JP2002068035A - Connection pin coming-off preventive mechanism for crawler belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a connection pin coming-off preventive function in track links exhibited in a stable condition over a very long period. SOLUTION: The adjacent track links 20, 21 are connected by two connection pins 24R, 24L to allow pivotal motion, the connection pin 24R is inserted into a pin insertion hole 25R provided ranging from a connection part 22a side to connection parts 22b, 22c, and the connection pin 24L is inserted into a pin insertion hole 25L provided ranging from a connection part 22f side to connection parts 22c, 22e. Overhang parts 27R, 27L are provided adjacently in connection parts 22a, 22f to prevent the respective connection pins 24R, 24L from coming off, a stopper plate 30 is attached to the each overhang part 27R, 27L by a bolt 29, and the stopper plate 30 is inserted into each of the pin insertion hole 25R, 25L to be brought into contact with other end face of the each connection pin 24R, 24L brought into a condition abutting on stopper step differences 26R, 26L.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a hydraulic shovel or the like,
The present invention relates to a crawler belt that constitutes a lower traveling body of a crawler type vehicle, and more particularly to a mechanism for preventing a link pin from pivotally connecting front and rear track links that constitute this crawler belt.

[0002]

2. Description of the Related Art A crawler-type vehicle such as a hydraulic excavator has a crawler belt as a lower traveling body. This crawler belt is provided by being wound between a driving wheel formed of a sprocket or a drive tumbler and a driven wheel formed of an idler. The vehicle is driven by rotating the drive wheels with a hydraulic motor. Here, the crawler track is formed by connecting a number of track links sequentially and pivotally using connecting pins to form a loop-like infinite track.

The track link is formed by extending a plurality of connecting portions on both left and right sides of a main body made of a metal plate. The main body is formed of a hollow member to reduce the weight and the like. Adjacent track links are pivotally connected by arranging a connection section of the other track link to be connected thereto between the plurality of connection sections of the track link and inserting a connection pin therebetween. You. In order to make the pivoting between the track links smoother, the connecting pins are inserted so as to be movable to some extent in the pin insertion holes in the track links. Therefore, the connecting pin can also move in the axial direction.

[0004] From the above, it is necessary to hold the connecting pin so that it does not come out of the pin insertion hole, and it is general to use a bolt-nut to prevent the connecting pin from coming off. For example, a mechanism disclosed in Japanese Unexamined Patent Application Publication No. Hei 7-144665 has been conventionally known as a mechanism for preventing the connection pin from coming off.

The structure of this known retaining mechanism is as follows.
A through hole is formed in the track link, and a collar provided with flange portions protruding outward at both ends of a cylindrical portion having a bolt shaft insertion hole in the through hole is simultaneously cast when the track link is cast. The collar is tightened so that the bolt head and the nut abut on both flange portions of the collar, so that one of the bolt head and the nut faces the direction in which the connecting pin comes out. Therefore, the bolt head or the nut functions as a stopper when the connecting pin tries to come off. By machining both end faces of the collar in advance to make them parallel planes, the bolts can be tightened extremely strongly. Even if the connecting pins repeatedly collide, the nuts will not loosen. Thus, the function of preventing the connection pin from falling off can be exhibited in a stable state for an extremely long time.

[0006]

As described above, both the bolt head and the nut are hexagonal, and are screwed with a predetermined tightening tool engaged with the outer surface. Will be tightened. For this reason, a gap always occurs between the end surface of the connecting pin and the member functioning as the stopper. As a result, the following problems occur.

First, while the vehicle is running, the connecting pin repeatedly collides with the bolt head or nut functioning as a stopper, and the bolt or nut is worn or damaged in a short period of time. In order to suppress such wear and damage, at least the side of the bolt or nut that functions as a stopper must be processed to have high hardness, so that a general-purpose bolt-nut cannot be used. That would be very expensive. Moreover, abrasion also occurs between the connecting pin and the inner wall of the pin insertion hole. In particular, if the clearance between the connection pin and the bolt-nut is large, the movement of the connection pin in the axial direction is correspondingly large, so that wear is remarkably advanced. Furthermore, if the flat portion of the bolt-nut is not extremely parallel to the end face of the connecting pin when tightening the bolt-nut, the bolt may still be loosened. Therefore, the mounting of the bolts and nuts is troublesome and difficult, so that the assemblability of the crawler belt deteriorates as a whole.

The present invention has been made in view of the above points, and an object of the present invention is to enable a function of preventing a connecting pin from coming off in a track link to be exhibited in a stable state for an extremely long time. It is in.

