MXPA01000211A - Synthetic resin forming metal mold, metal mold temperature regulating device, and metal mold temperature regulating method - Google Patents

Abstract

A metal mold, comprising an insert (2) contained in a base mold (1), insulating layers (5) provided between the base mold (1) and the insert (2), and one series of flow paths (A) to allow a heating medium and a cooling medium to flow in alternately and repeatedly which are provided near a cavity surface (4) of the insert (2), wherein a clearance is provided in a close-fitted portion between the insert (2) and the base mold (1) to compensate for the expansion amount of the insert (2), and input and output side communication flow paths of the flow paths (A) are provided in the insert (2), and communication pipes insulated from the base mold (1) are connected to the input and output side communication flow paths.

Description

METAL MOLD TO FORM SYNTHETIC RESIN. METAL MOLD TEMPERATURE REGULATOR DEVICE, AND METHOD TO] REGULATE THE TEMPERATURE OF THE METAL MOLD TECHNICAL FIELD The present invention relates to a mold for use for injection molding or compression molding with a thermoplastic resin or a thermosetting resin, and more particularly, to a mold for molding synthetic resin, to an apparatus and method for adjusting a temperature of the mold, where the surface of the cavity is heated and cooled alternately.

BACKGROUND TECHNICAL In general, when a thermoplastic resin is molded by injection molding or compression molding, in order to avoid prolongation of time in a molding cycle due to the change in mold temperature, the molding is performed at a marginal temperature scale that barely allows the melt to fill up in the mold and take the product out of the mold. Further, when a thermoplastic resin is subjected to an injection molding, if the temperature of the mold is maintained at a high temperature after being filled in it. melting in the mold, because it improves the flowability of the resin, it becomes possible to take advantage to form the product in a thin-walled product, as well as to improve the replication property, that is, how well the shape of the surface of the cavity with the surface of the product. In addition, a line of union becomes conspicuous. Accordingly, inventions have been made on a material in which heat is applied exclusively to the surface of the cavity during the injection of the melt into the mold. For example, a method wherein heating by heated air is effected is disclosed in the Japanese Examined Patent Publication Gazette Number 22020/1970; a combination method wherein heating is effected by an electric heater, and cooling by chilled water, is disclosed in the Gazette of Japanese Patent Laid-Open No. 22759/76; a method where heating is effected by high frequency induction is disclosed in Japanese Patent Laid-Open Gazette No. 109639/1980; a method wherein the heating is performed by supplying steam to a cavity, is disclosed in the Gazette of Japanese Patent Laid-open Publication No. 165229/1982; a method wherein heating is effected by the interposition of a heated plate between a cavity and a core, is disclosed in the Gazette of Japanese Patent Laid-Open No. 79614/1986; a method wherein heating is effected by a halogen bulb is disclosed in the Gazette of Japanese Patent Laid-Open No. 42217/1989; and a method wherein heating is performed on a surface of the cavity by an electrically conductive layer, is disclosed in the Gazette of Japanese Patent Laid-Open No. 265720/1992. In addition, a method wherein heating is performed by supplying a heating medium, such as steam, hot water, or hot oil, to a circuit commonly used for a cooling medium, is disclosed in the Japanese Patent Publication Gazettes. open Number 55219/1981; Number 12739/1983; Number 54828/1985, and Number 193223/1997. In addition, as an improvement of the above propositions, a method wherein the heating is effected by the use of two piping systems of the heating medium circuit, is disclosed in the Gazette of Japanese Patent Laid-open Publication Number 100867 / nineteen ninety five; a method wherein a heating means and a cooling medium are independently supplied from the respective tanks, and recovered thereto, is disclosed in the Gazette of Japanese Patent Laid-Open No. 215309 / 19E 3; » Aa ». tí' ^ -.4. ^ JstJS? a method in which a pipe system is arranged, such that a portion of the circuit commonly used by the heating means and the cooling medium becomes as small as possible, is disclosed in the Publication Gazette Japanese Patent Number 208918/1987; a method wherein a medium is heated to Half the middle circuit only when a mold is to be heated, is disclosed in the Gazette of Japanese Patent Laid-Open No. 269515/1989; and a method wherein heating is performed by heated agia flowing through a closed cycle, is disclosed in the Gazette of Japanese Patent Laid-Open No. 37108/1981. The method described above, wherein B1 heating is effected by heated air, suffers from a problem, that the heating capacity is small. The method wherein the heating is effected by an electric heater, and the method wherein the surface of the cavity is heated by an electrically conductive layer, encounter a problem that their apparatus becomes complicated and expensive. The method where the heating is effected by high frequency induction also encounters a problem, that a large amount of time is needed to insert or remove a heating device, and its apparatus becomes expensive. The method where steam is supplied to the cavity, encounters a problem that the method is applicable only for a situation where the cavity becomes moist so as not to cause any problem. The method where the heated plate is interposed between the cavity and the core, and the method where the heating is carried out by means of a halogen bulb, suffer from a problem that a large amount of time is needed to insert or remove a device of heating, in addition to the time to take out a product. In addition, the method wherein heating and cooling are effected using a common circuit encounters the following problem. That is, if the circuit is remote from a surface of the cavity, then the mold is heated and cooled not only in the surface portion, but also in the deep portion of the mold, and consequently, heating and cooling are performed in an excessive