Telescopic truck frame for construction machinery

Abstract

To provide an extensible truck frame capable of preventing the phenomenon that sediment accumulated on a guide member enters a slide face to a guide cylinder.SOLUTION: A pair of side frames 16 comprising a crawler 3 are arranged at left / right both sides of a center frame 15 to which an upper structure 5 is connected. Guide members 18 provided at a front and a rear of each side frame 16 are internally fitted into a guide cylinder 17 provided at a front and a rear of the center frame 15 from left and right so as to be slidable. An upper side slide member 19a is made to protrude from an opening of each guide cylinder 17 to outside, and a scratch plate 25 is arranged on its upper face 19a1. A retainer member 27 is arranged at an upper position of the scratch plate 25, and a cylindrical portion 27e extending downward is made to be in contact with the upper face 19a1 of the slide member 19a via a through hole 25b of the scratch plate 25 to be fastened with a bolt 28. A compression spring 29 is interposed between the retainer member 27 and the scratch plate 25, and energized to the slide member 19a side.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a telescoping track frame for a construction machine. [Background technology]

[0002] This type of construction machinery, such as a demolition machine used to demolish buildings, is configured by connecting a rotating upper body to a lower traveling body equipped with a pair of left and right crawlers for traveling, and attaching a front work unit consisting of a boom, arm, crusher, etc. to the front of the rotating upper body. Since the center of gravity of the vehicle changes significantly depending on the position of the front work unit during operation, it is desirable to increase the spacing between the left and right crawlers to maintain vehicle stability. However, increasing the spacing between the crawlers increases the area occupied by the demolition machine in a plan view, which creates another problem: a large space is required for transporting the demolition machine.

[0003] As a solution to these conflicting demands, for example, Patent Document 1 proposes a demolition machine equipped with a telescopic track frame. The lower traveling body of the demolition machine consists of a center frame to which an upper rotating body is rotatably connected, and a pair of left and right side frames arranged on the left and right of the center frame, each equipped with a crawler. A pair of front and rear guide tubes extending left and right is provided on the center frame, and a pair of front and rear guide members is provided on the left and right side frames extending toward the center frame. Each guide member is slidably fitted into the guide tube of the center frame from the left and right, thereby forming a track frame. A telescopic cylinder is provided inside each guide tube of the center frame, and depending on the operating direction, the left and right guide members slide within the guide tube, causing the track frame to extend or retract, thereby expanding or contracting the distance between the left and right crawlers and, ultimately, the overall width of the vehicle. Therefore, the track frame can be retracted to reduce space during transportation, and extended to stabilize the vehicle during operation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-219444 Summary of the Invention [Problem to be solved by the invention]

[0005] However, this type of construction machine operates at construction sites where dust is scattered due to the crawler kicking up earth and sand, and therefore the telescopic track frame described in Patent Document 1 has the following problems.

[0006] The weight of the upper rotating body and front work unit is supported by the left and right side frames via guide members fitted inside the guide tubes of the center frame, and the top surfaces of the guide members have a certain area to support this weight. During work, the construction machine extends its track frame, and each guide member protrudes from the guide tube, exposing its top surface. This causes dust and sand to gradually accumulate as sediment. When work is completed and the construction machine is transported, the track frame is retracted, and at this time, the sediment on the top surfaces of each guide member enters the sliding surfaces with the guide tubes. Although grease is applied to the sliding surfaces, mixing with the sediment makes smooth sliding difficult, accelerating wear on the sliding surfaces and ultimately reducing durability.

[0007] The present invention has been made to solve these problems, and its purpose is to provide a telescopic track frame for construction machinery that can prevent soil and sand accumulated on the upper surface of the guide member from entering the sliding surface with the guide tube, thereby suppressing wear on the sliding surface caused by soil and sand and improving durability. [Means for solving the problem]

[0008] In order to achieve the above object, the telescopic track frame for construction machinery of the present invention comprises a center frame to which an upper rotating body having a work front is rotatably connected, and a pair of left and right side frames disposed on the left and right of the center frame and each having a crawler for traveling, the center frame being disposed between the pair of left and right side frames, the guide members provided at the front and rear of each side frame being slidably fitted from the left and right into guide tubes extending left and right at the front and rear of the center frame, and the guide members can be extended and retracted in response to sliding within each guide tube. a sliding member disposed on an inner upper surface of the guide tube to guide the sliding of the guide member, one side of the sliding member protruding outward from the opening of the guide tube; A scraping member is disposed near the opening of each guide tube of the center frame, and the tip of each scraping member is brought into contact with the upper surface of each guide member of the left and right side frames. The scraping member is fixed to the upper surface of the protruding portion of the sliding member, and is bent downward so that the tip thereof abuts against the upper surface of the guide member. It is characterized by: [Effects of the Invention]

