JP2008230384A - Loading space tilting device for truck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a loading space tilting device for a truck capable of adjusting the position of a supporting leg according to the state of the ground. <P>SOLUTION: This loading space tilting device is equipped with a tilting cylinder 8 for tilting a guide frame on a chassis frame, and a sliding movement cylinder 13 for sliding the loading space on the guide frame. A hydraulic circuit for driving the cylinders 8, 13 is equipped with a grounding compensation means. The grounding compensation means is equipped with a grounding compensation circuit 24 for communicably connecting a margin Y of the tilting cylinder 8, and a rod side 8b and a tube side 8a of the tilting cylinder 8 with each other via a first check valve 21, and a pilot check valve 23 for opening and closing the communicating state of the grounding compensation circuit 24. These valves 21, 23 are connected only when the loading space is slid and moved to the rear of the own vehicle to allow the guide frame to move further to the tilting side than a predetermined tilting attitude. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cargo bed tilting device for a lorry equipped in a lorry for loading and transporting a cargo such as a vehicle.

For example, a technique described in Patent Document 1 is known as a freight car equipped with this kind of cargo bed tilting device.
In the technique described in Patent Document 1, for example, as illustrated in FIG. 5A, a guide frame 4 is provided on a chassis frame 3. The guide frame 4 has support legs 14 that can be grounded to the ground GL. The guide frame 4 is provided with a tilting cylinder 8 that expands and contracts in the vehicle front-rear direction. The tilting cylinder 8 is connected to the chassis frame 3 via arms 6 that are pivotally supported at both ends. Further, on the guide frame 4, a loading platform 1 for placing cargo such as a vehicle is provided. On the back surface of the loading platform 1, a slide moving cylinder 13 is attached that can slide the loading platform 1 along the guide frame 4 by expanding and contracting in the vehicle longitudinal direction. A rear end 2 that also serves as a slope when the vehicle is mounted is rotatably attached to the rear end of the loading platform 1.

And this kind of platform tilting apparatus is provided with the hydraulic circuit as shown, for example in FIG.
As shown in the figure, this hydraulic circuit includes a hydraulic pump 31 driven by an engine (not shown). The discharge side of the hydraulic pump 31 is connected to the control valve 33 via the main circuit 32 of the hydraulic circuit, and the return circuit 34 of the control valve 33 is connected to the tank 35. The control valve 33 includes a tilting electromagnetic valve 36 and a slide moving electromagnetic valve 37 for driving the tilting cylinder 8 and the slide moving cylinder 13. Each solenoid valve 36, 37 is driven in response to a signal from a controller (not shown) so that each cylinder 8, 13 can be expanded and contracted appropriately. The guide frame 4 is tilted by the expansion and contraction of the tilt cylinder 8, and the slide movement is performed. The loading platform 1 slides relative to the guide frame 4 by the expansion and contraction of the cylinder 13.

Accordingly, when a cargo vehicle equipped with this type of loading platform tilting device unloads cargo such as a vehicle, first, as shown in FIG. 5B, first, the support leg 14 should be grounded to the ground GL. The guide frame 4 is positioned in the inclined posture of the vehicle, and then, as shown in FIG. 5 (c), the loading platform 1 is slid to the rear of the host vehicle, and then the rear end 2 is tilted to form a slope. Can be loaded and unloaded.
JP 2001-163111 A

  Incidentally, in the conventional loading platform tilting device as described above, for example, the predetermined tilting posture shown in FIG. 5B is determined based on the premise that the ground GL is a horizontal surface. That is, the inclination angle at which the support leg 14 just contacts the ground GL assumed to be horizontal is the predetermined inclination posture. The controller stops the expansion (or shortening) operation of the tilt cylinder 8 based on a signal from a limit switch provided at a position corresponding to the predetermined tilt posture, and the slide moving cylinder 13. The hydraulic circuit is controlled to start the expansion (or shortening) operation.

