JP6064410B2 - Work machine - Google Patents

Description

  The present invention relates to a working machine such as a hydraulic excavator, and more particularly to a welded structure of a car body in a lower traveling body.

  FIG. 1 shows a hydraulic excavator 50 (an example of a work machine) as a comparative example of the present invention. In this hydraulic excavator 50, a machine main body 52 is installed on a crawler-type lower traveling body 51 so as to be rotatable. Note that front and rear, top and bottom, left and right, etc. follow the directions shown in the figure unless otherwise specified.

  At the front of the machine main body 52, a cab 53 on which an operator gets on and performs an operation, and an attachment 54 that performs a work operation in accordance with the operation are installed. A counterweight 55 that adjusts the front-rear balance with the attachment 54 is installed at the rear of the machine body 52, and a machine chamber 56 is installed at the front side of the counterweight 55. Inside the machine room 56, an engine, hydraulic equipment, and the like that drive and control the lower traveling body 51 and the attachment 54 are installed.

  In FIG. 2, the part of the lower traveling body 51 is shown. The lower traveling body 51 includes a car body 62 that supports the machine body 52 via a turning mechanism 61, and a pair of crawler bodies 63 and 63 that are detachably attached to both sides of the car body 62. .

  The car body 62 has a closed cross-sectional structure formed by welding a plurality of metal plates into a box shape in order to reduce the weight while ensuring the necessary strength. A turning mechanism 61 composed of a turning bearing or the like is installed at the center of the car body 62. A pair of jack devices 64 and 64 that can lift the car body 62 are provided in the front and rear ends of the car body 62 so as to be housed.

  The car body 62 has a substantially X-shaped appearance when viewed from above, and each of both side portions of the car body 62 is provided with an overhanging portion 62a that projects laterally from both front and rear end portions. .

  Each crawler body 63 includes a crawler frame 65 that is long in the front-rear direction, and a crawler 66 that is driven to go around the crawler frame 65. Each crawler body 63 is attached to each of both sides of the car body 62 via a support mechanism 70.

  FIG. 3 shows an enlarged portion of the support mechanism 70. The support mechanism 70 includes a coupling portion 71 and a regulation plate 72 and is provided at four locations between the inner portion of the crawler frame 65 and the protruding end portions of the overhang portions 62 a on the front and rear sides of the car body 62. . These support mechanisms 70 have the same structure and are arranged symmetrically.

  Each connecting portion 71 has an inner connecting portion 73 provided on the car body 62 side and an outer connecting portion 74 provided on the crawler frame 65 side.

  Each outer connecting portion 74 includes a pair of plate-like brackets 74a and 74a protruding from the inner wall 65a of the crawler frame 65, and is disposed corresponding to each inner connecting portion 73 (see FIG. 5). The pair of brackets 74a and 74a are disposed so as to be orthogonal to the inner wall 65a and to face each other in the front-rear direction. Each bracket 74a is formed with a crawler side connection hole 75 that penetrates the plate surface in the front-rear direction and is positioned to face each other.

  A shaft insertion device 76 is installed in a portion between the front and rear outer connecting portions 71 in the crawler frame 65. Two hydraulic cylinders 77 are installed in the shaft insertion device 76 in opposite directions, and a connecting shaft 78 is provided at the tip of the rod of each hydraulic cylinder 77.

  The restriction plate 72 is provided on the crawler frame 65. Each regulating plate 72 protrudes from the crawler frame 65 and is located above each outer connecting portion 71.

  As shown in FIG. 4, the inner connecting portion 73 is formed separately from the car body 62 and is retrofitted to the car body 62. This is because if the car body 62 and the inner connecting portion 73 are manufactured separately, both of them can be manufactured easily and the productivity is improved.

  The inner connecting portion 73 includes a support plate 81, a connecting plate 82, a reinforcing plate 83, and the like, and is attached to the protruding end portion of the overhang portion 62a of the car body 62.