way, with the result that a large amount of time is needed to switch between heating mode and cooling mode, and responsibility for heating and cooling is deteriorated. Further, according to the method wherein the heating is effected using two piping systems of the heating medium fluid passage as an improvement of the above-described method, to a first channel of heating means provided near the cavity surface , a heating means is supplied after the mold is heated, and a cooling medium is supplied after cooling the mold, while a second channel of heating means provided at a remote location from the surface of the cavity is provided, a heating means, a cooling medium or air is supplied after heating the mold, and a cooling medium is supplied after cooling the mold, whereby it is intended to reduce the molding time. However, the second heating medium channel hardly achieves the intended purpose, and rather, the configuration causes a problem, that a large number of processes are needed to form the fluid passage within the mold. In accordance with other improvements, that is, the method wherein the heated medium and the cooled medium are supplied in a dependent manner from the respective tanks, and recovered thereto, the method wherein the portion of the circuit commonly used by the medium heated and the cooled medium becomes as small as possible, the method where the medium is heated to the middle of the medium circuit only when a mold is going to be heated, and the method where the heating is carried out by heated water flowing through a closed cycle, does not intend to improve the heating and cooling system inside the mold, but the heating and cooling system inside the mold are left unchanged from a conventional configuration, but a different portion of the mold is improved to reduce the molding cycle. According to the foregoing, an object of the present invention is to provide a mold for molding synthetic resin, wherein it becomes possible to easily perform the change between the heating mode and the cooling mode to heat and cool a surface from . '.to. cavity inside the mold in a short period of time. Another object of the present invention is to provide a mold for molding synthetic resin, wherein it becomes possible to obtain a product without deformations or surface defects. A further object of the present invention is to provide a mold for molding synthetic resin, where it becomes possible to avoid mold fatigue caused by the change between the heating mode and the cooling mode of the mold. Still a further object of the present invention is to provide a mold for molding synthetic resin, wherein it becomes possible to reduce the flow of heating to a mold base, while making faster the increase in the surface temperature of the cavity.

DISCLOSURE OF THE INVENTION In accordance with the present invention, there is provided a mold for molding synthetic resin which includes a mold base, a cavity block provided inside the mold base, a heat insulating layer provided between the base of the mold and the block of the cavity, and a channel arranged near the cavity surface d = l block of the cavity, through which are supplied in an alternate and repeated manner, a heating means and a cooling medium, wherein provides a space in a contact portion between the base of the mold and the blockage of the cavity, based on the anticipation of a thermal expansion of the block of the cavity. When the melt is injected into the cavity, the heating means is supplied to the channel provided inside the cavity block, and then the cooling medium is supplied to the channel to cool a molded product inside the cavity. In this way, it becomes possible to make the product leave the cavity without deformations or superficial defects. Because an insulating layer of heat is provided between the base of the mold and the block of the cavity, heating and cooling can be effected more intensively on the block of the cavity, with the result that it can be reduced. the period of time needed to heat and cool the cavity block, and the responsibility for heating and cooling can be improved. Moreover, according to the configuration of the present invention, a space is provided in the contact portion between the base of the mold and the cavity block, based on the anticipation of a thermal expansion of the cavity block. Accordingly, even when the cavity block is expanded, the mold can be protected from internal thermal stress, with the result that the mold base and the cavity block can be used without fatigue. Further, in accordance with the configuration of the present invention, the cavity block has therein provided inlet and outlet slots communicating with the channel, and the inlet and outlet slots are joined to the thermally insulated conduits from the base of the mold. With the above configuration, it becomes possible to reduce the heating flow towards the base of the mold, while the increase in the temperature of the cavity becomes faster.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a diagram schematically showing a cross-section of a mold for molding synthetic resin in accordance with the present invention. Figure 2 is a diagram schematically showing a cross-section of a mold for molding synthetic resin, wherein a channel is provided which is used to supply a cooling medium exclusively. Figure 3 is a diagram schematically showing a cross section of a mold, sn where a channel is provided near a sidewall surface. Figure 4 is a diagram schematically showing a cross section of a mold for molding synthetic resin, having a cavity block where two sets of channels are provided. Figure 5 is a diagram showing a mold including a cavity block having a contact portion with a space. Figure 6 is a diagram illustrating the relationship between the contact portion and the cavity forming portion of the cavity block. Figure 7a is a front view of a mold having a slidable core. Figure 7b is a plan view thereof. . ? &, 8 Figure 7c is a plan view of a modification thereof. Figure 8 is a diagram of a pipe system for supplying a heating means and a cooling medium inwards of the blocks of the cavity, which are provided inside a movable mold half and a stationary mold half. Figure 9 is an operation diagram of the pipe system for supplying a heating means and a cooling medium. Figure 10 is a diagram illustrating the way in which the channels near the surface of the cavity are arranged. Figure 11 is another diagram illustrating the manner in which channels are configured near the surface of the cavity.