CN116255269A

CN116255269A - Cylinder head cooling structure, engine, vehicle and cooling method

Info

Publication number: CN116255269A
Application number: CN202310255021.7A
Authority: CN
Inventors: 张善永; 付云贵; 王利雨; 贺经纬; 王宁宁
Original assignee: Weichai Power Co Ltd
Current assignee: Weichai Power Co Ltd
Priority date: 2023-03-13
Filing date: 2023-03-13
Publication date: 2023-06-13

Abstract

The invention provides a cooling structure of a cylinder cover, an engine, a vehicle and a cooling method, relates to the technical field of engine cooling, and aims at solving the problem that the cooling structure of the cylinder cover can not meet the cooling requirements of different running states of the engine in the running process of the engine at present.

Description

Cylinder head cooling structure, engine, vehicle and cooling method

Technical Field

The invention relates to the technical field of engine cooling, in particular to a cylinder head cooling structure, an engine, a vehicle and a cooling method.

Background

In order to enhance the cooling of the cylinder head, a double-layer cooling liquid cavity structure is commonly used on a diesel engine at present, as shown in fig. 1 and 2, the cylinder head is cooled and partitioned, and the cooling of a high-temperature area of the cylinder head (the cylinder head bottom plate and an exhaust valve seat are used as areas and a fuel nozzle area of a fuel injector) is enhanced, so that the heat load of the cylinder head is reduced. Meanwhile, the cooling structure from bottom to top as shown in fig. 1 and the cooling structure from top to bottom as shown in fig. 2 are divided according to the flow direction of the internal coolant.

Although the double-layer cooling liquid cavity structure can improve cooling effect and reliability to a certain extent compared with the single-layer cooling liquid cavity structure, and reduces the heat load of the cylinder cover, the double-layer cooling liquid cavity is of a structure that two cooling liquid cavities are connected in series, and the flow resistance in the cooling liquid cavity is large, so that the flow of cooling liquid in the cylinder cover is reduced under the condition of the same liquid pump, and the cooling effect of the cylinder cover is influenced. Meanwhile, when the double-layer cooling liquid cavity is used for cooling the cylinder cover, the working state of the engine changes along with the running process, but the cooling modes of the cylinder cover are the same, the problem of single cooling mode exists, and when the engine is started in a cold mode and is in low-load operation, the temperature of the cylinder cover is too low to influence the speed of the engine; when the engine works under high load, the cooling efficiency is insufficient due to high flow resistance in the cooling liquid cavity, so that the temperature of the cylinder cover is too high, and the reliability of the cylinder cover and cylinder cover accessories is affected; the temperature of the cylinder cover is greatly changed along with the gradient of the load of the engine, the cooling system cannot be adjusted according to the cooling requirement of the cylinder cover, the reliability of the cylinder cover is unfavorable, and the cooling requirement of the gas engine during operation is difficult to meet.

Disclosure of Invention

The invention aims at overcoming the defects of the prior art, and provides a cooling structure of a cylinder cover, an engine, a vehicle and a cooling method, wherein liquid outlets are respectively arranged on two cooling cavities in the cylinder cover and matched with a control valve, so that the two cooling cavities are communicated, a liquid inlet is arranged on one cooling cavity, and the opening and closing of the liquid outlets and the adjustment of the opening degree are carried out through the control valve, so that the adjustment of the flow paths of cooling liquid in the cylinder cover is realized, the cooling states of the cooling cavities on different positions of the cylinder cover are changed, and the cooling structure is suitable for the requirements of the engine in different running states.

A first object of the present invention is to provide a cylinder head cooling structure, which adopts the following scheme:

the cooling device comprises a first cooling cavity and a second cooling cavity, wherein the first cooling cavity is positioned in a cylinder cover and is close to a fire face, the second cooling cavity is close to the top of the cylinder cover, the first cooling cavity is provided with a first liquid outlet and a first liquid inlet for accessing a cooling liquid source, the second cooling cavity is provided with a second liquid outlet and a second liquid inlet for communicating the first cooling cavity, the first liquid outlet is matched with a first valve, and the second liquid outlet is matched with a second valve;

by adjusting the first valve and the second valve, the flow path of the coolant in the cylinder head is changed so that the first cooling chamber operates alone or the first cooling chamber and the second cooling chamber operate simultaneously.

