JP6775994B2 - Manufacturing method of two-color molded products and two-color molded products - Google Patents

Description

The present invention relates to a two-color molded product.

Conventionally, as one method of injection molding, a technique for producing a two-color molded product by forming a primary molded product and then forming a secondary molded product around the primary molded product is known. The two-color molding technique is used, for example, when manufacturing a translucent cover for a lamp such as a vehicle headlamp (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-176974

In the case of the above-mentioned translucent cover, in order to regulate the area where the colored resin is filled in the mold after forming the primary molded product made of transparent resin, not only the mold but also the back surface of the primary molded product is used. The partition of the ridge provided in is also used.

However, in a secondary molded product in which welds are formed near the partition of the ridge, if gas cannot be discharged well from the partition of the ridge, air bubbles may remain in the secondary molded product or there may be a lack of meat. It happens. As a result, the joint strength between the primary molded product and the secondary molded product is lowered, and the appearance of the two-color molded product is poor.

The present invention has been made in view of these circumstances, and an object of the present invention is to provide a technique for improving the appearance and reliability of a two-color molded product.

In order to solve the above problems, the two-color molded product of a certain aspect of the present invention includes a first resin portion having a predetermined shape and a second resin portion that is in contact with the first resin portion so as to overlap at least a part thereof. The first resin portion has a ridge portion formed on the back surface side in contact with the second resin portion. The second resin portion has a contact portion that is in contact with the side surface of the ridge portion and a covering portion that protrudes from the contact portion so as to cover a part of the upper surface of the ridge portion.

According to this aspect, the covering portion of the second resin portion covers a part of the upper surface of the ridge portion of the first resin portion, and the bonding strength between the first resin portion and the second resin portion is improved.

The covering portion may be formed in the vicinity of the weld line of the second resin portion on the upper surface of the ridge portion. As a result, the covering portion can be formed as the gas is discharged during injection molding. Therefore, an extra step for forming the covering portion can be omitted.

The amount of protrusion of the covering portion may decrease as the distance from the weld line intersects the weld line. As a result, the force of the covering portion for pressing the ridge portion can be gradually weakened as the distance from the weld line increases.

The first resin portion is a translucent portion of a vehicle lamp cover, and the second resin portion may be made of a colored resin. As a result, in a vehicle lamp cover that takes design into consideration so that the second resin portion can be seen through the transparent first resin portion, the occurrence of cracks in the ridge portion is suppressed, resulting in poor appearance. Can be reduced.

Another aspect of the present invention is a method for producing a two-color molded product. In this method, a first step of injecting a first resin material into a first cavity formed by a first core mold and a cavity mold to form a first resin portion having a predetermined shape, and a first resin portion. The second core mold and the cavity mold, which are different in shape from the first core mold, are molded so that at least a part of the first resin portion is exposed in a state where the mold is placed inside the cavity mold. Then, the second resin material is injected into the second cavity formed by the second core mold and the cavity mold to form the second resin portion to be joined with at least a part of the first resin portion. And, including. In the first step, a first resin portion having a ridge portion on the side in contact with the second resin portion is formed, and in the second step, the second step is in a state where the ridge portion and the second core mold are in contact with each other. A resin material is injected to form a second resin portion having a covering portion that covers a part of the upper surface of the ridge portion.

According to this aspect, since a two-color molded product in which the coating portion of the second resin portion covers a part of the upper surface of the ridge portion of the first resin portion can be manufactured, the first resin portion and the second resin in the two-color molded product can be manufactured. The joint strength with the part can be improved.

The second core mold and the cavity mold are provided with a plurality of gates, and in the second cavity, the region where the first resin portion and the second resin portion are joined is in the middle of the flow path connecting the plurality of gates. It may have a shape configured to be. As a result, even when the resin is injected into the second cavity from a plurality of gates, the gas can be discharged to the outside from a part of the upper surface of the ridge portion together with the second resin material forming the covering portion. 2 It becomes difficult for air bubbles to be mixed in the resin part or for meat to be missing. In other words, since the coating portion can be formed by discharging the gas during injection molding to the outside of the mold, the process can be simplified and the configuration of the mold can be simplified.

