JP2000212986A - Boom construction for backhoe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve workability by permitting to easily insert a pin into an inserting hole and to easily pull it out even though the position of the insertion hole of the pin used for connection between a boom and a bucket is slightly deviated. SOLUTION: An arm 14 at the tip side is housed inside an arm 13 at the base end side in a freely slidable manner thereby constituting a boom 3 of a back hoe 1 in a flexible manner, and the arm 14 at the tip side is fixed to the arm 13 at the base end side with a fixing pin 33 penetrated to both the arms (13, 14). In addition, the fixing pin 33 is formed to a taper shape shrunk from the base end portion of the fixing pin 33 to the tip portion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backhoe boom structure.

[0002]

2. Description of the Related Art Conventionally, as a backhoe used in civil engineering work, a base end of a boom is disposed at a front end of a traveling vehicle body so as to be vertically rotatable, and a bucket is vertically rotatable at a tip of the boom. And a cylinder for rotating the bucket up and down is provided between the bucket and a middle part of the boom.

In such a boom of a backhoe, a bucket is rotatably connected to a tip of the boom by a cylindrical connecting pin penetrating the tip of the boom and the bucket.

Further, the same cylindrical pivot pin as described above has been used also in the middle part of the boom and the base end of the cylinder, and also at the tip of the bucket and the cylinder.

[0005]

However, in the above-mentioned conventional backhoe boom, since the respective parts are connected by using cylindrical pins, for example, when removing or inserting a pin at the time of bucket exchange or the like. , The through-hole drilled at the end of the boom and the through-hole drilled in the bracket of the bucket are slightly displaced and the pin cannot be pulled out or inserted. It took time and the workability was not good.

[0006] Further, in order to excavate the ground more deeply, there has been known a structure in which a distal end portion of a boom is slidably housed inside a proximal end arm so as to be slidable. However, when the base arm and the distal arm are fixed with fixing pins that penetrate both arms in order to reduce the cost, the use of a columnar fixing pin as in the related art is also described above. Similarly to the above, there is a possibility that a problem that a great deal of labor and time are required for inserting and removing the fixing pin may occur.

[0007]

Therefore, according to the present invention, the distal end arm is slidably housed inside the proximal end arm so that the boom of the backhoe can be extended and contracted. The distal arm is fixed to the end arm with a fixing pin penetrating both arms, and the fixing pin is formed in a tapered shape whose diameter decreases from the base end to the distal end of the fixing pin.

According to the present invention, the bucket is rotatably connected to the tip of the boom by a connecting pin penetrating the tip of the boom and the bucket. It is formed in a tapered shape whose diameter is reduced from the base end to the front end.

According to the third aspect of the present invention, the bucket is rotatably disposed at the tip of the boom, while the cylinder support is disposed in the middle of the boom, and the cylinder support is provided on the cylinder support. Pivotally connected to the base end of the cylinder with a pivot pin passing through the cylinder support and the base end of the cylinder, and the bucket is turned around the tip of the cylinder with a pivot pin passing through the tip of the cylinder and the bucket. The pivot pins are movably connected, and at least one of the pivot pins is formed in a tapered shape whose diameter is reduced from a base end to a distal end of the pivot pin.

According to the present invention, the distal arm is slidably housed inside the proximal arm so that the boom of the backhoe can be extended and contracted. While the bucket is rotatably disposed, the cylinder support is slidably disposed on the proximal arm along the proximal arm, and a connecting rod is provided between the cylinder support and the distal arm. And a pivot pin connecting the base end of the cylinder and the connecting rod to the cylinder support with a pivot pin that passes through the base end of the cylinder support, the base end of the cylinder, and the base end of the connecting rod. The pin is formed in a tapered shape in which the diameter is reduced from the proximal end to the distal end of the coaxial pin.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A boom structure of a backhoe according to the present invention is constructed such that a distal arm is slidably housed inside a proximal arm so that the boom of the backhoe can be extended and retracted, and the proximal arm is provided with The distal arm is fixed with a fixing pin penetrating both arms, and the fixing pin is formed in a tapered shape whose diameter decreases from the base end to the distal end of the fixing pin.

