JPS61272126A - Molding of grained synthetic resin molded body equipped with undercuts and device therefor - Google Patents

Abstract

PURPOSE:To obtain a molded body, which has excellent surface properties with no transfer of patting lines, by a method wherein blow-molding and vacuum forming are used at the same time in order to mold the body with undercuts. CONSTITUTION:Firstly, a core material C, the surface coated with bonding agent of which is faced outside, is fitted in the recess part 29 of a molding tool 52. Secondly, a synthetic resin sheet S consisting of a skin layer (a) and a cushioning layer (b) is pinchingly attached between the respective pressing parts 5c and 5'c provided at both ends of the molding tool 51 and of the molding tool 52. Thirdly, the sheet S is sucked under vacuum by means of a vacuum pump 231. In this case, a mold area 5a has an infinite number of fine vacuum vents 16 on the whole and grain pattern 15 is transferred clearly onto the surface of the sheet S. Fourthly, a semi-molded body having an end wall W and both side walls W1 and W2, all of which are formed out of the sheet S, is applied with blowing pressure by means of a blower 241 and at the same time sucked to the molding tool 52 side under vacuum by the actuation of a vacuum pump 232. Thus, the semi-molded body is released from the molding tool 51 and at the same time is brought through the window 32 of the core material C into close contact with an undercut molding part 5'b in order to mold an undercut (u).

Description

Detailed Description of the Invention A0 Object of the Invention (1) Industrial Application Field The present invention has an end wall, a side wall connected to the end wall, and an undercut connected to the side wall. The present invention also relates to a molding method and a molding apparatus for a synthetic resin molded article with grains (under cuff for molding a synthetic resin molded body with grain patterns on the end wall and side wall from a synthetic resin sheet).

(2) Conventional technology Conventionally, when molding the molded object, a synthetic resin sheet having a grain pattern is sandwiched between a male mold and a female mold to form the molded object, and then The undercut is formed by fitting the slide core into a recess provided in the other mold (see Japanese Utility Model Publication No. 56-160820).

(3) Problems to be solved by the invention However, according to the above-mentioned method, there is a problem that the end walls, side walls, and undercut molded special synthetic resin sheet are stretched, so that the grain pattern becomes blurred and becomes unclear, reducing the commercial value. .

In addition, the production of the slide core and the recess into which it is inserted requires a lot of work, which increases the cost of the device, and there is also the problem that the parting line between the slide core and the edge of the sliding hole is transferred to the molded product. be.

An object of the present invention is to provide the above-mentioned molding method and molding apparatus which can solve the above-mentioned conventional problems.

B9 Structure of the Invention (Means for Solving Problems 11) A method for molding a grained synthetic resin molded article having an undercut according to the present invention comprises an end wall, a side wall connected to the end wall, In molding a synthetic resin molded body having an undercut continuous to the side wall and having a wrinkled pattern on at least the end wall and the side wall from a synthetic resin sheet, vacuum forming is performed on the synthetic resin sheet heated to a high temperature. forming the end wall and side wall by applying a method and simultaneously embossing both walls; using a blow molding method and a vacuum forming method together on the unformed portion of the synthetic resin sheet that is connected to the side wall; and forming the undercut.

Further, a molding apparatus for a grained synthetic resin molded body having an undercut according to the present invention includes an end wall, a side wall connected to the end wall, and an undercut connected to the side wall, A molding device for molding a synthetic resin molded body having a wrinkled pattern on at least the end wall and the side wall from a synthetic resin sheet, the molding device having the wrinkled pattern on at least the end wall and the side wall so as to form the wrinkled pattern on both walls at the same time as molding the end wall and the side wall. A first mold comprising a molding part having countless fine vacuum holes uniformly distributed over the entire pattern and the grain pattern, and a blow pressure supply part having blow holes provided in a portion corresponding to the undercut. and; a clamping part that can clamp the synthetic resin in cooperation with the molding part, and an undercut that is connected to the clamping part so as to be able to face the blow pressure supply part and has a plurality of vacuum holes. Feature (2) Effect characterized in that it is comprised of: a second mold having a molding portion; According to the molding method, the end wall of the molded body and the side wall connected thereto are molded and both of them are simultaneously molded. Since the grain is applied to the wall, the grain pattern is clearly formed without running.

