JPH1119940A - Mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold manufactured at a low cost by effectively obtaining a locking effect of bolt without considering an installation space, and easily disassembling a die set. SOLUTION: The mold having a die set obtained by integrally coupling a die plate 18 with a die material 16 by a bolt 21 with one another comprises a locking plate 24 formed of a material having larger linear expansion coefficient than those of the plate 18 and material 16 and interposed between the plate 18 and the material 16 to be thermally expanded larger than the plate 18 and material 16 at the time of raising a mold temperature during processing, thereby increasing a clamping force of the bolt 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die having a die set in which a die plate and a die are integrally connected to each other by bolts, and more particularly to an effect of preventing bolts from loosening.

[0002]

2. Description of the Related Art A mold used for injection molding or compression molding of a resin generally includes a fixed die set and a movable die set, and is formed between the pair of die sets. The resin is molded into a shape corresponding to the molding cavity. In each die set, the die plate and the die are integrally connected to each other by bolts.However, the movable die set needs to incorporate the ejector mechanism of the molded product. In many cases, it is interposed between the mold members.

FIG. 3 shows an example of such a conventional resin molding die. That is, the fixed-side die set includes a locate ring 101, a die plate 102 to which the locate ring 101 is attached, a fixed mold 103, and a bolt 104 connecting the die plate 102 and the fixed mold 103. Is done. The movable-side die set includes a movable-side mold member 106 forming a molding cavity 105 into which resin is supplied between the fixed-side mold member 103, a guide plate 108 for slidably holding an ejector pin 107, and an ejector Ejector plate 109 for holding pin 107, spacer block 110 for slidably holding ejector plate 109, die plate 111, movable mold member 106, guide plate 108, spacer block 110, die plate 11
1 are connected to each other.

[0004] By the way, bolts 104 and 112 for connecting the die plates 102 and 111 and the mold members 103 and 106 are provided.
Is heated by the molten resin supplied to the molding cavity 105, and gradually loosened due to vibration accompanying opening and closing operations of the movable die set. Delicately deviates from the relative position, which may adversely affect the dimensional accuracy of the molded product. In addition, a guide pin (not shown) for positioning the fixed-side die set and the movable-side die set may be galled, which may cause trouble in the molding process.

For this reason, conventionally, bolts 104 and 112 having a special locking function are used, or locking of the bolts 104 and 112 is performed by using a spring washer or an adhesive.

[0006]

[Problems to be Solved by the Invention] Bolts 104 and 112
Die plates 102 and 111 and mold members 103 and 1
In the conventional mold as shown in FIG.
If a bolt having a special locking function is used, the cost of the bolt itself becomes high, which leads to an increase in the manufacturing cost of the mold.

[0007] Further, even if the bolt is prevented from being loosened by using a spring washer, it may not be used depending on the structure of the die set due to the installation space problem.

Further, when the bolt is prevented from being loosened using an adhesive, it is difficult to disassemble the die set, and the time required for the maintenance of the mold and the like increases. Further, as the temperature of the mold at the time of molding increases, there is a possibility that the adhesive may be thermally degraded and a sufficient locking effect may not be obtained.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a mold which can surely obtain a bolt locking effect without considering the installation space, and which can be easily disassembled and can be manufactured at low cost. Is to do.

[0010]

According to a first aspect of the present invention, there is provided a mold having a die set in which a die plate and a mold member are integrally connected to each other by bolts with a spacer block interposed therebetween. The mold is characterized in that the spacer block is formed of a material having a larger linear expansion coefficient than the die plate and the mold material.

According to the present invention, during processing, the mold temperature is increased, and a load is applied to the bolt to push and expand the die plate and the mold material due to the thermal expansion of the spacer block.
As a result, the tightening force of the bolt increases. When the mold temperature returns to normal temperature, the bolt tightening force is restored.

According to a second aspect of the present invention, there is provided a mold having a die set in which a die plate and a mold material are integrally connected to each other by bolts, wherein a linear expansion larger than that of the die plate and the mold material is provided. A mold is characterized in that a locking plate made of a material having a coefficient is interposed between the die plate and the mold.