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described hereinafter in detail with reference to the accompanying drawings. Figure 1 is a diagram schematically showing a cross-section of a mold for molding synthetic resin in accordance with the present invention. As shown in Figure 1, the mold for fr.-iS * "'J a» A - »? * >%. *, arA. molding is made up of the mold base 1 and the cavity block 2 provided in the mold base 1. The cavity block 2 is arranged to form the cavity 3. A system (ie channel A, through which are supplied in an alternate and repeated manner a heating means and a medium (ie cooling, is provided near the surface of the cavity 4. As shown in Figure 2, if the Al channel through which a cooling medium is constantly supplied , it is provided together with the channel A through which alternately and repeatedly a heating means and a cooling medium are supplied, the configuration will be convenient only when a local part of the cavity is to be cooled. d of channel A, it is set at 3 to 6 millimeters.The distance h between the surface of cavity 4 and the surface of channel A and AL, is set at 1 to 10 millimeters.Also, as the medium (ie heating, they use saturated steam, superheated steam, pressurized water, and hot water. Cooling water is used as the cooling medium. As described above, in accordance with the present invention, because the cavity block 2 is provided with the channel A, the manufacture of the channel A becomes easy, as compared to when the channel is directly formed inside a base of Thus, it becomes possible to manufacture channel A, where the medium can be prevented from becoming stagnant, and the temperature distribution of the surface of the cavity becomes uniform. channel A is provided only in a necessary portion, and other channels such as the Al channel are used, then it is expected to reduce the cooling process, and if the portion needed to be heated and cooled inside the mold is configured as the block cavity 2, then the mold can be heated and partially cooled easily.According to the configuration of the first invention, the heat insulating layer 5 formed of air, was provided na between the cavity block 2 and the base of the mold 1. The heat insulating layer 5 can be formed of any material other than air, having a low thermal conductivity. Due to the heat insulating layer 5, the block of the cavity 2 can be thermally insulated from the base of the mold 1, and consequently, the mold can be controlled in terms of temperature with a small amount of heat load, with the result that the surface of the cavity 4 of the block of the cavity 2 can be heated or cooled with a rapid response to heat. Moreover, the base of the mold 1 is provided with the circuit B through which a cooling means is constantly supplied. Circuit B is provided to control the temperature of the base of the mold. Due to the configuration of circuit B, * the entire mold can be free of the influence of the temperature change of the surface of the cavity 4, with the result that, when the molding mold is closed, it becomes possible to avoid the blistering caused by the difference in thermal expansion between a movable mold half and a stationary mold half. Although the above configuration is made to have the insulating layer (ie heat 5, layer 5 may not be provided, depending on the design of the mold) Furthermore, although in the configuration, the base of the mold 1 is divided into the movable mold half and the stationary mold half, and each of the halves (ie mold has the cavity block 2), and each of the cavity blocks 2 has the channel A formed therein, the channel A can be provided only inside one of the blocks of the cavity. When a flat plate product is going to be molded, it is desirable to additionally provide the channel through which the heating medium and the cooling medium are supplied alternately and repeatedly, outside the surface of the cavity 3. Without the channel, the cavity will suffer from a temperature reduction near the side portion of the cavity, due to the flow of heat from inside to outside the side face of the cavity. If a molding product has a cubic shape, with a sidewall surface and a wall surface. of the bottom, and the channel through which the heating means and the cooling medium are alternately and repeatedly supplied, is configured as two groups of channels, and is provided near the surface of the cavity that makes contact with the surface of the side wall and the wall surface of the cubic product bottom, respectively, as shown in Figure 3, it is desirable that the distance Pa from the nearest channel of a group of channels to the nearest channel of the other group of channels become smaller than the P separation in which the channels are arranged in each group of channels. If the distance Pa exceeds the distance P, it is preferable to additionally provide a channel at an intersection or within the intersection of the arrangement of the channels, along the bottom wall surface, and the arrangement of channels along the length of the channel. the side wall surface of the cubic cavity. Without the channel A2, the cavity 3 will suffer from a temperature reduction near the corner of the cavity 3. Figure 4 is a diagram schematically showing a cross-section of a mold for molding synthetic resin, having a cavity block in it. where two sets of channels are provided. As shown in the figure, the mold of the present embodiment has two groups of channels. That is, one Use .. -a ^ A. ^ *? *% of the groups of channels consists of the channels A through which the heating means and the cooling medium are supplied alternately and repeatedly, and are provided close to the surface of the cavity 4 of the cavity block 2. The other of the groups of channels is composed of the channel C through which the cooling medium is constantly supplied, and is provided in a remote portion of the surface of the cavity 4. In addition, the base of the mold 1 is configured to have the circuit B through which a cooling medium is constantly supplied, and the heat insulating layer 5 is provided between the block of the cavity 2 and the base of the mold 