JP4553932B2 - Lens cover manufacturing method - Google Patents

Description

  The present invention relates to a lens cover manufacturing method for manufacturing a lens cover of an automotive illumination lamp (for example, an automotive headlamp).

  FIG. 1 is a cross-sectional view of a car headlamp, and FIG. 2 is an enlarged view of a portion E in FIG. Referring to FIG. 1, an automotive headlamp is configured with a lens cover 8 bonded to a housing 9.

  Here, the lens cover 8 is specifically formed of a polycarbonate resin material, and includes a lens cover main body (design) 4 and a convex lens seal foot 5 formed at an edge of the lens cover main body 4. Have. Further, the housing 9 is formed with a concave housing 13. As shown in FIG. 2, the filler 12 is applied to the concave housing 13, and the convex lens seal foot 5 is applied to the concave housing 13. By inserting, the convex lens seal foot 5 and the concave housing 13 can be joined. In this way, the lens cover 8 is joined to the housing 9 by joining the convex lens seal foot 5 and the concave housing 13 (that is, the portion E of FIG. 1 shown in FIG. 9 and the lens cover 8).

  As described above, when the convex lens seal foot 5 and the concave housing 13 are joined, a seal height G of a certain level or more is required in order to ensure the sealing performance of the joint portion. When a lens cover body (design) is turned around in a lens cover of a type of automotive headlamp, the lens cover removal direction 10 and the concave housing molding removal direction 11 may be different. In this case, the opening angle of the joint is increased due to the difference in the molding direction, and the vicinity of the base of the convex lens seal foot 5 is thicker than the average thickness of the product, as indicated by F in FIG. Become. Taking FIG. 1 and FIG. 2 as examples, the extraction angle difference D between the lens cover and the concave housing is 17 °, and G = 4 mm and F = 6.7 mm. The portion 5a of the lens seal foot 5 which is thicker than the average thickness of such a product is called the thick portion of the lens seal foot 5, and the lens cover body (design) 4 of the thick portion 5a of the lens seal foot 5 The connecting portion 5b is called a standing wall. Note that the thickness H of the standing wall 5b of the lens seal foot 5 is about 2.5 mm, which is substantially equal to the average thickness.

  3 and 4 are views for explaining a conventional manufacturing method of the lens cover 8 of the automotive headlamp as described above. 3 is a front view of the lens cover 8, FIG. 4 is a cross-sectional view taken along the line AA of FIG. 3, and FIG. 4 shows molds 6a and 6b for manufacturing the lens cover 8. FIG. Has been. Here, the mold 6a is a fixed mold, and the mold 6b is a movable mold.

3 and 4, the lens cover 8 of the automobile headlamp as described above is manufactured by an injection molding method. That is, resin (specifically, polycarbonate) melted from a molding machine (not shown) is injected into the mold 6a from the injection point 1 and flows into the lens seal foot 5 through the cold runner 2 and the gate 3. Further, the lens cover 8 is manufactured by flowing into the lens cover main body (design) 4 from the lens seal foot 5. Here, the resin temperature of the resin material (polycarbonate) is about 290 ° C., and the temperatures of the molds 6a and 6b are about 80 ° C.
JP 2001-14915 A

  By the way, when manufacturing the lens cover 8 by the injection molding method as described above, the molten resin that has flowed into the lens seal foot 5 from the gate 3 flows first from the thick portion 5a that is easier to flow than the standing wall 5b. FIG. 5 is a diagram (enlarged view) showing a resin flow analysis result in the vicinity of the gate 3 0.5 seconds after the start of filling the molten resin 7 from the gate 3. From FIG. 5, the flow K along the lens seal foot 5 advances by 20 mm more as the flow length compared to the flow J in the direction of the standing wall 5b. After this flow of the molten resin 7 further proceeds, the flow tip after 3 seconds turns around the lens seal foot 5 as shown by 13 in FIG. 6 and further rises to the lens cover body (design) 4 after 5 seconds. Forming an unfilled bag closure (indicated by 14 in FIG. 7). Due to this phenomenon, an unfilled portion is generated on the lens cover main body (design) 4, and there is a problem that silver streaks and weld lines are generated due to heat generation when the gas in the unfilled portion is rapidly discharged.

