JP4479500B2 - Weld structure - Google Patents

Description

  The present invention contains inks such as writing instruments and ink jet printers, such as oil-based inks, water-based inks and / or pigment inks and dye inks, or liquids such as cosmetic liquids, paints, chemicals, repair liquids, seasonings, etc. The present invention relates to a welded structure of a bottle sealed with a stopper.

Conventionally, a container in which a bottle and a stopper made of a thermoplastic resin material formed by an injection molding method or a blow molding method (direct blow or injection blow) is hermetically bonded to each other by an ultrasonic welding method is widely known. ing. Further, in various containers, a screw cutting opening part formed integrally with a dispensing nozzle and the like, and a communication port that communicates the outside and the inside formed by cutting the opening part are provided. It is also widely known that there is a container used as a spout.
In the direct blow molding method of blow molding, a part of a parison (resin material) before being continuously extruded is sandwiched in a mold, and then air is fed into the parison and inflated in the mold. Next, the expanded parison is cooled and solidified, and then the molded product is taken out from the mold.
In addition, the injection blow molding method molds a molded product (preform) having a mouth portion that is similar to the final molded product with an injection mold. Next, the preform is set in a blow mold. The air is then pumped through the preform (hot or warm) opening and inflated in a blow mold. Next, the expanded molded product is cooled and solidified, and then the molded product is taken out from the mold. The injection blow molding method includes a hot parison method and a cold parison method. The hot parison method is a method in which a preform that remains hot is set in a blow mold and inflated immediately after injection molding. The cold parison method is a method in which a preform is temporarily stored, and then the preform is set in a blow mold and heated and then inflated.
JP-B 49-34718. Japanese Patent Laid-Open No. 10-156928. JP-A-7-68911.

With these conventional structures, a container stopper is formed by injection molding, a container bottle is formed by blow molding, and both the stopper and the bottle are ultrasonically welded. There was a problem that. Furthermore, when the inclination of the stopper is severe, there is a problem that the stopper and the bottle are not sufficiently sealed, and the liquid contained in the bottle leaks.
When investigating the cause, when the ultrasonic welding vibrator (horn) was pressed in front of the stopper and then the ultrasonic vibration was oscillated, the diameter-expanded step formed near the outer periphery of the opening of the bottle A phenomenon was observed in which a part of the base on the axial center side was bent in the pressing direction of the vibrator (see FIG. 8).
More specifically, it has been found that this occurs when the bottle of the container is formed by a blow molding method and has a stepped portion having an enlarged diameter near the opening end surface (welding surface) of the bottle.
This is because the inner surface of the opening of the bottle by the injection molding method can be formed into the intended thick wall shape by the mold core pin, but the intended thick wall shape can be obtained from the inner surface of the bottle by the blow molding method. It was because it was not possible. That is, in the direct blow molding method and the injection blow molding method, there is no core pin for regulating the inner surface shape of the bottle, and there is a variation in the bulging amount in the blow mold.
Furthermore, in the case of having a stepped portion whose diameter is increased in the vicinity of the outer periphery of the opening of the bottle by the blow molding method, this is because a sufficient thickness cannot be obtained on the inner surface of the stepped portion. That is, the inner surface shape of the opening cannot be restricted, and the stepped portion is a thin portion. This phenomenon becomes more prominent as the thickness becomes thinner. In addition, even when the bottle body is not cylindrical or uniform in the circumferential direction, and the cross-sectional shape is non-uniform (an irregular shape) such as an ellipse or a horseshoe, Tilt tends to occur.
An object of the present invention is to provide the above-described problem, that is, a welding structure in which the stopper is not inclined and welded.

