JP2020165093A - Cutting edge for work machine, blade for work machine and work machine - Google Patents

Abstract

To provide a cutting edge for a work machine which has a good excavation property and can easily improve durability, and to provide a blade for the work machine and the work machine.SOLUTION: A cutting edge 20 includes a mounting part 21 and an abrasion part 22. The mounting part 21 has a first thickness t1 which is the maximum value of the thickness between a first surface 20A and a second surface 20B. A first portion 22a of the abrasion part 22 has a third surface 20C connected to the first surface 20A, and a fourth surface 20D opposing to the third surface 20C, has a second thickness t2 between the third surface 20C and the fourth surface 20D thinner than the first thickness t1, and has a tip 22T positioned on the opposite side from the mounting part 21. The second portion 22b extends to the opposite side from the third surface 20C from a part of the fourth surface 20D of the first portion 22a, and extends toward the mounting part 21 from the tip 22T of the first portion 22a.SELECTED DRAWING: Figure 5

Description

The present disclosure relates to cutting edges for work machines, blades for work machines and work machines.

It is desired to improve work efficiency in work machines such as motor graders. One of the improvements in work efficiency is the improvement of excavability and the durability of the cutting edge. A cutting edge that addresses this issue is disclosed, for example, in US Pat. No. 3,021,626 (Patent Document 1).

The cutting edge described in Patent Document 1 has a raised portion on the front surface and a reinforcing rib on the rear surface.

U.S. Pat. No. 30,216,626

However, with the cutting edge described in Patent Document 1, it is difficult to improve the durability because the rigidity of the tip of the cutting edge is low.

An object of the present disclosure is to provide a cutting edge for a work machine, a blade for a work machine, and a work machine for which excavation property is good and durability can be easily improved.

The cutting edge for a work machine of the present disclosure is a cutting edge for a work machine to be attached to a work machine, and includes a mounting portion and a worn portion. The mounting portion has a first surface and a second surface facing each other, and has a first thickness which is the maximum value of the thickness between the first surface and the second surface. The worn part is integrated with the mounting part. The worn portion has a first portion and a second portion. The first portion has a third surface connected to the first surface and a fourth surface facing the third surface, and has a second thickness between the third surface and the fourth surface, which is thinner than the first surface. It has a tip located on the opposite side of the mounting portion. The second portion extends from a part of the fourth surface of the first portion to the side opposite to the third surface, and extends from the tip of the first portion toward the mounting portion.

According to the present disclosure, it is possible to realize a cutting edge for a work machine, a blade for a work machine, and a work machine for which excavation property is good and durability can be easily improved.

It is a perspective view which shows the structure of the motor grader as a work machine in Embodiment 1. FIG. It is a side view which shows the structure of the blade for a work machine included in the work machine of FIG. It is a perspective view which looked at the structure of the cutting edge included in the blade for a work machine of FIG. 2 from the front. It is a perspective view which looked at the structure of the cutting edge included in the blade for a work machine of FIG. 2 from the rear. It is sectional drawing which follows the VV line of FIG. It is sectional drawing which follows the VI-VI line of FIG. It is a partial perspective view which saw the structure of the cutting edge included in the work machine in Embodiment 2 from the front. It is a partial perspective view of the structure of the cutting edge included in the work machine in Embodiment 2 as seen from the rear. It is sectional drawing which follows the IX-IX line of FIG. It is sectional drawing which follows the XX line of FIG.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the specification and drawings, the same constituent elements or the corresponding constituent elements are designated by the same reference numerals, and duplicate description will not be repeated. Further, in the drawings, the configuration may be omitted or simplified for convenience of explanation. In addition, at least a part of each embodiment and each modification may be arbitrarily combined with each other.

(Embodiment 1)
<Structure of work machine>
First, the configuration of a motor grader, which is an example of a work machine to which the idea of the present disclosure can be applied, will be described. The present disclosure is also applicable to other work machines having blades other than the motor grader.

