JP2012162911A - Revolving frame of construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase an interval between left and right attaching pedestals and to reduce weight while securing strength of a frame.SOLUTION: A left rear vertical plate 20 which is one of left and right rear vertical plates 20 and 21 of a tail frame 18 is provided with a bend part 20C at an intermediate part in the front-to-back direction, and an interval in the left-to-right direction from the other right rear vertical plate 21 is made small on the side of a front part 20A and is made large on the side of a rear part 20B. The left and right rear vertical plates 20 and 21 are provided by joining front end sides thereof to rear end sides of left and right front vertical plates 14 and 15, and upper flanges 24 and 25 are provided on upper ends of both joint parts 22 and 23, so that beam structure with an I-shaped cross-section is formed. Attaching pedestals 32-35 for attaching an engine are joined to the left and right rear vertical plates 20 and 21 at a position where the interval is made large by the bend part 20C of the left rear vertical plate 20.

Description

  The present invention relates to a swing frame for a construction machine that is preferably used for an upper swing body such as a hydraulic excavator.

  In general, a construction machine such as a hydraulic excavator is provided with a lower traveling body, an upper revolving body mounted on the lower traveling body via a swirl wheel so as to be capable of swiveling, and earth and sand excavation work provided on the front side of the upper revolving body. It is comprised by the working device which performs etc. The upper revolving structure has a revolving frame formed as a support structure, and on this revolving frame, there is a cab that defines a driver's cab inside, and a prime mover and the like that are arranged on the rear side of the cab. An exterior cover that defines a machine room to be accommodated, and a counterweight that is disposed on the rear side of the exterior cover and balances the weight of the upper swing body with respect to the working device are provided (for example, see Patent Document 1). ).

  A turning frame according to this type of prior art includes a center frame that is turnable on the lower traveling body via a turning wheel, and is joined to the rear end side of the center frame, and the motor and the counterweight on the upper side. Equipped with a tail frame. The center frame has left and right front vertical plates that are erected on the center bottom plate so as to extend in the front and rear directions and are spaced apart from each other in the left and right directions. The tail frame is front and rear on the tail bottom plate. It has left and right rear vertical plates that extend in the direction and are spaced apart from each other in the left and right directions.

  The left and right rear vertical plates are located on the rear end side of each of the left and right rear weight plates, and the left and right weight attachment portions are attached to the left and right weight attachment portions, and the left and right motor attachment portions are attached to the front side of the weight attachment portions. The right mounting base is provided. Further, the left and right rear vertical plates are provided with their front end sides joined to the rear end sides of the left and right front vertical plates, and upper flanges are provided at the upper ends of both joints to provide an I-shaped cross section. The beam structure is formed. In this case, each upper flange is formed to extend to the rear end position of the left and right rear vertical plates, whereby the left and right weight mounting portions are similarly formed in a beam structure having an I-shaped cross section.

Japanese Patent No. 2613141

  By the way, in the above-described prior art, the left and right rear vertical plates are formed of plate members extending linearly in the front and rear directions, and a total of four mounting bases are joined to these plate members. However, depending on the type of prime mover to be mounted, there is a problem that the distance between the left and right mounting bases is small, and for example, an oil pan provided on the lower surface side of the prime mover cannot be accommodated between the left and right rear vertical plates.

  In particular, in the prior art, an upper flange is provided at each of the upper ends of the left and right rear vertical plates to form a beam structure having an I-shaped cross section. Therefore, the upper flange is an obstacle to mounting the prime mover. Therefore, there is a problem that a mounting space cannot be secured. On the other hand, when the upper flange is abolished, the left and right rear vertical plates must be formed of thick plate materials in order to ensure the strength as the revolving frame, and the overall weight increases. For this reason, it has become a big examination subject to aim at weight reduction, ensuring sufficient intensity | strength as a turning frame.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to increase the distance between the left and right mounting bases and to achieve weight reduction while ensuring strength. An object of the present invention is to provide a swing frame for a construction machine.

  In order to solve the above-described problems, the present invention provides a center frame that is turnable on a lower traveling body via a turning wheel, a motor frame and a counter that are provided on the upper side of the center frame joined to the rear end side of the center frame. A tail frame on which a weight is mounted, and the center frame is installed on the lower traveling body via the swivel wheel, and the center frame is erected on the center bottom plate so as to extend forward and backward. Left and right front vertical plates spaced apart in the left and right directions, the tail frame being joined to the rear end side of the center bottom plate and extending in the front and rear directions, and on the tail bottom plate The left and right rear vertical plates are erected so as to extend in the front and rear directions and are spaced apart from each other in the left and right directions. The counter weights are located on the rear end side of the left and right rear vertical plates. Left and right weight removal A left and right rear mounting base that is positioned on the front side of the left and right weight mounting portions and the prime mover is mounted; and a left that is positioned on the front side of the left and right rear mounting base and the prime mover is mounted; The present invention is applied to a swing frame of a construction machine provided with a right front mounting base.

  The feature of the configuration adopted by the invention of claim 1 is that the rear vertical plate of the left and right rear vertical plates of the tail frame is spaced from the other rear vertical plate on the front side. Is configured such that a bent portion is provided at an intermediate portion in the front and rear directions so that a gap between the other rear vertical plate is increased on the rear side, and the one rear vertical plate has a front end side thereof. The left and right front vertical plates are joined to the rear end side of one front vertical plate, and a short front upper flange is provided at the upper end of both joint portions.

