A cylinder head, engine friction work measurement system and measurement method

Abstract

The application discloses a cylinder head, an engine friction work measuring system and a measuring method, relates to the technical field of friction work measurement, and comprises a plurality of through holes and a plurality of connecting holes which are arranged side by side on the cylinder head, bolts are arranged in the connecting holes, and the cylinder head is further provided with a cooling liquid flow channel which comprises a buffer cavity with adjustable capacity; the tightening torque of the bolts and the capacity of the buffer cavity are adjusted according to the actual deformation amount and the preset deformation amount of the cylinder liner, and when the tightening torque and the capacity both reach the limit value and the actual deformation amount is less than the preset deformation amount, the cooling liquid flow is adjusted according to the actual deformation amount, the preset deformation amount and the cooling liquid temperature, so that the actual deformation amount is consistent with the preset standard deformation amount. The cylinder head of the application avoids generating pumping work by arranging the through holes at positions corresponding to the cylinder body, adjusts the deformation amount of the cylinder liner by adjusting the tightening torque of the bolts, the weight of the cylinder head and the cooling liquid flow, so that the deformation amount is consistent with the expected deformation amount, and the accuracy during friction work measurement is improved.

Description

Technical Field

[0001] This application relates to the field of friction work measurement technology, specifically to a cylinder head and engine friction work measurement system and method. Background Technology

[0002] To meet the increasingly stringent energy conservation and emission reduction challenges in the automotive industry, automotive companies worldwide are now adopting energy-saving technologies for their engine powertrain modules. These technologies mainly include friction reduction, weight reduction, turbocharging, direct injection, and start-stop systems. A reduction of approximately 10% in friction work can result in a fuel consumption reduction of about 2% to 3%. Therefore, reducing engine friction effectively reduces fuel consumption with minimal engine modifications, thus achieving overall vehicle fuel efficiency. Of the engine friction, the friction between the piston, piston rings, and cylinder liner accounts for about 40% of the total friction work; therefore, reducing friction in this area will yield considerable returns. Previous research shows that in a gasoline engine, the piston skirt accounts for approximately 17.6% of the overall engine friction work, while the piston rings account for approximately 23.5%. In other words, piston ring friction work accounts for approximately 4% of the total vehicle fuel consumption, with the first ring accounting for 1.6%, the second ring for 0.8%, and the oil ring for 1.6%. Therefore, reducing piston-piston ring friction work will effectively reduce piston-piston ring friction work and even engine friction work, thereby ultimately achieving the goal of effectively reducing overall vehicle fuel consumption. To reduce piston-piston ring friction work, improvements need to be made to the piston, piston rings, cylinder block, and other structures.

[0003] In existing technologies, after improving the piston structure, piston ring structure, cylinder block structure, and other structures, it is necessary to verify the benefits of reducing friction work brought about by the improvements to each structure. The verification is based on whether the piston-piston ring friction work value is within a preset range after each structural improvement. If it is within the preset range, it indicates that the improved structures meet the requirements. Current methods for verifying reduced piston-piston ring friction typically involve measuring the engine's mechanical loss work and then identifying friction work from this mechanical loss work. A significant portion of the engine's in-cylinder expansion work is consumed by friction loss, accessory loss, and pumping loss; these three losses are collectively referred to as the engine's mechanical losses.

[0004] When developing low-friction piston-piston ring and cylinder liner systems, the cylinder head of the engine covers the cylinder block, and cylinder liners are generally installed in the multiple cylinder bores within the cylinder block. The cylinder head also covers each cylinder liner, forming multiple enclosed piston cylinders. The piston and piston rings reciprocate within these cylinders. When the piston and piston rings move upwards, they compress the gas located above the piston and piston rings in the piston cylinder, generating pumping work. Simultaneously, the piston and piston rings rub against the inner wall of the piston cylinder, generating frictional work. Because both pumping work and frictional work are closely related to the engine's air and combustion systems, it is difficult to measure frictional work independently.

[0005] The current common practice is to first measure the pump work, and then subtract the accessory work and pump work from the mechanical loss work to obtain the friction work. However, for pump work measurement, major domestic and foreign OEMs currently use the cylinder pressure method, which often only measures the pump work of one cylinder and then calculates the total pump work using the cylinder translation method. Due to the differences in the state of each cylinder and the accuracy of related sensors, the measurement error of pump work is very large. Furthermore, pump work is mainly tested using a combustion analyzer, whose large range also leads to large measurement errors.

