JP2003071873A - Valve gate type mold assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the corrosion resistance of a valve casing. SOLUTION: The valve casing 16 has a support blade 19 for supporting a valve pin 36 in a freely slidable manner and a valve pin support hole 38. The valve casing 16 is formed from a super-corrosion-resistant material. Cores 61 and 71 provided with the support blade 19 and the valve pin support hole 38 are provided so as to be detachable from the valve casing 16. Since the valve casing 16 comprises the super-corrosion-resistant material, it can correspond to a highly corrosion-resistant fluororesin or the like. In the case of abrasion due to the slide with the valve pin, repairing can be performed only by replacing the abraded support blade 19 and the cores 61 and 71 of the valve pin support hole 38.

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, and is used for injection molding of a thermoplastic resin that corrodes a metal material such as a fluororesin.

[0002]

A hot runner mold apparatus used for injection molding of a thermoplastic resin always heats and melts the resin in the material passage to the gate to the product cavity in order to improve the molding efficiency. It keeps you in a state.
On the other hand, since the resin in the product cavity to be the product must be cooled and solidified, in the hot runner mold apparatus, it is necessary to open and close the gate by some means. As a method for opening and closing the gate, there is a valve gate method in which the gate is mechanically opened and closed by a valve pin.

In the valve gate type mold device, as described in, for example, Japanese Patent Application Laid-Open No. 2001-328859, a plurality of mold bodies that open and close each other to form a product cavity when the mold is closed, and these mold bodies. A valve casing provided in a mold body having a gate opening to a product cavity, a heater provided in the valve casing, and a valve pin provided inside the valve casing for opening and closing the gate, A plurality of support blades extending in the axial direction of the valve pin and slidably contacting the outer peripheral surface of the valve pin are radially formed on the inner peripheral surface of the material passage at the tip end on the gate side of the valve casing, and these support blades are also formed. A dividing material passage portion having a width larger than that of the supporting blade is formed between the dividing blade and the dividing material passage portion having a width larger than that of the supporting blade. It is formed and has said material passage of the gate side is formed in a cylindrical shape than the support vane.

The valve pin is supported by a guide bush fixed in the valve casing at the end of the valve casing on the manifold side, and the valve pin slidably penetrates through the guide bush.

In this type of valve casing, a high-temperature and high-pressure molten resin flows through the internal material passage, and the valve pin is reliably opened and closed at the gate. Therefore, the valve casing and the valve pin have predetermined strength and wear resistance. And are required. By the way, if a material that is highly corrosive to metal materials such as fluororesins is used, in conventional devices,
There is a problem that members such as the valve casing and the valve pin are remarkably corroded, the service life becomes relatively short, and the members need to be replaced.

The present invention is intended to solve the above problems, and an object thereof is to provide a valve gate type mold apparatus capable of enhancing the corrosion resistance of the valve casing, and in addition, maintenance and inspection are easy. An object of the present invention is to provide a new valve gate type mold device.

[0007]

According to a first aspect of the present invention, there is provided a valve gate type mold apparatus, wherein a plurality of mold bodies are formed to open and close each other to form product cavities between them when the molds are closed. A valve device provided in a mold body having an opening gate, the valve device being incorporated in the mold body and having a material passage formed therein, and the gate device provided in the valve casing. In a valve gate type mold device having a valve pin for opening and closing the valve and a valve pin support portion provided on the valve casing for slidably supporting the valve pin, the valve casing is made of a super-corrosion resistant material.

In molding, after closing a plurality of molds, the valve pin is moved to open the gate. In this state, the molding material is injected from the molding machine. The molding compound is filled from the gate into the product cavity through the material passage in the valve casing. Thereafter, the valve pin moves to fit the gate and the gate is closed. Further, after the molding material in the product cavity, that is, the product is solidified, the mold body is opened to take out the molded product. Meanwhile, the molding material in the material passage of the valve casing is always kept in a molten state by the heating of the heater.

Even if a highly corrosive material such as a fluororesin is used as the molding material, the valve casing is made of a super-corrosion resistant material, so that the occurrence of corrosion can be prevented.