Therefore, even if the position of the fixing pin formed in the base arm and the position of the fixing pin formed in the distal arm are slightly shifted, the fixing pin can be easily inserted into both the holes. In addition, the fixing pin can be easily pulled out from both the insertion holes, so that the time and labor required for extending and retracting the boom that can be extended and retracted can be reduced.

In the backhoe boom structure according to the present invention, the connecting pin used for connecting the boom to the bucket and the pivot pin used for connecting the bucket to the cylinder are also provided in the same manner as described above. It is formed in a tapered shape whose diameter is reduced from toward the tip.

Therefore, even if the positions of the insertion holes of the pins are slightly shifted, the pins can be easily inserted into the insertion holes, and the pins can be easily pulled out from the insertion holes, thereby improving workability. That can be done.

[0015]

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

FIG. 1 is a view showing a backhoe 1 according to the present invention. In the backhoe 1, a boom 3 is disposed at the front end of a traveling vehicle body 2 so as to be vertically rotatable. The bucket 4 is disposed so as to be vertically rotatable.

The ground 5 can be excavated by rotating the boom 3 and the bucket 4.

The boom 3 includes a supporting arm 6 and a rotating arm 7.
And a support bracket 8 at the front end of the traveling vehicle body 2.
The base end of the support arm 6, which is shaped like an ellipse in plan view, is pivotally attached to the support bracket 8 so as to be vertically rotatable. It is pivotally attached. In the figure, 9 is a support arm rotation cylinder for vertically rotating the support arm 6, 10 is a rotation arm rotation cylinder for vertically rotating the rotation arm 7, and 11 and 12 are cylinder rods.

As shown in FIGS. 2 to 4, the rotating arm 7 has a proximal arm 13 having a hollow rectangular cross section rotatably connected to the distal end of the supporting arm 6 and a proximal end. Side arm
The distal arm 14 is slidably housed in the hollow portion of the base 13 along the inner surface of the proximal arm 13. In addition, FIG. 2 shows that the distal arm is provided inside the proximal arm 13.
FIG. 3 shows a state in which the rotating arm 7 is shortened by accommodating the rotating arm 7, and FIG. 3 shows a state in which the distal arm 14 is pulled out from the inside of the proximal arm 13 and the rotating arm 7 is extended.

The proximal arm 13 includes a pair of left and right side walls 15,1.
6 and the upper and lower edges provided between the upper and lower edges of the left and right side walls 15, 16.
The lower walls 17 and 18 form a rectangular tube. In the figure, 19
Is a guide projection, 20 is a bracket formed at the base end of the base side arm 13, 21 and 22 are connection pin insertion holes, and the connection pin insertion hole 21 has a cylinder of the rotation arm rotation cylinder 10. The distal end of the rod 12 is connected with a connecting pin 23, and the distal end of the support arm 6 is inserted into the connecting pin insertion hole 22.
Connected by 24.

The distal arm 14 has a pair of left and right side walls 25, 2
6 and the upper and lower edges provided between the upper and lower edges of the left and right side walls 25 and 26.
The lower walls 27 and 28 form a rectangular tube.

The left and right side walls 1 of the proximal arm 13
The four outer fixing pin insertion holes 29 penetrating the left and right side walls 15, 16 are provided at intervals along the extension direction of the proximal arm 13 at the left and right side walls 15, 16, respectively. In the left and right side walls 25 and 26 of the arm 14, five inner fixing pin insertion holes 30 penetrating the left and right side walls 25 and 26 are provided at intervals along the extension direction of the distal arm 14. Between the inner fixing pin insertion holes 30 and 30 facing each other, the inner fixing pin insertion hole 30 of the left side wall 25 and the inner fixing pin insertion hole of the right side wall 26 are provided.
A fixing pin holding boss 32 having a tapered hollow portion 31 reduced in diameter toward 30 is installed, and both fixing pin insertion holes 29, 3 are provided.
0 and the fixing pin 33 is inserted into the hollow portion 31 of the fixing pin holding boss 32 to form a male screw portion 34 formed at the tip of the fixing pin 33.
The base arm 13 and the distal arm 14 are fixed by screwing a nut 35 to the arm. In the figure, 36
Is a reinforcing rib.

