JPH10235662A - Insert fixing jig for rotational molding mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an insert fixing jig for holding an insert in a mold in rotational molding in which an insert can easily be mounted from the outside of the mold. SOLUTION: An insert holder 10 has a flange portion 12 and a projecting portion 14 provided on a leading end side outwardly of the flange portion 12, and a spring coil 13 is fitted over between the flange portion 12 and the projecting portion 14. A locking groove 22 is formed in a holder receiver 20 in such a manner that the projecting portion 14 is fitted therein when a leading end portion of a cylinder portion 17 of the insert holder 10 is inserted into a through hole 21, and the movement of the insert holder 10 owing to a biassing force of the spring coil is restrained by virtue of an engagement of an engagement portion 22a of the locking groove 22 and the projecting portion 14, whereby the insert holder 10 is positioned in place.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing jig attached to a mold for holding an insert in the mold in rotational molding.

[0002]

2. Description of the Related Art A rotary molding method is known as a method for molding a resin molded product having a uniform thickness such as a large liquid tank. In the rotational molding method, a powdered resin is put into a mold having an outer shape of an object to be molded on an inner surface, and the molten resin is melted on the inner surface of the mold by rotating the mold while heating the resin. This is a method in which a mold is divided after being attached with a uniform thickness and then cooled to take out a molded product.

In such a rotational molding method, there are cases where it is desired to attach various parts to the surface of a molded product. For example, there is a case where a nut is embedded in the surface of a molded product, and various parts are to be screwed onto the surface of the molded product using the nut.

FIG. 7 is a sectional view showing an example of a conventional insert nut fixing jig when such an insert nut is embedded and formed. As shown in FIG.
An insert nut 2 is arranged inside an insert mounting through hole 1a formed in the insert nut 2.
Is fixed by screwing with a thumb screw 3 inserted from the outside. After the insert nut 2 is fixed to the inner surface of the mold 1 in this way, the resin 4 having a uniform thickness is attached to the inner surface of the mold 1 by charging the powder resin into the mold 1 and rotating while heating. Let it.

[0005] As shown in Fig. 7, by molding as described above, a resin molded product 4 in which the insert nut 2 is embedded can be obtained. After the molding, the thumb screw 3 is removed and the molded product is taken out of the mold 1.

[0006]

As described above, the conventional insert nut is disposed on the inner surface of the mold and screwed through a through hole. The mold used for the rotational molding method is generally large, has a mold having a deep tank shape or a tank shape having a narrow entrance, and the operation of disposing the insert from the inside of the mold is very troublesome. SUMMARY OF THE INVENTION An object of the present invention is to provide an insert fixing jig for a rotary molding die, which enables mounting of an insert from the outside of the die.

[0007]

SUMMARY OF THE INVENTION The present invention is a fixing jig for holding an insert in a mold in rotational molding, and includes an insert holder for holding an insert at a tip portion, and an insert holder for a mold. It has a holder holder attached and formed with a through hole for receiving the tip of the insert holder, and a positioning mechanism for determining the position of the insert holder when the insert holder is inserted into the through hole of the holder holder. ing.

[0008] In a more limited embodiment of the present invention, the insert holder has a flange portion and a protruding portion provided on the distal end side of the flange portion, and a spring is provided between the flange portion and the protruding portion. The coil is externally inserted, and the holder receiving member has a locking groove into which the projection is fitted when the tip of the insert holder is inserted into the through hole of the holder receiving member. The movement of the insert holder due to the urging force of the spring coil is suppressed by the engagement between the insert holder and the projection, and the insert holder is positioned.

According to the present invention, the insert is held at the tip of the insert holder, the insert holder is inserted into the through-hole of the holder receiving member, and the position of the insert holder is determined by the positioning mechanism. Can be held in place. Therefore, the insert can be held by the insert holder from the outside of the mold and held at a predetermined position.

