Split water-cooled diesel engine cylinder head

Abstract

The application discloses a split water-cooled diesel engine cylinder cover. The split water-cooled diesel engine cylinder cover is designed in a modular manner, and a cylinder cover body comprises a valve train assembly, a fuel injection system assembly, a cooling system assembly and a machine body connecting assembly. The three major functional systems of valve train, fuel injection and cooling are integrated in one body. Meanwhile, through precise mechanical processing areas and sealing structures, reliable connection with a machine body, a cylinder gasket and a cylinder sleeve is realized, and the working requirements of high power and high reliability of the diesel engine are met.

Description

Technical Field

[0001] This application relates to the field of diesel engine cylinder head technology, and in particular to a split-type water-cooled diesel engine cylinder head. Background Technology

[0002] During diesel engine operation, the cylinder head is one of the most critical and complex components. The cylinder head acts as the command center in the diesel engine's valve train control. Valves, valve springs, rocker arms, and tappets are all mounted on the cylinder head. Simultaneously, the cylinder head design must consider the routing of the intake and exhaust ports to create intake vortices and ensure smooth exhaust flow. The cylinder head provides structural support and sealing, forming the combustion chamber together with the piston top and cylinder liner, playing a decisive role in fuel-air mixing and combustion. To ensure a tight seal, a significant preload is required, necessitating sufficient rigidity and strength in the cylinder head itself to prevent deformation. The cylinder head also provides a mounting base for the fuel supply system, requiring the machining of highly precise injector mounting holes to ensure accurate injector positioning and a seal between the injector protective sleeve and the cylinder head.

[0003] The cylinder head of a diesel engine is a crucial component of the combustion chamber, integrating functions such as valve train operation, fuel injection, and cooling, while withstanding high temperatures, high pressures, and alternating loads. Existing integral cylinder heads suffer from problems such as high manufacturing difficulty, high maintenance costs, and insufficient cooling uniformity. Chinese invention patent CN105649815A discloses a cylinder head and a diesel engine equipped with the same cylinder head. This invention relates to the field of diesel engine technology, and particularly to a cylinder head and a diesel engine equipped with the same cylinder head. The cylinder head has intake and exhaust ports. The wall thickness of the intake port is positively correlated with the load magnitude at different locations on its inner wall, and the wall thickness of the exhaust port is also positively correlated with the load magnitude at different locations on its inner wall. The varying thickness of the cylinder head's heat spreader plates results in lower and more uniform temperatures within the cylinder head. The rationally designed reinforcing ribs within the cylinder head effectively resist cylinder head deformation caused by combustion. This invention improves the maximum combustion pressure and load that the cylinder head can withstand. However, this technical solution focuses on the rigidity and strength of the cylinder head, which requires high processing standards, and does not include any other reinforcements or improvements.

[0004] In view of this, and based on the aforementioned technical problems, considering that a split structure can effectively reduce the difficulty of processing and maintenance, and that a water-cooled structure can efficiently remove heat from the combustion chamber, ensuring reliable operation of the diesel engine, this application aims to develop a compact, highly efficient, and reliably sealed split-water-cooled diesel engine cylinder head. Summary of the Invention

[0005] The technical problem to be solved by this application is that existing integral cylinder heads have problems such as high processing difficulty, high maintenance cost, and insufficient cooling uniformity.

[0006] To solve the above-mentioned technical problems, this application provides a split-type water-cooled diesel engine cylinder head. The cylinder head body has bolt holes and locating pin holes evenly distributed around its perimeter for connection with the cylinder block. The left and right sides of the cylinder head body are respectively provided with an intake port and an exhaust port. The front and rear sides of the cylinder head body are provided with cooling water chamber interfaces. The cylinder head body includes a valve train assembly, a fuel injection system assembly, a cooling system assembly, and an engine block connection assembly. The fuel injection system assembly includes an injector mounting hole located in the center of the upper side of the cylinder head body. This injector mounting hole extends into the cylinder head body to form an injector mounting channel. An injector protective sleeve is embedded in the center of the lower side of the cylinder head body, connecting to the injector mounting channel. The valve train assembly includes an intake duct, an exhaust duct, an intake valve seat, and an exhaust valve seat. The intake and exhaust ducts are hollow cylindrical structures evenly arranged around the injector mounting hole and extending into the cylinder head body. The intake and exhaust valve seats are respectively located within the intake and exhaust valve holes of the cylinder head body. The intake valve seat is coaxially aligned with the intake duct and embedded in the cylinder head body. On the lower side, the exhaust valve seat ring and exhaust duct are coaxially arranged and embedded in the lower side of the cylinder head body; the cooling system assembly includes cooling water chambers located on the intake side and exhaust side, the water channels in the cooling water chambers adopt a variable cross-section design, small holes are symmetrically provided on the left and right sides of the cooling water chambers, the small holes are connected to the ends of the water channels and are equipped with plugs, the water channels are connected to the engine block circulating water; the engine block connection assembly includes a support plate and cylinder head fastening bolts, the support plate is distributed between the cylinder head body and the engine block, the cylinder head fastening bolts are evenly arranged around the cylinder head body, and the cylinder head fastening bolts pass through the support plate and the engine block, pressing the cylinder head, engine block and cylinder head gasket together for sealing.

