JP2006125277A - Cylinder head for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylinder head for an internal combustion engine, capable of adjusting temperature of a combustion chamber wall by adjusting temperature of intake/exhaust valves. <P>SOLUTION: The cylinder head 1 for the internal combustion engine having the intake/exhaust valves 6, 7 for communicating intake/exhaust passages with a combustion chamber 2 is provided with a valve water jacket 8 and a valve heating heater 9 as temperature adjusting devices for adjusting the temperature of the intake/exhaust valves 6, 7. The valve water jacket 8 cools the intake/exhaust valves 6, 7 in which heat is largely delivered to and received from the combustion chamber 2, for example, at the time of high temperature and high load of the internal combustion engine, so as to decline the temperature of the combustion chamber wall. The valve heating heater 9 heats the intake/exhaust valves 6, 7 in which heat is largely delivered to and received from the combustion chamber 2, for example, at the time of cold start of the internal combustion engine, so as to increase the temperature of the combustion chamber wall. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an internal combustion engine, and more particularly to an internal combustion engine that adjusts the temperature of a combustion chamber wall of a cylinder head.

  A cylinder head of a conventional internal combustion engine is formed with a combustion chamber corresponding to each cylinder constituting a cylinder row formed in a cylinder block. The cylinder head is formed with a water jacket through which cooling water passes as a combustion chamber cooling means for cooling the periphery of the combustion chamber. This water jacket is generally formed in the vicinity of the spark plug and the valve seat, respectively, and the cooling water passing through the water jacket is heated around the combustion chamber, that is, from the combustion chamber through the combustion chamber wall. Receiving heat transferred around the combustion chamber, the temperature of the combustion chamber wall is lowered, that is, adjusted.

  Here, in the cylinder head, an intake / exhaust valve that communicates between the intake / exhaust passage and the combustion chamber is disposed so as to freely reciprocate. In this intake / exhaust valve, the intake valve communicates between the intake passage and the combustion chamber, and the exhaust valve communicates between the combustion chamber and the exhaust passage. A part of this intake / exhaust valve is always exposed to the combustion chamber. It will be in the state. Therefore, the heat of the combustion chamber is not only transmitted around the combustion chamber via the combustion chamber wall, but also transmitted around the intake / exhaust valve via the intake / exhaust valve.

  Therefore, as shown in Patent Document 1, there is an intake / exhaust valve (hollow engine valve) that makes it easy to move the heat of the umbrella portion of the intake / exhaust valve toward the valve stem and easily transfers the heat around the intake / exhaust valve. Proposed. The intake / exhaust valve shown in Patent Document 1 includes a hollow portion, and sodium and a getter agent are sealed in the hollow portion. This conventional intake / exhaust valve suppresses a decrease in the thermal conductivity from the umbrella part of the intake / exhaust valve to the valve stem by suppressing a decrease in the purity of sodium sealed in the hollow portion by the getter agent. Is.

Japanese Patent Laid-Open No. 6-10628

  By the way, the area where the umbrella portion of the intake valve is exposed to the combustion chamber occupies most of the surface area (for example, about 60%) of the combustion chamber formed in the cylinder head. Therefore, as a method for adjusting the temperature of the combustion chamber wall, it is also effective to adjust the temperature of the intake and exhaust valves to which the heat of the combustion chamber is transmitted. However, in the conventional internal combustion engine, the temperature of the combustion chamber wall is adjusted by a water jacket, and the heat transmitted to the intake / exhaust valve is only transmitted around the intake / exhaust valve. In other words, the temperature of the combustion chamber wall is not adjusted by positively adjusting the temperature of the intake and exhaust valves.

  The present invention has been made in view of the above, and an object thereof is to provide a cylinder head of an internal combustion engine that can adjust the temperature of the combustion chamber wall by adjusting the temperature of the intake and exhaust valves. Is.

  In order to solve the above-described problems and achieve the object, according to the present invention, the temperature of the intake / exhaust valve is adjusted in a cylinder head of an internal combustion engine having an intake / exhaust valve that communicates the intake / exhaust passage with the combustion chamber. A temperature adjusting device is provided.

  According to the present invention, the temperature adjusting device can positively adjust the temperature of the intake / exhaust valve that transfers heat to and from the combustion chamber and adjust the temperature of the combustion chamber wall. Therefore, the water jacket formed around the conventional combustion chamber sufficiently reduces the temperature of the combustion chamber wall as compared with the case where only the temperature around the combustion chamber where the transfer of heat to and from the combustion chamber is small is adjusted. Can be adjusted.

