JPH0138008B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hood opening/closing device provided on a truck bed.

The conventional hood opening/closing device of this type was
There are some such as those shown in Publication No. 2496. That is, in the above-mentioned conventional device, a beam is constructed between the upper centers of the pillars fixed to the front and rear of the loading platform, and a pair of approximately L-shaped canopy frames that cover each side of the loading platform are mounted on both sides of the beam. The hood frame is movably supported, and the hood frame can be rotated by pulling a rope attached to the lever part of the hood frame. A coil spring is provided in which the direction of biasing the frame body is reversed.

According to this conventional structure, when opening the top frame, the rope is initially pulled by the elastic force of the coil spring and a force that overcomes the own weight of the top frame, and the elastic biasing force of the coil spring against the top frame is After being reversed, the elastic contraction force moves the top frame to open and bring it to the fully open state.

However, in the conventional device, as mentioned earlier, when the top frame is initially opened, in addition to the own weight of the top frame, the elastic force of the coil spring acts in the direction of closing the top frame, so it is difficult to lift the top frame. This requires considerable effort and places a heavy burden on the worker. Furthermore, after the elastic biasing force of the coil spring is reversed, the movement of the canopy frame becomes rapidly faster together with the operator's opening operation force, and the impact when the canopy frame is fully opened is large and can easily damage the canopy device. There is a problem.

The present invention was made in view of the above problems.
A torsion bar is arranged at a position closer to the center of the cargo bed than the rotation axis of the top frame, and its shaft support side end is linked to the top frame via an arm member, and the linked end of this arm member is connected to the top frame when the top frame is closed. The conventional problem is solved by having a structure in which the top frame body is always elastically biased in the opening direction by freely slidingly engaging at a position opposite to the torsion bar with respect to the rotating shaft in the opened state. The purpose is to

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

In FIG. 1 showing an embodiment of the present invention, substantially U-shaped supports 3 and 3' are fixed to the front and rear ends of a loading platform 2 of a truck 1, respectively, and between the two supports 3 and 3', , two rotating shafts 4, 4', which also serve as cross beams in the longitudinal direction of the loading platform, are installed in parallel with an interval and rotatably via bearings 5, 5' provided at the center of the upper ends of the columns 3, 3'. . Then, a pair of approximately L-shaped canopy frames 6, 6', which can open and close the sides of the loading platform 2, are attached to the support pillars by assembling pipe materials to each of the rotating shafts 4, 4' by welding or bolting. , 3', and a hood cloth (not shown) is stretched over the pair of hood frames 6, 6'. Further, each hood frame 6,
torsion bars 7, 7' that constantly apply an elastic force to 6' in the opening direction, that is, in the upward direction;
For example, two of them are attached to each of the hood frames 6, 6', for a total of four.

The details of this torsion bar mounting structure are shown in FIG. 2. Incidentally, since the mounting structure of each torsion bar is the same, only one part will be explained here and the others will be omitted.

One end of the torsion bar 7 is fixed to a bracket 10 fixed with a bolt 9 to a hollow pipe 8 passed through the rotating shaft 4, and the other end is fixed to a bracket 10 fixed to a support column 3.
1 and is rotatably attached to a bearing 12 provided therebetween. A base end of a first arm member 14 having a pin 13 at its tip is fixed to the end of the torsion bar 7 on the side supported by the bearing 12. , 1st
A second arm member 15 is paired with the arm member 14 and is fixed to the pipe material at the end of the hood frame 6 and to the tip of the rotating shaft 4. engaged. A bracket 10, which fixes one end of the torsion bar 7, is installed between the rotating shafts 4, 4' via hollow pipes 8, 8' (see FIG. 1).

Next, the effect will be explained.

First, in this embodiment, the torsional torque of the torsion bars 7, 7' is used to open the top frames 6, 6' in response to the force necessary to open the top frames 6, 6' shown by solid lines in FIG. The force acting in the opening direction is as shown by the broken line in FIG. That is, the force exerted by the torsion bars 7, 7' is greater at the beginning of the opening of the top frame bodies 6, 6' and when it is nearly fully opened, and the force is lower during the middle of opening.

In such a relationship between the two, the hood frame 6,
The opening operation of 6' will be explained with reference to FIG. First, when the locking device (not shown) that fixes the canopy frame 6 in a closed state at a proper position on the loading platform 2 is unlocked, the acting force of the torsion bar 7 to which a predetermined torsion torque has been applied is applied to the first arm member. 14 pins 13 and the second arm member 15
As a result, the top frame 6 automatically rotates upward about the rotating shaft 4 and is opened. Then, while the acting force of the torsion bar 7 and the acting force due to the own weight of the top frame 6 and the force in the opposite direction (indicated by the solid line in FIG. 3) are reversed, the operator attaches the A rope (not shown) is pulled to make up for the shortage, and the canopy frame 6 is brought close to being fully opened. After that, the top frame 6 is automatically rotated again to the fully open position shown by the dashed line by the acting force of the torsion bar 7.

