JPS6044168B2 - Load box hoisting device for dump trucks, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cargo box lifting device for tilting a cargo box rearward in a dump truck or the like.

In general, the characteristics of a dump truck when the cargo box is tilted are as follows:
At the beginning of the tilting of the cargo box, especially when the angle of repose is below the so-called angle of repose until the cargo is ejected, the greatest amount of the box lifting blade is required.After that, as the tilting angle increases, the lifting blade decreases, and the lifting blade becomes the same as in the initial stage. There is no longer a need for large scales.

Therefore, conventional cargo box lifting devices include those in which the lifting mechanism is provided between the lower center of the cargo box and the vehicle platform and presses the lower center of the cargo box, or the device in which the lifting mechanism is provided between the lower center of the cargo box and the vehicle platform, or the device in which the lifting mechanism is installed between the lower center of the cargo box and the vehicle platform. In the former case, the output of the lifting cylinder needs to be large enough to correspond to the large lifting blade at the initial stage of tilting the cargo box due to the above-mentioned characteristics. Moreover, the shape of the lifting cylinder becomes large, and there is a problem that a sufficient storage space for the lifting mechanism cannot be secured in the small space between the cargo box and the vehicle platform. In addition, in the latter case, since the lifting cylinder is installed between the front part of the cargo box and the chassis, the cylinder output is smaller than in the former case, but on the other hand, the cargo box is weak against lateral vibration of the cargo box. It became unstable, necessitating separate measures to prevent lateral vibration, and furthermore, there were other problems such as the stroke of the lifting cylinder becoming larger. The present invention has been made in view of this point, and by pressing the front part of the cargo box with a lifting cylinder and linking a lift arm and a stabilizer to the lifting cylinder, it is possible to lift the load even with a small cylinder output j. To provide a cargo box hoisting device such as a tap car which can tilt a box, has a small cylinder stroke, and is robust against lateral vibration of the cargo box.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to the drawings.

Embodiment 1 In this embodiment, as shown in FIGS. 1 to 3, 1 is a dump truck, and a cargo box 3 is mounted on a chassis 2.
is pivoted to the vehicle chassis 2 at the lower rear end thereof via a hinge pin 3a so as to be tiltable rearward, and a lifting mechanism 4 for tilting the cargo box 3 rearward is provided between the vehicle chassis 2 and the vehicle chassis 2.

The lifting mechanism 4 is composed of a bending link 5 consisting of a stabilizer 6 and a lift arm 7, and a lifting cylinder 8. The stabilizer 6 has a hollow rectangular box-shaped frame 9 with cylindrical connecting parts 10 at both ends. 11 are formed in a row in the horizontal direction.

A first pin 12 and a second pin 13 are fitted into the connecting parts 10 and 11, respectively. It is rotatably connected to the cargo box 3 around a pin 12. The lift arms 7 are formed into a triangular shape with two acute angle parts and one obtuse angle part, and are provided in pairs parallel to each other with the obtuse angle parts positioned upward. A cylindrical connecting portion 15 is provided in series between the portions, and bosses 16 and 17 are provided at the other acute angle portions and obtuse angle portions.

A third pin 18 is fitted into the connecting portion 15 , and the third pin 18 is inserted into the connecting portion 15 .
is held by a bracket 19 provided on the chassis 2, the bracket 19 is located forward of the bracket 14 of the cargo box 3, and the lift arm 7 is connected to the chassis 2 so as to be rotatable around the third pin 18. . Further, both ends of the second pin 13 of the stabilizer 6 are connected to a boss 1 at an obtuse angle part of the lift arm 7.
7, and the end of the stabilizer 6 is fitted with a pair of lift arms. The lift arm 7 is rotatably connected to the lift arm 7 while being held between the arms 7 and 7. The stabilizer 6 and the lift arm 7 are bent forward as the cargo box 3 moves, and when the cargo box 3 is in the horizontal position, the stabilizer 6 is approximately parallel to the bottom surface of the cargo box 3 (horizontal state). position. However, the acute angle portion of the front end of the lift arm 7 projects slightly forward from the front end of the cargo box 3. The lifting cylinder 8 is a two-stage cylinder in which an internal cylinder 21 is fitted into a barrel 20 and a plunger 22 is slidably fitted into the internal cylinder 21, and the lower part of the barrel 20 is connected to the lower part of the front end of the cargo box 3. The lower end of the plunger 22 is rotatably connected to a bracket 23 provided at the front end of the lift arm 7 by a fourth pin 24. is rotatably connected to.

