Machining method of engine cylinder body and engine

Abstract

The invention relates to a machining method of an engine cylinder block and an engine. The invention discloses a machining method of an engine cylinder block. The machining method comprises the following steps that S1, a cylinder block blank material is obtained through casting; s2, the bearing bush end assembling end face, the cylinder sleeve end assembling end face and the four side face assembling end faces of the cylinder body blank are subjected to semi-finish machining in sequence, and a first cylinder body semi-finished product is obtained; s3, the bearing bush end assembling end face and the four side face assembling end faces of the first semi-finished cylinder body are sequentially subjected to finish machining, and a second semi-finished cylinder body is obtained; s4, bearing bushes are assembled on the second cylinder body semi-finished product to obtain a third cylinder body semi-finished product; s5, finish machining is conducted on the assembling end face of the cylinder sleeve end of the third cylinder body semi-finished product and the inner circumferential faces of all shaft sleeve holes, and a fourth cylinder body semi-finished product is obtained; and S6, the inner circumferential faces of all cylinder sleeve holes in the cylinder sleeve end assembling end face of the fourth cylinder body semi-finished product are sequentially honed, and an engine cylinder body finished product is obtained. The machining precision of the cylinder sleeve hole can be effectively improved, and the rejection rate after machining is low.

Description

Technical Field

[0001] The present invention relates to the technical field of engine manufacturing, and in particular to a processing method for an engine cylinder block and an engine. Background Art

[0002] The engine cylinder block is the main body of the engine, which is used to connect each cylinder and the crankcase into one body. It is the supporting framework for installing pistons, crankshafts, and other parts and accessories. Its processing quality is directly related to the overall performance, service life, and fuel economy of the engine.

[0003] In the prior art, the processing technology of the engine cylinder block includes main processes such as die casting, rough machining, precision milling of the assembly surface, and precision boring of the assembly hole. Among them, precision boring of the cylinder liner hole is the key link to ensure the tight fit between the cylinder block and the cylinder liner, and to achieve efficient combustion and power output. However, in the face of the processing requirements of high-precision cylinder liner holes, the traditional boring machine processing method directly leads to an increase in the rejection rate due to insufficient processing accuracy, increasing the production cost and cycle.

[0004] In summary, in order to meet the requirements of the modern automotive industry for high-precision processing of engine cylinder blocks, it is urgent to introduce more advanced and efficient processing technologies to replace the traditional boring machine processing, reduce the rejection rate, and improve the processing efficiency and accuracy. Summary of the Invention

[0005] The applicant of the present invention aims at the above-mentioned disadvantages in the existing production technology, and provides a processing method for an engine cylinder block and an engine. Through six processing steps, it can effectively improve the processing accuracy of the cylinder liner hole, and has a low rejection rate after processing, which can meet the requirements of mass production and the usage requirements of the modern automotive industry.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A processing method for an engine cylinder block includes the following steps:

[0008] S1. Obtain a cylinder block blank by casting;

[0009] S2. Semi-finish machine the bearing end assembly end face, the cylinder liner end assembly end face, and the four side assembly end faces of the cylinder block blank in sequence to obtain a first cylinder block semi-finished product;

[0010] S3. Finish machine the bearing end assembly end face and the four side assembly end faces of the first cylinder block semi-finished product in sequence to obtain a second cylinder block semi-finished product;

[0011] S4. Prepare several bearing shells, make the assembly end face of a single bearing shell fit with the corresponding bearing shell assembly face in the bearing shell end assembly face of the second cylinder block semi-finished product, and use a bolt assembly to fix the bearing shell on the second cylinder block semi-finished product, so as to complete the assembly of the corresponding bearing shell. A bushing hole for mating with the crankshaft is formed between the single bearing shell and the second cylinder block semi-finished product;

[0012] Assemble the remaining bearing shells onto the second cylinder block semi-finished product respectively, so as to obtain a third cylinder block semi-finished product;

[0013] S5. Finish machining the cylinder liner end assembly face and the inner circumferential surfaces of all the bushing holes of the third cylinder block semi-finished product respectively, so as to obtain a fourth cylinder block semi-finished product;

[0014] S6. Hone the inner circumferential surfaces of all the cylinder liner holes in the cylinder liner end assembly face of the fourth cylinder block semi-finished product in sequence. After the honing process is completed, the finished engine cylinder block is obtained.

