Work claw and agricultural implement

Abstract

To provide a work claw achieving both improved wear resistance and reduced work resistance.SOLUTION: A work claw includes: a claw body having a thickness reduction part smaller than maximum thickness; and a hard metal part provided for the thickness reduction part and configured with a metallic material harder than the claw body. The thickness reduction part includes: a first thickness reduction part provided on a blade edge side; and a second thickness reduction part provided for a back edge side of the first thickness reduction part and thicker than the first thickness reduction part. A sum total of the thickness of the claw body at an arbitrary position of the thickness reduction part and the hard metal is not beyond a maximum thickness of the work claw.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to working claws and agricultural working machines.

Background Art

[0002] Conventionally, it has been known that working claws used in agricultural working machines for tilling fields are worn down due to abrasion as the tilling work continues, and the tilling performance deteriorates over time. Therefore, in recent years, agricultural working machines using working claws provided with an alloy layer having a higher hardness than the base material on the blade portion of the working claws have become mainstream. For example, Patent Document 1 discloses a technique for improving the durability of the blade portion by welding a metal material harder than the claw body to the blade portion of the claw body (base material) to form a hard portion on the surface of the blade portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a hard metal layer is formed on the surface of the claw body as in the above prior art, the thickness of the blade portion increases by the thickness of the hard metal layer, so the resistance (working resistance) when driving the working claw into the field increases. Therefore, if the thickness of the hard metal layer is increased to improve durability, the working resistance during tilling work may increase, leading to a decrease in productivity such as an increase in fuel consumption and a decrease in working speed.

[0005] An object of an embodiment of the present invention is to provide a working claw that achieves both improved abrasion resistance and reduced working resistance.

Means for Solving the Problems

[0006] In one embodiment of the present invention, the working claw includes a claw body having a thickness reduction portion with a thickness smaller than the maximum thickness, and a hard metal portion provided in the thickness reduction portion and made of a metal material harder than the claw body. The thickness reduction portion includes a first thickness reduction portion provided on the cutting edge side, and a second thickness reduction portion provided on the peak edge side of the first thickness reduction portion and having a thickness larger than the thickness of the first thickness reduction portion. The sum of the thicknesses of the claw body and the hard metal portion at any position of the thickness reduction portion does not exceed the maximum thickness of the working claw.

[0007] The thickness reduction portion may include a first thickness reduction portion having a first thickness, a second thickness reduction portion having a second thickness larger than the first thickness reduction portion, and a thickness change portion provided between the first thickness reduction portion and the second thickness reduction portion and having a continuously changing thickness.

[0008] In the thickness reduction portion, the thickness of the claw body may decrease stepwise.

[0009] The thickness reduction portion may have two or more inclined portions (also referred to as slopes).

[0010] In the hard metal portion, the thickness of the peak edge side end portion of the portion provided in the first thickness reduction portion may be larger than the thickness of the peak edge side end portion of the portion provided in the second thickness reduction portion.

[0011] In a cross-sectional view, the length of the first thickness reduction portion may be larger than the length of the second thickness reduction portion.

[0012] The maximum thickness of the claw body may be larger than the thickness of the claw body at the peak edge. At this time, there may be a step or an inclined portion between the peak edge and the hard metal portion.

[0013] The sum of the thickness of the first thickness reduction portion and the thickness of the edge side end portion of the portion provided in the first thickness reduction portion of the hard metal portion may be smaller than the sum of the thickness of the second thickness reduction portion and the thickness of the edge side end portion of the portion provided in the second thickness reduction portion of the hard metal portion.

[0014] The surface of the portion provided in the first thickness reduction portion of the hard metal portion may be convexly curved.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0016] Hereinafter, a working claw which is an embodiment of the present invention will be described with reference to the drawings. However, the embodiments of the present invention can be implemented in many different modes and are not to be construed as limited to the description of the examples shown below. In the drawings referred to in the present embodiment, the same parts or parts having the same function are denoted by the same reference numerals, and the repeated description thereof is omitted.

[0017] In this specification, regarding the description of the agricultural working machine, the direction in which gravity acts is "down", and the opposite is "up". Also, the traveling direction during operation is "forward", and the opposite is "backward". Further, facing "forward", the right side is "right" and the left side is "left".

[0018] In this specification, the "cross-section" refers to the cross-section (i.e., the vertical cross-section) obtained by cutting the working claw along the line segment connecting any point on the peak edge when the working claw is viewed from the side and any point on the blade edge that is at the shortest distance from the arbitrary point on the peak edge. That is, the "cross-sectional view" means the state of viewing the vertical cross-section of the working claw.

[0019] In this specification, the "maximum thickness of the working claw" is the thickness of the working claw that is maximum in the cross-sectional view. When no hard metal part is provided at the maximum thickness part of the claw body, the maximum thickness of the claw body is the "maximum thickness of the working claw". When a hard metal part is provided at the maximum thickness part of the claw body, it means the sum of the thickness of the claw body at the maximum thickness part of the claw body and the thickness of the hard metal part provided at the maximum thickness part of the claw body.

