JP2018030341A - Composite preform - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite preform capable of improving workability when attaching a preform cover to a preform. According to the present invention, a tubular preform and a tubular preform cover are provided, and the preform cover is an end portion on a side into which an insertion end of the preform is inserted. The preform cover is attached to the preform by having an end, the insertion end being inserted into the preform cover from the inserted end, and the inserted end being relatively moved to a predetermined position of the preform. The sliding resistance between the preform and the preform cover in the first state until the inserted end reaches the immediately preceding position, which is the position immediately preceding the predetermined position, is configured to be mounted. Provided is a composite preform configured such that the insertion end is configured to be less than the sliding resistance between the preform and the preform cover in the second state after the insertion end exceeds the immediately preceding position. [Selection diagram] Fig. 1

Description

  The present invention relates to a composite preform.

  As a method for molding a plastic container (bottle), a blow molding method is widely used. An injection molded preform is set in a mold, and air is blown to form a mold cavity 2 An axial stretch blow molding method or the like is known.

  In recent years, in the field of plastic containers, various functions and performances are often required, and ingenuity is required for the materials and molding methods used. For example, when a gas barrier property, a light shielding property, a heat retaining property, etc. are required, a material to be used has a gas barrier property, or a colorant or an ultraviolet absorber is added to a plastic material.

  However, there is a limit to the contrivance of materials, and various functions are imparted by multilayering plastic containers. By optimizing the constituent materials of each layer, it is expected that a plastic container having a composite function such as a light shielding container excellent in gas barrier properties can be realized.

  In order to mold a multilayer plastic container, it is considered that a multilayer preform may be injection-molded and blow-molded, and various methods for molding a multilayer preform have been proposed. However, there is a problem in terms of cost, for example, because advanced technology is required for molding a multilayer preform, and a large amount of equipment investment is required for the molding apparatus.

  Under such circumstances, it has been proposed to form a composite container by mounting a preform cover separately molded on the outside of the preform and blow-molding it (see Patent Document 1 and the like). By using the preform cover, it is considered unnecessary to form a multilayer preform, leading to cost reduction and the like.

JP 2006-097669 A

  By the way, the preform cover may be formed by direct blow molding, and it is difficult to control the wall thickness with high precision by direct blow molding, so the inner surface shape of the preform cover may vary. For this reason, it is difficult to attach the preform cover to the outside of the preform because the inner diameter of the preform cover is too small, or the preform cover is easily detached from the preform because the inner diameter of the preform cover is too large. There is a problem that it may be trapped.

  The present invention has been made in view of such circumstances, and provides a composite preform capable of improving workability when a preform cover is attached to the preform.

  According to the present invention, a cylindrical preform and a cylindrical preform cover are provided, and the preform cover includes an insertion end that is an end portion on the side where the insertion end of the preform is inserted, The insert end is inserted into the preform cover from the inserted end, and the inserted end moves relative to a predetermined position of the preform so that the preform cover is attached to the preform. The sliding resistance between the preform and the preform cover in the first state until the inserted end reaches a position immediately before the predetermined position is the inserted end. A composite preform is provided that is configured to be less than a sliding resistance between the preform and the preform cover in a second state after the previous position is exceeded It is.

  In the composite preform of the present invention, the sliding resistance in the first state is smaller than the sliding resistance in the second state. Therefore, until the inserted end of the preform cover reaches the predetermined position of the preform, the preform cover smoothly moves relative to the preform, and the inserted end of the preform cover is moved to the predetermined position of the preform. Since the preform cover can be surely attached to the preform at the stage of reaching, workability when attaching the preform cover to the preform can be improved.