[0009] The telescopic track frame for construction machinery of the present invention can prevent soil and sand accumulated on the upper surface of the guide member from entering the sliding surface with the guide tube, thereby suppressing wear on the sliding surface caused by soil and sand and improving durability. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a side view showing a demolition machine to which an embodiment of a telescopic track frame is applied. FIG. [Figure 2] FIG. [Figure 3] 3 is a cross-sectional view taken along line III-III in FIG. 2, illustrating the relationship between the guide tube and the guide member at the front left part of the lower traveling body, and the arrangement of the telescopic cylinder. [Figure 4] 3 is a detailed view of part A in FIG. 2 showing the arrangement of scraping units on the guide member. FIG. [Figure 5] FIG. 5 is an exploded perspective view corresponding to FIG. 4. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. 4, illustrating the structure for fixing the scraping unit to the sliding member. [Figure 7]FIG. 7 is a cross-sectional view corresponding to FIG. 6, illustrating the operation when the truck frame is jacked up and contracted. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present invention, in which the telescopic track frame of a demolition machine is embodied, will be described below. Figure 1 is a side view of a demolition machine to which the telescopic track frame of the embodiment is applied, and Figure 2 is a perspective view of the lower traveling body. In the following description, the front-rear, left-right, and up-down directions will be defined based on the operator aboard the demolition machine.

[0012] A pair of left and right crawlers 3 are provided on a lower traveling body 2 of a demolition machine 1 (hereinafter sometimes referred to as a vehicle), and these crawlers 3 are driven by a traveling hydraulic motor (not shown) to travel the lower traveling body 2. An upper rotating body 5 is connected to a slewing device 4 provided on the lower traveling body 2, and the upper rotating body 5 is driven by a slewing hydraulic motor (not shown) provided on the slewing device 4 to rotate.

[0013] An articulated front work unit 6 is provided on the front right side of the upper rotating body 5, and the front work unit 6 is made up of a boom 7, a middle arm 8, an arm 9, and a crusher 10 as an attachment. The angle of the boom 7 is changed by a boom cylinder 7a, the angle of the middle arm 8 is changed by a middle arm cylinder 8a, the angle of the arm 9 is changed by an arm cylinder 9a, and the angle of the crusher 10 is changed by an attachment cylinder 10a.

[0014] A cab 11 is provided on the front left side of the upper rotating body 5, and a machine room 12 is provided behind the cab 11. Although not shown, the machine room 12 is equipped with an engine, hydraulic pump, and control valve that constitute a hydraulic power unit, and the engine drives the hydraulic pump, supplying the discharged hydraulic oil to the control valve. The control valve switches the flow path of the hydraulic oil in response to the operation of the operator in the cab 11, and the hydraulic oil is supplied to the traveling and swing hydraulic motors or the cylinders 7a to 10a of the front work unit 6. This allows the operator to freely control the traveling of the demolition machine 1, the swing of the upper rotating body 5, the operation of the front work unit 6, etc.

[0015] Next, we will explain the configuration of the telescopic track frame 14 provided on the lower traveling body 2. Figure 3 is a cross-sectional view taken along line III-III in Figure 2, showing the relationship between the guide tube and guide member at the left front part of the lower traveling body 2 and the arrangement of the telescopic cylinder. Although not shown, the left rear part has the same configuration, and the right front and right rear parts have the same symmetrical configuration.

[0016] The lower traveling body 2 comprises a center frame 15 to which the upper rotating body 5 is connected, and a pair of left and right side frames 16 disposed on the left and right of the center frame 15 and each equipped with a crawler 3, with an extendable track frame 14 provided between them. Guide tubes 17 with a rectangular cross section that extend in the left-right direction are formed at the front and rear of the center frame 15. Each guide tube 17 is partitioned at the center in the left-right direction, and a total of four independent guide tubes 17 open on both the left and right side surfaces of the center frame 15.

[0017] The crawlers 3 are supported around the left and right side frames 16 by sprockets and rollers (not shown). Square cylindrical guide members 18 extending in the left-right direction are connected to the front and rear of the left and right side frames 16. Each guide member 18 extends toward the center frame 15, in other words, on the inside in the vehicle width direction, and is fitted slidably from the left and right within a guide tube 17 of the center frame 15. Sliding members 19a, 19b are attached to the upper and lower surfaces of the guide tube 17 to guide the sliding of each guide member 18.