[0006] For measuring friction work, existing technical solutions propose an engine friction work decomposition testing device and its testing method. This method uses simulated structural parameters to model and obtain the simulated cylinder bore deformation (the cylinder bore being the piston cylinder mentioned above). Simulated friction work data is then obtained based on the simulated cylinder bore deformation. Simulated cover plates are manufactured according to the simulated structural parameters, and these custom cover plates are used for actual testing to obtain actual friction work data. Finally, the actual friction work data is compared with the simulated friction work data. If the error between the actual and simulated friction work data is outside a preset error range, the preset cylinder bore deformation is adjusted, and the process is repeated until the error between the actual and simulated friction work data is within the preset error range. The actual friction work data is then the final measurement data. In this scheme, the structure of the customized cylinder head is set by simulation structural parameters. Therefore, the cylinder bore deformation can be determined by modeling based on the simulation structural parameters, making the cylinder bore deformation quantifiable. Furthermore, the customized cylinder head can be adjusted by adjusting the simulation structural parameters, ensuring that the simulated cylinder bore deformation corresponding to the customized cylinder head is under control. Ultimately, the error between the simulated cylinder bore deformation and the preset cylinder bore deformation is controlled within the preset deformation range, thus eliminating the friction work measurement error caused by the uncertainty of the cylinder bore deformation. However, this scheme only guarantees the cylinder bore deformation through simulation, neglecting many other factors that affect the cylinder bore deformation. Therefore, the final accuracy of friction work measurement is still insufficient. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the purpose of this application is to provide a cylinder head, engine friction work measurement system and method. By opening through holes in the cylinder head corresponding to the cylinder block position, pumping work is avoided. The cylinder liner deformation is adjusted by adjusting the bolt tightening torque, cylinder head weight, and coolant flow rate to match the expected deformation, thereby improving the accuracy of friction work measurement.

[0008] To achieve the above objectives, the technical solution adopted is:

[0009] The first aspect of this application provides a cylinder head for sealing multiple cylinder blocks of an engine, each of which is provided with a cylinder liner; characterized in that the cylinder head is provided with multiple through holes and multiple connecting holes arranged side by side, each of the connecting holes is provided with a bolt, and the cylinder head is also provided with a coolant flow channel, the coolant flow channel including a buffer chamber, the buffer chamber being provided with a capacity adjustment component for adjusting its chamber capacity;

[0010] The plurality of through holes are respectively matched with the top openings of the plurality of cylinder liners, the bolts are used to connect the cylinder head to the plurality of cylinders, the capacity adjustment assembly adjusts the weight of the coolant buffered in the buffer chamber by adjusting the capacity of the buffer chamber, and the coolant flow channel is used to deliver coolant to the cooling flow channel in the cylinder body.

[0011] In some embodiments, the capacity adjustment component includes:

[0012] A partition is used to divide the buffer cavity into a first cavity and a second cavity. The first cavity is used to contain coolant, and the second cavity is used to contain air. The coolant flow channel and the cooling flow channel are both connected to the first cavity.

[0013] An actuating component, one end of which is located in the second cavity and connected to the partition, and the other end of which is connected to the power output component;

[0014] The power output component is used to output power to drive the partition to move in the buffer cavity and adjust the capacity of the first cavity during the movement.

[0015] In some embodiments, the cylinder liner is interference-fitted with the cylinder block;

[0016] The diameter of the through hole is larger than the diameter of the cylinder liner.

[0017] In some embodiments, the connecting holes are evenly distributed around the outer periphery of the through holes.

[0018] An engine friction work measurement system includes the cylinder head; the system further includes:

[0019] Deformation testing device, which is used to detect the actual deformation of the cylinder liner;

[0020] A power adjustment device for adjusting the tightening torque of the bolt;

[0021] A flow regulating device for regulating the flow rate of coolant flowing through the cooling channel;

[0022] A temperature detection device for detecting the temperature of the coolant flowing through the cooling channel;

[0023] A control device is used to control the power adjustment device to adjust the tightening torque and the capacity adjustment component to adjust the capacity based on the actual deformation and the preset deformation. When both the tightening torque and the capacity reach their limit values ​​and the actual deformation is less than the preset deformation, the control device is used to adjust the coolant flow rate based on the actual deformation, the preset deformation, and the coolant temperature, so that the actual deformation matches the preset standard deformation.

