JPS6125446B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of fitting metal cylindrical bodies, and more particularly to a method of fitting open ends of two metal cylindrical bodies to each other via an adhesive layer.

As a method of joining two metal cylinders having the same diameter and relatively thin wall by fitting the open ends of the two metal cylinders through an adhesive layer, a first metal cylinder 1 (Fig. 1) is used. A liquid thermosetting adhesive is applied to the inner circumferential surface of the open end 1a of the second metal cylindrical body 2, and the outer circumferential surface of the open end 1a is tightened with a die (not shown). While squeezing the open end 2a with a die mainly within the range of elastic deformation, it is inserted into the open end 1a, and a thin layer of adhesive is applied between the inner circumferential surface of the open end 1a and the outer circumferential surface of the open end 2a. A method has been proposed in which the adhesive layer 3 is squeezed out, and then the tightening is released using a die, and the adhesive layer 3 is heated and cured to perform the bonding.

Reference numeral 4 in FIG. 1 shows a joint formed by such a method. After the die is released, the inner open end 2a springs back, and the outer open end 2a As shown in the figure, the portion 1a has a slight bulge in the shape of a truncated cone, and the end surface _1a1 of the open end portion 1a forms a step on the outside of the outer surface of the second metal cylindrical body 2. It stands out. Therefore, when packaging with heat-shrinkable plastic film, so-called shrink packaging, or pasting paper labels, the film or label may break due to the sharp corners 1a ₁ ' of the end surface 1a ₁ , or the joint may break. A problem arises in that the portion 4 swells and spoils the appearance.

Furthermore, since the amount of tightening during fitting is relatively large, a buckling portion 5 that is concave inward is generated at the open end 2a (especially when the metal cylindrical body 2 is made of a thin and soft material). Holes 5' communicating with the outside are likely to occur. When an assembly formed by joining the metal cylinders 1 and 2 is used as a container, such a hole 5' impairs airtightness and liquidtightness and becomes a fatal defect. Furthermore, since the adhesive layer 3 is formed through a process in which liquid adhesive is squeezed out, it is difficult to obtain a predetermined desired thickness, and there are localized areas where the adhesive layer 3 is hardly present. is also likely to occur,
There is a problem in that the sealing performance is easily impaired in this part.

It is an object of the present invention to solve the problems of the prior art described above.

In order to achieve the above object, the present invention provides a method of fitting the open ends of a first metal cylinder and a second metal cylinder through an adhesive layer made of a thermoplastic resin. After reducing the diameter of the open end of the first metal cylindrical body to form a reduced diameter part having an outer diameter substantially equal to the inner diameter of the open end of the first metal cylindrical body, the outer periphery of the reduced diameter part is a first hole having a cylindrical guide surface into which the open end of the first metal cylindrical body can be fitted; a step portion extending and having a width equal to or slightly greater than the thickness of the open end of the first metal cylinder; and a frusto-conical guide surface substantially contiguous with the step portion and extending outwardly. With the split tool tightened, the open end of the first metal cylindrical body is inserted into the first hole of the split tool having a second hole, and the end surface thereof is in contact with the stepped portion. Then, from the second hole, the reduced diameter part of the second metal cylinder on which the adhesive layer is formed is squeezed by the truncated conical guide surface, and then the first metal cylinder is The present invention provides a method for fitting an open end of a metal cylindrical body, characterized in that the diameter-reduced portion is fitted into the open end of the body over substantially the entire length of the reduced diameter portion.

