JPS6027050Y2 - Dump truck loading platform rear door opening/closing device - Google Patents

Description

[Detailed description of the invention] This invention relates to a rear door opening/closing device for a dump truck, and in particular, most of the wires for opening and closing the door are placed in the loading platform chassis to adjust the slack of the wire, prevent it from being cut, and prevent the wire from sagging during cutting. This invention provides a rear door opening/closing device for the purpose of prevention.

Normally, the rear doors of a dump truck are rotatably mounted on both the left and right edges of the loading platform, and when the loading platform is tilted to unload the load, the lower part opens due to the lowering blade of the load and its own weight.

If the cargo is gravel or sand, there is no problem with this unloading operation, but if the cargo is large stones, large tree roots, snow blocks, large concrete blocks, etc.
If the material is higher than the height of the loading platform, that is, the height of the rear door, such as waste materials, it will get stuck on the top of the rear door, making it difficult to dump.

In such a case, if you forcefully try to tamp the cargo, it will not only cause damage to the rear door, but also cause the entire vehicle body to stand on end due to the load, creating a risk of overturning.

Particularly when the dump site is on a high road side, it is not uncommon for the vehicle to fall onto the road, and this type of accident is a constant occurrence.

Therefore, when dumping a load that is higher than the height of the rear door, the rear door is removed in advance to prevent the above-mentioned danger and damage. This has led to a decline in

In order to eliminate the above-mentioned drawbacks and provide a rear door for a dump truck with good working efficiency, the present applicant first attempted to solve the above-mentioned drawbacks by providing a rear door for a dump truck with good working efficiency.
11657, devised and provided a device as shown in FIG. 7, Utility Model Application No. 56-78362.

FIG. 6 shows a support arm 41 with a rear door 40 pivotally attached to the upper edge of the dump bed by a pin 42, and an interlocking arm 43 pivotally attached to the other end of this support arm. is provided with a long groove 44, and is slidably and rotatably secured by a pin 45 provided on the chassis.

Therefore, when the cargo is tamped as shown in the figure, the support arm 41 is rotated by the interlocking arm 43 according to the inclination of the cargo platform.
0 is lifted upward from the end of the dump bed.

Therefore, the position of the rear door 40 is higher than the height of the loading platform, and the opening for dropping the cargo is wide open.
Even large loads can be dumped without difficulty.

However, this size is also limited by the length between the pivot shaft (pin 42) of the support arm and the pivot shaft 46 of the rear door.

Therefore, in order to use an arm of the same size as the one in Fig. 6 to open and close an even larger rear door, we decided to use an arm of the same size as the one in Fig.
As shown in the figure, a rear door opening/closing device has been devised and provided in which the support arm 47 is slid along the upper edge of the loading platform. However, especially when the road where the dump truck is stopped is uneven, the support arm 47 can also be moved by the interlocking rope 48. It is difficult to completely prevent the horizontal vibration of 47.

Therefore, the present invention solves the above two problems by providing a rear door opening/closing device in which the interlocking arm is made of wire and a mechanism is provided to prevent the support arm from swinging laterally and from cutting the wire.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view showing a part of the device of the present invention, and FIG. 2 is an explanatory view of the operation of the dump truck.

The rear door 1 is pivotally attached to the tip of a support arm 2 so as to be freely rotatable, and 3 is its rotation axis and 4 is a connecting plate.

Reference numeral 5 denotes a rotation axis of the support arm 2, which is attached to the upper edge of the platform frame 6 as shown in FIG. 3, and the support arm 2 is designed to move up and down about this axis.

7 is a wire mounting plate rotatably provided at the rear end of the support arm 2, 36 is its rotating shaft, and 8 is a wire fixing hole.

The wire does not necessarily need to be attached using a stopper hole, and any suitable means may be used.

Reference numeral 9 denotes a single pulley installed at the rear of the carrier frame 6, and as shown in FIG.
It is fixed to .

12 is a bearing and pulley protection plate, and 13 is a wire pipe that penetrates the platform frame downward and connects the wire 1 to this.
4 is inserted therethrough and guided to the loading platform chassis 15.

Reference numeral 16 denotes a single pulley attached to the lower part of the loading platform (loading platform chassis 15) directly below the single pulley 9.

