JP3621677B2 - Manufacturing method of resin molded product having inserts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a resin molded product having an insert. In particular, the present invention relates to a method of manufacturing a plurality of types of resin molded products having the same outer shape and size and different numbers of inserts.
[0002]
[Prior art]
As shown in FIG. 4, a resin molded article having inserts so that n resin cylinders 2 are arranged and erected on the resin substrate 1 by integral molding, and the inserts 3 are fixed to the resin cylinders 2, respectively. May be manufactured. Depending on the design specifications, the outer shape and dimensions of the molded product remain unchanged, and the arrangement of n resin cylinders is reduced to nx (n and x are positive integers, n> x), and nx A resin molded product may be manufactured so that each of the individual resin cylinders has an insert. For example, in any resin molded product, the mating member to be assembled is the same member.
In such a case, in order to mold a resin molded product in which n resin cylinders are arranged and a resin molded product in which nx resin cylinders are arranged, usually a dedicated mold is prepared for each. . However, even though most of the molded products have the same shape and dimensions, it is expensive to prepare individual molds individually. Also, mold replacement for molding a resin molded product in which n resin cylinders are arrayed and a resin molded product in which nx resin cylinders are arrayed, that is, attachment and removal of the mold from the molding machine The work is also complicated.
[0003]
Therefore, when molding a resin molded product having inserts in nx resin cylinders, the arrangement of the resin cylinders is the same as that for molding a resin molded product having inserts in n resin cylinders. In addition, in the x number of resin cylinders that do not have inserts, instead of placing inserts, pins are raised (adding pins to the mold) and molding is performed. It is conceivable to share the type.
The resin molded product shown in FIG. 4 is an example in which the resin cylinders 2 arranged in a row (n = 4) are arranged and erected in two rows on the resin substrate 1 by integral molding. Of the four resin tubes arranged in one row, inserts 3 are arranged in three (x = 1) resin tubes, and it is appropriately selected whether or not the inserts are arranged in the remaining one resin tube. It shows that it is a molded product specification. The resin cylinder in which the insert 3 is indicated by a two-dot chain line is a resin cylinder that appropriately selects whether or not the insert is arranged. An iron plate 4 is insert-molded on a part of the resin substrate 1, and a part of the iron plate is exposed on the surface where the resin cylinder 2 is erected, and the entire iron plate 4 is made of resin on the opposite surface. Covered. In the rectangular region located on the right side of the resin molded product shown in the drawing, the iron plate 4 is not inserted into the resin substrate 1. Further, a through hole is formed in the iron plate 4, and the front and back resin substrates are connected by this through hole.
[0004]
[Problems to be solved by the invention]
As described above, a part of the n-array resin cylinders has a specification that appropriately selects whether or not to place the insert, so that nx pieces of resin molded products having n inserts are also available. The resin molded product having the insert is also advantageous in that one molding die can be shared for the molding. In addition, the means for realizing the sharing of the molding die is also a simple means of carrying out molding by placing a pin in place of the insert at the molding die position corresponding to the resin cylinder in which the insert is not arranged. is there.
However, a resin molded product (referred to as “molded product a”) having inserts in all of the arranged n resin cylinders, and nx resin cylinders have inserts in the remaining x resin cylinders. It has been found that a completely different behavior appears in the flatness of the resin substrate with a resin molded product having no insert (referred to as “molded product b”). Therefore, in the case where the mating member a and the molding product b are the same mating member, if the flatness of the mating member is adjusted in accordance with the flatness of the molding product a, the molding product When assembling b, there arises a problem that the flatness does not match the flatness of the counterpart member. If a dedicated molding die is prepared for each of the molded product a and the molded product b, it is possible to adjust the flatness of each molding die so as to match the flatness of the mating member. As long as the mold is shared, such adjustment is difficult.
