JP5956480B2 - Track - Google Patents

Description

  The present invention relates to a crawler belt used for a crawler type vehicle such as a hydraulic excavator or a hydraulic crane.

  In general, a crawler type vehicle such as a hydraulic excavator or a hydraulic crane includes a lower traveling body that can be self-propelled, an upper revolving body that is turnably mounted on the lower traveling body, and a work device provided on the upper revolving body. It is comprised by.

  Here, the lower traveling body of the large crawler type vehicle includes a track frame having a center frame and left and right side frames, and driving wheels provided on one side in the length direction of each side frame of the track frame. Between the idler wheel provided on the other side of the length direction of each side frame, the crawler belt wound around the drive wheel and the idler wheel, and the drive wheel and idler wheel provided on the side frame. It is comprised with the guide roller which guides a crawler belt.

  The crawler belt is constructed by sequentially connecting a number of track links using connecting pins. During traveling of the lower traveling body, the crawler belt is rotated between the drive wheel and the idle wheel by rotating the drive wheel.

  Each track link constituting the crawler track of such a large crawler-type vehicle is formed of high-strength steel or the like because the entire weight of the vehicle acts. Here, each track link has a hollow box structure in order to reduce its weight and is integrally formed by casting.

  In this case, the track link has a three-dimensional shape extending in the left and right directions, a link base in which a through hole is formed in the left and right directions to remove casting sand for casting, and a plurality of links provided on the front outer periphery of the link base. A front boss and a plurality of rear bosses provided on the rear outer periphery of the link base are provided. Then, by sequentially connecting the front boss and the rear boss of adjacent track links using a connecting pin, a crawler belt in which a number of track links are connected endlessly is formed.

  Here, left and right reinforcing ribs are provided inside the track link, and the left and right reinforcing ribs are configured to receive a large load acting on the hollow track link. For this reason, the interior of the track link is divided into three chambers: a central chamber located between the left and right reinforcing ribs, a left chamber located on the left side of the left reinforcing rib, and a right chamber located on the right side of the right reinforcing rib. (Patent Document 1).

Japanese Patent Laid-Open No. 10-86864

  By the way, when casting the track link, it is necessary to use cores corresponding to the central chamber, the left chamber, and the right chamber formed in the track link. Therefore, in order to discharge the core casting sand to the outside after the track link is cast, the track link is formed with through holes penetrating in the left and right directions, and the left and right reinforcing ribs are provided with through holes. A hollow hole forming a part is provided.

  In the conventional track link, a column is provided in a hollow hole provided in the left and right reinforcing ribs, and a part of the load acting on the track link is received by this column. In other words, the left and right reinforcing ribs are provided with two hollow holes with a pillar interposed therebetween.

  However, the pillar provided in the hollow hole of the reinforcing rib is provided at a position away from the link base constituting the main body portion of the track link. For this reason, at the time of casting of the track link, the cooling of the column proceeds faster than the link base, and the molten metal is not easily replenished to the column portion from the feeder. As a result, there is a problem that casting defects such as shrinkage cavities are likely to occur around the reinforcing rib.

  Furthermore, the track link in which the pillar is provided in the hollow hole of the reinforcing rib has a problem that the weight of the track link increases and the shape of the mold or core for casting the track link becomes complicated.

  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 provide a crawler belt that can increase the strength of the reinforcing ribs constituting the track link and can increase the strength of the track link. It is said.

  In order to solve the above-described problems, the present invention is configured by sequentially connecting a large number of track links in the front and rear directions and wound between a driving wheel and an idler wheel of a vehicle body. A through-hole that has a three-dimensional shape extending in the left and right directions, the outer peripheral side is a ground contact surface that contacts the ground, and the inner peripheral side is a guide surface that is guided by the driving wheel or idler wheel, and the casting sand for casting is extracted in the left and right directions And a link base provided in the through-hole and provided with a gap in the left and right directions of the link base and having one hollow hole forming a part of the through-hole. A second reinforcing rib; a central chamber formed between the first and second reinforcing ribs and forming a part of the through hole; and a left and right one of the link base from the first reinforcing rib. A part of the through hole is formed toward the side end surface. And one side chamber having an open end surface and another side chamber formed from the second reinforcing rib toward the left and right side end surfaces of the link base to form part of the through hole and having an open end surface And at a position facing the first reinforcing rib, at a position facing the second reinforcing rib, and a front one-side boss formed on the front outer periphery of the link base, offset from the one-side chamber, and A front intermediate boss formed on the front outer periphery of the link base and offset from the central chamber; a front other boss positioned on the outer peripheral side of the other side chamber and formed on the front outer periphery of the link base; The rear side boss formed on the rear outer periphery of the link base so as to be offset from the other side chamber, the position facing the first reinforcing rib, and the center chamber. The rear side of the link base An intermediate boss after being formed on the peripheral, is applied to the crawler belt composed constituted by the one side boss after being formed on the side periphery after the link base is located on the outer peripheral side of the one side chamber.

  According to the first aspect of the present invention, the corner portion where the first reinforcing rib intersects with the portion facing the front one-side boss on the inner peripheral surface of the one-side chamber is thickly cast. The corner corner where the second reinforcing rib intersects with the one-side built-up portion formed by this, and the part of the inner peripheral surface of the other-side chamber facing the rear other-side boss and the second reinforcing rib is thickly cast. And forming the other side built-up portion in a circular arc shape at the corner of the inner peripheral surface of the central chamber where the first reinforcing rib intersects with the portion facing the rear intermediate boss. And the other side arc portion formed in an arc shape at a corner portion where the portion facing the front intermediate boss and the second reinforcing rib intersect on the inner peripheral surface of the central chamber. The one-side built-up portion and the one-side arcuate portion are configured to face each other diagonally across the first reinforcing rib, Serial and the other side arc portion and the other side padding portion lies in that a configuration in which diagonally opposed across the second reinforcing ribs.

  According to a second aspect of the present invention, the one-side arc portion is formed by subjecting the corner portion where the inner peripheral surface of the central chamber and the first reinforcing rib intersect to be thinned so as to be thin. The other side arc part is a side part formed by subjecting the corner part where the inner peripheral surface of the central chamber and the second reinforcing rib intersect to form a thin wall. It is in the meat cutting part.