The insert held by the insert fixing jig of the present invention is not particularly limited as long as it is an insert held in a mold in rotational molding. For example,
The insert nut described above can be held by the insert fixing jig of the present invention. In this case, for example, a holding rod is provided at the tip of the insert holder, and the inner nut hole of the insert nut is fitted to the holding rod to hold the insert nut. Further, it is preferable that a resin coating portion for preventing the insert nut from falling off is provided on the outer periphery of the holding rod. Such a resin covering portion hits the thread of the inner screw hole of the insert nut and prevents the insert nut from easily falling off.

Further, the insert may be an insert which forms a projection on the inner surface of a mold in order to form a depression on the surface of a molded product. Such inserts are removed from the molding after molding. According to the present invention, since the insert can be mounted from the outside of the mold, such an insert may be formed integrally with the insert holder.

[0012] The insert may be an insert that penetrates a mold to form a hollow portion in a molded product. Such inserts are removed from the molding after molding. Further, similarly to the above-mentioned insert, an insert formed integrally with the insert holder may be used. The rotational molding die according to the present invention is characterized in that the insert fixing jig according to the present invention is attached.

[0013]

FIG. 1 is a side view showing an insert fixing jig according to an embodiment of the present invention. The fixing jig 30 shown in FIG. 1 includes an insert holder 10 and a holder receiver 20.

FIG. 2A is a side view showing the insert holder 10, and FIG. 2B is a side view showing the holder holder 20. The insert holder 10 will be described with reference to FIG. Insert holder 1
0 has a cylinder part 17 and a cylinder part 1
7 is provided with a flange portion 12. A handle 11 is provided at an end slightly away from the flange 12. By gripping the handle 11, the cylinder 1
7 can be turned. A projection 14 is provided at a position on the distal end side from the flange 12. The protrusion 14 is formed, for example, by fitting a small cylindrical component into the cylinder 17. Flange 12 and protrusion 14
The spring coil 13 is extrapolated on the outer periphery of the cylinder 17 between the two. Tip surface 15 of cylinder 17
Is provided with a holding rod 16 at the center thereof.

FIG. 3 is a partially cutaway side view showing the vicinity of the holding rod 16 in an enlarged manner. As shown in FIG. 3, a holding rod base 16 a provided at the center of the distal end face 15 has an internal thread 16
c is formed. The head 16b has an outer thread 16e that fits into the inner thread 16c. The inner screw portion 16c and the outer screw portion 16e are formed so as to form a so-called reverse screw in order to prevent loosening. Also,
A step portion 16d is formed in the head portion 16b, and a cylindrical resin coating portion 16f fits into the step portion 16d.
The resin coating portion 16f is formed of a heat-resistant resin such as Teflon, for example, and the outer diameter of the resin coating portion 16f is set to be slightly larger than the outer diameter of the inner thread portion of the insert nut. Step 1
2A, and the outer threaded portion 16e of the head portion 16b is fitted into the inner threaded portion 16c of the holding rod base 16a to obtain a state shown in FIG. 2A. The holding rod 16
Is composed of a holding rod base 16a, a resin coating 16f, and a head 16b.

Referring to FIG. 2B, holder holder 2
0 will be explained. The cylindrical insertion portion 24 of the holder receiver 20 is inserted into the insert insertion hole 1a of the mold 1 and the flange portion 23 having an outer diameter larger than the insertion portion 24 abuts around the insertion hole 1a. The holder receiver 20 is attached to the mold 1 by attaching the periphery of 1a and the flange portion 23 by welding or the like. A cylinder portion 25 extends from the flange portion 23. In the cylinder portion 25, the flange portion 23, and the insertion portion 24, the through hole 2 is provided.
1 is formed. This through-hole 21 is formed in a shape and a dimension into which the cylinder part 17 of the insert holder 10 is fitted.

