JP2008121569A - Intake port structure of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake port structure of an internal combustion engine for surely solving the problem that fuel accumulating in a vicinity of a liner member enters into a combustion chamber at a stretch, which results in a rapid fluctuation of an air-fuel ratio. <P>SOLUTION: In the intake port structure of the internal combustion engine in which the sleeve-like liner member 21 is inserted into an intake port part 12 of a cylinder head 11 of the internal combustion engine, and a heat insulating layer 22 surrounding a periphery of the liner member 21 is formed between the liner member 21 and the cylinder head 11, a temperature control means 30 variably controlling temperature of the liner member 21 is provided. The temperature control means 30 is preferably provided with an electric heating member 33 or a heating means using exhaust heat from an exhaust gas recirculation system. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an intake port structure for an internal combustion engine, and more particularly to an intake port structure for an internal combustion engine having a port structure having a heat insulating layer by mounting a sleeve-like liner member on a cylinder head.

  In an internal combustion engine, particularly an engine for a vehicle such as an automobile, a cylinder head is formed with a plurality of ports extending from the opening of its side wall to the intake and exhaust ports of each cylinder. Insulation port structure with sleeve-like liner inserted in the cylinder head port to reduce heat energy from the exhaust system due to overheating of the cylinder head. It has been proposed to reduce the amount of heat transfer from the cylinder head to the intake air to increase the suction efficiency.

  As a port structure of this type of internal combustion engine, for example, as described in Patent Document 1, a ceramic port liner is inserted into a port of a cylinder head manufactured by casting to avoid the influence of heat by casting. In some cases, an air layer surrounding the port liner is formed between the ceramic port liner and the cylinder block.

  In addition, as described in Patent Document 2, a bellows-like flexible liner member is inserted into a port of a cylinder head produced by casting, and a cylindrical port liner is inserted into the inside thereof, so that the heat generated by casting There is a manufacturing method which can cope with a bent port shape while avoiding the influence of the above, and an air layer surrounding the port liner is formed between the port liner and the cylinder block.

Further, as described in Patent Document 3, a port liner and a plurality of guide rings surrounding the port liner are inserted into a port of the cylinder head, and an air layer surrounding the port liner is formed between the port liner and the cylinder block. On the other hand, there is one in which the thermal resistance is increased by using the support portion of the port liner as a line contact.
JP-A-11-229956 Japanese Patent Laid-Open No. 11-229957 JP 2005-256678 A

  However, when the port structure of the conventional internal combustion engine as described above is adopted for the intake port, a gap forming an air layer between the liner member inserted into the intake port portion of the cylinder head and the cylinder head, or the liner member and the intake port. There is a problem that the fuel easily accumulates in the gap portion or the step portion of the joint with the manifold, and the air-fuel ratio of the engine changes abruptly because the fuel is liable in the cylinder.

  That is, the air-fuel ratio, which is the main control parameter of the engine, is ensured from the aspect of ensuring the output performance according to the operating state, the fuel consumption, etc., and also from the aspect of ensuring the performance of the catalyst device used for purifying the exhaust gas. Therefore, if the air-fuel ratio changes abruptly, the operating condition of the engine deteriorates rapidly, causing a problem.

  Therefore, the present invention promotes the atomization of fuel near the liner member, and reliably prevents the problem that the air-fuel ratio fluctuates rapidly due to the fuel collected near the liner member entering the combustion chamber at once. An object of the present invention is to provide an intake port structure for an internal combustion engine.

  In order to achieve the above object, the present invention achieves (1) a sleeve-like liner member inserted into an intake port portion of a cylinder head of an internal combustion engine, and surrounds the periphery of the liner member between the liner member and the cylinder head. In the intake port structure of the internal combustion engine in which the heat insulation layer is formed, a temperature control means for variably controlling the temperature of the liner member is provided.

  With this configuration, it is possible to change the temperature of the liner member that changes according to the operating state and operating environment of the engine so as to promote the atomization of the fuel in the intake port.