  Specifically, a flat end face 84 surrounded by a plate material is formed on the protruding end portion of the projecting portion 62a so as to face the side. The support plate 81 is a rectangular plate-shaped metal plate material. The support plate 81 is fixed by welding to the overhanging portion 62a so as to close the end face 84 of the overhanging portion 62a.

  The connecting plate 82 is a thick metal plate, and is fixed by welding to the surface of the support plate 81 facing sideways. The connection plate 82 is arranged so as to extend in the vertical direction at a substantially central portion in the front-rear direction on the surface in a state orthogonal to the support plate 81.

  On the plate surface facing the front-rear direction of the connection plate 82, a body side connection hole 85 penetrating between these plate surfaces is formed. The body side connection hole 85 is located in the lower part of the connection plate 82 that protrudes greatly.

  When the crawler body 63 is attached to the car body 62, first, the crawler body 63 lifted by a crane or the like is carried to the side portion of the car body 62 lifted by the jack device 64. Thus, the front and rear connecting plates 82 are inserted between the pair of brackets 74a and 74a positioned corresponding to them.

  After positioning so that both the body side connection hole 85 and the crawler side connection hole 75 overlap in the front-rear direction, the shaft insertion device 76 is operated, and the connection shaft 78 is inserted into both the connection holes 85 and 75. The inner connecting portion 73 and the outer connecting portion 74 are connected by inserting the connecting shaft 78 into both the connecting holes 85 and 75.

  In a state in which the crawler body 63 is connected to the car body 62 and the car body 62 is lifted by the jack device 64, the crawler body 63 is inclined so as to wrap around the lower side of the car body 62, and the regulation plate 72 is Located away from. By lowering the car body 62, the crawler body 63 is received by the ground and rotates around the connecting shaft 78, so that the regulation plate 72 hits the car body 62. By doing so, each crawler body 63 is supported on both sides of the car body 62 in an appropriate state.

  Therefore, as shown by an arrow in FIG. 5A, a large moment of force acts on the support mechanism 70 around the connecting shaft 78 due to its own weight or a load during work. Further, as indicated by an arrow in FIG. 5B, a large force acts also in the front-rear direction due to a load or the like when the lower traveling body 51 travels. Therefore, extremely large stress tends to concentrate on the base portion of the connecting plate 82, particularly the lower end portion of the connecting plate 82.

  In the case of the hydraulic excavator 50, one side end of the connecting plate 82 is cantilevered by the support plate 81, and the support plate 81 and the connecting plate 82 have a substantially T-shaped structure. For this reason, there is a structural difficulty in the strength of the fixing portion of the connecting plate 82, and there is a desire to increase the strength.

  Therefore, in this excavator 50, a reinforcing plate 83 is attached to the lower end portion of the inner connecting portion 73.

  As shown in FIG. 5, at the time of connection, brackets 74 a and 74 a are positioned so as to be in close contact with both sides of the connection plate 82, and these brackets 74 a and 74 a enter close to the support plate 81. Therefore, it is necessary to install the reinforcing plate 83 so as not to contact the bracket 74a.

  Therefore, the reinforcing plate 83 is formed in an elongated shape so that it can be installed in a small space remaining below the bracket 74a, and is attached so as to extend along the support plate 81 so that the amount of welding with the support plate 81 is increased. ing.

  The basic structure of the lower traveling body is disclosed in Patent Document 1, for example.

JP 2010-216084 A

  Even if the reinforcing plate 83 is attached to the lower end portion of the inner connecting portion 73 as in the hydraulic excavator 50 of the comparative example described above, the welded portion W between the reinforcing plate 83 and the connecting plate 82 is only the thickness of the connecting plate. Since there is no weld width, the welding amount is small and the joint plate 82 is located at the base portion. Therefore, there is a risk that stress concentrates on the welded part W and cracks occur.

  Therefore, an object of the present invention is to provide a work machine that can attach the connecting plate to the support plate more stably and has excellent support stability.

