JPS6342040Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to a left-right sliding device for footboards in various heavy goods transport vehicles such as power shovels, bulldozers, and road rollers.

(Prior Art) For example, there is a guide device proposed in Japanese Utility Model Publication No. 18964/1983.

The configuration of this device is that a footboard is provided on the rotation axis of the rear end surface of the loading platform so that it can rotate integrally and slide freely in the axial direction, and cylinders are arranged on the left and right sides of the rotation axis in parallel with the same rotation axis. Each cylinder and the footboard are directly connected, respectively, so that the footboard slides left and right by the expansion and contraction of each cylinder rod.

(Problem that the invention aims to solve) However, since the left and right footboards are configured to slide using dedicated cylinders, it is assumed that the respective sliding widths of the left and right footboards are relative to the center of the loading platform. If they are not equidistant, there will be a misalignment between the center of the loading platform and the center between the left and right footboards, and the center of gravity of the heavy object loaded onto the loading platform through these footboards will be shifted laterally from the center of gravity of the loading platform. It is extremely dangerous to transport the cargo, and loading and unloading the cargo is even more dangerous due to its heavy weight. Moreover, since the rod of the cylinder is directly connected to the footboard, vibrations during loading and unloading of heavy objects are directly applied to the cylinder through the footboard, resulting in a problem of heavy burden on the cylinder.

Furthermore, the slide cylinders for the left and right footboards are exposed at the rear of the rear end of the loading platform and above the rotating shaft, and there is a risk that they will be damaged by external pressure from above, such as falling objects, without resistance. There is.

The present invention was developed in view of these circumstances, and the sliding width of the left and right footboards is equal to the center of the loading platform, and vibrations and the like are not applied from the footboard side to the sliding cylinder side. Moreover, it is an object of the present invention to provide a left-right slide device for a footboard in a heavy goods transport vehicle in which the entire slide drive system of the footboard is protected from external pressure from above.

(Means for solving the problem) In order to achieve the purpose of the present invention, a rotating shaft is installed at the rear end of the loading platform, and near the front ends of the left and right footboards are rotated integrally with the rotating shaft and along the axis. It is installed so that it can slide freely, and the knock pin is pivoted in a hanging manner at the front end of the footboard.
Operating arms are pivotally supported on the rear left and right sides of the bottom of the loading platform so that both their front and rear ends can swing freely left and right, and each operating arm protrudes rearward from the rear end of the loading platform and reaches the bottom of the pivot support part of the footboard. The above-mentioned dowel pin is loosely fitted into the elongated hole along the longitudinal direction of the rear end of the arm, and a connecting rod is horizontally mounted between the front end side of the arm and the rear end side of the arm, with the axis support as the boundary between the two operating arms. The actuating arms are connected in an integrally interlocking manner, and a cylinder is connected to one of the actuating arms.

(Function) In response to the driving force of the cylinder, the left and right operating arms swing equally with their swing direction and angle being regulated by the connecting rod, and the left and right footboards slide an equal width relative to the center of the loading platform. However, the center between the left and right footboards and the center of the loading platform always match regardless of the sliding width of the footboards.

Since the actuating arm and the footboard are interlocked with each other, with the knock pin on the footboard side playing with the long hole on the arm side, vibrations between the footboards are interrupted between the knock pin and the long hole. Therefore, it is not transmitted to the slide drive mechanism system side on the operating arm side.

Furthermore, the cylinder, most of the left and right operating arms, and the connecting rod are covered by the loading platform, and the elongated hole-forming portions of the left and right operating arms that protrude from the rear end of the loading platform are covered by the footboards. Therefore, the entire slide drive mechanism system of the left and right footboards is protected.

(Example) Hereinafter, an example of implementation of the present invention will be described in detail with reference to the drawings.

In the figure, reference numeral 1 denotes a loading platform, and the loading platform 1, which can freely tilt backwards, has a rotary shaft 2 suspended between left and right bearing pieces 9, 9 along the rear edge of the rear end surface 1b that continues from the loading platform surface 1a. In this case, the cylinder 10 is pivoted and fixed, and the tip of the cylinder rod 10a is pivotally connected to a bearing 11 and a pin 12 hanging down the center of the rotating shaft 2, so that the rotating shaft 2 rotates clockwise by reciprocating the cylinder rod 10a. Or try to turn counterclockwise.

The rotating shaft 2 is pivotally attached to the left and right shaft portions near the front ends of the walkways 3, 3 so as to be integrally rotatable and slidable in the axial direction.
The running boards 3, 3 are provided with grooves 14, 14 for the guide protrusions 13, 13,
The running boards 3, 3 rise and fall together with the rotation of the rotary shaft 2, and are also slidable along the shaft.

The footboards 3, 3 have a knock pin 4 pivotally attached to a groove 19 recessed from the top side to the bottom side of the front end so that the footboards always hang under their own weight. It fits into a long hole 8 opened along the front-back direction of the rear end of the arm 7.