  According to a third aspect of the present invention, there is provided a longitudinal rib extending leftward and rightward on the inner peripheral surface of the central chamber and connecting the first reinforcing rib and the second reinforcing rib in the leftward and rightward direction. It is that it was set as the structure which provides.

  According to invention of Claim 1, the connection site | part of a front one side boss | hub and a 1st reinforcement rib can be reinforced with one side build-up part, and a connection with a back other side boss | hub and a 2nd reinforcement rib is possible. A site | part can be reinforced with the other side build-up part. As a result, the crawler belt rotates in a state where the bosses of the plurality of track links are connected, so that the track link between the front one boss and the rear intermediate boss and the front intermediate boss and the rear other boss are between. Even if a large load due to tension, torsional force or the like is applied, this load can be reliably received by the first and second reinforcing ribs, and the strength of the track link can be increased.

  In addition, since each of the first and second reinforcing ribs is provided with one hollow hole, the columns of the reinforcing ribs as in the prior art can be dispensed with. Thereby, the weight of the track link can be reduced. Moreover, it is possible to suppress the occurrence of casting defects such as shrinkage cavities around the first and second reinforcing ribs during the casting of the track link, and the strength of the track link can be increased.

  Furthermore, by providing one hollow hole in the first and second reinforcing ribs, the shape of the mold and core for casting the track link can be simplified, and the core is destroyed after casting. Thus, the work of discharging from the through hole of the link base to the outside can be easily performed, so that the workability of the casting work can be improved.

  According to the invention of claim 2, by using the one side arc portion as the one side shaving portion, the extra thick portion can be eliminated while maintaining the strength of the first reinforcing rib, and the other side arc portion By using as the other side shaving portion, it is possible to eliminate an excessive thick portion while maintaining the strength of the second reinforcing rib. As a result, the strength of the track link can be increased and the track link can be reduced in weight.

  According to invention of Claim 3, between the 1st reinforcement rib and the 2nd reinforcement rib is connected in the left and right direction by the vertical rib, and the intensity | strength of the track link with respect to the protrusion from the ground is raised. be able to. Furthermore, even if a left and right load acts between the first reinforcing rib and the second reinforcing rib, the left and right loads can be received by the vertical rib. As a result, the entire track link can be prevented from being twisted in the left and right directions, and the durability of the track link can be improved.

It is a front view which shows the super-large hydraulic excavator provided with the crawler belt by the 1st Embodiment of this invention. It is a front view which expands and shows the lower traveling body in FIG. FIG. 3 is an enlarged cross-sectional view of a drive wheel and a track link as viewed from the direction of arrows III-III in FIG. It is an external appearance perspective view which decomposes | disassembles and shows a part of track link which comprises a crawler belt. It is the perspective view which looked at the single track link from the guide surface side. It is the top view which looked at the single track link from the guide surface side. It is the side view which looked at the track link from the arrow VII-VII direction in FIG. It is the bottom view which looked at the track link from the grounding surface side. It is a top view which shows the state which connected the track link. It is the cross-sectional perspective view which looked at the inside of a track link from the arrow XX direction in FIG. It is sectional drawing of the position similar to FIG. 10 which shows the internal structure of a track link. It is a cross-sectional perspective view similar to FIG. 10 which shows the inside of the track link by a comparative example. It is sectional drawing of the same position as FIG. 12 which shows the internal structure of the track link by a comparative example. It is a perspective view which shows the track link by 2nd Embodiment alone. It is sectional drawing which looked at the internal structure of the track link by 2nd Embodiment from the arrow XV-XV direction in FIG. FIG. 12 is a cross-sectional view similar to FIG. 11 showing the internal structure of a track link according to a modification.

  Hereinafter, as a crawler belt according to an embodiment of the present invention, a crawler belt of a hydraulic excavator will be described as an example and described in detail according to the accompanying drawings.

  First, FIG. 1 to FIG. 11 show a first embodiment. In the first embodiment, one side in the left and right directions is the right side, and the other side in the left and right directions is the left side.

  In the figure, reference numeral 1 denotes an ultra-large hydraulic excavator as a construction machine. The hydraulic excavator 1 includes a lower traveling body 5, which will be described later, an upper revolving body 3 that constitutes a vehicle body together with the lower traveling body 5 and is turnably mounted on the lower traveling body 5 via a turning wheel 2, and the upper revolving body It is provided on the front side of the body 3 so as to be able to move up and down, and includes a working device 4 that performs soil excavation work and the like.

  The crawler type lower traveling body 5 is for traveling stably on uneven ground, muddy ground, and the like. The lower traveling body 5 includes a track frame 6, a lower guide roller 9, an upper guide roller 10, drive wheels 11, idle wheels 12, and crawler belts 13 which will be described later.

  The track frame 6 includes a center frame 7 located at the center in the left and right directions, and side frames 8 provided on both the left and right sides of the center frame 7 and extending in the front and rear directions. At the center of the center frame 7, a turning wheel 2 constituting a turning device is attached, and the upper turning body 3 is mounted via the turning wheel 2.

  The left and right side frames 8 (only the right side is shown) constitute the track frame 6 together with the center frame 7. The side frame 8 is disposed so as to extend in the front and rear directions of the excavator 1, and is attached to the tip of each leg portion 7 A of the center frame 7. The side frame 8 is formed as a rectangular tube-shaped can-making structure that extends in the front and rear directions, for example, by welding steel plates.

  A plurality of lower guide rollers 9 are provided on the lower surface side of the side frame 8. As shown in FIG. 2, the lower guide rollers 9 are arranged at a predetermined interval in the front and rear directions. Each of the lower guide rollers 9 is positioned between a drive wheel 11 and an idler wheel 12 which will be described later and rolls on a guide surface 17 of a track 13 (track link 14) which will be described later. It is guided in the circumferential direction so as to be pressed.

  A plurality of upper guide rollers 10 are provided on the upper surface side of the side frame 8. Each upper guide roller 10 is arranged, for example, at a predetermined interval in the front and rear directions. Each upper guide roller 10 supports the crawler belt 13 from the lower side between a driving wheel 11 and an idler wheel 12 described later, and guides the crawler belt 13 in the circumferential direction.

