JP4473234B2 - Metal tubular body and manufacturing method thereof - Google Patents

Description

  The present invention relates to an irregularly shaped metal tubular body having at least two kinds of inner diameters and a method for producing the same. More specifically, the present invention relates to a small-diameter, irregular-shaped metal tubular body that can be used for pins, injection needles, connectors, liquid crystal electron guns for televisions, and the like, and a method for producing the same.

  When manufacturing a metal tubular body having a small diameter, for example, an outer diameter of 2 mm or less, used for medical pins, injection needles, connectors, TV electron guns, etc., a metal thin plate having a thickness of 0.2 mm or less After drawing the wire, it is welded where the end faces of the thin plates are joined before entering the drawing die, and is drawn as it is with a drawing die to form a tubular body having an outer diameter of about 4 to 6 mm, and then the drawing process is repeated. In particular, it is formed into a tubular body having at least two kinds of inner diameters in which the side surface has a tapered shape or a stepped shape. FIG. 12 shows an example of a drawing process. In FIG. 12, the metal tubular body 1 formed to have an outer diameter of about 4 to 6 mm is pulled through a die 2 having a die hole having a smaller cross-sectional area, so that the outer diameter is contracted to be the same as the die hole. It is formed into a tubular body having a cross-sectional shape. In order to prevent wrinkles due to shrinkage from occurring on the inner surface of the tubular body 1 during the drawing process, a plug 3 that defines the inner diameter thereof is inserted into the tubular body 1 during the drawing process.

However, if the diameter of the tubular body 1 is reduced by repeating the drawing process, the plug 3 cannot be inserted into the tubular body 1 and it is necessary to perform the drawing process without the plug 3. When the drawing process is performed without inserting the plug 3 into the tubular body 1, the inner surface of the tubular body 1 is wrinkled, and the inner surface becomes rough. Such roughness of the inner surface increases the resistance with which the fluid passes through the tubular body. Further, the roughness of the inner surface of the tubular body increases its surface area, and dirt and foreign matter are liable to adhere. This is an important problem in the case of a tubular body for medical use where hygiene is important. However, there has been no tubular body having a small diameter and a rough inner surface.
That is, there is a demand for a metal tubular body having a small diameter that can be used as an injection needle, having at least two kinds of inner diameters, and having a smooth inner surface, and a method for producing the same.

  An object of the present invention is to solve the above-mentioned problems of the prior art and provide a metal tubular body having a small diameter and at least two kinds of inner diameters, and a method for producing the same.

In order to achieve the above object, the present invention provides the following.
(1) A plate-like body having a tubular body developed from a metal thin plate is punched out in a state where the metal thin plate and the plate-like body are partially joined,
After pressing the plate-like body into a tubular body having at least two kinds of inner diameters,
A tubular body having at least two kinds of inner diameters obtained by cutting a joint between the metal thin plate and the plate-like body, and having a maximum height difference (Rf) of the surface roughness of the inner surface of 3 μm A metal injection needle having a minimum inner diameter of 2 mm or less and a maximum inner diameter of 5 mm or less .
(2) A plate-like body having a tubular body developed from a metal thin plate is punched in a state where the metal thin plate and the plate-like body are partially joined,
After pressing the plate-like body into a tubular body having at least two kinds of inner diameters,
A tubular body having at least two types of inner diameters by cutting a joint between the metal thin plate and the plate-like body, and the maximum height difference (Rf) of the surface roughness of the inner surface is 3 μm or less. A method for producing a metal injection needle having a minimum inner diameter of 2 mm or less and a maximum inner diameter of 5 mm or less .
In the method for producing a metal injection needle of the present invention, it is preferable to weld the joint portion of the pipe after the plate-like body is pressed into a pipe shape.

Although the tubular body of the present invention has at least two kinds of inner diameters, the inner surface is smooth, and can be preferably used for applications such as an injection needle for epidural injection.
According to the method of the present invention, it is possible to produce a metal tubular body having a small diameter and at least two or more kinds of inner diameters, for example, a side surface having a tapered shape or a stepped shape.

  Below, the manufacturing method of the metallic tubular body of this invention and the metallic tubular body manufactured by the method are demonstrated with reference to drawings.

