JP2005134315A - Torque measuring instrument, and torque measuring method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brake torque measuring instrument of a magnetic tape drive unit capable of reducing dispersion in measured values, allowing precise measurement control, easy to be handled and capable of reducing a cost. <P>SOLUTION: This torque measuring instrument is provided with a pair of turning bodies 2A, 2B having inner wheels 2A1, 2B1 engaged with a reel and turnable therewith, and outer wheels 2A2, 2B2 engaged loosely with the inner wheels and turnable therewith, and a driving motor 3 for turning the outer wheels. In the torque measuring instrument, the inner wheels are connected to the outer wheels by an elastic member 4 deformed elastically along a turning direction, the turning bodies are constituted to generate a turning angle difference in response to brake torque between the inner wheels and the outer wheels, when the inner wheels are engaged with the reel and when the outer wheels are turned by the driving motor, and detecting means 2A4, 2B4, 2A2b, 2B2b are provided in the turning bodies to detect the turning angle difference. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a torque measuring device for measuring a brake torque of a reel in a magnetic tape drive device such as a video tape recorder (VTR) and a torque measuring method using the torque measuring device.

In a magnetic tape drive device such as a VTR using a tape cassette, it is necessary to apply an appropriate tension to the tape so that the tape is not damaged during the operation. This tension is applied to the reel by a so-called reel brake that applies a load in a predetermined rotation direction.
The brake torque applied by the reel brake is measured and managed at the time of manufacturing the VTR so as to be a value within a predetermined torque range.

Conventionally, as a method of measuring the brake torque, a method of manually using a torque gauge that engages with a reel and makes it rotatable, or as disclosed in Patent Document 1, a torque detector is moved up and down by a cylinder. A method using an automated torque inspection apparatus as possible is known.
JP-A-60-214233

  However, due to the recent increase in the speed of tape rewinding, the tape is more easily damaged, and it has been required to accurately set the brake torque value within a very narrow range with respect to the total number of VTRs.

  Therefore, in the manual method, there is a problem that measurement values vary greatly, accurate measurement management cannot be performed, the burden is too large to perform 100% inspection, and work efficiency is remarkably deteriorated.

  Moreover, the torque inspection apparatus as shown in Patent Document 1 is large and difficult to handle, and the cost of the apparatus itself is high.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a brake torque measuring instrument that is easy to handle and inexpensive, and a torque measuring method using the brake torque measuring instrument that is capable of highly accurate measurement management with small variations in measured values.

In order to solve the above problems, the present invention has the following configuration as means.
That is, the invention according to claim 1 is a torque measuring device for measuring the brake torque of each reel of a magnetic tape drive device having a pair of reels each having a supply side and a take-up side,
An outer ring (2A2, 2B2) that engages with the reel and can freely rotate with the inner ring (2A1, 2B1) and an inner ring (2A1, 2B1) that can rotate together with the reel. And a drive motor (3) for rotating the outer ring (2A2, 2B2), and a pair of rotating bodies (2A, 2B) having
The inner ring (2A1, 2B1) and the outer ring (2A2, 2B2) are connected by an elastic member (4) that is elastically deformed in the rotation direction, and the rotating body (2A, 2B) is connected to the inner ring (2A1). , 2B1) is engaged with the reel and the outer ring (2A2, 2B2) is rotated by the drive motor (3), the inner ring (2A1, 2B1) and the outer ring (2A2, 2B2) And a detection means (2A4, 2B4, 2A2b, 2B2b) for detecting the rotation angle difference is provided in the rotating body (2A, 2B). A torque measuring device (100) characterized by

Moreover, this invention has the following procedure as a means.
That is, the invention according to claim 2 is a torque measuring method using the torque measuring device (100) according to claim 1,
An aging process in which the outer ring (2A2, 2B2) is rotated at a first rotational speed by the drive motor (3), and the outer ring (2A2, 2B2) is moved by the drive motor (3) after the aging process. And a measuring step of rotating at a second rotational speed lower than the rotational speed of 1.

