A method of producing a cylinder head

Abstract

The application provides a production method of a cylinder cover, which comprises the following steps: 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 casting sand core mold, manufacturing a cylinder cover blank by using the sand core, and marking a machining positioning reference on the cylinder cover blank, wherein the machining positioning reference is unified with the casting positioning reference; and performing finish machining on the cylinder cover blank based on the machining positioning reference by using a clamp, so as to obtain a final product. The method unifies the casting positioning reference used when the sand core mold is manufactured and the machining positioning reference used when the cylinder cover blank is finish machined, effectively reduces the deviation of the cylinder cover blank machining, improves the product manufacturing precision, improves the diesel engine manufacturing consistency level, and reduces the engine fuel consumption.

Description

Technical Field

[0001] This invention relates to the field of internal combustion engine cylinder head technology, specifically a method for producing a cylinder head. Background Technology

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

[0003] Currently, there is no separate design casting benchmark for cylinder heads in China. In the cylinder head casting process, the sand core mold is usually designed based on the large flat surface 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 primary reference. However, the bottom surface of the cylinder head is relatively large and the casting precision is poor, which can lead to overall skewness during machining. This results in a large deviation in the cylinder head intake passage, which in turn affects the intake swirl ratio of the cylinder head and the combustion organization in the engine cylinder. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for producing cylinder heads. This method unifies the casting positioning datum used in the production of sand core molds with the machining positioning datum used in the finishing of cylinder head blanks. This effectively reduces the deviation in the machining of cylinder head blanks, improves product manufacturing precision, enhances the consistency of diesel engine manufacturing, and reduces engine fuel consumption.

[0006] To achieve the above objectives, the specific solution adopted by the present invention is as follows:

[0007] A method for manufacturing a cylinder head mainly includes the following steps:

[0008] Step S1: Construct a three-dimensional model of the cylinder head and select a casting positioning datum on the three-dimensional model;

[0009] Step S2: Manufacture the sand core mold according to the casting positioning datum selected in step S1;

[0010] Step S3: Use the casting sand core mold to make the sand core;

[0011] Step S4: Use sand cores to make cylinder head blanks and mark machining positioning references on the cylinder head blanks. The machining positioning references are consistent with the casting positioning references in step S1.

[0012] Step S5: Use a fixture to perform precision machining on the cylinder head blank based on the machining positioning datum to obtain the final product.

[0013] Further, in step S4, 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 cylinder head blank has the first to fourth cylinder intake passage ports connected to the first to fourth cylinder intake passages respectively on the intake side, and the first to fourth cylinder exhaust passage ports connected to the first to fourth cylinder exhaust passages respectively on the exhaust side.

[0014] The outer surface of the intake port of the first cylinder in the cylinder head blank has a bottom plane M1, and the outer surface of the intake port of the fourth cylinder has a bottom plane M2. The bottom surface of the cylinder head blank is provided with a groove, and the groove has a bottom plane M3. The area of ​​the bottom planes M1, M2 and M3 is not less than 8mm×8mm and not more than 15mm×15mm. The distance between the bottom planes M1, M2 and M3 and the bottom surface of the cylinder head blank is H, where 6mm≤H≤8mm.

[0015] Further, in step S4, the machining positioning reference includes nine reference points: 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 positioning reference in the Z direction, reference point Y1, reference point Y2, reference point Y3, and reference point Y4 are used to determine the positioning reference in the Y direction, and reference point X1 and reference point X2 are used to determine the positioning reference in the X direction.

[0016] 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 points Z1, Z2, and Z3 constitute the positioning reference in the Z direction.

[0017] Furthermore, reference points Y1 and Y2 are located on the intake port of the first cylinder and intersect with the Z-direction positioning reference, and reference points Y3 and Y4 are located on the intake port of the fourth cylinder and intersect with the Z-direction positioning reference. The reference points Y1, Y2, Y3, and Y4 constitute the Y-direction positioning reference. The Y-direction positioning reference passes through the midpoint of the line connecting reference points Y1 and Y2 and the midpoint of the line connecting reference points Y3 and Y4, and is perpendicular to the Z-direction positioning reference.