The second core mold may have a contact region in contact with the ridge portion in a state where the first resin portion is arranged inside the cavity mold. The contact region has a first region in which a covering portion is formed between the ridge portion and a second region separated from the first region, and the pressing force F1 of the first region is the second region. It may be configured to be smaller than the pressing force F2. This makes it easier to form a covering portion in the first region.

The second cavity may have an outgassing path formed on a side surface of the ridge portion opposite to the side surface in contact with the second resin portion. As a result, the gas passing through the upper surface of the ridge portion can be smoothly discharged to the outside of the mold.

It should be noted that any combination of the above components and the conversion of the expression of the present invention between methods, devices, systems, etc. are also effective as aspects of the present invention.

According to the present invention, the appearance and reliability of a two-color molded product can be improved.

It is an external perspective view of the vehicle which applied the two-color molded article which concerns on this embodiment to the front cover of the headlamp provided in the front part of the vehicle body. It is a schematic front view of the translucent cover which concerns on this embodiment. It is a side sectional view which shows the mold used for the injection molding method. It is a side sectional view which shows the two-color molded article which is injection molded by an injection molding method. 5 (a) and 5 (b) are process diagrams showing an injection molding method according to a reference example. 6 (a) and 6 (b) are process charts showing an injection molding method according to a reference example. 7 (a) and 7 (b) are process charts showing an injection molding method according to a reference example. 8 (a) and 8 (b) are process diagrams showing an injection molding method according to a reference example. It is a schematic diagram explaining the mechanism which the crack occurs in the partition part of the ridge provided on the back surface of the primary molded product in a two-color molded product. 10 (a) is a cross-sectional view of the two-color molded product according to the present embodiment, and FIG. 10 (b) is an enlarged view of a main part in the vicinity of the covering portion as seen from the direction of arrow B in FIG. 10 (a). .. It is a front view which shows an example of the secondary core side mold used in the manufacturing method of the two-color molded article which concerns on this embodiment. It is a schematic diagram which shows the appearance that the weld line is formed in the two-color molded article which concerns on this embodiment. It is a top view of the vicinity of the contact area of the secondary core side mold that comes into contact with the ridge portion of the first resin portion.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings and the like. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted as appropriate.

FIG. 1 is an external perspective view of a vehicle in which the two-color molded product according to the present embodiment is applied to the front cover of a headlamp provided on the front portion of the vehicle body. FIG. 2 is a schematic front view of the translucent cover 104 according to the present embodiment. As shown in FIG. 1, left and right headlamps HL are arranged at the front portion of the vehicle body 102 of the vehicle 100. The headlamp HL is mainly composed of a lamp body (not shown) and a translucent cover 104. The lamp body is a container-shaped member having an open front surface, and a translucent cover 104 is attached to the front opening of the lamp body. The configurations of the lamp unit, the reflector, and the like inside the lamp are known, and the description thereof will be omitted.

The translucent cover 104 is a two-color molded product according to the present embodiment, and is manufactured by a method described later. More specifically, the translucent cover 104 includes a translucent resin portion 106 molded of a colorless and transparent translucent resin, and a black resin 108 laminated in the thickness direction at least at least a part of the outer edge of the translucent resin portion 106. , Is integrally molded. In the present embodiment, the translucent resin portion 106 constitutes the first resin portion, and the black resin 108 constitutes the second resin portion.

The translucent resin portion 106 is formed in a plate shape having a substantially uniform thickness that is convexly curved toward the front of the lamp so as to be continuous with the front curved surface of the vehicle body 102 of the vehicle 100, and is emitted from the lamp unit. It is possible to transmit the light to be transmitted and irradiate the front region of the vehicle 100. The translucent resin portion 106 corresponds to the first resin portion in the present embodiment. Similarly, the black resin 108 corresponds to the second resin portion according to the present embodiment.

Next, a manufacturing method of a two-color molded product and a reference example of a mold will be described.