The lifting cylinder 8 is positioned in a substantially straight position in front of the cargo box 3 when the cargo box 3 is inverted. The force F acting on the lift arm 7 is generated at the intersection point p of the straight line a passing through the axes of the first pin 12 and the second pin 13 and the straight line b passing through the axes of the fourth pin 24 and the fifth pin 25. 3 Straight line c passing through the axis of pin 18
It is located above and acts in two directions of the chassis.

Next, the tilting operation will be explained.

When the internal cylinder 21 and plunger 22 of the lifting cylinder 8 are sequentially projected due to the fallen state of the cargo box 3, the aforementioned force F acts on the lift arm 7, and the lift arm 7 moves upward around the third pin 18. , the stabilizer 6 is connected to the first pin 12
The loading box 3 pivots downward around the hinge pin 4, and the cargo box 3 tilts backward around the hinge pin 4, as shown in FIG. 2b. At this time, as shown in FIG. 4A, the cylinder output of the lifting cylinder 8 is maximum when the dump angle (tilting angle) is approximately 1 pitch.
Others are decreasing. Further, curve B shows the cylinder output of a lifting cylinder in an embodiment of a conventional cargo box lifting device, and the lifting cylinder is provided so as to press the center of the lower part of the cargo box. Compared to this conventional cylinder, the cylinder output of the lifting cylinder 8 of the present invention is about 113 at maximum output. Embodiment 2 In this embodiment, as shown in FIG. 5, the two-stage hoisting cylinder 8 in Embodiment 1 is replaced with a single-tube hoisting cylinder 26, and one cylinder is installed in the barrel 27. A piston rod 28 is slidably inserted.

Since the cylinder stroke of the single-tube lifting cylinder 26 is smaller than that of the two-stage lifting cylinder 8, the lift arm 29 has a longer longitudinal length than the lift arm 7 of the first embodiment. The lift arm 29 is connected to the vehicle chassis 2 and the cargo box 3 so that the acute angle part of the rear end of the lift arm 29 is positioned rearward than the rear end of the stabilizer 30. There is. The rest is the same as in Example 1, and the cylinder output is also substantially the same. Embodiment 3 As shown in FIG. 6, in this embodiment, the lift arm 7 in Embodiment 1 was provided with the obtuse angle part located upward, but the lift arm 7 was installed with the obtuse angle part downward. The second pin 13 provided on the stabilizer 6 is fitted into a boss 16 at the front end of the lift arm 7 at an acute angle, while the lower end of the plunger 22 of the lifting cylinder 8 is located on the lift arm 7. It is rotatably connected to a fifth pin 25 inserted between the bosses 17 of the obtuse angle portions of 7.

Note that the portion of the stabilizer 6 that intersects with the plunger 22 is cut out as appropriate to avoid interference.
(not shown). Alternatively, a pair of left and right links may be used. The rest is the same as in Example 1, and the force F acting on the lift arm 7 is also the same. Example 4 This example is based on FIGS. 7 and 8.
As shown in the figure, instead of connecting the stabilizer 6 and lift arm 7 to the cargo box 3 and chassis 2 in the first embodiment, the first pin 12 provided on the stabilizer 6 is connected to a bracket provided on the chassis 2. 14, the third pin 18 provided at the acute angle part of the rear end of the lift arm 7 is held on a bracket 19 provided on the cargo box 3, so that the stabilizer 6 is attached to the vehicle chassis 2, and the lift arm 7 is attached to the cargo box 3. are rotatably connected to each other.

Further, the lift arm 7 is provided so that the obtuse angle portion is located below. The lifting cylinder 31 is attached to the barrel 32 first.
The cylinder 33 is connected to the first cylinder 33 and the second cylinder 34
However, the plunger 35 is a three-stage cylinder in which the plunger 35 is slidably inserted into the second cylinder 34.
The lower end of the barrel 32 is rotatably connected to a bracket 36 provided on the chassis 2 by a fourth pin 24, while the lower end of the barrel 32 is connected to a fifth member provided at an acute angle at the front end of the lift arm 7.
It is rotatably connected to the pin 25.

The other configurations are the same as in the first embodiment. The force F acting on the lift arm 7 is generated at the intersection point p of the straight line a passing through the axes of the first pin 12 and the second pin 13 and the straight line b passing through the axes of the fourth pin 24 and the fifth pin 25. It exists on the straight line C passing through the axis of the three pins 18, and acts in the three directions of the cargo box.