[0018] Furthermore, reference point X1 is located on the exhaust port of the second cylinder and intersects with the Z-direction positioning reference, and reference point X2 is located on the exhaust port of the third cylinder and intersects with the Z-direction positioning reference. The reference points X1 and X2 constitute the X-direction positioning reference, which passes through the midpoint of the line connecting reference points X1 and X2 and is perpendicular to the Z-direction positioning reference and the Y-direction positioning reference.

[0019] 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 pressure claw, a second pressure claw, a third pressure claw, a first clamping mechanism, and a second clamping mechanism.

[0020] Furthermore, the specific method for step S5 is as follows:

[0021] S51. Fix the first positioning block, the second positioning block, and the third positioning block in the fixture at reference points Z1, Z2, and Z3 respectively. The first pressure claw, the second pressure claw, and the third pressure claw press on the air inlet of the first cylinder, the air inlet of the fourth cylinder, and the air outlet of the fourth cylinder respectively. The first self-centering mechanism rests on reference points Y1 and Y2, the second self-centering mechanism rests on reference points Y3 and Y4, the center of the first clamping mechanism presses on reference point X1, and the center of the second clamping mechanism presses on reference point X2.

[0022] S52. Machining the top surface of the cylinder head, and machining two bolt holes at each end of the top surface of the cylinder head as the first process positioning pin holes;

[0023] S53. Using the top surface of the cylinder head and the first process positioning pin hole as a reference, process the bottom surface of the cylinder head, and process two bolt holes on the bottom surface of the cylinder head as the second process positioning pin holes.

[0024] S54. Using the bottom surface of the cylinder head and the second process positioning pin hole as a reference, the cylinder head is machined to obtain the finished cylinder head.

[0025] Beneficial effects:

[0026] The cylinder head production method of this invention proposes the concept of unified datum. From the design of the sand core mold to the casting of the cylinder head blank and then to the finishing of the cylinder head blank, the unity of the casting positioning datum and the machining positioning datum is guaranteed. This not only eliminates the influence of casting error and cumulative error, but also greatly improves the accuracy of the machining datum compared with the previous method using the bottom plane of the cylinder head. At the same time, during the tooling positioning process, the pressure claw presses on the intake and exhaust ports, ensuring the consistency between the position of the intake port after the cylinder head is machined and the position of the intake port in the theoretical design, effectively improving the manufacturing consistency level of the diesel engine cylinder head. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used 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 those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a bottom view of the cylinder head blank in this invention.

[0029] Figure 2 yes Figure 1 Partial sectional view along the XX direction.

[0030] Figure 3 yes Figure 1 A cross-sectional view along the YY direction.

[0031] Figure 4 yes Figure 1 A cross-sectional view along the ZZ direction.

[0032] Figure 5 This is a side view of the intake section of the cylinder head blank.

[0033] Figure 6 This is a side view of the exhaust system on the cylinder head blank.

[0034] Figure 7 This is a top view of the fixture.

[0035] Figure 8 Left view of the fixture.

[0036] Figure 9 It is the bottom surface of the machined cylinder head.

[0037] Figure 10 It is the top surface of the machined cylinder head.

