JP2002172625A - Resin molding mold and resin molding method using the mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin molding mold the temperature of which is uniform and can be adjusted promptly and which can be manufactured simply and inexpensively and a resin molding method which can shorten a molding time eminently and can mold a resin molding with its surface defects controlled. SOLUTION: In the resin molding mold having a surface material 10 and a support material 20 for supporting it, a channel 22 to be a channel for a temperature adjusting fluid for adjusting the temperature of the surface of the mold is formed in at least one of the back 12 of the surface material 10 to be a mating face between the surface material 10 and the support material 20 and the surface 21 of the support material 20. The mold is used in resin molding such as blow molding and injection molding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molding die used for resin molding and a resin molding method using the mold.

[0002]

2. Description of the Related Art In order to obtain a product having a good appearance by resin molding such as blow molding or injection molding, a softened resin is caused to flow into a mold heated to a temperature near a glass transition point to form a product. In general, a resin is cooled and hardened by cooling the mold, followed by molding. And in actual resin molding,
Since this method is continuously repeated, heating and cooling of the mold surface are repeated. In such resin molding, heating and cooling (temperature control) of a mold, particularly a mold surface forming a cavity, forms a flow path through which a fluid flows in the mold. This is performed by flowing a temperature controlling fluid (temperature controlling fluid) such as steam.

[0003] Among the above-mentioned molds, there is a mold having a surface material whose surface is a mold surface to form a cavity, and a support material for supporting the surface material from the back. The surface material has good characteristics such as dimensional accuracy, smoothness, and corrosion resistance necessary to form a good molded product surface (design surface), and also has a molding time, especially a heating and cooling time for the mold. It is required that the heat conduction be good in order to shorten the length. Therefore, the surface material is made of a material such as nickel, and has a relatively constant thickness and a relatively small thickness by a method such as electroforming. The support is solely responsible for ensuring the strength of the mold itself, and the support is molded from, for example, an iron-based material by machining or the like due to its function. And the said surface material has a structure arrange | positioned so that it may be stuck on the surface of the said support body.

[0004] In a conventional resin molding die, a temperature control flow path formed in a straight line so as to penetrate the support is formed at a relatively large distance from the die surface. This is because the temperature control channel is easily formed. However,
When molding a resin molded product having not only a simple shape but also a three-dimensionally complex shape, the mold has a cavity having a complicated shape. In such a mold, since the temperature control flow path is formed at a relatively large distance from the mold surface, not only takes a long time to control the temperature of the mold surface, but also a straight temperature control flow. Since the path is formed, the distance from the flow path to the surface of the mold differs depending on the region, and temperature irregularity occurs on the mold surface due to the difference in temperature adjustment time.

[0005] In order to solve such a problem, a temperature control pipe made of a material having good heat conductivity such as copper is joined to the back surface of the surface material along the same, and this temperature control pipe is connected to the flow path of the temperature control fluid. The technology to do this was considered. However, the joining of the pipe to the surface material is generally performed by a method such as welding. However, if the joining temperature is too high, there is also a problem that the surface material is deformed by the heat.

Therefore, as shown in Japanese Patent Application Laid-Open No. Hei 7-227851, a temperature control tube is arranged so as to be in contact with the back surface of the surface material, and the temperature control tube is covered with a stainless steel net. A technique for fixing the temperature control pipe to the surface material by temporarily fixing the steel by spot welding, re-electroforming and fixing the steel was studied. Further, as disclosed in JP-A-11-348080, the surface material has a three-layer structure of a thin plate, and the thin plate serving as the intermediate layer is formed so as to have a wavy cross section. The technology for forming the passages was also studied.

