JPH07232334A - Mold for molding spiralled product and mold for spiral molding - Google Patents

Abstract

PURPOSE:To make a cross-sectional shape of a spiral flange rectangular by providing molding faces for molding an upper or lower face of a flange section, a side face thereof and half of an outer surface of a shaft section up to parting lines to upper and lower blocks of four split molds, respectively. CONSTITUTION:When a spiralled product P is quadrisected by parting mines S1-S4 in an axial direction, a split mold 2 has molding blocks 2A, each having a molding face 2a for molding the lower face of a flange (F) part P2 from S1 to S2, an F side face molding face 2b for molding a part of the side face of the F part P2 from S1 to S2 and a shaft part molding face 2c for molding half of the outside face of a shaft part P1 from S1 to S2. Further, the split mold 2 is provided with molding blocks 2B, each having a shaft part molding face 2d for molding half of the outside face of the shaft part P1 from S2 to S3, a molding face 2e for molding the upper face of the F part P2 from S2 to S3 and a side face molding face 2f for molding a part of the side face of the F part P2 from S2 to S3. The blocks 2A, 2B are alternately connected to one another. Furthermore, split molds 3, 4, 5 also have a structure similar to that of the split mold 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for forming a spiral product or a spiral product in which a spiral flange portion is integrally formed with an outer peripheral surface of a cylindrical or cylindrical shaft portion. The present invention relates to a mold for molding a product with a spiral or a mold for spiral molding used.

[0002]

2. Description of the Related Art A mold for forming a product with a spiral in which a spiral flange is integrally formed on the peripheral surface of a cylindrical or cylindrical shaft is disclosed in Japanese Patent Laid-Open No. 52-152962. The ones listed are proposed.

In this mold, a cavity for molding a product with a spiral is provided in a movable die, and a projecting pin having the same shape as the product with a spiral after molding is arranged so as to be aligned with the longitudinal direction of the cavity. The tip of the projecting pin is positioned at one end of the cavity so as to rotate integrally with the product, and a projecting guide ring having a spiral groove having the same pitch as the spiral groove of the cavity is screwed onto the outer circumference of the projecting pin. When the ejector pin is extruded after the spiral product is molded, the ejector pin is rotationally moved in accordance with the spiral of the spiral product, and the spiral product is rotationally lifted to be removed from the cavity. is there.

As another conventional mold, the one shown in FIG. 11 has been proposed. This mold 100 is shown in FIG.
1, the four split molds 101, 102, 103,
104 and a cylindrical shaft body 105 for forming an insertion hole at the center of the product with a spiral (shown by the broken line in FIG. 11) P in the longitudinal direction. As shown in FIG. 12, cavities 101a, 103a corresponding to the outer shape of the spiral product P are formed in 101, 102, 103, 104, respectively.

[0005]

However, the above-mentioned conventional mold has various problems described below.
That is, in the mold described in JP-A-52-152962, a protrusion pin, a protrusion guide ring, and the like must be newly provided as constituent elements in addition to changing the bush in which the cavity is formed. It is necessary to drastically change the mold, and thus it is unavoidable that the cost becomes extremely high, and since it takes a long time to remove the mold, the production efficiency is extremely low. Also,
In the other conventional molds described above, each split mold 101,
When 103 is moved in the direction of arrow A in FIG. 11, split molds 102 and 104 are moved in the direction of arrow B, split molds 101 and 102 are moved in the direction of arrow C, and split molds 103 and 104 are moved in the direction of arrow D, a spiral is formed. Since it becomes impossible to demold due to the inclination of, the demolding can be performed in the radial direction from the center of the product with spiral P (the diagonal direction of each split mold from the center of the product with spiral P). Conceivable. However, the split molds 101, 102,
In order to move 103, 104 in this way, the structure of the conventional device must be changed significantly, and the split molds 101, 102, 103, 1 in this direction.
When 04 is moved, as shown in FIG. 13, the flange F of the spiral product P cannot be demolded unless it has a trapezoidal cross section.