[0005]
The problem to be solved by the present invention is a resin molded product (molded product a) having an insert in all of the n resin cylinders that are integrally molded on a resin substrate and arranged and erected, and n resins When molding a resin molded product (molded product b) that does not have an insert in the x pieces of the cylinder by using one molding die in common, the resin of the molded product a and the molded product b It is to bring the flatness tendency of the substrate as close as possible.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the manufacturing method according to the present invention includes the above-described molded product a having an insert in each of n resin tubes and the molded product b having an insert in nx resin tubes. When the molded product b is molded by selectively molding with one molding die, the arrangement of the resin cylinders is the same as the arrangement of the n resin cylinders of the molded product a. And in the x resin cylinders that do not have an insert, ribs in the arrangement direction of the n resin cylinders are formed integrally with the inner wall of the resin cylinder. As a result, the resin cylinder is divided into two by the ribs in the left and right in the arrangement direction of the n resin cylinders.
[0007]
The resin molded product shrinks due to cooling after molding and causes a dimensional change. However, the degree of shrinkage differs between a resin cylinder having an insert and a resin cylinder having no insert. In a resin cylinder having an insert, the insert becomes a reinforcing material and shrinkage is suppressed, whereas in a resin cylinder having no insert, the shrinkage increases. This is presumed to cause a difference in the flatness tendency of the resin substrates of the molded product a and the molded product b. According to the above method, the ribs in the arrangement direction of the n resin cylinders effectively act to suppress the shrinkage of the resin cylinders instead of the inserts, and the resin substrates of the molded product a and the molded product b It leads to approximating the flatness tendency of.
[0008]
In another method according to the present invention, an inner cylinder is erected by integral molding in x resin cylinders that do not have an insert. And three or more radial ribs which connect the inner wall of the resin cylinder and the outer wall of the inner cylinder are integrally formed. Such arrangement of the radial ribs also effectively acts to suppress the shrinkage of the resin cylinder having no insert, and approximates the flatness tendency of the resin substrates of the molded product a and the molded product b. linked. In the configuration in which only the inner cylinder is simply arranged, or in the configuration in which the inner wall of the resin cylinder and the outer wall of the inner cylinder are connected by ribs in the arrangement direction of n resin cylinders, the resin of the molded product a and the molded product b The flatness tendency of the substrate will be quite different.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the invention in which the method according to the present invention is applied to the resin molded product described with reference to FIG. 4 will be described below. In addition, a comparative example and a reference example will be described.
As shown in FIG. 1, the resin cylinders 2 arranged in one row and four in a row are arranged and erected in two rows on the resin substrate 1 by integral molding. It is a molded product specification in which inserts 3 are arranged in three resin cylinders out of four resin columns arranged in a row, and whether or not the inserts are arranged in the remaining one resin cylinder. For the molding, insert molding is performed by injection molding. The insert 3 is, for example, a brass cylinder.
The resin to be molded is polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polybutylene-ethylene terephthalate (PBT-PET copolymer resin), polyether ether ketone (PEEK resin), polyphenylene sulfide (PPS), polyether Examples thereof include imide (PEI), 6 nylon (PA6), 6-6 nylon (PA66), and polycarbonate (PC). These are used alone or in combination. Moreover, you may mix | blend inorganic fillers, such as glass fiber, a glass bead, and a talc, with these resin suitably in order to improve heat resistance and dimensional stability.
[0010]
Reference example 1
In this example, a molded product a is manufactured. The resin cylinders 2 arranged in four rows are arranged and erected in two rows, and the inserts 3 are arranged in all the resin tubes.
[0011]
Example 1
In this example, the molded product b is manufactured. Of the resin tubes arranged in four rows, the inserts 3 are arranged in the three resin tubes 2, and the inserts are arranged in the remaining one resin tube. do not do. And as shown in FIG. 1, the rib 5 of the arrangement direction of four resin cylinders is integrally shape | molded with the resin cylinder inner wall in the said resin cylinder. As a result, the inside of the resin cylinder is divided into two by the rib 5 in the left and right directions in the four resin cylinder arrangement directions.
A pin for molding the rib 5 is added to a molding die position corresponding to a resin cylinder to be molded without arranging the insert 3 and injection molding is performed.
[0012]
Example 2
As shown to Fig.2 (a), the molded article b manufactured in this example sets up the inner cylinder 6 by integral molding in the resin cylinder 2 which does not arrange | position an insert. And the eight radial ribs 7 which connect the inner wall of the resin cylinder 2 and the outer wall of the inner cylinder 6 are also integrally formed. Other than that, injection molding is performed according to Example 1.
Three or more radial ribs are necessary.