The present invention has a structure in which a stopper is welded to an opening of a bottle by ultrasonic welding, and the front end of the opening of the bottle is an ultrasonic welding surface, and a step is disposed on the outer periphery near the opening. a was welded structure, only setting the reinforcing portion toward the axis of the stepped portion of the opening also forms the said reinforcing portion from the opening on the concave curved surface, such as to be widened toward the body portion In addition, a radius value of the concave curved surface is set to be equal to or greater than a thickness value of the step portion, and further, a flat stationary portion is formed on the side surface of the main body portion, and a circle is formed from the end of the planar stationary portion. An arcuate arc portion is continuously formed, and the planar stationary portion is formed in an inclined state with respect to the axis of the main body portion, and the main body portion is formed by the inclined stationary portion and the arc portion. The summary is at least formed .

The present invention has a structure in which a stopper is welded to an opening of a bottle by ultrasonic welding, and the front end of the opening of the bottle is an ultrasonic welding surface, and a step is disposed on the outer periphery near the opening. a was welded structure, only setting the reinforcing portion toward the axis of the stepped portion of the opening also forms the said reinforcing portion from the opening on the concave curved surface, such as to be widened toward the body portion In addition, a radius value of the concave curved surface is set to be equal to or greater than a thickness value of the step portion, and further, a flat stationary portion is formed on the side surface of the main body portion, and a circle is formed from the end of the planar stationary portion. An arcuate arc portion is continuously formed, and the planar stationary portion is formed in an inclined state with respect to the axis of the main body portion, and the main body portion is formed by the inclined stationary portion and the arc portion. since at least formed, because although the precise welding can be obtained, good volume etc. leakage does not occur It is possible to provide a Le.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. 1 to 7 show a first embodiment. 1 shows a front sectional view, FIG. 2 shows a left side view of FIG. 1, FIG. 3 shows a top view of FIG. 1, FIG. 4 shows a bottom view of FIG. 1, and FIG. 6 is a partially enlarged view, FIG. 6 is a left side enlarged view of the nozzle portion 1f after the screw cut portion 1g of FIG. 1 is screwed and separated, and FIG. 7 is a screw cut portion of the screw cut portion 1g of FIG. The right side surface enlarged view of the back screw cut part 1g is shown.
8 and 9 show a first comparative example, FIG. 8 shows a comparative view with FIG. 5, and FIG. 9 shows the bottle before ultrasonic welding in FIG.
Reference numeral 1 is a substantially cylindrical bottle formed by a direct blow molding method using a polypropylene resin material (manufactured by Nippon Polypro Co., Ltd., EA7A of Novatec PP) which is a flexible material. The bottle 1 is provided with an opening 1a that opens in a cylindrical shape from the front (upper in the figure).
A circular bottomed stopper 2 formed by an injection molding method is provided so as to cover the opening 1a with a polypropylene resin material made of a thermoplastic resin (manufactured by Nippon Polypro Co., Ltd., BC2E of Novatec PP). On the inner bottom surface of the stopper 2, a conical rib 2a pointed rearward is provided.
The front end of the opening 1a of the bottle 1 forms a horizontal end surface 1b, and this end surface 1b is also a bonding surface ultrasonically welded to the rib 2a of the stopper 2. Further, a stepped portion 1c having an enlarged diameter and a thickness value M of 0.60 mm is provided on the outer periphery of the opening 1a. On the axial center side of the stepped portion 1c, a reinforcing portion 1d having a concave curved radius value N of 0.80 mm is provided so as to expand from the opening toward the outer periphery (body portion) of the stepped portion 1c. . That is, the N (radius value) / M (thickness value) ratio is 1.33.
A barrel portion (main body portion) 1e that stores the expanded liquid is provided behind the step portion 1c of the bottle 1. On the side surface of the body portion 1e, a flat stationary portion 1f that is inclined forward and backward is provided. Therefore, the trunk | drum 1e is not cylindrical shape, but makes the cross section non-uniform | heterogenous shape in the circumferential direction like a horseshoe shape. The barrel 1e has a cylindrical shape with a reduced diameter, the rear of the cylindrical portion has a funnel shape, and the rear of the funnel has a thin cylindrical shape with a closed rear end. Part 1g is provided.
A screw cut portion 1h connected to the side surface of the nozzle portion 1g and on the opposite side of the stationary portion 1f with respect to the axial center of the nozzle portion 1g is a flat-plate-like home base shape with a part of the root swelled. Provided. In addition, an opening 1i is provided across the nozzle part 1g and the screw cutting part 1h, and the nozzle part 1g and the screw cutting part 1h are connected to the cutting part 1j. It is provided as.
In addition, a substantially rod-shaped filling rod 3 formed by an injection molding method using a polypropylene resin material (manufactured by Nippon Polypro Co., Ltd., Novatec PP) so as to be inserted into the nozzle portion 1 g of the bottle 1. Is provided. Reference symbol R indicates the liquid contained in the bottle 1, and reference symbol A indicates the air in the bottle 1.

