JP5012454B2 - Method for machining parting surface of molding apparatus - Google Patents

Description

  The present invention relates to a method for processing a parting surface of a molding apparatus.

  As shown in Patent Document 1, the molding apparatus includes a surface material that forms a cavity as a mold surface and a back surface of the surface material in order to quickly adjust the temperature of the three-dimensional mold surface without uneven temperature. It is proposed that a passage is formed with a support material that supports the substrate, a temperature adjusting pipe for flowing a temperature adjusting medium is disposed in the passage, and a low melting point metal is filled around the temperature adjusting pipe. ing. According to this, by forming grooves on the back side of the surface material or the surface side of the support material and assembling them, a passage can be formed at a certain close distance from the surface of the surface material, and the temperature control pipe is formed in the passage. Can be placed. In addition, a low melting point metal is filled between the passage and between the temperature control, so that a space layer can be eliminated between the inner wall of the passage and the temperature control pipe, and heat transfer not by convection but by conduction can be performed. it can. Thus, the temperature of the three-dimensional mold surface can be quickly adjusted without leaking the temperature adjusting medium.

  On the other hand, in the molding apparatus, a countermeasure against burrs is required, and as one of them, as shown in Patent Document 2, a cooling passage is formed in the mold near the parting surface, and a cooling medium is formed in the cooling passage. It is known that the parting surface is cooled by flowing a gas. According to this, the molten resin leaking from the cavity to the parting surface can be solidified, and thereafter, based on the solidified resin, the molten resin can be prevented from leaking from the cavity to the parting surface, thereby suppressing the generation of burrs. it can.

  Therefore, if the content shown in Patent Document 1 is applied to such a molding apparatus according to Patent Document 2, the parting surface can be quickly cooled and the occurrence of burrs can be suppressed without leaking the temperature adjusting medium.

JP 2002-172625 A JP 2005-297386 A

  However, when the parting surface is cooled at the time of molding, the parting surface contracts more than the other parts with the cooling. For this reason, a gap into which the molding material can enter the parting surface is generated, and the burr suppressing effect due to cooling of the parting surface is reduced.

  Then, an object of this invention is to provide the processing method of the parting surface which can improve the burr | flash suppression effect by cooling of the parting surface of a shaping | molding die.

  According to one aspect of the present invention, temperature adjusting means for adjusting the temperature of the cavity surface formed when the first mold and the second mold are closed, and at least the material is supplied into the cavity. A parting surface processing method in a molding apparatus comprising: a cooling unit that cools at least one parting surface of the first molding die and the second molding die. A temperature control step of cooling the parting surface by the cooling means, and maintaining the temperature adjustment of the cavity surface and the cooling of the parting surface in the temperature control step. A processing method for processing the parting surface so as to obtain close contact with the parting surface. It is.

  According to the above method, the temperature of the cavity surface is adjusted by the temperature adjusting means, and the parting surface is cooled by the cooling means, in order to process the parting surface in the same temperature environment as that during actual molding. In addition, a parting surface having a high degree of adhesion can be obtained at the time of molding, and the burr suppressing effect by cooling the parting surface can be enhanced.

  According to a preferred embodiment of the present invention, in the processing step, after the processing of the parting surface, the temperature adjustment of the cavity surface and the cooling of the parting surface in the temperature control step are maintained. It is preferable to perform mold alignment inspection of the parting surface, and when the adhesion state of the parting surface is poor, the parting surface is processed again.

  According to the above method, in a state where the temperature adjustment of the cavity surface and the cooling of the parting surface are performed, the processing of the parting surface and the mold alignment inspection are repeated, and a good adhesion state of the parting surface can be obtained. .

  ADVANTAGE OF THE INVENTION According to this invention, the processing method of the parting surface which can heighten the burr | flash suppression effect by cooling of the parting surface of a shaping | molding die can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an overall view showing a molding apparatus according to the present embodiment, and FIGS. 2 and 3 are views showing a mold opening state and a mold closing state of the molding apparatus according to the present embodiment, respectively.

