JP2005053290A - Crawler frame of construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two-forked leg made of cast steel employable as a leg of a crawler frame of a large construction machinery larger than a medium-size machine by integrating the cast-steel-made crotch-like leg split into two. <P>SOLUTION: The two-forked leg is split into two legs, namely a front leg and a rear leg and is made of the cast steel, the two-split front leg and rear leg made of the cast steel are integrated to form the two-forked leg, the base ends of the integrated two-forked leg are inserted into right and left side surfaces of a center frame and coupled to respective members of the center frame, and the coupling section is welded and fixed. The flange section at the outer end of the crotch-like leg is connected to a left truck frame or a right truck frame. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a crawler frame of a construction machine, and more particularly to a crawler frame of a construction machine suitable for use in a lower traveling body such as a hydraulic excavator.

  Conventionally, for example, in a swivel working machine such as a hydraulic excavator, a crawler traveling device having a rotatable crawler that is an endless track belt is adopted on the left and right, and this crawler traveling device is a track frame (in this application, a crawler frame). Equivalent). A track frame of such a turning work machine generally has a center frame (in this application, a leg is attached to the center frame) having a turning bearing that rotatably supports a turning frame on which a work machine, a cabin, an engine, and the like are mounted. And a pair of left and right side frames (corresponding to a track frame in the present application) which are connected by leg portions welded to the left and right side walls of the center frame and extend in the front-rear direction.

  In order to sufficiently support the load applied to the swivel frame, both the center frame having the swivel bearing at the center and the legs connecting the center frame and the side frame are welded by sheet metal welding such as a steel plate. Forming. That is, when forming the center frame and the leg portion, first, the pair of front and rear vertical walls and the left and right vertical walls parallel to the traveling direction are welded and fixed directly below the swivel bearing, and the pair of front and rear vertical walls The left and right ends of are fixed to the side frame by welding. The upper and lower connection plates are welded and fixed to the upper and lower surfaces so as to cover the pair of front and rear vertical walls and the upper and lower ends of the left and right vertical walls parallel to the traveling direction. Thus, a center frame and legs that connect the center frame and the side frame are formed. (See Patent Document 1 below).

  Further, when forming the center frame and the leg portion, a member for mounting the swivel bearing is formed with a round cylinder at the center, and the four leg portions extending to the left and right side frames are formed on the round cylinder. It is formed by sheet metal welding of a steel plate or the like. In order to support the load applied to the swivel bearing, these four leg portions form leg portions by appropriately using a total of eight longitudinal plate members, two on the front and rear. And the upper-end part and lower-end part of the vertical board member which forms a leg part are covered with an upper surface board and a lower surface board. (See Patent Document 2 below).

  Furthermore, when the center frame is formed together with the legs connected to the side frame by sheet metal welding of a steel plate or the like, the base plate on which the swivel bearing is placed is supported by the left and right vertical members, the front vertical member, and the rear vertical member. The load on the slewing bearing is directly received by them, and the four legs that extend to the left and right side frames are also continuous by welding cover plates to the upper and lower ends of these vertical members. To form. (See Patent Document 3 below)

JP-A-11-93209 JP-A-8-72615 JP 2000230252 A

The center frame (corresponding to the one in which the legs are removed from the center frame in the above-mentioned patent documents 1 to 3) is a steel plate or the like between the left and right track frames (corresponding to the side frame in the above-mentioned patent documents 1 to 3). Since the four leg portions formed by sheet metal welding are connected, the shapes of the steel plates and the like that form the four leg portions vary widely, and the plate cutting is complicated and the number of members increases.
In addition, many processes such as scribing, cutting, bending and welding are necessary, and the number of welding points and complicated welding lines increase the number of welding processes, which increases the manufacturing time and costs. There is.

  Further, the center frame has left and right leg portions connected to the left and right track frames (corresponding to side frames in the above Patent Documents 1 to 3), and the upper surface of the leg portions is relatively facing toward the track frame. Because it is formed of a flat steel plate that is slanted and slanted downward, it can fly or infiltrate when excavators, etc. perform excavation work, swivel transportation work, or when excavators run A large amount of mud adheres to and accumulates on the upper surface of the legs and the like. The adhered and accumulated mud eventually enters the swivel bearing with a ring gear in the upper center portion of the center frame and causes damage to the bearing. Also, the mud that adheres to and accumulates on the legs will eventually move to the upper surface of the track frame and accumulate, and this accumulated mud will prevent the upper wheel from rotating and cause the upper wheel to be unevenly worn. It becomes.

In addition, the accumulated mud is removed by washing, but a large amount of washing water and a lot of washing steps are required to remove the mud, which increases the washing cost.
In addition, a contractor who rents construction machines such as a hydraulic excavator collects a large amount of mud at the washing place after washing the construction machine, and disposal of the mud becomes a problem.

  The present invention has been made paying attention to the above-mentioned problems. By forming the leg of the central frame connected to the track frame from a cast steel casting, the manufacture is simple, and the adhesion and accumulation of mud are less. An object of the present invention is to provide a crawler frame leg of a construction machine that is easy to clean.

  Furthermore, if a leg made of this cast steel casting is used for models larger than medium-sized machines, the mold form of the cast steel casting becomes larger as the outer shape of the leg increases, and hot water flow, degassing, etc. In addition, the casting method becomes complicated, casting defects are likely to occur, and the manufacturing cost increases. The present invention has been made paying attention to this problem, and the above-mentioned casting problem occurs when a bifurcated leg connecting the track frame and the left and right track frames is divided into two parts and manufactured by a cast steel casting. It is an object of the present invention to provide a crawler frame for a construction machine in which there is no possibility.

In order to achieve the above object, in the invention of a crawler frame for a construction machine according to the present invention, a bifurcated leg is divided into a front leg and a rear leg and is formed of a cast steel casting. The rear leg is integrated, and the base end portions of the integrated leg are inserted and arranged on the left and right side surfaces of the central frame, respectively, and are fixedly welded to the members of the central frame.
Then, the base end portion of the integrated leg is inserted and arranged on the left and right side surfaces of the central frame, respectively, and the base end portion of the leg, the top and bottom of the central frame, and the front and rear plates and the entire circumference are welded (over the entire circumference). Welding).

  According to the crawler frame described above, the legs that connect the track frame and the center frame are made of cast steel, so that there is no complicated weld line as in the case of forming with sheet metal, and the weld line can be shortened, so that the welding process is reduced. It becomes easy and the man-hours for processing can be greatly reduced, and the number of parts such as steel plates has been reduced, so that material can be saved. Furthermore, the outer shape of the leg can be reduced in size by dividing the forked leg into two parts, a front leg and a rear leg, and made of cast steel.

As a result, even when a leg used for a hydraulic excavator of a relatively large medium-sized machine or more is manufactured from a cast steel casting, a mold frame that is not so large as in the conventional case can be used, and a casting plan is facilitated. Flow, degassing, etc. can be improved, casting defects can be eliminated, and manufacturing costs can be reduced.
For example, when a bifurcated leg is divided into two parts, a front leg and a rear leg, and a leg is manufactured by the lost wax casting method, a relatively small wax form is used as in the conventional case. Therefore, deformation of the shape of the wax-shaped formwork due to its own weight or the like can be eliminated, and a fine leg with high accuracy and no surface roughness can be obtained. In addition, since the outer surface can obtain a fine leg of grain, the appearance quality is improved, and the mud slides easily when washing and running, so the mud can be easily dropped on the ground. .

  In addition, as described later, the front leg and the rear leg are welded with a joint portion having a predetermined width so that the front leg and the rear leg are firmly integrated and rigid. Will increase. Further, the base end portion of the bifurcated leg formed by integrating the front side leg and the rear side leg is joined to each member of the central frame over the entire circumference. (All-around welding) It is fixed so that it has a strong structure, the load of the upper rotating body received by the central frame is transmitted to the leg reliably, and the load is evenly transmitted to and supported by the track frame via the leg. The

  In addition, since the legs made of cast steel have a convex shape on the top surface and, for example, a pentagonal shape on the top surface, the mud is not deposited on the convex portions on the top surface of the leg. It doesn't happen very much. Even if mud accumulates on the convex part of the upper surface of the leg, for example, the outer surface of the leg manufactured by the lost wax casting method is finely grained, so that it can be easily applied to the ground by vibration during traveling before the mud is fixed. Slide down. For this reason, there is no or no amount of mud deposits on the top of the leg. Since mud deposits on the convex portions on the upper surface of the leg are extremely reduced, the amount of washing water and the number of washing steps for washing the excavator can be reduced, and the washing cost can be greatly reduced. In addition, in rental companies and the like, mud accumulates at the washing place when the hydraulic excavator is washed, and the amount of mud accumulated can be greatly reduced, so that the problems related to the disposal place can be reduced.