[0009]

In order to achieve the above-mentioned object, the present invention provides a traveling body of a crawler type vehicle,
In a crawler track in which a large number of track links are sequentially pivotally connected by connecting pins to form an infinite track, in order to prevent the connecting pins between these track links from coming off, provided on one of the interconnected track links. A projecting portion projecting outward from an end of the connecting pin insertion hole between the track links, a screw hole provided in the projecting portion in a direction intersecting the axis of the connecting pin, and a screw inserted into the screw hole. And a stopper plate fixed to the overhanging portion by a bolt or a nut screwed to the bolt, and having an end face of the connecting pin in contact with the stopper plate.

Here, the contact portion of the stopper plate with the end face of the connecting pin is a flat surface or an arc surface. When the connecting pin is brought into contact with the flat surface, the connecting pin is constituted by a rectangular plate, and when the connecting pin is brought into contact with the circular arc surface, the stopper plate is formed into a circular plate. In either case, it is formed of a steel plate or the like in order to have high strength, but it is desirable to perform hardening treatment such as quenching to further improve the wear resistance.

[0011]

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

FIG. 1 shows a hydraulic excavator as an example of a crawler type vehicle. However, in this figure,
The front working mechanism is omitted.

In the drawings, reference numeral 1 denotes a lower traveling structure, and 2 denotes an upper revolving structure. The upper revolving structure 2 is installed on the lower traveling structure 1 so as to be capable of revolving. A cab 3 for operation is provided at a front position,
In the rear position, drive mechanisms such as an engine and a hydraulic pump,
Other equipment is installed. On the other hand, the lower traveling body 1 has a drive tumbler 10 as a driving wheel and an idler 11 as a driven wheel, and a crawler belt 12 wound and provided between the drive tumbler 10 and the idler 11. By rotating and driving the vehicle 10, the vehicle travels on the crawler belt 12.

FIG. 2 shows a partial configuration of the crawler belt 12. As shown in FIG. The crawler belt 12 constitutes an infinite traveling track by sequentially connecting the track links 20 so as to be pivotable.
The track link 20 has a main body 21 that forms the width of the crawler belt 12, and a plurality of connecting portions 22 a to 22 f extending in the front-rear direction of the main body 21. In the front and rear track links 20, 20, connecting portions 22 a to 22 c extending in opposite directions, and connecting portions 22 d to 22
f is in a mutually fitting relationship. In other words, the connecting portion 2 on the other side is located between the connecting portions 22a and 22b on one side.
2d enters, and the connecting portion 22c is connected to the connecting portion 2 of the other party.
It comes into between 2e and 22f. A predetermined interval is formed between the connecting portion 22b and the connecting portion 22e. Each main body 21 is provided with a driving claw 23 which protrudes from the extended portion of the space and engages with the teeth of the drive tumbler 10.

Adjacent track links 20, 20 are connected to each other by two connecting pins 24R, 24L so as to be pivotable. The connecting pin 24R is connected to the connecting portion 22a.
The pin is inserted into a pin insertion hole 25R provided from the side to the connecting portions 22d and 22b, and the connecting pin 24L is inserted into a pin insertion hole 25L provided from the connecting portion 22f side to the connecting portions 22c and 22e. And the pin insertion hole 2
For 5R, a reduced diameter portion is formed near the end of the connecting portion 22b, and for the pin insertion hole 25L, a reduced diameter portion is formed near the end of the connecting portion 22e, and the reduced diameter portion functions as stopper steps 26R and 26L. The end faces of the connecting pins 24R, 24L are respectively provided with stopper steps 26R, 26L.
Is in contact with

The front and rear track links 20, 20 connected in this manner can freely pivot about the connection pins 24R, 24L. Thus, the connecting pin 2
4R, 24L and the pin insertion holes 25R, 25L can be smoothly slid.
R and 24L are in a state where they can also move in the axial direction. For this purpose, as shown in FIGS. 3 to 5, a mechanism for preventing the connection pins 24R and 24L from falling off is provided.

In FIG. 3 and FIG.
0, three connecting portions 22a to 22c, 22 at the left and right, respectively.
Overhangs 27R and 27L are connected to the connecting portions 22a and 22f, respectively. These overhanging portions 27R, 27L are pin insertion holes 25R, 25L.
And bolt insertion holes 28R and 28L are provided so as to penetrate in the thickness direction. The extension lines of these bolt insertion holes 28R and 28L are pin insertion holes 25R.
It intersects with the extension of R, 25L. Each bolt insertion hole 2
8R and 28L are stopper plates 3 with bolts 29, respectively.
0 is to be attached. The stopper plate 30
It is arranged at a position intersecting with the extension of the pin insertion holes 25R and 25L.
Is screwed. The stopper plate 30 is fixed by the tightening of the bolts and nuts. Therefore, the stopper plate 30 is connected to the head 29b of the bolt 29 and the overhang 2
7R and 27L. Conversely, the stopper plate 30 may be held between the nut 31 and the overhang portions 27R and 27L.

