JPS5935770B2 - Hard-anodized aluminum alloy injection mold for synthetic resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Objective of the Invention) The present invention is aimed at high-mix, low-volume production or prototyping, and is intended to facilitate and speed up processing, reduce weight for ease of handling (and improve heat dissipation for quick cycle shots). This invention relates to an injection mold for synthetic resin made of an aluminum alloy coated with hard alumite for the purpose of improving work efficiency through chemical conversion, durability to withstand a considerable number of shots, and improvement in product quality through rapid cooling.

(Prior art) Conventionally, injection molds for synthetic resins were made of steel, which was suitable for mass production, but they were difficult to process, required a lot of time to manufacture, and the cost of the mold was extremely high. Not only was it expensive, but it was also heavy and inconvenient to handle.

Therefore, molds that do not require a large number of shots, such as high-mix low-volume production or prototyping, are not only costly, but also require many days to produce molds for prototyping, which requires rapid production. Not only did it take a lot of water, but it was also heavy, making it inconvenient and unsafe to handle.

In addition, with steel molds, once the mold gets heated, it takes a long time to cool down, so it is necessary to wait until the temperature of the mold drops to an appropriate temperature for injection, which is extremely inefficient.

Furthermore, since cooling is slow, the quality of products made from crystalline resins has deteriorated.

There are also products made of light alloy casting, with titanium, tantalum, or other molded products fixed to the cavity surface, and the entire body is anodized for rust prevention using conventional methods. Molding and installation of difficult materials is extremely troublesome, processing costs are high, and anodizing is merely for rust prevention purposes.

Furthermore, cast light alloys have the drawbacks of a rough surface, poor flow of molten metal, and only low-quality products.

(Structure of the Invention) In view of the above-mentioned disadvantages, the present invention has a cavity, a gate through hole, and a flow opening carved into an aluminum alloy plate, and the surface of the portion through which the injection material passes is designed to prevent abrasion and to form a mold. In order to improve efficiency and product quality by rapid cooling, hard alumite processing is applied, and the product has sufficient durability for high-mix, low-volume production or trial production.The present invention will be explained with reference to drawings of examples.

(Structure of the Invention) To explain the present invention with reference to figures of embodiments, in Figs. 3 are vertically combined on the mating plane XX.

To explain in more detail, the upper fixing part 2 conforms to the Japanese Industrial Standards J
High strength aluminum alloy plate specified in S-A-7075P and JIS-A-2017P or Japanese Industrial Standard J
A fixed mold 5 made of an aluminum alloy plate is placed on the lower surface of the fixed mounting plate 4 made of an aluminum alloy plate of a roll plate made of a corrosion-resistant aluminum alloy plate specified in IS-A-606IP, at the center of the upper surface of the fixed mounting plate 4. Tighten together with the rocket ring 6 (pol) 7,7.・・・・・・・・・・・・
...and 8,8.・・・・・・・・・・・・
A flow port 11 for a bowl-shaped molded material M is connected to the upper surface of the fixed mounting plate 4, collinearly with the guide hole 10 having the tapered guide surface 9 of the rocket ring 6. The through hole 12 has a downwardly expanding taper of approximately 2°.
is drilled through the lower fixed mold 5, and an upper half 13' of a water reservoir 13 (described later) is carved in the lower part of the through hole on the lower surface of the fixed mold 5, and at multiple locations on the fixed mold 5, a The guide bush 16 into which the threaded portion 15 of the guide pin 14 is slidably fitted is inserted before assembly, and set pins 21, 21, .・・・・・・・・・・・・
..., and fix the position accurately, and drill cooling holes 22 and 22 vertically and horizontally through which cooling water passes horizontally inside the fixed mold 5, and at both ends of the cooling holes 22 and 22. Nipple 23.2
Screw on 3.

Also, before assembling this fixing part 2, the flow port 11,
Portions 17', 18', and 19' that will become the upper surfaces of the through hole 12, the inner surface of the upper half 13' of the water reservoir 13, and the later-described gauges N7 and 18 and cavities 19 and 200.

2σ is coated with hard aluminium (approximately 20 micron thick hard aluminium) H, which will be detailed later.

