JPH10315241A - Method for integrally molding partial skin and partial skin integral mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily, effectively manufacture a partial skin integral molding at a low cost with high shape accuracy and external appearance quality. SOLUTION: In the method for integrally molding a partial skin comprises the steps of pouring resin in a first cavity in which the skin 2 is disposed in the state that a slide core 13 is brought into contact with a rib 12 to form a first molding 3 integrated with the skin 2, then retreating the core 13 to form a second molding 4 in a second cavity to integrate it with the molding 3, the skin 2 is disposed so that an end of the skin 2 along the rib 12 is lower than an end of the rib 12. Since the molding 3 cover an end face of the skin 2, the resin is prevented from being invaded between the skin 2 and the rib 12 at the time of molding the molding 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a partial skin integral molding method for integrally forming a molded article having a partial skin and a plurality of base materials, such as an automobile door trim, and a method used in the method. It relates to improvement of a mold.

[0002]

2. Description of the Related Art For example, molded articles having a skin are often used in automobile interiors in order to improve the feel. However, in order to keep the cost as low as possible, there are many cases where a skin is not provided in a part that is not touched by human hands. For example, many door trims do not have a skin at the lower part and have a skin only at the upper part.

[0003] In the case of manufacturing a two-color molded product having a partial skin as described above, the appearance quality of the parting part of the skin is important, and it is necessary to devise so that the end face of the terminal of the skin is not exposed. Therefore, in order to manufacture a partial skin integral molded product such as a conventional door trim, first, as shown in FIG.
00 is formed by injection molding or the like, and then a skin 200 is bonded to the upper portion of the resin base material 100. End 2 of skin 200
01 is inserted into the groove 101 formed in the resin base material 100 and adhered, so that the end face is not exposed, and the appearance is excellent.

Further, as shown in FIG. 10, a method of forming an upper molded product 102 having a skin 200 by integral molding in which a skin 200 is disposed in a mold and welding and integrating it with a separately formed lower molded product 103. Is also known. Also in this method, since the end 201 of the skin 200 is located between the upper molded product 102 and the lower molded product 103, the end surface is not exposed and the appearance quality is excellent.

[0005] However, the method of bonding the skin to a part of the resin substrate requires a large number of bonding steps and requires an adhesive, which is not preferable in terms of cost. In addition, in the method of integrating molded products with and without a skin with welding,
There is a problem in that misalignment tends to occur during welding and the shape accuracy is low, and a welding step is required, which is not preferable in terms of cost.

Therefore, Japanese Patent Application Laid-Open No. 2-47021 discloses that
A projecting rib is provided on one mold surface, and a slide core is provided on the other mold. The slide core moves forward and backward toward the rib.First, the slide core is advanced to sandwich the ornament members and the skin arranged on the left and right sides of the rib, respectively. Discloses a molding method for supplying molten resin between the ornament member and the other mold surface and between the skin and the other mold surface, and then filling the space formed by retracting the slide core with the molten resin. Have been. According to this molding method, the ornament member and the skin can be separately attached simultaneously with molding with one molding die, so that the number of steps is greatly reduced.

However, in this molding method, when the slide core is retracted, the end surface of the skin or the ornament member is exposed in the cavity, so that the molten resin enters between the design surface of the skin or the ornament member and the mold surface. In some cases, resulting in poor reliability. When this molding method is applied to the partial skin integral molding method, one of the ribs is a molded article of only the resin base material because no ornament member is used. Therefore, if the retraction stroke of the slide core is small, the resin material that has not been solidified on the skin side may flow down into the communication space created by the retraction of the slide core and enter the other cavity. Welds and wrinkles may appear on the surface of the molded product containing only the base material, and the appearance quality may be impaired.

The present invention has been made in view of such circumstances, and an object of the present invention is to make it possible to easily, reliably, and inexpensively manufacture a partially-skin-integrated molded article having high shape accuracy and appearance quality. .