  The drive wheel 11 is provided on one side of the side frame 8 in the length direction. The drive wheel 11 is attached to the side frame 8 via a hydraulic motor (not shown), and drives the crawler belt 13 around by the hydraulic motor. Here, as shown in FIG. 3, the drive wheel 11 includes a short cylindrical body 11A located in the center, and two discs 11B provided on the outer peripheral side of the cylindrical body 11A with an interval in the axial direction. A plurality of connecting portions 11C (only one is shown in FIG. 3) arranged at predetermined intervals in the circumferential direction on the outer peripheral side between the respective discs 11B, and connecting the discs 11B in a ladder shape over the entire circumference. Formed from.

  A concave portion 11D is provided between the adjacent connecting portions 11C, and the concave portion 11D engages (engages) with an engagement protrusion 18 of each track link 14 described later. Further, the outer peripheral surface of each disk 11B is a contact surface 11E, and this contact surface 11E is in contact with a later-described guide surface 17 provided on each track link 14.

  On the other hand, the idler wheel 12 is provided on the other side in the length direction of each side frame 8. The idler wheel 12 adjusts the tension of a later-described crawler belt 13 by a crawler belt tension adjusting mechanism (not shown), and is always urged away from the drive wheel 11.

  Next, the crawler belt 13 applied to the first embodiment will be described.

  Reference numeral 13 denotes a crawler belt (crawler) provided around the drive wheel 11 and the idle wheel 12. As shown in FIG. 4, the crawler belt 13 is configured as an endless endless track by sequentially connecting a number of track links 14 to be described later in the front and rear directions.

  Reference numeral 14 denotes a track link constituting the crawler belt 13. The track link 14 is configured as a hollow box structure having a hollow inside, and is integrally formed by, for example, casting means. As shown in FIGS. 5 to 8, the track link 14 includes a link base 15, a through-hole 20, first and second reinforcing ribs 23 and 24, a central chamber 25, a right chamber 26, and a left chamber. 27, a front right boss 28, a front intermediate boss 29 and a front left boss 30, a rear left boss 31, a rear intermediate boss 32 and a rear right boss 33.

  Reference numeral 15 denotes a link base that forms an outer shell of the track link 14, and the link base 15 constitutes a main body of the track link 14. The link base 15 has a hollow three-dimensional shape surrounded by an upper surface 15A, a lower surface 15B, a front surface 15C, a rear surface 15D, a right end surface 15E, and a left end surface 15F. The width dimension in the left and right directions is the front and rear directions. It is larger than the length dimension and the height dimension in the upper and lower directions.

  The grounding surface 16 is provided on the lower surface 15B side of the link base 15. The ground contact surface 16 is a surface that is in contact with the ground and becomes the outer peripheral side of each track link 14 when a large number of track links 14 are connected endlessly (annularly). As shown in FIGS. 7 and 8, on the ground contact surface 16, three jetty-shaped anti-skids 16 </ b> A extending in the left and right directions are projected in parallel in the front and rear directions.

  The guide surface 17 is provided on the upper surface 15A side of the link base 15 (the side opposite to the ground surface 16). This guide surface 17 becomes the inner peripheral side of each track link 14 when a large number of track links 14 are connected endlessly (annularly), and is guided by the drive wheels 11, idle wheels 12, and guide rollers 9, 10. Surface.

  Here, a trapezoidal engagement protrusion 18 is provided at the center of the guide surface 17 in the left and right directions. As shown in FIG. 3, the engagement protrusion 18 is engaged (engaged) with the recessed portion 11 </ b> D of the drive wheel 11 to transmit the rotation of the drive wheel 11 to the crawler belt 13 without slipping. . On the other hand, left and right restricting projections 19 projecting from the guide surface 17 with a height dimension smaller than that of the engaging projection 18 are provided at two places on the guide surface 17 in the left and right directions across the engaging projection 18. ing. These left and right restricting projections 19 are formed on the left side of each track link 14 when the outer peripheral edge of the drive wheel 11 comes into contact with the drive wheel 11 when the track link 14 is displaced in the left or right direction. , To regulate the displacement in the right direction.

  Reference numeral 20 denotes a through hole provided through the link base 15 in the left and right directions. The through-hole 20 is used for extracting casting sand such as a core filled in the track link 14 to the outside when the track link 14 having a hollow structure is cast. As shown in FIGS. 10 and 11, the through-hole 20 includes an opening 21 provided on the right end surface 15E of the link base 15, an opening 22 provided on the left end surface 15F of the link base 15, and a first to be described later. The first and second reinforcing ribs 23 and 24 include hollow holes 23A and 24A, a central chamber 25, a right chamber 26, and a left chamber 27.

  Reference numerals 23 and 24 denote first and second reinforcing ribs provided in the through hole 20 of the link base 15 with a spacing in the left and right directions. The first reinforcing rib 23 and the second reinforcing rib 24 are arranged at positions corresponding to the guide surface 17 of the link base 15, and are provided from the hydraulic excavator 1 acting on the link base 15 via the lower guide roller 9. It receives the load. Here, the first reinforcing rib 23 and the second reinforcing rib 24 are integrally formed on the link base 15 by casting, and the inside of the link base 15 is formed in the central chamber 25 by the first and second reinforcing ribs 23 and 24. The right chamber 26 and the left chamber 27 are divided into three chambers. On the other hand, in the central portion of the first reinforcing rib 23, one hollow hole 23A penetrating left and right is formed, and in the central portion of the second reinforcing rib 24, penetrating left and right. One hollow hole 24A is formed. The hollow holes 23 </ b> A and 24 </ b> A formed in the first and second reinforcing ribs 23 and 24 form a part of the through hole 20 provided in the link base 15.

  Reference numeral 25 denotes a central chamber formed between the first and second reinforcing ribs 23 and 24 and formed inside the link base 15, and the central chamber 25 forms a part of the through hole 20. Here, the central chamber 25 is formed as a space having a substantially rectangular cross-sectional shape extending in the left and right directions, and a hollow hole 23A of the first reinforcing rib 23 is opened on the right end side of the central chamber 25. On the left end side of 25, a hollow hole 24A of the second reinforcing rib 24 is opened. In the central chamber 25, vertical ribs 40 described later are provided.