  However, in reality, when the ground GL is a horizontal surface, it is rather rare, and there are usually irregularities. For this reason, usually, an operator performs loading and unloading work of cargo such as vehicles while confirming that the state of the ground contact surface is substantially horizontal. At that time, if the state of the ground contact surface of the ground GL is more convex than the horizontal position, the support leg 14 is grounded before reaching the position corresponding to the predetermined inclination posture, but the limit switch detects it. Continue tilting until the condition is reached. In this case, since the spring of the rear tire portion of the chassis frame 3 is only lifted with the movement of the loading platform 1, there is no significant problem in operation.

  On the other hand, if the state of the ground contact surface of the ground GL is more concave than the horizontal position, the support leg 14 is not grounded before reaching the position corresponding to the predetermined tilt posture, so that the limit switch is in the detection state and the guide The frame 4 is positioned in a predetermined inclined posture. At this time, the small concave portion can be absorbed by the long guide frame 4 and the deflection in the elastic region of the loading platform 1. However, when the state of the ground contact surface is larger than that and the operator does not have sufficient visual confirmation, the support leg 14 is left ungrounded and the platform 1 moves to slide. . Therefore, the guide frame 4 or the loading platform 1 is in a cantilever state, and receives a larger bending moment due to the sliding movement of the loading platform 1. If the elastic limit is exceeded, distortion will remain in the housing and the like.

  Accordingly, the present invention has been made paying attention to such problems, and an object thereof is to provide a cargo bed tilting device for a lorry capable of adjusting the position of a support leg in accordance with the state of the ground. .

  In order to solve the above-described problems, the present invention is a guide frame that is provided in a truck for loading and transporting cargo such as a vehicle, has support legs that can be grounded on the ground, and can be tilted on a chassis frame. A loading platform provided on the guide frame and slidable rearward of the host vehicle, a tilt cylinder that is a hydraulic cylinder for tilting the guide frame, and a slide that is a hydraulic cylinder for sliding the loading platform A loading cylinder tilting device that, when loading and unloading cargo such as the vehicle, after the guide frame is positioned in a predetermined tilting posture, slides the loading platform to the rear of the vehicle, The hydraulic circuit for driving the tilting cylinder and the slide moving cylinder slides the loading platform to the rear of the host vehicle. Only in is characterized in that it comprises a ground compensation means for permitting only further movement to the side is inclined than the guide frame the predetermined inclined position.

  According to the cargo bed tilting device of the lorry according to the present invention, the hydraulic circuit moves only to the side where the guide frame is tilted further than the predetermined tilting posture only when the cargo bed is slid backward to the host vehicle. Therefore, even if the ground surface of the ground GL is more concave than the horizontal position, the position of the support leg can be adjusted according to the ground state.

  The reason why further tilting operation for grounding compensation by the grounding compensation means is allowed only when the loading platform is slid rearward of the host vehicle (loading platform unloading side) is to allow the tilting motion only during the operation of the operator. This is to prevent the tilting operation from being performed unexpectedly. Further, by allowing further tilting operation for grounding compensation only during backward sliding movement, for example, if an operator feels danger in tilting the guide frame, the operation button (lever) etc. for the operation should be released. This is because the operation stops and safety is ensured.

  Furthermore, if further tilting operation for grounding compensation is allowed even during sliding movement of the loading platform forward (to the loading platform storage side), the guide frame will rotate with the loading platform rear end grounded. This is because a load is applied to the sliding portion between the loading platform and the guide frame, which is not preferable. In particular, the loading platform loaded with the vehicle is heavy and may be overloaded.

  In addition, in the above-described conventional loading platform tilting device, the predetermined tilting posture must be set as the tilting angle at which the support leg 14 just contacts the ground, but in the loading platform tilting device according to the present invention, Since the position of the support leg can be adjusted according to the state on the ground, the range of setting of the predetermined tilt posture can be widened. Therefore, for example, it is possible to roughly set the mounting accuracy (response accuracy) of the limit switch provided at a position corresponding to the predetermined tilt posture, and there is an effect that the mounting operation can be facilitated.