[0015] As a further improvement of the above technical solution:

[0016] The bearing shell end assembly face includes a first assembly face for mating and installing with the lower crankcase assembly face, and several bearing shell assembly faces for mating and installing with the corresponding bearing shells.

[0017] Several first threaded holes are formed on the first assembly face.

[0018] The bearing shell end assembly face further includes the inner threaded surfaces of all the first threaded holes.

[0019] The cylinder liner end assembly face includes a second assembly face for mating and installing with the cylinder head, and the inner circumferential surfaces of several cylinder liner holes for mating and installing with the corresponding piston assemblies.

[0020] In S2. and S3., a three-axis vertical CNC machining equipment is used for machining.

[0021] In S5., a five-axis horizontal CNC machining equipment is used for finish machining.

[0022] In S6., before the honing process, the unilateral honing allowance of the inner circumferential surface of a single cylinder liner hole is 0.03 mm.

[0023] In S6., a honing machine is used for honing.

[0024] An engine includes an engine cylinder block prepared by the above machining method of the engine cylinder block.

[0025] The beneficial effects of the present invention are as follows:

[0026] The structure of the present invention is compact and reasonable, and the operation is convenient. Through six processing steps, the honing is left to the last processing step, which can prevent the cylindricity and roundness of the engine cylinder block after honing from being affected by reprocessing, thereby effectively ensuring the processing accuracy; by setting the honing processing step, the roundness, cylindricity and surface roughness of the cylinder liner hole can be significantly improved, the friction and wear between the piston and the cylinder liner can be reduced, and the thermal efficiency and fuel economy of the engine can be improved; at the same time, the honing processing can also improve the geometric shape accuracy of the cylinder liner hole, which is beneficial to the smooth movement of the piston, reduce the vibration and noise of the engine, and has a low rejection rate and high processing efficiency after processing, which can meet the requirements of mass production and manufacturing and meet the usage requirements of the modern automotive industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 FIG. is a schematic structural diagram of a semi-finished cylinder block in the present invention.

[0028] Figure 2 is Figure 1 the rear view of.

[0029] Figure 3 is Figure 1 the right view of.

[0030] Figure 4 is Figure 1 the top view of.

[0031] Figure 5 FIG. is a schematic structural diagram of the engine cylinder block of the present invention Figure 1 .

[0032] Figure 6 FIG. is a schematic structural diagram of the engine cylinder block of the present invention Figure 2 .

[0033] Wherein: 1, semi-finished cylinder block; 2, bearing shell; 3, first assembly surface; 4, second assembly surface; 5, bearing shell assembly surface; 6, inner circumferential surface of cylinder liner hole. DETAILED DESCRIPTION OF THE INVENTION

[0034] The following combines the drawings to illustrate the detailed implementation manners of the present invention.

[0035] As Figures 1-6 shown, the processing method of the engine cylinder block of this embodiment includes the following steps:

[0036] S1. Obtain the cylinder block blank by casting;

[0037] The cylinder block blank is formed by the casting process, which provides the basic raw material for subsequent processing. Through the casting process, the semi-finished cylinder block 1 with complex shapes and meeting the production requirements can be mass-produced, reducing the production cost and improving the production efficiency; at the same time, the casting process can ensure the uniformity and density of the semi-finished cylinder block 1, providing a good foundation for subsequent processing;

[0038] The cylinder block blank is made of aluminum - magnesium alloy AZ91D material, which is light in weight itself, ensuring that the finished cylinder block has the advantage of being light in weight. And, during the subsequent semi - finishing, finishing, and honing processes, cutting fluid is required to improve processing efficiency, extend tool life, improve surface quality, and maintain the geometric accuracy of the workpiece.

[0039] S2. Semi - finish the bearing end assembly end face, cylinder liner end assembly end face, and four side assembly end faces of the cylinder block blank in sequence to obtain the first cylinder block semi - finished product.

[0040] The cylinder block semi - finished product 1 is in a cube shape as a whole, with six end faces, including a top face corresponding to the cylinder liner end, a bottom face corresponding to the bearing end, and four side faces.

[0041] The bearing end assembly end face includes a first assembly face 3 that is fitted and installed with the lower crankcase assembly end face, and several bearing assembly faces 5 that are fitted and installed with the corresponding bearings.

[0042] Several first threaded holes are opened on the first assembly face 3, and the bearing end assembly end face also includes the internal threaded surfaces of all the first threaded holes.