[0007] According to embodiments of this application, the intake valve seat and the exhaust valve seat are wear-resistant alloy rings embedded at the junction of the air passage and the combustion chamber to ensure a seal when the valves are closed.

[0008] According to an embodiment of this application, the injector mounting channel is machined from top to bottom with an M38x1.5-6H threaded hole, a 40H10 diameter mating hole, a 33.5H7 diameter positioning hole, and a 31.7H8 diameter mating hole; the lower side of the cylinder head body is machined with an M18x1-4H threaded hole for fixing the injector protective sleeve.

[0009] According to an embodiment of this application, an O-ring is fitted at the 31.7H8 diameter mating hole.

[0010] According to an embodiment of this application, four valve guide mounting holes with a specification of Φ8~10mm are symmetrically arranged around the injector mounting hole for installing intake and exhaust ducts; the valve guides are interference-fitted with the valve seat mounting grooves with an interference of 0.05~0.10mm, and the valve seat mounting grooves are used to install intake and exhaust valve seats.

[0011] According to an embodiment of this application, the cylinder head body is made of vermicular graphite cast iron, the valve seat ring is made of cobalt-based alloy, and the valve guide is made of powder metallurgy iron-based material.

[0012] According to an embodiment of this application, the water flow channel includes a first light hole at an angle of 57° to the lower side of the cylinder head body and a second light hole at an angle of 48° to the lower side of the cylinder head body. The ends of the first light hole and the second light hole are connected and symmetrically arranged on both sides of the exhaust outlet.

[0013] According to an embodiment of this application, the first aperture is a bore with a diameter of 10 mm and a depth of 105 mm; the second aperture is a bore with a diameter of 10 mm and a depth of 72 mm.

[0014] According to an embodiment of this application, the injector protective sleeve covers the injector, serving to provide heat insulation, vibration reduction, and protection.

[0015] According to an embodiment of this application, the intake duct is a spiral + tumble composite structure with a vortex ratio ≥2.5; the exhaust duct is a short and thick straight-through structure.

[0016] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0017] 1. Compact and integrated: The cylinder head of this application highly integrates functions such as valve distribution, intake and exhaust, combustion, and cooling into a single housing, resulting in a compact structure and high space utilization. The valve distribution, fuel injection, and cooling functions are modularly arranged, making the structure compact and easy to assemble and maintain.

[0018] 2. Multi-area precision machining for high installation and positioning accuracy: The injector area is equipped with multiple sets of high-precision mating holes, positioning holes, and threaded holes with strict tolerances, which can ensure the coaxiality, sealing, and operational stability of the injector installation; the precision machining quality of each mounting surface is high.

[0019] 3. Perfect sealing structure and reliable overall sealing: The bottom surface of the cylinder head is equipped with a special precision-machined sealing area, which forms a stable sealing surface with the cylinder head gasket, cylinder liner and engine block; the injector part adopts O-ring seal and the cooling hole adopts plug seal, so as to achieve no leakage between the three media of fuel gas, coolant and fuel, and ensure reliable operation of diesel engine under high pressure conditions.

[0020] 4. The support and fastening structure is reasonable, with strong rigidity and resistance to deformation: By uniformly loading the support plate and multiple sets of cylinder head fastening bolts, the rigidity of the cylinder head and engine block mating surface is improved, the bolt preload and cylinder burst pressure are effectively dispersed, the cylinder head warping deformation is suppressed, and the sealing reliability and structural durability are further improved.

