KR20240009028A - Bending-resistance fatigue life test device of conductive flexible composites - Google Patents

Abstract

The present invention is capable of fixing a conductive composite material sample on a bending fixed die with a fixed electrode and a bending rotary die with a rotating electrode, and then rotating the bending rotary die in an angle range of 90 degrees to 310 degrees with respect to the bending fixed die by a bending rotary motor while applying current to the fixed electrode and the rotating electrode. In this way, the bending rotary die, placed in line with the bending fixed die, is repeatedly rotated at a set angle in the angle range of 90 degrees to 310 degrees, so that the conductive composite material sample is subjected to repeated bending tension over the same area, and the resulting change in resistance can be accurately measured repeatedly.

Description

Bending-resistance fatigue life test device of conductive flexible composites}

The present invention relates to a fatigue life testing device for bending-resistance of conductive soft composite materials.

A wearable device has a variety of functions, including the ability to output audio or video while worn or attached to the user like a part of the body, the ability to input/output information, and the ability to store data. It is a portable device that performs These wearable devices have recently been used in various industrial fields such as the smart healthcare industry, medical device industry, and smart clothing industry.

Materials used to create wearable devices must be flexible and powered for operation. To this end, conductive composite materials with excellent electrical conductivity have recently been applied to wearable devices. Since wearable devices must be supplied with power without interruption not only in the unfolded state but also in the folded or rolled state, bending-resistance cycle testing at various angles and in repetitive bending states is required for conductive composite materials to be applied to wearable devices.

Meanwhile, in the past, to test the bending-resistance cycle of a conductive composite material, a method was used to attach copper tape to a conductive composite sample and weld or connect a power plug to the copper tape. Therefore, the preparation process for bending-resistance cycle testing of conductive composite materials was complex and took a lot of time to prepare. Additionally, if the copper tape or power plug did not properly adhere to the conductive composite material sample, there was a problem that the reliability of the test was reduced.

In addition, the conventional bending-resistance cycle test device performs a bending-resistance test by holding one end of the test sample and repeatedly moving it back and forth to the other end, so the device had to be large, and the bending-tensile area changes as it moves, so it is not fixed. It was difficult to test the repeated bending-resistance of the area.

Korean registered patent (10-1002236)

The purpose of the present invention is to provide a bending-resistance fatigue life test device for conductive soft composite materials that can solve the above-mentioned problems.

A bending-resistance fatigue life test device for conductive soft composite materials to achieve the above purpose,

A fixed die for bending coupled to the frame;

A bending rotation shaft rotatably coupled to the frame;

A bending rotary die, one end of which is coupled to the bending rotary shaft and rotated by rotation of the bending rotary shaft;

A fixed electrode coupled to the bending fixed die and transmitting current to the conductive composite sample placed on the upper surface;

a rotating electrode coupled to the bending rotating die and transmitting current to the conductive composite sample placed on the upper surface;

A fixing member for a fixed electrode connected to the upper surface of the conductive composite sample and fixing the conductive composite sample to the fixed electrode;

A fixing member for a rotating electrode connected to the upper surface of the conductive composite sample and fixing the conductive composite sample to the rotating electrode; and

It is coupled to the frame and includes a bending rotation motor connected to the bending rotation shaft to rotate the bending rotation shaft,

By changing the rotation angle, number of rotations, and rotation speed of the bending rotary motor, the bending angle, number of bending, and bending speed of the conductive composite sample can be changed and the bending-resistance change of the conductive composite sample can be repeatedly measured. It is characterized by having

In the present invention, a sample of a conductive composite material is fixed to a fixed die for bending combined with a fixed electrode and a rotating die for bending combined with a rotating electrode with a holding member for the fixed electrode and a holding member for the rotating electrode, and then an electric current is applied to the fixed electrode and the rotating electrode. The bending rotary die can be rotated in an angle range of 90 to 310 degrees with respect to the bending fixed die by the bending rotary motor while flowing. In this way, the bending rotary die arranged in a straight line with respect to the bending fixed die is repeatedly rotated at a set angle in the angle range of 90 degrees to 310 degrees, and the conductive composite material sample is subjected to repeated bending and tension in the same area. Changes in resistance can be measured accurately and repeatedly.