1. The channel A is may provide in a part of the block of the cavity near the cavity, and the channel C may be provided in a corresponding portion to a portion where the channel A is not provided. In this case, the C channel may be provided. provide over an area more The portion corresponding to the portion where channel A is not provided is provided. Alternatively, channel C may be provided over the entire area of the cavity block. Channel C may not be supplied with a cooling medium, or may be maintained under atmospheric pressure. As described above, if the block of the cavity 2 is configured to have the channel A through which the heating means and the cooling medium are alternately and repeatedly supplied, then the expansion on the block is caused. the cavity, leading to a thermal stress inside the molding mold, with the result that the block of the cavity 2 and the base of the mold 1 suffer fatigue. For this reason, it is necessary that the block of the cavity 2 and the base of the mold 1 be placed in a contiguous relationship with one another, or put into intimate contact with each other, by means of a small thermal stress, during which time a molten resin is injected. For this purpose, as shown in Figure 5, the space ti is provided between the block of the cavity 2 and the base of the mold 1, in a contact portion thereof, based on the anticipation of the thermal expansion of the block of the cavity 2. The space ti is determined in such a way that the thermal stress caused by the expansion of the block of the cavity 2 is lower than 200 MPa, preferably lower than 100 MPa, more preferably my lower than 50 MPa. If the space ti is provided in the contact portion between the block of the cavity 2 and the base of the mold 1, a tolerance is maintained between the block of the cavity 2 and the base of the mold 1, which becomes too large when the molds are kept at a low temperature. Accordingly, the block of the cavity 2 can be changed relative to the base of the mold 1, when the mold is heated or cooled. According to the present configuration, a fixing portion is provided between a contact portion of the block of the cavity 2 and the base of the mold 1, together with the gap t2 which is smaller than the space ti. The gap t2 of the fixing portion is set to 1 to 30 microns, preferably 1 to 20 microns, more preferably 1 to 10 microns. In addition, depending on the shape of the cavity, as shown in Figure 6, the block of the cavity 2 is designed in such a way that the contact portion of the cavity block 2 is remote from the cavity. More specifically, the block of the cavity 2 is designed in such a way that the surface of the block of the cavity 2 is larger than the surface of the cavity 4 formed by the block of the cavity 2. The counter-measure described above The thermal expansion of the cavity block can be applied in a similar manner to a mold having a slidable core, which will be described below. Figure 7a is a front view of a mold having a slidable core, Figure 7b is a plane thereof, and Figure 7c is a plan view of a modification thereof. As shown in Figure 7a, the first slidable core 6 provided on the side of the cavity 3, is configured to have the # block of the cavity 2 provided inside the first sliding core 6. The cavity block 2 is configured to having the channel A through which the heating means and the cooling medium are alternately and repeatedly supplied in a portion near the surface of the cavity 4. The heat insulating layer 5 is provided between the block the cavity 2 and the first sliding core 6. Furthermore, the first sliding core 6 is configured to have the circuit B, through which a cooling means is constantly supplied. As shown in Figure 7b, at both ends of the cavity 3 in its longitudinal direction, second and third sliding cores 7 and 8 are provided, by which the ends of the cavity 3 are defined. In accordance with the molding mold above, the space t3 is provided in a contact portion of the block of the cavity 2 and the second and third slide cores 7 and 8, based on the expansion of the block of 7th cavity 2. In accordance with the configuration of the modification shown in Figure 7c, the second and third sliding cores 7 and 8 are designed to have a small width, and a block surface of the cavity 2 is made SaA. í. larger than the surface of the cavity 4 that is formed by the block of the cavity 2, wherein the block of the cavity 2 can not come up against the second and third sliding cores 7 and 8, even when the block of the cavity is expanded. cavity 2. Figure 8 is a diagram of a pipe system for supplying a heating means and a cooling medium inwards of a cavity block, which is provided inside a stationary mold half 11, and a mold half. movable 12. As shown in the figure, a heating means and a cooling medium are alternately and repeatedly supplied to the channels, which are provided near the surface of the cavity of the cavity blocks inside the cavity. stationary mold half 11 and movable mold half 12. For this purpose, the pipe system includes switching valves on the upstream side (hereinafter referred to as a gas exchange valve). input voltage) Sa, Wa, Aa, Sb, Wb, and Ab on the upstream side of a fluid passage inlet. The piping system also includes downstream-side switching valves (hereinafter referred to as an "output switching valve") Ds4, WRa, Ds5, WRb, on the downstream side of the fluid passage outlet. The input switching valves and the output switching valves are preferably disposed at a location distant from the inlet of the fluid passage and the outlet of the fluid passage, respectively, by 3 meters or less. The pipe system also includes steam pressure regulating valves Ds6 and Ds7, and medium temperature sensing sensors Tbl and Tb2 provided near the outlet of the fluid passage on the upstream side in relation to the output switching valves Ds4 , WRa, Ds5, and WRb on the downstream side. The pressure regulating valves Ds6 and Ds7 are connected, on their drain side, to a drainage dam. The output switching valves Ds4 and Ds5 can be an automatic pressure regulating valve, in such a way that they have a pressure regulating function equal to that of the pressure regulating valves DS6 and Ds7. In accordance with the above embodiment of the present invention, saturated steam of 1 MPa (G) maximum, and 190 ° C, is used as the