[0021] 5. Split structure significantly improves machining and assembly: The split cylinder head structure has lower casting stress and more controllable deformation compared to an integral cylinder head. The machining difficulty of the internal air passages, water passages and precision mounting holes is reduced, which facilitates mass production and ensures precision. In case of partial damage, it can be replaced separately, reducing maintenance costs and repair difficulty. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this application, and are not intended to limit this application.

[0023] Figure 1 This is a schematic diagram of the structure of a split-water-cooled diesel engine cylinder head, as exemplified by the present invention.

[0024] Figure 2 This is a schematic diagram of a valve train assembly inside the cylinder head of a split-type water-cooled diesel engine, as an example of the present invention.

[0025] Figure 3 This is a schematic diagram of a fuel injection system assembly within the cylinder head of a split-type water-cooled diesel engine, as exemplified by the present invention.

[0026] Figure 4 This is a cross-sectional schematic diagram of the exhaust end cooling water chamber of a split-type water-cooled diesel engine cylinder head, which is an example of the present invention.

[0027] Figure 5 This is a schematic diagram illustrating the assembly and connection of a split-type water-cooled diesel engine cylinder head and engine block, as an example of the present invention.

[0028] The annotations in the attached figures are explained as follows:

[0029] 10. Cylinder head body; 11. Injector mounting hole; 12. Intake manifold inlet; 13. Exhaust manifold outlet; 14. Intake duct; 15. Exhaust duct; 16. Valve guide mounting hole; 20. Engine block; 21. Cylinder head fastening bolts; 22. Support plate; 111. Injector mounting hole; 112. Injector protective sleeve; 121. Intake manifold; 131. Exhaust manifold; 132. First clear hole; 133. Second clear hole; 134. Plug; 141. Intake valve seat; 151. Exhaust valve seat; 1121. M18×1-4H threaded hole; 1122. Diameter 31.7H8 mating hole; 1123. M38×1.5-6H threaded hole; 1124. Diameter 40H10 mating hole; 1125. O-ring. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the described embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains. The terms “first,” “second,” and similar terms used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a,” and similar terms, do not indicate a limitation of quantity, but rather indicate the presence of at least one.

[0032] like Figures 1 to 5 As shown in the example, this application discloses a split-type water-cooled diesel engine cylinder head. The split-type water-cooled diesel engine cylinder head adopts a modular design. The cylinder head body 10 includes a valve train assembly, a fuel injection system assembly, a cooling system assembly, and an engine block connection assembly, integrating the three major functional systems of valve train, fuel injection, and cooling into one unit. At the same time, through precision machining areas and sealing structures, a reliable connection with the engine block 20, cylinder head gasket, and cylinder liner is achieved, meeting the high power and high reliability requirements of diesel engines.

[0033] In this embodiment, bolt holes and locating pin holes are evenly distributed around the cylinder head body 10 for connection with the cylinder block; the left and right sides of the cylinder head body 10 are respectively provided with an intake port inlet 12 and an exhaust port outlet 13; the front and rear sides of the cylinder head body 10 are provided with cooling water chamber interfaces; the cylinder head body 10 includes a valve train assembly, a fuel injection system assembly, a cooling system assembly and an engine block 20 connection assembly.

[0034] Specifically, the cylinder head body 10 has 12 to 16 cylinder head bolt holes and 2 locating pin holes evenly distributed around its perimeter, which are fastened to the cylinder block with M12 to M16 high-strength bolts to ensure reliable sealing; the sides are respectively provided with intake manifold flange and exhaust manifold flange, with a flange surface roughness Ra≤3.2μm, for connecting the intake / exhaust manifold; the top surface is provided with injector mounting hole 11 and valve guide mounting hole 16.

[0035] Specifically, the intake duct 121 has a spiral + tumble composite structure with a vortex ratio ≥2.5; the exhaust duct 131 has a short and thick straight-through structure.

[0036] In this embodiment, as Figure 3As shown, the fuel injection system assembly includes an injector mounting hole 11 located in the middle of the upper side of the cylinder head body 10. The injector mounting hole 11 extends into the cylinder head body 10 to form an injector mounting channel 111. An injector protective sleeve 112 is embedded in the middle of the lower side of the cylinder head body 10 and connects to the injector mounting channel 111.

[0037] Specifically, the injector mounting channel 111 is machined from top to bottom with an M38x1.5-6H threaded hole 1121, a 40H10 diameter mating hole 1124, a 33.5H7 diameter positioning hole, and a 31.7H8 diameter mating hole 1122; the lower side of the cylinder head body 10 is machined with an M18x1-4H threaded hole for fixing the injector protective sleeve 112.