FIG. 1 is a perspective view schematically showing the configuration of a motor grader according to the first embodiment. As shown in FIG. 1, the motor grader 10 in the present embodiment mainly includes a working machine 1, a vehicle body frame 2, a cab (driver's cab) 3, and traveling wheels 4 and 5. Further, the motor grader 10 has components such as an engine arranged in the engine chamber 2aa. The working machine 1 includes, for example, a blade 11. The motor grader 10 can perform operations such as leveling work, snow removal work, light cutting, and material mixing with the blade 11.

In the description of the following figure, the direction in which the motor grader 10 travels straight is referred to as the front-rear direction of the motor grader 10. In the front-rear direction of the motor grader 10, the side where the front wheels 4 are arranged with respect to the work machine 1 is the front direction. In the front-rear direction of the motor grader 10, the side on which the rear wheel 5 is arranged with respect to the work machine 1 is the rear direction. The left-right direction of the motor grader 10 is a direction orthogonal to the front-rear direction in a plan view. Looking forward, the right and left sides of the left and right directions are the right and left directions, respectively. The vertical direction of the motor grader 10 is a direction orthogonal to a plane defined by a front-rear direction and a left-right direction. In the vertical direction, the side with the ground is the lower side, and the side with the sky is the upper side.

The body frame 2 includes a rear frame 2a and a front frame 2b. The rear frame 2a supports the exterior cover 2ab and components such as an engine arranged in the engine chamber 2aa. The exterior cover 2ab covers the engine chamber 2aa. For example, each of the four rear wheels 5 is attached to the rear frame 2a. Each of the four rear wheels 5 can be rotationally driven by a driving force from the engine.

The front frame 2b has a base end portion connected to the rear frame 2a and a tip end portion opposite to the base end portion. The base end portion of the front frame 2b is connected to the tip end portion of the rear frame 2a by a center pin extending in the vertical direction.

An articulated cylinder (not shown) is attached between the front frame 2b and the rear frame 2a. The front frame 2b is provided so as to be rotatable (articulate) with respect to the rear frame 2a by expanding and contracting the articulate cylinder.

For example, two front wheels 4 are rotatably attached to the tip of the front frame 2b. The front wheels 4 are rotatably attached to the front frame 2b by expanding and contracting the steering cylinder 6. The motor grader 10 can change the traveling direction by expanding and contracting the steering cylinder 6.

The cab 3 is mounted on the front frame 2b. Inside the cab 3, operation parts (not shown) such as a handle, a speed change lever, an operation lever of the work equipment 1, a brake, an accelerator pedal, and an inching pedal are provided. The cab 3 may be mounted on the rear frame 2a.

The working machine 1 mainly includes, for example, a blade 11, a drawbar 12, a swivel circle 13, lift cylinders 14 and 15, a drawbar shift cylinder 16, a blade shift cylinder 17, and a hydraulic motor 18.

The drawbar 12 is arranged below the front frame 2b. The front end portion of the drawbar 12 is connected to the tip end portion of the front frame 2b by using a ball shaft portion. The front end portion of the drawbar 12 is swingably attached to the tip end portion of the front frame 2b.

The rear end of the drawbar 12 is supported by the front frame 2b by a pair of lift cylinders 14 and 15. By expanding and contracting the pair of lift cylinders 14 and 15, the rear end portion of the drawbar 12 can be moved up and down with respect to the front frame 2b. Further, the drawbar 12 can swing about a shaft extending in the front-rear direction due to different expansion and contraction of the pair of lift cylinders 14 and 15.

The swivel circle 13 is arranged below the drawbar 12. The swivel circle 13 is rotatably attached to the rear end of the drawbar 12. The swivel circle 13 can be swiveled and driven by the hydraulic motor 18 with respect to the drawbar 12 in both the clockwise direction and the counterclockwise direction when viewed from above the work machine 10.

The blade 11 is supported by the swivel circle 13. The blade propulsion angle of the blade 11 is adjusted by the rotation drive of the rotation circle 13. The blade propulsion angle is an inclination angle of the blade 11 with respect to the front-rear direction of the motor grader 10 in a viewpoint (plan view) seen from above the work machine 10.

