JP4368697B2 - Method of forming skin on core material - Google Patents

Description

In the present invention, the core material is set on the first molding die, the first molding die is closed with respect to the second molding die, and formed between the first molding die and the second molding die. that the liquid resin is injected into the gap relates to skin formation how to form a skin on the core material.

  As a method of manufacturing resin molded products such as instrument panels, door rims, and console boxes that are automobile interior parts, the core material is fixed to the upper mold with a hook or the like, and the liquid resin is sprayed onto the lower mold for molding. Discloses a method of forming a skin on a core material (see FIG. 6 of Patent Document 1).

  However, in the method described in Patent Document 1, it is preferable that the liquid resin is thinly and continuously applied to the lower mold for molding many times, preferably 5 to 15 times. Therefore, the process becomes complicated. Therefore, a core material is set on the first molding die, the first molding die is closed with respect to the second molding die, and a gap formed between the first molding die and the second molding die. A method of injecting a liquid resin into the core material to form a skin on the core material is performed.

JP 2000-351351 A

  On the other hand, in recent years, there has been a demand for automobile interior parts in which a skin is formed only on part of the core material. However, in the method of injecting the liquid resin into the gap formed between the first molding die and the second molding die, the skin cannot be formed only on a part of the core material.

The present invention has been made in view of the above-described problems, and a core material is set on a first molding die, the first molding die is closed with respect to the second molding die, and the first molding is performed. type and by injecting a liquid resin into the gap formed between the second mold, a method of forming a skin on the core material, to provide a way of forming a skin on the part of the core Objective.

Means and effects for solving the problems

  In the present invention, the following features are provided alone or in combination as appropriate. A skin forming method for forming a skin on a core material according to the present invention for solving the above-described problems is to set a core material on a first molding die, and the first molding die to the second molding die. A skin forming method in which a liquid resin is injected into a gap formed between the core material and the second molding die to form a skin on the core material, the second molding The mold is provided with a projecting portion that reaches the core, and the first molding mold is closed with respect to the second molding mold so that the projecting section partitions the gap into a plurality of regions, and the projecting section is Injecting the liquid resin into any one of the plurality of regions so as to block outflow of the liquid resin from the region into which the liquid resin is injected into another region, It is characterized by forming an epidermis. According to this method, the gap formed between the first molding die and the second molding die is partitioned into a plurality of regions by the protrusions provided on the second molding die. And since this protrusion blocks the liquid resin injected into any one of the plurality of regions from flowing out to the other region, it is possible to form a skin only on a part of the core material. Become.

  Further, in the skin forming method for forming a skin on the core material according to the present invention, the tip of the projection is at an angle of 20 ° to 120 °, and the tip of the projection is inserted into the core. In addition, it is preferable that the first molding die is closed with respect to the second molding die. Generally, a resin molded body such as an instrument panel which is an automobile interior has a large surface area, and a gap formed between the upper mold for molding and the lower mold for molding is 0.5 to 1.5 mm. Since it is relatively narrow, a liquid resin that easily flows through a relatively narrow gap is used. Therefore, when the tip of the protrusion is set to an angle of 20 ° to 120 ° and the first molding die is closed with respect to the second molding die, the tip of the protrusion is easily inserted into the core material. Thus, it is considered that the liquid resin injected into any one of the plurality of regions can be more reliably blocked from flowing out to the other regions.

  In the skin forming method for forming the skin on the core material according to the present invention, the liquid resin is a thermosetting liquid resin, and a heating device for heating the protrusion is attached. According to this, since the heating device is provided on the protrusion, the protrusion is more easily inserted into the core material. Further, since the liquid resin is a thermosetting resin, the liquid resin injected into any one of the plurality of regions is cured at the protrusions. Therefore, it is considered that the liquid resin injected into any one of the plurality of regions can be more reliably blocked from flowing out to the other regions.

  In the skin forming method of forming the skin on the core material according to the present invention, it is preferable that the protrusion includes a movable part that can advance and retract relative to the first molding die. Generally, the thickness of the core material varies. There are also cases where it is desired to change the advancing and retracting direction of the molding die and the protrusion. According to this, since the protrusion provided on the second molding die includes the movable portion that can advance and retract relative to the first molding die, the protrusion and the molding die can be moved independently. Will be able to.

  Hereinafter, an example of a preferred embodiment of a skin forming method for a core material according to the present invention and a skin forming molding apparatus suitable for the method will be described.

