JPS62187576A - Welding method for blanking blade for die cutter - Google Patents

Abstract

PURPOSE:To improve the blanking accuracy by forming the profile which coincides with the weld zone shape of a blanking blade on the supporting face of a supporting block, then by performing TIG welding by abutting the weld zone of the blanking blade with its close-fitting on the supporting face. CONSTITUTION:A supporting block 14 is fixed via a bolt 18 to the back bar 16 which is installed at the lower part of the main body of a welding machine and the copper made position regulating block 20 is fixed by a bolt 22 to a horizontal supporting part 14b. In this case,the profile which coincides with the shape of the vicinity of the both end parts 10b, 10b to be welded of the blanking blade 10 is formed on the upper face of the supporting part 14b and a linear recessed groove 24 is worked as well. TIG welding is performed with passing an inert gas by clamping the blade 10, by holding the both end parts 10b, 10b of the blade 10 with their close-fitting onto this supporting part 14. The strength deterioration of the blade tip part can be prevented in this way, so the blanking accuracy by the blanking blade can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This 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 disadvantages A die cutter is made by bending a blade material with a cutting edge processed on one longitudinal edge of a strip steel plate to match the contour of the object to be punched, and inserting and fixing this blade material into a wooden mold. Punching blades (commonly referred to as ``Thomson blades'') are used in a wide variety of industrial applications. As shown in FIG. 1, the base of the punching blade 10 is fitted into a wooden mold 12, with the cutting edge 10a protruding from the surface of the mold by a required amount. In order to completely punch out the object to be punched, both ends 10b, . If this butting is incomplete, a minute gap will exist between the ends 10b, 10b when they are inserted and fixed in the wooden die 12, and the gap will gradually expand as the number of punches increases due to the operation of the die cutter. However, there are inconveniences such as the punched shape becoming irregular and the cut end not finishing well.

Conventionally, this problem has been dealt with by welding the mutually abutting ends 10b, 10b of the punching blade 10 shown in FIG. However, this welding requires a long heating time depending on the normal welding method, and the quench-hardened cutting edge is annealed, resulting in a decrease in sharpness.Furthermore, even if a slight resistance is encountered during punching, it is easy to weld. It has the disadvantage of being deformed. Therefore, silver brazing is generally used as a welding method, but punching blades made using this method are prohibited from being used for punching food products according to food hygiene regulations. Furthermore, in silver brazing, the molten hot material wraps around the back side of the joint and solidifies, forming uneven parts, which require a finishing process to scrape off, which is extremely troublesome.

Instead of the silver brazing, as shown in FIG. 3, it has also been attempted to perform a plurality of spot welds at appropriate locations (avoiding the cutting edge 10a) on both end edges 10b, 10b of the punching blade 10 that abut against each other. However, this has the disadvantage that the joint strength is poor due to the partial attachment, and it may break at the joint site during use. In addition, since spot welding is not performed at the cutting edge 10a, when punching fibrous material, the thread or the like gradually bites into the gap located at the abutting part of the cutting edge 10a, and gradually closes this gap. There are disadvantages such as enlargement and poor finish during punching.

Purpose of the Invention The present invention has been devised in view of the above-mentioned drawbacks inherent in the punching blade for a die cutter, and has been devised to suitably solve this problem, and provides a good finish after welding the butt part. The purpose of the present invention is to provide a welding method that has excellent joint strength and does not cause deterioration of the cutting edge.

Means for Solving the Problems In order to overcome the above-mentioned problems and achieve the intended purpose, the welding method according to the present invention provides a welding method in which a strip-shaped steel plate having a cutting edge processed on one longitudinal edge is used as a punching object. In the punching blade for a die cutter formed into a desired shape according to the outline of A contour that matches the shape of the vicinity including both ends of the punching blade to be welded is formed on the support surface of the support block to be welded, and both ends of the punching blade are placed at fixed positions on the support surface of the support block. The torch is then moved while the abutting portions are held closely abutted against each other, and then an inert gas is discharged and an accompanying arc from a tungsten electrode is irradiated onto the abutting portions.

EXAMPLE Next, a method of welding a punching blade for a die cutter according to the present invention will be explained. For this welding, a TIG welding machine is preferably used, which uses a tungsten electrode in the torch section and performs arc welding by discharging an inert gas such as argon between the electrode and the object to be welded. is equipped with a high-precision constant current circuit, so it is unaffected by fluctuations in power supply voltage, arc voltage, and other changes in ambient temperature.
A predetermined welding current can be supplied.

