JP3924541B2 - Foam mold with variable opening area of steam flow opening and variable opening area means used therefor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a foaming mold for producing a foamed resin molding block and an opening area variable means used therefor.
[0002]
[Prior art]
A mold composed of a pair of male mold and female mold used for foam molding of pre-foamed resin particles, and a large number of vapors on the molding surface constituting the cavity space formed when both molds are clamped Molds in which distribution openings are formed are known. Pre-expanded resin particles, pre-expanded with expandable resin particles, are filled into the cavity space, and then the pre-expanded resin particles are foam-molded by introducing a required amount of steam from the steam flow opening formed on the molding surface. To produce a molded block made of foamed resin.
[0003]
Usually, as a molding die, a rectangle formed by six molding surfaces: a front molding surface having a maximum area, a rear molding surface facing the front molding surface, and four side molding surfaces forming four side surfaces. Those having a hollow cavity shape are used. Depending on the type of pre-foamed resin particles and various physical properties expected of the foamed resin molded product to be obtained (for example, the expansion ratio, etc.), the total area of the steam circulation openings formed on each molding surface (openings relative to the total area) The ratio is different, and many types of molds having different opening ratios are prepared according to molding conditions.
[0004]
Further, for the purpose of obtaining a molded block having a constant quality when manufacturing a thick foamed resin molded block, Patent Document 1 (Japanese Patent Laid-Open No. 8-20035) discloses an opening of a molding surface that constitutes a cavity space. The rate is described as being dense at the center part of the molding surface and rough at the peripheral part. Moreover, in patent document 2 (Unexamined-Japanese-Patent No. 2002-264163), in the metal mold | die which manufactures the foaming resin block for disappearance models, the maximum opening width of the vapor | steam blowing hole (slit) of a metal mold | die is 0.8 mm or less. In addition, it is described that the opening ratio of the steam blowout holes on the opposite two surfaces of the front and back surfaces is 4 to 42% of the total area of the surface.
[0005]
[Patent Document 1]
JP-A-8-20035 [Patent Document 2]
Japanese Patent Laid-Open No. 2002-264163
[Problems to be solved by the invention]
As described above, in the production of the foamed resin molding block so far, even when the molded product having the same outer shape is foam-molded, for example, when trying to produce a molded product with a different expansion factor, each time, Optimal molds with different opening ratios are designed and manufactured. In addition, as described in the above patent document, when producing a thick foamed resin molding block, when trying to obtain a molding block with constant quality, the molding surface on the front and back surfaces and the four side molding surfaces It is necessary to have different aperture ratios or to have a difference in aperture ratio distribution within one molding surface. In this case as well, it is possible to prepare a large number of molds having various aperture ratios. Necessary. In either case, it is necessary to change the mold each time, and a space for storing each mold is also required.
[0007]
The present invention has been made in view of the circumstances as described above, and the purpose thereof is a foamed resin molded block having different physical property values such as different expansion ratios as long as it is a molded block having the same outer shape. Another object of the present invention is to provide an improved foam mold that can be easily manufactured using basically the same mold and an opening area variable means used therefor. Such common use reduces the total manufacturing cost of the foamed resin molded block.
[0008]
[Means for Solving the Problems]
The foaming mold according to the present invention is a foaming mold for foaming pre-foamed resin particles in which a large number of steam flow openings are formed on a molding surface that constitutes a cavity space formed when the mold is clamped. In addition, the whole or a part of the steam circulation opening has a variable opening area.
[0009]
In the mold according to the present invention, a large number of steam circulation openings are preferably formed with an equal distribution so as to have a certain opening ratio with respect to the molding surface. The aperture ratio may be the same on all molding surfaces, or molding surfaces having different aperture ratios may be mixed. And all or a part of the openings for steam circulation are provided with appropriate means capable of changing the opening area.
