KR200180502Y1 - Portable Stress-Strain Measuring Instrument and Stress-Strain Curve Analysis System with The Same - Google Patents

Abstract

Convert servomotors, reducers, and rotational movements into linear reciprocating motions to accurately maintain the position of the measurement points, measure stresses and displacements for varying loads, and analyze the measured values on site to inspect mechanical properties of the workpiece. Removable stress-displacement measuring device including a reciprocating device for conveying and transmitting a pressure member in contact with the workpiece, a load cell with a strain gauge capable of measuring stress, a differential transformer for measuring displacement, and a moving stress-displacement The controller receives the measured value from the measuring device, converts it into digital value, outputs it as numerical data and graph, and controls the servo motor and the reducer, and inputs the control value for the servo motor and the reducer and inputs the value from the controller. Output and save data and graphs as images or prints, and analyze the program It provides a displacement curve analysis device stress by the displacement measuring devices - the mobile computer including a stress.

Description

Portable Stress-Strain Measuring Instrument and Stress-Strain Curve Analysis System with The Same}

The present invention provides a mobile stress-displacement measuring instrument using a load cell, a differential transformer and a servomotor, and a stress-strain curve analysis device using the same to measure and analyze the mechanical properties of parts and axes of large-scale equipment directly in the field. It is about.

In general, a turbine shaft of a power generation facility, an aircraft, or a screw shaft of a ship consists of a large shaft of about 200 mm in diameter.

In the case of such a large shaft is expensive, it is possible to use it close to the endurance life, it is important to check the stress and fatigue, etc. on a regular basis for this purpose.

In the case of the above-mentioned large axis, it is always dangerous to be damaged in case of breakage, so it should always be inspected for the change in mechanical strength.

However, in the case of the large axis as described above, it is difficult to measure the stress or displacement accurately in the laboratory because it is difficult to transport, and most samples are collected and inspected or measured using a simple tester.

In the case of taking a sample and inspecting the sample, it is impossible to find out if a defect occurs at an unexpected position because it is a test of a part.

In addition, in the case of measuring using a simple tester, the error of a measured value changes according to a posture or a skill of a measurer.

In particular, in the case of a circular workpiece such as a large axis, the skill of the operator is required.

In addition, in the conventional inspection method, data for analyzing various mechanical properties is insufficient, so it is difficult to accurately grasp the overall state.

The present invention is to solve the above problems, it is possible to accurately maintain the position of the measuring point using a chain of variable length, and to apply a variable load set by using a servo motor and a reducer. In addition, stress and displacement of variable loads are measured by using a load cell with a built-in strain gauge and a linear varable differential transformer (LVDT), and using a computer, graphs or numerical data. It is to provide a mobile stress-displacement measuring device and a stress-strain curve analysis device using the same, which can examine the mechanical properties of the workpiece by outputting or analyzing the measured value.

1 is a perspective view showing an embodiment of a mobile stress-displacement measuring instrument according to the present invention.

Figure 2 is a partial cross-sectional front view showing an embodiment of a mobile stress-displacement measuring instrument according to the present invention.

Figure 3 is a partially enlarged cross-sectional view showing a pressing member in an embodiment of a mobile stress-displacement measuring device according to the present invention.

Figure 4 is a partially enlarged perspective view showing the state of use of the fixed chain in one embodiment of a mobile stress-displacement measuring device according to the present invention.

Figure 5 is a block diagram schematically showing an embodiment of a stress-displacement curve analysis device using a mobile stress-displacement measuring instrument according to the present invention.