According to a second aspect of the invention, in the valve gate mold apparatus according to the first aspect of the invention, the super-corrosion resistant material is a super-corrosion resistant Ni-based alloy.

By using the super-corrosion resistant Ni-based alloy, the valve casing has excellent corrosion resistance and high wear resistance as compared with other alloys having corrosion resistance.

According to a third aspect of the invention, in the valve gate mold apparatus according to the first or second aspect of the invention, the valve pin support portion is provided in the valve casing in a replaceable manner.

If the valve casing is made of a super-corrosion resistant material,
Generally, abrasion resistance is lower than that of conventional materials. On the other hand, it is preferable to use the valve pin having conventional strength and abrasion resistance for opening and closing the gate. If this is done, the valve pin, which has high wear resistance, will slide on the valve support, causing the valve support to wear mainly and the valve casing to be repaired and replaced.However, replace only the worn valve pin support. Just repair it and you can continue to use it.

According to a fourth aspect of the present invention, in the valve gate mold apparatus according to the third aspect of the present invention, the valve pin support portions are provided at both ends in the length direction of the valve casing, and the valve pin support portions are provided. The insert is provided so as to be detachable from the valve casing in the longitudinal direction of the valve casing.

Since the insert provided with the valve pin support can be attached and detached in the length direction of the valve pin, the valve pin support is also processed in the length direction of the valve casing, which is easy to manufacture, and the valve pin support is easily manufactured. It is possible to easily remove and insert the nest.

According to a fifth aspect of the present invention, in the valve gate mold apparatus according to the fourth aspect, a material passage is formed in a nest of the valve pin support portion on the side opposite to the gate.

Since the material passage is provided in the nest of the valve pin support portion, the structure and assembly are simpler than the case where the material passage is formed between the material and the built-in portion.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a valve gate type mold apparatus of the present invention will be described below with reference to the drawings. 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 move in the vertical direction (mold opening / closing direction) in FIG. The product cavities 3 having a product shape are formed between them when they are opened and closed and the mold is closed.

The fixed mold 1 has first and second fixed mold plates 5 and 6 which are main bodies forming the product cavity 3 and a back side of the fixed mold plate 6 (opposite to the movable mold 2). The fixed-side receiving plate 7 is fixed, and a fixed-side mounting plate (not shown) fixed to the back side of the fixed-side receiving plate 7 via a spacer block is provided. A manifold 8 is provided between the receiving plate 7 and the receiving plate 7. The manifold 8 has a runner 9 which is a material passage formed therein, and the thermoplastic resin which is a molding material in the runner 9 is always kept in a molten state by heating a heater (not shown) provided in the manifold 8. It is designed to be drunk. A direct gate 10 is formed on the fixed-side template 6.

Further, the fixed mold 1 is incorporated with a valve device 11 which is a gate opening / closing means for opening / closing the direct gate 10. Next, the configuration of the valve device 11 will be described. The fixed-side mold plate 6 that constitutes the main body of the fixed mold 1.
Has a built-in hole 12 penetrating in the mold opening / closing direction, and further, a built-in hole 13 communicating with the built-in hole 12 is formed inside the fixed-side mold plate 5 as a main body. The gate 10 is provided at the tip of the hole 13 so as to communicate with the product cavity 3. Then, a substantially cylindrical valve casing 16 is incorporated in the assembling holes 12, 13. A flange portion 17 is formed at one end of the valve casing 16 and is fixed to the manifold 8 and the stationary mold plate 6.

Further, the inside of the valve casing 16 is a material passage 18 for communicating the runner 9 in the manifold 8 with the gate 10. The material passage 18 has a linear portion 18A having a substantially cylindrical shape whose axial direction is the mold opening / closing direction, and an inlet portion 18B obliquely provided from an end portion of the linear portion 18A opposite to the gate 10. The inlet 18B communicates with the runner 9.

