KR880001371B1 - Metal tube & apparatus & method for manufacturing the same - Google Patents

Abstract

Mfr. is described in a single extrusion stage, of a thinwalled seamless metal tube. The tube has a tubular nipple section with aperture, a connecting shoulder section, and a transition section to a tubular cylindrical section, with a wall thickness of 20-70 . The appliance has a thrust mandrel and a die. The mandrel consists of a main shank, a head, and an intermediate extrusion edge. The die has a central recess, to form the shoulder-, transfer- and nipple sections of the tube. The angle between the mandrel axis and the tangent to the surface of the mandrel head, at the extrusion edge and a point on the mandrel axis, is 130 deg. <= <= 170 deg..

Description

Thin metal tube

1 is an explanatory view of a one-time extrusion method using a conventional punch and die.

2 is a cross-sectional view of the shoulder between metals produced by the method of FIG.

3 is a cross-sectional view showing one embodiment of a die according to the present invention.

4 is a cross-sectional view showing another embodiment of a die according to the present invention.

5 is a front view showing an embodiment of a punch according to the present invention.

6 is a front view showing another embodiment of the punch according to the present invention.

FIG. 6A is an enlarged explanatory view of the punch head portion of the punch shown in FIG.

7 is an impact extrusion method for forming a thin metal tube using a punch and a die according to the present invention. The left side is a state diagram before molding, and the right side is a state diagram after molding.

8 is a cross-sectional view showing a process of forming a resin layer on a thin metal tube.

9 is an enlarged view of a shoulder of a thin metal tube manufactured according to the present invention.

10 is an enlarged view of the shoulder of another thin-walled metal tube that is part of the present invention.

11 is a diagram comparing the effect of the present invention with the conventional one.

Figure 12 is a comparative diagram of the effects of the prior art and the present invention from another aspect.

TECHNICAL FIELD The present invention relates to a thin metal tube, and more particularly, to a thin metal tube having a wall thickness of 20-70 mu and having some characteristic elements at the boundary between the body portion and the shoulder portion.

Although it is used as a container for beverages or wheat products, it is required in the technical aspect of this field that the compression tube is a thin metal tube with a thickness of 20-70μ. It should be coated with resin of 50-500μ of thickness on the outside and the outer surface, and this composite extruded tube has the pressure resistance under a certain pressure and the phenomenon of excessive air-back if it has the stability to return to its original state after slight deformation. It must have the property of blocking air and steam without

In addition, the composite extruded tube is easy to handle in the manufacturing and transportation process, and the appearance is good, and these various features are combined to increase the product range of the composite extruded tube.

As an extruded tube that satisfies the above requirements, there is a thin laminate tube using a metal foil.

However, it is impossible to manufacture a thin tube without a seam in the longitudinal direction, and the shoulder and the body are generally manufactured separately, so that the joints or the joints are sometimes broken.

In addition, since the thermoplastic resin is used as the coating material in the joints to be joined in the heated state, the thin tube is not suitable for the storage container of the contents requiring heating and disinfection, and the sealing property of the shoulder is not good. .

In order to make up for the shortcomings of such thin tubes, a seamless metal tube with a body thickness of 20-70μ is required. A technique for manufacturing a single metal tube in a single extrusion process using a general punch and die has already been developed, for example, US Patent No. 2,112,085.

However, in the conventional technique of manufacturing a metal tube by a single extrusion process as in the conventional US patent, the thickness of the body is at least 75μ even when the diameter of the tube is small, and below that, the tube is ruptured or wrinkled. It was not possible to stably produce a single metal tube with a thickness of 20-70μ even when using an ideal metal material as a composite tube because of the failure of punches and dies.

As a result of many studies to solve the above problems of the metal tube, a method as shown in DT-OS 2,818,632 was devised.

In describing the technique, one method of one-time extrusion, deep drawing necking, uniform cutting, and jointing is used, and the second process is a specially designed method. Ironing with a die ring.

In this way, the wall thickness of the body is 20-70μ, and it is possible to stably manufacture metal tubes with good properties.However, in this method, it is not only cumbersome but expensive, because the plastic processing work has to be performed more than 2 times. It was required to manufacture metal tubes as a manufacturing technique.

In addition, since the resin flows from the boundary part when the metal tube is coated with resin, the thickness of the resin layer becomes thinner at this part, and the mechanical properties thereof are deteriorated. Therefore, when this part hits the rigid body, it will be worn or bent and the needle hole at the boundary part. This is a problem, especially when transported in the upright position may contain a problem that can be destroyed or deformed.