In addition, by changing the rotation angle, number of rotations, and rotation speed of the bending rotary motor, the bending angle, number of bending, and bending speed of the conductive composite sample can be changed and the bending-resistance change of the conductive composite sample can be measured repeatedly. . In particular, unlike conventional bending-resistance cycle test devices, the bending-resistance test is not performed by holding one end of the test sample and repeatedly moving it back and forth to the other end, so the device is small and the test area does not change due to movement. Intensive repetitive bending-resistance testing of the same area is possible.

Additionally, there is no need to previously attach copper tape to the conductive composite sample and weld or connect a plug to the copper tape to send current to the conductive composite sample, simplifying the preparation process for bending-resistance cycle testing of conductive composites. .

Figure 1 is a diagram showing a bending-resistance fatigue life test device for a conductive soft composite material according to an embodiment of the present invention.
FIG. 2 is a diagram showing the operation of the bending-resistance fatigue life test device of the conductive soft composite material shown in FIG. 1, and the plug connection of the resistance meter is omitted for convenience of explanation.

Hereinafter, a bending-resistance fatigue life test device for a conductive soft composite material according to an embodiment of the present invention will be described in detail.

As shown in Figures 1 and 2, the bending-resistance fatigue life test device of a conductive soft composite material according to an embodiment of the present invention includes a fixed die 100 for bending, a rotating shaft 200 for bending, and a bending die 100 for bending. Consisting of a rotating die (300), a fixed electrode (400), a rotating electrode (500), a fixing member for the fixed electrode (600), a fixing member for the rotating electrode (700), a rotating motor for bending (800), and a controller (900). do.

[Fixed die for bending (100), rotating shaft for bending (200), rotating die for bending (300)]

Fixed die for bending (100)

The fixed die 100 for bending is installed on the frame (F). As shown in FIG. 2, the bending fixed die 100 is basically formed in the shape of a square plate and has a flat upper surface on which the conductive composite material sample (S) is placed. The fixing die 100 for bending is fixed and installed in a straight line on the front of the frame (F).

Rotation shaft for bending (200)

The bending rotation axis 200 is installed to be rotatable with respect to the frame (F). The bending rotation shaft 200 is arranged in a straight line at a certain distance from one end of the bending fixed die 100.

Rotating die for bending (300)

One end of the bending rotary die 300 is coupled to the bending rotary shaft 200 and is rotated by the rotation of the bending rotary shaft 200. The rotating die 300 for bending is spaced apart from the fixed die 100 for bending at a certain distance. Due to the separation distance, the bending rotary die 300 is positioned between the upper surface of the conductive composite sample (S) placed on the fixed electrode 400 and the upper surface of the conductive composite sample (S) placed on the rotating electrode 500. It can be rotated in an angle ranging from 90 degrees to 310 degrees. That is, due to the spacing, the bending rotary die 300 can rotate at an angle greater than 270 degrees, that is, up to 310 degrees in this embodiment. If this is explained in the drawing, the bending rotary die 300 can rotate up to 90 degrees counterclockwise from a horizontal state (180 degrees) as shown in FIG. 2, and can be bent as shown in FIG. 2. The rotation die 300 can rotate clockwise up to 130 degrees in a horizontal state (180 degrees). When the bending rotary die 300 is rotated 130 degrees clockwise in a horizontal state, the total of 180 degrees in the horizontal state is rotated up to 310 degrees. Accordingly, the bending rotary die 300 can be rotated in the range of 90 degrees to 310 degrees.

The bending rotary die 300 is basically formed in the shape of a square plate and has a flat upper surface on which the conductive composite material sample (S) is placed. The left end portion of the bending rotary die 300 coupled to the bending rotary shaft 200 is formed as a curved surface. Therefore, when the bending rotary die 300 is rotated at an angle greater than 180 degrees to bend and stretch the conductive composite sample (S), the conductive composite sample (S) can be smoothly bent to a curved surface without being bent in the bending area. .

On the front of the frame (F) where the bending fixed die 100, the bending rotation axis 200, and the bending rotary die 300 are installed, there is an angle indicator for visually displaying the rotation angle of the bending rotary die 300. (A) is attached.