Further, the material passage of the valve casing 16
At the inner peripheral surface of the tip portion 16S of the gate 18 on the gate 10 side,
Three support blades 19 are integrally formed as a valve pin support portion extending in the mold opening / closing direction at intervals from 10. As shown in FIG. 3, the supporting blades 19 are formed by the material passages.
It is located radially 120 degrees apart from the central axis of 18. The inner edge of the support blade 19 has a convex arc-shaped curved portion 20 at a portion opposite to the gate 10 (upper portion in FIG. 1).
It has become. The curved portion 20 of the support blade 19 is for reducing the resistance to the flow of resin, which is a molding material. The groove-shaped portion between the support blades 19 serves as the dividing material passage portion 21. These divided material passage portions 21 form three divided passages because there are three support blades 19. The supporting blade 19 is relatively thin,
The width of the divided material passage portion 21 is significantly larger than the width of 19. The support blade 19 is formed near the tip of the valve casing 16, and the inner peripheral surface of the valve casing 16 is a columnar portion 22. From the columnar portion 22 toward the center of the valve casing 16, Support blade
19 are integrally formed. The valve casing 16 integrally including the supporting blades 19 can be manufactured by, for example, electric discharge machining.

The valve casing 16 incorporates a valve pin 36 as a valve body that opens and closes the gate 10 by moving in the mold opening and closing direction by driving a driving device such as a hydraulic cylinder provided on the fixed side mounting plate. ing.
The valve pin 36 closes the gate 10 by a gate closing portion 37 formed at the tip end on the gate 10 side being removably fitted into the gate 10. Further, the valve pin 36 has the mold opening / closing direction as an axial direction, and the outer peripheral surface is always slidably in contact with the inner edge of the support blade 19 of the valve casing 16. As a result, the tip of the valve pin 36 on the gate 10 side is supported. Further, the valve pin 36 is supported at the end of the valve casing 16 on the manifold 8 side by a valve pin support hole 38 provided as a valve pin support portion in the valve casing 16. That is, the valve pin 36 slidably penetrates through the valve pin support hole 38. The base end side of the valve pin 36 is connected to a vertically moving piston of a hydraulic cylinder device (not shown). The valve pin 36 can be inserted into and removed from the valve casing 16 in the longitudinal direction thereof. Specifically, in FIG. 1, the valve pin 36 is formed to be removable from the valve casing 16 upward.

Further, a band heater 41 for heating the material passage 18 and a substantially cylindrical heater cover 42 for covering the heater 41 from the outside are fitted to the center and the outer peripheral surface on the tip side of the valve casing 16. Further, a band heater 43 for heating the material passage 18 and a substantially cylindrical heater cover 44 that covers the heater 43 from the outside are fitted to the outer peripheral surface of the flange portion 17. A temperature sensor 45 such as a thermocouple is provided inside the heater 41 along with the flange portion 17, and a temperature sensor 46 such as a thermocouple along the valve casing 16 is provided inside the heater 43. It is provided.

An assembling hole fitting portion 51 is provided on the tip side of the valve casing 16, and an outer peripheral surface of the assembling hole fitting portion 51 is a cylindrical surface-shaped fitting surface formed in the assembling hole 13 and having the same diameter. It is fitted with 52. This allows the valve casing
16 is supported by the fixed-side template 5.

A flat portion 53 is provided at the tip of the fitting portion 51, and a tip portion 16S of the valve casing 16 is projected from the center of the flat portion 53. For heat insulation, gaps 54 and 55 are formed between the inner surfaces of the assembling holes 12 and 13 and the outer surfaces of the valve casing 16 and the heater cover 42.