[0010]
There are various means for making the opening area variable, but a member having a slit can be attached to and detached from the opening for steam circulation whose opening area should be made variable, and an opening ratio separately prepared for the opening. Means for selectively mounting various slit members of different sizes, or a slit member in which a slit group capable of partially closing the opening is formed, and the slit member is selectively provided for the opening. It may be a means that can be positioned so that the opening area of the opening can be changed by changing its position.
[0011]
Furthermore, an opening member having a through hole and a slit member in which a slit group is formed in a region corresponding to the through hole, the opening member can be attached to the opening, and the slit member is formed there A position where the slit group and the through-hole formed in the opening member overlap, a position where the through-hole is closed, and an intermediate position thereof can be selectively taken and can be attached to the opening member. Such means may be used.
[0012]
Materials for the opening member and slit member include metals such as aluminum and alloys such as magnesium and zinc, ceramics, or fluorine resin, polyphenylene ether resin (PPE), polysulfone resin, polyether sulfone resin, and polyphenylene sulfide resin (PPS). And heat-resistant resins such as polyetheretherketone resin (PEEK). What is necessary is just to select an optimal thing in relation with the material etc. which form a molding surface.
[0013]
The steam circulation openings formed on the molding surface may all have the same form, and the form may be different between the steam circulation opening to which the opening area variable means is attached and the other steam circulation openings. In addition, a required number of slits having a required width are usually formed in a steam circulation opening that does not include means for changing the opening area, as in a conventional mold.
[0014]
In any case, by appropriately adjusting the means for making the opening area variable, as a result, the opening ratio of the steam flow opening on the molding surface (the ratio of the opening area of the steam flow opening to the total area of the molding surface) ) Can be changed as required. Further, by performing this operation on each molding surface that is required, it is possible to give a necessary difference in the opening ratio of the steam circulation opening on each molding surface. It is also possible to create portions having different opening ratios on one molding surface. In this way, by adjusting the opening ratio of the steam flow opening on the molding surface in various manners, it is possible to easily form different types of molding blocks having the desired physical property values while using basically the same molding die. It can be manufactured.
[0015]
The resin for the foamed resin molding block manufactured with the mold according to the present invention is preferably a styrene resin, but an olefin resin such as polypropylene or a resin such as a mixture or copolymer of olefin and styrene resin. It may be.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the foam mold according to the present invention will be described below. FIG. 1 is a longitudinal sectional view schematically showing the molding machine 1 and includes a moving mold 10 and a fixed mold 20 that forms a cavity space together with the moving mold 10. In this example, the movable mold 10 has a front molding surface 11 having a maximum area, and the fixed mold 20 includes a rear molding surface 21 facing the front molding surface 11 and four side molding surfaces 22 to 25 around the rear molding surface 21. Have As shown in FIG. 2, the front molding surface 11 is shown as an example of the molding surface. Normally, each molding surface is formed with substantially the same number of distributions of steam flow openings 35 formed of slit groups. Further, although not shown, a resin particle supply path and a heating steam supply chamber are formed on the back surface of each molding surface, and at the time of foam molding, the pre-foamed resin particles are supplied into the cavity space from the resin particle supply path. Heated steam is supplied from the heated steam supply chamber into the cavity space through a steam flow opening 35 formed on the molding surface. A conventionally well-known method can be used for such a molding machine and a method of foam-molding a resin block using the molding machine.
[0017]
In the foam molding die 1 according to the present invention, the opening area is changed with respect to one or a plurality of steam flow openings 35 required on one or a plurality of molding surfaces 11, 22, 22 to 25. Means are provided. FIG. 3 shows a back molding surface 21 as an example of such a molding surface, and a steam circulation opening 35a indicated by a circle in FIG. 3 is “a steam circulation opening whose opening area is variable” according to the present invention. It is said. Of course, this is merely an example, and the number and location of the steam circulation openings 35a whose opening area is variable are not limited thereto.