  The work machine according to the present invention includes a lower traveling body that can travel on the lower side of the machine body. The lower traveling body includes a car body that supports the machine body, and a pair of crawler frames that support the crawler and are detachably attached to both sides of the car body via a support mechanism. The support mechanism includes an inner connecting portion provided on the car body side and an outer connecting portion provided on the crawler frame side. The inner connection portion has a support plate welded to the car body with one of the plate surfaces facing sideways, and a connection hole welded in a state orthogonal to the support plate and penetrating between the plate surfaces. And a reinforcing plate welded to a lower end portion of the inner connecting portion in a state orthogonal to the connecting plate and the support plate. The outer connecting part has a bracket having a plate surface provided with a hole. The plate surface of the connection plate and the plate surface of the bracket face each other, and the connection plate and the bracket are connected via a connection shaft inserted into the connection hole and the hole. And the said reinforcement plate has the base part extended along the said support plate, and the extension part orthogonal to the said base part and extended along the lower side of the said connection plate.

  According to the work machine configured as described above, the reinforcing plate welded to the lower portion of the inner connecting portion includes the base portion extending along the support plate and the extending portion extending along the lower side of the connecting plate. Therefore, it is possible to move the welded portion between the reinforcing plate with a small welding amount and the connecting plate away from the base portion of the connecting plate and move to a position closer to the connecting shaft which is the center of the moment of force. it can.

  As a result, it is possible to relieve the stress acting on the welded portion having a low strength, and the connection plate can be more stably attached to the support plate.

  And since the extension part is extended along the connection plate, the whole extension part bends and deform | transforms and stress is disperse | distributed. As a result, the stress acting on the weak welded part can be further alleviated.

  In particular, it is preferable that the lateral width of the extending portion is equal to or less than the thickness of the connecting plate.

  If it does so, since an extension part does not protrude from the both sides of a connection plate, an extension part can be extended freely, without contacting with an outer connection part.

  Moreover, it is good to provide the flange part which spreads toward the base at the base part of the extension part.

  Then, when a force acts on the reinforcing plate in the vertical direction or the front-rear direction and the reinforcing plate is bent and deformed, the reinforcing plate is easily deformed from the intermediate portion of the extending portion. Therefore, it can suppress that stress concentrates on any welding site | part with the support plate in a reinforcement plate, and any welding site | part with a connection plate.

  According to the present invention, since the connecting plate can be more stably attached to the support plate, a work machine having excellent support stability can be realized.

It is a schematic side view which shows the working machine of a comparative example. It is a schematic perspective view which shows the part of the lower traveling body of the working machine of FIG. FIG. 3 is a schematic plan view of a portion indicated by an arrow X in FIG. 2. It is a schematic assembly drawing of an inner connection part. (A) is a schematic sectional drawing of the part which the arrow Y shows in FIG. (B) is the schematic seen from the direction of arrow Z1 of (a). It is the schematic equivalent to FIG. 4 which shows the principal part of the working machine of this embodiment. It is a schematic assembly drawing of an inner connection part. It is a schematic perspective view of an inner connection part. It is the schematic corresponding to FIG. 5 which shows the support mechanism of this embodiment. (B) is the schematic seen from the direction of arrow Z2 of (a). It is the schematic which shows the modification of a support mechanism. (B) is the schematic seen from the direction of arrow Z3 of (a). It is the schematic equivalent to FIG. 3 which shows the modification of a working machine. FIG. 10 is a schematic view corresponding to FIG. 9 showing a modification of the work machine.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the following description is merely illustrative in nature and does not limit the present invention, its application, or its use.

  FIG. 6 shows a main part of the work machine 1 to which the present invention is applied. Except for the support mechanism, the basic configuration of the work machine 1 of the present invention, such as the lower traveling body, the machine main body, the cab, the attachment, the counterweight, the machine room, the car body, the crawler body, etc. This is the same as the working machine 50 of the comparative example. Accordingly, the same components are denoted by the same reference numerals and the description thereof is omitted.