In the valve gate type mold apparatus having the valve casing 16 as described above, in the present invention, the valve casing 16 is made of a super-corrosion resistant material. As this super-corrosion resistant material, a super-corrosion resistant Ni-based alloy is used, and as a suitable example of this super-corrosion resistant Ni-based alloy, blast hard (manufactured by Mitsubishi Materials Corporation) is cited. This blast hard contains Cr: 14-23%, Mo: 14- by weight%.
20%, W: 0.2-5%, Fe: 0.2-7%, Co: 0.2-
It has a composition containing 2.5% and the balance of Ni and inevitable impurities, and has Rockwell hardness (C scale): 30 to
It is composed of a Ni-based alloy having 60, and as an example of a manufacturing method using blast hard, in% by weight, C
r: 14-23%, Mo: 14-20%, W: 0.2-5%, F
e: 0.2 to 7%, Co: 0.2 to 2.5%, the balance being N
After forming a slab or billet by hot forging from a Ni-based alloy ingot having a composition of i and unavoidable impurities, hot rolled, hot forged, or hot extruded into a plate, a bar, or a tube, Then on these materials
After solution heat treatment at a temperature within the range of 1100 to 1200 ℃, cold work at a processing rate of 20 to 60% and finally 500
An age hardening treatment is performed at a temperature in the range of up to 800 ° C. to give a Rockwell hardness (C scale) of 30 to 60.

Another example of the super-corrosion resistant Ni-based alloy used in the present invention is C0.02 to 0.12% and Co5 to 5% by weight.
12%, Cr 7-9%, W 10-14%, Al 4.5-5.5%, T
i 0.1-1.5%, Ta 3-5%, Hf 0.3-1.3%, B0.00
5 to 0.018%, Zr 0.01 to 0.15%, the balance is a Ni-based alloy consisting essentially of Ni. As an example of the method for producing this Ni alloy, C0.02 to 0.12% by weight%, Co5
12%, Cr 7-9%, W 10-14%, Al 4.5-5.5%, T
i 0.1-1.5%, Ta 3-5%, Hf 0.3-1.3%, B0.00
A Ni-based alloy powder containing 5 to 0.018% and Zr 0.01 to 0.15%, and the balance being substantially Ni was placed in a container,
50 to 1225 ℃, extrusion method with an extrusion ratio of 4 to 15
And C0.02-0.12%, Co5-12%, Cr7-9%, W
10-14%, Al4.5-5.5%, Ti0.1-1.5%, Ta3-
5%, Hf 0.3-1.3%, B0.005-0.018%, Zr0.01-
A Ni-based alloy powder containing 0.15% and the balance being Ni is put in a container and heated at 1025 to 1250 ° C and 800 to 2000 atm for 3 times.
0 ~ 200min High temperature / high pressure processing and sintering, then 1050 ~ 1225 ℃
There is a manufacturing method in which the extrusion ratio is 4 to 15.

On the other hand, the material of the valve pin 36 is, for example,
Rockwell hardness (C scale) 6 using SKH51
It should be 0 or more.

In this embodiment, as shown in FIG. 2, the valve pin support portions on both sides of the valve casing 16 can be replaced.

A nest 61 having a support blade 19 which is a valve pin support portion on the gate 10 side is formed. The nest 61 on the gate 10 side is the support blade 19 and the tip from the side opposite to the gate 10 side of the support blade 19. A tubular portion 62 including up to the portion 16S is integrally provided, and a mounting hole 63 capable of removing and assembling the insert 61 from the length direction of the valve casing 16 is provided in the flat portion 53.
Is formed in the center of.

Further, a nest 71 having a valve pin support hole 38 which is a valve pin support portion on the side opposite to the gate 10 is formed, and the nest 71 on the side opposite to the gate 10 is formed in the valve pin support hole 38.
And a substantially frusto-conical block shape including the inlet portion 18B, and the mounting hole 73 that allows the nest 71 to be removed and assembled from the valve casing 16 in the length direction thereof.
17 is formed in the center of the surface on the side opposite to the gate 10, and the inner peripheral surface 73A of the mounting hole 73 is tapered so as to shrink toward the gate 10. Further, both ends of the inlet portion 18B are open to the surface of the nest 71 on the side opposite to the gate 10 and the surface on the side of the gate 10.