[0024] In some embodiments, the flow regulating device includes:

[0025] Multiple flow control valves are used to regulate the flow rate of coolant in the cooling channels of the multiple cylinders.

[0026] In some embodiments, the flow regulating device includes:

[0027] The pressure regulating chamber is located on the water inlet pipe connected to the inlet of the coolant flow channel, and is used to regulate the flow rate of coolant delivered to the coolant flow channel.

[0028] In some embodiments, the inlet of the coolant flow channel is connected to the inlet pipe via a water pipe connector, and the interface of the water pipe connector adopts a tapered thread design.

[0029] In some embodiments, the system further includes:

[0030] A cover is provided on the side of the cylinder head facing away from the cylinder body, and the side facing away from the cylinder body has multiple filter holes.

[0031] A method for measuring engine friction work, based on the aforementioned engine friction work measurement system; the method includes:

[0032] The actual deformation of the cylinder liner is detected, and if the actual deformation does not reach the expected deformation, the deformation is adjusted.

[0033] The deformation adjustment operation includes adjusting the tightening torque of the bolt and the capacity of the buffer cavity according to the actual deformation and the preset deformation. When the tightening torque and the capacity both reach their limit values ​​and the actual deformation is less than the preset deformation, the flow rate of the coolant is adjusted according to the actual deformation, the preset deformation, and the coolant temperature so that the actual deformation matches the preset standard deformation.

[0034] The beneficial effects of the technical solution provided in this application include:

[0035] A through hole is made on the cylinder head at the position corresponding to the cylinder block to avoid generating pumping work.

[0036] A buffer chamber is set inside the cylinder head. By adjusting the capacity of the buffer chamber, the weight of the coolant buffered in the chamber is adjusted, thereby adjusting the weight of the cylinder head. After the cylinder head is sealed on the cylinder block, the weight of the cylinder head affects the deformation of the cylinder liner.

[0037] Connecting holes are provided on the cylinder head, and bolts are installed in the connecting holes. After the cylinder head is sealed on the cylinder block, the tightening torque of the bolts affects the downward pressure of the cylinder head on the cylinder block and cylinder liner, and thus affects the deformation of the cylinder liner. The connecting holes are evenly distributed around the through holes of the corresponding cylinder block, which allows for precise adjustment of the tightening force of the bolts for each cylinder block, thereby precisely adjusting the downward pressure for each cylinder block.

[0038] When conducting friction work tests, the deformation of the cylinder liner is first adjusted by adjusting the tightening torque of the bolts and the weight of the cylinder head. If the actual deformation still cannot reach the expected deformation when both the tightening torque and the weight of the cylinder head reach their limits, the flow rate of the coolant flowing through the cylinder block is further adjusted to regulate the temperature of the cylinder block. The temperature of the cylinder block affects the temperature of the cylinder liner, and the deformation of the cylinder liner is related to the temperature of the cylinder liner. Therefore, the deformation of the cylinder liner can be adjusted by adjusting the flow rate of the coolant. When the deformation of the cylinder liner reaches the expected value, the accuracy of the friction work test can be guaranteed.

[0039] By setting up a pressure stabilizing chamber, the flow rate of coolant flowing through the coolant channel can be uniformly adjusted. By setting up flow regulating valves for each cylinder block, the flow rate of coolant flowing through each cooling channel can be precisely adjusted, thereby improving the adjustment accuracy of the cylinder liner deformation value of each cylinder block. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the cylinder head structure in an embodiment of the present invention.

[0041] Figure 2 This is a schematic diagram of the functional modules of the engine friction work measurement system in an embodiment of the present invention.