The stopper plate 30 has pin insertion holes 25R, 2
The connecting pins 24R, 24L which are inserted into the 5L and are in contact with the stopper steps 26R, 26L are in contact with the other end faces of the connecting pins 24R, 24L to prevent the connecting pins 24R, 24L from coming off. . For this purpose, as shown in FIG. 5, the stopper plate 30 is in the state of being in contact with the overhang portions 27R, 27L, and has a thickness so as to reach the extension of the pin insertion holes 25R, 25L. , For example, a steel plate, and a bolt 29
An insertion hole 32 larger than the outer diameter of the shaft portion 29a and smaller than the outer diameter of the head portion 29b is formed. The outer shape of the stopper plate 30 is sufficiently larger than the outer shape of the head 29b of the bolt 29. Further, at least the end face 30a of the stopper plate 30 on the side facing the connecting pins 24R and 24L, preferably the end face of the four circumferences, is subjected to a hardening treatment such as quenching to improve abrasion resistance.
Then, the stopper plate 3 is formed by the bolt 29 and the nut 31.
When 0 is fixed, the end surface 30a of the stopper plate 30 is brought into a state of substantially making surface contact with the end surfaces of the connecting pins 24R and 24L.

As a result, the movement of the connecting pins 24R and 24L in the axial direction is restricted, or the connecting pins 24R and 24L are fixed so as not to move in the axial direction. As a result, the connecting pins 24R, 24L can be prevented from repeatedly and violently colliding with the stopper plate 30 during running of the vehicle, and the connecting pins 24R, 24L can be prevented.
Not only can the wear of the L and the pin insertion holes 25R, 25L be reduced, but also the wear and damage of the stopper plate 30 can be minimized. Also, the end surface 30a of the square stopper plate 30
Are almost in surface contact with the connecting pins 24R, 24L,
Even if the connection pins 24R, 24L and the end face 30a of the stopper plate 30 have some gaps, the connection pins 24R, 24L
Even if the 4L moves, the movement is slight, and the end faces of the connecting pins 24R and 24L are connected to the end face 3 of the stopper plate 30.
Since there is a surface contact with Oa, no force in the direction of rotation acts on the stopper plate 30, so that there is no risk of loosening between the bolt 29 and the nut 31.

Here, the front and rear track links 20, 20
In order to make the pivoting operation between the connecting pins smoother,
4R and 24L must be able to move to some extent freely in the pin insertion holes 25R and 25L. Connecting pin 24
Even if both ends of R and 24L are sandwiched between stopper steps 26R and 26L and stopper plates 30 and 30 and are fixed so as not to move substantially in the axial direction, a pivot between the front and rear track links 20 and 20 is provided. There is no particular effect on the dynamic behavior. That is, as is clear from FIG. 2, both ends of the connecting pin 24R are sandwiched between the stopper plate 30 fixed to the projecting portion 27R from the connecting portion 22a of the track link 20 on one side and the same track. The linking portion 22d of the track link 20 of the other party is located between the connecting portion 22a and the stopper step 26R provided on the connecting portion 22b of the link 20 and at a position between these connecting portions 22a and 22b.
The connecting portion 22d is rotatable with respect to the connecting pin 24R. Both ends of the connecting pin 24L are clamped between a stopper plate 30 fixed to the projecting portion 27L of the connecting portion 22f of the mating track link 20 and a stopper step 26L provided on the connecting portion 22e of the same track link 20. The connecting portion 22c of the track link 20 on one side is located between the connecting portions 22e and 22f, and is rotatable with respect to the connecting pin 24L. Therefore, there is no hindrance to the pivoting movement between the front and rear track links.

Incidentally, the connecting pin may be constituted by one pin so as to penetrate the connecting portion of the adjacent track link. In this case, both ends of the connecting pin are prevented from coming off by the stopper plate.

In fixing the stopper plate 30, the stopper plate 30 is brought into contact with the lower surface side of each of the overhang portions 27R, 27L, and the shaft portion 29 of the bolt 29 is inserted into the insertion hole 32.
After inserting a, the nut 31 is screwed into the shaft portion 29a. However, unless the nut 31 is strongly tightened, the stopper plate 30 cannot be fixed in a stable state. In this tightening, a tightening tool is engaged with the nut 31, but the nut 31 and the connecting pins 24R, 24
Since an interval D (FIG. 5) is formed between the connecting pin 24 and the end face of the connecting pin 24 when the fastening tool is operated.
There is no possibility of interference with R, 24L and the like.