  The second embodiment is the same material as the first embodiment, the thickness value M of the step portion 1c of the first embodiment is 0.60 mm, the radius value N of the reinforcing portion 1d is 0.60 mm, and N / M The ratio is 1.00.

The operation will be described with reference to FIG. 5 of the first embodiment and FIGS. 8 and 9 of the first comparative example. The bottle 1 'in FIG. 8 is made of the same material as that of the first embodiment, and the body of the bottle 1' has an irregular shape other than a cylindrical shape. The thickness value M of the stepped portion 1c 'is 0.60 mm. The root radius value N on the axial center side of the step 1c ′ is 0.20 mm, and the N / M ratio is 0.33. When the stopper 2 is ultrasonically welded to the bottle 1 ′, the stopper 2 is easily welded so as to tilt toward the stationary portion 1f ′ of the bottle 1 ′ (see FIG. 8). This is because when a horn (ultrasonic vibrator / not shown) that oscillates ultrasonic vibration for ultrasonic welding from the front of the stopper 2 is pressed against the opening 1a ′ of the bottle 1 ′, vertical load + ultrasonic vibration. Is added, and the softening of the resin accompanying instantaneous heat generation due to ultrasonic vibration and the stress on the sloped stationary part 1f 'side becomes higher than the part other than the stationary part 1f' side (stress concentration) It is. That is, since the spreading length extending from the step portion 1c ′ of the bottle 1 ′ to the trunk portion is short on the stationary portion 1f ′ side, the bottle structure is such that the stationary portion 1f ′ side is stretched, and other than the stationary portion 1f ′ side. However, the stationary portion 1f ′ side is less likely to escape and deform, and the stationary portion 1f ′ side of the step portion 1c ′ is likely to be pushed in.
In addition, the welding inclination of the stopper 2 is not limited to the above reasons, and the horizontal angle variation of the end surface 1b 'of the bottle 1', the thickness variation of the body 1e '(not shown) of the bottle 1', and ultrasonic welding. There is a variation due to variations in the accommodation state of the bottle 1 'at the bottle cradle. That is, when the horn is pressed, stress is concentrated in a partial direction of the circumference of the step 1c ′ of the bottle 1 ′ due to the fit of the bottle 1 ′ and the variation in shape, and as a result, the stopper 2 becomes the step of the bottle 1 ′. The portion 1c ′ is welded while being inclined in each circumferential direction.
The second comparative example is the same material as the first example, the thickness M of the step 1c of the first example is 0.60 mm, the radius N of the reinforcing part 1d is 0.40 mm, and the N / M ratio is It is 0.67.
For the first example, the second example, the first comparative example, and the second comparative example, 30 samples were tested using the stopper 2 in common.
In the first example, there was no noticeable inclination of the plug 2. Further, there was no liquid leakage from the stopper 2 when the container containing the liquid was turned downward and the body part 1e of the bottle 1 was depressed by hand.
In the second embodiment, two stoppers 2 were slightly tilted, but there was no liquid leakage when the bottle was pushed.
In the first comparative example, all of the stoppers 2 were significantly inclined, and five liquid leaks were caused by pushing the bottle.
In the second comparative example, all of the stoppers 2 were tilted, three were significantly tilted, and one liquid leak occurred when the bottle was pushed.
The inclination of the stopper 2 in the comparative example is due to the stress concentration in the inclination direction of the stopper 2 of the step 1c ′ of the bottle 1 ′ during ultrasonic welding, and the inclination of the stopper 2 is other than the direction of the stationary part 1f ′. Some of them also happened.