[0020] <First Embodiment> [Configuration of Agricultural Working Machine] FIG. 1 is a side cross-sectional view showing the schematic configuration of the agricultural working machine 100 in the first embodiment of the present invention. The agricultural working machine 100 of this embodiment generally includes a top mast 102, a lower link connection part 104, an input shaft 106, a main frame 108, a shield cover 110, an apron 112, a control device 114, and a working rotor 120. However, the configuration of the agricultural working machine 100 is not limited to the example shown in FIG. 1, and it may include other elements not shown, or some of the shown elements may be omitted.

[0021] The main frame 108 is connected to a traveling body (not shown) such as a tractor by a top mast 102 and a lower link connection part 104. The main frame 108 is a cylindrical member with its longitudinal direction being the left - right direction, and has a power transmission shaft (not shown) inside that leads to a chain case (not shown). This power transmission shaft serves to transmit the rotational power transmitted from the PTO shaft of a traveling body such as a tractor through an input shaft 106 such as a PIC (Power Input Connection) shaft to the claw shaft 122 of the working rotor 120.

[0022] The working rotor 120 is composed of a claw shaft 122 extending in the left - right direction of the agricultural working machine 100 and a plurality of working claws 126 attached to the claw shaft 122 via a flange 124. The plurality of working claws 126 include a working claw curved leftward along the claw shaft 122 (hereinafter referred to as "L working claw 126L") and a working claw curved rightward (hereinafter referred to as "R working claw 126R"), and are attached at predetermined intervals in the axial direction of the claw shaft 122 via the flange 124. In this specification, when there is no need to distinguish between the L working claw 126L and the R working claw 126R, they may be collectively referred to as the working claw 126.

[0023] In this embodiment, a plurality of working claws 126 are attached to one flange 124. In FIG. 1, an example is shown where two L working claws 126L and two R working claws 126R are attached to the flange 124, but the types and numbers of the attached working claws are not limited to this. Also, when the agricultural working machine 100 is viewed from the back side, the opposing R working claws 126R and L working claws 126L are arranged such that their claw tips overlap each other. That is, the ranges in which the individual L working claws 126L and R working claws 126R dig up the soil partially overlap between the adjacent L working claws 126L and R working claws 126R. In the agricultural working machine 100 of this embodiment, the working rotor 120 rotates in the direction indicated by the arrow R in FIG. 1.

[0024] The shield cover 110 is arranged to cover above the working rotor 120. Although not shown in FIG. 1, a side plate is provided on the side surface of the shield cover 110. The side plate may also be called a chain case plate, a side frame, a support frame, etc.

[0025] The apron 112 is arranged behind the working rotor 120 and is pivotally connected to the shield cover 110 so as to be rotatable in the vertical direction about the connecting portion 111 as a central axis. Since the center of gravity of the apron 112 is behind the connecting portion 111, the apron 112 tends to descend due to its own weight. Therefore, during operation, the apron 112 has a function of flattening the field dug up by the working rotor 120 by pressing the field due to its own weight. However, by providing a pressing mechanism that applies a force in the direction in which the apron 112 presses the field, it can also be configured to press the field with a force greater than its own weight.

[0026] The control device 114 has a function of processing signals received from the outside (for example, remote control signals) and transmitting signals generated inside (for example, control signals for the drive unit) to the outside. For example, the control device 114 controls the operation of a drive unit such as an actuator provided in the agricultural working machine 100 according to an operation signal when an operator operates the remote control.

[0027] [Configuration of working claws] FIG. 2 is a diagram showing the configuration of the working claw 126 in the first embodiment of the present invention. Specifically, FIG. 2(A) is a view of the working claw 126 seen from the side of the first surface (the surface facing the left direction), and FIG. 2(B) is a view of the working claw 126 seen from the side of the second surface (the surface facing the right direction) opposite to the first surface. In the following description, for convenience of explanation, the surface on the first surface side may be referred to as the "front surface", and the surface on the second surface side may be referred to as the "back surface". Although the L working claw 126L is illustrated in FIG. 2, the R working claw 126R has the same structure except for the different bending directions, and thus, for convenience of explanation, it will be described as the working claw 126. However, the shape of the working claw 126 shown in FIG. 2 is merely an example and is not limited to this shape. Further, in the present embodiment, an example in which the thickness reduction portion 32 and the hard metal portion 40 are provided on the side of the first surface of the working claw 126 is shown, but the present invention is not limited to this example. For example, the thickness reduction portion 32 and the hard metal portion 40 may be provided on the side of the second surface of the working claw 126, or may be provided on both sides of the first surface and the second surface.

[0028] As shown in FIG. 2, the working claw 126 has a mounting base portion 10 and a blade portion 20. The mounting base portion 10 is a portion to be mounted on the flange 124 shown in FIG. 1, and two mounting holes 12 and 14 are provided in the longitudinal direction. The working claw 126 is mounted on the flange 124 by inserting a fixing member such as a bolt into these mounting holes 12 and 14. Such a mounting method is generally called a flange method, but the present invention is not limited to this, and a known holder method may also be adopted.