[0007]

However, according to the technique disclosed in Japanese Patent Application Laid-Open No. Hei 7-227851, since the contact between the temperature control tube and the surface material is in line contact, the temperature control tube and the surface material are in contact with each other. The heat transfer between them is not efficient, and the time required for temperature control cannot be sufficiently reduced, and the gas vent hole in a portion in contact with the surface material has a drawback. Further, Japanese Patent Application Laid-Open No.
In the technique disclosed in Japanese Patent Publication No. 80, in addition to the fact that gas vent holes in the cavity cannot escape to the outside of the gas mold, the gas vent holes cannot be applied to the surface material perforated on the surface. In addition, the production method of the surface material such as the elution of the core is complicated, and the die cost becomes extremely high.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the conventional resin molding die. Even if the resin molding die has a cavity having a complicated shape, the mold is not limited to the portion. The temperature control fluid flows to a position close to the mold surface, and a flow path that allows efficient heat transfer to the mold surface is formed, which enables quick temperature control without temperature unevenness, and
An object of the present invention is to provide a resin molding die that can be manufactured easily and at low cost.

Further, the present invention provides a resin molding method capable of significantly shortening the time required for resin molding and molding a resin molded article having few surface defects by resin molding using the resin molding die. The task is to provide.

[0010]

According to the present invention, there is provided a resin molding die comprising: a surface material whose surface is a mold surface to form a cavity; and a support material for supporting the surface material from the back. A resin molding die, wherein at least one of a back surface of the surface material and a surface of the support material, which is a mating surface of the surface material and the support material, includes a temperature control fluid for controlling the temperature of the mold surface. A groove serving as a flow path is formed.
In other words, the resin molding die of the present invention is configured such that a groove is formed in a portion of a mating surface between a surface material and a support material, and a fluid is caused to flow inside the groove to control the temperature of the mold surface. It is a molded resin mold.

The surface material which forms a cavity with its surface serving as a mold surface is generally formed to be thin, so that the temperature control fluid passes near the mold surface and the mold surface and the temperature control fluid communicate with each other. In the resin molding die of the present invention, the heating and cooling of the die can be performed in a short time, and the resin molding can be rapidly performed. Generally, since the surface material has a substantially constant thickness, a groove is formed along the mating surface between the surface material and the support. In this case, the distance from the mold surface is substantially constant, and temperature unevenness during heating and cooling of the mold hardly occurs. Further, since the processing of forming the groove is relatively simple and can be performed at low cost, the resin molding die of the present invention is a die having a low die manufacturing cost.

Next, a resin molding method of the present invention is a resin molding method performed using the resin molding die of the present invention,
A heating step of heating the mold surface by flowing the high-temperature control fluid in the groove, and a molding step of flowing a softened or molten resin into a cavity formed by the mold surface to form a product shape And a cooling step of cooling the mold surface by flowing the low-temperature temperature-controlling fluid into the groove, and cooling the resin. Since the advantages of the resin forming mold of the present invention can be enjoyed, according to the resin molding method of the present invention, the heating and cooling of the mold can be performed in a short time, and the resin molding can be rapidly performed. In addition, temperature unevenness during heating and cooling of the mold is unlikely to occur, and the molded resin product is good without surface defects such as flow marks, welds, and floating fillers.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the resin molding die of the present invention and the resin molding die of the present invention will be described in detail.

(1) In a basic embodiment of the resin molding die of the present invention, a surface material whose surface is a mold surface to form a cavity, and a supporting material for supporting the surface material from the back surface are provided. And a flow path of a temperature control fluid for controlling the temperature of a mold surface on at least one of a back surface of the surface material and a surface of the support material, which is a mating surface of the surface material and the support material. An aspect is provided in which a groove is formed (corresponding to claim 1). The basic configuration of the surface material and the support material may be in accordance with the configuration of a general resin molding die.

It is desirable that the surface material of the resin molding die of the present invention is formed of a material having good thermal conductivity.
As the material, for example, nickel, aluminum, copper, or the like can be used. Among these, nickel has the advantage of being excellent in corrosion resistance and having about three times the thermal conductivity of steel. In view of this, in the resin molding die of the present invention, the surface material is nickel or nickel-based. Preferably, it is an alloy. In addition, in the resin molding die of the present invention, since the flow path of the temperature control fluid is formed in the vicinity of the mold surface, heating and cooling of the mold can be performed in a shorter time than conventional resin molding dies. In that sense, it is also possible to use a normal mold material such as an Al casting, a Zas casting, a steel, Al, or Zas.