The mobile stress-displacement measuring device proposed by the present invention includes a servo motor capable of forward and reverse rotation, a speed reducer for reducing and transmitting the rotational force of the servo motor at a predetermined speed ratio, and a rotational motion transmitted from the speed reducer. A reciprocating device for converting and transferring the reciprocating motion, a pressure member connected to the reciprocating device and installed to move together and applying a load in contact with the measurement object, and installed between the reciprocating device and the pressure member and being provided with a pressure member. A load cell having a built-in strain gauge capable of measuring a stress transmitted through the differential, a differential transformer installed between the reciprocating device and the pressing member and measuring displacement in response to the movement of the pressing member; The support for the servo motor, the reducer and the reciprocating device is installed, and the support for the above is installed and in contact with the workpiece. Includes a pedestal.

In addition, the mobile stress-displacement measuring device proposed by the present invention further includes a fixing chain which can be fastened to maintain the state in which the pedestal is in close contact with the workpiece.

In addition, the stress-strain curve analysis device using the mobile stress-displacement measuring device proposed by the present invention is equipped with a load cell with a strain gauge for measuring stress and a differential motor for measuring displacement and a servomotor for applying a load. And a mobile stress-displacement measuring device equipped with a speed reducer and a measured value from the above-mentioned mobile stress-displacement measuring device. The measured value is converted into digital values and outputted as numerical data and graphs. A control device for controlling the controller, input control values for the servo motor and the reducer to the control device, and output and store numerical data and graphs inputted from the control device as images or printed materials, and include an analysis program. Includes a computer.

Next, a preferred embodiment of the mobile stress-displacement measuring device and the stress-strain curve analyzing apparatus using the same according to the present invention will be described in detail with reference to the accompanying drawings.

First, as shown in FIG. 1 and FIG. 2, the mobile stress-displacement measuring device according to the present invention decelerates the rotational force of the servo motor 10 capable of forward and reverse rotation and the servo motor 10 at a predetermined speed ratio. Is connected to the reciprocating device 16 and the reciprocating device 16 which converts and transmits the rotational movement received from the reducer 12 into a linear reciprocating motion, and is connected to the reciprocating device 16. The pressure member 20 is installed to apply a load in contact with the measurement object 2, and the stress transmitted between the reciprocating device 16 and the pressure member 20 and transmitted through the pressure member 20 is measured. Load cell 38 with a built-in strain gage, and the differential between the reciprocating device 16 and the pressing member 20 is installed and connected to the movement of the pressing member 20 to measure the displacement The transformer 30, the servomotor 10 and the deceleration described above And a support 4 on which the machine 12 and the reciprocating device 16 are installed, and a support 40 on which the support 4 is installed and in contact with the measurement object 2.

The bottom surface in contact with the measurement object 2 of the pedestal 40 is formed in an approximately '∧' shape so as to be inclined at a predetermined angle toward the central portion so as to be in close contact with the outer peripheral surface of the measurement object 2, which is a large shaft or the like, in double contact. do.

In addition, the center portion of the pedestal 40 is formed with a measuring hole 41 for moving the pressing member 20.

And the mobile stress-displacement measuring device according to the present invention, as shown in Figure 2 and 4, a fixed chain that can be fastened to maintain the state in close contact with the pedestal 40 and the measurement object 2 ( 46).

The fixed chain 46 is made so that there is no change in length even when the tension due to the load for measurement is applied, it is preferable to manufacture in two rows or more.

For example, when the load for measurement is about 100 kgf, the tension that can be tolerated without changing the length of the fixed chain 46 is made to be 500 kgf or more.

One end of the fixed chain 46 is provided with an adjusting bolt 47 to adjust the length to adjust the tension.

The fixing bolt 49 is screwed to the adjustment bolt 47 is assembled, and one or more adjustment rings 48 are inserted into a predetermined height to adjust the length.

On one side of the pedestal 40 (the right end face in FIG. 2), a fixing part 42 is provided in which a fixing hole 43 into which the adjusting bolt 47 of the fixing chain 46 is inserted is formed. On the other side (the left end face in FIG. 2), at least one latch 45 is inserted into the hole of the other end of the fixing chain 46 to secure the fixing chain 46 by being caught by the bush. The engaging portion 44 is formed.