An object of the present invention is to provide a thin metal tube of an ideal composite type thin tube coated with resin on both the inner surface, the outer surface, or both sides with a resin, the top of which is open, and the shoulder connected to the top. The shoulder and the tubular body part are connected by the boundary part, and these parts are made of one metal plate to hold the contents that can be used as a container, and the wall of the tubular body part described above is in the longitudinal direction. In seamless metal tubes, the wall thickness of the trunk is 20-70μ, and the wall thickness of the boundary between the shoulder and the trunk is generally larger than the thickness of the trunk. The part whose thickness is changed has a cross section which forms the axis of the tube in which the inclined part is formed in the inner surface of the boundary part, and the inclined part mentioned above. Silver first-predetermined angle in the range of about 130 ° -175 ° to the inner surface of the shoulder and second predetermined angle in the range of about 130-170 ° to the inner surface of the torso part described above. It is characterized in that configured to have.

Detailed description will be made in accordance with the accompanying drawings to help more clearly understand the invention.

1 shows a general stationary for producing a metal tube as a lamellar extrusion and a portion of the metal tube that is a product thereof, which is denoted by a die, a punch, and a thin-walled extruded metal tube, respectively.

The thickness t ₀ of the trunk portion 2 of the metal tube 8 can be represented by t ₀ = 1/2 (D ₀ -P ₀ ).

D ₀ : diameter of the punch head 26.

P ₀ : inner diameter of die.

J ₀ is the distance between the punch head 26 and the die 5 when the punch 6 is in the working position, and J ₁ is a single impact extrusion using the punch 6 and the die 5 as shown in the drawing. The thickness of the shoulder 1 of the extruded metal tube 8 of a thin thickness manufactured during operation is shown.

The wall thickness t ₁ of the body part 2 is the thickness t 'of the shoulder part 1 and the boundary part 3 of the body part 2 and the thickness t " of the end part of the metal tube 8. the average value as _{t 1 = (t '+ t} ") / 2 is expressed as.

2 is a cross-sectional view of an extruded metal tube manufactured by a single impact extrusion process using a punch 6 and a die 5 generally used. As shown in this figure, the trunk portion 2 of the shoulder 1 forms an obtuse angle at the boundary 3.

In practical industry, the thickness of the shoulder is usually 1.0-1.5mm when the wall thickness of the tube is 100-130μ for stable mass production operation.

In practice, a number of problems have arisen in producing a thin metal tube having a wall thickness of 20-70 μ in a single impact extrusion process using a punch 6 and a die 5.

For example, between the boundary part 3 and the trunk part 2, the lower part 4 of the shoulder is torn or ruptured, and the wrinkles are caused by work occurring during the work or uneven stretching. It is also very difficult to manufacture metal tubes with the correct dimensions as designed because the metal tubes deform when they are removed from the die after the end of work. To solve these problems, as the metal tube of the present invention, FIGS. 3 to 6 show the punch 6 and the die 5 according to the present invention.

In FIG. 3, the die 5 is recessed in the middle to form the shape of the groove 20, and has a side surface 21, and a boundary portion 3 connecting the shoulder 1 and the trunk portion 2. ) And the bottom 22 for processing the shoulder 1, and the bottom 23 for the machining of the top 12 of the metal tube 8 of FIG. 1.

The die 5 is designed such that the outer surface of the shoulder 1 of the metal tube 8 and the boundary portion 3 of the trunk portion 2 forms a curved surface, and the bottom surface 22 of the die 5 has a radius of curvature. It is 0.5-3.0mm and is particularly designed to have 1.0-2.0mm.

4 is another example of the die 5.

As shown in the drawing, the die 5 has a first inclined surface 22a at the bottom 22 of the recessed groove 20, the length 1 _{1 of} which is 0.5-5.0 mm, particularly preferably 1.0-. 3.0mm is good.

The first inclined surface 22a forms an inclination angle T with the second inclined surface 22b of the bottom surface 22, and the angle thereof is 130 ° -170 °, preferably 150 ° -170 °, particularly preferably Is 155 ° -165 °. The inclination angle T ₁ is 130 ° -170 ° from the axial direction of the metal tube, particularly preferably 140 ° -160 °.

