Machining device and method for controlling deformation of crankshaft of high-power and high-rotating-speed diesel engine

Abstract

The invention provides a machining device for controlling deformation of a crankshaft of a high-power and high-rotating-speed diesel engine. The machining device comprises a bolt and a threaded sleeve. The threaded sleeve comprises a shell, a containing section, a fixing section and a pre-tightening section, the containing section, the fixing section and the pre-tightening section are sequentially arranged in the shell, a containing hole is formed in the containing section, the fixing section is in threaded connection with the bolt, a movable channel is formed in the pre-tightening section, a movable nut is arranged in the movable channel and is in threaded connection with the bolt, and a pre-tightening bolt is arranged on the movable nut. And the end part of the pre-tightening bolt is in contact with the fixed section. According to the machining device, the fixing section is connected with the bolt, the two ends of the machining device can abut against or loosen from the surfaces of the two sides by rotating the threaded sleeve, and the machining device is suitable for machining crankshafts of various models; the movable nut can move close to or away from the fixed section and can rotate together with the fixed section along with the shell, the end of the pre-tightening bolt can provide pre-tightening force away from the fixed section, and relative fixing and loosening between the threaded sleeve and the bolt are prevented.

Description

Technical Field

[0001] The invention belongs to the technical field of diesel engine crankshaft manufacturing, and in particular relates to a processing device and method for controlling deformation of a high-power and high-speed diesel engine crankshaft. Background Art

[0002] As the core component of a diesel engine, the crankshaft collects the power generated by the diesel engine cylinder and converts it into torque to drive the load, output effective work to the outside, and drive other auxiliary devices of the diesel engine itself. When the diesel engine is running, the crankshaft is constantly subjected to alternating stress from the connecting rod. In addition, the crankshaft has a complex shape and severe stress concentration, which can easily cause the crankshaft to vibrate, resulting in deformation or wear of the crankshaft, causing the diesel engine to fail to work properly or even be damaged.

[0003] During the crankshaft machining process, controlling the deformation of the crankshaft is the key technology to ensure the performance of the crankshaft, especially when manufacturing slender crankshafts with a long length and thin journals and a large aspect ratio. It is necessary to control the deformation of the crankshaft as much as possible and reduce the journal runout as much as possible to ensure the normal operation of the diesel engine. Summary of the invention

[0004] In view of this, the present invention aims to provide a processing device and method for controlling the deformation of a high-power and high-speed diesel engine crankshaft, so as to control the degree of deformation during the processing of a slender crankshaft with a large aspect ratio.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] In a first aspect, a processing device for controlling deformation of a crankshaft of a high-power and high-speed diesel engine comprises a bolt and a threaded sleeve;

[0007] The screw sleeve includes: an outer shell, a receiving section, a fixing section and a pre-tightening section, wherein the receiving section, the fixing section and the pre-tightening section are sequentially arranged inside the outer shell, a receiving hole for accommodating the end of a bolt is arranged in the receiving section, the fixing section is threadedly connected to the bolt, a movable channel is arranged in the pre-tightening section, a movable nut is arranged in the movable channel, the movable nut is threadedly connected to the bolt, a pre-tightening bolt is also arranged on the movable nut, and the end of the pre-tightening bolt contacts the fixing section.

[0008] Furthermore, the fixing section is a fixing nut, and the fixing nut is fixedly connected to the inner surface of the shell.

[0009] Furthermore, the movable nut is provided with a threaded hole for accommodating the pre-tightening bolt.

[0010] Furthermore, the bolt and the screw sleeve are both provided with anti-wear pads, and the anti-wear pads are respectively arranged on the end surfaces of the bolt and the screw sleeve that are away from each other.

[0011] Furthermore, the inner surface of the accommodating hole is a smooth surface.