The blade 11 is arranged between the front wheel 4 and the rear wheel 5. The blade shift cylinder 17 is attached to the swivel circle 13 and the blade 11 and is arranged along the longitudinal direction of the blade 11. The blade 11 can be moved in the left-right direction with respect to the swivel circle 13 by the blade shift cylinder 17.

A tilt cylinder (not shown) is attached to the swivel circle 13 and the blade 11. By expanding and contracting the tilt cylinder, the blade 11 swings about the axis extending in the longitudinal direction of the blade 11 with respect to the swirling circle 13, and the inclination angle of the blade 11 with respect to the traveling direction can be changed.

As described above, the blade 11 is attached to the main body of the work machine composed of the traveling wheels 4, 5 and the vehicle body frame 2 and the cab 3. The blade 11 moves up and down with respect to the work machine main body via the drawbar 12 and the swivel circle 13, swings around an axis along the traveling direction of the work machine 10, changes the inclination angle in the front-rear direction, and the left-right direction. It is configured to be able to move and swing around an axis extending in the longitudinal direction of the blade 11.

<Structure of blade 11>
Next, the configuration of the blade 11 (blade for the work machine) included in the work machine 10 will be described with reference to FIG.

FIG. 2 is a side view showing the configuration of a blade for a work machine included in the work machine of FIG. As shown in FIG. 2, the blade 11 has a blade body 11a and a cutting edge 20. The blade body 11a has a front surface 11aa and a rear surface 11ab facing each other. The front surface 11aa and the rear surface 11ab of the blade body 11a are curved in a cross section cut vertically (in the lateral direction of the blade 11).

A pair of rails 11d are attached to the rear surface 11ab of the blade body 11a with a holding frame 11e interposed therebetween. A pair of rails 11d are slidably supported in the longitudinal direction of the blade 11 by a guide bracket (not shown). The blade 11 is attached to the main body of the work machine via a blade support mechanism (not shown) including the guide bracket.

A cutting edge 20 is attached to the lower end of the blade body 11a. The cutting edge 20 is fixed to the blade body 11a by, for example, a bolt 11b and a nut 11c. Specifically, the bolt 11b is inserted into the through hole 20h of the cutting edge 20 and the through hole 11f of the blade body 11a from the front, and is fastened to the nut 11c behind the blade body 11a. As a result, the cutting edge 20 is fixed to the blade body 11a.

<Structure of cutting edge 20>
Next, the configuration of the cutting edge 20 included in the blade 11 will be described with reference to FIGS. 3 to 6.

3 and 4 are a perspective view of the structure of the cutting edge included in the blade for the work machine of FIG. 2 as viewed from the front and a perspective view as viewed from the rear, respectively. 5 and 6 are a cross-sectional view taken along the line VV of FIG. 4 and a cross-sectional view taken along the line VI-VI of FIG. 5, respectively.

As shown in FIG. 5, the cutting edge 20 has a mounting portion 21, a worn portion 22, and an intermediate portion 23. The mounting portion 21, the worn portion 22, and the intermediate portion 23 are integrated.

The mounting portion 21 has a first surface 20A and a second surface 20B facing each other. The first surface 20A is the front surface of the mounting portion 21, and the second surface 20B is the rear surface of the mounting portion 21. The mounting portion 21 has a thickness t1 (first thickness) which is the maximum value of the thickness between the first surface 20A and the second surface 20B.

The first surface 20A and the second surface 20B of the mounting portion 21 are parallel to each other from the joint portion between the mounting portion 21 and the intermediate portion 23 to the position 21M. The thickness of the mounting portion 21 from the joint portion between the mounting portion 21 and the intermediate portion 23 to the position 21M is constant at the thickness t1.

