JPH0590210U - Home Gotatsu leg - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a leg for a home rattling, which has a small number of parts, can be strengthened in rigidity and can be reduced in weight, and can be easily and accurately manufactured. [Structure] A leg body 1 made of resin and a metal nut member 3 fixed to the upper ends of the leg body 1 are provided. By injecting gas into the uncured resin during injection molding, the leg body 1 is integrally formed so as to have a substantially uniform thickness as a whole. By this injection molding, the leg main body 1 is formed so as to have the hollow chamber 4 inside and the upper opening blind hole portion 7 in the upper wall portion 2. The metal nut member 3 is embedded in the blind hole portion 7 by insert molding during injection molding. The blind hole portion 7 and the metal nut member 3 can be embedded at the same time. Since the leg body 1 is an integral body, it is robust. The whole can be easily manufactured only by the injection molding process.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a leg for a home tattoo.

[0002]

[Prior Art]

 BACKGROUND ART Conventionally, a plastic leg for a home rattling has a hollow structure in which two plastic members each having a hollow chamber on one or both sides are connected to each other so as to close the recess. It was formed by adhesion and integration.

[0003]

[Problems to be solved by the device]

 However, the above-mentioned conventional leg for a home trowel has the drawback that the number of parts is large because it is composed of two members and that a bonding work step is required. Further, in order to obtain a strong adhesive force and rigidity, it is necessary to form ribs or the like on each member so as to increase the adhesive area, which is a drawback that the weight increases.

As shown in FIG. 9, the wall of the leg body a is slightly thicker in the vicinity of the corner k, but there is a drawback that shrinkage h, h occurs in the thickened portion. It was

Further, in order to mount the conventional leg for the home kotatsu to the home trawl frame main body, it is necessary to fix the bolt with a bolt and a nut, but the nut is embedded in the hollow plastic leg main body. I couldn't get into it.

Therefore, the present invention solves the above-mentioned problems, has a small number of parts, is lightweight and robust, and further, does not cause a shrinkage at the corners of the wall portion and can be easily manufactured. The purpose is to provide.

[0007]

[Means for Solving the Problems]

 The leg for home tatatsu according to the present invention has a leg body having a substantially uniform thickness by injection of gas into the uncured resin during injection molding. A metal nut member that is integrally formed so as to have an open blind hole and is screwed with a screw member for mounting the home natto frame is embedded in the blind hole by insert molding during the injection molding. It's complicated.

[0008]

[Action]

 The leg body can maintain a great rigidity and a great strength even if the wall thickness is made thin, and can be made lighter. Then, since a hollow chamber is formed inside by injecting gas into the uncured resin, in the injection molding process, the corner of the wall is pressed by the pressure of gas from the inside to the outside mold, The shape on the outer surface side of is accurate.

Further, the wall portion around the blind hole portion of the upper wall portion of the leg body is pressed from the inside of the hollow chamber to the metal nut member by the pressure of gas in the injection molding process. As a result, a gap due to resin shrinkage does not occur between the metal nut member and the inner surface of the blind hole portion, and the metal nut member can be firmly fixed.

[0010]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the drawings illustrating an embodiment.

FIG. 1 and FIG. 2 show an embodiment of a leg for a home diaper according to the present invention. The leg L for a home diaper is a leg body 1 made of a resin having a substantially rectangular column shape and provided on an upper end thereof. And a fixed metal nut member 3.

As shown in FIG. 2, the leg body 1 is formed to have a substantially uniform thickness as a whole by injecting gas into the uncured resin during injection molding.

Further, the leg body 1 is integrally formed by the above-mentioned injection molding so as to have a hollow chamber 4 inside and an upper open blind hole portion 7 in the upper wall portion 2.

The material of the leg body 1 is preferably a thermoplastic resin, for example, polypropylene, polycarbonate, ABS, polystyrene, acrylic, or the like.

Further, the metal nut member 3 is for screwing the screw member 6 for mounting the home troop frame H, and has a cylindrical shape with a blind hole screw hole 35 open to only one side (upward). It is said to be a body.

Thus, the metal nut member 3 is embedded in the blind hole portion 7 by insert molding during injection molding.

That is, at the time of injection molding, the side surface and the bottom surface of the metal nut member 3 are covered with a layer of molten resin, and when this layer is solidified, the blind hole portion 7 is formed around the metal nut member 3.

By this embedding, the side surface and the lower end surface of the metal nut member 3 are in close contact with the inner surface of the blind hole portion 7, and the entire metal nut member 3 is fixed in the blind hole portion 7. The upper end surface of the metal nut member 3 is flush with the upper end surface of the leg body 1.