[Fixed electrode (400)]

The fixed electrode 400 is coupled to the fixed die 100 for bending. The fixed electrode 400 forms all or part of the upper surface of the fixed die 100 for bending. In this embodiment, the fixed electrode 400 occupies a portion of the upper surface of the fixed die 100 for bending, that is, the outer area.

The fixed electrode 400 may be formed of one or multiple blocks and coupled to the fixed die 100 for bending. The fixed electrode 400 is fixed to the bending fixed die 100 with a bolt and is replaceable. When the fixed electrode 400 is formed of a plurality of blocks, each block is connected in electrical communication. A connection terminal (not shown) into which the plug of a resistance meter (not shown) is inserted is mounted on the left side of the fixed electrode 400, so that current is transmitted from the resistance meter.

In this embodiment, the fixed electrode 400 is formed of two blocks. One is located on the upper surface of the fixed die 100 for bending. The other one is located at the bottom of the bending fixed die 100 and is equipped with a connection terminal (not shown) to which the plug of the resistance meter is connected.

A conductive composite material sample (S) is placed on the upper surface of the fixed electrode 400. The fixed electrode 400 transmits current to the conductive composite sample (S) placed on the upper surface. The conductive composite material sample (S) according to this embodiment is formed in a rod shape with a length in the longitudinal direction longer than the length in the width direction. One end of this conductive composite sample (S) is placed on the upper surface of the fixed electrode 400, and the other end is placed on the upper surface of the rotating electrode 500.

The fixed electrode 400 is made of a conductive material. For example, the fixed electrode 400 is made of copper. A gold plating layer may be formed on the upper surface of the fixed electrode 400 to increase electrical conductivity.

[Rotating electrode (500)]

The rotating electrode 500 is coupled to the rotating die 300 for bending. The rotating electrode 500 forms all or part of the upper surface of the rotating die 300 for bending. In this embodiment, the rotating electrode 500 is located outside the upper surface of the bending rotating die 300.

The rotating electrode 500 may be formed of one or more blocks and coupled to the rotating die 300 for bending. The rotating electrode 500 is fixed to the bending rotating die 300 with a bolt and is replaceable. When the rotating electrode 500 is formed of a plurality of blocks, each block is connected in electrical communication. A connection terminal (T) into which the plug of the resistance meter is inserted is mounted on one side of the rotating electrode 500, and current is transmitted from the resistance meter.

In this embodiment, the rotating electrode 500 is formed as a single block and is coupled to one end of the bending rotating die 300 away from the bending rotating shaft 200. The upper surface of the rotating electrode 500 forms a part of the upper surface of the bending fixed die 100, and a connection terminal (T) is mounted on the front side to which the plug of the resistance meter is connected.

A conductive composite material sample (S) is placed on the upper surface of the rotating electrode 500. The rotating electrode 500 transmits current to the conductive composite sample (S) placed on the upper surface.

The rotating electrode 500, like the fixed electrode 400, is made of a conductive material. For example, the rotating electrode 500 is made of copper. A gold plating layer may be formed on the upper surface of the rotating electrode 500 to increase electrical conductivity.

[Fixing member for fixed electrode (600), fixing member for rotating electrode (700)]

Fixing member for fixed electrode (600)

The fixing member 600 for the fixed electrode is connected to the upper surface of the conductive composite sample (S) and fixes the conductive composite sample (S) to the fixed electrode (400).

The fixing member 600 for the fixed electrode is composed of a pressurizing block 610 for the fixed electrode and a fixing bolt 620 for the fixed electrode. The pressurizing block 610 for the fixed electrode presses the conductive composite material sample (S) in the direction of the fixed electrode 400. The pressure block 610 for the fixed electrode is made of a conductive material. For example, the pressurizing block 610 for the fixed electrode is made of copper.

The pressurizing block 610 for the fixed electrode is formed to be longer than the width of the conductive composite sample (S), and the conductive composite sample (S) is located in the center area of the pressurizing block 610 for the fixed electrode, and the conductive composite sample Through holes (not shown) for fixed electrodes are formed at both ends where (S) is not located.

The fixing bolt 620 for the fixing electrode passes through the through-hole for the fixing electrode and is screwed into the fixing electrode fastening groove (not shown) formed on the fixing electrode to provide pressing force to the pressurizing block 610 for the fixing electrode. The fixing bolt 620 for the fixing electrode is formed of an insulating material or coated with an insulating material.

