JP2005112444A - Wide-mouthed container body having undercut, and forced extraction die structure for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wide-mouthed container body, which has two undercuts, which are formed on a male screw on the outer peripheral surface of a mouth-to-neck part and on the inner peripheral surface of a shoulder, respectively, and the undercuts are extracted forcibly from a die one after another, and which has a trunk whose outer diameter is made identical with that of a cap, and also to provide a forced extraction die structure for the container body. <P>SOLUTION: A male die is used to regulate the bending elastic modulus of the material of the wide-mouthed container body 100, the height H of the thread of the male screw 111, the angle F of the flank of the thread, the flat width W of the front end face of the thread, a radius R<SB>1</SB>at an angled part of the front end face, a radius R<SB>2</SB>at the root of the thread, the wall thickness T of the mouth-to-neck part 110, a radius R<SB>3</SB>at the point where the inner peripheral surface upper end of the shoulder 120 connects to the inner peripheral surface lower end of the mouth-to-neck part 110, a radius R<SB>4</SB>at the point where the inner peripheral surface lower end of the shoulder 120 connects to the inner peripheral surface upper end of the trunk 130, and the width D of the undercut on the inner peripheral surface of the shoulder 120. The die has a forced extraction mechanism consisting of a die block for forming the top face and interior of the mouth-to-neck part 110, a die block for forming the exterior of the mouth-to-neck part 110, and a die block, which has a built-in center ejector pin at the center of the die block and forms the interior of the trunk 130. The die is used to forcibly extract the undercuts of the container body one after another. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention has a wide-mouth container body having an undercut that has an external cut on the outer peripheral surface of the mouth and neck portion and an inner peripheral surface of the shoulder portion, and that aligns the outer diameter of the torso with the outer diameter of the cap that is screwed to the mouth and neck portion. This is related to the forced die structure.

  Conventionally, when molding a molded product with an undercut by injection molding, usually a loose core or slide core is attached to the undercut part of the mold, a split mold is used, or a screw shape is used. Is to release the molded product from the mold by rotating the molded product or the mold, but when the material of the molded product is a soft thermoplastic resin, utilizing the elasticity of the material, In some cases, the molded product was forcibly removed from the mold.

  However, in the case of a wide-mouthed container body having an undercut on the outer peripheral surface of the mouth and neck portion and the inner peripheral surface of the shoulder portion, there are two portions that become undercuts, and the molded product is released from the mold. Requires a complicated mold structure, and it has been generally difficult to forcibly and continuously remove it in the same mold.

  The present invention solves the problem of the mold in the above-described conventional injection molding method, and two undercut portions of the outer peripheral surface of the mouth and neck portion and the inner peripheral surface of the shoulder portion are molded. Providing a wide-mouthed container body with an undercut capable of aligning the outer diameter of the barrel with the outer diameter of the cap and its forced-release mold structure To do.

That is, the first invention of the present invention is a wide-mouthed container body made of a thermoplastic resin having a flexural modulus of 1400 MPa or less and having an external thread on the outer peripheral surface of the mouth and neck and an undercut on the inner peripheral surface of the shoulder. The height (H) of the thread of the male screw is 1.0 mm or less, the flank angle (F) is 115 ° or more, and the flat width (W) of the tip surface is 0.2 mm or more, The radius (R ₁ ) at the corner of the tip is at least the height of the thread (H) × 1/3 mm, and the radius at the root (R ₂ ) is the height of the thread (H) × 2/3 mm. As described above, between the height of the screw thread (H) and the thickness (T) of the mouth and neck, H <T × 0.75 is satisfied, and the mouth and neck at the upper end of the inner peripheral surface of the shoulder in at Earl connecting the lower end inner peripheral surface (R ₃₎ is 3mm or more, Earl (R ₄₎ to be connected to the barrel upper end inner peripheral surface of the inner peripheral surface lower end of the shoulder is more 8 mm, material When the flexural modulus is 900 to 1400 Mpa, T + D = 4.0 ± 1.0 mm is satisfied between the thickness (T) of the neck and neck and the undercut width (D) of the shoulder inner peripheral surface. When the material has a flexural modulus of 900 Mpa or less, T + D = 5.0 ± 1.b between the thickness of the neck and neck (T) and the undercut width (D) of the shoulder inner peripheral surface. A wide-mouthed container body having an undercut characterized by satisfying 0 mm.

The second invention of the present invention is a body inner mold in which a center ejector pin is movably installed in the center position of the mouth and neck top surface, the inner mold block, the mouth neck outer mold block, and the center position. In the mold operation for forcibly removing and releasing the wide-mouthed container body having the undercut that has been left open from the male mold having a forced release mechanism composed of a mold block, in the first operation, Moving the surface and the inner mold block to form a gap between the mouth and neck top surface and the inner mold block and the mouth neck and top surface of the wide-mouth container body having the undercut, In the second operation, the mouth-and-neck outer mold block is moved to forcibly remove the male screw on the outer peripheral surface of the mouth-and-neck portion of the wide-mouthed container body having the undercut, and in the third operation, the inner part of the body is molded. Mold block center Projecting the Jekutapin a forced vent mold structure, characterized in that the forced disconnect the wide mouth container body having an undercut at the center ejector pin.