[0012] In a second aspect, a method for controlling deformation of a crankshaft of a high-power and high-speed diesel engine is provided, using the processing device for controlling deformation of a crankshaft of a high-power and high-speed diesel engine, wherein the method comprises the following steps:

[0013] Step S1: Processing the two ends and the center hole of the crankshaft;

[0014] Step S2: Rough milling of the main journal and connecting rod journal and stress release;

[0015] Step S3: repairing the center hole;

[0016] Step S4: Turn the main journal and connecting rod journal, and turn the cone;

[0017] Step S5: machining the weight-reducing holes and relieving the stress;

[0018] Step S6: Roughly grinding the main journal and connecting rod journal and relieving stress;

[0019] Step S7: semi-finishing the main journal and connecting rod journal;

[0020] Step S8: machining the oil hole and releasing the stress;

[0021] Step S9: repairing the center hole;

[0022] Step S10: fine grinding the main journal and connecting rod journal, and fine grinding the cone;

[0023] Step S11: nitriding treatment;

[0024] Step S12: polishing the main journal and connecting rod journal;

[0025] The nitriding treatment comprises:

[0026] Step S11-1: Connect the hanging piece to the central main journal of the crankshaft to hang the crankshaft;

[0027] Step S11-2: placing the processing device between the crank arms on both sides of the central main shaft neck, rotating the screw sleeve of the processing device, and pressing the two ends of the processing device against the crank arm surfaces on both sides of the central main shaft neck respectively;

[0028] Step S11-3: The processing devices are respectively arranged at the main journals symmetrically on both sides of the central main journal, and the processing devices are both arranged between the crank arms on both sides of the main journal, and the screw sleeves of the processing devices are rotated to press the two ends of the processing devices against the surfaces of the crank arms on both sides of the main journal;

[0029] Step S11-4: rotating the pre-tightening bolts of all the processing devices to pre-tighten and fix the processing devices;

[0030] Step S11-5: nitridation heat treatment;

[0031] Step S11-6: Reversely rotate the pre-tightening bolt of the processing device, and then reversely rotate the threaded sleeve of the processing device to disassemble all the processing devices.

[0032] Furthermore, the processing devices are arranged below the central main journal and the main journals symmetrically located on both sides of the central main journal.

[0033] Furthermore, the anti-wear pads at both ends of the processing device are respectively pressed against the relative surfaces of the crank arms on both sides of the main shaft neck.

[0034] Furthermore, the stress release is an aging treatment.

[0035] Compared with the prior art, the processing device and method for controlling the deformation of a high-power and high-speed diesel engine crankshaft according to the present invention have the following advantages:

[0036] (1) The processing device described in the present invention connects the screw sleeve to the bolt thread through the fixed section inside the shell. The screw sleeve can be rotated to adjust the length of the processing device so that the two ends of the processing device can be pressed against or loosened from the surfaces on both sides. It can also be applied to the processing of various types of crankshafts. The movable nut inside the shell can move toward or away from the fixed section along the axial direction of the receiving hole in the movable channel. The movable nut can rotate with the fixed section at the same time as the shell. The end of the pre-tightening bolt on the movable nut can press against the fixed section to provide a pre-tightening force away from the fixed section to the movable nut. When the movable nut and the fixed section are simultaneously threadedly connected to the bolt, the relative fixation between the screw sleeve and the bolt is prevented from loosening.

[0037] (2) The anti-wear pads provided at the two ends of the bolt and the screw sleeve of the processing device of the present invention, which are far away from each other, can prevent the screw sleeve from wearing the crankshaft surface during the process of tightening and abutting, causing the crankshaft processing to fail to meet the relevant requirements. The smooth inner surface of the receiving hole will not hinder the axial movement of the bolt under the premise of the guide screw, so that the processing device can be installed smoothly.