Further, the first valve and the second valve are control valves with adjustable opening degrees, and the proportion of the cooling liquid flowing out of the first cooling cavity and the second cooling cavity is adjusted by adjusting the opening degrees of the first valve and the second valve.

Further, the first liquid outlet and the first liquid inlet are positioned at two ends of the first cooling cavity, and the second liquid inlet is communicated with one end, close to the first liquid outlet, of the first cooling cavity.

Further, the first cooling cavity is located on one side, close to the cylinder piston, of the cylinder cover, and the second cooling cavity is located on one side, away from the cylinder piston, of the cavity cover.

Further, the first liquid outlet is connected to the liquid outlet pipe through a first outlet runner, the first valve is arranged on the first outlet runner, the second liquid outlet is connected to the liquid outlet pipe through a second outlet runner, the second valve is arranged on the second outlet runner, the first liquid inlet is connected to the cooling system through the liquid inlet pipe, and the liquid outlet pipe is connected to the cooling system.

A second object of the present invention is to provide an engine using the cylinder head cooling structure as described in the first object.

A third object of the invention is to provide a vehicle using an engine as described in the second object.

A fourth object of the present invention is to provide a cylinder head cooling method including:

two cooling cavities are arranged in the cylinder cover, liquid outlets of the two cooling cavities are respectively provided with a valve, a first cooling cavity close to the fire face is provided with a liquid inlet, and a second cooling cavity far away from the fire face is communicated with the first cooling cavity;

and according to the running state of the engine, changing the state of a valve corresponding to the cooling cavity, and adjusting the flow path of cooling liquid in the cooling cavity so as to enable the first cooling cavity to independently run or enable the first cooling cavity and the second cooling cavity to simultaneously run.

Further, the engine operating state is acquired,

when the engine is in a first state, a valve of the second cooling cavity is closed, and a valve of the first cooling cavity is opened, so that cooling liquid is discharged after passing through the first cooling cavity;

when the engine is in a second state, the valve of the first cooling cavity is closed, and the valve of the second cooling cavity is opened, so that the cooling liquid is discharged after passing through the first cooling cavity and the second cooling cavity in sequence;

when the engine is in a third state, valves of the first cooling cavity and the second cooling cavity are opened, so that cooling liquid enters the first cooling cavity and the second cooling cavity and is discharged respectively;

when the engine is in a fourth state, the valve of the second cooling cavity is closed, and the valve of the first cooling cavity is opened, so that the cooling liquid is discharged after passing through the first cooling cavity. .

Further, when the engine is in the third state, the valve opening of the first cooling cavity and the valve opening of the second cooling cavity are adjusted, and the proportion of the cooling liquid flowing out of the first cooling cavity and the second cooling cavity is adjusted.

Further, when the engine is in the first state or the fourth state, the opening of the valve of the first cooling cavity is adjusted, and the flow rate of the cooling liquid in the first cooling cavity is adjusted.

Compared with the prior art, the invention has the advantages and positive effects that:

(1) The cooling structure of the cylinder cover in the running process of the engine solves the problem that the cooling structure of the cylinder cover in the running process of the current engine cannot meet the cooling requirements of different running states of the engine, the liquid outlets are respectively arranged in the two cooling cavities in the cylinder cover and matched with the control valve, the two cooling cavities are communicated and are arranged on one cooling cavity, the liquid outlets are opened and closed through the control valve, the opening degree is adjusted, the adjustment of the flow path of cooling liquid in the cylinder cover is realized, the cooling states of the cooling cavities to different positions of the cylinder cover are changed, and the cooling structure is suitable for the requirements of the engine in different running states.

(2) According to different running states of the engine, the cooling structure can be adjusted to adapt to the cooling mode of the running state of the engine, the cooling liquid is firstly arranged in the first cooling cavity close to the fire surface, the cooling of the fire surface area is preferentially ensured, then according to the running state, the flow path of the cooling liquid in the cylinder cover is adjusted, the influence on the time of hot car during cold start can be reduced, the cooling effect of the cooling structure on the engine under the high-load and ultra-high-load state is improved, and the cooling capacity of the cylinder cover is ensured.

(3) Under different loads, the opening degree of the first valve and the opening degree of the second valve can be controlled to adjust the flow distribution of the cooling liquid in the cooling cavity of the cylinder cover, so that the cooling requirement of the cylinder cover under different working loads of the engine can be met. Finally, the temperature and thermal load change gradient of the cylinder cover under different loads are reduced, and the low cycle fatigue reliability of the cylinder cover is improved.

