JPH0441633A - Washer material - Google Patents

Abstract

PURPOSE:To obtain a washer material excellent in fatigue resistance and easy to manufacture by incorporating specified ratios of Mn and Ni into Cu. CONSTITUTION:A copper-base alloy contg., by weight, 10 to 35% manganese, 10 to 35% nickel and the balance copper is subjected to soln. treatment at 700 to 1000 deg.C, is thereafter subjected to plastic deformation into a prescribed shape by cold working and is thereafter subjected to age hardening treatment at 350 to 550 deg.C to obtain a washer material. In this way, the washer material having strength properties equal to or above those of beryllium bronze and an SUS material without using expensive and toxic beryllium can easily be manufactured at low cost.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a washer material used, for example, in a VTR rotary head, etc. The present invention relates to a washer material that has particularly excellent spring properties and fatigue resistance properties, and is easily manufactured. Regarding the washer material that can be used.

(Prior Art) In recent years, VTRs (Video Tape Recorders), which record and reproduce video and audio signals on magnetic tape, have been developed.
r) is widely used for commercial and home use. The frequency band of video signals is generally 0 to 4.5 MHz, which is 250 to 300 times wider than that of audio signals, and the video head is rotated to read signals recorded on magnetic tape at high speed. or has been adopted.

FIG. 1 is a cross-sectional view showing the configuration of the main parts of a rotating head drum of a VTR. The rotating head drum 1 includes a head disk 3 rotatably mounted on a rotating shaft 2, and The attached lower fixed cylinder 4,
A washer 5 is interposed between the head disk 3 and the lower fixed cylinder 4, and a video head 6 is mounted on the lower surface of the head disk 3. The washer 5 prevents direct contact between the head disk 3 and the lower fixed cylinder 4 even when the head disk 3 rotates, and also maintains a certain minute gap so that the two do not come closer than necessary and damage the video head 6. (Provided to hold.

Conventionally, the above-mentioned washers were generally made of 5O3304* or beryllium copper (Be-Cu alloy), etc., after rolling.
It is manufactured by punching it into a hollow disk shape using a mold press and then plastically deforming it into a wavy shape that undulates in the circumferential direction as shown in FIG.

(Problem to be solved by the invention) However, the washer made of 5US304 has a low spring limit value, and when attached to the rotating head drum of a VTR, it will sag and the friction between the head disk and washer will increase, making it difficult for the head disk to rotate smoothly. There is a drawback that you will not be able to obtain

Furthermore, 5US304 has a drawback of low workability due to its extremely high hardness. In particular, when punching a rolled material into an annular shape using a press machine, the mold is easily damaged. Therefore, it is necessary to frequently re-polish or replace the mold, which increases the manufacturing cost of the washer and reduces manufacturing efficiency.

On the other hand, when beryllium copper is used as a raw material, it has good workability due to its low hardness, but beryllium is rare and expensive, and the manufacturing process generates beryllium oxide, etc. that are toxic to the human body. However, the manufacturing equipment for beryllium copper alloy including the anti-toxic equipment becomes complicated, the process control becomes complicated, and the manufacturing cost rises.

The present invention was made to solve the above problems, and provides a washer material that is inexpensive, does not contain Be, has spring properties equal to or higher than conventional washer materials, and can be easily manufactured. The purpose is to provide

[Structure of the invention]

(Means and effects for solving the problem) In order to achieve the above object, the inventors of the present application prepared alloy materials with various compositions, tried various processing methods, and determined the characteristics of the washer materials obtained. When the values were measured, the weight percentages were 10-35% manganese and 10-35% nickel.
% and the remainder is copper, compared to conventional SUS
Spring limit value (K
A washer material having excellent strength properties such as b) and Young's modulus (E) and excellent workability was obtained. In particular, in addition to manganese and nickel in the above composition range, chromium is
Add oi~8% or add 0.01% zirconium
The washer material formed by adding up to 5% had better strength characteristics, and particularly exhibited excellent durability when used as a washer material for a VTR rotary head.

The present invention was completed based on the above findings.

The reasons for limiting the composition of the washer material according to the present invention will be described below.

