chain 62, and the loading platform support moving fitting 30 moves towards the front of the vehicle relative to the idle frame 20.

With the above configuration, for example, when the piston rod 40b extends by a length of "L mm", the play frame 20 moves rearward by a length dimension of "L mm", and the platform support moving fitting 30 moves rearward by a length dimension of "2L mm". At this time, the platform 50 connected to the platform support moving fitting 30 moves rearward by a length dimension of "2L mm" along the guide rail 10 together with the platform support moving fitting 30.
Also, for example, when the piston rod 40b contracts by a length dimension of "L mm", the play frame 20 moves forward by a length dimension of "L mm", and the platform support moving fitting 30 moves forward by a length dimension of "2L mm". At this time, the platform 50 connected to the platform support moving fitting 30 moves forward by a length dimension of "2L mm" along the guide rail 10 together with the platform support moving fitting 30.
The guide rail 10 itself does not move in the vehicle longitudinal direction (horizontal direction) because it is connected to the inclined base shaft 5. In addition, the fixed frame 15 is also fixed to the guide rail 10, so it does not move in the vehicle longitudinal direction (horizontal direction).

When the loading platform 50 moves rearward along the guide rail 10 to a certain extent, the weight of the loading platform 50 itself (or the combined weight of the loading platform 50 and the cargo) causes the guide rail 10 to tilt rearward, and the loading platform 50 moves rearward along the guide rail 10 while tilting together with the rail 10. In other words, when the moment acting rearward from the tilt base axis 5 around the tilt base axis 5 reaches a certain value, the loading platform 50 moves rearward along the guide rail 10 while tilting together with the guide rail 10, until the entire loading platform 50 is lowered to a substantially horizontal position on the ground GL.

Next, the components of the platform tilt movement mechanism of this embodiment will be explained using the above-mentioned Figures 1 and 2 and Figures 3 to 8.

Here, FIG. 3 is a schematic diagram of the guide rail, play frame, and hydraulic cylinder that constitute the platform tilt movement mechanism of this embodiment, viewed from above. FIG. 4 is a schematic diagram showing the guide rail that constitutes the platform tilt movement mechanism of this embodiment, (a) is a schematic diagram showing the plan view of the guide rail, and (b) is a schematic diagram showing the side view of the guide rail. FIG. 5 is a schematic diagram showing the play frame that constitutes the platform tilt movement mechanism of this embodiment, (a) is a schematic diagram showing the plan view of the play frame, and (b) is a schematic diagram showing the side view of the play frame.

Figure 6 is a schematic diagram for explaining the relationship between the guide rail, the play frame, the loading platform support moving fittings, the push chain, the retraction chain, and the fixed frame when the loading platform tilting movement mechanism of this embodiment is in a drivable state, where (a) is a schematic diagram showing the loading platform tilting movement mechanism in a plan view, (b) is a schematic diagram for explaining the connection relationship between the push chain and the retraction chain that constitute the loading platform tilting movement mechanism, the loading platform support moving fittings, and the fixed frame, and (c) is a schematic diagram showing the loading platform tilting movement mechanism as viewed from the rear side of the vehicle.
Figure 7 is a schematic diagram for explaining the relationship between the guide rail, the play frame, the loading platform support moving fittings, the push chain, the retraction chain, and the fixed frame when the loading platform tilting movement mechanism of this embodiment has lowered the loading platform to the ground surface, where (a) is a schematic diagram of the loading platform tilting movement mechanism viewed from above, (b) is a schematic diagram for explaining the connection relationship between the push chain and the retraction chain that constitute the loading platform tilting movement mechanism, the loading platform support moving fittings, and the fixed frame, and (c) is a schematic diagram of the loading platform tilting movement mechanism viewed from the rear side of the vehicle.
Figure 8 is a schematic diagram for explaining the state of the idle frame, the loading platform support fitting, the push chain, and the retraction chain when the idle frame of the loading platform tilting movement mechanism of this embodiment is moved, where (a) is a schematic diagram showing the state of the idle frame, the push chain, the loading platform push-out sheave, and the fixed frame when the idle frame and the loading platform support moving fitting are arranged on the front side of the vehicle, (b) is a schematic diagram showing the state of the idle frame, the push chain, the loading platform push-out sheave, and the fixed frame when the idle frame and the loading platform support moving fitting are arranged on the rear side of the vehicle, (c) is a schematic diagram showing the state of the idle frame, the retraction chain, the loading platform retraction sheave, and the fixed frame when the idle frame and the loading platform support moving fitting are arranged on the front side of the vehicle, and (d) is a schematic diagram showing the state of the idle frame, the retraction chain, the loading platform retraction sheave, and the fixed frame when the idle frame and the loading platform support moving fitting are arranged on the rear side of the vehicle.
Note that Figures 8(a) and (c) show a state in which the play frame 20 is positioned at the front end of the vehicle and the cargo bed support moving bracket 30 is positioned at the front end of the play frame 20, while Figures 8(b) and (d) show a state in which the play frame 20 is positioned at the rear end of the vehicle and the cargo bed support bracket 30 is positioned at the rear end of the play frame 20.