  1-3, the code | symbol 1 is the shaping | molding apparatus which concerns on embodiment, and the shaping | molding apparatus 1 can approach and move apart with respect to the fixed mold | type (one of the 1st, 2nd shaping | molding mold) 2 and the fixed mold | type 2. And a movable type (the other of the first and second molds) 3. The fixed mold 2 and the movable mold 3 are configured such that a parting surface 2a that is a mold-matching surface of the fixed mold 2 and a parting surface 3a that is a mold-matching surface of the movable mold 3 come into contact with each other from the mold open state and are closed When the state is reached, the cavity 4 is formed between the two and the cavity 3, and the cavity 4 is set in a shape corresponding to a predetermined shape of the molded product.

  In FIG. 1 to FIG. 3, for easy understanding, the cavity 4 and a simplified shape of the cavity recess 4 a in each mold (the fixed mold 2 and the movable mold 3) constituting the cavity 4 are shown. However, for example, when a molded product of a vehicle bumper is molded as a molded product, the inner surface of the fixed mold 2 is as shown in FIG. 4, and the inner surface of the movable mold 3 is as shown in FIG. In FIG. 4, reference numeral 5 denotes a slide core, and a portion 6 indicated by hatching indicates a parting surface 2 a on the outer peripheral edge side of the cavity 4 in the fixed die 2, and a portion 7 indicated by hatching in FIG. The parting surface 3a on the outer peripheral edge side of the cavity 4 in the corresponding movable mold 3 is shown.

  As shown in FIGS. 1 to 3, the fixed mold 2 is formed with a resin flow passage 8 that faces the cavity 4 from the outer surface. An injection molding machine 9 is connected to the resin flow passage 8 on the outer surface of the fixed mold 2, and molten resin as a material is supplied into the cavity 4 by the injection molding machine 9. In addition, the fixed mold 2 and the movable mold 3 are each formed with a circulation passage 10 so as to pass through the back side of the cavity 4, and a temperature adjustment device that allows a temperature adjustment medium (temperature-controlled water) to flow through the circulation passage 10. The mold temperature controller 11 is connected via a connection hose 12 (see FIGS. 2 and 3), and the temperature state in the cavity 4 is adjusted by the temperature adjusting medium. In FIG. 1, the arrows for the circulation paths 10 of the fixed mold 2 and the movable mold 3 indicate the flow state of the temperature adjustment medium. As the temperature adjusting medium, for example, temperature-controlled water of about 25 to 30 ° C. is always supplied so that the inner wall surface of the cavity 4 at the time of injection molding is about 40 ° C., for example. In FIG. 1, unlike the cases of FIGS. 2 and 3, the connection relationship between the circulation passage 10 and the mold temperature controller 11 is shown in a simplified manner.

  The parting surface 2a of the fixed mold 2 and the parting surface 3a of the movable mold 3 are respectively formed so that a groove 13 is opened to the outside, as shown in FIGS. ing. Both the grooves 13 are formed corresponding to each other, and when the fixed mold 2 and the movable mold 3 are in the mold-closed state, the openings of both the grooves 13 are combined. The grooves 13 are arranged in the vicinity of the outer peripheral edge of the cavity 4, and the distance from the outer peripheral edge of the cavity 4 does not affect the original resin molding in the cavity 4 as much as possible by the burr generation suppression process described later. It is set to be as close as possible. Specifically, it is set to a certain distance L (for example, about 0.5 to 1.0 cm) from the outer peripheral edge of the cavity 4. In FIGS. 1 to 3, 6, and 7, the groove 13 is disposed only in a part of the peripheral edge of the cavity 4 for simplification. A part is formed so as to surround substantially the entire circumference of the cavity 4. This will be described later.

  As shown in FIGS. 1 to 3, 6, and 7, a temperature control pipe 14 is press-fitted into each groove 13. The temperature adjusting tube 14 appropriately flows a heating medium or a cooling medium, which is a temperature adjusting medium, for the purpose of suppressing the generation of burrs and preventing the dew formation of the fixed mold 2 and the movable mold 3, and the temperature adjusting medium. Thus, the temperature of the parting surfaces 2a and 3a of the fixed mold 2 and the movable mold 3 is adjusted. In this embodiment, a copper (thermal conductivity: about 400 W / m · K) temperature control pipe is used as the temperature control pipe 14. By using the copper temperature control pipe 14, ductility is achieved. The ease of press-fitting work utilizing malleability, adhesion to the inner wall of the groove 13, and high thermal conductivity are ensured.

