JP2013053489A - Truck frame for undercarriage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve workability during removing a side frame by arranging bolts for mounting the side frame on a center frame at a position where rocks hardly collide therewith to prevent damage to the bolts.SOLUTION: Mounting flanges 15, 19 provided on leg parts 14, 18 of a center frame 12 have a plurality of female screws 15D, 19D, respectively. An outer vertical plate 22A and an inner vertical plate 22B of a frame body 22 as part of a side frame 21 have bolt insertion holes 22E, 22F at positions corresponding to the female screws 15D, 19D, respectively. Furthermore, through the bolt insertion holes 22E, 22F, long bolts 27 are inserted from the left and right outsides. The long bolts 27 have head parts just protruded from the outer vertical plate 22A of the frame body 22, and so damage thereto due to the collision of rocks can be avoided. The long bolts 27 can be easily handled from the left and right outsides.

Description

  The present invention relates to a track frame of a lower traveling body including a crawler such as a hydraulic excavator or a hydraulic crane.

  Generally, a hydraulic excavator is a self-propelled lower traveling body provided with a crawler belt, an upper revolving body that is turnably mounted on the lower traveling body, and a work device that is provided on the upper revolving body so as to be able to be raised and lowered. And is roughly composed. The hydraulic excavator travels on rough terrain such as a work site and performs excavation work of earth and sand using a work device.

  In this case, the lower traveling body of the hydraulic excavator is usually provided on one side of the front and rear directions of the track frame having side frames extending in the front and rear directions on the left and right sides of the center frame. The idler wheels, drive wheels provided on the other side of the front and rear sides of the side frames, and crawler belts wound around the idler wheels and the drive wheels are roughly configured.

  The center frame of the track frame has a front leg portion and a rear leg portion extending outward in the left and right directions, and the left and right side frames are located on both the left and right sides of the center frame and the front ends of the leg portions. Are attached to extend forward and backward.

  Here, among hydraulic excavators, there are some large hydraulic excavators whose outer dimensions exceed the passable width and height dimensions defined by the Road Traffic Law. For this reason, when a large hydraulic excavator is transported to the work site, the transport is divided into, for example, a lower traveling body, an upper swing body, and a work device. Larger, ultra-large hydraulic excavators exceed the dimensions that can be passed only by the lower traveling body. Therefore, this lower traveling body is assembled with the center frame and the idler wheels, drive wheels, and crawler belts on the side frame. It is divided into and. The individual parts thus divided are loaded on different transport vehicles, carried to the work site, and then assembled at the work site.

  Therefore, the track frame that constitutes the lower traveling body is configured such that the left and right side frames are attached to the respective leg portions of the center frame and are detachably attached. That is, each leg portion of the center frame is formed in a square shape having a hollow end surface on the front end side, and a mounting flange having a projecting portion on the front end side of the leg portion that projects outward from the square end surface. Is provided. On the other hand, the left and right side frames include an outer vertical plate located on the outer side in the left and right directions, an inner vertical plate disposed with a space from the outer vertical plate and in contact with the mounting flange, and an upper portion of the outer vertical plate. The upper horizontal plate is connected to the upper portion of the inner vertical plate.

  The inner vertical plate of the side frame is provided with a plurality of female screws at positions corresponding to the protruding portions of the mounting flanges of the respective leg portions, and bolts are respectively inserted into the protruding portions of the mounting flanges at positions corresponding to the respective female screws. A hole is provided. When attaching each side frame to each leg part of the center frame, the bolts are inserted from the left and right sides into the respective bolt insertion holes of the mounting flanges of the leg parts, and the leading end side is an inner vertical plate. The female screw is configured to be screwed (see, for example, Patent Document 1). Moreover, the bolt which has attached the side frame to the leg part prevents the loosening of the bolt using a long bolt under the neck by interposing a spacer between the head and the mounting flange. For example, see Patent Document 2).

JP 11-315557 A JP 2001-73409 A

  By the way, in a work site where a hydraulic excavator travels, rocks and the like are rolling, so when the rock is straddled during travel, the rock may collide with the track frame. In this case, since the bolt which attached the side frame to the leg part protrudes inside the side frame, the straddled rock may collide with the bolt. In particular, rocks are likely to collide with bolts that are protruded by a spacer for preventing loosening, and in the state where the bolts are bent due to the collision of rocks, work for removing the side frames is required.

  In addition, when loosening or tightening the bolts attached from the inside of the side frame, the operator has to sink into the lower side of the center frame, resulting in poor workability.