FIG. 3 is a side sectional view showing a mold 50 used in the injection molding method. Further, FIG. 4 is a side sectional view showing a two-color molded product 10 which is injection-molded by an injection molding method.

First, the configuration of the two-color molded product 10 will be described. As shown in FIG. 4, the two-color molded product 10 can be used as a translucent cover 104 for vehicle lamps such as the headlamp shown in FIG. 1, and the front portion 10A and the front portion 10A thereof. It is provided with a peripheral surface portion 10B extending rearward from the outer peripheral edge. At that time, the peripheral surface portion 10B is formed with a flange portion 10Ba extending from the rear end position toward the outer peripheral side and an annular projection portion 10Bb protruding rearward from the rear surface portion.

The two-color molded product 10 has a configuration in which the secondary molded product 14 is arranged around the primary molded product 12. At that time, the primary molded product 12 is composed of a transparent resin member, and the secondary molded product 14 is composed of an opaque (specifically, black) resin member.

The primary molded product 12 and the secondary molded product 14 have a configuration in which the primary molded product 12 is partially overlapped on the peripheral surface portion 10B with the primary molded product 12 positioned on the outer peripheral side. At that time, the rear end surface 12c of the primary molded product 12 is located at the intermediate portion of the peripheral surface portion 10B in the vehicle front-rear direction. A plurality of recesses 12b are formed on the outer peripheral surface (that is, the outer surface of the portion of the peripheral surface portion 10B where the primary molded product 12 is located) 12a of the primary molded product 12 (this will be described later). ..

Next, the configuration of the mold 50 will be described. As shown in FIG. 3, the mold 50 is configured as a so-called opposed type two-color molding mold.

That is, the mold 50 includes a primary core side mold 52 and a secondary core side mold 54 arranged so as to face each other on the X axis extending in the horizontally direction, and these primary core side mold 52 and the primary core side mold 52. A rotating member 56 rotatably arranged around the Y axis extending in the vertical direction orthogonal to the X axis between the secondary core side molds 54, and fixed to the rotating member 56 in a back-to-back state with respect to the Y axis. It includes a pair of cavity-side molds 58A and 58B having the same shape, a movable platen 62 that supports the primary core-side mold 52, and a fixing plate 64 that supports the secondary core-side mold 54.

At that time, the rotating member 56 can move in the X-axis direction with respect to the fixed plate 64, and the movable plate 62 can move in the X-axis direction with respect to the rotating member 56. .. In FIG. 3, the directions of these relative movements are indicated by arrows.

In the mold 50, the heating supported by the movable platen 62 is provided in the primary space portion C1 formed between the primary core side mold 52 and the first cavity side mold 58A which are in contact with each other by mold clamping. A transparent resin material supplied from the cylinder 66 is injected, and the secondary space portion C2 formed between the secondary core side mold 54 and the second cavity side mold 58B, which are in contact with each other by mold clamping. , The black resin material supplied from the heating cylinder 68 supported by the fixing plate 64 is injected.

In the mold 50, hydraulic cylinders 70 are arranged at a plurality of locations of the cavity-side molds 58A and 58B. At that time, the plurality of hydraulic cylinders 70 are arranged at predetermined intervals in the circumferential direction so that the plunger 72 faces the inner peripheral surfaces of the cavity-side molds 58A and 58B. As a result, each of these hydraulic cylinders 70 has a configuration in which the plunger 72 can be projected from the direction orthogonal to the X-axis into the primary space portion C1.

Next, the injection molding method according to the reference example will be described. 5 (a) to 8 (b) are process diagrams showing an injection molding method according to a reference example.

First, as shown in FIG. 5A, the primary core side mold 52 and the secondary core side mold 54 and a pair of cavity side molds 58A and 58B are molded. At that time, the plunger 72 of each hydraulic cylinder 70 arranged in the cavity side mold 58A on the primary core side mold 52 side is projected to the primary space portion C1. On the other hand, the plunger 72 of each hydraulic cylinder 70 arranged in the cavity side mold 58B on the secondary core side mold 54 side is kept in a state of being retracted from the secondary space portion C2. Then, in this state, as shown in FIG. 5B, the transparent resin material supplied from the heating cylinder 66 is injected into the primary space portion C1 to mold the primary molded product 12.

