JPH0346150A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve wear resistance by forming a titanium layer and a titanium nitride layer to be respectively specified by an ion plating method for a rotary drum and a fixed drum. CONSTITUTION:Various magnetic heads 4 are provided and a rotary drum (upper drum) 1 to be rotated together with the magnetic heads 4 and a fixed drum (lower drum) 2 to be provided on the lower face of the upper drum 1 are provided. A helical lead 3 is formed in the lower drum 2 and regulates the traveling direction of a magnetic tape 16. The upper drum 1 and lower drum 2 are composed of aluminium alloy and on the surfaces of the upper drum 1 and lower drum 2, the titanium layers are formed with 0.1-0.3mm thick ness by the ion plating method. Further, on the surfaces of the titanium layers, the titanium nitride layers are formed with 0.5-0.7mm thickness by the ion plating method. The above mentioned titanium nitride layers are composed of Ti2N and TiN with a 75-95% composition ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording and reproducing device used in video tape recorders and the like.

[Conventional technology]

Generally, magnetic recording/reproducing devices are used in, for example, video tape recorders. As shown in FIG. 10, this magnetic recording/reproducing apparatus includes various magnetic heads 34 and a rotating drum (hereinafter referred to as upper drum 31) that rotates together with the magnetic head 34. Further, a fixed drum (hereinafter referred to as the lower drum 32) on which a helical lead 33 is formed is provided on the lower surface of the upper drum 31, and this helical lead 33 runs the magnetic tape 46 along the format. It is designed to allow

For example, in the case of the NTS'C system, the upper drum 31 needs to be accurately controlled at about 1.80 rpm during steady rotation. Further, the upper drum 31 and the lower drum 32 are required to have processing accuracy on the - (micrometer) level. In particular, this machining accuracy is high when the lower drum 3 has a complex shape such as a helical lead 33
2 has strict requirements.

Therefore, conventionally, the upper drum 31 and the lower drum 32 have
For example, A2218 or A60, whose base material is aluminum, which has low specific gravity and excellent machinability and other workability.
Aluminum alloys such as 61 are often used.

As a result, the upper drum 31 and the lower drum 32 made of aluminum alloy are lightweight, so their inertia is reduced, and their rotation can be easily controlled. Further, the upper drum 31 and the lower drum 32 are made of an aluminum alloy with excellent workability so that high processing accuracy can be obtained.

[Problem to be solved by the invention]

However, the conventional magnetic recording and reproducing apparatus described above has a problem in that the upper drum 31 and the lower drum 32 are more likely to wear out than other parts of the tape running system that constitute the magnetic recording and reproducing apparatus.

This is because aluminum alloy is used for the upper drum 31 and the lower drum 32, while the other parts, such as the slanted balls 35 and 36, the guide posts 38 and 39, the tension post 37, and the capstan shaft 40, are made of aluminum alloy. For example, 5US303 is used in consideration of wear due to sliding contact with the magnetic tape 46.
This is because stainless steel such as or 5US420 is used.

That is, the aluminum alloy used for the upper drum 31 and the lower drum 32 has a Vickers hardness that is about 1/4 that of stainless steel. Therefore, the upper drum 31 and the lower drum 32 are more likely to wear than other parts made of stainless steel. In particular, the lower drum 32 is
Since the helical lead 33 formed on the lower drum 32 regulates the running of the magnetic tape 46, wear progresses significantly.

For example, the upper drum 31 and the lower drum 32
As shown in FIG. 11(a), the helical lead 33 formed on the lower drum 32 when the magnetic tape 46 is in sliding contact with the magnetic tape 46 for 3,000 hours has an initial shape in the range of approximately 0 to +6 μm. As shown in Figure 11(b),
．． After 000 hours have elapsed, the value changes in the negative (-) direction of 0- or less over almost the entire surface.

As a result, the angle between the tape edge of the magnetic tape 46, whose running is regulated by the helical lead 33 shown in FIG. 10, and the rotational direction of the magnetic head 340, as shown in FIG. The angle θ1 between the tape edge 46a and the rotation direction of the magnetic head 34 is 3,00
After 0 hours have elapsed, the angle between the tape edge 46b of the magnetic tape 46 and the rotational direction of the magnetic head 34 changes to θ8.

The above angles θ and θ2 have a relationship such that angle θ2 is larger than angle θ1, and the tape pattern linearity based on the tape edges 46a and 46b of the magnetic tape 46 is plus (・+). It will change direction.