  Reference numeral 26 denotes a right chamber as a one-side chamber disposed on one side (right side) in the left and right directions with respect to the central chamber 25. The right chamber 26 extends from the first reinforcing rib 23 toward the right end surface 15E of the link base 15 and forms a part of the through hole 20. Here, the right chamber 26 is formed as a space having a substantially rectangular cross-sectional shape extending in the left and right directions. A hollow hole 23A of the first reinforcing rib 23 is opened on the left end side of the right chamber 26, and the right chamber An opening portion 21 of the link base 15 (right end surface 15E) is opened on the right end side of 26.

  Reference numeral 27 denotes a left side chamber as the other side chamber disposed on the other side (left side) in the left and right directions with respect to the central chamber 25. The left chamber 27 extends from the second reinforcing rib 24 toward the left end surface 15F of the link base 15 and forms a part of the through hole 20. Here, the left chamber 27 is formed as a space having a substantially rectangular cross-sectional shape extending in the left and right directions. A hollow hole 24A of the second reinforcing rib 24 is opened on the right end side of the left chamber 27, and the left chamber An opening 22 of the link base 15 (left end surface 15F) is opened on the left end side of 27.

  Next, the front right boss 28, the front intermediate boss 29, and the front left boss 30 that are integrally formed on the front surface 15C side of the link base 15 will be described. The front right boss 28, the front intermediate boss 29, and the front left boss 30 are connected to the adjacent front track link 14 via a connecting pin 34 described later.

  Reference numeral 28 denotes a front right boss as a front one boss arranged on one side (right side) in the left and right directions. The front right boss 28 protrudes forward from the outer periphery of the front surface 15C of the link base 15 at a position facing the first reinforcing rib 23 and offset from the first reinforcing rib 23 to the right chamber 26. Yes. Further, the front right boss 28 is provided with a pin insertion hole 28A through which the connecting pin 34 is inserted, penetrating left and right.

  Reference numeral 29 denotes a front intermediate boss disposed at the intermediate portion in the left and right directions. The front intermediate boss 29 is provided so as to protrude forward from the outer periphery of the front surface 15C of the link base 15 at a position facing the second reinforcing rib 24 and offset from the second reinforcing rib 24 to the central chamber 25. Yes. The front intermediate boss 29 is provided with a pin insertion hole 29A through which the connecting pin 34 is inserted, penetrating left and right.

  Reference numeral 30 denotes a front left boss as a front other boss arranged on the other side (left side) in the left and right directions. The front left boss 30 is located on the outer peripheral side of the left chamber 27 and protrudes forward from the outer periphery of the front surface 15C of the link base 15. Further, the front left boss 30 is provided with a pin insertion hole 30A through which the connecting pin 34 is inserted, penetrating left and right. Further, the front left boss 30 is provided with a bracket 30B for attaching a bolt / nut 35 described later.

  Next, the rear left boss 31, the rear intermediate boss 32, and the rear right boss 33 that are integrally formed on the rear surface 15D side of the link base 15 will be described. The rear left boss 31, the rear intermediate boss 32, and the rear right boss 33 are connected to the adjacent rear track link 14 via a connecting pin 34.

  Reference numeral 31 denotes a rear left boss as a rear other boss arranged on the other side (left side) in the left and right directions. Thereafter, the left boss 31 protrudes rearward from the outer periphery of the rear surface 15D of the link base 15 at a position facing the second reinforcing rib 24 and offset from the second reinforcing rib 24 to the left chamber 27. Yes. The rear left boss 31 is provided with a pin insertion hole 31A through which the connecting pin 34 is inserted, penetrating in the left and right directions.

  Reference numeral 32 denotes a rear intermediate boss arranged at the intermediate portion in the left and right directions. Thereafter, the intermediate boss 32 is provided so as to protrude rearward from the outer periphery of the rear surface 15D of the link base 15 at a position facing the first reinforcing rib 23 and offset from the first reinforcing rib 23 toward the central chamber 25. Yes. Further, the rear intermediate boss 32 is provided with a pin insertion hole 32A through which the connecting pin 34 is inserted, penetrating left and right.

  Reference numeral 33 denotes a rear right boss as a rear one boss arranged on one side (right side) in the left and right directions. The rear right boss 33 is provided on the outer peripheral side of the right chamber 26 so as to protrude rearward from the outer periphery of the rear surface 15D of the link base 15. Further, the rear right boss 33 is provided with a pin insertion hole 33A through which the connecting pin 34 is inserted, penetrating leftward and rightward. Further, the rear right boss 33 is provided with a bracket 33B for attaching a bolt / nut 35.

  4 and 9, when connecting a plurality of track links 14, the track link 14 on the rear side is provided between the rear intermediate boss 32 and the rear right boss 33 on the front side of the track link 14. The front right boss 28 is disposed. In this state, the connecting pins 34 are sequentially inserted into the pin insertion holes 33A, 28A, 33A of the rear right boss 33, the front right boss 28, and the rear intermediate boss 32, and the retaining bolts The nut 35 is fixed. On the other hand, the rear left boss 31 of the front track link 14 is arranged between the front intermediate boss 29 and the front left boss 30 of the rear track link 14. In this state, the connecting pins 34 are sequentially inserted into the pin insertion holes 30A, 31A, 29A of the front left boss 30, the rear left boss 31, and the front intermediate boss 29, and the bolts and nuts 35 are fixed to the bracket 30B of the front left boss 30. To do. Thus, the endless crawler belt 13 can be formed by sequentially connecting a large number of track links 14 using the connecting pins 34.

  In this case, as shown in FIG. 9, a virtual line A connecting the left and right center of the front right boss 28 and the left and right center of the rear intermediate boss 32 and the left and right direction of the front intermediate boss 29. Imaginary lines B connecting the center of the rear and the left and right centers of the rear left boss 31 are inclined obliquely with respect to the running direction C (front and rear directions) of the crawler belt 13, respectively. Therefore, when the hydraulic excavator 1 travels, a load acts diagonally between the front right boss 28 and the rear intermediate boss 32 along the virtual line A, and the front intermediate boss 29 and the rear left side along the virtual line B. A load acts on the boss 31 obliquely.