The second surface 20B is inclined with respect to the first surface 20A so that the first surface 20A and the second surface 20B approach each other from the position 21M toward the tip 21T. Therefore, the thickness of the mounting portion 21 from the position 21M to the tip 21T of the mounting portion 21 becomes thinner from the position 21M toward the tip 21T.

The mounting portion 21 has a portion 20h for mounting on the blade main body 11a. This portion 20h is arranged between the joint portion between the mounting portion 21 and the intermediate portion 23 and the position 21M. The portion 20h is arranged in a portion of the mounting portion 21 having the maximum thickness t1.

The portion 20h for attaching to the blade body 11a is, for example, a through hole 20h for inserting the bolt 11b as described above. The through hole 20h penetrates the mounting portion 21 from the first surface 20A to the second surface 20B. The through hole 20h has a diameter-expanded portion 20ha extending from the second surface 20B side toward the first surface 20A while maintaining a diameter, and a same-diameter portion extending from the diameter-expanded portion 20ha toward the second surface 20B. It has 20 hb. The enlarged diameter portion 20ha has, for example, a truncated cone shape, and the same diameter portion 20hb has, for example, a prismatic shape.

The worn portion 22 is located below the mounting portion 21. The worn portion 22 has a first portion 22a and a second portion 22b. The second portion 22b is located behind the first portion 22a.

The first portion 22a has a third surface 20C and a fourth surface 20D facing each other. The third surface 20C is the front surface of the first portion 22a, and the fourth surface 20D is the rear surface of the first portion 22a. The third surface 20C is connected to the first surface 20A.

The first portion 22a has a thickness t2 (second thickness) between the third surface 20C and the fourth surface 20D. The thickness t2 is thinner than the thickness t1 of the mounting portion 21. The ratio of the thickness t2 to the thickness t1 (t2 / t1) is 50% or less.

The first portion 22a has a tip 22T located on the opposite side of the mounting portion 21. The third surface 20C and the fourth surface 20D of the first portion 22a are parallel to each other. Therefore, the first portion 22a extends from the end portion on the mounting portion 21 side to the tip end 22T while maintaining the thickness t2. The thickness t2 is constant from the tip 22T to the joint between the first portion 22a and the intermediate portion 23.

The second portion 22b extends from a part of the fourth surface 20D in the first portion 22a to the side opposite to the third surface 20C. The second portion 22b extends in the vertical direction (the lateral direction of the cutting edge 20) from the tip end 22T of the first portion 22a toward the mounting portion 21. The second portion 22b is in contact with the fourth surface 20D of the tip 22T. The second portion 22b extends vertically from the tip 22T to a portion where at least the first portion 22a is connected to the intermediate portion 23, and is connected to the first portion 22a.

The second portion 22b has a first end portion 22F connected to the fourth surface 20D of the first portion 22a and a second end portion 22R facing the first end portion 22F. The second end 22R is located behind the first end 22F.

The second end portion 22R of the second portion 22b has a portion located behind the second surface 20B of the mounting portion 21. Specifically, the second end portion 22R of the root portion 22b2 of the second portion 22b is located behind the second surface 20B of the mounting portion 21. The second end portion 22R has a portion located on the side opposite to the fourth surface 20D with respect to the second surface 20B. Specifically, the second end portion 22R of the root portion 22b2 is located on the side opposite to the fourth surface 20D with respect to the second surface 20B. As a result, the total thickness t4 (FIG. 6) of the thickness of the first portion 22a and the root portion 22b2 of the second portion 22b is thicker than the thickness t1 (FIG. 5) of the mounting portion 21.

The second portion 22b has a tip portion 22b1 and a root portion 22b2. The tip portion 22b1 is located below the root portion 22b2. The tip portion 22b1 is a portion extending from the tip end 22T of the first portion 22a toward the mounting portion 21 side. The root portion 22b2 is a portion connected to the tip portion 22b1 and located closer to the mounting portion 21 than the tip portion 22b1.

The second end 22R of the tip 22b1 is inclined with respect to the fourth surface 20D so that the closer to the tip 22T, the closer to the fourth surface 20D. The second end 22R at the root 22b2 is parallel to the fourth surface 20D.

