JPH11300534A - Method for surface treatment of blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the wear resistance of a rotary blade by forming a laminated blade part by covering an electrode rod material on a grinding surface with the electrical discharge between the grinding surface and the electrode rod to allow the electrode rod material to form a sharp edge projecting outward of a blade part, and to maintain the sharpness when a back side of the grinding surface is worn. SOLUTION: In a rotary blade 1 in which a teeth part 5 is formed on an outer circumferential part of a disk-like blade plate 1a, and a grinding surface 2a is formed on a front side (a side surface) of the teeth part 5, a laminated blade part 2 is formed by covering an electrode rod material 2b on the grinding surface 2a with the discharge between the grinding surface 2a and the electrode rod, and the electrode rod material 2b is covered on the grinding surface by the discharge between the grinding surface of the teeth part of the cutting blade and the electrode rod.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade such as a rotary blade mounted on a cutter of a combine, a cutting blade mounted on a threshing unit, a rotary blade of a mower, and a lawnmower or a tea mower. TECHNICAL FIELD The present invention relates to a technique for improving the wear resistance of a blade portion of a cutting tool used for a blade.

[0002]

2. Description of the Related Art Conventionally, there has been known a technique of cutting rice, wheat, and the like with a combine, threshing, and cutting a waste straw after threshing with a cutter device. A plurality of rotary blades (disk cutters) are fixed in parallel, and the rotary blades have a saw-shaped blade portion formed on the outer periphery of a disk-shaped blade plate. By rotating the rotating shaft of the above, the straw was thrown in during that time to cut the straw, and after the cutting, the straw was released to the field.

[0003]

However, the rotary blade is made of steel, and the blade is hardened by a process such as quenching. However, when a large number of straws are cut, the blade becomes hard. They wear quickly and therefore lose their sharpness, are released without being cut, or cause clogging, resulting in poor working efficiency. If the sharpness decreases, the worn rotary blade must be polished or the rotary blade must be replaced, but all of these operations are very troublesome and costly, so it is desirable to maintain the sharpness as long as possible. is there.

[0004] Therefore, in a rotary blade having a blade portion formed on the outer periphery of a disk-shaped blade plate, one side surface of the blade portion is coated with a wear-resistant metal by a thermal spray welding method, so that the resistance of the rotary blade is reduced. An invention for improving wear properties has been proposed by the present applicant. However, in order to further improve the work efficiency of threshing and mowing work by combining (reducing the number of replacements of the rotary blade and reducing the polishing operation time), it is desired to further improve the wear resistance of the rotary blade. -ing

[0005] In addition, when threshing,
A cutting blade for finely cutting a long straw that has been cut off halfway is also known, and the straw is cut by the cutting blade to reduce the load on the threshing unit. However, like the above-mentioned rotary blade, when the cutting blade cuts a lot of straw,
There is a problem that the blade portion wears out quickly, resulting in a decrease in sharpness. Therefore, improvement in wear resistance is also desired. Further, there is a demand for improved wear resistance of a blade portion of a blade used in a lawn mower, a tea mower, or the like.

[0006]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. That is, the blade portion 5 is formed on the outer peripheral portion of the disk-shaped blade plate 1a, and the polishing surface 2 is formed on the front side (one side surface) of the blade portion 5a.
In the rotary blade 1 formed with the a, the polishing surface 2a is coated with the electrode rod material 2b by the discharge between the polishing surface 2a and the electrode rod to form the laminated blade portion 2, thereby forming the back surface of the polishing surface 2a. When the (other side) is worn, the electrode rod material 2b
However, a sharp edge protruding outward from the blade portion 5 is formed to maintain sharpness, and the wear resistance of the rotary blade 1 is improved. Also, the polishing surface 14a of the blade portion 14 of the cutting blade 13
When the back surface of the polished surface 14a is worn by coating the polished surface 14a with the electrode rod material 2b by the discharge between the electrode bar and the electrode rod material, the electrode rod material 2b is moved outward with respect to the blade portion 14. A sharp edge protruding toward the cutting edge is formed to maintain sharpness and improve the wear resistance of the cutting blade 13.

