JP3187783B2 - Leaf spring for magnetic recording tape cassette, tape cassette provided with this leaf spring, and method of manufacturing leaf spring for magnetic recording tape cassette - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum alloy spring material suitable for electronic equipment such as a magnetic recording tape cassette and the like, in which the initial set and the deterioration of the spring force with the lapse of time are improved, and magnetic recording using this spring material. The present invention relates to a leaf spring for a tape cassette and a method for manufacturing the spring material.

[0002]

2. Description of the Related Art As shown in FIG. 1, stainless steel such as SUS304, which is non-magnetic and resistant to rust, is used as a material for a pair of reel springs 1 of a magnetic recording tape cassette. Have been. However, since stainless steel is heavy and expensive, it is desired that the leaf spring 2 be made of a light and inexpensive aluminum alloy spring material.

However, in a magnetic recording tape cassette, the temperature inside the deck rises to 40 to 70 ° C. during use.
With a normal aluminum alloy spring material such as 3003 alloy or 5182 alloy, there is a problem that the spring force deteriorates with time.

[0004] The increase in the use temperature is not limited to the magnetic recording tape cassette, but is a general tendency accompanying the reduction in size and weight of electronic devices.

[0005] With respect to the aging of the spring force due to the increase in the operating temperature, measures such as increasing the amount of solid solution elements of the aluminum alloy and finely dispersing precipitates have been taken. Sufficient effects have not been obtained.

The aluminum alloy spring material has a problem called "initial set" in which the spring is locally plastically deformed at a stage where the spring is pressed several times after the spring is formed, in addition to the deterioration of the spring force with time.

[0007] The initial settling can be improved by increasing the proof stress. However, in the case of the conventional material, when the proof stress is increased by cold working, the residual stress after spring forming increases, and the aging of the spring force deteriorates. However, there is a problem that the problem becomes worse.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aluminum alloy spring material in which the initial set and the deterioration with time of the spring force are improved.

Another object of the present invention is to provide a leaf spring for a magnetic recording tape cassette made of the above aluminum alloy spring material.

Another object of the present invention is to provide a magnetic recording tape cassette provided with the above-mentioned leaf spring for a magnetic recording tape cassette.

Still another object of the present invention is to provide a method for manufacturing the above aluminum alloy spring material.

[0012]

Means for Solving the Problems To achieve the above object, the present inventors dissolve the alloy element in a supersaturated solid solution, age-precipitate the alloy element by increasing the temperature during use, and apply a spring force. Of the method for suppressing the aging degradation of
They found that l-Mg-Cu-based or Al-Mg-Si-based precipitates are effective in preventing the deterioration of the spring force with time, and based on this finding, conducted research on spring materials of Al-Mg-Si-Cu-based alloys. Advanced.

As a result, it has been found that when the amount of Cu as an alloy element is increased, or when the proofing treatment is performed under predetermined conditions to increase the proof stress, the initial setting can be prevented without the aging of the spring force. Was. In addition, it has been found that when Mn is added to this alloy system, the deterioration of the spring force with the lapse of time at the initial stage is further improved.

Based on these findings, the present inventors have conducted intensive studies and as a result, have found that an aluminum alloy spring material having improved both initial set and deterioration with time of spring force, and a magnetic recording tape using this spring material The inventors succeeded in inventing a leaf spring for a cassette, a tape cassette provided with the leaf spring, and a method for manufacturing the spring material.

That is, according to the present invention, 0.3 to 1.8% by weight of Mg, 0.1 to 1.5% by weight of Si, 0.4 to 3.0 % by weight.
% Cu and 0.01 to 1.5% Mn by weight.
0.01 to 0.5% by weight of Cr,
01-0.2 wt% Zr, 0.01-0.2 wt% V, 0.01-0.2 wt% Sc, 0.001-0.
2% by weight of Ti, and 0.0001 to 0.05% by weight
An aluminum alloy spring material further comprising at least one member selected from the group consisting of B and comprising a balance of Al and inevitable impurities.

A chemical conversion coating, a resin coating, or both a chemical conversion coating and a resin coating may be formed on the surface of the aluminum alloy spring material of the present invention.

Further, according to the present invention, there is provided a leaf spring for a magnetic recording tape cassette comprising the above-mentioned aluminum alloy spring material.

Further, according to the present invention, there is provided a magnetic recording tape cassette comprising a pair of reels around which a magnetic recording tape is wound, and the above-described leaf spring attached to these reels.

