Production method of cylinder cover

Abstract

The invention provides a production method of a cylinder cover, which comprises the following steps of: constructing a three-dimensional model of the cylinder cover, selecting a casting positioning reference on the three-dimensional model, manufacturing a sand core mold according to the selected casting positioning reference, manufacturing a sand core by using the cast sand core mold, and manufacturing a cylinder cover blank by using the sand core, a machining positioning reference is marked on the cylinder cover blank, and the machining positioning reference and the casting positioning reference are unified; and performing finish machining on the cylinder cover blank by using a clamp based on the machining positioning reference to obtain a final product. According to the method, the casting positioning reference used during sand core mold manufacturing and the machining positioning reference used during cylinder cover blank finish machining are unified, the cylinder cover blank machining deviation is effectively reduced, the product manufacturing precision is improved, the diesel engine manufacturing consistency level is improved, and engine fuel consumption is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of internal combustion engine cylinder heads, in particular to a production method of a cylinder head. Background Art

[0002] As the country's requirements for environmental protection become increasingly stringent, the manufacturing level of internal combustion engines at home and abroad continues to improve. It is necessary to improve the manufacturing level of key components of diesel engines to improve the consistency of diesel engines. Therefore, it is necessary to optimize the casting and processing technology of diesel engine components.

[0003] At present, there is no separate casting benchmark for cylinder heads in China. During the casting process of the cylinder head, the sand core mold is usually designed based on the large plane on the bottom surface. Then, the cylinder head casting is completed by making the sand core, assembling the core, and casting.

[0004] During the machining process, the bottom surface of the cylinder head is usually selected as the first reference. However, the bottom plane of the cylinder head is large and the casting accuracy is poor, which will cause the overall machining to be skewed, resulting in a large deviation of the cylinder head airway, which in turn affects the cylinder head intake swirl ratio and the combustion organization in the engine cylinder. Summary of the invention

[0005] In order to address the deficiencies in the prior art, the present invention provides a method for producing a cylinder head, which unifies the casting positioning reference used in making the sand core mold and the machining positioning reference used in the fine machining of the cylinder head blank, thereby effectively reducing the deviation of the cylinder head blank machining, improving product manufacturing accuracy, enhancing the consistency level of diesel engine manufacturing, and reducing engine fuel consumption.

[0006] In order to achieve the above object, the specific scheme adopted by the present invention is: A method for producing a cylinder head mainly comprises the following steps: Step S1, constructing a three-dimensional model of the cylinder head, and selecting a casting positioning reference on the three-dimensional model; Step S2, manufacturing a sand core mold according to the casting positioning reference selected in step S1; Step S3, making a sand core using the cast sand core mold; Step S4, using the sand core to make a cylinder head blank, and marking a machining positioning reference on the cylinder head blank, wherein the machining positioning reference is consistent with the casting positioning reference in step S1; Step S5: Use a fixture to perform finish machining on the cylinder head blank based on the machining positioning reference to obtain a final product.

[0007] Further, in step S4, the manufactured cylinder head blank is provided with first to fourth cylinder intake passages and first to fourth cylinder exhaust passages corresponding to the first to fourth cylinders, the intake side of the cylinder head blank is provided with first to fourth cylinder intake passage ports respectively connected with the first to fourth cylinder intake passages, and the exhaust side is provided with first to fourth cylinder exhaust passage ports respectively connected with the first to fourth cylinder exhaust passages; The outer surface of the first cylinder intake duct port in the cylinder head blank has a bottom plane M1, and the outer surface of the fourth cylinder intake duct port has a bottom plane M2. A groove is provided on the bottom surface of the cylinder head blank, and the groove has a bottom plane M3. The areas of the bottom planes M1, M2 and M3 are not less than 8mm×8mm and not greater than 15mm×15mm. The distances between the bottom planes M1, M2 and M3 and the bottom surface of the cylinder head blank are all H, 6mm≤H≤8mm.

[0008] Further, in step S4, the processing positioning reference includes nine reference points, namely, reference point X1, reference point X2, reference point Y1, reference point Y2, reference point Y3, reference point Y4, reference point Z1, reference point Z2, and reference point Z3. Among them, reference point Z1, reference point Z2, and reference point Z3 are used to determine the Z direction positioning reference, reference point Y1, reference point Y2, reference point Y3, and reference point Y4 are used to determine the Y direction positioning reference, and reference point X1 and reference point X2 are used to determine the X direction positioning reference.

