Grinding method and tool for engine gear shaft

Abstract

The invention discloses a grinding method and tool for an engine gear shaft, and the grinding method for the engine gear shaft comprises the steps: firstly, carrying out the optimization design of the structural size of a core rod, and guaranteeing that the jumping of the small end of the gear shaft can be flexibly adjusted after the gear shaft is installed on the core rod; then an auxiliary positioning tool and a detachable tip are utilized to abut against the large end of the core rod, so that the runout of the large end of the gear shaft can be flexibly adjusted on a grinding machine, when the middle shaft neck part of the gear shaft is subjected to coping machining, the runout of the outer circle of the small end and the runout of the outer circle of the large end of the gear shaft can be conveniently aligned, and the runout of the outer circle of the small end and the runout of the large end are not larger than 0.004; and the coping machining quality and the machining precision are improved, so that the repair qualification rate is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of gear shaft grinding, and in particular, to a grinding method for an engine gear shaft. In addition, the present invention also relates to a grinding tooling for an engine gear shaft. Background Art

[0002] As one of the core components of the transmission system of a turboprop engine, the middle journal part of the gear shaft is the inner raceway surface of the gear bearing roller. During the operation of the engine, the bearing roller rolls on the middle journal part of the gear shaft, and micro wear will inevitably occur. When a certain type of engine is sent back to the factory for major overhaul, it is found that the middle journal part of the gear shaft often wears, and it is necessary to machine the middle journal part of the gear shaft to restore the geometric dimensions and surface quality of the part and ensure that the roller clearance is qualified. When grinding the middle journal part of the gear shaft, it is necessary to align the runout of the small end and the large end of the outer circle of the gear shaft to ensure the machining quality and machining accuracy. As Figure 1 shown, the position to be machined on the outer circle of the gear shaft is at ΦB, that is, the middle journal part. The small end outer circle of the gear shaft is at ΦC, and the large end outer circle of the gear shaft is at ΦA. During the grinding process of ΦB, it is necessary to flexibly adjust the runout of parts ΦA and ΦC to be no more than 0.004, so as to ensure that the outer circles of ΦA, ΦC, and ΦB are mutually runout by no more than 0.008, so as to ensure the grinding quality and repair qualification rate of the gear shaft.

[0003] The existing gear shaft grinding method is to first install the gear shaft on a micro taper mandrel, and install grinding machine centers at both ends of the mandrel respectively, so that the grinding machine centers tightly hold both ends of the mandrel to ensure that the mandrel remains stable on the grinding machine during the machining process. Specifically, as Figure 2 shown, then align the runout of ΦA and ΦC to be no more than 0.004, check the machining allowance at ΦB, and then machine the ΦB dimension according to the requirements of the process data. However, during the grinding process of the gear shaft, since the mandrel and the large end of the gear shaft are in interference fit, the clearance after combination is too small. At the same time, the used grinding machine centers are dead centers. After the installation position of the part is fixed, only the runout can be checked, and the runout values of ΦA and ΦC cannot be adjusted, resulting in a too low repair qualification rate of the gear shaft and a large number of parts being scrapped. Summary of the Invention

[0004] The present invention provides a grinding method and a grinding tooling for an engine gear shaft, which can flexibly adjust the runout of the small end and the large end of the gear shaft, so as to facilitate aligning the runout of the small end outer circle and the large end outer circle of the gear shaft, improving the grinding quality and machining accuracy, and thus improving the repair qualification rate.

[0005] According to one aspect of the present invention, a grinding method for an engine gear shaft is provided, including the following content:

[0006] The structural dimensions of the mandrel are optimized so that the runout of the small end of the gear shaft can be flexibly adjusted after the gear shaft is installed on the mandrel;

[0007] Install the gear shaft onto the mandrel processed according to the optimized design, use the grinding machine top to support the small end of the mandrel, and use the auxiliary positioning tooling and the detachable top to support the large end of the mandrel, so that the runout of the large end of the gear shaft can be flexibly adjusted on the grinding machine;

[0008] Find the runout of the small end outer circle and the large end outer circle of the spur gear shaft, and grind the intermediate journal part of the gear shaft.