Hereinafter, various embodiments of the present invention will be exemplified. The following embodiments can be combined with each other.
Preferably, the sliding resistance between the insertion end vicinity part and the preform cover which is a part near the insertion end in the first state is such that the insertion end vicinity part and the preform cover in the second state are Less than the sliding resistance between.
Preferably, the similarity ratio of the inner surface shape of the preform cover with respect to the outer surface shape of the preform is defined as an inner surface similarity ratio, and a region in the vicinity of the opposite end that is the end opposite to the inserted end is defined as a region near the opposite end. When the portion closer to the insertion end than the portion near the opposite end is the insertion end side portion, the inner surface similarity ratio at the portion near the opposite end is smaller than the inner surface similarity ratio at the insertion end side portion. .
Preferably, the thickness of the preform cover in the vicinity of the opposite end is larger than the thickness of the inserted end side portion.
Preferably, when the similarity ratio of the outer surface shape of the preform cover to the outer surface shape of the preform is an outer surface similarity ratio, the outer surface similarity ratio in the vicinity of the opposite end is the outer surface similarity ratio in the insertion end side portion. Smaller than.
Preferably, assuming that the portion of the preform cover near the inserted end is a portion near the inserted end, the sliding resistance between the preform and the portion near the inserted end in the first state is second. This is smaller than the sliding resistance between the preform and the vicinity of the inserted end in the state.
Preferably, the preform includes a preform small-diameter portion and a preform large-diameter portion, and the preform large-diameter portion has a larger outer shape than the preform small-diameter portion, and the preform small-diameter portion. Rather than the insertion end.
Preferably, the preform cover includes a preform cover small diameter portion and a preform cover large diameter portion, and the preform cover small diameter portion and the preform cover large diameter portion respectively include the preform small diameter portion and the preform cover small diameter portion and the preform cover large diameter portion. It arrange | positions in the position facing a preform large diameter part.
Preferably, the thickness at the large diameter portion of the preform cover is larger than the thickness at the small diameter portion of the preform cover.
Preferably, when the similarity ratio of the outer surface shape of the preform cover to the outer surface shape of the preform is an outer surface similarity ratio, the outer surface similarity ratio of the preform cover large-diameter portion is the outer surface of the preform cover small-diameter portion. It is smaller than the similarity ratio.

(A)-(e) is sectional drawing which shows the composite preform 10 of 1st Embodiment of this invention, (a) is the state from which the preform 1 and the preform cover 11 were isolate | separated, (b) is The state before the inserted end 13 reaches the immediately preceding position B, (c) the state where the inserted end 13 has reached the immediately preceding position B, (d) the state where the inserted end 13 has reached the predetermined position A, ( e) shows an enlarged view of region X in (b). It is sectional drawing corresponding to Fig.1 (a) which shows the molded object 21 formed in the middle of manufacture of the preform cover 11 of 1st Embodiment of this invention. It is an enlarged view corresponding to FIG.1 (e) which shows the composite preform 10 of 2nd Embodiment of this invention. It is an enlarged view corresponding to FIG.1 (e) which shows the composite preform 10 of 3rd Embodiment of this invention. (A)-(e) is sectional drawing which shows the composite preform 10 of 4th Embodiment of this invention, (a) is the state from which the preform 1 and the preform cover 11 were isolate | separated, (b) is The state before the inserted end 13 reaches the immediately preceding position B, (c) the state where the inserted end 13 has reached the immediately preceding position B, (d) the state where the inserted end 13 has reached the predetermined position A, ( e) shows an enlarged view of region Y in (c). It is an enlarged view corresponding to Drawing 5 (e) showing compound preform 10 of a 5th embodiment of the present invention. (A)-(d) is sectional drawing which shows the composite preform 10 of 6th Embodiment of this invention, (a) is the state from which the preform 1 and the preform cover 11 were isolate | separated, (b) is The state before the inserted end 13 reaches the immediately preceding position B, (c) shows the state where the inserted end 13 has reached the immediately preceding position B, and (d) shows the state where the inserted end 13 has reached the predetermined position A. . (A)-(c) is sectional drawing which shows the composite preform 10 of 7th Embodiment of this invention, (a) is the state which the to-be-inserted end 13 arrived at the front position B, (b) is covered A state in which the insertion end 13 has reached the position C, (c) shows a state in which the insertion end 13 has reached the predetermined position A. (A)-(d) is sectional drawing which shows the composite preform 10 of 8th Embodiment of this invention, (a) is the state from which the preform 1 and the preform cover 11 were isolate | separated, (b) is The state before the inserted end 13 reaches the immediately preceding position B, (c) shows the state where the inserted end 13 has reached the immediately preceding position B, and (d) shows the state where the inserted end 13 has reached the predetermined position A. . (A)-(d) is sectional drawing which shows the composite preform 10 of 9th Embodiment of this invention, (a) is the state from which the preform 1 and the preform cover 11 were isolate | separated, (b) The state before the inserted end 13 reaches the immediately preceding position B, (c) shows the state where the inserted end 13 has reached the immediately preceding position B, and (d) shows the state where the inserted end 13 has reached the predetermined position A. .

  Hereinafter, embodiments of the present invention will be described. Various characteristic items shown in the following embodiments can be combined with each other. In addition, the invention is independently established for each feature.