The outer fixing pin insertion hole 29 and the inner fixing pin insertion hole 30 are formed such that the inner diameters of the insertion holes 29, 30 formed in the left side wall 25 are larger than those of the insertion holes 29, 30 formed in the right side wall 26. Larger than the inside diameter of

As shown in FIG. 4, the fixing pin 33 has a disc-shaped receiving portion 37 and a tapered portion 38 connected to the receiving portion 37 and formed in a tapered shape whose diameter is reduced toward the distal end. And a male screw portion 34 formed from the base end to the tip end of the tapered portion 38. In the figure, reference numeral 39 denotes a slit.

As described above, the rotating arm 7 is connected to the base side arm.
Since the arm 13 and the distal end side arm 14 are configured to be extendable and contractable, and the arms 13 and 14 are fixed by the fixing pins 33, the rotating arm 7 can be extended and contracted with a simple configuration. The time and labor required for manufacturing the arm 7 can be reduced, and the manufacturing cost can be reduced.

In this embodiment, since the fixing pin 33 is formed in a tapered shape whose diameter is reduced from the base end to the tip end, the fixing pin insertion hole 29 and the tip Even if the position of the inner fixing pin insertion hole 30 of the side arm 14 is slightly shifted, the fixing pin 33 can be easily inserted into both the insertion holes 29, 30 and the fixing pin can be inserted from both the insertion holes 29, 30. 33 can be easily pulled out, so that the time and labor required for the extension and retraction of the rotatable arm 7 that can be extended and contracted can be reduced.

That is, the outer fixed pin insertion hole 29 of the proximal arm 13 and the inner fixed pin insertion hole 30 of the distal arm 14
Even if the position of the fixing pin 33 is slightly shifted, since the inner diameter of the outer fixing pin insertion hole 29 of the left side wall 25 is larger than the outer diameter of the tip of the fixing pin 33, the fixing pin 33 is inserted into the outer fixing pin insertion hole 30. Can be easily inserted and the fixing pin 33
When the leading end of the fixing pin 33 is inserted into the outer fixing pin insertion hole 29, the outer peripheral surface of the taper portion 38 of the fixing pin 33 is inserted into the inner fixing pin insertion hole.
By contacting the inner peripheral surface of 30 and further pressing the fixing pin 33 toward the distal end, the tapered portion 38 is formed in a tapered shape whose diameter is reduced toward the distal end.
The taper portion 38 of the inner fixing pin insert hole 30
9 and 30 are pressed in the direction to correct the misalignment, so that the gap between the outer fixing pin insertion hole 29 and the inner fixing pin insertion hole 30 is corrected, and the fixing pin 33 is easily inserted into both the insertion holes 29 and 30. Can be inserted.

On the other hand, when the fixing pin 33 is pulled out from both the insertion holes 29 and 30, the fixing pin 33 is formed in a tapered shape whose diameter is reduced from the base end toward the front end.
When 33 moves toward the base end, the diameter of the tapered portion 38 passing through both the insertion holes 29 and 30 gradually decreases, so that the distal end of the fixing pin 33 faces the base end. The fixing pin 33 can be easily pulled out from both the insertion holes 29 and 30 simply by pressing and slightly moving it.