  According to the invention of claim 2, one of the left and right front mounting bases is provided by being joined to the one rear vertical plate at the position of the bent portion, and the left and right front mounting bases are provided. Among the rear mounting bases, one rear mounting base is configured to be joined to the one rear vertical plate at a position rearward of the bent portion.

  According to a third aspect of the invention, the one front vertical plate and the one rear vertical plate are superposed on each other in the left and right directions at the position of the joint portion, and the superposed portion is joined by welding. The short front upper flange is configured to cover both overlapping portions from above.

  According to a fourth aspect of the present invention, a rear upper flange different from the short front upper flange is provided at an upper end of one of the left and right weight mounting portions, and the short front flange is provided. Between the upper flange and the rear upper flange, the upper end of the one rear vertical plate is exposed to the outside.

  Further, according to the invention of claim 5, the front and rear mounting bases located on one side in the left and right directions of the left and right front mounting bases and the rear mounting bases are the left and right rear vertical plates. The front and rear mounting pedestals are located between the left and right rear vertical plates and are located on the other side in the left and right directions. It is set as the structure provided in the back vertical board side.

  As described above, according to the first aspect of the present invention, one rear vertical plate of the left and right rear vertical plates of the tail frame is provided with a bent portion at an intermediate portion in the front and rear directions. , The distance between the right rear vertical plates can be reduced on the front side and increased on the rear side, and the distance between the left and right front mounting bases and the distance between the left and right rear mounting bases can be increased. Can do. As a result, even when the mounted components such as the prime mover are enlarged, the lower surface side (for example, oil pan) of the mounted components can be placed between the left and right front mounting bases and the left and right rear mounting bases. The space for mounting the prime mover can be secured. Moreover, of the left and right rear vertical plates, one of the rear vertical plates is provided with its front end joined to the rear end of one front vertical plate, and a short front upper flange at the upper end of the joint Thus, a beam structure having an I-shaped cross section can be formed, and a sufficient strength can be secured by suppressing the concentration of stress at the joint between the two. The thickness can be kept low, and the cost and weight can be reduced.

  According to the invention of claim 2, the left and right rear vertical plates at the positions where the left and right front mounting bases and the left and right rear mounting bases are enlarged by the bent portions. The lower side of the prime mover can be accommodated between these mounting bases.

  According to the invention of claim 3, the rear end side of one front vertical plate and the front end side of one rear vertical plate can be joined by welding in a state where they are overlapped with each other in the left and right directions. The front upper flange can be formed by joining the overlapping portions of the two from the upper side so as to form a beam structure having an I-shaped cross section.

  Further, according to the invention of claim 4, one of the rear vertical plates is configured to expose a portion located between the rear upper flange and the front upper flange constituting the weight mounting portion to the outside. The mounting space is not limited by the short front upper flange and the rear upper flange, and the necessary strength can be ensured while securing the mounting space.

  Further, the invention according to claim 5 is characterized in that the front and rear mounting bases located on one side in the left and right directions of the left and right front mounting bases and the rear mounting bases are positioned between the left and right rear vertical plates. The front and rear mounting bases located on the other side in the left and right direction can be provided on the outer side between the left and right rear vertical plates. And can be joined to the other rear vertical plate. Thereby, for example, the strength necessary for the mounting base for the prime mover can be secured while securing the mounting space for the prime mover.

1 is a front view showing a hydraulic excavator according to a first embodiment of the present invention. FIG. 2 is a plan view showing a turning frame in a state where a cab, an exterior cover, a counterweight, and the like in FIG. 1 are removed. It is the perspective view which looked at the turning frame of FIG. 2 from the left rear side. It is a disassembled perspective view of the turning frame shown in FIG. It is a perspective view which shows the state which mounted the engine in the turning frame of FIG. It is the perspective view which looked at the turning frame carrying an engine from the right rear. It is the perspective view which looked at the turning frame carrying an engine from the left front. It is the perspective view which looked at the turning frame carrying an engine from the right front. It is a top view which expands and shows the junction part and upper flange of the left front vertical board and left rear vertical board in FIG. It is sectional drawing which looked at the junction part and upper flange of a left front vertical board and a left rear vertical board from the arrow XX direction in FIG.

  Hereinafter, a case in which a turning frame of a construction machine according to an embodiment of the present invention is applied to a hydraulic excavator provided with a crawler type lower traveling body will be described as an example in detail with reference to the accompanying drawings.

  Here, FIG. 1 to FIG. 10 show an embodiment of the present invention. In the figure, reference numeral 1 denotes a hydraulic excavator as a construction machine. The hydraulic excavator 1 includes a crawler-type lower traveling body 2 and an upper revolving body mounted on the lower traveling body 2 via a swirling wheel 3 so as to be capable of swiveling. 4 and a work device 8 to be described later.

  Further, the upper swing body 4 has a swing frame 11 to be described later. On the swing frame 11, a cab 5, an exterior cover 6, a counterweight 7 and the like are provided as shown in FIG. 5 constitutes an operation operation unit on which an operator gets on and off, and defines a cab inside thereof. The exterior cover 6 together with the counterweight 7 defines a machine room in which an engine 46 and the like described later are accommodated.

