JP2007269224A - Crawler sleeve processing method - Google Patents

Abstract

When a crawler belt assembly is configured by mutually connecting crawler belt assemblies, it is possible to suppress the occurrence of backlash between a sleeve and a connecting shaft.
SOLUTION: A sleeve 28 includes a pair of outer sleeve portions 28a interposed between a pair of links 25 forming a crawler belt assembly 22 and a connecting shaft 27, and an intermediate sleeve portion 28b positioned between the links 25. It is divided into and. In this case, the inner peripheral surface S2 of the outer sleeve portion 28a is quenched and finished after being quenched.
[Selection] Figure 5

Description

  The present invention relates to a method for processing a crawler sleeve that is externally fitted to a connecting shaft between the crawler belt assemblies in order to connect the crawler belt assemblies constituting the crawler belt to each other.

  A crawler track of a lower traveling body in a tracked work machine such as a bulldozer or a hydraulic excavator is configured by connecting a plurality of crawler belt assemblies endlessly. The crawler belt is wound around the drive wheel and the idler wheel disposed at a predetermined interval around the vehicle body frame of the track type work machine, and each crawler belt assembly is engaged with the drive wheel made of a sprocket and driven. As a result, the crawler belt is rotated between the driving wheel and the idle wheel while being supported by the upper and lower wheels supported by the body frame.

  As a crawler belt assembly in such a crawler belt, for example, one having a configuration as disclosed in FIG. In this conventional crawler belt assembly, a pair of links are fixed in parallel to the surface opposite to the grounding surface of the crawler plate, a connecting shaft is fixed between one end portions of the links, and a sleeve is connected between the other end portions. Is fixed. The connecting shaft of the crawler belt assembly is rotatably inserted into the sleeves of other adjacent crawler belt assemblies, whereby a plurality of crawler belt assemblies are connected to each other to form an endless crawler belt.

  In the crawler belt assembly configured as described above, a shaft hole is formed at the end of each link, and both ends of the connecting shaft and the sleeve are fixed to the shaft hole by press-fitting. A lubricating oil accommodation hole is formed at the center of the connecting shaft, and a lubricating oil supply hole is formed from an intermediate portion of the lubricating oil accommodation hole toward the outer periphery of the connecting shaft. Then, the lubricating oil stored in the lubricating oil storage hole is exuded and supplied from the lubricating oil supply hole to the sliding portion between the outer peripheral surface of the connecting shaft and the inner peripheral surface of the sleeve, and the sliding portion is lubricated. It has become so.

  By the way, in the crawler belt having the above-described configuration, the sleeve has not only a function as a bearing member for rotatably connecting the crawler belt assemblies but also as a power transmission member that receives power transmission from the sprocket of the drive wheel. It also has the function of However, in this conventional crawler belt assembly, since the sleeve is fixed between the ends of the links, the specific portion of the outer peripheral surface of the sleeve is in sliding contact with the tooth surface of the sprocket. For this reason, since the sleeve of each crawler belt assembly wears unevenly, it is necessary to rotate or replace the sleeve with respect to the link. However, as described above, the sleeve is press-fitted and fixed to the link. It took a lot of work.

  In order to cope with such problems, a crawler belt assembly having a configuration as disclosed in Patent Document 2, for example, has been proposed. In this conventional configuration, the sleeve between the ends of the link is divided into three parts in the axial direction, and a pair of outer parts of the sleeve are press-fitted and fixed in the shaft holes of the links, and the intermediate part is It is rotatably fitted and supported on a connecting shaft of another adjacent crawler belt assembly. Thereby, the meshing position of the sleeve with respect to the teeth of the sprocket becomes an unspecified part, and uneven wear of the sleeve is prevented.