A plurality of plungers 72 are engaged with the primary molded product 12 from a direction orthogonal to the mold opening / closing direction. As shown in FIG. 4, a portion in which the plurality of plungers 72 are engaged is engaged. As a trace of the above, a plurality of recesses 12b are formed on the outer peripheral surface 12a of the primary molded product 12.

Next, as shown in FIG. 6A, the primary core side mold 52 and the secondary core side mold 54 and the pair of cavity side molds 58A and 58B are opened. At this time, the primary molded product 12 tries to be attached to the primary core side mold 52 by the shrinkage action of the resin material injected into the primary space portion C1, but the primary molded product 12 has a mold. Since the plunger 72 is engaged from the direction orthogonal to the opening / closing direction, when the primary core side mold 52 and the cavity side mold 58A are opened, the primary molded product 12 is held by the cavity side mold 58A. It is separated from the primary core side mold 52 as it is. Then, in this state, as shown in FIG. 6B, the rotating member 56 is rotated by 180 ° around the Y axis. At this time, a centrifugal force acts on the primary molded product 12 held by the rotating member 56, but since the plunger 72 is engaged with the primary molded product 12, it is held by the cavity-side mold 58A. The state as it is is maintained.

Next, as shown in FIG. 7A, the primary core side mold 52 and the secondary core side mold 54 and a pair of cavity side molds 58A and 58B are molded. Then, in this state, as shown in FIG. 7B, the black resin material supplied from the heating cylinder 68 is injected into a portion other than the primary molded product 12 in the secondary space portion C2 to inject the secondary molded product. 14 is molded. As a result, the two-color molded product 10 in which the primary molded product 12 and the secondary molded product 14 are integrated is completed.

Next, as shown in FIG. 8A, after the plunger 72 of each hydraulic cylinder 70 arranged in the cavity side mold 58A on the secondary core side mold 54 side is retracted from the secondary space portion C2, The primary core side mold 52 and the secondary core side mold 54 and a pair of cavity side molds 58A and 58B are opened. At this time, since the plunger 72 is not engaged with the primary molded product 12, the two-color molded product 10 is in a state of being attached to the secondary core side mold 54 when the mold is opened. Then, in this state, as shown in FIG. 8B, the two-color molded product 10 is taken out. This extraction is performed by extruding the two-color molded product 10 attached to the secondary core side mold 54 with an extrusion pin (not shown) and grasping it with an extraction machine (not shown).

The inventors of the present application have discovered problems hidden in the production of a two-color molded product by conventional injection molding, including the above-mentioned method, and devised a technique for improving the problems. Specifically, in order to regulate the area where the second resin material is filled in the mold after forming the primary molded product, it is provided not only on the mold but also on the back surface of the primary molded product. This is a problem that can occur in a two-color molded product having a structure that uses the partition portion of the ridge.

FIG. 9 is a schematic view illustrating a mechanism in which a crack is generated in a partition portion of a ridge provided on the back surface of a primary molded product in a two-color molded product.

In the two-color molded product 20, the space formed by the first resin portion 22 made of transparent resin and the molds 23a and 23b is filled with the second resin material made of colored resin to form the second resin portion 24. It is created by doing. The first resin portion 22 has a ridge portion 22a formed on the back surface side in contact with the second resin portion 24. Further, in the vicinity of the weld portion where the second resin material is finally filled, the gas during injection molding is finally concentrated and the pressure increases, so that the portion of the ridge portion 22a adjacent to the weld portion Excessive stress (arrow P) is generated. As a result, the ridge portion 22a is deformed, gas G1 is discharged at once from a part of the contact surface between the mold 23a and the upper surface 22c of the ridge portion 22a, and the base portion 22b of the ridge portion 22a is cracked. May occur.