  First, a skin forming apparatus 1 suitable for the skin forming method for a core material according to the present invention will be briefly described with reference to FIG. Here, FIGS. 1A to 1D are schematic views illustrating a process of forming a skin on the core 15 of a resin molded body such as an instrument panel, a door rim, a console box, or the like that is an automobile interior product. is there. Therefore, in explaining the skin forming apparatus 1 suitable for the skin forming method on the core 15 according to the present invention, FIG. 1 (a) arbitrarily selected from FIGS. 1 (a) to 1 (d). And (c).

  As shown in FIG. 1 (a), a skin forming apparatus 1 according to the present invention includes an upper mold 2 and a lower mold 3, and each of the molds 2 and 3 includes a mold part. 2a and 3a and closed surfaces 2b and 3b. The closed surfaces 2b and 3b are flat surfaces. When the upper mold 2 is closed with respect to the lower mold 3 so that the closing surface 2b of the upper mold 2 and the closing surface 3b of the lower mold 3 face each other, the upper mold 2 and the lower mold 3 As shown in FIG. 1C, a gap 10 is formed between the two.

  A core material fixing pin 4 for setting the core material 15 is attached to the mold portion 2 a of the upper mold 2. The core material fixing pin 4 is embedded in the upper mold 2 and the tip of the pin 4 protrudes from the surface of the mold part 2a. The core material 15 can be attached to the tip of the pin 4 protruding from the surface of the mold part 2a. The length of the pin 4 protruding from the surface of the mold part 2a is smaller than the thickness of the core material 15 so that the pin 4 does not penetrate the core material 15 when the core material 15 is set on the pin 4. It has become.

  The core material 15 is pre-injected with polypropylene (hereinafter referred to as “PP”) and talc resin. And in order to improve adhesiveness with the liquid resin 20 mentioned later, the surface of the core material 15 is flame-treated and the surface energy is raised to 40-50 dyne.

  A seat portion 5 is attached to the closing surface 3 b of the lower mold 3. This is to prevent the core material 15 from being bent. That is, the core material 15 cannot be bent only by fixing the core material 15 with the pins 4. Therefore, as illustrated in FIG. 1C, when the upper mold 2 is closed with respect to the lower mold 3, the core material 15 is sandwiched between the upper mold 2 and the lower mold 3, This suppresses the deflection of the core material 15. The boundary between the mold part 2a and the closing surface 2b of the upper mold 2 is located more than the innermost position of the seat part 5 so that the core material 15 can be sandwiched between the upper mold 2 and the lower mold 3. Located on the outside.

  The mold part 3 a of the lower mold 3 is provided with a protruding part 6 that reaches the upper mold 2 when the upper mold 2 is closed with respect to the lower mold 3. When the upper mold 2 is closed with respect to the lower mold 4, the gap 10 formed between the upper mold 2 and the lower mold 3 is divided into a plurality of regions 10 a and 10 b by the protrusions 6. Partitioned.

  In the present embodiment, the core material fixing pin 4 is provided in the mold part 2a of the upper mold 2. However, the present invention is not limited to this and may be provided in the mold part 3a of the lower mold 3. Furthermore, if the core material 15 can be set, it may not be a pin. When the core material fixing pin 4 is provided on the mold part 3 a of the lower mold 3, the protrusion 6 is provided on the mold part 2 a of the upper mold 2. That is, the core material fixing pin 4 and the protrusion 6 are provided in different molds, and the protrusion 6 reaches the core 15 when the upper mold 2 is closed with respect to the lower mold 3. That's fine. In the present embodiment, the base width of the protrusion 6 is 1.0 mm, and the height of the protrusion 6 is 1.0 mm.

  Further, in order to suppress the deflection of the core material 10, the seat portion 5 is attached to the lower mold 3, but is not limited thereto, and may be attached to the upper mold 2. Moreover, although it is preferable that the seat part 5 is attached from a viewpoint of suppressing the bending of the core material 15, it is not necessarily essential.

  Further, the closed surfaces 2b and 3b of the molds 2 and 3 are both flat surfaces, but are not limited thereto. For example, the closing surface 2b of the upper die 2 is a concave surface, and the closing surface 3b of the lower die 3 is a convex surface where the closing surface 2b of the upper die 2 and the closing surface 3b of the lower die 3 face each other. Good. That is, when the upper mold 2 is closed with respect to the lower mold 3, if the gap 10 formed between the upper mold 2 and the lower mold 3 can be closed, the respective closed surfaces 2b and 3b are closed. The shape of is not limited.

  Next, the skin forming method for the core material 15 according to the present invention will be briefly described with reference to FIGS. 1 (a) to 1 (d).

