A testing tool and method for testing the roughness of the fillet of a large crankshaft journal

Abstract

The present invention belongs to the technical field of engine parts manufacturing, and relates to crankshaft processing and manufacturing, and specifically to a gauge and method for detecting the roughness of the fillet of a large crankshaft journal, comprising a roughness meter, a support frame, the support frame comprising a base plate, a column vertically arranged on the base plate, and a posture adjustment device, the posture adjustment device comprising a lifting seat and a connecting block, the lifting seat being movably mounted on the column, the lifting seat being provided with a first rotating shaft, the connecting block being provided with a second rotating shaft, the second rotating shaft being horizontally arranged, the roughness meter being rotatably mounted on the second rotating shaft through its tail end, when the roughness meter rotates around the second rotating shaft, the stylus of the roughness meter rotates or swings in a vertical plane; the detection method, adjusting the measuring rod to be parallel to the sampling arc chord, can adapt to the travel path of the stylus for measuring the concave arc surface, solves the problem that the roughness fillet of a large crankshaft cannot be quantitatively detected at present, and realizes the control of the consistency of fillet roughness in the production process.

Description

Technical Field

[0001] The invention belongs to the technical field of engine parts manufacturing, and relates to crankshaft processing and manufacturing, and specifically relates to a testing tool and method for detecting the fillet roughness of a large crankshaft journal. Background Art

[0002] The crankshaft is a key component of the transmission system of the internal combustion engine. It will bear bending load and torsion load during the working process. The dangerous area of ​​the crankshaft is the transition fillet where the main journal, connecting rod journal and crank arm are connected. The fillet roughness directly affects the fatigue strength of the crankshaft. Too rough fillet roughness will reduce the fatigue resistance of the crankshaft. Therefore, it is an important process to detect the roughness of the crankshaft journal fillet during the crankshaft processing.

[0003] Small crankshafts are usually tested with a roughness profiler. Large crankshafts such as those of ship engines are usually larger than 2 meters in size. The existing roughness profiler detection parameters are not suitable for the detection of large crankshaft fillets. The existing comparison method is used to detect the fillet roughness of large crankshaft journals. This method compares with the roughness comparison sample and subjectively judges whether the measured fillet roughness meets the requirements. Obviously, this method can only make qualitative judgments on the fillet roughness of large crankshaft journals, and cannot achieve quantitative control of the fillet roughness consistency in the production process. This method cannot meet the high-precision production requirements of large crankshafts such as modern large ship engines. Summary of the invention

[0004] The purpose of the present invention is to solve the insufficiency of the existing detection equipment capabilities, to provide a detection fixture and method for detecting the fillet roughness of a large crankshaft journal, and to effectively realize quantitative detection of the fillet roughness of a large crankshaft journal.

[0005] The technical solution to achieve the above purpose is as follows:

[0006] A test fixture for detecting the roughness of the fillet of a large crankshaft journal comprises a roughness meter, the roughness meter comprises a measuring rod end and a tail end opposite to the measuring rod end, a stylus is installed at the end of the measuring rod end, and a support frame for installing the roughness meter, the support frame comprises a base plate, a column vertically arranged on the base plate and a posture adjustment device,

[0007] The posture adjustment device includes a lifting seat and a connecting block. The lifting seat can be lifted and lowered on the column. The lifting seat is provided with a first rotating shaft, which is vertically arranged. The connecting block can be rotatably installed on the first rotating shaft. The connecting block is provided with a second rotating shaft, which is horizontally arranged. The roughness meter is rotatably installed on the second rotating shaft through its tail end. The rotation angles of the connecting block and the roughness meter are both controllable. When the roughness meter rotates around the second rotating shaft, the stylus of the roughness meter rotates or swings in a vertical plane.

[0008] Furthermore, the posture adjustment device also includes a vertical rotating plate, which is fixed to the rear end of the roughness meter. The roughness meter is rotatably mounted on the second rotating shaft through the vertical rotating plate.

[0009] Furthermore, the posture adjustment device is provided with a horizontal positioning mechanism, which includes a positioning hole and a positioning pin matching the aperture of the positioning hole. The positioning pin is horizontally arranged and telescopically installed on the connecting block. The positioning hole is arranged on the vertical rotating plate, and the roughness meter is rotated around the second rotating axis. When the stylus of the rotating roughness meter rotates or swings to a horizontal state, the positioning pin extends into the positioning hole to prevent the roughness meter from continuing to rotate.

