Excavator

Abstract

To improve the safety.SOLUTION: A shovel in one embodiment of this invention includes an undercarriage including driven wheels, a shock absorber for movably supporting the driven wheels in the longitudinal direction, and a front end for supporting the shaft of the driven wheels, and an upper structure turnably mounted on the undercarriage, the front end having a guide members on both end sides of a truck link connected with a shoe plate constituting a crawler belt of which the tension is maintained by the shock absorber, each of the guide members being bent inside where the truck link exists so as to restrict the movement of the truck link in the cross direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a shovel. [Background technology]

[0002] Conventionally, a shock absorber is housed in the frame of a tracked vehicle (see, for example, Patent Document 1). The shock absorber is connected to a driven wheel. The shock absorber is a device for adjusting the tension of the track, and is configured to increase the distance between the shock absorber and the driven wheel by injecting grease into a volume chamber surrounded by a cylinder tube and a piston rod. The combined structure of the shock absorber and the driven wheel is housed in a receiving section provided at the front end of the frame. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-142822 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for shorter shock absorbers. In this case, in order to maintain performance while shortening the shock absorber, it is necessary to increase the diameter of the shock absorber. Increasing the diameter of the shock absorber also requires changing the shape of the front end portion for storing the shock absorber. The front end portion also functions to guide the shoe plate and other components of the crawler belt. For this reason, it is preferable to realize a shape for the front end portion that can simultaneously perform the functions of storing the shock absorber and guiding the shoe plate and other components.

[0005] In view of the above problems, the object is to provide a technology that allows the shock absorber to be stored by changing the shape of the front end portion, while preventing the crawler belt from coming off the track, thereby improving safety. [Means for solving the problem]

[0006] In order to achieve the above object, an excavator according to one embodiment of the present disclosure is an excavator comprising: a lower running body including a driven wheel, a shock absorber supporting the driven wheel so as to be movable in the front-rear direction, and a front end portion supporting the shaft of the driven wheel; and an upper rotating body rotatably mounted on the lower running body, wherein the front end portion has guide members on both ends of track links connecting shoe plates that constitute crawler belts maintained in a tensioned state by the shock absorber, and each of the guide members is bent inwardly where the track links are located so as to restrict movement of the track links in the left-right direction. a bent portion facing the track link, the lower side of the bent portion extending downward . [Effects of the Invention]

[0007] According to the above-described embodiment, an object is to provide a technique for improving safety. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view showing a shovel (excavator) as an example of a construction machine according to an embodiment. [Figure 2] FIG. 2 is a perspective view of a frame provided on a lower traveling body of the shovel according to the embodiment. [Figure 3] FIG. 3 is a diagram illustrating an example of the configuration of the shock absorber according to the embodiment. [Figure 4] FIG. 4 is a perspective view showing the appearance of the side front according to the embodiment. [Figure 5] FIG. 5 is a front view of the side front FCL according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a shovel 100 according to one embodiment of the present invention will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components in the drawings are denoted by the same reference numerals, and duplicated descriptions will be omitted.

[0010] In the following description, the X-axis, Y-axis, and Z-axis are axes perpendicular to one another. The X-axis corresponds to the longitudinal axis of the shovel 100, with the front of the shovel 100 corresponding to the positive direction of the X-axis and the rear of the shovel 100 corresponding to the negative direction of the X-axis. The Y-axis corresponds to the lateral axis of the shovel 100, with the left side of the shovel 100 corresponding to the positive direction of the Y-axis and the right side of the shovel 100 corresponding to the negative direction of the Y-axis. The Z-axis corresponds to the rotation axis of the shovel 100, with the upper side of the shovel 100 corresponding to the positive direction of the Z-axis and the lower side of the shovel 100 corresponding to the negative direction of the Z-axis. In the example of FIG. 1, the X-axis and Y-axis extend horizontally and the Z-axis extends vertically.

[0011] First, an outline of a shovel 100 will be described with reference to Fig. 1. Fig. 1 is a side view of the shovel 100.