  According to the present invention, in the cylinder head of the internal combustion engine, the temperature adjusting device includes valve cooling means for cooling the intake / exhaust valve in accordance with an operating state of the internal combustion engine.

  According to the present invention, in the operating state of the internal combustion engine, for example, at a high load, the intake / exhaust valves are actively adjusted by cooling the intake / exhaust valves by the valve cooling means, so that the temperature of the combustion chamber wall is increased. The rise can be suppressed. Accordingly, an increase in the compression end temperature of the mixed gas in the combustion chamber can be suppressed, so that instability of combustion and occurrence of knocking can be suppressed.

  According to the present invention, in the cylinder head of the internal combustion engine, the temperature adjusting device includes valve heating means for heating the intake / exhaust valve in accordance with an operating state of the internal combustion engine.

  According to the present invention, in the operating state of the internal combustion engine, for example, during cold start, the intake / exhaust valve is heated by the valve heating means to positively adjust the temperature of the intake / exhaust valve. The temperature can be raised. Further, since the temperature of the combustion chamber wall is increased via the intake / exhaust valve, even if the cylinder head is formed of a material having a low high-temperature strength (for example, a material containing aluminum), the temperature of the combustion chamber wall is set to a desired temperature. Can be raised. As a result, the startability of the internal combustion engine can be improved.

  According to the present invention, in the cylinder head of the internal combustion engine, the intake / exhaust valve has higher heat conductivity than a valve seat disposed between the combustion chamber and the intake / exhaust valve. .

  According to this invention, the heat in the combustion chamber is more easily transmitted to the intake / exhaust valve than to the cylinder head via the valve seat. In addition, the heat of the intake / exhaust valve becomes difficult to be transmitted around the combustion chamber via the valve seat. Therefore, by positively adjusting the temperature of the intake / exhaust valve, the temperature of the combustion chamber wall is likely to change according to the change in the temperature of the intake / exhaust valve, and the temperature of the combustion chamber wall can be easily adjusted. .

  According to the present invention, in the cylinder head of the internal combustion engine, the intake / exhaust valve includes a hollow portion, and a refrigerant is sealed in the hollow portion.

  According to this invention, the refrigerant having high heat conductivity, for example, sodium or sodium compound is sealed in the intake / exhaust valve. Accordingly, the heat conductivity of the intake / exhaust valve is improved, and the heat transfer in the intake / exhaust valve can be facilitated. Thus, heat can be easily transferred between the combustion chamber and the intake and exhaust valves, and the temperature of the combustion chamber wall can be easily adjusted.

  According to the present invention, in the cylinder head of the internal combustion engine, powder particles are mixed in the refrigerant.

  According to this invention, the granular material moves in the refrigerant by the reciprocating motion of the intake / exhaust valve with respect to the cylinder head. Therefore, forced convection occurs in the refrigerant sealed in the hollow portion of the intake / exhaust valve, and heat transfer in the intake / exhaust valve can be further facilitated. Thus, heat can be easily transferred between the combustion chamber and the intake and exhaust valves, and the temperature of the combustion chamber wall can be adjusted more easily.

  In the cylinder head of the internal combustion engine according to the present invention, the temperature of the combustion chamber wall is adjusted by a temperature adjusting device that adjusts the temperature of the intake and exhaust valves, so that combustion instability and knocking can be suppressed. There is an effect. Moreover, there exists an effect that startability can be improved.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same. Here, the internal combustion engine in the following embodiments includes a gasoline engine, a diesel engine, a hydrogen engine, a natural gas engine, and the like mounted on a vehicle such as a passenger car and a truck.

  FIG. 1 is a diagram showing a configuration example of a cylinder head of an internal combustion engine according to the present invention. FIG. 2 is an enlarged cross-sectional view of a main part of the intake / exhaust valve. As shown in FIG. 1, a cylinder head 1 of an internal combustion engine according to the present invention includes a plurality of combustion chambers 2 (formed in the vertical direction in the drawing in the figure), an intake port 3, an exhaust port 4, and the like. The valve chamber 5, an intake-side intake / exhaust valve 6, an exhaust-side intake / exhaust valve 7, a valve water jacket 8 serving as valve cooling means, and a valve heater 9 serving as valve heating means. Yes. That is, the cylinder head 1 of the internal combustion engine according to the present invention includes the valve water jacket 8 and the valve heater 9 as temperature adjusting devices for adjusting the temperatures of the intake and exhaust valves 6 and 7.