[0018] To ensure smooth sliding, a predetermined clearance is secured between the guide member 18 and the sliding members 19a, 19b. Therefore, under normal circumstances (other than when jacking up, which will be described later), the lower sliding members 19b are spaced apart from the lower surface of the guide member 18. The upper sliding members 19a abut against the upper surfaces 18a of the guide members 18, and the weight of the front work unit 6, the upper revolving body 5, and the center frame 15 are all supported by the upper surfaces 18a of the guide members 18.

[0019] A telescopic cylinder 20 is disposed within each guide tube 17 of the center frame 15, and its rod 20a faces the side frame 16, in other words, faces outward in the vehicle width direction, and is connected to a bracket 21 provided at the back through the corresponding guide member 18. When the rod 20a of the telescopic cylinder 20 protrudes, the guide member 18 slides outward in the vehicle width direction within the guide tube 17, thereby extending the telescopic track frame 14, increasing the distance L (total width / 2) from the center of rotation C of the upper rotating body 5 to the outer end of the crawler 3, and thus the overall width of the vehicle. When the rod 20a of the telescopic cylinder 20 retracts, the guide member 18 slides inward in the vehicle width direction within the guide tube 17, causing the telescopic track frame 14 to contract, thereby reducing the distance L from the center of rotation C to the outer end of the crawler 3, and thus the overall width of the vehicle.

[0020] Although not shown, the hydraulic hoses connected to each telescopic cylinder 20 are connected to the hydraulic power unit of the upper rotating body 5 via communication holes 15a opened on the front surface of the center frame 15, and the telescopic track frame 14 is extended or retracted as described above in response to operator operation. Because the hydraulic circuits driving the left and right telescopic cylinders 20 are independent, the operator can operate either the left or right telescopic cylinder 20 at their discretion to individually extend or reduce the distance L of the crawler 3 on that side. This configuration is necessary because the vehicle 1 needs to be jacked up when extending or reducing the overall width.

[0021] In other words, if the overall width is expanded or contracted without jacking up, a large load due to friction between the ground and the crawler 3 acts on the telescopic cylinder 20, preventing smooth operation. Therefore, for example, when expanding or contracting the distance L related to the left crawler 3, the crusher 10 of the front work unit 6 is placed on the ground on the left side of the vehicle, the vehicle is jacked up, the left crawler 3 is moved away from the ground, and the left telescopic cylinder 20 is then operated in the desired direction. The same procedure is then carried out on the right side, thereby eliminating the effect of friction with the ground and enabling smooth expansion or contraction of the overall width of the vehicle. Since it is impossible to jack up both the left and right sides simultaneously, a configuration is adopted in which the left and right telescopic cylinders 20 can be operated independently.

[0022] Incidentally, the demolition machine described in Patent Document 1 has a problem in that soil and sand accumulates on the upper surface 18a of the guide member 18 during work with the telescopic track frame 14 extended, and when the track frame 14 is then retracted during transportation, the soil and sand on the upper surface 18a of the guide member 18 enters the sliding surface with the guide tube 17. Therefore, in this embodiment, a measure is taken to prevent soil and sand from entering the sliding surface by using a scraping unit 23, the details of which are described below. Fig. 4 is a detailed view of part A in Fig. 2 showing the arrangement of scraping unit 23 on guide member 18, Fig. 5 is an exploded perspective view of the same, and Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 4. Based on these drawings, the scraping unit 23 at the front left side will be described as a representative example.

[0023] In simple terms, the scraping unit 23 is disposed on one side of the upper sliding member 19a that protrudes outward from the opening of the guide tube 17. More specifically, the upper sliding member 19a, which is provided on the inner upper surface of the guide tube 17, protrudes outward leftward from the opening of the guide tube 17, and a pair of screw holes 24 are formed at a predetermined distance in the front and rear on an upper surface 19a1 of the protruding portion of the sliding member 19a (hereinafter, this portion may be referred to as the sliding member 19a). A main body 25a of a scraping plate 25 (corresponding to the scraping member of the present invention) formed by bending a metal plate is placed on the upper surface 19a1 of the sliding member 19a, and the front-rear width of the main body 25a is set slightly larger than the front-rear width of the sliding member 19a and, therefore, the front-rear width of the guide member 18.