  8 is a working device provided at the front portion of the upper swing body 4 so as to be able to move up and down. The working device 8 includes a boom 8A, an arm 8B, a bucket 8C as a working tool, a boom cylinder 8D, an arm cylinder 8E, and a bucket cylinder. 8F is included. In the working device 8, the boom 8A is moved up and down by the boom cylinder 8D, and the arm 8B is moved up and down by the arm cylinder 8E. The tip-side bucket 8C performs excavation work such as earth and sand by being rotated by the bucket cylinder 8F.

  On the other hand, on the front side of the lower traveling body 2, as shown in FIG. The earth removal plate 9 is used when earth removal work such as earth and sand, leveling work, and the like are performed. Moreover, the earth discharging board 9 is used also as an outrigger for stabilizing a vehicle attitude | position.

  Reference numeral 11 denotes a revolving frame that constitutes a main frame of the upper revolving structure 4. The revolving frame 11 includes a center frame 12 located on the center front side and a tail frame located on the center rear side, as shown in FIGS. 18, and a left side frame 36 and a right side frame 40 that are disposed on both sides in the left and right directions across the center frame 12 and the tail frame 18.

  Reference numeral 12 denotes a center frame that constitutes a central front side portion of the revolving frame 11. The center frame 12 is provided with a flat center bottom plate 13 and standing on the center bottom plate 13 so as to extend forward and rearward, and to the left and right. The left front vertical plate 14 and the right front vertical plate 15 which are spaced apart in the direction, and are located on the front side of the left front vertical plate 14 and the right front vertical plate 15 and extend in the left and right directions, and between these front vertical plates 14 and 15. It includes a front plate 16 which will be described later.

  Here, the center bottom plate 13 of the center frame 12 is formed using, for example, a substantially rectangular thick steel plate. The center bottom plate 13 is provided with a plurality of bolt insertion holes 13A on a virtual circle 3A (indicated by a two-dot chain line in FIG. 2) of the turning wheel 3 centering on a turning center (not shown). Each bolt (not shown) for attaching the swivel wheel 3 shown in FIG. 1 to the lower surface side of the center bottom plate 13 is inserted into these bolt insertion holes 13A.

  In addition, the left front vertical plate 14 is positioned substantially on the left side of the center bottom plate 13 so as to extend forward and rearward, and the right front vertical plate 15 is disposed between the left front vertical plate 14 and the left front vertical plate 14. It is located on the right side of the center bottom plate 13 so as to form an interval in the direction, and is erected substantially vertically so as to extend in the front and rear directions. The left and right front vertical plates 14 and 15 are arranged at positions offset in the right direction with respect to the turning center of the turning wheel 3 (virtual circle 3A indicated by a two-dot chain line in FIG. 2). Further, the left and right front vertical plates 14 and 15 are boom mounting portions 14A and 15A in which intermediate portions in the front and rear directions form a mountain shape and protrude upward, and the boom mounting portions 14A and 15A have a work The boom 8A of the device 8 is pin-coupled so as to be able to move up and down.

  Reference numeral 16 denotes a front plate 16 that is located on the front side of the center bottom plate 13 and connects the left and right front vertical plates 14 and 15. The front plate 16 is formed by bending a plate material such as a steel plate. ing. The front plate 16 has a lower edge joined to the upper surface of the center bottom plate 13 and left and right side edges joined to the inner side surfaces of the left and right front vertical plates 14 and 15 using welding means. In addition, on the front surface of the front plate 16, cylinder mounting plates 17 to be described later are joined and provided.

  Reference numeral 17 denotes a pair of left and right cylinder mounting plates which are positioned on the front surface of the front plate 16 and extend in the front and rear directions and are erected on the upper surface of the center bottom plate 13. Each cylinder mounting plate 17 has a front left and right front. It is located between the vertical plates 14 and 15 and is joined to the front end side of the center bottom plate 13. The left and right cylinder mounting plates 17 are pin-coupled so that the boom cylinder 8D of the working device 8 can rotate.

  Reference numeral 18 denotes a tail frame that is joined to the rear end side of the center frame 12, and the tail frame 18 is erected on the tail bottom plate 19, which will be described later, and extends forward and rearward on the tail bottom plate 19. The left rear vertical plate 20 and the right rear vertical plate 21 separated from each other in the right direction, and the left rear vertical plate 20 and the right rear vertical plate 21 connected in the left and right directions and separated from each other in the front and rear directions. 29 and a rear horizontal plate 30.

  Here, the tail bottom plate 19, the left rear vertical plate 20, the right rear vertical plate 21, the horizontal plate 29 and the rear horizontal plate 30 of the tail frame 18 have a substantially rectangular frame structure as shown in FIG. When a corner portion by the bent portion 20C of the rear vertical plate 20 is added, a pentagonal frame structure is formed. Thereby, the tail frame 18 is configured to support mounting bases 32 to 35 described later with high rigidity and to increase bending strength and the like in the left and right weight mounting portions 26 and 27.

  Reference numeral 19 denotes a tail bottom plate that constitutes the lower surface of the tail frame 18. The tail bottom plate 19 is formed in a flat plate shape using a steel plate having a thickness smaller than that of the center bottom plate 13. The plates 20 and 21 are joined to a later-described lateral plate 29 and a rear lateral plate 30 using welding means. The front end of the tail bottom plate 19 is joined to the rear end side of the center bottom plate 13 by welding means, and extends in the front and rear directions. The tail bottom plate 19 is formed with a substantially rectangular opening 19A located between the left and right rear vertical plates 20, 21 and the horizontal plate 29, the rear horizontal plate 30, and the opening 19A is an upper swing body. 4 is used when performing maintenance work on equipment mounted on the engine 46 and the like from the lower side of the engine 4.