By the way, the force acting in the opening direction of the top frame 6 by the torsion bar 7 is related to the torsional torque of the torsion bar 7 and the distance from the rotation axis center of the top frame 6 to the pin 13, and the setting relationship between the two is By making various changes at the design stage, the force exerted by the torsion bar can be set as shown by the one-dot chain line or the two-dot chain line in FIG.

In this way, the force acting in the opening direction on the canopy frames 6, 6' is applied not by the coil springs but by the torsion bars 7, 7'.
It is possible to set an acting force that is not much different from the opening force curve of the top frame shown by the solid line in FIG. 3. Therefore, even if manual operation by the operator is required during the opening operation of the top frame bodies 6, 6', the effort required is much smaller than in the conventional system, and there is no burden on the operator. Furthermore, the impact when the top frames 6, 6' are fully opened can be greatly reduced, and the durability of the top frames 6, 6' is improved. Furthermore, the force required to open the canopy frame and the force acting in the opening direction by the torsion bar can be set in a well-balanced manner without the difference between the two forces being extremely different. Unnecessary and unreasonable force is not applied to components such as supporting parts and columns, and requirements for strength, rigidity, etc. can be easily met. Therefore, it can be made lightweight and low cost.

Further, in the above embodiment, the torsion bars 7, 7' are attached between the rotating shafts 4, 4' of the top frames 6, 6' via the brackets 10, but as shown in FIG. In the case of a canopy frame structure in which a spine frame 20 made of beam material is installed in parallel with the longitudinal direction of the loading platform, brackets 21 and bearings 22 are respectively fixed to both sides of the spine frame 20 as shown in FIG. , torsion bars may be attached to these.

As described above, according to the present invention, a torsion bar is used in place of the conventional coil spring, and this torsion bar is placed closer to the center of the cargo platform than the rotation axis of the hood frame body, so that the torsion bar is aligned with respect to the rotation axis. Since the hood frame is always elastically biased in the opening direction via the arm member which is slidably engaged in the opposite position, it is necessary to open the hood frame during the opening operation of the hood frame. The difference between the force acting on the elastic body and the force acting on the frame can be set small at the fully open position of the top frame.

Therefore, the labor of the operator when opening and closing the hood frame can be significantly reduced, and the impact when the hood frame is fully opened can be alleviated, thereby extending the life of the hood frame. In addition, the force necessary to open the canopy frame,
The force exerted by the torsion bar in the opening direction,
Since the settings can be made in a well-balanced manner, unreasonable force is not applied to each part, and requirements for strength, rigidity, etc. are low, and this has the effect of reducing weight and cost.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing one embodiment of the present invention, Fig. 2 is a perspective view showing one embodiment of the present invention;
The figure is an enlarged perspective view of the main part of the same embodiment as above, FIG. 3 is a diagram showing the relationship between the opening force of the torsion bar and the opening degree of the top frame, and FIG. 4 is a perspective view showing another embodiment of the present invention. FIG. 5 is an enlarged perspective view of the main part of the same embodiment. 2... Loading platform, 3, 3'... Support, 4, 4'... Rotating shaft, 6, 6'... Canopy frame, 7, 7'... Torsion bar, 13... Pin, 14... First arm member, 15... second arm member, 15a... elongated hole.

Claims (1)

[Claims] 1 Approximately U-shaped pillars are fixed to the front and rear parts of the loading platform, and a pair of hood frames framed in an approximately L-shape are attached to two rotating shafts arranged in parallel between the upper ends of the pillars. In the opening/closing device for a truck loading platform, which is configured to open and close the sides of the loading platform by rotating the top frame via a rotating shaft, the torsion bar is fixed at one end and rotatably supported at the other end. , the torsion bar is provided at a position closer to the center of the loading platform than the rotation axis of the top frame body and parallel to the rotation axis, and the shaft support side end of the torsion bar is linked to the top frame body via an arm member, and the arm member The connecting end of the canopy frame,
When the top frame is closed, the torsion bar is slidably engaged with the rotating shaft of the top frame at a position opposite to the shaft supporting end, and the torsion bar constantly moves the top frame in the opening direction. An opening/closing device for a truck loading platform hood, characterized in that it is configured to be elastically biased.