  Further, in the cargo bed tilting device of the lorry according to the present invention, the open / close valve is configured to be connected to the side on which the pressure stands when the slide bed is slid rearward of the vehicle among the rod side and the tube side of the slide moving cylinder and the ground. It is a pilot check valve that connects the compensation circuit to each other, and it is preferable that the pressure oil on the side where the pressure rises operates as a pilot pressure. Such a configuration is suitable as a configuration for operating the open / close valve in conjunction with the operation of the slide moving cylinder.

  Further, in the cargo carrier tilting device according to the present invention, the ground check means for providing the first check valve and the opening / closing valve further includes a second check valve, and the second check valve is configured as described above. The position of the ground compensation circuit between the first check valve and the open / close valve and the return-side oil passage of the hydraulic circuit are only moved from the return-side oil passage to the ground compensation circuit. It is preferable to be connected so as to allow With such a configuration, the second check valve can preferably prevent the ground compensation circuit from being in a negative pressure state. Therefore, it is suitable for making the operation of the ground compensation means more stable.

  As described above, according to the present invention, it is possible to provide a cargo bed tilting device for a lorry capable of adjusting the position of a support leg in accordance with the state of the ground.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate. In addition, about the structure similar to the conventional cargo vehicle mentioned above, the same code | symbol is attached | subjected and demonstrated.
FIG. 1 is a side view of a vehicle carrying vehicle which is an embodiment of a truck equipped with a platform tilting apparatus according to the present invention. 2 is a cross-sectional view in the vehicle width direction of the main part of the platform tilting device shown in FIG.

  As shown in FIG. 1, a guide frame 4 is provided on the chassis frame 3 of the truck. The guide frame 4 is attached to the chassis frame 3 so as to be tiltable via a support shaft 5 at the rear of the vehicle. The guide frame 4 is provided with a tilting cylinder 8 extending and contracting in the vehicle front-rear direction in front of the support shaft 5 of the chassis frame 3, and the tip of the rod 8r is rotatable. The other end of the arm 6 is connected to the chassis frame 3 via a rotary shaft 7 that is rotatable.

  Further, as shown in the right half part of FIG. 2, the guide frame 4 is provided with guide rails 10 made of a long groove steel in the longitudinal direction of the vehicle on both sides of the upper surface of the guide frame 4 in the vehicle width direction. A roller 9 is attached to one end of the arm 6 so as to be rotatable outward in the vehicle width direction. The roller 9 is supported by the guide rail 10. The left and right guide frames 4 are connected at several places by connecting members 15. Thus, the guide frame 4 can tilt the guide frame 4 to the rear side of the host vehicle by rotating the guide frame 4 around the support shaft 5 by extending the tilt cylinder 8.

  Here, as shown in FIG. 1, the rear end portion of the guide frame 4 has a support leg 14 that can be grounded to the ground GL, and the loading platform 1 and the guide frame 4 are tilted by the support leg 14. Sometimes it is possible to support them. The loading platform tilting device 20 is provided with a limit switch (not shown) as detection means for detecting a position corresponding to the predetermined tilting posture in order to position the support leg 14 in a predetermined tilting posture to be grounded. . The limit switch setting position is determined based on the premise that the ground GL is a horizontal surface. In other words, the inclination angle at which the support leg 14 just touches the ground GL assumed to be horizontal is a predetermined inclination posture.

  Further, as shown in FIG. 1, a loading platform 1 for placing cargo such as a vehicle is provided on the guide frame 4. On the rear surface of the loading platform 1, a slide moving cylinder 13 is attached that can slide the loading platform 1 along the guide frame 4 by expanding and contracting in the vehicle longitudinal direction. A rear end 2 that also serves as a slope when the vehicle is mounted is rotatably attached to the rear end of the loading platform 1.