[0009] Furthermore, the reference point Z1 is located on the bottom plane M1, the reference point Z2 is located on the bottom plane M2, and the reference point Z3 is located on the bottom plane M3. The reference point Z1, the reference point Z2, and the reference point Z3 constitute a Z-direction positioning reference.

[0010] Furthermore, reference point Y1 and reference point Y2 are located on the intake duct of the first cylinder and intersect with the Z-direction positioning reference, reference point Y3 and reference point Y4 are located on the intake duct of the fourth cylinder and intersect with the Z-direction positioning reference, and the reference point Y1, reference point Y2, reference point Y3, and reference point Y4 constitute the Y-direction positioning reference, and the Y-direction positioning reference passes through the midpoint of the line connecting the reference point Y1 and the reference point Y2 and the midpoint of the line connecting the reference point Y3 and the reference point Y4 and is perpendicular to the Z-direction positioning reference.

[0011] Further, the reference point X1 is located on the exhaust passage of the second cylinder and intersects with the Z-direction positioning reference, and the reference point X2 is located on the exhaust passage of the third cylinder and intersects with the Z-direction positioning reference. The reference point X1 and the reference point X2 constitute the X-direction positioning reference, and the X-direction positioning reference passes through the midpoint of the line connecting the reference point X1 and the reference point X2 and is perpendicular to the Z-direction positioning reference and the Y-direction positioning reference.

[0012] Further, in step S5, the fixture includes a first self-centering mechanism, a second self-centering mechanism, a first positioning block, a second positioning block, a third positioning block, a first pressing jaw, a second pressing jaw, a third pressing jaw, a first clamping mechanism, and a second clamping mechanism.

[0013] Furthermore, the specific method of step S5 is: S51, fix the first positioning block, the second positioning block and the third positioning block in the fixture at the reference point Z1, the reference point Z2 and the reference point Z3 respectively, press the first pressing claw, the second pressing claw and the third pressing claw on the air inlet of the first cylinder, the air inlet of the fourth cylinder and the air inlet of the fourth cylinder respectively, the first self-centering mechanism presses on the reference point Y1 and the reference point Y2, the second self-centering mechanism presses on the reference point Y3 and the reference point Y4, the center of the first clamping mechanism presses on the reference point X1, and the center of the second clamping mechanism presses on the reference point X2; S52, processing the top surface of the cylinder head, and processing two bolt holes at both ends of the top surface of the cylinder head as first process positioning pin holes; S53, using the top surface of the cylinder head and the first process positioning pin hole as a reference, processing the bottom surface of the cylinder head, and processing two bolt holes on the bottom surface of the cylinder head as the second process positioning pin holes; S54, the cylinder head is processed based on the bottom surface of the cylinder head and the second process positioning pin hole, so as to obtain a finished cylinder head.

[0014] Beneficial effects: The cylinder head production method of the present invention proposes the concept of unified datum, from sand core mold design to cylinder head blank casting and then to fine machining of the cylinder head blank, which ensures the unification of casting positioning datum and machining positioning datum, not only eliminates the influence of casting error and cumulative error, but also greatly improves the machining datum accuracy compared with the previous use of cylinder head bottom plane. At the same time, during the tooling positioning process, the pressure claws are pressed on the intake and exhaust passages, which ensures the consistency of the air passage position of the cylinder head after machining and the air passage position of the theoretical design, effectively improving the manufacturing consistency level of the diesel engine cylinder head. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a bottom view of the cylinder head blank in the present invention.

[0017] Figure 2 yes Figure 1 Partial cross-sectional view along the XX axis.

[0018] Figure 3 yes Figure 1 Cross-sectional view along the YY direction.

[0019] Figure 4 yes Figure 1 Cross-sectional view along the ZZ axis.

[0020] Figure 5 This is the intake side view of the cylinder head blank.

[0021] Figure 6 This is the exhaust side view of the cylinder head blank.

[0022] Figure 7 is a top view of the fixture.

[0023] Figure 8 Left side view of the fixture.

[0024] Fig. 9 It is the bottom surface of the cylinder head after processing.

[0025] Fig.10 It is the top surface of the cylinder head after processing.