  In the intake port structure of the internal combustion engine of the present invention, (2) the temperature control means detects the temperature of the liner member, and the heating means heats the liner member according to the temperature detected by the temperature sensor. It is good to have.

  With this configuration, when the ambient temperature of the liner member decreases, the liner member is heated by the heating means according to the temperature detected by the temperature sensor, and the atomization of the fuel in the intake port is promoted.

  In the intake port structure of the internal combustion engine having the configuration of (2) above, (3) the heating means may include an electric heating member that is attached to the liner member and generates heat when energized. With this configuration, the heating means can be reliably operated when the atomization of the fuel is necessary.

  In this case, it is more preferable that (4) the electric heating member is an electric heating member that is integrally attached to the outer peripheral portion of the liner member. This is because assembly workability and shape stability are good.

  Further, (5) the electric heating member may be constituted by a heating wire attached in a spiral winding state to the outer peripheral portion of the liner member.

  In the intake port structure of the internal combustion engine of the present invention, (6) the sleeve-like liner member has a plurality of protrusions on the outer peripheral side close to the cylinder head, and the heat insulating layer is provided between the cylinder head and the cylinder head. It is good to form the space which comprises.

  With this configuration, the heat insulating layer can be easily configured in the intake port. In addition, the said space can also be sealed by making several protrusion part into the annular part expanded in diameter in the axial direction both ends of the liner member.

  (7) The liner member may be made of a molded resin. The resin here has heat resistance that can sufficiently withstand temperature changes of the cylinder head that houses the liner member, and has low thermal conductivity and linear expansion coefficient. Further, when the intake manifold is molded of resin, the same resin may be used.

  In the intake port structure of the internal combustion engine of the present invention, (8) the internal combustion engine includes an exhaust gas recirculation device that recirculates part of the exhaust gas from the exhaust port side to the intake port side, and the temperature control means includes: The exhaust gas recirculation device may include a port heating exhaust introduction passage portion branched from the exhaust gas recirculation passage and extending close to the liner member.

  With this configuration, it is possible to promote atomization in the intake port using heat from the exhaust gas that is recirculated.

  In this case, (9) the temperature control means includes a temperature sensor that detects the temperature of the liner member, and a heating control valve that opens and closes the heating exhaust introduction passage according to the temperature detected by the temperature sensor. It should be provided.

  With this configuration, even if the temperature of the liner member decreases, the heating control valve opens according to the temperature detected by the temperature sensor, exhaust is introduced into the heating exhaust introduction passage, the vicinity of the liner member is heated, and the inside of the intake port Fuel atomization is promoted. The heating exhaust introduction passage can be formed as a detour that bypasses a part of the exhaust gas recirculation passage of the exhaust gas recirculation device and passes below the intake port. It is not always necessary to communicate with the intake passage side downstream from the branched branch point, and it can be returned to the exhaust passage side again.

  According to the present invention, the temperature of the liner member that changes according to the operating state and operating environment of the engine can be changed so as to promote the atomization of the fuel in the intake port, and the fuel accumulated in the vicinity of the liner member burns all at once. It is possible to provide an intake port structure of an internal combustion engine that can surely prevent the problem that the air-fuel ratio fluctuates rapidly by entering the room.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[First embodiment]
1 to 3 are views showing an intake port structure of an internal combustion engine according to a first embodiment of the present invention.

  First, the configuration will be described.

  In FIG. 1, a cylinder head 11 includes an intake port portion 12 for performing intake to each cylinder of the engine through an intake manifold 15 and an exhaust port portion 13 for performing exhaust from each cylinder of the engine through an exhaust manifold (not shown). And have. The cylinder head 11 is fastened and fixed to an upper portion of an engine cylinder block (not shown). Although not shown in detail, the engine in the present embodiment is a multi-cylinder internal combustion engine mounted on an automobile, and in the same manner as a known one, a combustion chamber partitioned by a piston is formed in each cylinder. The intake valve and the exhaust valve are equipped to be opened at a predetermined timing, and an ignition plug is disposed so as to be exposed in the combustion chamber. A throttle valve is provided upstream of the intake passage 15a formed by the intake manifold 15, and an injector (fuel injection device) for injecting fuel is provided between the intake passage and the combustion chamber of each cylinder. Yes. The fuel is gasoline, for example, but may be ethanol or gas fuel.