  The present invention has a lens cover main body and a lens seal foot formed on an edge of the lens cover main body, and the lens seal foot is connected to a thick portion and the lens cover main body of the thick portion. In a lens cover manufacturing method for manufacturing a lens cover of an automotive lighting lamp having a portion, a predetermined mold is used, and a portion to be a lens seal foot of the mold is changed to a portion to be a lens cover main body. Lens cover that can effectively prevent the occurrence of unfilled parts on the lens cover body and prevent the occurrence of silver streaks and weld lines when manufacturing molten lens resin The object is to provide a manufacturing method.

In order to achieve the above object, an invention according to claim 1 includes a lens cover main body and a lens seal foot formed on an edge of the lens cover main body, and the lens seal foot includes a thick portion. In the lens cover manufacturing method for manufacturing a lens cover of an automotive lighting lamp having a connection portion with the lens cover body of the thick part,
When manufacturing a lens cover by using a predetermined mold and injecting molten resin from the part that should become the lens seal foot of the mold toward the part that should become the lens cover body, the thick part of the lens seal foot By providing a movable member in the portion of the mold that should become, the inflow of the molten resin along the lens seal foot in the thick portion of the lens seal foot is limited.

Further, an invention according to claim 2, wherein, in the lens cover process according to claim 1 Symbol placement, the molten resin is characterized in that a polycarbonate.

According to invention of Claim 1 thru | or 2, it has a lens cover main body, and the lens seal | sticker leg formed in the edge part of a lens cover main body, The said lens seal | sticker leg | foot has this thick part, In a lens cover manufacturing method for manufacturing a lens cover for an automotive lighting lamp having a connection portion with a thick-walled lens cover main body, a predetermined mold should be used and the lens seal foot of the mold should be used When manufacturing a lens cover by injecting molten resin from the portion toward the lens cover main body, a lens is provided by providing a movable member on the mold portion that should be the thick portion of the lens seal foot. Since the flow of molten resin along the lens seal foot in the thick part of the seal foot is restricted, it is possible to effectively prevent the occurrence of an unfilled portion (gas reservoir) on the lens cover body. It is possible to prevent the occurrence of leakage and weld line can be produced efficiently produce a lens cover of the non-defective.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. In the following, a case where a lens cover for an automotive headlamp is manufactured as an automotive illumination lamp will be described.

The present invention includes a lens cover main body 4 and a lens seal foot 5 formed at an edge of the lens cover main body 4, and the lens seal foot 5 includes a thick portion 5a and a thick portion 5a. In the lens cover manufacturing method for manufacturing the lens cover 8 of the automotive lamp as shown in FIG. 1 having the connecting portion (standing wall) 5b with the lens cover main body 4,
A lens cover 8 is manufactured by using a predetermined mold and injecting molten resin (specifically, polycarbonate) from a portion to be the lens seal foot 5 to a portion to be the lens cover main body 4. In this case, the inflow of the molten resin along the lens seal foot 5 in the thick portion 5a of the lens seal foot 5 is limited.

  More specifically, according to the present invention, a movable member is provided in a portion of the mold that is to become the thick portion 5a of the lens seal foot 5 so as to follow the lens seal foot 5 in the thick portion 5a of the lens seal foot 5. It is characterized by restricting the inflow of molten resin.

  8 and 9 are views for explaining a method of manufacturing the lens cover 8 of the automotive headlamp according to the present invention. 8 is a front view of the lens cover 8, FIG. 9 is a cross-sectional view taken along line BB in FIG. 8, and FIG. 9 shows molds 17a and 17b for manufacturing the lens cover 8. Has been.