[0024] The main body 25a is provided with a pair of front and rear through-holes 25b corresponding to the screw holes 24 of the sliding member 19a. A pair of front and rear annular partition walls 25c, each of which has a predetermined height and is centered around the through-hole 25b, are welded to the top surface of the main body 25a. A sloped section 25d extends diagonally downward to the left from the left end of the main body 25a, maintaining the same front-to-rear width. This sloped section 25d is formed by bending a metal plate downward at an obtuse angle, starting from the left end of the main body 25a. A small, rounded bend 25e is spaced slightly to the left from the left end of the sliding member 19a. Reinforcing plates 26 are welded to both the front and rear of the scraping plate 25, maintaining the desired obtuse angle between the main body 25a and the sloped section 25d.

[0025] A retainer member 27 is disposed above the scraper plate 25, and a main body 27a (corresponding to the upper partition surface of the present invention) of the retainer member 27 is a flat metal plate that covers a pair of annular front and rear partition surfaces 25c on the scraper plate 25 from above. The left side of the main body 27a is bent downward at a right angle to form a side partition surface 27b, and metal plates are welded to both the front and rear of the retainer member 27 to form front and rear partition surfaces 27c. These side partition surfaces 27b and front and rear partition surfaces 27c cover a space S below the retainer member 27 (a space in which a compression spring 29, described below, is disposed).

[0026] A pair of front and rear bolt holes 27d are formed through the main body 27a corresponding to the screw holes 24, and a pair of front and rear cylindrical portions 27e are welded to the underside of the main body 27a corresponding to each bolt hole 27d. Each cylindrical portion 27e extends downward, and its lower end abuts against the upper surface 19a1 of the sliding member 19a through the through hole 25b of the scraper plate 25. While maintaining this positional relationship between the sliding member 19a and the retainer member 27, bolts 28 (corresponding to fastening members of the present invention) are inserted from above into the cylindrical portions 27e through each bolt hole 27d of the retainer member 27 and screwed into the screw holes 24 of the sliding member 19a.

[0027] As a result, the retainer member 27 is fastened to the sliding member 19a by a pair of front and rear bolts 28, and the position of the scraper plate 25 is also restricted by the bolts 28 via a pair of front and rear through-holes 25b, resulting in each being maintained in the posture shown in plan view in Fig. 4. A helical compression spring 29 is disposed within the space S so as to surround the periphery of each cylindrical portion 27e, and each compression spring 29 is interposed between the lower surface of the main body 27a of the retainer member 27 and the upper surface of the main body 25a of the scraper plate 25. Because the separation of the retainer member 27 from the sliding member 19a is restricted by the bolts 28, the scraper plate 25 is consequently biased toward the sliding member 19a by each compression spring 29.

[0028] The scraping unit 23 is configured as described above. When the scraping unit 23 is removed from the guide tube 17 together with the sliding member 19a, the main body 25a of the scraping plate 25 overlaps the upper surface 19a1 of the sliding member 19a due to the biasing force of the compression spring 29 as shown by the two-dot chain line in Figure 6, and the tip 25f of the inclined portion 25d protrudes downward from the lower surface of the sliding member 19a.

[0029] 6, when the sliding member 19a is attached inside the guide tube 17 and the scraping unit 23 is disposed in the normal position on the upper surface 19a1 of the sliding member 19a, the tip 25f of the inclined portion 25d of the scraping plate 25 abuts against the upper surface 18a of the guide member 18. At this time, the main body 25a of the scraping plate 25 is separated from the upper surface 19a1 of the sliding member 19a against the biasing force of the compression spring 29. The scraping unit 23 in the left front portion has the same configuration as the scraping unit 23 in the left rear portion, and the right front and right rear portions have the same configuration and are symmetrical, so duplicated explanations will be omitted.

[0030] Next, a case where the telescopic truck frame 14 configured as above is contracted in a state where earth and sand W has accumulated on the upper surface 18a of the guide member 18 will be described. For example, when shortening the distance L for the left crawler 3, the vehicle is jacked up to move the left crawler 3 away from the ground. At this time, the left side frame 16 is suspended from the center frame 15, and the weight of the side frame 16 is supported by the lower surface of the guide member 18. As shown in FIG. 7 , the upper surface 18a of the guide member 18 is inevitably separated from the lower surface of the sliding member 19a, forming a clearance therebetween, making it easier for soil and sand W to enter compared to normal times when the vehicle is not jacked up. However, the scraping plate 25 is displaced downward by the biasing force of the compression spring 29 in response to the lower displacement of the upper surface 18a of the guide member 18, so that the tip 25f of the inclined portion 25d remains in contact with the upper surface 18a of the guide member 18.