As shown in FIG. 6, an insertion hole for a connecting pin penetrating through the left and right side walls 25 and 26 is formed at the distal end of the distal arm 14.
A connecting pin holding having a tapered hollow portion 43 in which both the connecting pin insertion holes 42 are bored and the diameter of which is reduced from the left connection pin insertion hole 42 to the right connection pin insertion hole 42 in both the connection pin insertion holes 42. And a pair of left and right brackets 45, 45 are connected to the base end of the bucket 4, and the two brackets 45, 45 are used for connecting pins that penetrate both brackets 45, 45. An insertion hole 46 is formed, and a bearing holder 48 having a tapered hollow portion 47 is welded to the connection pin insertion hole 46 of the bracket 45 on the right side. A bearing 49 is provided between the boss 44 and the boss 44. In the figure, reference numeral 92 denotes an O-ring, which prevents dust from entering the bearing 49.

The connecting pin 50 is inserted into the connecting pin insertion holes 42 and 46, the hollow portion 43 of the connecting pin holding boss 44, and the hollow portion 47 of the bearing holder 48. The bucket 4 is rotatably connected to the distal end of the distal arm 14 by screwing a nut 52 to a male screw portion 51 formed in the portion. In the figure, 53 is a washer.

The inner diameter of the connection pin insertion holes 42, 46 on the left side is larger than the inner diameter of the connection pin insertion holes 42, 46 on the right side.
It is larger than the inner diameter of 42,46.

As shown in FIG. 6, the connecting pin 50 is, like the fixing pin 33, provided with a disk-shaped receiving portion 54 and connected to the receiving portion 54 so as to extend from the base end to the tip end. It comprises a tapered portion 55 formed in a tapered shape with a reduced diameter, and a male screw portion 51 formed at the tip of the tapered portion 55. In the figure, 56 is a slit.

As described above, in the present embodiment, since the connecting pin 50 is formed in a tapered shape whose diameter is reduced from the base end toward the front end, the connecting pin 50 is formed in the same manner as the fixing pin 33 described above. Even if the position of the connecting pin insertion hole 42 of the arm 14 and the position of the connecting pin insertion hole 46 of the bucket 4 are slightly displaced, the connecting pin 50 can be easily inserted into both the insertion holes 42, 46. The connecting pin 50 can be easily pulled out from the insertion holes 42 and 46, and the time and labor required for attaching and detaching the distal arm 14 and the bucket 4 can be reduced.

The bearing holder 48 and the connecting pin holding boss are also provided.
Since the bearing 49 is interposed between the boss 44 and the bearing 44, the frictional resistance between the boss 44 for holding the connecting pin and the bearing holder 48 is reduced, the bucket 4 can rotate smoothly, and Wear and breakage of the holding boss 44 and the bearing holder 48 can be prevented.

That is, since the connecting pin 50 is formed in a tapered shape whose diameter is reduced from the base end to the distal end, when the bucket 4 is rotated around the axis of the connecting pin 50, the distal arm 14 is A load is applied in the direction of moving the connecting pin 50 from the base end side to the distal end side along the tapered surface of the tapered portion 55 of the connecting pin 50.
Is pressed against the left side surface of the bearing holder 48, but by the action of the bearing 49 interposed between the bearing holder 48 and the connection pin holding boss 44, the connection pin holding boss is
The frictional resistance between 44 and bearing holder 48 is reduced.

At the distal end of the lower wall 18 of the proximal arm 13,
An inverted L-shaped stopper 40 is attached in side view, with the tip protruding toward the upper wall 17, while the lower wall of the tip side arm 14 is attached.
At the base end of 28, a plate-shaped receiver 41 is attached.

Then, as shown in FIG.
When the distal arm 14 is pulled out from 13, the stopper 40
As a result, the receiving body 41 is locked, and the distal arm 14 is prevented from falling off from the proximal arm 13, thereby improving the safety of the rotating arm 7 at the time of expanding and contracting.

When the stopper 40 and the receiver 41 are locked, the positions of the two outer fixing pin insertion holes 29 formed at the distal end of the proximal arm 13 and the proximal end of the proximal arm 14 are determined. The position of the two inner fixing pin insertion holes 30 formed in the part is matched so that the fixing pin 33 can be easily inserted or pulled out of both insertion holes 29, 30 to improve workability. ing.

