EP0809012A2 - Dispositif de recirculation de gaz d'échappement - Google Patents

Dispositif de recirculation de gaz d'échappement Download PDF

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Publication number
EP0809012A2
EP0809012A2 EP97107793A EP97107793A EP0809012A2 EP 0809012 A2 EP0809012 A2 EP 0809012A2 EP 97107793 A EP97107793 A EP 97107793A EP 97107793 A EP97107793 A EP 97107793A EP 0809012 A2 EP0809012 A2 EP 0809012A2
Authority
EP
European Patent Office
Prior art keywords
recirculated gas
passage
recirculated
intake
exhaust gas
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP97107793A
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German (de)
English (en)
Other versions
EP0809012B1 (fr
EP0809012A3 (fr
Inventor
Fuminori Suzuki
Shigeiku Enomoto
Yukihiko Takeuchi
Hidetoshi Ooiwa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Denso Corp
Soken Inc
Original Assignee
Denso Corp
Nippon Soken Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP9030304A external-priority patent/JPH1030504A/ja
Application filed by Denso Corp, Nippon Soken Inc filed Critical Denso Corp
Publication of EP0809012A2 publication Critical patent/EP0809012A2/fr
Publication of EP0809012A3 publication Critical patent/EP0809012A3/fr
Application granted granted Critical
Publication of EP0809012B1 publication Critical patent/EP0809012B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
    • F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
    • F02M25/0872—Details of the fuel vapour pipes or conduits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/17—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the intake system
    • F02M26/21—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the intake system with EGR valves located at or near the connection to the intake system
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/50—Arrangements or methods for preventing or reducing deposits, corrosion or wear caused by impurities
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/17—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the intake system
    • F02M26/19—Means for improving the mixing of air and recirculated exhaust gases, e.g. venturis or multiple openings to the intake system

Definitions

  • the present invention relates to an exhaust gas recirculation device provided in an internal combustion engine.
  • valve diameter of the recirculated gas control valve it is necessary to make the valve diameter of the recirculated gas control valve large, but in the conventional exhaust gas recirculation device as mentioned above, if the valve diameter of the recirculated gas control valve is enlarged and the flow rate of the recirculated gas is increased, there arises a problem that an actuator comprising a diaphragm or stepping motor or the like for opening or closing the recirculated gas control valve will be damaged due to the heat of the recirculated gas.
  • the inflowing port of the recirculated gas to the intake passage and the valve body of the recirculated gas control valve are provided at bottom portions of the intake pipe, the actuator is provided at an upper portion of the intake pipe, the two are connected by a long valve stem, and the valve stem is cooled by intake air (fresh air) of a relatively low temperature flowing through the intake passage so as prevent the heat of the recirculated gas received by the valve body from being directly transferred to the actuator as thereby preventing actuator damage (for example, refer to Japanese Unexamined Patent Publication (Kokai) No. 60-243359).
  • An object of the present invention is to provide an exhaust gas recirculation device which deals with problems mentioned above in the related art and which uses a new configuration to enable the recirculated gas can be smoothly fed into the engine.
  • Another object thereof is to provide an enhanced exhaust gas recirculation device with which the deposits can be prevented from being adhered around the throttle valve due to the back flow of the recirculated gas.
  • Still another object of the present invention is to provide an exhaust gas recirculation device with which the recirculated gas can be smoothly fed into the engine without trouble such as deposits being produced near the recirculated gas inflowing port at which the recirculated gas control valve is provided and the inflowing port being clogged or the valve body sticking to the valve seat portion.
  • the present invention provides exhaust gas recirculation devices as disclosed in the claims as means for achieving the above objects.
  • the recirculated gas inflowing port is opened in the forward flow area of the intake air flowing in the intake pipe from the upstream side to the downstream side at the downstream side part of the throttle valve provided in the intake pipe, therefore the recirculated gas flowing into the intake pipe from the recirculated gas inflowing port smoothly flows to the downstream side while riding the forward flow of the intake air so as to be fed into the engine again, so it is possible to avoid the recirculated gas flowing back in the intake pipe and reaching the throttle valve to cause the buildup of deposits.