  As shown in FIG. 1A, the core material 15 is brought close to the mold part 2 b of the upper mold 2. Then, as shown in FIG. 1B, the core material fixing pin that protrudes from the surface of the mold part 2 a of the upper mold 2 along the shape of the mold part 2 a of the upper mold 2 as shown in FIG. Set to 4. The material of the core material 15 is preferably pre-injected with PP and talc resin, but is not limited thereto. In this way, the upper mold 2 on which the core material 15 is set is placed on the upper mold 2 so that the closed surfaces 2b and 3b face each other as shown in FIG. 1 (c). Close against mold 3. At this time, the peripheral edge 15 a of the core member 15 is disposed between the seat 5 attached to the upper mold 2 and the lower mold 3, and is sandwiched and fixed between the upper mold 2 and the lower mold 3. . At this time, the mold part 2a of the upper mold 2 and the mold part 3a of the lower mold 3 are arranged to face each other, and a gap 10 is formed between the mold parts 2a and 3a. Then, as illustrated in FIG. 1D, when the liquid resin 20 is injected into the gap 10 and the liquid resin 20 is cured, a skin is formed on the core material 15. In addition, since the clearance gap formed between the upper metal mold | die 2 and the lower metal mold | die 3 is generally as small as 0.5-1.5 mm, it is preferable that it is a low viscosity liquid resin which is easy to flow.

  Next, the action of the protrusion 6 provided on the mold 3b of the lower mold 3 when the liquid resin 20 is injected into the gap 10 formed between the upper mold 2 and the lower mold 3 will be described. .

  Here, since the liquid resin 20 is easy to flow, the liquid resin 20 injected into the gap 10 formed between the upper mold 2 and the lower mold 3 goes to the details of the gap 10. As a result, a uniform skin is formed on the surface of the core material 15. Here, the protrusion 6 reaches the core member 15 and further partitions the gap 6 into a plurality of regions. Therefore, the protrusion 6 prevents the liquid resin 20 injected into any one of the regions partitioned into a plurality of regions from flowing into the other region 10b.

  In this manner, the protrusion 6 blocks the outflow of the liquid resin 20 from one region 10a to the other region 10b, so that a skin is formed only on the surface of the core material 15 disposed in the one region 10a. No skin is formed on the surface of the core material 15 arranged in the other region 10b. Therefore, it is possible to provide a resin molded body in which a skin is formed only on a part of the surface of the core material 15. Needless to say, the position of the protruding portion 6 provided on the mold portion 3 b of the lower mold 3 varies depending on the region in which the skin is desired to be formed on the surface of the core material 15.

  Next, the shape of the tip portion of the protrusion 6 will be described with reference to FIG. FIG. 2 is a detail of the portion A shown in FIG. 1, and is a cross-sectional view of the protrusion 6 as seen from the direction in which the gap 10 is partitioned into one region 10 a and another region 10 b. As shown in FIG. 2, the protrusion 6 has one tip 61, and the tip angle θ <b> 1 is formed in the range of θ <b> 1 = 20 ° to 120 °. Furthermore, it is preferable that the shape of the front-end | tip part 61 is a taper shape, ie, a pointed shape.

  Thus, when the tip shape of the protrusion 6 is pointed and the tip angle θ1 is in the range of θ1 = 20 ° to 120 °, the closing surface 2b of the upper mold 2 and the lower mold 3 are closed. When the upper mold 2 is closed with respect to the lower mold 3 so as to face the surface 3 b, the tip of the protrusion 6 is easily inserted into the core member 15. In the present embodiment, the tip 61 of the protrusion 6 is inserted into the core member 15 by about 0.5 mm. Thus, when the tip portion 61 of the protrusion 6 is inserted into the core material 15, the protrusion 6 moves to the other region 10 b of the liquid resin 20 injected into any one region 10 a of the plurality of regions. Can be more reliably blocked. By carrying out like this, it can suppress that an excess skin is formed in the boundary part of the surface of the core material 15 in which the skin was formed, and the surface of the core material 15 in which the skin is not formed. In addition, since the design is given to the surface of the resin molding, it is difficult to remove this excess skin.

  In view of the fact that the tip of the protrusion 6 is easily inserted into the core member 15, the tip angle θ <b> 1 is more preferably in the range of 45 ° to 90 °.

  In this embodiment, the liquid resin 20 to be injected into the gap 10 formed between the upper mold 2 and the lower mold 3 uses thermosetting urethane 20. A heating device 7 for heating the protrusion 6 is attached inside the protrusion 6. In the present embodiment, a coil heater 7 as the heating device 7 is attached inside the protrusion 6. The coil heater 7 can heat the protrusion 6 to 60 ° C. or higher in order to promote the curing of the thermosetting urethane 20 in the vicinity of the protrusion 6. From the viewpoint of promoting the curing of the thermosetting urethane 20, it is preferable that the protrusion 6 can be heated to about 150 ° C. Furthermore, the temperature of the protrusion 6 can be adjusted in the range of 40 ° C. to 60 ° C. so that the curing speed of the thermosetting urethane 20 can be adjusted.