[0009] Furthermore, the process of optimizing the structural dimensions of the mandrel includes the following:

[0010] Obtain the distance between the small end and the large end of the gear shaft and the historical maximum runout value of the small end outer circle and the large end outer circle of the gear shaft relative to the intermediate shaft neck position;

[0011] The optimization strategy of interference fit between the big end of the gear shaft and the mandrel and the single-side clearance between the small end of the gear shaft and the mandrel being greater than or equal to the historical maximum runout value is adopted to calculate the target taper of the mandrel.

[0012] The large end diameter of the mandrel and the overall length of the mandrel are obtained, and the small end diameter of the mandrel is calculated in combination with the target taper of the mandrel.

[0013] Furthermore, the target taper of the mandrel is calculated based on the following formula:

[0014] C=2d / L 0

[0015] Where C is the target taper of the mandrel, d is the historical maximum runout value, and L is 0 Indicates the distance from the small end to the large end of the gear shaft.

[0016] Furthermore, the small end diameter of the mandrel is calculated based on the following formula:

[0017] D 1 =D 2 -C×L 1

[0018] Among them, D 1 Indicates the small end diameter of the mandrel, D 2 Indicates the large end diameter of the mandrel, L 1 Indicates the overall length of the mandrel.

[0019] Furthermore, the auxiliary positioning tooling includes a three-jaw chuck and a faceplate. The faceplate is fixedly mounted on the grinder. There is a gap between the three-jaw chuck and the faceplate after they are combined. The removable center is then clamped on the three-jaw chuck. The runout of the outer circle of the large end of the gear shaft can be adjusted by tapping the three-jaw chuck.

[0020] In addition, the present invention also provides a grinding tooling for an engine gear shaft, including a mandrel, an auxiliary positioning tooling and a detachable center. Among them, the structural dimensions of the mandrel are optimized for installing the gear shaft. After the gear shaft is installed on the mandrel, the runout of the small end of the gear shaft can be flexibly adjusted. The auxiliary positioning tooling is installed on the grinding machine, and the detachable center is installed on the auxiliary positioning tooling for pressing against the large end of the mandrel. The small end of the mandrel is pressed against by the center of the grinding machine, and the runout of the outer circle of the large end of the gear shaft can be adjusted by knocking on the auxiliary positioning tooling.

[0021] Further, the process of optimizing the structural dimensions of the mandrel is as follows:

[0022] First, obtain the distance between the small end and the large end of the gear shaft and the historical maximum runout values of the outer circles of the small end and the large end of the gear shaft relative to the middle journal part. Then, adopt the optimization strategy of interference fit between the large end of the gear shaft and the mandrel and a unilateral clearance between the small end of the gear shaft and the mandrel greater than or equal to the historical maximum runout value, calculate the target taper of the mandrel, and finally, obtain the large end diameter of the mandrel and the overall length of the mandrel, and calculate the small end diameter of the mandrel in combination with the target taper of the mandrel.

[0023] Further, the target taper of the mandrel is calculated based on the following formula:

[0024] C = 2d / L 0

[0025] where C represents the target taper of the mandrel, d represents the historical maximum runout value, and L 0 represents the distance between the small end and the large end of the gear shaft.

[0026] Further, the small end diameter of the mandrel is calculated based on the following formula:

[0027] D 1 = D 2 - C×L 1

[0028] where D 1 represents the small end diameter of the mandrel, D 2 represents the large end diameter of the mandrel, and L 1 represents the overall length of the mandrel.

[0029] Further, the auxiliary positioning tooling includes a three-jaw chuck and a faceplate. The faceplate is fixedly installed on the grinding machine. There is a gap after the three-jaw chuck is combined with the faceplate, and then the detachable center is clamped on the three-jaw chuck. The runout of the outer circle of the large end of the gear shaft can be adjusted by knocking on the three-jaw chuck.

[0030] The present invention has the following beneficial effects:

[0031] The engine gear shaft grinding method of the present invention first optimizes the structural dimensions of the core rod to ensure that the runout of the small end of the gear shaft can be flexibly adjusted after the gear shaft is installed on the core rod, and then uses an auxiliary positioning tool and a detachable center to support the large end of the core rod, so as to flexibly adjust the runout of the large end of the gear shaft on a grinder. When the middle shaft neck position of the gear shaft is ground, it is convenient to find the runout of the small end outer circle and the large end outer circle of the spur gear shaft, so that the runout of the two is no more than 0.004, thereby improving the grinding quality and processing accuracy, thereby improving the repair qualification rate.

