JPH1034659A - Mold structure used for manufacturing multilayered molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold structure for manufacturing a multilayered molded article wherein a skin material can be surely positioned in a mold. SOLUTION: A skin material 16 formed by cutting a cloth raw fabric into a specified dimension is placed on a part surrounded by a recessed line channel 37 on a large projected part 25 of a bottom mold 22 under a condition where a top mold 21 is opened to the bottom mold 22 (unclosed condition). In this case, pine 30 of a positioning mechanism are brought into contact with the side wall 16a of the end part of the skin material 16 at four corners of the skin material 16 to position the skin material 16. The pins 30 are elevated and lowered in long holes 26 of the bottom mold 22 by means of springs 27 and cylinder devices 28 as elevating/lowering devices in accordance with movement of the top mold 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold structure for producing a multilayer molded article comprising a skin material in which only a predetermined portion of a surface of a thermoplastic resin is coated with a skin material and a thermoplastic resin alone. .

[0002]

2. Description of the Related Art A multilayer molded product of a skin material in which only a predetermined portion of the surface is covered with a skin material and a plain thermoplastic resin is used for interior parts such as door trims and rear trims of automobiles. To manufacture such a multilayer molded product, a thermoplastic resin is preliminarily molded by injection molding or the like, and a skin material having a predetermined shape is adhered to the molded product using an adhesive or the like, or the skin material is hardened in advance. There is a method of manufacturing a part attached to a board or the like, and attaching this part to the molded product using a screw or the like. However, such a method requires a post-process, is time-consuming, and is costly. It was a factor of up.

In order to improve the production of such a multilayer molded product, there has been proposed, for example, one described in Japanese Patent Application Laid-Open No. 64-26414.

According to this, a skin material and a molten resin are supplied between an unclosed upper and lower mold for molding, and upper and lower molds are closed to produce a multilayer molded product composed of the skin material and a thermoplastic resin. In doing so, the skin material cut into a predetermined shape is placed at a predetermined position on the upper or lower mold, and the welding resin is supplied to a substantially central portion on the back side of the skin material, so that only the predetermined portion is made of the skin material. The purpose is to obtain a multilayer molded product of the coated skin material and the thermoplastic resin alone.

[0005]

In the production of a multilayer molded product as described above, when a skin material previously cut into a predetermined shape is placed on a lower mold, the skin material is made of a thermoplastic resin. In order to cover the position, it is necessary that the skin material is positioned at a predetermined position on the lower mold, then the molten resin is supplied and the mold is formed. The mold structure has upper and lower molds 1 and 2 as shown in FIGS.
A small convex wall 5 is formed at a position corresponding to a parting portion where the skin material 3 covers the thermoplastic resin unit 4, and a concave groove 6 is formed on a cavity surface of the lower mold 2 corresponding to the small convex wall 5. The lower die 2 is provided with two pins 8. The pins 8 and the pieces 7 are slidable in the vertical direction of the lower die 2. The lower mold 2 is provided with a resin passage and a supply port (not shown).

[0006] When a multilayer molded article is manufactured, the following steps are performed.

[0007] The skin material 3 cut to a predetermined size is placed along the concave groove 6 of the lower mold 2 with its surface side facing up (the state shown in Fig. 14).

Next, an elevating mechanism (not shown) of the mold clamping device.
Is operated to lower the upper mold 1 and temporarily stop with a certain mold clearance between the upper mold 1 and the lower mold 2 in order to form a cavity with the lower mold 2. At the stop position, the two pins 8 are moved upward to lift the skin material 3 (the state shown in FIG. 15), and lightly contact a predetermined position on the cavity surface of the upper mold.

In this state, the supply of the molten resin 4a to the back side of the skin material 3 is started by a molten resin supply device (not shown) such as an extruder through a resin passage provided in the lower mold. The pin 8 and the piece 7 are retracted into the lower mold 2 within a predetermined time after the start.

Thereafter, the upper mold 1 is further lowered to spread the molten resin 4a into the cavity while pressing the skin material 3, so that the skin material 3 and the thermoplastic resin plain 4 are integrally formed to form. This is completed (the state shown in FIG. 16).

Then, after cooling, the upper mold 1 is raised, the upper and lower molds 1 and 2 are opened, and the formed multilayer molded article 1 is formed.
Take out 0.

However, the multilayer molded article 10 has a structure in which the skin material 3 is stretched on a part of the surface of the thermoplastic resin material 4, and the skin material 3 is made of the thermoplastic resin material 4. Since it is stretched in order to decorate the surface of the lower mold 2, it is necessary to securely stretch it at a predetermined position.
In the case where the positioning is performed only by simply placing on the piece 7 on the basis of In some cases, the upper mold 1 and the molten resin 4a are displaced during molding.