[0012] The excavator 100 is equipped with a crawler-type lower traveling body 1. An upper rotating body 3 is rotatably mounted on the lower traveling body 1 via a rotating mechanism 2. A boom 4 is attached to the upper rotating body 3. An arm 5 is attached to the tip of the boom 4, and a bucket 6 is attached to the tip of the arm 5. The boom 4, arm 5, and bucket 6 together make up an excavation attachment, which is an example of an attachment. The boom 4 is driven by a boom cylinder 7. The arm 5 is driven by an arm cylinder 8. The bucket 6 is driven by a bucket cylinder 9. A power source such as an engine 11 is mounted on the upper rotating body 3. In addition, a cabin 10 is installed on the upper rotating body 3.

[0013] The lower traveling body 1 is mainly composed of a frame 12, a crawler belt 13, carrier rollers 14, track rollers 15, a traveling hydraulic motor 16, driven wheels 17, and the like.

[0014] The frame 12 is a member that forms the framework of the lower traveling body 1. The carrier rollers 14, the track rollers 15, the traveling hydraulic motor 16, and the driven wheels 17 are attached to the frame 12.

[0015] The crawler belt 13 is an endless track (crawler belt) that is rotationally driven by a traveling hydraulic motor 16. The crawler belt 13 is engaged with a drive sprocket (not shown) connected to the rotary shaft of the traveling hydraulic motor 16 and with driven wheels 17.

[0016] The carrier roller 14 is a driven roller arranged on the upper side (+Z side) of the frame 12 between the frame 12 and the crawler belt 13. The track roller 15 is a driven roller arranged on the lower side (-Z side) of the frame 12 between the frame 12 and the crawler belt 13.

[0017] The traveling hydraulic motor 16 is attached to the rear end (-X side end) of the frame 12. The lower traveling body 1 is driven by the traveling hydraulic motor 16.

[0018] The driven wheel 17 is attached to the front end (+X side end) of the frame 12. Therefore, the driven wheel 17 is also called a front idler. The driven wheel 17 is attached to the frame 12 via a shock absorber 50 (see FIG. 2). As a result, the driven wheel 17 is supported by the shock absorber 50 so as to be movable in the front-rear direction (X-axis direction).

[0019] The shock absorber 50 is configured to be able to adjust the tension of the crawler belt 13. In this embodiment, the shock absorber 50 is disposed between the frame 12 and the crawler belt 13 so as to maintain the tension of the crawler belt 13 at an appropriate level. The tension of the crawler belt 13 increases, for example, when a foreign object such as a stone becomes stuck inside the crawler belt 13, i.e., between the frame 12 and the crawler belt 13. This is because the circumferential length of the crawler belt 13 tends to expand. In this case, the excavator 100 can relieve the tension of the crawler belt 13 by moving the driven wheels 17 rearward using the shock absorber 50, thereby preventing the tension of the crawler belt 13 from increasing excessively.

[0020] Furthermore, when the front end of the lower traveling body 1 of the excavator 100 comes into contact with an obstacle such as a rock, the shock absorber 50 moves the driven wheel 17 rearward, thereby mitigating the impact.

[0021] Fig. 2 is a perspective view of frame 12. As shown in Fig. 2, frame 12 has a central frame portion 12C that is connected to turning mechanism 2, a left frame portion 12L that is coupled to the +Y side of central frame portion 12C, and a right frame portion 12R that is coupled to the -Y side of central frame portion 12C.

[0022] Specifically, as shown in FIG. 2, the driven wheels 17 include a left driven wheel 17L and a right driven wheel 17R, and the shock absorber 50 includes a left shock absorber 50L and a right shock absorber 50R. The left driven wheel 17L is attached to the front end of the left frame portion 12L via a left shock absorber 50L, and the right driven wheel 17R is attached to the front end of the right frame portion 12R via a right shock absorber 50R.

[0023] The crawler belt 13 includes a left crawler belt 13L and a right crawler belt 13R, the carrier roller 14 includes a left carrier roller 14L and a right carrier roller 14R, the track roller 15 includes a left track roller 15L and a right track roller 15R, and the traveling hydraulic motor 16 includes a left traveling hydraulic motor 16L and a right traveling hydraulic motor 16R. Note that the right crawler belt 13R, right carrier roller 14R, right track roller 15R, and right traveling hydraulic motor 16R are not visible in FIG. 1.