  The metallic tubular body of the present invention is an irregular shaped tubular body having at least two kinds of inner diameters. Such a tubular body has a distal end portion having a small inner diameter and a proximal end portion having a large inner diameter as shown in FIG. 1 (a), a side surface having a tapered shape, and a circular sectional shape. The hollow tube 8 has a tip portion with a small inner diameter as shown in FIG. 1B and a base end portion with a large inner diameter. Between the tip portion and the base end portion, the tip portion and the base end portion are A hollow tube 8 having an intermediate portion with a different inner diameter and a stepped shape on the side surface and a circular cross-sectional shape, a tip portion having a small inner diameter as shown in FIG. 1 (c), and a base having a large inner diameter Widely includes a hollow tube having an end portion and a circular cross section having a transition portion between a distal end portion and a proximal end portion. In FIGS. 1A to 1C, 9 is the central axis of the tubular body 8. An example of the tubular body of the present invention is shown in FIGS. FIG. 2A is a hollow tube having a distal end portion having a small inner diameter and a base end portion having a large inner diameter, and a cross-sectional shape having a transition portion between the distal end portion and the base end portion having a square shape. FIG. 2B shows a distal end portion having a small inner diameter and a proximal end portion having a larger inner diameter, and a distal end portion having a transition portion between the distal end portion and the proximal end portion has a circular cross-sectional shape. A hollow tube having a square cross-sectional shape. FIG. 2C shows a hollow tube having a distal end portion having a small inner diameter and a base end portion having a large inner diameter, and having a circular cross section having a transition portion between the distal end portion and the base end portion. FIG. 2D shows a hollow tube having a distal end portion with a small inner diameter and a proximal end portion with a larger inner diameter, and a cross-sectional shape having a transition portion between the distal end portion and the proximal end portion having a hexagonal shape. FIG. 2 (e) has a distal end portion with a small inner diameter and a proximal end portion with a larger inner diameter, and the distal end portion and the proximal end portion have different inner diameters between the distal end portion and the proximal end portion, and the inner diameters are mutually different. Is a hollow tube having a circular cross-section with two different intermediate portions, each having a transition portion between the distal end portion and the intermediate portion, between the intermediate portions, and between the intermediate portion and the proximal end portion. .

Examples of the use of the metal tubular body having at least two kinds of inner diameters include an injection needle for epidural injection. With an injection needle for epidural injection, a tapered shape or a stepped shape acts as a sensor indicating the position of the tip of the needle at the time of puncture, the needle is punctured deeper than necessary, and delicate parts such as nerves are Prevent damage.
In the present invention, as shown in FIGS. 2A to 2E, the cross-sectional shape of the tubular body is not limited to a perfect circle, and may be a polygon such as a quadrangle or a hexagon, or may be an ellipse or the like. There may be.

  In the present invention, the outer diameter of the tubular body is usually 8 mm or less, preferably 5 mm or less. When the use of the tubular body is an injection needle, the outer diameter of the tubular body is 2 mm or less, preferably 1 mm or less, more preferably 0.4 mm or less. When the outer diameter is in the above range, when used as an injection needle, there is little piercing resistance, and pain during injection is alleviated.

In the present invention, among the two or more types of inner diameters of the tubular body, the maximum inner diameter is 5 mm or less, preferably 1.5 mm or less, more preferably 0.8 mm or less.
On the other hand, among the two or more types of inner diameters of the tubular body, the minimum inner diameter is 2 mm or less, preferably 1 mm or less, more preferably 0.5 mm or less.
If the inner diameter of the tubular body is in the above range, the strength required for the tubular body is not impaired even if the tubular body has an outer diameter in the above range.

  In the present invention, the maximum height difference (Rf) of the surface roughness according to JIS-B-0601-1994 on the inner surface of the tubular body is 3 μm, preferably 2 μm or less, more preferably 1 μm or less. If the Rf of the inner surface of the tubular body is in the above range, the entire inner surface is smooth, and there are no large scratches, so that the tubular body is suitable for use as a medical instrument.

