Automatic centering device and method for preparing a test piece of a part using the device

Abstract

The application relates to an automatic centering device and a method for preparing a part inspection sample block by using the device. The automatic centering device comprises a first layer of clamping positioning structure and a second layer of clamping positioning structure, the clamping positioning structure comprises a pair of toothed rods and a gear, the toothed rods are arranged in parallel, one end of the toothed rods is engaged with the gear, the other end of the toothed rods is provided with upwardly extending clamping portions, when the gear rotates along a central axis, the clamping portions on the two toothed rods arranged in pairs move towards each other to realize close or move away from each other to realize separation, so that a machined sample block is symmetrically clamped or released along the direction of the toothed rods; a shell is used for mounting the first layer of clamping positioning structure and the second layer of clamping positioning structure, the clamping portions extend upwards after being connected with the toothed rods at the bottom end, the top end of the clamping portions extends out of the shell and is used for clamping the machined sample block, and the top surface of the shell supports the machined sample block, wherein the first layer of clamping positioning structure and the second layer of clamping positioning structure are arranged at 90 DEG, the two gears are coaxially arranged and independently operate.

Description

Technical Field

[0001] This invention relates to the field of metallographic, hardness, and stress performance testing and processing technology for diesel engine parts. Specifically, it relates to an automatic centering device for preparing inspection samples of high-speed, high-power diesel engine parts and a method for preparing inspection samples of parts using the device. Background Technology

[0002] High-speed, high-power diesel engine components have stringent requirements for internal performance indicators such as internal metallographic structure, residual stress, and hardness. During the production process, regular sampling and batch inspection of finished products are necessary to conduct internal performance tests. The testing equipment cannot directly test complete parts; samples must be cut from the area to be tested and processed into standard cuboid / cube blocks before they can be tested.

[0003] The current sample preparation process is as follows: Raw sample blocks are cut from the part using laser / plasma hot cutting or sawing / wire cutting cold cutting methods; the upper and lower surfaces of the sample block are ground on a surface grinder to ensure parallelism; machining allowances are manually marked around the sample block; the operator clamps and mills / grinds the four sides in stages according to the markings, finally obtaining a standard inspection sample block. The manual marking operation is as follows: Figure 4 As shown, (1) is an irregularly shaped sample block cut from the part; (2) is to scribing on the sample block, where 2 is the scribing mark, and its internal area is the solid area of ​​the sample block after final processing; (3) according to the scribing mark, the sample block is first positioned and clamped on three sides, one of the four sides of the sample block is processed, and then this method is used one by one to complete the processing of the remaining three sides. It is equivalent to needing to perform three-sided positioning and clamping operation 4 times to complete the processing of the sample block. The parallelogram dashed area in the figure is the schematic area to be processed and removed.

[0004] The existing process has the following core defects: high labor demand and high personnel threshold, requiring at least two skilled personnel, namely a professional scribing operator and a machine tool operator; scribing and clamping adjustments rely on years of practical experience, making it impossible for newcomers to work independently, resulting in high labor costs and difficulty in recruitment; extremely low processing efficiency, as each blank sample has an irregular shape and large dimensional differences, requiring individual manual scribing and clamping adjustments for each piece, with four-stage positioning and clamping on all four sides, resulting in a long processing cycle per piece and significant capacity bottlenecks during large-scale testing; large human error and poor consistency, with visual and operational deviations in manual scribing, inconsistent clamping and positioning benchmarks, and poor consistency in the size and parallelism of the processed samples, affecting the accuracy of subsequent testing; cumbersome procedures and low error tolerance, with multiple manual intervention processes such as scribing, multiple clamping, and multiple cutting steps, where any operational error will result in the scrapping of the sample, leading to high raw material loss.