When the first resin portion 22 is transparent, such cracks can be visually recognized as poor appearance from the outside of the two-color molded product 20, and also the strength of the two-color molded product 20 itself and the first resin portion 22. It may contribute to a decrease in the bonding strength with the second resin portion 24. Therefore, a two-color molded product in which such a problem is unlikely to occur and a method for manufacturing the same will be described in detail below.

FIG. 10A is a cross-sectional view of the two-color molded product according to the present embodiment, and FIG. 10B is an enlarged view of a main part in the vicinity of the covering portion as seen from the direction of arrow B in FIG. 10A. .. 10 (a) is a cross-sectional view taken along the line AA of FIG.

The two-color molded product 30 according to the present embodiment includes a first resin portion 32 having a predetermined shape and a second resin portion 34 that is in contact with the first resin portion 32 so as to overlap at least a part thereof. The first resin portion 32 has a ridge portion 32a formed on the back surface side in contact with the second resin portion 34. The second resin portion 34 has a contact portion 34a that is in contact with the side surface 32b of the ridge portion 32a and a covering portion 34b that protrudes from the contact portion 34a so as to cover a part of the upper surface 32c of the ridge portion 32a. And have.

In the two-color molded product 30 configured in this way, the covering portion 34b of the second resin portion 34 covers a part of the upper surface 32c of the ridge portion 32a of the first resin portion 32, and the first resin portion 32 and the first resin portion 32 The bonding strength with the second resin portion 34 is improved. More specifically, since the ridge portion 32a of the first resin portion 32 is bonded not only to the contact portion 34a but also to the covering portion 34b, the bonding strength between the ridge portion 32a and the second resin portion 34 is improved. To do.

The covering portion 34b is formed in the vicinity of the weld line 36 of the second resin portion 34 on the upper surface 32c of the ridge portion 32a. As a result, the second resin material can form the covering portion 34b with the discharge of the gas G1 during the injection molding shown in FIG. Therefore, an extra step for forming the covering portion 34b can be omitted.

The amount of protrusion h of the covering portion 34b decreases as the distance from the weld line 36 in the direction D intersecting the weld line. As a result, the force of the covering portion 34b for pressing the ridge portion 32a can be gradually weakened as the distance from the weld line 36 increases.

The first resin portion 32 according to the present embodiment is a translucent portion of a vehicle lamp cover, and the second resin portion 34 is made of a colored resin. As a result, in the translucent cover 104 for vehicles in which the second resin portion 34 can be seen through the transparent first resin portion 32, the generation of cracks generated in the ridge portion 32a is suppressed. Therefore, poor appearance can be reduced.

Next, a method for manufacturing the two-color molded product according to the present embodiment will be described with reference to FIGS. 5 (a) to 8 (b). The shapes of the primary molded product 12 and the secondary molded product in FIGS. 5 (a) to 8 (b) are simplified in order to briefly explain each step, and are not necessarily in the present embodiment. It does not have the same shape as the first resin portion 32 and the second resin portion 34 of the two-color molded product 30 according to the above. The outline of the manufacturing method of the two-color molded product 30 shown in FIGS. 10 (a) and 10 (b) will be described below.

In the method for manufacturing a two-color molded product according to the present embodiment, a transparent resin material is injected into the primary space C1 (first cavity) formed by the primary core side mold 52 and the cavity side mold 58A. At least the first step of forming the primary molded product 12 (first resin portion) having a predetermined shape and the primary molded product 12 are arranged inside the cavity-side mold 58A. The secondary core side mold 54 and the cavity side mold 58A, which are different in shape from the primary core side mold 52, are molded so as to be partially exposed, and the secondary core side mold 54 and the cavity side mold are molded. A second step of injecting a black resin material into the secondary space (second cavity) C2 formed by the mold 58A to form the secondary molded product 14 to be joined with at least a part of the primary molded product 12. ,including.