  Moreover, each temperature control pipe | tube 14 is located in a part of outer peripheral part vicinity of the cavity 4 corresponding to each groove | channel 13, as shown in FIGS. 1-3, FIG. 6, FIG. However, this is because the illustration is simplified for easy understanding. Actually, as shown in FIGS. 4 and 5 showing the fixed mold 2 and the movable mold 3 when molding the bumper, each mold is shown. A plurality of temperature control tubes 14 are prepared for every second and third, and a part of each temperature control tube 14 cooperates to surround the outer peripheral edge of the cavity 4 over substantially the entire circumference. Along with this, the grooves 13 are also formed in the molds 2 and 3 in conformity with the temperature adjusting pipes 14 so that they can be arranged and press-fitted. 4 and 5, the arrow for each temperature control tube 14 indicates the flow of the temperature adjustment medium in each temperature control tube 14.

  The temperature control tubes 14 of the fixed mold 2 and the movable mold 3 are exposed to the outside through the opening of the groove 13 as shown in FIGS. Each temperature control tube 14 is disposed so that its exposed surface is substantially flush with the parting surface or slightly retracts into the groove 13, and the exposure of both the temperature control tubes 14 of the fixed mold 2 and the movable mold 3 is performed. The surfaces are opposed to each other in a very close state (including a contact state). Further, a closed space 15 is formed between the temperature control tube 14 and the bottom of the groove 13 based on the surface roughness of the temperature control tube 14 and the groove 13, processing variations, and the like. Agent 16 is filled. As the adhesive 16, an adhesive having a thermal conductivity higher than that of the air in the space 15 is used. In the present embodiment, the adhesive 16 is an adhesive containing silver as a main component. It is considered as an agent. Such an adhesive 16 containing silver as a main component has a composition of silver: about 65% by weight, the rest: boron nitride, a resin, and a curing agent, and its thermal conductivity is 7.5 W / m · K. The adhesive 16 is filled by putting the adhesive 16 in the groove 13 before press-fitting the temperature adjusting pipe 14 into the groove 13, or putting the adhesive 16 on the outer peripheral surface of the temperature adjusting pipe 14. This is done by attaching it. Further, the adhesive 16 is formed in the space in the groove 13 on the cavity side on the temperature control pipe 14 as shown in FIGS. 6 and 7 in order to further enhance the cooling effect of the parting surfaces 2a and 3a on the cavity 4 side. Filled.

  As shown in FIG. 1, a heating medium supply source 18 and a cooling medium supply source 19 are connected to one end of the temperature control pipe 14 of the fixed mold 2 and one end of the temperature control pipe 14 of the movable mold 3 via a medium supply pipe 17. Is connected to the other end of the temperature control tube 14 of the fixed mold 2 and the other end of the temperature control tube 14 of the movable mold 3 via a medium reflux tube 20 as shown in FIG. A supply source 18 and a cooling medium supply source 19 are connected.

  The heating medium supply source 18 includes a series of elements that send out a temperature adjustment medium (heating medium) such as a pump that sends out the temperature adjustment medium, a heating source that heats the temperature adjustment medium, and the like. An opening / closing valve 18 a made up of an electromagnetic valve is interposed between the supply port side of 18 and the medium supply pipe 17, and between the return port side of the heating medium supply source 18 and the medium return pipe 20. On-off valves 18b made of electromagnetic valves are respectively interposed.

  The cooling medium supply source 19 includes a series of elements that send out a temperature adjustment medium (cooling medium), such as a pump that sends out the temperature adjustment medium, a cooling source that cools the temperature adjustment medium, and the like. An on-off valve 19 a made up of an electromagnetic valve is interposed between the supply port side of the cooling medium and the medium supply pipe 17, and between the return port side of the cooling medium supply source 19 and the medium return pipe 20 On-off valves 19b each consisting of a valve are interposed.