As shown in FIGS. 2 to 4, guide rails 57 are provided on the upper end edges of the left and right side walls 15 and 16 of the proximal end arm 13.
Are formed along the extension direction of the proximal arm 13, and a cylinder support 58 is slidably mounted on the guide rail 57 along the upper wall 17 of the proximal arm 13.

As shown in FIG. 4, the cylinder support 58 is composed of a pair of left and right support component pieces 59, 59. Each support component piece 59 has a guide rail 57 engaged with the inside of the base end. To form a guide rail engagement recess 60 for
A pivot pin insertion hole 61 is formed at the tip. In the figure, 62
Is a wear reducing member made of a nylon material for reducing wear of the guide rail 57 due to friction between the guide rail 57 and the guide rail engaging recess 60.

The inner diameter of the pivot pin insertion hole 61 formed in the left support member piece 59 is smaller than the inner diameter of the pivot pin insertion hole 61 formed in the right support member piece 59. Larger than.

The cylinder support 58 has a base end portion of a cylinder 63 for rotating the bucket 4 up and down,
A pair of left and right connecting rods 64, 64 for fixing the cylinder support 58 relatively to the distal arm 14 are pivotally connected to the base ends of the pair of connecting rods 64 by a pivot pin 65. In the figure, 74 is a cylinder rod. The connecting rod 64 has a substantially U-shaped cross section to improve the strength.

As shown in FIG. 4, a hollow cylindrical boss 66 for inserting a pivot pin is formed at the base end of the cylinder 63. Axis pin insertion hole of support member 59 on right side from pin insertion hole 61
A tapered hollow portion 67 whose diameter is reduced toward 61 is formed.

At the base ends of the pair of left and right connecting rods 64, insertion holes 68, 68 for pivot pins are formed at positions facing each other. still,
The inner diameter of the pivot pin insertion hole 68 formed in the left connection rod 64 is larger than the inner diameter of the pivot pin insertion hole 68 formed in the right connection rod 64.

The pivot pin 65 is inserted through the pivot pin insertion hole 61 of the cylinder support 58, the pivot pin insertion hole 68 of the connecting rod 64, and the hollow portion 67 of the cylinder 63.
A nut 70 is screwed into a male screw portion 69 formed at the tip of the 65.

As shown in FIG. 4, the pivot pin 65, like the fixing pin 33 and the connecting pin 50, is connected to the disc-shaped receiving portion 71 and the receiving portion 71, and is directed toward the distal end. It comprises a tapered portion 72 formed in a tapered shape with a reduced diameter, and a male screw portion 69 formed at the tip of the tapered portion 72. In the figure, 73 is a slit.

As described above, in this embodiment, the pivot pin 65 is formed in a tapered shape whose diameter is reduced toward the distal end.
As in the case of the fixing pin 33 and the connection pin 50 described above, the positions of the pivot pin insertion hole 61 of the cylinder support 58, the pivot pin insertion hole 68 of the connection rod 64, and the hollow portion 67 of the cylinder 63 are slightly different. Even if it is misaligned, insert the pivot pin 65 into both insertion holes 61 and 6
8 and the hollow portion 67, and the pivot pin 65 can be easily pulled out from both the insertion holes 61 and 68 and the hollow portion 67, and the time required for assembling and disassembling the boom 3 of the backhoe 1 can be improved. And labor can be reduced.

In this embodiment, since the base end of the cylinder 63 and the base end of the connecting rod 64 are coaxially mounted on the cylinder support 58, the size and weight of the cylinder support 58 can be reduced. And the connecting rod 64 firmly supports the base end of the cylinder 63. When the cylinder rod 74 of the cylinder 63 is advanced and retracted, the cylinder support 58
Of the cylinder support 58 (particularly, the guide rail engaging recess 60 of the cylinder support 58). Damage) can be prevented.