1. First Embodiment As shown in FIG. 1, a composite preform 10 according to a first embodiment of the present invention includes a cylindrical preform 1 and a cylindrical preform cover 11.

  The preform 1 includes a cylindrical (preferably cylindrical) body 2. A mouth 3 is provided at one end of the body 2, and the mouth 3 is provided with an engaging part 3 a for attaching a cap (not shown). The cap may be attached by a stopper type or may be attached by a screw type. The other end of the body portion 2 is an insertion end 4 to be inserted into the preform cover 11, and the insertion end 4 is a bottom portion 5 of the preform 1. The bottom 5 is hemispherical in one example, but the shape is not particularly limited. The preform 1 can be formed by injection molding a resin material. As the resin material, it is preferable to use a thermoplastic resin, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or PC (polycarbonate).

  The preform cover 11 includes a cylindrical (preferably cylindrical) trunk portion 12. An insertion end 13 is provided at one end of the body portion 12, and the preform 1 is inserted into the preform cover 11 through the insertion end 13. The other end of the body 12 is an opposite end 14 which is an end opposite to the insertion end 13, and the opposite end 14 is a bottom 15 of the preform cover 11. The bottom portion 15 is hemispherical in one example, but the shape is not particularly limited. Although the formation method of the preform cover 11 is not particularly limited, in an example, the preform cover 11 is formed by direct blow molding in which a molten cylindrical parison is blow-molded as it is. The resin material for forming the preform cover 11 may be the same as or different from the preform 1. The preform cover 11 may have a single layer structure or a multilayer structure.

  In addition, as shown in FIG. 2, the preform cover 11, for example, forms a molded body 21 having a shape in which two preform covers 11 are connected by a connecting portion 22, and the molded body 21 is cut at a cutting position S. Can be formed. An end formed by cutting at the cutting position S is the insertion end 13. The thickness of the molded body 21 in the vicinity of the cutting position S is preferably 0.35 mm or more. This is because if the thickness is too small, when the molded body 21 is cut, the molded body 21 may be deformed by pressing with the blade and the cutting position may be shifted. Although the upper limit of this thickness is not specifically limited, For example, it is 1 mm. Specifically, this thickness is, for example, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8 0.85, 0.9, 0.95, and 1 mm, and may be within a range between any two of the numerical values exemplified here.

  In the preform 1 and the preform cover 11, as shown in FIGS. 1A to 1B, the insertion end 4 of the preform 1 is inserted into the preform cover 11 from the insertion end 13 of the preform cover 11. Then, after the state shown in FIG. 1 (c), as shown in FIG. 1 (d), the inserted end 13 moves relative to the predetermined position A of the preform 1, whereby the preform cover 11 is moved to the preform 1. It is comprised so that it may be mounted | worn with respect to. The preform cover 11 may be formed so as to cover the entire preform 1. However, in the present embodiment, the preform cover 11 partially covers the preform 1 (specifically, a large portion of the body portion 2). It is configured to cover the part and the bottom 5).

  In general, the inner surface shape of the preform cover 11 substantially matches the outer surface shape of the preform 1, and when the preform 1 is inserted into the preform cover 11, substantially the entire inner surface of the preform cover 11 is the preform 1. In this state, the preform 1 and the preform cover 11 are integrated. On the other hand, in the present embodiment, as will be described later, the preform 1 is not matched with the outer shape of the preform 1 according to the position of the inserted end 13 of the preform 1 without matching the outer shape of the preform 1. The preform 1 can be easily inserted into the preform cover 11 by changing the magnitude of the sliding resistance between the preform cover 11 and the preform cover 11. 11 is made difficult to come off from the preform 1.

  Specifically, in the present embodiment, when the part near the opposite end 14 of the preform cover 11 is the opposite end vicinity part 16 and the part closer to the insertion end 13 than the part 16 is the insertion end side part 17. The similarity ratio of the inner surface shape of the preform cover 11 to the outer surface shape of the preform 1 (hereinafter referred to as “inner surface similarity ratio”) is smaller at the part 16 than at the part 17. For this reason, as shown in FIG. 1 (b), the preform cover 11 is inserted into a portion 6 near the insertion end, which is a portion near the insertion end 4 of the preform 1 (as shown in FIG. 1 (d)). Since the sliding resistance between the preform 1 and the preform cover 11 is low while the portion facing the portion 16 near the opposite end in the state mounted on the reform 1 is facing the portion 17, the preform 1 is It can be smoothly inserted into the preform cover 11. On the other hand, as shown in FIG. 1C, when the insertion end vicinity portion 6 starts to face the portion 16, the sliding resistance between the preform 1 and the preform cover 11 increases. For this reason, as shown in FIG. 1D, the preform cover 11 does not easily fall off from the preform 1 when the preform cover 11 is attached to the preform 1. In the present specification, the two shapes for which the similarity ratio is to be calculated do not have to be strictly similar, and may be shapes that are similar to the extent that the similarity ratio can be calculated.