The cylinder 25 has a locking groove 22 into which the projection 14 on the cylinder 17 of the insert holder 10 can be fitted. The locking groove 22 extends in the insertion direction of the projection 14 and then bends in an L-shape in a substantially vertical direction, and has an engagement portion 22a formed at its end to engage with the projection 14 so as not to come off. ing. Therefore, the protrusion 14 of the insert holder 10 is
By rotating counterclockwise after inserting and pressing the insert holder 2, the protrusion 14 is engaged with the engaging portion 22a, and the movement of the insert holder 10 in the direction in which the insert holder 10 comes off is suppressed.

FIG. 1 shows a through hole 21 of a holder receiver 20.
2 shows a state in which the distal end of the cylinder portion 17 of the insert holder 10 is fitted into the insert holder 10, and at the same time, the protrusion 14 is fitted into the locking groove 22 and rotated counterclockwise to engage the protrusion 14 with the engaging portion 22a. ing. The cylinder portion 17 of the insert holder 10 is inserted into the through hole 21 of the holder receiving member 20.
When inserting the cylinder, the cylinder 25 of the holder receiver 20 is inserted.
The end of the spring coil 13 abuts against the end surface of the spring coil 13 and the repulsive force of the spring coil 13 acts. And insert holder 1
When 0 is pushed in and rotated counterclockwise, the projection 14 engages with the engagement portion 22a as described above. When the hand is released in this state, the insert holder 10 attempts to move in a direction away from the holder receiving member due to the repulsive force of the spring coil 13, but since the protrusion 14 is engaged with the engaging portion 22 a, the movement is prevented. Is suppressed and the insert holder 1
The position of 0 is fixed. In the present embodiment, the insert holder 10 inserted into the holder receiver 20 is positioned by such a mechanism.

In the above-described positioning state, the distal end face 15 of the insert holder 10 is positioned so as to be substantially flush with the end face of the insertion portion 24 of the holder receiver 20. Holding rod 1 at the tip of insert nut holder 10
6 is fitted with a screw hole 41 of an insert nut, thereby holding the insert nut 40. 4A and 4B are views showing an insert nut, FIG. 4A is a front view, FIG. 4B is a longitudinal sectional view, and FIG. 4C is a side view. As shown in FIGS. 4B and 4C, a groove 40b is formed on the outer peripheral surface of the insert nut 40. This is to make it hard to come off when embedded in a molded product by rotational molding.

Returning to FIG. 1, when the insert nut 40 is held by the holding rod 16, the resin coating 16f of the holding rod 16 is in contact with the screw hole 41 of the insert nut 40. The insert nut 40 is held so as not to fall off from the holding rod 16 by the contact of the resin coating portion 16f with the screw hole 41. As shown in FIG.
With the insert nut 40 held by the holding rod 16, the insert holder 10 is inserted into the through hole 21 of the holder receiver 20 from outside the mold 1 as described above. Then, as described above, the protrusions 14 are
And the insert holder 10 is positioned by engagement with the engagement portion 22a.

Accordingly, the insert fixing jig 3 of the present embodiment
0, the insert nut 40 from outside the mold 1
Can be mounted, and the mounting of the insert nut 40 can be performed with a simpler operation than before.

After molding, the insert holder 10
Is slightly pushed in and rotated clockwise to release the projection 14 from the locking groove 22 and pull out the insert holder 10 from the holder receiving member 20, whereby the holding rod 16 is pulled out from the screw hole 41 of the insert nut 40. The insert nut 40 is in a state of being embedded in the molded product, similarly to the insert nut shown in FIG. Therefore, the insert nut fixing jig of this embodiment can be removed by a simple operation after molding.

FIG. 5 is a side view showing an insert fixing jig of another embodiment according to the present invention. The insert holder 50 shown in FIG. 5 has substantially the same configuration as the insert holder 10 shown in FIGS. 1 and 2A, and a handle 51 is attached at a position slightly away from the flange portion 52. A spring coil 53 is externally inserted in the cylinder portion 57 between the projection 52 and the projection 52.
The difference between the insert holder 50 and the insert holder 10 in the present embodiment is that the distal end of the cylinder portion 57 is integrated with the insertion rod portion 55. The insertion rod portion 55 is a portion that is inserted into a mold during rotational molding, and corresponds to an insert.

