Segmented engine frame folding method

Abstract

The invention relates to a folding method of a sectional type engine rack, and belongs to the technical field of engine racks. The method comprises the following steps: roughly machining the surface of a first small end of a first section, turning over, finely machining a first large end surface and a first connecting surface, and machining a first positioning pin hole group and a first process pin hole group; turning over until the first small end face is upward, establishing a first reference, and measuring the positions of the first positioning pin hole group and the first process pin hole group; roughly machining the surface of the second small end of the second section, turning over, and finely machining the second large end surface and the second connecting surface; turning over until the second small end face is upward, and processing a second positioning pin hole group and a second process pin hole group according to the measurement result; and connecting the first connecting surface and the second connecting surface through a process pin. The positions of the pin holes in the first connecting face and the second connecting face are strictly symmetrical, deformation errors are avoided, and the finish machining face before folding can still meet the drawing requirement after folding.

Description

Technical Field

[0001] The invention belongs to the technical field of engine frames, and in particular relates to a closing method of a segmented engine frame. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] The main engine frame of the engine is also called the engine frame, which is an important part of the engine crankcase. Due to the huge size of large marine engines, their engine frames need to be made using a variety of processing methods including welding. In order to avoid the adverse effects of long continuous welds on product quality (including welding deformation and stress concentration, etc.), it is necessary to manufacture the engine frame in sections, specifically: the engine frame is divided into multiple frame sections in the length direction, the upper end of the frame section is the small end face, the lower end is the large end face, and the contact surface between the frame sections is the connecting surface, which is basically perpendicular to the small end face and the large end face. After producing each frame section separately, the connecting surfaces of multiple frame sections are assembled and machined to ensure the overall size requirements of the small end face and the frame.

[0004] The processing surfaces are distributed in various positions of the frame segments, so multiple frame segments need to be turned over. During the turning process, uncontrollable material deformation errors can easily cause the closed product to fail to meet the drawing requirements. Therefore, how to design the manufacturing process to improve production efficiency while meeting the accuracy requirements has become a challenge for technicians. Summary of the invention

[0005] In view of the problem that it is difficult to ensure the accuracy of the closing step, the purpose of the present invention is to provide a method for manufacturing a segmented engine frame, select a reasonable positioning reference, and process the positioning pin holes and process pin holes on another frame segment according to the positioning pin holes and process pin holes on the connecting surface of one frame segment, so as to ultimately ensure the accuracy of the closing step and provide a guarantee for the subsequent processing accuracy.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] A method for manufacturing a segmented engine frame comprises the following steps:

[0008] S1, rough-processing the first small end surface of the first section of the segmented engine frame, turning it over so that the first large end surface faces upward, fine-processing the first large end surface and the first connecting surface, and processing a first positioning pin hole group and a first process pin hole group on the first connecting surface;

[0009] S2, turning the first section over so that the first small end surface faces upward, establishing a first reference using the position dimensions of the first large end surface and the first connecting surface, and measuring the position dimensions of the first positioning pin hole group and the first process pin hole group;

[0010] S3. Rough-process the second small end surface of the second section of the segmented engine frame, flip it over so that the second large end surface faces upward, and then fine-process the second large end surface and the second connecting surface.

[0011] S4, turning the second section over so that the second small end surface faces upward, using the position dimensions of the second large end surface and the second connecting surface to establish a second reference basis, and processing the second positioning pin hole group and the second process pin hole group of the second section according to the position dimensions of the first positioning pin hole group and the first process pin hole group measured in S2;

[0012] S5. Connect the first connection surface and the second connection surface through process pins and positioning pins.

[0013] Optionally, in S1, the side position of the first large end face is processed as the first process reference plane, so that the first process reference plane, the first large end face and the first connecting surface are perpendicular to each other.

[0014] Optionally, in S1, the first positioning pin hole group includes a plurality of first positioning pin holes; and the first process pin hole group includes a plurality of first process pin holes.

[0015] Optionally, in S2, a first reference is established using the first large end surface, the first connecting surface and the first process reference surface.

[0016] Optionally, in S3, the side position of the second largest end face is processed as the second process reference plane, so that the second process reference plane, the second largest end face and the second connecting surface are perpendicular to each other.

[0017] Optionally, in S3, the relative positions of the second process reference plane and the second large end plane are symmetrical with the relative positions of the first large end plane and the first process reference plane, so that the second process reference plane and the first process reference plane are relative to each other after closing.