The intermediate portion 23 is located between the mounting portion 21 and the worn portion 22. The intermediate portion 23 has a fifth surface 20E and a sixth surface 20F facing each other. The fifth surface 20E is the front surface of the intermediate portion 23, and the sixth surface 20F is the rear surface of the intermediate portion 23. The fifth surface 20E is connected to each of the first surface 20A and the third surface 20C.

The intermediate portion 23 has a thickness t3 (third thickness) between the fifth surface 20E and the sixth surface 20F. The thickness t3 of the intermediate portion 23 becomes thinner from the mounting portion 21 toward the worn portion 22. The sixth surface 20F of the intermediate portion 23 is inclined with respect to the fifth surface 20E so as to approach the fifth surface 20E from the mounting portion 21 toward the worn portion 22. The sixth surface 20F of the intermediate portion 23 constitutes a step between the second surface 20B of the mounting portion 21 and the fourth surface 20D of the worn portion 22.

The second portion 22b of the wear portion 22 is connected to the sixth surface 20F of the intermediate portion 23. The second portion 22b is connected to the entire vertical direction of the sixth surface 20F from the connecting portion between the intermediate portion 23 and the first portion 22a to the connecting portion between the intermediate portion 23 and the mounting portion 21. The second portion 22b extends to the second surface 20B of the mounting portion 21. The second portion 22b is connected to a part of the second surface 20B.

The first surface 20A of the mounting portion 21, the third surface 20C of the first portion 22a, and the fifth surface 20E of the intermediate portion 23 form the front surface FS of the cutting edge 20.

As shown in FIG. 3, the first surface 20A of the mounting portion 21 and the fifth surface 20E of the intermediate portion 23 are continuously connected without causing a break or a step. Further, the fifth surface 20E of the intermediate portion 23 and the third surface 20C of the first portion 22a are continuously connected without causing a break or a step. As a result, the front surface FS composed of the first surface 20A of the mounting portion 21, the fifth surface 20E of the intermediate portion 23, and the third surface 20C of the first portion 22a constitutes a single surface.

As shown in FIG. 4, the cutting edge 20 has a plurality of second portions 22b. The plurality of second portions 22b are arranged side by side along the longitudinal LD of the cutting edge 20. The plurality of second portions 22b are arranged at equal intervals in the longitudinal LD of the cutting edge 20. The plurality of second portions 22b are arranged so as to be parallel to each other.

As shown in FIG. 5, the front surface FS is curved in a cross section cut in the vertical direction from the tip 21T of the mounting portion 21 to the tip 22T of the first portion 22a. In this cross section, the portion sandwiched between the two ends 21T and 22T is recessed with respect to both ends 21T and 22T.

As shown in FIG. 6, the second portion 22b is a reinforcing rib for reinforcing the strength of the first portion 22a. The total thickness t4 of the first portion 22a and the second portion 22b is thicker than the thickness t2 or more of the first portion 22a.

The thickness t2 of the first portion 22a is equal to or less than the thickness (t4-t2) of the second portion 22b. The ratio (t2 / (t4-t2)) of the thickness t2 of the first portion 22a to the thickness (t4-t2) of the second portion 22b is 50% or less.

The pitch P of the plurality of second portions 22b has a dimension that is, for example, five times the width W of one second portion 22b.

The front surface FS extends linearly in the cross section cut in the longitudinal direction LD shown in FIG. Each of the first surface 20A of the mounting portion 21, the third surface 20C of the first portion 22a, and the fifth surface 20E of the intermediate portion 23 extend linearly in the cross section cut in the longitudinal direction LD shown in FIG. ..

<Effect>
Next, the effect of this embodiment will be described.

According to the present embodiment, as shown in FIG. 5, the second thickness t2 of the first portion 22a is thinner than the first thickness t1 of the mounting portion 21. Therefore, the first portion 22a is easy to get into the excavation target. Therefore, the excavability is good.

