JPS59166416A - Shearing cutter - Google Patents

Abstract

PURPOSE:To enable complete repairing of cutter section through welding, by padding tool steel on the cutter body formed with structural steel then polishing the padded section to form the cutter section. CONSTITUTION:A cutter is made such that a notch 6 is formed at the corner of cutter body 4 formed with structural steel then tool steel is padded on said notch 6 and polished to form a cutter section 5. When a portion of cutter section is broken or cracked during shearing work, the circumference of broken section is removed through arc gauging then built up welded to bring uniform state. Thereafter the built-up section is polished to repair the cutter section 5 completely.

Description

[Detailed description of the invention] Technical field This invention relates to shear blades.

Conventional shearing machines sandwich the material between two lower or left and right blades and move one or both of the blades fully during hot or cold operation to cut the material to a certain size. It is a machine that cuts charges. As shown in FIG. 1, during shearing, forces PI, P2 and lateral pressures Ft, F2 are applied to the blade 2°3 from above and below the material 1. Therefore, a friction coefficient occurs between the material 1 and the total friction coefficient of μm and μ2. μ8
・If μ4, then the frictional force μIPt, μ8P2. μ2F1
1114F2. Therefore, the material for blades used in hot conditions is required to have heat resistance and wear resistance, and the material for blades used in cold conditions is required to have wear resistance.

Conventionally, as shown in FIG. 2, this type of blade 3 is formed by brazing a blade part 5 made of tool steel to a blade body 4 made of structural steel; Some were made entirely of tool steel. When the blade part 5 is chipped 9 or cracked due to shearing work, the Ministry of Penalties replaces the blade part 5 with a new brazed part and scraps the damaged blade part 5. or,
In the latter case, cut and sharpen the blade until the damaged part is removed and then make a new blade. was forming. However, since tool steel is more expensive than structural tool steel, scrapping the broken blade part 5 every time the blade part 5 is damaged poses a problem in that the cost I. is still high. Furthermore, if the entire blade is made of tool steel, expensive tool steel will be used even in unnecessary parts, which again results in a cost increase of 1 or more.

It is possible to repair the blade part 5 where a part is chipped or has a crack by welding the entire part, but since the metal melted by welding and the material of the blade part 5 are different, the welded part may be damaged. It cannot sufficiently withstand thermal stress and frictional force during shearing operations.

Moreover, the heat during welding has a negative effect on the solder joint. . Therefore, even if small cracks were repaired by welding as an emergency measure, welding could not be used to repair large cracks that were partially chipped. The purpose was to provide a complete shearing machine that can be repaired by welding if a part of the blade part is chipped or cracked.

EXAMPLE A fully embodied example of this invention will be described below with reference to FIGS. 3 to 6. As shown in FIG. 3, the blade 3 is formed by forming a notch 6 entirely at the corner of the blade body 4 made of structural steel, filling the notch 6 with welded tool steel, and then applying the welded tool steel. The blade portion 5 is formed by grinding the built-up portion. The method of fully overlaying the tool steel in the cutout portion 6 of the blade body 4 will be described in detail below.

The tool steel is built up by covered arc welding using a covered welding rod 7'. S K D in the notch 6 of the blade body 4
To explain the case of completely welding a tool steel similar to 8KD52, the coated welding rod 7 is a welding rod made of carbon steel with a carbon content of about 0.03%, and a welding rod made of carbon steel with a similar composition to 8KD52 steel (the amount of exposed molyftene is It is formed by completely covering the entire surface with a flux whose main component is an alloy (approximately 1% more). Welding is carried out using direct current across the entire bath welding frame side. The welding rod varies depending on the thickness of the coated welding rod 7 used, and the maximum diameter is 19t.
If you use the nm one, you will get 30 to 9 servings per hour. If the thickness T of the blade portion 5 is about 6 steel, a coated welding rod 7 with a diameter of about 4 mm is conveniently used. When forming a large blade 3 that requires a prolific welding rod, a thick one is used as the covered welding rod 7, so as shown in FIG. 5, it is connected by two links 8a. The welding is damaged by the large holder 8 having an arm 9b (i7). The gripping piece 9 of the holder 8 is opened and closed by an air cylinder 10, and the operator is protected from direct heat during welding by a heat shielding sheet 11.

The blade body 4 as a base material is preheated to about 450 to 540°C and kept at this temperature until the welding is completed. The blade body 4 has a slag 12 during welding.
Place it on an incline so that it can easily be tilted outward. Tilt the welding rod slightly in the direction of travel to keep the arc short. After the thermal stress is mechanically removed by welding a 100-layer weld layer, welding is continued again. Peening is also performed on the final layer of the common appetizer. As shown in FIG. 6, when the notch 6 of the blade body 4 is filled up, approximately
After air cooling to 50°C, tempering is further performed at about 540°C. Next, the slag 12 on the surface is completely removed and the entire surface is ground with a grinder to complete the blade 3.

The strength of the current during welding varies depending on the thickness of the covered welding rod 7, and in the case of a diameter 4 mm, the current strength is in the range of 125 to 175 amperes. Furthermore, if a flux-cored wire is used instead of the coated welding rod T and is continuously fed by a wire feeding device, welding can be performed continuously until the build-up is completed.

In the blade 3 configured as described above, if a part of the blade part 5 is chipped or cracked due to shearing work, remove the periphery of the chipped or cracked part using arc gouging or the like, and remove the part. By overlaying the blade portion 5, the newly welded portion is formed to be completely homogeneous with the original blade portion 5. Therefore, by polishing the build-up blade part in this state, the blade part 5 is completely repaired, and unlike the conventional case, there is no need to scrap expensive plywood every time the blade part 5 is damaged.

Note that the present invention is not limited to the above-mentioned embodiments, and the shape, structure, etc. of each part may be changed without departing from the spirit of the present invention, such as changing the materials of the blade body 4 and the blade portion 5 depending on the overall required strength. It is also possible to change it arbitrarily.

Effects As detailed above, this invention has a blade body shaped from structural steel, which is filled with tool steel welded by welding, and then the built-up portion is ground to form a blade portion. When the blade part is damaged, the damaged part can be completely repaired by welding, so unlike conventional blades, even if the blade part is made entirely of tool steel, every time the blade part is damaged, the damage will be completely repaired. This has the excellent effect of reducing costs by eliminating the need to scrap expensive alloys.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the blade that acts during shearing, Fig. 2 is a perspective view showing the blade of a conventional shearing machine, Fig. 3 is a perspective view showing all 10 examples embodying the invention, Fig. 4 The figure shows a cross-sectional view of seven wires in the middle of bath welding, Figure 5 is a schematic diagram showing a state in which welding is performed using a large holder, and Figure 6 is a perspective view showing the state of welding in the welding state. be. Blade 3, blade body 4, blade part 5, notch part 6, desired welding height 7゜Patent applicant Tadashi Ohnishi -

Claims (1)

[Scope of Claims] 1. Welding melted tool steel overlay on the J-shaped blade body (4) with structural w4, and then polishing the overlay part to form the blade part (5). A cutting l1J characterized by the fact that
T machine blade. 2. The shearing machine blade according to claim 1, wherein the welding I-t is controlled arc welding. 8. The shearing machine blade according to claim 1 or 2, wherein the build-up 9 is performed in a notch (6) formed in a corner of the blade (4). .