  The intake port portion 12 of the cylinder head 11 is a passage that opens on the connection end surface 11 a of the cylinder head 11 to which the intake manifold 15 is connected and communicates with the intake port 11 i on the combustion chamber side. The upstream and intermediate portions of the intake port portion 12 that are within a certain distance L from 11a have the following heat insulating port structure.

  In the cylinder head 11, a sleeve insertion hole 11b having a diameter larger than the inner diameter of the intake passage 15a inside the intake manifold 15 is formed within a certain depth (distance L) from the coupling end surface 11a. The inner bottom surface of 11 b is defined by a stepped portion 11 c of the cylinder head 11. As a result, the sleeve insertion hole 11b has a different diameter with respect to the downstream end portion 12c of the intake port portion 12 with the stepped portion 11c interposed therebetween.

  A substantially cylindrical sleeve-like liner member 21 having the same length as the distance L is inserted into the sleeve insertion hole 11 b of the cylinder head 11, and the liner member 21 has a shaft on the outer peripheral side close to the cylinder head 11. It has a plurality of annular protrusions 21a, 21b, 21c that are spaced apart in the direction. These protrusions 21a to 21c are formed to have a diameter substantially the same as the inner diameter of the sleeve insertion hole 11b, and the liner member 21 is in a zero-fitting state, for example, a predetermined press-fitting state in the sleeve insertion hole 11b of the cylinder head 11. Is inserted. Thus, the inner peripheral surface 21 d of the liner member 21 serves as the inner wall surface of the intake passage that continues from the intake passage 15 a of the intake manifold 15 to the downstream end portion 12 c of the intake port portion 12.

  A pair of cylindrical spaces 22 a and 22 b surrounding the liner member 21 are formed between the liner member 21 and the cylinder head 11, and these spaces 22 a and 22 b protrude around the intake port portion 12. The heat insulation layer 22 formed with the thickness corresponding to the height of the parts 21a-21c is comprised.

  The plurality of projecting portions 21 a, 21 b, and 21 c are annular portions that are expanded in diameter at least at both ends in the axial direction of the liner member 21, and the spaces 22 a and 22 b are formed by fitting both ends of the liner member 21 with the cylinder head 11. It has a function of sealing. In FIG. 1, the cross-sectional shape of each projecting portion 21 a to 21 c is a square, but each may have a tapered shape with a small diameter on the distal end side in the insertion direction, or may have an insertion guide rib extending in the axial direction. The cross-sectional shape of each projecting portion 21a to 21c can be an arbitrary cross-sectional shape such as an arc shape or a substantially triangular shape. The projecting portions 21 a to 21 c are preferably as narrow as possible in contact with the cylinder head 11 in consideration of the sealing property and in a state close to line contact with the cylinder head 11. The protrusions 21a to 21c may be continuous protrusions on the lower side in the vertical direction where fuel accumulation may occur, and may be a plurality of protrusions separated on the upper side. The protruding portion 21b at the center in the axial direction of the liner member 21 may not be annular, and may be formed by a plurality of protrusions that are spaced apart at equal intervals in the circumferential direction.

  The heat insulating layer 22 can contribute to increasing the suction efficiency by suppressing the amount of heat transfer from the cylinder head 11 to the liner member 21 that becomes a high temperature during operation, and can also contribute to suppressing knocking of the engine.

  On the other hand, the intake port portion 12 is provided with temperature control means 30 for variably controlling the temperature of the liner member 21.