  Here, of the left and right rear vertical plates 20, 21, one of the left rear vertical plates 20 has a front portion 20A side extending in parallel with the other right rear vertical plate 21, as shown in FIG. It extends in parallel with the right rear vertical plate 21. However, the left rear vertical plate 20 is a bent portion 20C that is bent so that an intermediate portion in the front and rear directions protrudes to the outside in the left and right directions by the dimension L. By this bent portion 20C, the rear portion 20B side of the left rear vertical plate 20 is formed such that the left and right spaces with the right rear vertical plate 21 are larger by the dimension L than the front portion 20A side. .

  The left rear vertical plate 20 is joined by welding with the front end on the front portion 20A side overlapped with the rear end side of the left front vertical plate 14 in the left and right directions, as shown in FIGS. The joint portion 22 is covered from above by a front upper flange 24 described later. However, a portion of the front portion 20A of the left rear vertical plate 20 on the rear side of the front upper flange 24 and a portion of the bent portion 20C and the rear portion 20B on the front side of the rear upper flange 28 are covered by the front upper flange 24. The upper end is exposed to the outside without being broken. For this reason, the left rear vertical plate 20 is formed by using a steel plate having a larger thickness than the left front vertical plate 14 and has a strength for supporting the counterweight 7 and the engine 46 from the lower side. Secured.

  On the other hand, the right rear vertical plate 21 is formed to extend linearly in the front and rear directions on the tail bottom plate 19. The front end of the right rear vertical plate 21 is joined to the rear end side of the right front vertical plate 15 so as to overlap in the left and right directions, and both joint portions 23 are covered from above by an upper flange 25 described later. However, the upper flange 25 is configured to cover the upper end of the right rear vertical plate 21 over almost the entire length, and the right rear vertical plate 21 uses a steel plate having the same thickness as the left and right front vertical plates 14 and 15. Is formed.

  The right rear vertical plate 21 of the tail frame 18 is disposed extending in the front and rear directions so as to be substantially linear with the right front vertical plate 15 of the center frame 12. On the other hand, the left rear vertical plate 20 has a bent portion 20C positioned in the middle between the front and rear directions in the left direction, that is, the dimension L in the direction opposite to the offset direction (right direction) of the front vertical plates 14 and 15. It is bent so that it only overhangs. As a result, a weight mounting portion 26 described later is disposed at a position moved in the direction opposite to the offset direction.

  24 is a left front upper flange provided on the upper end side of the front part of the left rear vertical plate 20, and the front upper flange 24 is formed using a flat plate material, and its length dimension is shown in FIGS. As shown in FIG. 10, the front end side of the front portion 20A of the left rear vertical plate 20 and the rear end side of the left front vertical plate 14 are overlapped in the left and right directions, that is, a single portion covering the joint portion 22 of both from the upper side. It is set to length. The front upper flange 24 is joined by welding in a state where the upper end of the overlapping portion (joining portion 22) between the front end side of the left rear vertical plate 20 and the rear end side of the left front vertical plate 14 is covered from above. Thus, as shown in FIG. 10, a beam structure having an I-shaped cross section is formed by the center bottom plate 13, the left front vertical plate 14, the left rear vertical plate 20, and the front upper flange 24.

  Reference numeral 25 denotes a right upper flange provided on the upper end side of the right rear vertical plate 21, and the upper flange 25 is also formed by using a long and thin plate-like plate material like the left front upper flange 24. However, as shown in FIGS. 2 to 4, the upper flange 25 on the right side has a longer length in the front and rear directions than the right rear vertical plate 21 and is formed in a long shape. The front side of the upper flange 25 covered the overlapped portion in which the rear end side of the right front vertical plate 15 and the front end side of the right rear vertical plate 21 were overlapped in the left and right directions, that is, the joint 23 between both from the upper side. In the state, it is joined to its upper end by welding.

  Further, the upper flange 25 on the right side is joined to the upper end of the right rear vertical plate 21 over its entire length, so that a beam structure having an I-shaped cross section is formed as shown in FIG. It is formed by a flange 25. The rear end side of the right upper flange 25 and the rear end side of the right rear vertical plate 21 constitute a weight attaching portion 27 described later. Moreover, on the front side of the upper flange 25, a beam structure having an I-shaped cross section is formed by the joint 23 between the right front vertical plate 15 and the right rear vertical plate 21 and the rear end side of the center bottom plate 13.

  26 and 27 are left and right weight mounting portions provided on the rear end sides of the left and right rear vertical plates 20 and 21, and the left weight mounting portion 26 of the weight mounting portions 26 and 27 is the same as described above. As shown in FIG. 3 and FIG. 4, the rear upper flange 28 made of a flat plate material different from the left front upper flange 24 is joined to the rear upper surface of the rear portion 20B of the left rear vertical plate 20 by welding. Are formed in a beam structure having an I-shaped cross section.

  Further, the right weight attaching portion 27 is formed with a beam structure having an I-shaped cross section by the right rear vertical plate 21 and the rear end side of the upper flange 25 described above. The left and right weight attaching portions 26 and 27 protrude rearward from the rear lateral plate 30 described later. The counterweight 7 is mounted on the left and right weight mounting portions 26 and 27 so that the counterweight 7 is placed on the rear side of the tail frame 18 from above.