  In the present embodiment, a heat insulating hose is used as the medium supply pipe 17 and the medium reflux pipe 20. This is because the movable mold 3 can move toward and away from the fixed mold 2 on the basis of the flexibility and flexibility of the heat insulating hose.

  The temperature adjusting medium used in the heating medium supply source 18 and the cooling medium supply source 19 is preferably a medium that can be used in a wide range from a low temperature to a high temperature, for example, a fluorinated fluid (for example, perfluoropolyether (PFPE)). This fluorine-based fluid is advantageous because it does not corrode the copper temperature control tube 14.

  In FIG. 1, the code | symbol U shows a control apparatus. The control device U is mainly for the purpose of controlling the temperature adjusting medium for the fixed mold 2 and the movable mold 3, and performs a predetermined control based on the elapsed time from the start of the mold closing process to the process of taking out the molded product. Is supposed to do. For this reason, the control device U receives a start signal from the switch SW for detecting the start of the mold closing process, and from the control device U, the heating medium supply source 18, the on-off valves 18a and 18b, the cooling medium supply Control signals are to be output to the source 19 and the on-off valves 19a and 19b.

  Next, the content of control by the control device U will be specifically described together with the molding process by the molding device 1.

  In the molding apparatus 1, as shown in FIG. 8, the steps of mold closing, injection, pressure holding, cooling, mold opening, and molded product taking out are sequentially performed. When the transition to the process is started, the supply of the heating medium from the heating medium supply source 18 is stopped by closing the on-off valves 18a and 18b based on the detection signal from the sensor SW, while the on-off valve 19a and 19b are opened, a cooling medium (fluorine-based fluid) is supplied from the cooling medium supply source 19 to the temperature adjusting pipe 14 of the fixed mold 2 and the temperature adjusting pipe 14 of the movable mold 3, and the fixed type is supplied by the cooling medium. The parting surface 2a of 2 and the parting surface 3a of the movable mold 3 are cooled. This cooling is performed from the injection process to the initial stage of the pressure holding process, and the temperatures of the parting surfaces 2a and 3a of the fixed mold 2 and the movable mold 3 are gradually lowered as shown in FIG. The temperature is lowered to the following temperature (specifically, for example, 23 to 24 ° C.).

  As a result, the molten resin 21 to be leaked from the cavity 4 to the parting surfaces 2a and 3a of the fixed mold 2 and the movable mold 3 is positively solidified, and thereafter the molten resin 21 in the cavity 4 is leaked by the solidified product. Is prevented, and burrs, which are a solidified product of molten resin, are suppressed from occurring on both parting surfaces 2a and 3a. In particular, in the pressure-holding step, the molten resin is pressurized and replenished as the molten resin is condensed, and based on this, the molten resin easily leaks to both the parting surfaces 2a and 3a (burr generation timing in FIG. 8). As shown in the region, leakage of the molten resin can be prevented by positive cooling of the parting surfaces 2a and 3a. At this time, each temperature control tube 14 is press-fitted into the inner wall of the groove 13 and is firmly attached, and adhesion with silver as a main component in the closed space 15 between each temperature control tube 14 and the bottom of the groove 13 Cooling effect on the molten resin which is filled with the agent 16 and can take away the heat of the parting surfaces 2a and 3a with conduction under high thermal conductivity, so as to leak between the parting surfaces 2a and 3a. (Coagulation) can be increased.

  When the cooling process for the cavity 4 is started through the pressure holding process, the control device U closes the on-off valves 19a and 19b and stops the supply of the cooling medium, while opening the on-off valves 18a and 18b to open the heating medium. (Fluorine-based fluid) is supplied to the temperature control pipe 14 of the fixed mold 2 and the temperature control pipe 14 of the movable mold 3, and heating of the parting surfaces 2a and 3a of the fixed mold 2 and the movable mold 3 is started. For this heating, for example, a heating medium of about 40 ° C. is supplied until the mold opening process, and the temperatures of the parting surfaces 2a, 3a of the fixed mold 2 and the movable mold 3 are, for example, temperatures exceeding 25 ° C. (specifically, for example, 26-27 ° C.). As a result, as in the case of the cooling described above with respect to the parting surfaces 2a and 3a of the fixed mold 2 and the movable mold 3, the parting surfaces 2a and 3a of the fixed mold 2 and the movable mold 3 are heated with high heat transfer, and the mold is opened. Occasionally, dew condensation is prevented from occurring in the fixed mold 2 and the movable mold 3.