[0026] Graphic markings: 1. Intake duct of first cylinder, 2. Intake duct of fourth cylinder, 3. Exhaust duct of second cylinder, 4. Exhaust duct of third cylinder, 5. Top surface of cylinder head, 6. Bottom plane M1, 7. Bottom plane M2, 8. Bottom plane M3, 9. Air port of intake duct of first cylinder, 10. Air port of intake duct of fourth cylinder, 11. Air port of exhaust duct of fourth cylinder, 12. First self-centering mechanism, 13. Second self-centering mechanism, 14. First positioning block, 15. Second positioning block, 16. Third positioning block , 17. The first pressing jaw, 18. The second pressing jaw, 19. The third pressing jaw, 20. The first clamping mechanism, 21. The second clamping mechanism, 22. The reference point X1, 23. The reference point X2, 24. The reference point Y1, 25. The reference point Y2, 26. The reference point Y3, 27. The reference point Y4, 28. The reference point Z1, 29. The reference point Z2, 30. The reference point Z3, 31. The first process positioning pin hole, 32. The second positioning pin hole, 33. The bottom surface of the cylinder head.

[0027] It should be noted that Figures 1 to 4 In the figure, X represents the X-direction screenshot, and the X with a box represents the X-direction positioning reference; Y represents the Y-direction screenshot, and the Y with a box represents the Y-direction positioning reference; Z represents the Z-direction screenshot, and the Z with a box represents the Z-direction positioning reference. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] In the description of the present invention, it is necessary to understand that the terms "upper" and "lower" etc. indicate orientations or positional relationships based on the orientations 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 scope of protection of the present invention.

[0030] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0031] The invention discloses a production method of a cylinder head, which mainly comprises the following steps: Step S1, constructing a three-dimensional model of the cylinder head using three-dimensional software, and selecting a casting positioning reference on the three-dimensional model; Step S2, manufacturing a sand core mold according to the casting positioning reference selected in step S1; Step S3, making a sand core using the cast sand core mold; Step S4, using the sand core to make a cylinder head blank, and marking a machining positioning reference on the cylinder head blank, wherein the machining positioning reference is consistent with the casting positioning reference in step S1; Step S5: Use a fixture to perform finish machining on the cylinder head blank based on the machining positioning reference to obtain a final product.

[0032] In step S1, based on the actual cylinder head, point cloud data is obtained by using both contact and non-contact measurement methods, and a series of measures such as noise removal, splicing, simplification, and parameter extraction are performed on the point cloud. Finally, a modular modeling method is used to obtain a high-precision digital model of the cylinder head.

[0033] Among them, step S1 to step S3 belong to the prior art and will not be described in detail in the present invention.

[0034] The finished cylinder head is a part formed by processing the cylinder head blank according to the requirements of the design drawing by using a fixture. The cylinder head blank is provided with the first to fourth cylinder intake passages and the first to fourth cylinder exhaust passages corresponding to the first to fourth cylinders, the intake side of the cylinder head blank is provided with the first to fourth cylinder intake passage ports respectively connected to the first to fourth cylinder intake passages, and the exhaust side is provided with the first to fourth cylinder exhaust passage ports respectively connected to the first to fourth cylinder exhaust passages; the outer surface of the first cylinder intake passage port in the cylinder head blank has a bottom plane M16, and the outer surface of the fourth cylinder intake passage port has a bottom plane M27, and the bottom surface of the cylinder head blank is provided with a groove, and the groove has a bottom plane M38, then the area of ​​the bottom plane M16, the bottom plane M27 and the bottom plane M38 is not less than 8mm×8mm and not more than 15mm×15mm, and the distances between the bottom plane M16, the bottom plane M27 and the bottom plane M38 and the bottom surface of the cylinder head blank are all H, 6mm≤H≤8mm.

[0035] See attached Figures 1 to 6 As shown, in step S4, the processing positioning reference includes nine reference points, namely, reference point X122, reference point X223, reference point Y124, reference point Y225, reference point Y326, reference point Y427, reference point Z128, reference point Z229 and reference point Z330. Among them, reference point Z128, reference point Z229 and reference point Z330 are used to determine the Z direction positioning reference, reference point Y124, reference point Y225, reference point Y326 and reference point Y427 are used to determine the Y direction positioning reference, and reference point X122 and reference point X223 are used to determine the X direction positioning reference.

[0036] See attached Figures 1 to 6As shown, the reference point Z128 is located on the bottom plane M16, the reference point Z229 is located on the bottom plane M27, and the reference point Z330 is located on the bottom plane M38. The reference points Z128, Z229, and Z330 constitute the Z-direction positioning reference. The reference points Y124 and Y225 are located on the first cylinder intake passage 1 and intersect with the Z-direction positioning reference. The reference points Y326 and Y427 are located on the fourth cylinder intake passage 2 and intersect with the Z-direction positioning reference. The reference points Y124, Y225, Y326, and Y427 constitute the Y-direction positioning reference. The Y-direction positioning reference passes through the midpoint of the line connecting the reference points Y124 and Y225 and the midpoint of the line connecting the reference points Y326 and Y427 and is perpendicular to the Z-direction positioning reference. The reference point X122 is located on the second cylinder exhaust port 3 and intersects with the Z direction positioning reference, and the reference point X223 is located on the third cylinder exhaust port 4 and intersects with the Z direction positioning reference. The reference point X122 and the reference point X223 constitute the X direction positioning reference. The X direction positioning reference passes through the midpoint of the line connecting the reference point X122 and the reference point X223 and is perpendicular to the Z direction positioning reference and the Y direction positioning reference.