[0042] Figure 3 This is a schematic diagram of the cover structure in an embodiment of the present invention. Detailed Implementation

[0043] The present application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0044] In power machinery, engines are widely used across various industries due to their advantages such as wide power and speed range, high thermal efficiency, good fuel adaptability, and high energy density. In recent years, with the increasing severity of the oil crisis and environmental pollution, people have placed increasingly higher demands on engine energy conservation and emission reduction. A considerable portion of the in-cylinder expansion work of an engine is consumed by friction losses, accessory losses, and pumping losses; these three losses are collectively referred to as the engine's mechanical losses. Due to the existence of mechanical losses, there is a significant difference between the engine's effective thermal efficiency and its indicated thermal efficiency. Improving the engine's mechanical efficiency and reducing mechanical losses and their proportion of the engine's total power are important ways to improve engine power and economy.

[0045] Currently, the development of low-friction piston rings has room for improvement within 10nm, which is a relatively small measurement value in engine mechanical loss work testing. However, removing the pumping work (which accounts for 45% of mechanical loss work) can reduce the measurement range, allowing for measurements within 10nm, thus improving test accuracy.

[0046] Therefore, this invention proposes to design a cylinder head 7 specifically for low-friction development, which eliminates the influence of pump power on mechanical loss power, reduces the test range of friction power, and the smaller the range, the higher the accuracy. Therefore, it can improve the test accuracy of friction power, thereby enabling the subsequent selection of low-friction solutions to proceed smoothly.

[0047] See Figure 1 As shown, this embodiment of the invention provides a specific embodiment of a cylinder head 7, which is used to cover multiple cylinder blocks of an engine. Each of the cylinder blocks is provided with a cylinder liner, and the cylinder block and cylinder liner are interference-fitted. The cylinder head 7 has multiple through holes 8 and multiple connecting holes 9 arranged side by side. Each of the connecting holes 9 is provided with a bolt (not shown in the figure). The cylinder head 7 is also provided with a coolant flow channel, which includes a buffer chamber. The buffer chamber is provided with a capacity adjustment component for adjusting its capacity.

[0048] The aforementioned through holes 8 are respectively matched with the aforementioned top openings of the aforementioned cylinder liners, the aforementioned bolts are used to connect the cylinder head 7 to the aforementioned cylinders, the aforementioned capacity adjustment assembly adjusts the weight of the coolant buffered in the buffer chamber by adjusting the capacity of the buffer chamber, and the aforementioned coolant flow channel is used to deliver coolant to the cooling flow channel in the cylinder body.

[0049] In this embodiment, the engine block is a structure that includes the cylinders and other components of an internal combustion engine. In early automobile engines, the engine block consisted only of the cylinder block and a separate crankcase. The engine block typically integrates the crankcase and cylinder block into a single assembly. The engine block usually also includes elements such as coolant passages and oil passages. The term "cylinder block" is often used interchangeably with "engine block," although technically, the cylinder block of a modern engine (i.e., multiple cylinders in a single assembly) would be classified as a monolith.

[0050] Cylinder liner is short for engine cylinder liner. It is installed inside the cylinder barrel of the cylinder block and together with the piston and cylinder head, it forms the combustion chamber.

[0051] The cylinder head 7 is mounted on top of the cylinder block, sealing the cylinder from above and forming the combustion chamber. It is frequently in contact with high-temperature, high-pressure combustion gases, thus bearing significant thermal and mechanical loads. In water-cooled engines, the cylinder head 7 has an internal cooling water jacket, and the cooling water holes on the lower end face of the cylinder head 7 communicate with the cooling water holes in the cylinder block. Circulating water is used to cool the combustion chamber and other high-temperature components.

[0052] In mechanical installation, many parts require tight fits to prevent disconnection or to transmit large torques, hence the development of interference fit technology. An interference fit utilizes the elasticity of the material to enlarge and deform a hole, allowing it to fit over a shaft. When the hole returns to its original shape, it generates a clamping force on the shaft, connecting the two parts. In interference fit tolerance zone diagrams, the tolerance zone of the hole is below that of the shaft.

[0053] The tightening torque of the bolts and the weight of the cylinder head 7 affect the static deformation of the cylinder liner, while the coolant flow rate in the cooling channel affects the dynamic deformation of the cylinder liner. Static deformation refers to the deformation value observed only within a certain period, that is, it is only a function of time. Dynamic deformation refers to the deformation caused by external forces, which is a function of the external forces, and its observation result represents the instantaneous deformation of the building at a certain moment.

[0054] A through hole 8 is made on the cylinder head 7 at the position corresponding to the cylinder block to avoid generating pumping power.