[0038] Specifically, an O-ring 1125 is fitted at the 31.7H8 diameter mating hole 1122.

[0039] Understandably, the fuel injection system components are used to install the injectors, enabling precise injection of high-pressure fuel. The injector protective sleeve 112 encloses the injector, providing heat insulation, vibration damping, and protection, preventing the injector from directly contacting the high-temperature combustion gases. Both the injector mounting channel 111 and the injector protective sleeve 112 are precision machined. Precision machining areas include: an M18×1-4H threaded hole 1121 with a surface roughness less than Ra3.2, used to fix the injector protective sleeve 112; the required tightening torque is 60 Nm. A 31.7H8 diameter mating hole 1122 provides radial precision positioning for the injector, with a surface roughness less than Ra3.2; an O-ring 1125 is fitted here to seal between the fuel and coolant, preventing leakage. The M18*1-4H threaded hole and the straight... The concentricity requirement for the 31.7H8 diameter mating hole 1122 is less than 0.1mm; the 33.5H7 diameter positioning hole is used for auxiliary positioning to ensure that the injector is coaxial with the center of the combustion chamber; the M38×1.5-6H threaded hole 1123 is used to install high-pressure oil pipe joints or injector clamping parts, with a surface roughness of less than Ra3.2. This part is used to assemble the injector clamping sleeve, and the tightening torque required is 100Nm; the 40H10 diameter mating hole 1124 provides installation and sealing space for the injector tail, with a surface roughness requirement of less than Ra3.2.

[0040] In this embodiment, as Figure 2As shown, the valve train assembly includes an intake duct 14, an exhaust duct 15, an intake valve seat 141, and an exhaust valve seat 151. The intake duct 14 and the exhaust duct 15 are hollow cylindrical structures evenly arranged around the injector mounting hole 11 and extending into the cylinder head body 10. The intake valve seat 141 and the exhaust valve seat 151 are respectively disposed in the intake valve hole and the exhaust valve hole of the cylinder head body 10. The intake valve seat 141 is coaxially arranged with the intake duct 14 and embedded in the lower side of the cylinder head body 10, and the exhaust valve seat 151 is coaxially arranged with the exhaust duct 15 and embedded in the lower side of the cylinder head body 10.

[0041] Specifically, the valve train assembly is integrated inside the cylinder head body to achieve precise control of the intake and exhaust passages: the intake side includes an intake duct 14 and an intake valve seat 141. The intake duct 14 provides motion guidance for the intake valve, and the intake valve seat 141 cooperates with the intake valve to form a sealing surface, controlling the air-fuel mixture to enter the combustion chamber; the exhaust side includes an exhaust duct 15 and an exhaust valve seat 151. The exhaust duct 15 provides motion guidance for the exhaust valve, and the exhaust valve seat 151 cooperates with the exhaust valve to form a sealing surface, controlling the high-temperature exhaust gas to be discharged from the combustion chamber.

[0042] Specifically, the intake duct 14 guides the intake valve, ensuring the coaxiality of the valve's reciprocating motion; the intake valve seat 141 mates with the intake valve to form a sealing surface, controlling the air-fuel mixture entering the combustion chamber while withstanding high temperatures and impact loads; the exhaust duct 15 guides the exhaust valve, with a structure similar to the intake duct 14, but it needs to withstand higher exhaust temperatures; the exhaust valve seat 151 mates with the exhaust valve to form a sealing surface, controlling the high-temperature exhaust gas from the combustion chamber, requiring higher heat resistance and wear resistance. The intake and exhaust ducts 15 and the seat rings are all embedded in pre-drilled holes in the cylinder head body 10, forming a complete intake and exhaust passage.

[0043] Specifically, such as Figure 1 As shown, four valve guide mounting holes 16 with a specification of Φ8~10mm are symmetrically arranged around the injector mounting hole 11 for installing the intake duct 14 and the exhaust duct 15. The valve guides are interference-fitted with the valve seat mounting grooves with an interference of 0.05~0.10mm. The valve seat mounting grooves are used to install the intake valve seat 141 and the exhaust valve seat 151.

[0044] Specifically, the intake valve seat 141 and the exhaust valve seat 151 are wear-resistant alloy rings embedded at the junction of the air passage and the combustion chamber to ensure a seal when the valves are closed.