[0024] 1, when the traveling hydraulic motor 16 rotates counterclockwise, the crawler belt 13 also rotates counterclockwise, and the excavator 100 moves forward. Conversely, when the traveling hydraulic motor 16 rotates clockwise, the crawler belt 13 also rotates clockwise, and the excavator 100 moves backward.

[0025] Next, the frame 12 will be described in detail with reference to Figure 2. The following description relates to the left frame portion 12L, but also applies to the right frame portion 12R.

[0026] The left frame portion 12L is provided with a front step FST and a rear step RST. The front step FST and the rear step RST are typically used as footholds when an operator gets on and off the cabin 10.

[0027] The left frame portion 12L is provided with a front pedestal FPD and a rear pedestal RPD for mounting the left carrier roller 14L. A front opening FOP is formed on the outer side (+Y side) of the front pedestal FPD, and a rear opening ROP is formed on the outer side (+Y side) of the rear pedestal RPD.

[0028] The front opening FOP is formed outside the front base FPD to prevent soil from accumulating on the upper surface of the left frame portion 12L. In other words, the front opening FOP is formed so that soil that is drawn into the rotating left crawler belt 13L and hits the front left carrier roller 14L falls to the ground without remaining on the upper surface of the left frame portion 12L.

[0029] Similarly, the rear opening ROP is formed outside the rear base RPD to prevent soil and sand from accumulating on the upper surface of the left frame portion 12L. In other words, the rear opening ROP is formed so that soil and sand that is drawn into the rotating left crawler belt 13L and hits the rear left carrier roller 14L falls to the ground without remaining on the upper surface of the left frame portion 12L.

[0030] The top surface of the left frame portion 12L is inclined so that the outer side (+Y side) is lower than the inner side (-Y side) to prevent soil and sand from accumulating. In other words, the left frame portion 12L is configured so that soil and sand on the top surface of the left frame portion 12L slides down to the outside of the left frame portion 12L.

[0031] Furthermore, the left frame portion 12L is provided with a side front cover FCL (an example of a front end portion) at an end portion forward (on the +X side) of the front end wall FEW. The side front cover FCL is welded to the front end wall FEW and is provided with a receiving portion RC.

[0032] The receiving portion RC is formed so as to be able to receive and support the combined structure of the left driven wheel 17L, the yoke 54, the bearing portion SH, and the left shock absorber 50L.

[0033] The yoke 54 is divided into an inner arm portion 58I and an outer arm portion 58O on the +X side. The inner arm portion 58I and the outer arm portion 58O are connected to and support the bearing portion SH. The bearing portion SH is attached to both sides of the left driven wheel 17L so as to support the rotation shaft of the left driven wheel 17L. The bearing portion SH is also referred to as a hub unit.

[0034] The receiving portion RC is configured to receive and support the bearing portions SH attached to both sides of the left driven wheel 17L. In the example shown in Fig. 2, the side front FCL (an example of a front end portion) has a guide rail structure that supports the bearing portions SH so that the bearing portions SH are slidable in the X-axis direction.

[0035] Next, the shock absorber 50 will be described in detail with reference to FIG. 3. FIG. 3 is a diagram showing an example of the configuration of the shock absorber 50. FIG. 3 is a cross-sectional view of the left shock absorber 50L attached to the front end of the left frame portion 12L. FIG. 3 corresponds to a cross-section in the XZ plane including the dashed-dotted line L1 shown in FIG. 2, viewed from the +Y side. However, for clarity, FIG. 3 shows only the left frame portion 12L and the left shock absorber 50L (excluding the piston rod 51) in cross section, and does not show the left carrier roller 14L, left track roller 15L, left driven wheel 17L, piston rod 51, and bearing portion SH in cross section.

[0036] The left shock absorber 50L is mainly composed of a piston rod 51, a cylinder tube 52, a threaded rod 53, a yoke 54, a spring 55, a grooved nut 56, and a spring pin 57. Most of the left shock absorber 50L is housed in the space between the front end wall FEW of the left frame portion 12L and a partition wall PW provided within the left frame portion 12L.