Furthermore, since the undercut is formed by using both blow molding and vacuum forming, parting lines are not transferred to the surface of the molded product, and the surface properties of the molded product are good.

Furthermore, since the forming apparatus does not require a slide core for undercut forming, the structure of the apparatus is simplified and costs can be reduced accordingly.

(3) Example Fig. 1 shows a grained synthetic resin laminate molded body with an undercut formed from a synthetic resin sheet S and a core material C, and the molded body has an end wall W and its A pair of side walls wl are connected to both ends of the end wall W.

W2, a shallow undercut U continuous to one side wall W1, and a pair of edges e, eg continuous to the undercut U and the other side wall W2, and has an end wall W and both side walls. A grain pattern is formed on the surfaces of the synthetic resin sheets Wl and W2.

FIG. 2 shows a first embodiment of a molding apparatus for molding the molded body, and the apparatus has a first movable part 1 which can be raised and lowered. and a second movable part 1□ which is located below it and is movable up and down.

The first movable part 11 is configured as follows.

The downward opening 4 of the box 3 having the top wall 2 is formed by the first mold 5. The outer periphery of the first mold 51 is fixed to the flange 7 of the box body 3 via the backing plate 6 with a plurality of bolts 8 and nuts 9. A support plate 10 is suspended from the top wall 2 of the box body 3, and intermediate parts of a plurality of angle members 11 are attached to the lower edge of the support plate 10 at predetermined intervals in a plane orthogonal to FIG. Both ends of each angle member 11 are welded to the inner surface of the box body 3. First mold 5. A plurality of bolts 1 are attached to each angle member 11 and are screwed into the threaded cylinder 12 of the first mold 51 through the angle member 11.
It is suspended by 3. A vacuum sealing material 14 is interposed between the inner peripheral edge of the flange 7 and the first mold 53.

The first mold 5I is the third mold. As shown in Figure 4, it is made of nickel electroformed body, and the underside has a grain pattern 15 that is faithful to cowhide.
is formed. In addition, the first mold 51 has the grain pattern 1.
A countless number of fine vacuum holes 16 are formed so as to be uniformly distributed over the entirety of the vacuum hole 5 .

The openings 16a of the vacuum holes 16 on the grain pattern 15 side are arranged at a pitch of about 0.2 tm in the vertical and horizontal directions.
Their diameter is 0.03-0.05w.

As described above, since the opening 16a of the vacuum hole 16 has an extremely small diameter, the grain pattern 15 is not damaged in any way.

First mold 5. The manufacturing process consists of a process of making a precision model from cowhide, a process of forming a conductive layer on the cowhide patterned surface of the precision bare model, that is, a grain patterned surface, and a process of four layers of polystyrene beads with a diameter of 0.2 nm on the surface of the conductive layer. The process of laminating the layers, placing an antifloating body with glass beads in a net on top of it, and placing the precision model in the plating solution layer.The plating layer is thick enough to expose the upper circumferential surface of the top layer of polystyrene beads. This is carried out through an electroforming process in which the spaces between adjacent polystyrene beads are filled with nickel, and a process in which the polystyrene beads are eluted from the nickel electroformed body.

This elution of the polystyrene beads creates an opening 1 at the contact point between the bottom polystyrene beads and the conductive layer on the precision model.
6a, and a cavity 16b corresponding to the size of the polystyrene bead in the nickel electroformed body, and a communication hole 16C of the adjacent cavity 16b at the contact point between the adjacent polystyrene beads.
Furthermore, openings 16d are formed at positions where the upper circumferential surfaces of the outermost polystyrene beads were exposed, thereby providing vacuum holes 16.

Inside the box body 3, a first mold 5. A back-up body 17 having numerous ventilation holes is integrally joined to the back side of the first mold 51 to reinforce the first mold 51. The back-up body 17 is arranged on the side of the first mold 5I and partially joins adjacent steel balls made of stainless steel or the like with excellent corrosion resistance using thermosetting synthetic resin such as epoxy resin. The first layer 17
1 and its first layer 17. A second layer 17□ is formed by stacking a large number of glass beads and partially bonding adjacent glass beads with the same thermosetting synthetic resin as described above.

