WO2023107021A1

WO2023107021A1 - A test device for use in detection of mechanical characteristics in sheet materials

Info

Publication number: WO2023107021A1
Application number: PCT/TR2021/051440
Authority: WO
Inventors: Seyed Sohrab HEIDARI SHABESTARI; Emre PEKGOZ
Original assignee: T.K.G. Otomotiv Sanayi Ve Ticaret Anonim Sirketi
Priority date: 2021-12-09
Filing date: 2021-12-20
Publication date: 2023-06-15
Also published as: TR2021019471A2

Abstract

The invention relates to at least one test device (1) for use in detection of the mechanical characteristics of at least one work piece (60), such as yield strain and elasticity module. The novelty of the invention is characterized in that it comprises at least one drive element (30) associated with at least one punch (32) that can be drilled in the work piece (60) in order to detect the mechanical characteristics due to drilling into the said work piece (60), at least one sensor (33) associated with detecting the stress of the said drive element (30) during drilling, at least one lower support (40) capable of detecting the load by means of at least one load cell (44) in case of a load on the work piece (60) while drilling and at least one control unit (50) for detecting the mechanical characteristics of the work piece (60) according to the data provided from the said sensor (33) and the said load cell (44).

Description

A TEST DEVICE FOR USE IN DETECTION OF MECHANICAL CHARACTERISTICS IN SHEET MATERIALS

TECHNICAL FIELD

The invention relates to at least one test device for use in detection of the mechanical characteristics of at least one work piece, such as yield strain and elasticity module.

PRIOR ART

One of the most common test methods, the tensile test, is used to determine the behaviour of a sample when applying an axial tensile load. Such experiments are used to determine the tension characteristics of a material. This test can be performed on a variety of materials including metals, plastics, elastomers, paper, composites, rubbers, fabrics, adhesives, films, etc.

The tensile test is used continuously in various fields in the present art. The tension characteristics of the sheet material to be processed are determined by this method. The strength characteristics of each sheet material may vary from one another. In these cases, the application of the tensile test causes various problems in continuous manufacturing. Some of the technical problems encountered in the present art are listed as follows;

1 . The mechanical characteristics of each roll of sheet cannot be checked even before feeding,

2. Tensile test specimen for each roll of sheet is not provided by the supplier,

3. Sample preparation and tensile testing according to predetermined standards for tensile testing cannot be done quickly,

4. It is not possible to accept goods suitable for the certification of the material and to verify them at the beginning of the line.

Application numbered US2013247645 known in the literature relates to a hardness test device and hardness test method in which hardness of an object can be accurately measured without removing a surface layer thereof. A hardness device evaluating the hardness of a sample with reference to the difference in a recess depth between a first and a second initial test load is applied to the sample by the recess and by adding an additional test load to the first test load and the load is returned to the first test load when an initial test load is applied to the surface of the sample.

The application numbered CN112362469 known in the literature relates to a small drilling test device. An upper pressing die and a lower pressing die are located in a clamp seat; the upper pressing die is placed in the lower pressing die; a ball's pressing head is placed in the upper pressing die and a punch is movably arranged in the upper pressing die. The device also includes the clamping nut and a sensor mounting structure; a pressing block is against the upper pressing die. The clamping nut is secured to the clamp slot and the pressing block is clamped.

The application numbered CN111307601 known in the literature relates to a test device for the yield strength of steel bars comprising a load cell, a support plate, a pressure plate and a force application plate. A portion of the device and a mounting plate are welded between the first support frame and the second support frame. A hydraulic push cylinder is provided on the plate and the lower part of the hydraulic cylinder is connected to the force application plate.

Even though alternative test methods have been tried instead of tensile test in the present art, it has not been preferable for reasons such as failure to obtain the same accuracy result for each material type, technical problems experienced during application and usage difficulties.

As a result, all the problems mentioned above have made it necessary to make an innovation in the relevant technical field.

BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to a test device in order to eliminate the above-mentioned disadvantages and to bring new advantages to the related technical field.

An object of the invention is to provide a test device use in detection of the mechanical characteristics of the sheet material.