(4) When the temperature of the cooling liquid is abnormally high and is high to the upper limit, the cylinder cover is cooled in a full-force mode, the cooling capacity of the cylinder cover is improved, and therefore the heat load of the cylinder cover is reduced, and the reliability of the cylinder cover, the cylinder cover gasket and other parts is guaranteed when the temperature of an engine is abnormally high.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention.

Fig. 1 is a schematic diagram of a double-layer cooling water cavity according to the background art and an embodiment of the present invention.

Fig. 2 is a schematic view of another double-layer cooling water cavity according to the background of the invention and an embodiment of the invention.

FIG. 3 is a schematic diagram of a cooling fluid flow path according to the background of the invention and an embodiment of the invention.

Fig. 4 is a schematic diagram of another cooling fluid flow path in the background of the invention and in the embodiment of the invention.

Fig. 5 is a schematic view showing the flow direction of the cooling liquid in the cooling structure according to embodiment 1 to embodiment 4 of the present invention.

Fig. 6 is a schematic view of the coolant flow paths in the cold start state in examples 1 to 4 of the present invention.

Fig. 7 is a schematic view of the coolant flow path in the low load state in examples 1 to 4 of the present invention.

Fig. 8 is a schematic diagram of the coolant flow path in the medium-high load state in examples 1 to 4 of the present invention.

Fig. 9 is a schematic diagram showing the flow paths of the coolant in the case of the overtemperature state in examples 1 to 4 of the present invention.

Fig. 10 is a schematic view of the cylinder head cooling structure in embodiment 1 to embodiment 4 of the present invention.

Fig. 11 is a schematic view showing the arrangement of the control valve in the water outlet flow passage in the embodiments 1 to 4 of the present invention.

Fig. 12 is a schematic view showing the flow of the cooling liquid in the first cooling chamber in examples 1 to 4 of the present invention.

Fig. 13 is a schematic view of the present invention in examples 1 to 4 when both the first valve and the second valve are opened.

Fig. 14 is a schematic view showing the flow of the cooling liquid through the first cooling chamber and the second cooling chamber in this order in examples 1 to 4 of the present invention.

In the figure, a first cooling cavity, a second cooling cavity, a first outlet flow passage, a second outlet flow passage, a first valve, a second valve, a liquid outlet pipe, a second liquid inlet, a cylinder cover base, a double-layer cooling water cavity, a first liquid outlet, a first liquid inlet, a second liquid outlet and a fuel injector nozzle area.

Detailed Description

The existing engine cylinder head cooling method and structure mainly comprises the following steps:

(1) A single-layer cooling water cavity structure. The cylinder cover only comprises a layer of cooling water cavity, and relatively, the cooling water flows and disperses, so that the high-heat load area of the cylinder cover can not be intensively cooled, and the cooling effect is poor.

(2) A double-layer cooling water cavity 10 structure. The cylinder cover comprises two layers of cooling water cavities, so that the cooling of a local high-temperature area is enhanced.

To enhance cylinder head cooling, a double-layer cooling water chamber 10 structure is commonly used in diesel engines, as shown in fig. 1 and 2. The double-layer cooling water cavity 10 is used for cooling the cylinder cover and partitioning the cylinder cover, so that the cooling of the high-temperature area (the cylinder cover bottom plate 9, the area around the exhaust valve seat and the oil nozzle area 14) of the oil sprayer is enhanced, and the heat load of the cylinder cover is reduced. Meanwhile, the cooling structure from bottom to top as shown in fig. 1 and the cooling structure from top to bottom as shown in fig. 2 are divided according to the flow direction of the internal coolant. The internal cooling fluid flow path of the double-layered cooling water chamber 10 structure shown in fig. 1 is shown in fig. 3, and the internal cooling fluid flow path of the double-layered cooling water chamber 10 structure shown in fig. 2 is shown in fig. 4.