First layer 17. In the case of forming a mold 40 having a thin resin layer R made of the thermosetting synthetic resin on the surface as shown in FIG.
A predetermined amount of steel balls 18 with a diameter of ~50μ is injected, and then the steel balls 18 and the resin layer R1 are heated to 50 to 60°C to form the resin layer R,
The parts located at the contact points between adjacent steel balls 18 are joined to form a gap 1 surrounded by each joint point. This air gap (1) allows the first Ji17. A ventilation hole is formed in the

When the steel balls 18 are bonded to each other, the first layer 17I and the first mold 51 are also bonded by the resin NRI.

In addition, when forming the second layer 17□, a member (not shown) having the same shape as the recess 17a should be formed in order to reduce the weight, and a member (not shown) having the same shape as the recess 17a should be suspended inside the box 3 and placed above the first layer 171. 500-6 having the thin resin layer R2 on the surface as shown in FIG.
A predetermined amount of glass beads 19 having a diameter of 0.00μ is injected, and then the glass beads 19 and the resin layer R2 are heated to 50 to 60°C to bond the parts of the resin layer R2 located at the contact points between adjacent glass beads 19. , to form a gap 2 surrounded by each junction point. This void ■2 creates the second layer 17□
A ventilation hole is formed in the When bonding the glass beads 19, the resin R2 is also used between the first layer 171 and the second layer 17□.
are respectively joined by.

A plurality of through holes 20 are formed in the support plate 10 so that the flow of the glass beads 19 is not obstructed by the support plate 10 when the glass beads 19 are injected.

First layer 17. A cooling pipe 21 is embedded in a meandering manner so that the first mold 51 can be cooled uniformly over the entire area. In this case the first layer 17. Since it is mainly composed of steel balls 18, it has good thermal conductivity, and therefore the first mold 5. can be efficiently cooled. Furthermore, the first layer 171 is reinforced by embedding the cooling pipe 21 in a meandering manner.

Inside the box body 3 is a switching valve 22. It is connected to the vacuum pump 231 and the blower 24+ via.

First mold 5. As shown in FIG. 2, a blow hole 28 is provided in a portion corresponding to a molding portion 5a and an undercut (u) for molding the end wall W and both side walls W, w2 of the molded body.
A blow pressure supply section 5b having a blow pressure supply section 5b and a blow pressure supply section 5b having
b, and sheet presser portions 5c, 5c connected to the molding portion 5a on the opposite side thereof. In this case, since the blow holes 28 are formed in the electroforming process, they are composed of numerous fine ventilation holes similar to the vacuum holes 16 of the molded part 5a.

The second movable part 1□ is configured as follows.

The upward opening 27 of the box body 26 having the bottom wall 25 is closed by the second mold 53 . The second mold 5□ is the first mold 5. A clamping part 5/a that can clamp the synthetic resin sheet S and the core material C in cooperation with the molding part 5a, and a clamping part 5/a that faces the blow pressure supply part 5b on one side of the clamping part 5'a. an undercut molding part s/b, which is connected to the other side of the undercut molding part s/b, and sheet pressing parts 5/c, 5/C which are connected to the other side of the undercut molding part s/b and the clamping part 5'a. It is equipped with

A plurality of vacuum holes 30. are provided in the clamping portion 5'a and the undercut molding portion 5'b so as to be approximately evenly distributed throughout them. ．． 302 is formed.

In addition, one sheet pressing portion 5 is provided on the upper surface of the second mold 5□.
'c from the vicinity of the undercut molding part 5'b to the clamping part 5'
A recess 29 into which the core material C is fitted is formed over substantially the entire area a. The inside of the box body 26 is connected to a vacuum pump 23□.

The synthetic resin sheet S may be a single sheet made of polyvinyl chloride or the like, or a laminated sheet in which the sheet is used as a skin layer and a polypropylene foam sheet is laminated thereon as a cushion layer.

Further, the core material C is attached to the sandwiching portion 5 on a plate made of ABS resin or the like.
A plurality of small-diameter vacuum holes 31 correspond to the vacuum holes 30 of 'a.
, and this plate is molded to match the recess 29 of the second mold 52, and a window 32 is formed in the part corresponding to the undercut molding part s/b of the second mold 5□. Ru.