Furthermore, the present invention provides a method of fitting open ends of a first metal cylinder and a second metal cylinder through an adhesive layer made of thermoplastic resin, the method comprising: After reducing the diameter of the open end to form a reduced diameter part having an outer diameter substantially equal to the inner diameter of the open end of the first metal cylinder, the adhesive is applied to the outer peripheral surface of the reduced diameter part. a first hole forming a layer and having a cylindrical guide surface into which the open end of the first metal cylinder can be fitted; a second hole having a step portion that is equal to or slightly larger than the thickness of the open end of the first metal cylinder; and a frusto-conical guide surface substantially connected to the step portion and expanding outwardly; In a state where the split tool is tightened, insert the first hole into the first hole of the split tool with the
The open end of the metal cylindrical body is inserted until the end face abuts the stepped part, and then the reduced diameter part of the second metal cylindrical body on which the adhesive layer is formed is inserted through the second hole. The tip of the tool is inserted into the open end of the first metal cylindrical body while being squeezed by the frusto-conical guide surface, and after releasing the tightening of the split tool, the tip is then inserted into the open end of the first metal cylindrical body while being squeezed by the frusto-conical guide surface. The present invention provides a method for fitting an open end of a metal cylindrical body, characterized by fitting the open end of the metal cylinder.

The present invention also provides a method of fitting open ends of a first metal cylinder and a second metal cylinder through an adhesive layer made of thermoplastic resin, the method comprising: reducing the diameter of the open end to form a reduced diameter portion having an outer diameter substantially equal to the inner diameter of the open end of the first metal cylinder; a first hole having a cylindrical guide surface into which the open end of the first metal cylindrical body can be fitted, the adhesive layer being formed around the periphery; a stepped portion extending outward and having a width equal to or slightly larger than the sum of the thickness of the open end of the first metal cylindrical body and the thickness of the adhesive layer; With the split tool tightened, the open end of the first metal cylindrical body is inserted into the first hole of the split tool, which has a second hole having a truncated conical guide surface that expands. , until its end surface abuts on the stepped portion, and then from the second hole, while squeezing the reduced diameter portion of the second metal cylindrical body with the frusto-conical guide surface, the first metal cylindrical body is The present invention provides a method for fitting an open end of a metal cylindrical body, the method comprising fitting the open end of the metal cylindrical body over substantially the entire length of the reduced diameter portion into the open end on which the adhesive layer is formed.

Furthermore, the present invention provides a first metal cylindrical body and a second metal cylindrical body.
A method of fitting open ends of a metal cylindrical body through an adhesive layer made of a thermoplastic resin, the second method comprising:
reducing the diameter of the open end of the first metal cylindrical body to form a reduced diameter portion having an outer diameter substantially equal to the inner diameter of the open end of the first metal cylindrical body; a first hole having a cylindrical guide surface into which the open end of the first metal cylindrical body can fit, the adhesive layer being formed on the inner circumferential surface of the open end; a step portion extending radially inwardly and having a width equal to or slightly larger than the sum of the thickness of the open end of the first metal cylindrical body and the thickness of the adhesive layer; A first metal cylinder is inserted into a first hole of a split tool having a second hole having a frusto-conical guide surface that extends outwardly and is connected to the first metal cylinder. The open end of the body is inserted until its end surface abuts the step part, and then the tip of the reduced diameter part of the second metal cylindrical body is inserted into the frusto-conical guide through the second hole. The first metal cylindrical body is inserted into the open end where the adhesive layer is formed while narrowing down the surface, and after releasing the tightening of the split tool, the substantially entire length of the reduced diameter part is subsequently inserted. The present invention provides a method for fitting an open end of a metal cylindrical body.

With reference to the drawings for illustrating embodiments below,
The present invention will be explained.

FIG. 2 shows that the open end 12a of the upper can 12 is fitted into the open end 11a of the upper can 11 through an adhesive layer 13 made of thermoplastic resin to form a fitting part 14. The metal container assembly 10 shown in FIG. After that, the metal container assembly 10 is manufactured by removing the fitting die 15 and heating the fitting part 14 to a temperature higher than the temperature at which the thermoplastic resin can be thermally bonded, that is, the melting point or softening point. By thermally bonding, a joint portion (corresponding to the fitting portion 14) is formed and a metal container is formed.