According to the present invention, during processing, the temperature of the mold increases, and a load is applied to the bolt to push and spread the die plate and the mold material due to the thermal expansion of the locking plate. As a result, the tightening force of the bolt is reduced. Increase. Therefore, when the mold temperature returns to the normal temperature, the bolt tightening force is restored.

According to a third aspect of the present invention, there is provided a mold having a die set in which a die plate and a die are integrally connected to each other by bolts, wherein the die has a larger linear expansion coefficient than the die plate. A metal mold formed of a material.

According to the present invention, during processing, the temperature of the mold increases, and a tensile stress acts on the bolt due to the thermal expansion of the mold, and as a result, the tightening force of the bolt increases.
Therefore, when the mold temperature returns to the normal temperature, the bolt tightening force is restored.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the mold according to the first embodiment of the present invention, the spacer block may be made of copper or a copper alloy.

In the mold according to the second aspect of the present invention, the locking plate may be made of copper or a copper alloy.

Further, in the mold according to the third aspect of the present invention, the mold material may be copper or a copper alloy.

The first, second and third embodiments of the present invention
May be a resin molding die.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Two embodiments in which the mold according to the present invention is applied to a resin molding mold will be described in detail with reference to FIGS. 1 and 2, which respectively show schematic sectional structures thereof. The present invention is not limited to the embodiment, and can be applied to technologies in other fields that include similar problems.

FIG. 1 shows a first embodiment according to the present invention.
That is, a fixed die 14 having a sprue 13 to which molten resin is supplied from the injection machine is superimposed on a fixed die plate 12 connected to an injection machine (not shown) via a locate ring 11. The die plate 12 and the fixed-side mold member 14 are integrally connected via a plurality of hexagon socket head bolts 15. The fixed-side die plate 12, the fixed-side mold member 14, the hexagonal bolt 15 and the like constitute a fixed-side die set.

A movable mold 16 having a separation surface PL formed between the movable mold 16 and the fixed mold 14 has a sprue 1 of the fixed mold 14.
Mold cavity 17 to which molten resin is supplied in communication with 3
Are formed between the fixed-side mold member 14. In the direction facing the fixed mold member 14 via a drive device (not shown) (in the drawing,
Movable die plate 18 reciprocally driven (up and down)
And a fixed side mold member 14, a spacer block 19 is provided.
And the guide block 20 are overlapped. The movable block 16 is formed by a plurality of hexagon socket head bolts 21 penetrating the spacer block 19 and the guide block 20.
Are integrally connected to the movable die plate 18 together with the spacer block 19 and the guide block 20.

In the spacer block 19, an ejector plate 23 having a plurality of ejector pins 22 projecting through the guide block 20 so that the front end faces the molding cavity 17 of the movable mold 16 is reciprocated by the movable mold 16. It is slidably accommodated in a direction parallel to the direction. The ejector plate 23 can be switched between a take-out position close to the guide block 20 side and a forming standby position close to the movable die plate 18 as shown by a driving unit (not shown).

The die set on the movable side in this embodiment is
The movable die 16, the guide block 20, the spacer block 19, the movable die plate 18, the ejector pins 22, the ejector plate 23, the hexagon socket head bolt 21, and the like are provided. And molding cavity 1
When taking out the resin filled in 7, the whole is moved away from the fixed-side die set with the separation plane PL as a boundary, and then the ejector plate 23 is moved to the take-out position.
The molding resin is removed from the movable mold 16 by projecting the ejector pins 22 into the molding cavity 17.

Usually, the die plates 12, 18 and the guide block 20 are made of a special steel or the like, and the hexagon socket head bolts 15, 21 are made of carbon steel. The block 19 is made of pure copper or a copper alloy such as brass or phosphor bronze having a larger linear expansion coefficient than the die plates 12, 18, the guide block 20, and the hexagon socket head bolts 15, 21, and the like.