Next, the bottle 1 will be further described in detail. As shown by the arrow direction P in FIG. 2, the screw cutting portion 1h is separated from the bottle 1 by rotating several times in the left or right direction around the cutting portion 1j. FIG. 6 shows the nozzle portion 1 g after the screw cutting portion 1 h is separated from the bottle 1. The range of the cut part 1j and the opening part 1i of FIG. 6 is the fracture surface 1k. By this screw cutting operation, a thin film-like burr 1l in which a resin material extends is generated in the opening 1i. FIG. 7 shows the screw cut portion 1 h after the screw cut portion 1 h is cut from the bottle 1. In the opening portion 1i of FIG. 7, when the screw cut portion 1h is screwed, a thin film-like burr 1l in which a resin material extends is generated. Here, the reason why the screw cutting portion 1h is provided in the flat-shaped home base shape is that the burr 11 formed in the opening 1i is screw-cut because the home base shape is connected to the nozzle portion 1g. The nozzle portion 1g side is smaller than the portion 1h side. By reducing the number of burrs 1l generated on the nozzle portion 1g side, the blocking action of the opening portion 1i by the burrs 11 is prevented. If the thermoplastic resin material is subjected to a resin elongation preventing process such as an ultraviolet irradiation process or a freezing process, it is possible to further reduce the elongation of the burr 11 and prevent the opening 1i from being blocked. .
As shown by the arrow direction Q in FIG. 4, the screw cutting portion 1h can be separated from the bottle 1 even if the screw cutting portion 1h is bent up and down around the cutting portion 1j. However, when the screw cutting portion 1h is separated while being rotated in the P direction in FIG. 2 rather than in the Q direction in FIG. 4, scattering of the liquid in the bottle 1 from the opening portion 1i when the separation is performed is suppressed. Here, even if the screw cutting portion 1h is bent in the Q direction and separated, it is possible to prevent the nozzle portion 1g from bending and twisting about the axis so that the screw cutting portion 1h cannot be separated. For this purpose, a structure in which the rotational torque value at which the nozzle portion 1g twists and deforms with respect to the shaft center is smaller than the bending torque value in the Q direction of the screw cutting portion 1h may be used. Specifically, structural elements such as the diameter, length, thickness, resin elastic modulus of the nozzle portion 1g, and the shape and area of the fractured surface 1k of the screw cutting portion 1h may be appropriately provided.
The filling rod 3 inserted into the nozzle portion 1g of the bottle 1 has a small volume in the nozzle portion 1g, that is, a small amount of liquid penetration. Further, by narrowing the gap between the inner surface of the nozzle part 1g and the outer periphery of the filling rod 3, the filling process of the liquid R into the bottle 1, the ultrasonic welding process of the stopper 2, the nozzle part 1g in the product distribution stage and the screw This is intended to make it difficult for the liquid R to move into the gap of the cut portion 1h. That is, by narrowing the gap between the inner surface of the nozzle portion 1g and the outer periphery of the filling rod 3, the liquid R infiltrated by capillarity forms a strong film in the gap, so the inside of the nozzle portion 1g and the screw cutting portion 1h The air A in the gap is not allowed to pass through the gap between the two members. Further, by narrowing the gap between the inner surface of the nozzle portion 1g and the outer periphery of the filling rod 3, the passage resistance of the liquid R is increased and the liquid discharge amount and liquid discharge speed are suppressed.
With this configuration, the amount of oozing out of the liquid R from the opening portion 1i when the bottle 1 is turned upside down and the screw cutting portion 1h is screwed off can be reduced. Even if the stationary part 1f is placed on the desk surface and the screw cutting part 1h is cut off and cut off, the amount of the liquid R oozing out from the opening part 1i can be reduced as described above. Further, even when the liquid R using a main solvent having a low boiling point and a high vapor pressure such as ethyl alcohol is incorporated, the screw cutting portion 1h is removed from the opening portion 1i when the screw cutting portion 1h is cut off in a high temperature environment. It is also intended to suppress the ejection amount of the liquid R.
Note that the temperature of the liquid R at the time of ultrasonic welding may be increased in order to further suppress the ejection amount of the liquid R when the screw cut portion 1h in the high temperature environment is cut off. The barrel 1e is recessed and the stopper 2 is ultrasonically welded. After the welding, the depression of the barrel 1e is released and the restoring force of the bottle 1 is applied so that the inside of the bottle 1 is decompressed. It is good.
In addition, when the inside of the bottle 1 is depressurized, the stationary part 1f of the bottle 1 after the stopper 2 is ultrasonically welded will be somewhat recessed from the shape of the bottle 1 immediately after molding. The shape of the bottle 1 may be partially bellows so that the depression of the bottle 1 is not noticeable. Further, in consideration of the amount of depression due to the decompression of the stationary portion 1f, the stationary portion 1f immediately after molding may be formed into a bulging shape instead of a flat surface.
In addition, although the said stuffing rod 3 was shown in the substantially rod shape, you may form a polygonal column shape, a slit, or a through-hole. Moreover, it is good also as porous bodies, such as sponge, a ceramic, and a fiber bundle body, instead of a solid injection molded product.