The present invention relates to the elastic modulus of the material of the wide-mouthed container main body having undercuts at two locations of the outer peripheral surface of the mouth and neck portion and the inner peripheral surface of the shoulder portion, the height H of the thread of the male screw 111, and the flank angle. F, flat width W of the tip surface, radius R _{1 at} the corner of the tip surface, thread height H, radius R _{2 at the} root portion, wall thickness T of the mouth and neck portion 110, upper end of the inner peripheral surface of the shoulder portion 120 R ₃ connected to the inner peripheral surface of the lower end of the neck and neck of the mouth, R ₄ connected to the inner peripheral surface of the upper end of the body 130 of the lower end of the inner peripheral surface of the shoulder, the wall thickness T of the neck and neck, the inner peripheral surface of the shoulder The width D of the undercut is regulated, and this wide-mouthed container body is made up of an inner neck mold block and a mouth neck outer mold block provided with a center ejector pin at the top and inner mold blocks and a central position. In order to mold using a male die with a forced die structure composed of a mold block, two undercuts on the molded wide-mouth container body The wide-mouth container main body can be released from the mold by forcing it continuously and continuously in the mold. For this reason, the mold structure does not become relatively complicated, and the unreasonable state is good, and the moldability is good.

  In addition, the wide-mouthed container body having an undercut according to the present invention regulates the undercut width D of the inner peripheral surface of the shoulder portion, so that the outer diameter of the trunk portion is set to the outer diameter of the cap screwed to the mouth-and-neck portion. The diameter can be aligned.

  Next, the wide-mouthed container main body having an undercut according to an embodiment of the present invention and its forced punching mold structure will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a main part of a wide-mouthed container main body having an undercut according to the present embodiment, and FIG. 2 is a cross-sectional view showing the structure of the wide-mouthed container main body, and FIGS. ) Is an explanatory view showing a male forced removal operation of the present embodiment.

  As shown in FIG. 2, the wide-mouthed container body (100) having an undercut according to the present embodiment has two locations, an external thread (111) on the outer peripheral surface of the mouth / neck portion (110) and an inner peripheral surface of the shoulder portion (120). A wide-mouthed container body having an undercut. A cap (300) having a female thread (311) on the inner peripheral surface of the peripheral wall (310) is screwed onto the mouth and neck (110). The outer diameter of the body (130) of the container body (100) is made uniform. In addition, the wide-mouthed container main body of the present embodiment is formed by an injection molding method in order to improve the quality of the product such as the appearance, the width of the body, the strength, and the dimensional accuracy.

The wide-mouthed container main body of this embodiment is obtained by injection molding a soft thermoplastic resin having a flexural modulus of 1400 Mpa or less. The height (H) of the thread of the male screw (111) shown in FIG. 1 is 1.0 mm or less, the angle (F) of the flank is 115 ° or more, and the flat width (W) of the tip surface Is 0.2 mm or more, the corner radius (R ₁ ) of the tip is not less than the height of the thread (H) × 1/3 mm, and the root radius (R ₂ ) is the height of the thread. (H) × 2/3 mm or more, satisfying H <T × 0.75 between the height of the screw thread (H) and the thickness (T) of the mouth and neck (110), and the shoulder The radius (R ₃ ) connected to the inner peripheral surface at the upper end of the inner peripheral surface of the part (120) is 3 mm or more, and is connected to the upper peripheral surface of the trunk (130) at the lower end of the inner peripheral surface of the shoulder. Earl with (R ₄₎ is more than 8 mm, and the musical piece elastic modulus of the material is 900~1400Mpa the thickness of the neck (T) and the shoulder inner peripheral surface of the undercut of the width of the (D) When T + D = 4.0 ± 1.0 mm is satisfied and the material has a flexural modulus of 900 Mpa or less, the thickness of the mouth and neck (T) and the width of the undercut on the inner peripheral surface of the shoulder (D) And the product specifications satisfying T + D = 5.0 ± 1.0 mm. The regulation of these product specifications is technical knowledge obtained from repeated trials by the inventors, and it is impossible to adjust the two undercut parts on the outer peripheral surface of the mouth and neck and the inner peripheral surface of the shoulder. As shown in FIG. 2, the outer diameter of the trunk portion (130) and the outer diameter of the peripheral wall (310) of the cap (300) can be made uniform. In the product specification exceeding the above-mentioned restriction range, it is difficult to forcibly remove the undercut portion without damaging the quality of the product by successively continuing in the same mold.