[0018] Optionally, in S3, the second connection surface and the first connection surface are oriented oppositely on the processing equipment.

[0019] Optionally, in S4, a second reference is established using the second large end surface, the second connecting surface and the second process reference surface.

[0020] Optionally, in S4, the second positioning pin hole group includes a plurality of second positioning pin holes; and the second process pin hole group includes a plurality of second process pin holes.

[0021] Optionally, in S4, the positions of the second positioning pin hole group and the second process pin hole group relative to the second datum are symmetrical left-right and top-bottom with the positions of the first positioning pin hole group and the first process pin hole group relative to the first datum, so that after closing, the second positioning pin hole group and the first positioning pin hole group are positioned relative to each other, and the second process pin hole group and the first process pin hole group are positioned relative to each other.

[0022] Optionally, in S5, a plurality of process pins are used to connect the first process pin hole group and the second process pin hole group, and the process pins are interference fit with the first process pin holes and the second process pin holes, respectively.

[0023] Optionally, the step further includes: S6, connecting the first section and the second section using bolts, and reducing the gap between the first connecting surface and the second connecting surface by tightening the bolts so that the gap is smaller than a set size.

[0024] The beneficial effects of the present invention are:

[0025] 1. In the manufacturing method of the segmented engine frame of the present invention, the finely machined product surface is selected as the reference, and the second process pin hole group and the first positioning pin hole group are processed according to the actual position sizes of the first process pin hole group and the first positioning pin hole group, so that the pin hole positions on the first connecting surface and the second connecting surface are strictly symmetrical, and the process pin holes and the positioning pin holes are respectively processed in the state where the large ends of the first section and the second section are downward, thereby avoiding uncontrollable deformation errors caused by material deformation and the like during the process, making the closing size accurate, and ensuring that the finely machined surface before closing can still meet the requirements of the drawing after closing.

[0026] 2. The present invention reasonably designs the working procedures, and retains a small processing allowance before closing, thereby reducing the workload of machining after closing, reducing the difficulty of processing and manufacturing, and greatly improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings in the specification, which constitute 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 improper limitations on the present invention.

[0028] Figure 1 This is a flow chart of the processing method for the first section in Example 1.

[0029] Figure 2 This is a flow chart of the processing method for the second stage in Example 1.

[0030] Figure 3 This is a schematic diagram of the first small end surface of the first section in Example 1.

[0031] Figure 4 This is a schematic diagram of the first large end surface and the first connecting surface of the first section in Example 1.

[0032] Figure 5 This is a posture diagram of the first segment of step S2 in Example 1.

[0033] Figure 6 This is a schematic diagram of the surface of the first small end of the second enzymatic hydrolysis section in Example 1.

[0034] Figure 7 This is a schematic diagram of the second large end surface and the second connecting surface of the second section in Example 1.

[0035] Figure 8 This is a posture diagram of the second stage of step S4 in Example 1.

[0036] Fig. 9 This is a schematic diagram of the assembly of the first section and the second section in Example 1.

[0037] Fig.10 For Example 1 Fig. 9 Schematic diagram of part A.

[0038] Fig.11 For Example 1 Fig. 9 Schematic diagram of part D of FIG.

[0039] Fig.12 For Example 1 Fig. 9 Schematic diagram of part C.

[0040] Fig.13 For Example 1 Fig. 9 Schematic diagram of part B.

[0041] Fig.14 Schematic diagram of the complementary relationship of the processed surfaces in Example 1.

[0042] Fig.15 Schematic diagram of the relative positions of the first reference, the first positioning pin hole group and the first process pin hole group in Example 1.

[0043] Fig.16 Schematic diagram of the relative positions of the second reference, the second positioning pin hole group and the second process pin hole group in Example 1.

[0044] Among them, 1, the first section; 11, the first small end face; 12, the first large end face; 13, the first connecting surface; 14, the first datum; 15, the first positioning pin hole; 16, the first process pin hole; 2, the second section; 21, the second small end face; 22, the second large end face; 23, the second connecting surface; 24, the second datum; 25, the second positioning pin hole; 26, the second process pin hole. DETAILED DESCRIPTION