As shown in FIGS. 3 and 4, the guide rail 10 has a rail portion 10a extending in the longitudinal direction of the vehicle, and a support leg 13 (see FIG. 4) that protrudes downward is provided at the rear end of the rail portion 10a.
The rail portion 10a is provided with an engagement portion 12 that protrudes downward from its rear end portion and is located forward of the support leg 13. The engagement portion 12 is rotatably supported by an inclined base shaft 5 that is supported between the left and right frames that constitute the chassis 3.

In addition, the guide rail 10 supports a play frame 20 inside the pair of rail portions 10a so that the play frame 20 can slide freely, and the play frame 20 can move back and forth along the longitudinal direction of the guide rail 10 (the fore-and-aft direction of the vehicle).
In addition, a cross plate 11 is installed on the front end side of the pair of rail portions 10a of the guide rail 10, and a cylinder tube 40a of a hydraulic cylinder 40 is fixed to the cross plate 11.
A substantially flat fixed frame 15 (see Figs. 6(b) and 7(b)) is installed and fixed to the guide rail 10 at substantially the middle in the vehicle front-rear direction of the pair of rail portions 10a. A push chain 60 and a pull chain 62 are connected to the fixed frame 15.
The guide rails 10 also support a loading platform 50 in a slidable manner, so that the loading platform 50 can move back and forth along the longitudinal direction of the guide rails 10 .

As shown in Figure 5, the play frame 20 is formed in a frame shape that is roughly U-shaped when viewed from above, and includes a pair of vertical pieces 20a extending in the fore-and-aft direction of the vehicle, and a horizontal piece 20b (a horizontal piece that is shorter than the vertical piece 20a) extending from the rear end of one vertical piece 20a to the rear end of the other vertical piece 20a.
As shown in FIG. 3, the play frame 20 has its outer circumferential side surface in the longitudinal direction supported slidably on the inner circumferential side surface in the longitudinal direction of the guide rail 10.

The play frame 20 is provided with a piston rod fixing piece 20c extending from one vertical piece 20a to the other vertical piece 20a at a position a predetermined distance forward of the horizontal piece 20b. The piston rod fixing piece 20c is parallel to the horizontal piece 20b, and the tip of the piston rod 40b of the hydraulic cylinder 40 is fixed to the piston rod fixing piece 20c.
The play frame 20 is adapted to move back and forth in the longitudinal direction of the vehicle along the longitudinal direction of the guide rail 10 by the extension and contraction of the piston rod 40b.
A platform support movable fitting 30 is slidably supported on the inner peripheral side surfaces of the pair of vertical pieces 20a of the play frame 20. The platform support movable fitting 30 is capable of reciprocating movement between the front end and the rear end of the play frame 20.

6 and 7, the idler frame 20 is provided with a pair of platform pushing sheaves (pulleys) 22 on both sides in the vehicle width direction at the rear end side of the platform pushing sheaves (pulleys) 22. A pushing chain 60, one end of which is connected to the platform support movement fitting 30, is wound around the platform pushing sheaves (pulleys) 22 (see FIGS. 8(a) and 8(b)). The other end of the pushing chain 60 is connected to the fixed frame 15 fixed to the guide rail 10.
A pair of platform retracting sheaves (pulleys) 21 are provided on both sides of the front end of the play frame 20 in the vehicle width direction. A retracting chain 62, one end of which is connected to the platform support moving fitting 30, is wound around the platform retracting sheaves (pulleys) 21 (see FIGS. 8(c) and 8(d)). The other end of the retracting chain 62 is connected to the fixed frame 15 fixed to the guide rail 10.
As shown in Figure 6 (c), the loading platform retracting sheave (pulley) 21 is located outside (outside in the vehicle width direction) the loading platform pushing sheave (pulley) 22 so that the loading platform retracting sheave (pulley) 21 does not interfere with the pushing chain 60 wound around the loading platform pushing sheave (pulley) 22.