[0029] The blade part 20 acts on the soil during operation and is the part responsible for tillage operations such as soil tillage, soil crushing, and throwing. In the present embodiment, among the blade part 20, the edge on the side that is first driven into the soil during operation is called the cutting edge 22, and the edge on the opposite side is called the peak edge 24. Also, the edge connecting the cutting edge 22 and the peak edge 24 is called the head edge 26. The blade part 20 has a shape that gently curves from the mounting base part 10 to the head edge 26. In the case of FIG. 2, for example, since the L working claw 126L is illustrated, as shown in FIG. 2(A), the blade part 20 curves toward the upstream side in the rotation direction R (see FIG. 1) and gently curves toward the front direction of the drawing. Thus, the blade part 20 of the working claw 126 has a shape that gently curves toward the head edge 26, and the first surface shown in FIG. 2(A) forms a so-called "scooping surface". The working claw 126 can throw the soil by the scooping surface and also perform soil gathering.

[0030] Also, in the working claw 126 of the present embodiment, a hard metal part 40 is provided with respect to the claw main body 30 that is the base material (see FIG. 2(A)). Specifically, in the working claw 126, the hard metal part 40 is provided on the cutting edge 22 side that extends substantially over the entire blade part 20. The range for providing the hard metal part 40 can be set in consideration of the deterioration of the tillage performance of the working claw 126 due to wear. Generally, since the working claw 126 gradually wears from the cutting edge 22 side during operation, it is replaced when the wear progresses until it reaches a predetermined line (hereinafter referred to as the "replacement line") that serves as a replacement criterion. The hard metal part 40 of the present embodiment is provided on the cutting edge 22 side rather than the replacement line (for example, a line 2 to 2.5 cm from the peak edge 24) of the working claw 126, but it may be configured such that the replacement line and the peak edge 24 side end of the hard metal part 40 coincide (including a substantially coincidence). The hard metal part 40 has a higher hardness than the claw main body 30. The hardness here only needs to be an index of the relative hardness between the claw main body 30 and the hard metal part 40, and for example, Rockwell hardness, Vickers hardness, Brinell hardness, etc. can be used.

[0031] In the present embodiment, since spring steel (for example, SUP6) is used as the metal material constituting the claw body 30, as the metal material constituting the hard metal part 40, for example, an alloy containing chromium carbide, niobium carbide, tungsten carbide, etc., or a self-fluxing alloy (for example, Colmonoy alloy, etc.) can be used. However, the alloys exemplified here are merely examples, and any material can be used as long as it can form a metal layer having a higher hardness than the claw body 30. As the method for forming the hard metal part 40, a welding method, a spraying method, a laser cladding method, etc. can be used, but it is not limited to these examples.

[0032] FIG. 3 is a cross-sectional view schematically showing the configuration of the working claw 126 in the first embodiment of the present invention. Specifically, FIG. 3 corresponds to a vertical cross-sectional view obtained by cutting the working claw 126 shown in FIG. 2(A) along the line A-A. As shown in FIG. 3, in the working claw 126 of the present embodiment, the thickness is reduced in a part of the claw body 30 (a part on the cutting edge 22 side), and a hard metal part 40 is formed in the portion where the thickness is reduced (hereinafter referred to as the "thickness reduction part").

[0033] In the present embodiment, the thickness reduction part 32 can be divided into a first thickness reduction part 34, a first thickness change part 35, a second thickness reduction part 36, a second thickness change part 37, and a third thickness reduction part 38 from the side close to the cutting edge 22. In the cross-sectional view shown in FIG. 3, there is no particular limitation on the length of each of the first thickness reduction part 34, the first thickness change part 35, the second thickness reduction part 36, the second thickness change part 37, and the third thickness reduction part 38. That is, the length of the first thickness reduction part 34 and the length of the second thickness reduction part 36 can be the same or substantially the same, or can have different configurations. In the description regarding FIG. 3, the "length" means the length in the direction from the peak edge 24 of the working claw 126 toward the cutting edge 22. The same applies to the descriptions regarding FIGS. 4 to 6 described later.

[0034] From the viewpoint of ensuring the durability of the working claw 126 (preventing wear), it is preferable to reduce the thickness of the claw body 30 in the portion near the cutting edge 22 (i.e., on the cutting edge side) and increase the thickness of the hard metal part 40. Also, from the viewpoint of ensuring the strength of the working claw 126, it is preferable to increase the thickness of the claw body 30 in the portion near the peak edge 24 of the working claw 126 (i.e., on the peak side) and reduce the thickness of the hard metal part 40.

[0035] In this embodiment, by configuring the length of the first thickness reduction portion 34 to be longer than the length of the second thickness reduction portion 36, the length of the first thickness reduction portion 34 where the hard metal portion 40 is thickly configured becomes longer, so that the durability of the working claw 126 can be provided. Also, by providing the second thickness reduction portion 36 in the working claw 126 (compared to the case where the second thickness reduction portion 36 is not provided), the strength of the working claw 126 can be ensured. Further, the length of the first thickness reduction portion 34 may be longer than the length of the second thickness reduction portion 36, or conversely, the length of the first thickness reduction portion 34 may be shorter than the length of the second thickness reduction portion 36. The same applies to the relationship between the first thickness reduction portion 34 and the third thickness reduction portion 38, and the relationship between the second thickness reduction portion 36 and the third thickness reduction portion 38. Note that the length of the first thickness reduction portion 34 where the thickness is the thinnest is preferably 25% or less, more preferably 15% or less, of the total length (W0) of the claw body 30. Also, the total length of the first thickness reduction portion 34, the first thickness change portion 35, and the second thickness reduction portion 36 is preferably 50% or less, more preferably 35% or less, of the total length (W0) of the claw body 30. Thereby, it is possible to further improve the strength of the working claw 126 and enhance the durability. Furthermore, the same applies to the relationship between the first thickness reduction portion 34, the second thickness reduction portion 36, or the third thickness reduction portion 38 and the first thickness change portion 35 or the second thickness change portion 37. For example, the length of the first thickness reduction portion 34 and the length of the first thickness change portion 35 may be the same or substantially the same, or may be different. Also, the total length of the first thickness reduction portion 34 and the first thickness change portion 35 may be longer than the total length of the second thickness reduction portion 36 and the second thickness change portion 37, or conversely, the total length of the first thickness reduction portion 34 and the first thickness change portion 35 may be shorter than the total length of the second thickness reduction portion 36 and the second thickness change portion 37.