[0045] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0046] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0047] In order to ensure the quality of the super-large marine engine frame (such as the main engine frame of the 9X92DF-2.0-iCER main engine), it is designed as a segmented structure, including an output end section (hereinafter referred to as the first section) and a free end section (hereinafter referred to as the second section). In order to meet the requirements of the drawings and subsequent assembly, in the processing process, the key parts need to be processed after the segmented frame is closed together (for example, the guide rails need to be processed uniformly to ensure that their shape and position tolerances are consistent), and finally meet the requirements of the drawings and assembly. The small end of the main engine frame is used to connect the cylinder body, and the large end of the main engine frame is used to connect the base. Therefore, the large end face and the small end face on the first and second sections need to ensure high processing accuracy: if the large end face is processed uniformly after closing, it cannot meet the internal structure processing of the frame, and the machining after closing requires connection and splitting, which is too much work and seriously reduces production efficiency; if the small end is processed before closing, it is necessary to ensure that the fine-machined surface can still meet the requirements of the drawings after closing, which requires extremely high accuracy in the closing process. Other segmented engine mounts face the same problem.

[0048] The machining equipment used in the following text is a machining center (Coburg gantry milling machine, model: PowerTec7000AG-S20). Before machining, a laser interferometer is used to calibrate the accuracy of the equipment to meet the accuracy requirement of 0.02 / 1000, and all machining is completed on the same equipment to reduce the influence of external factors such as time, temperature, and humidity.

[0049] In the following text, the surface processing procedures include rough machining and fine machining. Rough machining is a processing method that retains 2 to 3 mm of processing allowance, and fine machining is the final processing procedure of the surface. After fine machining is completed, the product surface meets the requirements of the drawing.

[0050] Example 1

[0051] The closing method of the segmented engine frame comprises the following steps (the processing method of the first segment is as follows Figure 1As shown, including steps S1 and S2, the processing method of the second section is as follows Figure 2 As shown, including steps S3 and S4):

[0052] Step 1: Figure 3 As shown, the first section 1 of the segmented engine frame is mounted on a machining center, and the first connecting surface is oriented toward the X-direction, and the surface of the first small end face 11 is rough-machined (retaining a 2 mm margin), as shown in FIG. Figure 4 As shown, after flipping to the point where the first large end face 12 faces upward, the first connecting face 13 faces the X+ direction, and the first large end face 12 and the first connecting face 13 are finely processed into product surfaces. Then, the side position of the first large end face 12 is processed as the first process reference surface, so that the first process reference surface, the first large end face 12 and the first connecting face 13 are perpendicular to each other, that is: the side of the first large end face is processed as the Y-direction reference, the first connecting face 13 in the length direction of the first large end face 12 is processed as the X-direction reference, and the first large end face 12 is processed as the Z-direction reference. The three references are used as the basis for setting the reference after flipping; then Fig.15 As shown, the first large end face 12, the first connecting face 13 and the first process reference face can become the first reference 14; the first positioning pin hole group and the first process pin hole group are processed on the first connecting face 13 to the product size required by the drawing; the first positioning pin hole group includes a plurality of first positioning pin holes 15; the first process pin hole group includes a plurality of first process pin holes 16, the first positioning pin holes 15 are used for positioning the four corners of the workpiece of the first section 1 and the second section 2, and are distributed at the four corners of the first connecting face; the first process pin holes 16 are used to increase the area of ​​the four corner positioning, and are distributed at the four corners of the first connecting face 13.

[0053] S2, such as Figure 5 As shown, the first section 1 is flipped over to a state where the first small end surface 11 faces upward and is placed on a square box of equal height, so that the measuring device can collect the position information of the first large end surface 12 facing downward, as shown in FIG. Fig.15 As shown, the first large end face 12, the first connecting face 13 and the first process reference face are used to establish the first reference 14, and the position dimensions of the first positioning pin hole group and the first process pin hole group are measured according to the first reference 14;

[0054] S3, such as Figure 6 As shown, the second section 2 of the segmented engine frame is mounted on the machining center, and the second connecting surface is oriented toward the X+ direction, and the surface of the second small end face 21 is rough-machined (retaining a 2 mm margin), as shown in FIG. Figure 7As shown, after flipping to the point where the second large end face 22 faces upward, the second connecting face 23 faces the X-direction, and the second large end face 22 and the second connecting face 23 are finely processed into the product surface; then the side position of the second large end face 22 is processed as the second process reference surface, so that the second process reference surface, the second large end face 22 and the second connecting face 23 are perpendicular to each other, that is: the side of the second large end face is processed as the Y-direction reference, the second connecting face 23 in the length direction of the second large end face 22 is processed as the X-direction reference, and the second large end face 22 is processed as the Z-direction reference. The three references are used as the basis for setting the reference after flipping; and the relative position of the second process reference surface and the second large end face 22 is symmetrical with the relative position of the first large end face 23 and the first process reference surface; then as shown Fig.16 As shown, the second large end surface 22, the second connecting surface 23 and the second process reference surface can become the second reference 24, and the second reference 24 is symmetrical with respect to the first reference 14, so that the positions of the second reference 24 and the first reference 14 are opposite after closing.

