JPH0669617B2 - Welding method of punching blade for die-cutting - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for welding a punching blade for a die cutter, which has excellent finish after welding and excellent joint strength.

Conventional technology and its drawbacks A die cutter that is formed by bending a blade material with one edge of one end of a strip-shaped steel sheet to be bent according to the contour of an object to be punched, and inserting and fixing the blade material in a wooden mold. The punching blade (generally referred to as "Thomson blade") for industrial use is widely used for various industrial applications. As shown in FIG. 1, this punching blade 10
The base is inserted into the wooden mold 12 and the cutting edge 10a is projected from the surface of the mold by a necessary amount. Then, in order to completely punch the object to be punched, both end portions 10 of the punching blade 10 are inevitably required.
b and 10b need to be perfectly abutted as shown in FIG. If this match is incomplete,
In the state of being fitted and fixed to 12, there are small gaps between the both end portions 10b, 10b, the gap gradually expands with an increase in the number of punches due to the operation of the die cutter, and the punched shapes become uneven, or the cut ends are cut. There are inconveniences such as not finishing well.

For this purpose, conventionally, it has been dealt with by welding both ends 10b, 10b of the punching blade 10 shown in FIG. However, in this welding, the heating time is longer depending on the normal welding method, so the quenching-hardened cutting edge is annealed to reduce the sharpness, and even if a slight resistance is encountered during punching, it is easy. It has the drawback of being transformed into. Therefore, as the welding means, silver brazing is generally carried out, but the punching blades due to this are prohibited from being used for punching foodstuffs due to food hygiene regulations.
In addition, in the case of silver brazing, the molten material melts around the back side of the joint and solidifies to form irregularities, which requires finishing work by scraping it off, which is extremely troublesome.

Instead of the silver brazing, as shown in FIG. 3, a punching blade
It has also been attempted to apply multiple spot welds at appropriate positions (avoid the cutting edge 10a) on both end edges 10b, 10b of which 10 are abutted together, but this has a poor joint strength due to partial attachment, and the joint is not formed during use. There is a drawback that it breaks at the part. Further, since the spot of the blade edge 10a is not spot-welded, when punching out a fibrous material, the blade edge 10a
Threads and the like gradually bite into the gap located at the abutting portion of a, the gap is gradually enlarged, and the finish at the time of punching becomes poor.

OBJECTS OF THE INVENTION The present invention has been devised in order to suitably solve the above-mentioned drawbacks inherent in a die-cutting punching blade, and has a good finish after welding of a butt portion and a joining strength. It is an object of the present invention to provide a welding method which is excellent in welding quality and does not cause deterioration of the cutting edge.

Means for Solving Problems The welding method according to the present invention for overcoming the above problems and achieving an intended object is a strip-shaped steel sheet having one longitudinal end edge processed with a cutting edge, a punching object. In a die cutter punching blade formed into a desired shape in accordance with the contour of, in the butt welding of both ends of the punching blade, of the support block that is arranged exchangeably in the torch running area of the TIG welding machine. A contour is formed on the support surface that matches the shape of the vicinity including both ends of the punching blade to be welded, and both ends of the punching blade are closely butted to a fixed position on the supporting surface of this support block. It is characterized in that the torch is run while irradiating the abutting portion with the discharge of the inert gas and the arc from the tungsten electrode accompanying it.

Example Next, a method for welding a punching blade for a die cutter according to the present invention will be described. For this welding, a TIG welding machine that uses a tungsten electrode in the torch and performs arc welding by discharging an inert gas such as argon between the electrode and the object to be welded is preferably used. A high-precision constant current circuit is incorporated in the device, so that a predetermined welding current can be supplied without being affected by fluctuations in power supply voltage, arc voltage, and changes in ambient temperature. Further, in the traveling region of the torch, a support block for supporting and clamping a punching blade which is an object to be welded is provided exchangeably.