Further, since the connecting pins 24R and 24L are kept in non-contact with the head 29b and the nut 31 of the bolt 29, they are not worn or damaged. Therefore, if the nut 31 is screwed, the stopper plate 30 can be removed, and the worn stopper plate 30 can be easily replaced.
Here, since the stopper plate 30 has four end faces, when one end face 30a is worn, the other end face can be brought into contact with or facing the connecting pins 24R and 24L. Thus, the frequency of replacement of the stopper plate 30 can be reduced, and the life of the stopper plate 30 can be extended.

Here, the stopper plate does not necessarily have to be a quadrangle but may be a polygon including a triangle, and a stopper plate 130 having a circular outer shape as shown in FIG. Can also. When the circular stopper plate 130 is used in this way, even if the connecting pins 24R, 2
Even if 4L collides with the stopper plate 130, the stopper plate 13
No force acts in the direction of rotating 0. As a result, loosening of the bolt 29 and the nut 31 can be reliably prevented. Further, as shown in FIG. 7, a circular stopper plate 230 is used, and an insertion hole 232 formed in the stopper plate 230 and through which the shaft 29a of the bolt 29 is inserted is formed in an eccentric position. You can also. With this configuration, when the stopper plate 230 is tightened by the bolt 29 and the nut 31, the stopper plate 23
0 rotates by a predetermined angle in the direction indicated by the arrow in the figure, and is reliably pressed against the end faces of the connecting pins 24R and 24L. As a result, even if there is a processing error or the like in the connection pins 24R, 24L and the interval between the pin insertion holes 25R, 25L and the stopper steps 26R, 26L, the connection pin 2
4R and 24L are fixed so as not to completely move in the axial direction. Therefore, the stopper plate 230, the connecting pin 24R,
Wear of the 24L and the pin insertion holes 25R and 25L is significantly suppressed. Further, as described above, the connecting portion 22c is connected to the connecting pin 2 on the track link 20 side.
4L, and the connecting portion 22d of the other track link 20 can freely rotate with respect to the connecting pin 24R, so that the front and rear track links 20, 20 pivot. There is no hindrance to the operation. Further, the connecting pins 24R, 2 of the stopper plate 230
When the contact portion with the 4L is worn, the bolt 29 can be further tightened to apply a pressing force to the connecting pins 24R and 24L.

[0025]

As described above, according to the present invention, the function of retaining the connecting pin in the track link can be exerted in a stable state for an extremely long period of time.
Since the nut does not directly contact the end of the pin, various effects such as the use of a versatile and inexpensive one can be obtained.

[Brief description of the drawings]

FIG. 1 is an external view of a hydraulic excavator as an example of a crawler type vehicle.

FIG. 2 shows the first embodiment of the present invention, and is a plan view showing a state where a part of a crawler belt is broken.

FIG. 3 is a front view of a track link shown partially broken.

FIG. 4 is a sectional view taken along line XX of FIG. 3;

FIG. 5 is an explanatory diagram showing an arrangement relationship between a connecting pin and a stopper plate.

FIG. 6 is an explanatory view similar to FIG. 5, showing a second embodiment of the present invention.

FIG. 7 is an explanatory view similar to FIG. 5, showing a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Lower traveling body 10 Drive tumbler 11 Idler 12 Crawler belt 20 Track link 21 Main body part 22a to 22f Connection part 23 Drive claw 24R, 24L Connection pin 25R, 25L Pin insertion hole 26R, 26L Stopper step 27R, 27L
Overhangs 28R, 28L Bolt insertion hole 29 Bolt 30, 130, 230 Stopper plate 30a End face 31 Nut 32,232 Insertion hole

Claims (2)

[Claims] 1. A crawler type vehicle comprising a traveling body, wherein a plurality of track links are sequentially and pivotally connected by connecting pins to form an infinite track, and the connecting pins between the track links are prevented from coming off. For this purpose, a projecting portion is provided on one of the interconnected track links and projects outward from the end of the connecting pin insertion hole between the track links, and the projecting portion intersects the axis of the connecting pin. And a stopper plate which is fixed to the overhang portion by a bolt inserted into the screw hole or a nut screwed to the bolt, and an end face of the connection pin comes into contact with the screw hole. A crawler belt connecting pin retaining device characterized by the above-mentioned. 2. The mechanism according to claim 1, wherein the stopper plate is formed of a square or circular steel plate.