  • one end of a bent passage means is connected to an end of the recirculated gas introduction passage, the internal portion thereof is defined as the recirculated gas guide passage and, at the same time, the other end thereof is defined as the recirculated gas inflowing port and opened toward the downstream side at the forward flow area of the flow of the intake air in the intake pipe, therefore, regardless of the positions of disposition of the recirculated gas introduction passage and recirculated gas control valve, the recirculated gas inflowing port can be opened in the forward flow area of the flow of the intake air at the downstream side of the throttle valve and, at the same time, the recirculated gas is smoothly guided to the opening thereof and can be discharged toward the downstream side of the flow of the intake air. Accordingly, the recirculated gas does not enter into the back flow area but flows into the forward flow area and flows to the downstream side, therefore it is possible to reliably prevent deposits from building up at the throttle valve.
  • a prevention wall for preventing the intrusion of the blow-by gas etc. as much as possible is formed at the upper portion of the intake passage at which the adhesion of the oil components in the blow-by gas is most difficult in the intake pipe and, at the same time, the valve seat portion of the recirculated gas control valve is provided in that prevention wall, thereby solving the problems possessed by the related art mentioned above.
  • the exhaust gas recirculation device of the present invention by providing the valve seat portion of the recirculated gas control valve at a position of the upper portion of the intake passage and, at the same time, providing the partition wall extending toward the downstream side so as to provide a space between the valve seat portion and the intake passage, the recirculated gas introduction port, which opens toward the downstream side when seen from the valve seat portion, is formed in the upper portion of the intake passage.
  • the recirculated gas passing through the valve gap of the valve seat portion passes through the recirculated gas introduction port and flows toward the downstream side where it merges with the intake air flowing in the intake passage and is taken into the engine to perform a purification action of the exhaust gas.
  • Figure 1 and Fig. 2 show an example of an internal combustion engine 2 provided with an exhaust gas recirculation device 1 as a first embodiment of the present invention.
  • Figure 1 is a front view showing a cylinder block 9 of a multi-cylinder engine 2 from the front of a not illustrated crankshaft; while Fig. 2 is a plan view showing this from above.
  • a throttle valve 3 of the engine 2 and a recirculated gas control valve 4 forming the principal element of the exhaust gas recirculation device 1 are successively attached at a predetermined interval in an intake pipe 5 in a direction (direction indicated by an arrow) in which the intake air, that is, an intaken fresh air (indicated as FA in the figure) flows.
  • FA intaken fresh air
  • the throttle valve 3 is provided as a variable opening valve at an appropriate position in the intake pipe 5 so as to adjust the flow rate of the intake air flowing in the intake pipe 5, while the recirculated gas control valve 4 is inserted as a variable opening valve at an appropriate position of the recirculated gas introduction passage 8 so as to adjust the flow rate of the recirculated gas (indicated as RG in the figure, with the gas exhausted to the outside being conversely indicated as EG) for taking out part of the exhaust gas from the exhaust manifold 6 side and refluxing the same into the intake air flowing in the intake pipe 5 at the intake manifold 7 side.
  • the first embodiment is an example showing a case where the recirculated gas control valve 4 is directly attached to the pipe wall of the intake pipe 5.
  • a blow-by gas introduction passage 10 which introduces the blow-by gas (the blow-by gas is indicated as BG in the figure) accumulated in a crank case or cylinder head cover of the engine 2 into the intake pipe 5 for processing is opened in the pipe wall of the intake pipe 5 on the upstream side of the throttle valve 3.
  • the characteristic feature of the present invention basically resides in that the recirculated gas inflowing port 11 is opened in the forward flow area of the intake air.
  • the shape of a curve B indicating the border of the forward flow area and the back flow area in the lateral cross sectional view is not a circular shape following the pipe wall of the intake pipe 5 in Fig. 4 indicating the lateral cross section of the intake pipe 5, but becomes a flat long oval shape due to the influence of the valve stem 12 of the throttle valve 3.
  • a phenomenon where the thickness of the forward flow area in the radial direction becomes the smallest at the part where the valve stem 12 intersects the pipe wall of the intake pipe 5 and becomes the largest at the part near a straight line R-R orthogonal to the valve stem 12 was found. Accordingly, one of the concrete characteristic features in the first embodiment resides in that, as shown in Fig.