[0037] The piston rod 51, the cylinder tube 52, and the threaded rod 53 are each members that separate a volume chamber VC. The volume chamber VC is a chamber that contains a fluid such as grease. The length of the left shock absorber 50L in the fore-and-aft direction (X-axis direction) is extended by increasing the volume of the volume chamber VC, i.e., by increasing the amount of fluid contained in the volume chamber VC.

[0038] In the example shown in FIG. 3, the volume chamber VC is a cylindrical space defined by the front end face (end face on the +X side) of the piston rod 51, the inner circumferential surface of the cylinder tube 52, and the rear end face (end face on the -X side) of the threaded rod 53.

[0039] The rear end surface (the end surface on the -X side) of the piston rod 51 is configured to come into contact with a partition wall PW provided inside the left frame portion 12L. The piston rod 51 is configured to maintain contact with the partition wall PW even when the volume chamber VC expands due to the inflow of fluid into the volume chamber VC.

[0040] The cylinder tube 52 is configured to be able to slide on the circumferential surface of the piston rod 51 and move forward (in the +X direction) when the volume chamber VC expands due to the inflow of fluid into the volume chamber VC.

[0041] The threaded rod 53 is configured to close the opening on the front side (+X side) of the cylinder tube 52. The threaded rod 53 is configured to be able to move forward (in the +X direction) together with the cylinder tube 52 when the volume chamber VC expands due to fluid flowing into the volume chamber VC.

[0042] The yoke 54 is configured to support the left driven wheel 17L so that the left driven wheel 17L can move backward (in the -X direction). In the example shown in Figures 2 and 3, an inner arm portion 58I and an outer arm portion 58O branching off from the yoke 54 are fixed to a bearing portion SH that supports the rotation shaft of the left driven wheel 17L.

[0043] The spring 55 is configured to generate a repulsive force that pushes the yoke 54 back forward (in the +X direction) when the yoke 54 moves backward (in the -X direction).

[0044] The slotted nut 56 is configured to limit the relative movement of the yoke 54 with respect to the threaded rod 53 in the forward (+X) direction.

[0045] 3, threaded rod 53 is configured to have a male thread on the circumferential surface of its cylindrical front end (the end on the +X side). This cylindrical front end is inserted into a through-hole formed in the rear end surface of yoke 54 and is configured to protrude into a cylindrical space formed inside yoke 54. Grooved nut 56 is screwed onto the front end protruding into this space.

[0046] Spring pin 57 is a member that prevents rotation of grooved nut 56 relative to threaded rod 53. In the example shown in Fig. 3, spring pin 57 passes through a groove formed at the tip of grooved nut 56 and is inserted into a through-hole formed at the front end of threaded rod 53. This through-hole is formed so as to extend in a direction perpendicular to the central axis of the cylindrical front end.

[0047] Next, the grease nipple 51N will be described with reference to Fig. 3. The grease nipple 51N is an example of a fluid injection mechanism for injecting grease, which is an example of a fluid contained in the volume chamber VC.

[0048] A grease supply passage 51T extending parallel to the central axis of the piston rod 51 is formed in the piston rod 51. Therefore, grease injected through a grease nipple 51N from a grease gun or the like (not shown) flows into the chamber VC through the grease nipple 51N and the grease supply passage 51T, expanding the chamber VC in the +X direction and pressing the left driven wheel 17L against the inner surface of the crawler belt 13.

[0049] For example, if an operator inspecting the tension of the crawler belt 13 detects that the amount of slack in the crawler belt 13 exceeds a predetermined value, the operator can adjust the amount of slack to below the predetermined value by injecting additional grease into the volume chamber VC through the grease nipple 51N.

[0050] Next, a support structure SP that supports the left shock absorber 50L inside the left frame portion 12L will be described.

[0051] The support structure SP is a member welded to the inner wall of the left frame portion 12L, and is configured to come into contact with the flange portion 52F of the cylinder tube 52 to support the left shock absorber 50L.