  According to the present invention, it is possible to make the torque measuring device extremely easy to handle and inexpensive, and it is possible to measure the brake torque of the reel with little variation and with high accuracy.

An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic plan view showing an embodiment of the torque measuring device of the present invention,
FIG. 2 is an exploded perspective view for explaining a main part of an embodiment of the torque measuring device of the present invention.
FIG. 3 is a perspective view for explaining torque measurement using an embodiment of the torque measuring device of the present invention.

  As shown in FIG. 3, the torque measuring device 100 of the present invention is used by being mounted so as to be engaged with a supply reel 50A and a take-up reel 50B in a mechanical deck 60 which is a magnetic tape drive device such as a VTR. Is.

1 and 3, the torque measuring device 100 includes a base 1, a supply side meter 2A, a winding side meter 2B, a drive motor 3, a switch 5, and a control circuit 8.
The base 1 is provided with a reference hole that is positioned with respect to the mechanical deck 60.
The supply-side meter 2A is a rotating body composed of an inner ring 2A1 that engages with the supply-side reel 50A and an outer ring 2A2 disposed on the outer side, and both the wheels 2A1 and 2A2 can rotate coaxially.
An elastic member 4 such as a spiral spring as shown in FIG. 2 is disposed between the inner ring 2A1 and the outer ring 2A2.
Bent portions 4a and 4b are formed at the tip of the elastic member 4, and the bent portions 4a and 4b are protrusions provided on the wheels 2A1 and 2A2 when rotating in the direction of arrow Ra in FIG. It is configured to engage with 2A1a and 2A2a.

  On the other hand, the take-up meter 2B is a rotating body having the same structure as the supply meter 2A, but the elastic member 4 is a protrusion provided on each of the inner rings 2B1 and 2B2 when rotating in the direction opposite to the arrow Ra in FIG. It is configured to engage with the parts 2B1a and 2B2a (not shown).

Rotational position marks 2A4 and 2B4 are marked near the outer periphery of the inner rings 2A1 and 2B1 so that the rotational position can be seen.
On the other hand, scales 2A2b and 2B2b are provided in the vicinity of the inner circumference of the outer rings 2A2 and 2B2, and the rotational positions of the inner rings 2A1 and 2B1 can be measured.
By these rotation position marks 2A4 and 2B4 and the scales 2A2b and 2B2b, the relative rotation positions of the inner rings 2A1 and 2B1 and the outer rings 2A2 and 2B2 can be detected.

Gears 2A3 and 2B3 are formed on the outer circumferences of the two outer rings 2A2 and 2B2.
Further, between the supply side meter 2A and the take-up side meter 2B, a drive motor 3 having a drive gear 3A connected to the shaft is disposed, and the drive gear 3A meshes with the gears 2A3 and 2B3. A DC servo motor is used as the drive motor 3.

The torque measuring device 100 is supplied with power from an external power source (not shown) via the power cord 6, and the drive motor 3 is driven by the control circuit 8. The control circuit 8 performs control of the drive motor 3, that is, rotation aging and constant speed rotation control of reels 50A and 50B described later.
Further, the driving ON / OFF of the driving motor 3 and the selection of the rotation direction can be performed by the switch 5.

  The base 1 of the torque measuring device 100 is provided with a pair of handles 7 so that it can be easily carried.

<About rotational aging>
Immediately after the reels 50A and 50B are activated, the friction coefficient between the brake and the reel disk is unstable, so that accurate torque measurement cannot be performed. Therefore, rotational aging is performed for a predetermined time (reel rotation about 3 turns) before torque measurement, thereby enabling accurate torque measurement.
Further, the rotational aging time is shortened and the measurement efficiency is improved by making the rotational speed at the time of rotational aging higher than the rotational speed at the time of measurement.