That is, at the time of sliding contact and 3. When comparing the above tape pattern linearity after 00 hours, the tape pattern linearity at the beginning of sliding contact is closer to the O-0° line, which is the ideal value of the format, as shown in Figures 1 and 2 (a). 4°0, which is relatively close to
However, as shown in Figure 12(b), the tape pattern linearity after 3,000 hours is within the range of 9.7n, which is largely shifted in the plus (+) direction. It has expanded to

As described above, the upper drum 31 and the lower drum 32 made of aluminum alloy shown in FIG. ing. Therefore, in the conventional magnetic recording and reproducing apparatus, it is difficult to maintain tape running compatibility between the upper drum 31 and the lower drum 32 over a long period of time. In addition, the wear of the upper drum 31 and the lower drum 32 is caused by the state of contact between the upper and lower drums 31 and 32 and the magnetic tape 46, and the state of contact between the magnetic tape 46 and other parts related to the running of the magnetic tape 46. This makes it difficult to maintain stable tape running.

Therefore, the present invention provides a magnetic recording and reproducing device that can maintain tape running compatibility and stable tape running over a long period of time by improving the wear resistance of the upper drum 31 and the lower drum 32. It is an object.

[Means to solve the problem]

In order to solve the above-mentioned problems, a magnetic recording and reproducing device according to the present invention includes a rotating drum made of an aluminum alloy that is provided with a magnetic head and rotates together with the magnetic head, and a rotating drum that is provided on the lower surface of the rotating drum and that records a magnetic tape. In a magnetic recording/reproducing device having a fixed drum made of an aluminum alloy on which helical leads are formed to regulate the running direction, the rotating drum and the fixed drum have a titanium layer of 0.1 to 0.
The titanium layer is formed with a layer thickness of 3μ, and the titanium layer also has T.
i, the titanium nitride layer containing N and TiN at a composition ratio of 75 to 95% is 0.5 to 0.7%; The titanium layer and the titanium nitride layer are formed by an ion plating method.

[For production]

According to the above configuration, the titanium layer formed on the rotating drum and the stationary drum is capable of adhering the titanium nitride layer formed on the titanium layer to the rotating drum and the stationary drum with sufficient strength. There is.

That is, when a titanium nitride layer is directly formed on the rotating drum and stationary drum, titanium, which is an evaporated positive ion atom accelerated by a negative potential, is deposited on the rotating drum and stationary drum in a nitrogen atmosphere, which is a reactive gas. It is formed.

At this time, the probability that the titanium will collide with nitrogen, which is a reactive gas, is extremely high, and the energy of collision with the rotating drum and fixed drum made of the aluminum alloy base material will be reduced. This reduction in collision energy is a main factor in reducing the adhesion between dissimilar metals between the aluminum alloy and titanium nitride of the rotating drum and the fixed drum.

However, when titanium is collided with titanium nitride, which is a similar metal, the above-mentioned decrease in collision energy does not have much effect on adhesion.

Therefore, in rotating drums and fixed drums made of aluminum alloy, firstly, a titanium layer is formed that reduces the drop in collision energy, so that the adhesion with the titanium layer is improved, and furthermore,
By forming a titanium nitride layer on this titanium layer, it is possible to increase the adhesion between the titanium nitride layer and the titanium nitride layer. Adhesion is determined when the thickness of the titanium layer is 0.
It is optimal when it is in the range of 1 to 0.34.

Next, the titanium nitride layer formed on the above titanium layer is
．． It is formed in a range of 5 to 0.7 μm.

This prevents deterioration of mechanical properties of the rotating drum and stationary drum made of Al-A alloy.

That is, the layer thickness of the titanium layer or titanium nitride layer formed on the rotating drum and the fixed drum is directly proportional to the coating time by ion plating. At this time, the temperature of the coating bath in which the titanium material is melted rises over time due to radiant heat to generate vaporized atoms of titanium.

Therefore, if the rotating drum and stationary drum are left in the coating tank for a long time, the film thickness will increase, but at the same time the temperature will also rise.

As a result, if the titanium nitride layer becomes thicker than 0.7 tna, the mechanical properties of the rotating drum and fixed drum made of aluminum alloy may deteriorate due to temperature rise. When it is formed in the range of 0.5 to O0'7J51, it is possible to form it with sufficiently high hardness while preventing a rise in temperature.

Further, the above titanium nitride layer has T i N z , T
Among iN2 and Tf, N, TiN and Ti, N are 7
It has a composition ratio of 5 to 95%.

