JPS6242993Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of the blade mounting structure of a bulldozer.

Conventionally, in this type of blade mounting structure, the front ends of a pair of left and right support arms, which are pivotally connected to both sides of the tractor by trunnions, are pivoted to both sides of the back of the blade, and the left and right support arms are attached to both sides of the upper back of the blade and the center of the support arms. A structure in which a pair of connecting rods are pivotally connected is known. When a lateral load is applied to the blade in its longitudinal direction, the blade swings laterally, so a brace is pivoted across the left and right support arms to prevent the blade from swinging laterally. The brace becomes a hindrance when moving the device from side to side.

Therefore, in order to solve this kind of problem, various proposals have been made, for example, Japanese Patent Publication No. 52-48403.
However, with this structure, four arms are used to resist lateral loads, and a pair of left and right arms are swingably connected to provide relief when the blade is moved at an angle.

For this reason, the number of parts is large, the ease of assembly is poor, and furthermore, since there are a large number of pivot joints, there are problems in that lateral vibration due to backlash increases.

The present invention was developed in view of the above, and its purpose is to prevent the blade from swinging laterally due to longitudinal lateral loads acting on the blade.
To provide a blade mounting structure for a bulldozer which can smoothly tilt the blade to left and right tilted positions, has fewer structural members and is inexpensive, can easily attach and detach the blade, and can further reduce lateral vibration. .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The base ends of support arms 3 are pivotally attached to trunnions 2 protruding from both sides of the tractor 1 so as to be able to rise and fall freely, and both back sides of blades 4 are attached to the front ends of each support arm 3 so as to be able to swing freely. In addition, blade lifting cylinders 5, 5 are respectively pivotally connected to both sides of the front part of the tractor 1 and to the back surface 4a of the blade 4.
The blade 4 moves up and down by extending and contracting the blade lifting cylinders 5, 5. Further, connecting rods 6 are pivotally connected to the left and right support arms 3 and both sides of the back surface 4a of the blade 4, and one of the connecting rods 6 is a cylinder.

A bracket 7 is fixedly attached to one of the support arms 3 facing forward, a bracket 8 is fixedly attached to the other support arm 3, and an arm 9 is attached to the brackets 7, 8 with joints (spherical joints). )1
0 and 10, and the arm 9
is inclined in the front-back direction.

The tip of one of the support arms 3 is bifurcated to form a pair of vertical walls 3a, 3a, and a block 12 is attached via a vertical pin 13 to a pair of upper and lower horizontal walls 11, 11 fixed to the back surface 4a of the blade. The pair of vertical walls 3a, 3a are inserted into both sides of the block 12, and a horizontal pin 14 is pivotally connected to the block 12 so as to be swingable up and down.

The tip of the other support arm 3 is bifurcated to form a pair of upper and lower horizontal walls 3b, and a pair of left and right vertical walls 15, 15 are fixed to the back surface 4a of the blade 4. A block 17 is supported vertically and swingably between the blocks 15 and 15 via a horizontal pin 16, and the pair of horizontal walls 3 of the support arm 3
b and 3b are inserted into the upper and lower surfaces of the block 17, and are pivotally connected by a vertical pin 18 so as to be swingable from side to side.

Then, one vertical pin 13 is connected to the other vertical pin 18.
It is positioned further back than the previous model.

Therefore, the lateral load in the longitudinal direction of the blade 4
When F ₁ and F ₂ act, compressive and tensile loads are generated on the arm 9 as shown in Figures 7 and 8, and a bending moment is generated on the support arm 3, which prevents the blade 4 from swinging laterally. can.

Furthermore, when the blade 4 is tilted to the left and right tilted positions, the arm 9 can be freely swung and displaced relative to the support arm 3, so the blade 4 can be smoothly tilted to the left and right tilted positions without the arm 9 getting in the way. can.

In addition, since the arm 9 is only pivotally connected to the left and right support arms 3, 3, the number of parts is reduced, resulting in lower costs, and the disassembly and assembly work is simple and easy, and furthermore, the weight is reduced. The lifting force of the blade 4 can be reduced, and there are fewer pivot joints, which reduces play.
lateral vibration is reduced.

Here, the relationship between the lever ratio and the load when the side load F is applied will be explained based on FIG. 9.

Trunnion reaction force R when side load F is applied
The left, R-right, and arm loads f are as shown in the following equations.

R left=bd/ac+b・d×F…(1) R right=ac/ac+bd×F…(2) Note that a is the distance between the trunnion 2 and one vertical pin 13, and b is the distance between one vertical pin 13 and one joint 10.
The distance c is the distance between the other vertical pin 18 and the other joint 1
0, d is the distance between trunnion 2 and the other vertical pin 1
It is the distance from 8.

From formula (3), to reduce the arm load f, b/a, c
It turns out that it is better to increase the value of /d.

Here, in order to increase the values of b/a and c/d, it is possible to do the following, but this causes a problem that will be described later.

One vertical pin 13 is moved to the rear position → the horizontal wall 11 becomes larger and the support arm 3 and blade 4
The gap between the two becomes larger.

If one joint 10 is placed in a forward position, the bracket 7 will interfere with the blade back surface 4a.

If one joint 10 is placed closer to the center in the longitudinal direction of the blade 4, then the bracket 7 will become larger.

The other joint 10 is placed in a rearward position → the arm 9 interferes with the front part of the tractor 1.

The other vertical pin 18 is placed in a forward position → it interferes with the blade back surface 4a.

Considering the above points, it is preferable that 6<a/b8 and 5<d/c<7.

In addition, in the embodiment, one vertical pin 13 is set at the rearward position, and the other vertical pin 18 is set at the forward position, so that b/a and c/ The value of d can be increased, and the arm load f can be decreased.

As described above, the present invention can prevent the blade 4 from swinging sideways due to lateral loads acting on the blade 4, reduce the number of parts, reduce costs, and facilitate easy disassembly and assembly. This makes it easier, and furthermore, the weight can be reduced, and since the number of joints is reduced, there is less backlash, thereby preventing the blade 4 from swinging laterally.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention.
The figure is an overall plan view, Figure 2 is a side view, Figure 3 is a perspective view of main parts, Figure 4 is a partially exploded perspective view of Figure 3, and Figure 5 is a side view.
6 is a partially exploded perspective view of FIG. 3, FIGS. 7 and 8 are explanatory diagrams of operation, and FIG. 9 is an explanatory diagram showing the relationship between lever ratio and arm load. 1 is a tractor, 3 is a support arm, 4 is a blade, 5 is a blade lifting cylinder, 6 is a connecting rod, 9
is an arm.

Claims (1)

[Scope of utility model registration request] Both sides of the back of the blade 4 are attached to the tips of a pair of left and right support arms 3, 3 which are pivoted on both sides of the tractor 1, and connecting rods 6, 6 are attached to each of the support arms 3 and both sides of the back of the blade 4, respectively. At the same time, blade lifting cylinders 5, 5 are installed on both sides of the tractor 1 and on both sides of the back of the blade, and an arm 9 is installed between the pair of left and right support arms 3, 3.
A bulldozer blade mounting structure characterized in that the blades are mounted and connected at an angle in the front-back direction.