In this embodiment, the rotational speed and aging time during rotational aging and the rotational speed during measurement are as follows.
During rotation aging: Rotation speed 77 (r / min), 2 (seconds)
During measurement: Rotational speed 20 (r / min)

<Torque measurement>
Next, a method for measuring the brake torque using the torque measuring device 100 described above will be described. The measurement is performed according to the following procedure.
(1) First, the torque measuring device 100 is placed on the mechanical deck 60, which is the object to be measured, so that the inner rings 2A1, 2B1 and the reels 50A, 50B are engaged (see FIG. 3).
(2) The switch 5 is selected, and the drive motor 3 is driven to rotate clockwise (in the direction of arrow RB in FIG. 1).
(3) Execute rotation aging set in advance.
(4) After that, continuously set to a low-speed constant-speed measurement mode. Since the rotational phase of the inner ring 2A1 and the outer ring 2A2 of the supply side meter 2A is shifted according to the brake torque, the shift is read from the rotational position marks 2A4, 2B4 and the scales 2A2b, 2B2b as torque values.
(5) The switch 5 is switched in the reverse rotation direction, and the drive motor 3 is driven in the left rotation (in the direction of arrow RA in FIG. 1). (6) Pre-set rotation aging is executed.
(7) After that, continuously enter the low-speed constant-speed measurement mode. Since the rotation phases of the inner ring 2B1 and the outer ring 2B2 of the winding side meter 2B are shifted according to the brake torque, the shift is read from the rotation position marks 2A4, 2B4 and the scales 2A2b, 2B2b as torque values.
(8) Remove the torque measuring device 100.
The brake torque is measured by the above procedure.

The torque measuring device described above is very easy to handle because it is small and lightweight. Moreover, since it can be manufactured with general-purpose parts, it is inexpensive.
In addition, by using this torque measuring device and performing measurement by performing rotational aging according to the above-described measurement procedure, measurement variation is small, and the brake torque can be easily measured with extremely high accuracy.

The embodiment of the present invention is not limited to the configuration and procedure described above, and it goes without saying that modifications may be made without departing from the scope of the present invention.
For example, the above-described torque measuring device has been described as a means for visually detecting the rotational position mark and the scale as the torque detecting means. However, the present invention is not limited to this, and it may be an electrical detecting means using a rotational angle sensor. Moreover, it is good also as an optical detection means by a light emitting element.

It is a schematic plan view which shows the Example of the torque measuring device of this invention. It is a disassembled perspective view explaining the principal part of the Example of the torque measuring device of this invention. It is a perspective view explaining the torque measurement using the Example of the torque measuring device of this invention.

Explanation of symbols

1 Base 2A Supply side meter (torque meter)
2B Winding side meter (torque meter)
2A1, 2B1 Inner ring 2A1a, 2B1a Protrusion 2A2, 2B2 Outer ring 2A2a, 2B2a Protrusion 2A2b, 2B2b Scale 2A3, 2B3 Gear 2A4, 2B4 Rotation position mark 3 Drive motor 3A Gear 4 Elastic member (spiral spring)
4a, 4b Bent part 5 Switch 6 Power cord 7 Handle 8 Control circuit 60 Mechanical deck 100 Torque measuring instrument

Claims (2)

A torque measuring device for measuring a brake torque of each reel of a magnetic tape drive device having a pair of reels each including a supply side and a winding side;
A pair of rotating bodies that have an inner ring that engages with the reel and can rotate with the reel, and an outer ring that loosely fits the inner ring and can rotate with the inner ring;
A drive motor for rotating the outer ring,
The inner ring and the outer ring are connected by an elastic member that is elastically deformed with respect to the rotation direction,
A configuration in which a rotation angle difference corresponding to the brake torque is generated between the inner ring and the outer ring when the rotating body engages the inner ring with the reel and the outer ring is rotated by the drive motor. And
A torque measuring instrument, wherein the rotating body is provided with detecting means for detecting the rotation angle difference. A torque measuring method using the torque measuring device according to claim 1,
An aging step of rotating the outer ring at a first rotational speed by the drive motor;
And a measuring step of rotating the outer ring at a second rotational speed lower than the first rotational speed by the drive motor after the aging step.

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