JP2022137843A - Crawler unit, lower traveling body, and construction machine - Google Patents

Abstract

To provide a crawler unit having excellent handleability of a crawler weight.SOLUTION: A crawler unit includes a crawler, a crawler frame mounted with the crawler, and a crawler weight arranged on a side surface of the crawler frame. The crawler weight includes a first member horizontally protruding from the side surface of the crawler frame so as to be stored in a position overlapping with the crawler in a plan view and a second member connected to a tip side of the first member to be swingable with respect to the first member. The second member can be held at a first position protruding outward from the crawler in a plan view and a second position overlapping with the crawler in the plan view.SELECTED DRAWING: Figure 3

Description

The present invention relates to crawler units, undercarriages and construction machines.

A construction machine comprising a lower traveling body having a pair of crawler units spaced apart in the vehicle width direction, an upper revolving body rotatably mounted on the lower traveling body, and an attachment attached to the upper revolving body. is widely used.

The crawler unit includes a crawler frame extending in the front-rear direction, a driving roller arranged at one end in the front-rear direction of the crawler frame, and a driven roller arranged at the other end in the front-rear direction of the crawler frame. , a plurality of lower rollers arranged at intervals in the front-rear direction on the lower end side of the crawler frame, a plurality of upper rollers arranged at intervals in the front-rear direction on the upper end side of the crawler frame, a driving roller, and a driven roller , a crawler that spans over the lower roller and the upper roller. A driving mechanism is connected to the driving roller for transmitting a driving force to the driving roller.

This construction machine is configured to perform work in a state in which the upper revolving body is revolved at a desired angle with respect to the lower traveling body. On the other hand, since the drive mechanism includes heavy objects such as a hydraulic motor and a speed reducer, the center of gravity of the lower traveling body is shifted toward the side where the drive mechanism is arranged from the center in the front-rear direction. Therefore, if the construction machine works with the attachment positioned on the side where the drive mechanism is arranged, the weight balance is impaired.

From this point of view, a technique has been proposed to attach a crawler weight for adjusting the center of gravity to the crawler frame so that the center of gravity of the lower traveling body is positioned at the center in the front-rear direction (see Japanese Patent Application Laid-Open No. 2018-70339).

JP 2018-70339 A

The crawler weight described in the above publication has a rectangular parallelepiped shape as a whole. The crawler weights are configured to be detachable from the crawler frame, and by attaching them before work, it is possible to adjust the center-of-gravity position of the undercarriage during work of the construction machine.

However, as a result of intensive studies by the present inventors, it was found that the crawler weight described in the above publication has room for further improvement in terms of handleability at the time of attachment and the like.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a crawler unit which is excellent in handleability of crawler weights.

A crawler unit according to an aspect of the present invention includes a crawler, a crawler frame to which the crawler is mounted, and crawler weights arranged on side surfaces of the crawler frame, and the crawler weights correspond to the crawlers in plan view. a first member that horizontally protrudes from the side surface of the crawler frame so as to fit in a position overlapping with the first member; and the second member is configured to be held at a first position projecting outside the crawler in plan view and a second position overlapping the crawler in plan view.

A crawler unit according to an aspect of the present invention is excellent in handleability of crawler weights.

FIG. 1 is a schematic side view showing a construction machine according to one embodiment of the invention. 2 is a schematic perspective view showing the undercarriage of the construction machine of FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III showing the positional relationship between the crawlers and the crawler weights in a state where the second member of the undercarriage shown in FIG. 2 is held at the first position. 4 is a schematic cross-sectional plan view showing the positional relationship between the crawlers and the crawler weights in a state where the second member of the undercarriage shown in FIG. 2 is held at the first position; FIG. 5 is a cross-sectional view corresponding to FIG. 3 showing the positional relationship between the crawler and the crawler weight in a state where the second member of the crawler weight is held at the second position; FIG. FIG. 6 is a schematic cross-sectional plan view corresponding to FIG. 4 showing the positional relationship between the crawler and the crawler weights in a state where the second member of the crawler weights is held at the second position. FIG. 7 is a cross-sectional view corresponding to FIG. 3 showing the procedure for removing the crawler weights from the crawler frame.