[0009]

According to a first aspect of the present invention, there is provided a method for integrally forming a partial skin, comprising: a first cavity and a second cavity communicating with each other at ends; A mold is made up of a rib that partitions the first cavity and the second cavity, and a slide core that is driven to move forward and backward facing the rib, and a skin is arranged in the first cavity along one mold surface. A first molding step of injecting a molten resin into the first cavity in a state where the slide core is in contact with the rib to cut off communication with the second cavity to form a first molded body integrated with the skin; A second molding step of retreating to form a communication space between the first cavity and the second cavity and communicating with each other, injecting a molten resin into the second cavity to form a second molded body integrated with the first molded body; Yo A partial skin integral molding method, wherein the skin is disposed such that the tip of the end along the rib is lower than the tip of the rib, and the end face of the skin after the first molding step is covered with the first molded body. It is in.

[0010] In the molding method according to the first aspect, the skin is disposed such that the tip of the end along the rib is lower than the tip of the rib. Therefore, in the first cavity, the portion where the tip of the rib is located is the final arrival point of the molten resin. Therefore, even if the end surface of the skin is exposed at that position, the flow direction of the molten resin is equal to the surface of the skin and one mold surface. And the opposite direction to the intrusion. Therefore, the molten resin does not enter between the surface of the skin and the one mold surface, and the skin end surface is covered with the first molded body.

[0011] In the second molding step, the molten resin is mixed with the first resin.
Since the molten resin does not come into direct contact with the skin end surface even when it comes into contact with the molded body, the molten resin does not enter between the surface of the skin and one of the mold surfaces even in the second molding step.
In other words, according to the molding method of the first aspect, a partial skin integral molded product can be manufactured with one molding die, and the step of joining the skins is unnecessary, so that an inexpensive partial skin integral molded product is obtained. In addition, in the skin-integrated molded product obtained by this molding method, the terminal of the skin is located in the groove formed by the rib, and the resin does not protrude to the surface of the skin, so that the appearance quality is excellent.

In the above molding method, if the first molding step and the second molding step are performed continuously, the first molded body is not solidified yet when the slide core is retracted, so that the first molded body is formed. In some cases, the molten resin flows down from the first cavity formed by the retreat of the slide core and enters the second cavity. In such a case, the boundary between the first molded product and the second molded product is exposed on the surface of the second molded product having no skin, and the appearance quality such as generation of weld may be impaired.

[0013] Therefore, a feature of the method for manufacturing a partial skin integral molded product according to claim 2 for preventing such a problem is as follows.
A first cavity and a second cavity communicating with each other at end portions; a rib protruding from one mold surface to partition the first cavity and the second cavity; and a slide core driven to advance and retreat facing the rib. Using a molding die, the skin is arranged in the first cavity along one mold surface, and the molten resin is injected into the first cavity in a state in which the slide core is brought into contact with the rib to cut off the communication with the second cavity. A first molding step of forming a first molded body integrated with the skin, and a sliding space being retracted to form a communication space communicating between the first cavity and the second cavity to inject molten resin into the second cavity; And a second molding step of forming a second molded body integrated with the first molded body, wherein the retreat stroke of the slide core is increased in the second molding step. Resin flowing out of the first molded body is characterized in that it is accommodated in the communicating space.

In the manufacturing method according to the second aspect, the retraction stroke of the slide core is increased in the second molding step, and the volume of the formed communication space is increased. Therefore, the molten resin that has flowed down from the first molded body is stored in the communication space, so that the molten resin is prevented from entering the second cavity, and is not exposed on the surface of the second molded body, so that a portion having excellent appearance quality is obtained. A skin integral molded product is formed.

[0015] It is particularly desirable that the molding method described in claim 1 and the molding method described in claim 2 be combined. By the way, it may be difficult to increase the stroke of the slide core due to the limitation of the shape of the obtained integral molded part skin product. In such a case, as described in claim 3, first, the slide core is largely retracted, and in the second molding step, the slide core advances to press the resin in the communication space when the molten resin is injected. Is preferred.