  The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to arrange bolts at positions where rocks and the like do not collide, thereby preventing damage to the bolts and removing the side frame. An object of the present invention is to provide a track frame of a lower traveling body that can improve workability.

  The track frame of the lower traveling body according to the present invention includes a center frame having a front leg portion and a rear leg portion extending outward in the left and right directions, and a front frame positioned on both the left and right sides of the center frame at the front end of the leg portion. The left side frame and the right side frame attached extending in the rear direction, and the end surface of the center frame on the distal end side of the leg portion is formed in a hollow quadrangular shape, the distal end side of the leg portion is A mounting flange having a projecting portion that projects to the outer diameter side of the rectangular end surface, and the left and right side frames are located on the outside in the left and right directions, and the outer longitudinal plate And an upper vertical plate that connects the upper portion of the outer vertical plate and the upper portion of the inner vertical plate.

  In order to solve the above-described problem, the feature of the configuration of the invention of claim 1 is that the projecting portion of the mounting flange is provided with a plurality of female screws with the left and right directions as axes, and the side frame. The outer vertical plate and the inner vertical plate are respectively provided with bolt insertion holes having the same axis in the left and right directions at positions corresponding to the respective female screws, and the bolt insertion holes are respectively provided with the outer vertical plate and the inner vertical plate. Bolts that are longer than the length between the vertical plate are inserted through the left and right outer sides, and the front ends of the bolts are screwed into the female screws, so that In other words, the side frames are attached to the legs.

  According to a second aspect of the present invention, a connecting cylinder is provided between the bolt insertion hole of the outer vertical plate of the side frame and the bolt insertion hole of the inner vertical plate to connect the bolt insertion holes. It is to have done.

  According to a third aspect of the present invention, the projecting portion of the mounting flange includes a front projecting portion extending in the front direction across the square end surface of the leg portion, a rear projecting portion extending in the rear direction, and a lower projecting portion extending in the downward direction. The female screw is provided in each of the front projecting portion, the rear projecting portion, and the lower projecting portion.

  According to a fourth aspect of the present invention, the mounting flange is provided with a mounting horizontal plate that extends outward in the left and right directions and abuts against the upper horizontal plate of the side frame. A plurality of bolt insertion holes are provided so as to pass through, and female screws are provided at positions corresponding to the respective bolt insertion holes in the upper horizontal plate of the side frame, and the mounting horizontal plates are provided in the respective bolt insertion holes. Bolts that are longer than the thickness of each of the bolts are inserted through the upper side in the upper and lower directions, and the end side of each bolt is screwed into the female screw, whereby the side plate is attached to the mounting lateral plate of the leg portion. The top horizontal plate of the frame can be attached.

  According to the first aspect of the present invention, the mounting flange provided on the distal end surface of the leg portion of the center frame is provided with a plurality of female screws with the left and right directions as axes on the protruding portion. The outer vertical plate and the inner vertical plate of the side frame are respectively provided with bolt insertion holes having the same axis in the left and right directions at positions corresponding to the respective female screws. Further, each bolt insertion hole is provided with a bolt longer than the length between the outer vertical plate and the inner vertical plate inserted from the outside in the left and right directions.

  Therefore, when the side frame is attached to the leg portion of the center frame, the bolts are sequentially inserted from the outside in the left and right directions into the bolt insertion hole of the outer vertical plate of the side frame and the bolt insertion hole of the inner vertical plate. The tip end side of the bolt protruding from the bolt insertion hole of the inner vertical plate is screwed to the female screw provided on the overhanging portion of the mounting flange of the leg portion. Thereby, a side frame can be attached to a leg part of a center frame using a bolt.

  As a result, the bolt for attaching the side frame to the leg part only protrudes from the outer vertical plate of the side frame, so that obstacles such as rocks are hard to collide and obstacles collide. Even if it does, it only collides with the head of the bolt, so that the bolt can be prevented from bending. Thereby, when disassembling the center frame and the side frame, the bolt can be easily loosened, and the workability of the disassembling work can be improved. In this disassembling and assembling work, the bolts can be tightened or loosened from the outside of the left and right sides of the side frame, so that the operator can easily get in an easy posture without going under the track frame. Can work. In addition, since the bolt is longer than the length dimension between the outer vertical plate and the inner vertical plate, the effect of preventing loosening can be exhibited when tightened.

  According to the second aspect of the present invention, in the connecting cylindrical body provided between the bolt insertion hole of the outer vertical plate of the side frame and the bolt insertion hole of the inner vertical plate, the outer vertical plate bends when the bolt is tightened. Therefore, the side frame can be firmly attached to the leg portion. Further, the connecting cylinder connecting the bolt insertion hole of the outer vertical plate and the bolt insertion hole of the inner vertical plate guides the bolt inserted into the bolt insertion hole of the outer vertical plate to the bolt insertion hole of the inner vertical plate. As a result, assembly workability can be improved.

