JP2007253558A - Screw-like object and molding die of screw-like object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable fabricating a screw-like object having a wing object which continues spirally from a synthetic resin by a couple of molds. <P>SOLUTION: The screw-like object made of a synthetic resin comprises a wing object 1 which continues spirally. A wing object 1 begins to open from one side of an imagination plane surface x including a central axis s of the spiral to a direction away from this imagination plane surface x and comprises a padding section 1b which makes avoid this undercut at a portion which serves as an undercut in a mold which forms a part which faces to this side of this wing object 1; and also begins to open from the other side of an imagination plane surface x including a central axis s of the spiral to a direction away from this imagination plane surface x and comprises a padding section 1b which makes avoid this undercut at a portion which serves as an undercut in a mold which forms a part which faces this side of this wing object 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an improvement of a synthetic resin screw-like body and a mold for molding the same.

  Conventionally, at least four molds are required to form a screw from a synthetic resin by injection molding. (See Patent Document 1)

After filling the filling space for molding the screw with synthetic resin, there is also a method of extracting the mold from the mold while rotating the molded screw. In this case, the mold does not become complicated, but the filled synthetic resin is sufficient. Extraction had to wait until it was cured, and a separate mechanism for rotating was required.
JP-A-7-112263

  The main problem to be solved by the present invention is that a screw-like body having a spirally shaped wing body can be molded from a synthetic resin by a pair of molds.

In order to achieve the above object, in the present invention, a screw-like body is used.
A screw-shaped body made of a synthetic resin with a spiral wing body,
This wing is
A portion that is hidden when the wing body is viewed from one side of a virtual plane including the central axis of the helix from a direction orthogonal to the virtual plane, and in a direction away from the virtual plane on this side. In the mold that opens and forms the part facing this side of the wing body, the portion that becomes the undercut has a built-up portion that avoids the undercut,
A portion that is hidden when the wing body is viewed from the other side of the virtual plane including the central axis of the helix when viewed from the direction orthogonal to the virtual plane, and away from the virtual plane on this side. In the mold that opens and forms the portion facing this side of the wing body, a portion that becomes an undercut is provided with a built-up portion that avoids the undercut.

In order to achieve the above object, in the present invention, a molding die for a screw-like body is provided.
It consists of a pair of molds,
Where the parting line of this pair of molds forms the screw-like body, the entry into the one side and the other side from the virtual plane including the central axis of the spiral that the wing body of the screw-like body to be molded follows It was assumed that the intrusion into and out was repeated alternately.

  According to such a configuration, at each position over the entire length of the wing body, at any position between the protruding end and the base portion, a pair of the wing bodies are aligned with each other as much as possible. A screw-like body made of synthetic resin can be molded only by the mold.

  If a wing body is formed integrally with a pair of shaft bodies formed along the central axis of the spiral, the screw body can be used in the flow path by using this shaft body. In addition, it is possible to attach and distribute in such a direction that the central axis runs along the flow path, or in a direction that crosses the central axis in the flow path.

  In addition, if the screw-like body is provided with two wing bodies so that the start ends and the end ends of the two wing bodies are positioned at opposite positions with the central axis in between, the wing bodies are provided with two wing bodies. The screw-like body provided is composed of a pair of molds and is made of synthetic resin with the thickness of each wing body being evenly aligned from the base to the tip and in the length direction of the wing body. Can be made.

  According to this invention, the screw-like body provided with the wing body that continues in a spiral shape can be appropriately formed only by the pair of molds that open away from the virtual plane.

  The best mode for carrying out the present invention will be described below with reference to FIGS.

  1 shows the screw-like body according to the embodiment as viewed from the side, and particularly FIG. 1 (ii) shows only the outline of the screw-like body in FIG. 1 (i). In this state, a parting line P at a molding position of the screw-like body in a pair of molds (not shown) that molds the screw-like body is shown by a bold line. 2 to 7 respectively show such screw-like bodies. In particular, in FIGS. 2 and 3, the surface of the built-up portion 1b is hatched so that the formation location of the built-up portion 1b can be easily understood. is doing.