The upper can body 11 is relatively thin (for example, 0.15~
0.30 mm) A seamless body portion 11b, a shoulder portion 11c, and a narrow mouth portion 11d are formed by drawing a metal blank (for example, tin, aluminum alloy, etc.). In this specification,
A can with this shape is also called a metal cylinder. The lower can body 12 is also a cup-shaped body formed by drawing a relatively thin metal blank, and includes a body portion 12b and a bottom portion 12c. In this specification, such a cup-shaped body is also referred to as a metal cylindrical body. The outer diameter and wall thickness of the body portion 11b of the upper can body 11 are substantially equal to the outer diameter and wall thickness of the body portion 12b of the lower can body 12, respectively. Reference numerals 16 and 17 are push bodies for the upper can body 11 and the lower can body 12, respectively, which are used for fitting.

The body portion 12b of the lower can body 12 immediately after being formed by drawing or the like has the same diameter up to the open end, but as shown in FIG. 3a, the open end is reduced in diameter. A short cylindrical reduced diameter portion 12a' having an outer diameter substantially equal to the inner diameter of the open end 11a of the upper can body 11 is formed. The length of the reduced diameter part 12a' is usually about 2 to 10 mm.
It is. 12a'' is a shoulder portion formed along with the formation of the reduced diameter portion 12a'.

Next, the outer circumferential surface 12a ₁ ′ of the reduced diameter portion 12a′ and the end surface 12
a ₂ ′ and the end face 12 of the inner circumferential surface 12 near the _{a 2} ′ part 12
An adhesive layer 13 is formed on a ₃ '. The reason why the end surface 12a ₂ ' is coated with the adhesive layer 13 is because the inner surface of the lower can 12 (the same goes for the inner surface of the upper can 11) is usually protected with an anticorrosive coating (not shown).
Since a ₂ ' is a cut edge, the metal is exposed, and this is to protect this exposed metal from erosion by the contents. Therefore, if such protection is not required, only the outer peripheral surface 12a ₁ ' may be coated. The formation of the adhesive layer 13 (on the outer circumferential surface 12a ₁ ') facilitates insertion due to the lubricating effect of the adhesive,
It also has the advantage of preventing the formation of pores in the joint due to burrs.

The adhesive layer 13 may be formed by powder coating, slurry coating, etc., but it may be formed by using a heat-adhesive plastic tape (for example, modified linear polyester, or nylon 11 or 12, which has a relatively low melting point and does not contain polar groups). It is most preferable to form the film by adhering a thermoplastic resin tape) with a primer layer interposed therebetween, if necessary. This is because it is possible to obtain an adhesive layer 13 having a predetermined uniform thickness, a smooth surface, and no pores.

Formation of the adhesive layer 13 using plastic tape can be performed, for example, as previously proposed by the present inventors.
It is done as follows. First, the outer circumferential surface 12 is held on the circumferential surface of the adhesive roll by vacuum suction.
a A piece of tape with a length substantially equal to the circumference of ₁ ′,
The reduced diameter part 12a', which is heated to a temperature that allows thermal bonding and whose inside is supported by a mandrel, is pressed while rotating at the same circumferential speed as the adhesive roll, leaving a protruding part on the outer peripheral surface _12a1 '. Move it down,
A piece of tape is thermally bonded onto the outer peripheral surface 12a ₁ '. Next, the protruding part is bent radially inward using a die so that the base of the protruding part comes into contact with the entire surface of the end face _12a2 ', and then a core is inserted into the reduced diameter part 12a' to bend the protruding part inward. The part is folded back, and the folded protruding part is pressed against the inner peripheral surface part _12a3 ' by a core, and in the pressed state, the reduced diameter part 12a' is heated to the temperature that allows thermal bonding, and the protruding part is attached to the end face 12a. ₂ ' and the inner peripheral surface portion _12a3 '. The thickness of the tape piece used and thus of the adhesive layer 13 is:
Usually about 30 to 100 μm, and the thickness of the open end 11a and the reduced diameter part 12a' (usually about 0.15 to 0.30 mm)
much thinner than.