Therefore, the present invention has been proposed in order to solve the problems of the above-described conventional mold for forming a product with a spiral, and does not significantly change the moving direction of the conventional mold. , It is sufficient to simply change the split mold in which the cavity is formed, and the spirally formed flange can make the cross-sectional shape of the flange rectangular. It is an object of the present invention to provide a spiral forming die.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been proposed in order to achieve the above-mentioned object, and the first and second inventions are both related to a die for molding a product with a spiral. The third and fourth aspects of the present invention relate to a spiral forming die for forming only a spiral, and further, the first aspect and the third aspect of the invention each have a spiral flange portion or a spiral shape. The present invention relates to a product molding die with a spiral or a spiral molding die that gradually rises in the counterclockwise direction, whereas the second invention and the fourth invention relate to a spiral flange portion or The present invention relates to a product forming mold with a spiral or a mold for spiral forming for forming a product with a spiral that gradually rises as the spiral advances in a clockwise direction. Then, the first invention is a product with a spiral or a product with a spiral formed by spirally forming a spiral flange on the outer peripheral surface of the shaft of a cylindrical or cylindrical shape integrally with the shaft or a spiral. A mold for molding, the mold including first to fourth split molds, wherein the first split mold is configured such that the spiraled product is divided into first to fourth dividing lines in the axial direction of the product. And a second dividing line from the first dividing line that forms the lower surface of the flange portion from the first dividing line to the second dividing line when divided into four equal parts. One flange side molding surface that molds approximately half of the side surface of the flange portion up to the line, and one shaft portion that molds approximately half of the outer surface of the shaft portion from the first dividing line to the second dividing line One molding block having a molding surface and a flat lower surface, and this one molding block Another shaft forming surface that is formed as a body and that forms approximately half of the outer surface of the shaft from the second dividing line to the third dividing line, and the second dividing line to the third dividing line. Up to the other flange portion molding surface for molding the upper surface of the flange portion, and the other flange side surface molding surface for molding substantially half of the side surface of the flange portion from the second dividing line to the third dividing line. And the other molding block having a flat upper surface, wherein the second split mold has a third dividing line from the third dividing line.
Flange side molding surface for molding the lower surface of the flange portion up to the dividing line, and one flange side molding surface for molding substantially half of the side surface of the flange portion from the second dividing line to the third dividing line. And one shaft portion molding surface that molds substantially half of the outer surface of the shaft portion from the second dividing line to the third dividing line, and the lower surface is a flat molding block. And the other shaft portion molding surface that is integrally formed with this one molding block and that molds approximately half of the outer surface of the shaft portion from the third dividing line to the fourth dividing line, The other flange portion molding surface for molding the upper surface of the flange portion from the dividing line to the fourth dividing line, and the other for molding approximately half of the side surface of the flange portion from the third dividing line to the fourth dividing line The flange side molding surface, and the upper surface is flat A molding block, wherein the third split mold is one flange portion molding surface that molds the lower surface of the flange portion from the third dividing line to the fourth dividing line, and the third dividing line. One of the flange side surface forming the half of the side surface of the flange portion up to the fourth dividing line and about half of the outer surface of the shaft portion from the third dividing line to the fourth dividing line are formed. One molding block having one shaft molding surface and a lower surface being a flat surface, and one molding block integrally formed with the one molding block from the fourth dividing line to the first dividing line. The other shaft portion molding surface that molds approximately half of the outer surface of the shaft portion, the other flange portion molding surface that molds the upper surface of the flange portion from the fourth dividing line to the first dividing line, and Form approximately half of the side surface of the flange portion from the dividing line 4 to the first dividing line. One of the flange side surface molding surface and the other molding block having a flat upper surface, and the fourth split mold is a flange from the fourth dividing line to the first dividing line. One flange side molding surface for molding the lower surface of the portion, one flange side molding surface for molding substantially half of the side surface of the flange section from the fourth dividing line to the first dividing line, and the fourth One molding block having one shaft molding surface that molds approximately half of the outer surface of the shaft from the dividing line to the first dividing line, and the lower surface is a flat molding block; The other shaft part molding surface which is integrated with the block and molds approximately half of the outer surface of the shaft part from the first dividing line to the second dividing line, and the first dividing line to the second The other flange portion molding surface for molding the upper surface of the flange portion up to the dividing line; Of the other side surface of the flange portion for molding substantially half of the side surface of the flange portion from the dividing line to the second dividing line, and the other molding block having a flat upper surface. It is characterized by that. Also, the second
The invention of (1) is a product with a spiral formed by integrally forming a spiral flange portion on the outer peripheral surface of a cylindrical or cylindrical shaft portion with the shaft portion, or a product with a spiral or a die for spiral forming. Therefore, the mold includes first to fourth split molds.
The split mold is the first product when the product with a spiral is divided into four equal parts by the first to fourth dividing lines in the axial direction of the product.
Forming one upper surface of the flange portion from the dividing line to the second dividing line, and forming approximately one half of the side surface of the flange portion from the first dividing line to the second dividing line. The upper surface is flat and includes one flange side surface molding surface and one shaft portion molding surface that molds approximately half of the outer surface of the shaft portion from the first dividing line to the second dividing line. And a molding surface of the other shaft portion which is integrated with the one molding block and which molds approximately half of the outer surface of the shaft portion from the second dividing line to the third dividing line. And the other flange portion molding surface for molding the lower surface of the flange portion from the second dividing line to the third dividing line, and the side surface of the flange portion from the second dividing line to the third dividing line. The other side of the flange that molds approximately half the molding surface, and the lower surface is a flat surface And the other molding block, wherein the second split mold comprises one flange portion molding surface for molding the upper surface of the flange portion from the second dividing line to the third dividing line, and One of the flange side molding surfaces that molds approximately half of the side surface of the flange portion from the second dividing line to the third dividing line and the outer surface of the shaft portion from the second dividing line to the third dividing line. One molding block having one shaft molding surface for molding substantially half and having a flat upper surface, and one molding block integrally formed with this one molding block Other shaft portion molding surface that molds approximately half of the outer surface of the shaft portion up to the dividing line, and the other flange portion molding that molds the lower surface of the flange portion from the third dividing line to the fourth dividing line. Surface and the side surface of the flange portion from the third dividing line to the fourth dividing line The other split side surface forming surface of the other half for forming one half, and the other forming block whose lower surface is a flat surface, the third split mold from the third dividing line to the fourth dividing line. One flange portion molding surface that molds the upper surface of the flange portion up to the line, and one flange side surface molding surface that molds approximately half of the side surface of the flange portion from the third dividing line to the fourth dividing line, One molding part having one shaft part molding surface for molding substantially half of the outer surface of the shaft part from the third dividing line to the fourth dividing line, and the one upper surface of which has a flat surface; The other shaft part molding surface which is integrated with one of the molding blocks and molds approximately half of the outer surface of the shaft part from the fourth dividing line to the first dividing line; and the fourth dividing line. To the first parting line, the other flange part is formed to form the lower surface of the flange part. The other molding, which comprises a shaping surface and another flange side surface molding surface for molding substantially half of the side surface of the flange portion from the fourth dividing line to the first dividing line, and the lower surface is a flat surface. A block, wherein the fourth split mold comprises one flange portion molding surface for molding the upper surface of the flange portion from the fourth dividing line to the first dividing line, and the fourth dividing line One of the flange side surface molding surfaces that molds approximately half of the side surface of the flange portion up to the first dividing line and one half that molds approximately half of the outer surface of the shaft portion from the fourth dividing line to the first dividing line Shaft part molding surface and one upper surface of the molding block having a flat upper surface, and the shaft from the first dividing line to the second dividing line integrated with the one molding block. Shaft part molding surface for molding approximately half of the outer surface of the portion, and the first dividing line To the second parting line, the other flange part molding surface for molding the lower surface of the flange part, and the other flange for molding substantially half of the side surface of the flange part from the first parting line to the second parting line. A side molding surface, and the other molding block having a lower surface and a flat surface,