Further, in the travel area of the torch, a support block for supporting and clamping the punching blade, which is the object to be welded, is replaceably arranged.

For example, as shown in FIG. 4, this support block 14 is
It is detachably attached via a bolt 18 to a back par 16 disposed in the torch travel area of the welding machine body and below the clamp mechanism. The support block 14 includes a rectangular base 14a that is integrally machined from gun metal and a horizontally extending support portion 14b.
A position regulating block 20 made of copper is fixed to b by bolts 22.

The upper surface of this support portion 14b has a contour that matches the shape of the vicinity of the punching blade 1o including both ends 10b to be welded. For example, in the support block 14 shown in FIG. 4, the punching blade 10 to be joined has a rectangular shape as a whole, and the vicinity of both ends 10b, 10b is a flat surface. Similarly, the upper surface of the support portion 14b is also formed as a flat surface. However, in the example shown in FIG. 5, the punching blade 10 is bent to match the outline of an extremely deformed animal such as a bear, so the punching blade 10 is made to match the shape in the vicinity of both ends 10b, 10b. A shape is provided on the upper surface of the support portion 14b. Further, in the example shown in FIG. 6, in order to weld a portion of the corner of the punching blade 10, the upper surface of the support portion 14b is formed into a chevron shape as shown.

Note that in the embodiments shown in FIGS. 4 to 6, the support portion 1
A linear concave groove 24 or a chamfer 26 is provided on the upper surface of 4b at a position aligned with the torch travel locus. The reason for providing this is that when both ends 10b, 10b of the punching blade 10 are butted and welded on this support part 14,
This is to promote heat dissipation.

Both ends 10b of the punching blade 10 are placed on the support portion 14b of the support block 14 configured in this manner.

10b are held closely against each other and clamped by a mechanism not shown. At this time, the position regulating block 2
0 restricts the punching blade 10 to a fixed position on the support block 14. Next, an inert gas is discharged and an arc from the tungsten electrode is connected to the butt portions 10b, 10.
Arc welding is carried out by running the torch while irradiating the area b. For elements such as the type of inert gas, the discharge time, and the arc irradiation time, optimal values are selected depending on the material, thickness, etc. of the punching blade 10.

As described above, according to the method of the present invention, end butt welding of thin steel plates, which was difficult in the past, can be done extremely easily.
Moreover, the finish at the time of joining is extremely good, and no deburring work is required as a post-process. Furthermore, since the welding takes place in a short time and the welding temperature by the arc is extremely high, the cutting edge will not be annealed and its strength will not deteriorate. In fact, quench hardening is further promoted in that part, so the tensile strength is improved more than in other parts. Therefore, it is recommended to perform some annealing with a gas burner if necessary, but this is not necessarily a requirement.

Since the punching blade obtained by the method of the present invention does not use silver solder, it does not comply with food hygiene regulations, and therefore can be suitably used for punching food products. In addition, since the abutted portions are completely joined, there is no possibility that fibers or the like will be caught through the gaps or that they will gradually spread out and reduce the punching accuracy, unlike in the conventional case.

[Brief explanation of drawings]

Fig. 1 is a perspective view schematically showing the general structure of a punching blade for a die cutter, Fig. 2 is an explanatory diagram showing the joining state of both ends of the punching blade, and Fig. 3 is a conventional one using spot welding. FIGS. 4 to 6 are perspective views showing the state of the punching blade obtained by the joining means, and FIGS. 4 to 6 are explanatory views of the jig used in the method of the present invention.

Claims (1)

[Claims] In a punching blade for a die cutter, which is made by forming a band-shaped steel plate with a cutting edge on one longitudinal edge into a desired shape to match the contour of the object to be punched, both ends of the punching blade are butt-welded. At this time, a contour that matches the shape of the vicinity including both ends of the punching blade to be welded is formed on the support surface of a support block that is replaceably disposed in the torch travel area of the TIG welding machine, and this support block holding both ends of the punching blade in a fixed position on the supporting surface of the blade, closely abutting each other;
A method for welding a punching blade for a die cutter, characterized in that the torch is run while the abutting portion is then irradiated with an inert gas discharge and an accompanying arc from a tungsten electrode.