  In FIG. 9, a mold 17a is a fixed mold, and a mold 17b is a movable mold. Further, 15 is a hydraulic cylinder, and 16 is a movable member (specifically, a movable pin). That is, the movable pin 16 is attached to the fixed mold 17 a and joined to the hydraulic cylinder 15.

  In such a configuration, the lens cover 8 of the automotive headlamp is manufactured by an injection molding method. That is, basically as described above, a resin (specifically, polycarbonate) melted from a molding machine (not shown) is injected into the mold 17a from the injection point 1, and the cold runner 2, the gate 3 are injected. The lens cover 8 is manufactured by flowing into the lens seal foot 5 and then flowing into the lens cover body (design) 4 from the lens seal foot 5, but in the present invention, the movable pin 16 is used. Thus, the inflow of the molten resin along the lens seal foot 5 in the thick portion 5a of the lens seal foot 5 is restricted.

  That is, in the present invention, when the lens cover 8 is manufactured by the injection molding method, the movable pin 16 is shown in FIG. 10 when a molten resin (specifically, polycarbonate) is injected from a molding machine (not shown). As shown, it is completely inserted and in contact with the movable mold 17b. When the hydraulic cylinder 15 is driven from this state, the movable pin 16 moves (moves) in the direction of the arrow 19 as shown in FIG. 11, and the tip of the movable pin 16 and the movable mold 17b are moved. A gap 21 of about 0.8 mm is generated between them, and the molten resin flows into the gap 21 to form the lens seal foot 5. Here, the movable timing of the movable pin 16 must be moved while the resin of the movable pin 16 is sufficiently melted after the lens cover main body (design) 4 is filled with the resin. Specifically, for example, it is necessary to move the movable pin 16 by 0.5 seconds before the completion of filling (when the filling time is 5 seconds, by 4.5 seconds after injection).

  12-15 is a figure which shows the resin inflow behavior to the product (lens cover 8) by the conventional manufacturing method without a movable pin. That is, FIG. 12 shows the filling state of the resin 7 0.5 seconds after the start of filling when there is no movable pin, and the resin inflow direction to the gate 3 is represented as P. The resin flowing through the gate 3 and flowing into the product (lens cover 8) spreads in the direction J0 of the lens cover body (design) 4 and the direction K0 of the lens seal foot 5. At this time, the flow front J1 of the resin 7 in the direction J0 of the lens cover body (design) 4 is 19 mm shorter than the flow front K1 of the resin 7 in the direction K0 of the lens seal foot 5. FIG. 13 further shows the state of filling of the resin 7 one second after the start of filling. After one second from the beginning of filling, the flow front J2 of the resin 7 in the direction J0 of the lens cover body (design) 4 is The lens seal foot 5 is 22 mm shorter than the flow front K2 of the resin 7 in the direction K0. FIGS. 14 and 15 show the filling state of the resin 7 after 2 seconds and 4 seconds from the start of filling, respectively, and the direction of the lens cover body (design) 4 after 2 seconds from the filling start. The flow front J3 of the resin 7 of J0 is 47 mm shorter than the flow front K3 of the resin 7 in the direction K0 of the lens seal foot 5, and after 4 seconds from the start of filling, the direction J0 of the lens cover body (design) 4 The flow front J4 of the resin 7 is 104 mm shorter than the flow front K4 of the resin 7 in the direction K0 of the lens seal foot 5, and the flow front of the resin 7 in the direction J0 of the lens cover main body (design) 4 and the lens seal. The difference from the flow front of the resin 7 in the direction K0 of the foot 5 is greatly opened, and the flow of the resin 7 in the direction J0 of the lens cover body (design) 4 is larger than the flow of the resin 7 in the direction K0 of the lens seal foot 5. Be late. Then, the unfilled portion of the lens cover main body (design) 4 is surrounded by the resin 7 that has flowed in (around) the lens seal foot 5, and the gas in the unfilled portion of the lens cover main body (design) 4 is rapidly released. The appearance is damaged by silver streak and weld line due to heat generation.

