JPH0525278B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a cylinder for a VTR, and more particularly to a cylinder for a videotape recorder that is cold-forged from aluminum or an aluminum alloy material. [Prior Art] Aluminum or aluminum alloys are widely used not only for cylinders for video tape recorders, but also for parts of home appliances, automobiles, communications devices, optical devices, etc., as well as for sashes, food cans, etc. due to their light weight and good appearance quality. It's being done. Many of these parts are manufactured using the highly productive forging process.
In particular, cold forging is becoming mainstream as it has great advantages in terms of economy, dimensional accuracy of parts, etc. In general, appearance of these molded products is important, so there are high requirements for dimensional accuracy, surface condition, gloss, etc., and high performance lubricants are required. Conventionally, in cold forging of aluminum or aluminum alloys, mineral oil is used as a base oil, and oiliness improvers such as fatty acids, fatty acid esters, and higher esters, and phosphate esters such as tricresyl phosphite and tridecyl phosphite are added to this oil. Lubricating oils containing extreme pressure agents or solid lubricants such as graphite and molybdenum disulfide are used. All of these lubricants are used for low-deformation rolling, wire drawing, etc., where the amount of deformation is small, but the cylinder, which is the core component of a video tape recorder,
It is an ultra-precision part with a complex shape. The shape of the cylinder is complex and the amount of plastic deformation is extremely large, so plastic deformation does not occur smoothly and uneven thickness and cracks are likely to occur. Even if plastic deformation occurs smoothly, the surface pressure and high temperature will be high on the machined surface, and if the lubricating oil does not have sufficient lubricity (friction coefficient), load capacity, and heat resistance, deformation will not occur smoothly and it will not be possible to form the specified dimensions. In many cases, not only the molded product cannot be obtained, but also a normal molded product cannot be obtained due to surface roughness, partial thickness, cracks, and seizures. For this reason, a warm forging method in which a mold and an aluminum material are heated and formed is widely adopted in order to make plastic deformation smoother, but a molded product of a predetermined size cannot be obtained. On the other hand, in order to form a cylinder by cold forging, the surface of the aluminum material is treated with a chemical conversion film using hydrogen fluoride, aluminum silicate, etc., and then the surface is coated with a lubricating agent that forms a metal soap film. There is a way to process it after that. The lubricant used in this case allows a normal molded product to be obtained without baking, surface roughness, partial thickness, cracks, etc. even when the processing degree is high or the processed product has a complicated shape. However, the surface of the molded product is covered with a dark gray film due to the above-mentioned lubricating agent, and this film is firmly attached, resulting in poor appearance quality and requiring mechanical cutting to obtain the luster unique to aluminum. is necessary. Furthermore, during processing, the lubricating agent that falls off remains and accumulates in the mold, reducing the dimensional accuracy of the molded product. Even if such a good molded product is obtained, the surface condition is poor and many parts are mechanically finished by cutting, which requires a great deal of labor and time, resulting in high production costs. Cold forging of aluminum or aluminum alloy materials reduces production costs, reduces material costs,
There is a growing need to reduce labor costs, and there is a growing desire to obtain molded products with high dimensional accuracy and good appearance quality, so that if possible, cutting and finishing by machining after forging can be omitted as much as possible. . [Problems to be Solved by the Invention] The above-mentioned conventional technologies each have their own advantages, but liquid lubricants are not suitable for processed products that undergo large plastic deformation such as cylinders for VTRs and are subject to the appearance of new surfaces and high heat of deformation. In this case, there are problems with dimensional accuracy, seizure resistance, surface roughness, and gloss. Also,
The chemical conversion film treatment + metal soap film treatment is a complicated treatment process and involves many incidental operations such as waste liquid treatment, requiring a great deal of labor and expense. Furthermore, the surface of the molded product becomes dark gray and does not have the luster characteristic of aluminum, so machining is required. The purpose of the present invention is to take advantage of the advantages of liquid lubricants,
There is no need for chemical conversion film treatment + metal soap film treatment, etc., and by simply supplying liquid lubricant to the aluminum or aluminum alloy material surface or mold surface using a known method, the number of cutting parts by machining can be significantly reduced. VTR made by cold forging
Our objective is to provide molded cylinders for [Means for Solving the Problem] In order to achieve the above object, the present invention includes the following:
When cold forging VTR cylinders, one or more organic phosphorus compounds selected from polyoxyalkylene alkyl ether phosphoric acid esters, alkyl pentaerythritol diphosphites, and phosphonic acid esters, and a lubricant A cylinder for a VTR, characterized in that the hydrophobic liquid lubricant is formed on the outer surface of the cylinder, using a hydrophobic liquid lubricant containing at least one kind selected from powdered organic compounds having the following: It is. The molded product of the VTR cylinder made by cold forging of the VTR cylinder made of aluminum or aluminum alloy material of the present invention is made of one or more selected from the following organic phosphorus compounds and a powdered organic compound with lubricant properties. Simply supplying a hydrophobic liquid lubricant containing one or more selected lubricants in a hydrophobic liquid to the surface of aluminum or aluminum alloy material or the machined surface of a mold using a known method such as brushing, spraying, or dipping. This prevents seizure during machining, greatly improves the appearance quality (especially gloss) and dimensional accuracy of the molded product surface of VTR cylinders, and greatly reduces the amount of cutting required during machining. This has the effect of reducing the cost of VTR cylinders by reducing material costs, cutting processes, and labor costs. As the organic phosphorus compound in the present invention, polyoxyethylene, polyoxypropylene or