[0005] Therefore, there is an urgent need to develop a solution for the process preparation of inspection samples for high-speed, high-power diesel engine parts, which can realize single-person full-process operation, eliminate manual scribing process, unify CNC machining benchmark, significantly improve processing efficiency, reduce personnel skill threshold, and improve the consistency of sample processing dimensions. Summary of the Invention

[0006] The technical problem to be solved by this invention is that the existing high-speed, high-power diesel engine parts inspection sample preparation process has problems such as high manpower input, low processing efficiency, reliance on senior technicians, and poor processing consistency.

[0007] To solve the above-mentioned technical problems, according to one aspect of the present invention, an automatic centering device is provided, comprising: a first-layer clamping and positioning structure and a second-layer clamping and positioning structure, each comprising: a pair of racks and a gear; the pair of racks are arranged in parallel, with one end of the rack meshing with the gear; the other ends of the paired racks, which are relatively far from the gear, are provided with upwardly extending clamping portions; when the gear rotates along the central axis, the clamping portions on the paired racks move towards each other to move closer or away from each other to move further apart, thereby achieving symmetrical clamping or loosening of the workpiece along the direction of the racks; and a housing for mounting the first-layer clamping and positioning structure and the second-layer clamping and positioning structure. The bottom end of the clamping part is connected to the toothed rod and extends upward, with the top end extending out of the housing and used to clamp the workpiece. The top surface of the housing supports the workpiece. The first-layer clamping and positioning structure and the second-layer clamping and positioning structure are set at 90°. The gears of the first-layer clamping and positioning structure and the second-layer clamping and positioning structure are coaxially set. The first-layer clamping and positioning structure and the second-layer clamping and positioning structure operate independently, clamping and positioning the workpiece in the X-axis and Y-axis directions respectively, forming a symmetrical clamping of the workpiece in the XOY plane, realizing automatic centering and clamping of the workpiece. The center of the workpiece and the center of the automatic centering device are on the same vertical line in the XOY plane, thus satisfying the CNC program to design and process based on the center.

[0008] According to an embodiment of the present invention, the clamping part may be provided with a stop portion extending toward the sample block to be processed. The stop portion is provided at the top of the clamping part and is located on the same horizontal plane as the sample block to be processed. The stop portions are arranged in pairs and facing each other to stop and press the sample block to be processed.

[0009] According to an embodiment of the present invention, the automatic centering device may further include: a top clamping structure for clamping the workpiece from the top of the workpiece, thereby fixing the workpiece in the Z-axis direction to facilitate processing of the workpiece, wherein the second clamping and positioning structure is clamped, the first clamping and positioning structure is released, and the two sides of the workpiece parallel to the direction of the second clamping and positioning structure are processed; the first clamping and positioning structure is clamped, the second clamping and positioning structure is released, and the two sides of the workpiece parallel to the direction of the first clamping and positioning structure are processed, thereby completing the processing of the workpiece on four sides parallel to the Z-axis direction.

[0010] According to an embodiment of the present invention, an opening may be provided on the upper surface of the housing in the running path of the clamping part to avoid the running of the clamping part.

[0011] According to an embodiment of the present invention, the automatic centering device may further include: a driving device for driving the gear to run, wherein the driving device is in two sets, which respectively drive the first clamping and positioning structure and the second clamping and positioning structure to clamp or loosen.

[0012] According to another aspect of the present invention, a method for preparing a component inspection sample block is provided, based on the aforementioned automatic centering device. The method includes the following steps: S0, blank sampling, cutting a blank sample block from the test area of ​​a diesel engine component using hot or cold cutting methods; S1, clamping, clamping the sample block to be processed onto the automatic centering device, wherein the first and second clamping positioning structures operate independently, synchronously and equidistantly clamping the blank sample block inward along the X and Y axes respectively, so that the geometric center of the blank sample block is aligned with the centering reference center of the tooling. S2, Clamping: A vertical clamping mechanism is set at the top of the tooling to press down and fix the sample block to ensure no displacement during the cutting process; S3, Vertical four-sided machining: The second layer of clamping and positioning structure is clamped, and the first layer of clamping and positioning structure is released. The two sides of the sample block parallel to the direction of the second layer of clamping and positioning structure are machined; The first layer of clamping and positioning structure is clamped, and the second layer of clamping and positioning structure is released. The two sides of the sample block parallel to the direction of the first layer of clamping and positioning structure are machined, thereby completing the four-sided machining of the sample block parallel to the Z-axis direction.