As shown in Figure 8, the platform support moving fitting 30 can move back and forth in the fore-and-aft direction of the vehicle (X direction) along the longitudinal direction of the play frame 20 between the position of the front end of the play frame 20 (Figures 8(a) and (c)) and the position of the rear end of the play frame 20 (Figures 8(b) and (d)) by means of chains (push chain 60, pull-in chain 62) that are operated by the movement of the play frame 20.

For example, when the idle frame 20 receives a load toward the rear of the vehicle from the hydraulic cylinder 40 and moves from the position shown in Figure 8(a) to the position shown in Figure 8(b), the cargo bed support moving fitting 30 supported by the idle frame 20 moves rearward together with the idle frame 20.
In addition, the push chain 60 connected to the platform support moving fitting 30 is wound around the platform push sheave 22 at the rear end of the idle frame 20, and the other end is connected to the fixed frame 15 which does not move in the fore-and-aft direction of the vehicle. Therefore, while the idle frame 20 is moving rearward, the platform push sheave (pulley) 22 rotates in the first rotation direction and the push chain 60 wound around the platform push pulley 22 operates in the first rotation direction, pulling the platform support moving fitting 30 connected to one end thereof toward the rear of the vehicle. As a result, the vehicle support moving fitting 30 moves toward the rear of the vehicle relative to the idle frame 20.
In addition, the retraction chain 62 wound around the loading platform retraction sheave 21 on the front end side of the idler frame 20 also moves in the first rotation direction while the idler frame 20 is moving rearward.

Also, for example, when the idle frame 20 receives a load toward the front of the vehicle from the hydraulic cylinder 40 and moves from the position shown in Figure 8(d) to the position shown in Figure 8(c), the cargo bed support moving fitting 30 supported by the idle frame 20 moves forward together with the idle frame 20.
In addition, the retraction chain 62 connected to the platform support moving fitting 30 is wound around the platform retraction sheave 21 on the front end side of the idle frame 20, and the other end is connected to the fixed frame 15 that does not move in the vehicle front-rear direction. Therefore, while the idle frame 20 is moving forward, the platform retraction sheave (pulley) 21 rotates in the second rotation direction (opposite to the first rotation direction) and the retraction chain 62 wound around the platform retraction sheave 21 operates in the second rotation direction, pulling the platform support moving fitting 30 connected to one end of the retraction chain 62 toward the front of the vehicle. As a result, the vehicle support moving fitting 30 moves toward the front of the vehicle relative to the idle frame 20. The push chain 60 wound around the platform push sheave 22 on the rear end side of the idle frame 20 also operates in the second rotation direction while the idle frame 20 is moving forward.

Next, the operation of the platform tilt movement mechanism of this embodiment will be described with reference to Figure 9.

Here, Figure 9 is a schematic diagram for explaining the operation of the loading platform tilting movement mechanism of this embodiment, where (a) is a schematic diagram showing the state in which the play frame and loading platform support moving fittings of the loading platform tilting movement mechanism are positioned at the front end of the vehicle, (b) is a schematic diagram showing the arrangement of the play frame and loading platform support moving fittings when the hydraulic cylinder of the loading platform tilting movement mechanism is extended by A mm from the state shown in (a), and (c) is a schematic diagram showing the arrangement of the play frame and loading platform support moving fittings when the hydraulic cylinder of the loading platform tilting movement mechanism is extended by B mm from the state shown in (b).
For ease of explanation, FIG. 9 shows a state in which the platform is removed from the platform tilting mechanism.

As shown in Figure 9 (a), when the "play frame 20 and loading platform support moving fitting 30" of the loading platform tilt movement mechanism are positioned at the front end of the vehicle, when the hydraulic cylinder 40 is driven to extend the piston rod 40b by "A mm", the play frame 20 is pushed by the piston rod 40b (pushed toward the rear of the vehicle) and moves "A mm" toward the rear of the vehicle along the longitudinal direction of the guide rail 10.
When the idle frame 20 moves "A mm" toward the rear of the vehicle, the platform support moving fitting 30 (and the platform 50), which is slidably supported by the idle frame 20, moves "A mm" toward the rear of the vehicle together with the idle frame 20. Also, while the idle frame 20 is moving "A mm" toward the rear of the vehicle, the push chain 60 wound around the platform push sheave 22 at the rear end of the idle frame 20 operates in the first rotation direction, and the platform support moving fitting 30 (and the platform 50) connected to one end of the push chain 60 is pulled and moves "A mm" toward the rear of the vehicle relative to the idle frame 20, to the state shown in FIG. 9B. At this time, the pull chain 62 wound around the platform pull sheave 21 at the front end of the idle frame 20 also operates in the first rotation direction while the idle frame 20 is moving backward.