It is characterized by comprising. A third aspect of the present invention is a spiral forming die for forming a spiral product, which includes the first to fourth split dies and the first to fourth dies.
And a columnar or cylindrical shaft body fixed to the center of the split mold of the first split mold, and the first split mold is configured such that the spiral is formed in the axial direction of the shaft body by the first to fourth dividing lines, and the like. Of the spirals from the first dividing line to the second dividing line and one spiral forming surface that forms the lower surface of the spiral from the first dividing line to the second dividing line. One spiral side surface molding surface for molding substantially half of the side surface, and one shaft body joining surface for joining with substantially half of the outer surface of the shaft body from the first dividing line to the second dividing line. The lower surface of the flat surface is one of the molding blocks whose flat surface is a flat surface, and is joined to approximately one half of the outer surface of the shaft body from the second dividing line to the third dividing line. And the other spiral forming surface for forming the upper surface of the spiral from the second dividing line to the third dividing line. A second side surface of the spiral from the second dividing line to the third dividing line, the other side surface forming surface of the spiral, and the other forming block having a flat upper surface. , The second split mold is the second
One spiral forming surface that forms the lower surface of the spiral from the dividing line to the third dividing line, and one spiral that forms approximately half of the side surface of the spiral from the second dividing line to the third dividing line One of which is provided with a side surface molding surface and one shaft body joining surface which is joined to substantially half of the outer surface of the shaft body from the second dividing line to the third dividing line, and the lower surface is a flat surface. And the other shaft body joining surface that is joined to one of the molding blocks and is joined to substantially half of the outer surface of the shaft body from the third dividing line to the fourth dividing line, The other spiral forming surface that forms the upper surface of the spiral from the third dividing line to the fourth dividing line and the other that forms approximately half of the side surface of the spiral from the third dividing line to the fourth dividing line. Spiral side molding surface of
And the other molding block having a flat upper surface, the third split mold forming one lower surface of the spiral from the third dividing line to the fourth dividing line. A molding surface, one spiral side surface molding surface that molds substantially half of the side surface of the spiral from the third dividing line to the fourth dividing line, and the axis from the third dividing line to the fourth dividing line One molding block having one shaft body bonding surface that is bonded to substantially half of the outer surface of the body and having a lower surface that is a flat surface, and one molding block that is integrated with this one molding block. The other shaft body joining surface that joins approximately half of the outer surface of the shaft body from the dividing line to the first dividing line, and the other that forms the upper surface of the spiral from the fourth dividing line to the first dividing line Of the spiral forming surface and the half of the side surface of the spiral from the fourth dividing line to the first dividing line Top it comprises a helical side molding surface, the is provided with the other of the forming block formed by a plane,
The fourth split mold is one spiral forming surface that forms the lower surface of the spiral from the fourth dividing line to the first dividing line, and the spiral from the fourth dividing line to the first dividing line. One of the spiral side surface molding surfaces that molds substantially half of the side surface of the shaft body, and one shaft body bonding surface that bonds to substantially half of the outer surface of the shaft body from the fourth dividing line to the first dividing line. One molding block having a flat lower surface and one half of the outer surface of the shaft body from the first dividing line to the second dividing line integrated with the one molding block. The other shaft joining surface to be joined, the other spiral forming surface that forms the upper surface of the spiral from the first dividing line to the second dividing line, and the first dividing line to the second dividing line Of the other side surface of the spiral forming a half of the side surface of the spiral, and the upper surface of the other side is a flat surface. And a form block, and characterized by comprising Te. A fourth aspect of the present invention is a spiral forming die for forming a spiral spiral, wherein the die is the first
To a fourth split mold and a columnar or cylindrical shaft body fixed to the center of these first to fourth split molds, and the first split mold has the spiral and the shaft of the shaft body. One spiral forming surface for forming an upper surface of the spiral from the first dividing line to the second dividing line when divided into four equal parts in the direction by the first to fourth dividing lines; From one parting line to the second parting line, and one half of the spiral side surface forming the half part of the side surface of the spiral, and about half of the outer surface of the shaft body from the first parting line to the second parting line. One molding block having one shaft body bonding surface to be bonded to and a top surface being a flat surface, and one molding block integrated with the one molding block, and the second dividing line to the third dividing line. The other half of the outer surface of the shaft up to the line, the other shaft-joining surface, and the second dividing line to the third
The other spiral forming surface for forming the lower surface of the spiral up to the dividing line, and the other spiral side forming surface for forming approximately half of the side surface of the spiral from the second dividing line to the third dividing line. And a second molding block having a lower surface that is a flat surface, and the second split mold is one spiral molding for molding an upper surface of the spiral from the second dividing line to the third dividing line. A surface, one spiral side surface molding surface for molding substantially half of the side surface of the spiral from the second dividing line to the third dividing line, and a shaft body from the second dividing line to the third dividing line A molding block having one shaft-bonding surface that is bonded to substantially half of the outer surface of the first molding block, and the upper surface of the molding block is flat; and the third molding block is integrated with the one molding block. From the line to the fourth dividing line, the other shaft body joining surface that joins approximately half of the outer surface of the shaft body, The other spiral forming surface that forms the lower surface of the spiral from the third dividing line to the fourth dividing line, and the other that forms approximately half of the side surface of the spiral from the third dividing line to the fourth dividing line. And the other molding block having a lower surface that is a flat surface, and the third split mold has a spiral side surface from the third dividing line to the fourth dividing line. One spiral forming surface for forming the upper surface, and the third
From one dividing line to the fourth dividing line, and one half of the spiral side surface forming the half side surface of the spiral, and approximately half of the outer surface of the shaft body from the third dividing line to the fourth dividing line. One molding block having one shaft body joining surface to be joined with and a top surface being a flat surface, and one molding block integrated with this one molding block from the fourth dividing line to the first dividing line. The other half of the outer surface of the shaft up to the line, the other shaft joining surface, the other spiral forming surface for forming the lower surface of the spiral from the fourth dividing line to the first dividing line, The other spiral side surface forming surface for forming substantially half of the side surface of the spiral from the fourth dividing line to the first dividing line, and the other forming block having a lower surface that is a flat surface, The fourth split mold forms one of the upper surface of the spiral from the fourth dividing line to the first dividing line. From the fourth dividing line to the first dividing line, a spiral forming surface and one spiral side forming surface that forms approximately half of the side surface of the spiral from the fourth dividing line to the first dividing line. One molding block having one shaft joint surface that is joined to substantially half of the outer surface of the shaft body and having a flat upper surface, and one molding block that is integrated with this one molding block. Forming the other shaft joint surface that joins approximately half of the outer surface of the shaft from the dividing line to the second dividing line, and the lower surface of the spiral from the first dividing line to the second dividing line. The other has the other spiral forming surface and the other spiral side surface forming surface for forming substantially half of the side surface of the spiral from the first dividing line to the second dividing line, and the lower surface is a flat surface. And a molded block of 1.

