JP2003245948A - Valve gate type mold assembly and molding method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve gate type mold assembly excellent in the filling properties of a product cavity with a molding compound. <P>SOLUTION: A valve casing 25 having a material passage 34 formed therein is incorporated in a fixed mold and a valve pin 30 for opening and closing a gate 20 is provided in the valve casing 25. The material passage 34 in the valve casing 25 is spirally formed. Since the material passage 34 in the valve casing 25 is spirally formed, a rotary flow in a spiral direction is generated in the molten resin passed through the spiral material passage 34. Since the product cavity is filled with the molten resin accompanying the rotary flow from the gate 20, the product cavity can be smoothly filled with the molten resin at a high speed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve gate mold apparatus used for injection molding of thermoplastic resin and a molding method using the same.

[0002]

In a hot runner die apparatus for heating a resin, which is a molding material in a material passage to a gate to a product cavity, to constantly keep a molten state,
2. Description of the Related Art A valve gate type mold device is known in which a gate is mechanically opened and closed by a valve pin which is a valve body. The hot runner mold device is intended to increase the molding efficiency, and the gate is closed to prevent the resin from leaking from the gate when the mold is opened.

Here, a conventional valve gate type mold device will be described. The fixed mold and the movable mold, which are mold bodies, move to each other to open and close, and when the mold is closed, a product cavity having a product shape is formed between them. The fixed mold includes a fixed-side mold plate and a fixed-side receiving plate, and a gate that opens to the product cavity is formed in the fixed-side mold plate. A valve casing of the valve device is incorporated in the mounting holes formed through the fixed-side receiving plate and the fixed-side template. The valve casing has a substantially cylindrical shape, and a material passage communicating with the gate is formed in the center of the valve casing. On the outer peripheral surface of the valve casing, there are provided a coil heater which is a means for keeping the thermoplastic resin, which is the molding material in the material passage, always in a molten state, and a heater cover which covers the coil heater from the outside. A liner, which is a material passage of a manifold, is connected to the material passage of the valve casing,
The molding material is sent to this runner from the injection molding machine. A valve pin that opens and closes the gate of the gate bush by moving while being supported by a guide bush by being driven by a hydraulic cylinder or the like is provided in the valve casing. The valve pin fits into the gate of the gate bush to close it. Then, at the time of molding, a plurality of mold bodies are closed to form a product cavity between these mold bodies, a gate is opened, and a molding material is filled in the product cavity from the material passageway through the gate. Then, the gate of the gate bush is closed by the valve pin, and after the molding material in the product cavity is solidified, the mold is opened to take out the molding material in the product cavity, that is, the molded product. After that, the mold is closed again and the above molding cycle is repeated.
The molding material in the material passage of the valve body is always kept in a molten state by the heating of the heating means.

In such a valve gate type mold apparatus, it is necessary to fill a molding material at a high speed in order to mold a thin product, but in the conventional one, a material passage is formed in the center of the valve casing. Since the valve pin moves back and forth in the material passage to open and close the gate, the valve pin becomes a resistance to the flow of the molding material. Then, for example, in injection molding of a thin lens or case having a thickness of 0.3 mm or less, the molding material filled in the product cavity needs to be filled at a high speed up to a position away from the gate.

The present invention is intended to solve such a problem and reduces resistance to the flow of the molding material in the material passage in the valve casing, and is excellent in the filling property of the molding material in the product cavity. An object is to provide a valve gate type mold device and a molding method using the same.

[0006]

In order to achieve the above object, a valve gate type mold apparatus according to a first aspect of the present invention includes a plurality of mold bodies which are opened and closed to form a product cavity between them when the mold is closed. A valve casing provided in a mold body having a gate opening to a product cavity among these mold bodies, the valve device being incorporated in the mold body and having a material passage formed therein; In a valve gate type mold device having a valve pin provided inside a valve casing for opening and closing the gate, the material passage is formed in a spiral shape.

At the time of molding, a plurality of mold bodies are closed to form a product cavity between these mold bodies and a gate is opened to fill the molding material into the product cavity. On this occasion,
The molding material flows from the gate through the material passages in the valve casing into the product cavity. Further, since the material passage in the valve casing is formed in a spiral shape, a rotating flow in a spiral direction is generated in the molding material that has passed through the spiral material passage, and the molding material accompanied with this rotating flow is filled from the gate. Therefore, the molding material can be smoothly filled into the product cavity at high speed. Then, the gate is closed by the valve pin, and after the molding material in the product cavity is solidified, the mold is opened to take out the molding material in the product cavity, that is, the molded product. Then, the mold is closed again and the above molding cycle is repeated.

