JPH0516259U - Mold - Google Patents

Abstract

(57) [Summary] [Purpose] Located in the dough flow end portion 6a of the cavity 6.
Parting surfaces 2 of the split molds 2 and 3 facing each other
1,31 due to the corrosive gas generated from the molding material
Prevents corrosion and premature burr leakage. [Structure] On each of the parting surfaces 21 and 31
By providing the corrosion-resistant plating layer 7, this parting surface 21, 31
To prevent corrosive gases from corroding. Again this
At least one of the parting surfaces 21 and 31 is cavite.
B-tapered split type with higher edge
When clamping the molds 2 and 3 in line contact with each other to increase the surface pressure.
Therefore, burr leakage occurs due to minute irregularities on the surface of the corrosion-resistant plating layer 7.
Prevent it from growing.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a molding die used for injection molding of chloroprene rubber or the like, which generates corrosive gas during molding.

[0002]

[Prior Art]

 Conventionally, as a type of molding die used for injection molding, as shown in FIG. 3, a cavity 6 is formed between a plurality of split dies 1 to 5 which are freely connected and separated, and a cavity 6 is formed in the cavity 6. In some cases, a product having a desired shape is formed by filling the dough.

By the way, in the production of such a molding die, in order to improve the flatness of the parting surface and prevent burr leakage, the parting surface is usually polished after the plating treatment of the mold. .. This is because when the mold is plated after polishing the parting surface, the thickness of the plating layer generally tends to increase at the corners and edges of the object to be plated, and variations in the thickness of the plating layer may occur. However, it is not possible to secure the plane accuracy of the parting surface. Therefore, in the conventional molding die, the inner wall of the cavity 6 is plated, but the plating layer is not formed on the parting surface under the present circumstances.

[0004]

[Problems to be solved by the device]

 However, according to the conventional molding die, when the molding dough is a material that generates corrosive gas during molding, such as chloroprene gum, the molding dough ejected into the cavity 6 is in the direction of the arrow in the figure. Since the gas generated from the dough converges toward the dough flow end portion 6a of the cavity 6 and passes between the parting surfaces 2a and 3a of the split molds 2 and 3 when flowing to There has been a problem that the parting surfaces 2a and 3a are corroded and burr leakage occurs at an early stage.

The present invention has been made in view of the above problems, and it is an object of the present invention that a parting surface of a cavity fluid end portion of a cavity is corrosive that is generated from a molding material during molding. This is to prevent early flash leakage due to gas corrosion.

[0006]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the mold according to the present invention is such that at least one of the parting surfaces facing each other of the split mold that forms the dough flow end portion of the cavity is made so that the edge on the cavity side becomes high. In addition to polishing in a tapered shape inclined at an angle, a hard corrosion-resistant plating layer is deposited on both parting surfaces.

[0007]

[Action]

 According to the mold of the present invention, when the molding material injected into the cavity flows in the direction of the arrow in the figure, the corrosive gas generated from this material causes the parting surface at the material flow end portion of the cavity to flow. Even if it passes, since it has a hard corrosion-resistant plating layer formed on this parting surface, it does not corrode. The corrosion-resistant plating layer is formed by polishing the parting surface into a taper shape and then plating the parting surface. Line contact is made at the side edge and the surface pressure is high, so burr leakage due to minute irregularities on the corrosion-resistant plating layer surface can be prevented.

[0008]

【Example】

 Next, the molding die of the present invention will be described with reference to an embodiment shown in FIGS. In the illustrated embodiment, the same reference numerals are used for the portions corresponding to the conventional structure of FIG. 3 described above, and the description thereof will be omitted.

That is, in this embodiment, among the parting surfaces 21 and 31 of the split dies 2 and 3 forming the dough flow end portion 6 a of the cavity 6, the parting surfaces on the split die 2 side are opposed to each other. 21 is formed in a taper shape inclined at a minute angle θ so that the edge 22 on the cavity 6 side becomes high, and the parting surface 31 on the split mold 3 side is formed in a flat shape, and A hard chromium plating layer 7 which is a hard corrosion-resistant plating layer is formed on the parting surfaces 21 and 31 continuously from the inner wall of the cavity 6.

In this embodiment, the hard chrome plating layer 7 on the parting surfaces 21, 31 is formed by polishing the parting surfaces 21, 31 and then plating the split molds 2, 3. It was done. For this reason, it is inevitable that minute irregularities are formed on the surface of the hard chrome plating layer 7 due to variations in the plating thickness, but the parting surface 21 is formed in a tapered shape inclined at an angle θ. Therefore, when the mold is clamped, the edge 22 is almost in line contact with the parting surface 31 and the contact surface pressure is large. Therefore, a gap due to minute unevenness of the hard chrome plating layer 7 is formed in the contact portion. It is possible to prevent burrs from leaking after being formed.