  Next, as shown in FIG. 3 (a) or (b), the male mold (200) used to mold the wide-mouth container main body of the present embodiment has a mouth and neck top surface and an inner mold block ( 210), an outer neck mold block (220), and a body inner mold block (230) in which a center ejector pin (240) is movably installed at a central position. It is to be prepared. Then, in order to forcibly release the wide-mouthed container body having the undercut that has been left open in the male mold, in the first operation, as shown in FIG. The inner mold block (210) is moved (indicated by an arrow), and the mouth / neck portion (110) top surface of the mouth / neck portion and the wide mold container body (100) having the inner mold block and the undercut A gap (201) is formed between the outer neck and the inner side, and the outer neck of the wide-mouth container body having an undercut is moved by moving the mouth-and-neck outer mold block (indicated by an arrow) in the second operation. Forcibly remove the male screw, and in the third operation, as shown in FIG. 3 (b), the center ejector pin (240) protrudes from the center position of the barrel inner mold block (230) (indicated by an arrow). With this center ejector pin Poked the inner surface of the bottom portion of the mouth container body (100) (140), it is to forcibly disconnect the portion of the undercut of the inner peripheral surface of the shoulder (120) (indicated by arrow).

  The wide-mouthed container body having an undercut according to the present invention and its forced die structure include a male screw in the mouth and neck used for a solid food containing liquid such as boiled or jam, powdered food such as instant coffee or powdered milk, and the like. It is possible to produce a product of good quality by using a relatively inexpensive injection mold with a wide-mouthed container body having undercuts at two locations on the shoulder.

It is sectional drawing which shows the principal part of the wide-mouthed container main body which has an undercut of one Embodiment of this invention. It is sectional drawing which shows the structure of the wide-mouthed container main body which has the undercut of FIG. It is explanatory drawing which shows the male punching operation | movement of one embodiment of this invention, (a) moves an opening | mouth neck part top surface and an inner side mold block by 1st operation | movement, and is the opening | mouth of a wide mouth container main body. The state which formed the clearance gap between a neck top surface and the inner side, (b) is the state which protruded the center ejector pin of the trunk | drum inner side shaping | molding die block by 3rd operation | movement, and forcibly extracted the wide-mouthed container main body Indicates.

Explanation of symbols

100 …… Wide mouth container body 110 …… Mouth neck portion 111 …… Male thread 120 …… Shoulder portion 130 …… Body portion 200 …… Male mold 201 …… Gap 210 …… Mouth surface of the mouth neck portion and inner mold block 220 ...... Mouth part inner mold block 230 ...... Body inner mold block 240 ...... Center ejector pin 300 ...... Cap 310 ...... Surrounding wall 311 ...... Female thread D ...... Undercut width F ...... Frank angle H: Thread height R ₁ ...... R at the corner of the tip R ₂ …… R at the root R ₃ …… R at the upper end of the inner periphery of the shoulder R ₄ ...... R is connected to the inner peripheral surface of the upper end of the trunk at the lower end of the inner peripheral surface of the shoulder T ...... Wall thickness W of the mouth and neck portion ...... Flat width of the tip surface

Claims (2)

A wide-mouthed container body made of a thermoplastic resin having a flexural modulus of 1400 Mpa or less, having a male screw on the outer peripheral surface of the mouth and neck and an undercut on the inner peripheral surface of the shoulder, the height of the thread of the male screw The length (H) is 1.0 mm or less, the flank angle (F) is 115 ° or more, the flat width (W) of the tip surface is 0.2 mm or more, and the corner radius (R ₁ ) of the tip surface is Is the height of the screw thread (H) × 1/3 mm or more, and the root radius (R ₂ ) is the height of the screw thread (H) × 2/3 mm or more, and the height of the screw thread (H). R (R ₃ ) that satisfies H <T × 0.75 and is connected to the inner peripheral surface of the lower end of the inner peripheral surface of the shoulder and the neck of the lower end of the neck of the mouth and neck. ) in the 3mm or more, Earl (R ₄₎ is at least 8mm to be connected to the barrel upper end inner peripheral surface of the inner peripheral surface lower end of the shoulder, the material song modulus of 900~1400Mp In this case, T + D = 4.0 ± 1.0 mm is satisfied between the thickness (T) of the neck and neck and the undercut width (D) of the inner peripheral surface of the shoulder, and the flexural modulus of the material is satisfied. When the thickness is 900 Mpa or less, T + D = 5.0 ± 1.0 mm is satisfied between the thickness (T) of the mouth and neck and the undercut width (D) of the inner peripheral surface of the shoulder. A wide-mouthed container body with an undercut.   An unreasonable punching mechanism comprising a mouth-and-neck top surface and an inner mold block, a mouth-and-neck outer mold block, and a barrel inner mold block in which a center ejector pin is movably installed at the center position. In the mold operation for forcibly pulling and releasing the wide-mouthed container body having the undercut that has been left open to the male mold, the top surface of the mouth neck and the inner mold block are moved in the first operation. Forming a gap between the mouth and neck top and inner mold block and the mouth and neck top and inside of the wide-mouth container main body having the undercut, and in the second operation, forming the mouth and neck outside Move the mold block, forcibly remove the male screw on the outer peripheral surface of the mouth-and-neck portion of the wide-mouth container body having the undercut, and in the third operation, project the center ejector pin of the mold part inner molding block, The Forcibly punching die structure characterized by forcibly disconnect the wide mouth container body having an undercut centers ejector pin.

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