  • the opening of the recirculated gas introduction passage 8, that is, the recirculated gas inflowing port 11, is provided particularly at the lower position of the pipe wall intersecting the straight line R-R in the forward flow area at the downstream side of the throttle valve 3.
  • the position suitable for providing the recirculated gas inflowing port 11 corresponds to the downstream side of the position where the throttle valve 3 opens earliest when it starts to open from the closed state.
  • Fig. 22 showing the related art, for example, in a four-cylinder internal combustion engine 2, the intake pipe 5 is extended in a right angle direction with respect to the direction of arrangement of the serially arranged four cylinders #1 to #4, but in order to make the distribution of the intake air to the combustion chambers 14 of the cylinders uniform, it is necessary to provide the valve stem 12 of the butterfly type throttle valve 3 parallel to the direction of arrangement of the cylinders.
  • the recirculated gas introduction passage 8 extending from one part of the exhaust manifold 6 to the intake pipe 5 side is guided to the opposite side of the cylinder block 9 at substantially the same height as that of the intake pipe 5, therefore due to the necessity of making the length of the passage 8 the shortest, the recirculated gas inflowing port 11 is provided in the plane containing the valve stem 12 of the throttle valve 3.
  • the thickness of the forward flow area of the intake air has become small as shown in Fig. 4, and the back flow area of the intake air extends to the considerably downstream side. Accordingly, as shown in Fig. 5, in the case of the conventional example where the recirculated gas inflowing port 11 is provided in the plane containing the valve stem 12, the inflowing port 11 will be opened in the back flow area of the intake air.
  • the recirculated gas inflowing port 11 When the recirculated gas inflowing port 11 is opened in the back flow area of the intake air of the intake pipe 5 as in the conventional example shown in Fig. 5, the recirculated gas flowing from the inflowing port 11 into the intake pipe 5 reaches the throttle valve 3 while riding the flow flowing back from the downstream side of the intake pipe 5 toward the upstream side and buildup of deposits on the throttle valve 3 occurs, but if the recirculated gas inflowing port 11 is provided in the forward flow area of the intake air as in the first embodiment of the present invention shown in Fig. 6, the inflowing recirculated gas flows to the downstream side from the inflowing port 11 while ridingthe forward flow of the intake air, so the buildup of deposits on the throttle valve 3 can be prevented.
  • the inflowing port 11 is provided at the position where the thickness of the forward flow area becomes the largest, that is, the valve stem 15 of the poppet type recirculated gas control valve is provided on a straight line at right angles relative to the valve stem 12, therefore the best effect is obtained.
  • the inflowing port 11 exists in the forward flow area of the intake air, substantially the same effect is obtained.
  • FIG. 7 A second embodiment of the present invention is shown in Fig. 7. If the recirculated gas inflowing port 11 is opened in the forward flow area of the intake air on the downstream side of the throttle valve 3 in this way, even if the recirculated gas control valve 4 is provided at the middle of the recirculated gas introduction passage 8 as exemplified in Fig. 7, a similar effect to that of the case of the first embodiment is obtained.
  • FIG. 8 An undesirable conventional example is shown in Fig. 8.
  • the valve stem 12 of the throttle valve 3 is provided in a direction at right angles with respect to the direction of arrangement of the cylinders #1 to #4 of the engine 2, therefore the distribution of the intake air to the cylinders is no longer uniformly carried out. If the recirculated gas inflowing port 11 is opened on the downstream side at the position where the valve stem 12 intersects with the pipe wall of the intake pipe 5, it will cause the flow of the recirculated gas into the back flow area of the intake air, therefore there arises the problem of buildup of deposits at the throttle valve 3. Contrary to this, in the second embodiment of the present invention shown in Fig. 7, these problems are simultaneously solved by merely aligning the valve stem 12 of the throttle valve 3 in Fig. 8 in direction with the direction of arrangement of the cylinders.
  • Figure 9A shows a similar configuration to that shown in Fig. 8, in which the valve stem 12 of the butterfly type throttle valve 3 is arranged in the direction at right angles with respect to the direction of arrangement of the plurality of cylinders.
  • Figure 10A compared with this shows a configuration of the present invention similar to that shown in Fig. 7, in which the direction of arrangement of the plurality of cylinders and the direction of the valve stem 12 of the throttle valve 3 coincide.