[0036] Also, in this embodiment, as the third thickness reduction portion 38, a portion where the thickness is slightly reduced compared to the claw body 30 is illustrated, but the third thickness reduction portion 38 may be omitted. That is, the second thickness change portion 37 may be provided on the side closest to the peak edge 24 in the thickness reduction portion 32.

[0037] The first thickness reduction portion 34, the second thickness reduction portion 36, and the third thickness reduction portion 38 each have a first thickness (Ha), a second thickness (Hb), and a third thickness (Hc), and constitute portions with a constant or substantially constant thickness. As shown in FIG. 3, the relationship among the first thickness (Ha), the second thickness (Hb), and the third thickness (Hc) is Hc>Hb>Ha. That is, the thickness reduction portion 32 is configured such that the thickness decreases as it approaches the cutting edge 22. In other words, the thickness reduction portion 32 is configured such that the thickness decreases stepwise as it approaches the cutting edge 22.

[0038] At this time, when the maximum thickness of the claw body 30 (in FIG. 3, the thickness of the claw body 30 at the peak edge 24) is H0, the thickness of the first thickness reduction portion 34 (the first thickness Ha) is preferably 20% or less of the maximum thickness (H0) of the claw body 30, more preferably 15% or less, and even more preferably 10% or less. Also, considering the strength of the working claw 126, the thickness of the second thickness reduction portion 36 (the second thickness Hb) is preferably 50% or more, more preferably 70% or more of the maximum thickness (H0) of the claw body 30. Further, the thickness of the third thickness reduction portion 38 (the third thickness Hc) is preferably 85% or more of the maximum thickness (H0) of the claw body 30, and more preferably 90% or more.

[0039] In FIG. 3, the maximum thickness (Hmax) of the working claw 126 is equal to the maximum thickness (H0) of the claw body 30. If the thickness of the first thickness reduction portion 34 is too thin, the first thickness reduction portion 34 will disappear immediately due to wear during operation, and only the portion of the hard metal part 40 provided in the first thickness reduction portion 34 will remain and be driven into the soil. In this case, the hard metal part 40 may disappear due to brittle fracture by the impact of driving, and the tip of the working claw 126 may become dull, resulting in deterioration of the tilling performance.

[0040] The first thickness change portion 35 is provided between the first thickness reduction portion 34 and the second thickness reduction portion 36, and is a portion where the thickness changes continuously. That is, in the present embodiment, the surface of the first thickness change portion 35 is inclined with respect to the back surface of the claw body 30. Specifically, the thickness of the first thickness change portion 35 continuously decreases from the second thickness reduction portion 36 to the first thickness reduction portion 34. Similarly, the second thickness change portion 37 is provided between the second thickness reduction portion 36 and the third thickness reduction portion 38, and is a portion where the thickness changes continuously. The thickness continuously decreases from the third thickness reduction portion 38 to the second thickness reduction portion 36. The virtual lines 51 and 52 indicated by the dashed-dotted line indicate planes parallel to the back surface of the claw body 30. The angle (α) formed by the surface of the first thickness change portion 35 and the plane parallel to the back surface of the claw body 30 and the angle (β) formed by the surface of the second thickness change portion 37 and the plane parallel to the back surface of the claw body 30 may be the same or different. When the above-mentioned angle (α) and angle (β) are different, the angle (α) may be smaller than the angle (β), or conversely, the angle (α) may be larger than the angle (β). By making the angle (α) larger than the angle (β), that is, by making the angle change on the peak edge 24 side gentle, the thickness of the claw body 30 does not change abruptly, and it becomes easier to secure the second thickness (Hb). Thus, the thickness reduction portion 32 gradually decreases in thickness in the order of the third thickness reduction portion 38, the second thickness reduction portion 36, and the first thickness reduction portion 34. In the present embodiment, an example in which the thickness reduction portion 32 includes two inclined portions (the first thickness change portion 35 and the second thickness change portion 37) is shown, but the present invention is not limited to this example. The inclined portion of the thickness reduction portion 32 may be one or two or more. Here, the relationship between the angle (α) formed by the surface of the first thickness change portion 35 and the back surface of the claw body 30 and the angle (β) formed by the surface of the second thickness change portion 37 and the back surface of the claw body 30 has been described, but the present invention is not limited to this example. The same applies to the relationship between the angle formed by the surface of the first thickness change portion 35 and the surface of the first thickness reduction portion 34 and the angle formed by the surface of the second thickness change portion 37 and the surface of the second thickness reduction portion 36.

