JP2748317B2 - Slip test method and test apparatus - Google Patents

Description

The present invention relates to a method for testing slipperiness and a test apparatus therefor.
More specifically, the present invention relates to a method for testing the slipperiness of a test object such as paper and a test apparatus therefor.

[Conventional technology]

Due to recent diversification of uses of paper such as luggage wrapping paper and information industry paper, various physical properties are required for paper. A coefficient of friction indicating slipperiness is one of them.

FIG. 6 (a) is a perspective view of a test apparatus for performing a slip test on paper or the like according to a conventional example.

In the figure, 1 is a fixed table, 2 is a level provided on the fixed table to detect the horizontal state of the fixed table, 3 is a slide,
Reference numeral 4 denotes a test paper placed on a table, and reference numeral 5 denotes a press for fixing the test paper 4 on the slide 3.

Reference numeral 6 denotes a weight having a test paper attached to the lower surface, 7 denotes a stopper for stopping the weight 6 when the weight 6 slides down, 8
Is a rotary drive shaft for gradually tilting the slide 3,
Reference numeral 9 denotes a tilt angle display plate for displaying the tilt angle, and reference numeral 10 denotes a scale indicator for indicating the tilt angle of the slide 3.

FIG. 6 (b) is a partially enlarged view of the weight to which the paper under test is attached, 11 is the paper under test on the weight side, and 12a and 12b are the papers 11 under test.
Is a test paper fixing grip for fixing the test paper to the lower surface of the weight 6 while suppressing both ends of the test paper.

According to the conventional method of testing slipperiness, first, level 2
The fixing table 1 is set in a horizontal state while watching the screen. Next, after the weight 6 to which the test paper 11 is attached is placed on the test paper 4 on the slide 3, the rotary drive shaft 8 is rotated to tilt the slide 3, and the weight 6 starts sliding. The operator sees this and immediately stops the rotation of the rotary drive shaft 8. Then, the inclination angle indicated by the scale indicator 10 at that time is read.

The operator measures the time for the weight 6 to travel the distance from the point E to the point F on the test paper 4 on the slope using a stopwatch.

[Problems to be solved by the invention]

By the way, according to the conventional test method and test apparatus, the worker performs the detection of the time of the start of slip, the stop of the rotary drive shaft after the detection, and the measurement of the slip time between the points E and F by the stopwatch. Therefore, the result largely depends on the personality and experience of the worker. For this reason, there is a problem that the reproducibility of the measurement is poor and that it is not always accurate.

The present invention has been made in view of such a conventional problem, and by automating a test method and a test apparatus, it is possible to reduce a work load on an operator, improve reproducibility of a test result, and improve a test apparatus. An object of the present invention is to provide a method for testing slipperiness and a test apparatus for the same, which enable improvement of test accuracy by improvement.

[Means for solving the problem]

The method for testing slipperiness of the present invention is to increase the inclination angle of a slide minutely and digitally through a rotation drive stepping motor that rotates stepwise and a rotation transmission mechanism that transmits the motor while changing the rotation step angle. When the DUT placed on the slide starts to slide, this is optically detected, the rotation of the motor is stopped, and the number of steps of the rotation step angle of the motor is integrated, whereby the slide at the time of the rotation stop is stopped. In addition to measuring the inclination angle of the slide, the slide is set to an inclination angle at the time of the rotation stop or an inclination angle larger than the inclination angle, and a predetermined distance is provided along a slope on the slide. The above-mentioned optical detection means measures the time during which the device under test slides between the optical detection means. A rotating stepping motor, a rotation transmission mechanism for transmitting the stepping motor by changing its rotation step angle, a slide whose inclination angle changes stepwise by a driving force transmitted by the transmission mechanism, and a slide along the surface of the slide. A plurality of (first, second,...) Optical detecting means provided, and a first object above the inclined surface when the test object placed on the slide starts to slide due to the inclination of the slide. By detecting this by the optical detecting means, the rotation of the stepping motor is stopped, and by adding the number of steps of the step angle of the stepping motor rotated by the time of the stop, the inclination angle at the start of sliding of the DUT is calculated. Means for measuring, and means for measuring the time of the test object sliding between the second, third,... Optical means provided at predetermined intervals along the slope of the slide. Characterized by Rukoto, to solve the above problems.

[Action]

According to the test method and test apparatus of the slip property of the present invention,
The slide on which the DUT is mounted is minutely and digitally tilted via the stepping motor and the rotation transmission mechanism, and immediately when the first optical detection means detects the start of the slide of the DUT, The rotation of the stepping motor is stopped, and the tilting operation of the slide is stopped. The inclination angle of the slide at the time of rotation stop is measured by integrating the number of steps of the step angle of the stepping motor.