[0013] According to an embodiment of the present invention, the step between steps S0 and S1 may further include:

[0014] The upper and lower planes are ground in parallel. The upper and lower surfaces of the blank sample are ground on a surface grinder to obtain two sets of mutually parallel reference planes.

[0015] According to an embodiment of the present invention, the method for preparing a component inspection sample block may further include: S4, unified reference CNC milling, using the tooling centering center as the unified machining reference to compile a general CNC program, without the need to adjust the program separately for a single blank; the CNC equipment completes the X and Y bidirectional four-sided allowance cutting in one go, removes the irregular edges of the blank, and obtains a standard cuboid inspection sample block with regular shape and uniform size.

[0016] Furthermore, the method for preparing inspection samples of parts may also include: S5, material cutting and inspection: after CNC milling is completed, the automatic centering fixture is released, the formed standard sample is removed, and metallographic, hardness and stress tests are carried out directly on the machine.

[0017] According to an embodiment of the present invention, blank sampling can be performed by laser / plasma hot cutting or sawing / wire cutting cold cutting to cut blank samples from the test area of ​​the diesel engine parts.

[0018] Compared with the prior art, the technical solution provided by the embodiments of the present invention can achieve at least the following beneficial effects:

[0019] The automatic centering device and the method for preparing inspection samples of parts using the device according to the present invention can reduce manpower and lower the threshold for employment: the dedicated marking worker is eliminated, and the entire process can be completed by only one ordinary operator; no professional marking or complex clamping and adjustment experience is required, and ordinary technicians can be put to work after short-term training, which greatly reduces labor costs and personnel management difficulties.

[0020] The automatic centering device of the present invention and the method for preparing inspection samples of parts using the device achieve simplified process and doubled processing efficiency: the manual scribing process is completely eliminated; four-sided CNC machining can be completed in a single centering clamping, replacing the original four-stage clamping; the universal CNC program is compatible with all irregular blank samples, eliminating the need for single-piece program adjustment, and significantly improving the production capacity of mass production.

[0021] The automatic centering device and the method for preparing inspection samples of parts using the device according to the present invention significantly improve machining accuracy and consistency: the centering center of the tooling is uniformly used as the CNC machining reference, eliminating the reference offset error caused by manual scribing and multiple clamping; the batch of samples has high consistency in shape, parallelism and surface roughness, avoiding human operation deviation and ensuring stable and reliable subsequent performance test data of parts.

[0022] The automatic centering device and the method for preparing inspection samples of parts using the device according to the present invention can reduce scrap losses: reduce manual intervention processes, avoid scrapping of samples caused by scribing deviations and clamping misalignments, save raw materials for diesel engine parts, and reduce testing and production costs.

[0023] The automatic centering device of the present invention and the method for preparing inspection samples of parts using the device employ highly versatile tooling: the double-layer gear rack automatic centering structure is adaptable to various irregular blank samples, eliminating the need to change tooling according to part specifications, and one set of tooling can cover all diesel engine parts sampling and processing needs. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0025] Figure 1 This is a side view schematic diagram illustrating an automatic centering device according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram illustrating the meshing of a gear and a rack according to an embodiment of the present invention;

[0027] Figure 3 This is a top view schematic diagram showing the first-layer clamping and positioning structure and the second-layer clamping and positioning structure according to an embodiment of the present invention;

[0028] Figure 4 A schematic diagram of the process for manually preparing test samples in the prior art;

[0029] Figures 5a-5d This is a schematic flowchart illustrating a method for preparing a component inspection sample block according to an embodiment of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a limitation of quantity, but rather indicate the presence of at least one.

