JPH04162950A - Parts related to injection for die casting machine - Google Patents

Abstract

PURPOSE:To improve the durability of parts related to injection for die casting machine by machining part or a part in contact with molten metal made of titanium alloy after forging or pressurized-extrusion forming and executing quenching or surface treatment. CONSTITUTION:The sleeve 9 for injection in cold chamber type die casting machine, is manufactured by finishing with race-machining after heating a round bar of the titanium alloy composed of the titanium as the main component and aluminum, vanadium, molybdenum and iron at 850-900 deg.C and executing pressing with a hydraulic press to form this into cylindrical shape. Successively, the sleeve is heated at 850 deg.C and after quenching with water cooling, the developed heat strain is finished into the normal size with precise machining. Thereafter that, aging treatment, i.e., this is heated at 510 deg.C for 1hr and at 400 deg.C for 2 hr and after cooling, grinding to inside and outside diameters are executed with honing to obtain the sleeve 9 having excellent shock resistance, heat resistance and erosion resistance. Further, as for a plunger 11, too, the same effect is obtd.

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to injection-related parts for die-casting machines that have extremely excellent impact resistance, heat insulation properties, and corrosion resistance, and are ideal for casting nonferrous metal alloys such as aluminum, tin, and lead/copper alloys. be. (Conventional technology) In recent years, die casting technology that can cast large quantities of non-ferrous metals such as aluminum, zinc, tin, lead and brass alloys with high precision has become popular.
It has become an increasingly important production means in all fields such as automobiles, industrial machinery, and home appliances, and various developments have been made.Conventional die casting machine injection part parts Niha, JIS standard 5KD-11 or 5KD Cold or hot die steel such as -61 was used, but in recent years, by casting ceramic parts, ceramics have been placed in the parts that come into contact with the molten metal, or in parts such as sleeves and plungers. Also, cast ceramic parts came to be used.Then, patent application No. 1-1 was developed to improve productivity.
At present, parts such as sleeves and plungers are used, which are manufactured by casting a composite material made of vacuum sintering of titanium powder No. 03186 and ceramics. (Problems to be Solved by the Invention) The injection parts of the above-mentioned die casting machines, which have been developed in various ways, have required characteristics. The properties required for injection parts of die casting machines and their rationale will be listed and explained below. ■ Low thermal conductivity This is to minimize the temperature drop inside the sleeve and minimize the formation of a solidified layer, and the target is 175 of the iron-based material (currently used 5KD-61). . - Stable and not eroded against molten non-ferrous alloys For example, when molten aluminum is heated to around 700'C, a 10mm round bar of 5KD-61 will erode within 48 hours. - Nonferrous alloy molten metal does not explode. This is related to the previous item (■), but to prevent melting and explosion, plunger oil is blown into the ferrous sleeve more than necessary for cooling. . This is one of the major causes of impairing the cleanliness of molten metal. ■Excellent abrasion resistance at high temperatures The longevity of the sleeve is determined by its corrosion and abrasion resistance. ■Excellent hardness and strength In the case of tie casting, extremely high impact strength and wear resistance are required at high temperatures of around 700'C. ■Although normal cutting machining is possible.Although the required characteristics have been listed above, there is no injection section of a die-casting machine that can satisfy all of them, and there are problems as shown below. ■For injection parts using Tice steel, when die steel (SKD-61) is used for squeeze tie casting (low-speed casting), non-ferrous alloys tend to react easily with iron, so they come into contact with the molten metal of the die-casting machine. Significant erosion occurs in the areas where the metal is removed. For this reason, the lifespan is short and the injection parts need to be replaced frequently. 2. Regarding parts in which the surface of die steel is nitrided for the purpose of increasing hardness, improving wear resistance, and suppressing erosion loss, the thickness of the nitrided layer is several μm, for example. Even if parts of sliding parts such as sleeves and plungers are subjected to nitriding treatment, the nitride film is easily worn away and the bare metal is exposed immediately, so the effect of extending the life of the parts of the injection part is very small. Furthermore, die steel has high thermal conductivity, and when molten metal with a die casting temperature of 700'C is poured into a die steel sleeve, the temperature drops to around 600'C, resulting in large heat loss and unstable casting. 3. Regarding patent application No. 1-103186, in which ceramics and titanium alloy powder bed were sintered and cast inside the sleeve, the problems of melting and insulation were solved by patent application No. 1-103186, but when pouring molten metal, Thermal strain is large (good when casting at a low piston speed (0.5 m/sec or less), but in the case of general die casting it is 1.5 m/sec to 3.
, 5m1 second, galling occurs due to the inner wall of the sleeve and the piston, and the temperature is high and thermal strain increases and cracks occur, making it impossible to work at the initial stages of casting. Unless all of the problems detailed above are solved, the value of the production method will not be fully demonstrated, and not only the tie casting industry but also related industries are experiencing great inconveniences in terms of production and use. Means for Solving the Problems) The present invention aims to eliminate these inconveniences and provide injection-related parts for die-casting machines that solve the problems associated with conventional materials for the first time. In other words, the parts that come into contact with the molten metal and some of them are formed by forging or pressure extrusion of a titanium alloy mainly composed of titanium, aluminum, vanadium, molybdenum, and iron. The final finish is made using precision machining to create a finished product. (Function) When the finished product formed in this way is used, it has excellent corrosion resistance and heat insulation against molten nonferrous metals, and
It has particularly excellent impact resistance and heat distortion resistance, and has good elongation (10% or more) as well as the required hardness, and is free from breakage and has good workability. The characteristics of the parts according to the present invention and the conventional parts will be explained below using the data in Table 1.

