JPS58166032A - Reaction injection molded product and its molding method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reaction injection molded product 2 and a method for molding the same.
At times, tightening of screws is related to reaction injection molded products having threaded parts and methods of molding the same, which are intended to improve strength.

Traditionally, reaction injection molded products, such as urethane foam molded products (
The following technology is known as a method for tightening related parts to a molded product (hereinafter referred to as a molded product).

(1) After drilling holes in the molded product, tap them and screw bolts into them to secure the parts.

(2) Self-tapping on the molded product and fixing the parts.

(3) Drill through holes in the molded product and secure the parts with pads and bolts.

141 After drilling a hole in the molded product and tapping it, fit the helicoil there and screw the bolt into it to fix the part. The third technique, which has a relatively high torque, is the maximum tightening that can be achieved without damaging the component and its threads, and is the most common and commonly practiced method. However, in this method, the tightening metal sometimes sinks into the molded product, causing the molded product to buckle, and the tightening speed of 5!Im is not sufficient.

In addition, since a through hole is made, a container S* that requires airtightness is used.
In addition, each of the techniques (1) to (1) described above also had the disadvantage that drilling required many man-hours.

An object of the present invention is to provide a reaction injection molded product having a threaded portion and a method for processing the same, which eliminates the drawbacks of the above-mentioned prior art, has a high screw tightening strength, and reduces the number of processing steps. .

The reaction injection molded product having a threaded portion according to the present invention has an immediate molded product body of a urethane foam molded product having a hole surrounded by a relatively dense surface layer such as a skin layer, and is disposed in the direction opposite to the molded product body. The device is characterized in that it has an internally threaded member held by the aforementioned surface layer. In addition, the method for molding a reaction injection molded product having a threaded part according to the present invention involves positioning a member having a threaded part in a cavity for reaction injection molding, and filling a urethane foam material, for example, alcohol or amine in each ridge, in this cavity. Polyether polyol obtained by adding alkylene oxide to (
100 parts by weight), a reaction accelerator (catalyst) consisting of tertiary amines, tin compounds, etc. (1 to 5 parts by weight), water and a blowing agent such as a low-boiling alkyl halide (3 to 50 parts by weight, 11 ifl)
U), a foam stabilizer (1 to 5 parts by weight) such as alkylene oxide-modified polydimethylsiloxane, and pigments such as carbon black, diazo compound, silica, and glass fiber, if necessary.
A mixture of 1 to 20 parts by weight of liquid L containing dyes and fillers and 100 to 200 parts by weight of liquid B consisting of MDI, TDI, crude MDI, crude TDI, etc. is injected, and the member having the threaded portion is integrally formed. Then, the member having the threaded portion is coated with a relatively dense rope layer such as a skin layer (0.7~
The 41F feature is to fix it with toy/Cd).

The present invention will be specifically described below based on embodiments shown in the drawings.

FIG. 1 is an lrr side view showing an embodiment of a reaction injection molded product having a threaded portion according to the present invention. ! @1 In Figure 3, the reference numeral 1 is a reaction injection molded product body such as a urethane foam molded product having a threaded portion. The material used for this reaction injection molding (y
Solution A) is a polyether alcohol obtained by adding alkylene oxide to various alcohols or amines.
100IL violet), a reaction accelerator (catalyst) consisting of a 5th class amine, a tin compound (1 to 5 parts by weight), and a low boiling point (50 to 70") of trichlorofluoromethane (8 to 30 parts by weight).
C/1~5kg/crl) blowing agent and water (15~5kg/crl)
Parts by weight) and Liquid B consisting of MDI or TDI, or G1 crude TDI or crude MD7 (100 to 200 parts by weight). Reference numeral 2 denotes a boss portion formed with the IK shadow of the molded product main body, reference numeral 3 designates a core layer of the molded product 1, reference number 4 designates a strong skin layer of the molded product main body 1, and 5 designates a member having a threaded portion. That is, it is a threaded insert, and this threaded insert 5 is embedded in the boss part 2 of the molded product body 1 with a solid layer of skin layer 4.Here, the formation mechanism of the skin layer will be described. When 1g of the above-mentioned material and liquid B are collision-mixed at high pressure (approximately 200 ky'cd) and injected into the mold cavity, a reaction begins and the temperature rises to 70-150'C due to the heat of reaction. The low-boiling point blowing agent evaporates and fills the mold cavity with foam. At this time, the material in contact with the mold cavity surface and the insert surface is cooled by the mold and the insert, so the vaporized low boiling point foaming agent condenses and becomes nearly non-foamed. This is the skin layer.