[0032] In addition, the engine gear shaft grinding tool of the present invention also has the above advantages.

[0033] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0035] Figure 1 It is a schematic diagram of the structure of the engine gear shaft;

[0036] Figure 2 It is a structural schematic diagram of the existing gear shaft grinding method in which the gear shaft is fixedly installed on the grinding machine;

[0037] Figure 3 It is a schematic flow chart of a grinding method for an engine gear shaft according to a preferred embodiment of the present application;

[0038] Figure 4 yes Figure 3 Schematic diagram of the sub-process of step S1;

[0039] Figure 5 It is a schematic diagram of the principle of optimizing the structural dimensions of the mandrel in the preferred embodiment of the present application;

[0040] Figure 6 It is a schematic diagram of installing the gear shaft and the core rod on the grinding machine in the preferred embodiment of the present application. DETAILED DESCRIPTION

[0041] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0042] Reference Figure 3As shown, the preferred embodiment of the present application provides a grinding method for an engine gear shaft, which is used to grind the intermediate journal portion of the gear shaft, and includes the following contents:

[0043] Step S1: Optimizing the design of the structure size of the mandrel so that the runout of the small end of the gear shaft can be flexibly adjusted after the gear shaft is installed on the mandrel;

[0044] Step S2: Install the gear shaft onto the mandrel processed according to the optimized design, use the grinding machine top to support the small end of the mandrel, and use the auxiliary positioning tool and the detachable top to support the large end of the mandrel, so that the runout of the large end of the gear shaft can be flexibly adjusted on the grinding machine;

[0045] Step S3: Find the runout of the small end outer circle and the large end outer circle of the spur gear shaft, and perform grinding on the intermediate shaft neck of the gear shaft.

[0046] It can be understood that the grinding method of the engine gear shaft of the present embodiment first optimizes the structural dimensions of the core rod to ensure that the runout of the small end of the gear shaft can be flexibly adjusted after the gear shaft is installed on the core rod, and then uses an auxiliary positioning tool and a detachable center to support the large end of the core rod to facilitate the flexible adjustment of the runout of the large end of the gear shaft on the grinder. When the middle shaft neck position of the gear shaft is ground, it is convenient to find the runout of the small end outer circle and the large end outer circle of the spur gear shaft, so that the runout of the two is no more than 0.004, thereby improving the grinding quality and processing accuracy, thereby improving the repair qualification rate.

[0047] It can be understood that when the gear shaft is matched with the existing mandrel, the large end of the gear shaft is interference fit with the mandrel, and the small end of the gear shaft is clearance fit with the mandrel. However, after the gear shaft is installed on the mandrel, the clearance between the small end of the gear shaft and the mandrel may be too small, making it difficult to find the runout of the outer circle of the small end of the spur gear shaft. For example, the inner hole size of the gear shaft is Φ34 (+0.027, 0) mm, while the small end diameter D of the existing mandrel is 1 The diameter of the large end of the mandrel is 34.014 mm. 2 The diameter of the gear shaft is 34.034mm. The small end of the gear shaft and the core rod are clearance fit, and the large end of the gear shaft and the core rod are interference fit. When the inner hole size of the gear shaft is positively biased due to machining accuracy, that is, >Φ34mm, the gap between the small end of the gear shaft and the core rod will be too small. In addition, the existing grinding method is to use the dead center on the grinder to support the two ends of the core rod. The dead center cannot be adjusted, resulting in the inability to adjust the runout value of the small end outer circle and the large end outer circle of the gear shaft. Therefore, in the step S1, in order to flexibly adjust the runout of the small end outer circle of the gear shaft, the present invention optimizes the structural size of the core rod, increases the gap between the core rod and the small end of the gear shaft, and thus facilitates the adjustment of the runout of the small end outer circle of the gear shaft.