  As shown in the left half of FIG. 2, guide rails 11 made of H-shaped steel that is long in the vehicle front-rear direction are attached to the cargo bed 1 on both sides of the lower surface in the vehicle width direction. On the other hand, the guide frame 4 is provided with rotatable rollers 12 on both outer sides in the vehicle width direction. The rollers 12 support the lower surface of the upper flange of the guide rail 11. The loading platform 1 is configured such that the roller 12 rolls rearward in the vehicle front-rear direction along the guide rail 11 by extending the slide moving cylinder 13 so that the guide is disposed above the chassis frame 3. The frame 4 is slidable rearward of the vehicle.

Here, the loading platform tilting device 20 is configured to include the hydraulic circuit shown in FIG.
Hereinafter, this hydraulic circuit will be described in detail with reference to FIG. In addition, FIG. 3 is a figure explaining the hydraulic circuit of the loading platform tilting apparatus which concerns on this invention.
As shown in FIG. 3, the platform tilting device 20 includes a hydraulic pump 31 driven by an engine (not shown). The discharge side of the hydraulic pump 31 is connected to a control valve 33 via a main circuit 32 of a hydraulic circuit, and a return circuit 34 of the control valve 33 is connected to a tank 35. The control valve 33 includes a tilting electromagnetic valve 36 and a slide moving electromagnetic valve 37 for driving the tilting cylinder 8 and the slide moving cylinder 13, and a signal from a controller (not shown). Accordingly, the cylinders 8 and 13 can be appropriately expanded and contracted. The controller stops the extending operation of the tilting cylinder 8 and the extending operation of the slide moving cylinder 13 based on a signal from a limit switch provided at a position corresponding to the predetermined tilting posture. The hydraulic circuit is controlled to start.

Here, this hydraulic circuit is provided with a ground compensation means that allows only the movement of the guide frame 4 to the side further tilting from the predetermined tilting posture only when the loading platform 1 is slid rearward of the host vehicle. .
Specifically, as shown in FIG. 3, the tilting cylinder 8 has a margin Y that allows the guide frame 4 to move to a side that further tilts the guide frame 4 from the predetermined tilting posture in its cylinder stroke. . The ground compensation means includes a ground compensation circuit 24 that connects the margin Y of the tilt cylinder 8 and the rod side 8b and the tube side 8a of the tilt cylinder 8 so that they can communicate with each other via the first check valve 21; A pilot check valve 23 that is an open / close valve that opens and closes the communication state of the ground compensation circuit 24 is provided. The first check valve 21 is connected so as to allow only the movement of the pressure oil from the rod side 8b to the tube side 8a by the margin Y of the tilt cylinder 8.

  On the other hand, the pilot check valve 23 is provided so as to operate so that the ground compensation circuit 24 communicates only when the slide moving cylinder 13 slides the loading platform 1 to the rear of the host vehicle. That is, the pilot check valve 23 is a tube side 13a that is a side where pressure is applied when the loading platform 1 in the present embodiment is slid rearward of the host vehicle among the rod side 13b and the tube side 13a of the slide moving cylinder 13. And the ground compensation circuit 24 are connected to each other so that the pressure oil on the tube side 13a is operated as a pilot pressure.

  Further, the ground compensation means further includes a second check valve 22. The second check valve 22 includes a position of the ground compensation circuit 24 between the first check valve 21 and the pilot check valve 23 and a return circuit 34 which is an oil path on the return side of the hydraulic circuit. It is connected so that only the movement of the pressure oil from 34 to the ground compensation circuit 24 is allowed.

Next, the operation and effect of the platform tilting device 20 will be described.
In the state in which the rod 8r of the tilt cylinder 8 is contracted, the platform tilting device 20 is such that the arm 6 is tilted backward (sleeping) with respect to the rotating shaft 7 as shown in FIG. The height position of the vehicle body side connection point at the lower end portion and the loading platform side connection point at the upper end portion is low, and the loading platform 1 and the guide frame 4 are in a horizontal or substantially horizontal state.

  When loading and unloading a cargo such as a vehicle, the loading platform tilting device 20 extends the roller 9 as shown in FIG. 4A when the rod 8r of the tilting cylinder 8 is extended from the state shown in FIG. Moves along the guide rail 10 in parallel with the loading platform 1 and in front of the vehicle, and accordingly, the arm 6 moves in the direction of rising upward in the front of the vehicle around the rotation shaft 7. The height position between the side connection point and the loading platform side coupling point at the upper end is increased, and the loading platform 1 and the guide frame 4 are tilted by pushing the vehicle front side upward.

