JP4666363B2 - Work machine - Google Patents

Description

  The present invention relates to a work machine provided with a crack observation groove.

  A work machine A such as a hydraulic excavator as shown in FIG. 8 is provided with a work device 2 in the front part of the machine body 1, and this work device 2 includes a boom 3bm, an arm 3am, and a bucket 3bk as constituent members. These are configured so as to be sequentially rotatable by a connecting member 4 such as a pin.

  Among these components, the boom 3bm and the arm 3am are particularly required to be strong, so in these productions, the plate members are welded to form a box-shaped cross-section arm body, and if necessary, a reinforcing structure Is provided.

  For example, in the case of the arm 3am, a working arm structure in which a bent portion of a plate member bent in a zigzag shape is welded inside an arm body formed in a box-shaped cross section (see Patent Document 1), and the arm body extends in the longitudinal direction. There is known a work arm structure (see Patent Document 2) in which a split surface is divided into a pair and these divided arm bodies are joined together.

On the other hand, the boom 3bm and the arm 3am formed in a box-shaped cross section do not have a mechanism for early detection of cracks, and each plate member is welded as a constituent member while being cut to a required size.
Japanese Patent Laid-Open No. 2000-265489 (page 3, FIG. 2) JP 2001-115480 A (page 3, FIG. 2)

  For this reason, for example, in a work site where confirmation by visual observation is difficult such as tunnel construction, an initial minor crack may be overlooked, and if the work is continued as it is, the crack may develop.

  For example, in the arm 3am shown in FIG. 8, the bearing plate 5 connected to the tip of the boom 3bm by a connecting member 4 such as a pin is welded to the arm main body plate 6 at the peripheral edge. The welded portions of the plates 5 and 6 are important in terms of strength, and when cracks are generated, there is a risk that cracks 7 and 8 are generated from these portions and progress.

  However, the location where this crack occurs is not fixed, and it is not easy to find a crack in the initial stage.

  In addition, in the test to verify the strength of the boom 3bm and arm 3am, the location of cracks has not been determined, so it is possible to grasp the stress state at the location of cracks and obtain useful information for new model development. Have difficulty.

  This invention is made | formed in view of such a point, and it aims at providing the working machine which can confirm the generation | occurrence | production and progress state of a crack easily.

The invention according to claim 1 includes an airframe and a work device provided on the airframe, and the work device is provided on at least one surface of the plurality of constituent members movably connected and the plurality of constituent members. And a crack observation groove for confirming the occurrence and progress of cracks.

  According to a second aspect of the present invention, in the work machine according to the first aspect, the crack observation groove is provided in the vicinity of a connecting member that connects a plurality of constituent members.

  According to a third aspect of the present invention, in the work machine according to the first or second aspect, holes are formed at both ends of the crack observation groove.

  According to a fourth aspect of the present invention, in the working machine according to any one of the first to third aspects, the cross-sectional shape of the crack observation groove is different from one end to the other end of the crack observation groove.

  According to a fifth aspect of the present invention, in the work machine according to any one of the first to fourth aspects, the plurality of crack observation grooves are arranged at intervals in the perspective direction centering on the connecting member. .

  According to a sixth aspect of the present invention, in the work machine according to the fifth aspect, the plurality of crack observation grooves have different cross-sectional shapes for each groove.

According to the first aspect of the present invention, the crack observation groove for confirming the generation and progress of cracks is provided on the surface of the component member of the working device, and when a crack occurs in the component member, the crack observation groove has a crack. By observing only the limited crack observation grooves at the confirmation location, inspection can be performed easily and in a short time even at sites where confirmation work is difficult. Discovery becomes easy and the fatigue strength level can be detected by the presence or absence of cracks. Also, in the test to verify the strength of the components of the work equipment, the crack occurrence location is fixed in the crack observation groove, so it is easy to grasp the stress state etc. of the crack occurrence location and provide useful information for new model development Can be easily obtained.

  According to the second aspect of the present invention, since the crack observation groove is provided in the vicinity of the connecting member where the crack is most likely to occur in the constituent members of the working device, the generation of cracks other than the crack observation groove can be reliably prevented.

  According to the third aspect of the present invention, it is possible to prevent the progress of cracks other than the crack observation groove by the holes formed at both ends of the crack observation groove.

  According to invention of Claim 4, a stress state can be grasped | ascertained from the crack progress condition in the crack observation groove from which cross-sectional shape differs from one end to the other end.