Further, as a result of simulating the excavation phenomenon by the present inventor, it was found that even if the contact area between the cutting edge 20 and the excavation object (for example, the ground) is increased, the contact stress (= wear rate) is hardly affected. Therefore, by reducing the second thickness t2 of the first portion 22a, the contact area with the excavation object can be reduced, and the excavation resistance (reaction force with respect to a constant depth of cut) is reduced while the wear rate remains the same. be able to. As a result, the force of pressing the blade 11 against the object to be excavated can be reduced, and fuel efficiency can be improved.

Further, since the excavation resistance is reduced, if the force for pressing the cutting edge 20 against the excavation object is the same, the width of the blade 11 in the left-right direction can be expanded. This increases the amount of work and improves excavability.

Further, the second portion 22b extends from a part of the fourth surface 20D of the first portion 22a to the side opposite to the third surface 20C. The strength of the first portion 22a is reinforced by the second portion 22b. This improves the rigidity of the cutting edge 20.

Further, the second portion 22b is also arranged at the tip 22T of the first portion 22a. As a result, the rigidity of the tip of the cutting edge 20 (the tip 22T of the first portion 22a) is improved, so that the rigidity of the cutting edge 20 is improved.

Further, it is not necessary to attach a high hardness bit to the cutting edge 20 of the present embodiment, and it is not necessary to add a wear resistant alloy. Therefore, the manufacturing cost of the cutting edge 20 can be suppressed.

Further, in the present embodiment, as shown in FIG. 5, the second thickness t2 of the first portion 22a is constant from the tip 22T of the first portion 22a to the end located on the mounting portion 21 side of the first portion 22a. is there. As a result, even if the tip 22T of the first portion 22a is worn by excavation, it is possible to obtain the same excavability as at the beginning of use. Further, since the second thickness t2 of the first portion 22a is constant, the biting resistance of the cutting edge 20 into the excavated object can be kept low.

Further, in the present embodiment, as shown in FIG. 5, the ratio (t2 / t1) of the second thickness t2 of the first portion 22a to the first thickness t1 of the mounting portion 21 is 50% or less. By reducing the second thickness t2 of the first portion 22a in this way, the excavability can be further improved.

Further, in the present embodiment, as shown in FIG. 5, the thickness t3 of the intermediate portion 23 becomes thinner from the mounting portion 21 toward the worn portion 22. By gradually changing the thickness t3 of the intermediate portion 23 in this way, there is no place where the thickness suddenly changes. If the thickness changes abruptly, stress concentration is likely to occur at that location during excavation, and damage is likely to occur. However, in the present embodiment, since such a portion does not occur, damage is less likely to occur.

Further, in the present embodiment, as shown in FIG. 5, the second portion 22b is a reinforcing rib. As a result, the first portion 22a is reinforced by the second portion 22b, and the rigidity is improved.

Further, in the present embodiment, as shown in FIG. 5, the second portion 22b extends to the mounting portion 21. As described above, the rigidity can be further increased by locating the second portion 22b in the entire vertical direction of the thin first portion 22a having a thickness t2.

Further, in the present embodiment, as shown in FIG. 5, the second end portion 22R of the second portion 22b is a portion located on the side opposite to the fourth surface 20D with respect to the second surface 20B of the mounting portion 21. have. As a result, the thickness (t4-t2) of the second portion 22b can be increased, and the rigidity can be further increased.

Further, if the front surface FS of the cutting edge 20 has irregularities in the cross section cut along the LD in the longitudinal direction, it becomes difficult for soil or the like to flow along the LD in the longitudinal direction of the cutting edge 20.

On the other hand, in the present embodiment, as shown in FIG. 3, the front surface FS of the cutting edge 20 is composed of a single surface (curved surface). Further, as shown in FIG. 6, the front surface FS of the cutting edge 20 has a linear shape or a single curved shape in a cross section cut along the longitudinal LD. As a result, soil and the like can be easily discharged to the outside of the LD in the longitudinal direction of the cutting edge 20, so that the efficiency of the ground leveling work is improved.