That is, in each of the above titanium nitrides, the Vickers hardness of TiN is approximately 1.50011V, the Vickers hardness of TiN is approximately 2,000Hv, and the Vickers hardness of Ti and N is approximately 2.2001 (V). In order to form a surface with higher hardness, the composition ratio of the titanium nitride layer should be changed to Ti.
It is preferable to set it to N and ThN. However, the composition ratio of these titanium nitride layers is approximately determined by the nitrogen content, and it is extremely difficult to control this nitrogen content to form TiN and ThN in the composition generation process. There is.

Therefore, in the titanium nitride layer, TiN, Ti, and N are
It is formed so that the composition ratio is 95%, and even in this case, it is possible to obtain sufficiently high hardness.

Furthermore, since the titanium layer and the titanium nitride layer are formed by an ion plating method, there is no need to excessively heat the rotating drum or fixed drum. Therefore, the mechanical precision of the aluminum alloy used for the rotating and stationary drums remains unchanged.

In this way, in the rotating drum and fixed drum, the titanium layer and the titanium nitride layer are formed in this order using the ion plating method, making it possible to form each of the above layers with sufficiently high mechanical precision. It has become. Furthermore, the rotating drum and fixed drum on which the titanium layer and titanium nitride layer are formed can maintain tape running compatibility over a long period of time by preventing wear of the helical lead.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 9.

As shown in FIG. 1, the magnetic recording and reproducing apparatus according to this embodiment is provided with various magnetic heads 4, and includes a rotating drum (hereinafter referred to as upper drum 1) that rotates together with these magnetic heads 4, and It has a fixed drum (hereinafter referred to as the lower drum 2) provided on the lower surface of the upper drum 1.

The upper drum l has a number 10 (not shown) for controlling the tape tensigon. A plurality of approximately n air grooves are formed. This air groove is designed to send air between the upper drum 1 and the magnetic tape 16 as the upper drum 1 rotates, and to prevent the magnetic tape 16 and the upper drum l from coming into extreme contact with each other. It has become.

Thereby, the magnetic tape 16 is given a advancing force by the frictional force of the upper drum 1 and the lower drum 2 acting in the drum rotation direction due to the infiltration of air through the air grooves. Further, a helical lead 3 is formed on the lower drum 2, and this helical lead 3 is
The magnetic tape 16 is made to run along the format.

The upper drum 1 and the lower drum 2 are made of aluminum, which has a low specific gravity and excellent workability, for example.
77p alloys such as 221B and A6061 are used. Furthermore, on the surfaces of the upper drum 1 and lower drum 2 made of aluminum alloy, a titanium layer is formed in the range of 0.1 to 0.3 μm by ion plating, and furthermore, the surface of this titanium layer is nitrided. A titanium layer is formed by ion plating to have a thickness in the range of 0.5 to 0.7 μm.

The ion plating method involves generating a glow discharge in a vacuum tank with an inert gas present, and as it passes through this electric field, positively ionized evaporated atoms are accelerated to a base material to which a negative potential is applied. The collision energy forms a coating with excellent adhesion.

The above titanium nitride layer is composed of TiN, , TiN, and Ti
, N, with a composition ratio of TiN, Ti, and N ranging from 75 to 95%.

Thereby, the surfaces of the upper drum 1 and the lower drum 2 have sufficient hardness.

In addition, as shown in FIG. 2, in the upper drum 1 and the lower drum 2, inclined balls 5 and 6 made of stainless steel are movable in directions A and B on the entrance and exit sides of the magnetic tape 16. It is designed to be placed in

Furthermore, the supply reel 1 is connected to the supply reel 13 on which the magnetic tape 16 is wound from the above-mentioned inclined ball 5.
From the 3 side, there are a tension post 7 that supplies the magnetic tape 16 with a constant tension, a guide post 8 that changes the running direction of the magnetic tape 16, a full width erase head 11 that erases signals such as video signals during recording, and a magnetic A roller guide 18 for regulating the height of the tape 16 is arranged in this order.

On the other hand, a winding wheel 14 winds the magnetic tape 16 from an inclined ball 6 disposed on the delivery side of the upper and lower drums 2.
Until the magnetic tape 16 is reached from the inclined ball 6 side,
a roller guide 19 that regulates the height of the tape, audio heads 20 and 12 that erase and record audio signals, and a guide post 9 that regulates the running direction of the magnetic tape 16.
, a pinch roller 15 movable in the C direction, and a capstan shaft 10 that runs the magnetic tape 16 at a constant speed are arranged in this order.