[0052] Specifically, the support structure SP is made up of a pair of metal plates each having a substantially L-shaped cross section. The flange portion 52F of the cylinder tube 52 is configured so that it can slide on the support structure SP when an operator installs the left shock absorber 50L inside the left frame portion 12L.

[0053] As shown in FIG. 3, the partition wall PW is disposed forward (on the +X side) of the front opening FOP formed directly below the front left carrier roller 14L. This arrangement prevents soil and sand carried by the left crawler belt 13L and striking the front left carrier roller 14L from accumulating on the left shock absorber 50L, even if it falls downward through the front opening FOP. In other words, this soil and sand does not accumulate on the left shock absorber 50L, but falls to the ground through the opening formed in the underside of the left frame portion 12L. Therefore, this arrangement prevents soil and sand from accumulating on the left frame portion 12L directly below the front left carrier roller 14L.

[0054] Next, the side front FCL (an example of a front end portion) will be described in detail with reference to Fig. 4 and Fig. 5. Fig. 4 is a perspective view showing the appearance of the side front FCL according to the embodiment. Fig. 5 is a front view of the side front FCL according to the embodiment.

[0055] 5, through holes H1 are formed in the front end wall FEW. The through holes H1 include a through hole H11 in the shock absorber 50, a through hole H12 in the outer arm portion 58O, and a through hole H13 in the inner arm portion 58I.

[0056] That is, the front end wall FEW is formed with a through-hole H11 for the shock absorber 50 to move the shock absorber 50 toward the -X side from the partition wall. A through-hole H12 is also formed for arranging the outer arm portion 58O that connects the bearing portion SH (on the +X side of the front end wall FEW) and the yoke 54 (on the -X side of the front end wall FEW). A through-hole H13 is also formed for passing the inner arm portion 58I that connects the bearing portion SH (on the +X side of the front end wall FEW) and the yoke 54 (on the -X side of the front end wall FEW).

[0057] The side front FCL has bearing guide portions SG1 provided on the inner upper side (+Y side and +Z side) and bearing guide portions SG3 provided on the inner lower side (+Y side and −Z side) based on the receiving portion RC.

[0058] The bearing guide portion SG1 on the inner upper side (upper right side, +Y side and +Z side) is formed, for example, from an L-shaped steel beam and extends in the X-axis direction. The -X side edge of the bearing guide portion SG1 is welded to the front end wall FEW. The +Y side edge of the bearing guide portion SG1 is welded to the inner surface plate ICP, and the +Z side edge is also welded to the inner surface plate ICP. The underside of the bearing guide portion SG1 supports the bearing portion SH. The outer end (-Y side end face) of the bearing guide portion SG1 is located outside (to the -Y side) of the inner end (+Y side end) of the through hole H13 (based on the center of the excavator 100).

[0059] The bearing guide portion SG3 on the inner lower side (lower right side, +Y side, and -Z side) is formed as a rectangular metal plate with a short side in the width (left-right) direction (Y-axis direction) and a long side in the front-rear direction (X-axis direction). The -X side side of the bearing guide portion SG3 is welded to the front end wall FEW, and the +Y side side of the bearing guide portion SG3 is welded to the inner surface plate ICP. In addition, the upper surface of the bearing guide portion SG3 may have a guide rail structure that supports the bearing portion SH so that the bearing portion SH can slide.

[0060] The distance between the lower surface of the bearing guide portion SG1 and the upper surface of the bearing guide portion SG3 is determined according to the length of the bearing portion SH in the Z-axis direction.

[0061] Furthermore, the side front FCL is provided with a bearing guide portion SG2 on the outer upper side (-Y side and +Z side) and a bearing guide portion SG4 on the outer lower side (-Y side and -Z side) based on the receiving portion RC.

[0062] The bearing guide portion SG2 on the outer upper side (upper left side, -Y side and +Z side) is formed, for example, from an L-shaped steel beam and extends in the X-axis direction. The -X side edge of the bearing guide portion SG2 is welded to the front end wall FEW. The -Y side edge of the bearing guide portion SG2 is welded to the outer surface plate OCP, and the +Z side edge is also welded to the outer surface plate OCP. The underside of the bearing guide portion SG2 supports the bearing portion SH. The inner end (end face on the +Y side) of the bearing guide portion SG2 is located inside (on the +Y side) the outer end (end face on the -Y side) of the through-hole H12.