As a result, a part of the molten resin flowing down into the communication space is pushed back into the first cavity by the advance of the slide core, but a part of the molten resin tends to enter the second cavity. However, since the pressure of the molten resin injected into the second cavity is extremely high, most of the molten resin flowing down from the first molded body exists in the communication space or is pushed back into the first cavity, and almost enters the second cavity. do not do. Therefore, the weld is located near the bottom of the rib, and is prevented from being exposed on the surface of the second molded body.

The advance of the slide core may be performed simultaneously with the injection into the second cavity, or may be performed after the injection into the second cavity. A feature of the partial skin integral molding method according to claim 4 is that a first cavity and a second cavity communicating with each other at ends are provided, and a rib protruding from one mold surface and dividing the first cavity and the second cavity. A slide core driven forward and backward against the ribs,
Using a molding die consisting of, a skin is arranged in the first cavity along one mold surface, and the molten resin is poured into the first cavity in a state in which the slide core is brought into contact with the rib to cut off the communication with the second cavity. A first molding step of injecting and forming a first molded body integrated with the skin, and retreating the slide core to form a communication space communicating between the first cavity and the second cavity to form a molten resin in the second cavity. Inject the first
A partial skin integral molding method comprising a second molding step of forming a second molded body integrated with a molded body, wherein a width of a first cavity in a portion along a rib is narrower than another portion to promote cooling. Is to be.

In the molding method according to the fourth aspect, the width of the first cavity in the portion along the rib is smaller than in the other portions. Therefore, since the volume of the first molded product in that portion is small and the area in contact with the rib or the slide core remains large, the first molded product has a large amount of heat removed from the molding die, and cooling is promoted. As a result, even if the slide core is retracted in the second molding step, the end of the first molded product is hardened to flow into the communication space due to the solidification or the increased viscosity, and therefore, the entry into the second cavity is prevented. Therefore, the appearance of weld on the surface of the second molded product is prevented.

Further, the feature of the partial skin integral molding die according to the fifth aspect is that the first cavity and the second cavity communicating with each other at the ends and the first cavity and the second cavity projecting from one mold surface are defined. And a slide core that is driven to move forward and backward in opposition to the rib. A skin is disposed in the first cavity along one mold surface, and the slide core is brought into contact with the rib to form a second cavity. Forming a first molded body integrated with the skin by injecting a molten resin into the first cavity in a state where the communication between the first and second cavities is stopped; A second molding step of forming a communicating space to communicate with the first cavity and injecting a molten resin into the second cavity to form a second molded body integrated with the first molded body; In the form type is that the uneven portion is formed on a surface opposing at least a first cavity of the slide core.

[0020] In the mold according to the fifth aspect, an uneven portion is formed on at least the surface of the slide core facing the first cavity, and the surface area is increased. Therefore, since the cooling of the first molded body in contact with the slide core is promoted, even if the slide core is retracted in the second molding step, the first molded body is not cooled.
The end of the molded product is hardened to flow down due to solidification or increased viscosity, and therefore is prevented from entering the second cavity, so that the appearance of weld on the surface of the second molded product is prevented. Further, the first molded body is formed with the concave and convex portions to which the concave and convex portions are transferred, and the molded body formed in the communication space is joined thereto, so that the joining strength between the first molded body and the second molded body is further increased. The effect of improving is also exerted.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments 1 to 4 embodying the invention described in each claim will be described below with reference to the drawings. In the following embodiment, the present invention is applied to manufacture of a door trim of an automobile. (Embodiment 1) The molding method of Embodiment 1 embodies claim 1.

FIGS. 1 and 2 show a molding die used in the present embodiment. This molding die includes an upper die 10 and a lower die 11 which is clamped to the upper die 10, and a rib 12 projects from the upper die 10 into the cavity. Further, a slide core 13 is provided on the lower mold 11, and the slide core 13 is configured to be able to move forward and backward facing the tip of the rib 12. The cavity is divided into a first cavity 14 and a second cavity 15 in a state where the slide core 13 advances and abuts on the tip of the rib 12, and the first cavity 14 and the second cavity 14 It is configured such that communication spaces 16 communicating with the cavities 15 are formed.