However, the single-layer cooling water cavity structure and the double-layer cooling water cavity 10 structure of the prior cylinder cover have certain defects, on one hand, the cylinder cover adopting the single-layer cooling water cavity structure has poor cooling effect and high heat load of the cylinder cover; the cylinder cover adopting the double-layer cooling water cavity 10 structure has high flow resistance of the water cavity of the cylinder cover, so that the cooling fluid flow of the cylinder cover is reduced under the same water pump condition, and the cooling effect of the cylinder cover is affected. On the other hand, the cooling mode is single, no matter the engine is in any working state, the cooling modes of the cylinder covers are the same, the temperature of the cylinder covers is quite low when the engine works under low load, the temperature of the cylinder covers is quite high when the engine works under high load, and the temperature gradient along with the engine load is large. The cooling system cannot be changed according to the cooling requirement of the cylinder head and the cooling system, which is disadvantageous to the reliability of the cylinder head. On the other hand, when the engine is started in a cold mode, the cooling liquid in the water cavity of the whole cylinder head needs to be heated, and the specific heat capacity of the cooling liquid is very large, so that the engine is heated slowly.

Example 1

In an exemplary embodiment of the present invention, a cylinder head cooling structure is provided as shown in fig. 5-14.

Based on the above-described problems, a cylinder head cooling structure is provided in the present embodiment, which is capable of adjusting the cooling state of the cylinder head to adapt to the cooling requirements of the engine in different operating states. In specific implementation, a double-layer cooling cavity is configured in the cylinder head, namely a first cooling cavity 1 close to a fire face and a second cooling cavity 2 close to the top of the cylinder head, wherein the first cooling cavity 1 corresponds to a cylinder head lower water cavity in the drawing, the second cooling cavity 2 corresponds to a cylinder head upper water cavity in the drawing, liquid outlets are respectively designed for the two cooling cavities, and control valves are respectively configured for the liquid outlets to perform independent control, as shown in fig. 5.

The cylinder head cooling structure provided by the present embodiment is described below with reference to the drawings.

Referring to fig. 10, the internal cooling cavity of the cylinder head structurally adopts a double-layer cooling cavity structure, wherein a first cooling cavity 1 is positioned close to a fire face and is positioned at a lower layer position, a second cooling cavity 2 is positioned close to the top of the cylinder head and is positioned at an upper layer position. When the cooling cavity is designed in the cylinder cover, independent liquid outlets are respectively arranged for the first cooling cavity 1 and the second cooling cavity 2.

The first cooling chamber 1 is provided with a first liquid outlet 11 and a first liquid inlet 12 for accessing a cooling liquid source, and the second cooling chamber 2 is provided with a second liquid outlet 13 and a second liquid inlet 8 for communicating with the first cooling chamber 1 (refer to fig. 12). The second cooling chamber 2 takes cooling liquid from within the first cooling chamber 1, and the first cooling chamber 1 takes cooling liquid from a cooling liquid source. And when the engine is in actual operation, the cooling liquid source is a cooling system matched with the engine, and the cooling liquid output by the cooling structure of the cylinder cover is also conveyed to the cooling system for cooling, so that the circulation of the cooling liquid is formed.

In this embodiment, the cooling liquid may be water, a liquid cooling medium such as cooling oil, or the like.

As shown in fig. 10 and 11, the first liquid outlet 11 is connected to the liquid outlet pipe 7 through the first outlet flow passage 3, the first valve 5 is arranged on the first outlet flow passage 3, the second liquid outlet 13 is connected to the liquid outlet pipe 7 through the second outlet flow passage 4, the second valve 6 is arranged on the second outlet flow passage 4, the first liquid inlet 12 is connected to the cooling system through the liquid inlet pipe, the liquid outlet pipe 7 is connected to the cooling system, and both the first valve 5 and the second valve 6 adopt electromagnetic control valves.

It should be noted that, in the above embodiments, the first valve 5 and the second valve 6 are both selected as an exemplary implementation, and are not limited to the above implementation.

The two outlet flow passages are jointly connected into the liquid outlet pipe 7, and a cooling water flow cavity is formed in the outlet flow passages, as shown in fig. 13. The first outlet flow passage 3 is connected with a first liquid outlet 11 of a first cooling cavity 1 in the cylinder cover, the second outlet flow passage 4 is connected with a second liquid outlet 13 of a second cooling cavity 2 in the cylinder cover, and the opening and closing and opening proportion of the two outlet flow passages are controlled by an electromagnetic control valve on a flow path of cooling liquid to the liquid outlet pipe 7, so that the outflow distribution of the cooling liquid in the first cooling cavity 1 and the second cooling cavity 2 in the cylinder cover is controlled, and the adjustment and the switching of the cooling state of the cylinder cover are further realized.