  According to the invention of claim 3, the overhanging portion of the mounting flange includes a front overhanging portion extending in the front direction across the square end surface of the leg portion, a rear overhanging portion extending in the rearward direction, and a lower overhanging portion extending in the downward direction. Part. In addition, female threads can be provided on the front overhanging portion, the rear overhanging portion, and the lower overhanging portion, respectively.

  According to the fourth aspect of the present invention, the mounting lateral plate extending outward in the left and right directions from the mounting flange of the leg portion is brought into contact with the upper lateral plate of the side frame. The bolt is inserted into the bolt insertion hole of the mounting horizontal plate, and the protruding tip end side of the bolt is screwed to the female screw of the upper horizontal plate of the side frame. As a result, the upper horizontal plate of the side frame can also be attached to the leg portion, and the side frame can be firmly attached to the leg portion together with the attachment portion of the inner vertical plate.

It is a front view which shows the super-large hydraulic excavator provided with the track frame by embodiment of this invention. It is a front view which expands and shows the lower traveling body in FIG. It is a front view which shows a center frame alone. It is a left view which shows a center frame alone. It is a top view which shows a center frame alone. It is the expanded sectional view which looked at the front leg part of the center frame from the arrow VI-VI direction in FIG. It is a front view which shows a left side frame alone. It is a top view which shows a left side frame alone. It is a front view of the principal part expansion which shows the state which attached the side frame to the leg part with each volt | bolt. It is a top view of the principal part expansion which shows the state which attached the side frame to the leg part with each volt | bolt. It is sectional drawing of the principal part expansion which looked at the state which attached the side frame to the leg part from the arrow XI-XI direction in FIG. It is sectional drawing of the principal part expansion which looked at the state which attached the side frame to the leg part from the arrow XII-XII direction in FIG. It is a decomposition | disassembly sectional drawing of the principal part expansion shown in the state which decomposed | disassembled the leg part, the side frame, and the bolt.

  Hereinafter, a case where the track frame of the lower traveling body according to the embodiment of the present invention is applied to an ultra-large hydraulic excavator will be described as an example and described in detail with reference to FIGS. Note that the front side and the rear side of the lower traveling body vary depending on the turning position of the upper revolving body. In this embodiment, the side on which the idle wheels are provided is the front side of the track frame, and the side on which the drive wheels are provided is the track frame. It will be described as the rear side.

  In FIG. 1, reference numeral 1 denotes an ultra-large hydraulic excavator which is a typical example of a construction machine applied to the present embodiment. The hydraulic excavator 1 includes a crawler-type lower traveling body 2 capable of self-propelling and the lower portion. An upper swing body 4 mounted on the traveling body 2 via a swing device 3 so as to be capable of swinging, and a working device 5 provided on the front side of the upper swing body 4 so as to be able to be lifted and lowered and for performing excavation work of earth and sand. It is roughly structured.

  Here, the crawler type lower traveling body 2 is for traveling on rough terrain where rocks and the like roll and have many irregularities, and as shown in FIG. An idler wheel 6 provided rotatably on the front side of the side frame 21, a drive wheel 7 provided on the rear side of the side frame 21, and a crawler belt wound around the idler wheel 6 and the drive wheel 7. 8 is roughly constituted.

  Next, the configuration of the track frame 11 of the excavator 1 that is a characteristic part of the present invention will be described with reference to FIGS. 3 to 13.

  Reference numeral 11 denotes a track frame that forms a support structure of the lower traveling body 2. The track frame 11 includes a center frame 12, a left side frame 21, and a right side frame (not shown) which will be described later.

  Reference numeral 12 denotes a center frame that forms the central portion of the track frame 11. As shown in FIGS. 3 to 5, the center frame 12 has a substantially H-shaped can-making structure by welding a plurality of steel plates. It is formed as a body. The center frame 12 includes a main body frame portion 13 located in the center, a left and right front leg portion 14 and a left and right rear leg portion 18 extending outward from the main body frame portion 13 in the left and right directions. Yes.

