JPH11139769A - Boom derricking cylinder mounting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boom derricking cylinder mounting device which is capable of improving the visibity of an operator, and also, of securing its strength, with light weight. SOLUTION: A tip side connecting bracket 4 is provided with a straight-line segment with a rising angle from a boom underside being angled at 10 deg. to 30 deg. to the bottom longitudinal direction, and a curved segment, extending in the boss direction in succession to this straight-line segment, and with a rising angle being angled at 80 deg. to 100 deg. to the boom longitudinal direction in its tangent with the outer diametral front end part of a boss 3, and further, having a curvature of more that the diameter of a supporting pin 7, in a connecting part with the tangent, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boom hoist cylinder mounting device.

[0002]

2. Description of the Related Art A boom hoist cylinder mounting device 50 disclosed in Japanese Patent Application Laid-Open No. Hei 8-91776 shown in FIG.
Like the boom hoisting cylinder mounting device 10 of FIG.
5 is attached to the lower surface of the boom 6 disposed on the side of
Similarly to the above, the piston rod 5a of the boom hoist cylinder 5 which is swingably mounted on the upper
It is swingably supported by.

[0003] The boom hoist cylinder mounting device 50 is shown in FIG.
As shown in FIG. 5, a pair of outer brackets 51 and inner brackets 52 and bosses 53 formed of flat plates having the same thickness are provided.
Each of the left and right outer brackets 51 is welded to a reinforcing plate 64 welded to the lower surface of the boom 6 at a side position of the boom 6. Also, inside the outer bracket 51 and the boom hoist cylinder 55
A pair of inner brackets 52, 52 are welded to the left and right outside the distal end of the piston rod 55a. A bush 53 is welded to each of the outer bracket 51 and the inner bracket 52.

[0004] The inclination angle β of the boom tip side inclined surfaces 51c and 52b of the pair of left and right outer brackets 51 and the inner bracket 52 is reduced to avoid abrupt changes in cross section to prevent stress concentration and increase the inclination angle α. To improve visibility. A connecting bracket 54 is welded to the boom tip side inclined portions 51c and 52b of the outer bracket 51 and the inner bracket 52. Tip 5 of connecting bracket 54
4a is attached to the reinforcing plate 64 and the connecting bracket 54
The rear end portion 54b is bent at a rising angle γ and is welded to the outer diameter portion of the bush 53.

[0005]

However, the above-mentioned Japanese Patent Application Laid-Open No. Hei 8-91776 has the following problems. (1) The outer bracket 51 protrudes from the outer diameter portion of the bush 53 toward the end of the boom as much as the rear end portion 54b of the connecting bracket 54 is bent at the rising angle γ.
Since this part blocks the view, it is insufficient as a measure to improve the visibility. (2) Since the outer bracket 51 and the inner bracket 52 have the same plate thickness and the same rigidity, the load and deformation of the outer bracket 51 and the inner bracket 52 are substantially the same. For this reason, a large load is transmitted to the boom abdomen of low rigidity to which the inner bracket 52 is welded, and there is a problem that stress concentration is likely to occur at the boom abdomen and the wick point of the inner bracket 52. (3) A pair of left and right outer brackets 5 formed of a flat plate
1, 1 and 51 are vertically extended from the side surface position of the boom 6 and are welded to the boss 53, so that the outer bracket 51 approaches the viewpoint of the operator, and does not reduce the visibility from the operator. There is a problem that the weight of the boss 53 and the support pin increases. (4) Since the connecting bracket is not welded to the boom base end side of the outer bracket 51 and the inner bracket 52, there is a problem that the strength of the boom hoist cylinder mounting device tends to be insufficient for a large pin load.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a boom hoist cylinder mounting device which improves the visibility of an operator, and is lightweight and has sufficient strength.

[0007]

In order to achieve the above object, a first aspect of the present invention relates to a boom hoisting cylinder mounting device according to the present invention. , A pair of left and right outer brackets fixed to the lower surface of a boom that is attached to the upper revolving structure by a boom lifting cylinder so as to be able to raise and lower, and a pair of left and right inner brackets arranged in parallel inside the outer bracket, and each outer bracket and the inner side The left and right bosses, which support the piston rod of the boom hoist cylinder fixed to the bracket and swingably mounted on the upper revolving structure on both sides with support pins, and the respective outer bracket and inner bracket Boom hoist cylinder mounting device comprising: a front end portion fixed to the boom lower surface; and a front end side connection bracket fixed to the rear end portion of the boss. The tip-side connecting bracket has a straight portion having a rising angle from the lower surface of the boom at an angle of 10 ° to 30 ° with respect to the boom longitudinal direction, and a boss direction extending continuously from the straight portion, and an outer diameter front end portion of the boss. Has a rising angle of 80 ° to 100 ° with respect to the longitudinal direction of the boom, and has a curved portion having a curvature equal to or larger than the diameter of the support pin at a connection portion with the tangent. It is characterized by.