In the embodiment shown in FIG. 5, the holder receiver 20 has the same structure as the holder receiver shown in FIGS. 1 and 2 (b). In the state shown in FIG. 5, the protrusion 54 of the insert holder 50 is fitted in the locking groove 22,
The position of the insert holder 50 is determined by contact with the engaging portion 22a. In this state, the resin is charged into the mold 1 and rotated while being heated, so that rotational molding is performed. The resin in the mold 1 adheres along the inner surface of the mold 1, but adheres along the surface of the insertion rod portion 55 at the portion where the insertion rod portion 55 is inserted. Therefore, a recess having a shape along the insertion rod portion 55 is formed. After the molding, the insert holder 50 is pushed in and rotated clockwise to disengage the projection 54 from the locking groove 22, and the insert holder 50 is pulled out, as in the above-described embodiment. On the surface of the molded product, a concave portion having a shape along the insertion rod portion 55 is formed. The recesses on the surface of this molded product
The inner surface of the molded product is formed as a convex portion. Therefore, when it is desired to form a recess on the surface of a molded product,
When it is desired to form a convex portion on the inner surface of the molded product, an insert fixing jig as in this embodiment can be used.

FIG. 6 is a partially cutaway sectional view showing an insert fixing jig of still another embodiment according to the present invention. The insert holder 70 according to the present embodiment has the same structure as the above embodiments, except for a portion corresponding to the insert at the distal end. That is, a spring coil 73 is externally inserted around the cylinder portion 77 between the flange portion 72 and the projection 74 with the handle 71.

The tip of the cylinder 77 is a through rod 78 formed integrally. The penetrating rod portion 78 is a portion corresponding to an insert, and is installed so as to penetrate through the dies 91 and 92 during rotational molding.

The insert holder 70 is inserted into the through hole 81 of the holder holder 80 on the mold 91 side, and is inserted into the through hole 86 of the holder holder 85 on the mold 92 side. The holder receiver 80 is attached to the mold 91 by bolts 83 and 84, and the holder receiver 85 is attached to the mold 92 by bolts 87 and 88. The holder receiving member 80 is formed with the same locking groove 82 and engaging portion 82a as the holder receiving members of the above embodiments.

In the state shown in FIG. 6, the insert holder 70 is positioned by the projection 74 of the insert holder 70 abutting on the engaging portion 82a of the locking groove 82 of the holder receiver 80. . In this state, resin is charged into the dies 91 and 92 and
By heating while rotating 1,92, the mold 9 is heated.
The resin is adhered to the inner surfaces of the first and second substrates. At this time, the resin also adheres to the inner surface of the penetrating rod portion 78. Therefore, the mold 9
A molded product having a hollow portion along the through rod portion 78 is formed in the first and second portions 92. The penetrating rod portion 78
A hole 79 is formed at the center of the hole. This is for reducing the heat capacity of the penetrating rod, increasing the effect of increasing the temperature of the penetrating rod, and making it easier for the resin to adhere to the outer periphery of the penetrating rod. . Further, the diameter of the penetrating rod portion 78 is formed in a tapered shape so that the diameter becomes smaller toward the distal end portion so as to be easily detached.

After molding, the protrusions 7 are formed in the same manner as in the above embodiments.
4 and the engaging portion 82a are disengaged, the insert holder 70 is pulled out from the dies 91 and 92, and the through rod portion 78 is pulled out from the hollow portion of the molded product in the dies 91 and 92 and removed.

As described above, according to the present invention, the insert can be easily mounted from the outside of the mold, and the insert fixing jig can be easily removed after molding. As described above, the present invention has been described with reference to specific examples.
The present invention is not limited to the above embodiment, but can be widely used for holding various inserts in rotational molding.