[0045] Specifically, based on the combustion surface, the assembly technical requirements for intake duct 14 and exhaust duct 15 include a perpendicularity tolerance of less than 0.05 mm, a surface roughness of less than Ra1.6, and a single-sided interference fit of 0.017 mm. Intake valve seat 141 and exhaust valve seat 151 are assembled in the cylinder head intake and exhaust valve holes, consistent with intake duct 14 and exhaust duct 15. Assembly requires liquid nitrogen. Before assembly, intake duct 14 and exhaust duct 15 are mounted on a mandrel and cooled in liquid nitrogen along with intake valve seat 141 and exhaust valve seat 151. Simultaneously, the cylinder head is heated to 80°C in water before assembly. Intake valve seat 141 and exhaust valve seat 151, together with the intake and exhaust valves, seal the combustion chamber. The equivalent pressure of intake valve seat 141 is 117 MPa, and the equivalent pressure of exhaust valve seat 151 is... The equivalent pressure of 51 is 63MPa. The diesel engine is required to have no leakage of compression pressure during the compression stroke and no leakage of combustion pressure during the power stroke. The concentricity of the intake valve seat 141 and exhaust valve seat 151 with the bottom hole of the intake duct 14 and the bottom hole of the exhaust duct 15 is required to be less than 0.06mm. After assembling the intake valve seat 141 and exhaust valve seat 151 with the intake duct 14 and the exhaust duct 15, the total runout between the valve seat and the intake duct 14 is required to be less than 0.025mm, and the total runout between the exhaust valve seat and the exhaust duct 15 is required to be less than 0.025mm.

[0046] In this embodiment, the cooling system component includes a cooling water chamber disposed on the side of the air intake duct inlet 12 and the side of the exhaust duct outlet 13. The water flow channel in the cooling water chamber adopts a variable cross-section design. Small holes are symmetrically provided on the left and right sides of the cooling water chamber. The small holes are connected to the end of the water flow channel and are equipped with a plug 134. The water flow channel is connected to the circulating water of the machine body 20.

[0047] Specifically, the cylinder head is the crucial hub for diesel engine cooling and lubrication. To address the excessively high exhaust temperature of the cylinder head, a cooling water circulation path is added to the cooling water chamber. The water flow path includes a first aperture 132 at a 57° angle to the lower side of the cylinder head body 10 and a second aperture 133 at a 48° angle to the lower side of the cylinder head body 10. The ends of the first aperture 132 and the second aperture 133 are connected and symmetrically arranged on both sides of the exhaust outlet 13. The first aperture 132 is a bore with a diameter of 10 mm and a depth of 105 mm, forming a branch path in the cooling water chamber and guiding the coolant flow to the high heat load area. The second aperture 133 is a bore with a diameter of 10 mm and a depth of 72 mm, assisting in the formation of the cooling flow path and optimizing the coolant flow path.

[0048] Specifically, the plug 134 is used to seal the machining opening of the cooling channel to ensure the water cavity is airtight and prevent coolant leakage.

[0049] In this embodiment, the connecting assembly of the engine body 20 includes a support plate 22 and cylinder head fastening bolts 21. The support plate 22 is distributed between the cylinder head body and the engine body 20. The cylinder head fastening bolts 21 are evenly arranged around the cylinder head body and pass through the support plate 22 and the engine body 20 to press and seal the cylinder head, engine body 20 and cylinder head gasket.

[0050] Specifically, the entire assembly is rigidly connected to the lower engine block 20 by cylinder head fastening bolts 21, with auxiliary support from a support plate 22 in the middle. The mating surface is the precision-machined area of ​​the cylinder head, which is used to form a reliable seal with the cylinder head gasket and cylinder liner to ensure the airtightness of the combustion chamber.

[0051] Specifically, the cylinder head fastening bolts 21203 are divided into common bolts and independent bolts. The preload of the common bolts is 139 kN / bolt, and the preload of the independent bolts is 108 kN / bolt. Because the elastic modulus of the support plate 22202 is relatively small, the support plate 22202 deforms preferentially under the preload of the cylinder head fastening bolts 21203. The support plate 22202 plays the role of evenly distributing the bolt preload and protecting the cylinder head 101 and the engine block 20.

[0052] In this embodiment, the cylinder head body 10 is made of vermicular graphite cast iron, the valve seat ring is made of cobalt-based alloy, and the valve guide is made of powder metallurgy iron-based material.