  The basic structure of the support mechanism 10 of the work machine 1 is the same as that of the support mechanism 70 of the comparative example. For example, the support mechanism 10 also includes a connecting portion 71 and a regulating plate 72, and is provided at four locations between the inner portion of the crawler frame 65 and the protruding end portions of the overhang portions 62 a on the front and rear sides of the car body 62. Are arranged symmetrically.

  Further, each connecting portion 71 has an inner connecting portion 73 provided on the car body 62 side and an outer connecting portion 74 provided on the crawler frame 65 side. The same is true in that a pair of plate-like brackets 74a in which the crawler side connection holes 75 are formed, a shaft insertion device 76 is installed between the front and rear outer connection portions 74, and the like.

  Further, also in the support mechanism 10, as shown in FIG. 6, the inner connecting portion 73 is formed separately from the car body 62 and is attached to the car body 62 later. An inner connecting portion 73 composed of a support plate 81, a connecting plate 82, a reinforcing plate 11 and the like is welded and fixed to the end face 84 of the protruding end portion of the overhang portion 62 a of the car body 62.

  The basic configuration of the support plate 81 and the connection plate 82 is the same as that of the comparative example, but the configuration of the lower part of the connection plate 82 and the reinforcing plate 11 is different from that of the comparative example.

  Specifically, as shown in FIG. 7, a cutout portion 12 is formed at the lower end portion of the connection plate 82 by cutting out a portion on the support plate 81 side at a predetermined depth.

  The reinforcing plate 11 includes a base portion 11a, an extending portion 11b, a flange portion 11c, and the like that are integrally formed.

  The base portion 11a is a portion fixed by welding to the support plate 81, and is formed in an elongated shape so that it can be installed in a small space remaining below the bracket 74a at the time of connection, like the reinforcing plate 83 of the comparative example. .

  The extension part 11b protrudes from the central part in the longitudinal direction of the base part 11a and extends in a direction orthogonal to the base part 11a. In the case of this support mechanism 10, the extension portion 11b projects to the lower side of the body side connection hole 85, specifically, when the body side connection hole 85 is projected from the vertical direction in the extension direction of the extension portion 11b. The extending portion 11b extends until the tip enters a region overlapping the body-side connecting hole 85 formed. The lateral width of the extending portion 11 b is equal to or less than the thickness (plate thickness) of the connecting plate 82, and is formed so as to fit into the cutout portion 12.

  The flange portion 11c is provided on both sides of the base portion of the extending portion 11b with the base portion 11a. The flange portion 11c spreads toward the base portion 11a, and the width of the end portion of the extending portion 11b on the base portion 11a side gradually increases toward the base portion 11a.

  In the reinforcing plate 11 formed in such a shape, the base portion 11a extends in the front-rear direction along the support plate 81, the extension portion 11b is fitted in the notch portion 12, and extends along the lower side of the connection plate 82. Are attached to the support plate 81 and the connection plate 82 in a connected state.

  Then, as shown in FIG. 8, the periphery of the reinforcing plate 11 is welded, and the reinforcing plate 11 is fixed to the support plate 81 and the connecting plate 82.

  In the case of this support mechanism 10, as shown in FIG. 9, the extension portion 11 b is provided along the lower side of the connection plate 82 without protruding from both sides of the connection plate 82, so that the outer connection portion 74 is connected. There is no contact.

  And since the welding site | part W of the reinforcement plate 11 with little welding amount and the connection plate 82 leaves | separates the base part of the connection plate 82, and is located in the connection axis | shaft 78 which is the center of the moment of force, it is located in the welding site | part W. The acting stress can be relaxed.

  And since the extension part 11b is extended along the connection plate 82, the whole extension part 11b bends and deforms, and the stress which acts on the welding site | part W is further relieve | moderated.

