JP7157672B2 - Loading table lifting device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load-receiving stand lifting device used for lifting and lowering a load-receiving stand mounted on a freight vehicle or the like.

For example, in Patent Document 1, a tilt cylinder is arranged inside each of a pair of stiffeners provided on the back surface of a load receiving table, and a hydraulic pipe for taking hydraulic oil into and out of each tilt cylinder is connected to one of the tilt cylinders. Arrangements are described that extend from one stiffener to the other stiffener.

One end of the tilt cylinder is positioned near the base of the load-receiving table (a portion near the center of rotation of the load-receiving table) so that the load-receiving table can be rotated with respect to the lifting mechanism ("slider" described in Patent Document 1). It is connected to the provided lifting mechanism. For this reason, the tilt cylinder is arranged at the base of the load receiving platform. On the other hand, hydraulic piping extends from the hydraulic drive mechanism on the vehicle body side to the loading platform. In the configuration described in Patent Literature 1, both the tilt cylinder and the hydraulic piping are arranged at the base of the loading platform.

Japanese Patent No. 3871541

Hydraulic piping is bent out of one stiffener and out to the other stiffener at the base of the loading platform. Therefore, it was necessary to bend the hydraulic pipe in the space where the tilt cylinder is arranged in one of the stiffeners. For this reason, there is a possibility that the bent portion of the hydraulic pipe may interfere with the telescopic tilt cylinder.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a loading platform lifting device in which a bent portion of hydraulic piping does not interfere with a tilt cylinder.

The present invention has a load receiving platform on which cargo can be loaded on the front surface, a pair of stiffeners arranged in parallel in the vehicle width direction on the back surface, and a load receiving platform that rotates with respect to the vehicle body, and a load receiving platform that is rotatably connected to the load receiving platform. a lifting mechanism for lifting and lowering the load receiving table; a lifting mechanism arranged inside each of the pair of stiffeners; connected to each stiffener and the lifting mechanism; a tilt cylinder, a hydraulic drive mechanism that delivers hydraulic oil to the tilt cylinder, and a hydraulic pipe that connects the hydraulic drive mechanism and each tilt cylinder and is arranged inside each of the pair of stiffeners, One of the pair of stiffeners has a one-side communication hole opened to the surface side of the load receiving base at a position farther from the center of rotation of the load receiving base than the tilt cylinder, and the hydraulic pipe is connected to the A load receiving table lifting and lowering device, which is introduced from a hydraulic drive mechanism into one of the stiffeners and connected to the tilt cylinder arranged inside the other stiffener of the pair of stiffeners via the one side communicating hole. It is a device.

According to the above configuration, in one stiffener, in a space where no tilt cylinder is arranged, the hydraulic pipe can be led out from the stiffener and directed to the other stiffener. Therefore, it is possible to prevent interference between the tilt cylinder and the hydraulic pipe within one of the stiffeners.

Further, the other stiffener may have a second side communication hole opened to the surface side of the load-receiving table at a position farther from the center of rotation of the load-receiving table than the tilt cylinder.

According to this configuration, the hydraulic pipe can be inserted into the other stiffener in a space where the tilt cylinder is not arranged and directed to the tilt cylinder. Therefore, interference between the tilt cylinder and the hydraulic pipe can be prevented even in the other stiffener.

According to the present invention, it is possible to prevent interference between the tilt cylinder and the hydraulic pipe within at least one of the stiffeners. For this reason, it is possible to provide a loading platform lifting device in which the bent portion of the hydraulic piping does not interfere with the tilt cylinder.

1 is a side view showing a freight vehicle provided with a load receiving platform lifting device according to an embodiment of the present invention; FIG. It is the bottom view shown so that the internal structure of a stiffener could be understood about the load-receiving stand in the said load-receiving stand raising/lowering apparatus. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2, showing the load receiving tray;

Next, an embodiment of the present invention will be described. Regarding the expression of directions below, "up and down" corresponds to the up and down direction shown in FIG. Also, "front and rear" correspond to the front and rear of the vehicle, with the driver's cab being the front and vice versa. Further, "left and right" correspond to the width direction of the vehicle and the left and right direction when viewed from the rear of the vehicle.

As shown in FIG. 1, the loading platform lifting device 1 of the present embodiment is provided at the rear portion of a freight vehicle B having a loading platform such as a loading box B1. This loading platform lifting device 1 mainly includes a loading platform 2 , a lifting mechanism 3 , a tilt cylinder 4 , a hydraulic drive mechanism 5 , and a hydraulic pipe (hydraulic hose) 6 .