  Reference numeral 13 denotes a main body frame portion that forms a central portion of the center frame 12, and the main body frame portion 13 has a substantially rectangular upper plate 13A and a substantially rectangular shape provided facing the lower side of the upper plate 13A. The lower plate 13B and a large-diameter cylindrical round cylinder 13C extending upward from the lower plate 13B through the upper plate 13A. And the main body frame part 13 supports the upper turning body 4 via the turning apparatus 3 on the round cylinder 13C. Here, the upper plate 13A and the lower plate 13B of the main body frame portion 13 are formed continuously with upper plates 14A and 18A and lower plates 14B and 18B, which will be described later.

  Reference numeral 14 denotes left and right front leg portions provided on the front side of the main body frame portion 13, and the left and right front leg portions 14 extend from the main body frame portion 13 outward in the left and right directions. Each front leg portion 14 is arranged to face the upper plate 14A extending leftward and rightward so as to be continuous with the upper plate 13A of the main body frame portion 13 and the lower side of the upper plate 14A. A lower plate 14B extending in the left and right directions so as to be continuous with the lower plate 13B, and a front vertical plate positioned on the front side between the upper plate 14A and the lower plate 14B and extending upward and downward. 14C, and a rear vertical plate 14D provided on the rear side between the upper plate 14A and the lower plate 14B and extending upward and downward. Thereby, each front leg part 14 is formed in a square shape having a hollow front end surface 14E, and a mounting flange 15 described later is integrally attached to the front end surface 14E.

  As shown in FIG. 6, the front leg portion 14 has the upper end edge of the front vertical plate 14C and the rear vertical plate 14D fixed to the upper plate 14A using welding means, and the lower end edge fixed to the lower plate 14B using welding means. Has been. The base end sides of the front vertical plate 14C and the rear vertical plate 14D are fixed to the round cylinder 13C of the main body frame portion 13 using welding means.

  Reference numeral 15 denotes a mounting flange provided on the front end surface 14E of the front leg portion 14. The mounting flange 15 constitutes a part of the front leg portion 14, and is fixed to the front end surface 14E by welding means. The mounting flange 15 extends to the outer diameter side from the front end surface 14E of the front leg portion 14, and its periphery projects in the front, rear direction, upper, and lower directions. That is, the mounting flange 15 is formed with a front overhanging portion 15A extending in the forward direction across the front end surface 14E of the front leg portion 14, a rear overhanging portion 15B extending in the rearward direction, and a lower overhanging portion 15C extending in the downward direction. Yes.

  The front overhanging portion 15A, the rear overhanging portion 15B, and the lower overhanging portion 15C are provided with a plurality of female screws 15D, for example, eight mounting flanges 15 in a substantially U shape. As shown in FIG. 13, each female screw 15 </ b> D is provided penetrating with the left and right directions as axes, and the front end side of a long bolt 27 described later is screwed together. Each female screw 15D may be configured as a bottomed screw hole that does not penetrate the mounting flange 15 and opens to the outside in the left and right directions.

  Reference numeral 16 denotes a mounting horizontal plate that extends from the upper position of the mounting flange 15 of the front leg portion 14 to the outside in the left and right directions. The mounting lateral plate 16 constitutes a part of the front leg portion 14 together with the mounting flange 15. The mounting horizontal plate 16 is in contact with the upper surface of an upper horizontal plate 22C of the frame main body 22 described later, and is firmly attached to the mounting flange 15 by an inclined plate 16A. A plurality of, for example, approximately 9 U-shaped bolt insertion holes 16B are formed around the mounting horizontal plate 16 so as to surround the inclined plate 16A, and these bolt insertion holes 16B are connected to the mounting horizontal plate 16 respectively. Bolts 26 to be described later for attaching the side frames 21 are inserted.

  Reference numeral 17 denotes a reinforcing plate provided on the front leg portion 14, and the reinforcing plate 17 is provided between the lower plate 14 </ b> B of the front leg portion 14 and the lower projecting portion 15 </ b> C of the mounting flange 15 with a space in the front and rear directions. Is provided. The reinforcing plate 17 increases the strength of the lower overhanging portion 15 </ b> C, and constitutes a part of the front leg portion 14.

  Reference numeral 18 denotes left and right rear legs provided on the rear side of the main body frame 13, and these left and right rear legs 18 are arranged in the left and right directions from the main body frame 13, as shown in FIG. It extends towards the outside. Each rear leg 18 has an upper plate 18A, a lower plate, a front vertical plate, a rear vertical plate (all not shown), a mounting flange 19 and a mounting horizontal plate 20 which will be described later, in substantially the same manner as the front leg 14 described above. The reinforcing plate (not shown) is fixed by using welding means.