[0055] A buffer chamber is set inside the cylinder head 7. By adjusting the capacity of the buffer chamber, the weight of the coolant buffered in the buffer chamber is adjusted, thereby adjusting the weight of the cylinder head 7. After the cylinder head 7 is sealed on the cylinder block, the weight of the cylinder head 7 affects the deformation of the cylinder liner.

[0056] In a preferred embodiment, the capacity adjustment assembly includes a partition that can reciprocate in the buffer cavity, an actuator connected to the partition, and a power output component connected to the actuator.

[0057] The partition is used to divide the buffer cavity into a first cavity and a second cavity. The first cavity is used to contain coolant, and the second cavity is used to contain air. The coolant flow channel and the cooling flow channel are both connected to the first cavity.

[0058] One end of the actuator is located in the second cavity and connected to the partition, while the other end is connected to the power output component.

[0059] The power output component is used to output power to drive the partition to move in the buffer cavity and adjust the capacity of the first cavity during the movement.

[0060] In this embodiment, a buffer cavity is provided inside the cylinder head 7. By adjusting the capacity of the first cavity in the buffer cavity, the weight of the coolant buffered in the buffer cavity is adjusted, thereby adjusting the weight of the cylinder head 7. After the cylinder head 7 is sealed on the cylinder block, the weight of the cylinder head 7 affects the deformation of the cylinder liner.

[0061] In a preferred embodiment, the cylinder liner is interference-fitted with the cylinder block. The diameter of the through hole 8 is larger than the diameter of the cylinder liner.

[0062] In this embodiment, the diameter of the through hole 8 is larger than the diameter of the cylinder liner. When the piston and piston ring reciprocate up and down inside the cylinder liner, if the piston and piston ring rise to the highest point, it can prevent the piston and piston ring from hitting the cylinder head 7.

[0063] In a preferred embodiment, the connecting holes 9 are evenly distributed around the outer periphery of the through holes 8.

[0064] In this embodiment, a connecting hole 9 is provided on the cylinder head 7, and a bolt is installed in the connecting hole 9. After the cylinder head 7 is sealed on the cylinder block, the tightening torque of the bolt affects the downward pressure of the cylinder head 7 on the cylinder block and cylinder liner, thereby affecting the deformation of the cylinder liner. Moreover, the connecting holes 9 are evenly distributed around the through holes 8 of the corresponding cylinder block, which can precisely adjust the tightening force of the bolts for each cylinder block, thereby precisely adjusting the downward pressure for each cylinder block.

[0065] like Figure 2 As shown, the present invention also discloses an engine friction work measurement system, including the cylinder head 7 mentioned above. The system includes a deformation testing device 1, a power adjustment device 2, a flow adjustment device 3, a temperature detection device 4, and a control device 5.

[0066] The deformation testing device 1 is used to detect the actual deformation of the cylinder liner.

[0067] The power adjustment device 2 is used to adjust the tightening torque of the above bolts.

[0068] The flow regulating device 3 is used to regulate the flow rate of the coolant flowing through the above-mentioned cooling channel.

[0069] Temperature detection device 4 is used to detect the temperature of the coolant flowing through the above-mentioned cooling channel.

[0070] The control device 5 is used to control the power adjustment device 2 to adjust the tightening torque and the capacity adjustment component to adjust the capacity according to the actual deformation amount and the preset deformation amount. When the tightening torque and the capacity both reach the limit value and the actual deformation amount is less than the preset deformation amount, the control device 5 controls the flow adjustment device 3 to adjust the coolant flow rate according to the actual deformation amount, the preset deformation amount and the coolant temperature, so that the actual deformation amount matches the preset standard deformation amount.

[0071] In this embodiment, the tightening torque of the bolts and the weight of the cylinder head 7 affect the static deformation of the cylinder liner, while the coolant flow rate in the cooling channel affects the dynamic deformation of the cylinder liner. Static deformation refers to the deformation value observed during a certain period, meaning it is only a function of time. Dynamic deformation refers to the deformation caused by external forces, which is a function of those forces, and its observed results represent the instantaneous deformation of the building at a certain moment.

[0072] A through hole 8 is made on the cylinder head 7 at the position corresponding to the cylinder block to avoid generating pumping power.