When the guide frame 4 is rotated to a predetermined tilting posture, the limit switch is detected at that position, the extension of the rod 8r of the tilting cylinder 8 is stopped, and then the extension of the rod of the slide moving cylinder 13 is started. .
At this time, according to the loading platform tilting device 20, the state of the ground contact surface of the ground GL is the case where the ground position GL1 has a horizontal position GL1 and a portion GL2 that is more concave than the horizontal position GL1, as shown in FIG. However, the hydraulic circuit includes a grounding compensation unit that allows only the movement of the guide frame 4 to the side further tilting from the predetermined tilting posture only when the loading platform 1 is slid rearward of the host vehicle. Therefore, even if the state of the ground contact surface of the ground GL serving as the ground contact point of the support leg 14 is more concave than the horizontal position, the position of the support leg 14 can be adjusted according to the ground state.

  That is, as shown in FIG. 4B, when the extension of the rod of the slide moving cylinder 13 is started, the pressure on the tube side 13a of the slide moving cylinder 13 shown in FIG. Therefore, the pilot check valve 23 that operates using the pressure oil on the tube side 13a as the pilot pressure operates so as to allow the ground compensation circuit 24 to communicate. The tilt cylinder 8 has a margin Y, and the grounding compensation circuit 24 is configured so that the first check valve 21 has a pressure from the rod side 8b to the tube side 8a by the margin Y of the tilt cylinder 8. Since it is connected so as to allow only the oil movement, only the movement of the pressure oil from the rod side 8b of the tilting cylinder 8 to the tube side 8a is allowed by the moment load due to the backward sliding movement.

  As a result, even if a moment load is applied due to the sliding movement of the loading platform 1 to the rear of the host vehicle, the guide frame 4 can be rotated in a range corresponding to the margin Y to a side further inclined than the predetermined tilting posture. it can. Therefore, if the height of the recessed portion GL2 is within a range corresponding to the margin Y, the support leg 14 is brought into contact with the surface of the recessed portion GL2 to reliably support the loading platform 1 and the guide frame 4. Can do. Even if the height of the concave portion GL2 exceeds the margin Y, the bending moment acting on the housing can be reduced, so that it is possible to prevent or suppress distortion that may occur on the housing. is there.

  Further, according to the platform tilting device 20, the grounding compensation means further includes the second check valve 22, and the second check valve 22 includes the first check valve 21 and the pilot of the grounding compensation circuit 24. Since the position between the check valves 23 and the return circuit 34 are connected so as to allow only the movement of the pressure oil from the return circuit 34 to the ground compensation circuit 24, the second check valve 22 is connected to the ground. It is possible to suitably prevent the inside of the compensation circuit 24 from entering a negative pressure state. For this reason, the operation of the ground compensation means can be made more stable.

  As shown in FIG. 4 (b), according to the platform tilting device 20, the platform slide cylinder 13 is further moved from the state in which the support leg 14 is in contact with the surface of the concave portion GL2. When extended, the loading platform 1 slides toward the vehicle rear side with respect to the guide frame 4 as shown in FIG. 4C, and the rear end portion thereof can be grounded to the ground. Then, it is possible to load and unload cargo such as vehicles by turning the rear end 2 backward and using it as an uphill road for automobiles. In order to store the loading platform 1 and return it to the horizontal position, the procedure may be reversed.

As described above, according to the platform tilting device 20, the position of the support leg 14 can be adjusted according to the state of the ground.
In addition, the platform tilting device for a truck according to the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the ground compensation circuit 24 has been described as an example using the pilot check valve 23 as an open / close valve for opening the slide moving cylinder 13 only while the load carrier 1 slides backward. For example, an electromagnetic valve may be used as the open / close valve. However, in order to obtain an on-off valve that can operate with a simple configuration in conjunction with the slide moving cylinder 13, it is preferable to use a pilot check valve as the on-off valve as in the above embodiment.