[Description of the embodiment of the present invention]
First, embodiments of the present invention will be listed and described.

A crawler unit according to an aspect of the present invention includes a crawler, a crawler frame to which the crawler is mounted, and crawler weights arranged on side surfaces of the crawler frame, and the crawler weights correspond to the crawlers in plan view. a first member that horizontally protrudes from the side surface of the crawler frame so as to fit in a position overlapping with the first member; and the second member is configured to be held at a first position projecting outside the crawler in plan view and a second position overlapping the crawler in plan view.

In the crawler unit, by swinging the second member, the crawler weights project outward from the crawlers in plan view, and the crawler weights overlap the crawlers in plan view. It can be easily transformed into different states. Therefore, the crawler unit is excellent in handleability of crawler weights.

In a state where the second member is held at the first position, the center of gravity of the crawler weight may be located outside the crawler in plan view. In this way, in a state where the second member is held at the first position, the center of gravity of the crawler weight is located outside the crawler in a plan view, so that the crawler can be lifted when the crawler weight is lifted. is less likely to interfere with lifting work. Moreover, according to this configuration, it is easy to improve the stability of the crawler unit in the vehicle width direction.

Preferably, the second member also serves as a step table for lifting. Since the second member protrudes horizontally outward beyond the edge of the crawler at the first position, it is preferable to provide it so as to function as a step platform for lifting.

Preferably, the first member and the second member are plate-shaped, and the second member is folded over the first member at the second position. Thus, the first member and the second member are plate-shaped, respectively, and the second member is folded over the first member at the second position, so that the second member becomes the first member. The second member can be easily and reliably held at the second position.

It is preferable that the crawler weight is provided so as to be removable from the crawler frame by lifting. Since the crawler weights are detachably provided from the crawler frame by lifting, the crawler weights can be easily attached to and detached from the crawler frame.

An undercarriage according to another aspect of the present invention includes the crawler unit.

Since the undercarriage includes the crawler unit, the crawler weight can be easily handled.

A construction machine according to another aspect of the present invention includes the undercarriage.

Since the construction machine includes the undercarriage, the crawler weight can be easily handled.

In the present invention, the "horizontal direction" means the horizontal direction when the crawler unit is in contact with the horizontal surface. The "side surface of the crawler frame" means an inner surface or an outer surface of the crawler frame in the vehicle width direction. “Protruding outside the crawler in plan view” means protruding to a position where it does not overlap the crawler in plan view. The "vehicle width direction" means the left-right direction with respect to the front-rear direction when the running direction during normal running (during forward movement) is defined as "front" and the opposite direction is defined as "rear".

[Details of the embodiment of the present invention]
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

[Construction machinery]
A construction machine 10 shown in FIG. 1 includes a lower traveling body 1 , an upper revolving body 2 horizontally rotatably mounted on the lower traveling body 1 , and an attachment 3 attached to the upper revolving body 2 . A specific configuration of the attachment 3 is not particularly limited. In FIG. 1, the attachment 3 has a hoisting member 3a that is hoistably attached to the upper revolving body 2, and a hook 3c that is suspended from the tip side of the hoisting member 3a via a hanging rope 3b. In FIG. 1, the construction machine 10 is a crawler crane.

[Lower running body]
As shown in FIG. 2, the undercarriage 1 has a car body 11 and a pair of crawler units 12 arranged on both sides of the car body 11 in the vehicle width direction. The lower traveling body 1 also includes telescopic cylinders 13 for expanding and contracting the crawler unit 12 in the vehicle width direction with respect to the car body 11, and axles arranged in front of and behind the telescopic cylinders 13 for connecting the car body 11 and the crawler unit 12. 14 (FIG. 2 shows a state in which only one crawler unit 12 is contracted). As the telescopic cylinder 13, for example, a hydraulic cylinder can be used. The telescopic cylinder 13 extends in the vehicle width direction. The telescopic cylinder 13 expands and contracts the crawler unit 12 in the vehicle width direction by expanding and contracting in its longitudinal direction. The telescopic cylinder 13 is configured to protrude outward in the vehicle width direction from the center of rotation of the upper rotating body 2 in plan view. The telescopic cylinder 13 is connected to the central portion of the crawler unit 12 in the front-rear direction.