In this embodiment, the metal nut member 3 has a substantially cylindrical shape, but it is also preferable to have a rectangular tubular shape such as a quadrangle or a hexagon other than the cylindrical shape. It is also desirable to use a metal nut member 3 (not shown) having a protrusion for preventing slipping out on the outer peripheral surface.

Next, a small tubular body 9 is integrally erected so as to project from the bottom wall portion 8 of the leg body 1 into the hollow chamber 4.

That is, the small tubular body 9 projects into the hollow chamber 4 and has a cylindrical wall portion 10 whose base end is integrated with the bottom wall portion 8 of the leg body 1, and the cylindrical wall portion 10 of the cylindrical wall portion 10. The upper end includes a disk-shaped wall portion 11 having a lid shape.

In addition, a gas injection hole 12 is formed in the disk-shaped wall portion 11 of the small tubular body 9 in the molding by injecting gas into the uncured resin.

The leg for home patella of the present invention configured as described above is attached to the corner portion C of the home patella frame H.

That is, a fitting recess 13 for fitting a portion of the leg main body 1 above the step portion 5 is formed in the corner portion C of the home shatter frame H.

The ceiling wall portion of the fitting recess 13 is provided with a two-stepped through hole 14 into which the screw member 6 to be screwed into the metal nut member 3 and the top plate receiving cushion 15 are fitted. ing.

Then, a portion of the leg main body 1 above the step portion 5 is fitted into the fitting recess 13 of the home mantling frame H, and the screw member 6 is inserted into the two-step through hole 14 from above. Then, the screw member 6 is screwed onto the metal nut member 3. Further, the top plate cushioning portion 15 is fitted on the upper part of the two-stage through hole 14.

In this way, the leg L for home diaper is attached to the home diaper frame H. Further, a top plate 16 (shown by phantom lines) is placed on the platform mat H through the top plate receiving cushion 15.

Next, in the case of injection-molding the leg for the home kotatsu of the present invention, the upper mold 17, the lower mold 18, and the protruding pin 23 as shown in FIG. 3 are used.

That is, the upper mold 17 and the lower mold 18 can move up and down on a frame body 21 having a fixed plate 20 at the upper end and rods 19 and 19 fixed to the fixed plate 20 and extending downward. Are fixed to the upper mold clamping plate 24 and the lower mold clamping plate 25, respectively, which are attached to.

The upper end of the protruding pin 23 is fixed to the center of the fixed plate 20 of the frame body 21 and is suspended from the fixed plate 20.

A hole 36 communicating with the inside of the mold engraving portion 22 of the upper mold 17 is formed at the upper part of the upper mold clamping plate 24 and the upper mold 17. The projecting pin 23 is inserted into the hole 36, and the lower part of the projecting pin 23 projects into the mold engraving portion 22 of the upper mold 17.

Further, a vertically protruding portion 27 having an upward protruding shape is formed at the center of the bottom surface of the mold engraving portion 26 of the lower mold 18.

Further, as shown in FIG. 4, the lower mold 18 and the lower mold clamping plate 25 have a resin injection passage 28 and a gas injection hole which pass through the inside of the lower mold 18 and open at the same position on the upper end surface of the vertical protrusion 27. A passage 29 is attached.

It should be noted that the openings of the resin injection passage 28 and the gas injection passage 29 may be provided at a position other than the upper end surface of the vertical protrusion 27. Further, in this embodiment, only one set of the resin injection passage 28 and the gas injection passage 29 is provided, but it is also possible to provide two sets thereof. Furthermore, it is also preferable to provide the resin injection passage 28 and the gas injection passage 29 separately.

Then, in order to injection-mold the leg for the home kotatsu according to the present invention (returning to FIG. 3), first, the metal nut member 3 is tightly fitted to the lower end of the protruding pin 23 or by heating. Attach via a chemical that loses adhesive strength.

After that, as shown by the arrows A and B in FIG. 5, the upper mold 17 and the lower mold 18 are brought into close contact with each other to close the mold to form the leg for the home kotatsu of the present invention. To form a hollow portion 30 for.

Further, since the projecting pin 23 is fixed to the fixed plate 20 of the frame body 21, when the mold is closed, the hole 36 of the upper mold 17 slides on the outer peripheral surface of the projecting pin 23. The upper die 17 moves downward.