Therefore, the time from the detection of the start of sliding to the stop of the inclination of the slide is extremely short and constant irrespective of the worker, as compared with the conventional testing method using the testing device by the worker. In addition, since the inclination angle is measured from the digital rotation amount of the stepping motor, a precise value can be obtained corresponding to the set minute step angle, the accuracy of measurement of the coefficient of static friction increases, and the reproducibility of the test increases. improves.

Further, a second optical detection means mounted on the slide at a predetermined angle at a predetermined angle set in accordance with the angle resolution of the stepping motor with a small step angle of the slide. , A third optical detecting means ...
Since the time required for the test object to slide down the distance between them can be accurately measured, the dynamic friction coefficient can be accurately measured.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view of a test apparatus and a test method according to an embodiment of the present invention, FIG. 2 is a flowchart schematically illustrating a test sequence of the embodiment of the present invention, and FIG. 3 is a test according to the embodiment of the present invention. FIG. 4 is a perspective view of the apparatus, FIG. 4 is an explanatory view of a method of setting a reference position of a slide according to the embodiment of the present invention, and FIG. 5 is an explanatory view of a rotation drive transmitting method of the embodiment of the present invention.

First, the outline of the configuration of the test apparatus of the present invention will be described with reference to the block diagram of FIG.

In the figure, 13 is an operation unit for setting a measurement distance, a rotation speed, etc., 14 is a control circuit for performing signal processing of the entire test apparatus, and 15 is a sensor amplifier circuit, which is an optical sensor A1.
D2, a limit position detection limit switch 21, and a function of amplifying a detection signal sent from the reference position detection sensor 22 and converting it to a logic level.

16 is a motor drive circuit controlled by the control circuit 14, 17 is a stepping motor that is controlled to start and stop rotation by the motor drive circuit 16, 18 is a rotation driving force transmission mechanism that transmits the rotation of the stepping motor 17, 19 is A slide for mounting the test object, and a display unit 20 for displaying test setting conditions of the measurement distance and the rotation speed, the inclination angle of the slide 19 and the test result of the sliding time of the test object. Reference numeral 21 denotes a limit position detection limit switch for detecting the inclination limit of the slide 19, and reference numerals 22 and 23 denote reference position detection sensors and reference position setting plates, respectively, for determining the inclination reference position of the slide 19. Further, A1 and A2 constitute a first optical sensor with a light emitting element and a light receiving element, respectively, for detecting the start of sliding of the test object. Also, a second optical sensor is composed of B1 (light emitting element) and B2 (light receiving element), and C1 (light emitting element) and C2 (light receiving element)
Constitutes a third optical sensor, D1 (light emitting element) and D2
(Light receiving element) constitutes a fourth optical sensor for measuring the sliding time of the DUT.

Next, the outline of the configuration of the test apparatus of the present invention will be described with reference to the perspective view of FIG. 3. Reference numeral 24 denotes a fixed table placed on a work table or the like (not shown), and 21 denotes a tilt limit of the slide table 19. Limit position detection limit switch for detection, 25 is a level for detecting the horizontal state of the fixed base 24, 26a and 26b are horizontal for adjusting the horizontal position of the fixed base 24 while observing the level 25 The adjuster 27 is a rotation drive mechanism box containing a stepping motor and a rotation drive mechanism.

Reference numeral 28 denotes a control box containing a control circuit and other circuits. 29 denotes an operation panel including an operation unit for setting a measurement distance and a rotation speed, and a display unit for displaying test results (inclination angle and measurement time). Reference numeral 30 denotes a sensor amplifier panel, and reference numeral 19 denotes a slide on which a test object (not shown) is mounted. On the slide 19, along the slope, the first optical sensor (A1, A2), the second optical sensor (B1, B2),
Optical sensors (C1, C2) and the fourth optical sensor (D1, D
It is provided in the order of 2).

FIG. 4 is a diagram for explaining a reference position setting method of the slide 19 according to the embodiment of the present invention. Reference numeral 22 denotes a reference position detection sensor as optical detection means, and reference numeral 23 denotes a reference position setting plate. In addition, the fifth
The figure is an explanatory view of the rotational drive transmission method of the embodiment of the present invention, 34, 36, 38 are timing pulleys, 35, 37 are timing belts, 39 is a tensioner, stepping motor 22 by the gear ratio of each timing pulley. The rotation of the slide 19 is reduced at a predetermined step angle and a predetermined inclination speed.
Can be inclined. Reference numeral 31 denotes a stopper for enabling the slide 19 to be attached to and detached from the fixed stand 24.