  Reference numeral 19 denotes a mounting flange provided on the front end surface of the rear leg 18. As shown in FIG. 3, the mounting flange 19 has a front overhanging portion 19A, a rear overhanging portion 19B, and a lower overhanging portion 19C, which are substantially the same as the mounting flange 15 of the front leg portion 14, and these front overhanging portion 19A and rear overhanging portion 19C. For example, eight female screws 19D are provided on the portion 19B and the lower overhang portion 19C.

  Reference numeral 20 denotes a mounting lateral plate that extends from the upper position of the mounting flange 15 to the outside in the left and right directions. As shown in FIG. 5, the mounting lateral plate 20 has an inclined plate 20 </ b> A substantially similar to the mounting lateral plate 16 of the front leg portion 14, and nine bolt insertion holes 20 </ b> B are provided around it.

  Reference numeral 21 denotes left and right side frames (only the left side is shown) constituting the track frame 11. Since the left and right side frames 21 have the same configuration except that they are symmetrical in the left and right directions, only the left side frame 21 will be described in the present embodiment, and the right side frame 21 The description of the side frame is omitted. That is, the left side frame 21 is provided to extend in the front and rear directions at the distal ends of the leg portions 14 and 18 of the center frame 12. Here, as shown in FIGS. 2, 7, 8, etc., the left side frame 21 is roughly constituted by a frame body 22, an idle wheel bracket 24, and a drive wheel bracket 25 which will be described later.

  Reference numeral 22 denotes a frame main body located in the center of the front and rear direction (length direction) of the side frame 21. As shown in FIGS. 11 and 13, the frame body 22 includes an outer vertical plate 22A located on the outer side (left side) in the left and right directions, and an inner side (right side) in the left and right directions with a space from the outer vertical plate 22A. ) And an upper horizontal plate 22C connecting the upper portion of the outer vertical plate 22A and the upper portion of the inner vertical plate 22B. Accordingly, the frame body 22 has an inverted U-shaped cross section, and a bottom plate 22D is provided below each of the vertical plates 22A and 22B.

  Here, out of the total length of the inner vertical plate 22B, two portions in the middle of contact of the mounting flanges 15 and 19 of the legs 14 and 18 of the center frame 12 are thick inner and thick portions 22B1. In addition, of the total length of the upper horizontal plate 22C, two places in the middle of contact of the mounting horizontal plates 16 and 20 of the leg portions 14 and 18 are thick upper and thick portions 22C1.

  As shown in FIGS. 7 and 13, the outer vertical plate 22A has eight bolt insertion holes 22E penetrating in the left and right directions at positions corresponding to the female threads 15D and 19D of the mounting flanges 15 and 19, respectively. Is provided. In addition, the inner thick portion 22B1 of the inner vertical plate 22B is provided with eight bolt insertion holes 22F having the same axial line in the left and right directions as the bolt insertion holes 22E formed in the outer vertical plate 22A. A long bolt 27 described later is inserted into the bolt insertion holes 22E and 22F from the outside in the left and right directions.

  Further, as shown in FIG. 8, the upper thick portion 22C1 of the upper horizontal plate 22C penetrates upward and downward at positions corresponding to the bolt insertion holes 16B, 20B of the mounting horizontal plates 16, 20, for example. Nine female screws 22G are provided. As shown in FIG. 13, a bolt 26 described later is screwed into these female screws 22G.

  Reference numeral 23 denotes a plurality of connecting cylinders provided inside the frame body 22. As shown in FIG. 12, the connecting cylinder 23 is made of a pipe member having an inner diameter dimension through which a long bolt 27 described later can be inserted. As shown in FIG. 13, the outer vertical plate 22A and the inner vertical plate 22B. It is provided to extend in the left and right directions with the same length as the distance between the left and right. The connecting cylinders 23 are respectively provided between the bolt insertion holes 22E of the outer vertical plate 22A and the bolt insertion holes 22F of the inner vertical plate 22B, and connect the bolt insertion holes 22E and 22F. That is, the connecting cylinder 23 is fixed to the outer vertical plate 22A and the inner vertical plate 22B using welding means in a state where it is coaxially arranged with the bolt insertion holes 22E and 22F.

  The connecting cylinder 23 increases the mounting strength of the left side frame 21 with respect to the legs 14 and 18 by preventing the outer vertical plate 22A from bending when the long bolt 27 is tightened. Further, the connecting cylinder 23 connecting the bolt insertion holes 22E and 22F can guide the long bolt 27 inserted into the bolt insertion hole 22E of the outer vertical plate 22A to the bolt insertion hole 22F of the inner vertical plate 22B. .

