JP6940255B2 - Cutting blade and agricultural machinery equipped with it - Google Patents

Description

The present invention relates to a cutting blade and an agricultural machine including the cutting blade.

Conventionally, agricultural machinery such as a combine harvester is provided with a cutting blade for cutting straw such as harvested rice and wheat. The surface of such a cutting blade is coated with a hard material in order to improve cutability and wear resistance.

For example, Patent Document 1 discloses a chopper knife used in an agricultural machine, in which a coating layer made of chromium carbide or tungsten carbide is provided on the surface of the blade. The chopper knife described in Patent Document 1 reduces the amount of the coating material used and reduces the cost by reducing the thickness of the coating layer toward the base of the chopper knife.

International Publication No. 2012/146452 (Released on November 1, 2012)

However, in the chopper knife described in Patent Document 1, if the coating layer on the cutting edge is peeled off by use, wear progresses starting from the peeled portion of the coating layer, and the cutability is deteriorated. Therefore, there is a problem that the durability is poor.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a cutting blade having excellent durability.

In order to solve the above problems, the cutting blade according to the present invention is a cutting blade used in an agricultural machine to cut agricultural products, and has a first surface and a second surface, and the first surface and the cutting blade. The cutting edge is formed by the second surface, and the first surface and the second surface have a coating layer on the surface, and the cutting blade is a plane along the direction of cutting the agricultural product. When the plane passing through the cutting edge is the first plane, the first angle formed by the first surface and the first plane is different from the second angle formed by the second surface and the first plane. It is a feature.

According to the above configuration, in the cutting blade, the inclinations of the first surface and the second surface are different, so that the load applied to each surface when cutting the crop is different. Therefore, among the coating layers formed on the surfaces of the first surface and the second surface by use, the coating layer formed on the surface having a large inclination progresses to wear, but on the surface having a small inclination. The formed coating layer wears slowly. Therefore, the angle of the cutting edge can be maintained, and it becomes possible to provide a cutting blade having excellent durability.

Further, in the cutting blade according to the present invention, the third angle formed by the first surface and the second surface is preferably 28.5 ° or more and 38 ° or less.

According to the above configuration, by setting the third angle to 28.5 ° or more and 38 ° or less, the cutability of the cutting blade and the strength of the cutting edge can be improved.

Further, in the cutting blade according to the present invention, the difference between the first angle and the second angle may be 6 ° or less.

According to the above configuration, the cutability of the cutting blade can be improved by setting the difference between the first angle and the second angle within 6 °.

Further, in the cutting blade according to the present invention, the coating layer may contain at least one selected from the group consisting of diamond-like carbon, TiN, TiAlN, and CrN as a main component.

According to the above configuration, a hard coating layer can be formed by using at least one selected from the group consisting of diamond-like carbon, TiN, TiAlN, and CrN as the main component of the coating layer.

An agricultural machine provided with the cutting blade is also included in the present invention.

According to the present invention, it is possible to provide a cutting blade having excellent durability.

(A) is a plan view showing the appearance of the cutting blade according to the embodiment of the present invention, and (b) is a cross-sectional view taken along the line AA in (a). It is an enlarged view of the region B shown in FIG. 1 (b). (A) and (b) are diagrams showing an example of the first surface and the second surface of the cutting blade after the cutting test.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1A is a plan view showing the appearance of the cutting blade 1 according to the embodiment of the present invention, and FIG. 1B is a cross section taken along the line AA in FIG. 1A. It is a figure.

The cutting blade 1 is a cutting blade for cutting agricultural products, and specifically, is provided in an agricultural machine such as a combine harvester and is a cutting blade for cutting straw or the like such as rice or wheat.

The cutting blade 1 has a substantially plate shape, and a hole 2 is formed in the vicinity of the end portion in the longitudinal direction. The cutting blade 1 is supported by a support member (not shown) by inserting a screw or the like into the hole 2. The cutting blade 1 moves along with the movement of the support member to cut crops such as straw. In this embodiment, an example in which the cutting blade 1 moves to cut an agricultural product such as straw will be described, but the present invention is not limited to this, and the cutting blade 1 may be fixed. That is, the present invention also includes a cutting blade 1 that cuts a crop by feeding a crop such as straw toward the fixed cutting blade 1.

The cutting blade 1 has double-edged blades 3 at both ends in the lateral direction. The double-edged blade 3 is formed along the longitudinal direction from the end portion in the longitudinal direction opposite to the side on which the hole portion 2 is formed. When the cuttability of one double-edged blade 3 is deteriorated due to the double-edged blades 3 being formed at the two locations in this way, the cutting blade 1 is used upside down to use the other double-edged blade whose cutability is not deteriorated. 3 can be used.

FIG. 2 is an enlarged view of the region B shown in FIG. 1 (b).

As shown in FIG. 2, the double-edged blade 3 has a first surface 3a and a second surface 3b, and the cutting edge 3c is formed by the first surface 3a and the second surface 3b.