  Reference numeral 29 denotes a horizontal plate provided between the left and right rear vertical plates 20 and 21. The horizontal plate 29 is joined at the lower end side to the front end portion of the tail bottom plate 19 and at the left and right ends at the rear side. By joining to the vertical plates 20 and 21, the tail bottom plate 19 and the rear vertical plates 20 and 21 are connected so as to be integrated with each other. The horizontal plate 29 is formed by using a single flat plate material by a dimension L shown in FIG. The left end portion of the horizontal plate 29 is joined to the front portion 20 </ b> A side of the left rear vertical plate 20.

  Reference numeral 30 denotes a rear horizontal plate provided on the rear end side of the tail bottom plate 19. The rear horizontal plate 30 is joined to the tail bottom plate 19 at the lower end side in the same manner as the horizontal plate 29, and both left and right end sides are rear vertical. By being joined to the plates 20 and 21, the tail bottom plate 19 and the rear vertical plates 20 and 21 are connected to each other. The rear horizontal plate 30 is formed longer than the front horizontal plate 29 by the dimension L by the bent portion 20C of the left rear vertical plate 20. The left end of the rear horizontal plate 30 is joined to the rear 20B side of the left rear vertical plate 20.

  The horizontal plate 29 and the rear horizontal plate 30 form an oil pan accommodating space 31 of the engine 46 described later between the left and right rear vertical plates 20 and 21. As shown in FIG. 2, the oil pan housing space 31 forms a pentagonal housing space when a corner portion formed by the bent portion 20 </ b> C of the left rear vertical plate 20 is added. The oil pan accommodating space 31 is formed as a space for accommodating an oil pan 50 of the engine 46 described later, that is, a lower side of the prime mover.

  32, 33, 34, 35 are left and right mounting bases provided on the left and right rear vertical plates 20, 21, and one (left side) of the mounting bases 32 to 35 is a front mounting base 32. It is located in the bread accommodating space 31 and is joined to the bent portion 20C side of the left rear vertical plate 20 and the horizontal plate 29 by welding. On the other hand, the rear mounting base 33 (left side) is located in the oil pan accommodating space 31 and is separated from the front mounting base 32 in the front and rear directions. They are joined by welding.

  The other (right side) front mounting base 34 is joined to the right rear vertical plate 21 by welding at a position outside the oil pan accommodating space 31. The other (right side) rear mounting base 35 is spaced forward and rearward from the front mounting base 34 at a position outside the oil pan accommodating space 31, and is joined to the upper flange 25 on the right rear vertical plate 21 side by welding. ing. The left and right front mounting bases 32 and 34 among these four mounting bases 32 to 35 are arranged at the same positions in the front and rear directions as shown in FIG. , 35 are also arranged at equivalent front and rear positions. A total of four mounting bases 32 to 35 support an engine 46 (to be described later) on the tail frame 18 in a vibration-damped state via the vibration-proof mounts 49 and the like.

  Reference numeral 36 denotes a left side frame attached to the left side position of the center frame 12 and the tail frame 18, and the left side frame 36 is formed of a cylindrical body having a D-shaped cross section, and a left outer frame 37 extending in the front and rear directions. A cab support frame 38 formed as a substantially rectangular frame provided to extend left and right between the left outer frame 37 and the center frame 12 to support the cab 5 shown in FIG. A left extension beam 39 is provided on the rear side of the cab support frame 38 and extends left and right between the left outer frame 37 and the tail frame 18.

  Reference numeral 40 denotes a right side frame attached to the right side position of the center frame 12 and the tail frame 18, and the right side frame 40 is formed by a cylindrical body having a D-shaped cross section and extends to the front and rear sides and to the right outer frame 41. A plurality of right extending beams 42, 43, 44, 45 provided to extend in the left and right directions between the right outer frame 41, the center frame 12, and the tail frame 18 are configured.

  46 is an engine that constitutes the prime mover of the hydraulic excavator 1, and the engine 46 is configured by using, for example, a diesel engine as shown in FIGS. 5 to 8, and is provided on both sides in the axial direction of a crankshaft (not shown). A cooling fan 47 and a flywheel 48 are provided. A hydraulic pump (not shown) or the like is attached to the flywheel 48 side, and a heat exchanger (not shown) such as a radiator is arranged on the cooling fan 47 side.

  The engine 46 is attached to the mounting bases 32 to 35 on the tail frame 18 side through a total of four vibration isolation mounts 49, and each vibration isolation mount 49 buffers vibrations of the engine 46. An oil pan 50 that contains lubricating oil or the like is provided on the lower surface side of the engine 46. The oil pan 50 projects downward from the upper surface of the mounting bases 32 to 35 and is accommodated with a gap inside the oil pan accommodating space 31.

  The hydraulic excavator 1 according to the present embodiment has the above-described configuration. Next, the assembly process of the turning frame 11 will be described with reference to FIG.

  First, the front center frame 12 is formed by joining a center bottom plate 13, left and right front vertical plates 14, 15 and a front plate 16 by welding means as shown in FIG. The rear tail frame 18 is also formed by joining the tail bottom plate 19, the left and right rear vertical plates 20, 21, the horizontal plate 29, the rear horizontal plate 30 and the like by welding means as shown in FIG.