According to a second aspect of the present invention, in the valve gate mold apparatus according to the first aspect of the present invention, the material passage is formed at a position apart from the valve pin.

Since the molding material flows away from the valve pin, the resin flow does not receive resistance from the valve pin.

According to a third aspect of the present invention, in the valve gate mold apparatus according to the second aspect of the present invention, a valve pin insertion hole for inserting the valve pin is formed in the valve casing,
The material passage is formed around the valve pin through hole.

As a result, the molding material flows through the material passage formed around the valve pin insertion hole, so that the flow of the molding material does not receive resistance from the valve pin. Further, by disposing the material passage around the insertion hole, it is possible to suppress the valve casing from expanding in the radial direction, and to make the valve casing compact.

According to a fourth aspect of the present invention, in the valve gate mold apparatus according to the third aspect of the invention, a nest having the valve pin insertion hole is formed in the valve casing, and a mounting hole for mounting the nest is formed. It is provided in the valve casing, and the material passage is provided between the insert and the mounting hole.

By processing the outer periphery of the insert or the mounting hole,
By mounting the nest in the mounting hole, the spiral material passage can be easily formed.

Furthermore, the invention of claim 5 is the same as that of claim 4.
In the valve gate mold apparatus according to the invention, the material passage is formed by a groove formed on the outer periphery of the insert.

A spiral material passage can be easily formed by forming a spiral groove on the outer periphery of the insert and closing the groove with a mounting hole.

Furthermore, the invention of claim 6 is the valve gate mold apparatus of the invention of claim 5, wherein the insert is diffusion-bonded to the mounting hole.

As a result, the outer periphery of the insert and the mounting hole can be tightly joined to each other, and the material passage provided between them can be excellent in liquid tightness.

In order to achieve the above object, the molding method according to claim 7 closes a plurality of molds which are opened and closed to each other to form a product cavity between the molds, and a material provided in the molds. In a molding method, a molding material is filled from a passage through a gate opened to the product cavity into the product cavity, and the gate is closed by a valve pin of a valve device except when the molding material is filled into the product cavity. Is passed through a spiral material passage communicating with the gate to fill the product cavity with a rotating flow.

Since the molding material is filled in the product cavity with a rotating flow, the molding material can be smoothly filled into the product cavity at high speed.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the valve gate mold apparatus of the present invention will be described below with reference to FIGS. First, the configuration of the injection molding die device will be described. Reference numeral 1 is a fixed mold as a first mold body, 2 is a movable mold as a second mold body, and these fixed mold 1 and movable mold 2 are moved in the vertical direction (mold opening / closing direction) in the drawing to open and close each other. , The product cavities 3 having a product shape are formed between them when the mold is closed.

The fixed mold 1 has a fixed side mold plate 6 forming a product cavity 3, a fixed side receiving plate 7 fixed to the back side of the fixed side mold plate 6 (the side opposite to the movable mold 2), and A fixed side mounting plate (not shown) fixed via a spacer block is provided on the back side of the fixed side receiving plate 7. This fixed-side mounting plate is attached to the fixed-side platen of the injection molding machine. And, in the fixed side mounting plate,
A locate ring and a sprue bush to which a nozzle of a heating cylinder device which is a molding material supply device of an injection molding machine is connected are fixed. The inside of this sprue bush is a sprue which is a material passage. Also,
The sprue bush is provided with a heater that is a heating unit that heats the sprue to constantly keep the thermoplastic resin, which is the molding material, in the sprue in a molten state. In addition, the manifold 8 is provided between the fixed-side receiving plate 7 and the fixed-side mounting plate.
Is provided.

Then, inside the manifold 8,
A runner 9 which is a material passage for branching the sprue into each product cavity 3 is formed. Further, the manifold 8 is provided with a heater 10 which is a heating means for heating the runner 9 and keeping the thermoplastic resin therein always in a molten state.

A direct gate 20 is formed on the fixed mold 1, and the direct gate 20 is formed on the fixed mold plate 6. Further, the fixed mold 1 is incorporated with a valve device 21 which is a gate opening / closing means for opening / closing the direct gate 20.