  Further, since the flange portion 11c that extends toward the base portion 11a is provided at the base portion of the extending portion 11b, a force acts on the reinforcing plate 11 in the vertical direction and the front-rear direction, so that the reinforcing plate 11 bends. In the case of deformation, it is easy to deform from an intermediate portion of the extending portion 11b. Therefore, it can suppress that stress concentrates on any welding site | part of the welding plate W with the support plate 81 in the reinforcement plate 11, and the welding site | part W with the connection plate 82. FIG.

  In addition, the working machine according to the present invention is not limited to the above-described embodiment, and includes various other configurations.

  For example, as shown in FIG. 10, the extending portion 11 b may be extended to the protruding end portion of the connecting plate 82. Further, the notch 12 is not essential, and the reinforcing plate 11 may be joined to the lower side of the connecting plate 82.

  In this case, since it is not necessary to provide the notch 12 in the connection plate 82, the connection plate 82 is easily manufactured. Moreover, since it is not necessary to fit the extension part 11b in the notch part 12, the protrusion part of the extension part 11b may protrude from the connection plate 82, and the burden at the time of the process of the reinforcement plate 11 can also be reduced.

  In addition, as shown in FIGS. 11 and 12, contrary to the work machine 1 described above, a pair of connection plates 82, 82 are provided in the inner connection portion 73, and the outer connection portion 74 is interposed between these connection plates. The present invention can also be applied to a model provided with one bracket 74a to be inserted.

  In this case, since the load is halved, each reinforcing plate 11A attached to each connecting plate 82 may be formed so that the length of the base portion 11a is shorter than the reinforcing plate 11 described above. For example, as shown in FIG. 12B, each reinforcing plate 11 </ b> A can be formed in a substantially L shape with the extending portion 11 b protruding from the end of the base portion 11 a.

  At this time, the portion of the base portion 11a that protrudes laterally from the extending portion 11b may be disposed between the connection plates 82 and 82 as illustrated, or may be disposed outside the connection plates 82 and 82. May be.

  In this case, the width of the extending portion 11b may be larger than the thickness of the connecting plate 82 on condition that the extending portion 11b does not protrude between the connecting plates 82 and 82.

DESCRIPTION OF SYMBOLS 1 Work machine 10 Support mechanism 11 Reinforcement plate 11a Base part 11b Extension part 11c Flange part 51 Lower traveling body 52 Machine main body 62 Car body 65 Crawler frame 66 Crawler 71 Connection part 73 Inner connection part 74 Outer connection part 74a Bracket 75 Crawler side connection Hole (hole)
78 Connection shaft 81 Support plate 82 Connection plate 83 Reinforcement plate 85 Body side connection hole (connection hole)

Claims (2)

A work machine having a lower traveling body capable of traveling on the lower side of the machine body,
The lower traveling body is
A car body that supports the machine body;
A pair of crawler frames that support the crawler and are detachably attached to both sides of the car body via a support mechanism;
With
The support mechanism is
An inner connecting portion provided on the car body side;
An outer connecting portion provided on the crawler frame side;
Have
The inner connecting portion is
A support plate welded to the car body with one of the plate surfaces facing sideways;
A connection plate welded in a state orthogonal to the support plate and having a connection hole penetrating between the plate surfaces;
A reinforcing plate welded to a lower end portion of the inner connecting portion in a state orthogonal to the connecting plate and the support plate;
Have
The outer connecting portion has a bracket having a plate surface provided with a hole,
The plate surface of the connection plate and the plate surface of the bracket face each other, the connection plate and the bracket are connected via a connection shaft inserted into the connection hole and the hole,
The reinforcing plate is
A base extending along the support plate;
An extension that is orthogonal to the base and extends along the underside of the connecting plate;
Have,
A work machine in which a lateral width of the extension portion is equal to or less than a thickness of the connection plate, and the extension portion is provided so as not to protrude from both sides of the connection plate . The work machine according to claim 1,
A working machine in which a flange portion that spreads toward the base portion is provided at a base portion of the extension portion.

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