  The internal surface similarity ratio at the portion 16 is preferably smaller than 1, and more preferably 0.8 to 0.99. Specifically, the internal surface similarity ratio in the region 16 is, for example, 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88. , 0.89, 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99. It may be within a range between any two of the numerical values. The internal surface similarity ratio at the portion 17 is preferably larger than 0.9, more preferably larger than 1, and further preferably 1.01 to 1.2. Specifically, the internal surface similarity ratio at the portion 17 is, for example, 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98. , 0.99, 1, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.1, 1.11 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, 1.2, between any two of the numerical values illustrated here It may be within the range.

  The value of {(inner surface similarity ratio in region 17) − (inner surface similarity ratio in region 16)} is preferably 0.01 to 0.4, and more preferably 0.05 to 0.2. Specifically, this value is, for example, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0. 23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, and may be within a range between any two of the numerical values exemplified here.

  Although the outer surface shape of the preform cover 11 is not particularly limited, in this embodiment, the outer surface shape of the preform cover 11 is similar to the outer surface shape of the preform 1. Therefore, the thickness at the portion 16 is larger than the thickness at the portion 17. Is also getting bigger.

  Further, if attention is given to the inserted end 13 of the preform cover 11, the composite preform 10 according to the present embodiment has a state in which the inserted end 13 reaches a position B immediately before the predetermined position A. The sliding resistance between the preform 1 and the preform cover 11 in the first state is that between the preform 1 and the preform cover 11 in the second state after the inserted end 13 exceeds the immediately preceding position B. It is comprised so that it may become smaller than sliding resistance. The state until the inserted end 13 reaches the immediately preceding position B shown in FIG. 1C through the states of FIGS. 1A and 1B is the first state. In this state, the preform 1 and the preform 1 The sliding resistance between the covers 11 is small, and it is easy to move the preform cover 11 relative to the preform 1. On the other hand, the state until the inserted end 13 exceeds the immediately preceding position B and reaches the predetermined position A is the second state. In this state, the sliding resistance between the preform 1 and the preform cover 11 is large. .

  The ratio of the distance LB from the insertion end 4 of the preform 1 to the immediately preceding position B with respect to the distance LA from the insertion end 4 of the preform 1 to the predetermined position A is not particularly limited, but is preferably 0.5 or more, 0.8 The above is more preferable. Although the upper limit of this ratio is not specifically limited, For example, 0.99 is preferable. The larger this ratio, the easier it is to insert the preform 1 into the preform cover 11. However, if this ratio is too large, the preform cover 11 may be easily removed after being attached. Specifically, this ratio is, for example, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 0.99, and may be within a range between any two of the numerical values exemplified here.

  By the way, when the preform cover 11 is formed by direct blow molding, the inner surface shape of the preform cover 11 tends to vary. For this reason, when the inner surface shape of the preform cover 11 is designed to match the outer surface shape of the preform 1, the preform 1 is inserted into the preform cover 11 when the inner diameter of the preform cover 11 varies so as to become smaller. When the preform cover 11 is dispersed so that the inner diameter of the preform cover 11 is increased, the preform cover 11 can be easily detached from the preform 1 even if the preform 1 is pushed into the bottom of the preform cover 11. . On the other hand, in the present embodiment, the inner surface similarity ratio at the portion 16 is designed so that the inner surface similarity ratio at the portion 17 is smaller than 1. For this reason, it is suppressed that it becomes difficult to insert the preform 1 into the preform cover 11 even if the inner diameter of the preform cover 11 varies at the portion 17, and the inner diameter of the preform cover 11 at the portion 16. The preform cover 11 is prevented from easily falling off from the preform 1 even if the dispersion is large. Therefore, according to the present embodiment, even when the inner shape of the preform cover 11 varies, the problem that the preform 1 becomes difficult to insert or the preform cover 11 falls off is less likely to occur. The workability at the time of attaching the preform cover 11 to the reform 1 can be improved.