[0007]

Embodiments of the present invention will be described.
FIG. 1 is an overall front view of the rotary blade, FIG.
3 is an overall front view of the polished surface of FIG. 1 coated with an electrode material, FIG. 4 is a partially enlarged view of FIG. 3, FIG. 5 is a sectional view taken along line AA of FIG. 3, and FIG. 5 is a sectional view showing a worn state;
7 is a perspective view of the electric discharge film processing apparatus, FIG. 8 is a perspective view of a cutting blade, FIG. 9 is a cross-sectional view taken along the line BB of FIG. 8, FIG. 10 is an overall front view of a rotary blade having a different blade shape, and FIG. Also the whole back view,
FIG. 12 is an overall front view when the polished surface of FIG. 10 is coated with an electrode material.

Referring to FIGS. 1, 2, 3 and 4, a method of processing the rotary blade 1 will be described. The rotary blade 1 is mounted in parallel on a rotating shaft of a combine cutter device, and in the combine, cuts a lower part of a grain culm in a field, transports it to a threshing unit, threshes, and removes a straw after threshing. The cutting is performed by the rotation of the rotary blade. The rotary blade 1 has a polygonal (hexagonal in this embodiment) mounting hole 1b for mounting on a rotary shaft of a cutter device at the center of a disk-shaped blade plate 1a. Is formed with a saw blade-shaped blade portion 5, and the blade plate 1 a is rotated to cut a straw by the blade portion 5. The blade portion 5 is composed of oblique straight portions 3, 3... And cutting edge blade bottom portions R, 4,... And is formed of a relatively hard base material such as steel.

Then, the periphery of the blade plate 1a is bent in a "-" shape toward the front surface as shown in FIG. 5, and the front surface of the blade portion 5 is cut substantially in parallel with the blade plate 1a to obtain a polished surface. 2a. The polished surface 2a is covered with an electrode rod material 2b, and the steel of the polished surface 2a and the electrode rod material 2b constitute a laminated blade portion 2. The electrode rod material 2b is formed on the polished surface 2a by electric discharge between the polished surface 2a and the electrode rod.

The above-mentioned coating method is called a discharge coating process, and direct current is discharged in a short time by a discharge coating device 6 as shown in FIG. At the contact portion, the electrode rod 7 is heated to 8000 to 25000 ° C. and is in a plasma ionized state, and the tip of the electrode rod 7 is melted and is discharged and coated on the polished surface 2a. The electrode rod material 2b coated by the discharge is metallurgically transferred to the polished surface 2a to be alloyed and deposited, and at the same time, diffuses and penetrates and adheres with high strength.

That is, in the discharge coating process, the electrode rod material 2b diffuses and penetrates into the polished surface 2a to form a permeable layer. Therefore, compared with the conventional thermal spray welding method, the electrode rod material 2b has higher adhesion and does not peel off. . Further, in the thermal spray welding method, after abrasion-resistant metal is welded to the back side surface of the blade portion, 1050 ° C.
It was reheated and melted at ~ 1100 ° C to form a dense and hard film. However, depending on the discharge coating process, it is not necessary to reheat the electrode rod material 2b after coating it on the polished surface 2a. Can be shortened.

The electrode rod material 2b is W
C, TiC, Cr3 O2, TiN, TiB2, TaC,
A sintered body containing a plurality of Mo2C or the like, or a cermet such as Ni, Co, etc., Mo, Ni, Ti, Ta, Z
Metals such as r, Nb, Pt, and Au can be used. The electrode rod material 2b becomes a dense and hard film, is excellent in abrasion resistance and corrosion resistance, and can extend the life of the rotary blade.

Next, the laminated blade portion 2 of the rotary blade 1 will be described with reference to FIGS. An operation of cutting the waste straw with the rotary blade 1 is performed by a combine cutter device having the rotary blade 1, but when cutting is repeated for a long period of time, the rotary blade 1 is worn, and the laminated blade portion 2 is moved from the state of FIG. The state changes to 6. That is, the back surface of the polished surface 2a made of steel or the like is
Since the abrasion resistance is inferior to the electrode rod material 2b, the cutting edge 4
It wears inward from the (edge R portion) before the electrode rod material 2b. Therefore, the electrode rod material 2b gradually protrudes outward as shown in FIG. In addition, when the front and back surfaces of the rotary blade 1 are treated such as quenching or covered with the electrode rod material 2b as in the related art, the blade edge bottom R portion 4
Are worn at the same time on the front and back sides, so that the peaks are worn and become almost circular, resulting in poor sharpness. In particular, electrode rod material 2
If not covered with b, wear will be even faster.