[0008]

According to the die for molding a product with a spiral according to the first aspect of the invention, the other molding block constituting the fourth split mold is inserted between the one molding block constituting the first split mold. And one molding block that constitutes the third split mold, and the other molding block that constitutes the first split mold is inserted and connected between the one molding block that constitutes the second split mold. The other molding block constituting the second split mold is inserted and connected between the two molding blocks, and the other molding block constituting the third split mold is inserted and connected between the one molding block constituting the fourth split mold. In this state, the first to fourth split molds are connected to each other, and the molding surfaces formed on the split molds are connected to each other to form a cavity into which the raw material of the spiral product is press-fitted. When the raw material is hardened in the cavity and the spiral product is molded and then released from the mold, the first
Of the split mold in the second dividing line direction from the axis of the product with a spiral, the second split mold in the third dividing line direction, the third split mold in the fourth dividing line direction, and the fourth dividing line direction. The split mold is moved in the direction of the first dividing line. At this time, one or the other of the molding blocks formed in the one molding block and the other molding block constituting each split mold is formed from the upper surface or the lower surface of the flange portion constituting the product with the spiral, As it is released in the direction of gradually separating as it is moved in the moving direction, without making the sectional shape of the flange part trapezoidal,
It can be molded into a square or rectangular shape, and the demolding time can be extremely shortened. Note that the second invention has the same operation as that of the first invention, and therefore description thereof will be omitted. Further, in the third invention, each spiral forming surface forming the first to fourth split molds has the same effect as each flange forming surface forming the first invention, while Since the one and the other shaft joint surfaces of each of the first to fourth split molds are literally joined to the outer surface of the shaft body, no cavity is formed between them. Therefore, the cavity is formed in a spiral shape by the one and the other spiral side molding surfaces and the one and the other spiral side surface shaping surfaces, and the shaft portion is not molded as in the first and second inventions. Even in the case of the spiral forming die having such a configuration, it is necessary to make the cross-sectional shape of the spiral trapezoidal as in the case of the spiral forming product forming die according to the first and second inventions. It can be molded into a square shape or a rectangular shape without using a mold, and the demolding time can be shortened.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. First, the first invention (claim 1)
The invention corresponding to the described invention) will be described with respect to the embodiment of the invention. The mold is a spiral-molded product molding mold for molding a spiral-molded product that gradually rises as the flange advances in the counterclockwise direction.