By adjusting the first valve 5 and the second valve 6, the flow path of the cooling liquid in the cylinder head is changed so that the first cooling chamber 1 operates alone or the first cooling chamber 1 and the second cooling chamber 2 operate simultaneously, depending on the specific application.

As shown in fig. 6 and 12, the first cooling chamber 1 is operated alone. By controlling the first valve 5 to be opened and the second valve 6 to be closed, the cooling liquid directly flows out from the first cooling cavity 1 to the first liquid outlet 11 and then enters the water outlet pipe to flow back, which is equivalent to carrying out short-circuit treatment on the second cooling cavity 2 on the upper layer of the cylinder cover. The cooling liquid in the second cooling cavity 2 at the upper layer of the cylinder cover does not temporarily participate in the whole cooling circulation, so that the coverage area of the second cooling cavity 2 cannot excessively absorb heat, the rapid increase of the water temperature and the oil temperature of the engine is facilitated, and the hot-rolling time of the engine is shortened.

By switching the cylinder head cooling structure, the upper water cavity of the cylinder head is short-circuited during cold starting of the engine, so that cooling in the second cooling cavity 2 at the upper layer of the cylinder head is not involved in cooling circulation temporarily, and therefore, heat cannot be absorbed excessively, the water temperature and the oil temperature of the engine are improved rapidly, and the hot-rolling time of the engine is shortened.

Similarly, the first cooling cavity 1 is independently operated and is also suitable for an over-temperature operation state of the engine, as shown in fig. 9 and 12, the first cooling cavity 1 is independently operated, and because the first cooling cavity 1 is arranged close to a fire surface, cooling liquid is fully supplied into the first cooling cavity 1 and does not enter the second cooling cavity 2, at the moment, the flow rate of the cooling liquid passing through the cylinder cover is improved, the flow rate of the cooling liquid is improved, the heat exchange capacity is improved, the cooling capacity of the cylinder cover can be improved to a great extent, and thus the heat load of the cylinder cover is reduced.

When the water temperature is higher than the upper limit, the thermal surface of the cylinder cover is cooled in a full-power mode, the cooling capacity of the cylinder cover is improved, and therefore the heat load of the cylinder cover is reduced. The reliability of the parts such as the cylinder cover, the cylinder cover gasket and the like is ensured when the engine is at abnormal high temperature.

As shown in fig. 7 and 14, the first cooling chamber 1 and the second cooling chamber 2 are operated simultaneously, and the cooling liquid flows through the first cooling chamber 1 and the second cooling chamber 2 in this order. By controlling the first valve 5 to be closed and the second valve 6 to be opened, the cooling liquid enters the first cooling cavity 1 and flows through the first cooling cavity 1 and then enters the second cooling cavity 2, then enters the second outlet flow passage 4 through the second liquid outlet 13 and is discharged to the liquid outlet pipe 7 for backflow. The first cooling chamber 1 at the lower layer of the cylinder head and the second cooling chamber 2 at the upper layer are connected in series. For a scenario where the cylinder head cooling demand is low, such as cooling in a low engine load operating mode, the process is similar to the path of operation of the existing double-layer cooling water chamber described above.

The first cooling cavity 1 is positioned at one side of the cylinder cover, which is close to the cylinder piston, namely one side of the cylinder cover, which is close to the fire surface, and the second cooling cavity 2 is positioned at one side of the cavity cover, which is far away from the cylinder piston; in order to enable the cooling liquid to flow in series in the cylinder cover, the first liquid outlet 11 and the first liquid inlet 12 are positioned at two ends of the first cooling cavity 1, and the second liquid inlet 8 is communicated with one end, close to the first liquid outlet 11, of the first cooling cavity 1.

As shown in fig. 8 and 13, the cooling demand of the cylinder head increases gradually with an increase in the engine load, and in particular, the cooling demand of the thermal surface of the cylinder head increases markedly. The first cooling cavity 1 and the second cooling cavity 2 are operated simultaneously, and the cooling liquid is discharged from the first liquid outlet 11 and the second liquid outlet 13 of the corresponding cooling cavities respectively. By controlling the first valve 5 to be opened and the second valve 6 to be opened, after the cooling liquid enters the first cooling cavity 1 and flows through the first cooling cavity 1, part of the cooling liquid enters the second cooling cavity 2, part of the cooling liquid is directly discharged through the first liquid outlet 11, and the cooling liquid entering the second cooling cavity 2 flows through the second cooling cavity 2 and then is discharged to a water outlet pipe through the second liquid outlet 13 for backflow.