Next, the molding of the molded body will be explained.

A hot melt adhesive is applied as an adhesive to the surface of the core material C, and the adhesive is softened by heating.

As shown in FIG. 2, the first movable part II is raised and the second movable part 1 □ is lowered to open the first mold 51 and the second mold 5 □, and the second mold 5 □ is opened. The core material C is fitted into the recess 29 with its adhesive coated surface facing outward, and its vacuum holes 31 are connected to the vacuum suction holes 3 of the second mold 5□.
0. In addition, the windows 32 are aligned with the undercut moldings 5'b, respectively.

Approximately 1 synthetic resin sheet S consisting of a polyvinyl chloride skin layer a and a polypropylene foam sheet cushion layer
It is heated to a high temperature of 80°C to soften it, and the synthetic resin sheet S is placed on the first and second movable parts II, 1□ with the skin layer a facing up.
Placed between.

As shown in FIG. 7, the first movable part 1 is lowered and the second movable part 1□ is raised to form the molding part 5a of the first mold 51.
and the clamping part 5/a of the second mold 5□ and both molds 51,
Place the synthetic resin sheet S between the sheet holding parts 5c and 5'C of 5□.
sandwich.

The inside of the box 3 of the first movable part II is the switching valve 22. It is connected to a vacuum pump 231 via the vacuum pump 23, and the synthetic resin sheet S is vacuum-suctioned by the vacuum pump 23.

The molded part 5a has countless thin vacuum holes 1 throughout the molded part 5a.
6, and since the synthetic resin sheet S is sufficiently adapted to the molded part 5a by the clamping part 5'a, the sheet S is strongly adhered to the entire molded part 5a, and as a result, the sheet S is The grain pattern 15 is accurately and clearly transferred to the surface, and at the same time, the sheet I-3 is molded into the shape of the molded portion 5a. Since the first mold 5I is cooled by the cooling pipe 21, the surface of the sheet S is immediately cooled, and the grain pattern 15
is maintained clearly. In this case, synthetic resin sheet 1-5,
The portion facing the undercut molding portion 5'b is also molded into the first mold 5. Since the blow pressure supply section 5b is vacuum-suctioned, the grain pattern 15 is also transferred to this portion.

The switching valve 22. Through the blower 24. Switching to the side, blow pressure is applied to the semi-molded body having the end wall W and both side walls W, W2 formed from the sheet S, and the vacuum pump 23 □ on the second movable part 1 □ side is operated to perform the semi-molding. The body is vacuum-suctioned to the second mold 5□ side.

As a result, the semi-molded body is released from the first mold 5I, and is brought into close contact with the core material C and integrally joined thereto. Since the semi-molded body is tightly adhered to the first mold 51, the combination of the vacuum suction action and the blow pressure is an extremely effective means for promoting release of the molded body.

Also, by using the blow pressure in the blow pressure supply section 5b and the vacuum suction pressure in the undercut forming section s/b, the synthetic resin sheet S is connected to the one side wall W of the synthetic resin sheet S and becomes the undercut forming section 5'b. The opposing unformed part passes through the window 32 of the core material C and forms an undercut molded part 5' b
This forms an undercut U.

The blower 241 is stopped, and the box body 26 of the second movable part 1□
Switch the inside to the atmosphere, then raise the first movable part 11,
Further, the second movable part 1□ is lowered to remove the molded body from the second mold 5□. In this molded body, the portion of the core material C facing the window 32 is cut off.

On the surfaces of the end wall W, both side walls Wl, WZ, and undercut U of this molded body, the grain pattern 15, which is the same as the skin pattern of cowhide, is clearly transferred without running, and the cushion layer and the core material C It also has high bonding strength and excellent durability. Moreover, since the undercut U is formed by a combination of blow molding and vacuum forming, the surface quality of that portion is good.

This type of molded body is used for automobile instrument panels,
Suitable for interior materials, etc.

8 to 10 show second to fourth embodiments of the present invention, and in these embodiments, the undercut molding portion 5'b of the second mold 5□ is formed deeply, and correspondingly, Various efforts have been made to increase the blow pressure.