[0010] Furthermore, the positioning pin is horizontally arranged and telescopically mounted on the vertical rotating plate, and the positioning hole is arranged on the connecting block.

[0011] Furthermore, the number of the positioning pins is two, and the two positioning pins are symmetrically distributed about the axis center of the second rotating shaft.

[0012] Furthermore, the number of the positioning holes is two, and the two positioning holes are symmetrically distributed about the axis center of the second rotating shaft.

[0013] Furthermore, the first rotating shaft and the second rotating shaft are both bolts.

[0014] Furthermore, the lifting seat is provided with a cantilever rod along the radial direction of the column, and the first rotating shaft is arranged at the end of the cantilever rod.

[0015] The present invention provides a method for detecting the fillet roughness of a large crankshaft journal. The method uses the above-mentioned inspection tool for detecting the fillet roughness of a large crankshaft journal, and comprises the following steps: step one, fixing the large crankshaft horizontally; step two, adjusting the posture of a roughness meter, rotating the roughness meter around a second rotating axis, making a probe of the roughness meter in a horizontal direction, fixing the roughness meter, adjusting the position of a lifting seat on a column, making the probe of the roughness meter and the center line of a crankshaft journal to be measured have the same height, moving a base plate, making the probe of the roughness meter contact the fillet surface of the crankshaft journal to be measured, rotating a connecting block around a first rotating axis, making a measuring rod of the roughness meter parallel to a chord of a sampling arc, fixing the connecting block; and step three, turning on the roughness meter to obtain the roughness of the fillet surface to be measured.

[0016] The fillet roughness inspection tool of the present invention installs the roughness meter on the posture adjustment device. After inspecting the fillet on one side of the shaft neck, it is only necessary to rotate the roughness meter 180 degrees so that the stylus points to the other side, move the base plate, and adjust the horizontal angle of the connecting block to continue inspecting the fillet on the other side of the shaft neck that needs to be inspected.

[0017] The fillet roughness inspection tool of the present invention has a simple structure and flexible posture adjustment, and can adapt to the characteristics of large crankshafts. The detection method adjusts the measuring rod to be parallel to the chord of the sampling arc, which can adapt to the travel path of the stylus to measure the concave arc surface. The use of a roughness meter to detect the fillet of a large crankshaft journal can obtain quantitative roughness data, which solves the current problem that the roughness fillet of a large crankshaft cannot be quantitatively detected, realizes the control of the consistency of the fillet roughness in the production process, ensures that the compliance detection requirements of the process product are met, and is conducive to improving the fatigue strength of the crankshaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0019] Figure 2 It is a schematic diagram of a partial cross-sectional structure of an embodiment of the present invention;

[0020] Figure 3 It is a schematic diagram of the use state of an embodiment of the present invention;

[0021] Figure 4 It is a schematic diagram of a partial cross-sectional structure of another embodiment of the present invention.

[0022] In the figure, 1. base plate; 2. column; 3. posture adjustment device; 3-1. lifting seat; 3-10. cantilever rod; 3-11. first rotating shaft; 3-2. connecting block; 3-21. second rotating shaft; 3-3. vertical rotating plate; 3-41. positioning pin; 3-410. pull rod; 3-42. positioning hole; 3-43. spring; 4. roughness meter; 4-2. stylus; 5. large crankshaft. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the embodiments.

[0024] See also Figures 1 to 3 A test fixture for detecting the roughness of the fillet of a large crankshaft journal includes a roughness meter 4, the roughness meter 4 includes a measuring rod end and a tail end opposite to the measuring rod end, a stylus 4-2 is installed at the end of the measuring rod end, and also includes a support frame for installing the roughness meter 4, the support frame includes a base plate 1, a column 2 vertically arranged on the base plate 1 and a posture adjustment device 3,