In this way, when the hydraulic cylinder 40 of the cargo bed tilt movement mechanism is driven to extend the piston rod 40b by "A mm" and move the play frame 20 "A mm" toward the rear of the vehicle, the cargo bed support movement fitting 30 supporting the cargo bed 50 moves "2 A mm" toward the rear of the vehicle, reaching the position shown in Figure 9 (b).
That is, according to the bed tilt movement mechanism of this embodiment, by driving the hydraulic cylinder 40 to extend the piston rod 40b by "A mm", the bed 50 can be moved "2 A mm" toward the rear of the vehicle.

Also, in the state shown in Figure 9 (b), when the hydraulic cylinder 40 is driven to extend the piston rod 40b by "B mm", the play frame 20 is pushed by the piston rod 40b and moves "B mm" toward the rear of the vehicle along the longitudinal direction of the guide rail 10.
When the idle frame 20 moves "B mm" toward the rear of the vehicle, the platform support moving fitting 30 (and the platform 50), which is slidably supported by the idle frame 20, moves "B mm" toward the rear of the vehicle together with the idle frame 20. Also, while the idle frame 20 is moving "B mm" toward the rear of the vehicle, the push chain 60 wound around the platform push sheave 22 at the rear end of the idle frame 20 operates in the first rotation direction, and the platform support moving fitting 30 (and the platform 50) connected to one end of the push chain 60 is pulled toward the rear of the vehicle, moving "B mm" toward the rear of the vehicle relative to the idle frame 20, to the state shown in FIG. 9(c). At this time, the pull chain 62 wound around the platform pull sheave 21 at the front end of the idle frame 20 also operates in the first rotation direction while the idle frame 20 is moving backward.

In this way, with the platform tilt movement mechanism of this embodiment, the platform 50 can be moved "2B mm" toward the rear of the vehicle by driving the hydraulic cylinder 40 to extend the piston rod 40b by "B mm."

On the other hand, for example, in the state shown in Figure 9 (c), when the hydraulic cylinder 40 is driven to contract the piston rod 40b by "B mm", the play frame 20 is pulled by the piston rod 40b (towards the front of the vehicle) and moves "B mm" towards the front of the vehicle along the longitudinal direction of the guide rail 10.
When the idle frame 20 moves "B mm" toward the front of the vehicle, the platform support moving fitting 30 (and the platform 50), which is slidably supported by the idle frame 20, moves "B mm" toward the front of the vehicle together with the idle frame 20. Also, while the idle frame 20 is moving "B mm" toward the front of the vehicle, the retraction chain 62 wound around the platform retraction sheave 21 on the front end side of the idle frame 20 operates in the second rotation direction (opposite to the first rotation direction), and the platform support moving fitting 30 (and the platform 50) connected to one end of the retraction chain 62 is pulled toward the front of the vehicle, moving "B mm" toward the front of the vehicle relative to the idle frame 20, to the state shown in FIG. 9(b). At this time, the push chain 60 wound around the platform retraction sheave 22 on the rear end side of the idle frame 20 also operates in the second rotation direction while the idle frame 20 is moving forward.

In this way, in the state shown in Figure 9(c), when the hydraulic cylinder 40 of the cargo bed tilt movement mechanism is driven to contract the piston rod 40b by "B mm" and move the play frame 20 by "B mm" toward the rear of the vehicle, the cargo bed support movement fitting 30 supporting the cargo bed 50 moves "2B mm" toward the front of the vehicle, resulting in the state shown in Figure 9(b).
That is, according to the platform tilt movement mechanism of this embodiment, by driving the hydraulic cylinder 40 to contract the piston rod 40b by "B mm", the platform 50 can be moved "2 B mm" towards the front of the vehicle.

As described above, when the guide rail 10 is in a horizontal state (parallel to the ground surface) and the loading platform 50 is moved backward, when the loading platform 50 moves backward along the guide rail 10 to a certain extent, the weight of the loading platform 50 itself causes the guide rail 10 to tilt backward. At this time, the loading platform 50 moves backward along the guide rail 10 while tilting together with the guide rail 10, and the entire loading platform 50 is lowered to a state where it is approximately horizontal on the ground GL.
In addition, when the loading platform 50 is moved forward along the guide rail 10 while the guide rail 10 is inclined backward, when the loading platform 50 moves forward to a certain extent along the guide rail 10, the weight of the loading platform 50 itself causes the inclined guide rail 10 to become horizontal. At this time, the loading platform 50 and the guide rail 10 become horizontal.