  Reference numeral 10 denotes a water jacket around the spark plug that is formed in the vicinity of the spark plug (not shown) and through which the cooling water flowing into the cylinder head 1 passes. Reference numeral 11 denotes a radiator that allows cooling water, which is a refrigerant, to pass through it and radiates the heat of the cooling water to the outside air. Reference numeral 12 denotes a water pump that operates by the rotational force of a crankshaft (not shown) of the internal combustion engine and circulates coolant, which is a refrigerant, to the cylinder head 1 and a cylinder block (not shown). Reference numeral 13 denotes an ECU (Engine Control Unit) that controls the operation of the internal combustion engine. Reference numeral 14 denotes a flow rate adjusting valve that adjusts the flow rate of the cooling water flowing into the cylinder head 1.

  The combustion chamber 2 is formed on the lower surface 1a of the cylinder head 1 corresponding to each of a plurality of cylinders (not shown) formed in a cylinder block (not shown). Valve seats 15 and 16 are disposed between the combustion chamber 2 and the intake and exhaust valves 6 and 7, respectively.

  The intake port 3 is formed corresponding to each combustion chamber 2, and is formed between an intake path (not shown) and each combustion chamber 2. The intake port 3 communicates from the combustion chamber 2 to one side surface (not shown) of the cylinder head 1 and is connected to, for example, an intake manifold (not shown) of the intake path. That is, air in an intake passage (not shown) is taken into each combustion chamber 2 via the intake port 3.

  The exhaust port 4 is formed corresponding to each combustion chamber 2, and is formed between an exhaust path (not shown) and each combustion chamber 2. The exhaust port 4 communicates from the combustion chamber 2 to the other side surface (not shown) of the cylinder head 1 and is connected to a hold, for example, between exhausts (not shown) of the exhaust path. That is, the exhaust gas exhausted from each combustion chamber 2 to the exhaust port 4 is exhausted to the exhaust path via the exhaust port 4.

  The valve operating chamber 5 is formed in the upper part of the cylinder head 1, and the intake and exhaust valves 6 and 7, an intake camshaft and an exhaust camshaft (not shown) are arranged. Valve guides 17 and 18 corresponding to the intake and exhaust valves 6 and 7 are arranged in the valve chamber 5. The intake / exhaust valves 6 and 7 are supported so as to be reciprocally movable with respect to the valve guides 17 and 18.

  The intake / exhaust valve 6 is an intake / exhaust valve on the intake side, that is, an intake valve. The intake / exhaust valve 6 communicates between an intake path (not shown) and each combustion chamber 2 by reciprocating the valve guide 17. On the other hand, the intake / exhaust valve 7 is an exhaust-side intake / exhaust valve, that is, an exhaust valve, and reciprocates the valve guide 18 to communicate each combustion chamber 2 with an exhaust path (not shown). That is, the intake / exhaust valves 6 and 7 communicate the intake / exhaust path and each combustion chamber 2.

One or more intake / exhaust valves 6 and 7 are arranged for each combustion chamber 2. As shown in FIG. 2 and FIG. 2, the intake / exhaust valves 6 and 7 are constituted by umbrella portions 6a and 7a and valve stems 6b and 7b. Part of the intake / exhaust valves 6, 7, that is, the surfaces 6 f and 7 f of the umbrella parts 6 a and 7 a are always exposed to the combustion chamber 2. The intake and exhaust valves 6 and 7 are formed with hollow portions 6c and 7c. The hollow portions 6c and 7c are filled with a sodium compound having a high heat transfer coefficient, for example, sodium potassium, as the refrigerants 6d and 7d. The amount of the sodium compound enclosed is preferably smaller than the capacity of the hollow portions 6c and 7c so that the sodium compound can move in the hollow portions 6c and 7c by the reciprocating motion of the intake and exhaust valves 6 and 7. . Further, what is enclosed in the hollow portions 6c and 7c is not limited to sodium compounds, and suppresses the decrease in the purity of sodium and this sodium, that is, suppresses the decrease in the heat transfer coefficient of sodium, and the intake and exhaust valves 6, 7 A getter agent (for example, Zr (zirconium), Ti (titanium), Zr ₂ Ni intermetallic compound, etc.) that suppresses the decrease in thermal conductivity in the glass may be enclosed. The getter agent preferably has a hydrogen storage capacity.