[Crawler unit]
The crawler unit 12 includes a crawler 21 , a crawler frame 22 to which the crawler 21 is attached, and crawler weights 23 arranged on side surfaces of the crawler frame 22 . The crawler unit 12 includes a drive roller 24a arranged at one end of the crawler frame 22 in the front-rear direction, a driven roller 24b arranged at the other end of the crawler frame 22 in the front-rear direction, A plurality of lower rollers 24c arranged at intervals in the front-rear direction on the lower end side of the crawler frame 22, a plurality of upper rollers 24d arranged at intervals in the front-rear direction on the upper end side of the crawler frame 22, and a driving roller. and a drive mechanism 25 for driving 24a. The crawler 21 is stretched around a driving roller 24a, a driven roller 24b, a plurality of lower rollers 24c and a plurality of upper rollers 24d. The crawler 21 is configured by connecting a plurality of crawler shoes in an endless manner. The drive mechanism 25 includes a travel motor and a speed reducer that reduces the rotational force of the travel motor. The drive mechanism 25 is arranged adjacent to or integrated with the drive roller 24a.

(crawler weight)
The crawler weights 23 will be described with reference to FIGS. 3 to 7. FIG. The crawler weight 23 functions as a car body weight for stabilizing the crane operation of the construction machine 10 . The crawler weights 23 can also function as a center-of-gravity adjusting device for adjusting the position of the center of gravity of the crawler unit 12 so that the center of gravity of the crawler unit 12 is positioned at the central portion of the crawler unit 12 in the longitudinal direction. As described above, the crawler unit 12 has the drive mechanism 25 for driving the drive roller 24a. The drive mechanism 25 includes heavy components such as a travel motor and a speed reducer. Therefore, the position of the center of gravity of the crawler unit 12 in the front-rear direction tends to shift toward the drive mechanism 25 with reference to the center in the front-rear direction. When the crawler weights 23 function as the center-of-gravity adjusting device, the crawler weights 23 are arranged with the front-rear center of the crawler unit 12 as a reference so as to return the position of the center of gravity shifted to the drive mechanism 25 side to the front-rear center of the crawler unit 12 . It is arranged on the side opposite to the side where the drive mechanism 25 is arranged.

When the crawler unit 12 functions as the center-of-gravity adjusting device, the crawler weight 23 adjusts the center-of-gravity position to the central portion in the front-rear direction. In other words, if the center of gravity of the crawler unit 12 is away from the central portion in the front-rear direction, it becomes difficult to expand and contract the crawler unit 12 with accuracy in the vehicle width direction when the telescopic cylinder 13 is expanded and contracted. In this case, the crawler frame 22 and the axle 14 interfere with each other, increasing the risk of damage to the crawler frame 22 and the axle 14 . Further, when the center of gravity of the crawler unit 12 is away from the central portion in the front-rear direction, if the telescopic cylinder 13 is connected to a position corresponding to the center of gravity of the crawler unit 12, the crawler unit 12 will protrude greatly forward or backward. As a result, there is a high possibility that the efficiency and safety of the work of the construction machine 10 will be impaired. On the other hand, in the crawler unit 12, the center of gravity is adjusted to the central portion in the front-rear direction by the crawler weight 23, and the telescopic cylinder 13 is connected to the central portion, thereby improving work efficiency and safety. The expansion and contraction by the telescopic cylinder 13 can be performed safely and reliably while ensuring the same.

The crawler weight 23 is a weight having enough weight to adjust the position of the center of gravity of the crawler unit 12 . The weight of the crawler weight 23 depends on the specific configuration of the crawler unit 12, but is, for example, 100 kg or more, and may be 200 kg or more.