A hard coating layer 4 is formed on the surface of the double-edged blade 3, that is, the surfaces of the first surface 3a and the second surface 3b. Here, the surface roughness Ra of the first surface 3a and the second surface 3b is preferably in the range of 1.6 μm to 6.3 μm. This is because if the surface roughness Ra of the first surface 3a and the second surface 3b is in the range of 1.6 μm to 6.3 μm, the adhesion to the coating layer 4 is good.

Further, the coating layer 4 preferably contains at least one selected from the group consisting of diamond-like carbon (DLC), TiN, TiAlN, and CrN as a main component. The thickness of the coating layer 4 is preferably in the range of 1.0 μm to 4.0 μm.

Here, the first surface 3a and the second surface 3b forming the cutting edge 3c of the double-edged blade 3 have different inclinations. That is, when the cutting blade 1 is a plane along the direction D for cutting the agricultural product and the plane including the cutting edge 3c is the first plane P, the first angle formed by the first plane 3a and the first plane P. α is different from the second angle β formed by the second surface 3b and the first plane P. Here, the first angle α and the second angle β are both angles exceeding 0 degrees, and the first plane P and the first plane 3a and the second plane 3b are not parallel to each other.

The angle formed by the first surface 3a and the second surface 3b and the first plane P is an acute angle among the angles formed by the first surface 3a and the second surface 3b and the first plane P. Point to the direction. Further, in the following, an example in which the second angle β is larger than the first angle α will be shown, but the present invention is not limited to this, and the first angle α may be larger than the second angle β. Further, the first plane P is, in other words, a plane perpendicular to the thickness direction of the substantially plate-shaped cutting blade 1, and is a plane including the cutting edge 3c.

The cutting blade 1 according to the present embodiment has different inclinations of the two surfaces (first surface 3a and second surface 3b) forming the cutting edge 3c in this way, so that the cutting blade 1 moves in a moving direction during use of the cutting blade 1. The load on the surface having the shorter length in D, that is, the surface having a large inclination, the second surface 3b, becomes large. Therefore, of the coating layer 4 formed on the second surface 3b and the coating layer 4 formed on the first surface 3a, the coating layer 4 formed on the second surface 3b has a faster progress of wear. Therefore, due to the use of the cutting blade 1, the coating layer 4 formed on the second surface 3b is worn out, but the coating layer 4 formed on the second surface 3b is worn slowly, and the coating layer 4 causes the cutting edge. Since the 3c is protected for a relatively long time, the angle of the cutting edge 3c is unlikely to change. By making the inclinations of the two surfaces forming the cutting edge 3c different in this way, the durability of the cutting blade 1 is improved.

The difference between the first angle α and the second angle β is preferably within 6 °. This is because when the difference between the first angle α and the second angle β becomes large, a large load is applied only to the surface on the side having a large angle, and the coating layer 4 on the surface is worn too much. This is because there is a high possibility that the coating layer 4 on the surface will be peeled off.

Further, the angle of the third angle γ formed by the first surface 3a and the second surface 3b, that is, the cutting edge 3c is preferably 28.5 ° or more and 38 ° or less. This is because when the third angle γ is less than 28.5 °, the strength of the cutting edge 3c decreases, and the cutting edge 3c is likely to be damaged during use. On the other hand, if the third angle γ exceeds 38 °, the cutting performance deteriorates. The angle of the cutting edge 3c is more preferably 29.5 ° or more and 37.5 ° or less, and even more preferably 30 ° or more and 34 ° or less.

(Example)
Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

The cutting blade 1 according to the above-described embodiment was prepared, and a straw cutting test was conducted. Specifically, a cutting blade 1 having a first angle α of 16 ° and a second angle β of 12 ° to 24 ° was created (Examples 1 to 24). Further, a cutting blade 1 having a first angle α of 15 ° and a second angle of 14 ° was created (Example 25). Further, for comparison, the cutting blade 1 having both the first angle α and the second angle β set to 16 ° (Comparative Example 1), and the cutting blade having both the first angle α and the second angle β set to 15 °. 1 (Comparative Example 2) was created. Then, the created cutting blade 1 was attached to the combine, and a straw cutting test was conducted for 50 hours under the conditions of a rotation speed of 2600 rpm and a vehicle speed of 0.60 m / s.

FIG. 3 is a diagram showing an example of the first surface 3a and the second surface 3b of the cutting blade 1 after the cutting test, in which (a) is the first surface 3a and (b) is the second surface 3c. Shown. Note that FIG. 3 shows a case where the test is performed using the cutting blade 1 having a second angle β larger than that of the first angle α. As shown in FIGS. 3A and 3B, the coating layer 4 shown in white in the figure remains on the first surface 3a, whereas the coating layer 4 on the second surface 3b. Can be seen to be worn out.

Further, as shown in FIG. 3A, on the first surface 3a where the coating layer 4 remains, streaky irregularities can be seen toward the cutting edge 3c. This is a polishing mark formed when the first surface 3a and the second surface 3b are formed on the cutting blade 1 before use, and thus, unevenness is formed on the first surface 3a and the second surface 3b. As a result, the adhesion to the coating layer 4 is improved.