  The screw-like body according to this embodiment is made of a synthetic resin and is used by being provided in a fluid flow path. If a screw-like body is fixedly provided in the flow path or the like, the fluid can be guided along the wing body 1 following the spiral shape of the screw-like body. In addition, if a screw-like body is rotatably provided in the flow path or the like, the fluid can be transferred by the wing body 1 following the spiral shape of the screw-like body.

  In this embodiment, the wing body 1 in such a screw-like body can be as much as possible at any position between its protruding end 1a and its base (location on the spiral central axis s side in the wing body 1). It is comprised so that it may have a substantially equal thickness.

The wing body 1 includes a built-up portion 1b that avoids the following undercut at the next portion.
(1) A portion that is hidden when the wing body 1 is viewed from one side of a virtual plane x including the central axis s of the spiral from a direction fa orthogonal to the virtual plane x, and on this side, A part that forms an undercut in a mold that opens away from the virtual plane x and forms a portion facing this side of the wing body 1 (hereinafter, this mold is referred to as a first mold) (2) the spiral Is a portion hidden when the wing body 1 is viewed from the other side of the virtual plane x including the central axis s in the direction fb perpendicular to the virtual plane x, and on this side, the virtual plane x A portion that is undercut in a mold that opens in a direction away from the wing body and forms a portion facing this side of the wing body 1 (hereinafter, this mold is referred to as a second mold).

  In this case, in each position over the entire length of the wing body 1, the thickness of the wing body 1 is made to be approximately equal as much as possible at any position over the protruding end 1 a and the base portion. A screw-like body made of synthetic resin can be molded only by a pair of molds.

  The first mold creates a filling space of a synthetic resin for molding the screw-like body in a state combined with the second mold, and opens from the combined state in a direction perpendicular to the virtual plane x. On the other hand, the second mold creates a filling space of a synthetic resin for molding the screw-like body in a state combined with the first mold, and is in a direction orthogonal to the virtual plane x from this combined state. The first mold opens in the opposite direction.

Specifically, the built-up portion 1b continues spirally around the central axis s, and at each position over the entire length of the wing body 1, at any position over the protruding end 1a and the base portion. In the virtual wing body 1 ′ in which the thicknesses of the wing bodies 1 are substantially equal, the surface of the hidden and undercut portion (hereinafter, referred to as a placement target surface 1 c),
In the first mold, a surface of the virtual wing body 1 ′ facing the opening side of the first mold and adjacent to the placement target surface 1c, and between the placement target surface 1c. By a synthetic resin that fills a space formed by a surface along the opening direction of the first mold (hereinafter referred to as a first mold-side positioning reference surface 1e) in contact with the ridge 1d considered in
In the second mold, a surface of the virtual wing body 1 'facing the opening side of the second mold and adjacent to the surface 1c to be arranged is between the surface 1c to be arranged. By a synthetic resin that fills the space formed by the surface along the opening direction of the second mold (hereinafter referred to as the second mold-side positioning reference surface 1e) in contact with the ridge 1d considered in
Each is formed. (See Figure 4)

  That is, the surface of the built-up portion 1b is included in the serving reference surface 1e and is substantially parallel to the mold opening direction.

The build-up part 1b in which the surface of the build-up part 1b is included in the placement reference surface 1e on the first mold side is a part that enters the other side of the virtual plane x,
A location (a portion in FIG. 7) where the virtual wing body 1 ′ starts to wrap around from one side to the other side of the virtual orthogonal surface y that includes the central axis s and is orthogonal to the virtual plane x; The virtual wing body 1 ′ is formed from the other side of the virtual orthogonal plane y to the one side (a ′ portion in FIG. 7) where the virtual wing body 1 ′ starts to wrap around.