Referring to the method of fixing the pedestal 40 in close contact with the measurement object 2 using the fixed chain 46 made as described above, the measurement object 2 from the adjustment bolt 47 of the fixed chain 46 described above. With the other end of the fixed chain 46 positioned at the length corresponding to the circumference of the circumference to the latch 45, the winding of the workpiece 2 with the fixed chain 46 one turn (47) is inserted into the fixing hole 43, and then the fixing nut 49 is fastened to the adjusting bolt 47.

When the fixing chain 46 is long when the adjusting bolt 47 is inserted into the fixing hole 43, the adjusting ring 48 is inserted into the adjusting bolt 47, and then the fixing nut 49 is inserted. Tighten.

In the locking portion 44 of the pedestal 40, the pedestal 40 is further measured for the direction of tension acting on the fixing chain 46 caught by the latch 45 and the winding direction of the fixing chain 46. In order to be in the direction of close contact with the water (2) is formed an insertion hole 50 into which the fixing chain 46 is inserted.

1 and 2, the flange portion of the lower part is fixed to the pedestal 40 by a bolt 52 or the like, and the load cell 38 and the differential transformer 30 are described above. The part in which is located is formed in a cylindrical shape.

In the reciprocating device 16, an LM guide, a ball screw, or the like, which is used to convert a rotational motion into a linear reciprocating motion, is generally applicable.

In addition, the pedestal 40 is provided with a reference protrusion 34 which is in contact with the end face of the measuring device 32 of the differential transformer 30.

In order to increase the surface roughness, the upper surface of the reference protrusion 34 in contact with the differential transformer 30 measuring device 32 is preferably subjected to finishing such as polishing or polishing.

The differential transformer 30 is provided with an adjusting knob 35 for adjusting the zero point.

In addition, the differential transformer 30 is fixedly installed in the adapter 36 which is integrally installed on the rod 17 of the reciprocating device 16 to move up and down with the pressing member 20.

As shown in FIG. 3, the pressing member 20 includes a pressing ball 28 in contact with the surface of the measurement object 2 and a ball receiving 26 into which the pressing ball 28 is inserted and the female thread is processed on the inner circumferential surface thereof. ), And a male thread 25 coupled to the female thread machined on the ball support 26 is formed, and a tapered portion 23 is formed to be inserted into and fixed to the rod 17 of the reciprocating device 16. The end face in contact with the pressing ball 28 is made of a load transfer member 22 attached with a cemented carbide 24 or the like so as not to be deformed.

That is, the cemented member 24 is attached to the surface of the pressing member 20 in contact with the pressing ball 28 so that when the load is applied, the pressing ball 28 causes the opposite direction to the measurement object 2 by the pressing ball 28. By preventing the concave indentation portion is formed in the load transmission member 22 located in the, it is configured so that the load always acts only on the measuring object 2 through the pressure ball 28.

The width of the pedestal 40 and the support 4 is preferably manufactured to a size that can be installed between the blades when measuring the turbine shaft or the like.

Next will be described the operation of the mobile stress-displacement measuring device according to the present invention configured as described above.

First, while holding the other end of the fixed chain 46 on the pedestal 40, the fixed chain 46 is wound along the outer circumferential surface of the workpiece 2, and then on one end of the fixed chain 46. Insert the adjusting bolt 47 into the fixing hole 43, and tighten the fixing nut 49 to fix it firmly.

When the servomotor 10 is operated in the above state and the reducer 12 is controlled, the rotational force is decelerated at a predetermined rotational speed and transmitted to the reciprocating device 16, and the rotation of the servomotor 10 is performed. Accordingly, the rod 17 of the reciprocating device 16 moves toward the workpiece 2, and the pressing ball 28 of the pressing member 20 comes into contact with the surface of the workpiece 2.