In the above configuration, as shown in FIG. 1, first, the magnetic tape 16 was brought into sliding contact with the upper drum 1 and the lower drum 2, and changes in the shape of the helical lead 3 were examined. As a result, it was found that there was almost no change in the helical lead 3 between the time of sliding contact and the time after 3,000 hours had elapsed, as shown in FIGS. 3(a) and 3(b).

Next, let's look at the initial stage and 3. The tape pattern linearity was compared with that after 00 hours had elapsed. As a result, the linearity of the tape pattern at the beginning of sliding contact is 5.5 as shown in FIG. 4(a).
The linearity of the tape pattern after 3,000 hours is 6°5μm, as shown in Figure 4(b).
It became clear that the range was m. Therefore, the tape pattern linearity of the upper drum 1 and lower drum 2 on which the titanium nitride layer is formed is relatively close to the O-0' line, which is the ideal format value, even after 3,000 hours. found.

From this, in the upper drum 1 and the lower drum 2 on which the titanium nitride layer is formed, the Vickers hardness of titanium nitride is 2.00 Hv compared to about 150 Hv of aluminum alloy A2218.
It was confirmed that the wear resistance was extremely good as it was about 0 Hv.

Next, the surfaces of the upper drum 1 and lower drum 2 are A2218
An A2218 drum is defined as an A2218 drum, and a titanium nitride drum is defined as a titanium nitride drum formed with a titanium nitride layer. As shown in FIG. 2, the tape tension T1 on the drum population side and the tape tension T2 on the drum exit side are respectively Examined.

Ratio of the above tape tension Tl-72 (T2/T1)
are shown in Table 1. In addition, the angle θ between the drum center and the inclined balls 5 and 6 is 1.
The ratio (T2/Tl) was the average value of the values obtained by measuring three times.

As a result, it was found that there was no significant difference in tape tension ratio (T2/TI) between the A2218 drum and the titanium nitride drum, and the titanium nitride drum had a slightly lower value. .

Therefore, the magnetic tape 16 has a Vickers hardness of 2.00.
Even when the tape is in sliding contact with a titanium nitride drum that has a high hardness of about 0 Hv, there is no significant difference in the friction coefficient μ of the sliding contact area between the two drums, so the tape tension increases and the tape is likely to be damaged. do not have.

Next, the lower drum 2 is required to have ultra-precise precision, which is the strictest precision among drum precisions, since this affects tape running compatibility. Therefore, changes in the material hardness of the aluminum alloy part of the lower drum 2 and changes in dimensional accuracy of each part of the lower drum 2 were measured when the titanium layer and the titanium nitride layer were formed by the ion plating method. The measurement results are shown in FIGS. 5 and 6.

The above-mentioned parts of the lower drum 2 refer to the roundness of the upper housing 2a, the roundness of the lower housing 2b, and the flatness of the reference surface 2c, as shown in FIG. Moreover, ten samples (a) to (j) were used.

As a result, it was found that the material hardness of the aluminum alloy part hardly changes during the initial stage of formation and after the formation, as shown in FIG. Similarly, as shown in FIG. 6, the change in dimensional accuracy in each part of the lower drum 2 was found to be extremely small, with almost no change at the initial stage of formation and after the formation, with a measurement error.

From this, it is clear that the formation of the titanium layer and the titanium nitride layer does not cause changes in the material hardness or dimensional accuracy of the lower drum 2 to the extent that it would impede tape running.

Next, in order to compare with the case of the lower drum 2 in which the titanium layer and the titanium nitride layer are formed, the above-mentioned A2218
Changes in material hardness and dimensional accuracy were investigated when the drum and A1050H34 drum were left at high temperatures. The results are shown in FIGS. 8 and 9.

Furthermore, the storage temperature for the A2218 drum is 210°C.
, 230°C, 250°C, 280°C, and 310°C, and two samples (a) to (j) were prepared for each temperature. In addition, the standing time at each temperature above is
The time was set at 60 minutes, which is the same as the time required for formation by ion plating.

As a result, the material hardness after forming the A2218 drum is
As shown in FIG. 8, it has been found that the temperature decreases as the temperature increases. Similarly, the hardness after the above molding is
It was also found that the A1050H34 drum had decreased.

Furthermore, it has been found that the change in dimensional accuracy of the A221B drum increases as the temperature increases, as shown in FIG.