  The tubular body may be any metal as long as it is made of, for example, steel materials including stainless steel, nonferrous metal structural materials such as aluminum, copper and titanium, heat resistant materials such as nickel, cobalt and molybdenum, lead Further, it may be a low melting point metal material such as tin, a noble metal material such as gold, silver or platinum, or an alloy thereof.

  The length of the tubular body is not particularly limited. However, since the tubular body whose use is an injection needle is inevitably thin, its length needs to be appropriately selected according to the strength required for the tubular body. For example, when used as an injection needle, a tubular body having a diameter corresponding to a 25 to 33 gauge injection needle is required to have a hardness of 200 Vickers or more.

  Next, the manufacturing method of the metal tubular body of this invention is demonstrated. 3 and 4 are diagrams showing an example of a manufacturing process of a metallic tubular body by the method of the present invention. 3 and 4 show a tubular body having a distal end portion with a small inner diameter and a proximal end portion with a large inner diameter shown in FIG. 1 (a), having a tapered side surface shape and a circular sectional shape. The process is shown. However, the illustrated procedure is an example of a manufacturing procedure in order to facilitate understanding of the method of the present invention, and the method of the present invention is not limited to this.

In the method of the present invention, as shown in FIG. 3A, a plate-like body 5 having a tubular shape is punched from a thin metal plate 4 having a thickness of 0.25 mm or less. Here, as an important point, the thin plate 4 is not punched out from the metal thin plate 4 in a completely cut state, but the thin plate 4 and the plate-like body 5 are left partially joined. Moreover, the shape of the plate-like body 5 to be punched is appropriately selected according to the final shape having at least two kinds of inner diameters. In FIG. 3A, the center part (joining part) 6 of the cutting line on the short side of the plate-like body 5 is still joined to the thin plate. 3 and 4 show an example of manufacturing a tubular body having a tapered side surface, the shape of the plate-like body 5 is one of the two sides on the short side. Is shorter than the other and has a trapezoidal shape.
The plate-like body 5 may be punched from the metal thin plate 4 by mechanical punching or by thermal punching using a laser or the like.

  Next, as shown in FIG.3 (b), the plate-shaped body 5 is press-processed using the type | mold 7 from an up-down direction. In FIG. 3 (b), a convex mold is used for the upper mold 7 and a concave mold is used for the lower mold 7, so that the plate-like body 5 is curved around the joint 6 with the thin plate. Pressed into shape.

Preferably, a portion of the plate-like body 5 corresponding to the distal end portion or the base end portion of the tubular body 8 to be pressed is pressed upward or downward with respect to the plane formed by the thin metal plate 4 during the pressing. The central axis of the tubular body 8 that is being pressed is made parallel to the plane formed by the metal thin plate 4 by being moved.
The plate-like body 5 corresponds to either the distal end portion or the proximal end portion because the portion corresponding to the distal end portion and the proximal end portion of the tubular body 8 to be pressed is joined to the metal thin plate 4. The center axis of the tubular body 8 to be pressed despite the fact that the molded tubular body 8 has two or more inner diameters by moving the portion to be moved upward or downward with respect to the metal thin plate 4 However, it is parallel to the plane formed by the thin metal plate 4.

  More preferably, the portion of the plate-like body 4 corresponding to the distal end portion or the base end portion of the tubular body 8 to be pressed is moved upward or downward with respect to the metal thin plate 4 and then pressed. The central axis of the tubular body 8 is located away from the plane formed by the thin metal plate 4.

  In FIG. 3 (b), the distal end of the tubular body is maintained while the base end portion (end portion on the side having the larger inner diameter) of the tubular body 8 being pressed is held on the same plane as the metal thin plate 4. The central axis of the tubular body 8 is parallel to the plane formed by the metallic thin plate 4 and the central axis of the tubular body 8 is raised by lifting the portion (the side with the smaller inner diameter) upward from the metallic thin plate 4. Is a position away from the plane formed by the metal thin plate 4, specifically, a position above the plane formed by the metal thin plate 4.