The surface material can be formed by various methods such as electroforming (electroforming), press forming, and machining. Among these, it is desirable to form by electroforming in consideration of the fact that the surface dimensional accuracy is improved and the surface material can be uniformly thinned. In consideration of the temperature control effect, the thinner the surface material is, the more preferable it is. However, since the minimum strength (rigidity) that can withstand resin molding is necessary, for example, the surface material formed of nickel or a nickel-based alloy is required. In such a case, the thickness is desirably 2 mm or more.

In the resin molding die of the present invention, the material, shape, thickness, and the like of the supporting material for supporting the surface material from the back surface are not particularly limited. For example, it may be formed from a material such as a commonly used mold material such as an SC material or an SCM material. The thickness is desirably as thin as possible so long as the strength of the mold itself can be ensured, in order to reduce the heat capacity of the entire mold. The formation of the support material may be performed according to a general method of manufacturing a mold such as machining. In addition, the combination of the support material and the surface material, that is, the attachment of the surface material to the surface of the support material is performed, for example, by electric discharge machining in order to bring the back surface of the surface material into close contact with the support material, and then screwed and fixed. What is necessary is just to do by the method of doing.

The kind of the temperature control fluid is not particularly limited, and for example, water (including steam), oil, ethylene glycol and the like can be used. Among them, it is desirable to use water in view of the merit of being safe and extremely inexpensive.

(2) The groove serving as the flow path of the temperature control fluid may be formed on at least one of the surface material side and the support material side as long as it is a mating surface between the surface material and the support material. It may be formed only on one of the surface material side or the support material side,
In addition, it may be formed on both. Furthermore, when formed in both, it may be formed in a position facing each other and one groove may be formed by both grooves.

As described above, the surface material is generally thin, and in that case, the resin molding die of the present invention is
It is desirable to carry out the present invention in such a form that it is formed only on the surface of the support material (corresponding to claim 2). When a groove is formed in a thin surface material, the groove further reduces the remaining thickness of the surface material, resulting in a decrease in strength. On the other hand, since the supporting material is formed thicker than the surface material, the strength of the mold itself is small even when the groove is formed.

Further, in the resin molding die of the present invention, in consideration of the fact that the surface material is generally formed to a substantially constant thickness, the back surface of the surface material and the surface of the support to which the surface material is fitted are formed on the mold surface. Has a surface shape separated by a substantially constant distance. Even if the mold surface has a complicated three-dimensional shape, the distance from the groove to the mold surface is substantially constant as long as a groove having a constant depth is formed. Without any special consideration, simply forming a groove of a constant depth can form a flow path of a temperature-regulating fluid having a substantially constant distance from the mold surface. Is also simple in its manufacture.

The resin molding die of the present invention can be embodied in such a manner that a plurality of grooves are formed at substantially constant intervals. With this configuration, a substantially constant temperature control effect can be obtained in almost all portions of the mold surface, and temperature unevenness during heating and cooling of the mold is extremely small.

(3) In the resin molding die of the present invention, as described above, the groove serves as a flow path of the temperature control fluid. The space formed by the groove can be implemented in such a manner that the fluid flows directly. However, in view of the leakage of the temperature control fluid, it is desirable to have a pipe disposed in the groove, and to carry out the mode in which the temperature control fluid flows inside the pipe (corresponding to claim 3). .

In this case, the tube is desirably made of a material having mechanical strength to withstand the pressure of the fluid and excellent in heat conductivity, and it is considered that the mold surface has a three-dimensional shape. For example, a material that easily bends or curves along the mold surface is desirable. In consideration of such conditions, in the resin molding die of the present invention, it is desirable to use a pipe made of copper or a copper alloy.

Although the sectional shape of the groove is not particularly limited, a tube having an outer shape matching the sectional shape of the groove can be provided. That is, it is possible to use a tube having an outer shape that just fits into the groove. The heat transfer is performed efficiently when the contact between the surface material and the tube and the contact between the support material and the tube are sufficient, so when arranging a tube with an external shape that matches the cross-sectional shape of the groove, The temperature control efficiency becomes higher.