[0031] When the rod 20a of the telescopic cylinder 20 retracts and the guide member 18 slides rightward, or inward in the vehicle width direction, within the guide tube 17, causing the truck frame 14 to retract. The tip 25f of the inclined portion 25d of the scraper plate 25 slides leftward relative to the upper surface 18a of the guide member 18. Because grease is applied to the upper surface 18a of the guide member 18 to ensure smooth sliding, soil W may adhere to the upper surface 18a mixed with the grease. However, the tip 25f of the scraper plate 25, made of a metal plate, scrapes the soil W thoroughly and holds it as a mass against the upper surface 18a of the guide member 18. As a result, soil W is prevented from penetrating the sliding surface between the guide member 18 and the sliding member 19a. Therefore, the sliding surface is well lubricated by the grease, which does not contain soil W. This reduces wear on the sliding surface and improves durability. The above-described scraping action of the soil and sand W is exerted not only by the left front scraping unit 23 but also by the left rear, right front and right rear scraping units 23 in the same manner.

[0032] Furthermore, suppressing wear on the sliding surface in this way also leads to improved maintainability of the demolition machine 1. That is, the sliding member 19a that functions as the sliding surface is made of a material that wears more easily than the guide member 18, and is replaced with a new one when it reaches a predetermined amount of wear. This is because suppressing wear on the sliding member 19a means that replacement is not required for a long period of time, which extends the interval between replacement operations and improves maintainability.

[0033] Furthermore, when scraping away soil and sand W from the upper surface 18a of the guide member 18, for example, the left scraping plate 25 receives a frictional force to the right as it slides against the upper surface 18a. If the inclined portion 25d is bent at a right angle to the main body 25a as shown by the two-dot chain line in Figure 7, in other words, if the bent point 25e and the tip 25f of the inclined portion 25d are substantially aligned in the left-right direction, the frictional force will cause the inclined portion 25d to bend in the direction of arrow A, separating the tip 25f from the upper surface 18a and allowing soil and sand W to enter the sliding surface through the gap.

[0034] In this embodiment, since the inclined portion 25d is bent downward at an obtuse angle from the left end of the main body portion 25a, the tip 25f of the inclined portion 25d is located to the left of the downward bend point 25e, in other words, on the outer side in the vehicle width direction. Therefore, when a frictional force acts in the direction of arrow B in Figure 7, the tip 25f of the inclined portion 25d is pressed against the upper surface 18a of the guide member 18, preventing the inclined portion 25d from bending. Therefore, the abutment between the tip 25f of the inclined portion 25d and the upper surface 18a of the guide member 18 is maintained, which provides the advantage of more reliably preventing the intrusion of soil and sand W.

[0035] In addition, while the demolition machine 1 is in operation, sand and dust scattered around the surrounding area accumulates not only on the upper surface 18a of the guide member 18 but also in various places, including on the compression spring 29, which is a movable part of the scraping unit 23. Also, some of the soil and sand W scraped off by the scraping plate 25 may not remain on the upper surface 18a of the guide member 18 but may fly in the direction of the compression spring 29 and accumulate there. If soil and sand W gets stuck between the wires of the helical compression spring 29, its expansion and contraction is hindered, and it is no longer able to perform its intended biasing function for the scraping plate 25.

[0036] In this embodiment, as shown in Figures 4 and 6, the compression spring 29 is disposed in the space S below the retainer member 27. The compression spring 29 is covered from above by the main body 27a of the retainer member 27, from the left side (i.e., the outer side in the vehicle width direction) by the side section screen 27b, and from the front and rear by the front and rear section screens 27c. Therefore, it is possible to prevent soil W from entering the space S. Even if soil W does enter the space S, the annular section screen 25c surrounding the compression spring 29 blocks the soil W and prevents contact between the soil W and the compression spring 29. As a result, adverse effects of the soil W on the compression spring 29 can be prevented, and the compression spring 29 biases the scraper plate 25 under any circumstances, which also significantly contributes to preventing the soil W from entering the sliding surface.