[0025] The posture adjustment device 3 includes a lifting seat 3-1, a connecting block 3-2, a vertical rotating plate 3-3 and a horizontal positioning mechanism. The lifting seat 3-1 can be lifted and lowered on the column 2. A cantilever rod 3-10 is provided on the lifting seat 3-1 along the radial direction of the column 2. A first rotating shaft 3-11 is provided at the end of the cantilever rod 3-10 along the vertical direction. The cantilever rod 3-10 is arranged to facilitate adapting to the size of the large crankshaft 5. In this embodiment, the connecting block 3-2 is composed of a connected horizontal plate and a vertical plate, and its cross section is L-shaped. The connecting plate can be rotated through its horizontal plate. The first rotating shaft 3-11 is movably installed, the vertical plate is provided with a second rotating shaft 3-21, the second rotating shaft 3-21 is horizontally arranged, the vertical rotating plate 3-3 is fixedly installed on the tail end surface of the roughness meter 4, the vertical rotating plate 3-3 is rotatably installed on the second rotating shaft 3-21, the first and second rotating shafts are bolts, and the connecting block 3-2 and the vertical rotating plate 3-3 can be fixed by tightening the bolts. When the roughness meter 4 rotates around the second rotating shaft 3-21 with the vertical rotating plate 3-3, the stylus 4-2 of the roughness meter 4 rotates or swings in the vertical plane.

[0026] See also Figure 2 The horizontal positioning mechanism includes a positioning hole 3-42 and a positioning pin 3-41 matched with the aperture of the positioning hole 3-42. The positioning hole 3-42 is arranged on the vertical rotating plate 3-3. The number of the positioning holes 3-42 is two. The two positioning holes 3-42 are symmetrically distributed about the axis center axis of the second rotating shaft 3-21. The positioning pin 3-41 is horizontally arranged and telescopically installed on the horizontal plate of the connecting block 3-2. In this embodiment, the rear end of the positioning pin 3-41 is provided with a spring 3-43, and the front end of the positioning pin 3-41 is squeezed in the water by the surface of the vertical rotating plate 3-3. In the flat plate, the vertical rotating plate 3-3 is rotated around the second rotating shaft 3-21. When the positioning pin 3-41 is aligned with one of the two positioning holes 3-42, the front end of the positioning pin 3-41 protrudes from the horizontal plate and extends into the positioning hole 3-42 to achieve positioning due to the extension of the spring 3-43. At this time, the stylus 4-2 of the rotating roughness meter 4 rotates or swings to a horizontal state. The vertical rotating plate is rotated 180 degrees. When the positioning pin 3-41 extends into the other positioning hole 3-42, the stylus 4-2 rotates or swings to a horizontal state again to achieve positioning. The setting of the horizontal positioning mechanism can quickly realize the positioning of the stylus 4-2 rotating to a horizontal state, thereby improving the measurement efficiency.

[0027] See also Figure 3, using the above-mentioned inspection fixture method for detecting the fillet roughness of a large crankshaft journal, comprises the following steps: step one, fixing the large crankshaft 5 horizontally, step two, adjusting the posture of the roughness meter 4, rotating the vertical rotating plate 3-3 around the second rotating axis 3-21, when the positioning pin 3-41 extends into the positioning hole 3-42, the stylus 4-2 of the roughness meter 4 swings to a horizontal state, tightening the bolts to fix the roughness meter 4, adjusting the position of the lifting seat 3-1 on the column 2, so that the stylus 4-2 of the roughness meter 4 is at the same height as the center line of the crankshaft journal to be measured, moving the base plate 1, so that the stylus 4-2 of the roughness meter 4 contacts the fillet surface of the crankshaft journal to be measured, rotating the connecting block 3-2 around the first rotating axis 3-11, so that the measuring rod of the roughness meter 4 is parallel to the chord of the sampling arc, tightening the bolts to fix the connecting block 3-2, step three, turning on the roughness meter 4 to obtain the roughness of the fillet surface to be measured;

[0028] When it is necessary to detect the fillet on the other side of the shaft neck, first loosen the vertical rotating plate 3-42, then rotate the vertical rotating plate 3-3. When the positioning pin 3-41 extends into the other positioning hole 3-42, the contact pin 4-2 now points horizontally to the other side. Tighten the vertical rotating plate 3-3, move the base plate 1, and adjust the angle of the connecting block 3-2 to continue detecting the fillet on the other side.