The crawler weights 23 horizontally protrude from the side surfaces 22a of the crawler frame 22 at positions overlapping the crawlers 21 in a plan view (in this embodiment, the crawler weights 23 are accommodated inside the outer edges 21a of the crawlers 21 in the vehicle width direction). and a second member 32 connected to the first member 31 so as to be swingable on the distal end side of the first member 31 . The second member 32 is configured to be vertically swingable with respect to the first member 31 . As shown in FIGS. 3 and 4, the second member 32 is a first member protruding outside the crawler 21 in a plan view (outside the edge 21a of the crawler 21 in the vehicle width direction in the present embodiment). It is configured to be able to be held at position P1. At the first position P1, the second member 32 protrudes horizontally. 5 and 6, the second member 32 is configured to be held at a second position P2 overlapping the crawler 21 in plan view. The second member 32 is configured to be swingable between a first position P1 and a second position P2. As shown in FIG. 3, the crawler weight 23 has a fixing member 40 for fixing the second member 32 at the first position P1.

As shown in FIG. 4, the center of gravity G of the crawler weight 23 as a whole is located outside the crawler 21 in a plan view while the second member 32 is held at the first position P1. More specifically, when the second member 32 is held at the first position P1, the center of gravity G of the crawler weight 23 is located on the base end side of the second member 32 (the side connected to the first member 31). ing. In the crawler unit 12, the center of gravity G of the crawler weights 23 as a whole is positioned outside the crawlers 21 in a plan view, so that the crawlers 21 hardly interfere with the lifting operation when the crawler weights 23 are lifted. More specifically, when hoisting the crawler weight 23, it is desirable to hoist the crawler weight 23 by connecting string members such as wire ropes at positions sandwiching the center of gravity G so as to maintain balance during hoisting. On the other hand, if the crawler 21 exists above the center of gravity G, the crawler 21 becomes an obstacle, making it difficult to connect the string member at a desired position. On the other hand, since the center of gravity G of the entire crawler weight 23 is positioned outside the crawler 21 in plan view, the string members can be easily connected at positions sandwiching the center of gravity G. Further, the center of gravity G of the entire crawler weight 23 is located outside the crawler 21 in plan view, so that the stability of the crawler unit 12 in the vehicle width direction can be enhanced.

(First member)
The first member 31 is plate-shaped. More specifically, the first member 31 includes a plate-like and rectangular main body 31a, a connection portion 33 connected to the crawler frame 22, a holding portion 34 that horizontally holds the main body 31a, and a second member. and a first connecting portion 35 connected to 32 .

The connecting portion 33 is arranged on the end surface of the base end side of the main body 31a. The connecting portions 33 are provided on both sides in the width direction (both sides in the front-rear direction) of the main body 31a. A specific configuration of the connecting portion 33 is not particularly limited, but includes, for example, a hook, a ring piece, and the like. The connecting portion 33 connects the main body 31a to the crawler frame 22 in a swingable manner by being engaged with, for example, a shaft member 22b arranged on the side surface 22a of the crawler frame 22 . More specifically, the connecting portion 33 is engaged with a shaft member 22b that extends in the front-rear direction and is separated from the side surface 22a of the crawler frame 22, thereby allowing the main body 31a to swing vertically with respect to the crawler frame 22. Connecting.

The holding portion 34 prevents the main body 31 a from swinging against the side surface 22 a of the crawler frame 22 . The holding portion 34 may be provided integrally with the main body 31a, or may be provided detachably from the main body 31a. The holding portion 34 protrudes from the end face on the base end side of the main body 31a. More specifically, the holding portion 34 protrudes from a position sandwiched between the pair of connecting portions 33 on the proximal end surface of the main body 31a. An end surface of the holding portion 34 on the tip end side in the projecting direction is a contact surface 34 a that contacts the side surface 22 a of the crawler frame 22 . The holding portion 34 prevents the main body 31a from swinging with respect to the crawler frame 22 by making surface contact with the side surface 22a of the crawler frame 22 at the contact surface 34a.