[0032] Figure 1 This is a side view schematic diagram illustrating an automatic centering device according to an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the meshing of a gear and a rack according to an embodiment of the present invention; Figure 3 This is a top view schematic diagram showing the first-layer clamping and positioning structure and the second-layer clamping and positioning structure according to an embodiment of the present invention.

[0033] like Figures 1 to 3 As shown, the automatic centering device includes: a first-layer clamping and positioning structure 3, a second-layer clamping and positioning structure 5, and a housing 1.

[0034] The first clamping and positioning structure 3 and the second clamping and positioning structure 5 each include: a pair of racks 6 and a gear 2. The pair of racks 6 are arranged in parallel, and one end of the racks 6 meshes with the gear 2. The other ends of the two racks 6, which are relatively far from the gear 2, are provided with upwardly extending clamping parts 7. When the gear 2 rotates along the central axis, the clamping parts 7 on the two racks 6 move towards each other to move closer or away from each other to move further apart, thereby achieving symmetrical clamping or loosening of the workpiece 4 along the direction of the racks 6.

[0035] The housing 1 is used to install the first clamping and positioning structure 3 and the second clamping and positioning structure 5. The clamping part 7 extends upward after the bottom end is connected to the toothed rod 6, and the top end extends out of the housing 1 and is used to clamp the sample block 4 to be processed. The top surface of the housing 1 supports the sample block 4 to be processed.

[0036] The first clamping and positioning structure 3 and the second clamping and positioning structure 5 are set at 90°. The gear 2 of the first clamping and positioning structure 3 and the gear 2 of the second clamping and positioning structure 5 are coaxially arranged. The first clamping and positioning structure 3 and the second clamping and positioning structure 5 operate independently and clamp and position the workpiece 4 in the X-axis and Y-axis directions respectively, forming a symmetrical clamping of the workpiece 4 in the XOY plane, realizing automatic centering and clamping of the workpiece 4. The center of the workpiece 4 and the center of the automatic centering device are on the same vertical line of the XOY plane, thus satisfying the requirement that the CNC program is designed and processed with the center as the reference.

[0037] The automatic centering device according to the present invention has strong tooling versatility: the double-layer gear rack automatic centering structure is adaptable to various irregular blank blocks, and there is no need to change tooling according to the specifications of the parts. One set of tooling can cover all the sampling and processing needs of diesel engine parts.

[0038] The automatic centering device of the present invention significantly improves machining accuracy and consistency: it uses the tooling centering center as the CNC machining reference, eliminating the reference offset error caused by manual scribing and multiple clamping; the batch of sample blocks has high consistency in shape, parallelism and surface roughness, avoiding human operation deviation and ensuring stable and reliable performance test data of subsequent parts.

[0039] According to one or more embodiments of the present invention, the clamping part 7 is provided with a stop (not shown) extending toward the sample block 4 to be processed. The stop is provided at the top of the clamping part 7 and is located on the same horizontal plane as the sample block to be processed. The stop are arranged in pairs and facing each other to stop and press the sample block 4 to be processed.

[0040] According to one or more embodiments of the present invention, the automatic centering device further includes: a top clamping structure for clamping the workpiece 4 from the top of the workpiece 4, thereby fixing the workpiece 4 in the Z-axis direction, facilitating the processing of the workpiece 4. Specifically, the second-layer clamping and positioning structure 5 is clamped, and the first-layer clamping and positioning structure 3 is released, and the two sides of the workpiece 4 parallel to the direction of the second-layer clamping and positioning structure 5 are processed; the first-layer clamping and positioning structure 3 is clamped, and the second-layer clamping and positioning structure 5 is released, and the two sides of the workpiece 4 parallel to the direction of the first-layer clamping and positioning structure 3 are processed, thereby completing the processing of the four sides of the workpiece 4 parallel to the Z-axis direction.

[0041] According to one or more embodiments of the present invention, an opening is provided on the upper surface of the housing 1 in the running path of the clamping part 7 to avoid the running of the clamping part 7.