[0038] (3) The processing method described in the present invention utilizes the processing device to hoist the crankshaft from the center main journal near the center of gravity, and sets the processing device below the center main journal, and sets the processing device below the main journals symmetrically on both sides of the center main journal, respectively. The processing device abuts against the crank arms on both sides of the main journal, and the two ends of the crankshaft are bent upward before the crankshaft is subjected to nitriding heat treatment, thereby offsetting the downward bending deformation of the two ends of the crankshaft caused by gravity during the nitriding heat treatment. The pre-tightening bolts can enable the processing device to maintain the stability of the crank arms, thereby avoiding uncontrollable deformation of the crankshaft caused by the loosening of the processing device. After the nitriding heat treatment is completed, all processing devices are disassembled, and the crankshaft can be restored to the shape before the reverse deformation, thereby ensuring that the crankshaft journal runout is within the range that meets relevant requirements.

[0039] (4) The processing method described in the present invention adds an aging treatment process after turning and rough grinding to fully release the cutting stress generated by the processing, and adds a semi-finishing grinding process. In the subsequent fine grinding process, the processing allowance is controlled within 0.3 mm, which greatly reduces the deformation caused by grinding heat and reduces the cutting stress generated. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings constituting a part of the present invention 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 accompanying drawings:

[0041] Figure 1 This is a schematic structural diagram of a processing device for controlling deformation of a high-power and high-speed diesel engine crankshaft according to Embodiment 1 of the present invention;

[0042] Figure 2 It is a cross-sectional schematic diagram of the screw sleeve according to the first embodiment of the present invention;

[0043] Figure 3 This is a flow chart of a processing method for controlling deformation of a high-power and high-speed diesel engine crankshaft according to a second embodiment of the present invention;

[0044] Figure 4 This is a flow chart of the nitriding treatment according to the second embodiment of the present invention;

[0045] Figure 5 This is a schematic diagram of the structure of the crankshaft described in Example 2 of the present invention.

[0046] Description of reference numerals:

[0047] 1-first anti-wear pad; 2-bolt; 3-screw; 4-threaded sleeve; 5-second anti-wear pad; 6-movable nut; 7-pre-tightening bolt; 8-fixing nut; 9-accommodating hole; 10-movable screw hole; 11-movable channel; 12-housing; 13-fixing screw hole; 14-accommodating section; 15-center main shaft neck. DETAILED DESCRIPTION

[0048] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0049] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0050] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0051] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0052] Embodiment 1

[0053] Figure 1 Schematic diagram of the structure of a processing device for controlling the deformation of a high-power and high-speed diesel engine crankshaft according to Embodiment 1 of the present invention. Figure 1 As shown, it includes a bolt 2 and a threaded sleeve 4;

[0054] Figure 2 FIG. 1 is a cross-sectional schematic diagram of the screw sleeve according to the first embodiment of the present invention. Figure 2As shown, the screw sleeve includes: an outer shell 12, a receiving section 14, a fixed section and a pre-tightening section, the receiving section, the fixed section and the pre-tightening section are arranged in sequence inside the outer shell, a receiving hole 9 for accommodating the end of the bolt is provided in the receiving section, the fixed section is threadedly connected to the bolt, a movable channel 11 is provided in the pre-tightening section, a movable nut 6 is provided in the movable channel, the movable nut is threadedly connected to the bolt, a pre-tightening bolt 7 is also provided on the movable nut, and the end of the pre-tightening bolt is in contact with the fixed section.

[0055] An opening is provided at one end of the housing, and the screw rod 3 of the bolt can extend into the interior of the housing from the opening. The receiving section, the fixing section and the pre-tightening section are arranged in sequence close to the opening inside the housing, and the end of the bolt extending into the housing is inserted into the receiving hole. The diameter of the receiving hole is slightly larger than the diameter of the screw rod. The receiving hole can prevent the axial direction of the bolt from deflecting when the bolt rotates, but will not hinder the axial movement of the bolt. Exemplarily, the inner surface of the receiving hole is a smooth surface.

[0056] The fixing section is provided with a screw hole for the screw rod to pass through, the center of the screw hole is located on the axis of the receiving hole, and the bolt can be connected with the screw hole by thread, so that the bolt can move closer to or away from the screw sleeve when rotating. An optional implementation of this embodiment is that the fixing section is a fixing nut 8, and the fixing nut is fixedly connected to the inner surface of the shell. The center of the fixing screw hole 13 of the fixing nut is located on the axis of the receiving hole, and the bolt is connected with the fixing nut through the fixing screw hole, so that the bolt can move closer to or away from the screw sleeve when rotating.