heating medium; Chilled water of 0.5 MPa (G) maximum, and 10 to 95 ° C, is used as the cooling medium; and maximum air of 0.7 MPa (G) is used, like gas. It is natural to say that the present invention is not limited to the embodiments wherein the pressures and temperatures described above are selected. The pressure regulating valves Ds6 and Ds7 can be adjusted to reduce the pressure loss in the fluid passage inside the mold, in such a way that the dispersion of the vapor pressure distribution within the fluid passage is reduced, and decrease the difference between the surface temperature of the cavity near the inlet of the fluid passage, and the temperature of the surface of the cavity near the outlet of the fluid passage. Furthermore, in accordance with the above configuration, the water condensed in the fluid passage inside the mold can be drained, while the vapor pressure inside the mold remains high. Accordingly, the temperature of the saturated steam can be kept high, the heat conductivity of the steam on the wall of the fluid passage inside the mold can be improved, and the heating capacity is improved. In the flow passage between the valves (ie input switching Sa, Wa, Aa, Sb, Wb, and Ab on the beat upstream of the fluid passage inlet, drain extraction valves Ds2 and Ds are provided. In addition, in the fluid passage on the upstream side of the steam inlet switching valves Sa and Sb, the drain extraction valves Dsl and Dsl 'are provided, and their extraction sides are connected respectively to the drain tank 13. Duct members 14 can be provided at the inlet of the fluid passage and at the outlet of the passage of fluid, and the conductive members 14 can be connected with the exhaust valves Ds2 and Ds3, and with the pressure regulating valves Ds6 and Ds7. In addition, in the flow passage between the inlet switching valve and the switching valve, "from * outlet, at least one inlet valve can be provided to introduce a gas (ie purge) ie, if they are entered separately air or something similar, to discharge the cooling water or similar inside the pipe system, then the cycle time of the molding process can be reduced.If the input switching valves Sa, Wa, Aa, Sb, Wb, and Ab on the upstream side, are arranged in the vertical direction, and steam, cooling water, and air are supplied from the lower side to the upper side of the pipe system, then it can be done flow cooling water to the upper side of the steam inlet switching valves Sa and Sb when changing the supplied fluid from steam to water (ie cooling) This can cause an abrupt change (ie temperature, leading to damage to the valves (ie steam input switching Sa and Sb.) With the object (ie to avoid this damage, it is desirable to supply air to the downstream side of the inlet switching valve before cooling water is introduced. , an air reservoir is formed in the upper portion of the steam inlet switching valves ~, -3__ttg-.

Sa and Sb, which prevents the cooling water from coming into direct contact with the steam, with the result that the steam inlet switching valves Sa and Sb ee can protect from damage. Further, based on a similar purpose, it is preferable to provide the one-way valve C on the downstream side of the steam inlet switching valves Sa and Sb. The heating and cooling fluid passage will be described with reference to the Figures 8 and 9. Initially, before the mold is opened, the air inlet switching valves Aa and Ab open on the upstream side, and the exhaust valves Ds2 and Ds3, to drain the cooled water into the passage. (ie fluid on the upstream side.) At the same time, the drain extraction valves Dsl and Dsl 'are opened on the upstream side, to discharge the drainage from the fluid passage, and then the valves are closed (ie extraction Ds2 and Ds3, and the output switching valves Ds4 and Ds5 are opened, in such a way that the cooling water inside the current flowing passage downstream of the exhaust valves Ds 2 and Ds3 is discharged with air. Then, during a period of time from the beginning of the opening of the mold until finishing it, or until finishing to remove a product, the valves of air change As and Ab and the valves of extraction of drainage of entrance of steam Dsl and Dsl ' they are closed, and the steam inlet switching valves Sa and Sb are opened, by means of which, steam introduction is initiated. If a period of time during which the output switching valves Ds4 and Ds5 open reaches a previously determined value, or the temperature of the medium flowing to the fluid passage reaches a previously determined value, then the switching valves are closed output Ds4 and Ds5, and the regulating valves (ie vapor pressure Ds6 and Ds7 on the downstream side) are opened, therefore the steam pressure is maintained, if a period of time during which the switching valves are opened The steam inlet Sa and Sb reach a previously determined value, or the mold temperature reaches a previously determined value, then a mold closing signal is generated to initiate the closure of the mold of the injection molding machine. When the mold is closed, the injection is started and the way in which the cooling water is introduced into the mold will be described. njection, the steam inlet switching valves Sa and Sb are closed on the upstream side, and the steam pressure regulating valves Ds6 and Ds7 on the downstream side, and the output switching valves Ds4 and Ds5 are opened on the downstream side, and the cooling water inlet switching valves, Wa, Wb on the upstream beat, whereby water is introduced (ie cooling into the pipe system, and the drain is discharged therefrom). . If a period of time during which the output switching valves Ds4 and Ds5 are opened, it reaches a predetermined value, or the temperature of the medium flowing in the flow passage reaches a previously determined value, then the output switching valves Ds4 and Ds5 are closed on the downstream side, and the output switching valves WRa and WRb are opened on the downstream side, whereby cooling water is recovered. If a predetermined period of time has elapsed, then the input switching valves Wa and Wb and the output switching valves WRa and WRb are closed. Accordingly, the processing passes to the step of discharging the cooling water in the flow passage with the air, and to the step of discharging the drain in the flow passage of