[Table 1] As shown in the attached sheet, particularly important characteristics are extracted and explained in Table 1. ■ Thermal conductivity is 0,017 caQ/cms'c,
Compared to others, the temperature of the molten metal injected into the sleeve does not drop and there is little heat loss, and the casting temperature can be adjusted to 30°C to 50°C.
It is possible to lower the temperature. ■ The tensile strength is 140 K9/vtrt", which means that it will not break due to impact, which often occurs with ceramics and titanium sintered alloys, and because it is a forged product, it is especially important now that high-pressure, high-speed casting is progressing. ■ The elongation is 12.4 %, it is much better than ceramics and titanium sintered alloys and can be formed and forged without breakage, making it highly suitable for mass production. It was found that the present invention was far superior to conventional products, and the present invention was able to provide the necessary characteristics for injection-related parts for die-casting machines and solve all of the problems that existed. (Example) Embodiments of the present invention will be explained below with reference to drawings showing the main parts of a cold chamber type die casting machine. (4) is a movable stand, which is movably provided on the rail (2) in correspondence with the fixed stand (1). (5) is a guide culm, which is attached to the fixed stand (1). 1) and movable platform (4)
A movable mounting base (6) is movably connected to the movable base (4) by a link or the like. (7) is a fixed die, and (8) is a movable die, which are attached to a fixed base (1) and a movable mounting base (6), respectively. (9) is an appropriately sized cylindrical injection sleeve provided with an injection port (10), and is attached to a fixed die (7) with a fixed base (1).
) is installed inset. (11) is a plunger whose one end is fitted into the injection sleeve (9) and the other end is connected to a hydraulic cylinder (12) provided on the bed (3) so that it can slide. The injection sleeve (9) is mainly composed of titanium (9).
5% to 60%) of titanium alloy round bar material consisting of aluminum, vanadium, molybdenum, and iron at 850°C to
It is heated to 900°C and extruded using a 600Q ton hydraulic press to form a cylindrical shape, and then finished using a lathe to produce a sleeve. The molded and finished sleeve is then heated at 850'C for 2 hours and water cooled to remove the thermal distortion that occurs after quenching and is finished to regular dimensions through precision machining. After that, the aging treatment section was heated to 510°C for 1.0 hour or 400 hours.
The sleeve was heated for 2 hours at 'C, and after cooling, the inner and outer diameters were polished using a honing machine to obtain a finished sleeve for injection. It can be used in the same manner as conventional products. Here, the results of implementing the injection sleeve (9) of the embodiment of the present invention and the conventional product will be explained. 1. The injection sleeve (9) of the embodiment of the present invention is replaced with the conventional product 5.
Comparison with KD-6 Tosialon/TSC. The results are shown in Table-1. However, the characteristics are measured by the test shown below. (1) Hardness test Measurement of hardness using Rockwell C scale (2) Tensile test Measurement of tensile strength and elongation using Amsler tensile tester (3) Abrasion test Measurement of specific wear amount using Tenba type specific wear measurement tester Measurement (4) Melting test Perform comparative measurements (explosion bonding and melting damage) with a 16-meter round bar of test piece 5KD-61. Photos are attached as reference materials.