[0037] like Figures 7-8 As shown, the present invention only provides a simple clamp diagram, and the clamp mainly includes a mounting plate including a hydraulic system, and the mounting plate is equipped with a first self-centering mechanism 12 connected to the hydraulic system, a second self-centering mechanism 13, a first positioning block 14, a second positioning block 15, a third positioning block 16, a first pressing claw 17, a second pressing claw 18, a third pressing claw 19, a first clamping mechanism 20, and a second clamping mechanism 21. The action of each component can be controlled by the hydraulic system. Among them, the specific structure of the self-centering mechanism belongs to the prior art, as long as the centering function can be achieved. The specific structure of the clamping mechanism belongs to the prior art, as long as the clamping function can be achieved.

[0038] Furthermore, during the processing of the cylinder head blank, the cylinder head blank is first clamped on the fixture. During this process, the first positioning block 14, the second positioning block 15, and the third positioning block 16 of the fixture are respectively fixed on the reference point Z128, the reference point Z229, and the casting reference Z330. The first pressing claw 17, the second pressing claw 18, and the third pressing claw 19 are respectively pressed on the first cylinder intake duct port 9, the fourth cylinder intake duct port 10, and the fourth cylinder exhaust duct port 11. The first self-centering mechanism 12 is pressed on the reference point Y124 and the reference point Y225, and the second self-centering mechanism 13 is pressed on the reference point Y326 and the reference point Y427. The center of the first clamping mechanism 20 is pressed on the reference point X122, and the center of the second clamping mechanism 21 is pressed on the reference point X223. After the position is fixed, the self-centering mechanism and the pressing claws completely limit the degrees of freedom of the cylinder head in six directions through the hydraulic mechanism of the fixture to ensure that the cylinder head blank is firmly fixed.

[0039] After the fixture is fixed, the cylinder head blank is processed. First, the cylinder head top surface 5 is processed, and two bolt holes are processed at both ends of the cylinder head top surface 5 as the first process positioning pin holes 31. Fig.10 Then, the cylinder head bottom surface 33 is processed based on the cylinder head top surface 5 and the first process positioning pin hole 31, and two bolt holes are processed on the cylinder head bottom surface 33 as the second process positioning pin holes 32, as shown in FIG. Fig. 9 Finally, the cylinder head is processed based on the bottom surface 33 of the cylinder head and the second process positioning pin hole 32 to obtain a finished cylinder head.

[0040] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any equivalent changes or modifications made according to the essence of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for producing a cylinder head, characterized in that: The main steps are as follows: Step S1, constructing a three-dimensional model of the cylinder head, and selecting a casting positioning reference on the three-dimensional model; Step S2, manufacturing a sand core mold according to the casting positioning reference selected in step S1; Step S3, making a sand core using the cast sand core mold; Step S4, using the sand core to make a cylinder head blank, and marking a machining positioning reference on the cylinder head blank, wherein the machining positioning reference is consistent with the casting positioning reference in step S1; Step S5: Use a fixture to perform finish machining on the cylinder head blank based on the machining positioning reference to obtain a final product.

2. The method for producing a cylinder head according to claim 1, characterized in that: In step S4, the manufactured cylinder head blank is provided with first to fourth cylinder intake passages and first to fourth cylinder exhaust passages corresponding to the first to fourth cylinders, the intake side of the cylinder head blank is provided with first to fourth cylinder intake passage ports respectively connected with the first to fourth cylinder intake passages, and the exhaust side is provided with first to fourth cylinder exhaust passage ports respectively connected with the first to fourth cylinder exhaust passages; The outer surface of the first cylinder intake duct port in the cylinder head blank has a bottom plane M1 (6), and the outer surface of the fourth cylinder intake duct port has a bottom plane M2 (7). The bottom surface of the cylinder head blank is provided with a groove, and the groove has a bottom plane M3 (8). The areas of the bottom plane M1 (6), the bottom plane M2 (7) and the bottom plane M3 (8) are not less than 8 mm × 8 mm and not more than 15 mm × 15 mm. The distances between the bottom plane M1 (6), the bottom plane M2 (7) and the bottom plane M3 (8) and the bottom surface of the cylinder head blank are all H, and 6 mm ≤ H ≤ 8 mm.

