JP2546925Y2 - Construction machine pin connection structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL APPLICATION Field of the Invention The present invention mainly relates to a structure of a pin connecting portion mounted on a construction machine such as a hydraulic shovel or a work vehicle.

2. Description of the Related Art FIG. 5 is a side view of a main part of a hydraulic excavator among construction machines. In the figure, 1 is a lower traveling body of a hydraulic shovel,
Reference numeral 2 denotes an upper revolving structure, 3 denotes a work attachment mounted on a front portion of the upper revolving structure 2, 4 denotes a boom of the work attachment 3, 5 denotes an arm, 6 denotes a bucket, and 7 denotes a single pin connecting portion. FIG. 6 is a cross-sectional view of the prior art pin joint 7 taken along line AA of FIG. In the figure, the pin coupling section 7 bracket 8, 9 _L is one side of the bracket plate of the bracket 8, 9 _R is the other side of the bracket plate, 10 is a boss,
11 and 12 are bushings, 13 is a gap adjusting bush, 14 is an adjusting bolt, 15 is a plurality of washers, 16 is a pin, 17 is a pin locking portion for fixing the pin 16 to the bracket 8, and 18 is a greasing. A grease nipple, which is a mouth, is an O-ring for sealing.

Next, the configuration of the conventional pin coupling section 7 will be described with reference to FIG. Allowed press-fitted wearing each bush 11, 12 in the boss hole both ends of the boss 10, the boss 10 to the bracket 8 pivotally connected via a pin 16, also on one side of the bracket plate 9 _L in the bracket 8 fitted gap adjusting bush 13, the a gap adjusting bush 13, the boss 10 is held between the other side of the bracket plate 9 _R, and to adjust the gap between the bracket 8 and the boss 10.

FIG. 7 is a cross-sectional view of a main part of the pin connecting portion 7 before the gap adjustment is performed. In the figure, S is a gap between the bracket 8 and the boss 10. A gap S as shown in FIG.
When the excavator performs excavation work, for example, the strength of the pin connection portion is adversely affected, and
An unpleasant rattling sound occurs. O-ring for sealing 19
Sealing effect is lost, so that the outside soil
Further, there is a possibility that the sliding portion between the inner peripheral surface of the bush 11 and the outer peripheral surface of the pin 16 may be damaged, causing a seizure accident or the like. To this end, the washer 15 is removed by a thickness corresponding to the gap S, and then the adjustment bolt 14 is tightened. Then, the flange portion A of the gap adjusting bush 13 is pressed, and the gap adjusting bush 13 moves inward. Since the gap S is eliminated as shown in FIG. 6, the bracket 8 and the boss 10 can rotate relative to each other without rattling.

Problems to be Solved by the Invention In the prior art pin joint portion, when adjusting the gap between the bracket and the boss, the flange portion of the gap adjusting bush is pressed with an adjusting bolt. For this purpose, a plurality of, for example, four, adjustment bolts are provided along the circumferential direction of the gap adjusting bush. The adjustment operation of the plurality of adjustment bolts is troublesome and takes a considerable amount of time because the number of adjustment bolts is large. Moreover, in the above operation, a plurality of adjustment bolts are adjusted one by one.
The gap adjusting bush was twisted and moved, and a smooth adjusting operation could not be performed.

In addition, since the gap adjusting bush must be adjusted and moved, the outer peripheral surface and the inner peripheral surface of the cylindrical portion of the gap adjusting bush are configured to be free from the inner peripheral surface of the bracket hole and the outer peripheral surface of the pin, respectively. I have. Therefore, when the boss rotates, the inner end surface of the flange portion of the gap adjusting bush comes into contact with the boss end surface, and the gap adjusting bush sometimes rotates with the rotation of the boss. Since the outer peripheral surface and inner peripheral surface of the gap adjusting bush are not lubricated, the outer peripheral surface and inner peripheral surface of the cylindrical portion of the gap adjusting bush, the inner peripheral surface of the bracket hole, and the outer peripheral surface of the pin are not required. It was found to cause damage.

According to the present invention, a cup-shaped metal fitting is fitted to a tip of a pin, and a cylindrical part of the cup-shaped metal is brought into contact with an end face of a gap adjusting bush. The gap between the side end face and the pin tip end face is set to a dimension that allows adjustment of the gap between the bracket and the boss, and the cup-shaped bracket is adjusted and tightened with one tightening bolt. Accordingly, an object of the present invention is to provide a pin connecting portion structure of a construction machine in which the gap adjusting bush can be slid and adjusted only in the direction of a pin axis.