In the first step, for example, as shown in FIGS. 10A and 10B, a first resin portion 32 having a ridge portion 32a on the side in contact with the second resin portion 34 is formed as a primary molded product. .. In the second step, for example, as shown in FIG. 9, the second resin material is injected into the cavity in a state where the ridge portion 32a and the mold 23a (corresponding to the mold on the secondary core side) are in contact with each other. Then, a second resin portion 34 having a covering portion 34b (see FIGS. 10A and 10B) covering a part of the upper surface 32c of the ridge portion 32a is formed.

As a result, the two-color molded product 30 in which the covering portion 34b of the second resin portion 34 covers a part of the upper surface 32c of the ridge portion 32a of the first resin portion 32 can be manufactured, so that the first resin portion in the two-color molded product can be manufactured. The bonding strength between 32 and the second resin portion 34 can be improved.

Next, the position where the covering portion of the second resin portion is provided will be described. FIG. 11 is a front view showing an example of the secondary core side mold 54 used in the method for manufacturing a two-color molded product according to the present embodiment. As shown in FIG. 11, in the method for manufacturing a two-color molded product according to the present embodiment, two or more gates 35 are provided on the secondary core side mold 54. In addition, a plurality of gates may be provided in each of the cavity side mold 58A and the cavity side mold 58B. Alternatively, the secondary core side mold 54 may be provided with one or more gates, and each of the cavity side mold 58A and the cavity side mold 58B may be provided with one or more gates.

FIG. 12 is a schematic view showing how a weld line is formed in the two-color molded product according to the present embodiment. In FIG. 11, the secondary core side mold 54 is not shown.

As shown in FIG. 12, the molten resin 37 injected into the cavity from the plurality of gates merges at a predetermined place to form a weld line 36. At that time, the concentrated gas G1 is discharged from between the upper surface 32c of the ridge portion 32a of the first resin portion 32 and the mold (not shown), and accordingly, a part of the molten resin 37 is discharged from the upper surface of the ridge portion 32a. The covering portion 34b is formed so as to penetrate between the 32c and the mold (not shown) and overlap a part of the ridge portion 32a.

Further, as described above, the secondary core side mold 54 and the cavity side mold 58A or the cavity side mold 58B are provided with a plurality of gates. Then, in the secondary space portion C2, the region where the primary molded product 12 (first resin portion 32) and the secondary molded product 14 (second resin portion 34) are joined is in the middle of the flow path connecting the plurality of gates 35. It is a shape configured to be (region B'shown in FIG. 11).

As a result, even when resin is injected into the secondary space portion C2 from a plurality of gates, the gas is discharged to the outside from a part of the upper surface 32c of the ridge portion 32a together with the second resin material forming the covering portion 34b. Since it can be discharged, it is difficult for air bubbles to be mixed into the second resin portion 34 or for meat to be missing. In other words, since the covering portion 34b can be formed by discharging the gas during injection molding to the outside of the mold, the process can be simplified and the configuration of the mold can be simplified.

FIG. 13 is a top view of the vicinity of the contact region of the secondary core side mold 54 that comes into contact with the ridge portion 32a of the first resin portion 32. The secondary core side mold 54 has a contact region 38 that comes into contact with the ridge portion 32a in a state where the first resin portion 32 is arranged inside the cavity side mold 58A or the cavity side mold 58B. (See FIG. 10 (a)). The contact region 38 has a first region 38a in which a covering portion 34b is formed between the ridge portion 32a and a second region 38b separated (adjacent) from the first region 38a, and is a first region. The pressing force F1 of 38a is configured to be smaller than the pressing force F2 of the second region 38b. As a result, the covering portion 34b can be easily formed between the first region 38a and the first resin portion 32.

In order to change the pressing force depending on the region, it can be realized by changing the roughness of the surface depending on the region, in addition to the method of forming a physical recess by polishing a part of the contact region 38. For example, in order to make the pressing force F1 of the first region 38a smaller than the pressing force F2 of the second region 38b, the arithmetic surface roughness Ra1 of the first region 38a is made smaller than the arithmetic average roughness Ra2 of the second region 38b. The surface of the first region 38a may be polished.