Next, the structure of the valve device 21 will be described. The fixed side receiving plate 7 constituting the main body of the fixed mold 1 is formed with a built-in hole 22 penetrating in the mold opening / closing direction, and further, inside the fixed side mold plate 6 as the main body, An assembling hole 23 communicating with the assembling hole 22 is formed, and the gate 20 is provided at the tip of the assembling hole 23 so as to communicate with the product cavity 3. Then, a substantially cylindrical valve casing 25 is incorporated in the assembling holes 22 and 23. The valve casing 25 includes a flange portion, which is a large-diameter portion, on the side opposite to the gate 20 of a main body portion 26, which is a small-diameter portion.
27 is integrally formed and is fixed to the manifold 8 and the fixed side receiving plate 7. The outer peripheral surfaces of the main body portion 26 and the flange portion 27 have a cylindrical surface shape. Further, the tip end portion 28 of the valve casing 25 on the gate 20 side has a tapered tapered shape.

Further, a valve pin insertion hole 31 in the mold opening / closing direction is formed through the center of the valve casing 25, and a substantially columnar valve pin 32 is slidably supported in the valve pin through hole 31. Moves in the mold opening / closing direction by driving a driving device (not shown) such as a hydraulic cylinder device to open / close the gate 20. The valve pin 32 has a gate closing portion 33 formed as a straight portion at the tip end thereof, which is removably fitted into the gate 20 to form the gate.
20 is to be closed. The valve pin 32 has the mold opening / closing direction as the axial direction.

Inside the valve casing 25, a spiral material passage 34 is formed around the valve pin insertion hole 31 at a position apart from the valve pin 32, and the material passage 34 is formed in the flange portion 27. The anti-gate side surface 35 has an inlet portion 36, and the runner 9 is connected to the inlet portion 36. The inlet portion 36 is formed to have a larger cross-sectional area than the other portions of the material passage 34, and a linear portion 37 is formed from the inlet portion 36 toward the gate side, and the diameter of the linear portion 37 on the gate side is small. A tapered portion 38 is provided. As shown in FIGS. 3 and 5, the material passage 34 has a spiral portion 39 that spirally rotates about the insertion hole 31 from the gate side end of the tapered portion 38 toward the gate side by approximately 135 degrees. Then, the gate side of the spiral portion 39 and the opening end portion 31A of the valve pin insertion hole 31 are connected to each other through the material passage.
They are connected by 34 oblique portions 40. The slanted portion 40 is slanted with respect to the valve pin insertion hole 31, is located on the same plane including the insertion hole 31, and has a tapered cross-sectional area slightly reduced toward the opening end 31A. ing.

A coil heater 41 which is a heating means for heating the material passage 34 and a substantially cylindrical heater cover 42 which covers the heater 41 from the outside are fitted on the outer peripheral surface of the main body portion 26 of the valve casing 25. There is.

A fixing ring 43 is provided on the outer peripheral surface of the gate-side end of the valve casing 41.
By fitting 43 into the cylindrical fitting hole 23A of the assembling hole 23, the gate side of the valve casing 41 is fixedly supported and fixed to the fixed side plate 6 which is a mold, while the flange of the valve casing 25 is provided. A built-in hole fitting portion 44 is provided on the tip side of the portion 27, and the outer peripheral surface of the built-in hole fitting portion 44 is fitted into the large-diameter fitting receiving portion 22A formed in the built-in hole 22 and having a substantially cylindrical shape. is doing. As a result, the gate side of the flange portion 27 of the valve casing 25 is supported and fixed to the fixed side receiving plate 7 which is a mold in a positioned state.

Next, a method of manufacturing the valve casing 25 will be described. The center of the valve casing 25 is formed in a nest 51, and the center of the nest 51 is the opening end portion.
The valve pin insertion hole 31 is formed except for 31A, and as shown in FIG. 5 etc., the insert 51 has a cylindrical outer peripheral surface 52, and a substantially conical tip surface 53 is formed on the gate side. ing. Further, the valve casing 25 is formed with a mounting hole 54 for mounting the insert 51 from the side opposite to the gate. The mounting hole 54 has a shape corresponding to the outer circumference of the insert 51, and is formed on the outer peripheral surface 52 and the tip surface 53. Correspondingly, it has an inner peripheral surface 55 and a substantially conical tip receiving surface 56.