[0018]
The specific means for changing the opening area in the steam flow opening 35a is arbitrary and is not particularly limited. Several examples will be specifically described below. In the example shown in FIG. 4, a circular hole 51 having an inner screw 52 is formed in a hot plate constituting the molding surface, and a slit member 54 having an outer screw 53 screwed around the inner screw 52 is formed in the circular hole. 51 is screwed. In addition, the surface of the slit member 54 and the molding surface are made to be the same surface in the screwed state. A slit group 55 is formed in the slit member 54 with an opening ratio different from that of the slit group formed in the steam flow opening 35 to which the slit member 54 is not attached. Therefore, as shown in FIG. 3, a required number of circular holes 51 are formed in a necessary region of the molding surface, and the slit member 54 is screwed into the circular holes 51, thereby allowing the steam flow in the group of circular holes 51. The opening area (opening ratio) of the opening can be made different from the opening area (opening ratio) of the steam flow opening 35 group to which the slit member 54 is not attached. By preparing a plurality of types of slit members 54 having slit groups 55 having different opening ratios, it is possible to form an opening area for steam circulation having a desired opening ratio in a desired area of the molding surface.
[0019]
FIG. 5 shows a means for changing the opening area of another embodiment. In this example, an opening member 60 having an external screw 61 around is screwed into the circular hole 51 described above. Also in this case, the surface of the opening member 60 and the molding surface are made to be the same surface in a screwed state. A circular recess 62 is formed on the surface of the opening member 60, and four through holes 63 having a fan shape with a pitch of 90 degrees and an opening angle narrower than 45 degrees are formed. A second through hole 64 is also formed at the center.
[0020]
The slit member 70 used here includes a disk 71 that enters a circular recess 62 formed on the surface of the opening member 60 so as to be flush with each other, and a column 72 provided at the center thereof. In the disk 71, four slit groups 73 are formed in a region corresponding to the four through holes 63 formed in the opening member 60. The support column 72 is long enough to pass through the second through-hole 64, and a screw 75 is cut at the lower end.
[0021]
At the time of molding, the opening member 60 is screwed into the circular hole 51, the column 72 is inserted into the second through hole 64, the slit member 70 is attached, and a double nut is attached to the screw 75 at the lower end via the leaf spring 76. Tighten 77. Thereby, the slit member 70 is fixed to the opening member 60 with an appropriate tightening pressure, and the slit member 70 does not move in a normal state. When necessary, a jig 80 with a handle 82 provided with projecting pieces 81 and 81 that can be inserted into the slit group 73 as shown in FIG. By applying torque (rotational force), the position of the slit member 70 can be adjusted to a required angle.
[0022]
The slit member 70 has the above-described configuration, and the slit member 70 has the through hole 63 by appropriately adjusting the position of the slit group 73 formed in the disk 71 of the slit member 70 with respect to the through hole 63 formed in the opening member 60. Are fully closed, a state in which all the regions of the through-hole 63 and the slit group 73 overlap (fully open state), and an arbitrary intermediate position (selective opening area state). As a result, the opening area of the steam circulation opening in the circular hole 51 can be adjusted steplessly from the fully closed position to the entire opening area of the slit group 73.
[0023]
FIG. 6 shows still another embodiment. Here, the above-described circular hole 51a is composed of the upper cylindrical portion 51b and the conical portion 51c following the upper cylindrical portion 51b, and does not have an internal screw. The opening member 60a has four through holes 63 as in the case of the opening member 60 described above, but the thickness thereof is accommodated in the conical portion 51c, and the outer peripheral surface 60c is the same as the conical portion 51c. Conical. No external screw is formed. The slit member 70a has the same configuration as the slit member 70 described above except that the disk 71a is of a size that enters the cylindrical portion 51b of the circular hole 51a. In order to prevent the slit member 70a and the opening member 60a from rotating together when the opening area is changed, the opening member 60a is not rotated to the conical portion 51c by means such as a key and a key groove (not shown). It is preferable to attach.