  On the other hand, FIGS. 16 to 19 are diagrams showing the resin inflow behavior into the product (lens cover 8) by the manufacturing method of the present invention having the movable pin 16. FIG. That is, FIG. 16 shows the state of filling the resin 7 0.5 seconds after the start of filling when the movable pin 16 is present, and the direction of resin inflow into the gate 3 is indicated as Q. The resin 7 that has flowed into the product (lens cover 8) through the gate 3 spreads in the direction L0 of the lens cover body (design) 4 and the direction M0 of the lens seal foot 5. However, in the present invention, since the movable pin 16 is inserted into the lens seal foot 5, the resin 7 once separated from the lens seal foot 5 becomes a flow M 0 that re-flows into the lens seal foot 5. As a result, the flow resistance in the direction M0 of the lens seal foot 5 increases, and a lot of resin 7 flows in the direction L0 of the lens cover body (design) 4 having a low flow resistance. As a result, the flow front L1 in the direction L0 of the lens cover body (design) 4 is 62 mm longer than the flow front M1 in the direction M0 of the lens seal foot 5. FIG. 17 further shows the state of filling of the resin 7 one second after the start of filling. After one second from the start of filling, the flow front L2 of the resin 7 in the direction L0 of the lens cover body (design) 4 is The lens seal foot 5 is 64 mm longer than the flow front M2 of the resin 7 in the direction M0. FIGS. 18 and 19 show the filling state of the resin 7 after 2 seconds and 4 seconds from the start of filling, respectively. The direction of the lens cover main body (design) 4 is 2 seconds after the filling start. The flow tip L3 of the resin 7 of L0 is 46 mm longer than the flow tip M3 of the resin 7 in the direction M0 of the lens seal foot 5, and after 4 seconds from the start of filling, the resin in the direction L0 of the lens cover body (design) 4 7 is 20 mm longer than the flow tip M4 of the resin 7 in the direction M0 of the lens seal foot 5, so that the resin 7 does not wrap around from the lens seal foot 5 to the lens cover body (design) 4 and is movable. Inconveniences due to the conventional manufacturing method without a formula pin are avoided.

  FIG. 20 shows the result of comparing the difference between the flow length of the resin 7 in the direction of the lens cover body (design) 4 and the flow length of the resin 7 in the direction of the lens seal foot 5 with the time from the start of filling. ing. In the conventional manufacturing method, the flow length of the resin 7 in the direction K0 of the lens seal foot 5 is already long after 0.5 seconds from the start of filling, and in order to prevent the lens seal foot 5 from flowing forward, the flow is as early as possible. It is effective to provide the movable pin 16 to prevent the resin 7 from flowing. In the case of the example of FIG. 16, the distance R from the gate 3 to the movable pin 16 is 10 mm.

  As described above, in the present invention, the predetermined molds 17a and 17b are used, and the molten resin 7 (from the part to be the lens seal foot 5 of the molds 17a and 17b toward the part to be the lens cover body 4 ( Specifically, when the lens cover 8 is manufactured by flowing polycarbonate in, the inflow of the molten resin 7 along the lens seal foot 5 in the thick portion 5a of the lens seal foot 5 is limited (more specifically, In addition, by providing a movable member (movable pin) 16 in the portion of the mold 17a, 17b to be the thick portion 5a of the lens seal foot 5, the lens seal foot 5 in the thick portion 5a of the lens seal foot 5 is provided. This effectively prevents unfilled parts (gas pools) from forming on the lens cover body, and prevents silver streaks and weld lines. It is possible to prevent the raw, can be manufactured lens cover non-defective.