[0063] The bearing guide portion SG4 on the outer lower side (lower left side, -Y side, and -Z side) is formed as a rectangular metal plate with a short side in the width direction (Y axis direction) and a long side in the front-rear direction (X axis direction). The -X side side of the bearing guide portion SG4 is welded to the front end wall FEW, and the -Y side side of the bearing guide portion SG4 is welded to the outer surface plate OCP. In addition, the upper surface of the bearing guide portion SG4 may have a guide rail structure that supports the bearing portion SH so that the bearing portion SH can slide.

[0064] The lower ends (-Z side end faces) of bearing guide parts SG1 and SG2 are located lower (in the -Z axis direction) than the upper end (+Z side end face) of through-hole H1. The distance between the lower surface of bearing guide part SG2 and the upper surface of bearing guide part SG4 is determined according to the length of bearing part SH in the Z axis direction.

[0065] An inner (+Y side) front guard FG1 is welded to the underside of bearing guide part SG3, and an outer (-Y side) front guard FG2 is welded to the underside of bearing guide part SG4.

[0066] The inner front guard FG1 (an example of a guide member) and the outer front guard FG2 (an example of a guide member) are metal plates extending in the X-axis and Z-axis directions.

[0067] As described above, the bearing guide portions SG1 to SG4 are arranged to allow the shock absorber 50 to pass through. Therefore, the width of the upper end between the front guards FG1 and FG2 welded to the bearing guide portions SG3 and SG4 corresponds to the diameter of the shock absorber 50.

[0068] On the other hand, the inner front guard FG1 and the outer front guard FG2 need to guide the structure related to the crawler belt 13 so that the crawler belt 13 does not come off.

[0069] The crawler belt 13 has a plurality of shoe plates 13S. Track links 13T are provided on the upper portions of the shoe plates 13S. The track links 13T provided on each shoe plate 13S are connected by link pins 13P. This allows the shoe plates 13S to be formed in an endless state.

[0070] The inner front guard FG1 and outer front guard FG2 of this embodiment are formed on both ends of the track link 13T so that the crawler belt 13 does not come off the track roller 15 or the driven wheel 17 (not shown). Note that the front guards FG1 and FG2 of this embodiment are not normally disposed so as to come into contact with the track link 13T. The front guards FG1 and FG2 are normally not in contact with the track link 13T, and only need to come into contact with the track link 13T and support it so that it does not come off when the track link 13T is unlikely to shift left or right (in the Y-axis direction) and come off.

[0071] In this way, the width between the lower end of the front guard FG1 and the lower end of the outer front guard FG2 is determined according to the length of both ends of the track link 13T and the link pin 13P. Specifically, the distance is determined by adding a gap depending on the embodiment to either the left or right end of the track link 13T or the link pin 13P, whichever is longer.

[0072] In order to set the width of the lower end portion to the above-mentioned distance, each of the front guards FG1 and FG2 is bent inward where both ends of the track link 13T and the link pin 13P are present.

[0073] Specifically, as the front guard FG1 extends downward (in the -Z-axis direction) from its welded upper end, it bends toward the -Y side at bend C11, bends toward the +Y side at bend C12, and then extends downward again (in the -Z-axis direction). The upper end (end on the +Z side) of the front guard FG1 is located outside (toward the -Y side) the inner end (end on the +Y side) of the through hole H13. The bending angles of bends C11 and C12 may be any angle and are determined to correspond to the distance between both ends of the track link 13T and the link pin 13P.

[0074] As the front guard FG2 extends downward (in the -Z-axis direction) from its welded upper end, it bends toward the +Y side at bend C21, bends toward the -Y side at bend C22, and then extends downward again (in the -Z-axis direction). The upper end (end on the +Z side) of the front guard FG2 is located more inward (toward the +Y side) than the outer end (end on the -Y side) of the through hole H12. The bending angles of bends C21 and C22 may be any angle, and are determined to correspond to the distance between both ends of the track link 13T and the link pin 13P.