On the other hand, to explain the movable part 3 in detail, the above-mentioned Japanese Industrial Standard JI
High strength aluminum alloy plate specified in S-A-7075P and JIS-A-2017P or Japanese Industrial Standard J
Made of corrosion-resistant aluminum alloy plate specified in IS-A-606IP.

A lower half 13'' corresponding to the upper half 13' of the water reservoir 13 and the cavity 19.20 are carved on the upper surface of the movable mold 24 made of an aluminum alloy plate.
, 20 and the lower half 13 of the pool 13) 17, 1
The lower half 13 of this pool 13 - the gates 17, 18 and the cavities 19, 200 are made of hard aluminium (about 200 microns thick, described later).
□' A movable back plate 25 made of an aluminum alloy plate is placed on the lower surface of this movable mold 24, spacers 26 and 26 made of an aluminum alloy plate are placed on the lower surface of the movable back plate 25, and aluminum alloy plate is placed on the lower surface of the movable back plate 25. The movable mounting plates 28 made of alloy plates and having an ejector through hole 27 in the center are stacked one on top of the other, and the movable back plate 25, spacers 26, 26, and movable mounting plate 28 are connected with a plurality of tightening bolts 29, 29.・・・・・・・・・
. . . and the spacers 26, 2 are fastened collinearly.
6, two upper and lower ejector plates 3L32, also made of aluminum alloy plates, are fastened with tightening bolts 33, 33°. This ejector plate is provided so that it can freely slide up and down.
．． The extrusion pin 3 is clamped at the base by 32 and planted upward.
4, 35, and 36 are provided vertically and slidably through the movable back plate 25 and the movable mold 24 from below, and these extrusion pins 3
4°35.36 upper ends 34', 35',
36' are exposed on the lower surface of the lower half portion 13' of the water reservoir 13' and the cavity 20, respectively. of the guide pins 14, 14. . . . The upper end fitting portions is, is, . . . . . . . . . . . . . . . . 16.・・・
・・・・・・・・・It is designed to fit in and out of the song,
A plurality of glue tampins 37.37. A spring insertion hole 38 with a concave bend concentrically formed in the movable back plate 25 and the spacer 26
, 38, coil spring press-fitted inside 39° 39,...
The coil springs 39 , 39 , .・・・・・・・・・
While the fixed part 2 is rising due to the elastic force of..., the movable mold 24 is elastically supported, and inside the movable mold 24, cooling holes 22 and 22 with nipples 23 provided at both ends are provided vertically and horizontally. to be drilled in

The movable part 3 is small (the material of the uppermost movable die 24 is the above-mentioned high-strength aluminum alloy plate or corrosion-resistant aluminum alloy plate, but the light alloy plates of other parts do not necessarily conform to this standard).

Next, the processing conditions for hard aluminium) H will be described in detail using examples. No masking agent is required as appropriate except for the flow port 11, through hole 12, pool 13, gates 17, 18, and cavity 19.200 inner surface. Apply or adhere to the area to mask it, and then perform alumite processing under the following conditions.

(1) In the case of constant current using direct current, current density: 2 amperes/1 dm' Electrolyte: 11% sulfuric acid Temperature: 5 to 0°C Time: Approximately 60 minutes (under sufficient stirring) (2) In the case of AC/DC superposition method, current density: DC 1.2 ampere/1 drrl: AC 13
Volt electrolyte 15% sulfuric acid Temperature: Approximately 10°C Time: Approximately 80 minutes In both cases, the hardness is 400° or higher, but the AC/DC superposition method has better adhesion and sinterability than the constant current method.

(Function of the Invention) To explain the function of the present invention with reference to drawings of embodiments, in FIGS. 1 to 4, when the injection molding machine operates the fixed part 2, the injection nozzle (not shown) of the injection part (path shown) (4) The fixing plate 4 is fixed to the upper part of the injection molding machine so that the tip of the injection nozzle is in close contact with the flow port 11.

Furthermore, the movable portion 3 firmly fixes the movable mounting plate 28 to the bed (path shown) of the injection molding machine.

