A method for detecting a press-bent plate by using an accuracy detection ruler

Abstract

A method for inspecting bent plates using a precision measuring ruler is disclosed. The ruler comprises a long plate and a short plate, hinged at their ends. An electronic measuring component is mounted on the hinged end of the long and short plates, and an angle display is fixed to the electronic measuring component. During inspection, the bottom plate of the long plate is first placed on one side of the bent plate. The start button of the electronic measuring component is pressed, initiating angle measurement. The short plate is then slowly opened until its bottom plate aligns with the other side of the bent plate. The angle value displayed on the angle display is the actual bending angle of the bent plate. Using this method, the measurement accuracy can reach ±0.01 degrees, a 20-fold improvement over previous methods. The measured value can be directly compared with tolerances without secondary calculations, avoiding random deviations caused by human operators. The new tooling allows for inspection by a single person, saving time.

Description

Technical Field

[0001] This invention belongs to the field of marine shipbuilding and design, and specifically relates to a method for inspecting bending plates using a precision measuring ruler. Background Technology

[0002] The angle between the inner bottom plate and the sloping bottom plate of most of the LNG ships under construction by the group is designed to be 135 degrees. The original design involved assembling and welding the inner bottom plate, sloping wall panels, and longitudinal girder together in a three-center alignment. After process optimization, the inner bottom plate and sloping plate are now formed by bending a single flat plate at a bending angle of 135 degrees. This saves on the amount of welding work between the inner bottom plate and the sloping plate. This design, which involves bending the inner bottom plate and sloping plate into a single sheet, saves on welding materials and assembly time compared to the traditional plate-by-plate welding method. To improve the manufacturing accuracy of the bent plate, it needs to be inspected after bending using an angle template.

[0003] During bending, a stamping die is used to complete the forming at room temperature. The cross-sectional arc shape of the die used in the hydraulic press is a positive arc. During bending, the upper die is used to press the bending plate (in a flat state) into the lower die. After the bending plate is in contact with the die mold surface, the upper die is released. After the bending plate rebounds due to internal stress on the lower die, a stable bending plate shape value is obtained.

[0004] Currently, a single steel template is used to test the bending angle accuracy. During testing, the fit between the template and the bending plate must be observed. The testing process involves placing the template inside the bending plate, aligning the template's baseline with the baseline on the bending plate, and observing for any gaps. If a gap is found, a feeler gauge is used to measure the gap value to determine if the bending angle is acceptable. The testing requires two people: one person holds the template upright with both hands, while the other uses the feeler gauge to measure the gap between the template and the bending plate. The angle deviation is calculated using distance conversion to determine if the bending angle is acceptable. However, the template is large and heavy, making position adjustment inconvenient; a single template can only test a fixed angle, making it impossible to measure bending plates with different angles, resulting in poor template versatility.

[0005] The detection deviation requires secondary conversion, and the bending angle deviation needs to be converted from distance values, which is cumbersome, inefficient, and prone to errors. Using a feeler gauge to check the gap between the bending plate and the template actually indicates a deviation in the bending plate's machining angle. When the actual machining angle is greater than the theoretical angle, a gap appears between the template and the upper part of the bending plate; when the machining angle is less than the theoretical angle, the template and bending plate do not fit together. Therefore, there is an urgent need for new tools and methods to quickly and accurately measure bending plate angles to meet the requirements of lean manufacturing. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a method for inspecting bent plates using a precision measuring ruler, the technical solution of which is as follows: A method for inspecting a bent plate using a precision measuring ruler, wherein the precision measuring ruler includes a long ruler and a short ruler, the ends of the long ruler and the short ruler are hinged together, and an electronic measuring component is provided at one end of the long ruler and the short ruler, and an angle display is fixed on the electronic measuring component.

[0007] A base plate is provided on one side of the long ruler and the short ruler along their length. Multiple magnets are embedded in the lower surface of the base plate. Long water bubbles are provided on the surface of both the long ruler and the short ruler.

[0008] During testing, the long ruler and the short ruler are in a closed state. First, place the bottom plate of the long ruler on one side of the curved plate, so that it is in contact with the surface of the curved plate. The magnet is attracted to the surface of the curved plate. The long ruler is perpendicular to the surface of the curved plate. Press the start button of the electronic measuring component to start the angle measurement. Slowly open the short ruler so that its bottom plate is in contact with the other side of the curved plate. The magnet is attracted to the surface of the curved plate. After they are in contact, observe the scale value on the angle display.