The positioning mechanism according to the present invention is not limited to the positioning mechanism including the spring coil, the projection, the locking groove, and the engaging portion in each of the above embodiments. For example, an internal screw is formed in a through hole in the holder receiver, an external screw that fits the internal screw is formed in the cylinder portion of the insert holder, the internal screw and the external screw are fitted, and the The insert holder may be pushed in while being rotated in this state, and the position of the insert holder may be determined in a state where the insert holder does not rotate. That is, the positioning mechanism may be configured by the inner screw of the through hole of the holder receiver and the outer screw of the cylinder of the insert holder.

[0032]

According to the insert fixing jig of the present invention,
The insert can be easily mounted from the outside of the mold. Also, after molding, it can be easily removed,
Production efficiency in rotational molding can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a side view showing an insert fixing jig according to an embodiment of the present invention.

FIG. 2 shows an insert holder (a) of the embodiment shown in FIG.
FIG. 6 is a side view showing a holder holder (b).

FIG. 3 is a partially cutaway side view showing a tip portion of the insert holder of the embodiment shown in FIG.

FIGS. 4A and 4B are a front view, a longitudinal sectional view, and a side view showing an insert nut in the embodiment shown in FIG.

FIG. 5 is a side view showing an insert fixing jig of another embodiment according to the present invention.

FIG. 6 is a partially cutaway sectional view showing an insert fixing jig of still another embodiment according to the present invention.

FIG. 7 is a sectional view showing an example of a conventional insert fixing jig.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Insert holder 12 ... Cylinder part 13 ... Spring coil 14 ... Protrusion part 15 ... Tip surface 16 ... Holding rod 16f ... Resin coating part 17 ... Cylinder part 20 ... Holder receiving member 21 ... Through hole 22 ... Locking groove 22a ... Joint 30: Insert fixing jig 40: Insert nut 41: Internal screw of insert nut 50: Insert holder 52: Flange 53: Spring coil 54: Projection 55: Insert rod 57: Cylinder 60: Insert fixing jig Reference numeral 70: Insert holder 72: Cylinder 73: Spring coil 74: Projection 77: Cylinder 78: Through rod 79: Hole in the through rod 80: Holder holder 81: Through hole 82: Locking groove 82a: Engagement Part 85: Holder holder 86: Through hole

Claims (6)

[Claims] 1. A fixing jig for holding an insert in a mold in rotational molding, comprising: an insert holder for holding an insert at a tip portion; A rotary metal mold having a holder receiving tool having a through hole for receiving a tip portion, and a positioning mechanism for determining a position of the insert holder when the insert holder is inserted into the through hole of the holder receiving tool. Fixture jig for mold insert. 2. A fixing jig for holding an insert in a mold in rotary molding, comprising: an insert holder for holding an insert at a tip portion; A holder receiving tool having a through-hole for receiving the distal end portion, wherein the insert holder has a flange portion, and a projection provided on the distal end side from the flange portion, and the flange portion and the projection portion A spring coil is externally inserted between the holder holders, and the holder receiver has a locking groove in which the protrusion is fitted when the tip of the insert holder is inserted into a through hole of the holder receiver. The movement of the insert holder due to the urging force of the spring coil is suppressed by the engagement between the locking groove and the projection, and Rotation molding die insert fixture, characterized in that the bets holder positioning is performed. 3. The insert is an insert nut, and a tip of the insert holder is provided with a holding rod to be fitted into an inner screw hole of the insert nut. The jig for a rotary molding die according to claim 1 or 2, wherein a resin coating portion is provided. 4. The insert, which forms a concave portion on the surface of the molded product, forms a convex portion on the inner surface of the mold, and is removed from the molded product after molding, and is formed integrally with the insert holder. The insert fixing jig for a rotary molding die according to claim 1 or 2, wherein: 5. An insert which is installed through a mold and removed from the molded product after molding to form a hollow portion in the molded product, and is formed integrally with the insert holder. The jig for fixing an insert for a rotary molding die according to claim 1 or 2, wherein 6. A rotational molding die to which the insert fixing jig according to claim 1 is attached.