  Further, for example, in the above embodiment, the ground compensation unit has been described as an example having the second check valve 22, but the present invention is not limited to this, and the second check valve 22 is not provided. You may comprise a ground compensation means. However, in order to suitably prevent the inside of the ground compensation circuit 24 from being in a negative pressure state and to make the operation of the ground compensation means more stable, as in the above embodiment, the ground compensation means It is preferable to have a check valve 22.

It is a side view of the vehicle for vehicle transportation which is one Embodiment of the lorry equipped with the platform tilting device concerning the present invention. It is sectional drawing in the vehicle width direction of the platform tilting apparatus principal part shown in FIG. It is a figure explaining the hydraulic circuit of the loading platform tilting apparatus which concerns on this invention. It is a figure explaining the effect | action of the loading platform tilting apparatus which concerns on this invention. It is a figure ((a)-(c)) explaining an example of the conventional loading platform tilting apparatus. It is a figure explaining an example of the hydraulic circuit of the conventional loading platform tilting apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Loading platform 2 Back turning 3 Chassis frame 4 Guide frame 5 Support shaft 6 Arm 7 Rotating shaft 8 Tilt cylinder 9 Roller 10 Guide rail 11 Guide rail 12 Roller 13 Slide moving cylinder 14 Support leg 15 Connecting member 20 Loading platform tilting device 21 First 1 Check valve 22 Second check valve 23 Pilot check valve 24 Ground compensation circuit 31 Hydraulic pump 32 Main circuit 33 Control valve 34 Return circuit 35 Tank 36 Solenoid valve for tilting 37 Solenoid valve for sliding movement Y Margin

Claims (4)

A guide frame that is mounted on a cargo vehicle for loading and transporting cargo such as a vehicle, has support legs that can be grounded on the ground, and can be tilted on a chassis frame, and the host vehicle provided on the guide frame A cargo bed that is slidable rearward, a tilt cylinder that is a hydraulic cylinder for tilting the guide frame, and a slide moving cylinder that is a hydraulic cylinder for sliding the cargo bed, When loading and unloading, after placing the guide frame in a predetermined inclination posture, the loading platform tilting device that slides the loading platform rearward of the host vehicle,
The hydraulic circuit for driving the tilt cylinder and the slide moving cylinder only moves the guide frame to the side where the guide frame is tilted further than the predetermined tilting posture only when the loading platform is slid backward to the host vehicle. A cargo bed tilting device for a lorry characterized by comprising grounding compensation means for allowing. The tilting cylinder has a margin to allow movement of the guide frame to the side further tilting the tilting frame than the predetermined tilting posture in its cylinder stroke;
The ground compensation means includes a ground compensation circuit that connects the allowance of the tilt cylinder and the rod side and the tube side of the tilt cylinder through a first check valve, and a communication state of the ground compensation circuit And an open / close valve that opens and closes
The first check valve is connected so as to allow only the movement of the pressure oil from the rod side to the tube side of the tilting cylinder by a margin, and the open / close valve is connected to the vehicle by the slide moving cylinder. 2. The cargo bed tilting device for a lorry according to claim 1, wherein the grounding compensation circuit is operated so as to communicate only when slid backward.   The open / close valve is a pilot check valve for mutually connecting the pressure rising side and the grounding compensation circuit when sliding the cargo bed to the rear of the host vehicle among the rod side and the tube side of the slide moving cylinder, 3. The cargo bed tilting device for a lorry according to claim 2, wherein the pressure oil on the side where the pressure stands is operated as a pilot pressure.   The ground compensation means further includes a second check valve, and the second check valve is a position of the ground compensation circuit between the first check valve and the open / close valve and a return of the hydraulic circuit. 4. The lorry according to claim 2, wherein the side oil passage is connected so as to allow only the movement of pressure oil from the return-side oil passage to the ground compensation circuit. 5. Loading platform tilting device.

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