  As shown in FIG. 1 (d), the composite preform 10 of the present embodiment is set in a blow molding die after the preform cover 11 is mounted on the preform 1, and blow molded to form a cavity inside the die. A container corresponding to the shape is formed. The composite preform 10 is blow-molded in a state of being heated and softened before or after being set in the mold.

2. Second Embodiment A second embodiment of the present invention will be described with reference to FIG. The present embodiment is similar to the first embodiment, and the main difference is the difference in the shape of the portion 16 near the opposite end of the preform cover 11. Hereinafter, the difference will be mainly described.

  In the present embodiment, the shape of the preform 1 and the inner shape of the preform cover 11 are the same as those in the first embodiment, and the preform cover 11 is attached to the preform 1 by the same action as in the first embodiment. The effect that the workability | operativity at the time can be improved is show | played. In the present embodiment, the outer shape of the portion 16 of the preform cover 11 is different from that of the first embodiment. In the first embodiment, by making the outer surface shape of the preform cover 11 similar to the outer surface shape of the preform 1 and making the thickness of the region 16 larger than that of the region 17, the inner surface similarity ratio at the region 16 is increased. A configuration in which the inner surface similarity ratio at 17 is smaller is realized. On the other hand, in this embodiment, when the similarity ratio of the outer surface shape of the preform cover 11 to the outer surface shape of the preform 1 is “outer surface similarity ratio”, the thickness at the portion 16 and the thickness at the portion 17 are substantially equal. Equally, the outer surface similarity ratio at the part 16 is smaller than the outer surface similarity ratio at the part 17. According to such a configuration, the preform cover 11 having a uniform thickness can be obtained. Preferred values for the outer surface similarity ratio are similar to those described for the inner surface similarity ratio.

3. Third Embodiment A third embodiment of the present invention will be described with reference to FIG. The present embodiment is similar to the first embodiment, and the main difference is the difference in the shape of the portion 16 near the opposite end of the preform cover 11. Hereinafter, the difference will be mainly described.

  In the present embodiment, the shape of the preform 1 is the same as that of the first embodiment. On the other hand, in the first embodiment, the preform cover 11 has the bottom 15, but in this embodiment, an opening 18 is provided at the opposite end 14 of the preform cover 11. Further, in the first embodiment, the outer surface shape of the preform cover 11 is similar to the outer surface shape of the preform 1, but in the present embodiment, it is not similar.

  The inner surface shape of the preform cover 11 is the same as that of the first embodiment except that the opening 18 is provided, and when the preform cover 11 is attached to the preform 1 by the same operation as that of the first embodiment. The workability can be improved.

4). Fourth Embodiment A fourth embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the first embodiment, and is mainly different in that a small diameter portion and a large diameter portion are provided in the body portions of the preform 1 and the preform cover 11. Hereinafter, the difference will be mainly described.

  In this embodiment, the trunk | drum 2 of the preform 1 is provided with the preform small diameter part 2a and the preform large diameter part 2b. The large-diameter portion 2b has a larger outer surface shape than the small-diameter portion 2a (outer diameter in the case of a cylinder) and is disposed at a position farther from the insertion end 4 than the small-diameter portion 2a. The large diameter portion 2b includes a large diameter body portion 2c and an inclined portion 2d. The inclined part 2d is disposed between the large diameter body part 2c and the small diameter part 2a. Although the value of the ratio of the outer diameter of the large-diameter trunk | drum 2c with respect to the outer diameter of the small diameter part 2a is not specifically limited, For example, it is 1.1-2, and 1.2-1.5 are preferable. Specifically, this value is, for example, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, It may be within a range between any two of the numerical values exemplified here. The inclined portion 2d may be planar in the cross section shown in FIG. 5A, or may be curved. The angle of the inclined portion 2d with respect to the central axis CA of the mouth 3 is not particularly limited, but is, for example, 10 to 60 degrees, and preferably 20 to 50 degrees. Specifically, this angle is, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60 degrees, and within a range between any two of the numerical values exemplified here. There may be. Either one of the large-diameter trunk portion 2c and the inclined portion 2d can be omitted.