A groove 134 for forming the material passage 34 is formed on the outer periphery of the insert 51, and the groove 134 corresponds to the straight line portion 37, the spiral portion 39 and the oblique portion 40. 13
7. The spiral forming part 139 and the oblique forming part 140 are provided. The forming parts 137, 139, 140 have substantially the same cross section and are formed in an arcuate groove having the center S at the same depth position from the outer surface. ing. In addition, a straight line forming portion 137A and a taper forming portion 138 are formed on the inner peripheral surface 55 of the mounting hole 54 corresponding to the straight line forming portion 137, and the inlet straight line portion formed by combining the straight line forming portions 137 and 137A. 37 has a circular cross section.

Then, the nest 51 inserted into the mounting hole 54.
Are fixed by brazing or diffusion bonding. Further, when diffusion bonding is used, as shown in FIG. 6, bonding grooves 61 and 61A are provided on both sides in the width direction of the groove 134 over the entire length of the groove 134. At the time of fixing by this diffusion bonding, the diffusion bonding is performed through a contact process between bonding interfaces, a process in which adhesion of the contact surface progresses with time, and a process in which the bonding boundary disappears. In the process, due to slip deformation due to pressure, destruction of the surface coating, migration, in the next process vacancy diffusion, boundary diffusion, that is, a process in which adhesion progresses due to the movement of dislocations, and in the next process recrystallization and crystal growth, etc. Is involved in the formation of a new crystal structure, the decomposition or dissolution of the coating film, inclusions, etc. existing at the bonding boundary, and almost complete bonding is achieved. Specifically, in diffusion welding using a solvent, a solvent made of a nickel alloy, such as BNi, is used, and the solvent is heated and melted, and the materials are joined together by capillary action, that is, the outer periphery of the insert 51 and the mounting. Hole
Infiltrate 54. For this reason, after the solvent is previously put into the grooves 61 and 61A, the insert 51 is inserted into the mounting hole 54, and then the solvent is heated and melted to perform diffusion bonding,
Both sides of the material passage 34 can be joined liquid-tightly. Then, in the diffusion bonding, the material structure is transformed in the bonded portion and firmly bonded, and the material leakage in the material passage 34 can be completely prevented.

Next, the operation of the above configuration will be described. First, the fixed mold 1 and the movable mold 2 are closed, a product cavity 3 is formed between the fixed mold 1 and the movable mold 2, and then the valve pin 41 is moved away from the movable mold 2 to open the gate 20. To do. Then, a molten thermoplastic resin, which is a thermoplastic molding material, is injected into the fixed mold 1 from the injection molding machine. This resin passes through the runner 9 of the manifold 8 and the like, and further passes through the spiral material passage 34 from the inlet portion 36 and the open end portion 31 of the tip end portion of the valve casing 25.
It flows into the product cavity 3 from A and the gate 20. In this case, a rotational flow in the spiral direction is generated in the molten resin passing through the spiral material passage 34, and the molten resin accompanied by this rotational flow is filled from the gate 20. Can be filled smoothly. Further, the spiral portion 39 causes the flow of the rotational component in the flow of the molten resin, and then the linear inclined portion 40 is passed through, whereby high-speed and high-speed injection molding can be performed. After the molten resin is filled in the product cavity 3 in this way,
After holding the pressure, the valve pin 32 moves toward the movable mold 2 and fits into the gate 20 to close the gate 20. Then, after the resin in the product cavity 3 is cooled and solidified, the fixed mold 1
The movable mold 2 is opened, and the resin in the product cavity 3, that is, the molded product is taken out. Then, the mold is closed again and the above molding cycle is repeated.

As described above, in this embodiment, in accordance with claim 1, the fixed mold 1 and the movable mold 2, which are a plurality of mold bodies that open and close each other to form the product cavity 3 between the mold cavities when the molds are closed,
Gate 20 of these molds that opens to product cavity 3
And a valve device 21 provided in the fixed mold 1 as a mold body, which is incorporated in the fixed mold 1 as the mold body and has a material passage 34 formed therein, and a valve casing 25. In a valve gate type mold device having a valve pin 32 provided inside 25 for opening and closing the gate 20, since the material passage 34 is formed in a spiral shape, the fixed mold 1 and the movable mold 2 are closed during molding. Then, the product cavity 3 is formed between the fixed mold 1 and the movable mold 2, the gate 20 is opened, and the product cavity 3 is filled with the molten resin. At this time, the molten resin flows from the gate 20 into the product cavity 3 through the material passage 34 in the valve casing 25. Further, since the material passage 34 in the valve casing 25 is formed in a spiral shape, a rotating flow in a spiral direction is generated in the molten resin that has passed through the spiral material passage 34, and the molten resin accompanied by this rotating flow is gated. Since the resin is filled from 20, the molten resin can be smoothly filled into the product cavity 3 at high speed. Therefore, it is particularly suitable for molding a substantially circular product such as a thin lens.