Also, according to the present invention, 0.3 to 1.8 layers
% Of Mg, 0.1 to 1.5% by weight of Si, 0.4 to
3.0% by weight Cu and 0.01-1.5% by weight
Mn and 0.01 to 0.5% by weight of C
r, 0.01-0.2% by weight of Zr, 0.01-0.2
Wt% V, 0.01-0.2 wt% Sc, 0.00
1 to 0.2% by weight of Ti, and 0.0001 to 0.0
A solution treatment of an aluminum alloy plate comprising at least one selected from the group consisting of 5% by weight of B and comprising the balance of Al and unavoidable impurities at a temperature of 400 to 550 ° C .; Cooling the aluminum alloy plate to a temperature of 100 ° C. or less at a cooling rate of 100 ° C./min or more, and cold rolling the cooled aluminum alloy plate. Provided.

The method of manufacturing the above aluminum alloy spring material is as follows.
The method may further include a step of performing an aging treatment of heating at a temperature of ° C. for 1 hour or more and less than 10 hours.

In the method for manufacturing an aluminum alloy spring material according to the present invention, the cold rolling step is performed under the condition that the surface temperature of the rolled material after the cold rolling is 70 ° C. or higher, and the rolling after the cold rolling is performed. The method may further include a step of winding the material into a coil.

Further, the method for producing an aluminum alloy spring material of the present invention includes the steps of:
The method may further include a step of performing at least one of a resin coating treatment of baking at a temperature of 60 ° C. or less.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The aluminum alloy spring material of the present invention contains Mg, Si and Cu as essential elements. All these essential elements are precipitated by the temperature rise during use,
This has the effect of suppressing the deterioration with time of the spring force.

If the content of Mg is less than 0.3% by weight, the effect cannot be sufficiently obtained. If the content is more than 2.0% by weight, the strength becomes too high, so that the cold workability is lowered and the mass productivity is lowered. Getting worse. Therefore, the content of Mg is specified to be 0.3% by weight or more and less than 2.0% by weight. The content of Mg is preferably 0.6 to 1.8% by weight, and more preferably 0.8 to 1.
8% by weight.

If the content of Si is less than 0.1% by weight, the effect cannot be sufficiently obtained. If the content exceeds 1.5% by weight, the strength becomes too high, the cold workability is reduced, and the mass productivity is low. Getting worse. Therefore, the content of Si is defined as 0.1 to 1.5% by weight.

As described above, Cu is the most important alloying element, and if its content is less than 0.1% by weight, its effect cannot be sufficiently obtained. And mass productivity deteriorates. Therefore, the content of Cu is:
It is defined as 0.1 to 3.0% by weight. The content of Cu is preferably 0.4 to 2.0% by weight, and more preferably 0.4 to 1.2% by weight.

The aluminum alloy spring material of the present invention preferably contains Mn if necessary.

Mn increases proof stress to prevent initial set,
At this time, the spring force does not deteriorate with time. Its content is
If it is less than 0.01% by weight, the proof stress cannot be sufficiently improved, and it does not contribute to the improvement of initial set. On the other hand, if the content exceeds 1.5% by weight, giant crystals are formed and the fatigue properties deteriorate. Therefore, the content of Mn is 0.01 to 1.5% by weight.
Stipulated.

The aluminum alloy spring material of the present invention may further contain Cr, Zr, V, S
It is preferable to contain one or more of c, Ti, and B.

The selected elements Cr, Zr, V, Sc, T
Both i and B have the effect of making the recrystallized grains fine, and prevent rough skin when press-formed into a spring shape.

The content of these alloy elements is Cr 0.01
0.5 to 0.5% by weight, Zr 0.01 to 0.2% by weight, V0.
01 to 0.2% by weight, Sc 0.01 to 0.2% by weight, T
i 0.001 to 0.2% by weight, B 0.0001 to 0.0
It is defined as 5% by weight. The reason is that if each is less than the lower limit value, a sufficient refining effect cannot be obtained, and if each exceeds the upper limit value, corrosion resistance and workability deteriorate.

In the present invention, the 0.2% proof stress is 300
When the pressure is equal to or less than MPa, the initial set-up tends to be slightly increased. When the pressure is equal to or more than 450 MPa, the deterioration with time of the spring force tends to be slightly increased.
Desirably, it is less than Pa.

By forming a chemical conversion film, a resin film, or both a chemical conversion film and a resin film on the surface of the aluminum alloy spring material of the present invention described above, corrosion resistance,
And it is possible to improve press formability.

The chemical conversion film can be formed by chromate chromate treatment, phosphoric acid chromate treatment, or the like.