When the cylinder head is under high load, the first valve 5 and the second valve 6 can be kept at a certain opening degree according to the temperature of the cooling liquid, so that the cooling capacity of the cylinder head can be improved to a certain degree.

The first valve 5 and the second valve 6 are control valves with adjustable opening degrees, and the opening degrees of the first valve 5 and the second valve 6 are adjusted to adjust the proportions of the coolant flowing out of the first cooling chamber 1 and the second cooling chamber 2. The water flow distribution of the cooling water cavity of the cylinder head can be adjusted by controlling the first valve 5 and the second valve 6 under different loads so as to meet the cooling requirement of the cylinder head under different working loads of the engine. Finally, the temperature and thermal load change gradient of the cylinder cover under different loads are reduced, and the low cycle fatigue reliability of the cylinder cover is improved.

Example 2

In another exemplary embodiment of the present invention, an engine is provided as shown in fig. 5-14.

The engine in this embodiment utilizes the cylinder head cooling structure as in embodiment 1, the cylinder block top of the engine is provided with the cylinder head cooling structure, and the first liquid inlet 12, the first liquid outlet 11 and the second liquid outlet 13 of the cylinder head cooling structure are connected to the cooling system of the engine, so as to realize circulation of cooling liquid in the cylinder head cooling structure.

It will be appreciated that since the cylinder head cooling structure as in embodiment 1 is mounted on the engine, the advantageous effects caused by this cylinder head cooling structure are seen in embodiment 1 and will not be described here again.

For other structures in the engine that are not mentioned, an existing structure may be adopted.

Example 3

In another exemplary embodiment of the present invention, a vehicle is provided as shown in fig. 5-14.

The vehicle in this embodiment uses the engine as in embodiment 2, and the vehicle mounts the engine and uses the engine as a power system of the vehicle to drive the vehicle.

It will be appreciated that since the engine as in example 1 is mounted on the vehicle, the beneficial effects of the engine are described in example 1 and will not be described in detail.

For other structures in the vehicle that are not mentioned, existing structures may be employed.

Example 4

In another exemplary embodiment of the present invention, as shown in fig. 5-14, a cylinder head cooling method is provided.

At present, the temperature of a cylinder head has large gradient change along with the load of an engine, a cooling system cannot be adjusted according to the cooling requirement of the cylinder head, the reliability of the cylinder head is unfavorable, the cooling requirement of a gas engine in operation is difficult to meet, and aiming at the problem, the cylinder head cooling method is provided in the embodiment. According to the method, the state of a valve corresponding to a cooling cavity is changed according to the running state of an engine, and the flow path of cooling liquid in the cooling cavity is adjusted so that the first cooling cavity 1 runs alone or the first cooling cavity 1 and the second cooling cavity 2 run simultaneously. Two cooling cavities are arranged in the cylinder cover, liquid outlets of the two cooling cavities are respectively provided with a valve, a liquid inlet is arranged on the first cooling cavity 1 close to the fire face, and the second cooling cavity 2 far away from the fire face is communicated with the first cooling cavity. With reference to the accompanying drawings, the cylinder head cooling method comprises the following steps:

acquiring an operation mode of an engine;

when the engine is in a cold start mode, corresponding to a first state, closing a valve of the second cooling cavity 2, and opening a valve of the first cooling cavity 1 to enable cooling liquid to be discharged after passing through the first cooling cavity 1;

when the engine is in a low-load mode, corresponding to a second state, closing a valve of the first cooling cavity 1 and opening a valve of the second cooling cavity 2, so that cooling liquid is discharged after passing through the first cooling cavity 1 and the second cooling cavity 2 in sequence;

when the engine is in a medium-high load mode, corresponding to a third state, opening valves of the first cooling cavity 1 and the second cooling cavity 2 to enable cooling liquid to enter the first cooling cavity 1 and the second cooling cavity 2 and then be discharged respectively;

when the engine is in the over-temperature mode, corresponding to the fourth state, the valve of the second cooling cavity 2 is closed, and the valve of the first cooling cavity 1 is opened, so that the cooling liquid is discharged after passing through the first cooling cavity 1.