The first connecting portion 35 is arranged on the end face of the main body 31a on the tip side (the side opposite to the side connected to the crawler frame 22). The first connecting portions 35 are provided on both sides in the width direction of the main body 31a. Each first connecting portion 35 has a pair of first brackets 35a arranged in parallel in the width direction of the main body 31a. A pair of first brackets 35a are provided with first through holes 35b arranged coaxially. The central axis of the first through hole 35b is parallel to the width direction of the main body 31a. A shaft member 38 is inserted into the first through hole 35b. Further, the pair of first brackets 35a are provided with first locking holes 35c into which the fixing member 40 is inserted while the second member 32 is arranged at the first position P1.

The first member 31 may be configured to be non-detachable from the crawler frame 22 or may be configured to be detachable. When the first member 31 is detachable from the crawler frame 22 , the weight of the crawler unit 12 can be reduced by removing the crawler weights 23 from the crawler frame 22 . Therefore, by removing the crawler weights 23 from the crawler frame 22, the crawler unit 12 can be easily transported by truck or the like.

When the first member 31 is configured to be detachable from the crawler frame 22, the first member 31 is attached to the crawler frame 22 together with the second member 32 by releasing the engagement between the connection portion 33 and the shaft member 22b. It is preferably configured to be removable. When the connecting portion 33 is the hook described above, the first member 31 is removed from the crawler frame 22 by extracting the hook from the shaft member 22b. When the connecting portion 33 is the hook, it is preferable that the connecting portion 33 has a retaining mechanism for preventing unintended disengagement while connected to the shaft member 22b.

(Second member)
The second member 32 is plate-shaped. More specifically, the second member 32 includes a main body 32a having a plate-like and rectangular shape in a plan view, a second connecting portion 36 connected to the first member 31, and extending outward in the width direction from a side face of the main body 32a. It has a plurality of protruding portions (a pair of first protruding portions 37a protruding from opposing positions on the base end side of the main body 32a and a pair of second protruding portions 37b protruding from opposing positions on the distal end side of the main body 32a). Since the second member 32 of the crawler unit 12 is plate-shaped, the second member 32 can be easily swung with respect to the first member 31 .

The second connecting portion 36 is arranged on the end face on the base end side of the main body 32a. The second connecting portions 36 are provided on both sides in the width direction of the main body 32a. The second connecting portion 36 has a second bracket 36 a arranged between the pair of first brackets 35 a of the first connecting portion 35 . The second bracket 36a has a second through hole (not shown) coaxially arranged with the first through hole 35b provided in the pair of first brackets 35a while being arranged between the pair of first brackets 35a. shown) are provided. The shaft member 38 described above is inserted into the second through hole. Further, the second connecting portion 36 is provided with a second locking hole (not shown) arranged coaxially with the first locking hole 35c when the second member 32 is arranged at the first position P1. It is The first member 31 and the second member 32 are connected to each other by inserting the shaft member 38 into the first through hole 35b and the second through hole. The second member 32 is swingably connected to the first member 31 with the shaft member 38 as the swing center.

The pair of first protrusions 37a are arranged at positions sandwiching the center of gravity G of the entire crawler weight 23 with the second member 32 arranged at the first position P1. The pair of first protruding portions 37a are engaged portions to which a string member such as a wire rope is connected when the crawler weight 23 is removed from the crawler frame 22 by lifting. Although the specific configuration of the first projecting portion 37a is not particularly limited, it may be, for example, a pin projecting outward in the width direction of the main body 32a.

A procedure for removing the crawler weights 23 from the crawler frame 22 by lifting will be described with reference to FIG. 7 . The crawler weight 23 is removed from the crawler frame 22 while the second member 32 is held at the first position P1. When removing the crawler weights 23, first, the string members X are connected to the pair of first projecting portions 37a, respectively. Then, the cord member X is pulled up vertically by an auxiliary crane (not shown) or the like, and the connecting portion 33 is extracted from the shaft member 22b. Subsequently, the string member X is moved outward in the vehicle width direction, and the crawler weight 23 is moved outward of the crawler frame 22 .