[0041] As described above, since the thickness of the claw body 30 changes toward the cutting edge 22, accordingly, the thickness of the hard metal portion 40 provided to overlap with the thickness reduction portion 32 also changes. Specifically, as shown in FIG. 3, among the hard metal portion 40, the thickness (ha) of the end portion on the peak edge 24 side in the portion provided in the first thickness reduction portion 34 (hereinafter referred to as "the first thickness (ha) of the hard metal portion 40") is larger than the thickness (hb) of the end portion on the peak edge 24 side in the portion provided in the second thickness reduction portion 36 (hereinafter referred to as "the second thickness (hb) of the hard metal portion 40"). Similarly, the second thickness (hb) of the hard metal portion 40 is larger than the thickness (hc) of the end portion on the peak edge 24 side in the portion provided in the third thickness reduction portion 38 (hereinafter referred to as "the third thickness (hc) of the hard metal portion 40"). However, the relationship of the thicknesses of the respective portions in the hard metal portion 40 shown in FIG. 3 is merely an example. For example, the first thickness (ha) of the hard metal portion 40 and the second thickness (hb) of the hard metal portion 40 may be the same or substantially the same.

[0042] Further, in the working claw 126 of the present embodiment, the sum of the thickness (Ha) of the first thickness reduction portion 34 and the first thickness (ha) of the hard metal portion 40 is smaller than the sum of the thickness (Hb) of the second thickness reduction portion 36 and the second thickness (hb) of the hard metal portion 40. Therefore, the working claw 126 decreases in thickness as it approaches the cutting edge 22 in the thickness reduction portion 32 and functions as a so-called cutting portion. In the present embodiment, an example in which the surface of the portion provided in the first thickness reduction portion 34 of the hard metal portion 40 is convexly curved is shown, but the present invention is not limited to this example, and the surface of the portion may be linear.

[0043] Also, as is apparent from FIG. 3, the working claw 126 of the present embodiment is configured such that the sum of the thicknesses of the claw body 30 and the hard metal part 40 at any position of the thickness reduction part 32 does not exceed the maximum thickness (Hmax) of the working claw 126. That is, the sum of the thickness (Ha) of the first thickness reduction part 34 and the first thickness (ha) of the hard metal part 40, the sum of the thickness (Hb) of the second thickness reduction part 36 and the second thickness (hb) of the hard metal part 40, and the sum of the thickness (Hc) of the third thickness reduction part 38 and the third thickness (hc) of the hard metal part 40 all do not exceed the maximum thickness (Hmax) of the working claw 126. In FIG. 3, the maximum thickness (Hmax) of the working claw 126 is equal to the maximum thickness (H0) of the claw body 30.

[0044] As described above, in the working claw 126 of the present embodiment, the hard metal part 40 does not protrude beyond the maximum thickness portion of the working claw 126, and the working resistance is significantly reduced as compared with the prior art. Further, by sequentially decreasing the thickness of the claw body 30 toward the cutting edge 22, the thickness of the hard metal part 40 provided in the thickness reduction part 32 can be increased, and the wear resistance can be significantly improved. That is, according to the present embodiment, it is possible to provide a working claw 126 that achieves both improved wear resistance and reduced working resistance.

[0045] (Modification example) In the present embodiment, as the modes of the first thickness change part 35 and the second thickness change part 37, a mode in which the thickness changes continuously is shown, but the present invention is not limited to this example. For example, in FIG. 3, the boundary parts between the first thickness reduction part 34 and the second thickness reduction part 36 and between the second thickness reduction part 36 and the third thickness reduction part 38 may be walls perpendicular or substantially perpendicular to the back surface of the claw body 30.

[0046] In the case of this modification example, the claw body 30 is in a mode in which the first thickness change portion 35 and the second thickness change portion 37 shown in FIG. 3 are substantially omitted. That is, the thickness reduction portion 32 of the claw body 30 in this modification example will have its thickness decreasing stepwise toward the cutting edge 22. In the case of this modification example, in order to make the change from the maximum thickness of the claw body 30 to the thickness of the first thickness reduction portion 34 as smooth as possible, it is preferable to provide two or more steps in the thickness reduction portion 32.

[0047] Even when, as in this modification example, the thickness of the claw body 30 changes stepwise in the thickness reduction portion 32, similar to the hard metal portion 40 shown in FIG. 3, the sum of the thicknesses of the claw body 30 and the hard metal portion 40 at any position in the thickness reduction portion 32 can be configured not to exceed the maximum thickness (Hmax) of the working claw 126.

[0048] 〈Second Embodiment〉 In this embodiment, a case will be described where the shape of the thickness reduction portion in the claw body is different from that of the first embodiment. In the description of the drawings of this embodiment, the same parts as those in the first embodiment will be described using the same reference numerals and the description will be omitted, and the description will focus on the different parts of the configuration.