In view of such circumstances, an object of the present invention is to provide a mold structure for producing a multilayer molded product in which a skin material is reliably positioned in a mold. .

[0014]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention relates to a mold comprising upper and lower dies, which is cut into a predetermined shape at a predetermined position on a lower die. By placing a plurality of skin materials and supplying the molten resin from the back side of the skin material, the skin material is exposed only on a part of the surface of the resin plain portion formed by the molten resin, and the like. In the mold structure used for manufacturing a multilayer molded product in which the plain resin is exposed as it is, in the lower mold of the upper and lower molds, a concave groove is provided at a position corresponding to the parting portion of the skin material. Forming
It is characterized in that a positioning mechanism for positioning the skin material by holding the side wall of the parting material of the skin material in contact with the recess groove as a reference is provided. With this positioning mechanism, the skin material is reliably positioned in the mold.

The plain resin portion is prepared by mixing a predetermined amount of a thermosetting resin such as vinyl chloride, polypropylene, polyester, or nylon into a thermoplastic resin material such as polyethylene, polystyrene, polyvinyl chloride, or polyamide. It can be composed.

The skin material is cloth, PVC sheet, foamed P
In order to use a VC sheet, a polyethylene foam sheet, a non-woven fabric, etc., and to improve the soft feeling, a two-layer structure composed of cloth + compressed urethane, cloth + polyethylene foam, polyethylene foam + PVC sheet, or cloth + urethane + 3 consisting of nonwoven fabric (backside treatment) or cloth + urethane + TPO sheet (backside treatment)
It is also conceivable that a layer configuration is used.

The molten resin is supplied from the back side of the skin material,
When molding a multilayer molded product in which the skin material and the resin material are integrally formed by the upper and lower molds, the upper mold is lowered with respect to the lower mold, and the mold clearance of the upper and lower molds becomes a predetermined width. , The upper mold is stopped once, molten resin is injected into the back side of the skin material, and after the fixed amount of injection is completed, the upper mold is lowered again to the mold clearance = 0, and the multilayer It is molded into a molded product. And the mold clearance of the upper and lower molds at which the upper mold temporarily stops is usually 15 mm to 2 mm.
Is optimal, and the lowering speed when lowering the upper mold once after stopping is in the range of 4 to 12 mm / sec, and the optimal value is 4 / sec.
mm.

As a measure against damage to the skin material during molding, the temperature of the molten resin is usually preferably around 190 degrees Celsius, and the temperature of the preheated mold is optimally in the range of 30 to 70 degrees Celsius.

The positioning mechanism includes a pin for projecting a predetermined height from the cavity surface of the lower mold and abutting against the side wall of the parting portion of the skin material at a line contact to position the skin material;
An elevating device that retracts the pin to a predetermined position in the lower mold side direction in synchronization with the movement of the upper mold at least by the time of completion of shaping, and projects again onto the cavity surface of the lower mold at the next molding. It is characterized by becoming.

The positioning mechanism includes a piece that projects from the mold surface of the lower mold by a predetermined height and abuts against the side wall of the parting portion of the skin material to position the skin material, and at least shapes the piece. A lifting / lowering device which retracts to a predetermined position in the direction of the lower die to a predetermined position in synchronization with the movement of the upper die by the time of completion, and projects again onto the cavity surface of the lower die at the next molding; Is characterized in that a step portion for placing the cavity side of the lower mold in the parting portion of the skin material is formed.

Further, the positioning mechanism includes a plate-shaped bar projecting a predetermined height from the cavity surface of the lower mold and abutting against a side wall of the parting portion of the skin material to position the skin material. At least until the shaping is completed, the elevating device is retracted to the predetermined position in the lower mold side direction in synchronization with the movement of the upper mold to the predetermined position, and projected again on the cavity surface of the lower mold at the next molding. The bar is characterized in that a support surface portion for supporting the peripheral portion of the skin material by a predetermined width is formed.

Further, the positioning mechanism is adapted to hold a peripheral corner or a central portion of the peripheral portion of the skin material.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) First, a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an automobile door trim 11 which is a multilayer molded product to be manufactured by the mold structure of the present invention.
It is a perspective view of. The door trim 11 includes an armrest portion 12, a pocket portion 13, or a speaker grill attachment portion 1.
4 and the like, and a base material 15 made of a thermoplastic resin alone.
And a skin material 16 stretched so as to cover a part of the base material 15 as an insulated skin material for the purpose of decoration or the like.