When the mold is closed, the upper end surface of the metal nut member 3 attached to the lower end of the protruding pin 23 contacts the ceiling surface of the mold engraving portion 22 of the upper mold 17. That is, the entire metal nut member 3 projects downward from the ceiling surface.

The parting line P, which is the boundary between the upper mold 17 and the lower mold 18, is located below the hollow portion 30.

Next, as shown in FIG. 6, while the molten thermoplastic resin M is injected and injected from the resin injection passage 28 into the hollow portion 30, the gas injection passage is introduced into the flow of the thermoplastic resin M. Gas is continuously injected at a controlled pressure from 29.

As the gas to be injected, an inert gas is used, preferably nitrogen gas.

The thermoplastic resin M injected in this manner spreads along the inner wall surface of the hollow portion 30 of the mold into a layer having a substantially uniform thickness, and an air chamber is formed by gas inside the layer. ..

Then, the thermoplastic resin M is solidified while maintaining the pressure of the injected gas. As a result, the volume decrease due to the volume contraction accompanying the solidification of the thermoplastic resin M is compensated by the pressure of the gas held.

That is, the layer of the thermoplastic resin M is solidified while being pressed against the wall surface inside the hollow portion 30 and the surface of the metal nut member 3 projecting into the hollow portion 30 by the pressure of the gas inside thereof.

Therefore, the metal nut member 3 and the layer of the thermoplastic resin M can be solidified without forming a gap, and a so-called “shrink” is formed in the vicinity of the corner portion of the formed wall portion. It never happens.

Further, since the whole has a substantially uniform thickness, the cooling time can be shortened.

Next, after the thermoplastic resin M is solidified, the pressure of the gas inside is made equal to the pressure of the outside air.

Then, as shown by the arrows E and F in FIG. 7, when the upper mold 17 and the lower mold 18 are separated from each other and the mold is opened, the formed leg L for home kotatsu is formed. Appears upright on the lower die 18 in a mounted state.

Therefore, it is possible to easily take out the leg L for home kotatsu after the injection molding.

Next, FIG. 8 shows a leg L for a home vowel according to another embodiment. In this example, the bottom wall portion 8 of the leg body 1 is formed in a flat shape.

Further, the leg body 1 is formed with a vertical standing piece 31 which has one side wall extending upward and which projects upward from the upper wall portion 2.

When the leg L for home pons is attached to the home pallet frame H, the vertical standing piece 31 is brought into contact with or close to the outer surface of the outer end wall of the corner C of the home pallet frame H. To do.

Note that the present invention can be freely modified in design within the scope not departing from the gist other than the above-described embodiment. For example, the leg body 1 can be a triangle or a pentagonal or more polygonal shape in cross section. The shape may be circular or elliptical.

[0054]

[Effect of the device]

 The present invention has the following significant effects with the above configuration.

The metal nut member 3 can be embedded in the blind hole portion 7 simultaneously with the formation of the blind hole portion 7 by injection molding. This eliminates the need for a core die for forming the blind hole 7.

Further, the total number of parts can be reduced (only the leg body 1 and the metal nut member 3). And the whole can be made light and strong.

Furthermore, so-called “retraction” can be prevented from occurring at each corner of the leg body 1, and the leg body 1 can be formed into an accurate shape.

Further, the cooling and solidification in the injection molding can be accelerated, and the molding efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a leg for a home kotatsu according to the present invention.

FIG. 2 is a cross-sectional view illustrating a usage state.

FIG. 3 is a sectional view illustrating an injection molding process.

FIG. 4 is a sectional view of a main part of a mold.

FIG. 5 is a sectional view illustrating an injection molding process.

FIG. 6 is a sectional view illustrating an injection molding process.

FIG. 7 is a cross-sectional view illustrating an injection molding process.

FIG. 8 is a sectional view showing another embodiment.

FIG. 9 is a cross-sectional view of a main part showing a conventional example.

[Explanation of symbols]

 1 Leg Main Body 2 Upper Wall Part 3 Metal Nut Member 4 Hollow Chamber 6 Screw Member 7 Blind Hole H Home Snack Frame

Claims (1)

[Scope of utility model registration request] 1. A leg body 1 having a substantially uniform thickness as a whole by gas injection into an uncured resin during injection molding, a hollow chamber 4 inside, and an upper open blind hole portion in an upper wall 2. 7, the metal nut member 3 integrally formed and screwed with the screw member 6 for mounting the home porcelain frame H is embedded in the blind hole portion 7 by insert molding during the injection molding. This is a leg for home kotatsu.