The density of this skin layer is α5~t1y/C- which is higher than the density of the core layer inside the material α05~α21/c-. The higher the density of the skin layer, the higher its strength (hardness).

This relationship is shown in FIG. This strong skin layer is obtained by increasing the blending ratio of low boiling point blowing agent and catalyst in the neat material, by increasing the filling rate in the molding conditions, and by decreasing the temperature of the mold and insert. Regarding these relationships, please refer to JIl! Shown in Figures 16 to 19 of the prefecture. The threaded insert 5 shown in FIG. 1 and fixed and embedded in the skin layer 4 is a substantially cylindrical steel member, and as shown in FIG. A screw 6 is formed and the outside thereof is threaded.

The reaction injection molded product having a threaded portion according to the present invention configured in this manner has a strong skin layer 4 formed around the outer circumference of the threaded insert, which bites into the threaded surface. The adhesive strength with the molded product main body 1 is high6. Therefore, the torque and thrust force (resistance of the threaded insert against the axial force during screw tightening) are improved compared to conventional screw tightening.

The limit screw tightening torque of the embodiment shown in Figure 41 is approximately 60
k)-am (for MS screwdrivers), and a comparison of this with that of the prior art is as shown in Fig. 3.

This iss diagram is a graph comparing the limit screw tightening torque in the prior art and the embodiment of the present invention, and N
011 to 4 indicate the above-mentioned conventional techniques 1 to 4, respectively, and N00
5 indicates the embodiment shown in FIG. 1, so, 6
shows another embodiment of the present invention which will be described later.

When measuring these limit screw tightening torques, please refer to Jap
aneJPe Industrial 5tandar
d(IIs') M5 screws were used and tested with a torque driver. Also, a tapping screw with a diameter of 6 mm was used. As is clear from this graph, in the example of the present invention shown in N005, the weight of 20 kg in the conventional technology shown in N015 is
It will be appreciated that this is a three times improvement over -eta.

Furthermore, unlike the conventional molded product 1, the molded product 1 of this embodiment does not require drilling after molding, and therefore has the effect of reducing the number of processing steps. In the embodiment shown in FIG. 1, the relationship between the limit screw tightening torque and the density of the skin layer fixed to the outer peripheral surface of the insert is as shown in FIG. 20. The limit screw tightening torque increases as the skin layer solidified on the outer peripheral surface of the insert increases. For example, limit screw tightening torque 6
If more than 0ky-Cm is required, increase the skin layer density to 0.6
5! It is only necessary to make it equal to or higher than V'Cr1p. In the embodiment shown in Fig. m1, the threaded insert 5 shown in Fig. 2 was used, but instead of this, the threaded inserts 5, 4. SB, 5C may also be used. Both of these are made of steel. The threaded insert 5A shown in FIG. 44 has a female thread 6 formed on the inside thereof, and has a cylindrical shape on the outside, which is knurled. This threaded insert 5A is almost the same as the threaded insert 5 shown in FIG. 2 (limited screw tightening has the effect of improving torque and thrust force.

The threaded inserts 5B and 5C shown in FIGS. 4B and 4C have a female thread formed on the inside thereof, and have a square and hexagonal polygonal shape on the outside, respectively, with a lateral groove 78 provided therein. By forming the outside into a polygonal shape, the corners resist rotational force, and the limit tightening torque is improved compared to the threaded inserter (5.54), and by providing the lateral groove 7, the thrust force is also reduced. ) Improved than 5.5.4.

The relationship between each shape of the threaded insert and the limit screw tightening torque is shown in Figure 421. In addition, each of the above threaded inserts 5
．． 54.5B and 5C are made by @, but they are not limited to steel, and are preferably made of metal such as brass or hard aluminum. The reason (L
1. This is due to the necessity of thread strength and for molding reasons which will be described later.

Next, with reference to FIG. 5, a method of molding a urethane foam molded product having a threaded portion shown in FIGS. 11 and 11 will be described. Fifth
In the figure, 8 is the upper mold for reaction injection molding, 9 is the lower mold, 9
A is the hole drilled in the lower mold 9, 10 is the upper mold 8 and the lower mold 9
The cavity 10a formed by the cavity 10a is
The boss 1111 is an after mixer that injects the molding material into the cavity 10 from there. Threaded insert 5
is fixed in the boss molding f110, 4 of the cavity 10 with its open end surface inserted into the digging hole 9JK of the lower mold 9.