  As described above, when the refrigerants 6d and 7d having high heat transfer coefficient, that is, high heat conductivity are enclosed in the intake and exhaust valves 6 and 7, the heat conductivity of the intake and exhaust valves 6 and 7 is improved, and the intake and exhaust valves are thereby improved. Heat transfer at 6 and 7 can be facilitated. Thus, heat can be easily transferred between the intake and exhaust valves 6 and 7 and the combustion chamber 2 and the periphery of the intake and exhaust valves.

  Moreover, the granular materials 6e and 7e are mixed in the refrigerant | coolants 6d and 7d enclosed with these hollow parts 6c and 7c. The granular materials 6e and 7e have a specific gravity heavier than that of the refrigerant, such as ceramic or metal (iron that is the same material as the intake and exhaust valves 6 and 7 that do not react or hardly react with the refrigerant sodium). It is comprised by. Moreover, the granular material 6e, 7e is formed so that the diameter of the largest granular material may become smaller than the diameter in the axial cross section of a hollow part. In addition, it is preferable that the granular materials 6e and 7e are comprised by the granular material of several magnitude | sizes from which a diameter differs.

  Thus, if the granular materials 6e and 7e are mixed in the refrigerants 6d and 7d sealed in the hollow portions 6c and 7c of the intake and exhaust valves 6 and 7, the intake and exhaust valves 6 and 7 reciprocate with respect to the cylinder head 1. By moving, the granular materials 6e and 7e move in the refrigerants 6d and 7d. Therefore, forced convection occurs in the refrigerants 6d and 7d sealed in the hollow portions 6c and 7c of the intake and exhaust valves 6 and 7, and the homogenization of the temperatures of the refrigerants 6d and 7d can be measured. Further, when the powder particles 6e and 7e collide with a wall surface (not shown) of the hollow portions 6c and 7c, the thermal boundary layer of the wall surface collapses, and heat between the intake and exhaust valves 6 and 7 and the refrigerants 6d and 7d is lost. Delivery can be performed easily. As a result, heat transfer in the intake / exhaust valves 6 and 7 can be further facilitated, and heat transfer between the intake / exhaust valves 6 and 7 and the combustion chamber 2 and around the intake / exhaust valves can be further facilitated. It can be carried out.

  The intake and exhaust valves 6 and 7 are formed to have a higher heat transfer coefficient than the valve seats 15 and 16 disposed between the combustion chamber 2 and the intake and exhaust valves 6 and 7. . For example, as the material for forming the intake / exhaust valves 6 and 7, a material having a higher heat transfer rate than the material for forming the valve seats 15 and 16 is used. Specifically, for example, when the intake and exhaust valves 6 and 7 are made of iron, the valve seats 13 and 14 are made of, for example, aluminum or an aluminum alloy.

  As described above, when the heat conductivity of the intake and exhaust valves 6 and 7 is higher than the heat conductivity of the valve seats 15 and 16, the heat in the combustion chamber 2 flows around the valve seats via the valve seats 15 and 16. That is, it is easier to transmit to the intake and exhaust valves 6 and 7 than to the cylinder head 1. Further, the heat of the intake / exhaust valves 6 and 7 becomes difficult to be transmitted around the combustion chamber via the valve seats 15 and 16. Therefore, by positively adjusting the temperatures of the intake and exhaust valves 6 and 7, the temperature of the combustion chamber wall can be easily changed in accordance with the change in the temperature of the intake and exhaust valves 6 and 7.

  In this embodiment, the temperature adjusting device for adjusting the temperature of the intake and exhaust valves 6 and 7 includes a valve water jacket 8 as a valve cooling means and a valve heater 9 as a valve heating means.

  The valve water jacket 8 is a valve cooling means for cooling the intake / exhaust valves 6, 7 according to the operating state of the internal combustion engine, and is provided corresponding to each intake / exhaust valve 6, 7. Here, the valve water jacket 8 is disposed so as to contact the valve guides 17 and 18 that support the valve stems 6b and 7b. In this embodiment, the cooling water in the valve water jacket 8 is arranged so as to be in direct contact with the valve guides 17 and 18. The cooling water flowing into the cylinder head 1 passes through the valve water jacket 8, and when the cooling water passes, the heat of the intake / exhaust valves 6 and 7 is passed through the valve guides 17 and 18 to the cooling water. Then, the intake and exhaust valves 6 and 7 are cooled. Note that the flow rate of the cooling water passing through the valve water jacket 8 is adjusted by the ECU 13 performing valve opening control of the flow rate adjustment valve 14.