  Next, a right padding portion 36 provided in the right chamber 26 of the link base 15, a left padding portion 37 provided in the left chamber 27, a right meat cutting portion 38 and a left meat cutting portion provided in the central chamber 25. 39 will be described.

  Reference numeral 36 denotes a right build-up portion as a one-side build-up portion formed on the inner peripheral surface of the right chamber 26. When the track link 14 is cast, the right build-up portion 36 is formed by build-up casting at the corner of the right chamber 26 where the portion facing the front right boss 28 and the first reinforcing rib 23 intersect. ing. In this case, the right build-up portion 36 has an arc shape that smoothly continues between the portion of the right chamber 26 facing the front right boss 28 and the first reinforcing rib 23, as shown in FIG. The curvature radius R1 of the right build-up portion 36 is set to be larger than the curvature radius R2 of the arc-shaped corner portion 26A where the portion of the right chamber 26 facing the rear right boss 33 and the first reinforcing rib 23 intersect. (R1> R2).

  Reference numeral 37 denotes a left padding portion as the other side padding portion formed on the inner peripheral surface of the left chamber 27. When the track link 14 is cast, the left build-up portion 37 is formed by build-up casting at a corner portion of the left chamber 27 where the second reinforcing rib 24 intersects with a portion facing the rear left boss 31. ing. In this case, the left padding portion 37 has an arc shape that smoothly connects the portion of the left chamber 27 facing the rear left boss 31 and the second reinforcing rib 24, and the curvature of the left padding portion 37 is The radius R1 is set larger than the radius of curvature R2 of the arc-shaped corner portion 27A where the second reinforcing rib 24 intersects the portion of the left chamber 27 facing the front left boss 30 (R1> R2). .

  In this case, the right chamber 26 in which the right heaping portion 36 is formed and the left chamber 27 in which the left heaping portion 37 is formed are formed in a point-symmetric shape with the central chamber 25 as the center. Further, a front right boss 28, a front intermediate boss 29, a front left boss 30 provided on the front surface 15C side of the link base 15, a rear left boss 31, a rear intermediate boss 32 provided on the rear surface 15D side of the link base 15, The rear right boss 33 is formed in a point-symmetric shape around the central chamber 25.

  Reference numeral 38 denotes a right cut portion as one side cut portion formed on the inner peripheral surface of the central chamber 25. The right side shaving portion 38 is formed by shaving and casting a corner portion of the central chamber 25 where the first reinforcing rib 23 intersects with a portion of the central chamber 25 facing the rear intermediate boss 32 when the track link 14 is cast. The center chamber 25 is recessed from the inner peripheral surface toward the rear intermediate boss 32. The right build-up portion 36 provided on the inner peripheral surface of the right chamber 26 and the right meat shaving portion 38 provided on the inner peripheral surface of the central chamber 25 are diagonally opposed with the first reinforcing rib 23 interposed therebetween. Are arranged.

  Thereby, the periphery of the virtual line A in the connection portion between the front right boss 28 and the first reinforcing rib 23 can be formed thick by the right build-up portion 36. On the other hand, the portion away from the imaginary line A among the connecting portions between the rear intermediate boss 32 and the first reinforcing rib 23 can be formed thin by the right cut portion 38.

  Reference numeral 39 denotes a left side shaving part as the other side shaving part formed on the inner peripheral surface of the central chamber 25. The left side shaving portion 39 is formed by shaving and casting a corner portion of the central chamber 25 where the second reinforcing rib 24 intersects with a portion of the central chamber 25 facing the front intermediate boss 29 when the track link 14 is cast. The center chamber 25 is recessed from the inner peripheral surface toward the front intermediate boss 29. Then, the left padding portion 37 provided on the inner peripheral surface of the left chamber 27 and the left meat shaving portion 39 provided on the inner peripheral surface of the central chamber 25 are diagonally opposed with the second reinforcing rib 24 interposed therebetween. Are arranged.

  As a result, the periphery of the virtual line B in the connection portion between the rear left boss 31 and the second reinforcing rib 24 can be formed thick by the left build-up portion 37. On the other hand, a portion of the connecting portion between the front intermediate boss 29 and the second reinforcing rib 24 that is away from the imaginary line B can be formed thin by the left cut portion 39.

  Reference numeral 40 denotes a vertical rib provided on the inner peripheral surface of the central chamber 25. The vertical ribs 40 protrude from the inner peripheral surface of the central chamber 25 in a jetty shape and extend in the left and right directions, and connect the first reinforcing rib 23 and the second reinforcing rib 24. Thereby, when the hydraulic excavator 1 is traveling, the strength of the track link 14 against the thrust from the ground can be increased.

  The crawler belt 13 according to the first embodiment has the above-described configuration. Next, a manufacturing operation of the track link 14 constituting the crawler belt 13 will be described.

  The track link 14 is integrally formed by casting. The mold (not shown) of the track link 14 has outer shapes such as a link base 15, a front right boss 28, a front intermediate boss 29, a front left boss 30, a rear left boss 31, a rear intermediate boss 32, and a rear right boss 33. Corresponding upper mold and lower mold, and the internal shape of the link base 15, that is, the central chamber 25, the right chamber 26, the left chamber 27, the hollow hole 23 </ b> A of the first reinforcing rib 23, and the hollow hole 24 </ b> A of the second reinforcing rib 24. It is comprised with the core corresponding to.

  Next, a core is formed between the upper mold and the lower mold to form a mold, and hot water made of a metal material dissolved in the mold is poured. Here, hot water is applied to portions of the mold corresponding to the bosses 28 to 33 of the track link 14, and hot water is replenished while discharging gas generated in the mold. In this way, the hot water filled in the mold is gradually cooled and solidified, whereby the track link 14 can be cast.

  In this case, in the first embodiment, since the first and second reinforcing ribs 23 and 24 are provided with one hollow hole 23A and 24A, respectively, the hollow hole of the reinforcing rib as in the prior art. Compared with a structure in which a pillar is provided in the inside, it is possible to suppress the occurrence of casting defects such as shrinkage cavities around the first and second reinforcing ribs 23 and 24, thereby forming a high-strength track link 14. be able to.