These include polyoxyalkylene alkyl ether phosphoric acid, alkyl pentaerythritol diphosphite, and phosphonic acid ester, which are polyoxybutylene derivatives whose ends are phosphoric acid esterified. Specific examples of these organic phosphorus compounds include polyoxyethylene lauryl ether phosphate, polyoxyethylene tridecyl ether phosphate, polyoxyethylene nonyl phenyl ether phosphate, ditridecyl pentaerythritol diphosphite, and distearyl pentaerythritol diphosphite. , dinonylphenyl pentaerythritol diphosphite, dibutyl butylphosphonate, di(2-ethylhexyl)2-
Examples include ethylhexylphosphonate and 2-ethylhexylphosphonic acid monomer ethylhexyl ester. Powdered organic compounds with lubricant properties include lithium stearate with a particle size of 0.5 to 300 μm, lithium 12-hydroxystearate, metal soaps such as aluminum complex soap and lithium complex soap, polyurea, and sodium terephthalamate. non-soap, hexanamide, lauramide, stearamide, N-hydroxyethyl
Examples include synthetic waxes such as 12-hydroxystearamide and N,N'-hexamethylenebis12-hydroxystearamide. The hydrophobic liquid containing the above-mentioned organic phosphorus compound and lubricant powder organic compound additives is as follows:
Any material that can supply an organic phosphorus compound or a lubricating powdery organic compound to the friction surface may be used. Generally, mineral or synthetic oils can be used. As a synthetic oil,
Examples include α-olefin oil, mono- or diester oil, polyol ester oil, polybutene oil, polyalkylene glycol oil, fluorine oil, silicone oil, etc. The properties can be determined as appropriate depending on processing conditions and working conditions, but generally speaking The viscosity at 40° C. is preferably 5 mm ² /s (cSt) or more. The above organic phosphorus compound blended into the hydrophobic liquid,
The blending ratio and particle size of the lubricant powder organic compound may be arbitrarily selected depending on the processing rate, processing shape, processing temperature, etc., but the total amount of additives is usually 5 to 20% by weight. , and hydrophobic liquid 80-95% by weight
is preferred. If the amount of the organic phosphorus compound and lubricant powder organic compound blended in the present invention is extremely small, a sufficient lubricating film will not be formed on the friction surface.
It is not possible to obtain a molded product with good appearance quality and dimensional accuracy for VTR cylinders. Depending on the processing conditions, seizure may occur. Further, if the amount is too large, no further effect will be observed, so the above-mentioned blending ratio is preferable. The particle size of the lubricant varies depending on the processing conditions, but
Generally, as the particle size increases, the spread layer of the particles becomes thicker and the glossiness of the surface of the molded product decreases. When improving gloss, it is better to use small particles. The molded product of a cylinder for a VTR produced by cold forging of the present invention is produced by applying a hydrophobic liquid lubricant containing the above-mentioned additives to aluminum or aluminum to be cold forged by a known method such as brushing, spraying, or dipping. The purpose can be achieved by supplying it to the surface of the aluminum alloy material or the processed surface of the mold. [Example] An example of the present invention will be shown below, but the present invention is not limited to this example. Example 1 A hydrophobic liquid lubricant was added to hydrophobic liquid mineral oil with a viscosity of 10 mm ² /s (cSt) at 40°C, containing an organic phosphorus compound and a powdered organic compound in the proportions shown in Table 1. After coating the surface of the JIS standard A2218 aluminum alloy material in the shape shown in the figure using a spray method, it is inserted into a mold and cold forged to form 500 cylinders for video tape recorders in the shape shown in Figure 2. did. The surface condition (gloss), dimensional accuracy, and cutting amount of the molded product were measured. Among Experimental Examples 1 to 19 in Table 1, Experimental Examples 1 to 6 are examples in which a phosphorus compound or a powdered organic compound is used alone, and Experimental Examples 16 to 19 are examples in which a phosphorus compound or a powdered organic compound is used alone. This is an example using a phosphorus compound,
Examples of the present invention are Experimental Examples 7 to 15. The measurement results are shown in Table 2. In the example of the present invention, a lubricating film generated by the reaction of additives is formed on the surface after processing, and a normal molded product is obtained without seizure, and the surface condition (gloss) is mirror-like. The dimensional accuracy was also good. Additionally, the amount of cutting required by machining is extremely small. However, the hydrophobic liquid lubricant containing phosphite and phosphate ester had numerous streak-like scratches and was on the verge of seizing. Although the surface condition (gloss) of the molded product was somewhat good, there was some thickness, poor dimensional accuracy, and a large amount of cutting. Since the outer circumferential surface 1 of the cylinder is in contact with the magnetic tape, it needs to be finished to a mirror surface by cutting and polishing, but other parts 2, 3, 4, and 5 can be cut and polished if they are mirror-finished and have good dimensional accuracy. It can be used as is without forming a reaction film. Comparative example 1 Lubricating oil: Mineral oil Comparative example 2 Lubricant film composition (chemical conversion film treatment) Aluminum fluoride film + metal soap (main component: sodium stearate)

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〔Effect of the invention〕

From the above results, when cold forging cylinders for VTRs, if the liquid lubricant of the present invention is used for cold forging, the surface quality and dimensional accuracy are extremely good, and cutting work can be reduced. Furthermore, it has a great effect on reducing cutting and production costs such as material costs and labor costs.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of an aluminum material for cold forging, and Figure 2 is a cross-sectional view of the aluminum material formed by cold forging.
FIG. 3 is a sectional view of a VTR cylinder.

Claims (1)

[Claims] 1. When cold forging a VTR cylinder, one or more organic phosphorus compounds selected from polyoxyalkylene alkyl ether phosphoric acid ester, alkyl pentaerythritol diphosphite, and phosphonic acid ester, and a lubricant are used. 1. A cylinder for a VTR, characterized in that the hydrophobic liquid lubricant is formed on the outer surface of the cylinder, and the hydrophobic liquid lubricant is formed on the outer surface of the cylinder.