  Reference numeral 24 denotes an idler wheel bracket provided on the front side of the frame body 22, and the idler wheel 6 is attached to the idler wheel bracket 24 via a yoke (not shown) or the like as shown in FIG. On the other hand, reference numeral 25 denotes a drive wheel bracket provided on the rear side of the frame body 22, and the drive wheel 7 is attached to the drive wheel bracket 25.

  26 is a bolt for attaching the left side frame 21 to the mounting lateral plates 16 and 20 of the leg portions 14 and 18, and the bolts 26 are the number corresponding to the bolt insertion holes 16B and 20B of the mounting lateral plates 16 and 20. Is provided. As shown in FIG. 13, the bolt 26 has a neck length L 1 that is longer than the thickness T of the mounting lateral plates 16 and 20. Thus, each bolt 26 is inserted into the bolt insertion holes 16B and 20B of the mounting horizontal plates 16 and 20 from the upper side, and the lower end portion is provided on the upper horizontal plate 22C of the frame body 22 of the left side frame 21. By screwing into the female screw 22G, the left side frame 21 can be attached to the attachment lateral plates 16 and 20, as shown in FIGS.

  Reference numeral 27 denotes a long bolt for attaching the left side frame 21 to the attachment flanges 15 and 19 of the leg portions 14 and 18. The number of the long bolts 27 corresponding to the female threads 15D and 19D of the mounting flanges 15 and 19 is provided. The long bolt 27 has a neck dimension L2 that is longer than the length dimension W between the outer vertical plate 22A and the inner vertical plate 22B. Thereby, each long bolt 27 is inserted into the bolt insertion hole 22E provided in the outer vertical plate 22A of the frame main body 22 constituting the left side frame 21 from the outside in the left and right directions, and the inner side through the connecting cylinder 23. As shown in FIGS. 10 and 11, the insertion flange 15 </ b> F is inserted into the bolt insertion hole 22 </ b> F provided in the vertical plate 22 </ b> B, and the tip portion thereof is screwed into the female threads 15 </ b> D and 19 </ b> D of the attachment flanges 15 and 19. A left side frame 21 can be attached to 19.

  In this case, since each long bolt 27 is inserted from the left and right outer sides of the left side frame 21, the work for attaching and removing can be performed in a posture that allows easy movement. Since the attached long bolt 27 has only the head exposed, damage such as bending can be prevented in advance. Further, the long bolt 27 has a sufficient length dimension that can exhibit a loosening prevention effect when tightened.

  As shown in FIG. 2, reference numeral 28 denotes, for example, three upper rollers provided on the upper side of the frame body 22 of the left side frame 21. Reference numeral 29 denotes, for example, eight lower rollers provided on the lower side of the frame body 22. The upper roller 28 and the lower roller 29 guide the crawler belt 8 in the front and rear directions.

  The hydraulic excavator 1 according to the present embodiment has the above-described configuration. Next, the operation of transporting the lower traveling body 2 of the super large hydraulic excavator 1 and assembling the lower traveling body 2 at the work site will be described. State.

  When transporting the large excavator 1 to the work site, the lower traveling body 2 is converted into a center frame 12 and an assembly in which the idler wheel 6, the drive wheel 7, the crawler belt 8 and the like are assembled to the side frame 21. It is divided. The individual parts thus divided are loaded on different transport vehicles and carried to the work site.

  Next, when the individual parts are brought to the work site, the assembly work is started. In this assembling operation, the side frames 21 are attached to the leg portions 14 and 18 of the center frame 12, so that the idler wheels 6, the drive wheels 7, the crawler belts 8, the side frames 21, etc. are assembled on both sides of the center frame 12. The traveling body 2 can be assembled.

  The center frame 12 is lifted and the legs 14 and 18 are placed on the left and right side frames 21. At this time, the attachment flanges 15 and 19 of the leg portions 14 and 18 are brought into contact with the inner thick portions 22B1 of the inner vertical plate 22B constituting the frame body 22 of the side frame 21, respectively. Further, the female threads 15D and 19D of the mounting flanges 15 and 19 constituting the respective leg portions 14 and 18 and the bolt insertion holes 22E and 22F of the outer vertical plate 22A and the inner vertical plate 22B forming the frame body 22 are on the same axis. Align to.

  Thus, after the center frame 12 and the side frame 21 are aligned, the operator stands at a position where the work can be performed comfortably on the outside of the left and right sides of the side frame 21, and each long bolt 27 is set. From the outside in the left and right directions, the bolt insertion hole 22E of the outer vertical plate 22A, the connecting cylinder 23, and the bolt insertion hole 22F of the inner vertical plate 22B are sequentially inserted, and the tips thereof are female threads 15D of the mounting flanges 15 and 19, respectively. Screw into 19D. Thereby, the left side frame 21 can be easily attached to the attachment flanges 15 and 19.