The die 15 consists of a pair of half molds 15a and 15b, as shown in FIG.
It has a hole 18 for inserting the open end 11a of the lower can body 12, and a hole 19 for inserting the reduced diameter portion 12a' of the lower can body 12. The hole 18 is formed with a truncated conical introduction guide surface 18a and a guide surface 18b into which a short cylindrical opening end 11a can be fitted. In this case, "fittable" means that it can be fitted relatively loosely to the extent that the opening end 11a is not substantially deformed even if it is fitted.
This refers to cases of 0.2 mm or less.

A stepped portion 20 that extends radially inward is formed in connection with the cylindrical guide surface 18b. In the figure, the radial width of the stepped portion 20 is equal to the thickness of the open end portion 11a, but it may be slightly larger than the latter (within a range that does not cause buckling; for example, about 0.2 mm or less). Reference numeral 21 denotes a very narrow cylindrical chamfered part for determining the inner diameter of the stepped part 20. The stepped part 20 is connected to the hole 1 through the cylindrical chamfered part 21
9 is connected to an outwardly expanding frusto-conical guide surface 19a. Such a mode of articulation is referred to herein as substantially articulating. The frusto-conical guide surface 19a has a taper such that it does not come into contact with the shoulder 12a'' of the lower can body 12 when the fitting is completed (see FIG. 3d).

Fitting is performed using the die 15 as follows. First, with the die 15 tightened and fixed, the open end 11a of the upper can body 11 is inserted by the pusher 16 until the end surface _11a2 contacts the stepped portion 20, and the open end 11a is fixed. and shaping (to a perfect circular cross section). Next, the lower can body 12
The reduced diameter portion 12a' is inserted into the die 15 coaxially with the upper can body 11 through the hole 19 by the pusher 17. The outer diameter of the reduced diameter portion 12a' is the same as that of the adhesive layer 13.
Since the inner diameter of the stepped portion ₂₀ is _twice the thickness of When it comes into contact with the frusto-conical guide surface 19a and is further pushed in, the tip of the reduced-diameter portion 12a' is substantially elastically squeezed, as shown in FIG. 3b, and the upper can body 11 is inserted into the open end 11a of.

At this point, as shown in FIG. 5, when the fastening of the die 15 is released, as shown in FIG.
The portion of the open end 11a and the portion of the reduced diameter portion 12a' corresponding to the fitting portion 14' are substantially elastically expanded and expanded by the thickness of the adhesive layer 13, which is the fitting margin of Shrink. Subsequently, with the tightening mentioned above released, the reduced diameter portion 12a' is stretched over almost its entire length,
By fitting into the open end portion 11a, an airtight fitting portion 14 is formed. Since the fitting portion 14 is subjected to internal pressing force due to springback, an airtight joint can be obtained by heating the adhesive layer 13 to a temperature at which it can be thermally bonded and thermally bonding it.

In the above embodiment, when the tip of the reduced diameter portion 12a' is inserted into the open end 11a, the die 1
Although the tightening of 5 is released, the fitting portion 14 may be formed by fitting the reduced diameter portion 12a' over almost the entire length thereof without releasing the tightening. However, in this case, the open end 11 during the fitting process
Since there is no expansion of a, the diameter reduction part 12 during the fitting process
The amount of contraction of a' is approximately twice that of the previous embodiment.
Therefore, if the reduced diameter portion is made of a thin and relatively soft material, or if the adhesive layer 13 is relatively thick, there is a risk that the reduced diameter portion 12a' may buckle during insertion.