  • the characteristic feature resides in that the valve stem 15 of the recirculated gas control valve 4 is supported in parallel to the valve stem 12 of the throttle valve 3 and, at the same time, the position of the former is set at a position separate from the position of the latter by exactly the required distance, whereby the valve stem 15 and the valve seat 16 of the recirculated gas control valve 4 are offset at the outside of the pipe wall of the intake pipe 5.
  • a recirculated gas directing passage 17 is mounted on the pipe wall of the intake pipe 5, and the valve seat 16 is connected to the recirculated gas inflowing port 11.
  • an inclined surface (indicated as 18) is provided so as to enable the recirculated gas to easily ride on the forward flow of the intake air.
  • the recirculated gas guide passage 18 having the inclined surface 18 inclined toward the forward flow area of the intake air was provided, even if the valve stem 12 of the throttle valve 3 and the valve stem 15 of the recirculated gas control valve are provided close to each other in the direction of the intake pipe 5, the back flow of the recirculated gas to the throttle valve 3 can be prevented. Further, if the partition flange 19 as shown in Fig. 12 and Fig.
  • the flow rate of the forward flow of the intake air (mixture of the fresh air and blow-by gas) in the inflowing port 11 can be raised in comparison with a case where the partition flange 19 is not provided, therefore the recirculated gas can easily ride on the forward flow and the back flow of the recirculated gas to the throttle valve 3 can be further effectively hindered.
  • the recirculated gas directing passage 17 is provided with the inclined surface 18 inclined toward the downstream side of the intake pipe 5, the recirculated gas gradually smoothly flows out into the intake air flow and diffuses uniformly, therefore the distribution of the recirculated gas with respect to the cylinders is uniformly carried out, occurrence of a variation in the output of the different cylinders can be prevented, and the speed of the engine at the time of a low load operation becomes smoother than in the conventional case.
  • valve stem 12 of the throttle valve 3 and the valve stem 15 of the recirculated gas control valve 4 are arranged in parallel and the distance between the valve stems 12 and 15 in the direction of the intake pipe 5 is made small, it becomes possible to shorten the length of the intake pipe 5 near the throttle valve 3, and consequently the entire engine can be made smaller in size. By this, the response of acceleration is improved.
  • the area of the flow path of the recirculated gas inflowing port 11 opened to the intake pipe 5 is made larger than the valve seat 16 of the recirculated gas control valve 4, and, for example, as in the fourth embodiment shown in Fig. 16, a fan-shaped gas inflowing port 20, the flow rate of the recirculated gas into the intake pipe 5 is lowered and, at the same time, the recirculated gas can flow into the flow of the intake air (mixture of the fresh air and blow-by gas) while being dispersed, therefore it becomes further easier for the recirculated gas having a lowered density to ride on the forward flow of the intake air, and the back flow to the throttle valve 3 can be prevented.
  • the position of the upper portion of the throttle valve 3 provided with the recirculated gas inflowing port 11 is downstream of the position at which the throttle valve 3 opens earliest when it starts to gradually open from the closed state. Accordingly, the recirculated gas flowing into the intake pipe 5 from the recirculated gas inflowing port 11 is mixed well with the intake air even if the degree of opening of the throttle valve 37 is small. Then, when the recirculated gas is shut off, the influence of the recirculated gas quickly disappears at the downstream side of the throttle valve 3, therefore the response with respect to the opening and closing of the recirculated gas control valve 4 becomes high. Also in this case, there is a large effect that the intrusion of the blow-by gas into the recirculated gas control valve 4 can be hindered by providing the recirculated gas directing passage 17 provided with the partition flange 19 and the inclined surface 18.
  • the throttle valve 3 can be made placed closer to the cylinder block 9 than that in the other embodiments, therefore, when the recirculated gas control valve 4 is opened for acceleration, the volume of the intake pipe 5 containing the intake manifold 7 on the downstream side from this is smaller than that of the case where the throttle valve 3 and the recirculated gas control valve 4 are provided at the more upstream position, therefore the amount of the recirculated gas remaining in the intake pipe 5 is small, and thus the acceleration response of the engine 2 becomes high and, at the same time, it becomes possible to make the exhaust gas recirculation device 1 compact in size.