[0057] The movable channel of the pre-tightening section is arranged between the opening of the shell and the fixed section, and a hexagonal guide rail that can match the shape of the movable nut is arranged in the movable channel, and the movable nut can move toward or away from the fixed section along the hexagonal guide rail. The center of the movable screw hole 10 of the movable nut is located on the axis of the receiving hole, and the movable nut is connected to the bolt through the movable screw hole. The hexagonal guide rail can keep the center of the movable nut coincident with the axis of the receiving hole during movement, and the axial direction of the movable nut will not deflect during movement. The movable nut can rotate simultaneously with the shell under the limitation of the hexagonal guide rail, and the movable nut can be threadedly connected with the bolt at the same time as the fixed section.

[0058] The axial direction of the pre-tightening bolt is parallel to the axial direction of the receiving hole. The pre-tightening bolt passes through the movable nut from the opening of the housing and extends toward the fixed section. The pre-tightening bolt can be rotated to provide a pre-tightening force to the movable nut in a direction away from the fixed section. Exemplarily, the movable nut is provided with a threaded hole for accommodating the pre-tightening bolt. The pre-tightening bolt passes through the threaded hole. The head of the pre-tightening bolt extends out of the opening of the housing. The end of the pre-tightening bolt extends toward the fixed section and contacts the fixed section.

[0059] When the screw sleeve is put on the bolt, the fixed section and the movable nut rotate simultaneously with the rotation of the shell, and are simultaneously connected with the bolt thread. At this time, the distance between the movable nut and the fixed section will be limited. The pre-tightening bolt can be rotated to move the pre-tightening bolt toward the fixed section, and the end of the pre-tightening bolt can be pressed against the fixed section to generate a force moving away from each other between the movable nut and the fixed section, namely, the pre-tightening force. The pre-tightening force can greatly avoid the possibility of the screw sleeve loosening after being tightened with the bolt, and the relative fixation between the screw sleeve and the bolt is more reliable.

[0060] Optionally, in order to prevent the bolts and the sleeves from contacting the surface of the crankshaft, especially when the bolts and the sleeves continue to rotate and press against the surface of the crankshaft after contacting the surface of the crankshaft, causing the crankshaft to fail to meet relevant processing requirements, anti-wear pads are provided on the bolts and the sleeves, and the anti-wear pads are respectively arranged on the end surfaces of the bolts and the sleeves that are away from each other, a first anti-wear pad 1 is provided on the end of the bolt away from the sleeve, and a second anti-wear pad 5 is provided on the end of the sleeve away from the bolt, and the two ends of the bolt and the sleeve that are away from each other are in contact with the crankshaft through the first anti-wear pad and the second anti-wear pad, respectively, to avoid damage to the crankshaft surface.

[0061] In order to facilitate the operation of the shell, a convex ridge with a hexagonal cross section can be set on the outer surface of the shell, so that the shape of the outer surface of the shell is close to the hexagon outside the nut, and the screw sleeve can be conveniently tightened using a tool for operating the nut.

[0062] Embodiment 2

[0063] Figure 3 Flow chart of a processing method for controlling the deformation of a high-power and high-speed diesel engine crankshaft according to Embodiment 2 of the present invention. Figure 3 As shown, the processing device for controlling the deformation of a high-power and high-speed diesel engine crankshaft comprises the following steps:

[0064] Step S1: Processing the two ends and the center hole of the crankshaft;

[0065] Step S2: Rough milling of the main journal and connecting rod journal and stress release;

[0066] Step S3: repairing the center hole;

[0067] Step S4: Turn the main journal and connecting rod journal, and turn the cone;

[0068] Step S5: machining the weight-reducing holes and relieving the stress;