[0075] The upper ends (ends on the +Z side) of the front guards FG1 and FG2 are located above (on the +Z side) the lower ends of the through-holes H1. Furthermore, a downward opening prevention member GP2 is provided between the front guards FG1 and FG2.

[0076] The bottom-side opening prevention member GP2 (an example of a first opening prevention member) is provided below the through-hole H1 provided for inserting the shock absorber 50, and supports the front guards FG1 and FG2. The bottom-side opening prevention member GP2 is a metal plate extending in the X-axis direction and the Y-axis direction, and the portion in contact with the front guards FG1 and FG2 is formed longer in the X-axis direction than the portion near the center in the Y-axis direction.

[0077] The +Y side edge of the bottom-side opening prevention member GP2 is welded to the front guard FG1, and the -Y side edge is welded to the front guard FG2. Furthermore, the -X side edge of the bottom-side opening prevention member GP2 is welded to the front end wall FEW. With this configuration, the bottom-side opening prevention member GP2 can support the front guards FG1 and FG2 so that they do not open up.

[0078] The inner surface plate ICP on the right side of the side front FCL is formed to cover one of the side surfaces of the side front FCL. The inner surface plate ICP is formed of an upper surface and a side surface. The corner between the upper surface and the side surface of the inner surface plate ICP has an arbitrary curvature. The −X side edges of the upper surface and side surface of the inner surface plate ICP are welded to the front end wall FEW. The +Z side edge of the bearing guide portion SG1 is welded to the −Z side of the upper surface of the inner surface plate ICP. Furthermore, the +Y side edge of the bearing guide portion SG1 is welded to the −Y side of the side surface of the inner surface plate ICP. Furthermore, the +Y side edge of the bearing guide portion SG3 is welded to the −Y side of the side surface of the inner surface plate ICP, below the position where the bearing guide portion SG1 is welded (in the −Z axis direction). The side surface of the inner surface plate ICP, below the position where the bearing guide portion SG3 is welded, is bent toward the −Y side to support the front guard FG1. The edge of the inner face plate ICP below the bent part on the -Y side (in the -Z axis direction) is welded to the inner surface (+Y side) of the front guard FG2. This allows the inner face plate ICP to support the front guard FG1 so that it does not open inward (+Y side).

[0079] The outer surface plate OCP on the left side of the side front FCL is formed so as to cover the other side surface of the side front FCL. The outer surface plate OCP is formed of an upper surface and a side surface. The corner between the upper surface and the side surface of the outer surface plate OCP has an arbitrary curvature. The −X side edges of the upper surface and side surface of the outer surface plate OCP are welded to the front end wall FEW. The +Z side edge of the bearing guide portion SG2 is welded to the −Z side of the upper surface of the outer surface plate OCP. Furthermore, the −Y side edge of the bearing guide portion SG2 is welded to the +Y side of the side surface of the outer surface plate OCP. Furthermore, the −Y side edge of the bearing guide portion SG4 is welded to the +Y side of the side surface of the outer surface plate OCP, below the position where the bearing guide portion SG2 is welded (in the −Z axis direction). The side surface of the outer surface plate OCP, below the position where the bearing guide portion SG4 is welded, is bent toward the +Y side to support the front guard FG2. The edge of the outer face plate OCP below the bent part on the +Y side (in the -Z axis direction) is welded to the outer surface (-Y side) of the front guard FG2. This enables the outer face plate OCP to support the front guard FG2 so that it does not open outward (to the -Y side).

[0080] The upward opening prevention member GP1 (an example of a second opening prevention member) is provided above the through-hole H1 provided for inserting the shock absorber 50, and supports the outer surface plate OCP and the inner surface plate ICP. The upward opening prevention member GP1 is a metal plate extending in the X-axis direction and the Y-axis direction, and is formed so that the portion in contact with the outer surface plate OCP and the inner surface plate ICP is longer in the X-axis direction than the portion not in contact with the outer surface plate OCP and the inner surface plate ICP.