Next, the operation of the above configuration will be described. In molding, first, the mold clamping device of the injection molding machine closes the fixed mold 1 and the movable mold 2 with a constant mold clamping force, and the product cavity 3 is formed between them. As shown in FIG. 1, the valve pin 36 is moved away from the movable mold 2 to open the gate 10. Even when the gate 10 is opened, the valve pin 36 is still fitted to the support blade 19 of the valve casing 16, and the valve pin 36 is attached to the support blade 19 on the tip side (gate 10 side) of the valve casing 16. It is slidably supported, and is also slidably supported in the valve pin support hole 38 on the base end side (counter gate 10 side). Then, a molten thermoplastic resin such as a fluororesin, which is a thermoplastic molding material, is injected from the injection molding machine into the fixed mold 1. The resin (not shown) passes through the runner 9 of the manifold 8 and the like, and further passes through the material passage 18 in the valve casing 16 and the divided material passage portion 21 between the support vanes 19 with which the valve pin 36 is fitted, Gate 10 to product cavity 3
Flows in. In this case, in this embodiment, since the valve casing 16 in which the material passage 18 is formed is made of a super-corrosion resistant material, the valve casing 16 has corrosion resistance against fluororesin and the like. After the resin is filled in the product cavity 3 in this way, the valve pin 36 is moved to the movable mold 2.
The valve pin 36 is fitted to the gate 10 and the gate 10 is closed.

After the resin in the product cavity 3, that is, the product is cooled and solidified, the fixed mold 1 and the movable mold 2 are opened, and the molded product is taken out. After that, the mold is closed again, the above steps are repeated, and the molding is repeated. Meanwhile, the resin in the material passage 18 of the valve casing 16 is always kept in a molten state by the heating of the heaters 41 and 43.

By the opening / closing operation of the gate 10 by the valve pin 36 described above, wear occurs on the valve pin 36, the support blades 19 that slidably support the valve pin 36, and the pable pin support holes 38. The reason why the support blade 19 and the valve pin support hole 38 are worn is that the gate pin 10 is opened and closed surely by using a material having a higher hardness than the valve pin 36. Therefore,
If repairs are required due to the progress of wear, remove the inserts 61, 71 on both sides from the valve casing 16 and install new inserts 61, 71 in the mounting holes 63, 73, respectively, to replace the valve pin support parts. Can be used. Although the valve pin 36 side is less worn, if it becomes corroded due to the influence of fluororesin or the like and needs to be replaced, the valve pin 36 used up to now is pulled out from the valve casing 16 and replaced with a new valve pin 36.

As described above, in the present embodiment, according to claim 1, the fixed mold 1 and the movable mold 2, which are a plurality of mold bodies which are opened and closed to form the product cavity between the mold cavities when the mold is closed, and these mold bodies. A valve device 11 provided on a fixed mold 1 which is a mold body having a gate 10 that opens to the product cavity 3, and the valve device 11 is incorporated in the fixed mold 1 and has a material passage 18 formed therein. A valve casing 16,
A valve gate type having a valve pin 36 provided inside the valve casing 16 for opening and closing the gate 10, a support vane 19 provided as a valve pin supporting portion for slidably supporting the valve pin 36, and a valve pin support hole 38. In the mold device, since the valve casing 16 is made of a super-corrosion resistant material, even if a highly corrosive material such as fluororesin is used as the molding material, the valve casing is made of a super-corrosion resistant material, so that the occurrence of corrosion can be prevented.

As described above, according to the second aspect of the present invention, since the super-corrosion resistant material is a super-corrosion resistant Ni-based alloy, the valve casing 16 has excellent corrosion resistance and other corrosion resistance. It is possible to obtain higher wear resistance than the alloys.

As described above, in this embodiment, the support vane 19 and the valve pin support hole 38, which are the valve pin support portion, are provided in the valve casing 16 so as to be replaceable. When used as a material, the wear resistance of the material is generally lower than that of conventional materials.On the other hand, the valve pin 36 reliably opens and closes the gate 10, and also has the conventional strength and wear resistance so that gate burrs do not occur. It is preferable to use the provided one. This way,
Since the valve pin 36, which has high abrasion resistance, slides on the valve support part, the valve support part is mainly worn and the valve casing 16 must be repaired and replaced.However, only the worn valve pin support part can be replaced. It has been repaired and can be used continuously.