As shown in FIG. 1, the mold 1 is for molding a product P with a spiral integrally molded with a synthetic resin, and the product P with a spiral has a cylindrical shaft portion P.
₁ and a flange portion P ₂ spirally formed on the outer peripheral surface of the shaft portion P ₁ . As shown in FIG. 2, the mold 1 for molding the product P with spirals has first to fourth split molds 2, 3, 4, 5 and a shaft portion P ₁ which constitutes the product P with spirals. And a cylindrical shaft body 1a for molding the inner peripheral surface of. The first split mold 2 is movable by a driving device (not shown) in the arrow E direction in the figure or the opposite direction by the first and second support shafts 6 and 7. The second split mold 3 is movable in the arrow F direction in the figure or the opposite direction by the third and fourth support shafts 8 and 9, and the third split mold 4 is supported by the support shafts 10 and 11. Is movable in the direction of arrow G in the figure or the opposite direction thereof, and the fourth split mold 5 is movable by the support shafts 12 and 13 in the direction of arrow H in the figure or the opposite direction. is there. The first to fourth split molds 2, 3, 4, 5 are formed with molding surfaces for molding the spiraled product P shown by the broken line in FIG. , 5 and shaft 1a
A cavity into which the melted synthetic resin material is press-fitted is formed inside.

As shown in FIG. 3, the first split mold 2 has the spiral product P shown in FIG. 1 in the axial direction of the spiral product P with the first to fourth dividing lines S _1. · · S ₄ when 4 equally divided by (the figure shows in a two-dot chain line), the first dividing line S
_One flange forming surface 2a for forming the lower surface of the flange portion P ₂ from ₁ to the second dividing line S ₂ , and the first dividing line S 2.
_One flange side surface 2b for molding a part of the side surface of the flange portion P ₂ from ₁ to the second dividing line S _2, and
A shaft portion forming surface 2c from dividing lines S ₁ of one of molding a substantially half of the outer surface of the shaft portion P ₁ to the second division line S _2, and one of the shaped blocks 2A having the second division The other shaft part molding surface 2d that molds approximately half of the outer surface of the shaft part P ₁ from the line S ₂ to the third parting line S ₃ , and the second parting line S ₂ to the third parting line S ₃ and the other flange molding surface 2e for molding the upper surface of the flange portion P ₂ to, from the second division line S ₂ other for forming a part of the flange portion side of the P ₂ up to the third dividing line S ₃ The flange side molding surface 2f and the other molding block 2B having the flange side molding surface 2f are alternately connected. The second to fourth split molds 3, 4, and 5 are also
The first split mold 2 has the same configuration.

As shown in FIG. 4, the first to fourth split molds 2, 3, 4, 5 constructed as described above are combined with each other to form the spiral product P shown in FIG. A cavity having the same shape as the shape is formed. That is, the other molding block 5B constituting the fourth split mold 5 is inserted between the one molding block 2A constituting the first split mold 2 and the one molding block 2A, and the first split mold 2A is inserted. 2 between the other molding block 2B forming the second molding block 2B and the other molding block 2B forming the second split mold 3
Is inserted, and one molding block 4A constituting the third split mold 4 is inserted between the other molding block 3B constituting the second split mold 3 not shown and the other molding block 3B.
Is inserted, and similarly, the fourth split mold 5 is formed with a fourth molding block 5A between the first molding block 5A and the second molding block 5A.
The other molding block 5A forming the split mold 5 is inserted and assembled. In addition, each split mold 2,
One of the molding blocks 2A, 3A, which composes 3, 4, 5
The lower surface of 4A, 5A and the other building blocks 2B, 3B,
The upper surfaces of 4B and 5B are flat surfaces, as shown in FIG. 3, FIG. 4 or FIG.
A, 4A, 5A upper surface and the other building block 2B, 3
The lower surface of B, 4B, 5B is E or F or G shown in FIG.
Alternatively, it has a corresponding shape so that it can slide in the H direction.

FIG. 5 is a sectional view taken along the line YY of FIG. 4, in which the outer shape of the product P with a spiral is formed by the first split mold 2, the fourth split mold 5, and the second split mold 3. FIG. 6 shows a state in which cavities corresponding to the half of FIG.
The first split mold 2, the fourth split mold 5, and the second split mold 3 shown in FIG. Of the split molds shown in FIGS. 5 and 6, the one in which all of the molding surfaces are shown is the split mold 2. As described above, the spiraled product P is provided on one of the molding blocks 2A. When the product P is divided into four equal parts in the axial direction by the first to fourth dividing lines S ₁ ... S ₄ ,
Flange portion P from the dividing line S ₁ to the second dividing line S ₂
And one of the flanging surface 2a for molding the _second lower surface, the first
Flange portion P from the dividing line S ₁ to the second dividing line S ₂
One flange of forming a portion of the _second side side molding surface 2
b and the first dividing lines S ₁ from the second dividing line one shaft portion forming surface for forming a substantially half of the outer surface of the shaft portion P ₁ to S ₂ 2
c is formed, and the other molding block 2B has
Shaft P ₁ from the _second dividing line S ₂ to the third dividing line S ₃
The other shaft part molding surface 2d that molds approximately half of the outer surface of
And the other flange molding surface 2e for molding the upper surface of the flange portion P ₂ of the second division line S ₂ to the third division line S _3,
And the other flange side forming surface 2f for forming a part of the side surface of the flange portion P ₂ of the second division line S ₂ to the third dividing line S ₃ is formed. Then, one molding block 2 that constitutes the first split mold 2 configured as described above.
The other molding block 5B constituting the fourth split mold 5 is inserted between A and 2A, and the other molding block 5 is formed.
In the same manner as the configuration of the other molding block 2B that constitutes the first split mold 2, the first split line S ₁
The other part of the outer surface of the shaft part P ₁ up to the parting line S ₂ of the other part, and the first parting line S ₁ to the second part
And the flange molding surface 5e other for molding the upper surface of the flange portion P ₂ of up to dividing line S _2, the first dividing lines S ₁ from the second
Of the other flange side molding surface 5f for molding a portion of the side surface of the flange portion P ₂ to the dividing line S ₂ is formed. On the other hand, one molding block 3A forming the second split mold 3 is inserted between the other molding blocks 2B and 2B forming the first split mold 2. This one molding block 3A also has a second dividing line S _{2 in the} same manner as the one molding block 2A constituting the first split mold 2 described above.
Third and one flange molding surface 3a for molding the bottom surface of the flange portion P ₂ to the dividing line S _3, the second dividing line from S ₂
To the third parting line S ₃ from one side surface of the flange part P ₂ for molding part of the side surface, and the shaft part from the _second parting line S ₂ to the third parting line S _{3 One} shaft portion molding surface 3c for molding substantially half of the outer surface of P ₁ is formed. Then, the respective molding surfaces 2a, 2 formed on the one molding block 2A constituting the first split mold 2 and the other molding block 5B constituting the fourth split mold 5, respectively.
b, 2c, 5d, 5e, 5f, and the respective molding surfaces 2 formed on the other molding block 2B that constitutes the first split mold 2 and the one molding block 3A that constitutes the second split mold 3, respectively.
d, 2e, 2f, 3a, 3b, 3c, the first parting line S ₁ to the third parting line S of the product P with spiral shown in FIG.
Up to ₃ are molded. The remaining third dividing line S ₃ to the first dividing line S ₁ are basically the same as the above-described configuration, and thus the description thereof will be omitted.