Then, the durability, cutability, and strength of the cutting edge 3c were evaluated using the cutting blade 1 after the test.

The durability of the cutting blade 1 was evaluated by the following method. First, in the cutting blade 1 after the test, about 20 mm from the end of the cutting blade 1 (the end in the longitudinal direction and opposite to the end on the side where the hole 2 is formed). For three points, the ratio of the peeled area where the coating layer 4 was peeled off was measured. The measurement results are shown in Table 1. Here, regarding the durability, those having an average value of the peeling area ratios at the three points of less than 10% were designated as “◯”, and those having a durability of 10% or more were designated as “x”. In the coating layer 4 for measuring the peeling area ratio, the measurement was performed on the surface of the first angle α and the second angle β, which is considered to have a small load on the coating layer 4, whichever is smaller. For Comparative Example 1 in which the first angle α and the second angle β are equal angles, the area ratio at which the coating layer 4 is peeled off was measured on both surfaces, and the average value was taken as the peeled area ratio.

The cutability of the cutting blade 1 was evaluated by the following method. First, the length of the straw cut by each cutting blade 1 was measured, and the volume ratio of the straw having a length of 150 mm or more was measured. The measurement results are shown in Table 1. Here, regarding the cutability, the proportion of straw having a length of 150 mm or more is "○" when it is less than 9 vol%, and "Δ" when it is 9 vol% or more and less than 10 vol%, and it is 10 vol% or more. Those that are are designated as "x".

Regarding the strength of the cutting edge 3c, the cutting edge 3c of the cutting blade 1 after the test was observed, and those in which no change was observed in the cutting edge before and after the test were marked with "○", and a slight defect was found in the cutting edge 3c after the test. Those with a clear defect were marked with "Δ", and those with a clear defect in the cutting edge 3c after the test were marked with "x". Table 1 shows the evaluation results of the strength of the cutting edge 3c of each cutting blade 1.

As shown in Table 1, Comparative Example 1 and Comparative Example 2 in which the first angle α and the second angle β are equal are peeled off as compared with Examples 1 to 25 in which the first angle α and the second angle β are different. The area ratio is high. From this, it was confirmed that the cutting blade 1 having a different first angle α and second angle β has high durability.

Further, the proportion of straw having a length of 150 mm or more tends to increase as the angle of the cutting edge 3c represented by the sum of the first angle α and the second angle β increases. In Examples 20 to 24 in which the angle of the cutting edge 3c exceeds 37.5 °, the proportion of straw having a length of 150 mm or more is 9 vol% or more, and the angle of the cutting edge 3c exceeds 38 °. In 21 to 24, the proportion of straw having a length of 150 mm or more is 10 vol% or more. From this, it was confirmed that the angle of the cutting edge 3c is preferably 38 ° or less, and more preferably 37.5 ° or less.

Further, in Examples 1 to 3 and Example 25 in which the angle of the cutting edge 3c is less than 29.5 °, the strength of the cutting edge 3c is higher than that in Examples 4 to 24 in which the angle of the cutting edge 3c is 29.5 ° or more. In Example 1 in which the angle of the cutting edge 3c is less than 28.5 °, the strength of the cutting edge 3c is further reduced. From this, it was confirmed that the angle of the cutting edge 3c is preferably 28.5 ° or more, and more preferably 29.5 ° or more.

Further, Examples 21 to 24 in which the difference between the first angle α and the second angle β exceeds 6 ° are compared with Examples 1 to 20 in which the difference between the first angle α and the second angle β is within 6 °. From this, it was confirmed that the difference between the first angle α and the second angle β is preferably within 6 °.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

1 Cutting blade 3 Double-edged blade 3a 1st surface 3b 2nd surface 3c Cutting edge 4 Coating layer P 1st plane α 1st angle β 2nd angle γ 3rd angle

Claims (4)

A cutting blade used in agricultural machinery to cut agricultural products.
It has a first surface and a second surface,
The cutting edge is formed by the first surface and the second surface.
A coating layer is formed on the surfaces of the first surface and the second surface.
When the cutting blade is a plane along the direction of cutting the agricultural product and the plane passing through the cutting edge is the first plane, the first angle formed by the first plane and the first plane and the first plane. The second angle formed by the two planes and the first plane is different.
The coating layer contains at least one selected from the group consisting of diamond-like carbon, TiAlN, and CrN as a main component.
The first surface and the second surface are formed with streaky irregularities toward the cutting edge .
A cutting blade characterized in that the first surface and the second surface are surfaces before the coating layer is formed. The cutting blade according to claim 1, wherein the third angle formed by the first surface and the second surface is 28.5 ° or more and 38 ° or less. The cutting blade according to claim 1 or 2, wherein the difference between the first angle and the second angle is 6 ° or less. An agricultural machine provided with the cutting blade according to any one of claims 1 to 3.

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