At this time, the ejector (path shown) of the injection molding machine is inserted into the ejector passage hole 27 of the movable mounting plate 28 so that the tip of the ejector comes into contact with the ejector plate 32 below.

At this time, the movable die 24 is moved to the movable back plate 25 by the coil spring 39.
It is elastically supported upwardly away from the base.

Cooling holes 22, 22. provided vertically and horizontally inside the fixed mold 15 and the movable mold 24. Each nipple 23, 23.・・・・・・・・・・・・
When the fixed mold 5 and the movable mold 24 of the mold 1 are cooled from inside by connecting a cooling water hose (shown in the diagram) to ,3
3. All except the guide pin 14, guide bush 16, set pin 21, return pin 37, and coil spring 39 are made of light alloy, so the thermal conductivity is 4 to 5 times greater than that of steel. (Therefore, the cooling effect is extremely good.

Next, the injection molding machine operates, the fixed part 2 descends, and the movable part 3
Guide pin 14゜14,・・・・・・・・・・・・
The fitting portions 15, 15.・・・・・・・・・・・・・・・
. . , the guide bushings 16, 16 of the fixed part 2.・・・・・・
The lower surface of the fixed mold 5 is in contact with the upper surface of the movable mold 24, and the movable mold 24 is floating against the elastic force of the coil spring 39. The fixed mold 5 and the movable mold 24 are brought into close contact with each other, and the cavities 19 and 20 carved on the upper surface of the movable mold 24 and the connected games 17 and 18, respectively, form the hot water pool 13. It communicates with a through hole 12 having a flow port 11 at its upper part.

At this time, the heated molding material M is powerfully injected from the injection nozzle of the injection molding machine described above, and is
Once the liquid passes through the molten metal and enters the pool 13, it fills the cavities 19 and 20 through the gates 11 and 18, respectively, and the injection ends.

Since mold 1 is sufficiently cooled by cooling water, mold 1
At the same time as the injected molding material M is cooled, the injected molding material M is also rapidly cooled, so when the molding material M is a crystalline resin such as nylon, propylene, styrene, etc., the quality of the molded product becomes strong.

Since the cooling is fast, the fixed part 2 immediately rises and the movable mold 24
is elastically floated from the movable back plate 25 by the coil spring 39, and the ejector (path shown) of the injection molding machine is activated to push up the lower ejector plate 32 through the ejector through hole 27, and the ejector plate 3
L32 moves upward through the cavity 30 surrounded by the spacers 26, 26, is guided by the tamper pin 37, and rises to the ejector pins 34, 35, 3 held by the ejector plates 31, 32.
6 also rises, and the upper ends 34', 35', and 36' of these extrusion pins 34, 35, and 36 push up the lower surfaces of the lower half of the pool 13'', the cavities 19, and the cavities 20, respectively, so that the product and the hot water are Reservoir 13, through hole 12
, the solidified portion of the flow port 11 is simultaneously pushed up and released from the mold.

When the ejector (path shown) is retracted, the ejector pin 34.35
, 36 are guided by the return pin 37 together with the ejector plates 31 and 32 to be lowered and restored.

Since the mold 1 is rapidly cooled, the next shot is immediately performed without waiting for a while for the mold to cool as in the conventional method.

Flow port 11, through hole 12, pool 13, gate 17.1B
The parts of the inner surfaces of the cavities 19 and 20 that are in direct contact with the heated molding material M are covered with a hard alumite coating of approximately 200 microns thick and having a hardness of 400° (Witzkaas) or higher, making it resistant to the wear of light alloys. It has enough durability to compensate for its weaknesses.

According to the thermal conductivity of steel 0.25 J/cm-S -K aluminum thermal conductivity 2.38 J/crrL-8-, aluminum alloy molds have 4 to 5 times better heat dissipation than steel molds. .