In the second embodiment shown in FIG. 8, the inner surface of the box 3 of the first movable part 11 and the partition wall 33 provided inside the box 3 allow
An air chamber 34 is defined on the back side of the blow pressure supply section 5b and surrounds the blow hole 28, and a switching valve 2 is installed in the air chamber 34.
The vacuum pump 233 and the prower 24□ are connected via 2□. The other configurations are the same as those of the first embodiment.

The vacuum pump 233 is used to emboss a portion of the synthetic resin sheet S facing the undercut molding portion 5'b.

The third embodiment shown in FIG. 9 is a modification of the second embodiment, in which each blow hole 28 is formed with a large diameter, and the steel balls 18 constituting the back-up body 17 in the air chamber 34 are made large. The ventilation hole is made coarse using a diameter of 1. Each blow hole 28 is formed to have a large diameter in an electroforming process.

In the fourth embodiment shown in FIG. 10, a ventilation pipe 35 having a blow hole 28 is provided on the back side of the blow pressure supply section 5b, and the ventilation pipe 35 is connected to a vacuum pump 233 and Blower 24□ is connected.

In addition, the present invention covers the end wall W and one side wall W of the molded body,
, w2 is also applied.

C1 Effects of the Invention According to the molding method of the present invention, the end wall of the molded body and the side wall connected to the end wall are molded and at the same time, both walls are grained, so that the grain pattern is clearly formed without flowing. can be formed into Furthermore, since the undercut is formed using both blow molding and vacuum forming, the parting line is not transferred to the surface of the molded product, and the surface properties of the molded product are good.

Further, according to the molding apparatus of the present invention, a conventional slide core is not required for undercut molding, so the structure of the dividing lid can be simplified and costs can be reduced.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a longitudinal cross-sectional view of a molded product obtained by the present invention;
3 is a partial plan view of the first mold, FIG. 4 is a sectional view taken along the line IV-rV in FIG. 3, and FIG. 6 is a cross-sectional view of a portion of the second layer in the bank-up body; FIG. 7 is a vertical cross-sectional view of the forming apparatus showing the graining and forming steps; and FIG. 9th. Figure 10 shows the second molding device.
．． FIG. 6 is a vertical cross-sectional view of main parts of third and fourth embodiments. L...Molded body, S...Synthetic resin sheet, U...Undercut, W...End wall, wl...Side wall, 58,
5□・・・1st. Second mold, 5a...molding part, 5b
... Blow pressure supply part, 5 / a ... Clamping part, 5'
b... Undercut molding part, 28... Blow hole,
30□...Vacuum hole ■ Figure 4 Figure 6 Figure 3 Figure 5 Figure 7'71 Procedural amendment (spontaneous) December-4, 1985 Patent Application No. 113831 2, 1985, Invention Name: Method and apparatus for forming a grained synthetic resin molded article with undercut (undercut)k; Relationship with the amended case Name of patent applicant: (532) Honda Motor Co., Ltd. 4, Representative
Administrator 〒105 5. Subject of amendment, Mi ■ Contents of amendment 1. The statement in the "Claims" column of the specification is corrected as follows. (11 Synthesizing a synthetic resin molded body having an end wall, a side wall connected to the end wall, and an undercut connected to the side wall, and having a wrinkled pattern on at least the end wall and the side wall) When molding from a resin sheet, a vacuum forming method is applied to the synthetic resin sheet heated to a high temperature to form the end wall and the side wall, and at the same time, both walls are embossed. Molding of a grained synthetic resin molded article with an undercut, comprising: forming the undercut in the unmolded part of the synthetic resin sheet using a blow molding method and a vacuum forming method in combination; Method. (2) A synthetic resin molded article having an end wall, a side wall connected to the end wall, and an undercut connected to the side wall, and having a wrinkled pattern on at least the end wall and the side wall. A molding device for molding from a synthetic resin sheet, the grain pattern and countless fine particles uniformly distributed over the grain pattern in order to form the end wall and the side wall and simultaneously grain both walls. a first mold comprising a molding part having a vacuum hole and a blow pressure supply part having a blow hole provided in a portion corresponding to the undercut; an undercut comprising: a clamping part that can be attached to the clamping part; and a second molding die that is connected to the clamping part so as to be able to face the blow pressure supply part and has a plurality of vacuum holes; A molding apparatus for a grained synthetic resin molded body, comprising: (3) The blow holes of the blow pressure supply section in the first mold are formed by numerous fine ventilation holes similar to the vacuum holes of the molding section. Claim No. (2) consisting of
A molding device for a grained synthetic resin molded article, which is equipped with the underforce and the underforce as described in 2. (4) Claim (2), wherein the blow hole of the blow pressure supply part in the first mold is constituted by a plurality of vent holes having a larger diameter than the vacuum hole of the molding part. A molding device for a grained synthetic resin molded article having the described undercut. (5) The blow pressure supply section in the first mold is provided with an air chamber surrounding the blow hole on the back surface thereof. A molding device for a grained synthetic resin molded body having an undercut. (6) The first mold is equipped with a reinforcing back-up body having a ventilation hole on its back surface, and the air chamber of the bank-up body is A molding apparatus for a grained synthetic resin molded body equipped with an undercut according to claim (5), in which the ventilation holes are roughly formed in the portion where the ventilation holes are formed. (7) The blowing pressure in the first molding die. The apparatus for molding a grained synthetic resin molded article with an undercut according to claim 2, wherein the supply section is equipped with a ventilation pipe having the blow holes on its back surface. Page 11, line 5, ..."40~50J..."..."70~
Corrected to ``150''... 3. On page 11 of the specification, lines 6-7, ..."50-60"...[70-
Corrected to 80J... 4. In the specification, page 11, line 18, ...r500J... is corrected to ...r400j... 5. On the last line of page 11 of the specification, ..."50-60" ... is replaced with "70-60"...
Corrected to ``80''... 6. Specification page 13, line 14, page 14, line 6, 17
On the 13th line of the page and the last line of the 17th page, the text "core material C" is corrected to "core material C." 7, Specification page 19, lines 14-15, r22. Correct the word "J" to "22□". that's all