At this time, the measuring device 32 of the differential transformer 30 is in contact with the upper surface of the reference protrusion 39 of the pedestal 40, and the differential transformer 30 is adjusted to zero at this position (measurement reference point setting). Will be performed.

Subsequently, when the rotational force of the servomotor 10 is transmitted, the pressing ball 28 of the pressing member 20 presses into the surface of the measurement object 2 and enters the surface of the workpiece 2, and the load cell 38 measures the change in stress. In the differential transformer 30, the change in displacement is measured.

As described above, the mobile stress-displacement measuring device according to the present invention measures the amount of change in stress and displacement of the workpiece 2 according to the load applied through the servomotor 10 and the load cell 38 and the differential transformer 30. ).

And one embodiment of the stress-displacement curve analysis device using a mobile stress-displacement measuring device according to the present invention, as shown in Figures 1 and 6, the load cell 38 with a built-in strain gauge capable of measuring the stress and displacement A mobile stress-displacement measuring instrument (1), in which a differential transformer (30) capable of measuring and a servomotor (10) and a reducer (12) for applying a load, is installed, and the above-mentioned mobile stress-displacement measuring instrument (1). The control device 60 which receives the measured value from the measured value and converts it into a digital value and outputs the numerical data and the graph, and controls the servo motor 10 and the reducer 12 of the above-described mobile stress-displacement measuring instrument 1. And inputting control values for the servo motor 10 and the reducer 12 to the control device 60, outputting and storing numerical data and graphs input from the control device 60 as images or printed matter. Analysis program And a stored computer 70.

The control device 60 is connected to a power source, and the servomotor 10, the speed reducer 12, the load cell 38, and the differential transformer 30 of the mobile stress-displacement measuring instrument 1 are connected through a wire. do.

The power is applied to the servo motor 10 through the control device 60 in the connected state as described above, and the control signal for controlling the rotational speed of the servo motor 10 and the speed ratio of the reduction gear 12 is controlled. Transmit from device 60.

In addition, the measured value for the stress or displacement measured from the load cell 38 and / or differential transformer 30 is transmitted to the control device 60 described above.

The control device 60 is provided with an analog-to-digital converter (A / D convertor), and converts the analog signal which is a measurement value for the stress or displacement transmitted from the mobile stress-displacement measuring instrument 1 into a digital signal. Then, it is transmitted to the computer 70 described above.

In addition, the control device 60 is provided with a power supply device that can be applied to the servo motor by controlling the power input from the external power source.

The computer 70 outputs data values converted into digital signals and transmitted as numerical data or graphs (images or printed matters).

The computer 70 is connected to a monitor or a printer.

In addition, the computer 70 stores the data values, processes them through a built-in analysis program, and analyzes the mechanical properties (strength, stiffness, fatigue limit, hardness, etc.) to be examined. I print a graph.

The computer 70 has a built-in control program for inputting a control value for controlling the servo motor 10 or the reducer 12 to the control device 60.

As described above, when the maximum load for the measurement and the fluctuation range of the load, the acting time of the load, the number of acts of the load, etc. are inputted through the control program built into the computer 70, the control device 60 receives the control value. ) Transmits a control signal for controlling whether the servomotor 10 is forward or reverse rotation, the rotation time, the speed ratio of the reducer 12, and the like.

For example, as the control device 60 transmits a control signal to repeatedly apply and remove loads, it is possible to analyze the value for the fatigue limit of the measurement object 2.

According to the stress-displacement curve analysis device using a mobile stress-displacement measuring device according to the present invention made as described above, the stress and displacement of the workpiece (2) is measured while applying a load under various conditions, and the numerical data and By outputting a graph and analyzing it, it is possible to read out the exact mechanical properties of the workpiece 2.

In the above, a preferred embodiment of the mobile stress-displacement measuring device and the stress-strain curve analysis device using the same has been described, but the present invention is not limited thereto. Various modifications can be made within the scope of the drawings, which also fall within the scope of the present invention.