[0053] Specifically, the cylinder head body 10 is made of vermicular graphite cast iron (RuT450), with a tensile strength ≥450MPa, a coefficient ≥45W / (m·K), and excellent thermal fatigue resistance; the lower intake port is made of high-nickel alloy cast iron (HT300+Ni), with excellent high-temperature corrosion resistance, suitable for the high-temperature exhaust gas environment of diesel engines; the valve seat ring is made of cobalt-based alloy with a hardness ≥HRC45, and is wear-resistant and corrosion-resistant; the valve guide is made of powder metallurgy iron-based material, with good self-lubricating properties and long service life.

[0054] Specifically, because the cylinder head needs to perform structural load-bearing and sealing functions, the cylinder head is made of vermicular graphite cast iron, which has an elastic modulus of 155 GPa and a Poisson's ratio of 0.26; the intake valve seat 141104 and exhaust valve seat 151105 are made of W6Mo5Cr4V2, which has an elastic modulus of 210 GPa and a Poisson's ratio of 0.3; the engine block 20 is made of QT500, which has an elastic modulus of 147 GPa and a Poisson's ratio of 0.3; the support plate 22 is made of ZL301, which has an elastic modulus of 70 GPa and a Poisson's ratio of 0.3; the cylinder liner is made of special cast iron, which has an elastic modulus of 138 GPa and a Poisson's ratio of 0.16; and the cylinder head fastening bolts 21203 are made of 42CrMo, which has an elastic modulus of 210 GPa and a Poisson's ratio of 0.28.

[0055] In this embodiment, the processing and assembly process of the diesel engine cylinder head of this application is as follows: Casting and machining: The cylinder head body 10 is formed by a split casting process, and then the sealing area, mating holes, threaded holes and cooling holes are precision machined; Component assembly: The intake duct 14 and exhaust duct 15 are press-fitted into the cylinder head body, and the intake valve seat 141 and exhaust valve seat 151 are press-fitted; After installing the O-ring 1125, the injector protective sleeve 112 is installed, and the injector assembly is fastened through the threaded hole; The cooling hole plug 134 is assembled to complete the sealing of the cooling water chamber; Engine assembly: The cylinder head is placed on the engine body 20 through the support plate 22, the cylinder head gasket is laid, and the fastening bolts are tightened to the specified torque to complete the sealed connection between the cylinder head and the engine body 20.

[0056] In summary, the technical solution of this application has the following beneficial effects:

[0057] 1. Compact and integrated: The cylinder head of this application highly integrates functions such as valve distribution, intake and exhaust, combustion, and cooling into a single housing, resulting in a compact structure and high space utilization. The valve distribution, fuel injection, and cooling functions are modularly arranged, making the structure compact and easy to assemble and maintain.

[0058] 2. Multi-area precision machining for high installation and positioning accuracy: The injector area is equipped with multiple sets of high-precision mating holes, positioning holes, and threaded holes with strict tolerances, which can ensure the coaxiality, sealing, and operational stability of the injector installation; the precision machining quality of each mounting surface is high.

[0059] 3. Perfect sealing structure and reliable overall sealing: The bottom surface of the cylinder head is equipped with a special precision-machined sealing area, which forms a stable sealing surface with the cylinder head gasket, cylinder liner and engine block; the injector part adopts O-ring seal and the cooling hole adopts plug seal, so as to achieve no leakage between the three media of fuel gas, coolant and fuel, and ensure reliable operation of diesel engine under high pressure conditions.

[0060] 4. The support and fastening structure is reasonable, with strong rigidity and resistance to deformation: By uniformly loading the support plate and multiple sets of cylinder head fastening bolts, the rigidity of the cylinder head and engine block mating surface is improved, the bolt preload and cylinder burst pressure are effectively dispersed, the cylinder head warping deformation is suppressed, and the sealing reliability and structural durability are further improved.

[0061] 5. Split structure significantly improves machining and assembly: The split cylinder head structure has lower casting stress and more controllable deformation compared to an integral cylinder head. The machining difficulty of the internal air passages, water passages and precision mounting holes is reduced, which facilitates mass production and ensures precision. In case of partial damage, it can be replaced separately, reducing maintenance costs and repair difficulty.

[0062] The above are merely exemplary embodiments of this application and are not intended to limit the scope of protection of this application, which is determined by the appended claims.