[0069] Step S6: Roughly grinding the main journal and connecting rod journal and relieving stress;

[0070] Step S7: semi-finishing the main journal and connecting rod journal;

[0071] Step S8: machining the oil hole and releasing the stress;

[0072] Step S9: repairing the center hole;

[0073] Step S10: fine grinding the main journal and connecting rod journal, and fine grinding the cone;

[0074] Step S11: nitriding treatment;

[0075] Step S12: polishing the main journal and connecting rod journal;

[0076] In order to reduce the cutting process in the crankshaft manufacturing process, precision die forgings are used as the blanks for crankshaft processing, and the shape of the crank arm is directly precision forged. The crank arm and crank are no longer processed, which greatly reduces the generation of cutting stress. First, the two ends of the crankshaft are processed to determine the center hole of the crankshaft processing, and then the main journal and connecting rod journal are rough milled. After the rough milling is completed, the cutting stress generated by the rough milling is released. In order to ensure the accuracy of crankshaft processing, the center hole needs to be repaired after rough milling to ensure the accuracy of the center hole positioning. Then the main journal and connecting rod journal are machined, and the crankshaft cone is machined. Then the weight reduction hole is processed to reduce the weight of the connecting rod journal and reduce the centrifugal force generated when the crankshaft rotates, and then the stress is released. Then the main journal and connecting rod journal are rough ground, and the stress is released again after the rough grinding. Then the main journal and connecting rod journal are rough ground for the second time, and the oil hole is processed again, and then the cutting stress is released. After releasing the stress, the center hole is ground again to ensure the accuracy of the crankshaft processing, and then the main journal and connecting rod journal are finely ground, and then the crankshaft cone is finely ground. At this point, the process involving cutting in the crankshaft processing is basically completed, and the crankshaft needs to be nitrided to strengthen the strength of the crankshaft. After the nitriding treatment, the main journal and connecting rod journal are polished. In order to increase the service life of the crankshaft, it is necessary to fully release the cutting stress in the crankshaft processing as much as possible. Exemplarily, the stress release is aging treatment. On the basis of the original processing technology, in step S5, an aging treatment is added after processing the weight reduction hole, and in step S6, an aging treatment is added after the rough grinding process. The cutting stress of turning and rough grinding can be fully released, avoiding the influence of uneven stress on the normal operation and service life of the crankshaft. In order to reduce the amount of cutting during finishing, on the basis of the original process, step S7 is added to the semi-finishing grinding process of the main journal and the connecting rod journal. Accordingly, in step S10, the machining allowance of the finishing grinding is reduced from 0.75mm to 0.3mm, which greatly reduces the deformation caused by grinding heat and controls the cutting stress to a smaller extent.

[0077] Figure 4 Flow chart of the nitriding treatment according to the second embodiment of the present invention. The nitriding treatment, such as Figure 4 As shown, including:

[0078] Step S11-1: Connect the hanging piece to the central main journal 15 of the crankshaft and hang the crankshaft. Figure 5 As shown;

[0079] Step S11-2: the processing device is arranged between the crank arms on both sides of the central main shaft neck, and the screw sleeve 4 of the processing device is rotated to press the two ends of the processing device against the crank arm surfaces on both sides of the central main shaft neck respectively;

[0080] Step S11-3: The processing devices are respectively arranged at the main journals symmetrically on both sides of the central main journal, and the processing devices are both arranged between the crank arms on both sides of the main journal, and the screw sleeves of the processing devices are rotated to press the two ends of the processing devices against the surfaces of the crank arms on both sides of the main journal;

[0081] Step S11-4: rotating the pre-tightening bolts of all the processing devices to pre-tighten and fix the processing devices;

[0082] Step S11-5: nitridation heat treatment;

[0083] Step S11-6: Reversely rotate the pre-tightening bolt of the processing device, and then reversely rotate the threaded sleeve of the processing device to disassemble all the processing devices.