The load-receiving platform 2 can be placed in a stowed state (a state in which the surface stands perpendicular to the ground G as indicated by a two-dot chain line in the vertical direction in FIG. 1) and an unfolded state (a 1 is rotatably provided so as to lie down so that the surface is parallel to the ground G as indicated by the solid line in the horizontal direction of FIG. In the stowed state, the front surface of the receiving tray 2 faces the rear surface of the packing box B1 as shown.

A load can be loaded on the surface of the receiving table 2 (upper surface indicated by the solid line in FIG. 1). A stiffener 22 is formed on the rear surface for reinforcement. The stiffener 22 is formed integrally with the plate-shaped load receiving tray main body 21 . As shown in FIG. 2, a pair of stiffeners 22 (a left stiffener 22L and a right stiffener 22R) are provided in parallel in the vehicle width direction (horizontal direction in the drawing). In order to explain the internal structure of each of the stiffeners 22L and 22R, FIG. 2 shows a state in which the plate on the back side is removed (actually, the internal structure does not appear externally).

The lifting mechanism 3 is a mechanism that is rotatably connected to the load receiving table 2 and moves the load receiving table 2 up and down. The lifting mechanism 3 of the present embodiment has an elongated rectangular frame shape when viewed from the side by connecting the front ends and the rear ends of vertically arranged rod-shaped link members 31 and 32 to each other by connecting members 33 and 34. A parallel link mechanism is formed by combining a lift cylinder 36 that expands and contracts depending on the inflow and outflow of hydraulic oil with respect to the formed frame portion 35 .

The frame portion 35 of the parallel link mechanism in the lifting mechanism 3 has a front end rotatably connected to the chassis and a rear end rotatably connected to the base end portion of the load receiving table 2 . The lift cylinder 36 has a front end rotatably connected to the chassis and a rear end rotatably connected to the frame portion 35 . Although not shown, the frame portion 35 and the lift cylinder 36 are provided as a pair in parallel in the vehicle width direction (the depth direction in FIG. 1 and the left-right direction in FIG. 2).

In the lifting mechanism 3 (parallel link mechanism) configured in this manner, the rear end of the frame portion 35 rises when the lift cylinder 36 is extended, and is lowered when the lift cylinder 36 is contracted. Accordingly, as shown in FIG. 1, the load receiving table 2 connected to the frame portion 35 can be raised and lowered. It should be noted that the surface of the load receiving table 2 in the unfolded state is continuously kept horizontal as shown in the drawing during the lifting and lowering. Incidentally, if the rear end of the load receiving platform 2 is raised from the ground G as indicated by the two-dot chain line in FIG. By operating the tilt cylinder 4 provided, the load receiving table 2 can be rotated with respect to the lifting mechanism 3 (parallel link mechanism), and the rear end of the load receiving table 2 can be grounded (not shown).

As shown in FIGS. 2 and 3, the tilt cylinder 4 is arranged inside each of a pair of left and right stiffeners 22L and 22R (a left tilt cylinder 4L and a right tilt cylinder 4R). Each tilt cylinder 4L, 4R is connected to each stiffener 22L, 22R and the lifting mechanism 3, and expands and contracts by taking in and out hydraulic oil. The load-receiving table 2 can be rotated according to this expansion/contraction operation. The tilt cylinder 4 is arranged inside each of the stiffeners 22L, 22R on the side closer to the center of rotation of the load receiving table 2. As shown in FIG.

The hydraulic drive mechanism 5 is a mechanism that delivers hydraulic oil to the lift cylinder 36, the tilt cylinder 4, and the like, and includes, for example, an oil tank, a hydraulic pump, a solenoid valve 51, a flow control valve, a check valve, and the like through oil passages. combined (not shown except solenoid valve 51). At least part of this hydraulic drive mechanism 5 is built in a cross member provided at the rear of the freight vehicle B (but not limited to this). The solenoid valve 51 is provided inside the left stiffener 22L as shown in FIG.

A hydraulic hose 6 as a hydraulic pipe in the present embodiment is a flexible pipe that connects the hydraulic drive mechanism 5 and the tilt cylinders 4L and 4R. The hydraulic hose 6 is arranged inside each of the pair of stiffeners 22L, 22R, and is passed through the inside of the load receiving table main body 21 between the pair of stiffeners 22L, 22R. Since the load receiving table main body 21 is generally formed by extruding an aluminum alloy or the like, it has a hollow structure as shown in FIG. Therefore, the hydraulic hose 6 can be passed through the inside of the load receiving base body 21 .