The pivoting position of the knock pin 4 in the groove 19 is such that when the foot plate 3 is in an upright state (see Fig. 3), the knock pin 4 is positioned on the side of the rear end surface 1b of the platform, that is, on the operating arm. 7
This reduces the burden on the cylinder 5 for sliding the footboard 3 in its upright position.

The thrust force F of the cylinder 5 is obtained from the following formula.

F=l ₁ ×F ₂ /l Note l ₁ : Length from the support shaft 6 to the knock pin 4 in the operating arm 7 F ₂ : Force for sliding the footboard 3 l : Length between the connection part of the cylinder 5 and the support in the operating arm 7 For example, if the length of the arm between the shaft 6 and the shaft 6 is twice as long as l ₁ , then F = 2l ₁ ×F ₂ /l, F is doubled, and the load on the knock pin 4 is also doubled. It is disadvantageous.

In addition, when the footboard 3 is sliding in the upright state, the length of the pin portion from the shaft portion of the knock pin 4 to the elongated hole 8 is short, and the bending stress on the pin portion is small, so that the knock pin 4 does not bend. I have to.

Furthermore, when the footboard 3 slides in the lowered state (the state shown by the imaginary line in FIG. 3), the knock pin 4 comes closer to the support shaft 6 side of the pivot support of the operating arm 7 than when it is in the upright state. The bending stress of the knock pin 4 is small.

In addition, the position of the pivot pin 4 in the same lowered state is different from that of the pivot pin 4 of the actuating arm 7 if the coaxial branch is located on the bottom side of the footboard 3.
However, in the same unloading state, that is, when loading and unloading heavy objects, the loading platform 1 is tilted until it is almost flush with the footboard 3, and the shaft support side of the actuating arm 7 is connected to the shaft support of the knock pin 4. Due to the closeness to the side, the knock pin 4 in the same state
The increase in the length between the shaft and the pivot portion of the actuating arm 7 is slight, the bending stress on the knock pin 4 is small, and the knock pin 4 does not bend.

The operating arms 7, 7 are attached to the bottom of the loading platform 1 with a support shaft 6 as a fulcrum, so that both front and rear ends can swing horizontally from side to side. The left and right sides are integrally linked by a connecting rod 15 suspended from the end side (in the form of a sash in the drawing), and one of the actuating arms 7 is connected to the cylinder 5. The rear ends of both operating arms 7 extend through horizontal long guide holes 16, 16 on the left and right sides of the rear end surface 1b below the knock pin 4, and are connected to the knock pin 4. 3 is configured to slide at equal intervals with respect to the center of the loading platform 1 so that the left and right width thereof can be varied.

The cylinders 5 and 10 are controlled by operating levers 17 and 18, respectively, arranged on the sides of the loading platform.

(Effect of idea) Therefore, the present invention has the following advantages.

The center of the left and right footboards is aligned with the center of the loading platform at each sliding position, and when loading and unloading heavy items, there is no deviation in the center of gravity between the loading platform and the loading platform, allowing for safe loading and unloading. It can be transported.

Vibrations and the like during loading and unloading of heavy objects are not applied to the slide drive mechanism system on the operating arm and cylinder side, and the mechanism system is protected, resulting in high durability of the entire mechanism.

operating arm and cylinder and connecting rod,
It can be placed by utilizing the space on the bottom of the loading platform and can be protected by the loading platform.Furthermore, the connecting part between the footboard and the operating arm includes a knock pin pivoted in a hanging manner at the front end of the footboard. Due to the connection between this and the elongated hole on the operating arm side with which it plays, the entire slide drive system is protected by the step board itself, making it easy to incorporate into existing trucks and is robust.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the slide device of the present invention incorporated into a loading platform. Figure 2 is a bottom view with a portion cut away. FIG. 3 is a longitudinal sectional view taken along the - line. In the diagram, 1 is the loading platform, 2 is the rotating shaft, 3 is the footboard, and 4
is the dowel pin, 5 is the cylinder, 7 is the operating arm,
8 is a long hole, 15 is a connecting rod.

Claims (1)

[Scope of utility model registration request] A rotating shaft is installed at the rear end of the loading platform, and the front ends of the left and right footboards are attached to the rotating shaft so that they can rotate integrally and slide freely along the axis.Knock pins are pivotally attached to the front ends of the footboards in a hanging manner, and the bottom of the loading platform is The operating arms are pivotally supported on the left and right sides of the rear so that their front and rear ends can swing freely left and right, respectively.
The above-mentioned knock pins are loosely engaged in the elongated holes extending in the front-rear direction of the rear ends of the arms that protrude rearward from the rear ends of the loading platform and reach the bottom of the pivot parts of the footboards. A step forward in a heavy goods transport vehicle in which a connecting rod is horizontally mounted on the front end side of the arm and the rear end side of the arm, which are bordered by the shaft support, and are linked in an integrally interlocking manner, and a cylinder is connected to one operating arm. A device that slides the board left and right.