As will be described later, by using the die 5, the boundary portion 3 of the metal tube 8 is inclined.

One example of a punch 6 to be used with this die 5 is shown in FIG. The punch 6 is composed of an extrusion edge 27 located between the main shaft 25 and the head 26, the head 26 of the punch 6 is a projection 26a, the first head surface ( 26b) and the second head surface 26c. The extrusion edge 27 is the largest diameter part of the punch 6 as mentioned above.

θ

170°로 되어 있다. 제5도 펀치(6)의 경우 제2두부면(26c)은 도면처럼 경사지어 있고, 이 경사진 제2두부면(26c)의 길이(I₂)는 0.5-5.0mm이며, 그중 1.0-3.0mm로 함이 좋다.The second head surface 26c has an angle T2 at which the longitudinal axis of the punch 6 forms the point contact surface of the second head surface 26c is 130 °.

θ

It is 170 degrees. In the case of the fifth degree punch 6, the second head surface 26c is inclined as shown in the drawing, and the length I ₂ of the inclined second head surface 26c is 0.5-5.0 mm, of which 1.0-3.0 It is good to set it to mm.

In addition, the inclined angle is 5 ° -50 ° with the first head surface 26c, and it is better to use 10 ° -30 ° and more preferably 15 ° -25 °.

The angle T ₂ between the longitudinal axis of the punch 6 and the second head surface 26c is between 130 ° -170 °, particularly 140 ° -160 °.

6 and 6a show another example of the punch 6. Unlike the punch of FIG. 5, this punch 6 has a radius of curvature of the second head surface 26c of 0.5-3.0 mm, and forms an arcuate curved surface of 1.0-2.0 mm.

θ

170°이다.In any case, the punch shaft and the second head surface 26c form an angle T ₂ and the range is 130 °.

θ

170 °.

From now on, a description will be given of a method for producing a thin metal tube 8 in which the wall thickness of the trunk portion 2 is 20-70 mu by using the above-described punch 6 and die 5.

First, a method of combining and using the die 5 of FIG. 4 and the punch 6 of FIG.

As shown in FIG. 7, the metal plate 30 having the central hole 29 drilled is placed on the bottom surface 22 of the die 5, and then the punch 6 is pushed. This machining is completed in one second. The trunk portion 2 of the machined metal tube 8 is extruded alongside the axis of the punch 6.

As is clear from the drawing, the distance J ₀ between the first and second head surfaces 26b and 26c of the punch head 26 and the bottom surface 22 of the die 5 during the machining operation is _equal to the side surface 21. It is kept larger than the distance t ₀ .

That is, the second head surface 26c of the punch head 26 when the structures of the punch 6 and the die 5, which are apparatuses for manufacturing the metal tube of the present invention, are folded into the punch 6 and the die 5; And the distance between the bottom surface 22 of the die 5 is larger than the distance between the extrusion edge 27 of the punch 6 and the side surface 21 of the die 5. The parts not shown, i.e., the method of fixing the die 5, the method of driving the punch 6 while maintaining it at an appropriate speed, and the like may be used.

Various metals may be used as the metal plate 30.

That is, aluminum or aluminum alloys are used, and also metals such as tin and south have good elongation and can be used in the machining operation of the present invention. The right part of FIG. 7 shows a thin metal tube 8 having a wall thickness of 20-70 μ of the trunk portion 2 produced by the method described above. In order to obtain the final product of the composite extruded pipe, a screw for attaching the lid is made at the top of the thin metal tube 8 and powder spraying using static electricity on the thin metal tube 8 as shown in FIG. Painting.

Specifically, the powder is packed and ground to 60-90 KV and adhered to the surface of the thin metal tube 8. The spraying speed is generally about 100-300g / min, and the killing distance is 100-200mm. The powdering pressure and the spraying pressure are 1-4Kg / ㎠ and 0-1.5Kg / ㎠.

The adhered powder is then baked at an appropriate temperature to form a coating layer.

This coating layer may be formed on the inner surface, outer surface or both sides of the thin metal tube 8, and in either case, the thickness thereof is 50-500 mu, most preferably 50-350 mu.

Resins that can be used in the present invention include polyolefin resins, polyester resins, epoxy resins, polyamide resins, or modified resins thereof, and polyethylene resins are widely used because of their high flexibility and chemical safety for contents.

In FIG. 8, a ground (32), a jig (31), and an electrostatic powder coating machine (33) are shown, and the resin powder (34) is shown.