[0043] The cylinder liner end assembly end face includes a second assembly face 4 that is fitted and installed with the cylinder head, and several inner circumferential surfaces 6 of cylinder liner holes that are fitted and installed with the corresponding piston assemblies.

[0044] Several second threaded holes are opened on the second assembly face 4, and the cylinder liner end assembly end face also includes the internal threaded surfaces of all the second threaded holes.

[0045] In addition, the bearing end assembly end face also includes a third assembly face for cooperating with the crankshaft, corresponding to the inner concave arc surface of the bearing, for limiting the crankshaft.

[0046] In this embodiment, the four side assembly end faces include a plurality of fourth assembly faces provided on the remaining four side walls of the cylinder block semi - finished product 1, and the fourth assembly faces are used for fitting and installing with corresponding accessories such as control equipment components and measuring equipment components during subsequent assembly.

[0047] Use a three - axis vertical CNC machining equipment for semi - finishing. Specifically, semi - finish mill the planes through the three - axis vertical CNC machining equipment, including the first assembly face 3, the second assembly face 4, the fourth assembly face, and the bearing assembly face 5; semi - finish bore the inner walls through the three - axis vertical CNC machining equipment, including the internal threaded surfaces of the first threaded holes, the internal threaded surfaces of the second threaded holes, the inner circumferential surfaces 6 of the cylinder liner holes, and the third assembly face.

[0048] Through the semi - finishing step, it prepares for the subsequent finishing, ensures uniform machining allowance, and improves machining accuracy.

[0049] S3. Finish the finish machining of the bearing cap end assembly end face and the four side assembly end faces of the first cylinder block semi-finished product in sequence, so as to obtain the second cylinder block semi-finished product;

[0050] Adopt a three-axis vertical CNC machining equipment for semi-finish machining. Specifically, finish milling the first assembly face 3, the fourth assembly face, and the bearing cap assembly face 5 through the three-axis vertical CNC machining equipment; finish boring the internal thread surface of the first threaded hole and the third assembly face through the three-axis vertical CNC machining equipment.

[0051] S4. Prepare several bearing caps 2, make the assembly end face of a single bearing cap 2 fit with the corresponding bearing cap assembly face 5 on the bearing cap end assembly end face of the second cylinder block semi-finished product, and use a bolt assembly to fix the bearing cap 2 on the second cylinder block semi-finished product, so as to complete the assembly of the corresponding bearing cap 2. A bushing hole for mating with the crankshaft is formed between the single bearing cap 2 and the second cylinder block semi-finished product;

[0052] Assemble the remaining bearing caps 2 onto the second cylinder block semi-finished product respectively, so as to obtain the third cylinder block semi-finished product;

[0053] By performing the bearing cap assembly step after finish milling the bearing cap assembly face 5, the fitting accuracy between the bearing cap 2 and the cylinder block semi-finished product 1 can be guaranteed, the friction and wear during the subsequent engine operation can be reduced, the engine operation can be ensured to be stable, and the service life and performance of the engine can be improved; at the same time, the precise fit between the bearing cap 2 and the cylinder block semi-finished product 1 can reduce the engine noise and vibration and improve the driving comfort.

[0054] S5. Finish the finish machining of the cylinder liner end assembly end face and the inner circumferential surfaces of all the bushing holes of the third cylinder block semi-finished product, so as to obtain the fourth cylinder block semi-finished product;

[0055] Adopt a five-axis horizontal CNC machining equipment for finish machining. Specifically, finish milling the second assembly face 4 through the five-axis horizontal CNC machining equipment; finish boring the internal thread surface of the second threaded hole, the inner circumferential surface 6 of the cylinder liner hole, and the inner circumferential surfaces of the bushing holes through the five-axis horizontal CNC machining equipment.

[0056] By performing the finish machining after the semi-finish machining, the semi-finish machining can provide a uniform machining allowance for the finish machining, reduce the cutting force and cutting heat during the finish machining, be beneficial to protecting the cutting tool and the machine tool, and improve the machining accuracy and surface quality; through the finish machining, the fitting accuracy and sealing performance of all parts of the cylinder block are ensured.

[0057] S6. Perform honing machining on the inner circumferential surfaces 6 of all the cylinder liner holes in the cylinder liner end assembly end face of the fourth cylinder block semi-finished product in sequence. After the honing machining is completed, the finished engine cylinder block is obtained;

[0058] Before the honing machining, the unilateral honing allowance of the inner circumferential surface 6 of a single cylinder liner hole is 0.03 mm.