[0055] S4, such as Figure 8 As shown, the second section 2 is turned over so that the second small end face 21 faces upward, and the second large end face 22, the second connecting face 23 and the second process reference face are used to establish the second reference 24. The second reference 24 is used as the processing reference, and according to the position and size of the first positioning pin hole group and the first process pin hole group collected in S2, the second positioning pin hole group and the second process pin hole group of the second section 2 are processed on the second connecting face 23 to the product size required by the drawing. The second positioning pin hole group includes a plurality of second positioning pin holes 25; the second process pin hole group includes a plurality of second process pin holes 26, and the positions of the second positioning pin hole group and the second process pin hole group relative to the second reference 24 are symmetrical with the positions of the first positioning pin hole group and the first process pin hole group relative to the first reference 14, that is, Fig.15 The dimensions m1 and Fig.16 The m2 size in is consistent, and Fig.15 The size n1 and Fig.16 The n2 size in the embodiment is consistent, so that after closing, the second positioning pin hole group and the first positioning pin hole group are located opposite to each other, and the second process pin hole group and the first process pin hole group are located opposite to each other;

[0056] S5, such as Fig. 9 As shown, the first connecting surface 13 and the second connecting surface 23 are connected as a whole: a plurality of process pins are used to connect the first process pin hole group and the second process pin hole group, and the process pins are respectively interference fit with the first process pin holes and the second process pin holes to ensure that the interference amounts of the first process pin holes and the second process pin holes are consistent; the process pins are assembled using a liquid nitrogen cold assembly process.

[0057] S6. Use the locating pin holes to install them in the first locating pin hole 15 and the second locating pin hole 25 respectively to achieve positioning installation. The other unmarked holes are bolt installation holes. When the two sections are connected, place a height pad under the two sections of the workpiece to ensure that the bottom surface reference is consistent (Z direction). By adjusting the lifting posture, align the pin holes of the first section 1 and the second section 2 (Y direction), so as to connect the locating pin holes and the process pin holes. After positioning, connect as shown Fig. 9 As shown, by bolt installation, the first section 1 and the second section 2 are gradually brought closer together, so that the assembly gap x (X direction) between the first connecting surface 13 and the second connecting surface 23 is smaller than the set size (0.02mm feeler gauge cannot be inserted).

[0058] In the process, Fig.10 As shown in the figure, because there is a certain deviation between the actual processing surface of the processing equipment and the theoretical surface, Fig. 9 The actual surface of the middle position A is biased to the right of the theoretical surface, so the first connecting surface 13 is oriented toward the X+ direction and the second connecting surface is oriented toward the X- direction. Fig.11 As shown in the figure, the actual surface at position D is biased to the left of the theoretical surface. The combination of the two can eliminate the influence caused by equipment error. Fig.12 Position B as shown and Fig.13 The position C shown can eliminate the influence caused by the equipment error according to the same principle, that is, the first connection surface and the second connection surface can eliminate the influence caused by the equipment error.

[0059] On the other hand, during the processing, it is ensured that the angle formed by the second large end face 22 and the second connecting face 23 and the angle formed by the first large end face 12 and the first connecting face 13 are complementary to each other. Fig.14 As shown: when the first section 1 and the second section 2 are connected, part A is connected to part D, and part B is connected to part C. Since the equipment accuracy cannot achieve zero error, the two single sections are processed in relative processing when processing the connection surface, that is: the first connection surface 13 is processed toward the X+ direction to be the product surface, and the second connection surface 23 is processed toward the X- direction to be the product surface; in the two processing processes, the deflection direction of the processing milling head is 0° and the other is 180°. Therefore, even if the processing surface is not perpendicular to the long side of the workpiece, when the first section 1 and the second section 2 are connected, the two connection surfaces are parallel, which can eliminate the influence caused by the equipment error. The same is true for the Y and Z directions, and finally all the connection surfaces and end faces meet the accuracy requirements.