Another object of the invention is to provide an accelerated and facilitated test device for the detection of the mechanical characteristics of the sheet material. Another object of the invention is to provide a test device that allows the detection of the mechanical characteristics of the roll-shaped sheet material without taking samples.

In order to realize all the purposes that will emerge from the abovementioned and the following detailed description, the present invention is at least one test device for use in detection of the mechanical characteristics of at least one work piece, such as yield strain and elasticity module. Accordingly, its novelty comprises at least one drive element associated with at least one punch that can be drilled in the work piece in order to detect the mechanical characteristics due to drilling into the said work piece, at least one sensor associated with detecting the stress of the said drive element during drilling, at least one lower support capable of detecting the load by means of at least one load cell in case of a load on the work piece while drilling and at least one control unit for detecting the mechanical characteristics of the work piece according to the data provided from said sensor and said load cell. Thus, various mechanical characteristics can be detected depending on the drilling of the work piece.

A possible embodiment of the invention is characterized in that it comprises at least one discharge box to allow the discharge of the waste by drilling a hole in the work piece on the lower support. Thus, it is possible to remove the waste material resulting from the drilling of the work piece from the test device.

Another possible embodiment of the invention is characterized in that said drive element is at least one hydraulic piston and the sensor is configured to detect the change in hydraulic pressure. Thus, the work piece is drilled with hydraulic pressure and the effort spent in this drilling process is detected by the change in hydraulic pressure.

Another possible embodiment of the invention is characterized in that it comprises at least one ruler to which the drift connected to the drive element is associated to detect the feed distance when drilling the work piece. Thus, the amount of feed during the drilling of the work piece is detected.

Another possible embodiment of the invention is characterized in that the feed rate of the drive element is adjustable according to the work piece. Thus, it is ensured that work pieces with different thickness and strength values can be drilled at different speeds.

Another possible embodiment of the invention is characterized in that it comprises the steps of placing the work piece on the lower support to detect the mechanical characteristics of the work piece such as yield strain and elasticity module, drilling the work piece by the drive element via the punch, detecting the load on the drive element during the drilling of the work piece by the sensor, detecting the load on the work piece during the drilling of the work piece by the load cell and determining the mechanical characteristics of the work piece by the control unit according to the detection results. Thus, various mechanical characteristics can be detected depending on the drilling of the work piece.

BRIEF DESCRIPTION OF THE FIGURES

A representative perspective view of the test device of the invention is given in Figure 1 .

A representative exploded view of the lower support in the test device of the invention is given in Figure 2.

A representative view of the force-time graph obtained from the test device of the invention is given in Figure 3a.

A representative view of the force-distance graph obtained from the test device of the invention is given in Figure 3b.

A representative view of a stress graph used in the detection of the material characteristic in the test device of the invention is given in Figure 3c.

DETAILED DESCRIPTION OF THE INVENTION

The subject of the invention is explained with examples that do not have any limiting effect only for a better understanding of the subject in this detailed description.

A representative perspective view of the test device (1 ) of the invention is given in Figure 1 . Accordingly, the inventive test device (1) is used to detect the mechanical characteristics of the work piece (60). These mechanical characteristics include physical characteristics such as yield strain, elasticity modulus, and n parameter value. The aforementioned n parameter value is the strain stiffening exponent (also known as the stress stiffening index), usually denoted by n, and is a constant frequently used in calculations of strain-stress behaviour in work stiffening. The n value found in Hollomon, Swift, Voce and similar equations is used to estimate stress-strain behaviours in the non-linear plastic deformation region of the material. The tested work piece (60) can be in the form of sheet metal. The work piece (60) is essentially a rolled sheet part in a preferred embodiment of the test device (1). Mechanical stress characteristics can be detected when the roll-shaped work piece (60) is separated from the roll before it is processed in this way.

There is at least one chassis (10) on the test device (1 ). The chassis (10) is mainly manufactured in the form of a carcass structure. Thus, a resistant chassis (10) structure is obtained. It is ensured that the necessary tests can be performed by placing the work piece (60) on the chassis (10). There is at least one connecting plate (11) on the side of the chassis (10) facing the work piece (60). There may be various test device (1) elements on the said connecting plate (11 ). There is at least one drive assembly (12) adjacent to the chassis (10). The said drive assembly (12) supports the positioning of at least one drive element (30) on the test device (1) and its operation during the test.