Fixing member for rotating electrode (700)

The fixing member 700 for the rotating electrode is connected to the upper surface of the conductive composite sample (S) and fixes the conductive composite sample (S) to the rotating electrode (500).

The fixing member 700 for the rotating electrode is composed of a pressing block 710 for the rotating electrode and a fixing bolt 720 for the rotating electrode. The fixing member 700 for the rotating electrode presses the conductive composite sample (S) in the direction of the rotating electrode 500. The pressing block 710 for the rotating electrode is made of a conductive material. For example, the pressing block 710 for the rotating electrode is made of copper.

The pressurizing block 710 for the rotating electrode is formed to be longer than the width of the conductive composite sample (S), and the conductive composite sample (S) is located in the center area of the pressing block 710 for the rotating electrode, and the conductive composite sample Through holes (not shown) for rotating electrodes are formed at both ends where (S) is not located.

The fixing bolt 720 for the rotating electrode passes through the through-hole for the rotating electrode and is screwed into the fastening groove for the rotating electrode (not shown) formed on the fixed electrode 400 to provide pressing force to the pressing block 710 for the rotating electrode. do. The fixing bolt 720 for the rotating electrode is formed of an insulating material or coated with an insulating material.

[Bending rotation motor (800), controller (900)]

Rotation motor for bending (800)

The bending rotation motor 800 is coupled to the frame (F) and is connected to the bending rotation shaft 200 to rotate the bending rotation shaft 200. The bending rotation motor 800 is preferably configured as a servo motor.

Controller(900)

The controller 900 controls the rotation angle and rotation speed of the bending rotation motor 800. The controller 900 includes a switch 910 that turns on/off the bending rotation motor 800 and an angle indicating the bending angle of the conductive composite sample (S) by the bending rotation motor 800. A display unit 920 is installed.

Hereinafter, the operation of the bending-resistance fatigue life test device for conductive soft composite material according to an embodiment of the present invention will be described. Reference is made primarily to FIGS. 1 and 2.

In the initial state, the fixed die 100 for bending and the rotary die 300 for bending are arranged at 180 degrees, that is, in a straight line. As shown in FIG. 2, a conductive composite material sample (S) is placed on the upper surface of the fixed electrode 400 and the rotating electrode 500 arranged in a straight line.

The conductive composite material sample (S) placed on the upper surface of the fixed electrode 400 is fixed with the fixing member 600 for the fixed electrode. That is, the pressurizing block 610 for the fixed electrode is placed on the upper surface of the conductive composite material sample (S) placed on the upper surface of the fixed electrode 400, and the fixing bolt 620 for the fixed electrode is fastened to secure the conductive composite material sample. Fix one end of (S).

Likewise, the conductive composite material sample (S) placed on the upper surface of the rotating electrode 500 is fixed with the rotating electrode fixing member 700. That is, the pressurizing block 710 for the rotating electrode is placed on the upper surface of the conductive composite material sample (S) placed on the upper surface of the rotating electrode 500, and the fixing bolt 720 for the rotating electrode is fastened to secure the conductive composite material sample. Fix one end of (S).

Meanwhile, using the present invention, before fastening the fixing bolt 620 for the fixed electrode and the fixing bolt 720 for the rotating electrode, the bending-tensile test can be intensively performed by moving the conductive composite sample (S) to the left and right. The parts can be easily adjusted.

Once the conductive composite material sample (S) is fixed, the plug of the resistance meter is inserted into each of the connection terminals (not shown) of the fixed electrode 400 and the connection terminal (T) of the rotating electrode 500. In a resistance meter, current flows through the conductive composite sample (S) and the resistance is measured.

When the switch 910 of the controller 900 is turned on to operate the bending rotation motor 800, the bending rotation motor 800 rotates the bending rotation shaft 200 at a set angle. The bending fixed die 100 does not move, and the bending rotary die 300 coupled to the bending rotary shaft 200 rotates according to the rotation of the bending rotary shaft 200, so that the conductive composite material sample (S) is bent. You lose.