According to the first aspect of the present invention, since the rising angle of the distal end side connection bracket from the lower surface of the boom is set to 10 ° to 30 °, there is no abrupt change in the cross section of the connection portion with the boom, so that stress concentration can be avoided. Also, the rising angle of the tangent line of the leading end side connection bracket in contact with the outer diameter front end portion of the boss is set to 80 ° or more.
Since the angle is set to 100 ° and the curvature is equal to or more than the diameter of the pin, the strength required for the connecting bracket on the tip side can be sufficiently satisfied, and the area occupied on the boom tip side in the side view of the boom hoisting cylinder mounting device is shown in FIG. The area shown by hatching in FIG. For this reason, the visibility from the operator ahead of the boom hoist cylinder mounting device is improved.

A second aspect of the boom hoisting cylinder mounting device according to the present invention is that a boom hoisting cylinder is mounted on an upper revolving structure at a side of a driver's cab. A pair of left and right outer brackets fixed to each other, and a pair of left and right inner brackets arranged in parallel inside the brackets, and fixed to each of the outer brackets and the inner bracket, and swingably attached to the upper revolving unit. The piston rod of the boom hoist cylinder is fixed between the left and right bosses, which are supported on both sides by support pins, and the respective outer bracket and inner bracket, and the front end is fixed to the lower surface of the boom, and the rear end is fixed. A boom hoisting cylinder mounting device comprising: a tip side connection bracket fixed to a boss; wherein the outer bracket is fixed to a lower side of a boom side plate; Bent Luo inwardly, characterized in that fixed to the boss.

According to the second invention, the outer bracket is fixed to the side of the lower surface of the boom, and the boss is fixed by bending inward from the side of the boom by a predetermined amount. As the performance improves,
Reducing the length of the boss and support pins also reduces weight.

A third aspect of the boom-lifting cylinder mounting device according to the present invention is characterized in that, in the first or second aspect, the thickness of the outer bracket is greater than the thickness of the inner bracket.

According to the third aspect of the invention, the load acting on the support pin is largely borne by the outer bracket having a large thickness and increased rigidity, and the load borne by the inner bracket is reduced. For this reason, the load transmitted to the abdominal part of the boom 6 having a small rigidity to which the inner bracket 52 is welded is reduced, and the concentration of stress acting on the boom of the boom 6 and the wick point of the inner bracket 52 is prevented. The durability is improved.

According to a fourth aspect of the present invention, in the first to third aspects of the present invention, each of the outer bracket and the inner bracket has a left and right outer side at a base end side of the boom with respect to a boss position. It is characterized by comprising a base end side connection bracket fixed to the bracket and the inner bracket, respectively, and fixed to the outer diameter portion of each boss and the lower surface of the boom.

[0014] According to the fourth aspect of the present invention, the right and left outer brackets, the inner bracket, and the outer diameter portion of each boss are located on the base end side of the boom with respect to the boss position so as not to interfere with the operating range of the piston rod of the boom hoist cylinder. Also, since the base end side connection bracket is fixed to the lower surface of the boom, the strength of the boom hoist cylinder mounting device is greatly improved.

According to a fifth aspect of the present invention, there is provided a boom hoisting cylinder mounting apparatus according to the first to fourth aspects, wherein a lower surface of the boom having a cross section perpendicular to a longitudinal direction is formed in a trapezoidal shape, and an outer bracket, an inner bracket, and a front end side connection bracket are provided. , And the base-side connecting booklet are fixed to the lower surface of the boom via a common mounting plate formed in a trapezoidal shape along the lower surface of the boom.

According to the fifth invention, after the boom-lifting cylinder mounting device fixed to the mounting plate is manufactured separately from the boom,
When the mounting plate is fixed to the boom, the mounting plate is easily positioned and mounted on the lower surface of the boom. For this reason, the boom hoist cylinder mounting device is easily manufactured, and the strength of the boom hoist cylinder mounting device and the boom lower surface is improved.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a boom raising / lowering cylinder mounting apparatus according to the present invention; FIG.

4 and 5, the lower surface of the boom 6 mounted on the upper swing body 21 so as to be able to undulate is shown in detail in FIG. 1 on the side of the driver's cab 22 mounted on the upper swing body 21. The boom hoist cylinder mounting device 10 is fixed. The piston rod 5a of the boom hoist cylinder 5 slidably mounted on the upper swing body 21 is swayably mounted on the boom hoist cylinder mounting device 10 by the support pin 7. Point P in FIG. 1 indicates the position of the eyes when the operator sits on the seat.