In this embodiment, first, the upper mold 10 and the lower mold 11
In a state in which the surface is separated, the skin 2 previously formed into a mold surface shape by vacuum forming is arranged on the mold surface of the upper mold 10 constituting the first cavity 14, and the mold is formed by vacuum suction from a suction hole (not shown). Held along the surface. At this time, the tip of the end of the skin 2 along the rib 12 is connected to the rib 1 as shown in FIG.
2 and is located lower than the tip of the skin 2, and the tip of the skin 2 and the tip of the rib 12 are separated by a predetermined distance.

In this state, the slide core 13 is advanced,
Before the upper mold 10 and the lower mold 11 are completely closed, a predetermined amount of molten resin is injected into the first cavity 14. Then, the upper mold 10 and the lower mold 11 are immediately closed, and at the same time, the slide core 13 is brought into contact with the ribs 12 to compress the injected molten resin. As shown in FIG.
The first molded body 3 is formed by filling the cavity 14 with the first molded body 3.
Covered. As described above, since the first molded body 3 is formed by so-called injection compression molding, the resin peak pressure during molding is 10 MPa or less, which is extremely smaller than the resin peak pressure (20 MPa or more) during normal injection molding. Therefore, no excessive pressure acts on the epidermis 2 and damage to the epidermis 2 is prevented.

Subsequently, when the slide core 13 is retracted to form the communication space 16, the molten resin is injected into the second cavity 15 to form the second molded body 4. As shown in FIG. 4, the second molded body 4 fills the second cavity 15 and the communication space 16 and is integrated with the first molded body 3 by fusion.
At this time, since the end face of the skin 2 is covered with the first molded body 3, the second molded body 4 does not come into direct contact with the skin 2. Therefore, the molten resin does not enter between the skin 2 and the ribs 12 at the time of molding the second molded body 4, and the appearance quality of the surface of the skin 2 serving as the design surface is not impaired.

After the first molded body 3 and the second molded body 4 are cooled and solidified, the upper mold 10 and the lower mold 11 are opened, and the skin 2
Is released from the mold. (Embodiment 2) The molding method of Embodiment 2 embodies claims 2 and 3. The present embodiment is different from the first embodiment in that a molding die similar to that of the first embodiment is used, and the retraction stroke of the slide core 13 is larger than that of the first embodiment.

First, the skin 2 is placed on the upper mold 10 in the same manner as in the first embodiment, and the first molded body 3 is formed by injection compression molding as shown in FIG. Next, as shown in FIG. 5, the slide core 13 is retracted farther than in the first embodiment, and the volume of the communication space 16 is made larger than in the first embodiment. Then, the first molten resin that has not yet solidified flows from the first molded body 3 into the communication space 16. However, since the volume of the communication space 16 is sufficiently large, the first molten resin that has flowed down flows into the second cavity 1.
5 does not enter.

Subsequently, the slide core 13 is advanced to the position shown in FIG. 4 of the first embodiment, and the second molten resin is injected into the second cavity 15. At this time, the communication space 16
A part of the first molten resin flowing down into the first cavity 14 is pushed back by the advance of the slide core 13, but a part of the first molten resin tends to enter the second cavity 15. However, since the pressure of the second molten resin injected into the second cavity 15 is extremely large, most of the first molten resin stops in the communication space 16 or is pushed back to the first cavity 14 and hardly enters the second cavity 15. .

Therefore, in the obtained molded part-skin integral product, as shown in FIG. 6, the second molded body 4 is fused with the first molded body 3 near the bottom of the groove formed by the rib 12. In addition, no weld appears on the design surface of the second molded body 4 and the appearance quality is excellent. Further, similarly to the first embodiment, since the second molten resin does not enter between the skin 2 and the ribs 12 at the time of molding the second molded body 4, the appearance quality of the surface of the skin 2 serving as a design surface is impaired. Not even.