In this manner, the laminating blade portion 2 is
Even if the back side of a is worn, the electrode rod material 2b is in a protruding state, so that the function of cutting the straw (sharpness) is maintained, and the abrasion resistance can be improved. In addition, by improving the wear resistance of the rotary blade 1, the number of replacements of the rotary blade can be reduced, and therefore, the polishing operation time can be reduced, and the harvesting and harvesting operation by the combine can be effectively performed. It becomes. 10 and FIG.
1, the rotary blade having a different blade shape shown in FIG.
A blade treatment similar to that described above is performed.

Next, the cutting blade 13 will be described. FIG.
As shown in FIG. 9, the cutting blade 13 was attached to the threshing part of the combine, and when cutting the lower part of the grain culm of the field with the combine and transporting it to the threshing part, the cutting blade 13 was pulled out from the root or cut off in the middle. The long straw is finely cut by the blade section 14 to reduce the load on the threshing section. The cutting blade 1
Numeral 3 is formed by bending a steel plate or the like to form a U-shape in a plan view, has a saw blade-shaped blade portion 14, and has a front surface of the blade portion 14 ground and polished surface 14a. And like the above-mentioned rotary blade, the polished surface 14a is covered with the electrode rod material 2b.

Therefore, when the back side surface of the blade portion 14 is worn, the electrode rod material 2b forms a sharp edge protruding outward with respect to the blade portion 14 to maintain sharpness and to reduce wear resistance. Therefore, the number of replacements of the cutting blade 13 can be reduced, the polishing operation time can be reduced, and the harvesting and harvesting operation by the combine can be effectively performed.

[0017]

As described above, the present invention has the following advantages. That is, the disk-shaped blade plate 1
a rotary blade 1 having a blade portion 5 formed on the outer peripheral portion thereof and a polishing surface 2a formed on the front side (one side surface) of the blade portion 5; By forming the laminated blade portion 2 by coating the electrode rod material 2b on the electrode rod material 2a, when the back surface (other side surface) of the polishing surface 2a is worn,
The electrode rod material 2b formed a sharp edge protruding outward with respect to the blade portion 5 to maintain sharpness, and the wear resistance of the rotary blade 1 could be improved. Further, the blade portion 1 of the cutting blade 13
When the back surface of the polished surface 14a is worn by coating the polished surface 14a with the electrode rod material 2b by the discharge between the polished surface 14a and the electrode rod, the electrode rod material 2b
A sharp edge protruding outward was formed with respect to the blade portion 14 to maintain sharpness, and the wear resistance of the cutting blade 13 could be improved.

[Brief description of the drawings]

FIG. 1 is an overall front view of a rotary blade.

FIG. 2 is an overall rear view.

FIG. 3 is an overall front view when the electrode surface is coated on the polished surface of FIG. 1;

FIG. 4 is a partially enlarged view of FIG. 3;

FIG. 5 is a sectional view taken along line AA of FIG. 3;

FIG. 6 is a cross-sectional view showing a state where the blade portion 5 of FIG. 5 is worn.

FIG. 7 is a perspective view of a discharge film processing apparatus.

FIG. 8 is a perspective view of a cutting blade.

FIG. 9 is a sectional view taken along line BB of FIG. 8;

FIG. 10 is an overall front view of a rotary blade having a different blade shape.

FIG. 11 is an overall rear view.

FIG. 12 is an overall front view when the polished surface of FIG. 10 is coated with an electrode material.

[Description of Signs] 1 Rotary blade 1a Blade plate 2 Laminated blade portion 2a Polished surface 2b Electrode bar material 5 Blade portion 13 Cutting blade 14 Blade portion 14a Polished surface

Claims (1)

[Claims] 1. A method for surface treatment of a blade, characterized in that a discharge is generated between one side surface of a blade portion and an electrode bar, and the one side surface is coated with an electrode bar material.