[0048] Among them, Figure 4As shown, the process of optimizing the structural dimensions of the mandrel includes the following:

[0049] Step S11: Obtain the distance between the small end and the large end of the gear shaft and the historical maximum runout values of the outer circles of the small end and the large end of the gear shaft relative to the middle journal part;

[0050] Step S12: Adopt the optimization strategy of interference fit between the large end of the gear shaft and the mandrel and the unilateral clearance between the small end of the gear shaft and the mandrel being greater than or equal to the historical maximum runout value, and calculate the target taper of the mandrel;

[0051] Step S13: Obtain the large end diameter of the mandrel and the overall length of the mandrel, and calculate the small end diameter of the mandrel in combination with the target taper of the mandrel.

[0052] Specifically, as Figure 5 shown, first obtain the distance L between the small end and the large end of the gear shaft 0 , and the historical maximum runout value d of the outer circles of the small end (i.e., at φC) and the large end (i.e., at φA) of the gear shaft relative to the middle journal part during the long-term use of the gear shaft. Then, adopt the optimization strategy of interference fit between the large end of the gear shaft and the mandrel and the unilateral clearance between the small end of the gear shaft and the mandrel being greater than or equal to the historical maximum runout value to optimize the taper of the mandrel to increase the adjustable clearance between the small end of the gear shaft and the mandrel. Among them, the target taper of the mandrel is specifically calculated based on the following formula:

[0053] C = 2d / L 0

[0054] where C represents the target taper of the mandrel, d represents the historical maximum runout value, and L 0 represents the distance between the small end and the large end of the gear shaft.

[0055] Then, obtain the large end diameter D of the mandrel 2 and the overall length L of the mandrel, and the small end diameter D of the mandrel can be calculated in combination with the target taper of the mandrel 1 . Finally, input the large end diameter D 2 and the small end diameter D 1 of the mandrel into the mandrel processing program, and the mandrel can be processed according to the optimized design scheme. Among them, the small end diameter of the mandrel is calculated based on the following formula:

[0056] D 1 = D 2 - C×L 1

[0057] where D 1 represents the small end diameter of the mandrel, D 2 represents the large end diameter of the mandrel, and L 1Indicates the overall length of the mandrel.

[0058] For example, assume the inner hole diameter of the gear shaft is D 0 is φ34.027mm, the distance L between the small end and the large end of the gear shaft 0 is 100mm, the large end diameter D of the mandrel 2 is 34.034mm, the overall length of the mandrel is 220mm, and the taper formula of the mandrel is: C = (D 2 - D 1 ) / L. It is required to solve for the small end diameter D of the mandrel 1 . First, according to the length of the section where the mandrel mates with the small end and the large end of the gear shaft, it can be obtained that: C = (D’ 2 - D’ 1 ) / L 0 , D’ 2 represents the diameter at the interference fit with the large end of the gear shaft on the mandrel, D’ 2 = D 0 = 34.027mm, D’ 1 represents the diameter corresponding to the small end of the mandrel at the gear shaft. By statistically analyzing the long-term use data of the gear shaft, it is obtained that the outer surface runout at φA and φC relative to φB is between 0.005mm and 0.03mm, that is, the historical maximum runout value d = 0.03mm. To ensure that the alignment requirement is met during the machining of φB, the minimum unilateral clearance between φC and the mandrel should be 0.03mm, D’ 1 ≥ (D 0 - 2d). Let D’ 1 = (D 0 - 2d). Combining C = (D’ 2 - D’ 1 ) / L, it can be known that C = (D 0 - (D 0 - 2d)) / L 0 = 2d / L 0 = 2 × 0.03mm / 100mm = 0.0006. Combining with the overall taper of the mandrel, it can be known that: C = (D 2 - D 1 ) / L. By derivation, D 1 = D 2 - C × L 1 , and then D 1 = 34.034mm - 0.0006 × 220mm = 33.902mm.

[0059] Of course, in other embodiments of the present invention, after calculating the small end diameter D of the mandrel 1After that, the dimension is a theoretical dimension, and a large number of experiments can be carried out on the theoretical dimension to correct the theoretical dimension. For example, the present invention calculates D 1 =33.902mm. After a lot of tests, it was found that when D 1 =33.900mm, the outer circle runout at φC meets the part processing requirements, so D 1 Set to 33.900mm.