Further, in the crawler belt assembly described in Patent Document 2, similarly to the configuration described in Patent Document 1, the connecting shaft is formed with a lubricating oil accommodation hole and a lubricating oil supply hole, and is accommodated in the lubricating oil accommodation hole. The lubricated oil is exuded and supplied from the lubricating oil supply hole to the sliding portion between the outer peripheral surface of the connecting shaft and the inner peripheral surface of the intermediate portion of the sleeve, and the sliding portion is lubricated. .
Japanese Patent Application Laid-Open No. 2004-249973 JP-T 6-504747

  However, the inner peripheral surface of the sleeve described in Patent Document 1 and the sleeve portion described in Patent Document 2 is finished to a high-precision dimension despite being a sliding portion with respect to the outer peripheral surface of the connecting shaft. Absent. This is because even if the sleeve is finished with high accuracy by cutting, an error occurs due to thermal distortion or the like in the subsequent quenching process. For this reason, there is a relatively large backlash between the sleeve and the connecting shaft as the sliding portion, and the sliding load of the seal ring for sealing the lubricating oil is large. As a result, the life of the seal ring was shortened, or there was a possibility of leakage of lubricating oil due to failure of the seal ring.

  Further, in the configuration described in Patent Document 2, a seal ring is provided between the intermediate portion and the outer portion of the sleeve and between the outer portion of the sleeve and the link, and the outer peripheral surface of the connecting shaft is provided by the seal ring. The lubricating oil is sealed in the sliding portion between the sleeve and the inner peripheral surface of the sleeve. However, since the outer portion of the sleeve is fixed to the link, it rotates integrally with the link when the crawler belt assembly goes around the drive wheel or idler wheel or exceeds the unevenness of the road surface. For this reason, the seal ring between the outer portion of the sleeve and the link has a remarkably large amount of rotation of the sealed portion as compared with the seal ring between the intermediate portion and the outer portion of the sleeve. When the play is repeated, the seal ring is slid in another direction such as a radial direction in addition to sliding in the rotational direction. Therefore, the seal ring between the outer part of the sleeve and the link seals due to early wear or damage in combination with the severe use environment such as vibration and earth and sand in the tracked work machine equipped with the crawler belt. There was a risk of losing function. As a result, the lubricating oil leaks from the sliding portion, and the intermediate portion of the sleeve that can rotate with respect to the connecting shaft is fixed to the connecting shaft, and as in the case of Patent Document 1, uneven wear occurs in the sleeve. There was a problem.

  The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide a method for processing a crawler sleeve that can prevent rattling from occurring between the sleeve and a connecting shaft when the crawler belt assembly is connected to each other to form the crawler belt.

  Another object of the present invention is that when the sleeve is divided into an outer part interposed between the connecting shaft and the pair of links and a rotatable intermediate part located between the pair of links, The crawler sleeve processing that can reduce the sliding load acting on the seal ring interposed between the intermediate portion and the outer portion of the sleeve, thereby suppressing the wear and damage of the seal ring. It is to provide a method.

In order to achieve the above object, the present invention provides a method for processing a crawler sleeve that is externally fitted to a connecting shaft of another adjacent crawler belt assembly in order to connect the crawler belt assemblies for constituting the crawler belt to each other. ,
The inner peripheral surface of the sleeve is subjected to a quenching process, and then the inner peripheral surface is ground.

  Accordingly, when the crawler belt assembly is connected to each other to form the crawler belt, the inner peripheral surface of the sleeve fitted on the connecting shaft can be made to have a high precision dimension equivalent to the outer peripheral surface of the connecting shaft, and the sleeve can be connected. It is possible to suppress the backlash of the sliding portion between the shafts.

  Further, in the above processing method, the sleeve includes a pair of links forming a crawler belt assembly and an outer portion interposed between the connecting shafts and an intermediate portion positioned between the links, and the outer side thereof. The inner peripheral surface of the part may be ground after the quenching process. When configured in this way, it is possible to suppress rattling between the outer portion of the sleeve having a large amount of rotation and the connecting shaft, and the intermediate portion of the sleeve moves relative to the outer portion. Can be suppressed. Therefore, the sliding load acting on the seal ring interposed between the intermediate portion and the outer portion of the sleeve can be reduced, and the possibility of losing the seal function due to damage to the seal ring can be prevented. .

  Furthermore, in the above processing method, if the outer peripheral surface of the connecting shaft is ground after the quenching process, both the sleeve and the connecting shaft can be finished with high accuracy, and damage to the seal ring can be prevented more effectively. it can.