In addition, when the engine is in the third state, the valve opening of the first cooling chamber 1 and the valve opening of the second cooling chamber 2 are adjusted, and the ratio of the coolant flowing out of the first cooling chamber 1 and the second cooling chamber 2 is adjusted.

When the engine is in the first state or the fourth state, the valve opening of the first cooling cavity 1 is adjusted, and the flow rate of the cooling liquid in the first cooling cavity 1 is adjusted.

Referring to fig. 5-14, in the cylinder head cooling method, liquid outlets are respectively designed by arranging a first cooling cavity 1 and a second cooling cavity 2 in the cylinder head, the liquid outlet of the first cooling cavity 1 is provided with a first valve 5, the liquid outlet of the second cooling cavity 2 is provided with a second valve 6, and the cooling process is controlled by controlling the first valve 5 and the second valve 6. The first valve 5 and the second valve 6 are connected to a water outlet pipe to discharge the cooling liquid in the cooling chamber. In this embodiment, the cooling liquid may be water, a liquid cooling medium such as cooling oil, or the like.

The double-layer cooling water cavity structure is adopted, and the cooling effect is better than that of a single-layer cooling water cavity cylinder cover.

The cylinder head cooling method includes a plurality of cooling modes corresponding to a plurality of operating conditions when a plurality of engines are running, as shown in table 1.

Table 1 cylinder head cooling mode

Sequence number	Schema name	Solenoid valve control state	Water temperature state
				1	Cold start mode	The first cooling cavity is communicated with a water outlet pipe	Extremely low
2	Low load mode	The second cooling cavity is communicated with a water outlet pipe	Low and low
				3	Medium and high load mode	The first cooling cavity and the second cooling cavity are communicated with a water outlet pipe	High height
4	Overtemperature mode	The first cooling cavity is communicated with a water outlet pipe	Extremely high

1. Cold start mode: the working principle is as shown in fig. 6, when the engine is started at low temperature, the engine needs to be heated, and the water temperature and the engine oil temperature are increased. As shown in fig. 12, the direct outflow of the coolant from the first cooling chamber 1 to the water outlet pipe can be achieved by controlling the first valve 5 and the second valve 6, and the return flow is performed, which corresponds to the "short-circuiting" of the cylinder head second cooling chamber 2. Therefore, the cooling in the second cooling cavity 2 of the cylinder cover does not participate in the cooling circulation temporarily, so that heat cannot be absorbed excessively, the rapid increase of the water temperature and the oil temperature of the engine is facilitated, and the hot-rolling time of the engine is shortened.

2. Low load mode: when the load factor is low after the engine is started. At this time, the cylinder head cooling requirement is low, and the cylinder head cooling mode is changed into a traditional double-layer cooling water cavity structure by controlling the first valve 5 and the second valve 6, as shown in fig. 7 and 14.

3. Medium-high load mode: as engine load increases, cylinder head cooling requirements also increase, particularly cylinder head thermal face cooling requirements increase significantly. At the time of high load in the cylinder head, the two channels for controlling the first valve 5 and the second valve 6 can be respectively kept at a certain opening degree according to the temperature of the cooling liquid, so that the cooling capacity of the cylinder head can be improved to a certain extent. As shown in fig. 8 and 13.

4. Overtemperature mode: when the water temperature is abnormally high and is high to the upper limit, the cylinder cover is easy to overheat, so that the cylinder cover cracks, the cylinder cover gasket sealing failure and other serious problems are caused. At this time, the cylinder head cooling water chamber is switched to the cooling-only fire plate mode (same as the cold start mode) by controlling the first valve 5 and the second valve 6, as shown in fig. 9 and 12. At the moment, the flow rate of the cooling liquid passing through the cylinder cover is improved, the flow rate of the cooling liquid is improved, the heat exchange capacity is improved, and the cooling capacity of the cylinder cover can be improved to a great extent, so that the heat load of the cylinder cover is reduced. The reliability of the parts such as the cylinder cover, the cylinder cover gasket and the like is ensured.