[0084] During the nitriding treatment, it is necessary to use the processing device for controlling the deformation of the high-power and high-speed diesel engine crankshaft described in the first embodiment of the present invention. During the hoisting, in order to make the deformation of the crankshaft generated during the nitriding treatment uniform, the hoisting position should be as close to the center of gravity of the crankshaft as possible, so the hoisting piece can be connected to the center main journal located at the center of the crankshaft, and the main shaft can be hoisted from the center of the main shaft for nitriding treatment.

[0085] Since the crankshaft will bend and deform due to gravity during the nitriding heat treatment, it is necessary to use the processing device described in Example 1 to reversely deform the crankshaft according to the deformation law and deformation amount of the crankshaft after nitriding before the nitriding heat treatment to offset the deformation of the crankshaft during the nitriding heat treatment. In this embodiment, the crankshaft is hoisted at the central main journal of the crankshaft. After the nitriding heat treatment, the two ends of the crankshaft will bend and deform downward due to gravity. Therefore, it is necessary to reversely bend and deform the crankshaft upward before the nitriding heat treatment to offset the downward deformation of the two ends of the crankshaft during the nitriding heat treatment. After the nitriding heat treatment, the processing device is disassembled so that the crankshaft can basically return to the state before the nitriding treatment when the reverse deformation is not performed, and the crankshaft journal runout is controlled within the range that meets the relevant requirements. In this embodiment, the crankshaft journal runout before the nitriding heat treatment is 0.03mm, and the crankshaft runout after the nitriding heat treatment can be controlled within 0.05mm, which meets the requirements of this model of crankshaft products.

[0086] When installing the processing device, the two ends of the processing device, i.e., the bolt head and the end of the screw sleeve away from the bolt head, need to be respectively oriented toward the crank arms on both sides of the center main journal, and the screw sleeve is rotated so that the two ends of the processing device are respectively pressed against the surface of the crank arm, and the two ends of the crankshaft are bent upward by pressing against the crank arm. Next, the processing devices are respectively set at the main journals at symmetrical positions on both sides of the center main journal, and the processing devices are also set between the crank arms on both sides of the main journal, and the two ends of the processing device are respectively pressed against the crank arms on both sides of the main journal by rotating the screw sleeve. Since the deformation of the crankshaft is smaller as it is closer to the two ends, it is also necessary to control the degree of upward bending deformation caused by the processing device pressing against the crank arms close to the two ends of the crankshaft to be reduced accordingly.

[0087] After installing all the processing devices, turn the pre-tightening bolts on the processing devices to generate pre-tightening force between the movable nut and the fixing part of the processing device to prevent the loosening of the processing device from causing uncontrolled deformation of the crankshaft. After the nitriding heat treatment is completed, the pre-tightening bolts must be turned first to release the pre-tightening force between the movable nut and the fixing part, and then the threaded sleeve must be turned to loosen the processing device and remove all the processing devices. At this point, the nitriding heat treatment of the crankshaft is completed, and under the action of the processing device, the deformation degree of the crankshaft will be controlled within the range that meets the relevant requirements.

[0088] Since the deformation of the crankshaft is caused by gravity, the processing devices are arranged below the central main journal and the main journals symmetrically on both sides of the central main journal, so that the crankshaft is bent and deformed upward to offset the downward bending deformation of the crankshaft caused by gravity during nitriding heat treatment.

[0089] An optional implementation of the present embodiment is that the anti-wear pads at both ends of the processing device are respectively pressed against the relative surfaces of the crank arms on both sides of the main shaft neck, and the two ends of the processing device are pressed against the surfaces of the crank arms through the anti-wear pads. Due to the presence of the anti-wear pads, the processing device will not cause damage to the surface of the crank arm during the process of rotating and pressing against the crank arm.