  The temperature control means 30 includes a temperature sensor 31 that detects the temperature of the outer peripheral portion of the liner member 21, and a heating means 32 that heats the liner member 21 according to the temperature detected by the temperature sensor 31. The temperature sensor 31 is disposed in any one of the spaces 22a and 22b between the liner member 21 and the cylinder head 11, and temperature information detected by the temperature sensor 31 is taken into the controller 40 which is a part of the engine control computer. It is. The heating means 32 includes a heating wire 33 as a heating member that generates heat when energized, and a current-carrying portion 35 that selectively supplies power to the heating wire 33, and the heating wire 33 is connected to the outer periphery of the liner member 21. It is attached to the part integrally. Note that the temperature sensor 31 can be integrally mounted on the outer peripheral portion of the liner member 21.

  More specifically, the heating wire 33 is, for example, at least one side between the protruding portions 21a and 21b and between the protruding portions 21b and 21c, as shown in FIG. And is integrally formed in the wound state or coated with an insulating layer after being wound and fixed to the liner member 21. Of course, the electric heating member referred to in the present invention is not a linear member, but may be a plate member (planar member) fixed to the outer peripheral surface portion of the liner member 21, and its shape and installation range are arbitrary. However, it is desirable to extend to the lower side in the vertical direction of the intake port portion 12. Further, the electric heating member may be a plurality of electric heating members that partially heat a plurality of portions of the liner member 21, and a part or all of these electric heating members may be selectively energized.

  The energization unit 35 has functions of a transformer and a switch, and is controlled by the controller 40 using the battery 38 as a power source, thereby switching the energization of the heating wire 33 and further variably controlling the energization amount. it can. Note that the drive system by energization is the same as that of a normal electric actuator or electric load, and will not be described in detail here.

  The controller 40 includes a CPU, a ROM, a RAM, and an input / output interface circuit, and includes a program for executing predetermined processing (to be described later), threshold setting data, and the like along with electronic control of the engine.

  On the other hand, the liner member 21 is made of molded resin. The resin referred to here has moldability that can ensure a predetermined shape accuracy by injection molding or the like, heat resistance and strength that can withstand temperature change and vibration after mounting on the intake port portion 12, and The thermal conductivity and linear expansion coefficient are sufficiently small. For example, a material mainly containing a polyamide resin is preferable, and a reinforced resin subjected to fiber reinforcement or the like can also be used. Further, when the intake manifold 15 is molded from resin, the liner member 21 and the intake manifold 15 can be integrally molded from the same resin.

  In FIG. 1, the cylinder head 11 has holes 11f and 11g through which the stem portions of the intake valve and the exhaust valve are slidably inserted. The intake valve and the exhaust valve are not shown in the figure. It is driven in the valve opening / closing direction by a valve operating mechanism. A water jacket 11w is formed near the downstream end 12c of the intake port 12 of the cylinder head 11. Further, the inner diameter d1 of the outer end portion of the liner member 21 is equal to the opening diameter d0 of the intake passage 15a of the intake manifold 15, and the inner diameter d2 of the inner end portion of the liner member 21 is the inner diameter of the downstream end portion 12c of the intake port portion 12. The inner diameters d1 and d2 are set so as to be equal to d3. The inner diameters d1 and d2 may be substantially the same diameter, but may be different diameters. The outer diameter of the liner member 21 may be smaller on the inner end side than on the outer end side of the liner member 21, and the sleeve insertion hole 11b may have a tapered hole shape.

  Next, the operation will be described.

  In the present embodiment configured as described above, the temperature of the liner member 21 that changes according to the operating state and operating environment of the engine is controlled by the controller 40 with the control logic as shown in FIG. A process of changing so as to promote atomization of the fuel is executed.

  That is, in the figure, first, the output of the temperature sensor 31 is taken into the controller 40 (step S11), and the detected temperature is a predetermined threshold value that is the minimum temperature required for atomization of the attached fuel in the intake port portion 12. It is determined whether or not the temperature is equal to or higher than the temperature (step S12), and if the detected temperature of the temperature sensor 31 has not reached the threshold value (NO in step S12), the controller 40 instructs the energization unit 35 to energize. Then, the heating wire 33 having a large electric resistance generates heat when energized (step S13). When the temperature detected by the temperature sensor 31 is equal to or higher than the threshold (YES in step S12), the controller 40 stops energization of the energization unit 35 (step S14). Needless to say, the controller 40 outputs an indicated current value to the energization unit 35 and can control the energized current value of the heating wire 33 in accordance with the indicated current. Moreover, the output which designates the one part heating wire 33 which should be energized among the plurality may be made, and the heating range of the liner member 21 may be adjusted depending on the number of heating wires 33 to be energized.