  Next, when connecting the plurality of cast track links 14, as shown in FIGS. 4 and 9, the rear side boss 32 and the rear right boss 33 are arranged between the rear intermediate boss 32 and the rear right boss 33. A front right boss 28 of the track link 14 is arranged. In this state, the connecting pins 34 are sequentially inserted into the pin insertion holes 33A, 28A, 33A of the rear right boss 33, the front right boss 28, and the rear intermediate boss 32, and the retaining bolts The nut 35 is fixed.

  On the other hand, the rear left boss 31 of the front track link 14 is arranged between the front intermediate boss 29 and the front left boss 30 of the rear track link 14. In this state, the connecting pins 34 are sequentially inserted into the pin insertion holes 30A, 31A, 29A of the front left boss 30, the rear left boss 31, and the front intermediate boss 29, and the bolts and nuts 35 are fixed to the bracket 30B of the front left boss 30. To do. Thus, the endless crawler belt 13 can be formed by sequentially connecting a large number of track links 14 using the connecting pins 34.

  Here, as shown in FIG. 9, a virtual line A connecting the left and right centers of the front right boss 28 and the left and right centers of the rear intermediate boss 32 and the left and right directions of the front intermediate boss 29. Imaginary lines B connecting the center of the rear and the left and right centers of the rear left boss 31 are inclined obliquely with respect to the running direction C (front and rear directions) of the crawler belt 13, respectively. For this reason, when the hydraulic excavator 1 travels, a load acts along the virtual line A between the front right boss 28 and the rear intermediate boss 32, and the virtual line between the front intermediate boss 29 and the rear left boss 31. A load is applied along B.

  On the other hand, in the first embodiment, the right build-up portion 36 is formed at the corner where the first reinforcing rib 23 intersects with the portion facing the front right boss 28 in the right chamber 26 of the link base 15. Is provided. Thereby, the periphery of the imaginary line A in the connection portion between the front right boss 28 and the first reinforcing rib 23 can be reinforced by the right padding portion 36. On the other hand, in the left chamber 27 of the link base 15, a left build-up portion 37 is provided at a corner portion where the portion facing the rear left boss 31 and the second reinforcing rib 24 intersect. Thereby, the periphery of the imaginary line B in the connection portion between the rear left boss 31 and the second reinforcing rib 24 can be reinforced by the left padding portion 37.

  As a result, as the crawler belt 13 rotates, a large amount of tension, torsional force, or the like is generated between the front right boss 28 and the rear intermediate boss 32 and between the front intermediate boss 29 and the rear left boss 31 of each track link 14. Even if a load is applied, this load can be reliably received by the first and second reinforcing ribs 23, 24, and the strength of each track link 14 can be increased.

  Furthermore, in the first embodiment, the right cut portion 38 is provided at the corner where the first reinforcing rib 23 intersects the portion of the central chamber 25 of the link base 15 that faces the rear intermediate boss 32. ing. As a result, the portion away from the imaginary line A among the connecting portions between the rear intermediate boss 32 and the first reinforcing rib 23 can be thinned by the right cut portion 38. On the other hand, in the central chamber 25 of the link base 15, a left cut portion 39 is provided at a corner where the front intermediate boss 29 and the second reinforcing rib 24 intersect. Thereby, the part away from the virtual line B among the connection parts between the front intermediate boss 29 and the second reinforcing ribs 24 can be thinned by the left meat shaving part 39.

  As a result, an extra thick portion can be eliminated while maintaining the strength of the first and second reinforcing ribs 23, 24, so that the weight of the track link 14 can be reduced while increasing the strength of the track link 14. Can do.

  Further, a longitudinal rib 40 that connects the first reinforcing rib 23 and the second reinforcing rib 24 is provided on the inner peripheral surface of the central chamber 25 of the link base 15. Thereby, the strength of the track link 14 against the thrust from the ground can be increased when the excavator 1 is traveling. Further, even if a load in the left and right directions acts between the first reinforcing rib 23 and the second reinforcing rib 24, the load between the left and right reinforcing ribs 23 and 24 is received by the vertical rib 40. Can do. As a result, the entire track link 14 can be prevented from being twisted in the left and right directions, and the durability of the track link 14 can be enhanced.

  Next, a comparison between the track link 14 according to the first embodiment and the track link 101 according to the comparative example shown in FIGS. 12 and 13 will be described.

  First, the track link 101 according to the comparative example is similar to the track link 14 according to the first embodiment. The link base 102, the first reinforcing rib 103, the second reinforcing rib 104, the central chamber 105, and the like. A right chamber 106, a left chamber 107, a front right boss 108, a front intermediate boss 109, a front left boss 110, a rear left boss 111, a rear intermediate boss 112, and a rear right boss 113. Has been.

  Here, the track link 101 according to the comparative example is provided with a pillar 103A in the center of the first reinforcing rib 103, and the first reinforcing rib 103 is provided with two hollow holes 103B with the pillar 103A interposed therebetween. Yes. Similarly, a column 104A is provided at the center of the second reinforcing rib 104, and the second reinforcing rib 104 is provided with two hollow holes 104B with the column 104A interposed therebetween.

  Further, a built-up portion is not formed at a corner portion 106 </ b> A where the first reinforcing rib 103 intersects with a portion of the inner peripheral surface of the right chamber 106 facing the front right boss 108. Similarly, no built-up portion is formed at the corner portion 107A where the second reinforcing rib 104 intersects the portion of the inner peripheral surface of the left chamber 107 that faces the rear left boss 111.

  For this reason, in the track link 101 according to the comparative example, the portion around the virtual line P connecting the front right boss 108 and the rear intermediate boss 112 is thin among the connection portions between the front right boss 108 and the first reinforcing rib 103. It becomes. On the other hand, of the connection portion between the rear left boss 111 and the second reinforcing rib 104, the periphery of the virtual line Q connecting the front intermediate boss 109 and the rear left boss 111 is thin. For this reason, the track link 101 according to the comparative example may not be able to sufficiently secure the strength of the first and second reinforcing ribs 103 and 104 against the load acting along the virtual lines P and Q. is there.

  On the other hand, in the track link 14 according to the first embodiment, the connection portion between the front right boss 28 and the first reinforcing rib 23 is thick due to the right build-up portion 36, and the left left build-up portion 37 causes the rear left The connecting portion between the boss 31 and the second reinforcing rib 24 is thick. As a result, the strength of the first and second reinforcing ribs 23 and 24 can be ensured against the load acting along the virtual lines A and B, and the strength of the track link 14 can be increased.