[0013]
Comparative Example 1
As shown in FIG. 2B, in the molded product b manufactured in this example, an inner cylinder 6 is erected by integral molding in a resin cylinder 2 in which no insert is arranged. And the auxiliary rib 8 which connects between the inner wall of the resin cylinder 2 and the outer wall of the inner cylinder 6 is integrally molded. The auxiliary rib 8 exists only in the arrangement direction of the four resin cylinders. Other than that, injection molding is performed according to Example 1.
[0014]
Comparative Example 2
The molded product b manufactured in this example is left as it is without any modification on the resin cylinder in which the insert is not disposed. However, only the pins that replace the inserts are added to the molding die for injection molding.
[0015]
About the resin molded product in each said example, the flatness of the surface on the opposite side to the surface which erected the resin cylinder was measured. As shown in FIG. 3, the entire surface is a resin substrate, and this surface is surrounded by a rising portion having a low periphery. No. indicated by circled numbers. 1-No. FIG. 5 shows the result of measuring the height of each portion around 30 and confirming the flatness tendency. In addition, the measurement of the said height is No. 1, no. 20, no. The surface including 3 points of 26 was measured as a reference surface.
[0016]
As is clear from FIG. 5, the flatness tendency of the molded product b of the example is in good agreement with the molded product a of the reference example 1. In particular, the flatness tendency of the molded product b in Example 1 is very close to that of the molded product a of Reference Example 1. This means that if the flatness tendency of the mating member to which the molded product a and the molded product b are assembled is matched to the molded product a (or molded product b), either the molded product a or the molded product b is the same counterpart. It also shows that there is no hindrance when assembling to the member.
On the other hand, the molded product b of the comparative example is remarkably different in flatness tendency from the molded product a of the reference example 1. This means that if the flatness tendency of the mating member to which the molded product a and the molded product b are assembled is matched with either the molded product a or the molded product b, the assembly of the other molded product cannot be supported. Is shown.
[0017]
【The invention's effect】
As described above, according to the method of the present invention, a resin molded product (molded product a) that is integrally formed on a resin substrate and has inserts in all of the n resin cylinders arranged and erected, When molding a resin molded product (molded product b) that does not have an insert in n resin cylinders and molding a single mold, the molded product a and the molded product The flatness tendency of the resin substrate of the product b can be made closer. Since it is not necessary to prepare a dedicated molding die for each of the molded product a and the molded product b having the same flatness tendency, the molding cost can be reduced and each molded product is molded. In order to change the mold, it is only necessary to replace a part of the forming pins, so that the setup can be easily changed.
[Brief description of the drawings]
FIG. 1 is a plan view of a resin molded product molded in an embodiment of the present invention.
FIG. 2A is a plan view of a main part of a resin molded product molded in another embodiment of the present invention, and FIG. 2B is a plan view of a main part of a resin molded product molded in a comparative example.
3 is a rear view of the resin molded product shown in FIGS. 1, 2, and 4. FIG.
FIG. 4 is a plan view illustrating a resin molded product to which the present invention is applied.
FIG. 5 is a curve diagram showing the flatness tendency of resin molded products in Examples, Comparative Examples, and Reference Examples.
[Explanation of symbols]
1, resin substrate 2, resin cylinder 3, insert 4, iron plate 5, rib 6, inner cylinder 7, radial rib 8, auxiliary rib

Claims (2)

In producing a resin molded product having an insert so that the resin cylinder is erected on the resin substrate by integral molding and the insert is fixed in the resin cylinder,
A resin molded product having an insert in each of n resin cylinders and a resin molded product having an insert in nx resin cylinders are selectively molded with a single mold (n, x is a positive integer, n> x),
Even when a resin molded product having an insert is formed on nx resin cylinders, the arrangement of the resin cylinders is the same as the arrangement of the n resin cylinders, and no inserts are included. A method of manufacturing a resin molded article having an insert, wherein the n resin cylinders are integrally molded with the inner wall of the resin cylinder in the x resin cylinders. In the x resin cylinders that do not have inserts, the inner cylinder is erected by integral molding, and at least three radial ribs that connect the inner wall of the resin cylinder and the outer wall of the inner cylinder are integrated. The method for producing a resin molded article having an insert according to claim 1, wherein the molding is molded.

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