3. The method for producing a cylinder head according to claim 2, characterized in that: In step S4, the processing positioning reference includes nine reference points, namely, reference point X1 (22), reference point X2 (23), reference point Y1 (24), reference point Y2 (25), reference point Y3 (26), reference point Y4 (27), reference point Z1 (28), reference point Z2 (29), and reference point Z3 (30). Among them, reference point Z1 (28), reference point Z2 (29), and reference point Z3 (30) are used to determine the Z direction positioning reference, reference point Y1 (24), reference point Y2 (25), reference point Y3 (26), and reference point Y4 (27) are used to determine the Y direction positioning reference, and reference point X1 (22) and reference point X2 (23) are used to determine the X direction positioning reference.

4. The method for producing a cylinder head according to claim 3, characterized in that: The reference point Z1 (28) is located on the bottom plane M1 (6), the reference point Z2 (29) is located on the bottom plane M2 (7), and the reference point Z3 (30) is located on the bottom plane M3 (8). The reference point Z1 (28), the reference point Z2 (29), and the reference point Z3 (30) constitute the Z-direction positioning reference.

5. The method for producing a cylinder head according to claim 3, characterized in that: The reference point Y1 (24) and the reference point Y2 (25) are located on the first cylinder intake passage (1) and intersect with the Z direction positioning reference. The reference point Y3 (26) and the reference point Y4 (27) are located on the fourth cylinder intake passage (2) and intersect with the Z direction positioning reference. The reference point Y1 (24), the reference point Y2 (25), the reference point Y3 (26) and the reference point Y4 (27) constitute the Y direction positioning reference. The Y direction positioning reference passes through the midpoint of the line connecting the reference point Y1 (24) and the reference point Y2 (25) and the midpoint of the line connecting the reference point Y3 (26) and the reference point Y4 (27) and is perpendicular to the Z direction positioning reference.

6. The method for producing a cylinder head according to claim 3, characterized in that: The reference point X1 (22) is located on the exhaust passage (3) of the second cylinder and intersects with the Z-direction positioning reference. The reference point X2 (23) is located on the exhaust passage (4) of the third cylinder and intersects with the Z-direction positioning reference. The reference point X1 (22) and the reference point X2 (23) constitute the X-direction positioning reference. The X-direction positioning reference passes through the midpoint of the line connecting the reference point X1 (22) and the reference point X2 (23) and is perpendicular to the Z-direction positioning reference and the Y-direction positioning reference.

7. The method for producing a cylinder head according to claim 3, characterized in that: In step S5, the clamp includes a mounting plate containing a hydraulic system, and the mounting plate is equipped with a first self-centering mechanism (12) connected to the hydraulic system, a second self-centering mechanism (13), a first positioning block (14), a second positioning block (15), a third positioning block (16), a first pressing jaw (17), a second pressing jaw (18), a third pressing jaw (19), a first clamping mechanism (20), and a second clamping mechanism (21).

8. The method for producing a cylinder head according to claim 7, characterized in that: The specific method of step S5 is: S51, fix the first positioning block (14), the second positioning block (15), and the third positioning block (16) in the fixture at the reference point Z1 (28), the reference point Z2 (29), and the reference point Z3 (30), respectively, the first pressing claw (17), the second pressing claw (18), and the third pressing claw (19) are pressed on the first cylinder intake duct air port (9), the fourth cylinder intake duct air port (10), and the fourth cylinder exhaust duct air port (11), respectively, the first self-centering mechanism (12) is pressed on the reference point Y1 (24) and the reference point Y2 (25), the second self-centering mechanism (13) is pressed on the reference point Y3 (26) and the reference point Y4 (27), the center of the first clamping mechanism (20) is pressed on the reference point X1 (22), and the center of the second clamping mechanism (21) is pressed on the reference point X2 (23); S52, processing the top surface (5) of the cylinder head, and processing two bolt holes at both ends of the top surface (5) of the cylinder head as first process positioning pin holes (31); S53, using the cylinder head top surface (5) and the first process positioning pin hole (31) as a reference, processing the cylinder head bottom surface (33), and processing two bolt holes on the cylinder head bottom surface (33) as the second process positioning pin holes (32); S54, processing the cylinder head with the cylinder head bottom surface (33) and the second process positioning pin hole (32) as a reference, thereby obtaining a finished cylinder head.

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