(Embodiment 2)
<Structure of cutting edge 20>
Next, the configuration of the cutting edge in the second embodiment will be described with reference to FIGS. 7 to 10.

7 and 8 are a partial perspective view and a partial perspective view of the configuration of the cutting edge included in the work machine according to the second embodiment as viewed from the front and a rear view, respectively. 9 and 10 are a cross-sectional view taken along the line IX-IX and a cross-sectional view taken along the line XX of FIG. 8, respectively.

As shown in FIG. 7, the cutting edge 20 of the present embodiment is different from the configuration of the first embodiment in that a recess 20G is provided in the front surface FS of the cutting edge 20.

A plurality of recesses 20G are arranged along the longitudinal LD of the cutting edge 20. The plurality of recesses 20G are arranged at equal intervals, for example. Each of the plurality of recesses 20G extends from the tip 22T of the first portion 22a toward the tip 21T of the mounting portion 21.

As shown in FIG. 8, the recess 20G is composed of a second portion 22b. The second portion 22b has an inclined portion 22ba, a rear end portion 22bb, and a pair of side portions 22bc.

Each of the pair of side portions 22bc extends from a portion of the fourth surface 20D of the first portion 22a to the side opposite to the third surface 20C. The pair of side portions 22bc are spaced apart from each other. A pair of side portions 22bc extend parallel to each other, for example.

Each of the inclined portion 22ba and the rear end portion 22bb is arranged so as to bridge a pair of side portions 22bc. Each of the pair of side portions 22bc connects the fourth surface 20D of the first portion 22a and the side end portion of the inclined portion 22ba. Further, each of the pair of side portions 22bc connects the fourth surface 20D of the first portion 22a and the side end portion of the rear end portion 22bb.

As shown in FIG. 9, the inclined portion 22ba extends from a position corresponding to the tip end 22T of the first portion 22a toward the mounting portion 21. The inclined portion 22ba is inclined with respect to the front FS of the cutting edge 20 so as to approach the front FS of the cutting edge 20 as it approaches the position corresponding to the tip 22T of the first portion 22a.

The rear end portion 22bb is connected to the end portion of the inclined portion 22ba on the mounting portion 21 side. The rear end portion 22bb extends from the end portion of the inclined portion 22ba on the mounting portion 21 side toward the mounting portion 21. The rear end portion 22bb extends beyond the intermediate portion 23 to reach the mounting portion 21. The rear end portion 22bb is connected to the mounting portion 21. The portion of the rear end portion 22bb extending from the portion connected to the inclined portion 22ba toward the mounting portion 21 side extends parallel to the front surface FS of the cutting edge 20.

The front surfaces of the inclined portion 22ba and the rear end portion 22bb each form the bottom surface of the recess 20G. The side surfaces of the pair of side portions 22bc form the side surfaces of the recess 20G.

The second end 22R of the rear end 22bb on the side opposite to the front FS side is located farther from the front FS than the second surface 20B of the mounting portion 21. The distance t4 from the front FS to the second end 22R at the rear end 22bb is larger than the thickness t1 of the mounting portion 21.

The configuration of the cross section along the VV line in FIG. 8 is the same as the configuration of the first embodiment shown in FIG.

As shown in FIG. 10, the side portion 22bc of the second portion 22b functions as a reinforcing rib for reinforcing the strength of the first portion 22a.

The distance t4 from the front end portion 22bb to the second end portion 22R in the rear end portion 22bb is larger than the sum of the thickness t2 of the first portion 22a and the thickness t5 of the rear end portion 22bb. The depth D of the recess 20G is larger than the thickness t2 of the first portion 22a.

Since the configuration of the cutting edge 20 of the present embodiment other than the above is almost the same as the configuration of the first embodiment, the same elements as those of the first embodiment are designated by the same reference numerals, and the description thereof will be repeated. Absent.

