JPS61227200A - Surface working method of capstan - Google Patents

Abstract

PURPOSE:To produce a capstan having a good rough surface without discoloration and rust formation by etching electrolytically the capstan as an anode in an acidic soln. contg. an inhibiting liquid then neutralizing and washing the same with an alkaline soln. CONSTITUTION:The electrolyte 3 consisting of an aq. soln. of 25-35% HNO3 as a base and mixed with a diluting liquid dissolved with CrO3 or triethanol amine or urea as the inhibiting agent is put into a bath cell 2. An anode 4 and the stainless steel capstan 6 as the cathode is grasped by a clip 7 and is dipped thereon. electricity is conducted to the capstan 6 from a power source 8 to roughen 6a the surface by electrolytic etching. The electrolyte sticking thereto is neutralized by the alkaline aq. soln. dissolved with NaOH, etc. and after the capstan is thoroughly washed with water, the capstan is dried. The capstan having the good rough surface which does not discolor and rust is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for surface processing a capstan, which can prevent discoloration, rust, etc. on the surface of a capstan, and can process the capstan into a good rough surface.

[Technical background of the invention and its problems]

Capstans used in tape recorders pass through Usually made of stainless steel.

However, in order to run the tape in cooperation with the pinch roller, for example, as shown in Figure 1, a rough surface a1 is formed on the curved surface of the capstan a and the pinch roller C is run at a constant speed to avoid wow and flutter. Efforts are being made to reduce this. At this time, if the rough surface a of the capstan a is made rough, the frictional force will increase and wow and flutter will be reduced.
However, due to the slippage, an abnormal noise called squeal occurs in the tape C. On the other hand, if the degree of formation of the rough surface a1 of the capstan a is made sparse, the tape C will no longer run at a constant speed due to slippage, and wow and 7-tap will worsen.

By the way, the conventional surface processing method for capstan a is to roughen the surface by liquid honing after machining.

However, in the above conventional surface processing method, the degree of formation of the rough surface a on the circumferential surface of the capstan a is large, and the surface is too rough, resulting in an increase in frictional force on the tape C and an increase in tensile force. Wrinkles and flutter are reduced, but when the running direction of tape C suddenly changes to the opposite state, such as when tape C is reversed, the frictional force between tape C and capstan a causes abnormal noise called squealing in tape C. sometimes occurred.

In order to solve the above-mentioned drawbacks, the applicant of the present application electrolytically etched the capstan in an electrolytic solution containing nitric acid as a paste and a suppressing solution, thereby reducing the wow and rattling phenomenon and the tape squealing phenomenon. We are proposing an invention to eliminate this.

However, in the above invention, since the electrolyte is acidic,
Thorough cleaning was required, and a large amount of water was used for the cleaning.

Furthermore, if cleaning is insufficient, discoloration, rust, etc. may occur over time.

[Purpose of the invention]

The present invention has been developed to solve the above-mentioned drawbacks, and requires only a small amount of water for cleaning, and also forms a smooth surface with good surface resistance without causing discoloration or rust on the capstan. [Summary of the Invention] The surface processing method for a capstan of the present invention involves electrolytically etching a capstan in an acidic liquid, and then etching the capstan. It is characterized by washing (neutralizing) with an alkaline liquid.

[Embodiments of the invention]

The details of the present invention will be explained below along with the device 1 used according to Figure 2.

2 is a bathtub, and 3 is an electrolytic solution placed in the bathtub 2;
A mixed solution with s) is used.

The nitric acid used is, for example, a 60% solution diluted with water and a 25 to 35% solution. For example, a diluted solution containing about 1 to 2 g of chromic acid per 10 cc of water is used. As the suppressing liquid, for example, a diluted solution of triethanolamine mixed in 1 to 10 g per 100 cc of water or a diluted solution in which 0.5 to 1 g of urea is mixed in 100 cc of water is used.

4 is an anode, and 5 is a cathode provided with a clip 7 for setting and fixing a capstan 6 made of stainless steel to be processed. The anode 4 may be made of the same material as the capstan 6 to be treated, or may be made of lead (Pb). 8 is a power supply, and this power supply 8 is a constant current power supply.