Here, if the taper angle θ of the parting surface 21 is too large, the strength at the time of mold clamping becomes weak, and conversely, if the taper angle θ is too small, a good line contact state at the time of mold clamping can be obtained. Considering this point, θ is most preferably set to 0 ° 5 '(± 3').

When the molding material is a material such as chloroprene rubber that generates a corrosive gas during molding, the molding material injected into the cavity 6 flows in the direction of the arrow in FIG. At this time, the gas generated from the dough is converged to the dough flow end portion 6a side of the cavity 6 and reaches between the parting surfaces 21 and 31. However, since the hard chrome plating layer 7 is applied to the parting surfaces 21 and 31, it is possible to prevent burrs from leaking between the parting surfaces 21 and 31 at an early stage due to corrosion and wear. The life can be greatly improved.

Although the parting surface 21 is tapered in the above embodiment, the same effect can be obtained by forming the parting surface 31 in a tapered shape. Further, the shape of the cavity 6 and the combined shape of the split molds 1 to 5 are not limited to the illustrated embodiment.

[0014]

[Effect of the device]

 According to the mold of the present invention, the corrosive gas generated from the molding material prevents the corrosion of the parting surface at the fluid end portion of the cavity by the hard corrosion-resistant plating layer, thus improving the mold life. it can. Further, since the parting surface of the material flow end portion is in line contact with the cavity side edge portion under high surface pressure during mold clamping, burr leakage due to minute irregularities on the corrosion-resistant plating layer surface can be prevented. Therefore, the labor of deburring work and mold repair is reduced, and the mold manufacturing cost is also reduced, so that it is possible to reduce the product cost, which is an excellent effect.

[Submission date] October 9, 1992

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006]

[Means for Solving the Problems]

To solve the above problems, the mold according to the present invention, the split mold located dough flow terminal portion of the cavity, a corrosion-resistant plating key layer provided in each of the parting surfaces facing each other, at least in the parting plane One is tapered so that the edge on the cavity side becomes higher .

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

[Action]

According to the mold of the present invention, when the molding material injected into the cavity flows in the cavity , the corrosive gas generated from this material passes through the parting surface of the cavity at the flow end of the material. However , since the corrosion-resistant plating layer is formed on this parting surface , this parting surface is not corroded . The corrosion-resistant plating layer is formed by processing the parting surface into a taper shape and then plating it.However, during mold clamping, the partitioning surface at the end of the cavity material flow is tapered due to the taper shape. Line contact is made at the edge of the and the surface pressure is high, so burr leakage due to minute irregularities on the corrosion-resistant plating layer surface can be prevented.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

That is, in this embodiment , the parting surfaces 21 and 31 of the split molds 2 and 3 located at the dough flow end portion 6 a of the cavity 6 are respectively continuous with the parting surfaces 21 and 31 facing each other from the inner wall of the cavity 6. Te are formed hard chrome plating key layer 7 is corrosion-resistant plating layer of rigid, and of the pair of parting surfaces 21 and 31, the parting surface 21 of the split mold 2 side, the cavity 6 side The edge portion 22 is formed in a tapered shape that is inclined at a minute angle θ so as to be high .

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

[0014]

[Effect of the device]

The present invention has the following effects. That is, a corrosion-resistant plating layer is provided on each of the parting surfaces of the split mold located at the end of the cavity material flow to prevent the parting surfaces from being corroded by the corrosive gas generated from the molding material. By doing so, it is possible to prevent early occurrence of burr leakage due to this corrosion . Also, when clamping a split at least one of the parting surface as cavitation I side of the edge portion becomes higher such tapering is linear contact with each other, in order to have so as to increase the surface pressure, corrosion-resistant plating layer can burrs leakage due fine unevenness of the surface is prevented.

[Brief description of drawings]

FIG. 1 is a schematic half sectional view showing an embodiment of a molding die of the present invention.

FIG. 2 is likewise an enlarged cross-sectional view of a main part.

FIG. 3 is a schematic half sectional view showing an example of a conventional molding die.

[Explanation of symbols]

 1, 2, 3, 4, 5 Split type 6 Cavity 6a Material flow end part 7 Corrosion resistant plating layer (hard chrome plating layer) 21, 31 Parting surface 22 Cavity side edge

[Procedure amendment]

[Submission date] October 9, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

Claims (1)

[Scope of utility model registration request] 1. At least one of the parting surfaces 21, 31 of the split molds 2, 3 forming the dough flow end portion 6a of the cavity 6 facing each other at a small angle so that the edge on the cavity 6 side becomes high. A molding die characterized in that it is polished in a taper shape inclined at θ and hard corrosion-resistant plating layer 7 is adhered to both parting surfaces 21 and 31.