  In order to lift the tip of the tubular body 8 in the middle of the pressing process upward from the metal thin plate 4, the mold 7 having an appropriate shape is obtained with the tubular body 8 and the metal thin plate 4 partially joined. And press working. For example, as shown in FIG. 1 (a), the tubular body 8 to be molded has a distal end portion with a small inner diameter and a proximal end portion with a large inner diameter, the side surface has a tapered shape, and the cross-sectional shape is In the case of a circular hollow tube, a die 7 having a cross-sectional shape corresponding to the side surface shape of the tubular body 8 may be used as shown in FIG. As understood from the figure, when the mold 7 is used, the central axis 9 of the tubular body 8 to be pressed is parallel to the plane formed by the metal thin plate 4 and is formed by the metal thin plate 4. Located away from the plane. FIG. 6 is a diagram showing a stage corresponding to FIG. 4C when the tubular body shown in FIG. 1A is manufactured using the mold shown in FIG. 6A is a cross-sectional view of the tubular body 8 as viewed from the small inner diameter side, and FIG. 6B is a cross-sectional view of the tubular body 8 as viewed from the large inner diameter side. As understood from the drawing, the position of the central axis 9 of the tubular body 8 is at an upper position away from the plane formed by the metal thin plate 4.

  Regarding the method of making the central axis of the tubular body 8 being pressed parallel to the plane formed by the metal thin plate 4 and away from the metal thin plate 4, the tip of the tubular body 8 ( The portion of the plate-like body 5 corresponding to the end portion on the side having a smaller inner diameter is lifted upward from the metal thin plate 4 so that the central axis of the tubular body 8 is parallel to the plane formed by the metal thin plate 4. In addition, although the case where the upper position is set as an example has been described with reference to the drawings, the method of the present invention is not limited to this, and the plate-like body 5 and the metal thin plate 4 are partially joined. In this state, if the portion of the plate-like body 5 corresponding to either the distal end portion or the base end portion of the tubular body 8 to be pressed is moved upward or downward with respect to the metal thin plate 4 Good. That is, contrary to the figure, the portion of the plate-like body 5 corresponding to the tip end portion (end portion on the side having a smaller inner diameter) of the tubular body 8 is held on the same plane as the metal thin plate 4 while being tubular. By moving a portion of the plate-like body 5 corresponding to the base end portion (end portion on the side having a larger inner diameter) of the body 8 downward from the metal thin plate 4, the central axis of the tubular body 8 is made to be a metal thin plate. You may make it a parallel and downward position with respect to the plane which 4 forms.

  In addition, although it is a preferable aspect that the center axis | shaft of the tubular body 8 to be pressed exists in the position away from the metal thin plate 4, the center axis | shaft of the tubular body 8 to be pressed is the metal thin plate 4 and A method of pressing into a tube shape while being on the same plane is also included in the scope of the present invention. In this case, by using a mold having an appropriate shape, the deformation amount of the distal end side (end portion with a smaller inner diameter) and the proximal end side (end portion with a larger inner diameter) of the tubular body 8 are different from each other. That's fine. For example, the central axis of the tubular body can be adjusted in a state where the central axis of the tubular body is on the same plane as the plane formed by the thin metal plate by appropriately adjusting the amount of deformation in the lower mold direction of the plate-like body. Are pressed into a tubular body having two or more kinds of inner diameters in parallel with a plane formed by a thin metal plate.

In a preferred embodiment of the method of the present invention, since the position of the central axis 9 of the tubular body 8 is away from the plane formed by the metal thin plate 4, the joint 6 between the plate-like body 5 and the metal thin plate 4 is It is necessary to have a length equal to or longer than the distance corresponding to the distance between the central axis 9 of the tubular body 8 and the plane formed by the metal thin plate 4. The length of the joint portion 6 can be appropriately selected according to the dimensions (outer diameter, length) of the tubular body, but the length X (mm) of the joint portion and the outer diameter R (mm) of the tubular body 8 Is preferably a relationship represented by the following formula.
X ≧ R / 2
In the above formula, R is the outer diameter on the side of the distal end portion or the proximal end portion of the tubular body 8 where the movement amount from the metal thin plate is large.
If the length of the joint and the outer diameter of the tubular body are in the above relationship, it is preferable because the tubular body can be easily manufactured.