  Under the control as described above, for example, at the time of cold, a joint portion between the liner member 21 and the downstream end portion 12c of the intake port portion 12 (a joint portion where the liner member 21 and the stepped portion 11c of the cylinder head 11 face each other). Even if the fuel is likely to adhere in the vicinity, if the temperature of the liner member 21 decreases, the controller 40 instructs the energizing section 35 to energize, and the heating wire 33 generates heat, and the intake port section 12 and the stage are heated. Atomization of the fuel near the attachment portion 11c is promoted. Therefore, the problem that the fuel accumulates in the vicinity of the liner member 21 and enters the combustion chamber at once is surely solved.

  Thus, in this embodiment, when the ambient temperature of the liner member 21 falls, the liner member 21 is heated by the heating means 32 according to the temperature detected by the temperature sensor 31, and fuel atomization is ensured. The heating means 32 is activated, and the atomization of the fuel in the intake port portion 12 is promoted.

  Moreover, in this embodiment, since the heating wire 33 is integrally attached to the liner member 21, the assembly workability | operativity of the liner member 21 with a heating wire and the shape stability of the heating wire 33 are favorable.

  The liner member 21 has a plurality of annular protrusions 21a, 21b, and 21c at predetermined intervals in the axial direction, and these are fitted in the sleeve insertion hole 11b of the cylinder head 11 in a zero-fitting state. 11, the annular protrusions 21 a, 21 b, and 21 c have a pair of cylindrical spaces that not only have low thermal conductivity but are almost close to line contact, and surround the liner member 21. Since 22a and 22b are formed, it is difficult to collect fuel in the intake port portion 12, and the heat insulating layer 22 capable of controlling the temperature of the intake port portion 12 near the liner member 21 can be configured.

[Second Embodiment]
4 to 6 are views showing an intake port structure of the internal combustion engine according to the second embodiment of the present invention. Note that the same or equivalent configurations as those of the first embodiment described above will be described using the same reference numerals as those in FIGS. 1 and 2.

  As shown in FIGS. 4 and 5, in the present embodiment, a part of the exhaust gas from the exhaust manifold 16 side connected to the exhaust port portion 13 is recirculated to the intake passage 15 a side in the intake manifold 15 in the present embodiment. A known exhaust gas recirculation device 50 (not shown in detail) is provided. The basic structure of the exhaust gas recirculation device 50 is the same as that of a known device, and although not described in detail, an EGR control valve 52 for controlling the exhaust gas recirculation amount is provided on the exhaust gas recirculation passage 51. Yes. In FIG. 5, the engine 1 has four cylinders 1a, and a known catalyst device 17 for purifying the exhaust gas is provided on the downstream side of the exhaust manifold 16 for collecting exhaust from each cylinder 1a. It has been. The exhaust gas recirculation passage 51 extends from the exhaust passage upstream of the catalyst device 17 to the intake manifold 15.

  In this embodiment, the temperature control means 30 for variably controlling the temperature of the liner member 21 in the intake port portion 12 branches from the temperature sensor 31 and the exhaust gas recirculation passage 51 of the exhaust gas recirculation device 50, and the liner member. 21 includes a port heating exhaust introduction passage portion 53 extending so as to be close to 21, and a heating control valve 55 that opens and closes the port heating exhaust introduction passage portion 53 in accordance with the temperature detected by the temperature sensor 31. Yes.