[0060] It can be understood that after the core rod is optimized, the gear shaft is installed on the core rod processed according to the optimized design, the small end of the core rod is supported by the dead center of the grinder, and the large end of the core rod is supported by the auxiliary positioning tool and the detachable center. At this time, the small end of the gear shaft cannot be adjusted by the grinder center, while the large end of the gear shaft can be adjusted by the auxiliary positioning tool and the detachable center. Figure 6 As shown, the auxiliary positioning tooling includes a three-jaw chuck and a faceplate. The faceplate is fixedly mounted on the grinder, and the three-jaw chuck is mounted on the faceplate. There is a gap after the three-jaw chuck and the faceplate are combined. The removable center is then clamped on the three-jaw chuck. When aligning the outer circle at φA, the center of the removable center can be fine-tuned by tapping the three-jaw chuck, thereby adjusting the runout of the outer circle of the large end of the gear shaft. The three-jaw chuck also has the advantages of automatic centering, high positioning accuracy, and fast clamping.

[0061] It can be understood that after the gear shaft and the core rod are installed on the grinding machine, the runout of the small end outer circle and the large end outer circle of the gear shaft are adjusted respectively through the adjustable gap between the small end of the gear shaft and the core rod, and the gap between the three-jaw chuck and the faceplate, so that the runout at ΦA and ΦC is no more than 0.004, thereby ensuring that the mutual runout of the outer circles at ΦA, ΦC and ΦB is no more than 0.008, thereby improving the quality of the grinding process at ΦB and the repair qualification rate.

[0062] In addition, another embodiment of the present invention further provides a grinding tool for an engine gear shaft, which is preferably suitable for the grinding method for an engine gear shaft as described above, comprising a core rod, an auxiliary positioning tool and a detachable center, wherein the structural dimensions of the core rod are optimized and designed for installing the gear shaft, and the runout of the small end of the gear shaft can be flexibly adjusted after the gear shaft is installed on the core rod, the auxiliary positioning tool is installed on the grinding machine, and the detachable center is installed on the auxiliary positioning tool for tightening the large end of the core rod, and the small end of the core rod is tightened by the center of the grinding machine, and the runout of the outer circle of the large end of the gear shaft can be adjusted by tapping the auxiliary positioning tool.

[0063] It can be understood that for the grinding tooling of the engine gear shaft in this embodiment, the optimized mandrel can adjust the runout of the small end of the gear shaft, and the auxiliary positioning tooling and the detachable center point can adjust the runout of the large end of the gear shaft. When grinding the middle journal part of the gear shaft, it is convenient to align the runout of the outer circle of the small end and the outer circle of the large end of the gear shaft, so that the runout of both is not greater than 0.004, improving the grinding quality and machining accuracy, and thus increasing the repair qualification rate.

[0064] Among them, the process of optimizing the structural dimensions of the mandrel is as follows:

[0065] First, obtain the distance between the small end and the large end of the gear shaft and the historical maximum runout values of the outer circles of the small end and the large end of the gear shaft relative to the middle journal part. Then, adopt the optimization strategy of interference fit between the large end of the gear shaft and the mandrel and the unilateral clearance between the small end of the gear shaft and the mandrel being greater than or equal to the historical maximum runout value, calculate the target taper of the mandrel, and finally, obtain the large end diameter and the overall length of the mandrel, and calculate the small end diameter of the mandrel in combination with the target taper of the mandrel.

[0066] Specifically, first obtain the distance L 0 between the small end and the large end of the gear shaft, and the historical maximum runout value d of the outer circles of the small end (i.e., at φC) and the large end (i.e., at φA) of the gear shaft relative to the middle journal part during the long-term use of the gear shaft. Then, adopt the optimization strategy of interference fit between the large end of the gear shaft and the mandrel and the unilateral clearance between the small end of the gear shaft and the mandrel being greater than or equal to the historical maximum runout value to optimize the taper of the mandrel, so as to increase the adjustable clearance between the small end of the gear shaft and the mandrel. Among them, the target taper of the mandrel is specifically calculated based on the following formula:

[0067] C = 2d / L 0

[0068] where C represents the target taper of the mandrel, d represents the historical maximum runout value, and L 0 represents the distance between the small end and the large end of the gear shaft.