  Thereafter, a mold opening process for opening the fixed mold 2 and the movable mold 3 is performed, and in the take-out process, the molded product is taken out from the mold and the molding of one molded product is completed.

Therefore, in the present embodiment, by increasing the thermal conductivity from each temperature control tube 14 to both the parting surfaces 2a, 3a of the fixed mold 2 and the movable mold 3, both the parting surfaces 2a, particularly in the pressure holding step. , 3a can be immediately solidified to prevent the molten resin 21 from leaking and the occurrence of burrs can be suppressed. Further, in the cooling process of the cavity 4, both the parting surfaces 2a and 3a can be heated by the heat from the respective temperature control tubes 14 with the same high heat transfer property, and the fixed mold 2 and the movable mold 3 are moved to each other when the mold is opened. Condensation can be prevented from occurring.
In addition, the mounting operation of each temperature control tube 13 is simply a work of press-fitting the temperature control tube 13 into each groove 13, so that the mounting operation can be facilitated.

  On the other hand, a unique problem occurs in the molding apparatus employing the above-described configuration. That is, in the pressure holding process, the parting surfaces 2a and 3a are actively cooled, so that the parting surfaces 2a and 3a have a lower temperature than the other parts. Therefore, the parting surfaces 2a and 3a are lower than the other parts. Also, the amount of shrinkage increases. Specifically, as shown in FIG. 9, the parting surfaces 2a and 3a at the time of cooling contract with the ideal surfaces 2a ′ and 3a ′, respectively. A gap is formed between the sealing surface 3a and the molten resin. Due to this defective phenomenon, the burr reduction effect by cooling the parting surface is reduced.

  In order to solve this problem, in the present embodiment, the parting surfaces 2a and 3a are processed by the following steps when the molding apparatus is manufactured or repaired.

(1) First, temperature control similar to that at the time of actual injection molding of the molding apparatus 1 is performed. That is, the temperature of the cavity 4 is adjusted by the mold temperature controller 11. Specifically, as described above, for example, temperature-controlled water of about 25 to 30 ° C. is supplied so that the inner wall surface of the cavity 4 at the time of injection molding is about 40 ° C., for example. Then, while the mold temperature controller 11 supplies the temperature-controlled water, the control device U supplies the cooling medium from the cooling medium supply source 19 to the temperature adjusting pipe 14 of the fixed mold 2 and the temperature adjusting pipe 14 of the movable mold 3. Then, the parting surfaces 2a and 3a are cooled by the cooling medium. Thereafter, this temperature state is maintained. As described above, in this state, the parting surfaces 2a and 3a contract with respect to the ideal surfaces 2a 'and 3a', respectively.

(2) As shown in FIG. 10, the welding material 20 is built up on the parting surfaces 2a and 3a. As this welding material 20, for example, a material containing Fe (iron) as a main component and containing, for example, Mn (manganese), Si (silicon), C (carbon), and Mo (molybdenum) may be used.

(3) As shown in FIG. 11, a portion that is convex with respect to the ideal surfaces 2 a ′ and 3 a ′ is cut using a grinder 21.

(4) As shown in FIG. 12, for example, Komyotan is applied to the entire surface of the parting surface 2 a of the fixed mold 2, and as shown in FIG. 13, the parting surface 2 a of the fixed mold 2 and the parting of the movable mold 3 The mold is closed by contacting the surface 3a.

(5) Thereafter, as shown in FIG. 14, the mold is opened, and the transfer state of the light phosphor to the parting surface 3 a of the movable mold 3 is confirmed. The parting surface floats (protrudes) with respect to the ideal surface in the part where Komyotan is darkly transferred, and conversely, in the part where Komyotan is thinly transferred or not transferred at all, the parting surface Can be determined to be recessed with respect to the ideal surface. In this way, the defective part can be easily visually observed by Kokaritan.