  The body portion 12 of the preform cover 11 includes a preform cover small diameter portion 12a and a preform cover large diameter portion 12b. The large-diameter portion 12b has a larger outer surface size (outer diameter in the case of a cylinder) than the small-diameter portion 12a. The small diameter portion 12a and the large diameter portion 12b are disposed at positions facing the small diameter portion 2a and the large diameter portion 2b, respectively. The large diameter portion 12b includes a large diameter body portion 12c and an inclined portion 12d. The inclined portion 12d is disposed between the large diameter trunk portion 12c and the small diameter portion 12a.

  In the present embodiment, the portion near the inserted end 13 of the preform cover 11 is replaced with a portion 19 near the inserted end (in the present embodiment, the portion 19 near the inserted end coincides with the large diameter portion 12b). Assuming that the portion on the opposite end 14 side from the inserted end vicinity portion 19 is the opposite end portion 20, the inner surface similarity ratio in the portion 19 is smaller than the inner surface similarity ratio in the portion 20. The inner surface similarity ratio at the portion 19 is preferably smaller than 1, and more preferably 0.8 to 0.99. Specifically, the inner surface similarity ratio in the region 19 is, for example, 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88. , 0.89, 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99. It may be within a range between any two of the numerical values. The inner surface similarity ratio at the site 20 is preferably larger than 0.9, more preferably larger than 1, and further preferably 1.01 to 1.2. Specifically, the inner surface similarity ratio at the portion 20 is, for example, 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98. , 0.99, 1, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.1, 1.11 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, 1.2, between any two of the numerical values illustrated here It may be within the range.

  The value of {(the inner surface similarity ratio at the portion 20) − (the inner surface similarity ratio at the portion 19)} is preferably 0.01 to 0.4, and more preferably 0.05 to 0.2. Specifically, this value is, for example, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0. 23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, and may be within a range between any two of the numerical values exemplified here.

  As shown in FIG. 5B, the preform 1 and the preform cover 4 are inserted while the insertion end 4 of the preform 1 is inserted into the preform cover 11 and the portion 19 near the insertion end faces the small diameter portion 2a. Since the sliding resistance between 11 is small, the preform 1 can be smoothly inserted into the preform cover 11. On the other hand, as shown in FIG. 5C, when the inserted end vicinity portion 19 starts to face the large diameter portion 2b, the sliding resistance between the preform 1 and the preform cover 11 increases. For this reason, as shown in FIG. 5D, the preform cover 11 is not easily detached from the preform 1 when the preform cover 11 is attached to the preform 1.

  Although the outer surface shape of the preform cover 11 is not particularly limited, in this embodiment, the outer surface shape of the preform cover 11 is similar to the outer surface shape of the preform 1, so that the thickness at the portion 19 is greater than the thickness at the portion 20. Is also getting bigger.

  Further, if attention is given to the inserted end 13 of the preform cover 11, the composite preform 10 according to the present embodiment has a state in which the inserted end 13 reaches a position B immediately before the predetermined position A. The sliding resistance between the preform 1 and the preform cover 11 in the first state is that between the preform 1 and the preform cover 11 in the second state after the inserted end 13 exceeds the immediately preceding position B. It is comprised so that it may become smaller than sliding resistance. The state until the inserted end 13 reaches the immediately preceding position B shown in FIG. 5C through the states shown in FIGS. 5A and 5B is the first state. In this state, the preform 1 and the preform 1 are formed. The sliding resistance between the covers 11 is small, and it is easy to move the preform cover 11 relative to the preform 1. On the other hand, the state until the inserted end 13 exceeds the immediately preceding position B and reaches the predetermined position A is the second state. In this state, the sliding resistance between the preform 1 and the preform cover 11 is large. . Thus, in this embodiment as well, as in the first embodiment, the sliding resistance in the second state is larger than the sliding resistance in the first state. The same effect as the embodiment is achieved.

5). Fifth Embodiment A fifth embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the fourth embodiment, and the main difference is the difference in the shape of the inserted end vicinity portion 19. Hereinafter, the difference will be mainly described.

