JPH0280042A - Point end part forming method for dental washing needle - Google Patents

Abstract

PURPOSE:To enable manufacture to be facilitated further in a short time in addition preventing a point end closed part from decreasing its thickness by using a plasma spot welder machine melting and closing a metal tube in its point end. CONSTITUTION:A canal 1 is fixed to a clasping jig 5, forming an l1mm protruding margin, next an electrode 4, for instance, of tungsten is mounted to be inserted to the point end of a torch 3 in a welder machine 2, and moving the torch 3, a point end of the electrode 4 approaches the canal 1 till a spark distance obtains l2mm. Subsequently, while a fixed flow amount of inactive gas, for instance, argon is produced between the electrode 4 and the canal 1, a hot start current (current in the start time of welding) is allowed to flow for a fixed time heating an electrode rod, thereafter when a predetermined current is allowed to flow for a fixed time generating plasma scattering, a point end part of the canal is melted and sealed. By the method thus obtained, because the point end part is prevented from decreasing its thickness, possibility of using an inferior product by mistake can be avoided while improving a yield rate of production of a dental washing needle.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a novel method for efficiently forming the tip portion of a dental cleaning needle.

<Prior art> A dental cleaning needle is a medical needle whose tip is closed and rounded, and a hole for irrigating solution is perforated in the side wall near the tip. Formation was generally performed by the method shown in FIG.

That is, while rotating the camera (11) about its longitudinal axis, the tip portion (12) of the camera (11) is closed off by pressing it against a die (10) that rotates in the opposite direction on the same axis as the camera (11). and then remove the protruding part at the tip (
13) (see Figure 4).

However, in the above method, the wall of the tip is thin and
Occasionally, the seal would fail to close, leaving a hole, and the protruding portion of the tip would have to be cut, which was a problem.

<Problems to be Solved by the Invention> The present invention has been made in view of the above-mentioned problems, and provides a dental cleaning needle that can be manufactured easily and in a short time, and that does not cause thinning of the wall at the tip of the needle. An object of the present invention is to provide a method for forming a tip.

Means for Solving the Problems> In order to solve the above problems, the present invention provides a method for forming the tip of a dental cleaning needle in which the tip of a metal tube is melted and closed using a plasma spot welder. A distinctive method is adopted.

According to the present invention, the camera forming material, such as stainless steel, melted by a plasma spot welding machine tends to become round due to surface tension. A tip (6) can be formed (see Figure 2).

Furthermore, since plasma spot welding involves electric discharge in the vapor of gas and electrode material, it is possible to weld, that is, to close the tip, almost instantaneously and easily.

<Example> Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a detailed explanatory diagram of the present invention, in which (1) is a camera, (2) is a plasma spot welding machine, (5) is a clamp jig for fixing the camera (1), and Ql is a The workpiece extension, that is, the protrusion length of the camera (1) from the clamp jig, l! is the spark distance, that is, the distance from the tip of the electrode of the welding machine (2) to the tip of the camera (1).

When forming the tip of a dental cleaning needle, first use a camera (1
) to the clamp jig (5) with a protrusion of 1, trra, then insert a tungsten electrode (4), for example, into the tip of the torch (3) of the welding machine (2), and tighten the torch (3). ) to bring the tip of the electrode (4) closer to the camera (1) until the spark distance is 2□mm. Then electrode (4)
While flowing a constant flow of inert gas, such as argon, between the camera (1) and the camera (1), first a hot start current (the current at the start of welding) is passed for a fixed period of time to heat the electrode rod, and then a predetermined current is passed for a fixed period of time. When the plasma is released, the tip of the camera is melted and sealed.

In addition to non-consumable tungsten, a metal rod made of the same material as the object to be welded can be used as the electrode material, and helium can also be used as the inert gas.

The workpiece extension distance (11) is not particularly limited, but is generally 0.5≦C, ≦7 (unit: ffl11), and the spark distance (p, z) depends on the material and size of the workpiece, hot start current, etc. Although it varies depending on the magnitude of the welding current, etc., it is approximately 0.5≦lt≦1.0 (unit: mm).

Also, the hot start current (10) is generally 30A as a standard, but it can be made smaller if the spark distance (12) is made smaller, and generally 10≦to/j! It is selected so as to satisfy the expression i≦30.

The energization time of hot start current is generally 50 to 100
m5ec. The welding current (i) is the same as the hot start current! The smaller the value, the smaller the value of l!, and although it varies depending on the material and size of the workpiece, in general, i should be set to 1 to 2 A so that the current application time (i.e., arc time) and l! is selected.

Then, the current (1) is controlled so that the relationship 50≦i/e zd"≦70 holds between i, 12, and the radius (d) of the camera (1). i/j!2d" is 50 or less This is because it takes too much time to seal, and when it is 70 or more, the amount of melting is too thick and overflows to the outside of the camera (1), resulting in a seal with the tip end swollen outward.

Although the flow rate of the inert gas is not particularly limited,
-a is 6 to 81/min.

<Examples 1 and 2> Plasma spot welding 1 (YP-050S: manufactured by Matsushita Electric Industry ■) was applied to a cannula made of 5US304 with an outer diameter of 0.55 nuw and 0.5 mm, welding current 2 A, arc time 60 + AAEC, argon. Gas flow Mt61 /+
When welding was performed with sin, the diameter Q of the tungsten electrode, and 5 mm, and the workpiece was exposed 3 to 5 times, good results were obtained with no bulge occurring in the welded part (see Table 1).

<Example 3> The same welding machine as in Example 1 was used as an S U with an outer diameter of 0.4 mm.
Applicable to S 304 cannula, welding current IA, arc time 60m5ec, argon gas flow rate 51! , /mi
n.

When welding was carried out with a tungsten electrode diameter of 0.5 tlwl and a workpiece extension of 3 to 5 m, 50% of the welded parts had bulges (see Table 1).

<Comparative Example 1> Under the same conditions as Example 3, 5US with an outer diameter of 0.3 mm
When cannulas made of 304 were welded, bulges occurred in the welds in all of them (see Table 1).

Incidentally, the hot start current was 6A in both Examples 1 to 3 and Comparative Example 1, and the current was applied for 5Q msec. Further, the wall thickness of the camera was the same in Examples 1 to 3 and Comparative Example 1, which was 0.
It is 12mm.

<Effects of the Invention> By adopting the present invention, the thickness of the tip portion does not become thinner, so the production yield of dental cleaning needles is improved, and the risk of defective products being used by mistake is avoided. Can be done. Further, since the tip can be sealed easily and in a short time, dental cleaning needles can be provided at low cost.

[Brief explanation of the drawing]

FIG. 1 is a detailed explanatory diagram of the present invention, and FIG. 2 is a diagram showing the tip of a dental cleaning needle formed by the method of the present invention. Further, FIG. 3 is an explanatory diagram of the conventional method, and FIG. 4 is a diagram showing the tip of a dental cleaning needle formed by the conventional method, and the protruding portion of the tip has not yet been canted. <Explanation of main symbols> l: Camera 2: Welder 3: Torch 4: Electrode 5: Clamp jig

Claims (1)

[Claims] 1) A method for forming the tip of a dental cleaning needle, which comprises melting and sealing the tip of a metal tube using a plasma spot welder. 2) The method according to claim 1, wherein the metal is stainless steel.