  The valve heater 9 is a valve heating means for heating the intake / exhaust valves 6, 7 according to the operating state of the internal combustion engine, and is provided corresponding to each of the intake / exhaust valves 6, 7. Here, the valve heater 9 is disposed so as to contact the valve guides 17 and 18 that support the valve stems 6b and 7b. In this embodiment, the cooling water in the valve heater 9 is arranged so as to be in direct contact with the valve guides 17 and 18. The valve heater 9 transmits heat to the intake / exhaust valves 6 and 7 via the valve guides 17 and 18 so that the intake / exhaust valves 6 and 7 are heated. Here, heating of the intake / exhaust valves 6 and 7 by the valve heater 9 is performed by the ECU 13 controlling power supply to the valve heater 9.

  The ECU 13 is a control device for an internal combustion engine according to the present invention, and controls the operation of the internal combustion engine. The ECU 13 receives various input signals from sensors attached to various parts of a vehicle (not shown) on which the internal combustion engine is mounted. For example, the engine speed detected by an angle sensor attached to a crankshaft (not shown) of the internal combustion engine, the intake air amount detected by an air flow meter attached to an intake passage (not shown), and the accelerator opening detected by an accelerator pedal sensor The temperature of the combustion chamber wall detected by a combustion chamber wall temperature sensor in the vicinity of the combustion chamber 2 or in the combustion chamber 2 is included. The ECU 13 controls the operation of the internal combustion engine based on these input signals and various maps stored in the storage unit. For example, valve opening control of a throttle valve attached to an intake passage (not shown) is performed, injection control of a fuel injection valve (not shown) is performed, flow rate adjustment valve opening control of the flow rate adjustment valve 14 is performed, and the valve heater 9 is controlled. Power supply control.

  Specifically, the ECU 13 stores an input / output port (I / O) for inputting and outputting the input signal and an output signal necessary for controlling the operation of the internal combustion engine, a processing unit, various maps, and the like. And a storage unit. The processing unit includes a memory and a CPU (Central Processing Unit), and implements an operation control method for the internal combustion engine by loading a program based on the operation control for the internal combustion engine into the memory and executing the program. Also good. The storage unit is a non-volatile memory such as a flash memory, a volatile memory such as a ROM (Read Only Memory) or a volatile memory such as a RAM (Random Access Memory) that can be read and written. A memory or a combination thereof can be used.

  Next, a method for adjusting the temperatures of the intake and exhaust valves 6 and 7 using the valve water jacket 8 and the valve heater 9 as temperature adjusting means will be described. The valve water jacket 8 and the valve heater 9 operate according to the operating state of the internal combustion engine.

  First, a method for adjusting the temperatures of the intake and exhaust valves 6 and 7 using the valve water jacket 8 as temperature adjusting means will be described. The flow rate of the cooling water that is the refrigerant flowing into the valve water jacket 8 is adjusted by controlling the flow rate adjustment valve opening degree of the flow rate adjustment valve 14. The storage unit of the ECU 13 has a valve opening map for determining the valve opening of the flow rate adjusting valve 14 based on the engine speed of the internal combustion engine and the load of the internal combustion engine. Therefore, the processing unit of the ECU 13 calculates the valve opening of the flow rate adjustment valve from the input engine speed, the load corresponding to the input accelerator opening or intake air amount, and the valve opening map, The flow rate adjustment valve 14 is controlled to have the calculated valve opening. Basically, as the load on the internal combustion engine increases, the valve opening of the flow rate adjustment valve 14 also increases, increasing the flow rate of the cooling water flowing into the valve water jacket 8, and at the time of high load of the internal combustion engine, The flow rate of the cooling water flowing into the valve water jacket 8 is maximized.

