JPS6154063A - Method for processing surface of capstan - Google Patents

Abstract

PURPOSE:To improve the performance of a capstan by carrying out an electrolytic etching of a stainless-made capstan in an electrolytic liquid mixed with a depression liquid on the basis of nitric acid. CONSTITUTION:An electrolytic liquid 3 is based on nitric acid and a mixed liquid with chromic acid is used as a depression liquid. Aside from chormic acid, triethanol amine or urea is used as a depression liquid. Firstly, a stainless-made capstan 6 is set by a crip 7 as a cathod 5. Secondly, a current is flown from a power source in an electrolytic liquid mixed with a depression liquid on the basis of nitric for electrolytic etching on the peripheral surface of the capstan 6. After the electrolytic etching, the captan 6 is washed before drying. By such a method for surface processing, a constant and micro roughened surface is formed on the surface of the capstan to decrease a wow, flatter phenomenon, eliminate a flutter echo at a tape and make possible manufacturing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a capstan surface processing method that can process the surface of a capstan to a good roughness.

[Technical background of the invention and its problems] Capstans used in tape recorders are usually made of stainless steel. However, in order to run the tape in cooperation with the pinch roller, for example, as shown in FIG. Efforts are being made to reduce flags. At this time, if the rough surface a1 of the capstan a is roughened, the frictional force will increase, the wah flag will decrease, and the tape C will run, but the slip will cause the tape C to make an abnormal sound called squealing. 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 slip, and the wow flag 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 conventional surface finishing method described above, the capstan a
Since the degree of formation of rough surface Al on the circumferential surface of Tape C is large and the surface is too rough, the frictional force against Tape C increases and the tensile force increases, which reduces wow and flutter, but the reverse of Tape C At times, when the running direction of the tape C suddenly changes to the opposite state, the frictional force between the tape C and the capstan a sometimes causes the tape C to make an abnormal sound called squealing.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned points, and its purpose is to perform electrolytic etching on the surface of a stainless steel capstan in an electrolytic solution containing a nitric acid base and a suppressing solution. Since it forms an oxide film against the etching solution, it can form a uniform and finely roughened surface, thereby reducing the wow/flag phenomenon and eliminating the tape squeal phenomenon. An object of the present invention is to provide a capstan surface processing method that is inexpensive because it can perform a large amount of processing.

The basic feature of the present invention is that electrolytic etching is carried out by attaching a stainless steel capstan to the cathode in an electrolytic solution containing nitric acid as a base and mixed with an inhibitor for suppressing its oxidation action.

[Embodiments of the invention]

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

2 is a bathtub, and 3 is an electrolytic solution placed in the bathtub 2. This electrolytic solution 3 is based on nitric acid (HNO3), and also contains chromic acid (CrO] as an inhibitor agent).
Use a mixed solution with 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 Qcc of water is used. The inhibitory liquid may be, for example, a diluted solution of triethanolamine mixed in 1 to 10 g per 100 cc of water, or a diluted solution of urea of 0.5 to 1 g per 100 cc of water.
Use a diluted solution containing g.

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 a first step, a stainless steel plate, for example 5US-
Connect the capstan 6 of 420-J2 to the cathode 5 with the clip 7.
As a second step, a current is applied from a power source 8 in an electrolytic solution containing a nitric acid base mixed with a suppressing solution to perform electrolytic etching on the circumferential surface of the capstan 6, which is set as the cathode 5.

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

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

First, set and fix the capstan 6 formed using 5US-420-J2 on the cathode 4 in the bathtub 2 using the clip 7. Then, add nitric acid (HNO3) water with a concentration of 60% to a concentration of 25 to 35%. Chromic acid (CrO) with a concentration of 1 to 2 (g) added to 100 cc of water is mixed in an electrolytic solution at a ratio of 50:50, and processed from the power supply 8. By applying a constant current of 0.08 to 0.1 (A) to each capstan 6 for 5 to 6 seconds at the temperature of the electrolytic solution 3 of 25 to 35 ° C. Perform electrolytic etching. After that, remove the capstan 6 from the clip 7 and soak it in water in an aquarium.
Rinse with water for about 3 seconds, then use ultrasonic waves under running water to
Perform ultrasonic water washing for ~3 seconds.

The reason why the water washing work is divided into two steps is to ensure that the water washing work is carried out reliably and to wash out unnecessary impurities from the capstan 6.

The peripheral surface of the capstan 6 made of 5US-420-J2, which has been electrolytically etched by being set and fixed as the cathode 5 in an electrolytic solution based on nitric acid (HNO3), has a minute and uniform rough surface 6a. is formed, so the tape can be run at a constant speed by the cooperation between the capstan 6 and the pinch roller (rubber roller), reducing wow flags and causing the tape to suddenly change direction in the opposite direction, such as during reverse operation. In this case, the friction between the tape and the capstan 6 does not cause abnormal noise called squealing, and the fine and uniform rough surface 6a is formed on the circumferential surface of the capstan 6 by electrolytic etching. By setting and fixing the capstan 6 to be treated as a cathode 5, different from the anode 4, nitric acid (HNO) is used as an etching solution.
3), and by the action of chromic acid (CrO3) as a suppressing liquid mixed with this nitric acid (HNO3),
5O3-420-J2 An oxide film of iron (Fe), which constitutes most of the atoms, is formed on the surface of the capstan 6, so that nitric acid (HNO) as an electrolytic etching solution is
It is thought that the oxidation of 3) 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 (CrO3) is used as an inhibitor against nitric acid (HNO3), but in addition to chromic acid, triethanolamine added to 100 cc of water at a concentration of about 1 to Log and 100 cc of water are also used as inhibitors. 0 in water
．． A urea solution to which about 5 to 1 g is added 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〕

As described above, since the present invention performs electrolytic etching in an electrolytic solution mixed with a nitric acid-based inhibitor, an oxide film is formed on the surface of the stainless steel capstan to resist etching. As a result, a uniform and finely roughened surface is formed on the circumferential surface of the capstan by electrolytic etching using nitric acid as a base etching solution. Therefore, unlike the conventional capstan surface processing method that performs liquid honing after machining, the tape can be run at a constant speed in cooperation with a pinch roller, eliminating wow and flagging. The so-called tape squealing phenomenon can be eliminated, and since a large amount of processing can be done at once, it is inexpensive.

[Brief explanation of the drawing]

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... Apparatus, 2... Bathtub, 3... Electrolyte, 4...
・Anode, 5...Cathode, 6...Capstan, 6a・
...Rough surface, 7...Clip, 8...Power supply.

Claims (3)

[Claims] (1) A capstan surface processing method characterized by electrolytically etching a stainless steel capstan in an electrolytic solution containing a nitric acid-based electrolyte and a suppressing solution. (2) The capstan surface processing method according to claim 1, wherein the suppressing liquid is a chromic acid solution. (3) The method for surface processing captason according to claim 1, wherein the inhibitory liquid is triethanolamine or urea.