[0059] Honing is carried out using a honing machine;

[0060] By carrying out honing, the roundness, cylindricity and surface roughness of the cylinder liner hole can be significantly improved, the friction and wear between the piston assembly and the cylinder liner can be reduced, and the thermal efficiency and fuel economy of the engine can be improved; at the same time, honing can also improve the geometric shape accuracy of the cylinder liner hole, which is beneficial to the smooth movement of the piston assembly and reduces the vibration and noise of the engine.

[0061] The engine of this embodiment includes an engine cylinder block prepared by the above-mentioned processing method of the engine cylinder block; the structure of the engine cylinder block includes a cylinder block semi-finished product 1 obtained after casting, semi-finishing and finishing. Five bearing shells 2 are fitted and installed on the cylinder block semi-finished product 1. A cylinder head is fitted and installed at the cylinder liner end, and the inner walls of the cylinder head and the cylinder block together form a part of the combustion chamber; a lower crankcase is fitted and installed at the bearing shell end. The lower crankcase is used to enclose the crankcase as the outer shell of the oil storage tank to prevent impurities from entering; Four cylinder liner holes are provided on the engine cylinder block, and a piston assembly is fitted and installed in each cylinder liner hole. The engine cylinder block of the present invention has high machining accuracy and can improve the overall performance and service life of the engine.

[0062] The above description is an explanation of the present invention, not a limitation of the invention. For the scope defined by the present invention, refer to the claims. Any form of modification can be made within the protection scope of the present invention.

Claims

1. A machining method for an engine cylinder block, characterized in that: It includes the following steps: S1. Obtain a cylinder block blank by casting; S2. Semi-finish the bearing cap end assembly end face, cylinder liner end assembly end face, and four side assembly end faces of the cylinder block blank in sequence to obtain a first cylinder block semi-finished product; S3. Finish machine the bearing cap end assembly end face and four side assembly end faces of the first cylinder block semi-finished product in sequence to obtain a second cylinder block semi-finished product; S4. Prepare several bearing caps, make the assembly end face of a single bearing cap fit with the corresponding bearing cap assembly surface on the bearing cap end assembly end face of the second cylinder block semi-finished product, and use a bolt assembly to fix the bearing cap to the second cylinder block semi-finished product, thereby completing the assembly of the corresponding bearing cap. A bush hole for mating with the crankshaft is formed between the single bearing cap and the second cylinder block semi-finished product; Assemble the remaining bearing caps onto the second cylinder block semi-finished product respectively to obtain a third cylinder block semi-finished product; S5. Finish machine the cylinder liner end assembly end face and the inner circumferential surfaces of all bush holes of the third cylinder block semi-finished product to obtain a fourth cylinder block semi-finished product; S6. Hone the inner circumferential surfaces of all cylinder liner holes in the cylinder liner end assembly end face of the fourth cylinder block semi-finished product in sequence. After the honing process, an engine cylinder block finished product is obtained.

2. The processing method of the engine cylinder block according to claim 1, characterized in that: The bearing cap end assembly end face includes a first assembly surface for mating and installing with the lower crankcase assembly end face, and several bearing cap assembly surfaces for mating and installing with the corresponding bearing caps.

3. The machining method of the engine cylinder block according to claim 2, characterized in that: Several first threaded holes are formed on the first assembly surface.

4. The machining method of the engine cylinder block according to claim 3, characterized in that: The bearing cap end assembly end face further includes the internal thread surfaces of all the first threaded holes.

5. The machining method of the engine cylinder block according to claim 1, characterized in that: The cylinder liner end assembly end face includes a second assembly surface for mating and installing with the cylinder head, and the inner circumferential surfaces of several cylinder liner holes for mating and installing with the corresponding piston assemblies.

6. The machining method of the engine cylinder block according to claim 1, characterized in that: In S2. and S3., a three-axis vertical CNC machining equipment is used for machining.

7. The processing method of the engine cylinder block according to claim 1, characterized in that: In S5., a five-axis horizontal CNC machining equipment is used for finish machining.

8. The processing method of the engine cylinder block according to claim 1, characterized in that: In S6., before the honing process, the unilateral honing allowance of the inner circumferential surface of a single cylinder liner hole is 0.03 mm.

9. The machining method of the engine cylinder block according to claim 1, characterized in that: In S6., a honing machine is used for the honing process.

10. An engine, characterized in that: It includes an engine cylinder block prepared by the processing method of the engine cylinder block according to any one of claims 1-9.

Images