  As described above, according to the present invention, when the crawler belt assembly is connected to each other to form the crawler belt, it is possible to suppress the backlash between the sleeve and the connecting shaft, and the length of the seal ring can be reduced. Life can be extended.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the crawler belt 21 of this embodiment is configured by connecting a plurality of crawler belt assemblies 22 in an endless manner. Then, the crawler belt 21 is wound around a drive wheel 24 and an idler wheel 23 disposed at a predetermined interval around a vehicle body frame of a lower traveling body in a tracked work machine such as a bulldozer or a hydraulic excavator (not shown), In this state, each crawler belt assembly 22 is engaged with and driven by the teeth 24a of the drive wheels 24 made of sprockets. As a result, the crawler belt 21 is circulated while being supported by the upper and lower wheels (not shown) supported by the body frame between the driving wheel 24 and the idler wheel 23 so that the work machine travels on the road surface. It has become.

  As shown in FIGS. 2 to 5, each of the crawler belt assemblies 22 includes a pair of links 25 arranged in parallel and a crawler plate 26 fixed to the outer surfaces of both the links 25. A connecting shaft 27 is fixed between one end portions of both links 25, and a sleeve 28 that is rotatably fitted to the connecting shaft 27 of another adjacent crawler belt assembly 22 is interposed between the other end portions. Then, the crawler belt assembly 22 is connected to each other via the connecting shaft 27 by externally fitting the sleeve 28 between the two links 25 of the adjacent other crawler belt assembly 22 to the connecting shaft 27 between the both links 25. An endless crawler belt 21 is formed.

  Therefore, the configuration of the crawler belt assembly 22 will be described in detail below. As shown in FIGS. 4 and 5, a pair of shaft holes 31 and 32 are formed at both ends of each link 25 in the crawler belt assembly 22. One shaft hole 31 is formed in a small diameter so that the end of the connecting shaft 27 is press-fitted and fixed, and the other shaft hole 32 is formed in a large diameter so that the end of the sleeve 28 is press-fitted and fixed. Has been. A pair of insertion holes 33 extending in a direction perpendicular to the axis of the shaft holes 31 and 32 are formed at intermediate positions of the links 25 at a predetermined interval. A pair of window holes 34 are formed in the central portion of each link 25 so as to communicate with the inner end portions corresponding to the respective insertion holes 33. A pair of insertion holes 35 are formed in the crawler plate 26 of each crawler belt assembly 22 corresponding to the insertion holes 33 of both links 25. The bolts 36 are inserted into the insertion holes 33 and 35 from the outer surface side of the shoe plate 26, and the nuts 37 are screwed into the front ends of the bolts 36 in the window holes 34. A shoe plate 26 is fixed to the outer surface of the shoe.

On the grounding side of the crawler belt 21, a single row of grousers 38 extending in the width direction is formed on one side edge of the grounding surface of the crawler plate 26 so as to be located on the rear side of the work machine.
As shown in FIG. 5, the sleeve 28 in the crawler belt assembly 22 is divided into three portions 28 a and 28 b along the axial direction, and a pair of outer portions 28 a are respectively formed in the large-diameter shaft holes 32 of both links 25. It is press-fitted and fixed. The outer portion 28a and the intermediate portion 28b between the outer portions 28a are rotatably supported on the connecting shaft 27 between the links 25 in the other adjacent crawler belt assembly 22. The teeth 24a of the drive wheel 24 made of the sprocket are meshed with the intermediate portion 28b of the sleeve 28. In this case, the intermediate portion 28b is rotatable, so that the teeth 24a and the sleeve 28 There is no meshing at a specific portion, and uneven wear of the sleeve 28 is prevented.

  A lubricating oil accommodation hole 39 is formed at the center of the connecting shaft 27 in the crawler belt assembly 22, and a lubricating oil supply hole 40 is formed from an intermediate portion of the lubricating oil accommodation hole 39 toward the outer periphery of the connecting shaft 27. Sealing plugs 41 are fitted to both ends of the lubricating oil accommodation hole 39. The lubricating oil accommodated in the lubricating oil accommodating hole 39 is slid between the outer peripheral surface of the connecting shaft 27 and the inner peripheral surface of the intermediate portion 28b of the rotatable sleeve 28 via the lubricating oil supply hole 40. The sliding portion is lubricated by being supplied to the moving portion.