FIG. 7 shows one molding block 2A forming the first split mold 2, one molding block 3A forming the second split mold 3, and a third split mold 4. It shows a state in which only one molding block 4A and one molding block 5A constituting the fourth split mold 5 are combined, and each one of these blocks 2A, 3A, 4A, 5A.
One of the flange forming surfaces 2a, 3a, 4a,
Due to 5a, the lower surface of the flange portion P ₂ from the third dividing line S ₃ to the third dividing line S ₃ (one round along the spiral flange P ₂ ) and the one flange side surface molding surface 2b,
3b, 4b, 5b partially (around half) of the side surface of the flange portion P ₂ from the third dividing line S ₃ to the third dividing line S ₃ (one round along the spiral flange P ₂ ). ), But the third shaft forming surface 2c, 3c, 4c, 5c
About half of the shaft portion P ₁ from the dividing line S ₃ to the third dividing line S ₃ ( _one round along the spiral flange P ₂ ) is formed. Then, one of these blocks 2A, 3A,
4A and 5A are moved in the directions of arrows E, F, G, and H or in the opposite direction, as in the case shown in FIG. 1, FIG. 2 or FIG.

According to the mold 1 for molding a product with a spiral according to the above-mentioned embodiment, the molding surfaces (reference numerals are omitted) formed on each split mold 2, 3, 4, 5 are integrally formed. After the spiraled product P having the shape shown in FIG. 1 is molded by the cavity, the first split mold 2 is moved in the direction of arrow E and the second split mold 3 is moved in the direction of arrow E as shown in FIG. 2 or 4. If the third split mold 4 is moved in the F direction, the fourth split mold 5 is moved in the arrow G direction, and the fourth split mold 5 is moved in the arrow H direction, the product P with a spiral (particularly, the flange portion P ₂ ) is securely deformed. Not only can it be removed from the mold, the production efficiency can be effectively improved without requiring a long time for the mold removal. Further, according to the spiral-molded product molding die 1 according to this embodiment, because of the above-described configuration, it is not necessary to make the cross-sectional shape of the flange portion P ₂ into a trapezoidal shape.

The spiral product mold 1 according to the above embodiment.
Then, one molding block 2A, 3A, 4A, 5A and the other molding block 2 constituting each split mold 2, 3, 4, 5
Flange side forming surfaces (reference numerals are omitted) are formed on both B, 3B, 4B and 5B, that is, the flange P ₂
Since the side surfaces of all are formed by the two flange side forming surfaces, a more stable product with a spiral P can be formed, but it is not always the same as the above-mentioned forming blocks 2A, 3A, 4A, 5A. The other molding block 2
B, 3B, 4B, 5B without forming the flange side molding surface, the molding blocks 2A, 3A, 4
In A and 5A, only one flange forming surface for forming the lower surface of the flange portion P ₂ from the _first dividing line S ₁ to the second dividing line S ₂ and the first dividing line S ₁ to the second dividing line S _{1 are formed} . Dividing line S ₂
Up to approximately one half of the shaft portion P ₁ is provided with one shaft portion molding surface, while the other molding block 2B, 3B, 4
B and 5B include the second dividing line S ₂ to the third dividing line S ₃
The other shaft part molding surface for molding half of the shaft part P ₁ up to
The second parting line S ₂ to the third parting line S ₃ and the other flange forming surface that forms the upper surface of the flange portion P ₂ and the second parting line S ₂ to the third parting line S ₃ It is also possible to provide a flange side molding surface for molding the side surface of the flange portion P ₂ up to.

Further, in the die for molding a product with a spiral 1 described in the above embodiment, as shown in FIG. 1, a metal for molding a product with a spiral P in which a shaft portion P ₁ is formed in a cylindrical shape. Since it is a mold, not only the first to fourth split molds 2, 3, 4, 5 but also the shaft body 1a is used as a constituent element of the spiral mold product molding die 1. Claims 1 and 2
(Invention described) is not limited to _{one in} which the shaft portion P ₁ is not formed into a cylindrical shape but is formed into a cylindrical shape, and may be a mold for forming a product with a spiral shape formed into a cylindrical shape. The shaft 1a does not necessarily have to be a constituent element.

Next, a spiral forming die 20 according to a second embodiment of the present invention will be described. This spiral mold 2
0 is a mold for forming the spiral R shown in FIG.
As shown in FIG. 9, first to fourth split molds 21, 22, 2
3, 24 and a cylindrical shaft body 20a for molding the inner peripheral surface R ₁ of the spiral R. And the first
The split mold 21 of the first and second parts is driven by a driving device (not shown).
The second split mold 22 is configured to be movable in the direction of arrow E in the figure or in the opposite direction by the support shafts 25 and 26 of FIG.
Is indicated by an arrow F in the figure by the third and fourth support shafts 27 and 28.
The third split mold 23 is movable by the support shafts 29 and 30 in the direction of arrow G in the figure or in the opposite direction, and the fourth split mold 24 is The support shafts 31 and 32 are movable in the arrow H direction in the figure or in the opposite direction. Then, in each of the first to fourth split molds 21, 22, 23, 24,
Part of the upper surface R ₂ and part of the lower surface R ₃ of the spiral R shown in FIG.
Each molding surface for molding a part of the outer peripheral surface R ₄ is formed, and the split molds 21, 22, 23, 24 and the shaft body 20a are integrally formed into a cavity into which a molten synthetic resin material is press-fitted. Are formed inside the spiral forming die 20.