  In this way, by heating the protrusion 6 to 60 ° C. or more with the coil heater 7, the curing of the thermosetting urethane 20 in the vicinity of the protrusion 6 can be promoted, so the thermosetting urethane injected into the one region 10 a. 20 can surely be blocked from flowing into the other region 10b. Furthermore, since the temperature of the coil heater 7 can be adjusted in the range of 40 ° C. to 60 ° C., the curing speed of the thermosetting urethane 20 can be adjusted.

  The heating device 7 is not limited to the coil heater, and is not necessarily limited to the one attached to the inside of the protrusion 6. That is, it suffices if the vicinity of the protrusion 6 is heated so that the thermosetting urethane 20 injected into one region can be prevented from flowing out to the other region.

  In the present embodiment, as shown in FIG. 3, the protrusion 6 is configured to be able to advance and retract relative to the core material 15. FIG. 3 is a detail of the portion A shown in FIG. 1, in which the protrusion 6 is configured to be able to advance and retract with respect to the core material 15. Specifically, the protrusion 6 is divided from the lower mold 3, and the protrusion 6 and the lower mold 3 are configured separately. Then, the dividing surface 6A of the protrusion 6 and the dividing surface 3A of the lower mold 3 slide. A sealing material 11 made of an elastic member is disposed between the dividing surface 6A of the protrusion 6 and the dividing surface 3A of the core material 15. This is to prevent the liquid resin 20 injected into the one region 10a from flowing out from between the divided surface 6A of the protrusion 6 and the divided surface 3A of the core member 15.

  Since the thickness of the core material 15 generally varies, the projecting portion 6 is configured to be capable of advancing and retreating with respect to the core material 15 as described above, so that one region can be obtained regardless of the thickness of the core material 15. The liquid resin 20 injected into 10a can be prevented from flowing into the other region 10b.

  Next, the modification about the shape of the front-end | tip part of the projection part 6 is demonstrated using FIG. 4A to 4F are cross-sectional views of the protruding portion 6 as seen from the direction in which the gap 10 is partitioned into one region 10a and another region 10b, and show variations regarding the shape of the tip portion.

  The protrusion 6 illustrated in FIG. 4A has one tip 62, and the tip angle θ2 is formed in the range of θ2 = 20 ° to 120 °. Further, the cross-sectional shape of the protrusion 6 is a right triangle in which the surface 6 a of the protrusion 6 on the one region 10 a side rises perpendicularly to the mold 3 a of the lower mold 3. Moreover, the shape of the front-end | tip part 62 is a taper shape, ie, a cusp.

  The protrusion 6 shown in FIG. 4B has two tip portions 63 and 64. Specifically, the surface 6a of the protruding portion 6 on the one region 10a side and the surface 6b of the protruding portion 6 on the other region 10b side rise vertically with respect to the mold portion 3a of the lower mold 3, and A recess 12 is formed at the center of the tip. The recess 12 has a shape of an equilateral triangle or an isosceles triangle, and faces from the surface 6a of the projection 6 on the one region 10a side and the surface 6b of the projection 6 on the other region 10b side to the inside of the projection 6. It is cut and formed. At this time, the tip angles θ3 and θ4 of the tip portions 63 and 64 are both formed at 60 °, and the tip portions 63 and 64 have a tapered shape, that is, a pointed shape. Note that the two tip portions 63 and 64 do not have to be pointed, and at least the tip shape of the tip portion 63 formed on the one region 10a side may be pointed. Further, the tip angles θ3 and θ4 of the tip portions 63 and 64 are preferably in the range of 45 ° to 90 °.

  The protrusion 6 shown in FIG. 4C has one tip 65, and the tip angle θ5 is a regular triangle or isosceles triangle formed in the range of θ5 = 20 ° to 120 °. is doing. And the shape of the front-end | tip part 65 is a taper shape, ie, a cusp.

  4D, the surface 6a of the protrusion 6 on the one region 10a side and the surface 6b of the protrusion 6 on the other region 10b side are formed on the mold portion 3a of the lower mold 3. The protrusion 6 shown in FIG. On the other hand, it stands upright. Then, from the surface 6a of the projection 6 on the one region 10a side and the surface 6b of the projection 6 on the other region 10b side, a gentle slope is once inwardly in the range of angle θ6 = 120 ° to 170 °. Forming. Further, it has one tip portion 66 formed with a tip angle θ7 of θ7 = 60 °. The tip 66 has a tapered shape, that is, a pointed shape. The tip angle θ7 of the tip 67 is preferably in the range of 45 ° to 90 °.