Thus, according to this embodiment, the platform 50 can be moved a distance twice as long as the extension/retraction length of the hydraulic cylinder 40, and the movement distance required to lower the entire platform 50 substantially horizontally to the ground surface GL can be secured. Therefore, according to this embodiment, it is not necessary to provide a rear guide frame moving mechanism for moving the rear guide frame back and forth, as in the trucks sold by the applicant of the present application, and the number of parts can be reduced, and the structure can be simplified, resulting in reduced manufacturing costs.
In addition, this embodiment is more durable than the mechanism described in Patent Document 1, which includes "a hydraulic motor, a drive shaft, a sprocket, and a chain" that slides the loading platform, and therefore reduces maintenance costs compared to the truck described in Patent Document 1.

As described above, according to this embodiment, a platform tilt movement mechanism for a freight vehicle W can be provided that allows the entire platform to be lowered substantially horizontally to the ground for loading and unloading cargo, and that reduces the number of parts, thereby reducing manufacturing costs, and also reduces maintenance costs. Furthermore, according to this embodiment, a freight vehicle W equipped with the platform tilt movement mechanism can be provided.

The present invention is not limited to the above embodiment, and various modifications are possible within the scope of the gist.

W... cargo vehicle 1... cabin 3... chassis 5... inclined base axis 10... guide rail 10a... rail section 11... cross member 12... engagement section 13... support leg 20... play frame 20a... vertical piece 20b... horizontal piece 20c... piston rod fixing piece 21... platform retraction sheave 22... platform push-out sheave 30... platform support moving fitting 40... hydraulic cylinder 40a... cylinder tube 40b... piston rod 50... platform 51... floor section 52... torii section 60... push-out chain 62... retraction chain

Claims (3)