[0090] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A processing device for controlling the deformation of a high-power and high-speed diesel engine crankshaft, characterized in that: It comprises a bolt (2) and a threaded sleeve (4); The screw sleeve (4) comprises: an outer shell (12), a receiving section (14), a fixing section and a pre-tightening section. The receiving section (14), the fixing section and the pre-tightening section are arranged in sequence inside the outer shell (12). A receiving hole (9) for accommodating the end of a bolt (2) is provided in the receiving section (14). The fixing section is threadedly connected to the bolt (2). A movable channel (11) is provided in the pre-tightening section. A movable nut (6) is provided in the movable channel (11). The movable nut (6) is threadedly connected to the bolt (2). A pre-tightening bolt (7) is also provided on the movable nut (6). The end of the pre-tightening bolt (7) contacts the fixed section.

2. A processing device for controlling deformation of a high-power and high-speed diesel engine crankshaft according to claim 1, characterized in that: The fixing section is a fixing nut (8), and the fixing nut (8) is fixedly connected to the inner surface of the outer shell (12).

3. A processing device for controlling deformation of a high-power and high-speed diesel engine crankshaft according to claim 1, characterized in that: The movable nut (6) is provided with a threaded hole for accommodating a pre-tightening bolt (7).

4. A processing device for controlling deformation of a high-power and high-speed diesel engine crankshaft according to claim 1, characterized in that: Anti-wear pads are provided on both the bolt (2) and the screw sleeve (4), and the anti-wear pads are respectively arranged on end surfaces of the bolt (2) and the screw sleeve (4) that are away from each other.

5. The processing device for controlling the deformation of a high-power and high-speed diesel engine crankshaft according to claim 1, characterized in that: The inner surface of the accommodating hole (9) is a smooth surface.

6. A method for controlling the deformation of a high-power and high-speed diesel engine crankshaft, using the device for controlling the deformation of a high-power and high-speed diesel engine crankshaft according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step S1: Processing the two ends and the center hole of the crankshaft; Step S2: Rough milling of the main journal and connecting rod journal and stress release; Step S3: repairing the center hole; Step S4: Turn the main journal and connecting rod journal, and turn the cone; Step S5: machining the weight-reducing holes and relieving the stress; Step S6: Roughly grinding the main journal and connecting rod journal and relieving stress; Step S7: semi-finishing the main journal and connecting rod journal; Step S8: machining the oil hole and releasing the stress; Step S9: repairing the center hole; Step S10: fine grinding of the main journal and connecting rod journal, and fine grinding of the cone; Step S11: nitriding treatment; Step S12: polishing the main journal and connecting rod journal; The nitriding treatment comprises: Step S11-1: Connect the hanging piece to the central main journal (15) of the crankshaft to hang the crankshaft; Step S11-2: the processing device is arranged between the crank arms on both sides of the central main journal (15), and the screw sleeve (4) of the processing device is rotated to press the two ends of the processing device against the surfaces of the crank arms on both sides of the central main journal (15); Step S11-3: The processing devices are respectively arranged at the main journals symmetrically on both sides of the central main journal (15), and the processing devices are both arranged between the crank arms on both sides of the main journal, and the screw sleeve (4) of the processing device is rotated to press the two ends of the processing device against the surfaces of the crank arms on both sides of the main journal; Step S11-4: rotating the pre-tightening bolts (7) of all the processing devices to pre-tighten and fix the processing devices; Step S11-5: nitridation heat treatment; Step S11-6: Reversely rotate the pre-tightening bolt (7) of the processing device, and then reversely rotate the threaded sleeve (4) of the processing device to disassemble all the processing devices.

7. A processing method for controlling deformation of a high-power and high-speed diesel engine crankshaft according to claim 6, characterized in that: The processing devices are arranged below the central main journal (15) and the main journals symmetrical on both sides of the central main journal (15).

8. A processing method for controlling deformation of a high-power and high-speed diesel engine crankshaft according to claim 6, characterized in that: The anti-wear pads at both ends of the processing device are respectively pressed tightly against the relative surfaces of the crank arms at both sides of the main shaft neck.

9. A processing method for controlling deformation of a high-power and high-speed diesel engine crankshaft according to claim 6, characterized in that: The stress release is an aging treatment.

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