  4 (e), the surface 6a of the protrusion 6 on the one region 10a side and the surface 6b of the protrusion 6 on the other region 10b side form the mold portion 3a of the lower mold 3. On the other hand, it stands upright. Then, a slope is formed inward from the surface 6a of the protrusion 6 on the one region 10a side and the surface 6b of the protrusion 6 on the other region 10b side to form one tip 67. The tip angle θ8 of the tip portion 67 is formed in the range of θ8 = 20 ° to 120 °. And the shape of this front-end | tip part 67 is a taper shape, ie, a pointed shape.

  The protrusion 6 illustrated in FIG. 4F has three tip portions 68, 69, and 70. Specifically, the surface 6a of the protruding portion 6 on the one region 10a side and the surface 6b of the protruding portion 6 on the other region 10b side rise vertically with respect to the mold portion 3a of the lower mold 3, and Two recesses 13 and 14 are formed at the tip. The recesses 13 and 14 are both regular triangles or isosceles triangles. At this time, the tip angles θ9 and θ10 of the tip portions 68 and 70 are both formed at 60 °, and the tip angle θ11 of the tip portion 69 is formed in the range of θ11 = 20 ° to 120 °. And all the front-end | tip parts 68 * 69 * 70 are taper-shaped, ie, a pointed shape. The three tip portions 68, 69, and 70 do not have to be pointed, and at least the tip shape of the tip portion 68 formed on the one region 10a side may be pointed. The tip angles θ9 and θ10 of the tip portions 68 and 70 are preferably in the range of 45 ° to 90 °.

  In each of the protrusions 6 illustrated in FIGS. 4A to 4F, the shapes of the tip portions 61 to 70 have a predetermined angle, and the tip shape is pointed. Therefore, when the upper mold 2 is closed with respect to the lower mold 3, it is easily inserted into the core material 15, and the liquid resin 20 injected into one area 10 a is blocked from flowing out to the other area 10 b. It is considered possible.

  In addition, although this invention is described in said preferable embodiment, this invention is not restrict | limited only to it. It will be understood that various other embodiments may be made without departing from the spirit and scope of the invention.

It is the schematic which showed the process of forming a skin on the core material 15 of the resin molding. FIG. 2 is a detail of a portion A illustrated in FIG. 1, and is a cross-sectional view of a protrusion when viewed from a direction in which a gap is divided into one region and another region. It is the detail of the A section shown in Drawing 1, and is a figure constituted so that a projection part can advance and retreat with respect to a core material. (A)-(f) It is sectional drawing of the projection part seen from the direction which partitions off a clearance gap into one area | region and another area | region, Comprising: The variation about the shape of a front-end | tip part is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Skin forming apparatus 2 Upper mold 2a Upper mold part 2b Upper mold closing surface 3 Lower mold 3A Lower mold dividing surface 3a Lower mold part 3b Lower mold closing surface 4 Core material fixing pin 5 Seat 6 Projection 6A Projection split surface 6a Projection surface 6b on one area side Projection surface 7 on another area 7 Heating device (coil heater)
DESCRIPTION OF SYMBOLS 10 Crevice 10a One area | region 10b Other area | region 11 Seal member 12-14 Recessed part 15 Core material 15 Perimeter 20 of core material Liquid resin (thermosetting urethane)
61-70 Tip portion of projection portion θ1-θ11 Tip angle of projection portion

Claims (4)

A core material is set on the first molding die, the first molding die is closed with respect to the second molding die, and a gap is formed between the core material and the second molding die. A skin formation method in which a liquid resin is injected to form a skin on the core material,
The second molding die is provided with a protruding portion that reaches the core material, and the first molding die is closed with respect to the second molding die so that the protruding portion partitions the gap into a plurality of regions. ,
Injecting the liquid resin into any one of the plurality of regions so that the protrusion blocks the outflow of the liquid resin from the region into which the liquid resin is injected into another region, and the core material A method of forming an epidermis in which a part of the skin is formed.   The first molding die is positioned with respect to the second molding die so that the tip of the projection has an angle of 20 ° to 120 ° and the tip of the projection is inserted into the core member. The method for forming an epidermis according to claim 1, wherein the skin is closed.   The skin forming method according to claim 1 or 2, wherein the liquid resin is a thermosetting liquid resin, and a heating device for heating the protrusion is attached. The skin forming method according to any one of claims 1 to 3, wherein the protrusion includes a movable part that can move forward and backward with respect to the first molding die.

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