A conventional crawler weight has a rectangular parallelepiped shape as a whole and is arranged along the side surface of the crawler frame. Therefore, when removing the conventional crawler weights from the crawler frame, it is necessary to swing the entire crawler weights by about 90 degrees so that the crawler weights protrude outside the crawlers in a plan view. On the other hand, in the crawler unit 12, with the second member 32 held at the first position P1, the center of gravity G of the entire crawler weight 23 is located outside the crawler 21 in plan view. The crawler weight 23 can be easily removed from the crawler frame 22 by lifting. Further, the crawler unit 12 can easily attach the crawler weights 23 to the crawler frame 22 by reversing the removal procedure. When lifting the crawler weights 23, the string members X may be connected at two points on both sides of the crawler weights 23 in the width direction. In this case, it is preferable that the center of gravity of the quadrangle whose vertex is the connecting portion of the string member X coincides with the center of gravity G of the entire crawler weight 23 .

The pair of second projecting portions 37b are engaged portions that are connected to the string member X when the second member 32 swings between the first position P1 and the second position P2. Although the specific configuration of the second projecting portion 37b is not particularly limited, it may be, for example, a pin projecting outward in the width direction of the main body 32a. The second member 32 swings between the first position P1 and the second position P2 by moving the string member X in the vehicle width direction while the string member X is connected to the pair of second protrusions 37b. can move. When the second member 32 swings beyond 90° from the first position P1, it folds toward the first member 31 due to its own weight. At this time, it is sufficient that the string member X supports the second member 32 appropriately. According to the crawler unit 12, since it is not necessary to adjust the position of the second member 32 by controlling the position of the string member X, the second member 32 can be moved between the first position P1 and the second position P2. It is easy to swing.

The second member 32, more specifically the main body 32a of the second member 32, also serves as a step table for lifting. A conventional crawler weight has a rectangular parallelepiped shape as a whole and is arranged along the side surface of the crawler frame. Therefore, the conventional crawler weight is difficult to function as a step board for lifting. On the other hand, in the crawler unit 12, the second member 32 protrudes horizontally outward beyond the edge 21a of the crawler 21 when the crawler unit 12 is located at the first position P1. Therefore, the second member 32 functions favorably as a step table for lifting.

(fixing member)
As shown in FIG. 3, the fixing member 40 fixes the second member 32 at the first position P1. The fixing member 40 is a pin that passes through the first locking hole 35c of the first connecting portion 35 and the second locking hole of the second connecting portion 36 in a state where the second member 32 is arranged at the first position P1. be. The crawler weight 23 can easily fix the second member 32 at the first position P1 by inserting the fixing member 40 into the first locking hole 35c and the second locking hole. Further, the crawler weight 23 can easily swing the second member 32 with respect to the first member 31 by extracting the fixing member 40 from the first locking hole 35c and the second locking hole. The second connecting portion 36 may be provided with a third locking hole that overlaps with the first locking hole 35c when the second member 32 is arranged at the second position P2. According to this configuration, the second member 32 is moved to the second position P2 by inserting the fixing member 40 into the first locking hole 35c and the third locking hole after the second member 32 is swung to the second position P2. It can be fixed at position P2. Further, by inserting the fixing member 40 into the first locking hole 35c and the third locking hole, loss of the fixing member 40 can be suppressed.

As shown in FIGS. 5 and 6, the second member 32 is folded over the first member 31 at the second position P2. More specifically, at the second position P2, the main body 32a of the second member 32 is folded toward the upper surface of the main body 31a of the first member 31. As shown in FIG. By folding the second member 32 onto the first member 31, the crawler unit 12 can easily hold the second member 32 at the second position P2.

<Advantages>
By swinging the second member 32, the crawler unit 12 is arranged such that the crawler weights 23 protrude outward from the crawlers 21 in plan view, and the crawler weights 23 overlap the crawlers 21 in plan view. It can be easily transformed into the state where it is. Therefore, the crawler unit 12 is excellent in handleability of the crawler weights 23 .

Conventional crawler weights are rectangular parallelepiped as a whole and are arranged along the side surface of the crawler frame, so when removing the crawler weights from the crawler frame, first swing the entire crawler weights by about 90 degrees. requires. At this time, if the entire crawler weight is to be swung by being lifted by the string member, the crawler will hinder the swinging of the crawler weight, making it difficult to swing the crawler weight smoothly. On the other hand, when removing the crawler unit 12 from the crawler frame 22, the second member 32 may be held at the first position P1, and both the first member 31 and the second member 32 are swung. does not require Therefore, the crawler unit 12 is excellent in detachability with respect to the crawler frame 22 .