  • the point that the recirculated gas directing passage 17 and the recirculated gas inflowing port 11 are provided in the intake manifold 7 for this purpose is different from the fifth embodiment, but substantially the same mode of operation and effect are obtained.
  • Both of the fifth embodiment and the sixth embodiment have the recirculated gas directing passage 17 provided with the inclined surface 18 as shown in Fig. 17 and Fig. 20, therefore, similar to the above embodiments, the distribution of the recirculated gas with respect to the cylinders of the engine becomes more uniform, the variation of output of the different cylinders becomes small, the speed becomes stable in the time of a low load operation, etc.
  • a seventh embodiment of the present invention is shown in Fig. 23 to Fig. 25.
  • a common characteristic feature of the seventh embodiment with an eighth embodiment (Fig. 26) and ninth embodiment (Fig. 27) mentioned later resides in that an elbow-shaped bent pipe 24 is provided so as to be connected to the end of the recirculated gas introduction passage 8, the recirculated gas directing passage 17 is formed inside the bent pipe 24 and, at the same time, the opening of the other end of the bent pipe 24 is defined as the recirculated gas inflowing port 11 opening toward the downstream side of the intake pipe 5, whereby the recirculated gas inflowing port 11 of this bent pipe 24 is opened at a relatively downstream part of the flow of the intake air in the forward flow area of the intake air formed in the intake pipe 5.
  • bent pipes 24 are shaped as elbows, but the pipes used as the bent recirculated gas guide passage in the present invention are not always formed by just elbow-shaped bent pipes 24 and be any bent pipes 24 so far as the bent recirculated gas directing passage 17 is formed and the recirculated gas flowing inside this is guided to the forward flow area at the relatively downstream side of the intake pipe 5 and, at the same time, they can discharge the recirculated gas toward the downstream side of the flow of the intake air in the opening of the other end. Therefore the bent pipe 24 should be generally read as a bent passage means .
  • the flow rate of the fresh air in the intake pipe 5 becomes low, but in contrast, the flow rate of the recirculated gas flowing out of the inflowing port 11 becomes high, therefore there is a case where the recirculated gas penetrates through the forward flow area of the fresh air and flows into the back flow area. In such a case, similar to the related art, the recirculated gas will flow back, although the amount thereof is small, and a deposit will sometimes be produced in the throttle valve 3, etc.
  • the recirculated gas flowing in the introduction passage 8 passes the valve seat 16 of the recirculated gas control valve and is then guided by the smooth directing passage 17 formed inside the bent pipe 24 and changes in direction of flow, then is discharged to the direction of flow of the forward flow area of fresh air from the inflowing port 11 opened in the forward flow area of the fresh air, therefore even if the recirculated gas control valve 4 is provided close to the throttle valve 3 and even in a case where the valve stem 15 of the recirculated gas control valve 4 is located at the upstream side in the direction of the intake pipe 5 from the valve stem 12 of the throttle valve 3 as an extreme case, it becomes possible to open the inflowing port 11 in the forward flow area of the fresh air by using the bent pipe 24.
  • the recirculated gas is fed into the forward flow area of the fresh air (intake air) sufficiently downstream from the throttle valve 3 by the directing passage 17 of the bent pipe 24, and therefore the back flow of the recirculated gas to the throttle valve 3 is reliably hindered.
  • Figure 26 shows the eighth embodiment of the present invention.
  • the bent pipe 24 is used at the end of the recirculated gas introduction passage 8.
  • the recirculated gas control valve 4 is not provided in the pipe wall of the intake pipe 5, but is provided in the middle of the recirculated gas introduction passage 8.
  • the recirculated gas can be fed into the forward flow area of the fresh air in the intake pipe 5 sufficiently downstream from the throttle valve 3 by the bent pipe 24, therefore an adverse influence upon the throttle valve 3 due to the back flow of the recirculated gas can be prevented.
  • FIG. 27 shows the ninth embodiment of the present invention.