[0037] In addition, the effect of the compression spring 29 is achieved without adding any additional components. That is, the scraper plate 25 is provided with an annular partition surface 25c, the main body 27a of the retainer member 27 functions as an upper partition surface, and the retainer member 27 is provided with side partition surfaces 27b and front and rear partition surfaces 27c. Therefore, the telescopic truck frame 14 of this embodiment can be implemented at low cost without increasing the number of parts constituting the scraper unit 23.

[0038] On the other hand, in this embodiment, the upper sliding member 19a, which is normally disposed only inside the guide tube 17 of the center frame 15, is protruded to the outside through the opening of the guide tube 17 and is used to dispose of the scraping unit 23. In other words, in order for the scraping unit 23 to function, it needs to be supported from the center frame 15, and for this purpose, some kind of base member to support the scraping unit 23 needs to be provided on the center frame 15. Using the existing sliding member 19a eliminates the need to add a base member, etc., which also contributes greatly to cost reduction. However, the present invention is not limited to this configuration. For example, a base member may be provided on the center frame 15 as described above to support the scraping unit 23.

[0039] Although the description of the embodiment has been completed above, the aspects of the present invention are not limited to this embodiment. For example, in the above embodiment, the telescopic track frame 14 of the demolition machine 1 is embodied, but the type of construction machine is not limited to this, and the present invention may be applied to, for example, a hydraulic excavator.

[0040] In the above embodiment, the retainer member 27 is fastened to the upper surface 19a1 of the sliding member 19a, and the compression spring 29 is interposed between the retainer member 27 and the scraper plate 25 to bias the scraper plate 25, but this configuration is not limited to this. For example, the compression spring 29 may be omitted, and the elasticity of the scraper plate 25 may be used to bring the tip 25f into contact with the upper surface 18a of the guide member 18. In this case, the scraper plate 25 itself will function as the biasing member of the present invention, and such an embodiment is also included in the present invention. [Explanation of symbols]

[0041] 1 Demolition machine (construction machinery) 3. Crawler 5 Upper rotating body 6 Working Front 14 Telescopic Track Frame 15 Center frame 16 Side frame 17 Guide tube 18 Guide member 18a Top side 19a Sliding member 19a1 Top surface 25 scraping plate (scraping member) 25b Through hole 25c Circular area screen 25e Bending point 25f tip 27 Retainer member 27a Main body (upper section screen) 27b Side section screen 27e Cylindrical part (cylindrical part) 28 Bolts (fastening members) 29 Compression spring (biasing member)

Claims

1. A telescopic track frame for a construction machine comprising: a center frame to which an upper rotating body having a work front is rotatably connected; and a pair of left and right side frames disposed on the left and right of the center frame, each having a crawler for traveling, wherein guide members provided at the front and rear of each side frame are slidably fitted from the left and right into guide tubes extending left and right provided at the front and rear of the center frame, and the guide members can be extended and retracted in response to sliding within each guide tube, a sliding member disposed on an inner upper surface of the guide tube to guide the sliding of the guide member; one side of the sliding member protruding outward from the opening of the guide tube; a scraping member is disposed near the opening of each guide tube of the center frame, and a tip of each scraping member is brought into contact with an upper surface of each guide member of the left and right side frames; The scraping member is fixed to the upper surface of the sliding member at a protruding portion thereof, and is bent downward so that its tip abuts against the upper surface of the guide member.

1. A telescopic track frame for construction machinery.

2. The scraping member is biased toward the upper surface of the guide member by a biasing member.

2. The telescopic track frame for a construction machine according to claim 1.

3. a retainer member having a cylindrical portion extending downward from the lower surface of the main body portion, the retainer member being disposed in a position in which the lower end of the cylindrical portion abuts against the upper surface of the sliding member through a through hole formed in the scraping member; a fastening member that is inserted into the cylindrical portion of the retainer member and fastens the retainer member to the upper surface of the sliding member; a compression spring disposed so as to surround the cylindrical portion of the retainer member, and elastically interposed between the lower surface of the main body portion and the upper surface of the scraping member, for biasing the scraping member toward the sliding member; 2. The telescopic track frame for a construction machine according to claim 1, further comprising:

4. The retainer member has at least an upper section covering the compression spring from above and a side section covering the compression spring from the outside in the vehicle width direction.

4. The telescopic track frame for a construction machine according to claim 3.

5. An annular partition wall is provided on the upper surface of the scraping member to surround the compression spring.

5. The telescopic track frame for a construction machine according to claim 3 or 4.

6. The tip of the scraping member is positioned outside the downward bent portion in the vehicle width direction.

6. The telescopic track frame for a construction machine according to claim 1.

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