The base material 15 is composed of a thermoplastic resin material such as polyethylene, polystyrene, polyvinyl chloride, polyamide or the like mixed with a predetermined ratio of a thermosetting resin such as vinyl chloride, polypropylene, polyester and nylon.

As the skin material 16, a cloth, a PVC sheet, a foamed PVC sheet, a polyethylene foam sheet, a non-woven fabric, or the like is used.
3 layers composed of compressed urethane, cloth + polyethylene foam, polyethylene foam + PVC sheet, etc., or cloth + urethane + non-woven fabric (backside treatment) or cloth + urethane + TPO sheet (backside treatment)
A layered structure may be used.

The skin material 16 has a substantially quadrangular shape, and the entire outer peripheral edge is a parting portion, and the parting portion is cut into the wood cut groove 17 of the base material 15.

In the present embodiment, the door trim 11 configured as described above is manufactured by the mold structure shown in FIGS.

That is, as shown in FIG. 2, this mold structure is composed of an upper mold 21 and a lower mold 22. In order to form the outer shape, a large concave portion 23 is formed, and an annular small protrusion 24 is formed at the center of the large concave portion 23 so as to protrude toward the lower mold 22.

Similarly, a large convex portion 25 is formed on the cavity forming surface 22a of the lower mold 22 so as to form the outer shape of the door trim 11 together with the large concave portion 23. Corresponding to the small protrusion 24, an annular groove 37 for forming a wood grain groove formed in an annular shape is formed.

As shown in detail in FIGS. 5 to 7, the concave groove 37 is provided with a step 38 on its outer periphery.
The step portion 38 is provided with four elongated holes 26 extending downward with respect to the lower mold 22 corresponding to the four corners of the skin material 16 (see the circles in FIG. 1). The cavity forming surface portion 22 a of the lower mold 22 is provided in each of the elongated holes 26.
A pin 30 for positioning the skin material 16 is inserted so as to protrude toward the upper mold 21 by the elastic force of the spring 27. The pin 30 is connected to the cylinder device 28
Thereby, the spring 27 is retracted from the cavity forming surface 22a toward the lower mold 22 side. Therefore, the spring 27 and the cylinder device 28 constitute an elevating device for the pin 30.

When the door trim 11 is manufactured by using the thus configured mold structure, first, as shown in FIG. 2, the upper mold 21 is opened (not closed) with respect to the lower mold 22. In this state, the skin material 16 formed by cutting the cloth cloth or the like into a predetermined size is placed on a portion of the large mold 25 of the lower mold 22 surrounded by the groove 37. At this time, the pin 30
In the four corners of the skin material 16, the skin material 16 is positioned by contacting the parting side wall 16 a of the skin material 16. This contact is a line contact because the pin 30 has a round bar shape. Therefore, the pin 30 provided in the elongated hole 26 and the spring 2
The 7 and the cylinder device 28 constitute a positioning mechanism for the skin material 16.

Next, in the same manner as in the prior art, the surface of the skin material 16 is guided by the pins 30 along the side walls 16a of the parting-off portion of the lower mold 22 using a pin device (not shown).
Raise a predetermined gap from 2a (state in FIG. 3).

Next, from this state, the upper mold 21 is lowered in the direction of the lower mold 22, and when the mold clearance reaches a predetermined width, the upper mold 21 is temporarily stopped, and the molten resin 31 is removed from the gate 29. After the charging, a predetermined amount of charging is completed, the upper mold 21 is lowered again until the mold clearance = 0 (the state of FIG. 4), and the molten resin 31 is filled in the cavity 32, and the door trim is performed. Form 11. At this time, the parting-off portion of the skin material 16 is inserted into the grained groove 17 to improve the appearance.

In the state shown in FIG. 4, the upper mold 21 is raised again through a cooling step for a predetermined time.
The solidified door trim 11 is taken out of the cavity 32, and the molding process is completed.

The optimal mold clearance C when the upper mold 21 temporarily stops is 15 mm to 2 mm. Then, the lowering speed of the upper mold 21 after stopping once is 4 to 12 mm per second, and the optimum value is 4 mm per second.

The temperature of the molten resin is usually 190 degrees Celsius.
Around the temperature, measures are taken to prevent the skin material 16 from being damaged by the resin temperature.

The mold temperature to be preheated is optimally in the range of 30 to 70 degrees Celsius.

The MI value of the molten resin is selected in the range of 80 to 120.