(Effects of the Invention) The present invention is characterized in that an injection mold for synthetic resin is engraved on a roll plate made of aluminum alloy, and surfaces such as flow openings, through holes, pools, gates, cavities, etc. that come into direct contact with the flow of the molding material are overlapped in a vertical direction. The adhesiveness and flexibility is approximately 200 microns thick with a hardness of 400° or more (Witzkaas) by the method, or the hard alumite processing with high hardness is performed by the constant current method, so it is 4. ~5 times better heat dissipation, so there is almost no need to wait for the mold to cool down (combined with good mold release, it has the effect of improving productivity by making it possible to perform shots quickly and continuously) (Also, since the injected molding material is rapidly cooled, the quality of products made from crystalline resins such as nylon, propylene, and styrene is significantly improved.)

Furthermore, since the mold material is an aluminum alloy plate,
The mold is easy to process, quick, and has low processing costs. Moreover, the hard alumite processing is applied to the inner surface, which improves wear resistance. It is suitable for prototype production or small-lot production of a wide variety of products, even though the quantity is not huge. It is the most suitable for the needs of molds that require quick production.

In addition, since the mold is made of lightweight aluminum alloy, the weight of the mold as a whole is light (not only is it extremely convenient to handle and transport, but it is also highly effective in terms of safety).

Next, experimental results according to examples of the present invention will be listed.

Machine used in the example Manufactured by Sumitomo Electric Industries, Ltd. Model NEOMAT 150/75A Clamping force 75 tons Injection cylinder output 14.3) Machine number Ml 681040-11 Date of manufacture September 1970 ISO screw example 1 Duracon M2O- 02 Made by Polyplastic Co., Ltd. / I61-13 Mold clamping force 5 tons AI4-23 Mold clamping force 33 tons 424-28 // 35) Injection pressure
380 kg/crA Resin temperature 65℃ Result: Cavity Good example 2 PBT Juramex #3300 (30% glass
Contains) A1-10 Mold clamping force 33 tons A11-18 Mold clamping force 33 tons Injection pressure 380 kg/cni Resin temperature 240°C Result: Cavity Good example 3 ABS Part 1 (acrylic, rubber, styrene) JSK Japan Synthetic Rubber Co., Ltd. /16.1~20 Mold clamping force 33 tons Injection pressure 380kg/crA Resin temperature 220℃ Injection time 5 seconds Cooling time 8 seconds Result: Cavity Good ABS Part 2 A21~40 Mold clamping force 45 tons Injection pressure 390kg/crA Result: Especially the capacity is good (other conditions are same as part 1)

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view including the cavity of a mold embodying the present invention, FIG. 2 is a vertical cross-sectional view taken in a direction perpendicular to FIG. 1, and FIG.
The figure is a view taken in the direction of arrow A in FIG. 1, and FIG. 4 is a view taken in the direction of arrow B in the same figure. (Explanation of symbols of main parts), 1...11. (Injection for synthetic resin made of aluminum ram alloy) Mold, 2...
...Fixed part, total...Movable part, 4,------
Fixed mounting plate, 5...Fixed type, 6...Rocket ring, 11...Flow port, 12...
...Through hole, 13...,..., Hot water pool, 14...
Guide pin, 17.18...Gate, 19゜2
0... Capity, 22... Cooling: f
L24...Movable type, 25...Movable back plate, 26...Spacer, 28...Movable mounting plate, 31, 32... ejector plate,
34, 35, 36... Extrusion pin, 31...
... Retan pin, 39... Coil spring, H river... Hard alumite.

Claims (1)

[Claims] 1 A fixed part consisting of a plurality of aluminum alloy plates made of high-strength aluminum alloy plates or corrosion-resistant aluminum alloy plates tightened with bolts, and a fixed part made of a plurality of aluminum alloy plates made of the above-mentioned material, the uppermost movable part being bolted together. A movable part formed by tightening is assembled so as to be freely separable via a guide bin, and a flow opening cut into the upper surface of the fixed mold and an upper half of the hot water reservoir cut into the lower surface of the fixed mold. A gate is cut between the lower half of the hot water pool cut into the upper surface of the movable mold and the cavity cut into the upper surface of the movable mold. Furthermore, the inner surfaces of these flow holes, through holes, sumps, gates, and cavities are coated with a wear-resistant hard alumite coating with a thickness of about 200 microns or less and a Witzkars hardness of about 400' using the AC/DC superimposition method or the DC constant current method. An injection mold for synthetic resin made of aluminum alloy with hard alumite.