Claims (7)

[Claims] (1) Synthesize a synthetic resin molded body having an end wall, a side wall connected to the end wall, and an undercut connected to the side wall, and having a wrinkled pattern on at least the end wall and the side wall. When molding from a resin sheet, a vacuum forming method is applied to the synthetic resin sheet heated to a high temperature to form the end wall and the side wall, and at the same time, both walls are embossed; Molding of a grained synthetic resin molded article with an undercut, comprising: forming the undercut in the unmolded part of the synthetic resin sheet using a blow molding method and a vacuum forming method in combination; Method. (2) Synthesize a synthetic resin molded body having an end wall, a side wall connected to the end wall, and an undercut connected to the side wall, and having a wrinkled pattern on at least the end wall and the side wall. A molding device for molding from a resin sheet, wherein the end wall and the side wall are molded and at the same time both walls are grained, the grain pattern and countless fine vacuums uniformly distributed over the grain pattern are provided. a first mold comprising a molding part having a hole and a blow pressure supply part having a blow hole provided in a portion corresponding to the undercut; capable of sandwiching the synthetic resin in cooperation with the molding part; a second mold including a clamping part and an undercut molding part connected to the clamping part so as to face the blow pressure supply part and having a plurality of vacuum holes; Molding equipment for grained synthetic resin molded bodies. (3) Claim (2), wherein the blow holes of the blow pressure supply section in the first molding die are composed of numerous fine ventilation holes similar to the vacuum holes of the molding section.
A molding device for a grained synthetic resin molded article having an undercut as described in 2. (4) Claim (2), wherein the blow hole of the blow pressure supply part in the first mold is constituted by a plurality of vent holes having a larger diameter than the vacuum hole of the molding part. A molding device for a grained synthetic resin molded article having the described undercut. (5) The blow pressure supply section in the first mold is provided with an air chamber surrounding the blow hole on the back surface thereof. Molding equipment for grained synthetic resin molded bodies with undercuts. (6) The first mold is provided with a reinforcing backup body having a ventilation hole on its back surface, and the ventilation hole is roughly formed in a portion of the backup body that exists in the air chamber. (5) A molding device for a grained synthetic resin molded article having an undercut as described in item (5). (7) The blow pressure supply section in the first mold is
It is equipped with a ventilation pipe having the blow hole on its back side.
A molding apparatus for a grained synthetic resin molded article having an undercut according to claim (2).