Claims

1. A split-type water-cooled diesel engine cylinder head, wherein bolt holes and locating pin holes are evenly distributed around the perimeter of the cylinder head body for connection to the cylinder block; an intake inlet and an exhaust outlet are respectively provided on the left and right sides of the cylinder head body; and cooling water chamber interfaces are provided on the front and rear sides of the cylinder head body, characterized in that... The cylinder head body includes a valve train assembly, a fuel injection system assembly, a cooling system assembly, and an engine block connection assembly. The fuel injection system assembly includes an injector mounting hole located in the middle of the upper side of the cylinder head body, the injector mounting hole extending into the cylinder head body to form an injector mounting channel, and an injector protective sleeve embedded in the middle of the lower side of the cylinder head body to connect the injector mounting channel. The valve train assembly includes an intake duct, an exhaust duct, an intake valve seat, and an exhaust valve seat. The intake and exhaust ducts are hollow cylindrical structures evenly arranged around the injector mounting holes and extending into the cylinder head body. The intake and exhaust valve seats are respectively disposed within the intake and exhaust valve holes of the cylinder head body. The intake valve seat is coaxially arranged with the intake duct and embedded in the lower side of the cylinder head body, and the exhaust valve seat is coaxially arranged with the exhaust duct and embedded in the lower side of the cylinder head body. The cooling system component includes a cooling water chamber disposed on the inlet side of the air intake and the outlet side of the exhaust. The water channel in the cooling water chamber adopts a variable cross-section design. Small holes are symmetrically provided on the left and right sides of the cooling water chamber. The small holes are connected to the end of the water channel and are equipped with plugs. The water channel is connected to the circulating water of the machine body. The engine block connection assembly includes a support plate and cylinder head fastening bolts. The support plate is distributed between the cylinder head body and the engine block. The cylinder head fastening bolts are evenly arranged around the cylinder head body and pass through the support plate and the engine block to press and seal the cylinder head, engine block, and cylinder head gasket.

2. The split-type water-cooled diesel engine cylinder head according to claim 1, characterized in that, The intake valve seat and exhaust valve seat are wear-resistant alloy rings embedded at the junction of the air passage and the combustion chamber to ensure a seal when the valves are closed.

3. A split-type water-cooled diesel engine cylinder head according to claim 1, characterized in that, The injector mounting channel is machined from top to bottom with an M38x1.5-6H threaded hole, a 40H10 diameter mating hole, a 33.5H7 diameter positioning hole, and a 31.7H8 diameter mating hole; the lower side of the cylinder head body is machined with an M18x1-4H threaded hole for fixing the injector protective sleeve.

4. A split-type water-cooled diesel engine cylinder head according to claim 3, characterized in that, An O-ring is fitted at the 31.7H8 diameter mating hole.

5. A split-type water-cooled diesel engine cylinder head according to claim 1, characterized in that, Four valve guide mounting holes with a specification of Φ8~10mm are symmetrically arranged around the injector mounting hole for installing the intake and exhaust ducts. The valve guides are interference-fitted with the valve seat mounting grooves with an interference of 0.05~0.10mm. The valve seat mounting grooves are used to install the intake and exhaust valve seats.

6. A split-type water-cooled diesel engine cylinder head according to claim 5, characterized in that, The cylinder head body is made of vermicular graphite cast iron, the valve seat ring is made of cobalt-based alloy, and the valve guide is made of powder metallurgy iron-based material.

7. A split-type water-cooled diesel engine cylinder head according to claim 1, characterized in that, The water flow channel includes a first light hole at an angle of 57° to the lower side of the cylinder head body and a second light hole at an angle of 48° to the lower side of the cylinder head body. The ends of the first light hole and the second light hole are connected and symmetrically arranged on both sides of the exhaust outlet.

8. A split-type water-cooled diesel engine cylinder head according to claim 7, characterized in that, The first aperture is a bore with a diameter of 10 mm and a depth of 105 mm; the second aperture is a bore with a diameter of 10 mm and a depth of 72 mm.

9. A split-type water-cooled diesel engine cylinder head according to claim 1, characterized in that, The injector protective sleeve covers the injector, serving to insulate against heat, reduce vibration, and provide protection.

10. A split-type water-cooled diesel engine cylinder head according to claim 1, characterized in that, The air intake is a spiral + tumble composite structure with a vortex ratio ≥2.5; the exhaust is a short and thick straight-through structure.

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