Next, the operation will be explained.

The first cylinder 33 and the second cylinder 3 of the lifting cylinder 31
4 and the plunger 35 in sequence, the aforementioned force F of the lift arm 7 acts, causing the lift arm 7 to rotate downward around the third pin 18 and the stabilizer 6 to rotate upward around the first pin 12. The cargo box 3 tilts backward around the hinge pin 4, and the lifting cylinder 31 moves below the cargo box 3 as it approaches the maximum tilting angle.
Further, the cylinder output of the lifting cylinder 31 is the same as in the first embodiment. Example 5 In this example, as shown in FIG.
In the fourth embodiment, the lift arm 7 is provided so that the obtuse angle part is located upward, instead of being provided so that the obtuse angle part is located upward. The second pin 13 is fitted into a boss 16 at an acute angle at the front end of the lift arm 7, while the fifth pin 25 is fitted between bosses 17 at an obtuse angle at the lower part of the barrel 32 of the lifting cylinder 31. is rotatably connected to.

The rest is the same as in Example 4, and the force F acting on the lift arm 7 is also the same. Embodiment 6 As shown in FIGS. 10 to 12, this embodiment has one stabilizer 6 in Embodiment 1, so instead of integrally forming the stabilizer 37, a joint 3 is provided at the center of the stabilizer 37.
8, the rear end of the long front stabilizer 39 and the front end of the short rear stabilizer 40 are connected to the horizontal axis 4.
1, and a stabilizer 37 is formed to be vertically bendable.

Further, the stabilizer 37 is provided so that it is bent at an acute angle toward the rear in a dogleg shape when the cargo box 3 is inverted. Reference numeral 42 denotes a contact member provided on the vehicle chassis 2 and against which the front lower surface of the lift arm 7 comes into contact.

The other configurations are the same as in the first embodiment. Next, the operation will be explained.

The plunger 22 of the lifting cylinder 8 from the fallen state of the cargo box 3
When the contact member 42 is projected, the contact member 42 is moved through the lift arm 7.
As a result, the cargo box 3 begins to tilt backward. At that time, no effect is exerted on the stabilizer 37. Next, when the cargo box 3 is slightly tilted, the stabilizer 37 becomes straight as shown in FIG. 11, and the force F acting on the lift arm 7 is transferred to the first pin 12 and the
The intersection point p of the straight line a passing through the axis of the pin 13 and the straight line b passing through the axis of the fourth pin 24 and the fifth pin 25 and the third pin 18
When the plunger 22 is subsequently projected, the lift arm 7 is rotated upward and the stabilizer 37 is rotated downward, as shown in FIG. 12. The cargo box 3 is tilted backward. Therefore,
At the initial stage of tilting the cargo box 3, which requires a large cylinder force, the front part of the cargo box 3 is pressed substantially vertically, so that the cylinder force of the launching cylinder 8 can be reduced. Embodiment 7 In this embodiment, as shown in FIGS. 13 to 15, instead of connecting the stabilizer 37 and lift arm 7 to the cargo box 3 and the chassis 2 in Embodiment 6, the stabilizer 3
7's rear stabilizer 40 to the chassis 2, and the lift arm 7
The acute angle part of the rear end is rotatably connected to the cargo box 3.

The stabilizer 37 is provided so that it is bent at an acute angle toward the rear in a dogleg shape when the cargo box 3 is tipped, while the lift arm 7 is provided so that the obtuse angle portion is located downward, and both acute angle portions are bent. An L-shaped step 43 is formed on one side connecting the two, and the step 43 is in contact with the front lower surface of the cargo box 3.
In the lifting cylinder 31, a plunger 35 is fitted into a barrel 32, and the lower end of the plunger 35 is connected to the chassis 2 via the fourth pin 24, while the lower part of the barrel 32 is connected to the acute angle part of the front end of the lift arm 7. They are connected via a 5-pin 25.

Therefore, at the beginning of the tilting of the cargo box 3, the lifting cylinder 31
is the cargo box 3 via the lift arm 7 as shown in FIG.
When the lower front surface of the stabilizer 37 is pressed almost vertically and the cargo box 3 is slightly tilted, the stabilizer 37 becomes straight, and then the stabilizer 37 becomes straight.
As shown in FIG. 5, the stabilizer 37 rotates upward, the lift arm 7 rotates downward J, and the cargo box 3 tilts rearward.