<Effect>
According to the present embodiment, as shown in FIG. 5, the second thickness t2 of the first portion 22a is thinner than the first thickness t1 of the mounting portion 21. Therefore, as in the first embodiment, the excavation property is improved, and the force for pressing the blade 11 against the excavation object can be reduced.

Further, the side portion 22bc of the second portion 22b extends from a part of the fourth surface 20D of the first portion 22a to the side opposite to the third surface 20C. The strength of the first portion 22a is reinforced by the side portion 22bc. This improves the rigidity of the cutting edge 20.

Further, the side portion 22bc is also arranged at the tip end 22T of the first portion 22a. As a result, the rigidity of the tip of the cutting edge 20 (the tip 22T of the first portion 22a) is improved, so that the rigidity of the cutting edge 20 is improved.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Work machine, 2 Body frame, 2F front end, 2a rear frame, 2aa engine room, 2ab exterior cover, 2b front frame, 3 cab, 4 front wheel, 5 rear wheel, 6 steering cylinder, 10 work machine (motor grader), 11 Blade, 11a Blade body, 11aa, FS front, 11ab rear surface, 11b bolt, 11c nut, 11d rail, 11e holding frame, 11f, 20h through hole, 12 drawbar, 13 swivel circle, 14,15 lift cylinder, 16 drawbar shift cylinder , 17 blade shift cylinder, 18 hydraulic motor, 20 cutting edge, 20A 1st surface, 20B 2nd surface, 20C 3rd surface, 20D 4th surface, 20E 5th surface, 20F 6th surface, 20h part, 20ha diameter expansion Part, 20hb same diameter part, 21 mounting part, 21M intermediate position, 21T, 22T tip, 22 wear part, 22F 1st end, 22R 2nd end, 22a 1st part, 22b 2nd part, 22b1 tip, 22b2 root part, 22ba inclined part, 22bb rear end part, 22bc side part, 23 middle part.

Claims (11)

A cutting edge for work machines that can be attached to work machines.
A mounting portion having a first surface and a second surface facing each other and having a first thickness which is the maximum value of the thickness between the first surface and the second surface.
A wear portion integrated with the mounting portion is provided.
The worn part is
A second thickness between the third surface and the fourth surface, which has a third surface connected to the first surface and a fourth surface facing the third surface and is thinner than the first surface. , A first portion having a tip located on the opposite side of the mounting portion,
For work machines having a second portion extending from a part of the fourth surface of the first portion to a side opposite to the third surface and extending from the tip of the first portion toward the mounting portion. Cutting edge. The cutting edge for a work machine according to claim 1, wherein the mounting portion has a through hole, and the through hole has an enlarged diameter portion connected to the first surface. The cutting edge for a work machine according to claim 1 or 2, wherein the second thickness is constant from the tip of the first portion to the end of the first portion located on the mounting portion side. The cutting edge for a work machine according to any one of claims 1 to 3, wherein the ratio of the second thickness to the first thickness is 50% or less. Further provided with an intermediate portion located between the mounting portion and the worn portion.
The cutting edge for a work machine according to any one of claims 1 to 3, wherein the thickness of the intermediate portion becomes thinner from the mounting portion toward the worn portion. The cutting edge for a work machine according to any one of claims 1 to 5, wherein the second portion is a reinforcing rib. The work machine cutting according to any one of claims 1 to 5, wherein the second portion constitutes a recess on the fourth surface side with respect to the third surface of the first portion. Edge. The working machine cutting edge according to any one of claims 1 to 7, wherein the second portion extends to the mounting portion. The second portion has a first end portion connected to the fourth surface and a second end portion facing the first end portion.
The second end portion according to any one of claims 1 to 8, wherein the second end portion has a portion located on the side opposite to the fourth surface of the mounting portion with respect to the second surface. Cutting edge for work machines. The cutting edge for a work machine according to any one of claims 1 to 9.
A blade for a work machine, comprising a blade body to which the cutting edge for the work machine is attached. The blade for a work machine according to claim 10,
A work machine including a work machine main body to which the blade for the work machine can be attached.