[Refer to Material-1] 6) Practical experiment lL'J125 or 250t cold chamber type die-casting machine with injection sleeve attached, aluminum alloy (ADC-12/ADC-6) temperature 650°C ~
100% car engine cover made from 700'C molten metal
00 shots, this result shows that the injection sleeve was not melted and therefore the causes of product defects were likely to be caused by factors other than melting, and the defective rate was 7.8% (approximately 11%) compared to the conventional monthly average of 36%.
5). 2. The injection sleeve (9) of the embodiment of the present invention was heated at a piston speed of 2 mm/sec to 3 m/sec and a molten water temperature of 650'C to 7
This figure shows the observation of melting damage, wear, and elongation when the injection sleeve was used at 00°C and the hardness of the injection sleeve was changed. The results are shown in Table-2.

[Table-2] As shown in the attached sheet, from the above results, hard 2HIIC52, HRC-5
A range of 6 is good. 3. Using the injection sleeve of the embodiment of the present invention, cast a bicycle crank using a cold chamber type die-casting machine at a piston speed of 0.14-0161/sec and aluminum material 4CH (JIS standard) at 720°C-760'C. The results show observations of melting damage, wear, and elongation when the hardness of the injection sleeve was changed. The results are shown in Table-3.

[Table 3] As shown in the attached sheet, from the above results, both wear and erosion are good in low speed die casting. 4. The conventional 5KD-61 material and the titanium alloy material of the present invention, which are round bars with a diameter of 16 m, are heated to a temperature of 740°C using the aluminum JCH material.
'C The melting state was observed when immersed in molten water. The results are shown in Appendix Material-1. Although the results of the study on the injection sleeve were explained in the examples, similar results were obtained for other injection-related parts such as the plunger, and the details are the same, so the explanation will be omitted. (Effects of the Invention) As described above, the present invention uses injection-related parts made of titanium alloy, thereby creating a 0.2 mm nitrided or oxidized film through surface treatment to protect the surface and particularly improve wear resistance and erosion resistance. things are possible. It also has excellent acid and alkali resistance properties, so even if it is left unused for a long time, there is no need to polish it every time before polishing. In addition, it has good abrasion resistance and erosion resistance in low-speed die casting, and in particular, when it comes to erosion, conventional 5KD-61 produces holes in 3 to 4 weeks, but the present invention takes more than 6 months ( It has at least 7 times the durability of conventional products. In addition, due to this erosion and wear, the defective rate of products reached an average of 36% per month in the conventional case, but with the present invention, the rate of defective products reached an average of 7% per month.
．． 8%, which not only improves workability but also improves product retention, reduces costs, increases productivity, and stabilizes die casting production in all fields including automobiles, home appliances, and other fields.
This invention has many features such as playing a revolutionary role in automation and labor saving, and is an extremely excellent invention for industrial use.

[Brief explanation of the drawing]

The figures show embodiments of the present invention; Fig. 1 is a schematic front view of a cold chamber type die casting machine using the present invention;
The figure is an enlarged sectional view of section A in FIG. 1. (1) Fixed base (2) Rule (3) Bed (4) Movable base (5) Guide rod (6) Movable mounting base (7) Fixed die (8) Movable die (9) Injection Sleeve (10) Inlet (11) Plunger (12) Hydraulic sill or more

Claims (2)

[Claims] (1) An injection-related part for a die-casting machine, characterized in that the part that comes into contact with molten metal and a part thereof are formed by processing after forging or pressure extrusion of a titanium alloy, and by quenching or surface treatment. (2) The injection-related parts for a die-casting machine according to claim 1, wherein the titanium alloy is composed of titanium as a main component and aluminum, vanadium, molybdenum, and iron.