[0060] Since the frame body has a certain flexibility, the data of the first locating pin hole group and the first process pin hole group of the first section shall prevail when processing the second locating pin hole group and the second process pin hole group. This method can eliminate the error caused by the deformation of the workpiece during the flipping process. It can ensure that after the final connection, the misalignment of the large end faces of the two finished sections does not exceed 0.02mm, and the 0.02 feeler gauge does not enter the seam. After the closure is completed, the small end face and the cylinder guide rail of the frame are uniformly processed to make the shape and position tolerances of the 9-cylinder guide rails of the product consistent.

[0061] Example 2

[0062] The difference between this embodiment and Embodiment 1 is that in S1, the first large end face (Z-direction reference), the first connecting face (X-direction reference) and the center of the bolt hole on the first large end face (Y-direction reference) are selected to establish the first reference, and in S3, the second large end face (Z-direction reference), the second connecting face (X-direction reference) and the center of the bolt hole on the second large end face (Y-direction reference) are selected to establish the second reference, which can also achieve assembly accuracy, but the operation process is more complicated.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for closing a segmented engine frame, characterized in that: The following steps are involved: S1, rough-processing the first small end surface of the first section of the segmented engine frame, turning it over so that the first large end surface faces upward, fine-processing the first large end surface and the first connecting surface, and processing a first positioning pin hole group and a first process pin hole group on the first connecting surface; S2, turning the first section over so that the first small end surface faces upward, establishing a first reference using the position dimensions of the first large end surface and the first connecting surface, and measuring the position dimensions of the first positioning pin hole group and the first process pin hole group; S3, rough-machining the second small end surface of the second section of the segmented engine frame, flipping it so that the second large end surface faces upward, and then fine-machining the second large end surface and the second connecting surface; S4, turning the second section over so that the second small end surface faces upward, using the position dimensions of the second large end surface and the second connecting surface to establish a second reference basis, and processing the second positioning pin hole group and the second process pin hole group of the second section according to the position dimensions of the first positioning pin hole group and the first process pin hole group measured in S2; S5. Connect the first connection surface and the second connection surface through process pins.

2. The method for closing a segmented engine frame according to claim 1, characterized in that: In S1, the first positioning pin hole group includes a plurality of first positioning pin holes; and the first process pin hole group includes a plurality of first process pin holes.

3. The method for closing a segmented engine frame according to claim 1, characterized in that: In S1, the side position of the first large end surface is processed as the first process reference surface, so that the first process reference surface, the first large end surface and the first connecting surface are perpendicular to each other.

4. The method for closing a segmented engine frame according to claim 3, characterized in that: In S2, a first reference is established using the first major end surface, the first connecting surface, and the first process reference surface.

5. The method for closing a segmented engine frame according to claim 1, characterized in that: In S3, the second connection surface and the first connection surface are oriented oppositely on the processing equipment.

6. The method for closing a segmented engine frame according to claim 1, characterized in that: In S3, the side position of the second largest end surface is processed as the second process reference surface, so that the second process reference surface, the second largest end surface and the second connecting surface are perpendicular to each other; Optionally, the relative positions of the second process reference surface and the second large end surface are symmetrical with the relative positions of the first large end surface and the first process reference surface, so that the second process reference surface and the first process reference surface are relative to each other after closing.

7. The method for closing a segmented engine frame according to claim 6, characterized in that: In S4, a second reference is established using the second major end surface, the second connecting surface, and the second process reference surface.

8. The method for closing a segmented engine frame according to claim 1, characterized in that: In S4, the second positioning pin hole group includes a plurality of second positioning pin holes; the second process pin hole group includes a plurality of second process pin holes; Optionally, in S4, the positions of the second positioning pin hole group and the second process pin hole group relative to the second datum are symmetrical to the positions of the first positioning pin hole group and the first process pin hole group relative to the first datum, so that after closing, the second positioning pin hole group and the first positioning pin hole group are relative to each other, and the second process pin hole group and the first process pin hole group are relative to each other.

9. The method for closing a segmented engine frame according to claim 1, characterized in that: In S5, a plurality of process pins are used to connect the first process pin hole group and the second process pin hole group, and the process pins are respectively interference fit with the first process pin holes and the second process pin holes.

10. The method for closing a segmented engine frame according to claim 1, characterized in that: The method comprises the following steps: S6, connecting the first section and the second section using bolts, and reducing the gap between the first connection surface and the second connection surface by tightening the bolts, so that the gap is smaller than a set size.

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