  Further, each bolt 26 is inserted into the bolt insertion holes 16B and 20B of the mounting lateral plates 16 and 20 from the upper side in the upper and lower directions, and the tip portion thereof is screwed into the female screw 22G of the upper lateral plate 22C. Thereby, the side frame 21 can be easily attached to the attachment horizontal plates 16 and 20.

  When the lower traveling body 2 is assembled, the excavator 1 can be assembled by sequentially assembling the upper revolving body 4 and the work device 5 on the upper side of the lower traveling body 2.

  Next, the operation of the assembled hydraulic excavator 1 will be described. When the hydraulic excavator 1 travels, the crawler belt 8 rotates around the idler wheel 6 by rotating the drive wheel 7 so that the hydraulic excavator 1 travels to the work site. On the other hand, when the working device 4 is moved up and down, excavation work of earth and sand can be performed.

  Here, since an obstacle such as a rock is rolling on the work site where the excavator 1 travels, the rock may collide with the track frame 11 when it is avoided while straddling the rock during traveling. In this case, as in the prior art, when a bolt or the like protrudes inside the left and right directions of the side frame 21, the straddled rock may collide with the bolt and the bolt may be bent.

  However, according to the present embodiment, the mounting flanges 15 and 19 provided on the front end surfaces 14E of the leg portions 14 and 18 of the center frame 12 have left and right directions on the overhang portions 15A to 15C and 19A to 19C. Is provided with a plurality of female screws 15D and 19D. On this, the outer vertical plate 22A and the inner vertical plate 22B of the frame main body 22 constituting the side frame 21 are bolt insertion holes having the same axis in the left and right directions at positions corresponding to the female screws 15D and 19D. 22E and 22F are provided. Further, in each of the bolt insertion holes 22E and 22F, a long bolt 27 having a neck length L2 longer than the length dimension W between the outer vertical plate 22A and the inner vertical plate 22B is left and rightward. It is set as the structure provided by inserting from the outside respectively.

  Accordingly, when the side frames 21 are attached to the legs 14 and 18 of the center frame 12, the long bolts 27 are connected to the bolt insertion holes 22E of the outer vertical plate 22A of the frame body 22 from the outside in the left and right directions. The bolts can be sequentially inserted through the bolt insertion holes 22F of the inner vertical plate 22B. Further, the distal end side of the long bolt 27 protruding from the bolt insertion hole 22F of the inner vertical plate 22B can be screwed to the female screw 22G provided on the mounting flanges 15 and 19 of the respective leg portions 14 and 18. Accordingly, the side frame 21 can be attached to the leg portions 14 and 18 of the center frame 12 using the long bolts 27 and the like.

  As a result, the long bolts 27 for attaching the side frames 21 to the leg portions 14 and 18 have their heads only protruding from the outer vertical plate 22A of the frame main body 22, so that obstacles such as rocks are present. Is difficult to collide, and even if an obstacle collides, it only collides with the head of the bolt. Thereby, since the deformation of the long bolt 27 can be prevented, when the center frame 12 and the side frame 21 are disassembled, the long bolt 27 can be easily loosened, and the workability of the disassembling work can be improved.

  In addition, the long bolt 27 can be tightened or loosened from the outside of the left and right sides of the side frame 21 in the disassembling operation and the assembling operation, so that the operator does not go under the track frame 11. Can work easily in an easy posture. Moreover, since the long bolt 27 has a length L1 longer than the length dimension W between the outer vertical plate 22A and the inner vertical plate 22B, it exhibits a loosening prevention effect when the long bolt 27 is tightened. can do.

  In the frame body 22 constituting the side frame 21, connecting cylinders 23 are respectively provided between the bolt insertion holes 22E of the outer vertical plate 22A and the bolt insertion holes 22F of the inner vertical plate 22B. Accordingly, the outer vertical plate 22A can be prevented from bending when the long bolt 27 is tightened, so that the side frame 21 can be firmly attached to the leg portions 14 and 18. Further, the connecting cylinder 23 can guide the long bolt 27 inserted into the bolt insertion hole 22E of the outer vertical plate 22A to the bolt insertion hole 22F of the inner vertical plate 22B, thereby improving the assembling workability. .