  According to the fifth aspect of the present invention, the crack progressing state and the stress progressing stepwise in the strength verification test or the like by the plurality of crack observation grooves arranged with the distance in the perspective direction centering on the connecting member. It is possible to grasp the condition by visual observation and obtain useful demonstration data for new model development.

  According to the invention described in claim 6, by the plurality of crack observation grooves having different cross-sectional shapes for each groove, it is possible to grasp the crack progress status, the stress state, etc., which differ depending on the cross-sectional shape, and to develop a new model. Useful empirical data can be obtained.

  Hereinafter, the present invention will be described in detail with reference to an embodiment shown in FIGS.

  FIG. 1 shows a hydraulic excavator type work machine A, in which a work device 2 is mounted on a machine body 1 in which an upper turning body is turnable with respect to a lower traveling body and protrudes from the machine body 1. In this working device 2, a plurality of constituent members (3bm, 3am, 3bk) are sequentially and movably connected by a connecting member 4 such as a pin. That is, in this work device 2, a base end portion of a boom 3bm as a constituent member is pivotally supported on the machine body 1 by a connecting member, and an arm 3am as a constituent member is provided at the distal end portion of the boom 3bm by the connecting member. A bucket 3bk as a constituent member is pivotally supported by a connecting member at the distal end portion of the arm 3am.

  Crack observation grooves 31, 32, 33 are provided in the vicinity of the connecting member 4 on the surface of at least one of the plurality of constituent members, in the illustrated example, the arm 3am.

  FIG. 2 shows an arm 3am, which is one component of the work machine. The arm body 11 is formed by sequentially welding the thick plate 12, thin plate 13 and thick plate 14 on one side as plate members. A thick plate, a thin plate, and a thick plate on the side are sequentially welded, and the peripheral plate 15 is welded to the outer peripheral portions of the plate members on both sides, thereby forming a box-shaped cross section.

  An arm cylinder coupling pin mounting bracket 16 and a bucket cylinder coupling pin mounting bracket 17 are welded to the peripheral plate 15 of the arm body 11.

  In addition, a bearing member 22 having a through hole 21 connected to the boom tip and the connecting member 4 is fitted and welded in the arm body 11. The bearing member 22 has a bearing plate 24 welded to both ends of a cylindrical bearing cylinder 23 fitted to a pin, and the bearing plate 24 is further welded to the thick plate 12 of the arm body 11.

  Similarly, on the distal end side of the arm body 11, a cylindrical bearing member 26 having a through hole 25 pin-coupled to the bucket base end, and a cylindrical shape having a through hole 27 pin-coupled to the bucket linkage base end. The bearing members 28 are respectively fitted and welded.

  As shown in FIGS. 2 and 3, the vicinity of the bearing member 22 is in the vicinity of a critical part where stress is concentrated, and the surface of the thick plate 12 constituting the arm body 11 has crack observation grooves 31, 32, 33 is formed in a linear shape. These crack observation grooves 31, 32, 33 are arranged with a distance in the perspective direction centering on the connecting member 4 or the bearing member 22. Holes 34, 35, and 36 are formed at both ends of the crack observation grooves 31, 32, and 33, respectively.

  Each crack observation groove 31, 32, 33 may have the same overall cross-sectional shape, but as shown in FIG. 4, one crack observation groove 32 has a different cross-sectional shape from one end to the other, The groove width and groove depth become smaller toward the upper side. Other crack observation grooves 31 and 33 may be formed similarly.

  The crack observation grooves 31, 32, and 33 may all be formed in the same cross-sectional shape, but may be formed so that the cross-sectional shape is different for each groove as shown in FIGS. For example, the crack observation groove 31-33V shown in FIG. 5 is formed in a V-shaped cross-sectional shape, and the crack observation groove 31-33R shown in FIG. 6 is formed in an arc-shaped cross-sectional shape.

  Next, the function and effect of this embodiment will be described.

  As shown in FIG. 7, the crack observation grooves 31, 32, 33 arranged with a distance in the perspective direction centered on the bearing member 22 are visually observed, and the crack observation grooves 31, 32, 33 are inside. The progress of cracks 37 and 38 progressing step by step, the stress state, etc. are grasped, and measures such as member reinforcement and replacement are taken according to the progress of cracks 37 and 38.