  At this time, the left rear vertical plate 20 is formed so that the front portion 20A side and the rear portion 20B side extend in the front and rear directions in parallel with the right rear vertical plate 21, and the left and right middle portions have a left A bent portion 20C is formed in advance so as to be bent outward by a dimension L (see FIG. 2). A single front upper flange 24 is joined to the upper end side of the front portion 20A by welding so as to protrude toward the rear upper end side of the left front vertical plate 14. On the other hand, a long upper flange 25 is joined to the upper end side of the right rear vertical plate 21 by welding so as to extend over its entire length, and the front end side of the upper flange 25 also protrudes toward the rear upper end side of the right front vertical plate 15. Arrange to do.

  Next, in this state, the tail frame 18 is joined to the rear end side of the center frame 12 by welding. At this time, they are joined in an abutting state so that the rear end of the center bottom plate 13 and the front end of the tail bottom plate 19 abut against each other. Further, as shown in FIGS. 9 and 10, the left rear vertical plate 20 is joined by overlapping the front end on the front portion 20 </ b> A on the rear end side of the left front vertical plate 14 in the left and right directions. The front upper flange 24 is joined to 22 so as to be covered from the upper side. The front rear side of the right rear vertical plate 21 is joined to the rear end side of the right front vertical plate 15 in the left and right directions and joined, and the front end side of the upper flange 25 is covered from the upper side to the joint portion 23 of both. To join.

  Next, in a state where the center frame 12 and the tail frame 18 are joined by welding, the left side frame 36 and the right side frame 40 assembled in advance in separate steps are connected to the left and right sides of the center frame 12 and the tail frame 18. Join on both sides using welding means. Thereby, as shown in FIG.2 and FIG.3, the turning frame 11 which consists of a support structure welded can be assembled.

  Further, when the engine 46 is mounted on the revolving frame 11, the anti-vibration mounts 49 on the engine 46 side are placed on the mounting bases 32 to 35 on the tail frame 18 side, and both are fastened with bolts or the like. 46 is attached in a vibration-proof state. On the revolving frame 11, a cab 5, an exterior cover 6, a counterweight 7 and the like are mounted as shown in FIG. The exterior cover 6 defines a machine room in which the engine 46 and the like are accommodated with the counterweight 7, and the upper swing body 4 is assembled.

  The hydraulic excavator 1 configured in this manner can self-travel on the work site by the crawler-type lower traveling body 2. When performing excavation work or the like of earth and sand, the boom 8A and the arm 8B of the work device 8 are moved up and down while turning the upper turning body 4 on the lower traveling body 2. At this time, earth and sand are excavated on the front end side of the bucket 8C by rotating the bucket 8C.

  Here, when excavation work or the like is performed by the work device 8, a large load such as excavation reaction force is applied to the left and right front vertical plates 14 and 15 of the center frame 12 that supports the work device 8. . In addition, the load from the mounting device such as the engine 46 acts on the mounting bases 32 to 35 on the tail frame 18 side, and the load of the counterweight 7 which is a heavy object is applied to the left and right weight mounting portions 26 and 27. Works.

  For this reason, a joint portion (for example, a joint portion 22 between the rear end side of the left front vertical plate 14 and the left rear vertical plate 20, a rear end side of the right front vertical plate 15, which is a joint between the center frame 12 and the tail frame 18. A large bending stress due to the excavation reaction force and the weight of the counterweight 7 acts on the joint 23) with the right rear vertical plate 21. Therefore, in the prior art disclosed in Patent Document 1, an upper flange is provided at such a joint, and the entire left and right rear vertical plates are formed into a beam structure having an I-shaped cross section, thereby increasing the bending rigidity of the frame. I am doing so.

  However, in the case of the prior art, depending on the type of engine mounted on the tail frame side, the distance between the left and right mounting bases is small. For example, an oil pan provided on the lower surface side of the engine is placed between the left and right rear vertical plates. It can be difficult to fit. In particular, in the prior art, an upper flange is provided at each of the upper ends of the left and right rear vertical plates to form a beam structure having an I-shaped cross section. Therefore, it may be difficult to secure a mounting space.

  Therefore, according to the present embodiment, one left rear vertical plate 20 of the left and right rear vertical plates 20 and 21 of the tail frame 18 is provided with a bent portion 20C at an intermediate portion in the front and rear directions. The distance between the other right rear vertical plate 21 in the left and right directions is small on the front portion 20A side, and is large on the rear portion 20B side. Further, the left and right rear vertical plates 20 and 21 are provided with their front end sides joined to the rear end sides of the left and right front vertical plates 14 and 15, and the front ends of both joint portions 22 and 23 are arranged at the front. Upper flanges 24 and 25 are provided to form a beam structure having an I-shaped cross section.

  Further, the left and right front mounting bases 32 and 34 and the rear mounting bases 33 and 35 for mounting the engine 46 on the tail frame 18 side are spaced in the left and right directions by the bent portion 20C of the left rear vertical plate 20. The left and right rear vertical plates 20 and 21 are joined to each other at an enlarged position, and the lower side of the engine 46, that is, the oil pan 50 or the like is accommodated between these mounting bases 32 to 35. It is set as the structure to provide.