Next, with reference to FIGS. 1 to 5, a first slip test method (measurement of static friction coefficient and dynamic friction coefficient) and a second slip test method (measurement of dynamic friction coefficient) according to the embodiment of the present invention. ) Will be described.

First, the slide 19 is positioned horizontally (FIGS. 3 and 4).
See figure). To do this, press the up button on the operation panel 29 to drive the motor and control the slide box 19
Incline a little so that the 28 side rises. Next, press the down button and rotate the motor to the opposite side to lower the control box 28 side of the slide 19, and the reference position detection sensor
When the reference 22 is shielded from light by the reference position setting plate 23, this is detected and the rotation of the motor is stopped. Next, the horizontal adjusters 26a and 26b are adjusted so that the level 25 becomes horizontal. In the position where the level 25 indicates horizontal, the slide
The reference position setting plate 23 is adjusted in advance so that the surface 19 is horizontal.

Next, a DUT (not shown) (a paper having a DUT attached to a weight, see FIG. 6) is attached to a sliding surface of a slide 19 (similar paper is attached on the surface). ) (Control box 28 side).

Next, the first slip test method (measurement of static friction coefficient, measurement of dynamic friction coefficient) will be described with reference to the flowchart of FIG.

First, when the start button on the operation panel 29 is pressed, the stepping motor 17 rotates at the set step angle, and the slide 19 is gradually inclined via the rotation driving force transmission mechanism 18. For example, the stepping motor 17 has a step angle of 0.36
゜, and deceleration to, for example, 1/36 by the gear ratio of the timing pulleys 34, 36, 37, the slide 1 in 100 steps
An angular resolution of 9 inclination angles of 1 ° is obtained.

At some point, the test object slides against the frictional force.
When sliding down the slope of 19, the first optical sensor composed of A1 (light emitting element) and A2 (light receiving element) detects this and sends a detection signal to the control circuit 14 via the sensor amplifier circuit 15. Thus, the control circuit 14 immediately stops the rotation of the stepping motor 17 via the motor drive circuit 16 and stops the inclination of the slide 19. The inclination angle at that time is displayed on the display unit 20 in units of 1/100 °.

As described above, according to the first slip test method of the present invention, the inclination angle can be measured with high precision angular resolution, so that an accurate coefficient of static friction can be obtained and automatically without human recognition. , The reproducibility of the measurement is further improved.

The static friction coefficient of the test object can be easily obtained by measuring the inclination angle θ according to the following equation (1).

Mg × sin θ = μ ₁ × Mg × cos θ Therefore, μ ₁ = tan θ (1) where μ ₁ is the coefficient of static friction, M is the mass of the test object including the weight, g is the gravitational acceleration, and θ is the gravitational acceleration. It is the value of the measured tilt angle.

On the other hand, even if the rotation of the stepping motor 17 is stopped, the DUT continues to slide on the slope, and the second optical sensor (B1, B2), the third optical sensor (C1, C2), and the fourth optical sensor (C1, C2). Pass through the optical sensors (D1, D2). At this time, each optical sensor is connected to the control circuit 14 via the sensor amplifier circuit 15.
Send a detection signal to In the control circuit 14, the time when these detection signals are sent is counted by a counter, for example, by counting the number of pulses by a crystal oscillator.
Thereby, the time for sliding down between the second optical sensor and the third optical sensor (short distance) and the time for sliding down between the second optical sensor and the fourth optical sensor (long distance). The time is measured with high accuracy, and the time is displayed on the display unit 20.

As described above, according to the first slip test method of the present invention, the slip time at the inclination angle at which the test object starts to slide can be measured with high accuracy, so that the value of the dynamic friction coefficient of the test object at that time is accurate. Since the measurement is automatically performed without the intervention of human recognition, the reproducibility of the measurement is further improved.

Next, a description will be given of a second slip test method for measuring the dynamic friction coefficient of the test object by setting the inclination angle to be larger than the inclination angle at the start of sliding of the test object obtained by the first slip test method. . The test is performed according to the flowchart in FIG.

First, when the tilt angle setting button on the operation panel 29 is pressed, the stepping motor 17 rotates at the set step angle,
The slide 19 is gradually inclined through the rotary driving force transmission mechanism 18, and when the number of steps at the step angle corresponding to the set inclination angle is counted by the counter, the stepping motor stops there. The tilt angle at that time is indicated on the display
20 is displayed in 1/100 ゜ units.

Note that the set inclination angle at this time is larger than the inclination angle when the static friction coefficient in the first slip test method is measured.