  In the vicinity of the bearing member 22, linear crack observation grooves 31, 32, 33 are provided on the surface of the thick plate 12 of the arm body 11, and when cracks are to occur in the arm body 11, these cracks are observed. Since the generation of cracks is limited only to the grooves 31, 32, 33, it is only necessary to observe the crack observation grooves 31, 32, 33 where the cracks are confirmed. Therefore, even at sites where confirmation work is difficult, inspections can be performed easily and in a short time, and cracks 37 and 38 can be easily detected at the initial stage. The fatigue strength level can be detected based on the presence or absence of cracks 37 and 38. Thus, measures such as member reinforcement and replacement can be taken.

  Also, in the test to verify the strength of the arm 3am, the crack occurrence location is fixed in the crack observation grooves 31, 32, 33, so it is easy to grasp the stress state of the crack occurrence location, which is useful for developing new models. Information can be easily obtained.

  Since the crack observation grooves 31, 32, 33 are provided in the vicinity of the bearing member 22 where the cracks are most likely to occur in the arm 3am of the working device 2, the crack observation grooves 31, 32, 33 are provided in places other than the crack observation grooves 31, 32, 33. Cracks can be reliably prevented.

  By the holes 34, 35, and 36 formed at both ends of the crack observation grooves 31, 32, and 33, it is possible to prevent the cracks 37 and 38 from spreading to other than the crack observation grooves 31, 32, and 33.

  Furthermore, the cross-sectional shape, cross-sectional change, size, and number of the crack observation grooves 31, 32, and 33 can be controlled to grasp the stepwise crack progress and the stress state by visual observation.

  That is, as shown in FIG. 4, it is possible to grasp the stress state at the crack occurrence location from the crack progress in the crack observation groove 32 having a different cross-sectional shape from one end to the other end. For example, the stress state can be determined from the length that the crack 32 generated in the thin portion in the crack observation groove 32 progresses to the thick portion, and useful demonstration data for developing a new model can be obtained.

  Further, the crack progressing state progresses stepwise as shown in FIG. 3 in the strength verification test or the like by the crack observation grooves 31, 32, 33 arranged with the distance in the perspective direction centered on the bearing member 22. In addition, it is possible to grasp the stress state by visual observation, and to obtain useful demonstration data for new model development.

  Furthermore, as shown in FIGS. 5 and 6, the crack observation grooves 31, 32, and 33 having different cross-sectional shapes for each groove make it possible to grasp the crack progress and stress state that differ depending on the cross-sectional shape by visual observation. Useful data for model development can be obtained.

  When the present invention is applied to a strength verification test, a strength test is performed by attaching a detecting means such as a strain gauge on the back surface of the crack observation grooves 31, 32, 33, etc. Stable and reliable demonstration data can be obtained compared to the case where a strength test is performed with a strain gauge attached to the position.

  The present invention can also be applied to other components of the working device 2 of the working machine A shown in FIG. 8, that is, the boom 3bm and the bucket 3bk. Furthermore, the present invention can be applied to a working device of another working machine such as a loader or a dozer.

1 is a perspective view showing an embodiment of a work machine according to the present invention. It is a perspective view which shows the structural member of the working device of a working machine same as the above. It is the perspective view which expanded the principal part of the structural member same as the above. It is the IV-IV sectional view taken on the line of FIG. It is sectional drawing which shows an example of the crack observation groove | channel of a structural member same as the above. It is sectional drawing which shows the other example of the crack observation groove | channel of a structural member same as the above. It is a front view which shows the example of an observation of the crack observation groove | channel of a structural member same as the above. It is a side view which shows an example of a working machine.

Explanation of symbols

A Work machine 1 Airframe 2 Work device
3bm boom as a component
3am Arm as component
3bk Bucket as component 4 Connecting member
31, 32, 33 Crack observation groove
34, 35, 36 holes

Claims (6)

The aircraft,
With a working device provided on the fuselage,
Work equipment
A plurality of movably coupled components;
A work machine comprising: a crack observation groove provided on at least one surface of a plurality of constituent members for confirming generation and progress of cracks. The work machine according to claim 1, wherein the crack observation groove is provided in the vicinity of a connecting member that connects a plurality of constituent members. The working machine according to claim 1, further comprising holes formed at both ends of the crack observation groove. The work machine according to any one of claims 1 to 3, wherein the crack observation groove has a different cross-sectional shape from one end to the other end. The work machine according to any one of claims 1 to 4, wherein a plurality of crack observation grooves are arranged at intervals in a perspective direction centering on the connecting member. The work machine according to claim 5, wherein the plurality of crack observation grooves have different cross-sectional shapes for each groove.

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