(6) As shown in FIG. 15, the part where the light agitation is strongly transferred, that is, the part where the parting surface is lifted with respect to the ideal surface, is cut using the grinder 21 and is resurfaced. In addition, the welding material is piled up again on the portion where Komyotan is thinly transferred or not transferred at all, and cutting and re-facing are performed.

(7) Wipe the light once, apply the light again to the whole surface of the parting surface 2a of the fixed mold 2, and bring the parting surface 2a of the fixed mold 2 and the parting surface 3a of the movable mold 3 into contact with each other. Closed.

(8) After that, when the mold is closed, the parting surface 2a of the fixed mold 2 and the parting surface 3a of the movable mold 3 are in close contact with each other, so that the light is transferred uniformly over the entire area of the parting surface 3a. Steps (5) and (6) are repeated until

  As described above, the parting surface processing method in the present embodiment is performed in a temperature environment controlled at the time of actual injection molding. Therefore, considering the shrinkage phenomenon of the parting surface that may occur at the time of actual injection molding. To smooth the parting surface. As a result, by actively cooling the parting surface, especially during the pressure holding process, the molten resin that easily leaks to the parting surface is immediately solidified, preventing subsequent leakage of the molten resin and thereby suppressing the occurrence of burrs. In the molding apparatus configured to do so, the effect of suppressing the occurrence of burrs can be further ensured.

  In addition, in the above-mentioned embodiment, although demonstrated on the assumption of injection molding, it cannot be overemphasized that this invention is applicable to a casting mold.

1 is an overall view showing a molding apparatus according to an embodiment. Explanatory drawing explaining the mold open state of the shaping | molding apparatus which concerns on embodiment. Explanatory drawing explaining the mold closing state of the shaping | molding apparatus which concerns on embodiment. Explanatory drawing which shows the position of the parting surface of a cavity peripheral part in the fixed mold inner surface which shape | molds a bumper. Explanatory drawing which shows the position of the parting surface of a cavity peripheral part in the movable inner surface which shape | molds a bumper. Explanatory drawing explaining the state of the parting surface at the time of a mold opening. Explanatory drawing explaining the state of the parting surface at the time of a mold closing. Explanatory drawing explaining the temperature state of the parting surface in each manufacturing process and a manufacturing process. The figure explaining the shrinkage phenomenon of a parting surface. The figure explaining the build-up process of the welding material to a parting surface. The figure explaining the cutting process of the convex part of the welding material on a parting surface. The figure explaining the application | coating process of Komyotan to a parting surface. The figure explaining the mold closing process of the parting surface where Komyotan was applied. The figure explaining the process of confirming the transcription | transfer state of Komyotan from the mold closed state of FIG. 11 to a mold open state. The figure explaining the re-cutting and re-facing process according to the transfer state of Komyotan.

Explanation of symbols

1 Molding device 2 Fixed mold (one of the first and second molds)
2a Parting surface (mating surface)
3 Movable mold (the other of the first and second molds)
3a Parting surface (mating surface)
4 Cavity 13 Groove 14 Temperature control tube 16 Adhesive 21 Molten resin

Claims (3)

Temperature adjusting means for adjusting the temperature of the cavity surface formed when the first mold and the second mold are closed; and at least while the material is being supplied into the cavity, the first mold and the A processing method of a parting surface in a molding apparatus comprising a cooling means for cooling at least one parting surface of a second molding die,
A temperature control step of adjusting the temperature of the cavity surface by the temperature adjusting means, and cooling the parting surface by the cooling means;
A processing step of processing the parting surface so as to obtain close contact of the parting surface while maintaining temperature adjustment of the cavity surface and cooling of the parting surface in the temperature control step;
A method of processing a parting surface, comprising:   In the processing step, after the parting surface is processed, a mold alignment inspection of the parting surface is performed in a state where temperature adjustment of the cavity surface and cooling of the parting surface are maintained in the temperature control step. The parting surface processing method according to claim 1, wherein the parting surface is processed again when the adhesion state of the parting surface is poor.   The method of processing a parting surface according to claim 1 or 2, wherein the material is a molten resin.

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