  In the present embodiment, the shape of the preform 1 and the inner shape of the preform cover 11 are the same as those in the fourth embodiment, and the preform cover 11 is attached to the preform 1 by the same action as in the fourth embodiment. The effect that the workability | operativity at the time can be improved is show | played. In the present embodiment, the shape of the portion 19 of the preform cover 11 is different from that of the first embodiment. In the first embodiment, by making the outer surface shape of the preform cover 11 similar to the outer surface shape of the preform 1 and making the thickness of the portion 19 larger than the portion 20, the inner surface similarity ratio at the portion 19 is increased. A configuration in which the inner surface similarity ratio at 20 is smaller is realized. For this reason, in the first embodiment, the angle of the inclined portion 2d with respect to the central axis CA and the angle of the inclined portion 12d with respect to the central axis CA are substantially the same. On the other hand, in the present embodiment, the thickness at the part 19 is substantially equal to the thickness at the part 20, and the angle of the inclined part 12d with respect to the central axis CA is smaller than the angle of the inclined part 2d with respect to the central axis CA. By configuring as described above, a configuration is realized in which the inner surface similarity ratio at the portion 19 is smaller than the inner surface similarity ratio at the portion 20. According to such a configuration, the preform cover 11 having a uniform thickness can be obtained. Preferred values for the outer surface similarity ratio are similar to those described for the inner surface similarity ratio.

6). Sixth Embodiment A sixth embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the fourth embodiment, and the difference in the shape of the preform cover 11 is the main difference. Hereinafter, the difference will be mainly described.

  In the fourth embodiment, the inner surface similarity ratio at the insertion end vicinity portion 19 (large diameter portion 12b) is smaller than 1, and the sliding resistance at the large diameter portion 12b is increased. In this embodiment, the internal diameter similarity ratio at the large diameter portion 12b is greater than 1, and the sliding resistance at the large diameter portion 12b is reduced. On the other hand, in this embodiment, the inner surface similarity ratio at the opposite end vicinity portion 16 is smaller than 1 and the inner surface similarity ratio at the inserted end side portion 17 is larger than 1, as in the first embodiment. For this reason, the effect similar to 1st Embodiment is show | played.

  In the present embodiment, the shape of the outer surface of the preform cover 11 is similar to the shape of the outer surface of the preform 1, and the thickness at the portion 16 is larger than the thickness at the portion 17. 16, the inner surface similarity ratio at the portion 17 is smaller than that at the portion 17, but the thickness at the portion 16 and the thickness at the portion 17 are substantially the same as in the second embodiment. And by making the outer surface similarity ratio at the portion 16 smaller than the outer surface similarity ratio at the portion 17, the inner surface similarity ratio at the portion 16 becomes smaller than the inner surface similarity ratio at the portion 17. It may be realized.

7). Seventh Embodiment A seventh embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the sixth embodiment, and the difference in the shape of the preform cover 11 is the main difference. Hereinafter, the difference will be mainly described.

  In the present embodiment, the inserted end vicinity portion 19 of the preform cover 11 has the same shape as that of the fourth embodiment, and the opposite end vicinity portion 16 has the same shape as that of the sixth embodiment. Yes.

  In the present embodiment, the state until the inserted end 13 reaches the immediately preceding position B shown in FIG. 8A is the first state, and after the inserted end 13 exceeds the immediately preceding position B, FIG. The state until reaching the position C shown in FIG. 9 is the second state in the first half, and the state from the insertion end 13 exceeding the position C to the predetermined position A shown in FIG. It is. The “second state” in the claims is constituted by the second state in the first half and the second state in the second half.

  In the first state, the sliding resistance between the preform 1 and the preform cover 11 is small, and it is easy to move the preform cover 11 relative to the preform 1. In the second state of the previous period, the sliding resistance between the preform 1 and the preform cover 11 at the portion 16 near the opposite end increases. In the latter second state, the sliding resistance between the preform 1 and the preform cover 11 also increases in the portion 19 near the insertion end, so that the sliding resistance between the preform 1 and the preform cover 11 is further increased. Become. As described above, in this embodiment, the sliding resistance changes in three stages, so that the problem that it becomes difficult to insert the preform 1 or the preform cover 11 falls off is further less likely to occur.

8). Eighth Embodiment An eighth embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the fourth embodiment, and the difference in the shape of the preform cover 11 is the main difference. Hereinafter, the difference will be mainly described.

  In the present embodiment, the preform 1 is provided with a small-diameter portion 2a and a large-diameter portion 2b, but the preform cover 11 is not provided with the small-diameter portion 2a and the large-diameter portion 2b. , Has a certain shape over its longitudinal direction.

  In the present embodiment, as shown in FIG. 9C, when the preform cover 11 is strongly pressed against the preform 1 from a state where the inserted end 13 is in contact with the inclined portion 2d, a portion 19 near the inserted end. As shown in FIG. 9 (d), the preform 19 is attached to the preform 1 with the portion 19 surrounding the large-diameter trunk 2 c.