The resin film is a resin film of epoxy, acrylic, vinyl chloride, urethane or the like.

When forming both of the above-mentioned films, usually,
A resin film is formed on the chemical conversion film. By forming both films in such a manner, the corrosion resistance and press formability are further improved.

In the case of a chemical conversion film, a resin film, or an aluminum alloy spring material having both films formed on the surface, a volatile oil can be used as a lubricating oil at the time of press molding, and the lubricating oil washing step can be omitted. it can.

The thickness of the chemical conversion film, the resin film, or the film formed with both films is preferably 10 μm or less, because it is difficult for scum to be formed during press molding.

Next, a method for manufacturing the above-described aluminum alloy spring material of the present invention will be described.

In the method of the present invention, first, an aluminum alloy plate is subjected to a solution treatment. The aluminum alloy plate subjected to the solution treatment is any ingot or rolled plate having a predetermined alloy composition. That is, a DC cast ingot, a hot rolled plate of this ingot, a cold rolled plate of this hot rolled plate, a continuous cast rolled plate, a cold rolled plate of this continuous cast rolled plate, and the like.

According to the method of the present invention, the alloy element is supersaturated in the solution treatment step, and a part of the supersaturated solid solution element is
Precipitated by cooling at a predetermined cooling rate after solution treatment or by aging treatment under specified processing conditions, increasing proof stress, preventing initial set, and using remaining supersaturated solid solution elements To prevent the spring force from deteriorating with time.

In the method of the present invention, the reason for setting the solution treatment temperature to 400 to 550 ° C. is that if the solution treatment temperature is less than 400 ° C., the alloy element is not sufficiently dissolved in supersaturation,
If the temperature exceeds 550 ° C., the alloy plate is locally melted.

After the solution treatment, the temperature is lowered to a temperature of 100 ° C. or less.
The reason for performing rapid cooling at a cooling rate of 00 ° C./min or more is that if this condition is not satisfied, the amount of supersaturated solid solution will be insufficient, and deterioration with time of the spring force cannot be suppressed.

In the method of the present invention, the proof stress can be increased by cold working, but the proof stress can be further increased by aging treatment.

In the method of the present invention, the aging treatment is carried out at 80 to
The reason why it is preferable to perform heating by heating at a temperature of 180 ° C. for 1 hour to less than 10 hours is that even when the temperature is
Even if it is less than the time, it is difficult to sufficiently increase the proof stress, and even if the temperature exceeds 180 ° C., the supersaturation tends to decrease even if the time exceeds 10 hours, and the precipitation amount during use decreases,
This is because it is difficult to suppress deterioration with time of the spring force.

Prior to the aging treatment, it is more preferable to carry out natural aging at a temperature of 30 to 70 ° C. for 1 hour or more, since the aging treatment further improves the proof stress.

In the method of the present invention, it is possible to use a method in which a rolled material is wound around a coil at a temperature of 70 ° C. or higher by utilizing the heat generated during cold rolling, and then subjected to an aging treatment in the step of gradually cooling the coil.

The surface temperature of the rolled material at the time of coil winding is 70 ° C.
In order to achieve the above, the time between the cold rolling passes of a plurality of passes may be shortened or the rolling ratio of one pass may be increased. When performing cold rolling in a plurality of passes, high-temperature winding may be performed in only one pass.

The aluminum alloy spring material obtained by the method of the present invention described above is further subjected to a chemical conversion treatment or 26
At least one of the resin coating processes of baking at a temperature of 0 ° C. or lower can be performed.

The chemical conversion treatment includes chromate chromate treatment,
Phosphoric acid chromate treatment is applied.

The resin coating film treatment is performed by applying a resin paint such as an epoxy, acrylic, vinyl chloride, or urethane resin .

The reason why the baking temperature in the resin coating treatment is set to 260 ° C. or less is that if the temperature exceeds 260 ° C., the supersaturated solid solution amount of the alloy element decreases, and the deterioration with time of the spring force cannot be improved.

[0053]

The present invention will be described in more detail with reference to the following examples.

Example 1 An Al alloy (N) having a composition within the scope of the present invention shown in Table 1 below
o. a to e ) were sequentially melted, cast, homogenized, and hot rolled in a conventional manner to obtain a hot rolled plate having a thickness of 4 mm.
Next, the hot-rolled plate was cold-rolled in three passes to obtain a thickness of 1.
It was a 0 mm cold-rolled plate. Next, on this cold rolled plate,
Achieved temperature 500 ℃, 50 by continuous annealing furnace (CAL)
After reaching 0 ° C., solution treatment and quenching were performed at an average cooling rate of 800 ° C./min to 100 ° C.