  On the other hand, in the track link 101 according to the comparative example, two hollow holes 103B are provided with the pillar 103A sandwiched between the first reinforcing ribs 103, and the two hollow holes 104B sandwiched with the pillar 104A between the second reinforcing ribs 104. Is provided. For this reason, at the time of casting the track link 101, the columns 103A and 104A located away from the link base 102 cool faster than the link base 102, and the molten metal from the molten metal to the columns 103A and 104A. Is difficult to replenish. As a result, casting defects such as shrinkage can easily occur around the first reinforcing rib 103 having the pillar 103A and the second reinforcing rib 104 having the pillar 104A.

  On the other hand, the track link 14 according to the first embodiment is provided with one hollow hole 23A and 24A for the first and second reinforcing ribs 23 and 24, respectively. The pillars 103A and 104A can be eliminated. For this reason, at the time of casting of the track link 14, it is possible to suppress the occurrence of casting defects such as shrinkage cavities around the first and second reinforcing ribs 23 and 24, and the first and second reinforcing ribs 23. , 24 can be ensured. Moreover, the weight of the track link 14 can be reduced by the amount that the columns 103A and 104A as in the comparative example can be dispensed with.

  Furthermore, by providing one hollow hole 23A, 24A in each of the first and second reinforcing ribs 23, 24, the shape of the mold or core for casting the track link 14 can be simplified, And since the operation | work which collapses a core after casting and discharges outside from the through-hole 20 of the link base 15 can be performed easily, workability | operativity of a casting operation can be improved.

  On the other hand, in the track link 101 according to the comparative example, two hollow holes 103B are provided with the pillar 103A sandwiched between the first reinforcing ribs 103, and the two hollow holes 104B sandwiched with the pillar 104A between the second reinforcing ribs 104. Is provided. Therefore, in the track link 101 according to the comparative example, stress is easily concentrated around the hollow holes 103B and 104B formed in the first and second reinforcing ribs 103 and 104, respectively.

  On the other hand, the track link 14 according to the first embodiment has only one hollow hole 23A and 24A for the first and second reinforcing ribs 23 and 24, respectively. It is possible to suppress the concentration of stress around the reinforcing ribs 23 and 24, and to increase the strength of the track link 14.

  Next, FIG. 14 and FIG. 15 show a second embodiment of the present invention. In this second embodiment, one side in the left and right directions is the left side, and the other side in the left and right directions is the right side. It is said.

  In the figure, reference numeral 41 denotes a track link according to the second embodiment. This track link 41 is substantially the same as the track link 14 according to the first embodiment, and a link base 42, a through hole 43, which will be described later, First and second reinforcing ribs 44, 45, central chamber 46, left chamber 47 and right chamber 48, front left boss 49, front intermediate boss 50 and front right boss 51, rear right boss 52, rear intermediate boss 53 and a rear left boss 54.

  However, the track link 41 according to the second embodiment has a left side wall to be described later at a corner where the first reinforcing rib 44 intersects a portion of the inner circumferential surface of the left chamber 47 that faces the front left boss 49. The portion 55 is formed, and the right build-up portion 56 described later is formed at the corner where the second reinforcing rib 45 intersects the portion facing the rear right boss 52 on the inner peripheral surface of the right chamber 48. This is different from the track link 14 according to the first embodiment.

  Here, the link base 42 has a hollow three-dimensional shape extending in the left and right directions, and its lower surface side is a ground contact surface. On the other hand, on the upper surface side of the link base 42, a guide surface 42A, an engaging protrusion 42B, and a restricting protrusion 42C are provided. A through hole 43 that penetrates in the left and right directions is provided inside the link base 42, and the through hole 43 is provided in the opening 42 </ b> D provided in the left end surface of the link base 42 and the right end surface of the link base 42. The opening 42E, hollow holes 44A and 45A described later, a central chamber 46, a left chamber 47, and a right chamber 48 are configured.

  In the through hole 43 of the link base 42, first and second reinforcing ribs 44 and 45 are provided with a spacing in the left and right directions. The inside of the link base 42 includes a central chamber 46 positioned between the first and second reinforcing ribs 44, a left chamber 47 as one side chamber positioned on the left side of the first reinforcing rib 44, and a second The chamber is divided into three chambers, a right chamber 48 as the other chamber located on the right side of the reinforcing rib 45. The first and second reinforcing ribs 44 and 45 are provided with hollow holes 44 </ b> A and 45 </ b> A that respectively form part of the through hole 43.

  On the front side of the link base 42, a front left boss 49, a front intermediate boss 50, and a front right boss 51 are provided as front one side bosses. The front left boss 49, the front intermediate boss 50, and the front right boss 51 are provided with pin insertion holes 49A, 50A, 51A, respectively. On the other hand, on the rear surface side of the link base 42, a rear right boss 52 as a rear other boss, a rear intermediate boss 53, and a rear left boss 54 as a rear one boss are provided. The rear right boss 52, the rear intermediate boss 53, and the rear left boss 54 are provided with pin insertion holes 52A, 53A, 54A, respectively.

  Here, at the corner of the inner peripheral surface of the left chamber 47 where the first reinforcing rib 44 intersects with the portion facing the front left boss 49, a left heaping portion 55 is formed as one side heaping portion. Has been. In addition, a right padding portion 56 as the other side padding portion is formed at a corner portion of the inner peripheral surface of the right chamber 48 where the portion facing the rear right boss 52 and the second reinforcing rib 45 intersect. ing.

  On the other hand, at the corner of the inner peripheral surface of the central chamber 46 where the first reinforcing rib 44 intersects with the portion facing the rear intermediate boss 53, a left cut portion 57 as a one side cut portion is formed. In the corner of the inner peripheral surface of the central chamber 46 where the second reinforcing rib 45 intersects with the portion facing the front intermediate boss 50, a right cut portion 58 is formed as the other side cut portion. Yes.

  Thereby, in the track link 41, the left build-up portion 55 and the left cut-off portion 57 are diagonally opposed to each other with the first reinforcing rib 44 interposed therebetween, and the right build-up portion 56 and the right cut-off portion 58 are The second reinforcing ribs 45 are opposed to each other diagonally. Further, the inner circumferential surface of the central chamber 46 is provided with vertical ribs 59 extending in the left and right directions, and the first reinforcing ribs 44 and the second reinforcing ribs 45 are connected by the vertical ribs 59. Yes.