In FIG. 1, a mounting plate 9 is fixed to the lower surface of the boom 6, and a pair of left and right outer brackets 1, 1 and inner brackets 2, 2 are fixed to the mounting plate 9. The thickness t1 of the outer bracket 1 is formed to be greater than the thickness t2 of the inner bracket 2, and the outer bracket 1 is fixed to a side portion of the lower surface of the boom 6, and a boss 3 is formed at a portion bent inward by 1 from the boom side. It is fixed. The outer bracket 1 and the inner bracket 2 include a boom hoist cylinder 5
Left and right bosses 3 that support the piston rod 5a on both sides by support pins 7 are fixed.

The distal end side connecting bracket 4 fixed to the outer bracket 1 and the inner bracket 2 is moved from the front end fixed to the lower surface of the boom 6 to the longitudinal direction of the boom 6 by 10 mm.
Rise angle θ1 from the lower surface of the boom 6 forming an angle of 30 °
And a rising angle θ2 at which a tangent line between the straight portion having the following shape and the straight portion extends in the direction of the boss 3 and the tangent line of the outer diameter front end portion of the boss 3 forms 80 ° to 100 ° with respect to the longitudinal direction of the boom 6.
And a curvature R (= 2D) twice the diameter D of the support pin 7
And a curved portion having

Also, at the base end side of the boom 6 from the position of the boss 3 of the boom hoisting cylinder mounting device 10, the left and right outer brackets 1 and the inner bracket 2, the outer diameter portions of each boss 3 and the lower surface of the boom 6 are located. Each of the base end side connection brackets 8 is fixed.

According to the structure of FIG. 1, the operation is as follows.
Since the rising angle of the distal end side connection bracket 4 from the lower surface of the boom 6 is set to approximately 20 °, there is no abrupt change in the cross section of the connection portion with the boom 6 and stress concentration can be avoided. Further, the curvature R of the curved portion that extends in the direction of the boss 3 continuously to the linear portion and has a rising angle of a tangent to the outer diameter front end portion of the boss 3 of approximately 90 ° is twice the diameter D of the pin 7. As a result, the strength required for the distal end side connection bracket 4 can be sufficiently satisfied, and the area occupied by the boom distal end side in the side view of the boom hoisting cylinder mounting device 10 is reduced by the area shown by hatching in FIG. . For this reason, the visibility from the operator ahead of the boom hoist cylinder mounting device 10 is greatly improved.

When the outer bracket 1 is fixed to the side of the lower surface of the boom 6 and the boss 3 is fixed to a portion bent inward by 1 from the side of the boom, the operator before the boom raising and lowering cylinder mounting device 10 is fixed as follows. The visibility is improved, and the weight is reduced if the lengths of the boss 3 and the support pin 7 are reduced.

FIG. 3 shows that the lower end 51a of the conventional outer bracket 51 is raised by .delta.
a and the lower end 5 of the conventional outer bracket 51
1a apart from 1a (the equivalent rise of the lower end 51a is δ
b) When the lower end portion 1b of the outer bracket 1 is used, the lower end portion 51a of the conventional outer bracket 51 is raised upward by δa and separated by 1 (the equivalent rise amount of the lower end portion 51a is δc). It is a figure which shows the expansion amount of visibility in the case where it is set as the lower end part 1c of FIG. In the mobile crane 20 shown in FIG. 4, the distance from the operator's eye position P to the side end of the mobile crane is almost four times the distance L from the operator's eye position P to the outer bracket 1. . Therefore, the amount of expansion of the field of view with respect to the lower end 51a at the side end of the mobile crane is 4δ at the lower end 1a.
a, 4δb at the lower end 1b, and 4δc at the lower end 1c. In each case, a field of view that is four times the amount of rise δa from the lower end 51a and the corresponding amount of rise δb, δc is obtained. As described above, the slight rise of the lower end portion 1a of the outer bracket 1 makes the visibility more remarkable as the distance increases.

Also, as in the embodiment of the present invention, the lower end 51a of the conventional outer bracket 51 is raised upward by δa and the amount of expansion of the field of view by the lower end 1c further away by 1 from the viewpoint of the operator. It can be seen that 4δc is the largest as compared with the amount of view expansion 4δa, 4δb by the lower end 1a and the lower end 1b.

The load acting on the support pin 7 is more borne by the outer bracket 1 having a greater plate thickness t1 and increased rigidity, and the load borne by the inner bracket 2 is reduced as compared with the prior art. For this reason, the load transmitted to the boom 6 having a small rigidity to which the inner bracket 2 is welded is reduced, and the concentration of stress acting on the boom of the boom 6 and the wick point of the inner bracket 2 is prevented. The durability is improved.