Manganese (Mn) is an element necessary to ensure spring strength such as toughness and tensile strength, and if its content is less than 10%, spring strength equivalent to that of conventional beryllium copper cannot be obtained. Moreover, if the Mn content exceeds 35%, the elongation elasticity decreases, and if a displacement exceeding the spring limit value is applied to the washer material, it becomes easy to break and permanent deformation increases. Therefore, the Mn content should be 10 to 35%. The range is set to . Note that it is preferably 12 to 20%.

Nickel (Ni) is an element necessary to form a compound with manganese and precipitate into the alloy matrix to increase toughness, increase the modulus of longitudinal elasticity (E), and improve the spring strength.
If the content is less than 10%, sufficient spring strength will not be obtained, and if it exceeds 35%, the elongation rate will decrease, and if the washer material is displaced beyond the spring limit value, it may break. The N1 content is 1.
It is adjusted in the range of 0 to 35%. Preferably 12~
20% is good.

By limiting it to this range, as with Mn, the permanent strain due to displacement exceeding the spring limit value is reduced, and it is possible to obtain a spring material equivalent to or better than beryllium copper.

Further, by adding chromium (Cr) and/or zirconium (Zr) to the copper alloy to which manganese and nickel have been added, a more preferable alloy can be obtained. These elements precipitate in the copper alloy matrix, improve the strength of the member through precipitation hardening, and increase corrosion resistance. By adding chromium in combination with zirconium, it forms an intermetallic compound, which has the effect of dramatically improving the spring characteristics. If the chromium content is too small, less than 0.01%, it is difficult to ensure spring strength due to precipitation hardening.
On the other hand, if it exceeds 8%, the washer material tends to break due to decreased elongation. Therefore, the content of chromium is 0.0
It is set in the range of 1 to 8%. In addition, if the content is high, the amount of precipitation tends to increase during the manufacturing process, so
Desirably, it is 0.1 to 5%.

Zirconium (Zr) also forms precipitates in the base material to harden the member, and also forms an intermetallic compound with chromium to improve spring characteristics. If the content of Zr is too small (less than 0.01), precipitates sufficient to ensure spring strength will not be formed, and although the elongation is large, the spring limit value will be low.
The function of the spring cannot be fully demonstrated. On the other hand, zirconium (
When the content of Zr) exceeds 5%, although the desired spring strength is sufficiently ensured, hot processing becomes difficult. Therefore, the Zr content is set in the range of 0.0L to 5%. Note that in order to obtain the optimum amount of precipitation, it is preferably adjusted to 0.1 to 2%.

As described above, nichrome (Cr) and zirconium (z+) are elements that precipitate in the alloy matrix and improve the spring strength and fatigue strength through precipitation hardening. A similar effect can be obtained when only one of these elements is added, but when both elements are used in combination in appropriate amounts, the spring limit value is significantly improved. Note that by reducing the contents of Ni, Mn, and Cr and relatively increasing the amount of Zr added, toughness can be increased and a washer material with better fatigue strength can be obtained.

The washer material according to the present invention is obtained by solution treatment of a copper-based alloy having the above composition at a temperature of 700 to 1000°C, cold working to plastically deform it into a predetermined shape, and then at a temperature of 350 to 550°C. Manufactured through age hardening treatment. Solution treatment is a treatment to homogenize the alloy components, further improve formability, and impart uniform spring strength in the subsequent age hardening treatment, and a treatment temperature of at least 700°C or higher is required, and preferably A temperature of 800°C or higher is good.

However, even if the temperature is set higher, the effect is only a slight increase, and it tends to cause coarsening of crystal grains, so generally 1
The temperature is set at 000°C or less, preferably 850°C.
~950°C is good.

Next is cold working, which has a great effect on the formability when manufacturing the washer material according to the present invention.

Therefore, the cold working ratio must be at least 5%, preferably 10% or more, but excessive cold working will increase the hardness of the washer material and may damage the press mold during molding. Since cracks are likely to occur in the bent portion, it is practically set to 80% or less, preferably 70% or less.