Means for solving the problem a. In the pin connecting portion of the present invention, the bush is press-fitted to both ends of the boss hole of the boss, and the boss is turned between the left and right bracket plates of the bracket via pins fixed non-rotatably to the bracket plate. A gap-adjusting bush with a flange is connected to the bracket plate on one side of the bracket so as to be rotatable, but is not rotatable but slidably movable in the axial direction of the pin. The outer end face is inserted so as to be opposed to the end face of the boss, and the gap adjusting bush is adjusted and moved in the axial direction of the pin to adjust the gap between the flange outer end face and the boss end face. A pin connecting portion for adjusting a gap between the boss and the boss; (C) retracting and forming the outer end surface of the cylindrical portion of the gap adjusting bush so as not to protrude outward from the outer end surface of the bracket plate; Separately from the gap adjusting bush, the outer diameter dimension is smaller than the gap adjusting bush fitting insertion hole diameter of the bracket plate, and the inner diameter dimension has a dimension to fit loosely with the outer diameter dimension of the pin. And forming a cup-shaped bracket with a bolt hole formed in one end face side thick portion, d. The cylindrical portion of the cup-shaped metal fitting is fitted to the tip of the pin to bring the end surface of the cylindrical portion into contact with the end surface of the gap adjusting bush, and a tightening bolt is attached to the end surface side thick portion. Insert the bolt into the bolt hole and tighten it into the screw hole drilled in the pin end face, and also assemble the initial clearance between the inner end face of the end face side thick part of the cup-shaped bracket and the pin tip end face. , And the gap was set to an adjustable size.

Action b. In the present invention, a cup-shaped fitting is fitted to the tip of the pin, the end face of the cylindrical part of the cup-shaped fitting is brought into contact with the end face of the gap adjusting bush, and one tightening bolt is connected to the cup. It is inserted into a bolt hole drilled in the thick part on the end face side of the shaped metal fitting and tightened to the pin end face, so when performing the above tightening bolt adjustment and tightening operation, the cylindrical part side end face of the cup shaped metal fitting With a uniform force over the entire surface, the gap adjusting bush can be adjusted and moved smoothly and easily without twisting and moving.

B. In addition, since the gap dimension at the time of assembly between the inner end face of the end face side thick portion of the cup-shaped bracket and the tip end face of the pin is set to a gap adjustable dimension, the construction machine is operated for a long time and After multiple gap adjustments,
When the gap size at the time of the initial assembly becomes 0 (zero), that is, when the adjusting and tightening operation with the tightening bolts becomes impossible, at least one of the gap adjusting bush and the boss bush is subject to a wear limit. You can judge that there is.

C. Since the gap adjusting bush can be slid and adjusted only in the direction of the pin axis, when the boss is rotated with respect to the bracket, the cylindrical portion of the gap adjusting bush is formed on the inner peripheral surface of the bracket hole and It does not rotate with respect to the pin outer peripheral surface. Therefore, it is possible to prevent the outer peripheral surface or the inner peripheral surface of the cylindrical portion of the gap adjusting bush from damaging the inner peripheral surface of the bush insertion hole or the outer peripheral surface of the pin of the bracket plate.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing the pin connecting portion 20 of the present invention. In the figure, the same reference numerals are given to components using the same components as the conventional technology. 8 'is a bracket, 9' _L
Is a bracket plate on one side of the bracket 8 ', 9' _R is a bracket plate on the other side, 21 is a bush for adjusting the gap, 22 is a pin, 23 is a screw hole formed in the end face of the pin 22, and 24 is a cup type. A fitting, 25 is a fastening bolt, 26 is a detent pin, and 27 is a detent hole formed in the flange 28 of the gap adjusting bush 21. Note that the dimension φd ₁ shown in FIG. ₁ is the outer diameter of the pin 22 (the pin 22 is a straight pin), φD ₁ is the diameter of the gap adjusting bush 21 insertion hole of the bracket plate 9 ′ _L , φd ₂
Inner diameter of the cylindrical portion of the cup-shaped brackets 24, [phi] D ₂ is the outer diameter, the boss 10 dimensioned S 'bracket 8' of the cup-shaped fitting 24
The gap size at the time of assembling at the time of assembling, the dimension Sa is the cup-shaped bracket 24
At the time of assembling between the inner end face E of the thick portion d on the end face side and the end face of the pin tip. FIG. 2 is a detailed view of a portion B in FIG. FIG. 3 is a view as seen from CC of FIG.