(Embodiment 3) The molding method of Embodiment 3 embodies claim 4. In the present embodiment, as shown in FIG. 7, a molding die similar to that of the first embodiment is used except that the space between the first cavities 14 is narrowed only in a portion near the rib 12.

First, the skin 2 is disposed on the upper mold 10 in the same manner as in the first embodiment, and the first molded body 3 is formed by injection compression molding as shown in FIG. Next, the slide core 13 is retracted as in the first embodiment, and the second molded body 4 is formed as in the first embodiment. At this time, since the space between the first cavities 14 near the ribs 12 is narrowed, the heat capacity of the first molded body 3 in that portion is reduced, and cooling is facilitated.
Therefore, since the end portion 30 of the first molded body 3 is cooled and solidified or has a high viscosity, the molten resin of the first molded body 3 in an unsolidified state is prevented from flowing down to the communication space 16.

As a result, even if the slide core 13 retreats, the state where the first molded body 3 is filled in the first cavity 14 is maintained, and the second molded body 4 is formed similarly to the first embodiment shown in FIG. Is done. Further, since the end portion 30 of the first molded body 3 is solidified or has an increased viscosity, the molten resin is further prevented from entering between the skin 2 and the ribs 12 during the molding of the second molded body 4.

(Embodiment 4) A molding die used in the molding method of Embodiment 3 embodies claim 4. In the present embodiment, as shown in FIG. 8, a molding die similar to that of the first embodiment is used except that an uneven portion 17 is formed on the surface of the slide core 13 facing the first cavity 14.

First, the skin 2 is placed on the upper mold 10 in the same manner as in the first embodiment, and the first molded body 3 is formed by injection compression molding as shown in FIG. At this time, the end face of the first molded body 3 comes into contact with the slide core 13 with a large surface area due to the presence of the uneven portion 17. Therefore, the amount of heat radiation through the slide core 13 increases, and the end 30 of the first molded body 3 is further cooled to solidify or increase the viscosity.

Next, the slide core 13 is retracted in the same manner as in the first embodiment, and the second molded body 3 is formed in the same manner as in the first embodiment. At this time, since the end portion 30 of the first molded body 3 is solidified or has a high viscosity, the molten resin of the first molded body 3 in an unsolidified state is prevented from flowing down to the communication space 16. As a result, even if the slide core 13 retreats, the state where the first molded body 3 is filled in the first cavity 14 is maintained, and the second molded body 4 is formed as in the first embodiment shown in FIG. Further, since the end portion 30 of the first molded body 3 is solidified or has an increased viscosity, the molten resin is further prevented from entering between the skin 2 and the ribs 12 during the molding of the second molded body 4. Further, since the concave and convex portions on which the shape of the uneven portion 17 is transferred are formed on the end surface of the first molded body 3, the contact area with the second molded body 4 is increased, and the bonding strength is further improved.

[0036]

According to the method for integrally molding a partial skin according to the first aspect of the present invention, the molten resin is prevented from entering between the skin and the ribs, so that the integrally molded partial skin having excellent appearance quality is obtained. Can be easily, reliably, and inexpensively manufactured. According to the partial skin integral molding method and the partial skin integral molding die according to claims 2 to 5, since a weld or the like is prevented from appearing on the surface of the second molded body, a part excellent in appearance quality is provided. It is possible to easily, reliably and inexpensively manufacture an integral skin molded product.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a molding die used in an embodiment of the present invention in a state where a first molding step is performed.

FIG. 2 is a cross-sectional view showing a molding die used in an embodiment of the present invention in a state where a second molding step is performed.

FIG. 3 is an enlarged sectional view of a main part showing a mold used in an embodiment of the present invention after a first molding step.

FIG. 4 is an enlarged sectional view of a main part showing a mold used in an embodiment of the present invention after a second molding step.

FIG. 5 is a cross-sectional view of a molding die used in a second embodiment of the present invention.
It is a principal part enlarged sectional view which shows the state which retracted the slide core in the shaping | molding process.