Then, the thickness was reduced to 0.40 by two-pass cold rolling.
After holding the plate at 60 ° C. for 3 hours (natural aging), the plate was aged at 120 ° C. for 3 hours to form a spring.
As shown in, the rising height _{h 1} is 14mm of the plate spring 2
I got

Press molding was carried out using a lubricant having a viscosity of 15 cst, but press molding could be carried out without any problem.

Comparative Example 1 An alloy (No. 1) out of the composition range of the present invention shown in Table 1 below .
A leaf spring was manufactured in the same manner as in Example 1 except that f to j ) was used.

The leaf springs obtained in Example 1 and Comparative Example 1 were examined for tensile strength, 0.2% proof stress, elongation, initial set (spring rising height), and deterioration with time of spring force.

In the initial setting, a cycle of loading and unloading a weight of 1 kg for 5 seconds was repeated 10 times, and then the height of rise of the spring was determined and evaluated. When a weight of 1 kg is put on the spring, the spring is a flat plate having a rising height of 0 mm.

[0060] aging of the spring force, the spring force F ₁ when depressing the spring to a height of 2mm was measured, then placed a weight weighing 1kg in the spring and held at a temperature of 70 ° C. 14 days later, it measures the spring force F ₂ in the same manner as described above, P =
[(F ₁ −F ₂ ) / F ₁ ] × 100%
(Spring force reduction rate) was determined and evaluated. Spring force reduction rate is 20
%, It is considered impractical.

The results are shown in Table 2 below. As a reference example
Alloy No. f spring, 0.3 mm thick as conventional
mm SUS304 (alloy No. j) leaf spring is also described.

[0062]

[Table 1]

[0063]

[Table 2]

As is clear from Table 2 above, the sample No. of the present invention example. Nos. 1 to 5 are all excellent in mechanical properties, small in initial set (spring rising height) and time-dependent deterioration of spring force (spring force reduction rate).
It can be replaced with S304 spring material.

On the other hand, the sample No. 7 is S
Since i was not contained, the deterioration of the spring force with time was large. Sample No. Sample No. 8 has a low Mg content,
o. Since No. 9 did not contain Cu, the proof stress was low and the initial set was increased accordingly. Further, the deterioration of the spring force with time was large.

Example 2 Of the Al alloys in the composition range of the present invention shown in Table 1 above, alloy No. a is melted, cast, homogenized, and hot-rolled in order by a conventional method, and processed into a hot-rolled plate having a thickness of 4 mm.
This hot rolled sheet is subjected to a first cold rolling to have a thickness of 1.4, 1..
0 and 0.4 mm plate materials were subjected to solution treatment under various conditions, and the 1.4 and 1.0 mm thick plate materials were further subjected to the second process.
Cold rolling was performed to obtain a plate material having a thickness of 0.4 mm.

In the second cold rolling, the temperature after the rolling was set to 70 ° C. or higher, and the coil was wound. Further, some plate materials were subjected to natural aging treatment and aging treatment (the conditions of the present invention) or / and chemical conversion treatment and resin coating treatment.

Table 3 below shows the solution treatment conditions and the like.

Comparative Example 2 A spring material was manufactured in the same manner as in Example 2, except that the conditions for the solution treatment or the aging treatment were outside the conditions of the present invention. The solution treatment conditions are shown in Table 3 below.

Each of the 0.40 mm-thick spring materials manufactured according to Example 2 and Comparative Example 2 was kept at 60 ° C. for 3 hours, then aged at 120 ° C. for 3 hours, and then press-molded to obtain FIG. and height _{h 1} is 14m rising 3
m leaf spring 2.

For each of the obtained leaf springs, the tensile strength, 0.2% proof stress, elongation, initial set (spring rising height), and deterioration with time of spring force (spring reduction rate) were measured in Example 1.
The same method was used for the examination. The results are shown in Table 4 below.

[0072]

[Table 3]

[0073]

[Table 4]

As is clear from Table 4 above, the sample No. of the present invention example. All 11 to 16 have excellent mechanical properties,
In addition, the initial set (spring rising height) and the deterioration with time of the spring force (spring reduction rate) were small, and there was no practical problem. As a result, the spring material of the present invention can
It has been found that a spring material made of US304 can be used instead.

Further, it was demonstrated that good moldability was obtained even when volatile oil was used as the lubricating oil, and that the washing step could be omitted.