  Here, the passage of the cooling water of the internal combustion engine according to the present invention will be described. As shown in FIG. 1, the flow rate of cooling water, which is a refrigerant discharged from a water pump 12 that is operated by the rotational force of a crankshaft (not shown), is adjusted by a flow rate adjusting valve 14 that is controlled by the ECU 13, and is supplied to the cylinder head 1. Inflow. Specifically, the cooling water discharged from the water pump 12 flows into the intake-side valve water jacket 8 corresponding to the intake-side intake / exhaust valve 6. Heat from the intake / exhaust valve 6 on the intake side is transmitted to the cooling water flowing into the intake side valve water jacket 8 via the valve guide 17. As a result, the intake / exhaust valve 6 on the intake side is cooled, and the temperature of the intake / exhaust valve 6 on the intake side decreases.

  Next, the cooling water that has passed through the valve water jacket 8 on the intake side flows into the water jacket 10 around the spark plug. The cooling water that has flowed into the water jacket 10 around the spark plug transmits heat around a portion of each combustion chamber, particularly around the spark plug (not shown). Thereby, a part around the combustion chamber is cooled, and a temperature of a part of the combustion chamber wall (not shown) is lowered.

  Next, the cooling water that has passed through the water jacket 10 around the spark plug flows into the exhaust-side valve water jacket 8 corresponding to the exhaust-side intake / exhaust valve 7. The cooling water flowing into the exhaust-side valve water jacket 8 is transmitted with heat from the exhaust-side intake / exhaust valve 7 via the valve guide 18. As a result, the exhaust-side intake / exhaust valve 7 is cooled, and the temperature of the exhaust-side intake / exhaust valve 7 decreases.

  The cooling water that has passed through the intake-side valve water jacket 8 and has flowed out of the cylinder head 1 flows into the radiator 11 via a cooling water pipe (not shown). The radiator 11 includes a pipe through which the cooling water passes and a plurality of fins formed around the pipe. Therefore, when the heat of the intake and exhaust valves 6 and 7 and a part of the heat around each combustion chamber are transmitted and heated, the cooling water flowing into the radiator 11 passes through the piping of the radiator 11. The transmitted heat is transmitted to the outside air through the fins, that is, dissipated. That is, the cooling water passing through the radiator 11 is cooled by exchanging heat with the outside air.

  The cooling water cooled by the radiator 11 is sucked into the water pump 12 via a cooling water pipe (not shown). The sucked cooling water flows into the cylinder head 1 again. As described above, the coolant that is the refrigerant circulates in the cylinder head 1.

  As described above, the valve water jacket 8 that is a temperature adjusting device cools the intake and exhaust valves 6 and 7 in the operating state of the internal combustion engine, for example, at a high load, thereby adjusting the temperature of the intake and exhaust valves 6 and 7. Adjust actively. Thereby, the temperature rise of the combustion chamber wall can be suppressed, and the rise of the compression end temperature of the mixed gas in the combustion chamber 2 can be suppressed, so that the instability of combustion and the occurrence of knocking are suppressed. be able to.

  Next, a method for adjusting the temperature of the intake / exhaust valves 6 and 7 by the valve heater 9 as temperature adjusting means will be described. The valve heater 9 generates heat when the ECU 13 controls power supply, that is, when power is supplied to the valve heater 9. The processing unit of the ECU 13 determines the supply of electric power to the valve heater 9 based on the input engine speed and the input temperature of the combustion chamber wall. Basically, the ECU 13 supplies electric power to the valve heater 9 when the operating state of the internal combustion engine is cold starting, for example, when the temperature of the combustion chamber wall is low. The valve heater 9 generates heat when electric power is supplied. The heat of the valve heater 9 is transmitted to the intake and exhaust valves 6 and 7 through the valve guides 17 and 18. Thereby, the intake / exhaust valves 6 and 7 are heated, and the temperature of the intake / exhaust valves 6 and 7 rises.

  As described above, the valve heater 9 which is a temperature adjusting device heats the intake / exhaust valves 6 and 7 in the operating state of the internal combustion engine, for example, during cold start, so that the temperature of the intake / exhaust valves 6 and 7 is increased. Actively adjust. Thereby, the temperature of a combustion chamber wall can be raised. Here, the cylinder head 1 may be formed of a material having low high-temperature strength, for example, a material containing aluminum. In this case, since the high-temperature strength of the cylinder head 1 is low, it is difficult to provide a heater around the combustion chamber. In order to raise the temperature of the combustion chamber wall to a desired temperature, for example, 200 degrees, the temperature around the combustion chamber needs to be 200 degrees or more, and the cylinder head 1 may be deformed or cracked. Because there is. However, since the valve heater 9 raises the temperature of the combustion chamber wall via the intake / exhaust valves 6 and 7 having high high-temperature strength, even if the high-temperature strength of the cylinder head 1 is low, the temperature of the combustion chamber wall is set to the desired temperature. Can be raised. As a result, the startability of the internal combustion engine can be improved.