Next, the configuration of the pin connecting portion 20 of the present invention will be described with reference to FIGS. Pin connector 20 of the present invention is allowed to press-fit wearing each bush 11, 12 in the boss hole both ends of the boss 10, the bracket plate 9 of the left and right bosses 10 bracket 8 _'L
When 9 'between _R, the bracket plate 9' _L and 9 'via a pin 22 which is non-rotatably fixed with respect to _R rotatably connected, also bracket plate 9 on one side of the bracket 8' Gap adjusting bush 21 with collar 28 for _L
Although the bush 21 is not rotatable due to the installation of the detent pin 26, the bush 21 is slidably movable in the axial direction of the pin 22, and the outer end face of the collar 28 is formed of the boss.
The bush 21 is adjusted to move in the axial direction of the pin 22 so as to face the end face of the boss 10, and the outer end face of the collar 28 and the end face of the boss 10 (in this case, the end of the boss 10 is 11 is fitted so that the gap between the bracket 8 and the boss 10 is adjusted by adjusting the gap between the bracket 8 and the boss 10. the outer end surface of the cylindrical portion of the bushing 21 b (shown in FIG. 2) is formed by recessed so as not to protrude outwardly from the bracket plate 9 _'L outer end face c, also bush 21
Separately, the outer diameter is smaller than the diameter (φD ₁ ) of the bush 21 fitting hole (φD ₁ ) of the bracket plate 9 ′ _L (the smaller dimension is φD ₂ ), and the inner diameter is the pin 22. Cup-shaped fitting 24 having a dimension (φd ₂ ) that can be loosely fitted to the outer diameter dimension (φd ₁ ), and having a bolt hole (indicated by the symbol “g”) drilled on one end face side thick portion d. The cylindrical part of the cup-shaped bracket 24 is fitted to the tip of the pin 22 so that the end face of the cylindrical part is brought into contact with the end face of the bush 21, and the tightening bolt is formed.
25 is inserted through the bolt hole and tightened into the screw hole 23 drilled in the end face of the pin 22, and the cup-shaped bracket 24
The gap Sa at the time of assembling between the inner end face E of the thick part d on the end face side and the tip end face of the pin 22 was set to a gap adjustable dimension.

Next, the operation of the pin connecting portion 20 of the present invention will be described. In the present invention, when adjusting the gap between the bracket 8 and the boss 10, the adjusting and tightening operation of one tightening bolt 25 shown in FIGS. 1 and 2 is performed. When performing the adjusting and tightening operation of the tightening bolt 25, the outer end surface B of the cylindrical portion of the bush 21 can be pressed with a uniform force over the entire end surface of the cup-shaped bracket 24 on the cylindrical portion side. Therefore, it is possible to smoothly and easily adjust and move the bush 21 without twisting it. In addition, the gap Sa at the time of initial assembly between the inner end face E of the thick part d on the end face side of the cup-shaped bracket 24 and the end face of the tip end of the pin 22 is set to a gap adjustable dimension. In the case where the gap size Sa at the initial stage of the assembly becomes 0 (zero) after the gap adjustment for the pin connecting portion 20 has been performed a plurality of times during the operation of the construction machine, that is, the adjustment tightening operation by the tightening bolt 25, If it is no longer possible, it can be determined that at least one of the bush 21 and the bush 11 for the boss 10 is at the wear limit.

Note the bracket plate 9 _'L in the present invention, since the detent pin 26 between the flange portion 28 of the bushing 21 is provided so that it can slide adjusted only move pin 22 to the bush 21, the bracket 8 cylindrical portion of the bush 21 when the boss 10 is rotated does not rotate relative to the inner peripheral surface and the pin 22 the outer peripheral surface of the bush holes in the bracket plate 9 _'L against. Therefore it is possible to prevent the outer peripheral surface or inner peripheral surface of the cylindrical portion of the bush 21 cause damage to the bush hole inner peripheral surface or the pin 22 the outer peripheral surface of the bracket plate 9 _'L.