  A portion of the port heating exhaust introduction passage portion 53 downstream from the branch point branched from the exhaust gas recirculation passage 51 may communicate with the intake passage side (for example, a surge tank), but facilitates EGR control. Therefore, it is possible to provide a route for returning to the exhaust passage side again. When the exhaust gas recirculation passage 51 is bypassed and the heating exhaust gas introduction passage portion 53 is formed as a bypass that passes through the lower side in the vertical direction of the intake port portion 12, the heating exhaust gas introduction passage portion 53 is also recirculated. Although it becomes a part of the exhaust gas recirculation passage of the circulation device 50, the port heating exhaust introduction passage portion 53 can be closed by the heating control valve 55 when the temperature of the intake port portion 12 near the liner member 21 rises. It is desirable to do so.

  The heating control valve 55 has a function of opening and closing the inlet of the port heating exhaust introduction passage portion 53, and is controlled by the controller 40 using the battery 38 as a power source. The valve opening degree can be adjusted so as to switch the presence / absence of exhaust introduction and to variably control the flow rate. The control of the exhaust gas recirculation amount by the control valve itself is the same as in the case of normal EGR control, and will not be described in detail here.

  As described above, the controller 40 includes a CPU, a ROM, a RAM, and an input / output interface circuit. The controller 40 executes a predetermined heating exhaust introduction process (to be described later) together with electronic control of the engine 1 or a threshold value or Equipped with tabular map data.

  The controller 40 controls the heating amount of the intake port portion 12 by the exhaust gas passing through the port heating exhaust introduction passage portion 53 by the heating control valve 55 together with the predetermined EGR control.

  Specifically, the controller 40 promotes atomization of the fuel in the intake port portion 12 by controlling the temperature of the liner member 21 that changes according to the operating state and operating environment of the engine, for example, as shown in FIG. The exhaust gas introduction process for heating to be changed is executed.

  That is, in the figure, first, the output of the temperature sensor 31 is taken into the controller 40 (step S21), and the opening degree of the heating control valve 55 is atomized with respect to the detected temperature of the adhering fuel in the intake port portion 12. Is determined based on the map data as shown in FIG. 7 (step S22). In the heating control map shown in FIG. 7, when the temperature detected by the temperature sensor 31 reaches a predetermined temperature, the valve opening is reduced so as to reduce the heating exhaust introduction amount at a temperature higher than that.

  Here, if the relationship between the detected temperature and the valve opening does not match the map (NO in step S22), the detected temperature of the temperature sensor 31 based on the table data in the controller 40 corresponding to the map shown in FIG. The opening degree of the heating control valve 55 is adjusted so as to be an optimum amount of heating exhaust introduced according to the above, and the amount of heating to the vicinity of the liner member 21 by the exhaust is controlled (step S23).

  On the other hand, when the relationship between the detected temperature and the valve opening matches the map (YES in step S22), the opening of the heating control valve 55 is maintained, and the amount of heating to the vicinity of the liner member 21 by the exhaust is maintained. (Step S24).

  Under such control, even if the fuel is likely to adhere to the vicinity of the joint portion between the liner member 21 and the downstream end portion 12c of the intake port portion 12 under cold conditions, for example, the temperature of the liner member 21 is When it decreases, the opening degree of the heating control valve 55 is increased by the controller 40, the flow rate of the hot exhaust gas passing through the lower side of the intake port portion 12 is increased, and the heating amount to the vicinity of the liner member 21 is increased. The atomization of the fuel in the intake port portion 12 is further promoted. Therefore, the problem that the fuel accumulated in the vicinity of the liner member 21 enters the combustion chamber all at once and the air-fuel ratio of the engine fluctuates rapidly is surely solved.

  As described above, in this embodiment, the liner member 21 is heated by the heating means 32 including the port heating exhaust introduction passage portion 53 and the heating control valve 55 in accordance with the temperature detected by the temperature sensor 31, and fuel atomization is required. At any time, the heating means 32 is reliably operated, and the atomization of the fuel in the intake port portion 12 is promoted by utilizing the heat from the recirculated exhaust gas.

  In the present embodiment, when the ambient temperature of the liner member 21 decreases, the heating control valve 55 opens according to the temperature detected by the temperature sensor 31, and the liner member 21 is heated by the heat from the recirculated exhaust gas. Therefore, the power consumption from the battery can be reduced as compared with the case where a heating wire is used.