The rest is the same as in Example 6. Embodiment 8 In this embodiment, as shown in FIGS. 16 to 18, the lift arm 7 in Embodiment 6 is formed in a triangular shape j, and the stabilizer 37 and the plunger 22 of the lifting cylinder 8 are connected separately. Instead, the lift arm 44 is formed into a slightly diamond-shaped link shape (note that it is not limited to a diamond shape and may be straight), and the front end of the stabilizer 37 is attached to the front end of the lift arm 44. and the tip of the plunger 22 of the lifting cylinder 8 are connected to one common pin 4.
They are rotatably connected at 5.

The other configurations are the same as in the sixth embodiment. Therefore, when the plunger 22 of the lifting cylinder 8 is projected, it presses the abutment member 42 almost vertically at the initial stage of tilting, and when the cargo box 3 is slightly tilted, the stabilizer 37 is moved in a straight line as shown in FIG. Then, as shown in FIG. 18, the lift arm 44 rotates upward and the stabilizer 37 rotates downward.

Embodiment 9 In this embodiment, as shown in FIGS. 19 to 21, the lift arm 7 in Embodiment 7 is formed in a triangular shape, and the stabilizer 37 and the barrel 32 of the lifting cylinder 31 are connected separately. Instead, the lift arm 46 is formed into a link shape, and a contact surface 47 on which the lower part of the cargo box 3 abuts is formed on the upper part, and the stabilizer 37 is attached to the front end of the lift arm 46. The upper cylinder 31 and the tip of the barrel 32 are rotatably connected to each other by a common pin 45.

The other configurations are the same as in the seventh embodiment. Therefore, when the plunger 35 of the lifting cylinder 31 is protruded, it presses the lower front surface of the cargo box 3 almost vertically at the initial stage of tilting, and when the cargo box 3 is slightly tilted, the stabilizer 37 is pressed as shown in FIG. becomes a straight line, and then, as shown in FIG. 21, the lift arm 46 rotates downward and the stabilizer 37 rotates upward.

Embodiment 10 In this embodiment, as shown in FIGS. 22 and 23, the lift arm 7 in Embodiment 4 is formed in a triangular shape, and the stabilizer 6 and the barrel 32 of the lifting cylinder 31 are connected separately. Instead, a lift arm 44 is formed in the shape of a slightly diamond-shaped link, and the front end of the stabilizer 6 and the tip of the barrel 32 of the lifting cylinder 31 are connected to the front end of the lift arm 44 by a common pin 45. They are connected so that they can move freely.

The other configurations are the same as in the fourth embodiment. Therefore, the first cylinder 33, the second cylinder 33 of the lifting cylinder 31 and the plunger 3
3 are sequentially extended, the lift arm 44 rotates downward, the stabilizer 6 rotates upward, the cargo box 3 tilts backward, and the lifting cylinder 31 moves the cargo box 3 as shown in FIG. As the angle approaches the maximum tilt angle, the loading box 3
Move downwards.

Embodiment 11 In this embodiment, as shown in FIG. 24, the lift arm 7 in Embodiment 4 was connected to the cargo box 3 and the lifting cylinder 31, and the stabilizer 6 was connected to the chassis 2 and the lift arm 7. Instead, the stabilizer 48 is connected to the chassis 2 and the lifting cylinder 31.
In addition, a lift arm 44 is connected to the cargo box 3 and the stabilizer 48.

The stabilizer 48 has three shapes in side view with two acute angle parts and one obtuse angle part, and the acute angle part at the rear end is formed by the vehicle chassis 2.
The acute angle portion of the front end is rotatably connected to the bracket 14 by a pin 12 and to the barrel 32 of the lifting cylinder 31 by a pin 49, respectively. On the other hand, the lift arm 44 is formed into a slightly diamond-shaped link shape, and its rear end is rotatably connected to the bracket 19 of the cargo box 3 with a pin 18, and its front end is rotatably connected to the obtuse angle part of the stabilizer 48 with a pin 50. There is. The rest is the same as in Example 4. Example 12 In this example,
As shown in FIG. 25, instead of the lift arm 7 in the first embodiment having a triangular shape and connecting the stabilizer 6 and the plunger 22 of the lifting cylinder 8 separately, the lift arm 44 has a slightly diamond-shaped link. The front end of the stabilizer 6 and the tip of the plunger 22 of the lifting cylinder 8 are rotatably connected to the front end of the lift arm 44 by a common pin 45.