Therefore, when the molding material is injected into the cavity 10, it does not penetrate into the internal thread 6 of the threaded insert 5. Into the reaction injection molding mold shown in FIG. 5145 constructed in this manner, a polyether polyol (100%
A reaction accelerator (catalyst) consisting of a tertiary amine tin compound (1 to 5 parts) and a low boiling point (30 to 70℃7) of trichlorofluoromethane (8 to 50g parts)
1~5kg/cd) A solution consisting of a blowing agent and water (0.5~to heavy electric parts) and MDI or TDI or crude TD
A mixture of liquid B consisting of I or Crude &D/(100 to 200 parts) is injected into the cavity 10. The injected mixed liquid reacts in the cavity 10 and foams and hardens, and then the upper mold 83 and the lower mold 4! ! 9. Urethane that is cooled by the threaded insert 5 and has a core layer 3 inside and a strong skin layer 4 on the outer surface and the outside of the threaded insert 5 as shown in FIG. A foam molded product is formed. - A strong skin layer can give you four sensations by increasing the density of the skin layer, but the density of this skin layer! Of the aforementioned material compositions, it is the reaction accelerator and foaming agent that have a severe effect on the corpse. These relationships are shown in FIGS. 16 and 417.

Note that the opening end surface of the threaded insert 5 is connected to the molded product body 1.
It protrudes from the boss portion 2 by the depth of the digging 9A of the lower die 9 described above. In this molding, since the threaded insert 5 was made of steel with high thermal conductivity, the area around the threaded insert 5 was rapidly cooled due to the difference in the reaction temperature of the resin in the boss molded part 10A and the temperature of the threaded insert 5. This is done to form a strong and thick skin layer 4 on the outside of the threaded insert 5. Therefore, as described above, it is possible to mold a urethane foam molded product with a threaded portion of 4 ji, which has excellent torque and thrust force when tightening the screw to the limit.

FIG. 6 shows another embodiment of the invention. In FIG. 6, 1.4 is a reaction injection molded product such as a urethane foam molded product having a threaded portion, 2A is a boss portion formed on this molded product 1A, and 12 is a screw i! ! This is a helicoil related to a member having 58, and this helicoil 12 has a molded product body 14
Embedded in the boss @2A with a solid layer by skin layer 4
ing.

The helicoil 12 is made of steel, and as shown in FIG.
There is a snake-shaped elastic body that can be inserted between a male thread and a female thread, and is manufactured and sold by Tsugami Corporation under the trade name IIELI-5ERT, for example.

The urethane foam molded body 1.4 (FIG. 6) having the threaded portion of this embodiment configured as described above has a strong skin layer 4 formed around the helicoil 12.
Since 4tilfih is biting into the outside (male thread side) of 2, the contact S strength between the helicoil 12 and the molded product main body 1a is high. Nabo 3 is the core layer. Therefore, as shown at N006 in Fig. 3, the limit screw tightening torque is:
Although it is not as good as the example (NO, 5), it is 40?
-cns (in the case of ms screws) reaches vc, and it can be seen that the above-mentioned conventional example (# (j, 45)) has a double improvement of 20kF0rIL. In order to use a helicoil (for example, the above-mentioned helisert) which is commercially available as a member having S, the molded product 1 shown in FIG.
This has the advantage that the number of processing steps is further reduced.

Next, a method of molding a urethane foam molded product having a threaded portion shown in FIG. 6 will be explained. FIG. 8 is a sectional view showing an example of a reaction injection mold used for molding the embodiment shown in FIG. 6. In FIG. 8, the same parts as those in FIG. 85 are denoted by the same numbers. The helicoil 12 has a digging 9 in which the heads 15 and 4 are processed into the lower die 9.
It is fixed in the boss molded part IM of the cavity 10 while being screwed into the steel bolt 13 inserted in the hole B. The molding method using the reaction injection molding mold shown in FIG. After molding is completed,
When the bolt 15i is removed from the molded product 1A, the molded product 1A as shown in Figure 1IA6 is obtained. In this molding, since the bolt 15 is screwed into the helicoil 12, the area around the helicoil 12 of the boss portion 2A is rapidly cooled by the helicoil 12 and the bolt 13, and a strong and thick skin layer 4 is formed on the outside of the helicoil 12. be done.