Further, the build-up portion 1b in which the surface of the build-up portion 1b is included in the placement reference surface 1e on the second mold side is a portion that enters one side of the virtual plane x,
A location (b portion in FIG. 7) where the virtual wing body 1 ′ starts to wrap around from one side to the other side of the virtual orthogonal plane y that includes the central axis s and is orthogonal to the virtual plane x, The virtual wing body 1 ′ is formed from the other side of the virtual orthogonal plane y to the one side (b ′ portion in FIG. 7) where the virtual wing body 1 ′ starts to wrap around.

That is, a mold for molding the screw-like body composed of a pair of molds (the first mold and the second mold) is
In the part where the pair of mold parting lines P form the screw-like body, the entry into the one side and the entry into the other side from the virtual plane x are alternately repeated. (See Fig. 1 (ii))

Further, in this embodiment, the wing body 1 is formed integrally with a pair of shaft bodies 2 and 2 formed along the central axis s of the spiral.
Specifically, in the illustrated example, a gap is provided between one end of the shaft-shaped portion 2a along the central axis s and the start end 1f of the wing body 1, and the other of the shaft-shaped portion 2a. The shaft-like portion 2a and the wing body 1 are integrally formed so as to have a gap between the end and the terminal end 1g of the wing body 1. The part which opened this space | interval functions as the said shaft body.

  In this case, using this shaft body, the screw-like body is placed in the flow path or the like so that the central axis s runs along the flow path, or the direction in which the central axis s intersects the flow path. Can be attached and distributed.

  Further, in this embodiment, the screw-like body has two wing bodies 1. That is, in this embodiment, the screw-like body sandwiches the central axis s between the two wing bodies 1, 1 and the two end wing bodies 1, 1 between the start ends 1f and the end ends 1g, respectively. It is provided so as to be positioned at the opposite position.

  In this case, the screw-shaped body provided with two wing bodies 1 is formed of a pair of molds, the thickness of each wing body 1 is extended from the base to the tip, and the length of the wing body 1 is extended. It can be made of a synthetic resin in a state where they are aligned as much as possible.

  The pitches of the two wing bodies 1 are substantially equal. Further, in both of the two wing bodies 1, the projecting dimension from the central axis s is gradually decreased toward the start end 1f on the start end 1f side and toward the end end 1g on the end end 1g side. Is formed.

Side view of screw-like body ((i) figure) and explanatory drawing (part (ii)) with parting line P attached to the figure representing only the contour line of figure (i) Perspective view of screw-like body Side view AA line sectional view in FIG. BB sectional view in FIG. Top view of screw-like body Same left side view

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wing body 1b Overlay part s Center axis x Virtual plane fa Fa direction orthogonal to virtual plane x fb Direction orthogonal to virtual plane x

Claims (4)

A screw-shaped body made of a synthetic resin with a spiral wing body,
This wing is
A portion that is hidden when the wing body is viewed from one side of a virtual plane including the central axis of the helix from a direction orthogonal to the virtual plane, and in a direction away from the virtual plane on this side. In the mold that opens and forms the part facing this side of the wing body, the portion that becomes the undercut has a built-up portion that avoids the undercut,
A portion that is hidden when the wing body is viewed from the other side of the virtual plane including the central axis of the helix when viewed from the direction orthogonal to the virtual plane, and away from the virtual plane on this side. A screw-like body characterized in that a build-up portion for avoiding this undercut is provided in a portion that becomes an undercut in a mold that opens and forms a portion facing this side of the wing body.   2. The screw-like body according to claim 1, wherein a wing body is formed integrally with a pair of shaft bodies formed along the central axis of the spiral.   The screw according to claim 1 or 2, wherein the two wing bodies are provided so that the start ends and the end ends of the two wing bodies are positioned at opposing positions sandwiching the central axis, respectively. The state. A mold for molding the screw-like body according to any one of claims 1 to 3,
It consists of a pair of molds,
Where the parting line of this pair of molds forms the screw-like body, the entry into the one side and the other side from the virtual plane including the central axis of the spiral that the wing body of the screw-like body to be molded follows A mold for molding a screw-like body, characterized in that it repeatedly repeats entering and exiting.

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