First, as the first step, stainless steel, for example 5US-
Set the capstan 6 of 420-J 2 as the cathode 5 with the clip 7, and then: ? As a second step, an electric current is applied from a power source 8 in an electrolytic solution containing a nitric acid paste and a suppressing solution to perform electrolytic etching on the circumferential surface of the capstan 60 set as the cathode 5.

In the third step, the electrolytically etched capstan 6 is washed with an alkaline liquid, then washed with water, and dried.

Next, one embodiment of the present invention will be described.

First, the capstan 6 formed using 5US-420-J2 is set and fixed to the cathode 4 in the bathtub 2 using the clip 7 . Next, nitric acid (HNOs) with a concentration of 6 (liters) was diluted with water to a concentration of 25 to 35 liters, and then chromic acid (Cr Os) with a concentration of 1 to 2 g added to 100 cc of water was added to 50 liters of water. :1 in the electrolyte mixed in the ratio of 50 to the capstan 6 to be processed from the power supply 8.
True, 0.08~0. Electrolytic etching is carried out by applying a constant current of IA for 5 to 6 seconds at a temperature of the electrolytic solution 3' of 25 to 35°C. Thereafter, the capstan 6 is removed from the clip 7 and immersed in alkaline chemical soda liquid with a pH of about 9 to 10 to neutralize the nitric acid adhering to the capstan surface, and then soaked in water in a water tank for 2 to 3 hours. Rinse with water for about seconds, then perform ultrasonic water washing for 2 to 3 seconds using ultrasonic waves under running water. Alternatively, ultrasonic water washing alone may be sufficient after neutralization.

The circumferential surface of the capstan 6 made of 5US-420-52, which has been electrolytically etched by being set and fixed as a cathode 5 in an electrolytic solution using nitric acid (HNOs) as a paste, has a minute and uniform rough surface. 6a is formed, the tape can be run at a constant speed due to the cooperation between the capstan 6 and the pinch roller (rubber roller), reducing wow and black, and the running direction of the tape is suddenly reversed as in the case of reverse operation. In this case, even friction between the tape and the capstan 6 does not cause abnormal noise called squealing.

Further, the reason why a fine and uniform rough surface 6a is formed on the surface of the capstan 6 by electrolytic etching is that the capstan 6 to be treated is set and fixed as a cathode 5, unlike an anode 4. Nitric acid (HN) as a liquid
Oxidation of iron (Fe), which is the majority of the constituent atoms of 5US-420-J2, is suppressed by the action of chromic acid (CrOs) as an inhibitory liquid mixed with this nitric acid (HNOs). It is believed that by forming the film on the surface of the capstan 60, oxidation of nitric acid (HN Os ) as an electrolytic etching solution is suppressed, and the peripheral surface of the capstan 6 is etched uniformly and minutely. In this case, the degree of etching can be controlled by changing the energization time and current from the power source 8.

In the above example, chromic acid (Cro) is used as an inhibitor against nitric acid (HNOs).
A solution of about 0.5 to 1 g of triethanolamine added to 100 cc of water is also used. Moreover, in the above embodiment, the rough surface 6a of the capstan 6 is processed uniformly and minutely by cathode etching, but it goes without saying that the capstan 6 can be attached to the anode 4 and etched using the same electrolyte 3. Nor.

〔Effect of the invention〕

In the present invention, after electrolytic etching, the acidic electrolyte adhering to the surface of the capstan is neutralized in an alkaline liquid, so that subsequent cleaning can be performed with a small amount of water, and the water used for cleaning can be can be reduced. Even if the chemical soda solution adheres to the surface of the capstan, unlike an acidic electrolyte, it will not discolor or stain the surface of the capstan. Moreover, since the roughened surface is formed by electrolytic etching, a good product can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a conventional example in which a tape is run using a capstan and a pinch roller, and FIG. 2 is a perspective view showing an example of an apparatus used to carry out the present invention. 1... Device 2... Bathtub 3.
... Electrolyte 4 ... Anode 5 ...
... Cathode 6 ... Capstan 6a
... Rough surface 7 ... Clip 8.
...Power supply diagrams 1 and 2

Claims (1)

[Claims] A method for surface processing a capstan, which comprises electrolytically etching the capstan in an acidic liquid and then cleaning the capstan with an alkaline liquid.