  FIG. 4C shows a plate-like body that has been further pressed. In FIG. 4C, the plate-like body 5 is further curved and has a U shape. In order to press the plate-like body into such a shape, it may be pressed as it is with the die 7 shown in FIG. 3B, or may be pressed using a die having a different shape. The plate-like body pressed into a U-shape is pressed into a tube shape using a concave die for the upper die 7 as shown in FIG. FIG. 7 is a side sectional view for showing the positional relationship between the tubular body 8 formed into a tubular shape, the mold 7 and the metal thin plate 4 by the process shown in FIG. As can be seen from the figure, the central axis of the tubular body 8 sandwiched between the molds 7 from above and below is parallel to and above the plane formed by the thin metal plate 4. As will be readily understood by those skilled in the art, press processing using a mold having a different shape is further performed in several stages before pressing into a tube shape as shown in FIG. Also good. Furthermore, in order to round the upper part of the plate-like body 5 pressed into the U-shape shown in FIG. 4C, a core 10 may be used in addition to the mold 7 as shown in FIG.

  According to the method of the present invention, not only the tapered tubular body as described above, but also a distal end portion having a small inner diameter as shown in FIG. 1B and a proximal end portion having a large inner diameter, Producing a hollow tube having a step between the tip and the base end, having an intermediate portion with a different inner diameter from the tip and the base end, and having a stepped side shape and a circular cross-sectional shape You can also. In order to manufacture the tubular body having the shape shown in FIG. 1B, specifically, as shown in FIG. 9, a plate-like body 5 having a tubular body 8 developed from a metal thin plate 4 is shortened. A die 7 having a step corresponding to the side shape of the tubular body 8 whose cross-sectional shape is formed as shown in FIG. 10 is punched out while the center portion 6 of the cutting line on the hand side is joined to the thin plate 4. What is necessary is just to press-work.

  Although the tubular body manufactured by press working depends on the application, for example, when the fluid is circulated inside the pipe as in the case of use as an injection needle, the joint portion of the tubular body is made liquid-tight. Must be joined. As a method for joining the tubular bodies, an adhesive or the like can be used, but it is preferable to use welding because it is made of metal and the outer diameter is as small as 1 mm or less, for example. Welding is preferably welding in which the joint portion including the base material is melted and joined, and laser welding such as carbon dioxide laser welding, YAG laser welding, and excimer laser welding is preferred, and among them, it is widely used and inexpensive. Carbon dioxide laser welding and YAG laser welding suitable for microfabrication are particularly preferable.

After welding the seam portion, the tubular body of the present invention can be obtained by cutting the joint between the thin plate and the plate-like body. Since it is used for applications that do not need to be joined in a liquid-tight manner, the tubular body is formed by cutting the joint between the thin plate and the plate-like body after making the plate-like body into a tubular shape by pressing. Can be obtained.
The tubular body manufactured in this way can be further processed and used according to its application. For example, when it is used as an injection needle, it is necessary to perform processing such as attaching a blade edge by a conventional method.

The present invention will be further described below using examples.
Example 1
A tip having a small inner diameter shown in FIG. 1 (a) is pressed from a thin plate made of stainless steel (SUS304) having a thickness of 0.05 mm using the mold shown in FIG. 5 according to the procedure shown in FIGS. And a hollow tube having a base end portion with a large inner diameter, a side shape tapered, and a circular cross section. The dimensions of the manufactured hollow tube are as follows.
Maximum diameter outer diameter 1mm, inner diameter 0.9mm
Minimum diameter part outer diameter 0.7mm, inner diameter 0.6mm
Length 20mm
Rmax 0.8μm

(Example 2)
9 is punched out from a thin plate made of stainless steel (SUS304) having a thickness of 0.1 mm and pressed using the mold shown in FIG. 10 to obtain an inner diameter shown in FIG. Has a small distal end and a proximal end with a large inner diameter, and has a step between the distal end and the proximal end, and an intermediate portion with a different inner diameter from the distal end and the proximal end. A hollow tube having a circular shape and a sectional shape was manufactured. The dimensions of the manufactured hollow tube are as follows.
Maximum diameter outer diameter 1.5mm, inner diameter 1.3mm
Middle diameter outer diameter 1mm, inner diameter 0.8mm
Minimum diameter part outer diameter 0.8mm, inner diameter 0.6mm
Length 20mm
Rmax 1.1μm