[0073] A buffer chamber is set inside the cylinder head 7. By adjusting the capacity of the buffer chamber, the weight of the coolant buffered in the buffer chamber is adjusted, thereby adjusting the weight of the cylinder head 7. After the cylinder head 7 is sealed on the cylinder block, the weight of the cylinder head 7 affects the deformation of the cylinder liner.

[0074] A connecting hole 9 is provided on the cylinder head 7, and a bolt is installed in the connecting hole 9. After the cylinder head 7 is sealed on the cylinder block, the tightening torque of the bolt affects the downward pressure of the cylinder head 7 on the cylinder block and cylinder liner, and thus affects the deformation of the cylinder liner. The connecting holes 9 are evenly distributed around the through holes 8 of the corresponding cylinder block, which can precisely adjust the tightening force of the bolts for each cylinder block, thereby precisely adjusting the downward pressure for each cylinder block.

[0075] When conducting friction work tests, the deformation of the cylinder liner is first adjusted by adjusting the tightening torque of the bolts and the weight of the cylinder head 7. If the actual deformation still cannot reach the expected deformation when both the tightening torque and the weight of the cylinder head 7 reach their limit values, the flow rate of the coolant flowing through the cylinder block is further adjusted to regulate the temperature of the cylinder block. The temperature of the cylinder block affects the temperature of the cylinder liner, and the deformation of the cylinder liner is related to the temperature of the cylinder liner. Therefore, the deformation of the cylinder liner can be adjusted by adjusting the flow rate of the coolant. When the deformation of the cylinder liner reaches the expected value, the accuracy of the friction work test can be guaranteed.

[0076] In a preferred embodiment, the flow regulating device 3 includes a plurality of flow regulating valves, which are used to regulate the flow rate of coolant in the cooling channels of the plurality of cylinders.

[0077] In a preferred embodiment, because the combustion load of each cylinder of the engine is different, the water flow rate of each cylinder is different during actual operation. Different water flow rates will affect the temperature of the cylinder liner, resulting in different cylinder liner deformation. In order to ensure the accuracy of the friction work test results, it is necessary to ensure the consistency of water flow rate before and after cylinder head 7 is installed. For this purpose, a PID algorithm is needed to adjust the opening of the flow control valve of each cylinder, thereby ensuring the consistency of water flow rate of cylinder head 7 under the two conditions.

[0078] In industrial process control, a control system that uses the proportional, integral, and derivative of the error generated by comparing real-time data of the controlled object with a given value is called a PID (Proportional Integral Derivative) control system. PID control has advantages such as simple principle, strong robustness, and wide applicability, making it a mature and widely used control system.

[0079] The aforementioned flow regulating device 3 includes a pressure stabilizing chamber, which is located on the water inlet pipe connected to the inlet of the coolant flow channel, and is used to regulate the flow rate of coolant delivered to the coolant flow channel.

[0080] In this embodiment, the flow rate of coolant flowing through the coolant channel can be uniformly adjusted by setting a pressure stabilizing chamber, and the flow rate of coolant flowing through each cooling channel can be precisely adjusted by setting a flow regulating valve for each cylinder, thereby improving the adjustment accuracy of the cylinder liner deformation value of each cylinder.

[0081] In a preferred embodiment, the inlet of the coolant flow channel is connected to the water inlet pipe via a water pipe connector, and the interface of the water pipe connector adopts a tapered thread design.

[0082] In this embodiment, the water pipe interface adopts a tapered thread design to ensure sealing.

[0083] In a preferred embodiment, such as Figure 3 As shown, the system also includes a cover 6, which is disposed on the side of the cylinder head 7 facing away from the cylinder body, and the side of the cover facing away from the cylinder body is provided with a plurality of filter holes 10.

[0084] In this embodiment, the cover 6 must ensure a clean environment so that no impurities enter the combustion chamber during diesel engine operation, thus preventing cylinder scoring, while also allowing air to be discharged smoothly without pumping losses.

[0085] The present invention also discloses an engine friction work measurement method, based on the above-mentioned engine friction work measurement system, including detecting the actual deformation of the cylinder liner, and performing deformation adjustment operation when the actual deformation does not reach the expected deformation.