At the base end side of the boom 6 from the position of the boss 3, the outer diameter parts of the left and right outer brackets 1, the inner bracket 2, and each boss 3 are located at positions that do not interfere with the operating range of the piston rod 5 a of the boom hoist cylinder 5. Also, since the base end side connection bracket 8 is fixed to the lower surface of the boom 6, the strength of the boom base cylinder mounting device 10 at the base end side of the boom is greatly improved.

After the boom hoist cylinder mounting device 10 fixed to the mounting plate 9 is manufactured separately from the boom 6, the mounting plate 9 is easily positioned on the lower surface of the boom 6 and the mounting plate 9 is moved to the boom 6.
Can be fixed.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a boom hoist cylinder mounting device according to the present invention, wherein (A) is a side view, (B) is a bottom view,
(C) is a front view.

FIG. 2 is a comparison diagram of the boom hoist cylinder mounting device according to the present invention and a conventional technology.

FIG. 3 is an explanatory diagram of visibility corresponding to an AA cross section in FIG. 1;

FIG. 4 is a view showing a mobile crane equipped with a boom hoist cylinder mounting device according to the present invention, wherein (A) is a plan view,
(B) is a side view.

FIG. 5 is a view showing a mounting relationship of the boom hoist cylinder of FIG. 4;

FIG. 6 is a view showing a conventional technique, (A) is a side view,
(B) is a front view, and (C) is a CC sectional view of (A).

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 outer bracket 2 inner bracket 3 boss 4 distal connection bracket 5 boom hoist cylinder 5 a piston rod 6 boom 7 support pin 8 base end connect bracket 9 mounting plate 10 boom hoist cylinder mounting device 20 mobile crane 21 upper revolving unit 22 operation Room

Claims (5)

[Claims] An operator's cab (2) mounted on an upper revolving superstructure (21).
A pair of left and right outer brackets (1) fixed to the lower surface of a boom (6) that is mounted on the upper revolving unit (21) by a boom lifting cylinder A pair of left and right inner brackets (2) arranged on the upper and lower surfaces of the outer bracket (1) and the inner bracket (2) and swingably mounted on the upper revolving unit (21). (5) Insert the piston rod (5a)
(7) is fixed between the left and right bosses (3) supported on both sides by the outer bracket (1) and the inner bracket (2), and the front end is fixed to the lower surface of the boom (6). A boom hoisting cylinder mounting device comprising a front end connecting bracket (4) having a rear end portion fixed to a boss (3);
Boom (0) to 30 ° Boom (6) A straight part having a rising angle from the lower surface and a tangent line between the straight part and the boss (3) extending in the direction of the boss (3) and the front end of the outer diameter of the boss (3). (6)
It has a rising angle of 80 ° to 100 ° with respect to the longitudinal direction, and has a curved portion having a curvature equal to or larger than the diameter of the support pin (7) at a connection portion with the tangent line. Boom hoisting cylinder mounting device. 2. A driver's cab (2) mounted on the upper revolving superstructure (21).
A pair of left and right outer brackets (1) fixed to the lower surface of a boom (6) that is mounted on the upper revolving unit (21) by a boom lifting cylinder A pair of left and right inner brackets (2) arranged on the upper and lower surfaces of the outer bracket (1) and the inner bracket (2) and swingably mounted on the upper revolving unit (21). (5) Insert the piston rod (5a)
(7) is fixed between the left and right bosses (3) supported on both sides by the outer bracket (1) and the inner bracket (2), and the front end is fixed to the lower surface of the boom (6). And a boom hoisting cylinder mounting device having a front end connecting bracket (4) having a rear end fixed to a boss (3), wherein the outer bracket (1) is fixed to a lower side of the boom side plate and bent inward from the same. A boom hoist cylinder mounting device, characterized in that a boss (3) is fixedly attached. 3. The boom hoist cylinder mounting device according to claim 1, wherein the thickness of the outer bracket (1) is greater than the thickness of the inner bracket (2). 4. A boss according to claim 1, wherein each of the outer bracket (1) and the inner bracket (2) has a boss.
At the base end of the boom (6) from the position (3), they are fixed to the left and right outer brackets (1) and the inner bracket (2), respectively, and the outer diameter of each boss (3) and the boom (6) A boom hoist cylinder mounting device, comprising: a base-side connecting bracket (8) fixed to the lower surface, respectively. 5. A boom (6) having a cross section perpendicular to the longitudinal direction, wherein the lower surface is formed in a trapezoidal shape, and an outer bracket (1), an inner bracket (2), and a front connection bracket are provided.
(4) and the base-side connecting booklet (8) are fixed to the lower surface of the boom (6) via a common mounting plate (9) formed in a trapezoidal shape along the lower surface of the boom (6). Boom hoisting cylinder mounting device.