In this embodiment, the left stiffener 22L, which is one of the pair of stiffeners 22L and 22R, is positioned on the tip side of the left tilt cylinder 4L in order to dispose the hydraulic hose 6 on the load receiving table 2. A left communication hole 221L, which is a one-side communication hole opened on the surface side, is provided at a position far from the center of rotation. 221 L of left communication holes connect the internal space of the left stiffener 22L, and the internal space of the load-receiving stand main body 21. As shown in FIG.

As shown in FIG. 2, the left communication hole 221L has an oval shape elongated in the vehicle width direction (horizontal direction). Since the peripheral edge of the left communication hole 221L does not have a corner, even if the hydraulic hose 6 touches the peripheral edge, the hydraulic hose 6 is less likely to be damaged. In addition, the length and width of the left communication hole 221L are set sufficiently large with respect to the outer diameter of the hydraulic hose 6, and the bending curvature of the hydraulic hose 6 is taken into consideration. The dimensions are set so as not to cause excessive bending that could cause damage in an early stage.

In addition, since the left communication hole 221L has an oval shape that is elongated in the vehicle width direction (lateral direction), the left communication hole 221L extends in the bending direction of the hydraulic hose 6 that extends upward and is bent rightward in FIG. can be made substantially coincident with each other. For this reason, the degree of freedom in handling (in particular, bending) of the hydraulic hose 6 on the load receiving table 2 can be increased.

As shown in FIG. 2, the hydraulic hose 6 is introduced from the hydraulic drive mechanism 5 into the left stiffener 22L from the base end side, and passes through the left communication hole 221L to the right stiffener, which is the other stiffener of the pair of stiffeners 22L and 22R. It is connected to the right tilt cylinder 4R arranged inside the stiffener 22R. Inside the left stiffener 22L, the hydraulic hose 6 is branched via a joint, one of which is connected to the left tilt cylinder 4L, and the other of which exits the left stiffener 22L and is connected to the right tilt cylinder 4R toward the right stiffener 22R. It is

According to the configuration described above, since the left tilt cylinder 4L is not arranged in the left stiffener 22L, the hydraulic hose 6 can be extended from the left stiffener 22L and directed toward the right stiffener 22R in a relatively large space. Therefore, it is possible to prevent interference between the left tilt cylinder 4L and the hydraulic hose 6 which extend and contract within the left stiffener 22L. Therefore, it is possible to prevent the hydraulic hose 6 from being damaged inside the left stiffener 22L.

Here, since the hydraulic hose 6 is flexible, it tries to straighten by receiving the pressure of the hydraulic fluid passing through the inside, and the curvature becomes small. As a result, the hydraulic hoses 6 inside the stiffeners 22L and 22R and the hydraulic hoses 6 passed through the inside of the load receiving base body 21 are both deformed to straighten. In the conventional structure in which the hydraulic hose is bent in the space where the tilt cylinder is arranged in the stiffener, the hydraulic hose may move toward the tilt cylinder as the hydraulic hose deforms in an attempt to straighten. As a result, the deformed hydraulic hose sometimes interferes with the tilt cylinder. On the other hand, in the present embodiment, since the left tilt cylinder 4L is not arranged, the hydraulic hose 6 is bent in a space with a relatively large margin. I have nothing to do.

In the present embodiment, the right stiffener 22R also has a right communication hole 221R, which is the other side communication hole opened on the surface side, at a position closer to the tip than the right tilt cylinder 4R. 221 R of right communication holes connect the internal space of the right stiffener 22R, and the internal space of the load-receiving stand main body 21. As shown in FIG. The right communication hole 221R of this embodiment has the same shape as the left communication hole 221L. However, it is not limited to this, and the right communication hole 221R is made different from the left communication hole 221L according to, for example, the layout plan of the hydraulic hose 6 on the load receiving platform 2 (the layout plan according to the setting of the curvature of bending, etc.). can also Further, the right communication hole 221R of the present embodiment is provided at a symmetrical position with respect to the left communication hole 221L in the vehicle width direction, that is, at a left-right symmetrical position. However, it is not limited to this, and the right communication hole 221R can be provided at a position asymmetrical to the left communication hole 221L.

According to this configuration, since the right tilt cylinder 4R is not arranged in the right stiffener 22R, the hydraulic hose 6 can be inserted into the right stiffener 22R and directed toward the right tilt cylinder 4R in a relatively large space. Therefore, interference between the right tilt cylinder 4R and the hydraulic hose 6 can be prevented within the right stiffener 22R. Therefore, breakage of the hydraulic hose 6 within the right stiffener 22R can be suppressed.

As mentioned above, although one embodiment was taken up and described about this invention, this invention is not limited to the said embodiment.