There is at least one body (20) on the test device (1). The said body (20) is positioned between the chassis (10) and the drive assembly (12). The body (20) has a substantially C shape. Drilling is performed in the work piece (60) inserted between it thanks to this form of the body (20). The side of the body (20) facing the chassis (10) will be referred to as at least one body base (21 ) and the other side as at least one body ceiling (22).

The said drive element (30) is positioned on the test device (1). The drive element (30) is essentially positioned on the body ceiling (22). The drive element (30) has the ability to apply force to drill a hole in the work piece (60). The drive element (30) may be a piston in a possible embodiment of the invention for this. The drive element (30) is driven by the hydraulic pressure it receives from a hydraulic source (not shown in the figure). The advancing velocity of the drive element (30) may be set in a predetermined manner by analog valves. It is possible to drill different work pieces (60) at different speeds in this way. The drive element (30) is associated with the at least one punch (32) by means of the at least one punch holder (31). The punch holder (31 ) allows the punch (32) to be retained. The punch (32) allows the work piece (60) to be drilled as a result of plastic deformation with the force it receives from the drive element (30).

The drive element (30) is associated with the at least one sensor (33). The said sensor (33) is configured to detect the stress of the drive element (30). In a possible embodiment of the invention, it detects the pressure change in the fluid during the supply of the fluid required for the drive element (30). Control of the hydraulic pressure in a control unit (50) of the analog signal received instantly from the transmitter, monitoring and control above the determined limit values in a way that it can reduce the pressure in a time t with the appropriate software by interrupting the system. The force required by the work piece (60) is detected while it is drilled in this way. In addition, there is at least one ruler (34) around the drive element (30). The said ruler (34) allows the detection of the progression distance on the work piece (60) of the end of the punch (32). This ruler (34) may be a device capable of electronically detecting the amount of advance in a possible embodiment of the invention. Thus, the amount of feed can be detected as time-distance in the drilling process applied by the drive element (30).

A representative exploded view of the lower support (40) in the test device (1) of the invention is given in Figure 2. Accordingly, at least one lower support (40) is positioned on the test device (1). The lower support (40) is essentially positioned on the body base (21). The work piece (60) to be tested is positioned on the lower support (40). The lower support (40) allows the detection of the reaction force on the work piece (60) during hole drilling. There is at least one load cell (44) on the lower support (40) to do this. It enables the load on the load cell (44) to be converted into an electrical signal. To do this, the load cell (44) is positioned between at least one support base (41) and at least one support ceiling (42). Thanks to the slot form in the support base (41), it allows it to be positioned in the load cell (44). The said support ceiling (42) transmits to the load cell (44) when a load is placed on the work piece (60). Thus, the load is transferred to the work piece (60).

In addition, the lower support (40) allows the discharge of the waste part that occurs during the drilling of the hole in the work piece (60). There is at least one discharge box (45) between the load cell (44) and the support ceiling (42) to do this. There is a space in the said discharge box (45) in order to transport the waste part. The discharge box (45) is associated with at least one discharge hole (43) on the support ceiling (42). The said discharge hole (43) is positioned so that it is essentially in line with the punch (32). The waste formed in the work piece (60) drilled by the punch (32) enters the discharge box (45) and is discharged from that part in this way. The punch is allowed to move for the next operation step in this way.