[0049] FIG. 4 is a cross-sectional view showing the configuration of the working claw 126a in the second embodiment of the present invention. In this embodiment, in a cross-sectional view, the length (Wa) of the first thickness reduction portion 34a, the length (Ws) of the first thickness change portion 35a, and the length (Wb) of the second thickness reduction portion 36a in the thickness reduction portion 32a of the claw body 30a are the same or substantially the same. In FIG. 4, the lengths of the second thickness change portion 37 and the third thickness reduction portion 38 are different from the lengths of the first thickness reduction portion 34a, the first thickness change portion 35a, and the second thickness reduction portion 36a, but it is also possible to make the length of either one or both of the second thickness change portion 37 and the third thickness reduction portion 38 the same or substantially the same as the lengths of the first thickness reduction portion 34a, the first thickness change portion 35a, and the second thickness reduction portion 36a.

[0050] 〈Third Embodiment〉 In this embodiment, a case where the shape of the claw body is different from that of the first embodiment will be described. In the description of the drawings of this embodiment, the same parts as those of the first embodiment will be described using the same reference numerals, and the description will focus on the different parts of the configuration.

[0051] FIG. 5 is a cross-sectional view showing the configuration of the working claws 126b and 126c in the third embodiment of the present invention. The working claw 126b shown in FIG. 5(A) has a claw body 30b divided into a first claw body portion 61 and a second claw body portion 62. The first claw body portion 61 shown in FIG. 5(A) is formed along the peak edge 24 over substantially the entire length of the blade portion 20, and is a portion processed so as to have a constant or substantially constant thickness. By providing the first claw body portion 61, the manufacturing (material) cost can be reduced compared to a configuration without the first claw body portion 61 (a configuration in which the entire portion without the hard metal portion 40 has a uniform thickness), and the weight of the claw can be reduced. The first claw body portion 61 is preferably formed on the peak edge 24 side within a range not exceeding the replacement line described in the first embodiment.

[0052] The second claw body portion 62 is the portion of the claw body 30b other than the first claw body portion 61. In the example shown in FIG. 5(A), the maximum thickness (H0) of the second claw body portion 62 is larger than the maximum thickness (Hd) of the first claw body portion 61. In other words, the maximum thickness (H0) of the claw body 30b is larger than the thickness (Hd) of the claw body 30b at the peak edge 24.

[0053] Note that in FIG. 5(A), an example where the thickness (Hd) of the first claw body portion 61 is constant or substantially constant is shown, but the present invention is not limited to this example, and the thickness of the first claw body portion 61 may be configured to increase toward the peak edge 24 side or may be configured to increase toward the blade edge 22 side. Also, in the working claw 126b shown in FIG. 5(A), the hard metal portion 40 is provided so as to overlap the entire second claw body portion 62. However, the present invention is not limited to this example.

[0054] The working claw 126c shown in Fig. 5(B) has a claw body 30c that is divided into a first claw body portion 61a and a second claw body portion 62a. The first claw body portion 61a shown in Fig. 5(B) is formed along the peak edge 24 over substantially the entire length of the cutting edge 20, similar to the first claw body portion 61 shown in Fig. 5(A), and is a portion processed so as to have a constant or substantially constant thickness. The second claw body portion 62a is the portion of the claw body 30c other than the first claw body portion 61a. The difference from the working claw 126b shown in Fig. 5(A) is that a hard metal part 40 is provided so as to overlap a part of the second claw body portion 62a. Specifically, on the peak edge 24 side of the second claw body portion 62a, there is a portion where the hard metal part 40 is not provided. Since the basic structure of the first claw body portion 61a is the same as that of the first claw body portion 61 described above, duplicate explanations are omitted.

[0055] As described above, in the present embodiment, there is a step (which may be an inclined portion instead of a step) between the peak edge 24 of the claw bodies 30b and 30c and the hard metal part 40. In the working claw 126b shown in Fig. 5(A) described above, since the first claw body portion 61 with a reduced thickness is provided on the peak edge 24 side of the claw body 30b, it is possible to further reduce the working resistance during work compared to the first embodiment. Further, the above-mentioned step is provided on the first surface that functions as a "scooping surface" for throwing soil during work. However, since the flow of soil moving along the first surface occurs from the cutting edge 22 side toward the peak edge 24 side, the presence of the step does not become an obstacle to the flow of soil and does not significantly affect the throwing performance of the working claw 126d. In the working claw 126b, the thickness (Hd) of the first claw body portion 61 with respect to the maximum thickness (H0) of the claw body 30b is preferably about 50% to 80% in consideration of the strength of the working claw 126b. If the thickness (Hd) of the first claw body portion 61 is below the above range, there is a risk that the strength (durability) of the working claw 126b will be insufficient. The same applies to the working claw 126c shown in Fig. 5(B) regarding these matters.

[0056] (Modification example) In the example shown in FIG. 5, a step is formed on the first surface side of the claw body 30 which is the scooping surface, but the present invention is not limited to this example, and a step may be formed on the second surface side of the claw body 30 which is the surface opposite to the scooping surface.

[0057] FIG. 6 is a cross-sectional view showing the configuration of the working claw 126d in a modified example of the third embodiment of the present invention. Specifically, it corresponds to a modified example of the configuration of FIG. 5(B), and other configurations are the same except that the surface where the step is provided is different from that of FIG. 5(B). Here, a modified example of FIG. 5(B) is illustrated, but a modified example of FIG. 5(A) is also possible.