Thus, according to this embodiment, when the skin 16 is placed on the lower mold 22, the four corners of the side wall 16a of the parting portion 16a of the skin 16 abut against the pin 30 in a line contact. Without requiring the skill of the person, the skin material will be easily positioned without causing displacement,
In the wood trimming line of the door trim after completion, the parting portion of the skin material 16 is wood grained into the base material 15 in a predetermined shape, thereby contributing to the improvement of the overall appearance.

(Embodiment 2) FIG. 8 shows a second embodiment of the present invention, in which the positioning pins 30 used in the first embodiment are replaced with pieces 40. It is.

That is, the piece 40 has a round bar shape, and is formed with a positioning step 41 on which the four corners of the skin material 16 are placed.
The cylinder device 28 constitutes an elevating device for the piece 40.

Positioning step 41 formed on the piece 40
Since the four corners of the skin material 16 are R-shaped, the R-shaped standing wall 42 is also formed so as to conform to the R-shape.

In the present embodiment, the parting-off portion of the skin material 16 comes into contact with the positioning step portion 41 of the piece 40, and the parting-off portion side wall 16a comes into contact with the standing wall 42.
The positioning of the skin material 16 is further ensured.

(Embodiment 3) In the above-described two embodiments, the skin material 16 is shown in all four corners as being grained in the grained groove 17 of the base material 15, but is not limited thereto. Instead, for example, in the third embodiment shown in FIGS.
May be joined to the waist line portion 11a of the door trim 11.

In this case, before the skin material 16 is placed on the lower mold 22, a plurality of sides 43 joined to the waistline portion 11 a are installed in the axial direction of the long set bar 33. It pierces the set pin 34 and temporarily positions it on the set bar 33.

Then, the set bar 33 on which the skin material 16 is temporarily positioned is moved to the clamp-type set pin 3 of the lower die 22.
6, the clamp mold set hole 35 is inserted, and the lower mold 22 is inserted.
Set to. At this time, the cavity surface side of the lower mold 22 on the opposite side 44 facing the one side 43 set on the set bar 33 of the skin material 16 is positioned by the positioning step of the two pieces 40a, 40b installed on the lower mold 22. 41 (see FIG. 11), and the parting-side wall 16 of the opposite side 44.
a is held in contact with the standing wall 42 of the positioning step portion 41 to reliably position the skin material 16.

Therefore, the piece 40 of the present embodiment is different from that of the second embodiment in that the standing wall 42 of the positioning step 41 abuts against the central portion of the parting side wall 16a of the opposing side 44. Thus, it is not an R shape but a face shape as shown in FIG. However, as in the second embodiment, the opposing side 44 (partition part) of the skin material 16 comes into contact with the positioning step part 41 of the piece 40, and the parting side wall 16 a of the opposing side 44 faces the standing wall 42. The contact makes the positioning of the skin material 16 more reliable.

(Embodiment 4) Embodiment 4 of the present invention
12 and 13. According to this, the points at which the four corners of the skin material 16 are positioned are the same as those in the above-described first or second embodiment, except that the positioning member of the positioning mechanism is constituted by the plate-like bar 50. It is characterized by. That is, the bar 50 is formed by bending a plate material by a press or the like, and
However, the surface material 16 is positioned when the lower mold 22 is placed in contact with the side walls of the four corners of the skin material 16.

Therefore, the skin material 16 may come into contact with the side wall 16 a of the parting-off portion on the standing wall 51 of the bar 50.
The standing wall 51 forms a support surface of the parting-part side wall 16a, and the positioning of the skin material 16 is further ensured.

[0051]

As described above, according to the present invention, in the mold structure for manufacturing a multilayer molded product in which the skin material is exposed only on a part of the surface of the resin-free portion, the skin material is cut off. As a result of having a positioning mechanism for positioning the skin material by holding the side wall in contact, the positioning mechanism abuts the parting side wall of the skin material, and places the skin material at a predetermined position in the mold, The skin material can be easily placed at a predetermined position without requiring much skill of the worker, and the molten resin is not disturbed by a positioning mechanism such as a pin or a piece, so that the entirety of the inside of the cavity can be prevented. It is possible to prevent the skin material from being displaced by the movement of the molten resin and the upper mold, and to produce an accurate multilayer molded product that the skin material reliably covers a predetermined position on the surface of the resin alone. Can be. As a result, it is possible to increase the added value and the yield of the molded multilayer molded product, and it is possible to expect a cost reduction from this aspect.

Since the abutting of the positioning mechanism on the side wall of the skin material may come in contact with not only the line but also the surface, the positioning of the skin material can be expected to be more reliable. .

