JPH0446793A - Cutter for sheet cutting device - Google Patents

Abstract

PURPOSE:To make adhere a bed plate and a blade to each other, and bond them securely by bonding a blade, on which hardening processing is performed, and a bed plate with local welding. CONSTITUTION:Bed plates 2, 7 and blades 3, 8, on which hardening processing is performed, are bonded with local welding such as spot welding, projection welding and or the like. Both the bed plates and blades (2 and 3, 7 and 8) can be bonded without generation of curvature and bending or, at least, with curvature and bending at a restricted fine value.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a sheet cutting device that is incorporated into office machines such as copying machines, facsimiles, and printers and cuts sheet materials such as roll paper and film. Regarding the cutlery used.

[Conventional technology]

Conventionally, this type of cutting device consists of a rotary blade and a fixed blade, both of which are elongated and supported at both ends (for example, Japanese Utility Model Publication No. 48-5909), or a fixed blade and a device that moves up and down relative to the rotating blade. A movable blade (for example, the one shown in FIG. 8 of Japanese Utility Model Publication No. 58-11511) is known.

The office machine to which the present invention is directed also has a compact main body;
Due to the general demand for lightweight and low-cost products,
It is desired that the sheet cutting device attached to this sheet cutting device be made smaller, lighter, and less expensive.

In order to make the sheet cutting device smaller and lighter, it is necessary to reduce the cross section of the blade, but it is necessary to ensure the minimum rigidity required to cut the sheet material.

In order to meet this demand and to save on high-quality cutting edge materials, it is necessary to use a base metal made of a structural material with a cross-sectional shape that has a large moment of inertia, such as an L-shaped cross-section, and a thin plate with a rectangular cross-section. It is effective to use a knife with a structure in which the cutting edge material is integrally fixed, and a metal material such as knife steel (hereinafter referred to as blade metal) is suitably used as the tip.

[Problem to be solved by the invention]

These blades have an elongated shape, and in order for them to mesh properly, it is especially necessary for the blade edge to maintain a straight and uniform shape. Therefore, as a method for joining the base metal and the blade, it is inappropriate to use a joining method that involves high-temperature treatment that causes warping or bending between the base metal and the blade due to the difference in thermal expansion; Adhesion using metal adhesive may be considered.

However, when joining by riveting or screwing, the hardened blade material lacks adhesion between the base metal and the blade metal, and it is difficult to drill holes in the hardened blade material.On the other hand, when hardening the blade material after drilling,
There is a problem in that the pitch of the drilled holes changes due to this hardening process. In addition, metal adhesives alone may be insufficient in terms of strength, and there are also concerns about aging and weather resistance.

[Means for Solving the Problems] The present invention provides a blade for a sheet cutting device, characterized in that platinum and a hardened blade are joined by local welding such as spot welding or projection welding. It is.

[Effect]

By welding the joint between the base metal and the blade in a dotted manner, the present invention is capable of bonding both the base metal and the blade metal without causing any warping or bending, or by suppressing these to minute values, even though the metal is locally subjected to high-temperature treatment. This is because we have confirmed that it is possible to join.

In the present invention, the so-called projection welding method, in which a spot-like protrusion for welding is provided on one side of the materials to be joined, is more effective than spot welding because it can more reliably control the spread of the heat-affected zone, thereby controlling warping and bending. It is easy to weld, and it is also possible to weld multiple points at the same time, leading to a reduction in man-hours.

The number or pitch of welding points needs to increase or become smaller as the slenderness ratio of the blade increases, but in the case of projection welding, the more welding points there are, the higher the welding current needs to be. There is a limit to the number depending on the capacity of the machine.

It is effective for the blade used in the present invention to have the surface that forms the cutting edge finished by polishing or the like after hardening treatment.

That is, since the blade of the present invention is prevented from warping or bending after joining, it is preferable to finish the cutting edge before joining, which is convenient for the finishing. However, it may be finished after bonding.

When the number of welding points is small, gaps are likely to occur between the welding points and the welding materials, which causes chatter, vibration, and noise. In this case, by sandwiching double-sided adhesive tape between the welding points or by applying adhesive,
Or it is possible to almost completely prevent them.

In the case of double-sided adhesive tape, steps such as wiping and drying are not necessary, and the process can be simplified.

On the other hand, when using metal adhesives such as epoxy resin,
Strong bonding force can be expected.

As a welding method when these double-sided adhesive tapes or adhesives are used together, a projection welding method is suitable because it allows welding without bending the blade and allows the presence of the adhesive tape.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

Although this embodiment uses both projection welding and double-sided adhesive tape, the same applies to cases where only spot welding or only projection welding is used.