Attach one end of the wire 14 to the wire fixing hole 8 of the wire mounting plate 7, hang it on the single pulley 9, and pass it through the wire pipe 13.
Pass it through the single pulley 16 and attach it to the loading platform chassis 15.
Guide and arrange.

FIG. 4 is an explanatory plan view of the arrangement of the wire 14 in the loading platform chassis 15 section, and an explanatory diagram showing the attachment of each pulley and its structure. The first double pulley 17 and the second double pulley 18 each have a cross section.

The first double pulley 17 and the second double pulley 18 are also provided with single pulley mounting frames 21 and 21' fixed to the platform chassis plate 19 and the chassis frame 20, respectively, and the wire 14 is provided with a wire through hole in the platform chassis frame 20. 22 is provided and it is continuous.

Note that a loosening adjustment spring 23 is attached to the chassis frame 20 and engages the wire 14.

Next, the wire 14 is passed through a single pulley 25 provided with a wire guide 24, which is attached to the vehicle body chassis 32 as shown in FIG.

Reference numeral 26 denotes a vehicle body chassis frame, and the single pulley 25 is attached to a pulley mount 27 attached to this frame 26, and can be rotated up and down by a rotating shaft 28.

29 is a strong spring for preventing wire breakage, 30 is a wire guide, and 31 is a hydraulic cylinder.

The present invention has the above-mentioned configuration, and its operation and effects will be explained next.

When unloading the dump truck, when the loading platform 6' is raised by the operation of the hydraulic cylinder 31, the single pulley 25 provided on the vehicle body chassis 32 rotates upward in the direction of arrow Y around the rotating shaft 28, and the wire 14 is moved to the wire mounting plate. 7, the support arm 2 rotates upward about the rotating shaft 5 in the direction of arrow Y' as shown in FIG. 2, and the rear door 1 opens.

Since the highest and most effective lifting rotational position of the rear door is the position where the support arm 2 is perpendicular to the vehicle body chassis 32, the rear door 1 must be able to rise (open) most effectively at the highest lifting position of the cargo platform 6'. Bye.

The wire 14 is not directly connected to the rear end of the support arm 2, but is attached via the wire attachment plate 7, and the wire attachment plate 7 is designed to rotate around its rotation axis 36, so that the tension of the wire is reduced. The rotational force is smoothly transmitted to the support arm 2 and its rotating shaft 5.

The wire 14 is stretched with a certain amount of slack, and this slack is such that the female jacketing 33 of the rear door 1 can be easily removed from the male and female jacket dumper 34, and the slack adjustment spring 23 can compensate for this slack (length). This is done so that the wire 14 does not slacken by pulling.

Therefore, when the loading platform 6' starts to rise, the wire tension is loose, so the rear door 1
(If they start rising at the same time, the male and female keys will remain engaged and the rear door will not open and there is a risk of cutting the wire.)

) After the female covering 33 is detached from the female covering 34, the rising starts.

The wire 14 is connected to the second double pulley 18 in parallel to the left and right cross at the first double pulley 17 at the center of the width of the cargo chassis 15, and then connected as a single wire to the single pulley 25 provided at the longitudinal center line of the vehicle body chassis 32. (Originally, a single wire was connected to a single pulley 25, and both ends of the wire were connected to support arms on both sides of the loading platform.

) Since the hook is extended, the support arm 2 is always strongly attracted to the cargo platform frame 6, so that the support arm 2 and the rear door 1 are prevented from swinging laterally.

In particular, even if the vehicle body is tilted to either the left or right, the single pulley 25 rotates to either the left or right and has the effect of adjusting the balance of forces applied to both the left and right support arms.

Further, the wire guide frame 24 provided on the single pulley 25 prevents the wire 14 from swinging, and the wire 14 is connected to the second double pulley 1.
8 and the single pulley 25 so that it always hangs correctly.

Next, there is the strong spring 29 for preventing wire breakage.Since dump truck work sites are not always on flat ground and are usually inclined from side to side or front to back, the rear door can be moved smoothly when the loading platform 6' is raised. 1 keying 3
3 and 34 are not necessarily off.

Particularly on a front slope, in such a case, the rear door 1 cannot be opened simply by loosening the slack adjustment spring 23 (sag length), so the spring 23 expands and the keying comes off.

However, if the keying cannot be removed by the adjustment function of the spring 23 alone due to unfavorable conditions at the work site, there is a risk that the wire 14 will be cut by the push-up blade of the hydraulic cylinder 31 (although this is rare).