[0042] According to one or more embodiments of the present invention, the automatic centering device further includes: a driving device for driving the gear 2 to run, wherein the driving device is in two sets, which respectively drive the first clamping and positioning structure 3 and the second clamping and positioning structure 5 to clamp or loosen.

[0043] The automatic centering device of the present invention and the method for preparing inspection samples of parts using the device achieve simplified process and doubled processing efficiency: the manual scribing process is completely eliminated; four-sided CNC machining can be completed in a single centering clamping, replacing the original four-stage clamping; the universal CNC program is compatible with all irregular blank samples, eliminating the need for single-piece program adjustment, and significantly improving the production capacity of mass production.

[0044] Figures 5a-5d This is a schematic flowchart illustrating a method for preparing a component inspection sample block according to an embodiment of the present invention.

[0045] Based on the above-mentioned automatic centering device, such as Figures 5a-5d As shown, the method for preparing component inspection samples includes the following steps:

[0046] S0. Raw material sampling: Raw material samples are cut from the test area of ​​the diesel engine parts using hot or cold cutting methods.

[0047] S1. Clamping: The sample block 4 to be processed is clamped on the automatic centering device. The first clamping and positioning structure 3 and the second clamping and positioning structure 5 operate independently, clamping the blank sample block synchronously and equidistantly along the X and Y axes respectively, so that the geometric center of the blank sample block coincides with the centering reference center of the tooling.

[0048] S2. Clamping: A vertical clamping mechanism is installed at the top of the tooling to press down and fix the sample block to ensure no displacement during the cutting process;

[0049] S3. Vertical four-sided machining: clamp the second-layer clamping and positioning structure 5, loosen the first-layer clamping and positioning structure 3, and machine the two sides of the sample block 4 parallel to the direction of the second-layer clamping and positioning structure 5; clamp the first-layer clamping and positioning structure 3, loosen the second-layer clamping and positioning structure 5, and machine the two sides of the sample block 4 parallel to the direction of the first-layer clamping and positioning structure 3, thereby completing the four-sided machining of the sample block 4 parallel to the Z-axis direction.

[0050] The automatic centering device and the method for preparing inspection samples of parts using the device according to the present invention can reduce scrap losses: reduce manual intervention processes, avoid scrapping of samples caused by scribing deviations and clamping misalignments, save raw materials for diesel engine parts, and reduce testing and production costs.

[0051] According to one or more embodiments of the present invention, a further step is included between steps S0 and S1:

[0052] The upper and lower planes are ground in parallel. The upper and lower surfaces of the blank sample are ground on a surface grinder to obtain two sets of mutually parallel reference planes.

[0053] According to one or more embodiments of the present invention, the method for preparing component inspection samples further includes:

[0054] S4. Unified reference CNC milling: The tooling centering center is used as the unified machining reference to compile a general CNC program, which does not require separate program adjustment for a single blank. The CNC equipment completes the X and Y bidirectional four-sided allowance cutting in one go, removes the irregular edges of the blank, and obtains a standard cuboid inspection sample with regular shape and uniform size.

[0055] Furthermore, the method for preparing component inspection samples also includes:

[0056] S5. Material unloading and inspection: After CNC milling is completed, release the automatic centering fixture, remove the formed standard sample block, and directly put it on the machine for metallographic, hardness, and stress testing.

[0057] According to one or more embodiments of the present invention, blank sampling is performed by laser / plasma hot cutting or sawing / wire cutting cold cutting to cut blank sample blocks from the test area of ​​the diesel engine parts.

[0058] The automatic centering device and the method for preparing inspection samples of parts using the device according to the present invention can reduce manpower and lower the threshold for employment: the dedicated marking worker is eliminated, and the entire process can be completed by only one ordinary operator; no professional marking or complex clamping and adjustment experience is required, and ordinary technicians can be put to work after short-term training, which greatly reduces labor costs and personnel management difficulties.