  In the crawler belt assembly 22, an accommodation recess 42 is formed at the inner periphery of the small-diameter shaft hole 31 of each link 25, and a first seal ring 43 is accommodated in the accommodation recess 42. The first seal ring 43 is provided with an outer peripheral lip portion that is bonded to the inner peripheral surface of the housing recess 42 and a side lip portion that is bonded to the outer surface of the outer portion 28 a of the adjacent sleeve 28.

  As shown in FIG. 5, an accommodation recess 45 is formed in the inner periphery of the outer portion 28 a of the sleeve 28, and a second seal ring 46 is accommodated in the accommodation recess 45. The second seal ring 46 is provided with an outer peripheral lip portion that is bonded to the inner peripheral surface of the receiving recess 45 and a side lip portion that is bonded to the end surface of the adjacent intermediate portion 28b. By the cooperative action of the second seal ring 46 and the first seal ring 43, sliding between the outer peripheral surface of the connecting shaft 27 and the inner peripheral surface of the intermediate portion 28b of the sleeve 28 in each crawler belt assembly 22 is performed. The lubricating oil leakage from the part is suppressed.

  By the way, in this embodiment, the outer part 28a of the sleeve 28 is formed from chromium molybdenum steel (SCM415-822). Then, the outer peripheral surface S1 and the inner peripheral surface S2 of the outer portion 28a are carburized and quenched so as to have a Rockwell hardness C55 to 61, and then subjected to grinding to finish with high accuracy so as to have a predetermined dimension. . In this case, the quenching depth is about 1.6 to 2.0 mm, and the tolerance is about ± 0.05 mm. In the grinding process, an aluminum oxide tool or a CBN (cubic boron nitride) tool is used.

The intermediate portion 28b of the sleeve 28 is made of the same material as the outer portion 28a, but is carburized and quenched after grinding.
The connecting shaft 27 is made of the same material as that of the sleeve 28, and the outer peripheral surface of the connecting shaft 27 is cut after carburizing and quenching in the same manner as the outer portion 28 a.

  Therefore, when the crawler belt 21 is formed by connecting the crawler belt assembly 22 to each other using the outer portion 28a processed as described above, the outer portion 28a has a small tolerance and high accuracy. And backlash between the connecting shaft 27 and the connecting shaft 27 can be suppressed. Thereby, relative movement other than the rotation direction can be suppressed between the intermediate portion 28b, the outer portion 28a, the outer portion 28a, and the portion of the small diameter shaft hole 31 of the adjacent link 25, and the intermediate portion 28b, the outer portion 28a, and the outer portion can be suppressed. The sliding load acting on the second seal ring 46 and the first seal ring 43 interposed between the portion 28a and the adjacent link 25 can be reduced. Therefore, the second seal ring 46 and the first seal ring 43 are not worn or damaged at an early stage, and the sealing function is not lost, and the lubricating oil is removed from the sliding portion between the intermediate portion 28b and the connecting shaft 27. Can be prevented from leaking and the intermediate portion 28b can be fixed to the connecting shaft 27.

The effects of the embodiment described above are listed as follows.
(1) The inner peripheral surface of the outer portion 28a of the sleeve 28 can be processed with high accuracy. Incidentally, in the embodiment, the tolerance can be suppressed to about ± 0.05 mm by grinding, but in the conventional method in which quenching is performed after the polishing, the tolerance is increased to about ± 0.25 mm due to thermal distortion or the like. It cannot be avoided. Accordingly, in this embodiment, as described above, the early wear and damage of the seal rings 46 and 43 can be suppressed, and the intermediate portion 28b can be prevented from being fixed. The possibility that the transmission efficiency of power from 24 to the crawler belt 21 deteriorates can be prevented.

  (2) In order to obtain the tolerance of ± 0.05 mm, the outer portion 28 a of the sleeve 28 is quenched and then cut by an amount that eliminates thermal distortion (maximum of about 0.5 mm). Even if the treatment is performed, the cutting process is easy.