[Brief description of the drawings]

FIG. 1 is a front perspective view of an automobile door trim formed by a mold structure of the present invention.

FIG. 2 is a cross-sectional view illustrating a mold structure of the multilayer molded product according to the first embodiment of the present invention, showing a mold open state when a skin material is placed on a lower mold.

FIG. 3 Similarly, in order to put molten resin on the back surface of the skin material,
The mold opening state when the skin material is lifted to the mold side above a predetermined position is shown.

FIG. 4 also shows a mold closed state.

FIG. 5 is an enlarged sectional view showing a main part of FIG. 2;

FIG. 6 is an enlarged sectional view showing a main part of FIG. 4;

FIG. 7 is a perspective view showing a main part of a lower mold according to the first embodiment of the present invention.

FIG. 8 is an enlarged perspective view of a main part of a positioning mechanism using a piece according to a second embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a positional relationship between a skin material and a piece of a positioning mechanism according to a third embodiment of the present invention.

FIG. 10 is a plan perspective view showing the lower mold when the skin material is placed thereon.

FIG. 11 is an enlarged perspective view of a main part of a positioning mechanism using a piece.

FIG. 12 is an explanatory diagram showing a positional relationship between a bar and a skin material of a positioning mechanism using a bar made of a plate material according to a fourth embodiment of the present invention.

FIG. 13 is an enlarged perspective view of a main part of the positioning mechanism.

FIG. 14 is a cross-sectional view showing a mold structure of a conventional multilayer molded product, and shows a mold opening state when a skin material is placed on a lower mold.

FIG. 15 shows a mold opening state when the skin material is lifted to a mold position above a predetermined position in order to supply molten resin to the back surface of the skin material.

FIG. 16 also shows a mold closed state.

[Explanation of symbols]

 Reference Signs List 15 base material (only thermoplastic resin) 16 skin material 16d side wall of parting part 21 upper die 22 lower die 30 pin (positioning mechanism) 37 concave groove 40 piece (positioning mechanism) 41 positioning step part 42 standing wall 50 bar 51 Standing Wall

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B29L 31:58

Claims (6)

[Claims] 1. One or a plurality of skin materials cut into a predetermined shape are placed at predetermined positions on a lower die among upper and lower dies, and a back surface of the skin material is provided. By supplying the molten resin from the side, the skin material is exposed only on a part of the surface of the resin single part formed by the molten resin, and the other parts are exposed with the resin single part as it is, a multilayer molded product. In the mold structure used for manufacturing, in the lower mold among the upper and lower molds, a concave groove is formed at a position corresponding to a parting portion of the skin material,
A mold structure for use in manufacturing a multilayer molded product, comprising: a positioning mechanism for positioning the skin material by holding the side wall of the skin material in contact with the recess groove as a reference. 2. A pin for projecting a predetermined height from a cavity surface of a lower mold and abutting against a side wall of a parting portion of the skin material to position the skin material, and the positioning mechanism completes at least shaping of the pin. An elevating device which retracts to a predetermined position in the lower mold side direction in synchronization with the movement of the upper mold by time, and projects again onto the cavity surface of the lower mold at the next molding. Item 7. A mold structure used for producing a multilayer molded product according to Item 1. 3. A piece for positioning the skin material by projecting a predetermined height from a mold surface of a lower mold and abutting against a side wall of a parting portion of the skin material to position the skin material, and at least shaping the piece. A lifting / lowering device which retracts to a predetermined position in the direction of the lower die to a predetermined position in synchronization with the movement of the upper die by the time of completion, and projects again onto the cavity surface of the lower die at the next molding; 2. A mold structure for use in manufacturing a multilayer molded product according to claim 1, wherein a stepped portion for placing a cavity surface side of the lower mold in a parting portion of the skin material is formed in the mold. 4. The positioning mechanism includes a plate-shaped bar that projects a predetermined height from a cavity surface of a lower mold and abuts against a side wall of a parting portion of the skin material to position the skin material. At least until the shaping is completed, the elevating device is retracted to the predetermined position in the lower mold side direction in synchronization with the movement of the upper mold to the predetermined position, and projected again on the cavity surface of the lower mold at the next molding. 2. The mold structure according to claim 1, wherein the bar has a support surface for supporting the peripheral portion of the skin material by a predetermined width. 5. The mold structure used for manufacturing a multilayer molded product according to claim 1, wherein the positioning mechanism holds a peripheral corner of the skin material. 6. The apparatus according to claim 1, wherein the positioning mechanism holds a central portion of a peripheral portion of the skin material.
5. A mold structure used for manufacturing a multilayer molded product according to any one of items 4 to 4.