[0009] The angle value displayed on the angle display is the actual bending angle of the bending plate. By comparing the measured value with the theoretical value and comparing it with the standard, it can be determined whether the processing angle of the bending plate meets the standard requirements.

[0010] The above-mentioned method for inspecting a bent plate using a precision measuring ruler is further improved by having an inwardly recessed long ruler plate located in the arc-shaped area of ​​the bent plate.

[0011] Furthermore, in the above-mentioned method of using a precision measuring ruler to inspect a bent plate, both the base plate of the long ruler plate and the base plate of the short ruler plate are L-shaped.

[0012] The above-mentioned method for inspecting a bent plate using a precision measuring ruler is further improved by setting the distance between the hinge holes of the long and short ruler plates and the surface of the bent plate to 50mm.

[0013] The above-mentioned method for inspecting a bent plate using a precision measuring ruler is further improved by having an R-stop line on the surface of the bent plate, and overlapping reference lines engraved on the bottom surfaces of the long ruler plate and the short ruler plate. During inspection, the overlapping reference lines coincide with the R-stop line.

[0014] Furthermore, in the above-mentioned method of using a precision measuring ruler to inspect a bent plate, the magnet is a button magnet, and the diameter of the insertion hole of the button magnet is 5mm.

[0015] The above-mentioned method for inspecting the bending plate using a precision measuring ruler is further improved by specifying that the thickness of the long and short ruler plates is 7 mm and the width of the base plate is 15 mm.

[0016] The above-mentioned method for detecting a bending plate using a precision measuring ruler is further improved by setting one long bubble on the long ruler plate and two long bubble on the short ruler plate, with the two long bubble being set horizontally and vertically to the short ruler plate, respectively.

[0017] The measurement method of this invention achieves a measurement accuracy of ±0.01 degrees, a 20-fold improvement over previous methods. The testing fixture is easy to operate, the results are digitized, and the measured values ​​can be directly compared with tolerances without secondary calculations, avoiding random deviations by the measuring personnel. Horizontal and vertical long bubble wrap are installed on the ruler plate, allowing for the inspection of the installation accuracy of other horizontal and vertical components. It is suitable for various component inspections and meets the needs of diverse testing environments. Using the new fixture, one person can perform the inspection, saving time. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the bending plate inspection (short ruler half open); Figure 2 This is a schematic diagram of the testing process (with the short ruler open); Figure 3 yes Figure 1 Schematic diagram of the structure from the perspective of AA; Figure 4 This is a schematic diagram of a curved plate structure; Among them, 1-long ruler, 2-short ruler, 3-electronic measuring component, 4-base plate, 5-R stop line, 6-magnet, 7-angle display, 8-long bubble, 9-bending plate, 10-arc center line. Detailed Implementation

[0019] The invention will be further described with reference to the accompanying drawings.

[0020] A method for inspecting bent plates using a precision measuring ruler, wherein the precision measuring ruler used is, for example... Figure 1 and 2 As shown, the precision measuring ruler includes a long ruler plate and a short ruler plate, which are hinged at their ends. An electronic measuring component is provided at one end of the long ruler plate that is hinged to the short ruler plate, and an angle display is fixed on the electronic measuring component.

[0021] A base plate is provided on one side of the long ruler and the short ruler along their length. Multiple magnets are embedded in the lower surface of the base plate. Long water bubbles are provided on the surface of both the long ruler and the short ruler.

[0022] During testing, the long ruler and the short ruler are in a closed state. First, place the bottom plate of the long ruler on one side of the curved plate, so that it is in contact with the surface of the curved plate. The magnet is attracted to the surface of the curved plate. The long ruler is perpendicular to the surface of the curved plate. Press the start button of the electronic measuring component to start the angle measurement. Slowly open the short ruler so that its bottom plate is in contact with the other side of the curved plate. The magnet is attracted to the surface of the curved plate. After they are in contact, observe the scale value on the angle display.