In particular, in Sample No. 14, since the proper aging treatment including the coil aging treatment was performed twice, the initial set was remarkably improved. In addition, the sample No. 15,16
Since cold rolling was not performed after the solution treatment, the proof stress was low and the initial set was slightly increased, but the deterioration with time of the spring force was extremely small.

On the other hand, the sample No. 17 is
Because the cooling rate after solution treatment was slow, the sample N
o. In No. 18, since the aging treatment temperature was high, the solid solution elements decreased in all cases, and the spring force was significantly deteriorated with time. Also,
Sample No. No. 17 had a large initial set because the yield strength was low.

[0078]

As described above, according to the present invention,
It is possible to obtain an aluminum alloy spring material in which the spring force is improved with time in the initial set. The aluminum alloy spring material is suitable for a leaf spring for preventing a spinning of a reel of a magnetic tape cassette, and the spring material of the present invention can be easily manufactured by using an ordinary method and defining the conditions. it can. Therefore, the present invention has an industrially significant effect.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a leaf spring for preventing a reel from spinning of a magnetic tape cassette;

FIGS. 2A and 2B are a plan view and a side view illustrating a leaf spring used in a magnetic tape cassette. FIGS.

FIG. 3 is a side view illustrating a leaf spring used in the magnetic tape cassette.

[Explanation of symbols]

 1. Reel 2. Anti-spin leaf spring

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI C22F 1/00 682 C22F 1/00 682 686 686A 691 691B 692 692A 692B 694 694B 1/057 1/057 C23C 22/56 C23C 22 / 56 (72) Inventor Koichi Suzuki 1-13-1, Nihonbashi, Chuo-ku, Tokyo TDK Corporation (72) Inventor Toshio Niizuma 1-13-1, Nihonbashi, Chuo-ku, Tokyo TDK Corporation (56) References JP-A-62-45915 (JP, A) JP-A-9-316584 (JP, A) JP-A-10-168536 (JP, A) JP-A-4-330683 (JP, A) −226839 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 23/00-23/50 C22C 21/00-21/18 C22F 1/04-1/057

Claims (6)

(57) [Claims] (1) 0.3 to 1.8% by weight of Mg, 0.1 to
It contains 1.5% by weight of Si, 0.4 to 3.0% by weight of Cu, and 0.01 to 1.5% by weight of Mn, and contains 0.01 to 0.5% by weight of Cr, 0%. .01-0.2
Wt% Zr, 0.01-0.2 wt% V, 0.01
~ 0.2 wt% Sc, 0.001-0.2 wt% T
i, and at least one selected from the group consisting of 0.0001 to 0.05% by weight of B, with the balance being Al
And a leaf spring for a magnetic recording tape cassette made of an aluminum alloy spring material containing unavoidable impurities. 2. The leaf spring for a magnetic recording tape cassette according to claim 1, wherein a chemical conversion film, a resin film, or both the chemical conversion film and the resin film are formed on the surface. 3. A magnetic recording tape cassette comprising: a pair of reels around which a magnetic recording tape is wound; and the leaf spring according to claim 1 attached to these reels. 4. The composition according to claim 1, wherein the Mg content is 0.3 to 1.8% by weight.
It contains 1.5% by weight of Si, 0.4 to 3.0% by weight of Cu, and 0.01 to 1.5% by weight of Mn, and contains 0.01 to 0.5% by weight of Cr, 0%. .01-0.2
Wt% Zr, 0.01-0.2 wt% V, 0.01
~ 0.2 wt% Sc, 0.001-0.2 wt% T
i, and at least one selected from the group consisting of 0.0001 to 0.05% by weight of B, with the balance being Al
And 4 aluminum alloy plates consisting of unavoidable impurities
A step of performing a solution treatment at a temperature of 00 to 550 ° C .;
A method for manufacturing a leaf spring for a magnetic recording tape cassette, comprising: a step of cooling to a temperature of 100 ° C. or less at a cooling rate of not less than / min; and a step of cold rolling the cooled aluminum alloy sheet. 5. The cold rolling step is performed under the condition that the surface temperature of the rolled material after the cold rolling is 70 ° C. or higher, and the rolled material after the cold rolling is wound into a coil shape. The method for manufacturing a leaf spring for a magnetic recording tape cassette according to claim 4, further comprising a step. 6. The method according to claim 4, further comprising a step of subjecting the rolled material after the cold rolling to at least one of a chemical conversion treatment and a resin coating treatment of baking at a temperature of 260 ° C. or less. A method for manufacturing a leaf spring for a magnetic recording tape cassette.