(4) However, in a mold having a three-dimensional mold surface, a groove must be formed along the mold surface, so that the pipe must be bent or curved.
For example, when a copper tube or the like is used, the outer shape may be deformed when the tube is bent or bent.
For this reason, it is difficult to make each part of the groove just fit into the groove, that is, to ensure the contact between the surface material and the support material and the pipe at any part. In view of this, in the resin molding die of the present invention, a tube having an outer shape smaller than the space formed by the groove is used, and the periphery thereof is filled with a low melting point metal and disposed. (Claim 4)
Corresponding to). If carried out in this manner, in any part, heat transfer between the surface material and the support material and the pipe is sufficiently performed via the low melting point metal, so that the resin molding metal having a high temperature control effect can be obtained. Type. Furthermore, the filled low melting point metal has the advantage that the tube is firmly fixed in the groove, and the filling work of the low melting point alloy does not require high heat, so that deformation of the mold due to heat can be prevented. It also has benefits.

The type of the low melting point metal is not particularly limited, and may be any metal having a melting point higher than the maximum temperature of the temperature control fluid flowing through the tube and having a high thermal conductivity. For example, a Pb-Sn-based solder or the like can be used. The filling of the low melting point metal may be performed by placing the tube in the groove and then pouring the molten low melting point metal into the groove. Since this operation itself is a relatively simple operation, the resin molding die of this embodiment is
A mold with low manufacturing cost.

(5) The resin molding die of the present invention may be embodied in a form having a heat insulating material for covering the outer surface of the support material which is not the mating surface with the surface material.
Corresponding to). That is, a mode in which part or all of the outside of the support member is covered with the heat insulating material. The temperature control fluid flowing through the groove serving as the flow path also performs heat transfer with the supporting material. Therefore, if the heat transferred to the outside of the mold by transmitting the support is reduced,
The heat of the temperature control fluid can more effectively heat and cool the mold surface. In the resin molding die of this embodiment, since heat escaping to the outside can be reduced, more rapid heating and
Cooling is performed, and a mold having a higher temperature control effect is obtained. The type of the heat insulating material is not particularly limited.
For example, various materials such as bakelite, epoxy resin, ceramics, and glass wool can be used.

(6) Next, the resin molding method of the present invention is a resin molding method performed using the resin molding die of the present invention. A heating step of flowing a temperature-regulating fluid to heat a mold surface, and a molding step of flowing a softened or molten resin into a cavity formed by the mold surface to form a product shape,
A cooling step of cooling the mold surface by flowing the low-temperature temperature-controlling fluid into the groove, and cooling the resin.

The resin molding method of the present invention may be any method as long as it is performed using the above-described resin molding die of the present invention, and the specific molding method is not particularly limited. For example, the present invention can be applied to various resin molding methods such as blow molding, injection molding, rotation molding, slush molding, injection molding, vacuum molding, reaction injection molding, stamping molding, compression molding, and sheet molding.

The process of the resin molding method of the present invention comprises a heating step, a molding step, and a cooling step. In the heating step, the mold surface is heated so as to be near the glass transition temperature of the resin. Specifically, a high-temperature temperature-regulating fluid is caused to flow into a groove serving as a flow path, and the heat is transmitted to a mold surface. In the molding step performed next, in a mode according to the above-listed molding methods, the softened resin is introduced into the mold cavity,
The resin is made to conform to the surface of the surface material of the mold to form a predetermined design surface corresponding to the surface of the surface material of the mold. Thereafter, in a cooling step, the temperature of the mold surface is lowered to cool and harden the resin, and further, the molded product is cooled to a temperature at which the molded product can be removed from the mold. Specifically, this is performed by flowing a low-temperature temperature-controlling fluid into a groove serving as a flow path, and transferring heat of a molded product and a mold surface to the temperature-controlling fluid. By repeating such a cycle, a resin molded product can be manufactured continuously.

In the resin molding method of the present invention, since the molding is performed using the resin molding die of the present invention having a high temperature control effect, the time of the heating step and the cooling step can be shortened, and the resin molding with high production efficiency can be performed. Become. Further, the product molded by the above-described molding method using the resin molding die of the present invention can effectively prevent surface defects such as flow marks, welds, and floating fillers, and can produce a resin molded product having a good surface condition. become. In addition, the resin molding die of the present invention used in the resin molding method of the present invention is not limited to the first basic embodiment, but may be any of the various embodiments described above. In that case, the special effects obtained by each aspect,
It can also be enjoyed in the resin molding method of the present invention.