10 and 11 show a third embodiment. 10 shows a front sectional view of the bottle 11, and FIG. 11 shows a top view of FIG.
The bottle 11 is substantially the same as in the first embodiment. The difference from the first embodiment resides in the reinforcing portion. In other words, the step portion 11c of the bottle 11 is provided with reinforcing portions 11d that have a large number of radial ribs on the front and rear. The reinforcing part 11d is constituted by a number of protrusions on the inner surface of the step part 11c according to the arrangement of the ribs.
The rear part of the body part 11e of the bottle 11 has a cylindrical shape with a reduced diameter, and the rear part of the cylindrical part has a funnel shape. A curved portion 11m is provided from the middle of the funnel-shaped portion so as to be curved and connected to the rear nozzle portion 11g. From the front of the inner surface of the nozzle portion 11g to the curved portion 11m, the funnel-shaped portion, the cylindrical portion, and the trunk portion 11e, three straight vertical ribs that protrude toward the axis in parallel with the shaft are provided, Between the three vertical ribs, two capillary ribs 11n are provided at two places on the left and right when the stationary portion 11f is viewed from the front. A hemispherical tip convex portion 11o is provided at the rear end of the nozzle portion 11g.
The operation will be described. When the stopper 2 is ultrasonically welded to the end surface 11b of the bottle 11, the stress concentration at a specific position on the circumference of the step portion 11c during ultrasonic welding is caused by the reinforcing portions 11d that are radially uneven in the shape of uneven ribs in the front and rear. Can be avoided. This prevents the stopper 2 from being inclined and welded. Note that the large number of the reinforcing portions 11d may not be of an equal shape but may be alternately arranged with deep portions and shallow portions, or may be arranged more on the stationary portion 11f side.
The curved portion 11m and the capillary rib 11n of the bottle 11 move the bottle 11 containing the liquid upside down and move the liquid that has entered the nozzle portion 11g to the barrel portion 11e side when the screw cut portion 11h is separated. It makes things easier. That is, the curved portion 11m has a curved shape that spreads toward the body portion 11e, so that the residual force of the liquid nozzle portion 11g is weakened, and as a result, the liquid in the nozzle portion 11g easily moves in the direction of gravity. Become. Moreover, since the capillary rib 11n connects the liquid in the nozzle part 11g and the liquid on the body part 11 side through the liquid on the capillary rib 11n, the liquid in the nozzle part 11g is connected to the body part 11 side in the gravity direction. Make it easy to move to liquid.
Here, when replenishing the liquid in the bottle 11 to another container or the like, since the tip convex part 11o at the tip of the nozzle part 11g protrudes, it becomes easy to insert the nozzle part 11g into the replenishing port of the other container. ing.