That is, for example, an A2218 drum may be heated to approximately 230°C for 60 minutes.
It has become clear that if the tape is left in the atmosphere, the hardness of the material will decrease and the mechanical accuracy of each part of the lower drum 2 will change to the extent that it will cause trouble to the tape running system. .

Therefore, if the mechanical properties such as material hardness or dimensional accuracy of the upper drum 1 and lower drum 2 change, even if the wear resistance is improved by a titanium nitride layer, etc., the VTR
If the mechanical accuracy, which is essential to the characteristics of the product, is disrupted, other problems will occur.

In this way, when forming a titanium nitride layer etc., it is necessary to take adhesion into consideration and to avoid changing the mechanical properties of the upper drum 1 and lower drum 2. When a titanium layer, etc. is formed, as shown in FIGS. 5 and 6, there is no change in the material hardness and dimensional accuracy, and this ion plating method allows a titanium nitride layer, etc. to be formed. In addition, the upper drum 1 and the lower drum 2 have improved abrasion resistance, and can maintain tape running compatibility and stable tape running over a long period of time.

〔Effect of the invention〕

As described above, the magnetic recording and reproducing apparatus according to the present invention includes a rotating drum made of an aluminum alloy that is provided with a magnetic head and rotates together with the magnetic head, and a rotating drum that is provided on the lower surface of the rotating drum and that controls the running direction of the magnetic tape. In a magnetic recording/reproducing device having a fixed drum made of an aluminum alloy on which regulating helical leads are formed, a titanium layer is formed on the rotating drum and the fixed drum with a layer thickness of 0.1 to 0.3 μm, and further , this titanium layer contains Ti, N and T.
A titanium nitride layer having a composition ratio of 75 to 95% iN is formed with a layer thickness of 0.5 to 0.7μ, and the titanium layer and the titanium nitride layer are formed by an ion plating method. This is a configuration where there is

As a result, the titanium layer and the titanium nitride layer are formed in this order on the rotating drum and fixed drum using the ion plating method, so there is no change in material hardness or dimensional accuracy, and the layer is highly adhesive and wear resistant. This has the effect of making it possible to improve tape running compatibility and maintaining stable tape running over a long period of time.

[Brief explanation of drawings]

1 to 9 show an embodiment of the present invention. FIG. 1 is a perspective view showing a state in which a magnetic tape is run on a magnetic recording/reproducing device. FIG. 2 is a plan view showing a state in which a magnetic tape is run on the magnetic recording/reproducing device. FIGS. 3(a) and 3(b) are graphs showing the shape of helical leads. FIGS. 4(a) and 4(b) are graphs showing tape pattern linearity. FIG. 5 is a graph showing changes in material hardness when forming a titanium layer and a titanium nitride layer on a fixed drum. FIG. 6 is a graph showing changes in dimensional accuracy when forming a titanium layer and a titanium nitride layer on a fixed drum. FIG. 7 is a longitudinal sectional view of the stationary drum. FIG. 8 is a graph showing changes in material hardness when the fixed drum is left at high temperatures. FIG. 9 is a graph showing changes in dimensional accuracy when the fixed drum is left at high temperatures. 10 to 13 show conventional examples. FIG. 10 is a perspective view showing a state in which a magnetic tape is run on a magnetic recording/reproducing device. FIGS. 11(a) and 11(b) are graphs showing the shape of helical leads. FIGS. 12(a) and 12(b) are graphs showing tape pattern linearity. FIG. 13 is an explanatory diagram showing the angle between the tape edge of the magnetic tape and the rotating direction of the magnetic head. 1 is an upper drum (rotating drum), 2 is a lower drum (fixed drum), 3 is a helical lead, 4 is a magnetic head, and 16 is a magnetic tape.

Claims (1)

[Claims] 1. A rotating drum made of aluminum alloy that is provided with a magnetic head and rotates together with the magnetic head, and a helical lead that is provided on the lower surface of this rotating drum and that regulates the running direction of the magnetic tape. In a magnetic recording/reproducing device having a fixed drum made of an aluminum alloy, the rotating drum and the fixed drum have a titanium layer of 0.50%.
A titanium nitride layer containing Ti_2N and TiN at a composition ratio of 75 to 95% is further formed on this titanium layer to a thickness of 0.5 to 0.7 μm. A magnetic recording/reproducing device characterized in that the titanium layer and the titanium nitride layer are formed by an ion plating method.