(7) The embodiment of the resin molding die of the present invention and the resin molding method of the present invention using the same have been described above. However, the above-described embodiment is merely one embodiment,
The resin molding die of the present invention and the resin molding method of the present invention using the same can be implemented in various forms with various changes and improvements based on the knowledge of those skilled in the art, including the above-described embodiment. it can.

[0034]

Next, a specific embodiment of the resin molding die and the resin molding method of the present invention will be described in detail with reference to the drawings. This embodiment relates to blow molding of a rear spoiler of an automobile.

FIG. 1 shows a main part of the resin molding die as viewed from the front, and FIG. 2 shows the resin molding die in FIG.
FIG. 3 shows a cross section taken along the line BB of FIG. 1 of the resin molding die, that is, a cross section, and FIG. 4 shows a part of the vertical cross section (part C in FIG. 2). Are enlarged and shown respectively.

The resin molding die 1 is divided into two parts, each comprising one of a first mold 2 and a second mold 2 '. In both the first mold 2 and the second mold 2 ′, the surface material 1 whose surface 11 serves as a mold surface to form the cavity 3
0 and a supporting material 2 for supporting the surface material 10 from its back surface 12
0, so that the support member 20 is fixed to the base plate 30.

A groove 21 having a substantially constant depth along the surface 21 of the support member 20 which is a mating surface with the surface member 10 is provided at a predetermined interval in a straight line when viewed from the front. A plurality of sections are formed. Each of the grooves 22 has a tube through which a temperature control fluid flows, that is, a temperature control tube 40.
Are bent or curved along the groove 21. One end and the other end of each temperature control tube 40 are connected to the manifold 50, respectively. One of the manifolds 50 serves as a supply-side manifold, and the other manifold serves as a reception-side manifold.

The inside of the groove 22, that is, the space defined by the back surface 12 of the surface material 10, the wall surface of the groove 22, and the outer peripheral surface of the temperature control tube 40 is filled with a low melting point metal 60. Further, a surface excluding the surface 21 of the support member 20, that is, an outer surface 23 of the support member 20 which is not a mating surface with the surface member 10.
Is covered with a heat insulating material 70.

Incidentally, in the present resin molding die 1, the surface material 10 is made of nickel, and is formed to a substantially constant thickness of 4 mm by electroforming. Further, the support member 20 is formed of F
It is made of CD550, is formed by machining, and has a thickness of about 35 mm in a direction perpendicular to the mold surface. Water (steam) is used as the temperature control fluid, and the temperature control pipe 40 through which the temperature control fluid flows is a copper pipe having a thickness of 1 mm and an outer diameter of φ10.
mm. The groove 22 of the support 20 in which the temperature control tube 40 is provided has a width of 15 mm and a depth of 1 mm.
5 mm, and are formed at substantially equal intervals at a pitch of about 30 mm in the vertical direction. The low melting point metal 60 filled in the groove 22 is made of a soft solder. Further, the heat insulating material 70
Adopts glass wool and has a thickness of about 5 mm and a support material of 20 mm.
The outer surface 23 is covered. Although not shown, the space between the base plate 30 and the support member 20 is filled with another type of glass wool.

FIG. 5 is an enlarged view of a part of another longitudinal section of the resin molding die 1 of the present invention. As shown in FIG. A number of air holes 13 are provided to allow air in the cavity to escape, and air passing through the air holes 13 is exhausted to the outside of the mold through a gap between the support member 10 and the surface member 20. Has become. Incidentally, in the present resin molding die, the ventilation holes 13
Has a diameter of 0.15 mm. As described above, even in a resin molding die having a ventilation hole on the mold surface, the ventilation hole can form a flow path of the temperature control fluid near the mold surface without obstructing the ventilation hole. This is one advantage of the resin mold of the present invention.