Further, in this embodiment, as described above, according to the fourth aspect, the support vanes 19 serving as the valve pin supporting portions and the valve pin supporting holes are provided at both ends in the length direction of the valve casing 16.
Since the support blades 19 and the nests 61 and 71 provided with the valve pin support holes 38 are provided to be removable from the valve casing 16 in the length direction of the valve casing 16, the support blades 19 and the valve pin support holes 38 are provided. Since the processing is also based on the length direction of the valve casing 16, the manufacturing is easy, and the nesting 61, 71 can be easily removed and assembled.

Further, as described above, in the present embodiment, in response to the fifth aspect, the inlet 71 of the material passage is provided in the nest 71 of the valve pin supporting hole 38 which is the valve pin supporting portion on the side opposite to the gate 10.
Since B is formed, the mounting hole 73 and the
Compared with the case where the material passage is formed between the outer periphery of 71, the structure and assembly are simpler.

The present invention is not limited to the above embodiment, and various modifications can be made. For example,
Various types of valve pin support portions may be used in shape and structure.

[0042]

According to the valve gate mold apparatus of the present invention, the valve casing is made of a super-corrosion resistant material, and even if a highly corrosive material such as fluororesin is used as the molding material, the valve casing is Because it is made of super-corrosion resistant material,
It can prevent the occurrence of corrosion.

According to a second aspect of the present invention, in the valve gate mold apparatus according to the first aspect of the invention, the super-corrosion resistant material is a super-corrosion resistant Ni-based alloy, and the valve casing has excellent corrosion resistance and Higher abrasion resistance than alloys with corrosion resistance.

The invention of claim 3 is the same as claim 1 or 2
In the valve gate mold apparatus according to the invention described above, the valve pin support portion is replaceably provided in the valve casing, and the valve pin having high abrasion resistance slides on the valve support portion to mainly support the valve support. The part is worn and the valve casing needs to be repaired and replaced, but repairing is only required by replacing the worn valve pin support.
Can be used continuously.

Further, the invention of claim 4 is the valve gate mold apparatus of the invention of claim 3, wherein the valve pin support portions are provided at both ends in the length direction of the valve casing, and these valve pin support portions are provided. The provided insert is provided so as to be removable from the valve casing in the length direction of the valve casing, and since the processing of the valve pin support portion is also based on the length direction of the valve casing, it is easy to manufacture, and , It is possible to easily remove and insert the nest.

Furthermore, the invention of claim 5 is the valve gate mold apparatus according to claim 4, wherein a material passage is formed in the nest of the valve pin support portion on the side opposite to the gate.

Since the material passage is provided in the nest of the valve pin support portion, the structure and assembly are simpler than the case where the material passage is formed between the material and the built-in portion.

[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 sectional view of the same valve casing.

FIG. 3 is a sectional view of the valve pin support portion on the gate side of the same.

[Explanation of symbols]

1 Fixed type 2 Movable type 3 product cavity 10 gates 11 Valve device 16 valve casing 18 Material passage 18B entrance 19 Support blade (Valve pin support) 36 valve pin 38 Valve pin support hole (valve pin support part) 61 Nesting 71 Nesting

Claims (5)

[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 includes a valve casing incorporated in the mold body and having a material passage formed therein, a valve pin provided inside the valve casing for opening and closing the gate, and a valve pin provided in the valve casing for sliding the valve pin. A valve gate type mold device having a valve pin support part that supports freely, wherein the valve casing is made of a super-corrosion resistant material. 2. The valve gate mold apparatus according to claim 1, wherein the super-corrosion resistant material is a super-corrosion Ni-based alloy. 3. The valve gate mold apparatus according to claim 1, wherein the valve pin support portion is provided on the valve casing in a replaceable manner. 4. The valve pin support portions are provided at both ends of the valve casing in the length direction, and a nest provided with the valve pin support portions is provided so as to be removable from the valve casing in the length direction of the valve casing. The valve gate mold apparatus according to claim 3, wherein 5. A material passage is formed in a nest of the valve pin support portion on the side opposite to the gate.
A valve gate mold device according to the item.