9 and 10 are a composite extruded tube of a flexible shape according to the present invention, Figure 9 is a composite extruded tube manufactured by the method of the above-described one, Figure 10 is a punch 6 and the It is an extrusion tube manufactured using the die 5 of 3 degree together.

The wall thickness t ₁ of the trunk | drum 2 of the metal tube 8 is 20-70 micrometers, and the wall thickness J ₁ of the shoulder ₁ is 400-1000 micrometers.

In addition, the thickness of the shoulder portion 1 and the boundary portion 3 of the trunk portion 2 is changed, the thickness of which is greater than the thickness of the trunk portion (2).

Specifically, in the case of a tube as shown in FIG. 10, the radius of curvature of the outer surface of the boundary portion 2 is 0.5-3.0 mm. In FIG. 9, the boundary portion 3 has an inclined portion 10 and the length l ₁ is 0.5. -5.0mm.

The angle T ₁ between the inclined portion 10 and the trunk portion 2 is between 130 ° and 170 ° like the angle T between the inclined portion 10 and the shoulder 1. In each tube 8 of FIGS. 9 and 10, the inclined portion L 'of the boundary portion 3 has a length of 0.5-5.0 mm l' ₂ , and the angle T between the inclined surfaces of the shoulder 1. ' ₂ ) is between 130 ° and 175 ° and the angle (T ₂ ) between the body part 2 and the inclined part L' parallel to the axis of the metal tube 8 is between 130 ° and 170 °, which is generally 140 °. It is good to set it to about 160 ° Reference numeral 11 in FIG. 9 and FIG. 10 denotes a resin layer uniformly formed on the entire outer surface of the metal tube 8.

As described above, at least one of the inner surface or the outer surface of the thin metal tube 8 manufactured by using the punch 6 and the die 5 for producing the thin metal tube is a curved surface or an inclined surface.

In terms of ease of die and punch manufacturing, there is a big difference between making a curved surface and an inclined surface, especially in view of the ease of processing a thin body thickness.

In addition, the properties of the metal tube are different depending on whether the inner or outer surface of the boundary portion 3 is curved or inclined, and this difference appears to play a significant and decisive role.

When the inner surface of the boundary portion 3 is inclined or curved, the following six shapes may appear depending on the processing method of the outer surface.

1, T-T 2, R-T 3, Ⅹ-T4, T-R 5, R-R 6, X-R

T: slope.

R: curved surface.

X: neither

The sign on the left shows the outside and the protection on the right shows the inside. Compared to giving punches and dies with inclined surfaces and giving curved surfaces respectively, giving an inclined surface is more advantageous than giving a curved surface in the ease of processing of punches and dies and the ease of making the body thinner. In particular, it has been proved that a remarkable effect is given when inclining the punch and die.

From this point of view, it is most advantageous to use the T-T type, that is, the inclined surface of the inner and outer surfaces of the boundary portion.

In other words, this results in a healthy product free of wrinkles, dents, ruptures, uneven stretches or other defects when the body is thinly processed. In addition, by the T-T type, the inner and outer surfaces of the boundary portion of the thin-walled metal tube have a smooth inclination, thereby making it possible to uniformly extend the processed tube.

Next to T-T, R-T and X-T are good, followed by T-R, R-R, and X-R.

In model RR, if the radius of curvature of the inner surface is larger than or equal to the radius of curvature of the outer surface, the inner curvature radius may increase unevenly during processing. Therefore, the inner radius of curvature is smaller than the outer radius of curvature. It needs to be small.

However, in the T-R type, when the length of the inclined portion is smaller than or equal to the radius of curvature of the inner surface, the workability is improved, and the result is better.

As mentioned above, the remarkable matter in the thin-walled metal tube according to the present invention is that the thickness of the wheel is gradually changed by giving a slope or curvature to the boundary between the shoulder and the trunk. Furthermore, by giving such an inclined curvature, uniform resin coating is possible on the outer surface of the boundary portion, and a perfect resin coating is achieved by appropriately thicknessing the resin layer.

This uniform coating can successfully solve problems such as wear of the coating layer during transportation and handling, and direct exposure of the metal tube to the outside or deformation of the fracture door. Also, the shoulder portion is destroyed by increasing the strength of the boundary part. This eliminates the possibility of vertical loading, which was difficult with conventional metal pipes, resulting in significant savings in transportation costs.