When a rear spoiler is manufactured by blow molding ABS resin using the resin molding die 1, first, water at 150 ° C. is flowed through the temperature control tube 40 to heat the die surface. Next, a softened parison at a temperature of 225 ° C. is located between the first mold 2 and the second mold 2 ′, and the first mold 2 and the second mold 2 ′ are closed to close the cavity 3.
To form Then, compressed air is injected into the parison by the blow pin, and the parison is inflated until the surface contacts the entire mold surface. In this state, the resin is cooled and hardened by flowing water at 30 ° C. through the temperature control tube 40 to cool the mold surface. After the temperature of the molded resin is lowered to a temperature at which the molded resin can be released, the first mold 2 and the second mold 2 ′ are formed.
And release the molded article. In this way, the rear spoiler is blow molded. By repeating these series of steps, the rear spoiler is mass-produced.

[0042]

According to the present invention, a resin molding die having a surface material and a support material for supporting the surface material is provided at least on the back surface of the surface material and the surface of the support material, which are the mating surfaces of the surface material and the support material. On the other hand, a groove serving as a flow path of a temperature control fluid for controlling the temperature of the mold surface is formed. With such a configuration, the resin molding die of the present invention enables heating and cooling of the die in a short time, and the distance from the die surface is substantially constant at any part of the groove. In addition, temperature unevenness during heating and cooling of the mold hardly occurs.

Further, the present invention is a resin molding method characterized in that resin molding such as blow molding and injection molding is performed using the resin molding die of the present invention. The resin molding method of the present invention can quickly perform resin molding by enjoying the advantages of the resin molding die of the present invention, and the molded resin molded product has good quality without surface defects. Become.

[Brief description of the drawings]

FIG. 1 shows a main part of a resin molding die according to an embodiment of the present invention as viewed from the front.

FIG. 2 shows a longitudinal section of a resin molding die according to an embodiment of the present invention.

FIG. 3 shows a cross section of a resin molding die according to an embodiment of the present invention.

FIG. 4 is an enlarged view of a part of a longitudinal section of a resin molding die according to an embodiment of the present invention.

FIG. 5 is an enlarged view of a part of another longitudinal section of a resin molding die according to an embodiment of the present invention.

[Explanation of symbols]

 1: Resin molding die 2: First die 2 ': Second die 3: Cavity 10: Surface material 11: Surface 12: Back surface 13: Vent hole 20: Support material 21: Surface 22: Groove 23: Outer surface 30 : Base plate 40: Pipe (temperature control pipe) 50: Manifold 60: Low melting point metal 70: Heat insulating material

Continuing from the front page (72) Inventor Fumihiko Sugiura 2-1-1 Asahi-machi, Kariya-shi, Aichi Prefecture Inside Aisin Seiki Co., Ltd. 72) Inventor Saburo Yasuda F-term (reference) 4F202 AJ02 AJ08 AJ13 CA11 CA15 CB01 CD26 CN01 CN05 CN13 CN15 CN21

Claims (6)

[Claims] 1. A resin molding die comprising: a surface material whose surface is a mold surface to form a cavity; and a support material for supporting the surface material from a back surface. A groove is formed on at least one of the back surface of the surface material, which is a mating surface with the support material, and the surface of the support material, as a channel for a temperature control fluid for controlling the temperature of the mold surface. Resin mold. 2. The resin molding die according to claim 1, wherein the groove is formed only on a surface of the support member. 3. The resin molding die according to claim 1, further comprising a tube disposed in the groove, wherein the temperature control fluid flows inside the tube. 4. The resin molding die according to claim 3, wherein the tube is provided by filling a periphery thereof with a low melting point metal. 5. The resin molding die according to claim 1, further comprising a heat insulating material that covers an outer surface of the support member that does not form a mating surface with the surface member. 6. A surface material forming a cavity with its surface serving as a mold surface, and a support material for supporting the surface material from the back surface, wherein a mating surface between the surface material and the support material is provided. A resin molding die, characterized in that at least one of the back surface of the surface material and the surface of the support material, a groove serving as a flow path of a temperature control fluid for controlling the temperature of the die surface is formed. A resin molding method performed by using a heating step of flowing a high-temperature control fluid into the groove to heat a mold surface, and softening or melting the resin in a cavity formed by the mold surface. A resin molding method, comprising: a molding step of flowing and molding into a product shape; and a cooling step of flowing the low-temperature temperature-controlling fluid into the groove to cool a mold surface and cool the resin.