[0038] Diagram markings: 1. Intake port of cylinder 1; 2. Intake port of cylinder 4; 3. Exhaust port of cylinder 2; 4. Exhaust port of cylinder 3; 5. Top surface of cylinder head; 6. Bottom plane M1; 7. Bottom plane M2; 8. Bottom plane M3; 9. Intake port of cylinder 1; 10. Intake port of cylinder 4; 11. Exhaust port of cylinder 4; 12. First self-centering mechanism; 13. Second self-centering mechanism; 14. First positioning block; 15. Second positioning block; 16. Third positioning block. 17. First clamping jaw, 18. Second clamping jaw, 19. Third clamping jaw, 20. First clamping mechanism, 21. Second clamping mechanism, 22. Reference point X1, 23. Reference point X2, 24. Reference point Y1, 25. Reference point Y2, 26. Reference point Y3, 27. Reference point Y4, 28. Reference point Z1, 29. Reference point Z2, 30. Reference point Z3, 31. First process positioning pin hole, 32. Second positioning pin hole, 33. Cylinder head bottom surface.

[0039] It should be noted that, Figures 1 to 4 In the diagram, X represents a screenshot in the X direction, while an X with a box indicates the positioning reference in the X direction; Y represents a screenshot in the Y direction, while a Y with a box indicates the positioning reference in the Y direction; Z represents a screenshot in the Z direction, while a Z with a box indicates the positioning reference in the Z direction. Detailed Implementation

[0040] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0041] In the description of this invention, it should be understood that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0042] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0043] This invention discloses a method for manufacturing a cylinder head, which mainly includes the following steps:

[0044] Step S1: Construct a three-dimensional model of the cylinder head using three-dimensional software, and select a casting positioning datum on the three-dimensional model;

[0045] Step S2: Manufacture the sand core mold according to the casting positioning datum selected in step S1;

[0046] Step S3: Use the casting sand core mold to make the sand core;

[0047] Step S4: Use sand cores to make cylinder head blanks and mark machining positioning references on the cylinder head blanks. The machining positioning references are consistent with the casting positioning references in step S1.

[0048] Step S5: Use a fixture to perform precision machining on the cylinder head blank based on the machining positioning datum to obtain the final product.

[0049] In step S1, point cloud data is acquired using both contact and non-contact measurement methods based on the actual cylinder head. A series of measures are then taken on the point cloud, including noise removal, stitching, simplification, and parameter extraction. Finally, a modular modeling method is used to obtain a high-precision digital model of the cylinder head.

[0050] Steps S1 to S3 are existing technologies and will not be described in detail in this invention.

[0051] The cylinder head finished product is a part formed by machining a cylinder head blank according to the design drawings using a fixture. The cylinder head blank has intake and exhaust ports corresponding to the first to fourth cylinders. The intake side of the cylinder head blank has intake ports for the first to fourth cylinders, respectively connected to the intake ports of the first to fourth cylinders; the exhaust side has exhaust ports for the first to fourth cylinders, respectively connected to the exhaust ports of the first to fourth cylinders. The outer surface of the intake port of the first cylinder has a bottom plane M16, and the outer surface of the intake port of the fourth cylinder has a bottom plane M27. A groove is provided on the bottom surface of the cylinder head blank, and the groove has a bottom plane M38. The areas of the bottom planes M16, M27, and M38 are not less than 8mm × 8mm and not more than 15mm × 15mm. The distances between the bottom planes M16, M27, and M38 and the bottom surface of the cylinder head blank are all H, where 6mm ≤ H ≤ 8mm.

[0052] See attached document Figures 1-6 As shown, in step S4, the machining positioning reference includes nine reference points: 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 positioning reference in the Z direction, reference point Y124, reference point Y225, reference point Y326, and reference point Y427 are used to determine the positioning reference in the Y direction, and reference point X122 and reference point X223 are used to determine the positioning reference in the X direction.