  Further, the mounting horizontal plates 16 and 20 provided on the respective leg portions 14 and 18 are in contact with the upper horizontal plate 22C of the frame main body 22, and a plurality of bolts 26 are inserted through the bolts of the mounting horizontal plates 16 and 20. The upper horizontal plate 22C of the frame main body 22 can also be attached to the leg portions 14 and 18 by screwing the female screws 22G of the upper horizontal plate 22C through the holes 16B and 20B. Accordingly, the side frame 21 can be firmly attached to the leg portions 14 and 18 together with the attachment portion of the inner vertical plate 22B.

  In the embodiment, eight female screws 15D and 19D are provided on the mounting flanges 15 and 19 of the legs 14 and 18 of the center frame 12, respectively, and eight bolts are inserted through the female screws 15D and 19D. Holes 22E and 22F and eight connecting cylinders 23 are provided, and these are fastened using eight long bolts 27. However, the present invention is not limited to this. For example, the long bolt 27 is provided with five, six, seven, or nine or more, and a corresponding number of female screws, bolt insertion holes, and connecting cylinders are provided. Also good.

  Further, in the embodiment, the track frame 11 of the lower traveling body 2 provided in the hydraulic excavator 1 is described as an example of the track frame of the lower traveling body. However, the present invention is not limited to this, and can be widely applied to a work vehicle having a track frame on the lower traveling body, such as a hydraulic crane.

1 Excavator (construction machine)
2 Lower traveling body 6 Idle wheel 7 Drive wheel 8 Crawler track 11 Track frame 12 Center frame 13 Main body frame portion 14 Front leg portion 14A, 18A Upper plate 14B Lower plate 14C Front vertical plate 14D Rear vertical plate 14E Front end surface 15, 19 Mounting flange 15A , 19A Front projecting part 15B, 19B Rear projecting part 15C, 19C Lower projecting part 15D, 19D Female thread 16, 20 Mounting lateral plate 16B, 20B, 22E, 22F Bolt insertion hole 18 Rear leg part 21 Left side frame 22 Frame body 22A Outside Vertical plate 22B Inner vertical plate 22C Upper horizontal plate 23 Connection cylinder 26 Bolt 27 Long bolt W Length between outer vertical plate and inner vertical plate L2 Dimension under long bolt

Claims (4)

A center frame having a front leg portion and a rear leg portion extending outward in the left and right directions, and a left side located on both the left and right sides of the center frame and extending forward and rearward at the front ends of the leg portions It consists of a frame and a right side frame.
The end face on the tip side of the leg portion of the center frame is formed in a hollow quadrangular shape,
Provided on the distal end side of the leg portion is a mounting flange having a projecting portion that projects to the outer diameter side from the square end surface;
The left and right side frames include an outer vertical plate located on the outside in the left and right directions, an inner vertical plate that is disposed at a distance from the outer vertical plate and contacts the mounting flange, and an upper portion of the outer vertical plate, In the track frame of the construction machine constituted by the upper horizontal plate connecting the upper part of the inner vertical plate,
The overhanging portion of the mounting flange is provided with a plurality of female screws with the left and right directions as axes.
The outer vertical plate and the inner vertical plate of the side frame are respectively provided with bolt insertion holes having the same axis in the left and right directions at positions corresponding to the female screws,
In each bolt insertion hole, a bolt longer than the length dimension between the outer vertical plate and the inner vertical plate is inserted from the outside in the left and right directions, respectively,
A track frame for a construction machine, wherein each side frame is attached to each leg portion of the center frame by screwing a front end side of each bolt to the female screw.   2. The structure according to claim 1, wherein a connecting cylinder that connects the bolt insertion holes is provided between the bolt insertion holes of the outer vertical plate and the bolt insertion holes of the inner vertical plate of the side frame. Truck frame for construction machinery. The overhang portion of the mounting flange is formed of a front overhang portion extending in the front direction across the square end surface of the leg portion, a rear overhang portion extending in the rear direction, and a lower overhang portion extending in the downward direction.
The track frame for a construction machine according to claim 1 or 2, wherein the female screw is provided in each of the front projecting portion, the rear projecting portion, and the lower projecting portion. The mounting flange is provided with a mounting horizontal plate that extends outward in the left and right directions and contacts the upper horizontal plate of the side frame,
The mounting lateral plate is provided with a plurality of bolt insertion holes penetrating upward and downward,
The upper horizontal plate of the side frame is provided with a female screw at a position corresponding to each bolt insertion hole,
In each bolt insertion hole, a bolt that is longer than the thickness dimension of the mounting lateral plate is provided by being inserted from above and below in the upper direction,
The truck of a construction machine according to claim 1, 2 or 3, wherein the upper side plate of the side frame is attached to the mounting side plate of the leg portion by screwing the front end side of each bolt to the female screw. flame.

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