Since the undercarriage 1 includes the crawler unit 12, the crawler weights 23 are excellent in handleability.

Since the construction machine 10 includes the crawler unit 12, the crawler weights 23 are excellent in handleability.

[Other embodiments]
The above embodiments do not limit the configuration of the present invention. Therefore, in the above embodiment, the components of each part of the above embodiment can be omitted, replaced, or added based on the description of the present specification and common general technical knowledge, and all of them are interpreted as belonging to the scope of the present invention. should.

For example, in addition to the first member and the second member, the crawler unit is arranged between the first member and the second member, or another member arranged on the tip side of the second member. may have

The position of the center of gravity of the crawler unit is not particularly limited. Since the crawler unit is divided into the first member and the second member, it is not necessary to swing the first member and the second member at the same time. Therefore, the crawler unit is excellent in handleability even when the position of the center of gravity of the whole is different from the position described in the above embodiment.

The second member may not also serve as a step platform for lifting. Moreover, the specific shapes of the first member and the second member are not limited to the shapes described in the above embodiment. For example, in the above-described embodiment, the configuration in which the first member is horizontally held by the holding portion protruding from the edge on the base end side of the main body of the first member has been described. However, the first member may be configured to be horizontally held using a member similar to the fixing member that fixes the second member at the first position.

The second member may not be folded over the first member in the second position. For example, the second member may be held in a vertically hanging state.

In the crawler weight, for example, the second member may be detachably attached to the first member. Further, even if the crawler weight is provided so as to be detachable from the crawler frame by lifting, the specific configuration of the engaged portion connected to the string member is not particularly limited. The locked portion may be, for example, a hanging hole.

The crawler weight may be arranged on the inner side surface of the crawler frame in the vehicle width direction.

A crawler unit according to an aspect of the present invention is suitable for adjusting the position of the center of gravity.

1 Lower running body 2 Upper rotating body 3 Attachment 3a Rising member 3b Hanging rope 3c Hook 10 Construction machine 11 Car body 12 Crawler unit 13 Telescopic cylinder 14 Axle 21 Crawler 21a Edge 22 Crawler frame 22a Side 22b Shaft member 23 Crawler weight 24a Drive Roller 24b Driven roller 24c Lower roller 24d Upper roller 25 Drive mechanism 31 First member 31a Main body 32 Second member 32a Main body 33 Connecting portion 34 Holding portion 34a Contact surface 35 First connecting portion 35a First bracket 35b First through hole 35c First locking hole 36 Second connecting portion 36a Second bracket 37a First projecting portion 37b Second projecting portion 38 Shaft member 40 Fixing member P1 First position P2 Second position G Center of gravity X String member

Claims (7)

A crawler, a crawler frame on which the crawler is mounted, and a crawler weight arranged on the side of the crawler frame,
The above crawler weight is
a first member that horizontally protrudes from a side surface of the crawler frame so as to fit in a position overlapping the crawler in plan view;
a second member that is pivotably connected to the first member on the distal end side of the first member;
A crawler unit, wherein the second member is configured to be held at a first position where the second member projects outward from the crawler in plan view and a second position where the second member overlaps the crawler in plan view. 2. The crawler unit according to claim 1, wherein the center of gravity of the crawler weight is located outside the crawler in a plan view while the second member is held at the first position. The crawler unit according to claim 1 or 2, wherein the second member also serves as a step platform for lifting. 4. The crawler unit according to claim 1, claim 2, or claim 3, wherein the first member and the second member are plate-shaped, and the second member is folded over the first member at the second position. . The crawler unit according to any one of claims 1 to 4, wherein the crawler weights are provided so as to be removable from the crawler frame by lifting. An undercarriage provided with the crawler unit according to any one of claims 1 to 5. A construction machine comprising the undercarriage according to claim 6 .

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