  • the valve stem 12 of the throttle valve 3 and the valve stem 15 of the recirculated gas control valve 4 have become parallel, therefore it is difficult to make the recirculated gas evenly flow into the flow of fresh air at the downstream side of the throttle valve 3 as it is, but by providing the bent pipe 24 so as to be connected to the downstream side of the valve seat 16 of the recirculated gas control valve 4 and opening the inflowing port 11 of the end of the recirculated gas directing passage 17 in the forward flow area of the fresh air sufficiently downstream from the throttle valve 3, it becomes possible to prevent the back flow of the recirculated gas to the direction of the throttle valve 3 and, at the same time, the recirculated gas can be evenly mixed into the fresh air.
  • the bent pipe 24 opened at the end of the recirculated gas introduction passage 8 there is an advantage that a large degree of freedom is obtained in the positional relationship between the throttle valve 3 and the recirculated gas control valve
  • the example of using a diaphragm actuator operating by the negative pressure so as to operate the throttle valve 3 and the recirculated gas control valve 4 (the negative pressure added is indicated as NP in the figure, while atmospheric pressure is indicated as AP) was shown, but needless to say other types of actuators, for example, a stepping motor, a piezoactuator, and a solenoid type actuator can be used as the actuator of these valves.
  • Fig. 31 101 is a multi-cylinder engine, and 102 indicates a conventional exhaust gas recirculation device mounted on this.
  • Reference numeral 103 is an air cleaner, and 104 is an intake passage connected to this and formed in an intake pipe 105, an intake manifold 106, etc.
  • Reference numeral 107 indicates an exhaust manifold of the engine 101.
  • the exhaust gas recirculation device 102 is constituted by a recirculated gas introduction passage 108 which extracts part of the exhaust gas EG from the exhaust manifold 107 as the recirculated gas and feeds this to part of the intake passage 104 and a recirculated gas control valve 109 provided at the end of the passage 108.
  • the conventional recirculated gas control valve 109 comprises a valve seat 110 acting also as the recirculated gas inflowing port formed in the lower portion of the intake pipe 105, a valve body 111 of a frustoconical shape opening and closing this, a long rod-like valve stem 112 which is integrally formed with the valve body 111 and crosses the intake passage 104, and an actuator 113 driving the upper end of the valve stem 112. Further, the actuator 113 is provided with a diaphragm 114 engaged with the upper end of the valve stem 112 and a compression spring 116 placed in a negative pressure chamber 115 formed in the upper portion of the diaphragm 114.
  • blow-by gas introduction passage 118 Separate from the exhaust gas recirculation device 102, in order to guide and process the blow-by gas BG accumulated in the crank case and the cylinder head cover 117 of the engine 101, a blow-by gas introduction passage 118 connecting them is provided.
  • the blow-by gas inflowing port 119 which is the outlet opening thereof is opened in the pipe wall of the intake pipe 105 at the upstream side of the valve seat 110 of the recirculated gas control valve 109.
  • a long valve stem 112 of the recirculated gas control valve 109 is provided so as to cross the intake passage 104 in which the intake air containing a large amount of low temperature fresh air flows, therefore even if the temperature of the valve seat 110 and the valve body 111 becomes high, the heat is scattered from the long valve stem 112 into the intake air, therefore the breakage of the diaphragm 114 etc. of the actuator 113 due to the heat can be prevented.
  • the valve seat 110 which is the opening of the end of the recirculated gas introduction passage 108, emits the recirculated gas, therefore there is the possibility as mentioned above that the carbon particles contained in this will be mixed with the oil component in the blow-by gas and build up near the valve seat 110 to form a deposit that reduces the sectional area of the flow path or that causes the valve body 111 to stick to the valve seat 110 to make the operation impossible.
  • the present invention provides the exhaust gas recirculation device of the 10th embodiment shown in Fig. 28 to Fig. 30.
  • the configuration thereof will be explained in detail.
  • the same reference symbols will be used for constituent parts substantially the same as those of the conventional example mentioned above.
  • 101 denotes a multi-cylinder engine, 103 an air cleaner, 104 an intake passage, 105 an intake pipe, 106 an intake manifold, 107 an exhaust manifold, 108 a recirculated gas introduction passage, 113 a diaphragm actuator, 114 a diaphragm, 115 a negative pressure chamber, 116 a compression spring, 117 a cylinder head cover, 118 a blow-by gas introduction passage, and 119 a blow-by gas inflowing port.
  • the characteristic feature of the exhaust gas recirculation device 120 of the 10th embodiment of the present invention shown in Fig. 28 to Fig. 30 resides in the related configuration of the recirculated gas control valve 121 attached to the intake pipe 105 and the downstream side part thereof.