  In order to prevent the occurrence of an unfilled portion (gas pool) on the lens cover main body without using the present invention, the thick portion 5a of the lens seal foot 5, the standing wall 5b and the thickness of the lens cover main body 4 are increased. However, in this case, it takes a lot of raw materials, and as the wall thickness increases, the cooling time at the time of molding becomes longer and the production efficiency decreases. It is desirable to use the present invention which does not require a large amount of raw materials and does not reduce the production efficiency.

In the above-described example, the case where a lens cover for a vehicle headlamp is manufactured as a vehicle illumination lamp has been described. However, when a lens cover for a lamp other than a vehicle headlamp is manufactured as a vehicle illumination light. The present invention can be similarly applied to.

1 is a cross-sectional view of a car headlamp. It is an enlarged view of the part E of FIG. It is a figure for demonstrating the conventional manufacturing method of the lens cover of the headlamp for motor vehicles. It is a figure for demonstrating the conventional manufacturing method of the lens cover of the headlamp for motor vehicles. It is a figure for demonstrating the problem of the conventional manufacturing method of a lens cover. It is a figure for demonstrating the problem of the conventional manufacturing method of a lens cover. It is a figure for demonstrating the problem of the conventional manufacturing method of a lens cover. It is a figure for demonstrating the manufacturing method by this invention of the lens cover of the headlamp for motor vehicles. It is a figure for demonstrating the manufacturing method by this invention of the lens cover of the headlamp for motor vehicles. It is a figure for demonstrating the manufacturing method by this invention of the lens cover of the headlamp for motor vehicles. It is a figure for demonstrating the manufacturing method by this invention of the lens cover of the headlamp for motor vehicles. It is a figure which shows the resin inflow behavior to the product (lens cover) by the conventional manufacturing method without a movable pin. It is a figure which shows the resin inflow behavior to the product (lens cover) by the conventional manufacturing method without a movable pin. It is a figure which shows the resin inflow behavior to the product (lens cover) by the conventional manufacturing method without a movable pin. It is a figure which shows the resin inflow behavior to the product (lens cover) by the conventional manufacturing method without a movable pin. It is a figure which shows the resin inflow behavior to the product (lens cover) by the manufacturing method of this invention which has a movable pin. It is a figure which shows the resin inflow behavior to the product (lens cover) by the manufacturing method of this invention which has a movable pin. It is a figure which shows the resin inflow behavior to the product (lens cover) by the manufacturing method of this invention which has a movable pin. It is a figure which shows the resin inflow behavior to the product (lens cover) by the manufacturing method of this invention which has a movable pin. It is a figure which shows the result of having compared the difference of the flow length of the resin of the direction of a lens cover main body (design), and the flow length of the resin of the direction of a lens seal | sticker foot with the time from a filling start.

Explanation of symbols

1 Injection point 2 Cold runner 3 Gate 4 Lens cover body (design)
DESCRIPTION OF SYMBOLS 5 Lens seal foot 5a Thick part 5b Standing wall 7 Molten resin 8 Lens cover 9 Case 12 Filler 13 Concave housing 15 Hydraulic cylinder 16 Movable member (movable pin)
17a Mold on the fixed side 17b Mold on the movable side 21 Crevice

Claims (2)

A lens cover body and a lens seal foot formed at an edge of the lens cover body, the lens seal foot having a thick portion and a connection portion between the thick portion and the lens cover body. In a lens cover manufacturing method for manufacturing a lens cover for an automotive lighting lamp,
When manufacturing a lens cover by using a predetermined mold and injecting molten resin from the part that should become the lens seal foot of the mold toward the part that should become the lens cover body, the thick part of the lens seal foot and by providing the movable member to the mold portion to become the lens cover manufacturing method characterized by limiting the flow of molten resin along the lens sealing portion in the thick portion of the lens sealing portion. In the lens cover process according to claim 1 Symbol placement, the molten resin, the lens cover manufacturing method which is a polycarbonate.

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