[0069] Then, obtain the large end diameter D 2 of the mandrel and the overall length L of the mandrel, and the small end diameter D 1 of the mandrel can be calculated in combination with the target taper of the mandrel. Finally, input the large end diameter D 2 and the small end diameter D 1 of the mandrel into the mandrel processing program, and the mandrel can be processed according to the optimized design scheme. Among them, the small end diameter of the mandrel is calculated based on the following formula:

[0070] D 1 = D 2 - C×L 1

[0071] Among them, D 1 represents the small-end diameter of the mandrel, D 2 represents the large-end diameter of the mandrel, and L 1 represents the overall length of the mandrel.

[0072] For example, assume that the inner hole diameter of the gear shaft is D 0 is φ34.027 mm, the distance L 0 between the small end and the large end of the gear shaft is 100 mm, the large-end diameter D 2 of the mandrel is 34.034 mm, the overall length of the mandrel is 220 mm, and the taper formula of the mandrel is: C = (D 2 - D 1 ) / L. It is required to solve for the small-end diameter D 1 of the mandrel. First, according to the length of the section where the mandrel mates with the small end and the large end of the gear shaft, it can be obtained that: C = (D’ 2 - D’ 1 ) / L 0 , where D’ 2 represents the diameter at the interference fit position of the mandrel with the large end of the gear shaft, D’ 2 = D 0 = 34.027 mm, D’ 1 represents the diameter of the mandrel corresponding to the small end of the gear shaft. By statistically analyzing the long-term use data of the gear shaft, it is obtained that the outer surface runout at φA and φC relative to φB is between 0.005 mm and 0.03 mm, that is, the historical maximum runout value d = 0.03 mm. To ensure that the alignment requirement is met during the machining of φB, the minimum unilateral clearance between φC and the mandrel should be 0.03 mm, D’ 1 ≥ (D 0 - 2d). Let D’ 1 = (D 0 - 2d). Combining C = (D’ 2 - D’ 1 ) / L, it can be known that C = (D 0 - (D 0 - 2d)) / L 0 = 2d / L 0 = 2 × 0.03 mm / 100 mm = 0.0006. Combining with the overall taper of the mandrel, it can be known that: C = (D 2 - D 1 ) / L. By derivation, D 1 = D 2 - C × L 1 , and then D 1 = 34.034 mm - 0.0006 × 220 mm = 33.902 mm.

[0073] Certainly, in other embodiments of the present invention, after calculating the small-end diameter D of the mandrel 1 this size is a theoretical size, and a large number of tests can be carried out on the theoretical size to correct the theoretical size. For example, after calculating D 1 = 33.902 mm in the present invention, a large number of tests were carried out and it was found that when D 1 = 33.900 mm, the outer circle runout at φC all meets the part processing requirements, so D 1 is set to 33.900 mm.

[0074] In addition, the auxiliary positioning tooling includes a three-jaw chuck and a faceplate. The faceplate is fixedly installed on the grinding machine, the three-jaw chuck is installed on the faceplate, and there is a gap after the combination of the three-jaw chuck and the faceplate. Then the detachable center is clamped on the three-jaw chuck. When aligning the outer circle at φA, the center of the detachable center can be finely adjusted by knocking the three-jaw chuck, so that the runout of the large-end outer circle of the gear shaft can be adjusted. Moreover, the three-jaw chuck also has the advantages of automatic centering, high positioning accuracy, and fast clamping.

[0075] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0076] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

[0077] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for grinding an engine gear shaft, characterized in that: Includes the following: The structural dimensions of the mandrel are optimized so that the runout of the small end of the gear shaft can be flexibly adjusted after the gear shaft is installed on the mandrel; Install the gear shaft onto the mandrel processed according to the optimized design, use the grinding machine top to support the small end of the mandrel, and use the auxiliary positioning tooling and the detachable top to support the large end of the mandrel, so that the runout of the large end of the gear shaft can be flexibly adjusted on the grinding machine; Find the runout of the small end outer circle and the large end outer circle of the spur gear shaft, and grind the intermediate journal part of the gear shaft.