Next, in the age hardening treatment, the supersaturated solid solution obtained by the solution treatment is heated and hardened by precipitating intermetallic compounds of chromium and zircolumn, which gives the washer material spring strength. Heat treatment, 350
It is necessary to process at a temperature of 'C or higher. but,
At temperatures exceeding 550°C, a decrease in hardness is observed, so the treatment temperature is set in the range of 350°C to 550°C, but industrially preferred is 380°C to 500°C, and more preferably 380°C to 500°C. The appropriate temperature is 430°C to 480°C.

According to the washer material of the present invention, beryllium copper alloy and S
A spring material having strength characteristics equal to or higher than that of US alloy can be provided at a low cost.

In particular, the copper-based alloy constituting the washer material is an alloy that exhibits age hardening properties, and has low hardness in the processing and forming stage before heat treatment. Therefore, operations for cold working and plastic working into a predetermined shape are extremely easy, and damage to the mold, especially during mold forming, is greatly reduced.

On the other hand, after aging heat treatment, Vickers hardness (Hv)
The hardness is about 400 to 450, which is the same as that of conventional materials, and the spring limit value is high, so the set-off is small. For example, when installed on a VTR rotating head drum, the head drum will remain Smooth rotation can be guaranteed.

The washer material according to the present invention is not limited to VTR rotary head drums, but can also be applied to various other uses, and has excellent effects.

(Examples) Next, the characteristics of the washer material according to the present invention will be explained with reference to the following examples.

That is, as Examples 1 to 11, copper-based alloys having the compositions shown in the left column of Table 1 were processed according to the manufacturing method shown in the middle column of Table 1, respectively, to a thickness of 0.25 mm.
A test piece with a width of 10 days and a length of 100 m+ was prepared, and its mechanical properties such as spring limit value (Kb), Young's modulus (E), and hardness (Hv) were measured. The hardness (Hv) is 50 for the test piece.
It was determined as Vickers hardness when a load of 0 g was applied.

On the other hand, as Comparative Examples 1 to 3, the characteristic values of conventional material 5US304, a commercially available Be-Cu alloy, and an alloy outside the composition range were also measured, and as shown in the lower column of Table 1, the washer according to the present invention Comparisons were made with the property values of the material.

Margin below C] As is clear from the results shown in Table 1, according to the washer material of the present invention, the conventional 5US304° commercially available Be-
Almost the same Vickers hardness as Cu alloy can be obtained, and the spring limit value (Kb) and Young's modulus (E)
It is confirmed that it exhibits superior spring properties equivalent to or better in terms of strength characteristics.

In addition, because the Vickers hardness of the washer material before age hardening is smaller than that of conventional materials, it is extremely easy to plastically process it into a predetermined shape, and there is less damage to the mold during mold forming. It has become possible to significantly extend the life of the mold.

Furthermore, when the washer shown in FIG. 2 was prepared using the washer material according to the example and was mounted on a VTR rotating head drum, no settling occurred for a long period of time, and the connection between the lower fixed cylinder and the head disk was improved. The gap was kept constant and smooth rotation of the head disk was obtained.

〔Effect of the invention〕

As explained above, according to the present invention, a washer material having strength characteristics equal to or higher than beryllium copper alloy or SUS material can be easily manufactured at low cost without using expensive and toxic beryllium.

In particular, since the hardness before age hardening is low, it is easy to plastically process it into a predetermined shape, and it also has great effects in the manufacturing process, such as being able to extend the life of a molding die to a greater extent than before.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the main parts of a VTR rotating head drum.
FIG. 2 is a perspective view showing the shape of the washer. 1... Rotating head drum, 2... Rotating shaft, 3...
Head disk, 4...lower fixed cylinder, 5...
Washer, 6...video head.

Claims (1)

[Scope of Claims] 1. A washer material containing 10 to 35% manganese and 10 to 35% nickel by weight, with the remainder being substantially copper. 2. A washer material containing 10 to 35% manganese, 10 to 35% nickel, and 0.01 to 8% chromium, with the balance being substantially copper. 3. Manganese 10-35%, nickel 10-35%, chromium 0.01-8%, zirconium 0 in weight percent
．． A washer material characterized in that it contains 01 to 5% of copper, and the remainder is substantially made of copper. 4. The washer material according to any one of claims 1 to 3, which is used in a VTR rotating head.