  Therefore, the space between the left and right rear vertical plates 20 and 21 is set to the front by the bent portion 20C provided on one of the left and right rear vertical plates 20 and 21 of the tail frame 18. The distance can be reduced on the part 20A side, and the distance can be increased on the rear part 20B side, and the distance between the mounting bases 32 to 35 in the left and right directions can be increased. Thereby, even when the mounted components such as the engine 46 are enlarged, the lower surface side (for example, the oil pan 50) of the mounted components can be accommodated with a gap between the mounting bases 32 to 35, and the rear vertical plate of the tail frame 18 A mounting space for the engine 46 can be ensured between 20, 21 (in the oil pan accommodating space 31).

  Further, since the space between the left and right rear vertical plates 20 and 21 is made small on the front portion 20A side in the left and right directions in the same manner as between the front vertical plates 14 and 15, for example, the working device 8 The front 20A side can be set at a distance (width dimension) in the left and right directions corresponding to the boom 8A, and the boom mounting portions 14A and 15A provided on the left and right front vertical plates 14 and 15 are supported on the boom 8A. Sufficient strength, bending rigidity, etc. can be secured.

  Further, since the space between the left and right rear vertical plates 20 and 21 is increased in the left and right directions on the rear portion 20B side, the left and right weight attaching portions 26 provided on the rear end side of the tail frame 18 are provided. , 27 can be widened, and the counterweight 7 can be stably supported by the weight attaching portions 26, 27. Thereby, the support strength of the counterweight 7 by the left and right front vertical plates 14 and 15 can be increased, and the torsional rigidity and the like can be improved when the counterweight 7 rolls to the left and right.

  The left weight mounting portion 26 of the left and right weight mounting portions 26, 27 is opposite to the offset direction (right direction) of the front vertical plates 14, 15 by the bent portion 20C of the left rear vertical plate 20. It is arranged at a position moved by the dimension L. For this reason, the center position between the left and right weight attaching portions 26 and 27 can be brought close to the center of gravity of the counter weight 7, and the support balance of the counter weight 7 by the left and right weight attaching portions 26 and 27 is increased. As a result, the counterweight 7 can be stably supported.

  Moreover, the left and right rear vertical plates 20 and 21 are provided with their front end sides joined to the rear end sides of the left and right front vertical plates 14 and 15, respectively. Since the front upper flange 24 and the upper flange 25 are provided to form a beam structure having an I-shaped cross section, it is possible to suppress the concentration of stress at the joint portions 22 and 23 of the both, and to ensure sufficient strength, and the rear vertical plate 20 , 21 can be kept to a minimum thickness, and the cost and weight can be reduced.

  In this case, the joining portion 22 is formed by welding in such a manner that the rear end side of the left front vertical plate 14 and the front end side of the left rear vertical plate 20 are overlapped with each other in the left and right directions as shown in FIGS. be able to. Then, a beam structure having an I-shaped cross section can be formed by providing a single front upper flange 24 so as to cover both overlapping portions from above. For this reason, it is possible to increase the bending rigidity at the joint portion 22 that is a joint between the rear end side of the left front vertical plate 14 and the front end side of the left rear vertical plate 20, and minimize the thickness of the left rear vertical plate 20. The thickness can be suppressed.

  Further, the joint 23 by welding can be formed on the rear end side of the right front vertical plate 15 and the front end side of the right rear vertical plate 21 in a state where they are overlapped with each other in the left and right directions. It can join to the upper end side of 23 so that the front-end side of the elongate upper flange 25 may be covered from an upper side. A beam structure having an I-shaped cross section can be formed on the upper end side of the right rear vertical plate 21 by providing a long upper flange 25 over its entire length. For this reason, the bending rigidity of the joint (joining part 23) etc. with respect to the right front vertical board 15 can be improved also about the right rear vertical board 21, and the plate | board thickness of the right rear vertical board 21 is equivalent to the front vertical boards 14 and 15, Alternatively, it can be suppressed to a thickness less than this.

  The left rear vertical plate 20 is configured to be exposed to the outside without covering the upper end side with the front upper flange 24 at the position of the bent portion 20C. That is, the left rear vertical plate 20 is configured to expose a portion located between the rear upper flange 28 and the front front upper flange 24 constituting the weight mounting portion 26 to the outside. Is not restricted by the front upper flange 24, the rear upper flange 28, or the like, and the necessary strength can be ensured while securing the mounting space.

  In this case, the left rear vertical plate 20 is not provided with the upper flange 25 extending over the entire length unlike the right rear vertical plate 21, so that, for example, the left and right front plates can be secured in order to secure the strength as the revolving frame 11 as described above. It must be formed of a plate material thicker than the vertical plates 14 and 15. However, the upper left side of the left rear vertical plate 20 is provided with the single front upper flange 24 and the rear upper flange 28 constituting the weight mounting portion 26 as described above.

  For this reason, the left rear vertical plate 20 having the bent portion 20C can be formed with the minimum necessary I-shaped cross-section beam structure, thereby reducing the thickness of the left rear vertical plate 20 to the minimum necessary. The thickness can be suppressed, and an increase in weight can also be suppressed. As a result, it is possible to reduce the weight and the manufacturing cost while securing sufficient strength as the revolving frame 11.

  Therefore, according to the present embodiment, even when a large engine 46 or the like is mounted on the tail frame 18 side, the interval between the mounting bases 32 to 35 can be increased correspondingly. In addition, the bending strength and the like at the joint between the center frame 12 and the tail frame 18 can be ensured, and the entire revolving frame 11 can be reduced in weight and cost.