2. The engine gear shaft grinding method according to claim 1, characterized in that: The process of optimizing the structural dimensions of the mandrel includes the following: Obtain the distance between the small end and the large end of the gear shaft and the historical maximum runout value of the small end outer circle and the large end outer circle of the gear shaft relative to the intermediate shaft neck position; The optimization strategy of interference fit between the big end of the gear shaft and the mandrel and the single-side clearance between the small end of the gear shaft and the mandrel being greater than or equal to the historical maximum runout value is adopted to calculate the target taper of the mandrel. The large end diameter of the mandrel and the overall length of the mandrel are obtained, and the small end diameter of the mandrel is calculated in combination with the target taper of the mandrel.

3. The engine gear shaft grinding method according to claim 2, characterized in that: The target taper of the mandrel is calculated based on the following formula: C=2d / L0 Among them, C represents the target taper of the mandrel, d represents the historical maximum runout value, and L0 represents the distance from the small end to the large end of the gear shaft.

4. The engine gear shaft grinding method according to claim 3, characterized in that: The small end diameter of the mandrel is calculated based on the following formula: D1=D2-C×L1 Wherein, D1 represents the small end diameter of the mandrel, D2 represents the large end diameter of the mandrel, and L1 represents the overall length of the mandrel.

5. The engine gear shaft grinding method according to claim 1, characterized in that: The auxiliary positioning tooling includes a three-jaw chuck and a faceplate. The faceplate is fixedly installed on the grinder. There is a gap between the three-jaw chuck and the faceplate after they are combined. The removable center is then clamped on the three-jaw chuck. The runout of the outer circle of the large end of the gear shaft can be adjusted by tapping the three-jaw chuck.

6. A grinding tool for an engine gear shaft, characterized in that: It includes a core rod, an auxiliary positioning tool and a detachable center. The structural dimensions of the core rod are optimized and designed for installing the gear shaft. After the gear shaft is installed on the core rod, the runout of the small end of the gear shaft can be flexibly adjusted. The auxiliary positioning tool is installed on the grinder, and the detachable center is installed on the auxiliary positioning tool for tightening the large end of the core rod. The small end of the core rod is tightened by the center of the grinder, and the runout of the outer circle of the large end of the gear shaft can be adjusted by tapping the auxiliary positioning tool.

7. The engine gear shaft grinding tool as claimed in claim 6, characterized in that: The structural dimension optimization design process of the mandrel is as follows: First, the distance between the small end and the large end of the gear shaft and the historical maximum runout values ​​of the small end outer circle and the large end outer circle of the gear shaft relative to the intermediate shaft neck position are obtained. Then, an optimization strategy is adopted in which the large end of the gear shaft and the mandrel have an interference fit, and the unilateral clearance between the small end of the gear shaft and the mandrel is greater than or equal to the historical maximum runout value. The target taper of the mandrel is calculated. Finally, the large end diameter of the mandrel and the overall length of the mandrel are obtained, and the small end diameter of the mandrel is calculated in combination with the target taper of the mandrel.

8. The engine gear shaft grinding tool as claimed in claim 7, characterized in that: The target taper of the mandrel is calculated based on the following formula: C=2d / L0 Among them, C represents the target taper of the mandrel, d represents the historical maximum runout value, and L0 represents the distance from the small end to the large end of the gear shaft.

9. The engine gear shaft grinding tool as claimed in claim 8, characterized in that: The small end diameter of the mandrel is calculated based on the following formula: D1=D2-C×L1 Wherein, D1 represents the small end diameter of the mandrel, D2 represents the large end diameter of the mandrel, and L1 represents the overall length of the mandrel.

10. The engine gear shaft grinding tool as claimed in claim 6, characterized in that: The auxiliary positioning tooling includes a three-jaw chuck and a faceplate. The faceplate is fixedly installed on the grinder. There is a gap between the three-jaw chuck and the faceplate after they are combined. The removable center is then clamped on the three-jaw chuck. The runout of the outer circle of the large end of the gear shaft can be adjusted by tapping the three-jaw chuck.

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