Next, when the DUT placed above the slope of the slide 19 is released from fixing means (not shown), the DUT is moved to the slide.
Sliding down the slope of 19, the second optical sensor (B1, B2),
Third optical sensor (C1, C2), fourth optical sensor (D
1, D2). At this time, each optical sensor sends a detection signal to the control circuit 14 via the sensor amplifier circuit 15. In the control circuit 14, the time when these detection signals are sent is counted by a counter, for example, by counting the number of pulses by a crystal oscillator. This allows
The time to slide down between the second optical sensor and the third optical sensor (short distance) and the time to slide down between the second optical sensor and the fourth optical sensor (long distance), Each is measured with high precision, and the time is displayed on the display unit 20.

In this manner, according to the second slip test method of the present invention, the slip time can be measured with high accuracy, so that the kinetic friction coefficient obtained based on the slip time can be increased, and the slip time can be increased through human recognition. Since the measurement is performed automatically without the need, the reproducibility of the measurement is further improved.

In addition, the dynamic friction coefficient of the test object is obtained by the following equation (2).

The equation of motion for the weight M when the weight M slipping off, given by _{Mα = Mg × sinθ-μ 2} × Mg cosθ α = g (sinθ-μ 2 × cosθ), Integrating both sides in time, v = [alpha] t = G (sin θ−μ ₂ × cos θ) t Solving for μ ₂ gives Is obtained.

Here, μ ₂ is the coefficient of kinetic friction, M is the mass of the test object including the weight, g is the constant of the gravitational acceleration, α is the acceleration of the test object along the inclined surface, and v is the speed of the test object along the inclined surface. is there.

Further, theta is set tilt angle, S is a predetermined distance, t is because a slip time when sliding down a predetermined distance S, it is possible to easily calculate the dynamic friction coefficient mu _2.

[Effects of the Invention] As described above, according to the present invention, a slip test device is configured by electrical means and optical means, and a slip test method is automated without intervention of a worker's recognition work. .

For this reason, the measurement work is much simpler than before, the measurement time can be shortened, the measurement results do not change by the operator, the reproducibility is further improved, and the static friction coefficient and the dynamic friction coefficient can be measured. Accuracy also improves.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a test apparatus and a test method of the present invention, FIG. 2 is a flowchart illustrating an embodiment of the present invention, FIG. 3 is a perspective view of a test apparatus according to an embodiment of the present invention, FIG. 4 is an explanatory diagram of a reference position setting method of the present invention, FIG. 5 is an explanatory diagram of a rotational drive transmitting method of an embodiment of the present invention, and FIG. 6 is an explanatory diagram of a conventional example. (Explanation of reference numerals) 13 ... operating unit, 14 ... control circuit, 15 ... sensor amplifier circuit, 16 ... motor drive circuit, 17 ... stepping motor, 18 ... rotary driving force transmission mechanism, 19 ... slide , 20 display part, 21 limit position detection limit switch, 22 reference position detection sensor, 23 reference position setting plate, 24 fixed base, 25 level, 26a, 26b horizontal Adjuster, A1, B1, C1, D1 ... Light emitting element, A2, B2, C2, D2 ... Light receiving element.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takuji Oikawa 4- 14-12 Koishikawa, Bunkyo-ku, Tokyo Within Kyodo Printing Co., Ltd. (72) Inventor Hiroshi Fujii 4- 14-12 Koishikawa, Bunkyo-ku, Tokyo In Kyodo Printing Co., Ltd. (56) References Japanese Utility Model Showa 49-1000058 (JP, U) Japanese Utility Model Showa 63-81243 (JP, U)

Claims (2)

(57) [Claims] An inclination angle of a slide is minutely and digitally increased through a rotation drive stepping motor that rotates stepwise and a rotation transmission mechanism that changes and transmits the rotation step angle of the motor, and is mounted on the slide. When the test object starts sliding, the rotation of the motor is stopped by optically detecting the slip, and the angle of inclination of the slide when the rotation is stopped is measured by integrating the number of steps of the rotation step angle of the motor. In addition, the slide is set to an inclination angle at the time of the rotation stop or an inclination angle larger than the inclination angle, and at least one optical detection provided at a predetermined interval along a slope on the slide. A slip test method comprising: measuring a time required for the test object to slide between the optical detection means by means. 2. A stepping motor that rotates at a set step angle, a rotation transmission mechanism that transmits the stepping motor while changing the rotation step angle, and a slide whose inclination angle changes stepwise by a driving force transmitted by the transmission mechanism. And a plurality (first, second,...) Provided along the surface of the slide.
···) and when the test object placed on the slide starts to slide due to the inclination of the slide, the first optical detection means above the inclined surface detects this. Stopping the rotation of the stepping motor, measuring the inclination angle at the beginning of sliding of the DUT by integrating the number of steps of the step angle of the stepping motor rotated until the stop, along the slope of the slide A means for measuring the time of the test object sliding between the second, third,... Optical means provided at predetermined intervals.