The spiral forming die 20 according to the second embodiment is substantially the same in diameter as the shaft 1a constituting the spiral forming product forming die 1 according to the first embodiment. Is made longer, and the outer peripheral surface of the shaft 1a and the first to fourth split molds 2, 3,
Shaft molding surfaces 2c, 2 of the one and the other that constitute 4,5
d, 3c, 3d, 4c, 4d, 5c, 5d are joined together. Therefore, the shapes of the first to fourth split molds 21, 22, 23 and 24 are the first to fourth split molds 2 and 3 which form the spiral-molded product molding die 1 according to the first embodiment. , 4, 5 and has exactly the same configuration as the first and second shaft forming surfaces 2 constituting the first embodiment.
The surfaces corresponding to c, 2d, 3c, 3d, 4c, 4d, 5c and 5d are the products with a spiral in the first to fourth split molds 21, 22, 23 and 24 according to the second embodiment. The shaft body 2 shown in FIG. 10 is not the shaft molding surface for molding the outer peripheral surface of the shaft.
It is a shaft joint surface that is joined to the outer peripheral surface of 0a.

Even in the case of the spiral forming die 20 according to the second embodiment having the above-mentioned structure, it is the same as the case of the spiral product forming die 1 according to the first embodiment. As shown in FIG. 9 or 10, the first split mold 21 is in the arrow E direction, the second split mold 22 is in the arrow F direction, the third split mold 23 is in the arrow G direction, and By moving the split mold 24 of No. 4 in the direction of the arrow H, not only can the mold R be surely demolded without deforming the spiral R, but also the demolding time does not take a long time and the production efficiency can be effectively made. Can be improved. Further, according to the spiral forming die 20 according to this embodiment, since it has the above-described configuration, the spiral R
It is not necessary to make the cross-sectional shape of the trapezoidal.

[0021]

According to the present invention, as is clear from the description of each of the above-described embodiments, the other molding block forming the fourth split mold is provided between the one molding block forming the first split mold. One of the molding blocks that is inserted and connected, and the other molding block that forms the first split mold is inserted and connected between the one molding block that forms the second split mold, and the other molding block that forms the third split mold. The other molding block forming the second split mold is inserted and connected between the molding blocks, and the other molding block forming the third split mold is formed between the molding blocks forming the fourth split mold. In a state of being inserted and connected, the first to fourth split molds are linked, and various molding surfaces formed on the split molds are connected to each other to form a cavity into which a spiral product or a spiral raw material is press-fitted. It is formed. When the raw material is hardened in this cavity and the product with a spiral or the spiral is molded and then released from the mold, the first split mold is the product with the spiral or the axial center of the spiral in the second dividing line direction. The second split mold is moved in the third split line direction, the third split mold is moved in the fourth split line direction, and the fourth split mold is moved in the first split line direction. At this time, the one or the other flange forming surface or the spiral forming surface formed in the one forming block and the other forming block forming each split mold is the upper surface of the flange portion or the spiral forming the spiral product or the spiral, or As it moves from the lower surface in the moving direction of each split mold, it gradually escapes in a direction in which it is separated, so that the flange or spiral is formed into a square or rectangular shape without being trapezoidal in cross section. Moreover, the demolding time can be extremely shortened, and the efficient production of the spiral product or the spiral can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view showing an external appearance of a spiral product manufactured by a spiral product molding die according to a first embodiment.

FIG. 2 is a view showing a main part of a mold for forming a product with a spiral according to the first embodiment, schematically showing a state in which first to fourth split molds are connected and integrated. FIG.

FIG. 3 is a perspective view showing a main part of a first split mold.

FIG. 4 is a perspective view showing a partially cutaway main part of a state in which first to fourth split molds are connected to each other.

5 is a cross-sectional view taken along the line YY of FIG. 4, showing a connection state of the first to fourth split molds.

FIG. 6 is an explanatory diagram showing the constituent elements shown in FIG. 5 by disassembling each constituent element.

FIG. 7 is a perspective view showing a state in which only one molding block constituting the first to fourth split molds is connected.

FIG. 8 is a perspective view showing a spiral formed by a spiral forming die according to a second embodiment.

FIG. 9 is a view showing a main part of a spiral forming die according to a second embodiment, and schematically shows a state in which the first to fourth split dies are connected and integrated. It is a top view.

FIG. 10 is a perspective view showing a partially cutaway main part in a state where the first to fourth split molds are connected to each other.

FIG. 11 is a plan view showing a moving direction of a conventional product molding die with a spiral.

FIG. 12 is a side view showing a main part in a state where the first and third split molds are connected to each other among the first to fourth split molds constituting the conventional product molding die with a spiral. Is.

FIG. 13 is a cross-sectional view showing a flange portion of a product with a spiral formed by a conventional split mold.

[Explanation of sign]

1 Mold for Forming Product with Spiral 2 First Split Mold 2A One Molding Block 2B Another Molding Block 2a One Flange Molding Surface 2b One Flange Side Molding Surface 2c One Shaft Molding Surface 2d The Other Shaft Molding Surface 2e Other flange molding surface 2f Other flange side molding surface 3 Second split mold 3A One molding block 3B Other molding block 3a One flange molding surface 3b One flange side molding surface 3c One shaft molding surface 3d Other Shaft molding surface 3e The other flange molding surface 3f The other flange side molding surface 4 The third split mold 4A One molding block 4B The other molding block 4a One flange molding surface 4b One flange side molding surface 4c One Shaft molding surface 4d Other shaft molding surface 4e Other flange molding surface 4f Other flange side molding surface 5 Fourth split mold 5A One forming block 5B Another forming block 5a One flange forming surface 5b One flange side forming surface 5c One shaft forming surface 5d Another shaft part forming surface 5e Other flange forming surface 5f Another flange side forming surface P Product with spiral P ₁ Shaft P ₂ Flange S ₁ 1st parting line S ₂ 2nd parting line S ₃ 3rd parting line S ₄ 4th parting line 20 Spiral forming mold 20a Shaft 21st 1 split mold 22 2nd split mold 23 3rd split mold 24 4th split mold R spiral

Claims (4)