Further, as shown in FIG. 6a, an adhesive layer 33 is formed on the inner circumferential surface _31a3 of the open end 31a of the upper can body 31 by powder coating or slurry coating (drying and solidifying after coating). As shown in FIG. 6b, a fitting part 44 may be formed by fitting the reduced diameter part 32a' into the open end part 31a on which the adhesive layer 33 is formed. The die 35 used in this case is
It is the same as the die 15 described above, except that the radial width of the stepped portion 40 is equal to or slightly larger than the sum of the thickness of the open end portion 31a and the thickness of the adhesive layer 33. In this case as well, after the tip of the reduced diameter portion 32a' is fitted into the open end 31a, the fastening of the die 35 may be released and the fitting may be continued to form the fitting portion 44; The fitting portion 44 may be formed by continuing the fitting without performing the above-mentioned release.

However, in this case, as mentioned above, it is difficult to obtain an adhesive layer with a desired constant thickness and a smooth surface. Buckling may occur in the reduced diameter portion 32a' in a locally thick portion of the layer 33, or pores that penetrate the inside and outside may occur in a locally thin portion of the adhesive layer 33 even after thermal bonding by heating, resulting in airtightness. may be damaged.

According to the present invention, the fitting margin when fitting the open end of the metal cylinder through the adhesive layer is small and substantially equal to the thickness of the adhesive layer, so the opening on the side to be fitted is small. This has the effect that there is little risk of buckling occurring at the end portion, that is, the reduced diameter portion. In addition, if the outer diameters of the bodies of both metal cylinders are the same, the fitting part and therefore the joint part will be located on almost the same cylinder as the body, and in the case of shrink packaging or label attachment, the film or label may break. , they have the advantage that there is no risk of forming a step.

[Brief explanation of the drawing]

Figure 1 is a vertical sectional view of the fitting part for comparison, Figure 2
The figure shows an example of a metal container assembly having a fitting part formed by the method of the present invention, and a vertical cross-sectional view of an example of a tool used for this formation, and FIG. 3 shows a case where the fitting part of FIG. 2 is formed. FIG. 3 is a longitudinal sectional view of main parts showing the process;
Figure a shows the state before mating, Figure 3 b shows the initial state of mating, Figure 3 c shows the state when the die is released, and Figure 3 d shows the state after mating is completed. 4 is a longitudinal cross-sectional view taken along the - line of FIG. 3 a, FIG. 5 is a longitudinal cross-sectional view taken along the - line of FIG. 3 c, and FIG. FIG. 6 is a vertical cross-sectional view of a main part showing a part of the process of forming a fitting part by the method, FIG. 6 a shows a state before fitting, and FIG. 6 b shows a state after fitting. It is a drawing. 11, 31... Upper can body (first metal cylindrical body), 11a, 31a... Open end, 12, 32
...Lower can body (second metal cylindrical body), 12a', 3
2a′...Reduced diameter part, 13, 33...Adhesive layer, 1
4, 44... Fitting portion, 15, 35... Fitting die (split tool), 18, 19... Hole, 18b... Cylindrical guide surface, 20, 40... Step portion, 19a...
Frustoconical guide surface.

Claims (1)