[0086] The aforementioned deformation adjustment operation includes adjusting the tightening torque of the bolt and adjusting the capacity of the buffer cavity according to the actual deformation and the preset deformation. When the tightening torque and the capacity both reach their limit values ​​and the actual deformation is less than the preset deformation, the coolant flow rate is adjusted according to the actual deformation, the preset deformation, and the coolant temperature to make the actual deformation match the preset standard deformation.

[0087] In this embodiment, the tightening torque of the bolts and the weight of the cylinder head 7 affect the static deformation of the cylinder liner, while the coolant flow rate in the cooling channel affects the dynamic deformation of the cylinder liner. Static deformation refers to the deformation value observed during a certain period, meaning it is only a function of time. Dynamic deformation refers to the deformation caused by external forces, which is a function of those forces, and its observed results represent the instantaneous deformation of the building at a certain moment.

[0088] A through hole 8 is made on the cylinder head 7 at the position corresponding to the cylinder block to avoid generating pumping power.

[0089] A buffer chamber is set inside the cylinder head 7. By adjusting the capacity of the buffer chamber, the weight of the coolant buffered in the buffer chamber is adjusted, thereby adjusting the weight of the cylinder head 7. After the cylinder head 7 is sealed on the cylinder block, the weight of the cylinder head 7 affects the deformation of the cylinder liner.

[0090] A connecting hole 9 is provided on the cylinder head 7, and a bolt is installed in the connecting hole 9. After the cylinder head 7 is sealed on the cylinder block, the tightening torque of the bolt affects the downward pressure of the cylinder head 7 on the cylinder block and cylinder liner, and thus affects the deformation of the cylinder liner. The connecting holes 9 are evenly distributed around the through holes 8 of the corresponding cylinder block, which can precisely adjust the tightening force of the bolts for each cylinder block, thereby precisely adjusting the downward pressure for each cylinder block.

[0091] When conducting friction work tests, the deformation of the cylinder liner is first adjusted by adjusting the tightening torque of the bolts and the weight of the cylinder head 7. If the actual deformation still cannot reach the expected deformation when both the tightening torque and the weight of the cylinder head 7 reach their limit values, the flow rate of the coolant flowing through the cylinder block is further adjusted to regulate the temperature of the cylinder block. The temperature of the cylinder block affects the temperature of the cylinder liner, and the deformation of the cylinder liner is related to the temperature of the cylinder liner. Therefore, the deformation of the cylinder liner can be adjusted by adjusting the flow rate of the coolant. When the deformation of the cylinder liner reaches the expected value, the accuracy of the friction work test can be guaranteed.

[0092] In a preferred embodiment, the flow regulating device 3 includes a plurality of flow regulating valves, which are used to regulate the flow rate of coolant in the cooling channels of the plurality of cylinders.

[0093] In a preferred embodiment, the method includes designing a pressure regulating chamber, which is disposed on an inlet pipe connected to the inlet of the coolant flow channel, for regulating the flow rate of coolant delivered to the coolant flow channel.

[0094] In this embodiment, due to the different combustion loads of each cylinder in the engine, the water flow rate of each cylinder is different during actual operation. Different water flow rates will affect the temperature of the cylinder liner, resulting in different cylinder liner deformation. In order to ensure the accuracy of the friction work test results, it is necessary to ensure the consistency of the water flow rate before and after installing the cylinder head 7. For this purpose, a PID algorithm is needed to adjust the opening of the flow control valve of each cylinder, thereby ensuring the consistency of the water flow rate of the cylinder head 7 under the two conditions.

[0095] By setting up a pressure stabilizing chamber, the flow rate of coolant flowing through the coolant channel can be uniformly adjusted. By setting up flow regulating valves for each cylinder block, the flow rate of coolant flowing through each cooling channel can be precisely adjusted, thereby improving the adjustment accuracy of the cylinder liner deformation value of each cylinder block.

[0096] In a preferred embodiment, the method includes designing the inlet of the coolant flow channel to be connected to the inlet pipe via a water pipe connector, wherein the interface of the water pipe connector adopts a tapered thread design.

[0097] In this embodiment, the water pipe interface adopts a tapered thread design to ensure sealing.

[0098] In a preferred embodiment, the method includes designing a cover 6, which is disposed on the side of the cylinder head 7 facing away from the cylinder body, and the side facing away from the cylinder body is provided with a plurality of filter holes 10.