At the tip of the cylinder rod 74, FIG.
As shown in FIG. 3 and FIG.
The middle part of 5,75 is pivotably connected to the middle part, and the interlocking link 75,75
The brackets 45, 45 of the bucket 4 are rotatably connected to the tip of the bracket.

That is, a pivot pin insertion hole 76 penetrating both link links 75, 75 is formed at the tip of a pair of left and right link links 75, 75. Welding is performed while a pivot pin holding boss 78 having a tapered hollow portion 77 whose diameter is reduced from the pin insertion hole 76 toward the right pivot pin insertion hole 76 is inserted, and the bucket 4 is welded.
The bracket 45 has a through hole 79 for a pivot pin passing through both brackets 45, 45, and the bearing holder 81 having a tapered hollow portion 80 in the through hole 79 for the pivot pin of the right bracket 45. And a bearing 82 is interposed between the bearing holding body 81 and the boss 78 for holding the pivot pin. In the figure, reference numeral 93 denotes an O-ring, which prevents dust from entering the bearing 82.

Then, the pivot pin 83 is inserted through the insertion holes 76 and 79 for the pivot pin, the hollow portion 80 of the boss 78 for retaining the pivot pin, and the hollow portion 80 of the bearing holder 81, and the tip of the pivot pin 83 The bucket 4 is rotatably connected to the distal end of the interlocking link 75 by screwing a nut 85 to a male screw portion 84 formed in the portion. In the figure, reference numeral 86 denotes a washer.

The pivot pin insertion holes 76 and 79 are formed such that the inner diameter of the left pivot pin insertion holes 76 and 79 is larger than that of the right pivot pin insertion hole.
It is larger than the inner diameter of 76,79.

As shown in FIG. 5, the pivot pin 83 has a disc-shaped receiving portion 87 and a tapered shape connected to the receiving portion 87 and reduced in diameter toward the distal end as shown in FIG. Formed taper section 88
And a male screw portion 84 formed at the tip of the tapered portion 88. In the figure, reference numeral 89 denotes a slit.

As described above, in this embodiment, since the pivot pin 83 is formed in a tapered shape whose diameter is reduced toward the distal end,
As described above, even if the position of the pivot pin insertion hole 76 of the interlocking link 75 and the position of the pivot pin insertion hole 79 of the bucket 4 are slightly shifted, the pivot pin 83 can be easily inserted into both the insertion holes 76, 79. Axis pins 83 can be inserted through both insertion holes 76 and 79.
Can be easily pulled out, and the time and labor required for attaching and detaching the interlocking link 75 and the bucket 4 can be reduced.

Further, the bearing holder 81 and the boss for holding the pivot pin are provided.
Since the bearing 82 is interposed between the bearing 78 and the bearing 78, the frictional resistance between the pivot pin holding boss 78 and the bearing holder 81 is reduced as described above, and the bucket 4 can rotate smoothly. Can,
Further, wear and breakage of the pivot pin holding boss 78 and the bearing holder 81 can be prevented.

The distal end of the connecting rod 64 is pivotally attached to a support 90 projecting from the distal end of the upper wall 27 of the distal arm 14. In the figure, reference numeral 91 denotes a support shaft.

Then, as shown in FIG.
When the rotating arm 7 is shortened by housing the distal arm 14 inside the base 13, the base of the support body 90 contacts the distal end of the proximal arm 13, and the distal end of the proximal arm 13. Positions of the two outer fixing pin insertion holes 29 formed in the base part and the base end, and two inner fixing pin insertion holes 30 formed in the base end and the tip part of the base side arm 14, respectively. And the fixing pin 33 can be easily inserted or pulled out from both the insertion holes 29, 30 to improve workability.

[0058]

The present invention is embodied in the form described above and has the following effects.

That is, in the present invention, since the tapered pin whose diameter is reduced from the base end to the distal end is used, even if the position of the pin insertion hole is slightly shifted, the pin is inserted. The pin can be easily pulled out from the insertion hole, and the workability can be improved.