[0029] See also Figure 4 The present invention provides another embodiment, which is different from the above embodiment in that the rear end of the positioning pin 3-41 is also connected to a pull rod 3-410, and the other parts have the same structure. When the roughness meter needs to be rotated, the pull rod 3-410 can be manually pulled to shrink the positioning pin 3-41 in the connecting block 3-2. After the positioning hole 3-42 leaves the original position, the pull rod 3-41 is released. When another positioning hole rotates to align with the positioning pin, the positioning pin extends out of the connecting block 3-2 under the action of the spring and is inserted into the positioning hole 3-42. The setting of the pull rod 3-410 improves the convenience of switching the state of the roughness meter and improves work efficiency.

Claims

1. A test fixture for testing the roughness of the fillet of a large crankshaft journal, comprising a roughness meter, the roughness meter comprising a measuring rod end and a tail end opposite to the measuring rod end, a stylus being mounted at the end of the measuring rod end, and characterized in that: The support frame for installing the roughness meter is also included, the support frame includes a base plate, a column vertically arranged on the base plate and a posture adjustment device, the posture adjustment device includes a lifting seat, a connecting block, a vertical rotating plate and a horizontal positioning mechanism, the lifting seat can be lifted and installed on the column, the lifting seat is provided with a first rotating shaft, the first rotating shaft is vertically arranged, the connecting block can be rotatably installed on the first rotating shaft, the connecting block is provided with a second rotating shaft, the second rotating shaft is horizontally arranged, the roughness meter is rotatably installed on the second rotating shaft through its tail end, and the rotation angles of the connecting block and the roughness meter are both The roughness meter is controllable, when the roughness meter rotates around the second rotating axis, the stylus of the roughness meter rotates or swings in the vertical plane; the vertical rotating plate is fixed to the tail end of the roughness meter, and the roughness meter is rotatably mounted on the second rotating axis through the vertical rotating plate; the horizontal positioning mechanism includes a positioning hole and a positioning pin matching the aperture of the positioning hole, the positioning pin is horizontally arranged and telescopically mounted on the connecting block, the positioning hole is arranged on the vertical rotating plate, and the roughness meter is rotated around the second rotating axis. When the stylus of the rotating roughness meter rotates or swings to a horizontal state, the positioning pin extends into the positioning hole.

2. The inspection tool for inspecting the roughness of the fillet of a large crankshaft journal according to claim 1 is characterized in that: The positioning pin is arranged horizontally and is telescopically mounted on the vertical rotating plate, and the positioning hole is arranged on the connecting block.

3. The inspection tool for inspecting the roughness of the fillet of a large crankshaft journal according to claim 1 or 2, characterized in that: The number of the positioning pins is two, and the two positioning pins are symmetrically distributed about the axis center of the second rotating shaft.

4. The inspection tool for inspecting the roughness of the fillet of a large crankshaft journal according to claim 2 or 3, characterized in that: The number of the positioning holes is two, and the two positioning holes are symmetrically distributed about the axis center of the second rotating shaft.

5. The inspection tool for inspecting the roughness of the fillet of a large crankshaft journal according to claim 1 is characterized in that: The first rotating shaft and the second rotating shaft are both bolts.

6. The inspection tool for inspecting the roughness of the fillet of a large crankshaft journal according to claim 1 is characterized in that: The lifting seat is provided with a cantilever rod along the radial direction of the column, and the first rotating shaft is arranged at the end of the cantilever rod.

7. A method for detecting the roughness of the fillet of a large crankshaft journal, characterized in that: The use of the inspection tool for inspecting the fillet roughness of a large crankshaft journal as described in claim 1 comprises the following steps: step one, fixing the large crankshaft horizontally, step two, adjusting the posture of the roughness meter, rotating the roughness meter around the second rotating axis so that the stylus of the roughness meter is in a horizontal direction, fixing the roughness meter, adjusting the position of the lifting seat on the column so that the stylus of the roughness meter is at the same height as the center line of the crankshaft journal to be tested, moving the base plate so that the stylus of the roughness meter contacts the fillet surface of the crankshaft journal to be tested, rotating the connecting block around the first rotating axis so that the measuring rod of the roughness meter is parallel to the chord of the sampling arc, fixing the connecting block, and three, turning on the roughness meter to obtain the roughness of the fillet surface to be tested.

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