As described above, in this embodiment, the material passage 34 is provided at a position apart from the valve pin 32 according to the second aspect.
Since the molten resin flows away from the valve pin 32, the resin flow does not receive resistance from the valve pin 32, and high-pressure high-speed filling is possible.

As described above, according to the third embodiment, the valve pin insertion hole 31 for inserting the valve pin 32 is formed in the valve casing 25, and the material passage 34 is formed around the valve pin through hole 31. Since it is formed, the molten resin is formed in the material passage around the valve pin insertion hole 31.
The flow of molten resin does not receive resistance from the valve pin 32 because it flows through 34. Further, by disposing the material passage 34 around the insertion hole 31, it is possible to suppress the valve casing 25 from expanding in the radial direction and to make the valve casing 25 compact.

Further, in this embodiment, as described above, according to the fourth aspect, the insert 51 having the valve pin insertion hole 31 is formed in the valve casing 25, and the attachment hole 54 for installing the insert 51 is formed in the valve casing. 25, and the material passage 34 is provided between the insert 51 and the mounting hole 54. Therefore, the outer periphery of the insert 51 or the mounting hole 54 is processed to insert the insert 51 into the mounting hole 54.
The spiral material passage 34 can be easily formed by mounting.

Furthermore, as described above, in this embodiment,
Corresponding to claim 5, the groove 134 formed on the outer periphery of the insert 51.
Since the material passage 34 is formed by the method, the groove 134 is spirally formed on the outer periphery of the nest 51, and the groove 134 is closed by the mounting hole 54, whereby the spiral material passage 34 can be easily formed.

Moreover, in this embodiment, as described above, since the insert 51 is diffusion-bonded to the mounting hole 54 in accordance with claim 6, the outer periphery of the insert 51 and the mounting hole 54 can be closely bonded. The material passage 34 provided between the two has excellent liquid tightness.

As described above, in this embodiment, according to claim 7, a fixed mold 1 and a movable mold 2, which are a plurality of mold bodies that are opened and closed with each other, are closed to form a product between the fixed mold 1 and the movable mold 2. The gate 20 that forms the cavity 3 and is opened to the product cavity 3 from the material passage 34 provided in the fixed mold 1 that is the mold body.
Fill the molding material into the product cavity 3 through the gate, and except when filling the molding material into the product cavity 3.
In the molding method in which 20 is closed by the valve pin 32 of the valve device 21, the molding material is passed through the spiral material passage 34 communicating with the gate 20 to fill the product cavity 3 with a rotating flow. Since the flow of the molding material filled in is uniform, the molding material can be smoothly filled into the product cavity 3 at high speed.

Further, as an effect of the embodiment, the linear portion 37
Since the cross-sectional area of each is formed larger than the others, the connection with the runner 9 is easy and reliable, and by providing the taper portion 38, the molten resin of the straight portion 37 can be smoothly spiraled.
Flows into. Moreover, since the cross-sectional area of the obliquely installed portion 40 is tapered slightly toward the opening end 31A, the flow of the molten resin is restricted, and the opening end 31A formed in the mold opening / closing direction further reduces the mold. It flows in the opening / closing direction and is filled into the product cavity 3 through the gate 20.

The present invention is not limited to the above embodiment, and various modifications can be made. For example,
In the embodiment, the spiral portion has a structure in which it spirally rotates about 135 degrees around the insertion hole, but the angle is 1
The spiral shape may be less than 35 degrees or more than 135 degrees. Further, it is not necessary to provide the joining groove on both sides of the material passage, and the pressure of the molding material is large on the gate side with respect to the spiral portion in the material passage. Only the groove 61 for use may be provided for diffusion welding. Further, a groove serving as a material passage may be formed on the inner surface of the mounting hole.

[0042]

According to the first aspect of the present invention, since the material passage is formed in a spiral shape, it is possible to provide a valve gate type mold device excellent in filling the molding material with the molding material.