Therefore, during the injection molding, the molten resin is supplied from the sprue 13 of the stationary mold 14 into the molding cavity 17 and the mold temperature gradually increases. The expansion amount is larger than that of other members such as the die plates 12 and 18 and the hexagon socket head bolts 15 and 21.
A tensile stress acts on 5, 21 to exert its loosening preventing effect. However, when the temperature of the mold is lowered to room temperature, the tightening force of the hexagon socket head bolts 15 and 21 returns to the state at the time of assembling the mold. Does not occur.

In the above embodiment, the spacer block 1
Although 9 is made of copper or copper alloy, a locking plate made of the same material may be incorporated in the movable die set. FIG. 2 shows such a second embodiment of the present invention. Elements having the same functions as those of the previous embodiment are denoted by the same reference numerals, and overlapping descriptions are omitted. That is, between the spacer block 19 and the guide block 20, a locking plate 24 made of copper or a copper alloy of the same material as that of the fixed mold plate is interposed. And the ejector pin 22 has penetrated.

The locking plate 24 is a hexagon socket head bolt 21
Movable die plate 18, spacer block 1
9, the guide block 20, and the movable side mold member 16 are integrally connected to form a part of the movable side die set. In addition, the spacer block 19 in the present embodiment includes the die plates 12 and 18 and the guide block 20 and the movable mold 1.
6. It is made of special steel of the same material as the hexagon socket head bolts 15 and 21.

Therefore, as in the previous embodiment, during injection molding, the molten resin is supplied from the sprue 13 of the stationary mold 14 into the molding cavity 17, and the mold temperature gradually increases. As a result of the thermal expansion of the mold member 14 and the locking plate 24 being larger than that of other members such as the die plates 12 and 18 and the hexagon socket head bolts 15 and 21, tensile stress acts on the hexagon socket head bolts 15 and 21. The loosening effect is exhibited.

[0030]

According to the mold of the present invention, a spacer block or a locking plate made of a material having a larger linear expansion coefficient is interposed between the die plate and the mold, and these are bolted. Because they are integrally connected, the temperature of the mold rises during processing and the tightening force of the bolts can be increased, and the bolt locking effect can be reliably obtained without considering the installation space. It is possible.

As a result, the dimensional accuracy of the processed product can be stabilized, and trouble during processing can be prevented. Moreover, the die set can be easily disassembled, the time required for maintenance can be shortened, and the die can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a schematic structure of a first embodiment in which a mold according to the present invention is applied to a resin molding mold.

FIG. 2 is a sectional view showing a schematic structure of a second embodiment in which the mold according to the present invention is applied to a resin molding mold.

FIG. 3 is a cross-sectional view illustrating a schematic structure of an example of a conventional mold that is an object of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Locating ring 12 Fixed die plate 13 Sprue 14 Fixed mold 15 Hexagonal bolt 16 Movable mold 17 Molding cavity 18 Movable die plate 19 Spacer block 20 Guide block 21 Hexagonal bolt 22 Ejector pin 23 Ejector plate 24 Loose Stop plate PL separation surface

Claims (7)

[Claims] 1. A mold having a die set in which a die plate and a mold material are integrally connected to each other by bolts with a spacer block interposed therebetween, wherein the spacer block is larger than the die plate and the mold material. A mold formed of a material having a coefficient of linear expansion. 2. The mold according to claim 1, wherein the spacer block is made of copper or a copper alloy. 3. A mold having a die set in which a die plate and a mold member are integrally connected to each other by bolts, wherein a locking member formed of a material having a larger linear expansion coefficient than the die plate and the mold material. A mold, wherein a plate is interposed between the die plate and the mold. 4. The mold according to claim 3, wherein the locking plate is made of copper or a copper alloy. 5. A mold having a die set in which a die plate and a mold material are integrally connected to each other by bolts, wherein the mold material is formed of a material having a larger linear expansion coefficient than the die plate. A mold. 6. The mold according to claim 5, wherein said mold material is copper or a copper alloy. 7. The mold according to claim 1, wherein the mold is a resin molding mold.