FIG. 12 shows an enlarged cross-sectional view of the main part of the fourth embodiment. The bottle 21 and the stopper 22 are substantially the same as in the first embodiment. The step portion 21c of the bottle 21 is provided with a funnel-shaped reinforcing portion 21d that expands from the opening portion toward the body portion. The stopper 22 has a disk shape and is provided with a cylindrical portion 22b to be inserted into the opening 21a of the bottle 21.
The operation will be described. When the stopper 22 is ultrasonically welded to the end surface 21b of the bottle 21, a stepped portion 21c is reinforced by a reinforcing portion 21d that spreads in a funnel shape so as to expand from the opening toward the body portion. The stress deformation of the stepped portion 21c can be prevented. This prevents the stopper 2 from being inclined and welded. The step portion 21c may have a substantially funnel shape as a whole, and may be a concave curved surface, a convex curved surface, or a multi-step shape. Moreover, you may provide so that it may spread in the funnel shape from the middle of the outer periphery of the end surface 21b to the step part 21c. Further, the reinforcing portion may be combined with the first embodiment to the fourth embodiment.

The front sectional view of a 1st example. The left view of FIG. The top view of FIG. The bottom view of FIG. FIG. 1 is a partially enlarged view of the front of FIG. The left side enlarged view of the nozzle part 1f after carrying out the screw cutting separation of the screw cutting part 1g of FIG. The right side enlarged view of the screw cut part 1g after the screw cut part 1g of FIG. The comparison figure of FIG. The principal part longitudinal cross-sectional view of the bottle 1 'before the ultrasonic welding of FIG. Front sectional view of the third embodiment. FIG. 11 is a top view of FIG. 10. The principal part expanded sectional view of 4th Example.

1, 1 ′, 11, 21 Bottles 1a, 1a ′, 11a, 21a Openings 1b, 1b ′, 11b, 21b End surfaces 1c, 1c ′, 11c, 21c Stepped portions 1d, 11d, 21d Reinforcing portions 1e, 11e, 21e Body (body part)
1f, 1f ′, 11f Standing part 1g, 11g Nozzle part 1h, 11h Screw cutting part ii, 11i Opening part 1j, 11j Cutting part 1k Burst surface 1l Burr 11m Curved part 11n Capillary rib 11o Tip convex part 22b Cylindrical part P , Q Screw cutting direction M Step thickness value N Radius value

Claims (3)

It is a structure in which a stopper is welded to the opening of a bottle by ultrasonic welding, and the front end of the opening of this bottle is an ultrasonic welding surface, and a welding structure in which a step is arranged around the opening. there, only setting the reinforcing portion toward the axis of the stepped portion of the opening, also with forming the said reinforcing portion from the opening on the concave curved surface, such as to be widened toward the body portion, the concave The radius value of the curved surface is set to be equal to or greater than the thickness value of the step portion, and further, a flat stationary part is formed on the side surface of the main body part, and an arcuate arc part from the end of the planar stationary part In addition, the planar stationary part is formed in an inclined state with respect to the axis of the main body part, and at least the main body part is formed by the inclined stationary part and the arc part . A welded structure characterized by that. The welding structure according to claim 1, wherein a plurality of the reinforcing portions are provided in a rib shape . The welding structure according to claim 1, wherein the reinforcing portion is provided in a funnel shape so as to expand from the opening toward the main body .

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