For example, in the above embodiment, the left and right communication holes 221L and 221R are oblong in shape, but they may be in a perfect circle. In some cases, it may be a shape having corners on its periphery, such as a polygon. Further, the dimensions of the left and right communication holes can be set to various dimensions as long as the hydraulic hose 6 can be passed between the stiffeners 22L, 22R and the load receiving base body 21. FIG.

As described above, the right communication hole 221R (the other side communication hole) can be provided at a position asymmetrical to the left communication hole 221L (the one side communication hole). In this regard, the right communication hole 221R can also be provided at a position adjacent to the right tilt cylinder 4R. Even so, a certain effect can be achieved by preventing the bent portion of the hydraulic hose 6 from interfering with the left tilt cylinder 4L inside the left stiffener 22L.

Further, regarding the shape of the stiffener 22, in the above-described embodiment, the height dimension (thickness dimension) gradually decreases toward the tip of the load receiving table 2 as shown in FIG. 3, but the shape is not specified. The height may be uniform, or the height dimension may be increased toward the tip of the load receiving tray 2 . With such a shape, even if the space inside the stiffener 22 is widened, there is a possibility that the tilt cylinder 4 will rub against the hydraulic hose 6 as it moves into the widened space, so the configuration of the present invention is effective. acts on

Also, the hydraulic hose 6 does not have to be branched as in the above embodiment. For example, two hydraulic hoses 6, 6 are separately inserted into the left stiffener 22L, one of which is inserted into the left tilt cylinder 4L within the left stiffener 22L and the other into the right tilt cylinder 4R within the right stiffener 22R. may be connected.

Moreover, although the hydraulic piping was the flexible hydraulic hose 6 in the above embodiment, it may be a non-flexible pipe. Even if the hydraulic piping is a pipe, changing the direction of the pipe in the narrow space where the left tilt cylinder 4L is arranged requires high machining precision and reduces the degree of freedom in machining. Since the left tilt cylinder 4L is not arranged as in the embodiment, the degree of freedom in processing can be increased by changing the direction of the pipe in a relatively large space, and interference of the pipe with the left tilt cylinder 4L can be prevented. can. Therefore, the same effects as those of the above-described embodiment can be obtained.

In the above-described embodiment, all the hydraulic pipes in the stiffeners 22L and 22R are flexible hydraulic hoses 6, but only a portion of them are hydraulic hoses 6 and the other portions are inflexible pipes. may be In this case, for example, the hydraulic hose 6 can be used only for the portion of the hydraulic pipe that bends from the left stiffener 22L, which is one stiffener, toward the right stiffener 22R, which is the other stiffener.

Further, the elevating mechanism 3 may be configured to elevate using a parallel link mechanism as in the above embodiment, or may be configured to elevate in the vertical direction by a slider as described in Patent Document 1. good.

DESCRIPTION OF SYMBOLS 1... Load-receiving stand lifting device, 2... Load-receiving stand, 3... Lifting mechanism, 4... Tilt cylinder, 4L... Left tilt cylinder, 4R... Right tilt cylinder, 5... Hydraulic drive mechanism, 6... Hydraulic hose, 21... Load-receiving stand body , 22... Stiffener, 22L... One stiffener (left stiffener), 22R... The other stiffener (right stiffener), 31, 32... Link member, 33, 34... Connecting member, 35... Frame, 36... Lift cylinder, 221L ... one side communication hole (left communication hole), 221R ... other side communication hole (right communication hole), B ... freight vehicle, B1 ... packing box, G ... ground

Claims (2)

a cargo receiving platform which can be loaded with cargo on its front surface, has a pair of stiffeners arranged in parallel in the vehicle width direction on its back surface, and rotates with respect to the vehicle body;
an elevating mechanism rotatably connected to the load receiving platform for lifting and lowering the load receiving platform;
a tilt cylinder arranged inside each of the pair of stiffeners, connected to the respective stiffeners and the elevating mechanism, and configured to expand and contract by taking in and out hydraulic oil to rotate the load receiving platform;
a hydraulic drive mechanism for delivering hydraulic oil to the tilt cylinder;
a hydraulic pipe connecting the hydraulic drive mechanism and each tilt cylinder and arranged inside each of the pair of stiffeners;
one of the pair of stiffeners has a one-side communication hole opening to the surface side of the load-receiving table at a position farther from the center of rotation of the load-receiving table than the tilt cylinder,
The hydraulic pipe is introduced from the hydraulic drive mechanism to the one stiffener and connected via the one side communication hole to the tilt cylinder arranged inside the other stiffener of the pair of stiffeners. A loading platform lifting device characterized by: 2. The stiffener according to claim 1, wherein said other stiffener has a second side communication hole opened to the surface side of said load-receiving table at a position farther from the center of rotation of said load-receiving table than said tilt cylinder. Loading table lifting device.

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