In such a case, a strong spring 29 for preventing cutting, which is disposed at an appropriate position on the wire 14, works to prevent this.

In such cases, it is normal for the driver of the dump truck to notice that the rear door will not open (it is common sense for the driver to always look at the rear of the dump truck while proceeding with work.

), the hydraulic cylinder 31 will not be operated until the spring 29 is activated, but the spring 29 serves to further ensure safety.

Also, during dumping operations, before the loading platform has fully risen, a large lump of cargo may suddenly roll down from the front of the loading platform and hit the rear door 1. In such cases, a large impact is applied to the wire, so There is a risk of cutting.

In such a case, the spring 29 has the effect of alleviating the impact and preventing the wire from breaking.

In addition, this strong spring 29 for preventing cutting is normally used (
Within the range in which the slack adjustment spring 23 functions.

) of course uses a strong spring which does not work.

Next, the wire guides 30 are installed at appropriate locations on the wire route, and although there is almost no risk of the wires 14 being cut, if they are cut due to some kind of accident, they may be placed on the vehicle chassis 32 or outside the vehicle body. If the wire 14 is inserted into the wire guide 30, the wire 14 can be inserted into the wire guide 30 to prevent the wire 14 from sagging during cutting and the danger caused by it.

When the hydraulic cylinder 31 is retracted when the load is finished being tamped, the rear door 1 is lowered and the single pulley 25 rotates downward in the direction of the arrow shown in FIG.

The bearing/pulley protection plate 12 not only stabilizes the pulley 9, but also prevents the wire from protruding outside by completely accommodating the wire within the structure of the carrier frame, and prevents rotation failure due to adhesion of earth and sand. is prevented.

In this way, according to the present invention, the tension wire 14 is arranged from the left and right loading platform frames to the vertical center line of the loading platform chassis 15, and the loosening adjustment spring 23 of the wire 14 is arranged. Wire guide 30. Strong spring 2 to prevent wire breakage
9 is provided, and the force applied to both support arms 2 is balanced by a left and right rotating single pulley 25 on the center line of the vehicle body chassis 32, so that the ground surface of the load dump is tilted either left or right or front or rear. There is no need to worry about the wire breaking even if the rear door is suddenly subjected to a large impact.Furthermore, even if the wire breaks for some reason, the danger of it hanging down is prevented, and the wire can be attached to the rear end of the support arm. This has great advantages such as the support arm can be rotated easily by the plate.

[Brief explanation of the drawing]

The drawings show an embodiment, and FIG. 1 is a side view of the loading platform of the device of the present invention, FIG. 2 is an explanatory diagram of the operation, and FIG. 3 is a sectional view taken along the line 2-2 in FIG. 1, showing the structure of the loading platform frame. Figure 4A is an explanatory sectional view showing the rotation of the support arm installed in Yamauchi and the state of the single pulley and its protection plate.
-1 is a front view of a single pulley, B-2 is a side view thereof, C-1 is a front view of the first double pulley, and C-2 is a side view thereof. FIG. 5A is a front view illustrating the operation of a single pulley installed on the vehicle body chassis, and the imaginary line indicates the second double pulley attached to the carrier chassis. B is a perspective explanatory view of the single pulley 25, and C is a front view of the wire guide. 6 and 7 are explanatory side views of a dump truck having a conventional rear door opening/closing device for a dump truck loading platform.

Claims (1)

[Scope of utility model registration request] A rear door is pivotally attached to the tip, a wire mounting plate is rotatably attached to the other end of the support arm which is rotatably pivoted to the upper edge of the dump bed, a wire is attached, and the wire is inserted through the wire guide plate. At the same time, the hook is passed from the rear lower end of the loading platform frame to a first double pulley and a second double pulley provided on the vertical center line of the loading platform chassis, and a wire guide is provided from the second double pulley to the vertical center of the vehicle body chassis. The hook is passed to a single pulley removably installed on the car body chassis, and the wire is connected to the loading platform frame and the first pulley.
A wire loosening adjustment spring is engaged at an appropriate position between the double pulley, and a strong spring to prevent wire breakage is attached at an appropriate position on the installed wire, and the rear door opens in conjunction with the vertical movement of the loading platform. A rear door opening/closing device for a dump truck loading platform that can be opened and closed.