Next, still another embodiment of the present invention will be described with reference to FIG. In FIG. 9, reference numeral 21 designates a reaction injection molded product body consisting only of a core layer 22 of a cell structure in which a screw pilot hole 21B is preformed in a boss portion 21.4. This molded product body 2
In No. 1, the cell structure around the screw hole 21B has a higher density f than the cell structure at the center due to the cooling effect of the mold (not shown). For example, in the material composition of the material used for molding, when Q, 5 parts by weight and 8x parts by weight of water and a foaming agent such as a low boiling point alkyl halide are used, respectively, the cell structure and the area around the prepared hole 21B are used. The densities of the parts are about Q, 21/cvl and about α7g10-, respectively. The reaction injection molded product main body 21, which is mainly composed of cell structure, is molded by a foaming method using water and a foaming agent such as a low-boiling alkyl halide as a foaming agent. Next, the helicoil 12 as shown in FIG. By screwing as shown in FIG. 2, a female thread can be easily formed in the reaction injection molded product main body 21.

In order to fasten an accessory part to a reaction injection molded product using the internal thread formed in this way, as shown in FIG. The steel plate 4 can be fixed to the reaction injection molded product 1 by contacting the boss portion 217 of the reaction injection molded product main body 21 and screwing the threaded portion of the bolt 25 into the helicoid 12 .

The maximum tightening torque for this threaded part is approximately 20 &, F-c
It was m.

Next, still another embodiment of the present invention will be described with reference to FIG. 12, FIG. 9m, and FIG. 14. In these drawings, the same parts are denoted by the same reference numerals as those in FIGS. 9, 10, and 11.

The reaction injection molded product body 31 shown in FIG.
It consists of a high-density skin layer 34 on the surface in which a pre-screw hole 51B has been formed in advance, and a core layer 32 with a low-density cell structure inside the skin layer 34. The reaction injection molded product 31/4, which consists of two layers, such as a skin layer and a core layer formed by an internal cell structure, uses a foaming method that uses only a foaming agent such as a low boiling point alkyl halide as a foaming agent. It is molded by

Next, the skin layer 3 of the molded product body 31 is formed with high density.
As shown in Fig. 1S, tap the screw hole 51B of No. 4 so that it fits into the helicoil tap (not shown),
By screwing the helicoil 12 shown in FIG. 1147 therein, a female thread can be easily formed in the reaction injection molded product main body 51.

In order to fasten accessory parts to a reaction injection molded product using the internal thread formed in this way, as shown in Fig. 14,
Accessory parts 2 such as steel plates with bolt holes 23 of predetermined dimensions drilled
4 into contact with the bottom 31/4 of the reaction injection molded product main body 31,
By screwing the threaded portion of the bolt 25 into the helicoil 12, the accessory part 24 can be fixed to the reaction injection molded product. In this embodiment, as described above, the helicoil 12 is screwed into the pre-screw hole 51B of the skin layer 34, so the maximum tightening torque of the threaded portion is larger than that of the previous embodiment, and is approximately 5011-atyr. there were. Among the compositions of the urethane foam material used in the present invention, the polyols include a propylene oxide adduct of 4,4'-diaminodiphenylmethane (40fIIi parts), a propylene oxide adduct of glycerin with ethylene oxide (10x parts), and a propylene oxide adduct of monoethanolamine. Things (501
When using the three-component system of the IT part), the mechanical!
J position is improved by about 20 to 50% compared to commercially available materials, and heat resistance is improved by 30 to 50"C. Also, if clade MDIy is used as liquid B, it has good reactivity with polyols. In each of the above embodiments, the threaded insert and helicoil are described as being made of steel, but other metals, non-ferrous metals, strong plastics such as 4BS etc. may be used. You can also.

Further, although the explanation has been given using a urethane foam molded product as an example of a reaction index molded product, it will be easily understood that the present invention is applicable not only to urethane foam molded products but also to other reaction injection molded products.

[Brief explanation of drawings]