  The track link 41 according to the second embodiment has the above-described configuration, and this track link 41 can obtain the same operational effects as the track link 14 according to the first embodiment.

  In the first embodiment described above, the corner of the inner peripheral surface of the central chamber 25 that faces the rear intermediate boss 32 and the first reinforcing rib 23 is directed to the rear intermediate boss 32. The right cut portion 38 is formed in a concave shape, and is directed toward the front intermediate boss 29 at the corner where the second reinforcing rib 24 intersects the portion of the inner peripheral surface of the central chamber 25 that faces the front intermediate boss 29. The case where the left side shaving part 39 which was dented and formed is illustrated. However, the present invention is not limited to this. For example, the present invention may be configured as a track link 14 'according to a modification shown in FIG.

  That is, the corner portion where the first reinforcing rib 23 intersects the portion of the inner circumferential surface of the central chamber 25 facing the rear intermediate boss 32 and a smooth arc shape that does not dent toward the rear intermediate boss 32. The corner portion where the second reinforcing rib 24 intersects with the portion facing the front intermediate boss 29 on the inner circumferential surface of the central chamber 25 is recessed toward the front intermediate boss 29. You may form as the left circular arc part 62 which makes | forms the smooth circular arc shape which does not do. The same applies to the track link 41 according to the second embodiment.

  Further, in the above-described embodiment, the crawler belt 13 provided in the ultra-large hydraulic excavator 1 is described as an example. However, the present invention is not limited to this, and can be widely applied to a work vehicle having a crawler track on the lower traveling body, such as a hydraulic crane.

DESCRIPTION OF SYMBOLS 11 Drive wheel 12 Idle wheel 13 Crawler belt 14,41,14 'Track link 15,42 Link base 16 Grounding surface 17 Guide surface 20 Through-hole 23,44 1st reinforcement rib 23A, 24A Hollow hole 24,45 2nd reinforcement Rib 25, 46 Central room 26 Right room (one side room)
27 Left room (other room)
28 Front right boss (front one boss)
29,50 Front intermediate boss 30 Front left boss (front other boss)
31 Rear left boss (rear other boss)
32, 53 Rear intermediate boss 33 Rear right boss 36 Right padding part (one side padding part)
37 Left fill (other fill)
38 Right meat cutting part (one side meat cutting part)
39 Left meat shaving part (other side meat shaving part)
40,59 Longitudinal rib 47 Left chamber (one side chamber)
48 Right room (other room)
49 Front left boss (front one boss)
51 Front right boss (front other boss)
52 Rear right boss (rear one boss)
54 Rear left boss (rear other boss)
55 Left fill (one side fill)
56 Right fill (other fill)
57 Left meat shaving part (one side shaving part)
58 Right meat cutting part (other side meat cutting part)
61 Right arc part (one side arc part)
62 Left arc part (other side arc part)

Claims (3)

A number of track links are sequentially connected in the forward and backward directions and are wound between the drive wheel and idler wheel of the vehicle body.
The track link has a three-dimensional shape extending in the left and right directions, the outer peripheral side is a ground contact surface that contacts the ground, and the inner peripheral side is a guide surface that is guided by the drive wheel or idler wheel, and casting sand for casting in the left and right directions. A link base provided with a through hole for removing
First and second reinforcing ribs having one hollow hole located in the through hole and spaced apart in the left and right directions of the link base and forming a part of the through hole;
A central chamber formed between the first and second reinforcing ribs and forming a part of the through hole;
A one-side chamber that is formed from the first reinforcing rib toward one side end surface of the link base in the left and right directions and forms a part of the through-hole and has an open end surface;
The other side chamber that is formed from the second reinforcing rib toward the other side end surface of the link base in the left and right directions, forms a part of the through hole, and has an end surface opened;
A front one-side boss formed on a front outer periphery of the link base at a position facing the first reinforcing rib and offset from the one-side chamber;
A front intermediate boss formed on a front outer periphery of the link base at a position facing the second reinforcing rib and offset from the central chamber;
A front other side boss located on the outer periphery side of the other side chamber and formed on the front side outer periphery of the link base;
A rear other side boss formed on a rear outer periphery of the link base at a position facing the second reinforcing rib and offset to the other side chamber;
A rear intermediate boss formed on the rear outer periphery of the link base at a position facing the first reinforcing rib and offset from the central chamber;
In the crawler belt formed by a rear one-side boss formed on the rear outer periphery of the link base located on the outer peripheral side of the one-side chamber,
A one-side built-up portion formed by thickly casting a corner portion where a portion of the inner peripheral surface of the one-side chamber facing the front one-side boss and the first reinforcing rib intersect with each other; ,
The other-side built-up portion formed by thickly casting the corner portion where the second reinforcing rib intersects with the portion facing the rear other-side boss in the inner peripheral surface of the other-side chamber; Provided,
A one-side arc portion formed in an arc shape at a corner portion where the portion facing the rear intermediate boss and the first reinforcing rib of the inner peripheral surface of the central chamber intersect;
Provided with the other side arc portion formed in an arc shape at a corner corner where the second reinforcing rib intersects with a portion facing the front intermediate boss in the inner peripheral surface of the central chamber,
The one-side built-up portion and the one-side arcuate portion are configured to face each other diagonally across the first reinforcing rib,
The crawler belt characterized in that the other-side built-up portion and the other-side arcuate portion are configured to face each other with the second reinforcing rib interposed therebetween.   The one-side arc portion is a one-side cut-off portion formed by thin-cutting the corner portion where the inner peripheral surface of the central chamber and the first reinforcing rib intersect so as to be thin, The other-side arc portion is an other-side cut-off portion formed by thin-cutting the corner portion where the inner peripheral surface of the central chamber and the second reinforcing rib intersect so as to be thin. The crawler belt according to 1.   The inner circumferential surface of the central chamber is provided with a vertical rib that extends in the left and right directions and connects the first reinforcing rib and the second reinforcing rib in the left and right directions. The crawler belt according to 1 or 2.

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