JPH08101081A - Stress measuring apparatus for tape - Google Patents

Abstract

PURPOSE: To obtain a stress measuring apparatus for tape in which the stress can be measured at the end of a tape by preventing the measurements from fluctuating in the breadthwise direction of the tape. CONSTITUTION: A cylindrical member 4 born coaxially with a shaft 11a has cylindrical outer circumference larger than that of the shaft 11a and a tape 1 is guided on the cylindrical outer circumferential surface thereof. A force detecting means 2 measures a force being applied to the cylindrical member 4. Cylindrical members 20, 21 arranged substantially in parallel with the shaft 11a have cylindrical outer circumferential surfaces having a specified radius for guiding the traveling of the tape 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape tension measuring device for measuring the tension of a tape-shaped medium such as a video tape recorder and an audio tape recorder.

[0002]

2. Description of the Related Art A conventional tape tension measuring device will be described below with reference to the drawings. FIG. 4 is an exploded layout view of essential parts showing a tension measurement state by a conventional tape tension measuring device.

In FIG. 4, shafts 11a, 11b, 11c
Are arranged in parallel. The cylindrical members 4a, 4b, 4c are fixed to the respective shafts. The upper end of the shaft 11a is the force detecting means 2
It is stuck to. The force detecting means has an upper end portion fixed to the fixing member 13.
It is stuck to.

The operation of the conventional tape tension measuring device constructed as described above will be described. The tape 1 is sandwiched between the outer peripheral cylindrical surfaces of the first, second, and third cylindrical members 4a, 4b, 4c, and runs in the direction indicated by arrow A. The tape 1 is deformed on the outer peripheral cylindrical surface of the first cylindrical member 4a, and the tension of the tape 1 applies a force to the first cylindrical member 4a in the direction indicated by the arrow B. The first cylindrical member 4a is movable in the direction indicated by arrow B and movable in the direction indicated by arrow B. The amount of movement is detected by the force detecting means 2. The force detected by the force detecting means 2 is displayed as a value corresponding to the stress on the display unit built in the force detecting means 2. This first cylindrical member 4a
Since the force applied to the tape has a correlation with the stress of the tape 1, the displayed value displayed is observed as a value having a correlation with the stress of the tape 1.

[0005]

In the tape stress measuring device constructed as described above, the second and third shafts 11b, 11 are provided.
The tape is tent-shaped in the width direction of the tape 1 by the cylindrical members 4b and 4c attached to c. FIG. 5 schematically shows how the tape 1 is lifted by the cylindrical member 4b. The tape 1 is lifted as shown and the forces F0 and F1 are applied to the tape. This force also affects the portion of the cylindrical member 4a that measures the tape stress. That is, the forces F0 and F1 which should not be present are detected by the force detection means 2 as forces. As a result, an error occurs in the measured value. Also,
FIG. 6 shows the result of measuring the stress of the tape 1 by using a conventional tape stress measuring device in which the tape 1 is uniformly stressed. The vertical axis is the display value displayed on the display unit of the force detecting means. As is clear from this figure, the stress measurement result is small at the end of the tape. Originally, this curve should have a constant value at any position in the tape width direction. Therefore, it is considered that the measurement cannot be accurately performed in the areas of the ends P and Q of the tape. As described above, the conventional tape stress measuring device has a problem that there is a measurement error due to the cylindrical members 4b and 4c and that the measurement cannot be performed at the end portion of the tape. Further, the second and third cylindrical members 4b, 4
Since c is short in the width direction of the tape, it is difficult to install the cylindrical members 4b and 4c in parallel with the width direction of the tape.

The present invention solves the above-mentioned conventional problems and prevents the deformation of the tape by the cylindrical members 4b and 4c and reduces the measurement error due to the deformation of the tape. Further, it is possible to easily set the cylindrical member.

[0007]

In order to achieve the above object, a tape tension measuring device of the present invention has a shaft and an outer peripheral cylindrical surface which is supported coaxially with the shaft and is larger than the shaft diameter. A cylindrical member for guiding and guiding the tape on the cylindrical surface, a force detecting means for measuring the force applied to the cylindrical member, and at least 2 for guiding and guiding the tape on the outer peripheral cylindrical surface having a constant radius and arranged substantially parallel to the axis. And a book axis.

[0008]

With the above construction, the deformation of the tape due to the cylindrical member can be prevented, the tape stress can be measured at the tape end, and the apparatus can be installed easily.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A tape stress measuring device of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration diagram of a main part of a tape stress measuring device according to an embodiment of the present invention.