The rest is the same as in Example 1.

Although each embodiment has been described with reference to a dump truck, it goes without saying that the present invention can be applied to various types of vehicles that tilt cargo boxes.

According to the above-mentioned item 1), according to the cargo box hoisting device for a dump truck or the like of the present invention, the hoisting cylinder is provided in front of the cargo box and in a substantially vertical state when the cargo box is inverted. Since the cylinder part is pressed, the cylinder output can be reduced and sufficient storage space can be secured.

Furthermore, since the stabilizer and lift arm are linked to the lifting cylinder, the cylinder stroke can be reduced, and it is robust against lateral vibration of the cargo box, so there is no need to take separate measures to prevent lateral vibration. It has various advantages.

[Brief explanation of drawings]

The drawings illustrate embodiments of the present invention, and FIGS. 1 to 4 show Embodiment 1. FIG. 1 is a side view of a dump truck, FIG. Fig. b is a side view of the dump truck when the cargo box is tilted, with some parts omitted; Fig. 3 is a plan view of the bending link; Fig. 4 is a diagram showing changes in the output of the lifting cylinder between the present invention and the conventional example; 5 is a partially omitted side view of a dump truck showing a second embodiment, FIG. 6 is a partially omitted side view of a dump truck showing a third embodiment, FIGS. 7 and 8 are a partially omitted side view of a dump truck showing a fourth embodiment, and FIG. The figure is a partially omitted side view of the dump truck when the cargo box is tilted, FIG. 8 is a partially omitted side view of the dump truck when the cargo box is tilted, FIG. Figures to Figures 12 show Embodiment 6, Figure 10 is a partially omitted side view of the dump truck when the cargo box is tilted, and Figures 11 and 12 are partially omitted side views of the dump truck when the cargo box is tilted. Figures 13 to 15 show Embodiment 7, and Figure 13 C (↓ Partially omitted side view of the dump truck when the loading box is tilted; Figures 14 and 15 are the same partially omitted side view when the loading box is tilted. The side views, FIGS. 16 to 18 show Example 8, FIG. 16 is a partially omitted side view of the dump truck when the cargo box is tilted, and FIGS. 17 and 18 are the same parts when the cargo box is tilted. The omitted side views, Figs. 19 to 21 show Example 9, Fig. 19 is a partially omitted side view of the dump truck when the cargo box is tilted, and Figs. 20 and 21 are the partially omitted side views of the dump truck when the cargo box is tilted. Side view with the same parts omitted, Figure 22 and Figure 2
Fig. 3 shows Embodiment 10, Fig. 22 is a partially omitted side view of the dump truck when the cargo box is tilted, Fig. 23 is a partially omitted side view of the dump truck when the cargo box is tilted, and Fig. 24 shows Embodiment 11. FIG. 25 is a partially omitted side view of a dump truck showing a twelfth embodiment. 1... Dump truck, 2... Chassis, 3.
... Packing box, 53a ... Hinge pin, 4.
... Lifting mechanism, 5 ... Refraction link, 6,
30, 37, 48... Stabilizer, 7, 29, 4
4, 46... Lift arm, 8, 26, 31...
... Lifting cylinder, 9 ... Frame, 10, 1
1, 15... Connection part, 12... First pin ON, 13... Second pin, 18... Third pin, 24... ...4th pin, 25...5th pin, 38... joint.

Claims (1)

[Scope of Claims] 1. A cargo box is pivotably supported at its rear end on a vehicle chassis, and a lifting mechanism is provided between the vehicle chassis and the cargo box, and one end of the lifting mechanism is connected to the vehicle chassis or the cargo box. A bending link consisting of a stabilizer and a lift arm that are connected to the box and whose other ends are connected to each other; and a bending link that is located in front of the cargo box in a substantially vertical state when the cargo box is laid down, and that is connected to the cargo box or the vehicle platform. A cargo box hoisting device for a dump truck, etc., comprising a hoisting cylinder. 2. A cargo box lifting device for a dump truck or the like according to claim 1, wherein the stabilizer has a joint and is freely bendable. 3. A cargo box hoisting device for a dump truck or the like as set forth in claim 1, wherein the stabilizer is configured by providing cylindrical connecting portions at both ends of a box-like frame.