[0024]
At the time of molding, after the opening member 60a is fitted into the circular hole 51a, the support member 72 is inserted into the second through hole 63 and the slit member 70a is mounted. A fastener 79 having a cross-shaped leg 78 larger than the diameter on the back surface side of the circular hole 51a is inserted into the support column 72 protruding to the back surface, and in this state, a leaf spring 76 is attached to the screw 75 of the support column 72. Then, the double nut 77 is tightened. Thereby, the opening member 60a and the slit member 70a are fixed to the circular hole 51a with a required tightening force, and the disc 71a of the slit member 70a is moved along the surface of the opening member 60a using the jig 80 shown in FIG. The opening area can be changed in the same manner as shown in FIG.
[0025]
FIG. 7 shows still another embodiment. In this embodiment, the above-described circular hole 51 (51a) is formed on the molding surface, and the separately prepared opening member 60 (60a) is not attached thereto, but four through holes formed in the opening member 60 (60a). 63 and the second through-hole 64 are formed directly on the hot plate constituting the molding surface. The slit member 70 (70a) to be used and the fixing means thereof are the same as those described above. In this aspect, the jig 80 and the like are used to change the opening area of the steam circulation opening as described above. Can do.
[0026]
【The invention's effect】
As described above, according to the present invention, it is possible to change the opening area of some or all of the steam circulation openings in a state in which the mold is attached to the molding machine, so that the expansion ratio is different. It is possible to manufacture foamed resin molding blocks having different physical properties using basically the same molding die. By sharing this molding die, the total manufacturing cost of the foamed resin molding block can be reduced.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an outline of a foam molding machine.
FIG. 2 is a front molding surface as an example of a molding surface.
FIG. 3 is a back molding surface as an example of a molding surface provided with a steam circulation opening whose opening area is variable.
FIG. 4 is a view for explaining one mode of means capable of changing the opening area.
FIG. 5 is a diagram for explaining another aspect of the means capable of changing the opening area.
FIG. 6 is a view for explaining still another aspect of the means capable of changing the opening area.
FIG. 7 is a view for explaining still another aspect of the means capable of changing the opening area.
FIG. 8 is a diagram showing an example of a jig used when changing the opening area.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Foam molding machine, 10 ... Moving mold, 20 ... Fixed mold, 11 ... Front molding surface, 21 ... Back molding surface, 22-25 ... Side molding surface, 35 ... Steam distribution opening, 35a ... Opening area Vapor flow openings 51, 51a ... round holes, 51b ... cylindrical portions, 51c ... conical portions, 52 ... inner screws, 53 ... outer screws, 54, 70, 70a ... slit members, 55, 73 ... Slit group, 60, 60a ... opening member, 63 ... through hole, 64 ... second through hole, 71 ... disc, 72 ... strut, 75 ... screw, 76 ... leaf spring, 77 ... nut, 78 ... cross-shaped Leg, 79 ... Fastener, 80 ... Jig

Claims (5)

A foam molding die for foam-molding pre-expanded resin particles in which a large number of steam circulation openings are formed on a molding surface constituting a cavity space formed when the mold is clamped, A foam molding die characterized in that the opening area of all or part thereof is variable. A steam flow opening with a variable opening area allows a member with a slit to be attached and detached, and the opening area can be changed by selectively attaching a slit member with a different opening ratio to the opening. The foaming mold according to claim 1, wherein: The steam flow opening having a variable opening area includes a member having a slit capable of partially closing the opening, and selectively positioning the slit member with respect to the opening. The foaming mold according to claim 1, wherein the opening area is variable. A means for varying the opening area of the opening to be mounted on the opening formed on the molding surface of the foam molding die, comprising a slit member formed with a slit group capable of partially closing the opening, The opening area variable means characterized in that the slit member can be selectively positioned with respect to the opening, whereby the opening area of the opening is variable. A means for changing the opening area of the opening to be mounted on the opening formed on the molding surface of the foam molding die, an opening member having a through hole, and a slit having a slit group formed in a region corresponding to the through hole The opening member is attachable to the opening, the slit member is formed there, and a position where the slit group and the through hole formed in the opening member overlap, and a position where the through hole is closed An opening area variable means characterized in that it can be attached to the opening member so that the intermediate position can be selectively taken.

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