  Further, as the amount of mud deposited on the leg decreases, the amount of mud deposited on the track frame also decreases, and uneven wear of the upper roller can be prevented to smooth the rotation of the upper roller. Similarly, less mud is deposited on the leg, very little mud adheres to the swivel bearing, and the bearing is hardly damaged.

Hereinafter, the best mode of a crawler frame of a construction machine according to each embodiment of the present invention will be described with reference to the drawings.
The embodiment of the crawler frame of the construction machine according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4, 5, 6, 8 (a), 8 (b), and 9. The embodiment of the crawler frame of the construction machine according to the second embodiment of the present invention will be described with reference to FIGS. 1 to 4, 5, 7, 8 (a), 8 (b), and 9. In addition, with respect to the embodiment of the crawler frame of the construction machine according to the third embodiment of the present invention, FIG. 1 to FIG. 4, FIG. 7, FIG. It explains using.
First, an embodiment of a crawler frame for a construction machine according to a first example of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view of a crawler frame of a construction machine according to a first embodiment of the present invention, FIG. 2 is a plan view of the crawler frame of the construction machine according to the first embodiment of the present invention, and FIG. FIG. 4 is a front view of a crawler frame of a construction machine according to one embodiment, and FIG. 4 is a side view of the crawler frame of the construction machine according to the first embodiment of the present invention. In the following description of the crawler frame of the construction machine according to the second and third embodiments, the same members as those used for the description of the crawler frame of the construction machine according to the first embodiment of the present invention are used. Sometimes the number is used as it is without changing the number.

A crawler frame 1 shown in FIGS. 1 to 4 is used in a construction machine, for example, a turning work machine such as a hydraulic excavator, and is used in a crawler traveling device having a crawler that is an endless track belt.
In the following, the traveling direction of the turning work machine is referred to as the front-rear direction (longitudinal direction of the track frame 5) as in the conventional example, and the lateral direction perpendicular to the front-rear direction is referred to as the left-right direction.

  The crawler frame 1 is mainly provided with a central frame 3, left and right track frames 5L and 5R which are disposed on the left and right sides of the central frame 3 and extend in the front-rear direction of the vehicle body, and a left side surface of the central frame 3. And a left leg 7L that connects the left track frame 5L and a right side surface 7R that connects the right side surface of the central frame 3 and the right track frame 5R (see FIGS. 1 and 2). The left track frame 5L and the right track frame 5R are each provided with a support frame 11 having a gate-shaped cross section disposed at the center in the longitudinal direction, and a front vertical plate 13 and a rear vertical plate 15 at front and rear ends of the support frame 11. And an idler support 17 and a drive wheel support 19 supported via a front vertical plate 13 and a rear vertical plate 15. Although not shown in the figure, the idler support 17 and the drive wheel support 19 support the idler and the drive wheel, respectively (see FIGS. 1 and 2).

  Next, FIGS. 6 and 7 will be described. FIG. 6 is an exploded perspective view showing the members constituting the central frame of the crawler frame of the construction machine according to the first embodiment of the present invention in an exploded manner. In particular, the central frame is parallel to the inner wall of the track frame. It is an exploded perspective view in the case of having as one member left and right side support plates provided with a flat face plate portion of a certain length and subsequently an arcuate face plate portion matched with the inner peripheral wall of the circle base. is there. FIG. 7 is an exploded perspective view showing the members constituting the central frame in the crawler frame of the construction machine according to the second embodiment of the present invention in an exploded manner. In particular, the central frame is parallel to the inner wall of the track frame. A flat face plate portion of a certain length, followed by a straight flat face plate portion that is aligned with a straight line that is not parallel to the inner wall of the track frame but is inclined so that the rear side is slightly narrower. It is a disassembled perspective view in the case of having the left and right side support plates provided as one member.

  First, FIG. 6 will be described. The central frame 3 is formed by cutting a steel plate or the like, and mainly includes an upper surface plate 21, a lower surface material 23, a left side support plate 24L, a right side support plate 24R, a front plate 25, and a rear surface material 27. It has become. The outer shape of the upper surface plate 21 is generally formed into a substantially semi-elliptical shape, and a hole 21a into which a swivel joint or a hydraulic pipe (not shown) is inserted is formed in the central portion. The outer shape of the upper surface plate 21 will be described in more detail. When the side on which the semi-elliptical edge is not formed is assembled to the central frame 3, it corresponds to the front side, and there is a straight side extending in the left-right direction. Exists. The front portion of the upper surface plate 21 has the same width in the left-right direction by a certain length W, and subsequently, a semi-elliptical edge is formed on the rear side.

  The outer surface of the lower surface plate 23 is the same as that of the upper surface plate 21, and is generally formed in a semi-elliptical shape. In the form according to the embodiment of the present invention, as shown in FIG. 6, a front plate 25 is provided on the front side of the lower plate 23 so as to be perpendicular to the lower plate 23 and integral with the lower plate 23. The shape of the lower surface plate 23 will be described in more detail. In the front portion of the lower surface plate 23 following the front surface plate 25, the width in the left-right direction is made the same by a certain length (W). A semi-elliptical edge is formed on the rear side. The left side support plate 24L has a portion in which the width in the left-right direction is the same by a certain length (W) at the front portion of the lower surface plate 23, but is almost the same as this length (W). A face plate portion 24Lb parallel to the inner side wall of the left track frame 5L, followed by a bulge to the left outer side and an arcuate face plate portion 24Lc along the inner peripheral wall of the circle base 31 (FIG. 2). See also). Also, the right side support plate 24R is omitted and is omitted because it has the same configuration. Further, insertion holes 24La and 24Ra into which hydraulic pipes and the like are inserted are formed in the left side support plate 24L and the right side support plate 24R. Although the front plate 25 is formed of a long rectangular plate material, in the form according to the embodiment of the present invention, as shown in FIG. 6, the front plate 25 is a side of the lower plate 23 that is not elliptical, that is, the side. The front side is bent vertically by a predetermined width and integrally formed, but this is stopped, and the front plate 25 of a rectangular long plate material, and the bottom member 23 having a substantially semi-elliptical shape as a whole, These may be cut into a predetermined size and formed separately. Further, the rear plate 27 is configured by bending a rectangular plate material at a required position in the left-right direction with the central surface as a boundary to form three surfaces. The rear plate 27 shown in FIG. 6 has a central surface formed wider than the left and right surfaces. By appropriately adjusting the width of the central surface of the rear plate 27, the side edges of the left and right side plates of the rear plate 27 are securely joined to the rear surface portions of the rear legs of the left and right bifurcated legs described later. It is formed as possible (see also FIG. 2).

  Next, a method for forming the box-shaped central frame 3 will be described. The inner side of the circle base 31 is appropriately inside the part where the width in the left-right direction is the same by a certain length (W) of the upper surface of the lower surface plate 23, and the edge of the semi-elliptical part on the rear side. The left and right side support plates 24L, 24R are vertically joined at positions where the arc-shaped face plate portions 24Lc, 24Rc of the left and right side support plates 24L, 24R are arranged so as to be directly under the peripheral wall. The joint portions are welded and fixed, and the front portions of the parallel face plate portions 24Lb and 24Rb are joined to the rear surface of the front plate 25, and the joint portions are welded and fixed. And on the upper surface slightly inside from the elliptical end edge on the rear side of the lower surface plate 23, a rectangular plate material is bent at a required position in the left-right direction with the central surface as a boundary to form three surfaces. The constructed rear plate 27 is joined vertically, and this joined portion is fixed by welding. The rear surface plate 27 is adjusted and arranged so that the center surface of the three surfaces is exactly at the center of the end edge of the elliptical shape on the rear side of the lower surface plate 23. Further, the side edges of the left and right face plates of the rear face plate 27 are joined to the rear surface 7m of the base end portion of the rear leg of the bifurcated leg, which will be described later, and the joint portions are welded. Further, the rear side edges of the arcuate face plate portions 24Lc and 24Rc are joined to the inner surfaces of the rear ends of the rear legs of the left and right bifurcated legs, and the joints are welded (FIG. 2). See also). The left and right side support plates 24L and 24R and the rear plate 27 have the same height as the front plate 25.

  The lower surface of the upper surface plate 21 is joined to the upper end portion of the front plate 25, the upper end portions of the left and right side plates 24L and 24R, and the upper end portion of the rear plate 27 in accordance with the shape of the lower surface plate 23. The joint is welded. In this manner, the bottom plate 23 is formed at the bottom, the front plate 25, the left and right side support plates 24L and 24R, and the rear plate 27 are formed at the periphery, and the hole 21a is formed at the center at the top. A box-shaped central frame 3 composed of the upper plate 21 is formed.

Next, FIG. 7 will be described.
FIG. 7 is an exploded perspective view showing the members constituting the central frame of the crawler frame of the construction machine according to the second and third embodiments of the present invention in an exploded manner. 7 is also an exploded perspective view in which each member constituting the central frame 3 in the crawler frame of the construction machine is disassembled and shown in the same manner as FIG. 6, and the difference from FIG. 6 is that in FIG. The flat face plate portions 24Lb and 24Rb having a fixed length (W) in which the central frame 3 is parallel to the inner walls of the track frames 5L and 5R, and subsequently the arcuate face plate portions that match the inner peripheral wall of the circle base 31 The left and right side support plates 24L and 24R formed by 24Lc and 24Rc are provided as one member, whereas in FIG. 7, the central frame 3 has inner walls of the track frames 5L and 5R. The flat face plate portions 74Lb and 74Rb of a certain length (W) parallel to the horizontal plane, and subsequently, are inclined not to be parallel to the inner walls of the left and right track frames 5L and 5R but slightly narrower on the rear side. That is, the left and right side support plates 74L and 74R having straight flat face plate portions 74Lc and 74Rc that match the drawn straight line are provided as one member. In this respect, the one shown in FIG. 7 is different from the one shown in FIG. As shown in FIG. 6, it is somewhat difficult to form the face plate portions 24Lc and 24Rc of the left and right side support plates 24L and 24R in an arc shape matching the inner peripheral wall of the circle base 31. The face plate portions 74Lc and 74Rc of the left and right side support plates 74L and 74R are linear flat face plate portions 74Lc and 74Rc. The left side support plate 74L and the right side support plate 74R are formed with insertion holes 74La and 74Ra into which hydraulic piping or the like is inserted.
When the box-shaped central frame 3 is formed, the left and right side support plates 74L and 74R are pulled in an inclined manner so that the rear side is slightly narrower and not parallel to the inner walls of the left and right track frames 5L and 5R. The upper surface of the lower surface plate 73 of the left and right side support plates 74L and 74R is arranged on the upper surface of the lower surface plate 73 and the lower surface of the upper surface plate 71 according to the straight line, and the one shown in FIG. , And the position where the joint is welded to the lower surface of the upper surface plate 71 and the joint is welded to the inner side is different, but the method for forming the other box-shaped central frame 3 is described above. Since these are exactly the same as those shown in FIG. 6, these points will not be described here.

7 also has a bottom plate 73 on the bottom, a front plate 75 on the side, left and right side support plates 74L and 74R, and a rear plate 77 on the bottom, as in FIG. The box-shaped central frame 3 is formed by the upper surface plate 71 or the like in which the holes 71a are formed. Generally speaking, the left and right legs 7 (left leg) are formed in an arc shape in accordance with the inner circumference of the circle base 31. 7L, the front leg 7F of the right leg 7R) and the end edge of the cylindrical body of the base end part of the rear leg 7B are not formed, but the front end leg of the front leg 7F and the rear leg 7B It is best to adopt the center frame shown in FIG. 7 when the end edge of the cylindrical body is a relatively simple shape, for example, a straight shape, but the front leg 7F, the rear When the edge part edge of the cylindrical body of the base end part of the side leg 7B is formed in a comparatively gentle curved shape But it can be used.
The front plate 25, the rear plate 27, and the left side support plate 24L and the right side support plate 24R in the central frame 3 shown in FIG. 6, or the front plate 75 and the rear plate in the central frame 3 shown in FIG. 77, and the left side support plate 74L and the right side support plate 74R both carry the load of the large upper swing body on the upper surface plate 21 or the circle base 31 holding the swing bearing on the upper surface of the upper surface plate 71. It is for support.

  A circle base 31 that holds a swivel bearing is fixed to the upper surface of the upper surface plate 21 of the central frame 3 (see FIGS. 1, 3, and 4). Further, as will be described later, the left and right side surfaces of the central frame 3 are respectively inserted into the bifurcated left leg 7L and the base end of the right leg 7R (the base part of the leg welded and fixed to the central frame 3). The entire circumference of the base end portion of the left leg 7L and the right leg 7R is joined to the side edge of each member of the central frame 3 and the joined portions are fixed by welding. The left leg 7L and the right leg 7R extend from the side surface of the central frame 3 to which the left leg 7L and the left leg 7R are attached to the left and right track frames 5L and 5R while being inclined obliquely downward while drawing an arc. The outer end of the leg 7L or the right leg 7R is joined to the inner side walls of the left and right track frames 5L, 5R, and the joints are fixed by welding.

  Next, FIG. 5 will be described. FIG. 5 is a front leg of an integrated bifurcated left and right leg (left leg, right leg) in the crawler frame leg of the construction machine according to the first embodiment and the second embodiment of the present invention; It is the perspective view which looked at the back side leg from the lower part. The left leg and the right leg are different and have the same configuration. In the embodiment according to the first embodiment of the present invention, for the reason of manufacturing described later, one bifurcated left and right leg 7 (left leg 7L, right leg 7R) integrated as shown in FIG. ) Is divided into two parts, a front leg 7F and a rear leg 7B, and each is manufactured by casting. Then, the front and rear end faces of the front leg 7F and the rear leg 7B manufactured by casting are joined together to form a joined part 7d. A bifurcated leg 7 (the left leg 7L and the right leg 7R) is formed by welding the portions 7d. And the edge part of the cylindrical body of the base end part of this bifurcated leg 7 (left leg 7L, right leg 7R) faces the side support plates 24L, 24R of the central frame 3 and is inserted into the left and right side surfaces. It arrange | positions and it is made to join to the side edge of each member of the center frame 3, etc., and the junction part is weld-fixed.

  The cross-sectional shape of the intermediate portion of the bifurcated leg 7 (left leg 7L, right leg 7R) is, for example, such that the base end is fixed while maintaining a pentagonal cylindrical body with a convex top surface. It extends from the center frame 3 side toward the track frame 5 (left track frame 5L, right track frame) while gradually inclining downward while drawing an arc, and the bifurcated leg 7 (left leg 7L or right side) The outer ends of the front leg 7F and the rear leg 7B of the leg 7R) are joined to the inner side walls of the track frame 5 (left track frame 5L, right track frame 5R), and the joints are fixed by welding. . In the embodiment of the leg according to the embodiment of the present invention, as described above, the cross-sectional shape of the middle part of the front leg 7F and the rear leg 7B is a pentagonal cylindrical body whose top surface is convex. However, the front leg 7F and the rear leg 7B do not necessarily have to be pentagonal as long as the cross-sectional shape of the intermediate portion thereof is a cylindrical body whose top surface is convex. , A substantially triangular shape, a quadrangular shape whose upper surface is an arc, or a substantially hexagonal shape. Further, as described above, the leg 7 is formed of a cast steel casting into a cylindrical body, so that its thickness (see t in FIG. 2) can be easily changed according to the load acting on the leg 7, Thereby, the internal stress (bending stress, shearing stress) of the leg 7 can be made substantially uniform. For example, it is possible to increase the thickness of the leg 7 on the side closer to the track frame 5 where the internal stress increases, and gradually decrease the thickness toward the central frame 3 side. Thus, the weight can be reduced as compared with the case where the plate thickness is set where the stress is large and the entire thickness is the same.

  A front flange portion 7i fixed to a front side inner wall of the support frame 11 of the track frame 5 (the left track frame 5L and the right track frame 5R) is provided at an outer end portion of the front leg 7F. A rear flange portion 7j fixed to the inner side wall on the rear side of the support frame 11 of the track frame 5 (left track frame 5L, right track frame 5R) is formed at the outer end portion of 7B. A U-shaped flange portion 7k that is welded to the front side of the rear vertical plates 15 and 15 of the track frame is formed on the rear end surface of the outer end portion of the side leg 7B (FIGS. 2 and 5). See). The base end portions of the front leg 7F and the rear leg 7B of the integrated bifurcated leg 7 (the left leg 7L or the right leg 7R) are joined to the side edge of each member of the central frame 3, etc. It is fixedly welded and extends from the left and right track frames 5 (left track frame 5L, right track frame 5R) while gradually inclining downward and extending while drawing an arc, and the front leg 7F and the rear leg 7B. The front flange portion 7i, the rear flange portion 7j, or the U-shaped flange portion 7k at the outer end of the inner wall of the support frame 11 of the left and right track frames 5 (left track frame 5L, right track frame 5R), or Joined to the front side of the rear vertical plate 15, the joined portions are welded and fixed here (see FIGS. 2 and 5).

  As described above, the front leg 7F and the rear leg 7B are made of cast steel, and the front and rear end portions of the base end portions of the front leg 7F and the rear leg 7B are joined to each other. Are joined together to form a bifurcated (substantially V-shaped plan view) leg (left leg 7L, right leg 7R). As described above, the outer ends of the integrated bifurcated left leg 7L and right leg 7R, whose base ends are fixed to the members of the central frame 3, are obliquely below the track frame 5 (left side). The inner side walls of the track frame 5L and the right side track frame 5R) are joined and welded. The central portion is formed in a substantially X shape in plan view as a whole by the central frame 3 and the bifurcated left leg 7L and right leg 7R (see FIG. 2). The load of the upper rotating body acting on the circle base 31 on the upper surface plate 21 of the frame 3 is distributed to the four legs by the bifurcated left leg 7L and the right leg 7R, and the load is effectively supported. (See FIGS. 2 and 5). 2 and 5, the left leg 7L and the right leg 7R are inserted and arranged on the side surface of the central frame 3, and joined to the side edges and the like of each member of the central frame 3. It is designed to be X-shaped when fixed by welding, but this is a plan view as a whole by slightly changing the shapes of the left leg 7L, the front leg 7F and the rear leg 7B, which are components of the right leg 7R. It may be H-shaped. This H-shaped leg 7 also enters the bifurcated leg. Also, an integrated bifurcated (planar view substantially V-shaped) left leg 7L and left track frame 5L, and an integrated bifurcated (planar view generally V-shaped) right leg 7R and right track frame 5R A relatively large left hole 65 and a relatively large right hole 65 are formed (see FIGS. 2 and 5). When excavation work or traveling / turning work is performed using a construction machine such as a hydraulic excavator, the mud becomes the front leg 7F and the rear leg 7B of the left leg 7L, or the front leg 7F and the rear leg of the right leg 7R. Mud that has infiltrated into the upper surface of 7B or scattered and some mud adheres to the upper surface of the legs 7L and 7R. Easily falls to the ground from the relatively large right hole 65 or left hole 65.

  In the embodiment of the leg in the crawler frame of the construction machine according to the first embodiment and the second embodiment of the present invention, the integrated bifurcated leg 7 (left leg 7L, right leg 7R) is cast steel. It is formed by joining the front and rear end portions of the front end portion 7F and the rear end portion 7B of the casting, respectively, and welding and fixing the joint portion 7d. There is no vertical wall on the end face of the base end portion of the front leg 7F and the rear leg 7B made of cast steel before integration, and the base ends of the front leg 7F and the rear leg 7B made of cast steel No wall is formed on the end surface of the end portion in the front-rear direction of the portion.

  The integrated bifurcated leg 7 (left leg 7L, right leg 7R) is attached to the side support plates 24L and 24R on the side surface of the central frame 3 as described in the paragraph numbers (0021) to (0028). The end edges of the tubular bodies at the base ends of the front leg 7F and the rear leg 7B made of cast steel are inserted and arranged so as to face each other with an appropriate interval. As shown in FIG. 6, the shape of the side support plates 24L, 24R of the central frame 3 is a flat face plate portion of a certain length (W) parallel to the inner walls of the left and right track frames 5L, 5R. 24Lb, 24Rb, followed by arc-shaped face plate portions 24Lc, 24Rc matched to the inner peripheral wall of the circle base 31, but a bifurcated leg 7 integrated so as to substantially match this shape The end edges of the cylindrical body at the front end of the front leg 7F and the rear leg 7B of the left leg 7L and the right leg 7R are shaped. That is, the end of the cylindrical body at the base end portion of the front leg 7F in the front-rear direction from the front wall of the front leg 7F that hits and joins the rear surface of the front plate 25 of the center frame described later. The edge is formed in parallel with the left and right track frames 5L, 5R, and the end edge of the cylindrical body at the base end is made the same in the left-right direction by the length (W) from the front to the rear. After the length (W), a cylindrical body at the rear end of the base end of the front leg 7F and the subsequent base end of the rear leg 7B in an arc shape substantially matched to the inner peripheral wall of the circle base 31. The edge of the is made its shape.

The upper surface and the lower surface of the base end of the integrated bifurcated leg 7, that is, the front leg 7F and the rear leg 7B of the left leg 7L or the right leg 7R are stepped on the upper or lower side of the base end. Step portions 7e and 7e are formed so as to be lowered. The shape of the boundary between the stepped portions 7e and 7e matches the shape of the side edges of the upper surface plate 21 and the lower surface plate 23 of the central frame 3 in plan view. In the embodiment according to the present invention, the shape of the stepped portions 7e, 7e is straight so as to match the shape of the side edges of the substantially semi-elliptical upper surface plate 21 and lower surface plate 23 of the central frame 3 shown in FIG. Or a curved shape (see FIGS. 2 and 5).
When attaching the left leg 7L and the right leg 7R to the left and right side surfaces of the center frame 3, first, face the side support plates on the left and right side surfaces of the center frame 3 so as to face the base end portions of the left leg 7L and the right leg 7R. The end edges of the cylindrical body are inserted and arranged, and the side edges of the upper surface plate 21 and the lower surface plate 23 are inserted into the integrated bifurcated leg 7, that is, the front of the left leg 7L or the right leg 7R. The side legs 7F and the rear side legs 7B are joined to the stepped portions 7e and 7e at the base end portions, and the joined portions are welded and fixed here (see FIGS. 2 and 5).

Further, the rear surface of the front plate 25 of the central frame 3 is joined to the front wall 7g of the base end portion of the left and right front side legs 7F, and the joined portions are welded and fixed here (see FIGS. 2 and 5). reference).
Furthermore, a joint 7m is formed at the proximal end of the rear wall of the rear wall of the left and right rear legs 7B, and the left and right sides of the rear plate 27 of the central frame 3 are formed at the joint 7m. The edges are joined and the joints are welded and fixed here (see FIGS. 2 and 5).

  The upper and lower surfaces, front and rear sides of the base ends of the left and right front legs 7F and rear legs 7B of the bifurcated leg 7 (the left leg 7L or the right leg 7R) integrated in this way are all around the circumference. Then, the joint portion is joined to the side edge of each member of the central frame 3 and the joint portion is welded and fixed all around, so that it can be firmly fixed and the left and right track frames 5L and 5R. The load of the upper swing body is securely distributed and supported by the four legs of the left and right bifurcated legs 7 connected to the left and right legs.

Generally speaking, manufacturing the entire bifurcated leg 7 (the entire left leg 7L or the entire right leg 7R) used for medium-sized or larger machines of construction machinery by casting is that one part is large. It is difficult because the structure is somewhat complicated. Therefore, in the embodiment of the present invention, the bifurcated leg 7 (left leg 7L, right leg 7R) is divided into a front leg 7F and a rear leg 7B to make a small size, and the two parts are casted. By manufacturing, the above various problems in casting can be solved, and even a relatively large leg such as a hydraulic excavator of a medium-sized machine or more does not have a large shape as a whole.
For this reason, for example, when the front leg 7F or the rear leg 7B is manufactured separately by the lost wax casting method, the mold formed by brazing does not become extremely large. The leg 7 (left leg 7L, right leg 7R) can be manufactured with high accuracy, and if the leg is manufactured by this lost wax casting method, the surface roughness of the outer shape of the leg 7 can be reduced. Since it can be made fine, the appearance quality can be improved and the surface roughness of the outer shape of the leg 7 becomes fine, so that the mud slides on the ground after a while even after the mud has adhered. As it falls, there will be no or very little mud accumulation. In this way, if each of the left leg 7L and the right leg 7R is divided into two parts, the front leg 7F and the rear leg 7B, and separately manufactured by casting, a relatively small formwork can be used as in the conventional case. Since the casting method becomes easy, the flow of hot water, degassing, etc. can be improved and casting defects can be eliminated. Therefore, the manufacturing cost can also be reduced.

Next, FIG. 8 will be described.
FIG. 8 shows the rear edge and the rear edge of the base end of the front leg of the leg divided into two in the leg of the crawler frame of the construction machine according to the first embodiment and the second embodiment of the present invention. FIG. 8 (a) is a diagram showing that a bifurcated leg is formed by joining the front end edge of the base end portion of the leg and welding and fixing the joined portion together. FIG. 8 (b) is a cross-sectional view showing that an end edge on the side and an end edge on the front side of the rear leg are fitted and joined, and the joint is welded and fixed to form an integrated bifurcated leg. ) Is a cross section showing that the rear end edge of the front leg and the front end edge of the rear leg are butted and joined, and the joint is welded and fixed to form an integrated bifurcated leg FIG.

8 (a) and 8 (b) are cross-sectional views of the vicinity of the joint 7d of the integrated bifurcated leg 7 shown in FIG.
First, FIG. 8A will be described. The vertical dimension between the upper surface and the lower surface of the rear end edge of the front leg 7F is made smaller than the vertical dimension between the upper surface and the lower surface of the front edge of the rear leg 7B. When the upper and lower surfaces of the rear edge of the side leg 7F are fitted to the upper and lower surfaces of the front edge of the rear leg 7B, the upper and lower surfaces of the rear edge of the front leg 7F Then, the upper surface and the lower surface of the end edge on the front side of the rear leg 7B are overlapped with each other, and a joint portion 7d is formed near the overlapping upper and lower surfaces, and this portion becomes the J-shaped groove 35. The joint 7d, that is, the J-shaped groove 35 is welded to integrate the front leg 7F and the rear leg 7B to form a bifurcated left leg 7L or right leg 7R. Since the joining portion 7d has a predetermined width, the integration of the front leg 7F and the rear leg 7B becomes strong by performing welding over the entire width using the width 7d.
The joint 7d, that is, the portion of the J-shaped groove 35 is filled by welding, and the outer surface of the leg is arranged so that the surface of the front leg 7F and the surface of the rear leg 7B are flush with each other. By adjusting by welding, the appearance quality of the bifurcated left leg 7L or right leg 7R can be further improved.

Next, FIG. 8B will be described.
The upper and lower dimensions of the upper and lower surfaces of the rear edge of the front leg 7F are the same as the upper and lower dimensions of the upper and lower edges of the front edge of the rear leg 7B. The thickness of the cross-section of the upper and lower end portions of the rear edge of the side leg 7F is inclined downward so as to become thinner toward the rear end so that the thickness is eliminated. The thickness of the cross section of the upper end and the lower end of the front edge of the leg 7B is slanted downward so as to become thinner as it goes to the forefront, thereby eliminating the thickness. The upper surface of the rear edge of the front leg 7F and the rearmost edge of the lower surface of the front leg 7F, the upper surface of the front edge of the rear leg 7B and the leading edge of the lower surface of the rear leg 7B are formed. When the butting is performed, a joint portion 7d is formed in the vicinity of the both butting, and a V-shaped groove 39 is formed. When integrating the front leg 7F and the rear leg 7B, it is possible to perform strong welding by preliminarily attaching the back metal 41 to the joint 7d.

Next, FIG. 9 will be described.
FIG. 9 shows the base end portion of the bifurcated leg integrated between the left and right side edges of the central frame of the crawler frame of the construction machine according to the first to third embodiments of the present invention. The end of the cylindrical body is inserted and arranged, and the upper edge of the base end of the integrated bifurcated leg and the stepped portion of the lower face are joined to the side edge of the upper face plate of the central frame and the lower face plate, and the joint is welded. It is sectional drawing explaining the structure of the side part support plate which joins perpendicularly | vertically to the appropriate position inside a little from the side edge of the upper surface board of a center frame, and a lower surface board, and the joined part is weld-fixed. is there. In order to describe the first embodiment of the present invention, the numbers used in FIG. 9 are the same as those in FIG. 6 and the numbers in FIG. However, when describing the second embodiment of the present invention, the reference numerals shown in FIG. 7 and the reference numerals shown in FIG. 5 are read, and this is also replaced by the third embodiment of the present invention. When describing the embodiment, it is assumed that the reference numerals in FIG. 7 and the reference numerals in FIGS. 10 (a) and 10 (b) are read.
Also, the end of the cylindrical body at the base end of the bifurcated leg is inserted between the upper and lower side edges of the central frame of the crawler frame of the construction machine, and the integrated For the structure in which the side edges of the upper surface plate and the lower surface plate of the central frame are joined to the upper and lower step portions of the base end of the bifurcated leg and the joint is welded and fixed, the paragraph number ( 0035), and the structure of the side support plate that is joined perpendicularly to an appropriate position slightly inside from the side edge of the upper surface plate and the lower surface plate of the central frame, and the joint portion is welded and fixed. Since the description has been made with paragraph numbers (0023) to (0027) in the specification, FIG. 9 will be described with a focus on portions not described in these paragraph numbers.

The front end leg 7F and the rear end leg 7B of the bifurcated leg 7 (right leg 7L, left leg 7R) integrated between the left and right side edges of the upper surface plate 21 and the lower surface plate 23 of the central frame 3 The end of the cylindrical body is inserted and arranged. Then, the side edges of the upper surface plate 21 and the lower surface plate 23 of the central frame 3 are welded and fixed to the upper and lower step portions 7e and 7e of the base end portions of the front and rear side legs 7F and 7B of the leg 7. As a result, the upper surface plate 21 of the central frame 3 and the upper surfaces of the cylindrical bodies at the base ends of the front and rear legs 7F and 7B of the bifurcated leg 7 (the right leg 7L and the left leg 7R) overlap each other. 7d is formed in the vicinity of this, and this portion becomes the J-shaped groove 35.
Further, the bottom plate 23 of the center frame 3 and the bottom surface of the cylindrical body at the base end portion of the front and rear side legs 7F and 7B of the bifurcated leg 7 (the right leg 7L and the left leg 7R) are overlapped to overlap each other. 7d is formed, and this portion becomes the J-shaped groove 35. A bifurcated leg 7 integrated with the central frame 3 is fixed by welding the J-shaped groove 35.
The J-shaped groove 35 has a certain width and can be firmly fixed by completely filling the portion having the certain width by welding. Further, when the portion of the J-shaped groove 35 is buried by welding for improving the appearance quality, the front side leg 7F of the bifurcated leg 7 integrated with the surfaces of the upper surface plate 21 and the lower surface plate 23 of the center frame. It is preferable that the upper surface and the lower surface of the base end of the rear leg 7B are flush with each other.
In addition, the shape of the boundary line of the step part 7e of the upper surface and lower surface of the base end part of the said front side leg 7F and the said back side leg 7B is the upper surface board 21 of the center frame 3, and the lower surface board 23, as shown in FIG. It becomes the same as the linear shape and curved shape formed by the side edge.

  Further, when the base end portions of the front leg 7F and the rear leg 7B of the bifurcated leg 7 are welded and fixed to the central frame 3, side edges of the upper surface plate 21 and the lower surface plate 23 of the central frame 3 and In addition to fixing the upper and lower stepped portions 7e and 7e of the front end of the front leg 7F and the rear leg 7B by welding, the front wall of the front end of the front leg 7F of the leg 7 is also fixed. Welding and fixing between the step 7g and the left and right side edges of the front plate 25 of the central frame 3, and the joint 7m and the central frame 3 on the proximal end of the rear wall of the rear leg 7B of the leg 7 There is welding fixation with the left and right side edges of the rear plate 27.

Next, the structure of the side support plates 24L and 24R that are vertically joined to appropriate positions slightly inside from the left and right side edges of the upper surface plate 21 and the lower surface plate 23 of the central frame 3 and the joint portions are welded and fixed. Will be described.
As shown in FIG. 2, the side support plates 24 </ b> L and 24 </ b> R are vertically joined to appropriate positions slightly inside from the side edges of the upper surface plate 21 and the lower surface plate 23 of the central frame 3, and the joint portions are welded 36. , 36. The left side support plate 24L and the right side support plate 24R have a portion in which the width in the left-right direction is the same by a certain length (W) at the front portion of the bottom plate 23. The face plate portions 24Lb and 24Rb parallel to the inner side wall of the left track frame 5L are formed by approximately the same length as (W), followed by swelling on the left outer side and on the right outer side, along the inner peripheral wall of the circle base 31. And arc-shaped face plate portions 24Lc and 24Rc. The left side support plate 24L and the right side support plate 24R are formed with insertion holes 24La and 24Ra into which hydraulic pipes 37 and the like are inserted. The insertion holes 24La, 24Ra are circular along the inner peripheral wall of the circle base 31 so as to be connected to the end of the cylindrical body at the base end of the rear leg 7B as shown in FIGS. The insertion holes 24La and 24Ra are formed on the rear leg 7B side of the face plate portions 24Lc and 24Rc formed in an arc shape. 6 and 1, only one insertion hole 24La, 24Ra is formed, but if necessary, another insertion hole is provided at a position connected to the end opening of the cylindrical body at the base end of the front leg 7F. Holes 24La and 24Ra may be provided.

The side support plates 24L and 24R are formed by cutting a steel plate and bending it appropriately to form insertion holes 24La and 24Ra at predetermined positions, so that the insertion holes 24La and 24Ra have no guards. If the hydraulic pipe 37 is inserted without being attached, the hydraulic pipe 37 may be damaged by the edges of the insertion holes 24La and 24Ra. Therefore, the grommets 24Lg and 24Rg are preferably attached to the peripheral portions of the insertion holes.
The left side support plate 24L and the right side support plate 24R are members provided to support the load of the upper swing body related to the circle base 31 in the vertical direction. When assembling, the side support plates 24L and 24R are joined perpendicularly to appropriate positions slightly inside from the left and right side edges of the upper surface of the bottom plate 23, and the inside and outside of the side support plates 24L and 24R are joined. The joints 36 and 36 are welded. Similarly, the rear plate 27 is joined perpendicularly to an appropriate position slightly inside from the semi-elliptical side edge on the rear side of the upper surface of the lower plate 23, and the inner side and the outer side of the rear plate 27 are welded. Then, the upper surface plate 21 is placed over the upper end portion of the front plate 25, the upper end portions of the left and right side support plates 24 </ b> L and 24 </ b> R, and the upper end portion of the rear plate 27 according to the shape of the lower surface plate 23. The upper end of the front plate 25, the upper ends of the left and right side support plates 24L and 24R, and the upper end of the rear plate 27 are joined to the lower surface of the top plate 21, and the joints are welded from the inside through the holes 21a. Then, one central frame 3 is formed by welding each part from the outside. FIG. 9 shows only a sectional state in which the left and right side support plates 24L and 24R are joined to the upper surface of the lower surface plate 23 and the lower surface of the upper surface plate 21, and the joint portions are welded from the inside and the outside. ing.
It is to be noted that the ends of the cylindrical bodies at the base end portions of the front leg 7F and the rear leg 7B that are integrated on the left and right side surfaces between the side edges of the upper surface plate 21 and the lower surface plate 23 of the central frame 3 are inserted. When arranged, the ends of the cylindrical bodies at the base end portions of the front leg 7F and the rear leg 7B face the left side support plate 24L and the right side support plate 24R at an appropriate interval. It will be.

Next, FIG. 10 will be described.
FIG. 10 shows a leg structure in a crawler frame of a construction machine according to a third embodiment of the present invention, and a front leg and a rear leg formed by this structure are integrated to form a bifurcated leg. FIG. 10A is a perspective view showing a structure in which an integrated leg is inserted and arranged in a central frame, joined to each member of the central frame and welded and fixed, and FIG. 10A particularly shows the rear side of the base end portion of the front leg. By joining the end edge of the base to the front end edge of the base end of the rear leg, the joints are overlapped and welded to form an integrated bifurcated leg. FIG. 10B is a vertical plate formed on the rear end surface of the base end portion of the front leg and the front end surface of the base end portion of the rear leg, in particular. The vertical plate is joined by butting in the front-rear direction, Is a perspective view illustrating the formation of a bifurcated leg integrated by an upper edge and a lower edge of the joint is welded and fixed.

First, FIG. 10A will be described.
The bifurcated leg 57 (left leg 57L, right leg 57R) shown in FIG. 10A is also the front leg 7F and the rear side of the bifurcated leg 7 (left leg 7L or right leg 7R) shown in FIG. Similar to the leg 7B, the bifurcated leg 57 (the left leg 57L or the right leg 57R) is divided into a front leg 57F and a rear leg 57B, and these are formed of a cast steel casting, and Then, the bifurcated leg 57 is formed by integrating the two parts formed by cast steel casting.
In the embodiment according to the third example of the present invention, the shapes and the like of the front leg 57F and the rear leg 57B formed by cast steel casting are as follows.

The end portions 57c of the cylindrical bodies at the base end portions of the front leg 57F and the rear leg 57B are both formed in a substantially rectangular cross section. The rear end surface of the base end portion of the front leg 7F and the front end surface of the rear end portion of the rear leg 7B in the first and second embodiments of the present invention shown in FIG. In the leg of the crawler frame of the construction machine according to the second embodiment of the present invention shown in FIG. 10 (a), the rear end of the base end of the front leg 57F is formed. A wall, that is, a vertical plate 57a is provided on the surface, and a wall, that is, a vertical plate 57b (shown by an alternate long and short dash line) is provided on an end surface on the front side of the base end portion of the rear leg 57B. The vertical dimension between the upper and lower surfaces of the rear end of the base end of the front leg 57F is made smaller than the vertical dimension between the upper and lower surfaces of the front end of the base end of the rear leg 57B. In this way, when the upper surface and the rear end of the rear end portion of the base end portion of the front leg 57F with the reduced size are fitted to the upper surface of the front end portion of the base end portion of the rear leg 57B and the front end of the lower surface, respectively. The vertical plate 57a on the end surface of the rear end portion of the base end portion of the front leg 57F just faces the vertical plate 57b near the end surface of the front end portion of the base end portion of the rear leg 57B. By the way, the vertical plate 57b in the vicinity of the end surface of the front end portion of the base end portion of the rear side leg 57B is the base plate of the rear side leg 57B, and the vertical plate 57a on the rear end surface of the base end portion of the front side leg 57F. In order to be able to be inserted and fitted between the upper surface and the lower surface of the front end portion of the end portion, it is disposed slightly on the rear side (inner side).
The longitudinal plate 57a on the rear end surface of the base end portion of the front leg 57F is inserted and fitted between the upper surface and the lower surface of the front end portion of the base end portion of the rear leg 57B, whereby the front leg 57F. 57d is formed between the upper surface of the rear end portion of the base end portion, the rear end of the lower surface, the upper surface of the front end portion of the base end portion of the rear leg 57B, and the front end of the lower surface. Becomes J-shaped groove 59. The joint 57d, that is, the J-shaped groove 59 is welded to integrate the front leg 57F and the rear leg 57B into a bifurcated leg 57 (left leg 57L or right leg 57R). ).

A base formed in a substantially rectangular shape at the end of the cylindrical body at the base end of the front leg 57F and the rear leg 57B of the bifurcated leg 57 (left leg 57L or right leg 57R) integrated in this way. The base end surface 57c of the end portion is inserted and disposed on the left and right side surfaces of the central frame 3. In addition to the vertical plate provided with the stepped portion 57g on the front surface portion of the front end of the front leg 57F and the vertical plate provided with the stepped portion 57m on the rear surface portion of the rear leg 57B, the base of the front leg 57F is provided. A circle base on the upper part of the central frame 3 by a vertical plate 57a on the end face of the rear end portion of the end portion and a vertical plate 57b slightly inward (inner side) from the front end portion of the base end portion of the rear leg 57B. The large load applied to 31 can be supported more firmly.
If the vertical plate provided with the stepped portions 57g and 57m is relatively thick, only the vertical plate 57a may be formed and the vertical plate 57b may be omitted.

  Further, the upper and lower surfaces of the base end portions of the front leg 57F and the rear leg 57B of the integrated bifurcated leg 57 (the left leg 57L or the right leg 57R) are the upper surface side of the base end portion, Alternatively, stepped portions 57e and 57e are formed so that the lower surface side is stepped down. The shape of the boundary between the stepped portions 57e and 57e is formed in a linear shape or a curved shape so as to match the shapes of the left and right side edges of the upper surface plate 71 and the lower surface plate 73 of the central frame 3 in plan view. The side edges of the upper surface plate 71 and the lower surface plate 73 are joined to the front leg 57F, the upper surface of the base end portion of the rear side 57B, and the step portions 57e and 57e on the lower surface, and the joint portions are welded. From the viewpoint of improving the appearance, the thicknesses of the upper surface plate 71 and the lower surface plate 73 are adjusted so that the surfaces of the upper surface plate 71 and the lower surface plate 73 are exactly flush with the surface having no leg step. (See FIG. 9).

  Furthermore, a step is formed on the front side of the vertical plate at the base end of the front leg 57F of the integrated bifurcated leg 57 (left leg 57L, right leg 57R) so as to have a slightly recessed surface on the rear side. A portion 57g is formed, and the left and right side edges of the front plate 75 of the central frame 3 are joined to the stepped portion 57g, and the joined portion is welded and fixed. Further, a stepped portion 57m is provided on the rear surface side of the vertical plate at the base end of the rear leg 57B so as to be a slightly recessed surface on the front side, and the rear of the central frame 3 is located at the stepped portion 57m. The left and right side edges of the face plate 77 are joined, and the joined part is fixed by welding. When joining the rear plate 77, a member as shown in the joint 7m at the proximal end of the rear wall of the rear end of the rear leg 7B in FIG. 5, that is, the rear leg 57B. A joining portion {this joining portion is not shown in FIG. 10 (a)} may be provided at the distal end of the vertical plate on the rear surface portion of the base end portion. In short, the step portions 57e and 57e on the upper and lower surfaces of the front leg 57F and the rear leg 57B of the integrated bifurcated leg 57 (the left leg 57L or the right leg 57R) and the front leg 57F. The step portion 57g of the vertical plate on the front surface of the base end portion and the step portion 57m of the vertical plate on the rear surface portion of the rear leg 57B, that is, the base end portions of the front leg 57F and the rear leg 57B Are joined to the left and right side edges of the upper surface plate 71 and the lower surface plate 73, the left and right side edges of the front plate 75, and the left and right side edges of the rear surface plate 77. Then, the joint is fixed by welding. Since it is welded and fixed to each member of the center frame 3 over the entire circumference of the base end portions of the front leg 57F and the rear leg 57B, the integrated bifurcated leg 57 (the left leg 57L or the right leg 57R) is strong. Fixed to the central frame.

Next, FIG. 10B will be described.
Both the end portions 67c of the cylindrical bodies at the base end portions of the front side leg 67F and the rear side leg 67B are formed in a substantially rectangular cross section. The rear end surface of the base end portion of the front leg 7F and the front end surface of the rear end portion of the rear leg 7B in the first and second embodiments of the present invention shown in FIG. In the leg of the crawler frame of the construction machine according to the third embodiment of the present invention shown in FIG. 10 (b), the rear end portion of the base end portion of the front leg 67F is formed. A wall, that is, a vertical plate 67a is provided on the surface, and a wall, that is, a vertical plate 67b is provided on an end surface on the front side of the base end portion of the rear leg 67B. The vertical dimension between the upper surface and the lower surface of the rear end portion of the base end portion of the front leg 67F is made the same as the vertical size between the upper surface and the lower surface of the front end portion of the base end portion of the rear leg 67B. In addition, the upper and lower corners of the vertical plate 67a at the rear end portion of the base end portion of the front leg 67F are chamfered and cut off with a triangular cross section, and the vertical plate at the front end portion of the base end portion of the rear leg 67B. The upper and lower corners of 67b are chamfered with a triangular cross section and cut off. As described above, the vertical plate 67a at the rear end portion of the base end portion of the front leg 67F having the same size between the upper surface and the lower surface of the base end portion is located at the front end portion of the base end portion of the rear leg 67B. The vertical plate 67b is joined by butting, and a joint portion 67d composed of a V-shaped cut portion, that is, a V-shaped groove 69 is formed above and below the surface where the vertical plate 67a and the longitudinal plate 67b are butted. The joint 67d, that is, the V-shaped groove 69 is welded to integrate the front leg 67F and the rear leg 67B into a bifurcated leg 67 (left leg 67L or right leg 67R). ).

  A base formed in a substantially rectangular shape at the end of the cylindrical body at the base end of the front leg 67F and the rear leg 67B of the bifurcated leg 67 (left leg 67L or right leg 67R) integrated in this way. The base end surfaces 67 c and 67 c at the end are inserted and arranged on the left and right side surfaces of the central frame 3. In addition to the vertical plate provided with the stepped portion 67g at the front surface portion of the front end of the front leg 67F and the vertical plate provided with the stepped portion 67m at the rear surface portion of the rear leg 67B, the base of the front leg 67F is provided. Due to the vertical plate 67a on the end surface of the rear end portion of the end portion and the vertical plate 67b on the front end portion of the base end portion of the rear leg 67B, a large load applied to the circle base 31 at the upper part of the central frame 3 is more increased. It can be firmly supported.

  Further, the upper surface and the lower surface of the base end portion of the front leg 67F and the rear leg 67B of the integrated bifurcated leg 67 (the left leg 67L or the right leg 67R) include the upper surface side of the base end portion, Alternatively, step portions 67e and 67e are formed so that the lower surface side is stepped down. The shape of the boundary between the stepped portions 67e and 67e is formed in a linear shape or a curved shape so as to coincide with the shapes of the left and right side edges of the upper surface plate 71 and the lower surface plate 73 of the central frame 3 in plan view. The side edges of the upper surface plate 71 and the lower surface plate 73 are joined to the front leg 67F, the upper surface of the base end portion on the rear side 67B, and the stepped portions 67e and 67e on the lower surface, and the joint portions are welded. From the viewpoint of improving the appearance, the thicknesses of the upper surface plate 71 and the lower surface plate 73 are adjusted so that the surfaces of the upper surface plate 71 and the lower surface plate 73 are exactly flush with the surface having no leg step. (See FIG. 9).

  Furthermore, a step is formed on the front side of the vertical plate of the base end portion of the front leg 67F of the integrated bifurcated leg 67 (left leg 67L, right leg 67R) so as to have a slightly recessed surface on the rear side. A portion 67g is formed, and the left and right side edges of the front plate 75 of the central frame 3 are joined to the stepped portion 67g, and the joined portion is welded and fixed. Further, a stepped portion 67m is provided on the rear surface side of the vertical plate at the base end portion of the rear leg 67B so as to be a slightly recessed surface on the front side, and the rear of the central frame 3 is located at the stepped portion 67m. The left and right side edges of the face plate 77 are joined, and the joined part is fixed by welding. When joining the rear plate 77, a member as shown in the joint 7m at the proximal end of the rear wall of the rear end of the rear leg 7B in FIG. 5, that is, the rear leg 67B A joining portion {this joining portion is not shown in Fig. 10 (b)} may be provided at the distal end of the vertical plate on the rear surface portion of the base end portion. In short, the upper and lower surfaces of the base end portions of the front leg 67F and the rear leg 67B of the integrated bifurcated leg 67 (left leg 67L, right leg 67R), and the front surface portion of the base end portion of the front leg 67F. A central frame is provided on the stepped portion 67g of the vertical plate and the stepped portion 67m of the vertical plate on the rear surface portion of the base end portion of the rear leg 67B, that is, on the entire circumference of the base end portions of the front leg 67F and the rear leg 67B. 3 are joined to the left and right side edges of the upper plate 71 and the lower plate 73, the left and right side edges of the front plate 75, the left and right side edges of the rear plate 77, etc. Is done. Since it is welded and fixed to each member of the center frame over the entire circumference of the base end portion of the front leg 67F and the rear leg 67B, the integrated bifurcated leg 67 (the left leg 67L or the right leg 87R) is firmly Fastened to the center frame.

Next, FIG. 11 will be described.
FIG. 11 is a plan view of a crawler frame of a construction machine according to a third embodiment of the present invention. In particular, the crawler frame is inserted and arranged on the left and right side surfaces of the central frame, joined to various members of the central frame, and the joint is fixed by welding. It is a top view which shows the arrangement | positioning with respect to the center frame of the crawler frame of the construction machine based on 3rd Example of this invention and welding fixed structure.
The legs mounted in FIG. 11 are legs 57 and 67 in the crawler frame of the construction machine according to the third embodiment of the present invention shown in FIGS. 10 (a) and 10 (b). The central frame mounted on 11 is the central frame 3 in the crawler frame of the construction machine according to the second and third embodiments of the present invention shown in FIG. The numbers shown in FIG. 11 are used for the numbers in the common parts in the present application, especially the numbers used in the description of the leg 57 in FIG. 10A and the description of the central frame 3 in FIG. The number used in the description of the leg 67 in FIG. 10B is not used, but even the leg 67 in FIG. The legs of the crawler frame of the construction machine according to the third embodiment of the present invention are inserted and arranged on the left and right side surfaces (shown in FIG. 7), joined to various members of the central frame 3 and welded to the joints. The arrangement and the weld fixing structure are the same. Therefore, regarding the leg 67, the number of the leg 57 is replaced.

  Steps 57e and 57e on the upper and lower surfaces of the front leg 57F and the rear leg 57B of the integrated bifurcated leg 57 (left leg 57L or right leg 57R), and the base end of the front leg 57F. The stepped portion 57g of the vertical plate on the front surface of the front portion and the stepped portion 57m of the vertical plate on the rear surface portion of the rear leg 57B, that is, all of the base end portions of the front leg 57F and the rear leg 57B. The left and right side edges of the upper surface plate 71 and the lower surface plate 73, which are members of the central frame 3, the left and right side edges of the front plate 75, the left and right side edges of the rear plate 77, and the like are joined to the periphery. The joint is fixed by welding. Since it is welded and fixed to each member of the center frame 3 over the entire circumference of the base end portions of the front leg 57F and the rear leg 57B, the integrated bifurcated leg 57 (the left leg 57L or the right leg 57R) is strong. Fixed to the central frame.

  The features of the front leg 57F and the rear leg 57B of the integrated bifurcated leg 57 (left leg 57L, right leg 57R) of FIG. 10 (a) shown in FIG. 11 are the front leg 57F, and A cylindrical body at the base end of the front leg 57F and the rear leg 57B leg, which is inserted into the side surface of the central frame 3 as measured from the flanges (57i, 57j) at the outer end of the rear leg 57B. That is, the length S to the end portion 57c of the is constant. What this means is that, as shown in FIG. 11, the positions of the ends 57c of the cylindrical bodies at the base ends of the front leg 57F and the rear leg 57B leg are the same in the left-right direction. It is. That is, the left and right leg 57 (left leg 57L, right leg 57R) front side leg 57F and rear side leg 57B are joined to the inner side walls of the left and right track frames 5L and 5R, and the joints are fixed by welding. The length S from the flange portion of the outer end portion to the end portion 57c of the cylindrical body at the base end portion of the front leg 57F and the rear leg 57B leg inserted and arranged on the side surface of the central frame 3 is determined. Keep constant (see FIG. 11). This is done so that the end portions 57c of the cylindrical bodies at the base ends of the front leg 57F and the rear leg 57B leg do not protrude from the side support plates 74L, 74R on the side surface of the central frame. This is so that they can face each other at intervals. Note that a hole 71a into which a swivel joint or a hydraulic pipe (not shown) is inserted is provided in the central portion of the central frame.

Although the crawler frame according to the first to third embodiments of the present invention has been described based on FIGS. 1 to 11, the crawler frame according to the first to third embodiments of the present invention is illustrated in the drawings and specifications. However, according to the essence of the present invention, the crawler frames according to the first and second embodiments of the present invention are still in various forms. An example is shown below.
(a) In the embodiment according to the first embodiment of the present invention, the end of the cylindrical body at the front end of the integrated bifurcated leg (left leg, right leg) and the base end of the rear leg Is formed in an arc surface having substantially the same curvature as the inner peripheral surface of the circle base 31, but this is stopped to make the length in the left-right direction constant (for example, fixed to the inner wall of the track frame) The length from the outer end of the leg being measured to the end of the cylindrical body at the base end of the bifurcated leg integrated is set to a constant value S). This avoids complex mold shapes on the front and rear legs of the leg. Of course, at this time, a central frame shown in FIG. 7 in which the side support plates are linear is used.
(b) In the above, in the leg of the crawler frame of the construction machine according to the third embodiment of the present invention, both side support plates are used to support the load of the upper swing body applied to the circle base 31 on the side surface of the central frame. (The side support plates 24L and 24R are shown in FIG. 6 and the side support plates 74L and 74R are shown in FIG. 7). In the leg of the crawler frame of the construction machine, vertical walls (vertical plates) are provided at various points of the leg itself to support the load of the upper swing body applied to the circle base 31 (for example, in FIG. 10A) Are the vertical plate 57a at the rear end of the base end of the front leg 57F and the vertical plate 57b at the front end of the base end of the rear leg 57B, and in FIG. Vertical plate at the rear end of the base end 7a and the vertical plate 67b} at the front end portion of the base end portion of the rear leg 67B, so that the side support plates 74L and 74R are used to support the load of the upper swing body on the circle base 31 on the left and right side surfaces of the center frame 3. However, these side support plates 74L and 74R may be omitted.
(c) Also, the front legs of the crawler frame legs 57 and 67 (left leg and right leg) of the construction machine according to the third embodiment of the present invention shown in FIGS. 10 (a) and 10 (b), In the rear leg, the end portion of the cylindrical body having a substantially rectangular cross section has a constant length S in the left-right direction, but this is stopped and the legs 57 and 67 (left leg 57L, 67L, or the front leg of the right leg 57R, 67R) and the shape of the end 57c, 67c of the substantially rectangular base end of the rear leg are substantially the same as the inner peripheral surface of the circle base 31 described above. It forms in the circular arc surface of curvature, and this is inserted and arranged directly under the circular arc-shaped inner peripheral surface of the circle base 31.
These also constitute one embodiment of the crawler frame according to the third embodiment of the present invention.

1 is an external perspective view of a crawler frame of a construction machine according to a first embodiment of the present invention. It is a top view of the crawler frame of the construction machine which concerns on 1st Example of this invention. It is a front view of the crawler frame of the construction machine of the crawler frame of the construction machine which concerns on 1st Example of this invention. It is a side view of the crawler frame of the construction machine which concerns on 1st Example of this invention. In the leg of the crawler frame of the construction machine according to the first embodiment and the second embodiment of the present invention, the front leg and the rear leg of the integrated bifurcated left and right legs (left leg, right leg) It is the perspective view which looked at from the bottom. It is the disassembled perspective view which exploded and showed each member which comprises the center frame in the crawler frame of the construction machine which concerns on 1st Example of this invention. It is the disassembled perspective view which decomposed | disassembled and showed each member which comprises the center frame in the crawler frame of the construction machine which concerns on 2nd Example of this invention, and 3rd Example. In the leg of the crawler frame of the construction machine according to the first embodiment and the second embodiment of the present invention, FIG. 8 (a) shows the rear end edge in the front-rear direction of the front leg and the front-rear direction of the rear leg. FIG. 8B is a cross-sectional view showing that a front end edge is fitted and joined, and the joint is welded and integrated to form a bifurcated leg; FIG. FIG. 4 is a cross-sectional view showing that a side end edge and a front end edge in the front-rear direction of a rear leg are butted and joined, and the joint is welded and integrated to form a bifurcated leg. The structure of the side support plate that is vertically joined to an appropriate position between the upper surface plate and the lower surface plate of the central frame of the crawler frame of the construction machine according to the first to third embodiments of the present invention, and the joint portion is welded and fixed. FIG. FIGS. 10 (a) and 10 (b) show the structure of the legs in the crawler frame of the construction machine according to the third embodiment of the present invention, and the front leg and the rear leg by this structure are integrated into a bifurcated leg. It is a perspective view which shows the structure which inserts and arranges these integrated legs in a center frame, joins with each member of a center frame, and is weld-fixed by forming. It is a top view of the crawler frame of the construction machine which concerns on 3rd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Crawler frame 3 ... Center frame 21, 71 ... Upper surface board 21a, 71a ... Hole 23, 73 ... Lower surface board 24L, 74L ... Left side support plate 24R, 74R ... Right side support plate 24La, 24Ra ... Insertion Holes 74La, 74Ra ... insertion holes 25, 75 ... front plate 27, 77 ... rear plate 5 ... track frame 5L ... left track frame 5R ... right track frame 7, 57, 67 ... leg 7L, 57L, 67L ... left leg 7R, 57R, 67R ... right leg 7F, 57F, 67F ... front leg 7B, 57B, 67B ... rear leg 7d, 57d, 67d ... junction 7e, 57e, 67e ... step 7g ... step 7m ... junction 57g, 67g ... Steps 57m, 67m ... Steps 7i, 7j ... Flange 7k ... U-shaped flange 11 ... Left side support frame, Right side support frame 13 ... Front part Straight plate 15 ... rear vertical plate 17 ... idler support 19 ... drive wheel support 31 ... Circle table 65 ... left hole, right hole

Claims (2)

  A bifurcated leg is divided into a front leg and a rear leg and is formed of a cast steel casting. The front leg and the rear leg are integrated, and the base end of the integrated leg is connected to the center frame. A crawler frame for a construction machine, wherein the crawler frame is inserted and arranged on each of the left and right side surfaces and welded to each member of the central frame.   The base end portion of the integrated leg is inserted and arranged on the left and right side surfaces of the central frame, respectively, and the base end portion of the leg and the top and bottom of the central frame are welded across the entire circumference of the front and rear plates (full circumference welding). The crawler frame for a construction machine according to claim 1, wherein the crawler frame is configured as described above.

Images