FIG. 6 shows a molding die used in a second embodiment of the present invention,
It is a principal part expanded sectional view shown in the state after a molding process.

FIG. 7 shows a mold used in a third embodiment of the present invention as a first mold.
It is a principal part expanded sectional view shown in the state after a molding process.

FIG. 8 shows a molding die used in a fourth embodiment of the present invention,
It is a principal part expanded sectional view shown in the state of the molding process.

FIG. 9 is an explanatory view showing a conventional molding method.

FIG. 10 is an explanatory view showing a conventional molding method.

[Explanation of symbols]

2: skin 3: first molded body 4:
Second molded body 10: Upper mold 11: Lower mold 1
2: rib 13: slide core 14: first cavity 1
5: second cavity 16: communication space 17: uneven portion

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29L 31:30

Claims (5)

[Claims] 1. A first cavity and a second cavity communicating with each other at ends thereof, a rib projecting from one mold surface and dividing the first cavity and the second cavity, and a reciprocating drive opposing the rib. And a molding die composed of a slide core to be formed, a skin is arranged in the first cavity along the one mold surface, and the slide core is brought into contact with the rib to communicate with the second cavity. A first molding step of injecting a molten resin into the first cavity in a cut-off state to form a first molded body integrated with the skin, and retreating the slide core between the first cavity and the second cavity; And a second molding step of forming a communication space with each other and injecting a molten resin into the second cavity to form a second molded body integrated with the first molded body. The epidermis is in front A partial skin integral molding, wherein the end of the end along the rib is disposed so as to be lower than the end of the rib, and the end surface of the skin after the first molding step is covered with the first molded body. Method. 2. A first cavity and a second cavity communicating with each other at their ends, a rib protruding from one mold surface and dividing the first cavity and the second cavity, and a reciprocating drive opposing the rib. And a slide die to be used, and a skin is arranged in the first cavity along the one mold surface, and the slide core is brought into contact with the rib to communicate with the second cavity. A first molding step of injecting a molten resin into the first cavity in a cut-off state to form a first molded body integrated with the skin, and retreating the slide core between the first cavity and the second cavity; And a second molding step of forming a communication space with each other and injecting a molten resin into the second cavity to form a second molded body integrated with the first molded body. And the second molding Wherein the extent retraction stroke of the slide core is large, the resin flowing out of the first molded body portion integral skin molding method characterized in that it is accommodated in the communicating space. 3. The partial skin integral molding method according to claim 2, wherein in the second molding step, when the molten resin is injected, the slide core moves forward and presses the resin in the communication space. 4. A first cavity and a second cavity communicating with each other at their ends, a rib protruding from one mold surface and dividing the first cavity and the second cavity, and a reciprocating drive opposing the rib. And a molding die composed of a slide core to be formed, a skin is arranged in the first cavity along the one mold surface, and the slide core is brought into contact with the rib to communicate with the second cavity. A first molding step of injecting a molten resin into the first cavity in a cut-off state to form a first molded body integrated with the skin, and retreating the slide core between the first cavity and the second cavity; And a second molding step of forming a communication space with each other and injecting a molten resin into the second cavity to form a second molded body integrated with the first molded body. Along the rib Part integral skin molding method is a width of the first cavity portion, characterized in that cooling is narrower than other portions is promoted. 5. A first cavity and a second cavity communicating with each other at ends thereof, a rib protruding from one mold surface to partition the first cavity and the second cavity, and a reciprocating drive opposing the rib. Slide core,
A skin is arranged in the first cavity along the one mold surface, and the molten resin is injected into the first cavity in a state where the slide core is brought into contact with the rib to cut off the communication with the second cavity. A first molding step of forming a first molded body integrated with the skin; and a step of retracting the slide core to form a communication space between the first cavity and the second cavity to communicate with each other. A second molding step of injecting a molten resin into the cavity to form a second molded body integrated with the first molded body; and a molding die used for a partial skin integral molding method, comprising: A partial skin integral molding die, wherein an uneven portion is formed on a surface facing the first cavity.