A platform tilt movement mechanism for moving a platform in the fore-and-aft direction of a truck along a guide rail provided on a chassis of the truck, to lower the entire platform to a substantially horizontal position on the ground surface or to place the platform in a horizontal position on the chassis,
a pair of the guide rails rotatably supported by an inclined base shaft provided on the rear side of the chassis;
a play frame that moves in the front-rear direction of the vehicle along an inner side surface of the guide rail;
a platform support movable fitting slidably supported by the play frame and movable in the front-rear direction of the vehicle along the play frame;
A hydraulic cylinder that reciprocates the play frame in the front-rear direction of the vehicle;
a fixed frame fixed to the pair of guide rails;
The loading platform is connected to the loading platform support and moving fitting and is slidable on the guide rail.
The idle frame is provided with a platform push pulley around which a push chain is wound on the rear end side thereof, and a platform retract pulley around which a retract chain is wound on the front end side thereof.
One end of the push chain is connected to the platform support moving fitting and is wound around the platform push pulley provided at the rear end side of the idle frame, and the other end is connected to the fixed frame fixed to the guide rail,
The retracting chain has one end connected to the platform support moving fitting and is wound around the platform retracting pulley provided at the front end side of the idle frame, and the other end connected to the fixed frame fixed to the guide rail,
When the guide rail is parallel to the ground surface, the loading platform support movable fittings are arranged at the front end of the play frame, and in this state, by extending the hydraulic cylinder, the play frame moves towards the rear of the vehicle so that the rear end of the play frame protrudes from the rear end of the guide rail towards the rear of the vehicle, and the loading platform support movable fittings move towards the rear of the vehicle together with the play frame and are moved from the front end to the rear end of the play frame by the push chain, and when the loading platform moves to a certain extent towards the rear of the vehicle together with the loading platform support movable fittings due to these operations, the guide rail tilts towards the rear due to the weight of the loading platform itself, and the loading platform moves towards the rear of the vehicle while tilting together with the loading platform support movable fittings, until the entire loading platform is lowered to the ground surface,
A bed tilting and moving mechanism characterized in that when the guide rail is inclined rearward, the bed support moving fittings are positioned at the rear end of the play frame, and in this state, by contracting the hydraulic cylinder , the play frame protruding from the rear end of the guide rail toward the rear of the vehicle moves to the front of the vehicle , and the bed support moving fittings move toward the front of the vehicle together with the play frame and move from the rear end to the front end of the play frame by the pulling chain, and when the bed moves to the front of the vehicle to a certain extent together with the bed support moving fittings due to these operations, the weight of the bed itself causes the tilted guide rail to become horizontal, and the bed moves toward the front of the vehicle together with the bed support moving fittings while becoming horizontal, so that the bed is positioned horizontally on the chassis . The push chain and the pull chain are both disposed within the idle frame,
When the hydraulic cylinder is extended, the idler frame is pushed by the hydraulic cylinder and moves toward the rear of the vehicle, and when the idler frame moves toward the rear of the vehicle, the bed support moving fitting supported by the idler frame moves toward the rear of the vehicle together with the idler frame, and while the idler frame is moving toward the rear of the vehicle, the push chain wound around the bed push pulley on the rear end side of the idler frame operates in a first rotation direction and pulls the bed support moving fitting connected to one end thereof toward the rear of the vehicle, causing the bed support moving fitting to move toward the rear of the vehicle relative to the idler frame,
2. The bed tilting and moving mechanism of claim 1, wherein, when the hydraulic cylinder is contracted, the play frame is pulled by the hydraulic cylinder and moves toward the front of the vehicle, and when the play frame moves toward the front of the vehicle, the bed support moving fitting supported by the play frame moves toward the front of the vehicle together with the play frame, and while the play frame is moving toward the front of the vehicle, the retracting chain wound around the bed retracting pulley on the front end side of the play frame operates in a second rotational direction opposite to the first rotational direction, pulling the bed support moving fitting connected to one end thereof toward the front of the vehicle, and the bed support moving fitting moves toward the front of the vehicle relative to the play frame. A freight vehicle comprising: a chassis connected to a cabin and extending in a longitudinal direction of the vehicle; and a platform tilting mechanism for moving the platform in the longitudinal direction of the vehicle; and the platform can be lowered substantially horizontally to the ground surface to load and unload cargo,
The loading platform tilt movement mechanism includes:
a pair of guide rails rotatably supported by an inclined base shaft provided on the rear side of the chassis;
a play frame that moves in the front-rear direction of the vehicle along an inner side surface of the guide rail;
a platform support movable fitting slidably supported by the play frame and movable in the front-rear direction of the vehicle along the play frame;
A hydraulic cylinder that reciprocates the play frame in the front-rear direction of the vehicle;
a fixed frame fixed to the pair of guide rails;
The loading platform is connected to the loading platform support and moving fitting and is slidable on the guide rail.
The idle frame is provided with a platform push pulley around which a push chain is wound on the rear end side thereof, and a platform retract pulley around which a retract chain is wound on the front end side thereof.
One end of the push chain is connected to the platform support moving fitting and is wound around the platform push pulley provided at the rear end side of the idle frame, and the other end is connected to the fixed frame fixed to the guide rail,
The retracting chain has one end connected to the platform support moving fitting and is wound around the platform retracting pulley provided at the front end side of the idle frame, and the other end connected to the fixed frame fixed to the guide rail,
When the guide rail is parallel to the ground surface, the loading platform support movable fittings are arranged at the front end of the play frame, and in this state, by extending the hydraulic cylinder, the play frame moves towards the rear of the vehicle so that the rear end of the play frame protrudes from the rear end of the guide rail towards the rear of the vehicle, and the loading platform support movable fittings move towards the rear of the vehicle together with the play frame and are moved from the front end to the rear end of the play frame by the push chain, and when the loading platform moves to a certain extent towards the rear of the vehicle together with the loading platform support movable fittings due to these operations, the guide rail tilts towards the rear due to the weight of the loading platform itself, and the loading platform moves towards the rear of the vehicle while tilting together with the loading platform support movable fittings, until the entire loading platform is lowered to the ground surface,
When the guide rail is inclined rearward, the loading platform support movable fittings are positioned at the rear end of the play frame, and in this state, by contracting the hydraulic cylinder, the play frame protruding from the rear end of the guide rail toward the rear of the vehicle moves toward the front of the vehicle, and the loading platform support movable fittings move toward the front of the vehicle together with the play frame and are moved from the rear end to the front end of the play frame by the pulling chain, and when these operations cause the loading platform to move to a certain extent toward the front of the vehicle together with the loading platform support movable fittings, the weight of the loading platform itself causes the inclined guide rail to become horizontal, and the loading platform moves toward the front of the vehicle together with the loading platform support movable fittings while becoming horizontal, so that the loading platform is positioned horizontally on the chassis .

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