A representative view of the force-time-distance graphs obtained from the test device (1) of the invention is given in Figure 3a and 3b. Accordingly, the test device (1 ) allows various graphs to be obtained depending on the data it receives from the load cell (44), the sensor (33) and the ruler (34). The test device (1 ) is associated with at least one control unit (50) in order to do this. The said control box (50) allows various data to be received and compiled on the test device (1). The control unit (50) is operated in a PLC controlled manner in order to do this. There may also be a control panel on the control unit (50). The said control panel enables the operator to control the test device (1) and to report the test result to the operator. A representative view of a stress graph used in the detection of the material characteristic in the test device (1) of the invention is given in Figure 3c. Accordingly, the control unit (50) obtains various graphs according to the detection results of the test device (1) during the drilling of the work piece (60). The V-Mises theory region (I), Tresca theory region (II) and approval region (III) of the material are formed depending on the results of this detection. These intervals can be determined according to previous experiments. Thus, the suitability of the work piece (60) is determined by determining the characteristic of the graph based on the data obtained as a result of the drilling process. Subsequently, the user provides an audible, visual or graphical warning of the operator by the control unit (50).

Environmental elements such as light curtains, distance sensors, double hand protected controlled starting system can be used on the test device (1 ) to be protected against occupational accidents with the necessary equipment in terms of occupational safety. In addition, very fast contactable safety relays can be used for safety controls to be provided with emergency stop. Stop buttons can be used for emergencies.

It is ensured with this embodiment that the work piece (60) can make a multidirectional detection depending on the results of the load cell (44), the sensor (33) and the ruler (34). Analog hydraulic starters are determined for the system that provides the movements of the drive element (30), allowing the piston speed to operate on the basis of PID according to the amount of pressure and extending the reception time of the processed analog signal while receiving instantaneous force data. Thus, it is aimed to increase the number of sampling/accuracy parameter values. Thus, it is ensured that the values such as yield strain, n parameter value and elasticity module of the work piece (60) are detected together.

The scope of protection of the invention is specified in the attached claims and cannot be limited to those explained for exemplary purposes in this detailed description. It is evident that a person skilled in the art may exhibit similar embodiments in light of above-mentioned facts without departing from the main theme of the invention. REFERENCE NUMBERS GIVEN IN THE FIGURE

I Test Device

10 Chassis

I I Connecting Plate

12 Drive Assembly

20 Body

21 Body Base

22 Body Ceiling

30 Drive Element

31 Punch Holder

32 Punch

33 Sensor

34 Ruler

40 Lower Support

41 Support Base

42 Support Ceiling

43 Discharge Hole

44 Load Cell

45 Discharge Box

50 Control Unit

60 Work Piece

(I) V-Mises Theory Region

(II) Tresca Theory Region

(III) Approval region

Claims

1. At least one test device (1) for use in detection of mechanical characteristics of at least one work piece (60), such as yield strain and elasticity module, characterized in that it comprises at least one drive element (30) associated with at least one punch (32) that can be drilled in the work piece (60) in order to detect the mechanical characteristics due to drilling into the said work piece (60),

At least one sensor (33) to which the said drive element (30) is associated to detect the stress during drilling,

At least one lower support (40) capable of detecting the load by means of at least one load cell (44) in case of a load on the work piece (60) while drilling and at least one control unit (50) for detecting the mechanical characteristics of the work piece (60) according to the data provided from said sensor (33) and said load cell (44).

2. A test device (1 ) according to claim 1 , characterized in that it comprises at least one discharge box (45) to allow the discharge of the waste by drilling a hole in the work piece (60) on the lower support (40).

3. A test device (1 ) according to claim 1 , characterized in that the said drive element (30) is at least one hydraulic piston and the sensor (33) is configured to detect the change in the hydraulic pressure.

4. A test device (1 ) according to claim 1 , characterized in that it comprises at least one ruler (34) to which the punch (32) connected to the drive element (30) is associated to detect the feed distance when drilling the work piece (60).

5. A test device (1 ) according to claim 1 , characterized in that the feed rate of the drive element (30) is adjustable according to the work piece (60).

6. A method suitable for the test device (1 ) according to claim 1 , characterized in that it comprises the following steps for detecting the mechanical characteristics of the work piece (60) such as yield strain and elasticity module;

Placing the work piece (60) on the lower support (40),

Drilling the work piece (60) by the drive element (30) through the punch (32), Detecting the load on the drive element (30) by the sensor (33) during the drilling of the work piece (60),

9 Detecting the load on the work piece (60) during drilling of the work piece (60) by the load cell (44) and determining the mechanical characteristics of the work piece (60) by the control unit (50) according to the detection results.