[0059] In use, the metallographic inspection sample block for the crankshaft of a high-speed, high-power diesel engine is prepared using the method for preparing component inspection sample blocks. The steps are as follows:

[0060] Raw material sampling: Select the journal area of ​​the crankshaft to be tested of a high-speed, high-power diesel engine, and cut an irregular raw material sample block using wire cutting cold cutting method. The length and width of the raw material are 5~10mm larger than the finished size of the standard sample block, leaving a machining allowance.

[0061] Double-sided parallel grinding: Place the blank sample on a surface grinder and grind the upper and lower end faces to ensure that the parallelism of the two end faces is ≤0.02mm, forming a stable upper and lower reference surface;

[0062] Automatic centering fixture clamping: A double-layer 90° gear rack automatic centering fixture is used to place the ground blank sample on the fixture support base; the fixture drive mechanism is started, and the two sets of central drive gears rotate synchronously, and the X and Y direction racks move inward synchronously at equal distances to clamp the blank, so that the geometric center of the sample coincides with the fixture reference center; the top vertical clamping mechanism is started to vertically clamp the upper surface of the sample and lock it to prevent cutting vibration displacement;

[0063] Tooling structure operation logic: The central drive gear rotates in the forward direction, meshing with the racks on both sides to move inward synchronously for centering; when rotating in the reverse direction, the racks move backward synchronously to release the workpiece; the two-layer mechanism is perpendicular to each other and driven independently to achieve bidirectional centering of the rectangular blank.

[0064] Unified reference CNC milling: Call the preset general CNC program, and set the program reference point as the tooling centering center; the CNC milling machine sequentially mills the sample block on both sides of the X direction and both sides of the Y direction, removing all irregular excess material on all four sides in one go, and machining a standard cuboid inspection sample block with a length, width and height tolerance of ±0.03mm and a surface roughness Ra≤1.6μm; there is no need to modify the program or adjust the coordinates of a single blank.

[0065] Material loading and inspection: After CNC cutting is completed, the reverse rotation center drive gear loosens the rack, lifts the top clamping mechanism, removes the standard sample block, and directly sends it into the metallographic microscope and hardness tester to carry out component performance testing.

[0066] Comparative Explanation (Traditional Process vs. This Invention)

[0067] Traditional process: blank → double-sided grinding → manual scribing (1 scribing worker) → four-stage clamping and milling of four sides (1 operator), 2 people working together, processing time for a single piece is 12~18 minutes; manual scribing has dimensional deviation, the clamping reference is offset, the batch sample block size dispersion is large, and the scrap rate is about 8%.

[0068] The process of this invention is as follows: blank → double-sided grinding → automatic centering clamping + CNC four-sided integrated cutting (single-person operation), single-piece processing time is 4~6 minutes; no manual scribing, unified centering datum, batch sample block size dispersion is extremely small, and the scrap rate is reduced to less than 0.5%.

[0069] The above description is merely an exemplary embodiment of the present invention and is not intended to limit the scope of protection of the present invention, which is determined by the appended claims.

Claims

1. An automatic centering device, wherein, include: The first-layer clamping and positioning structure and the second-layer clamping and positioning structure each include: a pair of racks and a gear. The pair of racks are arranged in parallel, and one end of the racks meshes with the gear. The other end of the pair of racks, which is away from the gear, is provided with an upwardly extending clamping part. When the gear rotates along the central axis, the clamping parts on the pair of racks move towards each other to move closer or away from each other to move further apart, thereby achieving symmetrical clamping or loosening of the sample block along the direction of the racks. The housing is used to install the first and second clamping and positioning structures. The clamping part extends upward after being connected to the bottom of the toothed rod, and its top extends out of the housing and is used to clamp the workpiece. The top surface of the housing supports the workpiece. The first and second clamping and positioning structures are set at 90° to each other. The gears of the first and second clamping and positioning structures are coaxially arranged. The first and second clamping and positioning structures operate independently and clamp and position the workpiece in the X and Y directions respectively, forming a symmetrical clamping of the workpiece in the XOY plane. This achieves automatic centering and clamping of the workpiece. The center of the workpiece and the center of the automatic centering device are on the same vertical line in the XOY plane, thus satisfying the requirement that the CNC program designs and processes based on the center.