[0081] The upper-side opening prevention member GP1 is welded to the upper surface of the outer surface plate OCP and the upper surface of the inner surface plate ICP. Furthermore, the -X side edge of the upper-side opening prevention member GP1 is welded to the front end wall FEW. With this configuration, the upper-side opening prevention member GP1 can support the outer surface plate OCP and the inner surface plate ICP so that they do not open up.

[0082] The upper opening prevention member GP1 supports the outer surface plate OCP and the inner surface plate ICP so that they do not open up, and therefore also supports the front guards FG1 and FG2 welded to the outer surface plate OCP and the inner surface plate ICP so that they do not open up.

[0083] In this embodiment, when soil that strikes the front left carrier roller 14L falls downward through the front opening FOP, the length of the shock absorber 50 is shortened so that the soil does not accumulate on the shock absorber 50. In this way, in order to shorten the length of the shock absorber 50 and maintain the performance of the shock absorber 50, the diameter of the shock absorber 50 is made larger than in the conventional case.

[0084] It is desirable that the side front FCL is configured to be able to store the shock absorber 50 and also configured so that the track link 13T does not come off. Therefore, each of the front guards (one example of a guide member) FG1, FG2 provided on the side front FCL is configured to bend inward where the track link 13T is present.

[0085] In other words, in this embodiment, by setting the bending angle of each of the front guards (an example of a guide member) FG1 and FG2 according to the size of the shock absorber 50 to be stored, the shock absorber 50 can be stored regardless of its size.

[0086] By configuring each of the front guards (examples of guide members) FG1 and FG2 to bend inward toward the track link 13T, it is possible to prevent the crawler belt 13 from coming off the track roller 15 or the driven wheel 17. Therefore, it is possible to improve the safety of the excavator according to this embodiment.

[0087] In this manner, in this embodiment, the shape of the front guards (an example of a guide member) FG1, FG2 of the side front FCL makes it possible to store the shock absorber 50 and also prevents the crawler belt 13 from coming off, thereby improving safety.

[0088] Although the embodiments have been described in detail above, the present disclosure is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist described in the claims. [Explanation of symbols]

[0089] 100 Shovel 1 Undercarriage 2. Swivel mechanism 3 Upper rotating body 4. Boom 5 Arm 6 buckets 7 Boom cylinder 8 Arm Cylinder 9 Bucket cylinder 10 Cabins 11 Engine 12 frames 12L left frame 12C central frame 12R Right frame section 13 Crawler Belt 13S shoe plate 13T track link 13P link pin 14 Carrier roller 15 Track roller 16 Hydraulic motor for travel 17 Driven wheels 50 Shock absorber 50L left shock absorber 50R right shock absorber 51 Piston rod 52 Cylinder tube 54 York 55 Spring 58O outer arm 58I Inner arm FCL Side Front FEW front end wall H1 through hole SG1~SG4 Bearing guide section FG1, FG2 front guard ICP inner side plate OCP outer side plate GP1 Upper opening prevention member GP2 Bottom opening prevention member

Claims

1. a lower traveling body including a driven wheel, a shock absorber that supports the driven wheel so as to be movable in the front-rear direction, and a front end portion that supports the shaft of the driven wheel; An excavator comprising: an upper rotating body rotatably mounted on the lower traveling body, The front end portion has guide members on both ends of a track link that connects shoe plates that constitute a crawler belt maintained in a tensioned state by the shock absorber, each of the guide members has a bent portion that bends inward toward the track link so as to restrict movement of the track link in the left-right direction, and a lower side of the bent portion that faces the track link extends downward; Shovel.

2. The width between the guide members is such that the upper end side of the guide members corresponds to the diameter of the shock absorber, and the lower end side of the guide members corresponds to the width of the track link. The shovel according to claim 1.

3. Each of the guide members has a first portion extending further downward, and the bent portion is provided at a position below the first portion extending downward; a first opening prevention member is welded between the downwardly extending first portions of the guide members present on both ends of the track link and below a hole provided in the front end portion for inserting the shock absorber; The shovel according to claim 1 or 2.

4. the front end portion has a face plate that supports the guide member from the outside, The left face plate and the right face plate are connected by a second opening prevention member provided above a hole provided in the front end portion for inserting the shock absorber. The shovel according to any one of claims 1 to 3.

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