[0053] See attached document Figures 1-6As shown, reference point Z128 is located on bottom plane M16, reference point Z229 is located on bottom plane M27, and reference point Z330 is located on bottom plane M38. Reference points Z128, Z229, and Z330 constitute the Z-direction positioning reference. Reference points Y124 and Y225 are located on the first cylinder intake port 1 and intersect with the Z-direction positioning reference. Reference points Y326 and Y427 are located on the fourth cylinder intake port 2 and intersect with the Z-direction positioning reference. 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 reference points Y124 and Y225 and the midpoint of the line connecting reference points Y326 and Y427, and is perpendicular to the Z-direction positioning reference. Reference point X122 is located on the exhaust port 3 of the second cylinder and intersects with the Z-direction positioning reference. Reference point X223 is located on the exhaust port 4 of the third cylinder and intersects with the Z-direction positioning reference. Reference points X122 and X223 constitute the X-direction positioning reference. The X-direction positioning reference passes through the midpoint of the line connecting reference points X122 and X223 and is perpendicular to the Z-direction positioning reference and the Y-direction positioning reference.

[0054] like Figures 7-8 As shown, this invention only provides a simplified fixture diagram. The fixture mainly includes a mounting plate containing a hydraulic system. The mounting plate is equipped with a first self-centering mechanism 12, a second self-centering mechanism 13, a first positioning block 14, a second positioning block 15, a third positioning block 16, a first clamping jaw 17, a second clamping jaw 18, a third clamping jaw 19, a first clamping mechanism 20, and a second clamping mechanism 21, all connected to the hydraulic system. The hydraulic system can control the movement of each component. The specific structure of the self-centering mechanism is prior art; as long as it achieves the centering function, it is acceptable. The specific structure of the clamping mechanism is also prior art; as long as it achieves the clamping function, it is acceptable.

[0055] Furthermore, during the cylinder head blank machining process, 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 fixed on the reference points Z128, Z229, and Z330, respectively. The first pressure claw 17, the second pressure claw 18, and the third pressure claw 19 press on the intake port 9 of the first cylinder, the intake port 10 of the fourth cylinder, and the exhaust port 11 of the fourth cylinder, respectively. The first self-centering mechanism 12 presses on the reference points Y124 and Y225, the second self-centering mechanism 13 presses on the reference points Y326 and Y427, the center of the first clamping mechanism 20 presses on the reference point X122, and the center of the second clamping mechanism 21 presses on the reference point X223. After the positions are fixed, the self-centering mechanism and the pressure claw completely restrict the six degrees of freedom of the cylinder head through the hydraulic mechanism of the fixture, ensuring that the cylinder head blank is firmly fixed.