9. Ninth Embodiment A ninth embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the eighth embodiment, and the difference in the shape of the preform cover 11 is the main difference. Hereinafter, the difference will be mainly described.

  In the present embodiment, the preform cover 11 has a pipe shape having only the body portion 12. The preform 1 is provided with a locking portion 2e at a position farther from the insertion end 4 than the large-diameter barrel portion 2c. When the preform 1 is inserted into the preform cover 11, the portion 19 is enlarged by the same action as in the eighth embodiment to surround the large-diameter body portion 2 c, and the preform cover 11 is further pushed into the preform 1. Then, the preform cover 11 is brought into contact with the locking portion 2e, and the preform cover 11 is mounted in a state of being positioned with respect to the preform 1. In the present embodiment, since the preform cover 11 is pipe-shaped, it can be manufactured at low cost by extrusion molding or the like.

1: Preform 2: Body part 2a: Preform small diameter part 2b: Preform large diameter part 2c: Large diameter body part 2d: Inclined part 2e: Locking part 3: Mouth part 3a: Engaging part 4: Insertion end 5 : Bottom 6: Insertion end vicinity part 10: Composite preform 11: Preform cover 12: Body 12a: Preform cover small diameter part 12b: Preform cover large diameter part 12c: Large diameter trunk 12d: Inclined part 13: Covered Insertion end 14: Opposite end 15: Bottom portion 16: Opposite end vicinity portion 17: Insertion end side portion 18: Opening portion 19: Insertion end vicinity portion 20: Opposite end side portion A: Predetermined position B: Immediate position C: Position S: Cutting position CA: Center axis LA: Distance LB: Distance

Claims (10)

It has a cylindrical preform and a cylindrical preform cover,
The preform cover includes an insertion end that is an end portion on a side where the insertion end of the preform is inserted;
The insert end is inserted into the preform cover from the inserted end, and the inserted end moves relative to a predetermined position of the preform so that the preform cover is attached to the preform. Composed of
The sliding resistance between the preform and the preform cover in the first state until the inserted end reaches a position immediately before the predetermined position, and the inserted end is at the immediately preceding position. A composite preform configured to be smaller than a sliding resistance between the preform and the preform cover in the second state after exceeding.   The sliding resistance between the insertion end vicinity part and the preform cover in the first state is a part between the insertion end vicinity part and the preform cover in the second state. The composite preform according to claim 1, wherein the composite preform is smaller than dynamic resistance. The similarity ratio of the inner surface shape of the preform cover to the outer surface shape of the preform is an inner surface similarity ratio,
The site near the opposite end that is the end opposite to the inserted end is the site near the opposite end,
When the insertion end side portion is a portion closer to the insertion end than the portion near the opposite end,
3. The composite preform according to claim 1, wherein an inner surface similarity ratio in the vicinity of the opposite end is smaller than an inner surface similarity ratio in the inserted end side portion.   The composite preform according to claim 3, wherein the preform cover has a wall thickness in the vicinity of the opposite end larger than a wall thickness in the inserted end side portion. When the similarity ratio of the outer surface shape of the preform cover to the outer surface shape of the preform is the outer surface similarity ratio,
The composite preform according to claim 3 or 4, wherein an outer surface similarity ratio in the vicinity of the opposite end is smaller than an outer surface similarity ratio in the inserted end side portion. When a portion near the inserted end of the preform cover is a portion near the inserted end,
The sliding resistance between the preform in the first state and the portion near the insertion end is smaller than the sliding resistance between the preform in the second state and the portion near the insertion end. The composite preform according to any one of claims 1 to 5. The preform includes a preform small diameter part and a preform large diameter part,
The preform large diameter portion has a larger outer shape than the preform small diameter portion, and is disposed at a position farther from the insertion end than the preform small diameter portion. A composite preform according to any one of the above. The preform cover includes a preform cover small diameter portion and a preform cover large diameter portion,
The composite preform according to claim 7, wherein the preform cover small-diameter portion and the preform cover large-diameter portion are disposed at positions facing the preform small-diameter portion and the preform large-diameter portion, respectively.   The composite preform according to claim 8, wherein a thickness at the large diameter portion of the preform cover is larger than a thickness at the small diameter portion of the preform cover. When the similarity ratio of the outer surface shape of the preform cover to the outer surface shape of the preform is the outer surface similarity ratio,
The composite preform according to claim 8 or 9, wherein an outer surface similarity ratio at the preform cover large diameter portion is smaller than an outer surface similarity ratio at the preform cover small diameter portion.