That is, since the tapered pin whose diameter is reduced from the base end toward the tip is used, even if the position of the pin insertion hole is slightly shifted, the outer diameter of the pin tip is smaller than the outer diameter of the pin. Because the inside diameter of the insertion hole of one pin is larger,
The tip of the pin can be easily inserted into the insertion hole, and when the tip of the pin is inserted into the insertion hole, the outer peripheral surface of the tapered portion of the pin comes into contact with the inner peripheral surface of the insertion hole, and the pin is further inserted. By pressing toward the distal end, the tapered portion is formed in a tapered shape whose diameter is reduced toward the distal end, so that the tapered portion of the pin presses the insertion hole in a direction to correct the displacement between the insertion holes. Therefore, the displacement between the insertion holes is corrected, and the pins can be easily inserted into the insertion holes.

On the other hand, when pulling out the pin from the insertion hole,
Because the tapered portion is formed in a tapered shape with a diameter reduced from the base end to the tip, the diameter of the tapered portion passing through the insertion hole gradually decreases when the pin moves toward the base end. Therefore, the pin can be easily pulled out from the insertion hole only by pressing the distal end of the pin toward the base end and moving it slightly.

[Brief description of the drawings]

FIG. 1 is a side view showing a backhoe according to the present invention.

FIG. 2 is a side view showing a state where a rotating arm is shortened.

FIG. 3 is a side view showing a state where a rotating arm is extended.

FIG. 4 is a sectional view taken along the line II of FIG. 2;

FIG. 5 is a sectional view taken along line II-II of FIG. 2;

FIG. 6 is a sectional view taken along the line III-III in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Backhoe 3 Boom 4 Bucket 6 Support arm 7 Rotating arm 13 Base arm 14 Distal arm 33 Fixing pin 57 Guide rail 58 Cylinder support 63 Cylinder 64 Connecting rod 65,83 Axis pin

Claims (4)

[Claims] 1. A distal arm inside a proximal arm (13).
(14) slidably housed and boom (3) of backhoe (1)
The telescopic arm is configured to be telescopic and the distal arm is attached to the proximal arm (13).
(14) is fixed with a fixing pin (33) penetrating both arms (13, 14), and the fixing pin (33) is reduced in diameter from the base end of the fixing pin (33) to the tip end. Backhoe boom structure characterized by a tapered shape. 2. A connecting pin which penetrates the bucket (4) at the tip of the boom (3) and penetrates the tip of the boom (3) and the bucket (4).
(50) to be connected rotatably, and the connecting pin (50)
(50) The boom structure of the backhoe, wherein the boom is formed in a tapered shape whose diameter is reduced from the base end to the tip. 3. A bucket (4) is rotatably disposed at the tip of the boom (3), and a cylinder support (58) is disposed in the middle of the boom (3). (58), the base end of the cylinder (63) is rotatably connected with a pivot pin (65) penetrating the cylinder support (58) and the base end of the cylinder (63), and the cylinder (63) Bucket at the tip of
(4) is rotatably connected by a pivot pin (83) penetrating the tip of the cylinder (63) and the bucket (4), and at least one of the pivot pins (65, 83) is the same. Axis pin (6
5,83) The boom structure of the backhoe, characterized in that it is formed in a tapered shape whose diameter is reduced from the base end to the tip. 4. A distal arm inside a proximal arm (13).
(14) slidably housed and boom (3) of backhoe (1)
The bucket (4) is rotatably arranged at the distal end of the distal arm (13), while the proximal arm (13)
A cylinder support (58) is slidably disposed along the proximal arm (13), and a connecting rod (64) is provided between the cylinder support (58) and the distal arm (14). Install the base of the cylinder (63) and the connecting rod (64) on the cylinder support (58) and the base of the cylinder support (58) and the cylinder (63) and the base of the connecting rod (64). The pivot pin (65) is rotatably connected with a pivot pin (65) that penetrates the part, and the pivot pin (65) is formed in a tapered shape whose diameter decreases from the base end to the tip of the same pivot pin (65). Backhoe boom structure characterized by: