JP5415384B2 - Construction machine swivel frame - Google Patents

Description

  The present invention relates to a turning frame of a construction machine used for, for example, a hydraulic excavator, a hydraulic crane, or the like.

  Generally, a hydraulic excavator as a construction machine includes a self-propelled lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and a working device provided on the front side of the upper revolving body. And is roughly composed. The upper swivel body has a swivel frame that forms a support structure, and a work device is provided on the front side of the swivel frame so that the work device can be lifted and lowered. A counterweight for balancing is provided. A cab that defines a cab is supported on the left side of the front portion of the swivel frame.

  Here, the revolving frame of a construction machine is usually a center frame composed of a bottom plate and left and right vertical plates erected on the bottom plate, and left and right sides disposed on both left and right sides of the center frame. The left and right extension beams provided between the side frame, the center frame and the left and right side frames, and the left and right vertical plates, respectively, are provided outside the vertical plate. An inner frame for supporting the cab that extends in the front and rear directions while the end side is joined to the center frame and the front end faces one of the side frames with a gap, and the front end of the inner frame for cab support, A front frame for supporting a cab that connects the front end of one side frame is provided.

  The rear end side of the cab is supported by one of the extension beams provided between the left side frame and the center frame, and the front end side of the cab is an inner frame for supporting the cab and for supporting the cab. The structure is supported by the front frame (see, for example, Patent Documents 1 and 2).

JP 2007-32262 A JP 2002-61226 A

  Incidentally, one end side of the boom cylinder is usually attached to the front end portion of each vertical plate constituting the revolving frame. Therefore, in order to avoid interference between the boom cylinder and the cab, it is necessary to maintain a certain distance between the left vertical plate of the revolving frame and the cab. For this reason, in the swivel frame of the construction machine according to the prior art, the inner frame for cab support is arranged on the left side of the left vertical plate of the swivel frame, and the base end side of the inner frame for cab support is the center frame. The base plate is joined to the extension beam disposed below the cab among the extension beams connecting the center frame and the side frames.

  However, in a small rear turning type hydraulic excavator that is suitably used in narrow work sites such as urban areas, it is necessary to keep the front and rear lengths of the turning frame small in order to reduce the turning radius of the upper turning body. There is. For this reason, the dimension (width dimension) of the extension beam which connects the center frame and each side frame in the front and rear directions is reduced, and the width dimension of the extension beam disposed below the cab is also reduced.

  In addition, in order to reduce the length of the swivel frame, when the air conditioner unit is arranged below the driver's seat floor, to avoid interference between the air conditioner unit and the overhanging beam arranged below the cab. The height dimension from the bottom plate of the overhanging beam disposed on the lower side of the cab is reduced.

  As described above, in the small rear swivel type hydraulic excavator, the width and height of the overhanging beam disposed on the lower side of the cab are small, so that the rigidity of the overhanging beam tends to be low. Therefore, when the base end side of the cab supporting inner frame is joined to the overhanging beam arranged on the lower side of the cab as in the prior art, a large stress acts on the overhanging beam, and the cab There is a problem that the supporting strength is lowered.

  The present invention has been made in view of the above-described problems of the prior art, and can improve the bonding strength of the inner frame for supporting the cab to the center frame, and the turning frame of the construction machine that can increase the supporting strength of the cab. The purpose is to provide.

  In order to solve the above-mentioned problems, the present invention has a center frame composed of a bottom plate and left and right vertical plates erected on the bottom plate, and extends forward and rearward on both the left and right sides of the center frame. Left and right side frames arranged, and left and right extending beams that are provided between the center frame and the left and right side frames, respectively, and join the side frames to the center frame; The left and right vertical plates are located outside one of the vertical plates, the base end side is joined to the center frame, and the tip side faces one side frame of the side frames with a gap. However, the inner frame for supporting the cab extending forward from the bottom plate, and the key for connecting the front end of the inner frame for cab support and the front end of the one side frame in the left and right directions. It applied to the pivoting frame for a construction machine comprising a blanking supporting previous frame.

According to a first aspect of the present invention, the cab supporting inner frame is joined to the one vertical plate and the bottom plate and extends leftward and rightward on the bottom plate. a lateral frame portion by an outer plate that form a closed section space, by a projecting upper plate in front than the bottom plate from the transverse frame portion and an inner plate and an outer plate distal portion to form a closed section space said as An L-shaped box structure formed by a vertical frame portion joined to a cab supporting front frame, an outer plate forming a vertical frame portion of the cab supporting inner frame, and an inner surface of the one side frame; An intermediate connection beam forming one of the overhanging beams is connected between the intermediate connection beams, and the intermediate connection beam is formed using a plate-like body extending in the left and right directions. is there.

According to a second aspect of the present invention, the intermediate connection beam includes an upper plate portion connecting the vertical frame portion and the one side frame constituting the inner frame for supporting the cab, the bottom plate, and the one side. The lower plate portion connecting the frame and the frame is formed as a plate-like body extending in the left and right directions with a substantially Z-shaped cross-sectional shape .

The invention of claim 3, wherein the cabin supporting the frame, the bottom plate and the upper an L-shape in plan view, and the upper plate facing in the downward direction, the one vertical plate-side across the upper plate wherein an inner plate arranged on the said sides of the upper plate disposed on one side frame side and an outer plate facing with the inner plate and spacing, the cab frame supporting the said one In the state joined to the vertical plate and the bottom plate, the upper plate, the inner plate, and the outer plate form a box structure that forms a closed cross-sectional space.

  According to the invention of claim 1, the cab supporting inner frame is formed as an L-shaped box structure by the horizontal frame portion and the vertical frame portion, and is joined to the bottom plate of the center frame and one vertical plate. Thus, the cab support inner frame can be directly joined to the center frame, which is the strongest member of the swivel frame, without using an overhanging beam or the like. The joint strength of the frame can be increased.

  As a result, for example, in a small rear turn type construction machine, even if the width and height of the extended beam connecting the center frame and the side frame are reduced, the inner frame for supporting the cab is joined to the extended beam. There is no need. As a result, it is possible to increase the bonding strength of the cab support inner frame to the center frame regardless of the specifications of the construction machine.

Moreover, by using the cab supporting inner frame as a box structure, the strength of the cab supporting inner frame itself can be increased. Thus, in addition to increasing the bonding strength of the cab supporting inner frame to the center frame, the strength of the cab supporting inner frame itself can be increased, so that the cab of the cab supporting inner frame and the cab supporting front frame can be increased. Support strength can be increased.
Further, since the vertical frame portion of the cab supporting inner frame and one side frame are connected by the intermediate connecting beam, the cab supporting inner frame joined to the bottom plate and the one vertical plate is connected by the intermediate connecting beam. Can be reinforced. As a result, the support strength of the cab by the cab support inner frame and the cab support front frame can be further increased.

According to the invention of claim 2, the intermediate connecting beam, at the same time connecting between the center frame and one of the side frame by the lower plate, it reinforces the vertical frame of the frame for the cab supported by the upper plate portion be able to.

According to the invention of claim 3, with the cab supporting inner frame joined to one vertical plate and the bottom plate of the center frame, there is a cab supporting gap between the cab supporting inner frame and the center frame bottom plate. A closed cross-sectional space surrounded by the upper plate, the inner plate and the outer plate of the inner frame and the bottom plate of the center frame can be formed. As a result, the cab support inner frame can be firmly joined to the center frame, and the cab support strength by the cab support inner frame and the cab support front frame can be increased.

It is a front view which shows the hydraulic excavator provided with the turning frame by embodiment of this invention. It is the top view which looked at the turning frame from the upper part. It is a perspective view which shows a turning frame alone. It is a perspective view of the principal part expansion which expands and shows the bottom plate of a revolving frame, the left vertical board, the inner frame for cab support, the front frame for cab support, the intermediate connection beam, and the like. FIG. 5 is an exploded perspective view showing the cab supporting inner frame, the cab supporting front frame, and the intermediate connection beam in FIG. 4 in an exploded manner. It is a disassembled perspective view which shows the inner frame for cab support by itself. FIG. 3 is an enlarged plan view of a main part showing an enlarged view of a bottom plate, a left vertical plate, a cab support inner frame, a cab support front frame, an intermediate connection beam, and the like in FIG. 2. It is sectional drawing which looked at the baseplate, the left vertical board, the inner frame for cab support, etc. from the arrow VIII-VIII direction in FIG. It is sectional drawing which looked at the baseplate, the left vertical board, the left side frame, the inner frame for cab support, etc. from the arrow IX-IX direction in FIG. It is sectional drawing which looked at the baseplate, the left vertical board, the front frame for cab support, the intermediate connection beam, etc. from the arrow XX direction in FIG.

  Hereinafter, an embodiment of a turning frame for a construction machine according to the present invention will be described in detail with reference to the accompanying drawings, taking as an example a case where it is applied to a hydraulic excavator.

  In the figure, reference numeral 1 denotes a hydraulic excavator, which is a typical example of a construction machine. The hydraulic excavator 1 turns on a self-propelled crawler-type lower traveling body 2 and a swiveling wheel 3 on the lower traveling body 2. The upper revolving body 4 that can be mounted is generally configured. And the working device 5 which performs excavation work, such as earth and sand, is provided in the front part side of the upper revolving body 4 so that a vertical movement is possible.

  In this case, the excavator 1 is a small rear turning type in which the rear surface of the counterweight 7 described later is substantially within the vehicle width of the lower traveling body 2 when the upper revolving body 4 performs the turning operation on the lower traveling body 2. It is configured as a hydraulic excavator.

  Here, the upper revolving structure 4 is provided on the rear end side of the revolving frame 11, which will be described later, the cab 6 which is disposed on the left side of the front portion of the revolving frame 11 and defines the cab, and the working device. 5 and a building cover 8 which is disposed on the front side of the counterweight 7 and accommodates an engine, a hydraulic pump and the like (none of which are shown).

  On the other hand, the working device 5 includes a boom 5A whose base end is rotatably attached to a turning frame 11 described later, an arm 5B rotatably attached to the distal end of the boom 5A, and a tip of the arm 5B. Bucket 5C rotatably attached to the side, a boom cylinder 5D provided between the swing frame 11 and the boom 5A, an arm cylinder 5E provided between the boom 5A and the arm 5B, and an arm 5B And a bucket cylinder 5F provided between the bucket 5C and the bucket 5C.

  Next, 11 shows a turning frame according to this embodiment. The revolving frame 11 serves as a base for the upper revolving structure 4 and, as shown in FIGS. 2 and 3, a center frame 12, a left side frame 18, a left extending beam 19, a right side frame 21, and a right extending as will be described later. The beams 23 and 24, the cab support inner frame 26, the cab support front frame 32, the intermediate connection beam 35, and the like constitute a strong support structure.

  Reference numeral 12 denotes a center frame that constitutes a central portion of the revolving frame 11. The center frame 12 is formed in a flat plate shape using a thick steel plate or the like, and extends in the front and rear directions, and an upper surface of the bottom plate 13. The left vertical plate 14 and the right vertical plate 15 which are provided upright by means of welding or the like and extend forward and backward while maintaining a constant interval in the left and right directions. Further, the space between the front side of the left vertical plate 14 and the front side of the right vertical plate 15 is reinforced by the front vertical plate reinforcing plate 16 joined to both, and the rear end side of the left vertical plate 14 and the right side A space between the rear end side of the vertical plates 15 is reinforced by a rear vertical plate reinforcing plate 17 joined to both.

  Here, the front side of the left vertical plate 14 and the right vertical plate 15 are bracket portions 14A and 15A raised in a mountain shape, respectively, and the left and right bracket portions 14A and 15A include work devices shown in FIG. 5, the base end side of the boom 5A and the base end side of the boom cylinder 5D are configured to be pin-coupled so as to be spaced apart from each other upward and downward. The rear side of the left and right vertical plates 14 and 15 has an I-shaped cross section and extends rearward from the bracket portions 14A and 15A. The rear end sides of the left and right vertical plates 14 and 15 are The weight attaching portions 14B and 15B to which the counterweight 7 shown in FIG. 1 is attached are provided.

  Further, an outer side surface of the left vertical plate 14 facing a left side frame 18 described later becomes a beam bonding surface 14C to which a left protruding beam 19, a cab supporting inner frame 26 and the like described later are bonded, and the right vertical plate 15 Of these, the outer surface facing the right side frame 21 described later is a beam bonding surface 15C to which each of the right protruding beams 23 and 24 described later are bonded.

  Reference numeral 18 denotes a left side frame arranged on the left side of the center frame 12. Here, the left side frame 18 and a right side frame 21 to be described later are formed using, for example, a D-shaped frame made of a cylindrical body having a D-shaped cross section, and extend forward and rearward along the center frame 12. . The left side frame 18 is attached to the left side of the center frame 12 via a left projecting beam 19 and an intermediate connecting beam 35 which will be described later.

  Reference numeral 19 denotes a left extending beam which is located between the center frame 12 and the left side frame 18 and is located behind the intermediate connecting beam 35 which will be described later. The left extending beam 19 together with the intermediate connecting beam 35 etc. The left side frame 18 is joined to the frame 12.

  Here, the left extending beam 19 is formed as a plate-like body extending in the left and right directions with a substantially Z-shaped cross-sectional shape by, for example, bending a steel plate material (see FIG. 10). Then, one end side in the length direction (left and right directions) of the left overhanging beam 19 is welded to the upper surface of the bottom plate 13 and the beam joining surface 14C of the left vertical plate 14. The end side is welded to the left side frame 18. Further, left and right mount mounting holes 19A are provided on the upper surface side of the left extension beam 19 so as to be located on both sides in the length direction, and the rear side of the cab 6 is elastically attached to each of the mount mounting holes 19A. A mounting member (not shown) is attached to be attached.

  Reference numeral 20 denotes a left rear plate provided between the rear end side of the left vertical plate 14 and the rear end side of the left side frame 18. The left rear plate 20 is formed by bending a steel plate or the like into a substantially square shape. Is formed. The left rear plate 20 connects the left vertical plate 14 and the rear end side of the left side frame 18.

  Reference numeral 21 denotes a right side frame disposed on the right side with the center frame 12 interposed therebetween. The right side frame 21 is formed by using a D-type frame similar to the left side frame 18, and the front side, It extends in the rear direction. The right side frame 21 is attached to the right side of the center frame 12 via respective right projecting beams 23 and 24, which will be described later. Further, the front end side of the right side frame 21 is a bent portion 21A bent at a right angle toward the center frame 12, and the front end portion of the bent portion 21A is connected to the front end side of the right vertical plate 15 via the connecting plate 22. It is connected to.

  Reference numerals 23 and 24 denote front and rear right extension beams provided between the right vertical plate 15 and the right side frame 21 of the center frame 12, and these right extension beams 23 and 24 are moderate in the front and rear directions. The right side frame 21 is joined to the center frame 12 with an interval. Here, each of the right extension beams 23 and 24 is formed, for example, by bending a steel plate material, the left end side is welded to the beam joining surface 15C of the right vertical plate 15, and the right end side is connected to the right side frame 21. Welded.

  Reference numeral 25 denotes a right rear plate provided between the rear end side of the right vertical plate 15 and the rear end side of the right side frame 21. The right rear plate 25 is formed by bending a steel plate or the like into a substantially square shape. Is formed. The right rear plate 25 connects the right vertical plate 15 and the rear end side of the right side frame 21.

  Next, reference numeral 26 denotes a cab support inner frame applied to the present embodiment. The inner frame 26 for cab support is located on the outer side of one left vertical plate 14 (on the side opposite to the right vertical plate 15) and is disposed on the front end side of the left vertical plate 14, and is described below with a front frame for cab support. 32 supports the front end side of the cab 6.

  Here, the cab supporting inner frame 26 is joined to the bottom plate 13 and the left vertical plate 14 constituting the center frame 12 and extends on the bottom plate 13 in the left and right directions, as shown in FIGS. An overall L-shape is formed by an end-side horizontal frame portion 26A and a vertical frame portion 26B that protrudes forward from the horizontal frame portion 26A than the bottom plate 13 and has a tip portion joined to a cab support front frame 32 described later. Is formed as a box structure. The cab support inner frame 26 is formed by joining together three members, which will be described later, an upper plate 27, an inner plate 28, and an outer plate 29, as shown in FIG.

  Reference numeral 27 denotes an upper plate constituting the cab supporting inner frame 26, and the upper plate 27 faces the bottom plate 13 in the upward and downward directions. Here, the upper plate 27 is formed as a flat plate having a substantially L shape in plan view using a steel plate material or the like, and has a wide portion 27A that is wide in the left and right directions corresponding to the horizontal frame portion 26A, and a vertical frame portion. Corresponding to 26B, it has a narrow portion 27B extending in the front and rear directions and narrowing in the left and right directions.

  The front edge 27A1 of the wide portion 27A is joined to a rear surface 28A of an inner plate 28 described later, and the rear edge 27A2 is bonded to a rear surface 29A of an outer plate 29 described later. Further, the right end edge portion 27A3 of the wide width portion 27A is joined to the beam joining surface 14C of the left vertical plate 14, and the left end edge portion 27A4 is joined to a side surface portion 29B of the outer plate 29 described later. On the other hand, the right end edge portion 27B1 of the narrow width portion 27B is joined to a side surface portion 28B of the inner plate 28 described later, and the left end edge portion 27B2 of the narrow width portion 27B is bonded to a side surface portion 29B of the outer side plate 29 described later. It has a configuration.

  Reference numeral 28 denotes an inner plate disposed on the left vertical plate 14 side of the left vertical plate 14 and the left side frame 18 with the upper plate 27 interposed therebetween. The inner plate 28 faces the outer plate 29 with the upper plate 27 interposed therebetween. To do. Here, the inner plate 28 is formed by bending a steel plate material or the like, and is bent forward from the rear surface portion 28A corresponding to the horizontal frame portion 26A and the vertical frame portion 26B. It has a side surface portion 28B and a lower surface portion 28C that is bent leftward from the lower end side of the side surface portion 28B and corresponds to the vertical frame portion 26B.

  The lower end edge 28A1 of the rear surface portion 28A and the lower end edge portion 28B1 of the side surface portion 28B are joined to the upper surface of the bottom plate 13, and the right end edge portion 28A2 of the rear surface portion 28A is joined to the beam joining surface 14C of the left vertical plate 14. It becomes the structure joined. Further, the front end edge portion 28B2 of the side surface portion 28B and the front end edge portion 28C1 of the lower surface portion 28C are configured to be joined to a cab supporting front frame 32 described later.

  29 is an outer plate disposed on the left side frame 18 side of the left vertical plate 14 and the left side frame 18 with the upper plate 27 interposed therebetween. The outer plate 29 faces the inner plate 28 with the upper plate 27 interposed therebetween. To do. Here, the outer plate 29 is formed by bending a steel plate material or the like, and is bent forward from the rear surface portion 29A corresponding to the lateral frame portion 26A and corresponding to the vertical frame portion 26B. And a side surface portion 29B.

  The upper end edge 29A1 of the rear surface portion 29A and the upper end edge 29B1 of the side surface portion 29B are joined to the lower surface of the upper plate 27. Further, the lower end edge portion 29A2 of the rear surface portion 29A and the rear portion side of the lower end edge portion 29B2 of the side surface portion 29B are joined to the upper surface of the bottom plate 13, and the front side of the lower end edge portion 29B2 of the side surface portion 29B is the inner plate 28. It is the structure joined to the lower surface part 28C. Further, the right end edge portion 29A3 of the rear surface portion 29A is joined to the beam joining surface 14C of the left vertical plate 14, and the front end edge portion 29B3 of the side surface portion 29B is joined to a cab supporting front frame 32 described later. ing.

  As described above, the cab support inner frame 26 is formed by joining the two members of the upper plate 27, the inner plate 28, and the outer plate 29 to each other, and is formed into an L shape as a whole by the horizontal frame portion 26A and the vertical frame portion 26B. A box structure is formed.

  The lateral frame portion 26A of the cab supporting inner frame 26 includes a rear surface portion 28A constituting the inner plate 28 and lower end edge portions 28A1, 28B1 of the side surface portion 28B, and a rear surface portion 29A constituting the outer plate 29 and the side surface portion 29B. The lower edge portions 29A2 and 29B2 are firmly joined to the bottom plate 13 by joining them to the upper surface of the bottom plate 13 by welding or the like.

  Further, the lateral frame portion 26A of the cab supporting inner frame 26 constitutes the right end edge portion 27A3 of the wide width portion 27A constituting the upper plate 27, the right end edge portion 28A2 of the rear surface portion 28A constituting the inner plate 28, and the outer plate 29. The right end edge portion 29A3 of the rear surface portion 29A is firmly joined to the left vertical plate 14 by joining the beam joining surface 14C of the left vertical plate 14 by welding or the like.

  Here, as shown in FIG. 8, the wide width of the upper plate 27 constituting the cab supporting inner frame 26 in a state where the horizontal frame portion 26A of the cab supporting inner frame 26 is joined to the bottom plate 13 and the left vertical plate 14. A closed cross-sectional space 30 is formed between the bottom plate 13 and the portion 27A, the rear surface portion 28A of the inner plate 28, the rear surface portion 29A of the outer plate 29, and the bottom plate 13.

  Further, the vertical frame portion 26B of the cab supporting inner frame 26 is surrounded by the narrow width portion 27B of the upper plate 27, the side surface portion 28B and the lower surface portion 28C of the inner plate 28, and the side surface portion 29B of the outer plate 29. A closed cross-sectional space 31 is formed.

  As described above, the cab supporting inner frame 26 according to the present embodiment includes the horizontal frame portion 26A that extends left and right on the bottom plate 13, and the vertical frame portion that protrudes forward from the horizontal frame portion 26A to the bottom plate 13. As shown in FIG. 4, the left vertical plate 14 is formed by joining the horizontal frame portion 26 </ b> A to the bottom plate 13 and the left vertical plate 14 of the center frame 12. A space S having a constant interval for avoiding interference between the cab and the boom cylinder (both not shown) is secured on the left side of the.

  Reference numeral 32 denotes a cab support front frame that connects between the front end of the cab support inner frame 26 and the front end of the left side frame 18, and the cab support front frame 32 is connected to the cab support inner frame 26 together with the cab support inner frame 26. The front end side of 6 is supported. As shown in FIGS. 4 and 5, the cab supporting front frame 32 includes an upper surface plate 33 extending in the left and right directions between the vertical frame portion 26 </ b> B of the cab supporting inner frame 26 and the left side frame 18. The front plate 34 joined to the front end portion of the upper surface plate 33 is roughly constituted.

  Here, the upper surface plate 33 has left and right wide portions 33A and 33B arranged on both left and right ends, and has an L-shaped cross section downward from the rear end side of the wide portions 33A and 33B. It has bent left and right bent portions 33C and 33D. The left and right wide portions 33A and 33B are provided with mount mounting holes 33E, respectively. Mount members (not shown) for elastically supporting the front side of the cab 6 are provided in these mount mounting holes 33E. ) Is attached.

  On the other hand, the front plate 34 has a length dimension larger than that of the upper plate 33 and extends in the left and right directions. The inclined surface portion 34A is inclined obliquely rearward from the upper end side toward the lower end side, and the lower end side of the inclined surface portion 34A. A lower surface portion 34B extending horizontally from the rear to the rear, and the upper end portion of the inclined surface portion 34A is joined to the front end edge portion of the upper surface plate 33 by welding or the like.

  Then, the right end edge portion of the right wide portion 33B of the upper surface plate 33 and the inclined surface portion 34A of the front plate 34 is joined to the side surface portion 28B of the inner plate 28 constituting the cab supporting inner frame 26, The bent portion 33D is joined to the rear edge of the narrow portion 27B of the upper plate 27 and the side surface portion 29B of the outer plate 29 constituting the inner frame 26 for supporting the cab, and the rear end of the lower surface portion 34B of the front plate 34 By joining the edge to the rear edge of the lower surface portion 28C constituting the inner plate 28 of the cab supporting inner frame 26, the vertical frame portion 26B of the cab supporting inner frame 26 and the front frame 32 for cab supporting It is the structure which can be joined firmly between.

  On the other hand, the left end edge portion of the left wide portion 33A constituting the upper surface plate 33 is joined to the inner side surface of the left side frame 18, and the rear surface of the inclined surface portion 34A constituting the front plate 34 is joined to the front end edge portion of the left side frame 18. By doing so, the cab supporting front frame 32 and the left side frame 18 can be firmly joined.

Next, 35 denotes an intermediate connecting beam disposed between the vertical frame portion 26 B and the left side frame 18 of the cab supporting frame 26 located in front of the left outrigger beam 19. Similar to the left overhanging beam 19, the intermediate connection beam 35 forms an overhanging beam for joining the left side frame 18 to the center frame 12 and reinforces the cab supporting inner frame 26.

Here, as shown in FIGS. 4 and 5, the intermediate coupling beam 35 is formed as a plate-like body extending leftward and rightward with a substantially Z-shaped cross-sectional shape, for example, by bending a steel plate material. It is, disposed between the upper plate portion 35A disposed between the vertical frame portion 26 B and the left side frame 18 of the cab supporting frame 26, a bottom plate 13 and the left side frame 18 of the center frame 12 And a lower plate portion 35B.

The intermediate connecting beam 35, a right end edge of the upper plate portion 35A, along with being joined to the side portions 29B of the outer plate 29 constituting the vertical frame portion 26 B of the cab supporting frame 26, the upper plate portion 35A Are joined to the inner surface of the left side frame 18. Further, the right end edge of the lower plate portion 35B is joined to the left end portion of the bottom plate 13, and the left end edge portion of the lower plate portion 35B is joined to the inner side surface of the left side frame 18.

  As a result, the intermediate connection beam 35 connects the center frame 12 and the left side frame 18 by the lower plate portion 35B, and simultaneously reinforces the horizontal frame portion 26A of the cab supporting inner frame 26 by the upper plate portion 35A. It has become.

  The swivel frame 11 of the excavator 1 according to the present embodiment has the above-described configuration. The cab support inner frame 26 that supports the cab 6 together with the cab support front frame 32 is provided on the bottom plate 13 on the left and right sides. A horizontal frame portion 26A extending in the direction and a vertical frame portion 26B projecting forward from the bottom frame 13 from the horizontal frame portion 26A form an L-shaped box structure.

  For this reason, by joining the horizontal frame portion 26A of the cab support inner frame 26 to the bottom plate 13 and the left vertical plate 14 of the center frame 12, the right side surface and the left side of the cab 6 indicated by a two-dot chain line in FIG. In a state where a space S having a certain interval for avoiding interference between the cab 6 and a boom cylinder (not shown) is secured between the bracket portion 14A of the vertical plate 14 and the cab supporting inner frame 26, The cab 6 can be firmly supported by the front frame 32 for supporting the cab. As a result, the lateral frame portion 26A of the cab supporting inner frame 26 directly does not directly interfere with the center frame 12 that is the strongest member of the swivel frame 11 without interposing other members such as a protruding beam. Thus, the proximal end side of the cab supporting inner frame 26 can be joined.

  Therefore, even if the width dimension and height dimension of the overhanging beam connecting the center frame 12 and the left side frame 18 are reduced in the rear small turning type hydraulic excavator 1, for example, 26 need not be joined. As a result, regardless of the specifications of the excavator 1, the bonding strength of the cab support inner frame 26 to the center frame 12 can be increased.

  Moreover, since the cab supporting inner frame 26 according to the present embodiment is formed as a box structure in which three members of the upper plate 27, the inner plate 28, and the outer plate 29 are combined, the cab supporting inner frame 26 is provided. In the state where the horizontal frame portion 26A is joined to the bottom plate 13 and the left vertical plate 14, the wide portion 27A of the upper plate 27, the rear surface portion 28A of the inner plate 28, and the rear surface portion 29A of the outer plate 29 and the bottom plate 13 are interposed. A closed sectional space 30 can be formed (see FIG. 8). Further, the vertical frame portion 26B of the cab supporting inner frame 26 is surrounded by the narrow width portion 27B of the upper plate 27, the side surface portion 28B and the lower surface portion 28C of the inner plate 28, and the side surface portion 29B of the outer plate 29. A closed cross-sectional space 31 can be formed.

  Thus, the strength of the cab supporting inner frame 26 itself can be increased by using the cab supporting inner frame 26 as a box structure. Therefore, in addition to increasing the bonding strength of the cab supporting inner frame 26 to the center frame 12, the strength of the cab supporting inner frame 26 itself can be increased, so the cab supporting inner frame 26 and the cab supporting front frame The support strength of the cab 6 by 32 can be increased.