[0056] After the fixture is fixed, the cylinder head blank is machined. First, the top surface 5 of the cylinder head is machined, and two bolt holes are machined at both ends of the top surface 5 of the cylinder head as the first process positioning pin holes 31, as shown below. Figure 10 As shown. Then, using the top surface 5 of the cylinder head and the first process positioning pin hole 31 as a reference, the bottom surface 33 of the cylinder head is machined, and two bolt holes are machined on the bottom surface 33 of the cylinder head as the second process positioning pin holes 32, as shown. Figure 9 As shown; finally, the cylinder head is machined using the bottom surface 33 of the cylinder head and the second process positioning pin hole 32 as the reference, and the finished cylinder head is obtained.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention in any way. All equivalent transformations or modifications made in accordance with the essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for producing a cylinder head, characterized in that, The main steps include the following: Step S1: Construct a three-dimensional model of the cylinder head and select a casting positioning datum on the three-dimensional model; Step S2: Manufacture the sand core mold according to the casting positioning datum selected in step S1; Step S3: Use the casting sand core mold to make the sand core; Step S4: Use sand cores to make cylinder head blanks and mark machining positioning references on the cylinder head blanks. The machining positioning references are consistent with the casting positioning references in step S1. Step S5: Use a fixture to finish the cylinder head blank based on the machining positioning datum to obtain the final product; In step S4, 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 cylinder head blank has the first to fourth cylinder intake passage ports connected to the first to fourth cylinder intake passages respectively on the intake side, and the first to fourth cylinder exhaust passage ports connected to the first to fourth cylinder exhaust passages respectively on the exhaust side. The outer surface of the intake port of the first cylinder in the cylinder head blank has a bottom plane M1 (6), the outer surface of the intake port of the fourth cylinder has a bottom plane M2 (7), and the bottom surface of the cylinder head blank has a groove with a bottom plane M3 (8). The area of ​​the bottom plane M1 (6), bottom plane M2 (7) and bottom plane M3 (8) is not less than 8mm×8mm and not more than 15mm×15mm. The distance between the bottom plane M1 (6), bottom plane M2 (7) and bottom plane M3 (8) and the bottom surface of the cylinder head blank is H, 6mm≤H≤8mm. In step S4, the machining positioning reference includes nine reference points: 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 positioning reference in the Z direction, reference point Y1 (24), reference point Y2 (25), reference point Y3 (26), and reference point Y4 (27) are used to determine the positioning reference in the Y direction, and reference point X1 (22) and reference point X2 (23) are used to determine the positioning reference in the X direction. 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 points Z1 (28), Z2 (29), and Z3 (30) constitute the Z-direction positioning reference. Reference points Y1 (24) and Y2 (25) are located on the intake port (1) of the first cylinder and intersect with the Z-direction positioning reference. Reference points Y3 (26) and Y4 (27) are located on the intake port (2) of the fourth cylinder and intersect with the Z-direction positioning reference. The reference points Y1 (24), Y2 (25), Y3 (26), and Y4 (27) constitute the Y-direction positioning reference. The Y-direction positioning reference passes through the midpoint of the line connecting reference points Y1 (24) and Y2 (25) and the midpoint of the line connecting reference points Y3 (26) and Y4 (27) and is perpendicular to the Z-direction positioning reference. Reference point X1 (22) is located on the exhaust port (3) of the second cylinder and intersects with the Z-direction positioning reference. Reference point X2 (23) is located on the exhaust port (4) of the third cylinder and intersects with the Z-direction positioning reference. The reference points X1 (22) and X2 (23) constitute the X-direction positioning reference. The X-direction positioning reference passes through the midpoint of the line connecting reference points X1 (22) and X2 (23) and is perpendicular to the Z-direction positioning reference and the Y-direction positioning reference.

2. The method for producing a cylinder head according to claim 1, characterized in that, In step S5, the fixture includes a mounting plate containing a hydraulic system. The mounting plate is equipped with a first self-centering mechanism (12), a second self-centering mechanism (13), a first positioning block (14), a second positioning block (15), a third positioning block (16), a first pressure claw (17), a second pressure claw (18), a third pressure claw (19), a first clamping mechanism (20), and a second clamping mechanism (21) connected to the hydraulic system.

3. A method for producing a cylinder head according to claim 2, characterized in that, The specific method for step S5 is as follows: S51. Fix the first positioning block (14), the second positioning block (15), and the third positioning block (16) in the fixture to reference points Z1 (28), Z2 (29), and Z3 (30) respectively. The first pressure claw (17), the second pressure claw (18), and the third pressure claw (19) press on the air inlet (9) of the first cylinder, the air inlet (10) of the fourth cylinder, and the air outlet (11) of the fourth cylinder respectively. The first self-centering mechanism (12) presses on reference points Y1 (24) and Y2 (25). The second self-centering mechanism (13) presses on reference points Y3 (26) and Y4 (27). The center of the first clamping mechanism (20) presses on reference point X1 (22). The center of the second clamping mechanism (21) presses on reference point X2 (23). S52. Machining the top surface (5) of the cylinder head, and machining two bolt holes at both ends of the top surface (5) of the cylinder head as the first process positioning pin holes (31). S53. Based on the top surface (5) of the cylinder head and the first process positioning pin hole (31), process the bottom surface (33) of the cylinder head, and process two bolt holes on the bottom surface (33) of the cylinder head as the second process positioning pin hole (32). S54. The cylinder head is machined based on the bottom surface (33) of the cylinder head and the second process positioning pin hole (32) to obtain the finished cylinder head.

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