  As described above, according to the present invention, the temperature of the liner member that changes according to the operating state and operating environment of the engine can be changed so as to promote the atomization of the fuel in the intake port, and accumulated in the vicinity of the liner member. It is possible to provide an intake port structure of an internal combustion engine that can surely prevent the problem that the air-fuel ratio fluctuates suddenly when fuel enters the combustion chamber at once. A sleeve-like liner member is provided on the cylinder head. It is useful for the entire intake port structure of an internal combustion engine with a heat insulation layer structure.

1 is a block configuration diagram including an essential part cross-sectional view showing an intake port structure of an internal combustion engine according to a first embodiment of the present invention. It is a perspective view which shows the mounting state to the liner member of the electric heating member in the intake port structure of the internal combustion engine which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the electricity supply control procedure of the electrothermal member in the intake port structure of the internal combustion engine which concerns on the 1st Embodiment of this invention. It is a block block diagram including the principal part sectional drawing which shows the intake port structure of the internal combustion engine which concerns on the 2nd Embodiment of this invention. It is the principal part schematic plan view which shows the intake port structure of the internal combustion engine which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows the heating control procedure of the heating means in the intake port structure of the internal combustion engine which concerns on the 2nd Embodiment of this invention. It is explanatory drawing of the map used for the heating control of the heating means in the intake port structure of the internal combustion engine which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Cylinder head 11a Connection end surface 11b Sleeve insertion hole 11c Stepped part 12 Intake port part 12c Downstream end part 13 Exhaust port part 15 Intake manifold 15a Intake passage 21 Liner member 21a, 21b, 21c Protrusion part 22 Thermal insulation layer 22a, 22b Space 30 Temperature control means 31 Temperature sensor 32 Heating means 33 Heating wire (electric heating member)
35 Current-carrying part 38 Battery 40 Controller 50 Exhaust gas recirculation device 51 Exhaust gas recirculation passage 52 EGR control valve 53 Port heating exhaust introduction passage part 55 Heating control valve

Claims (9)

In an internal combustion engine intake port structure in which a sleeve-like liner member is inserted into an intake port portion of a cylinder head of an internal combustion engine, and a heat insulating layer surrounding the liner member is formed between the liner member and the cylinder head.
An intake port structure for an internal combustion engine, comprising temperature control means for variably controlling the temperature of the liner member.   The said temperature control means has a temperature sensor which detects the temperature of the said liner member, and a heating means which heats the said liner member according to the detection temperature of the said temperature sensor, The Claim 1 characterized by the above-mentioned. Intake port structure of an internal combustion engine.   The intake port structure for an internal combustion engine according to claim 2, wherein the heating means includes an electric heating member attached to the liner member and generating heat when energized.   The intake port structure for an internal combustion engine according to claim 2, wherein the electric heating member is constituted by an electric heating member integrally attached to an outer peripheral portion of the liner member.   The intake port structure for an internal combustion engine according to claim 4, wherein the electric heating member is constituted by an electric heating wire mounted in a spirally wound state on an outer peripheral portion of the liner member.   The sleeve-shaped liner member has a plurality of protrusions on an outer peripheral side close to the cylinder head, and forms a space constituting the heat insulating layer between the cylinder head and the cylinder head. Item 2. An intake port structure for an internal combustion engine according to Item 1.   The intake port structure for an internal combustion engine according to claim 1, wherein the liner member is made of molded resin. The internal combustion engine includes an exhaust gas recirculation device that recirculates part of the exhaust gas from the exhaust port side to the intake port side,
The temperature control means includes a port heating exhaust introduction passage portion that branches from the exhaust gas recirculation passage of the exhaust gas recirculation device and extends so as to be close to the liner member. An intake port structure for an internal combustion engine according to claim 1. A temperature sensor for detecting the temperature of the liner member;
The intake port structure for an internal combustion engine according to claim 8, further comprising a heating control valve that opens and closes the heating exhaust introduction passage according to a temperature detected by the temperature sensor.

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