[0099] In this embodiment, the cover 6 must ensure a clean environment so that no impurities enter the combustion chamber during diesel engine operation, thus preventing cylinder scoring, while also allowing air to be discharged smoothly without pumping losses.

[0100] This application is not limited to the above-described embodiments. For those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. A cylinder head for sealing a plurality of cylinder blocks of an engine, each of the cylinder blocks having a cylinder liner; characterized in that, The cylinder head is provided with a plurality of through holes and a plurality of connecting holes arranged in a row. Each connecting hole is provided with a bolt. The cylinder head is also provided with a coolant flow channel. The coolant flow channel includes a buffer chamber. The buffer chamber is provided with a capacity adjustment component for adjusting its chamber capacity. The plurality of through holes are respectively matched with the top openings of the plurality of cylinder liners, the bolts are used to connect the cylinder head to the plurality of cylinder blocks, the capacity adjustment assembly adjusts the weight of the coolant buffered in the buffer chamber by adjusting the capacity of the buffer chamber, and the coolant flow channel is used to deliver coolant to the cooling flow channel in the cylinder block.

2. The cylinder head as described in claim 1, characterized in that, The capacity adjustment component includes: A partition is used to divide the buffer cavity into a first cavity and a second cavity. The first cavity is used to contain coolant, and the second cavity is used to contain air. The coolant flow channel and the cooling flow channel are both connected to the first cavity. An actuating component, one end of which is located in the second cavity and connected to the partition, and the other end of which is connected to the power output component; The power output component is used to output power to drive the partition to move in the buffer cavity and adjust the capacity of the first cavity during the movement.

3. The cylinder head as described in claim 1, characterized in that, The cylinder liner is interference-fitted with the cylinder block; The diameter of the through hole is larger than the diameter of the cylinder liner.

4. The cylinder head as described in claim 1, characterized in that, The connecting holes are evenly distributed around the outer periphery of the through holes.

5. An engine friction work measurement system, characterized in that, The system includes the cylinder head as described in claim 1; the system further includes: Deformation testing device, which is used to detect the actual deformation of the cylinder liner; A power adjustment device for adjusting the tightening torque of the bolt; A flow regulating device for regulating the flow rate of coolant flowing through the cooling channel; A temperature detection device for detecting the temperature of the coolant flowing through the cooling channel; A control device is used to control the power adjustment device to adjust the tightening torque and the capacity adjustment component to adjust the capacity based on the actual deformation and the preset deformation. When both the tightening torque and the capacity reach their limit values ​​and the actual deformation is less than the preset deformation, the control device is used to adjust the coolant flow rate based on the actual deformation, the preset deformation, and the coolant temperature, so that the actual deformation matches the preset standard deformation.

6. The engine friction work measurement system as described in claim 5, characterized in that, The flow regulating device includes: Multiple flow control valves are used to regulate the flow rate of coolant in the cooling channels of the multiple cylinders.

7. The engine friction work measurement system as described in claim 5, characterized in that, The flow regulating device includes: The pressure regulating chamber is located on the water inlet pipe connected to the inlet of the coolant flow channel, and is used to regulate the flow rate of coolant delivered to the coolant flow channel.

8. The engine friction work measurement system as described in claim 7, characterized in that, The inlet of the coolant flow channel is connected to the water inlet pipe through a water pipe joint, and the interface of the water pipe joint adopts a tapered thread design.

9. The engine friction work measurement system as described in claim 5, characterized in that, The system also includes: A cover is provided on the side of the cylinder head facing away from the cylinder body, and the side facing away from the cylinder body has multiple filter holes.

10. A method for measuring engine friction work, characterized in that, Based on the engine friction work measurement system of claim 5; the method includes: The actual deformation of the cylinder liner is detected, and if the actual deformation does not reach the expected deformation, the deformation is adjusted. The deformation adjustment operation includes adjusting the tightening torque of the bolt and the capacity of the buffer cavity according to the actual deformation and the preset deformation. When the tightening torque and the capacity both reach their limit values ​​and the actual deformation is less than the preset deformation, the flow rate of the coolant is adjusted according to the actual deformation, the preset deformation, and the coolant temperature so that the actual deformation matches the preset standard deformation.

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