The mold configuration may be devised so that the change in the pressing force F becomes smaller as the distance from the weld line increases in the direction intersecting the weld line, centering on the vicinity of the weld line. That is, the pressing force may be changed in three or more steps instead of two steps, or continuously.

Further, as shown in FIG. 10A, the secondary space portion C2 formed by the secondary core side mold 54 and the cavity side mold 58A has a side surface 32b in contact with the second resin portion 34 of the ridge portion 32a. A gas discharge path 40 is formed on the side surface 32d on the opposite side to the above. As a result, the gas passing through the upper surface of the ridge portion can be smoothly discharged to the outside of the mold.

The present invention has been described above based on the embodiments and modifications. It is to those skilled in the art that this embodiment and each modification are examples, and that various modifications are possible for the combination of each component and each processing process, and that such modifications are also within the scope of the present invention. It is about to be understood.

C1 primary space part, F1 force, C2 secondary space part, F2 force, 10 two-color molded product, 12 primary molded product, 14 secondary molded product, 20 two-color molded product, 22 first resin part, 22a protrusion Stripe, 22c top surface, 23a mold, 24 second resin part, 30 two-color molded product, 32 first resin part, 32a ridge part, 32b side surface, 32c top surface, 32d side surface, 34 second resin part, 34a Contact part, 34b coating part, 35 gate, 36 weld line, 37 molten resin, 38 contact area, 38a first area, 38b second area, 40 gas discharge path, 50 mold, 52 primary core side mold, 54 Secondary core side mold, 58A, 58B Cavity side mold, 100 vehicle, 102 car body, 104 translucent cover, 106 translucent resin part, 108 black resin.

Claims (6)

A two-color molded product comprising a first resin portion having a predetermined shape and a second resin portion that is in contact with the first resin portion so as to overlap at least a part thereof.
The first resin portion has a ridge portion formed on the back surface side in contact with the second resin portion.
The second resin portion includes a contact portion that is in contact with the side surface of the ridge portion and a covering portion that protrudes from the contact portion so as to cover a part of the upper surface of the ridge portion. And
The covering portion is formed on the upper surface of the ridge portion in the vicinity of the weld line of the second resin portion, and the amount of protrusion decreases as the distance from the weld line intersects the weld line. two-color molded article according to claim Tei Rukoto. The first resin portion is a translucent portion of a vehicle lamp cover.
The two-color molded product according to claim 1, wherein the second resin portion is made of a colored resin. The first step of injecting the first resin material into the first cavity formed by the first core mold and the cavity mold to form the first resin portion having a predetermined shape, and
With the second core mold having a shape different from that of the first core mold so that at least a part of the first resin portion is exposed in a state where the first resin portion is arranged inside the cavity mold. The cavity mold is clamped, the second resin material is injected into the second cavity formed by the second core mold and the cavity mold, and the second resin material is joined to at least a part of the first resin portion. 2 Including the second step of forming the resin part
In the first step, a first resin portion having a ridge portion on the side in contact with the second resin portion is formed.
In the second step, the second resin material is injected in a state where the ridge portion and the second core mold are in contact with each other, and the second step has a covering portion that covers a part of the upper surface of the ridge portion. 2 Form the resin part,
A method for manufacturing a two-color molded product. The second core mold and the cavity mold are provided with a plurality of gates.
The second cavity has a shape such that the region where the first resin portion and the second resin portion are joined is in the middle of the flow path connecting the plurality of gates.
The method for producing a two-color molded product according to claim 3 , wherein the two-color molded product is produced. The second core mold has a contact region that comes into contact with the ridge portion in a state where the first resin portion is arranged inside the cavity mold.
The contact region has a first region in which the covering portion is formed between the ridge portion and a second region separated from the first region, and the pressing force F1 of the first region is applied. , It is configured to be smaller than the pressing force F2 in the second region.
The method for producing a two-color molded product according to claim 3 or 4 , wherein the two-color molded product is produced. The second cavity according to any one of claims 3 to 5 , wherein a gas release path is formed on a side surface of the ridge portion opposite to the side surface in contact with the second resin portion. Manufacturing method of two-color molded products.

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