  In the above-described embodiment, the case where the left rear vertical plate 20 is provided with the bent portion 20C among the left and right rear vertical plates 20 and 21 has been described as an example. However, the present invention is not limited to this. For example, a bent portion is provided on the right rear vertical plate 21 side, and the left and right intervals with respect to the other rear vertical plate are reduced on the front side and increased on the rear side. Also good.

  Moreover, in the said embodiment, the case where the junction part 22 by welding is formed in the state which superposed | stacked the rear end side of the left front vertical board 14 and the front end side of the left rear vertical board 20 in the left and right direction as an example. And explained. However, the present invention is not limited to this, and for example, the two may be joined in a state where the rear end of the left front vertical plate 14 and the front end of the left rear vertical plate 20 are abutted against each other. The same applies to the joint between the rear end side of the right front vertical plate 15 and the front end side of the right rear vertical plate 21.

  On the other hand, in the said embodiment, the hydraulic excavator 1 provided with the cab 5 which defines a driver's cab inside was mentioned as an example, and was demonstrated. However, the present invention is not limited to this. For example, the operation driving unit on which the operator gets on and off may be configured to cover the driver's seat from the upper side using a canopy.

  Moreover, in the said embodiment, the hydraulic excavator 1 provided with the working apparatus 8 which consists of boom 8A, arm 8B, etc. was mentioned as an example, and was demonstrated. However, the present invention is not limited to this. For example, the present invention may be applied to a swing frame used in a construction machine such as a hydraulic excavator provided with a swing post type working device.

  Furthermore, in the said embodiment, the hydraulic excavator 1 provided with the crawler type lower traveling body 2 was described as an example. However, the present invention is not limited to this. For example, the present invention may be applied to a construction machine such as a hydraulic excavator or a hydraulic crane provided with a wheel type lower traveling body.

1 Excavator (construction machine)
2 Lower traveling body 3 Revolving wheel 4 Upper revolving body 5 Cab 6 Exterior cover 7 Counterweight 8 Working device 8A Boom 8B Arm 8C Bucket 11 Revolving frame 12 Center frame 13 Center bottom plate 14 Left front vertical plate (one front vertical plate)
15 Right front vertical plate (the other front vertical plate)
16 Front plate 18 Tail frame 19 Tail bottom plate 20 Left rear vertical plate (one rear vertical plate)
20C bending part 21 right rear vertical plate (the other rear vertical plate)
22, 23 Junction (joint)
24 Front upper flange 25 Upper flange 26, 27 Weight mounting portion 28 Rear upper flange 29 Horizontal plate 30 Rear horizontal plate 31 Oil pan accommodating space 32 Left front mounting base 33 Left rear mounting base 34 Right front mounting base 35 Right side mounting base 35 Rear mounting base 36 Left side frame 40 Right side frame 46 Engine (motor)
49 Anti-vibration mount 50 Oil pan (lower side of prime mover)

Claims (5)

A center frame provided on the lower traveling body so as to be turnable via a turning wheel, and a tail frame joined to the rear end side of the center frame and provided with a prime mover and a counterweight on the upper side.
The center frame includes a center bottom plate mounted on the lower traveling body via the swivel wheel, and left and right left and right sides extending vertically and rearwardly on the center bottom plate and spaced apart from each other in the left and right directions. Having a front vertical plate,
The tail frame is joined to the rear end side of the center bottom plate and extends in the front and rear directions. The tail frame extends in the front and rear directions on the tail bottom plate and is left and spaced apart from each other in the left and right directions. , Right rear longitudinal plate,
The left and right rear vertical plates are mounted on the left and right weight mounting portions on the rear end side to which the counterweight is mounted, and on the front side of the left and right weight mounting portions on which the prime mover is mounted. In a swivel frame of a construction machine comprising left and right rear mounting bases and left and right front mounting bases on the front side of the left and right rear mounting bases to which the prime mover is mounted,
Of the left and right rear vertical plates of the tail frame, one rear vertical plate has a small space between the other rear vertical plate on the front side and the other rear vertical plate on the rear side. It is configured to provide a bent part at the intermediate part in the front and rear direction so that the interval of
The one rear vertical plate is provided with its front end side joined to the rear end side of one of the left and right front vertical plates, and a short front upper flange at the upper end of both joints A swivel frame for a construction machine, characterized in that a structure is provided. One of the left and right front mounting bases is provided by joining the one rear vertical plate at the position of the bent portion,
2. The construction machine according to claim 1, wherein one of the left and right rear mounting bases is configured to be joined to the one rear vertical plate at a position rearward of the bent portion. Swivel frame. The one front vertical plate and the one rear vertical plate are superposed on each other in the left and right directions at the position of the joint, and the superposed portion is joined by welding,
The turning frame for a construction machine according to claim 1 or 2, wherein the short front upper flange is configured to cover both overlapping portions from above. On the upper end of one of the left and right weight mounting portions, a rear upper flange different from the short front upper flange is provided,
The turning frame for a construction machine according to claim 1, 2 or 3, wherein an upper end of the one rear vertical plate is exposed to the outside between the short front upper flange and the rear upper flange. Of the left and right front mounting bases and rear mounting bases, the front and rear mounting bases located on one side in the left and right directions are located between the left and right rear vertical plates and the one rear vertical Provided on the plate side,
The front and rear mounting bases located on the other side in the left and right directions are arranged outside the left and right rear longitudinal plates and provided on the other rear longitudinal plate side. , 3 or 4 swing frame of construction machine.

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