As described above, since the metal tube according to the present invention has a very simple manufacturing process, the conditions of the process are easy and the defective product generation rate is low. It also eliminates the need for many skilled workers and significantly reduces installation and operating costs.

The actual operation by this invention is taken as the following example.

관)]Example 1 (35

tube)]

Example 2

11A, 11B and 11C show changes in the quality of the metal tube appearing as the angle σ is changed.

Each graph represents the average of 100 specimens processed with the same temperature and material.

In each graph, the properties of the conventional metal tube are shown on the left and in the figure, on the right.

t₀

70μ이다. 또한 각도 δ₀, δ₁, δ₂는 각각 0°, 15-20°, 25-30°이다.Specifically, Figure 11a shows the characteristics of the metal tube seen from the poor surface, such as rupture, wrinkles at the end of the tube, wrinkles of the tube portion occurring during the machining operation. Body wall thickness of test tube is 50μ

t ₀

70μ. Incidentally, the angles δ ₀ , δ ₁ , δ ₂ are 0 °, 15-20 °, and 25-30 °, respectively.

The analysis value is represented by the axis.

The rupture is indicated by the sign (0), and the points (4) and (0) represent the healthy products without rupture and the defective products generated during the processing, respectively.

In addition, the wrinkles generated at the end of the tube are indicated by the symbol (X), and the points (3) and (0) indicate healthy products without wrinkles at the ends and defective products with wrinkles, respectively.

The mark (△) indicates wrinkles appearing in the lower part of the shoulder, and the points (3) and (0) indicate the pass and fail products, respectively.

11b shows workability, that is, plastic deformation characteristics. The ratio of the length of the torso (l) to the head wall thickness (m) of the shoulder is indicated as 1 / m. As this ratio increases, ductility and workability increase.

Figure 11c shows the accuracy of the product, ie the shape and dimensions of the product relative to the designed shape and dimensions.

The ratio t '/ CR and the ratio t "/ CR are respectively shown.

t ', t ": the final thickness of the body

CR: distance between die and punch

As the values t '/ CR and t "/ CR are close to 1, a metal tube with a similar wall thickness to the design value is produced.

As shown in Figs. 11A, 11B and 11C, the operation result is best when the angle δ is between the angles δ ₁ and δ ₂ , ie between 15 ° and 25 °.

Example 3

Figure 12 shows the accuracy of the tube according to the die shape.

Specifically, data on the accuracy of conventional metal tubes are shown on the left, and data on the accuracy of the metal tubes of the present invention are shown on the right.

The vertical side indicates the angle δ of the punch head.

Angle δ ₀ represents 0 ° and angle δ ₁ represents 15 ° -20 °.

In the following case, symbol A means a conventional die, symbol B has a curved surface, and symbol C has an inclined surface. The abscissa represents the values t '/ CR and t "/ CR.

t ': actual thickness right under shoulder

t ": actual thickness of the end of the tube

CR: gap between punch and die

In the graphs showing the values of t '/ CR and t "/ CR, the two curves represent the upper limit and the lower limit, respectively.

Using the same die A in this figure, it can be seen that the combination of the head angle σ ₁ together with the punch of the present invention is more accurate than the conventional punches with the head angle σ ₂ . have.

In addition, when using a punch having the same head angle σ ₁ , using a die having an inclined surface is more advantageous than using a die having a curved surface, and the change width is reduced, which is advantageous in terms of improving processing stability. .

Claims (1)

The stem part 12 is opened, and the shoulder part 1 is connected to this stem part, and this shoulder part and the tubular trunk part 2 are connected by the boundary part 3, and these parts are one whole. It consists of a metal plate (30) of the retaining the contents that can be used as a container, the wall of the tubular body portion described above is a seamless metal tube in the longitudinal direction, the wall thickness (t ₁ ) of the body portion (2) Is 20-70μ, and at the boundary between the shoulder (1) and the trunk (2), the wall thickness has a portion that is generally larger in thickness than the former trunk, and the portion where the thickness changes is the inner surface of the boundary. It has a cross section constituting the axis of the tube formed with an inclined portion (L '), the inclined portion is the first preliminary angle in the range of about 130 ° -175 ° angle (T' ₂ ) with respect to the inner surface of the shoulder Even if the angle T ₂ with respect to the inner surface of the part has a second predetermined angle in the range of 130 ° -170 ° A thin metal tube, characterized in that the lock is configured.

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