Before starting the bending test, the bending rotary motor 800 rotates the bending rotary die 300 90 degrees counterclockwise in a horizontal state as shown in FIG. 2, and then rotates the bending die 300 to a horizontal position again in a 90-degree state. Rotate it clockwise to get the zero point.

Once the zero point is corrected, the bending rotary die 300 is rotated at a set angle within the range of 90 degrees to 310 degrees. When the bending rotary die 300 is rotated within the range of 90 degrees to 310 degrees, the conductive composite material sample (S) is bent and stretched around the rotation center end of the bending rotary die 300. At this time, the bending area of the conductive composite sample (S) is stretched and pulled, thereby increasing the resistance of this area.

The bending angle of the conductive composite sample (S) can be confirmed through the angle indicator (A) attached to the frame (F). Additionally, it can also be confirmed through the angle display unit 920 of the controller 900. Measure the change in resistance using a resistance meter.

Repeatedly change the bending angle, number of bends, and bending speed of the conductive composite sample (S) by replacing the conductive composite sample (S) or changing the rotation angle, number of rotations, and rotation speed of the bending rotation motor (800). Bending-resistance can be tested by measuring the change in resistance.

100: Fixed die for bending 200: Rotating shaft for bending
300: Rotating die for bending 400: Fixed electrode
500: Rotating electrode 600: Fixing member for fixed electrode
610: Pressure block for fixed electrode 620: Fixing bolt for fixed electrode
700: Fixing member for rotating electrode 710: Pressure block for rotating electrode
720: Fixing bolt for rotating electrode 800: Rotating motor for bending
900: Controller A: Angle indicator
F: Frame S: Conductive composite sample
T: Connection terminal

Claims (5)

A fixed die for bending coupled to the frame;
a rotating shaft for bending rotatably coupled to the frame;
A bending rotary die, one end of which is coupled to the bending rotary shaft and rotated by rotation of the bending rotary shaft;
A fixed electrode coupled to the bending fixed die and transmitting current to the conductive composite sample placed on the upper surface;
a rotating electrode coupled to the bending rotating die and transmitting current to the conductive composite sample placed on the upper surface;
A fixing member for a fixed electrode connected to the upper surface of the conductive composite sample and fixing the conductive composite sample to the fixed electrode;
A fixing member for a rotating electrode connected to the upper surface of the conductive composite sample and fixing the conductive composite sample to the rotating electrode; and
It is coupled to the frame and includes a bending rotation motor connected to the bending rotation shaft to rotate the bending rotation shaft,
By changing the rotation angle, number of rotations, and rotation speed of the bending rotary motor, the bending angle, number of bending, and bending speed of the conductive composite sample can be changed and the bending-resistance change of the conductive composite sample can be repeatedly measured. A bending-resistance fatigue life test device for conductive soft composite materials, characterized in that there is. The method of claim 1, wherein the bending rotary die is,
A conductive soft composite material, characterized in that the angle between the upper surface of the conductive composite sample placed on the fixed electrode and the upper surface of the conductive composite sample placed on the rotating electrode is rotated in an angle range of 90 degrees to 310 degrees. Bending-resistance fatigue life testing device. The bending-resistance fatigue life test device of a conductive flexible composite material according to claim 2, wherein the left end portion of the bending rotary die is formed as a curved surface. The method of claim 1, wherein the fixing member for the fixing electrode is:
a pressurizing block for a fixed electrode that presses the conductive composite material sample in the direction of the fixed electrode and has a through hole for the fixed electrode; and
A conductive soft composite comprising a fixing bolt for the fixing electrode that penetrates the through-hole for the fixing electrode and is screwed into a fastening groove for the fixing electrode formed on the fixing electrode to provide pressing force to the pressurizing block for the fixing electrode. Bending-resistance fatigue life test device for materials. The method of claim 1, wherein the fixing member for the rotating electrode is,
A pressing block for a rotating electrode that presses the conductive composite material sample in the direction of the rotating electrode and has a through hole for the rotating electrode; and
A conductive soft composite comprising a fixing bolt for the rotating electrode that penetrates the through-hole for the rotating electrode and is screwed into the fastening groove for the rotating electrode formed in the rotating electrode to provide pressing force to the pressing block for the rotating electrode. Bending-resistance fatigue life test device for materials.