1 and 2 are a perspective view and a cross-sectional view of the rotary blade and the fixed blade, respectively, taken from different viewing directions. It consists of a blade metal 3 and shafts 4 and 5 welded to both ends of the base metal 2 and a blade metal 3 joined together using double-sided adhesive tape 15, and the shafts 4 and 5 at both ends are connected to the base 13.
It is rotatably supported by being supported by a shaft hole provided in the shaft hole.

In the fixed blade 6, a blade 8 having a guide portion 9 for guiding the blade edge on the cutting start end side is joined to the base metal 7 using a combination of projection welding and double-sided tape 17.

Note that 14 and 16 are concave marks created due to the formation of projections for welding. In general, double-sided adhesive tapes include paper thread, base-based, and film-based tapes. Paper thread and base-based tapes have a thickness of 0.1 m or more, but when used in conjunction with projection welding, they can be used for Since the electrode is in the shape of a flat surface plate, by setting and controlling its compressive force, welding is completed after the adhesive tape makes full contact with the adhesive tape, thereby warping and bending the blade. It can be welded without any need for welding.

On the other hand, film-based materials are available with a thickness of 0.05 mm or less, and if these are used, there will be little adverse effect on flatness even in spot welding.

The fixed blade -q- is screwed to the base 13 by screws 10.11 in a position where the rotary blade top and the fixed blade -q- themselves are securely engaged with each other without any gaps.

The base metal 2 of the rotary blade 1 and the base metal 7 of the fixed blade 6 are both made of cold rolled steel plate (JIS G 31415PCC;),
It has an L-shaped cross section, and this shape ensures the necessary rigidity for cutting sheet materials.

Both the blade 3 on the rotating blade and the blade 8 on the fixed blade are made of hardened band steel made of stainless steel.

Next, the connection between the base metal 2 and the blade metal 3 of the rotary blade 1 will be explained with reference to FIGS. 3 and 4.

In FIG. 3, the base metal 2 on the rotary blade has three protrusions 20 (projections) formed during outline punching press processing,
Zinc plating (MFZnm C) is applied as rust prevention treatment.

The double-sided adhesive tape 15 is attached to the blade 3 with a hole formed in the part corresponding to the welding part.

Figure 4 shows the welding process, and shows the electrode (lower side) 1
After placing the base metal 2 at a predetermined position on the blade metal 3 (actually using paper thread with a thickness of 0.1 mm), attach the double-sided adhesive tape 15 on top of the electrode (upper side). 19 is lowered, energized, and welded. By controlling the current to be cut off at the point where the double-sided adhesive tape reaches an appropriate compression force after being fully compressed, it is possible to weld without warping or bending the blade.

The method of joining the fixed blade 6 is also the same as the method of joining the rotary blade 1 described above.

In addition, in this example, there were three welding points, but the number of welding points should be determined taking into consideration the length, shape, etc. of the blade, as described above, and any number of welding points may be used. .

In addition, the adhesion between the welding points is good, and the double-sided adhesive
If it is determined that projection welding is not necessary, only projection welding may be used.

Further, in this embodiment, as the most preferable embodiment of the present invention, platinum with an L-shaped cross section and a blade with a thin rectangular cross section are shown as examples, but it goes without saying that the present invention is not limited to this.

A sheet cutting device was assembled by incorporating the as-welded fixed blade and rotary blade prototyped in the above example (without final polishing), and a cutting test was performed, and no abnormalities were observed.

From the above, it can be seen that it is also possible to use metal adhesive and projection welding together.

Next, the procedure was almost the same as explained in Figure 1, except that double-sided adhesive tape was not used and there were only 5 spot welds.
A prototype sheet cutting device was manufactured. As a result of the trial test, there was no chatter, noise, or vibration, and no other abnormalities were found.
It turns out that adhesives and double-sided adhesive tape can be omitted.

〔Effect of the invention〕

As described above, according to the present invention, platinum and blade metal can be brought into close contact with each other and reliably joined by local welding such as spot welding or projection welding.

By using the blade according to this method, it is possible to provide a lightweight and inexpensive sheet cutting device.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention, FIG. 2 is a sectional view of FIG. 1, FIG. 3 is a perspective view showing the configuration of the rotary blade in this embodiment, and FIG. It is a perspective view showing the spot welding method in an example. 1-Rotary blade, 2, 7: Base metal, 3, 8: Blade metal, 6: ＼ and no diagram diagram

Claims (1)

[Scope of Claims] 1. A blade for a sheet cutting device comprising a base metal and a blade, both of which are elongated, joined in parallel, wherein the hardened blade is joined to the base metal by local welding. A blade for a sheet cutting device, which is characterized by: 2. The blade for a sheet cutting device according to claim 1, wherein the base metal and the blade metal are joined together using a double-sided adhesive tape or an adhesive and projection welding.