[0058] The working claw 126d shown in FIG. 6 has a claw body 30d divided into a first claw body portion 61b and a second claw body portion 62b. Similar to the example shown in FIG. 5(B), the first claw body portion 61b is formed along the peak edge 24 over substantially the entire length of the blade portion 20, and is a portion processed so as to have a constant or substantially constant thickness. Thus, in the example shown in FIG. 6, the step is provided on the surface opposite to that of FIG. 5(B), and the surface on the side where the hard metal portion 40 of the first claw body portion 61b is provided is not processed.

[0059] According to this modified example, since no step is provided on the first surface that functions as the above-mentioned "scooping surface", the flow of soil moving along the first surface during work does not change due to the step, and there is an advantage that the influence on the throwing performance of the working claw 126d can be further reduced.

[0060] <Fourth Embodiment> In the present embodiment, a case where the shape of the claw body is different from that of the first embodiment will be described. In the description of the drawings of the present embodiment, the same parts as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted, and the description will focus on the parts having different configurations.

[0061] FIG. 7 is a cross-sectional view showing the configuration of the working claw 126e in the fourth embodiment of the present invention. In the working claw 126e of the present embodiment, the surface of the first thickness reduction portion 34e in the thickness reduction portion 32e is inclined such that the thickness increases as it approaches the cutting edge 22 with respect to the back surface of the claw body 30e when the claw body 30e is placed on a horizontal plane. Specifically, the surface of the first thickness reduction portion 34e is inclined with respect to the back surface such that the thickness (Ha') closer to the cutting edge 22 is relatively thicker than the thickness (Ha) closer to the peak edge 24. In other words, the surface of the first thickness reduction portion 34e and the surface of the second thickness reduction portion 36 are not parallel, and the surface of the first thickness reduction portion 34e is inclined with respect to the surface of the second thickness reduction portion 36. In the example shown in FIG. 7, a configuration in which the thickness of the first thickness reduction portion 34e increases as it approaches the cutting edge 22 is shown, but the present invention is not limited to this example. Specifically, when the working claw 126e is placed on a plane with the back surface of the claw body 30e facing down, it is sufficient that the surface of the first thickness reduction portion 34e rises as it approaches the cutting edge 22. Therefore, the back surface of the first thickness reduction portion 34e may be inclined with respect to the back surface of the other portion of the claw body 30e, and the thickness (Ha') may be relatively thinner than the thickness (Ha), or the thickness (Ha') may be equal to the thickness (Ha). Further, in the example shown in FIG. 7, an example in which the entire surface of the first thickness reduction portion 34e is inclined is shown, but the present invention is not limited to this example, and a configuration in which only a part of the first thickness reduction portion 34e on the cutting edge 22 side is inclined may be used.

[0062] When the working claw 126e of the present embodiment is installed on a plane with the back surface of the claw body 30e facing down, in a cross-sectional view, the first thickness reduction portion 34e has a shape that rises as it approaches the cutting edge 22. Therefore, when forming the hard metal portion 40, the molten metal material has an advantage of being likely to stay in the thickness reduction portion 32e. That is, the inclination of the surface of the first thickness reduction portion 34e serves as a stopper for suppressing the molten metal material from flowing down from the cutting edge 22 when the molten metal material is supplied to the thickness reduction portion 32e. From this, the degree to which the surface of the first thickness reduction portion 34e rises can be appropriately set according to the viscosity (fluidity) of the metal material (molten metal material) to be constructed.

[0063] In the example shown in FIG. 7, only the surface of the first thickness reduction portion 34e is inclined, but the present invention is not limited to this example. In addition to or instead of the first thickness reduction portion 34e, the surface of the second thickness reduction portion 36 may be inclined with respect to the back surface of the claw body 30e. In other words, the surface of the first thickness reduction portion 34e and the surface of the second thickness reduction portion 36 are not parallel, and the surface of the second thickness reduction portion 36 may be inclined with respect to the surface of the first thickness reduction portion 34e. Further, in the present embodiment, the first thickness reduction portion 34e and the second thickness reduction portion 36 are shown to be inclined such that the thickness increases as approaching the cutting edge 22, but the present invention is not limited to this example, and the thickness may be configured to increase stepwise as approaching the cutting edge 22. Further, when the first thickness reduction portion 34e and the second thickness reduction portion 36 are configured to be inclined such that the thickness increases as approaching the cutting edge 22, the inclined surface is not limited to being a straight line in a cross-sectional view, and may be a curve in a cross-sectional view. Furthermore, although only the configuration in which only one of the first thickness reduction portion 34e and the second thickness reduction portion 36 is inclined has been described, the configuration in which both the first thickness reduction portion 34e and the second thickness reduction portion 36 are inclined may be employed. Specifically, the first thickness reduction portion 34e may be configured such that the thickness increases as approaching the cutting edge 22 and the second thickness reduction portion 36 may be configured such that the thickness decreases as approaching the cutting edge 22, or the first thickness reduction portion 34e may be configured such that the thickness decreases as approaching the cutting edge 22 and the second thickness reduction portion 36 may be configured such that the thickness increases as approaching the cutting edge 22, or both the first thickness reduction portion 34e and the second thickness reduction portion 36 may be configured such that the thickness increases as approaching the cutting edge 22, or both the first thickness reduction portion 34e and the second thickness reduction portion 36 may be configured such that the thickness decreases as approaching the cutting edge 22.