According to the invention of claim 2, in addition to the effect of claim 1, since the material passage is formed at a position separated from the valve pin, the flow of resin does not receive resistance from the valve pin. .

According to the invention of claim 3, in addition to the effect of claim 2, a valve pin insertion hole for inserting the valve pin is formed in the valve casing, and the material passage is formed around the valve pin through hole. Because it is
Molding material flow does not experience resistance from the valve pin. Further, by disposing the material passage around the insertion hole, it is possible to suppress the valve casing from expanding in the radial direction, and to make the valve casing compact.

Furthermore, in addition to the effect of claim 3, the invention of claim 4 forms a nest having the valve pin insertion hole in the valve casing, and provides a mounting hole for mounting the nest in the valve casing. Since the material passage is provided between the insert and the mounting hole, the spiral material passage can be easily formed by processing the outer periphery of the insert or the mounting hole and mounting the insert in the mounting hole. Can be formed.

The invention of claim 5 is the same as that of claim 4.
In addition to the effect of the above, since the material passage is formed by the groove formed on the outer circumference of the nest, the spiral groove is formed on the outer circumference of the nest, and the groove is closed by the mounting hole to form a spiral shape. The material passage can be easily formed.

Moreover, in addition to the effect of claim 5, the invention of claim 6 is one in which the insert is diffusion-bonded to the mounting hole, so that the outer periphery of the insert and the mounting hole can be closely bonded. Therefore, the material passage provided between the two has excellent liquid-tightness.

According to a seventh aspect of the present invention, a molding material is passed through a spiral material passage communicating with the gate so as to fill the product cavity with a rotating flow.

Since the molding material is filled in the product cavity with a rotating flow, the molding material can be smoothly filled into the product cavity at high speed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a valve gate mold apparatus of the present invention.

FIG. 2 is a plan view of the valve device.

FIG. 3 is a sectional view of an essential part of the valve device, showing a spiral section in the longitudinal direction.

FIG. 4 is a plan sectional view of a main part of the valve device.

FIG. 5 is a front view of the nest of the same.

FIG. 6 is a front view of the insert having the joining groove formed therein.

[Explanation of symbols]

1 fixed type 2 movable 3 product cavity 20 gates 21 valve device 25 valve casing 31 Valve pin insertion hole 32 valve pin 34 Material passage 51 Nesting 54 mounting hole 134 groove

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Ueno             3-1-1 Koganecho, Niigata City, Niigata Prefecture Mitsubishi             Niigata Works, Material Co., Ltd. F-term (reference) 4F202 CA11 CB01 CK02 CK07

Claims (7)

[Claims] 1. A plurality of mold bodies that are opened and closed to form product cavities between them when the molds are closed, and a valve device provided on the mold body having a gate opening to the product cavity among these mold bodies, This valve device is a valve gate type mold device having a valve casing incorporated in the mold and having a material passage formed therein, and a valve pin provided inside the valve casing for opening and closing the gate. A valve gate type mold device, wherein the passage is formed in a spiral shape. 2. The valve gate mold apparatus according to claim 1, wherein the material passage is formed at a position apart from the valve pin. 3. The valve gate type gold according to claim 2, wherein a valve pin insertion hole for inserting the valve pin is formed in the valve casing, and the material passage is formed around the valve pin through hole. Mold device. 4. A nest having the valve pin insertion hole is formed in the valve casing, a mounting hole for mounting the nest is provided in the valve casing, and the material passage is provided between the nest and the mounting hole. The valve gate mold apparatus according to claim 3, wherein the mold apparatus is a valve gate mold apparatus. 5. The valve gate mold apparatus according to claim 4, wherein the material passage is formed by a groove formed on the outer periphery of the insert. 6. The valve gate mold apparatus according to claim 4, wherein the insert is diffusion-bonded to the mounting hole. 7. A product cavity is formed by closing a plurality of mold bodies that are opened and closed with each other, and a product cavity is formed between these mold bodies, and the product cavity is passed from a material passage provided in the mold body through a gate opened to the product cavity. In a molding method in which the molding material is filled in and the gate is closed by a valve pin of a valve device except when the molding material is filled in the product cavity, the molding material is passed through a spiral material passage communicating with the gate. A molding method using a valve gate type mold device, which is characterized in that the product cavity is filled with a rotating flow.