For example, as shown in FIG. 4, the support block 14 is detachably attached to a back bar 16 arranged below the torch traveling region of the welding body and the clamp mechanism via a bolt 18. The support block 14 is provided with a short-shaped base 14a integrally machined from the gun metal and a horizontally extending support portion 14b, and a position control block 20 made of copper is fixed to the support portion 14b with bolts 22. There is.

The upper surface of the support portion 14b is formed with a contour that matches the shape of the punching blade 10 in the vicinity including both end portions 10b, 10b to be welded. For example, in the support block 14 shown in FIG. 4, the punching blade 10 to be joined has a short shape as a whole, and both ends 10b, 10b have flat surfaces in the vicinity thereof, so that they are subordinately supported. The upper surface of the portion 14b is also shaped as a flat surface. However, in the example shown in FIG.
Since 10 is bent and formed in the contour shape of an extremely deformed bear or other animal, a shape matching the shape in the vicinity of both ends 10b, 10b thereof is applied to the upper surface of the support portion 14b. . Further, in the example shown in FIG. 6, in order to weld the corner portion of the punching blade 10, the upper surface of the support portion 14b is formed into a chevron shape as shown.

In addition, in the embodiment shown in FIGS.
A linear groove 24 or a chamfer 26 is formed at a position aligned with the torch travel locus on the upper surface of b. The reason for providing this is that both end portions 10b of the punching blade 10 on the support portion 14,
This is for promoting heat dissipation generated when the 10b are butt-welded together.

On the support portion 14b of the support block 14 configured in this way,
Both ends 10b, 10b of the punching blade 10 are closely butted and held, and clamped by a mechanism not shown. At this time, the position regulation block 20 regulates the punching blade 10 to the fixed position of the support block 14 by the 20. Next, arc welding is performed by running the torch while irradiating the butted portions 10b, 10b with the discharge of the inert gas and the accompanying arc from the tungsten electrode. Optimum numerical values are selected for factors such as the type of inert gas, discharge time, and arc irradiation time according to the material and thickness of the punching blade 10.

As described above, according to the method according to the present description, the butt welding of the thin steel plates, which has been difficult in the past, is extremely easily performed,
Moreover, the finish at the time of joining is extremely good, and no deburring work as a post process is required. Further, since the welding is performed in a short time and the welding temperature due to the arc is extremely high, the blade edge portion is not annealed and the strength is not deteriorated. Rather, since the quench-hardening in that portion is further promoted, the tensile strength is improved as compared with other portions. Therefore, it is recommended to slightly anneal with a gas burner if necessary, but this is not always a requirement.

Since the punching blade obtained by the method of the present invention does not use silver brazing, it does not come into contact with food hygiene regulations, and is therefore suitable for use in punching food products. Further, since the abutting portions are completely joined, there is no possibility that the fibers or the like are caught through the gaps or gradually expanded to reduce the punching accuracy as in the conventional case.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing a general structure of a punching blade for a die cutter, FIG. 2 is an explanatory view showing a joined state of both end portions of the punching blade, and FIG. 3 is a conventional spot-welded type. FIG. 4 is a perspective view showing the state of a punching blade obtained by the joining means of FIG. 4, and FIGS. 4 to 6 are explanatory views of a jig used in the method of the present invention.

Claims (1)

[Claims] 1. A punching blade for a die cutter, which comprises a strip-shaped steel sheet having one longitudinal end edge processed into a desired shape in accordance with the contour of a punching object, and both ends of the punching blade. When butt-welding the parts, a contour that matches the shape of the vicinity including the both ends of the punching blade to be welded is formed on the support surface of the support block that is exchangeably arranged in the torch travel area of the TIG welding machine. Then, the both ends of the punching blade are closely butted and held at a fixed position on the supporting surface of the supporting block, and then the inert gas is discharged and the arc from the tungsten electrode is irradiated to the butted portion. At the same time, the method of welding a punching blade for a die cutter, characterized in that the torch is run.