the upstream side with the steam. According to the present embodiment, when the supplied medium is changed from cooling water to steam, the cooling water is purged with air. S: However, the supplied medium can change directly < Jki &L? »- •». from the cooling water to the steam without purging the cooling water with air. As described above, it is preferable that the step of closing the molcfe starts at half the increase or the end of the increase in the temperature of the surface of the cavity to a previously determined value, due to the supply of heating medium. , after the supplied medium is changed from the cooling medium to the heating means, and a previously determined period of time has elapsed. If this scheme is made, the period of time during which the mold is opened or closed, it can also be used as a period of time to increase the temperature of the mold, the fact of which results in the reduction of the molding process cycle . Moreover, the transfer of heat through a contact face between the stationary mold half and the movable mold half can be prevented. Accordingly, the above described scheme can be conveniently applied to the case where the stationary mold half and movable mold half are set at different temperatures, respectively. In addition, if the medium supply change is made from the heating medium to the medium (ie cooling in a different manner on the movable half of the mold and the stationary mold half, or alternatively, it is only supplied to the mold half Movable or in the stationary mold half the heating means, then the product removed from the mold can be prevented from deforming or having sinking marks.If a synthetic resin is configured by increasing or reducing the surface temperature repeatedly of the cavity, the temperature of the surface of the cavity when heated is set to charge deviation temperature + (0 to 70) ° C, to 4.6 kg / cm2 of a raw material resin, preferably + (0 to 50) ) ° C, more preferably + (0 to 30) ° C. Subsequently, the manner in which the channel is preferably constructed near the surface of the cavity of the cavity block will be described herein. In Figure 10, a plurality of channels are configured in the block of the cavity 2, in such a way that the passages are erect. Each upper end and lower end of the passages connects with the slot (ie horizontally left inlet 15, and also horizontally exit outlet slot 16. A downstream end portion of the inlet slot 15, and a portion of The upstream end of the outlet slot 16 is sealed in. When steam is introduced as a heating medium into the flow passages thus configured, the condensed water derived from the steam can be easily discharged, due to the action of gravity. Accordingly, heat can easily be transferred from the vapor to a wall of the flow passage within the mold, with the result that the surface temperature of the cavity can be rapidly increased. , the input slot 15 and the output slot 16 are provided inside the cavity block 2, and the input slot L5 and the output slot 16 are connected with the ducts 17, respectively, which are thermally insulated from the base of the mold 1 by means of an air layer. In this way, little heat is made to flow into the base of the mold 1, and consequently, the temperature of the cavity 3 can be increased rapidly. Furthermore, because the input slot L5 and the output slot 16 are provided outside the cavity 3, there will be little influence of the inlet slot 15 and the outlet slot 16 for the temperature distribution inside the cavity surface, with the result that the dispersion of the temperature distribution becomes small . It is preferable that the plurality of channels A have an equivalent hydraulic diameter equal to, and an equal effective length. In this way, a quantity of flow of a medium flowing through the plurality of channel A provided near the surface of the cavity becomes uniform, which makes it possible to limit the dispersion of the temperature distribution of the surface of the cavity. the cavity to a small range. In addition, the equivalent hydraulic diameters D of the inlet slot 15 and the outlet slot 16 are set to one to three times the equivalent hydraulic diameter d of the channel A. In this way, the pressure loss of the inlet slot 15 and the outlet slot 16 becomes small, the temperature of the steam flowing into the channel A provided near the surface of the cavity becomes uniform, and the dispersion of the temperature distribution of the surface of the cavity reaches be small Alternatively, the channel can be constructed close to the surface of the cavity, as shown in FIG. 11. That is, a pair of upstanding inlet slots 15 is provided near the right and left edges of the block. cavity, one opposite to the other. Also, a pair of outlet slots 16, also upright, are provided inside the inlet slots 15, near the right and left edges of the cavity block, one opposite the other. A plurality of channels A are arranged for adjusting the temperature of the cavity in parallel, in order to extend from an input slot 15 to the other output slot 16, and to connect with the input slot 15 and the slot output 16. The plurality of channels A can be tilted downward, downstream side. The upper and lower end portions of both inlet slots 15, and upper end portions (ie both outlet slots 16, are sealed in. A medium is then supplied from the upper end side of both inlet slots 15. According to this configuration, the medium is supplied from both sides in an opposite manner, and consequently, the temperature distribution of the surface of the cavity becomes uniform.In the pair of examples of the construction of the fluid passage, it forms a cavity block to have the channel through which a heating means and a cooling medium and its groove are alternately and repeatedly supplied, however, the cavity block can be divided into a part which have therein provided the channel through which a heating means and a cooling medium, and a part having the slot provided, are supplied in an alternate and repeated manner. a sealing member of the medium, such as an adhesive agent, is provided on a face that divides the block of the cavity into the two parts. According to the mold for molding synthetic resin of the present invention, the surface of the cavity can be heated and cooled within a short period of time. Accordingly, the present