[0064] <Fifth Embodiment> In the first to fourth embodiments, the thickness reduction portions are shown as examples in which the thickness sequentially decreases toward the cutting edge through the inclined portion, but the thickness reduction portion may be one in which the thickness continuously decreases toward the cutting edge. Specifically, the surface of the thickness reduction portion may be one in which the thickness linearly changes from the maximum thickness (H0) of the claw body to the thickness of the cutting edge.

[0065] According to the present embodiment, in the thickness reduction portion, since the thickness of the claw body continuously decreases toward the cutting edge, as the thickness decreases, the thickness of the hard metal portion provided in the thickness reduction portion increases, and the durability of the working claw is improved. Further, similar to the working claws shown in the first to fourth embodiments, by ensuring that the sum of the thicknesses of the claw body and the hard metal portion at any position in the thickness reduction portion does not exceed the maximum thickness of the working claw, an increase in working resistance can be prevented.

[0066] <Sixth Embodiment> Examples in which each thickness reduction portion and each thickness change portion of the thickness reduction portion from the first to fourth embodiments are straight lines in a cross-sectional view have been shown, but at least one of them may be a concave curve or a convex curve.

[0067] According to the present embodiment, similar to the working claws shown in the first to fourth embodiments, by ensuring that the sum of the thicknesses of the claw body and the hard metal portion at any position in the thickness reduction portion does not exceed the maximum thickness of the working claw, an increase in working resistance can be prevented.

[0068] In each of the above embodiments, a rotary tiller is exemplified as the agricultural working machine 100, but the present invention is not limited to this example, and can be applied to other agricultural working machines as long as they are agricultural working machines including a working rotor having a plurality of working claws. For example, it can also be applied to the working claws provided on the working rotor of a ridging machine or the working claws provided on the pretreatment section of a bed coating machine.

[0069] The present invention has been described above with reference to the drawings, but the present invention is not limited to the above-described embodiments, and can be appropriately modified without departing from the spirit of the present invention. For example, based on each embodiment, those in which a person skilled in the art appropriately adds, deletes, or changes the design of components are also included in the scope of the present invention as long as they have the gist of the present invention. Further, the above-described embodiments can be appropriately combined as long as there is no contradiction between them, and technical matters common to each embodiment are included in each embodiment even if not explicitly described.

[0070] Even other operational effects different from the operational effects brought about by the aspects of the above-described embodiments, those that are obvious from the description in this specification or can be easily predicted by those skilled in the art shall naturally be construed as being brought about by the present invention.

Description of Reference Numerals

[0071] 10... Mounting base, 12... Mounting hole, 20... Blade part, 22... Blade edge, 24... Crest edge, 26... Head edge, 30, 30a to 30e... Claw body, 32, 32a, 32d, 32e... Thickness reduction part, 34, 34a, 34d, 34e... First thickness reduction part, 35, 35a... First thickness change part, 36, 36a... Second thickness reduction part, 37... Second thickness change part, 38... Third thickness reduction part, 40... Hard metal part, 51, 52... Virtual line, 61, 61a, 61b... First claw body part, 62, 62a, 62b... Second claw body part, 100... Agricultural work machine, 102... Top mast, 104... Lower link connection part, 106... Input shaft, 108... Main frame, 110... Shield cover, 111... Connection part, 112... Apron, 114... Control device, 120... Working rotor, 122... Claw shaft, 124... Flange, 126, 126a to 126e... Working claw, 126L... L working claw, 126R... R working claw

Claims

1. A working claw comprising a claw body having a thickness reduction portion with a thickness smaller than the maximum thickness, and a hard metal portion provided in the thickness reduction portion and composed of a metal material harder than the claw body. The thickness reduction portion includes a first thickness reduction portion provided on the cutting edge side, and a second thickness reduction portion provided on the peak edge side of the first thickness reduction portion and having a thickness larger than that of the first thickness reduction portion. The sum of the thicknesses of the claw body and the hard metal portion at any position of the thickness reduction portion does not exceed the maximum thickness of the working claw.

2. The thickness reduction portion includes a first thickness reduction portion having a first thickness, a second thickness reduction portion having a second thickness larger than that of the first thickness reduction portion, and a thickness change portion provided between the first thickness reduction portion and the second thickness reduction portion and having a continuously changing thickness. The working claw according to Claim 1.

3. The hard metal portion is such that the thickness of the peak edge side end portion of the portion provided in the first thickness reduction portion is larger than the thickness of the peak edge side end portion of the portion provided in the second thickness reduction portion. The working claw according to Claim 2.

4. In a cross-sectional view, the length of the first thickness reduction portion is larger than the length of the second thickness reduction portion. The working claw according to Claim 2.

5. The maximum thickness of the claw body is larger than the thickness of the claw body at the peak edge. The working claw according to any one of Claims 1 to 4.

6. The sum of the thickness of the first thickness reduction portion and the thickness of the peak edge side end portion of the portion of the hard metal portion provided in the first thickness reduction portion is smaller than the sum of the thickness of the second thickness reduction portion and the thickness of the peak edge side end portion of the portion of the hard metal portion provided in the second thickness reduction portion. The working claw according to Claim 2.

7. The surface of the portion of the hard metal portion provided in the first thickness reduction portion is convexly curved. The working claw according to Claim 2.

8. An agricultural working machine comprising the working claw according to any one of Claims 1 to 4. ​

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