Fig. 41 is a 1Ifr side view showing one example of a reaction injection molded product having a threaded portion according to the present invention, and Fig. 2 is a side view of the n shown in Fig. 1.
FIG. 3 is a partial cross-sectional enlarged perspective view of the threaded insert used in the embodiment described above, and FIG. 3 is a graph comparing the limit tightening torque between the prior art and the embodiment of the present invention. Figure 4 (4
, and (C) are perspective views of a -S cross section showing a modified example of the insert shown in FIG. Fig. m6 is a sectional view showing another embodiment of the present invention, Fig. 7 is an enlarged sectional view of a helicoil used in the embodiment shown in Fig. 6, and Fig. 8 is a sectional view showing another embodiment of the present invention. FIG. 9 is a cross-sectional view of a mold for molding a molded product. 10 is an enlarged sectional view showing the main parts of the molded product after further processing is performed on the molded product shown in FIG. 9, and FIG. is a sectional view showing the molded product shown in FIG. 10 and the attached parts attached thereto, and FIG. 12 is a sectional view showing the molded product shown in FIG. 1 of the molded product body in other embodiments! 13 is an enlarged sectional view showing the main part of the molded product after further processing has been applied to the molded product body shown in FIG. 9, and FIG. 14 is shown in FIG. 912. FIG. 15 is a graph showing the relationship between skin layer density and skin layer hardness;
Figure 16 shows trichlorofluoromethane and skin layer vlj
Figure 17 is a graph showing the relationship between reaction accelerator and skin layer density, Figure @18 is a graph showing the relationship between light*rate and skin layer density, and Figure 19 is a graph showing the relationship between light*rate and skin layer density. or a graph showing the relationship between insert temperature and skin layer density;
FIG. 20 is a graph showing the relationship between the skin layer density and the limit screw tightening torque, and FIG. 21 is a graph showing the relationship between the shape of the threaded insert and the limit screw tightening torque. DESCRIPTION OF SYMBOLS 1... Urethane foam molded product, 2... Boss part of molded product 1, 5... Core layer of molded product 1, 4... Skin layer of molded product 1, 5.5A, 5B, sC- ...Threaded insert, 6...Female thread, 7...Horizontal groove, 8...Upper mold, 9...
...Lower mold, 9J4...Lower mold digging, 10...Cavity, 10A...Boss molding part, 11...After mixer, 12...Helicoil, 1...Boldt's agent, patent attorney Usui 1 ）Rice Hato, He Punishment 4 Figure (△) (B) (C) Close Go Figure Kabuto Figure 6 Sanskrit 7 Figure z Figure f3 Close Figure 9 Yu 1?1 Yu 11 Figure

Claims (1)

[Scope of Claims] t. A molded article body having a hole surrounded by a relatively dense surface layer; and a member having an internal thread, with electrical current distributed within the hole and retained by the relatively dense surface layer. A reaction injection molded product having a threaded portion. 2. The reaction agent and extruded molded product having a threaded portion according to claim 1, wherein the surface layer having a relatively high density is a skin layer. 3. The reaction injection molded product having a threaded portion according to claim 41, wherein the member having the threaded portion 8 is a gold layer or a strong plastic insert. 4. The insert is cylindrical, and has a female thread formed on the inside thereof, and an unevenness such as a screw or knurling formed on the outside 114 of the insert.
li! A reaction injection molded product having a threaded portion according to item 3 of the desired yoke system. 5. Reaction injection having a thread S according to claim 5, wherein the insert has a polygonal shape, an internal thread is formed on the inside thereof, and a lateral groove is formed on the outside thereof. Molding. The reaction injection molded product according to claim 1 or 2, wherein the member having the internal thread is a helicoil. (s) positioning a member having a threaded part in a cavity of a reaction injection mold, injecting a molding material into the cavity to integrally mold the member having the threaded part; A method for molding a reaction injection molded product having a threaded part, characterized by solidifying the molding material with a surface layer of a relatively dense molding material. Tortoise A method for molding a reaction injection molded article according to claim 7, characterized in that a blowing agent such as a low boiling point alkyl halide is used as a blowing agent in the molding material 1. 9. A method for molding a reaction injection molded article according to claim Iji47, characterized in that water and a foaming agent such as a low boiling point alkyl halide are used as the foaming agent in the molding material. 10. The method for molding a reaction injection molded product according to claim 97, wherein the member having the threaded portion is an insert made of metal or strong plastic. 1t A helicoil is used as the member having the threaded portion, the helicoil is screwed into a bolt, the bolt and the helicoil are positioned in the cavity, and the bolt is removed after the molded product is molded. A method for molding a reaction injection molded product according to claim 47. 12. Prepare a molded product body in which a pilot hole for a female screw has been formed by molding, and screw the helicoil into the pilot hole for the screw! A method of forming a female thread in a reaction injection molded product called f111. 1. A method for forming a female thread in a reaction injection molded product according to claim 12, wherein the helicoil is made of metal or strong plastic. 14. When molding a reaction injection molded product,
Claim 12, characterized in that a relatively dense surface layer is formed around the screw hole by using a foaming agent such as a low boiling point alkyl halide in the molding material. A method for forming an internal thread in a reaction injection molded product as described in Section 1. 15. When forming reaction injection molded products,
Forming a female thread in a reaction injection molded product according to claim 12, characterized in that the skin layer is formed using a foaming agent such as water and a low boiling point alkyl halide as a foaming agent among the molding materials. Method.