2. The automatic centering device as described in claim 1, wherein, The clamping part is provided with a stop part extending toward the sample block to be processed. The stop part is located at the top of the clamping part and is located on the same horizontal plane as the sample block to be processed. The stop parts are arranged in pairs and facing each other to stop and press the sample block to be processed.

3. The automatic centering device as described in claim 1, wherein, Also includes: The top clamping structure is used to clamp the workpiece from the top, thereby fixing the workpiece in the Z-axis direction and facilitating its processing. Specifically, the second-layer clamping and positioning structure is clamped, the first-layer clamping and positioning structure is released, and the two sides of the sample block parallel to the direction of the second-layer clamping and positioning structure are processed; the first-layer clamping and positioning structure is clamped, the second-layer clamping and positioning structure is released, and the two sides of the sample block parallel to the direction of the first-layer clamping and positioning structure are processed, thereby completing the processing of the sample block on four sides parallel to the Z-axis direction.

4. The automatic centering device as described in claim 1, wherein, The upper surface of the housing is provided with an opening on the running path of the clamping part to avoid the running of the clamping part.

5. The automatic centering device as described in claim 1, wherein, Also includes: A drive device is used to drive the gear to run. The drive device consists of two sets, which respectively drive the first layer clamping and positioning structure and the second layer clamping and positioning structure to clamp or loosen.

6. A method for preparing inspection samples of parts, implemented based on the automatic centering device as described in claims 1-5, wherein, The method for preparing component inspection samples includes the following steps: S0. Raw material sampling: Raw material samples are cut from the test area of ​​the diesel engine parts using hot or cold cutting methods. S1. Clamping: The sample block to be processed is clamped on the automatic centering device. The first clamping and positioning structure and the second clamping and positioning structure operate independently, clamping the blank sample block synchronously and equidistantly along the X and Y axes, respectively, so that the geometric center of the blank sample block coincides with the centering reference center of the tooling. S2. Clamping: A vertical clamping mechanism is installed at the top of the tooling to press down and fix the sample block to ensure no displacement during the cutting process; S3. Vertical four-sided machining: clamp the second layer clamping and positioning structure, loosen the first layer clamping and positioning structure, and machine the two sides of the sample block parallel to the direction of the second layer clamping and positioning structure; clamp the first layer clamping and positioning structure, loosen the second layer clamping and positioning structure, and machine the two sides of the sample block parallel to the direction of the first layer clamping and positioning structure, thereby completing the four-sided machining of the sample block parallel to the Z-axis direction.

7. The method for preparing component inspection samples as described in claim 6, wherein, The steps between steps S0 and S1 include: The upper and lower planes are ground in parallel. The upper and lower surfaces of the blank sample are ground on a surface grinder to obtain two sets of mutually parallel reference planes.

8. The method for preparing component inspection samples as described in claim 7, wherein, Also includes: S4. Unified reference CNC milling: The tooling centering center is used as the unified machining reference to compile a general CNC program, which does not require separate program adjustment for a single blank. The CNC equipment completes the X and Y bidirectional four-sided allowance cutting in one go, removes the irregular edges of the blank, and obtains a standard cuboid inspection sample with regular shape and uniform size.

9. The method for preparing component inspection samples as described in claim 8, further comprising: S5. Material unloading and inspection: After CNC milling is completed, release the automatic centering fixture, remove the formed standard sample block, and directly put it on the machine for metallographic, hardness, and stress testing.

10. The method for preparing component inspection samples as described in claim 6, wherein, The blank samples are cut from the test area of ​​the diesel engine parts using laser / plasma hot cutting or sawing / wire cutting cold cutting methods.

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