It should be noted that, in this embodiment, the first valve 5 and the second valve 6 are electromagnetic control valves, and may be connected to an ECU of the vehicle, and the working states of the corresponding first cooling chamber 1 and the second cooling chamber 2 are adjusted according to a control command of the ECU, so that they are adapted to the working states of the engine.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The cooling structure of the cylinder head is characterized by comprising a first cooling cavity (1) which is positioned in the cylinder head and is close to a fire surface, and a second cooling cavity (2) which is close to the top of the cylinder head, wherein the first cooling cavity (1) is provided with a first liquid outlet (11) and a first liquid inlet (12) for accessing a cooling liquid source, the second cooling cavity (2) is provided with a second liquid outlet (13) and a second liquid inlet (8) for communicating the first cooling cavity, the first liquid outlet (11) is matched with a first valve (5), and the second liquid outlet (12) is matched with a second valve (6);

by adjusting the first valve (5) and the second valve (6), the flow path of the cooling liquid in the cylinder head is changed so that the first cooling chamber (1) operates alone or the first cooling chamber (1) and the second cooling chamber (2) operate simultaneously.

2. The cylinder head cooling structure according to claim 1, characterized in that the first valve (5) and the second valve (6) are control valves of adjustable opening degrees, and the proportion of the coolant flowing out of the first cooling chamber (1) and the second cooling chamber (2) is adjusted by adjusting the opening degrees of the first valve (5) and the second valve (6).

3. The cylinder head cooling structure according to claim 2, wherein the first liquid outlet (11) and the first liquid inlet (12) are positioned at two ends of the first cooling cavity (1), and the second liquid inlet (8) is communicated with one end of the first cooling cavity (1) close to the first liquid outlet (11).

4. The cylinder head cooling arrangement according to claim 1, characterized in that the first cooling chamber (1) is located in the cylinder head on the side close to the cylinder piston and the second cooling chamber (2) is located in the chamber head on the side remote from the cylinder piston.

5. The cylinder head cooling structure according to claim 4, characterized in that the first liquid outlet (11) is connected to the liquid outlet pipe (7) through the first outlet flow passage (3), the first valve (5) is arranged on the first outlet flow passage (3), the second liquid outlet (13) is connected to the liquid outlet pipe (7) through the second outlet flow passage (4), the second valve (6) is arranged on the second outlet flow passage (4), the first liquid inlet (12) is connected to the cooling system through the liquid inlet pipe, and the liquid outlet pipe (7) is connected to the cooling system.

6. An engine comprising the cylinder head cooling structure according to any one of claims 1 to 5.

7. A vehicle comprising the engine of claim 6.

8. A cylinder head cooling method, characterized by comprising:

two cooling cavities are arranged in the cylinder cover, liquid outlets of the two cooling cavities are respectively provided with a valve, a liquid inlet is arranged on the first cooling cavity (1) close to the fire face, and the second cooling cavity (2) far away from the fire face is communicated with the first cooling cavity (1);

according to the running state of the engine, the corresponding valve state of the cooling cavity is changed, and the flow path of the cooling liquid in the cooling cavity is adjusted so that the first cooling cavity (1) runs independently or the first cooling cavity (1) and the second cooling cavity (2) run simultaneously.

9. The cylinder head cooling method according to claim 8, characterized in that an engine operating state is obtained, and when the engine is in the first state, the valve of the second cooling chamber (2) is closed, the valve of the first cooling chamber (1) is opened, and the cooling liquid is discharged after passing through the first cooling chamber (1);

when the engine is in a second state, the valve of the first cooling cavity (1) is closed, and the valve of the second cooling cavity (2) is opened, so that cooling liquid is discharged after passing through the first cooling cavity (1) and the second cooling cavity (2) in sequence;

when the engine is in a third state, valves of the first cooling cavity (1) and the second cooling cavity (2) are opened, so that cooling liquid enters the first cooling cavity (1) and the second cooling cavity (2) and is discharged respectively;

when the engine is in a fourth state, the valve of the second cooling cavity (2) is closed, and the valve of the first cooling cavity (1) is opened, so that the cooling liquid is discharged after passing through the first cooling cavity (1).

10. The cylinder head cooling method according to claim 9, characterized in that when the engine is in the third state, the valve opening of the first cooling chamber (1) and the valve opening of the second cooling chamber (2) are adjusted, and the ratio of the coolant flowing out of the first cooling chamber (1) and the second cooling chamber (2) is adjusted.

11. The cylinder head cooling method according to claim 9, characterized in that the valve opening of the first cooling chamber (1) is adjusted to adjust the flow rate of the coolant in the first cooling chamber (1) when the engine is in the first state or the fourth state.