  (3) Since only the outer portion 28a having a short axial length needs to be cut in the sleeve 28, the processing is easy even if the inner peripheral surface is processed. Incidentally, since the intermediate portion 28b of the sleeve 28 has a remarkably smaller amount of rotation than the outer portion 28a, the inner peripheral surface accuracy like the outer portion 28a is not required, and cutting after quenching is unnecessary.

  (4) By cutting the outer peripheral surface of the outer portion 28a of the sleeve 28 after quenching, the accuracy of the outer peripheral surface can be improved, and the press-fitting of the outer portion 28a into the shaft hole 32 of the link 25 can be loosened or conversely press-fitted. It can be done properly without becoming impossible.

  (5) Since the outer peripheral surface of the connecting shaft 27 is cut after quenching, the accuracy of the connecting shaft 27 can be improved, and in combination with the improved accuracy of the outer portion 28a of the sleeve 28, the seal rings 43 and 46 are prematurely worn and damaged. Prevention can be achieved more effectively.

(Example of change)
In addition, this embodiment can also be changed and embodied as follows.
The cutting after the quenching process is performed only on the inner peripheral surface of the outer portion 28a of the sleeve 28. Even if it does in this way, the effect similar to the said embodiment can be acquired.

  In the crawler belt in which the crawler belt assembly 22 is configured by press-fitting and fixing both ends of one sleeve 28 into the large-diameter shaft holes 32 of the pair of links 25 without dividing the sleeve 28 into three parts. The entire inner peripheral surface 28 is quenched and then ground and finished.

-The sleeve 28 and the connecting shaft 27 are made of a material other than the above-described embodiment, for example, nickel chrome molybdenum steel, nitride steel, or the like.
・ Use a treatment other than the carburizing method, such as a nitrogen diffusion penetration method, as the hardening treatment.

(Other technical ideas)
Other technical ideas other than the technical idea described in claims can be grasped from the above-described configuration.

(A) In a crawler belt sleeve that is externally fitted to a connecting shaft of another adjacent crawler belt assembly in order to connect the crawler belt assemblies for constituting the crawler belt to each other,
A crawler belt sleeve characterized by comprising grinding an inner peripheral surface after quenching the inner peripheral surface.

  (B) A pair of outer portions fitted in shaft holes of a pair of links constituting the crawler belt assembly and an intermediate portion located between both outer portions, and after quenching the inner peripheral surface of the outer portion The crawler belt sleeve according to item (a), which is ground.

  (C) In a crawler belt assembly comprising a pair of links, a connecting shaft fixed between one end portions of the links, a sleeve provided between the other end portions of the links, and a crawler plate fixed to both links. A sleeve for a crawler belt using the sleeve described in the item (a) or (b) as the sleeve.

The front view which shows a crawler belt provided with the sleeve for crawler belts which implemented this invention. The partial front view which expands and shows a part of crawler belt of FIG. FIG. 3 is a partial plan view of the crawler belt of FIG. 2. The perspective view which shows the crawler belt assembly in the crawler belt of FIG. FIG. 5 is a partially enlarged sectional view taken along line 5-5 in FIG.

Explanation of symbols

  21 ... crawler belt, 22 ... crawler belt assembly, 25 ... link, 26 ... crawler plate, 27 ... connecting shaft, 28 ... sleeve, 28a ... outer portion, 28b ... intermediate portion, 31, 32 ... shaft hole, 43 ... first seal ring 46 second seal ring, S1 outer peripheral surface, S2 inner peripheral surface.

Claims (3)

In a method of processing a crawler sleeve that is externally fitted to a connecting shaft of another adjacent crawler track assembly in order to connect the crawler belt assemblies for constituting the crawler track to each other,
A crawler sleeve processing method, comprising: quenching the inner peripheral surface of the sleeve and then grinding the inner peripheral surface. The sleeve includes a pair of outer portions fitted in shaft holes of a pair of links constituting the crawler belt assembly, and an intermediate portion located between both outer portions, and the inner peripheral surface of the outer portion is quenched. 2. The method for processing a crawler sleeve according to claim 1, wherein grinding is performed later. 3. The crawler sleeve processing method according to claim 1, wherein the outer peripheral surface of the connecting shaft is ground after the quenching process.

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