Further, according to this embodiment, between the vertical frame portion 26 B and the left side frame 18 of the cab supporting frame 26, and is configured to be connected by the intermediate connecting beam 35. Thereby, the base end side of the cab support inner frame 26 joined to the bottom plate 13 and the left vertical plate 14 can be reinforced by the intermediate connection beam 35. As a result, the joining strength of the cab supporting inner frame 26 can be further increased, and the supporting strength of the cab 6 by the cab supporting inner frame 26 and the cab supporting front frame 32 can be further increased.

  In the embodiment described above, the cab supporting inner frame 26 is formed as an L-shaped box structure by joining the three members of the upper plate 27, the inner plate 28, and the outer plate 29 to each other. Is illustrated. However, the present invention is not limited to this, and the inner frame for supporting the cab may be formed, for example, by bending a hollow pipe material or the like into an L shape.

  In the above-described embodiment, the cab support inner frame 26 and the cab support are provided between the left vertical plate 14 and the left side frame 18 in order to support the cab 6 disposed on the left side of the front portion of the revolving frame 11. The case where the front frame 32 is disposed is illustrated. However, the present invention is not limited to this, for example, a configuration in which an inner frame for cab support and a front frame for cab support are disposed between a right vertical plate and a right side frame, and the cab is supported on the front right side of the revolving frame. It is good.

  Furthermore, in the above-described embodiment, the swivel frame applied to the hydraulic excavator has been described as an example. However, the present invention is not limited to this, and can be widely applied to other construction machines such as a hydraulic crane. It is something that can be done.

1 Excavator (construction machine)
6 Cab 11 Revolving frame 12 Center frame 13 Bottom plate 14 Left vertical plate 15 Right vertical plate 18 Left side frame 19 Left overhanging beam 21 Right side frame 23, 24 Right overhanging beam 26 Cab inner frame 26A Horizontal frame portion 26B Vertical frame portion 27 Upper plate 28 Inner plate 29 Outer plate 30, 31 Closed section space 32 Front frame for cab support 35 Intermediate connection beam

Claims (3)

A center frame comprising a bottom plate and left and right vertical plates erected on the bottom plate; left and right side frames extending forward and rearward on the left and right sides of the center frame; A left and right extended beam provided between the center frame and the left and right side frames and joining the side frames to the center frame, and one of the left and right vertical plates. A cab support provided on the outer side of the vertical plate and having a base end side joined to the center frame and a front end side facing one side frame of each of the side frames at an interval and extending forward from the bottom plate. And a front frame for cab support that connects the front end portion of the inner frame for cab support and the front end portion of the one side frame in the left and right directions. In the machine of the revolving frame,
The cab supporting the frame, the left the bottom plate upper is joined the the one of the vertical plate and the bottom plate, top plate and the inner plate extending in the right direction and the transverse frame portions that form a closed section space by an outer plate And a vertical frame portion projecting forward from the lateral frame portion with respect to the bottom plate to form a closed cross-sectional space by the upper plate, the inner plate and the outer plate, and the front end portion being joined to the front frame for supporting the cab. Formed as a box-shaped body ,
Between the outer plate forming the vertical frame portion of the cab supporting inner frame and the inner side surface of the one side frame, an intermediate connecting beam forming one of the overhanging beams is connected and provided,
In addition, the intermediate connecting beam is formed by using a plate-like body extending in the left and right directions . The intermediate connection beam connects an upper plate portion connecting the vertical frame portion and the one side frame constituting the inner frame for supporting the cab, and a connection between the bottom plate and the one side frame. The turning frame for a construction machine according to claim 1, wherein the lower plate portion is formed as a plate-like body extending in the left and right directions with a substantially Z-shaped cross-sectional shape . The cab supporting the frame, the bottom plate and the upper an L-shape in plan view, and the upper plate facing in a downward direction, the inner plate arranged on the vertical plate side of the one across the upper plate When disposed on the one side frame side across the upper and an outer plate facing with the inner plate and the distance,
The inner frame for supporting the cab is formed as a box structure that forms a closed cross-sectional space by the upper plate, the inner plate, and the outer plate in a state of being joined to the one vertical plate and the bottom plate. Item 3. A turning frame for a construction machine according to Item 1 or 2.

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