invention can be conveniently applied to a coating inside the mold, wherein a thermoplastic resin is injected into the mold, and a thermosetting resin is then injected therein, to obtain a painted product. The thermosetting resin is injected into the mold according to the present invention, to coat the thermoplastic resin with the thermosetting resin, then a medium is supplied (ie heating to the channels, to cure the thermosetting resin, and then a medium is supplied. of cooling to the channels to solidify the thermoplastic resin Accordingly, the painted product can be obtained with ease The raw material resins molded by the mold according to the present invention, can be an amorphous polymeric resin, such as chloride of polivini or (resin compounds, including rigid resin and soft resin, and the following materials are the same as above), acrylic ester resin (material containing acrylic acid, methacrylic acid, etc., as an acid, and also containing methyl group and ethyl group, etc., as an alkyl group), polystyrene (of the general purpose type, of the high impact strength type, etc.), acrylonitrile-butadiene-styrene resin, acrylonitrile-butadiene-styrene resin, oxide of modified polyphenylene, polycarbonate, polysulfone, polyarylate, polyetherimide, polyethersulfone, et cetera, and crystalline polymer, such as polyethylene (including low density, linear low density, (ie medium density, high density, etc.), polypropylene (such as homopolymer, random polymer, block polymer, etc.), polybutene-1, polymethylpentene-L, polyfluorocarbon (polyvinylidene fluoride, etc.), poly oxymethylene, polyamide (6.66, etcetera), terephthalic acid ester resin (polyethylene terephthalate, polybutylene terephthalate, etc.), polyphenylene sulfide, polyetheretherketone, polyetherketone, polyimide, etc., liquid crystal polymer (aromatic polyester, amide of aromatic polyester, etc.), thermosetting resin, such as epoxy resin, melamine resin, phenolic resin, urea resin, unsaturated polyester resin, polyurethane, silicone resin, alkyd resin, and alloys or fillers (particle filling, such as talc, etc., or fiber material, such as fiberglass, etc.), and compounds of the above resins. In addition, a molding method to which the mold for molding can be applied in accordance with the present invention, includes injection molding, transfer molding, compression molding, reaction injection molding, blow molding, thermoforming, and so on. In addition, injection molding includes, in addition to ordinary injection molding, injection-compression molding, local oscillation pressurization method, gas press method, gas assisted method, hollow molding, sandwich molding, two-part molding. colors, in-mold method, push-pull molding, high-speed injection molding, and so on. INDUSTRIAL APPLICABILITY As described above, the synthetic resin molding mold according to the present invention is useful as a mold for use with injection molding, compression molding, etc., of a thermoplastic ream, a thermosetting resin, and the like, wherein a surface (ie, a cavity) is alternately heated and cooled in a particular manner, according to the mold of the present invention, heating is effected only on the surface of the cavity when a melt is injected In the mold, therefore, the flowability of the resin is improved, and therefore, a thin-walled product can be appropriately molded, the shape of the surface of the cavity can be replicated in a satisfactory manner in a product, and the line of union or similar becomes less conspicuous.

Claims (26)

1. CLAIMS 1. A mold for molding synthetic resin, which comprises a mold base (1), a cavity block (2) having a cavity (3) provided inside the base of the mold (1), an insulating layer of heat (5) provided between the base of the mold (1) and the block of the cavity (2), and a channel (A) provided near a surface of the cavity (4) through which tare supplied in an alternating manner and a heating means and a cooling medium are repeated, wherein a space (ti) is provided in a contact portion between the block of the cavity (2) and the base of the mold (1), based on the anticipation of a thermal expansion of the cavity block (2). The mold for molding synthetic resin according to claim 1, wherein the space (ti) is established in such a way that a thermal stress caused when the block of the cavity (2) expands, becomes equal or lesser of 200 MPa. 3. The mold for molding synthetic resin according to claim 1, wherein a fixing portion with a recess (t2) smaller than the space (ti) between the cavity block (2) and the base of the mold is provided. (l) 4. The mold for molding synthetic resin according to claim 3, wherein the hollow (t2) of the 'Afea-,. - felfean ..? '-setting ratio is set $$ ^, the range of 1 to 30 microns. The mold for molding synthetic resin (ie according to claim 1, wherein a surface of the block of the cavity (2) is larger than a surface (4) (ie the cavity (3) 6. The mold for molding The synthetic resin according to claim 1, wherein the heating means is vaporized 7. The mold for molding synthetic resin according to claim 1, wherein there is provided an (Al) channel through which it is constantly supplied to cooling medium, in addition to the channel (A) 8. The mold for molding synthetic resin according to claim 1, wherein the block of the cavity (2) is composed of a stationary mold half and a mold half. movable, and is provided to at least one of the stationary mold half and movable mold half, the channel (A) 9. The mold for molding synthetic resin according to claim 1, wherein the cavity (3) it is configured as a cubic body that has a sup background wall surface and a side wall surface, two groups of channels, wherein the channels (A) are arranged in a separation (P), and through which the heating means is alternately and repeatedly supplied and the cooling medium, and are provided separately near the bottom wall surface and the sidewall surface of the cavity (3), and the distance (Pa) from the nearest passage of a group of channels to the The passage closest to the other group of channels becomes smaller than the separation (P) to which the channels (A) are arranged in each group of channels. The mold for molding synthetic resin according to claim 1, wherein the cavity (3) is arranged as a cubic body having a bottom wall surface and a side wall surface, two separate groups are provided separately. of channels, where mess channels (A) are arranged to a separation (P), and through which the heating means and the cooling medium are supplied in an alternate and repeated manner, close to the surface of the wall of the At the bottom and the surface of the side wall of the cavity (3), the distance (Pa) from the nearest channel of a group of channels to the nearest channel of the other group of channels is greater than the separation (P) a which channels (A) are arranged in each group of channels, and a channel is additionally provided (A2) at an intersection or in the intersection of the arrangement of channels (A), along the surface of the bottom wall, and of the arrangement of channels (A) along the surface of the side wall of the cubic cavity (3). 