FIG. 4 is a sectional view of a main part of a pin connecting portion 29 according to another embodiment of the present invention. Since the head of the tightening bolt 25 is surrounded by the outer end of the cup-shaped bracket 30 at the pin connecting portion 29, the tightening bolt 25 is protected against external debris and the like. Further, a plurality of washers 31 are provided between the end face of the pin 22 and the inner end face of the cup-shaped bracket 30. Also, bracket plate 3
The protrusion 32 protrudes from the inner peripheral surface of the 9 ′ _L hole, and the protrusion 32
A long groove 33 that can be engaged in accordance with
Are formed in the outer peripheral portion of the cylindrical portion in a direction parallel to the axis of the pin 22. The operation of the structure of the pin connecting portion 29 is the same as that of the pin connecting portion 20.

Effect of the Invention When adjusting the gap between the bracket and the boss in the pin connection portion of the present invention, one tightening bolt for fixing the cup-shaped bracket to the pin tip side is adjusted and tightened. . When performing the adjusting tightening operation of the tightening bolt, the outer end surface of the gap adjusting bush can be pressed with a uniform force over the entire end surface of the cup-shaped bracket on the cylindrical portion side. Therefore, the gap adjusting bush can be adjusted and moved smoothly and easily without being twisted and moved. In addition, since the gap dimension at the time of assembly between the inner end face of the end face side thick portion of the cup-shaped bracket and the tip end face of the pin is set to a gap adjustable dimension, the construction machine is operated for a long time and After the gap adjustment for the pin joint is performed a plurality of times, the gap dimension at the time of the
When the value becomes (zero), that is, when the adjusting and tightening operation with the tightening bolt becomes impossible, it can be determined that at least one of the gap adjusting bush and the boss bush is the wear limit. . Therefore, in the pin connecting portion of the present invention, the gap between the bracket and the boss can be easily adjusted in a very short time, and
The maintainability of the pin connection part can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a pin connecting portion of the present invention, FIG. 2 is a detailed view of a portion B in FIG. 1, FIG. 3 is a view taken along line CC of FIG. 2, and FIG. FIG. 5 is a side view of a main part of a hydraulic shovel, and FIGS. 6 and 7 are cross-sectional views of a conventional pin connecting part. 7,20,29… Pin joint 8,8 ′… Bracket 9 _L , 9 _R , 9 ′ _L , 9 ′ _R , 39 ′ _L … Bracket plate 10… Boss 13,21,21 ′… Gap adjusting bushing 16,22 Pin 23 Screw hole 24,30 Cup bracket 25 Tightening bolt 26 Rotating pin 28 Collar

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Koichiro Niwata 731-1 Minamishitazu, Gion-cho, Asanami-ku, Hiroshima, Hiroshima Hiroshima Prefecture Examiner Gozo Yanagi (56) Reference: Japanese Utility Model Application Sho-57-46124 (JP, U) Japanese Utility Model Application No. Sho 61-93548 (JP, U) Japanese Utility Model Application No. 64-47860 (JP, U) Japanese Utility Model Utility Model No. 63-1055 (JP, U) JP, U)

Claims (1)

(57) [Scope of request for utility model registration] A bush is press-fitted at both ends of a boss hole of a boss, and the boss is inserted between left and right bracket plates of the bracket.
It is rotatably connected to the bracket plate via a pin fixed non-rotatably, and the gap-adjusting bush with a flange portion on one bracket plate of the bracket is not rotatable as described above. The flange is inserted so as to be slidable in the axial direction of the pin, and the outer end surface of the collar portion is opposed to the end surface of the boss, and the gap adjusting bush is adjusted and moved in the axial direction of the pin. A pin coupling portion that adjusts the gap between the bracket and the boss by adjusting the gap between the outer end surface and the boss end surface, wherein the outer end surface of the cylindrical portion of the gap adjusting bush is a bracket. Formed so as not to protrude outward from the outer end surface of the plate, and separately from the gap adjusting bush, the outer diameter is smaller than the gap adjusting bush fitting insertion hole hole diameter of the bracket plate, A cup-shaped metal fitting whose inner diameter dimension has a size that fits loosely with the outer diameter dimension of the pin, and in which a bolt hole is formed in a thick portion on one end face side, is formed in a cylindrical shape of the cup-shaped metal fitting. Is fitted to the tip of the pin, the end face of the cylindrical portion is brought into contact with the end face of the gap adjusting bush, and the tightening bolt is inserted through a bolt hole drilled in the thick portion on the end face side. In addition to tightening into the screw hole drilled in the pin end face, the gap dimension at the time of assembly between the inner end face of the end face side thick part of the cup-shaped bracket and the pin tip end face was set to a gap adjustable dimension. A construction machine pin joint structure characterized by the above-mentioned.