(Example 3)
A thin plate made of stainless steel (SUS304) having a thickness of 0.05 mm is punched out and pressed using a die corresponding to the side surface shape of the tubular body as shown in FIG. A hollow tube with a circular cross section having a tip portion with a small inner diameter and a base end portion with a large inner diameter and a transition portion between the tip portion and the base end portion was manufactured. The dimensions of the manufactured hollow tube are as follows.
Minimum diameter outer diameter 0.35mm
Inner diameter 0.25mm
Minimum diameter outer diameter 0.2mm
0.1mm inside diameter
Length 20mm
Rmax 1.7μm

(A) thru | or (c) are the front views, side views, and back views which showed the specific example of the tubular body of this invention. (A) thru | or (e) are the front views, side views, and back views which showed the specific example of the tubular body of this invention. It is a figure which shows the manufacturing process of the tubular body by the method of this invention, (a) has shown the state which punched the plate-shaped body which developed the tubular body from the metal thin plate, (b) is plate shape The state which pressed the body into the curved shape is shown. It is a figure which shows the manufacturing process of the tubular body by the method of this invention, (c) has shown the state which pressed the plate-shaped body into the U shape, (d) has pressed the plate-shaped body into the tube shape Shows the state. It is side sectional drawing of the type | mold used for manufacture of the metal tubular bodies shown to Fig.1 (a). It is a figure which shows the step corresponding to FIG.4 (c) when manufacturing the tubular body shown to Fig.1 (a) using the type | mold shown in FIG.5, (a) is from the small internal diameter side of a tubular body. It is sectional drawing at the time of seeing, (b) is sectional drawing at the time of seeing from the large internal diameter side of a tubular body. FIG. 5 is a side cross-sectional view for illustrating a positional relationship between a tubular body formed into a tubular shape, a mold, and a metal thin plate by the process illustrated in FIG. It is a figure for demonstrating another aspect of the method of this invention, and the core is used besides the type | mold at the time of manufacture of a tubular body. It is a figure for demonstrating the process of manufacturing the tubular body shown in FIG.1 (b) by the method of this invention, and represents the process corresponded to Fig.3 (a). It is side part sectional drawing of the type | mold used when manufacturing the metal tubular body shown in FIG.1 (b). It is a figure for demonstrating the process of manufacturing the tubular body shown in FIG.1 (c) by the method of this invention, and represents the process shown to Fig.3 (a). It is a figure which shows the drawing process in the manufacturing method of the conventional tubular body.

Explanation of symbols

1: Tubular body 2: Die 3: Plug 4: Thin plate 5: Plate body 6: Joint part 7: Mold 8: Tubular body 9: Central shaft 10: Core

Claims (4)

A plate-like body having a tubular body developed from a metal thin plate is punched out in a state where the metal thin plate and the plate-like body are partially joined,
After pressing the plate-like body into a tubular body having at least two kinds of inner diameters,
A tubular body having at least two kinds of inner diameters obtained by cutting a joint between the metal thin plate and the plate-like body, and having a maximum height difference (Rf) of the surface roughness of the inner surface of 3 μm A metal injection needle having a minimum inner diameter of 2 mm or less and a maximum inner diameter of 5 mm or less . The metal injection needle having at least two kinds of inner diameters according to claim 1, wherein the plate-like body is pressed into a tubular body having at least two kinds of inner diameters, and then a joint portion of the pipe is welded . A plate-like body having a tubular body developed from a metal thin plate is punched out in a state where the metal thin plate and the plate-like body are partially joined,
After pressing the plate-like body into a tubular body having at least two kinds of inner diameters,
A tubular body having at least two types of inner diameters by cutting a joint between the metal thin plate and the plate-like body, and the maximum height difference (Rf) of the surface roughness of the inner surface is 3 μm or less. A method for producing a metal injection needle having a minimum inner diameter of 2 mm or less and a maximum inner diameter of 5 mm or less . The metal injection needle having at least two kinds of inner diameters according to claim 3, wherein the plate-like body is pressed into a tubular body having at least two kinds of inner diameters, and then a joint portion of the pipe is welded. how to.

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