[Scope of Claims] 1. A method of fitting open ends of a first metal cylinder and a second metal cylinder through an adhesive layer made of thermoplastic resin, the method comprising: After reducing the diameter of the open end of the body to form a reduced diameter part having an outer diameter substantially equal to the inner diameter of the open end of the first metal cylindrical body, the outer peripheral surface of the reduced diameter part is a first hole forming an adhesive layer and having a cylindrical guide surface into which the open end of the first metal cylinder can be fitted; a step portion having a thickness equal to or slightly greater than the thickness of the open end of the first metal cylinder; and a second frusto-conical guide surface substantially contiguous with the step portion and extending outwardly. With the split tool tightened, the open end of the first metal cylindrical body is inserted into the first hole of the split tool having a hole until the end surface abuts the stepped part. Then, from the second hole, the opening of the first metal cylinder is squeezed by the frusto-conical guide surface of the reduced diameter part of the second metal cylinder, on which the adhesive layer is formed. A method for fitting an open end of a metal cylindrical body, the method comprising fitting substantially the entire length of the reduced diameter part into the end. 2. A method of fitting the open ends of a first metal cylinder and a second metal cylinder through an adhesive layer made of thermoplastic resin, the method comprising: After reducing the diameter to form a reduced diameter part having an outer diameter substantially equal to the inner diameter of the open end of the first metal cylindrical body, the adhesive layer is formed on the outer peripheral surface of the reduced diameter part. , a first hole having a cylindrical guide surface into which the open end of the first metal cylinder can be fitted; a first metal cylinder extending radially inward in connection with the cylindrical guide surface and having a width; a step portion having a thickness equal to or slightly greater than the thickness of the open end of the body; and a second hole portion having a frusto-conical guide surface substantially contiguous with the step portion and extending outwardly. With the split tool tightened, the open end of the first metal cylindrical body is inserted into the first hole of the split tool until its end surface abuts the stepped portion, and then the second The lost end of the reduced diameter part of the second metal cylindrical body on which the adhesive layer is formed is inserted into the open end of the first metal cylindrical body through the hole of A method of fitting an open end of a metal cylindrical body, the method comprising fitting the open end of a metal cylindrical body, and then, after releasing the tightening of the split tool, fitting substantially the entire length of the reduced diameter part. 3. A method of fitting the open ends of a first metal cylinder and a second metal cylinder through an adhesive layer made of thermoplastic resin, the method comprising: A diameter reduction process is performed to form a reduced diameter portion having an outer diameter substantially equal to the inner diameter of the open end of the first metal cylinder, and the adhesive is attached to the inner periphery of the open end of the first metal cylinder. a first hole forming an agent layer and having a cylindrical guide surface into which the open end of the first metal cylinder can be fitted;
extending radially inward in connection with the cylindrical guide surface;
a step portion whose width is equal to or slightly larger than the sum of the thickness of the open end of the first metal cylinder and the thickness of the adhesive layer; and a step portion substantially contiguous with the step portion and expanding outward. With the split tool tightened, the open end of the first metal cylinder is inserted into the first hole of the split tool, which has a second hole having a frusto-conical guide surface.
The second metal cylindrical body is inserted until its end surface abuts the stepped portion, and then from the second hole, the first metal cylindrical body is squeezed by the frustoconical guide surface 1. A method of fitting an open end of a metal cylindrical body, the method comprising fitting substantially the entire length of the reduced diameter part into the open end of the cylindrical body on which the adhesive layer is formed. 4. A method of fitting the open ends of a first metal cylinder and a second metal cylinder through an adhesive layer made of thermoplastic resin, the method comprising: The diameter is reduced to form a reduced diameter portion having an outer diameter substantially equal to the inner diameter of the open end of the first metal cylinder, and the reduced diameter portion is applied to the inner circumferential surface of the open end of the first metal cylinder. a first hole forming an adhesive layer and having a cylindrical guide surface into which the open end of the first metal cylinder can be fitted; is equal to or slightly larger than the sum of the thickness of the open end of the first metal cylindrical body and the thickness of the adhesive layer, and a cut portion substantially connected to the step portion and expanding outward. With the split tool being tightened, the open end of the first metal cylindrical body is inserted into the first hole of the split tool, which has a second hole having a conical guide surface. Insert until it comes into contact with the stepped part,
Next, from the second hole, the tip of the reduced diameter part of the second metal cylinder is squeezed by the truncated conical guide surface, and the adhesive layer of the first metal cylinder is formed. A method for fitting an open end of a metal cylindrical body, the method comprising fitting into the open end, releasing the tightening of the split tool, and subsequently fitting substantially the entire length of the reduced diameter part. 5. A method for fitting an open end of a metal cylindrical body according to claim 1 or 2, wherein the adhesive layer is formed by thermal adhesion of a thermoplastic resin tape.