In FIG. 1, the cylindrical members 4, 20, 21 are arranged in parallel. The cylindrical member 4 is fixed to the shaft 11a, and the force detecting means 2 is fixed to the shaft 11a. The force detecting means 2 detects the force in the direction indicated by arrow B. Also,
The outer peripheral cylindrical surfaces of the cylindrical members 20 and 21 have the same diameter in the portion for guiding the tape to travel. The concrete structure of the force detection means 2 is shown in FIG. The force detection means 2 includes a plate member 16 and a plate member 16
Strain gauge 15 fixed on a surface parallel to the tape running surface
And a voltage conversion unit 20 for converting the strain amount of the strain gauge 15 into a voltage and a display unit 21 for displaying the voltage.
The lower end of the plate member 16 is fixed to the block 22, and the block 22 is fixed to the cylindrical member 11a. The upper end of the plate member 16 is fixed to the fixing member 13.

The upper ends of the cylindrical members 20 and 21 are fixed to the fixing member 13. The operation of the tape tension measuring device of the present embodiment configured as described above will be described. As shown in FIG. 1, the tape 1 includes cylindrical members 4, 20,
It is sandwiched between outer peripheral cylindrical surfaces 21 and wound around the cylindrical member 4. The tape 1 runs in the direction indicated by arrow A. Due to the stress of the tape 1 wound around the cylindrical member 4, a force is applied to the cylindrical member 4 in the direction indicated by the arrow B. The cylindrical member 4 is movable in the direction indicated by the arrow B. Further, the plate member 16 is a cantilever with the upper end side fixed to the fixing member 13 as the fixed end, and is deformed by the movement of the cylindrical member 4, and the strain gauge 15 is distorted. The strain amount of the plate member 16 is converted into a voltage by the strain gauge 15 and the voltage conversion unit 20, and the display unit 2
Displayed as 1. Since the force applied to the cylindrical portion 4 has a correlation with the stress of the tape 1, the value displayed on the display unit 21 is the tape 1
It is observed as a value correlated with the stress of.

With the above-mentioned structure, the tape 1
It is possible to suppress the deformation of the tape 1 by the cylindrical members 20 and 21 that guide the traveling of the vehicle, and the deformation of the tape 1 is hardly exerted on the cylindrical member 4 that detects the force. Further, since the axial length of the cylindrical members 20 and 21 in contact with the tape 1 is long, the tape 1 runs stably. Even when the cylindrical member 4 was arranged at a position close to the upper and lower end surfaces of the tape 1, the tape ran stably.

Using the tape stress measuring device of this embodiment,
The measurement results when a uniform stress is applied to the tape are shown in FIG. Compared to FIG. 6, the difference in the measurement results due to the difference in the position in the tape width direction on the tape 1 was reduced, and stable measurement results were obtained.

Further, since the display value corresponding to the stress is observed also at the end portion of the tape 1, it becomes possible to measure at the end portion of the tape.

Further, since the axial length of the cylindrical members 20 and 21 for guiding and guiding the tape 1 is long, the cylindrical members can be easily installed parallel to the width direction of the tape. As a result, the time required for measurement can be shortened and efficiency can be improved.

Although the shaft 11a is fixed to the force detecting means 2, it may be rotatable by a bearing without being fixed. Although the cylindrical members 20 and 21 are fixed to the fixed member 13, they may be rotatable by bearings.

[0017]

EFFECTS OF THE INVENTION Cylindrical members 20, 2 for guiding the running of tapes
The deformation of the tape due to 1 can be suppressed, and the influence of the deformation of the tape on the cylindrical member 4 for detecting the force can be suppressed. As a result, the measurement accuracy can be improved, and even when the cylindrical member 4 is arranged at a position close to the upper and lower end surfaces of the tape, the tape travels stably and stable measurement results can be obtained. Furthermore, since the axial length of the cylindrical members 20 and 21 for guiding the tape to travel is long, the cylindrical members 20 and 21 can be easily arranged parallel to the width direction of the tape. As a result, the time required for installation can be shortened.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of a tape tension measuring device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of force detection means of the same embodiment.

FIG. 3 is an explanatory view showing a tape stress measurement result measured by using the tape stress measurement device of the same embodiment.

FIG. 4 is a configuration diagram of a main part of a conventional tape stress measuring device.

FIG. 5 is a schematic diagram of how the tape 1 is lifted by a cylindrical member 4b.

FIG. 6 is an explanatory view showing a tape stress measurement result measured using a conventional tape stress measuring device.

[Explanation of symbols]

 1 Tape 2 Force Detection Means 4, 20, 21 Cylindrical Member 11a Shaft 13 Fixing Member 15 Strain Gauge 16 Plate Material 20 Voltage Converter 22 Block

Claims (1)

[Claims] 1. A shaft, a cylindrical member which is supported coaxially with the shaft and has an outer peripheral cylindrical surface larger than the shaft diameter, and guides the tape to travel on the outer peripheral cylindrical surface, and the force applied to the cylindrical member is measured. A tape stress measuring device comprising: force detecting means; and at least two shafts which are arranged substantially parallel to the shaft and which guide the tape in a traveling circumferential cylindrical surface having a constant radius.