According to the mobile stress-displacement measuring device according to the present invention made as described above, it is possible to directly measure the measurement object in the field to obtain accurate measurement values and inspection results, and to measure by setting the measuring points of various positions. .

In addition, according to the mobile stress-displacement measuring device according to the present invention, it can be fixed so that it does not shake and does not change the position of the measuring point by being in close contact with the round outer circumferential surface using a chain, so that accurate measurement values can always be obtained.

In addition, according to the mobile stress-displacement measuring instrument according to the present invention, it is possible to measure stress and displacement in combination by using a load cell and a differential transformer with a strain gauge and to apply various loads using a servomotor and a reducer, so that accurate measurement is possible. It is possible and reproducible in various situations, making it possible to diagnose the exact condition of the workpiece.

According to the stress-strain curve analysis device using the mobile stress-displacement measuring instrument according to the present invention, since the measured values obtained from the mobile-strain measuring device are analyzed and provided as graphs and numerical data, it is necessary to accurately analyze the mechanical properties of the workpiece. It is possible.

In addition, according to the stress-strain curve analysis device using a mobile stress-strain measuring device according to the present invention, it is possible to analyze all the mechanical properties of the workpiece in the field, so that necessary measures can be taken in a short time.

Claims (6)

Servo motor capable of forward and reverse rotation, A reduction gear for reducing and transmitting the rotational force of the servomotor to a predetermined speed ratio; A reciprocating device for converting and transmitting the rotational movement received from the speed reducer into a linear reciprocating motion, A pressurizing member connected to the reciprocating device and installed to move together and applying a load in contact with the measurement object; A load cell installed between the reciprocating device and the pressing member and having a strain gage capable of measuring a stress transmitted through the pressing member; A differential transformer installed between the reciprocating device and the pressing member and measuring displacement in conjunction with the movement of the pressing member; A support on which the servomotor, the reducer, and the reciprocating device are installed; A movable stress-displacement meter, comprising a pedestal in which said support is installed and in contact with the workpiece. The mobile stress-displacement measuring device of claim 1, wherein a bottom surface of the pedestal contacting the measurement object is formed to be inclined at a predetermined angle at both corners toward the center portion so as to closely contact the outer peripheral surface of the pedestal in double contact. The method of claim 1, further comprising a fixed chain to maintain the state in which the pedestal is in close contact with the measurement object without change and one end adjustment bolt is installed, On one side of the pedestal, a fixing part is formed in which a fixing hole into which the adjusting bolt of the fixing chain is inserted is installed, and on the other side of the pedestal, it is inserted into the hole of the other end of the fixing chain and fixed by being caught by the bush. A mobile stress-displacement meter with a catch formed by at least one catch that secures the chain. The mobile stress-displacement measuring device of claim 1, wherein the pedestal is in contact with the end face of the differential transformer and is provided with a reference protrusion having a polished or polished upper surface. According to claim 1, wherein the pressing member is a pressing ball in contact with the surface of the workpiece, The ball bearing is inserted into the pressure ball and the female thread is processed on the inner peripheral surface, A male thread machine coupled to the female thread machined on the ball support is formed, and a tapered portion is formed to be inserted into and fixed to the rod of the reciprocating device. Stress-displacement meter. A mobile stress-displacement measuring instrument equipped with a load cell with a strain gauge capable of measuring stress, a differential transformer capable of measuring displacement, and a servomotor and a speed reducer for applying load; A control device which receives the measured value from the mobile stress-displacement measuring instrument, converts it into a digital value, outputs the numerical data and the graph, and controls the servomotor and the reducer of the mobile stress-displacement measuring instrument; A mobile stress-displacement measuring instrument comprising a computer with inputting control values for the servomotor and the reduction gear to the control device, outputting and storing numerical data and graphs input from the control device as an image or printed matter, and having an analysis program embedded therein. Stress-strain curve analysis device.