  As described above, the valve water jacket 8 and the valve heater 9 which are temperature adjusting devices positively adjust the temperatures of the intake and exhaust valves 6 and 7, which transfer large heat to and from the combustion chamber 2, so that the combustion chamber wall The temperature of can be adjusted. Therefore, heat is transferred to and from the combustion chamber 2 by a conventional water jacket formed around the combustion chamber, for example, the water jacket 10 around the spark plug and the water jacket around the valve seat 17, 18. Compared with the case where only the temperature around the small combustion chamber is adjusted, the temperature of the combustion chamber wall can be sufficiently adjusted. Further, as shown in the embodiment, when the valve water jacket 8 is used instead of the conventional water jacket around the valve seat, the heat transfer between the intake / exhaust valves 6 and 7 and the combustion chamber 2 is large. When the water passes at a constant flow rate, the cooling efficiency of the valve water jacket 8 is higher than that of the water jacket around the valve seat. Therefore, the capacity of the valve water jacket 8 can be made smaller than that of the conventional water jacket around the valve seat, and the cylinder head 1 and the internal combustion engine can be downsized.

  In the above embodiment, the temperature of the combustion chamber wall is adjusted by adjusting the flow rate of the cooling water passing through the valve water jacket 8 with the flow rate adjusting valve 14, but the present invention is not limited to this. Without. The temperature of the combustion chamber wall may be adjusted by controlling the operation of a cooling fan that cools the radiator 11 and adjusting the temperature difference between the cooling water passing through the radiator 11 and the outside air.

  In the above embodiment, the spark plug surrounding water jacket 10 is provided to cool a part around the combustion chamber, but the present invention is not limited to this. For example, by only cooling the intake and exhaust valves 6 and 7 with the valve water jacket 8 corresponding to each of the intake and exhaust valves 6 and 7, an increase in the temperature of the combustion chamber wall when the internal combustion engine is at a high load is suppressed. If possible, it is not necessary to provide the water jacket 10 around the spark plug.

  As described above, the cylinder head of the internal combustion engine according to the present invention is useful for the cylinder head of the internal combustion engine that adjusts the temperature of the combustion chamber wall, and in particular, by adjusting the temperature of the intake and exhaust valves, Suitable for adjusting the temperature.

It is a figure which shows the structural example of the cylinder head of the internal combustion engine concerning this invention. It is a principal part expanded sectional view of an intake / exhaust valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder head 2 Combustion chamber 3 Intake port 4 Exhaust port 5 Valve train chamber 6,7 Intake / exhaust valve 6a, 7a Umbrella part 6b, 7b Valve stem 6c, 7c Hollow part 6d, 7d Refrigerant 6e, 7e Powder body 6f, 7f Surface 8 Valve water jacket 9 Valve heater 10 Water jacket around the spark plug 11 Radiator 12 Water pump 13 ECU
14 Flow control valve 15, 16 Valve seat 17, 18 Valve guide

Claims (6)

In a cylinder head of an internal combustion engine having an intake / exhaust valve that communicates between an intake / exhaust path and a combustion chamber,
A cylinder head for an internal combustion engine, comprising a temperature adjusting device for adjusting a temperature of the intake / exhaust valve.   2. The cylinder head of the internal combustion engine according to claim 1, wherein the temperature adjusting device includes valve cooling means for cooling the intake and exhaust valves in accordance with an operating state of the internal combustion engine.   3. The cylinder head of the internal combustion engine according to claim 1, wherein the temperature adjusting device includes a valve heating unit that heats the intake and exhaust valves in accordance with an operating state of the internal combustion engine.   The internal combustion engine according to any one of claims 1 to 3, wherein the intake / exhaust valve has higher heat conductivity than a valve seat disposed between the combustion chamber and the intake / exhaust valve. Engine cylinder head. The intake / exhaust valve includes a hollow portion,
The cylinder head for an internal combustion engine according to any one of claims 1 to 4, wherein a refrigerant is sealed in the hollow portion.   6. A cylinder head for an internal combustion engine according to claim 5, wherein powder particles are mixed in the refrigerant.

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