11. The mold for molding synthetic resin according to claim 1, wherein the channel (A) through which the heating means and the cooling medium are alternately and repeatedly supplied, is made to have an equivalent hydraulic diameter from 3 to 6 millimeters, and the distance (h) from one surface of the cavity (4) to a surface of the channel, is set at 1 to 10 millimeters. The mold for molding synthetic resin according to claim 1, wherein the block of the cavity (2) has provided therein inlet and outlet slots (15, 16) communicating with the channel (A), and the inlet and outlet slots (15,16) are joined with the ducts (17) thermally insulated from the mold base (1). The mold for molding synthetic resin according to claim 12, wherein the equivalent hydraulic diameter of the groove (15, 16) is set at one to three times the equivalent hydraulic diameter of the channel (A). The mold for molding synthetic resin according to claim 12, wherein the block of the cavity (2) is divided into a part having therein the channel (A), and a part having the slot ( 15, 15) provided, and a half-sealing member is provided on one face that divides the cavity block (2) into two parts. The mold for molding synthetic resin according to claim 14, wherein the medium sealing member is formed of an adhesive agent. 16. A product molded by the mold for molding synthetic resin according to claim 1 or 12. 17. A method for molding a synthetic resin, which comprises the steps of: injecting a thermoplastic resin into the molcie according to the claim 1 or 12; injecting a thermosetting resin into the mold to coat the thermoplastic resin on its surface, with the thermosetting resin; provide a heating medium to the channel (A) for curing the thermosetting resin; and providing a cooling medium in the channel (A) to cool the thermoplastic resin. 18. An apparatus for adjusting the temperature of the mold for molding synthetic resin according to claim 1 or 12, wherein an inlet switching valve (Sa, Wa, Aa, Sb, Wb, Ab), and a valve are provided. switching output (Ds4, Ds5, WRa, WRb), to select the supply of a heating medium and a cooling medium, in an upstream input and in a downstream output of the channel (A), and is provided when less an extraction valve (Ds2, Ds3) to discharge the heating means, the cooling medium, and a gas, in the flow passage, in a portion between the inlet switching valve (Sa, Wa, Aa, Sb , Wb, Ab) and the output switching valve (Ds4, Ds5, WRa, WRb). The apparatus according to claim 18, wherein at least one inlet valve is provided through which a purge gas is supplied in the fluid passage in the portion between the inlet switching valves (Sa, Wa, Aa, Sb, Wb, Ab) and the output switching valves (Ds4, Ds5, WRa, WRb). The apparatus according to claim 18, wherein a one-way valve (c) is provided on the downstream side of the inlet switching valve (Sa, Sb) for the heating means. A method for adjusting the temperature of the mold for molding synthetic resin according to claim 1 or 12, the method comprising a step of supplying a heating means and a cooling medium to the channel (A) in an alternate and repeated manner , for heating and cooling the surface (4) of the cavity (3), wherein, when the supply of the medium is changed from the cooling medium to the heating means, at least one of the extraction valves is opened (Ds2 , Ds3) provided on the upstream side and the downstream side of the channel (A), and the cooling medium remaining inside the channel is discharged by means of a gas or the heating medium. 22. The method according to claim 2, wherein, when the medium supply is changed from the heating medium to the cooling medium, a purge gas is supplied to the channel. 23. The method according to claim 2, wherein the supply of the heating medium begins at a point of time between the opening of the mold until the expulsion of a molded product. 24. The method according to claim 23, wherein the mold does not close until a predetermined period of time has elapsed after the supply of the heating medium is started. 25. The method according to claim 23, wherein the mold is not closed until the heating means is supplied to heat a surface (4) of the cavity (3), or to finish heating the surface (4). ) from the cavity (3) to a predetermined temperature. 26. The method according to claim 21, wherein the heating means is steam. SUMMARY A metal mold, which comprises an insert (2) contained in a base mold (1), insulating layers (5) provided between the base mold (1) and the insert (2), and a series of trajectories of flow (A) to allow a heating means and a cooling medium to flow in an alternate and repeated manner, which are provided near the surface of the cavity (4) of the insert (2), wherein a tolerance is provided in a closed adjustment portion between the insert (2) and the base mold (1) to compensate for the amount of expansion of the insert (2), and communication flow paths are provided on the input side and the output side of the toolpaths. flow (A) in the insert (21), and the communication tubes isolated from the base mold (1) are connected to the communication flow paths of the input side and the output side. * * * * * g ^ - - * - ~ «• ** fe- & - -. - • - -f tf itilfr ¡t? G ^^ - *: - - »• - * - ^ Fig.5 Fig.6 ^^^ ^ ¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡ -J -__-_-_-_ 7 * ig.7b ^^^ jH ^ mt ^ M¡i? l? _ ^^^^^^^^^^ ijiMS »2jfj¡l¡jg ^^ Fig.7c t ^ S ^^^ ü ^ gg * n * ' Fig.9 VAFOR ENTRY SOLIDA DE ^^^ jgj¡¡ ^^ ¡iiiriiWi i ^^^^^^ --- if-ir --- ^ - ^^ "-'-- ^ - 2 ^ '--- - - ..A ^ AJ ^, »