[Claims] 1. A mold for forming a product with a spiral, which molds a product with a spiral, wherein a spiral flange portion is integrally molded with the outer peripheral surface of a cylindrical or cylindrical shaft portion, the mold comprising: The mold includes first to fourth split molds, which are used when the product with a spiral is divided into four equal parts in the axial direction of the product by the first to fourth dividing lines. ,
One half of the flange portion molding surface for molding the lower surface of the flange portion from the first dividing line to the second dividing line, and approximately half of the side surface of the flange portion from the first dividing line to the second dividing line. And one shaft side molding surface for molding substantially half of the outer surface of the shaft section from the first dividing line to the second dividing line, and the lower surface is One molding block formed into a flat surface, and the other shaft that is integrated with this one molding block and that molds approximately half of the outer surface of the shaft portion from the second dividing line to the third dividing line. Part molding surface, the other flange part molding surface for molding the upper surface of the flange portion from the second dividing line to the third dividing line, and the flange portion from the second dividing line to the third dividing line On the other side of the flange that molds approximately half of the side surface of the And a second molding block that is a flat surface, and the second split mold is one flange part molding surface that molds the lower surface of the flange part from the second dividing line to the third dividing line. , One of the flange side surface forming surfaces of substantially half of the side surface of the flange portion from the second dividing line to the third dividing line, and the shaft portion from the second dividing line to the third dividing line. One molding block having one shaft molding surface for molding substantially half of the outer surface and having a flat lower surface, and the third dividing line integrally formed with this one molding block. To the fourth parting line, the other part of the outer surface of the shaft part is formed, and the other part of the flange part from the third parting line to the fourth parting line is formed. Flange molding surface and flange from the third dividing line to the fourth dividing line The other side surface of the flange for molding substantially half of the side surface, and the other molding block having an upper surface that is a flat surface. One of the flange side molding surfaces that molds the lower surface of the flange portion up to the dividing line 4 and one flange side surface molding that molds approximately half of the side surface of the flange portion from the third dividing line to the fourth dividing line. Surface, and one shaft portion molding surface that molds approximately half of the outer surface of the shaft portion from the third dividing line to the fourth dividing line, and the lower surface is a flat surface A block; and a molding surface of the other shaft portion, which is integrated with one of the molding blocks and molds approximately half of the outer surface of the shaft portion from the fourth dividing line to the first dividing line, Of the other part that forms the upper surface of the flange from the dividing line to the first dividing line And a flange side molding surface that molds substantially half of the side surface of the flange portion from the fourth dividing line to the first dividing line, and the upper surface is a flat surface. And the fourth split line, wherein the fourth split mold has one flange part molding surface for molding the lower surface of the flange part from the fourth split line to the first split line, and the fourth split line. To one side of the flange portion from the first to the first dividing line, and one flange side surface, and about half of the outer surface of the shaft portion from the fourth to the first dividing line. One molding block having one shaft molding surface, and the lower surface being a flat surface, and one molding block integrated with the one molding block from the first dividing line to the second dividing line. The other shaft part molding surface that molds approximately half of the outer surface of the shaft part of Of the flange part from the dividing line to the second dividing line, and the other half of the side face of the flange part from the first dividing line to the second dividing line. A mold for forming a product with a spiral, comprising: the other flange side molding surface; and the other molding block having a flat upper surface. 2. A spiral product molding die for molding a spiral product, wherein a spiral flange is integrally molded with the outer peripheral surface of a cylindrical or columnar shaft, and the spiral product is molded. The mold includes first to fourth split molds, which are used when the product with a spiral is divided into four equal parts in the axial direction of the product by the first to fourth dividing lines. ,
One flange part molding surface for molding the upper surface of the flange portion from the first dividing line to the second dividing line, and approximately half of the side surface of the flange portion from the first dividing line to the second dividing line And one shaft side molding surface for molding substantially half of the outer surface of the shaft section from the first dividing line to the second dividing line, and the upper surface is provided. One molding block formed into a flat surface, and the other shaft that is integrated with this one molding block and that molds approximately half of the outer surface of the shaft portion from the second dividing line to the third dividing line. Part molding surface, the other flange part molding surface for molding the lower surface of the flange portion from the second dividing line to the third dividing line, and the flange portion from the second dividing line to the third dividing line The other flange side molding surface, which molds approximately half of the side surface of the And the other molding block formed into a flat surface, and the second split mold is one flange portion molding surface that molds the upper surface of the flange portion from the second dividing line to the third dividing line. , One of the flange side surface forming surfaces of substantially half of the side surface of the flange portion from the second dividing line to the third dividing line, and the shaft portion from the second dividing line to the third dividing line. One molding block having one shaft molding surface for molding substantially half of the outer surface and having a flat upper surface, and the third dividing line integrally formed with this one molding block. To the fourth parting line, the other part of the outer surface of the shaft part is formed, and the other part of the flange part from the third parting line to the fourth parting line is formed. Flange molding surface and flange from the third dividing line to the fourth dividing line The other split side surface molding surface that molds substantially half of the side surface, and the other molding block that includes a lower surface that is a flat surface, and the third split mold includes a third split line from the third split line. One of the flange side molding surfaces that molds the upper surface of the flange portion up to the dividing line 4 and one flange side surface molding that molds approximately half of the side surface of the flange portion from the third dividing line to the fourth dividing line. Surface, and one shaft portion molding surface that molds substantially half of the outer surface of the shaft portion from the third dividing line to the fourth dividing line, and the upper surface is a flat surface. A block; and a molding surface of the other shaft portion, which is integrated with one of the molding blocks and molds approximately half of the outer surface of the shaft portion from the fourth dividing line to the first dividing line, Of the other part that forms the lower surface of the flange part from the dividing line to the first dividing line And a flange side molding surface for molding substantially half of the side surface of the flange portion from the fourth dividing line to the first dividing line, and the lower surface is a flat surface. And a fourth split line, wherein the fourth split mold has one flange portion molding surface for molding the upper surface of the flange portion from the fourth split line to the first split line, and the fourth split line. To one side of the flange portion from the first to the first dividing line, and one flange side surface, and about half of the outer surface of the shaft portion from the fourth to the first dividing line. One molding block having one shaft molding surface and a flat upper surface, and one molding block integrated with the one molding block from the first dividing line to the second dividing line. The other shaft part molding surface that molds approximately half of the outer surface of the shaft part of Of the other flange portion forming surface of the flange portion from the dividing line to the second dividing line and approximately half of the side surface of the flange portion from the first dividing line to the second dividing line. A mold for molding a product with a spiral, comprising: the other side surface of the flange, and the other molding block having a flat lower surface. 3. A spiral forming die for forming a spiral product, wherein the die is a first to fourth split mold and a circle fixed to the center of these first to fourth split molds. A columnar or cylindrical shaft body is provided, and the first split mold is configured such that the spiral is first arranged in the axial direction of the shaft body.
To one spiral forming surface for forming the lower surface of the spiral from the first dividing line to the second dividing line when divided into four equal parts by the fourth dividing line, and from the first dividing line One of the spiral side surface forming surface forming one half of the side surface of the spiral up to the second dividing line and one half of the outer surface of the shaft body extending from the first dividing line to the second dividing line And a shaft body joining surface, and a lower surface of which is a flat molding block, and a shaft which is integrated with the one molding block from the second dividing line to the third dividing line. The other shaft body joining surface that joins approximately half of the outer surface of the body, the other spiral forming surface that forms the upper surface of the spiral from the second dividing line to the third dividing line, and the second dividing surface. The other spiral side forming surface for forming approximately half of the side surface of the spiral from the line to the third dividing line, The surface is provided with the other molding block formed into a flat surface, and the second split mold is one spiral molding surface for molding the lower surface of the spiral from the second dividing line to the third dividing line, One spiral side surface forming surface for forming substantially half of the side surface of the spiral from the second dividing line to the third dividing line, and the outer surface of the shaft body from the second dividing line to the third dividing line. And one shaft joint surface that is joined to approximately half of the above, and the lower surface is a flat molding block, and the one molding block is integral with the molding block, No. 4 division line, the other shaft body joining surface that is joined to approximately half of the outer surface of the shaft body, and the other spiral forming surface that forms the upper surface of the spiral from the third division line to the fourth division line. And the other spiral side surface forming approximately half of the side surface of the spiral from the third dividing line to the fourth dividing line A shaping surface, and the other shaping block having a flat upper surface, the third split mold shaping a lower surface of the spiral from the third dividing line to the fourth dividing line. One spiral forming surface, one spiral side forming surface that forms substantially half of the side surface of the spiral from the third dividing line to the fourth dividing line, and the third dividing line to the fourth dividing surface. One molding block having one shaft joint surface that is joined to approximately half of the outer surface of the shaft up to the line, and the lower surface is a flat molding block, and one molding block is integrated with this one molding block. The other shaft joint surface that joins with approximately half of the outer surface of the shaft from the fourth dividing line to the first dividing line, and the upper surface of the spiral from the fourth dividing line to the first dividing line The other half of the spiral forming surface for forming the above-mentioned and the half of the side surface of the spiral from the fourth dividing line to the first dividing line. And the other molding block having the other spiral side molding surface that is shaped, and the upper surface of which is a flat surface, and the fourth split mold from the fourth dividing line to the first dividing line. One spiral forming surface for forming the lower surface of the spiral, one spiral side forming surface for forming approximately half of the side surface of the spiral from the fourth dividing line to the first dividing line, and the fourth dividing Line and the first parting line, and one of the shaft body joint surface that is joined to approximately half of the outer surface of the shaft body, and the lower surface is one molding block, and the one molding block And the other shaft body joining surface that is joined to approximately half of the outer surface of the shaft body from the first dividing line to the second dividing line, and from the first dividing line to the second dividing line. Another spiral forming surface for forming the upper surface of the spiral up to the line, and from the first dividing line to the second dividing line Spiral mold, characterized in that the upper surface becomes comprise the other helical side molding surface for molding the substantially half of the side surface of the spiral, a is the provided with the other mold blocks formed by a plane, comprising Te. 4. A spiral forming die for forming a spiral helix, the die being a first to a fourth split mold and a circle fixed to the center of the first to the fourth split mold. A columnar or cylindrical shaft body is provided, and the first split mold is configured such that the spiral is first arranged in the axial direction of the shaft body.
To one spiral forming surface that forms the upper surface of the spiral from the first dividing line to the second dividing line when divided into four equal parts by the fourth dividing line, and from the first dividing line One of the spiral side surface forming surface forming one half of the side surface of the spiral up to the second dividing line and one half of the outer surface of the shaft body extending from the first dividing line to the second dividing line And a shaft-body-joining surface, the upper surface of which is a flat molding block, and the one molding block which is integrated with the shaft from the second dividing line to the third dividing line. The other shaft body joining surface that joins approximately half of the outer surface of the body, the other spiral forming surface that forms the lower surface of the spiral from the second dividing line to the third dividing line, and the second dividing surface. The other spiral side forming surface for forming approximately half of the side surface of the spiral from the line to the third dividing line, The surface includes the other molding block that is a flat surface, and the second split mold is one spiral molding surface that molds the upper surface of the spiral from the second dividing line to the third dividing line, One spiral side surface forming surface for forming substantially half of the side surface of the spiral from the second dividing line to the third dividing line, and the outer surface of the shaft body from the second dividing line to the third dividing line. And one shaft joint surface to be joined to approximately half of the above, and one molding block having an upper surface that is a flat surface, and one molding block that is integrated with this one molding block No. 4 division line, the other shaft body joining surface that is joined to approximately half of the outer surface of the shaft body, and the other spiral forming surface that forms the lower surface of the spiral from the third dividing line to the fourth dividing line. And the other spiral side surface forming approximately half of the side surface of the spiral from the third dividing line to the fourth dividing line A shaping surface, and the other shaping block having a lower surface that is a flat surface, and the third split mold shapes an upper surface of the spiral from the third dividing line to the fourth dividing line. One spiral forming surface, one spiral side forming surface that forms substantially half of the side surface of the spiral from the third dividing line to the fourth dividing line, and the third dividing line to the fourth dividing surface. One molding block having one shaft bonding surface that is bonded to approximately half of the outer surface of the shaft up to the line, and the upper surface is a flat molding block, and this molding block is integrated with this one molding block. The other shaft body joining surface that joins approximately half of the outer surface of the shaft body from the fourth dividing line to the first dividing line, and the lower surface of the spiral from the fourth dividing line to the first dividing line The other half of the spiral forming surface for forming the above-mentioned and the half of the side surface of the spiral from the fourth dividing line to the first dividing line. The other split side molding surface having a shape, and the other molding block having a flat lower surface, and the fourth split mold from the fourth dividing line to the first dividing line. One spiral forming surface for forming the upper surface of the spiral, one spiral side forming surface for forming substantially half of the side surface of the spiral from the fourth dividing line to the first dividing line, and the fourth dividing Line and the first parting line, one shaft body joint surface that is joined to substantially half of the outer surface of the shaft body, and the upper surface is a flat molding block, and the one molding block And the other shaft body joining surface that is joined to approximately half of the outer surface of the shaft body from the first dividing line to the second dividing line, and from the first dividing line to the second dividing line. The other spiral forming surface that forms the lower surface of the spiral up to the line, and from the first dividing line to the second dividing line Spiral mold, characterized in that the lower surface becomes comprise the other helical side molding surface for molding the substantially half of the side surface of the spiral, a is the provided with the other mold blocks formed by a plane, comprising Te.