[0023] The angle value displayed on the angle display is the actual bending angle of the bending plate. By comparing the measured value with the theoretical value and comparing it with the standard, it can be determined whether the processing angle of the bending plate meets the standard requirements.

[0024] When inspecting a bent plate, first place the L-shaped base plate of the angle ruler onto the bent plate, ensuring the L-shaped base plate is flush with the plate surface and the ruler plate upright is perpendicular to the bent plate surface. Press the start button of the measuring component to begin angle measurement. Slowly open the ruler plate, and after the ruler plate base plate is flush with the other side of the bent plate, observe the scale value on the angle display of the measuring component.

[0025] The electronic metering unit has three buttons: measure, shut down, and zero, which can be used to control the measurement process.

[0026] The long ruler is located in the curved area of ​​the curved plate and has an inward indentation. During testing, the opening and closing of the ruler is not affected by the curved plate.

[0027] During measurement, the long ruler can be placed against the curved plate first, and the magnet will attract the steel plate to form a fixed contact surface. Then, the short ruler can be placed against the other side of the curved plate. The angle value on the angle display is the actual bending angle of the curved plate.

[0028] After testing, the rulers are closed, with the upper surface of the long ruler's upright plate touching the upper surface of the short ruler's L-shaped base plate, and the upper surface of the long ruler's upright plate touching the base plate of the short ruler's base plate. The angle display shows an angle of 0.00°.

[0029] When using the device again after it has been turned off, first align the bottom plate of the long ruler with the surface of one side of the curved plate, then turn on the measurement button, then open the short ruler and spread it out until it contacts the surface of the other side of the curved plate. The bottom plate of the short ruler is fixed to the plate surface by magnetic attraction, and the angle value of the electronic angle component is accurately read.

Claims

1. A method for inspecting a bent plate using a precision measuring ruler, characterized in that, The precision measuring ruler used includes a long ruler plate and a short ruler plate, which are hinged at the ends. An electronic measuring component is provided at one end of the long ruler plate that is hinged to the short ruler plate, and an angle display is fixed on the electronic measuring component. A base plate is provided on one side of the long ruler and the short ruler along their length. Multiple magnets are embedded in the lower surface of the base plate. Long water bubbles are provided on the surfaces of both the long ruler and the short ruler. During testing, the long ruler and the short ruler are in a closed state. First, place the bottom plate of the long ruler on one side of the curved plate, so that it is in contact with the surface of the curved plate. The magnet is attracted to the surface of the curved plate. The long ruler is perpendicular to the surface of the curved plate. Press the start button of the electronic measuring component to start the angle measurement. Slowly open the short ruler so that the bottom plate of the short ruler is in contact with the other side of the curved plate. The magnet is attracted to the surface of the curved plate. After they are in contact, observe the scale value on the angle display. The angle value displayed on the angle display is the actual bending angle of the bending plate. By comparing the measured value with the theoretical value and comparing it with the standard, it can be determined whether the processing angle of the bending plate meets the standard requirements.

2. The method for inspecting a bent plate using a precision measuring ruler according to claim 1, characterized in that, The long ruler is located in the curved area of ​​the curved plate and has an inward recess.

3. The method for inspecting a bent plate using a precision measuring ruler according to claim 1, characterized in that, Both the base plates of the long and short rulers are L-shaped.

4. The method for inspecting a bent plate using a precision measuring ruler according to claim 1, characterized in that, The distance between the hinge holes of the long and short rulers and the surface of the curved plate is 50mm.

5. A method for inspecting a bent plate using a precision measuring ruler according to claim 1, characterized in that, The curved plate has an R-stop line on its surface. The bottom plates of the long plate and the short plate are engraved with a coincident reference line. During inspection, the coincident reference line coincides with the R-stop line.

6. The method for inspecting a bent plate using a precision measuring ruler according to claim 1, characterized in that, The magnet is a button magnet, and the diameter of the insertion hole for the button magnet is 5mm.

7. A method for inspecting a bent plate using a precision measuring ruler according to claim 1, characterized in that, The thickness of the long and short boards is 7mm, and the width of the base plate is 15mm.

8. A method for inspecting a bent plate using a precision measuring ruler according to claim 1, characterized in that, There is one long bubble on the long ruler and two long bubbles on the short ruler, with the two long bubbles positioned horizontally and vertically to the short ruler, respectively.

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