  • This control valve 121 is constituted in a pipe part 122 which is provided so as to be inserted into the middle of the intake pipe 105 and forms part of the intake passage 104.
  • One part 105a of the intake pipe 105 which is located on the downstream side of the pipe part 122 has a shape matched with the end surface of the control valve 121 including the pipe part 122.
  • the part 105a of the intake pipe 105 is separately provided from the pipe part 122 of the control valve 121, but it is also possible to integrally form them from the first.
  • the partition wall 123 with the intake passage 104, the intake air and blow-by gas flowing toward the downstream side are prevented from directly flowing into the recirculated gas control valve 121.
  • the partition wall 123 it is possible for the partition wall 123 to he formed by part of the pipe part 122 so far as it does not hinder installation of the recirculated gas control valve 121.
  • the recirculated gas control valve 121 is provided with a valve body 124 which is attached in a direction with its axial line intersecting the axial line of the pipe part 122 at right angles at the upper portion of the pipe part 122 and accordingly at the upper portion of the intake passage 104, an inlet 125 of the recirculated gas provided there, an annular valve seat 126 formed in the valve body 124, a valve body 127 of a frustoconical shape opening and closing this, and a recirculated gas introduction port 128 which is opened toward the downstream side so that, when the valve body 127 is separated from the valve seat 126, the recirculated gas flowing through the valve gap between them is guided to the intake passage 104 and flows into the intake flow.
  • the valve stem 129 integrally formed with the valve body 127 is driven by the actuator 133 in the same way as that of the conventional example.
  • the actuator 113 By attaching the valve body 124 of the recirculated gas control valve 121 so as to intersect with the pipe part 122, the actuator 113 can be located at a position close to the intake pipe 105, therefore it will be cooled together with the valve body 124 by the intake air of the relatively low temperature flowing in the intake pipe 105. Accordingly, when the actuator 113 is a diaphragm type, deterioration of the diaphragm 114 due to the heat of the recirculated gas transferred from the valve body 127 via the valve stem 129 can be prevented.
  • the valve body 127 of the recirculated gas control valve 121 opens or closes the valve gap with the valve seat 126 and makes an appropriate amount of recirculated gas flow into the flow of the intake air flowing in the intake passage 104 toward the downstream side from the introduction port 128 when necessary.
  • the blow-by gas flowing from the blow-by gas inflowing port 119 opened at the upstream side from the recirculated gas control valve 121 is contained in the intake air, and therefore the oil component in the blow-by gas adheres to the inner wall surface of the intake pipe 105 and coagulates to form an oil film, but the oil film flows downward due to gravity.
  • the partition wall 123 is provided in the lower portion of the recirculated gas control valve 121 with the intake passage 104, even if there is no inflow of the recirculated gas, the blow-by gas will not slip around to near the valve seat 126.
  • the intrusion and adhesion of the oil component in the blow-by gas to the periphery of the valve seat 126 of the recirculated gas control valve 121 are reliably hindered.
  • the trouble of the carbon particles contained in the recirculated gas flowing out of the control valve 121 to be mixed with the oil component in the blow-by gas and forming a deposit in the flow path which reduces the sectional area of the flow path or causes sticking of the valve body 127 and the valve seat 126 and thereby poor operation of the control valve 121 can be avoided.
  • the 11th embodiment is characterized by the provision of an inclined recirculated gas inflowing passage 131 which not only is shaped so that the control valve 121 and the part 105b of the intake pipe 5 connected to the downstream side of the pipe part 122 thereof match with the upstream side in the connected end surface, but also is connected to the recirculated gas introduction port 128 of the control valve 121 on the upstream side and, at the same time, opens in the intake passage 104 on the downstream side.
  • the opening of the inflowing passage 131 with respect to the intake passage 104 that is, the recirculated gas inflowing port 132, can smoothly combine the recirculated gas flowing while passing through the control valve 121 with the intake air in the intake passage 104.
  • the flow rate is lowered during the period when the recirculated gas passing through the valve gap between the valve body 127 and valve seat 126 of the control valve 121 flows in the inflowing passage 131, thus there are the advantages that the mixture with the intake air flowing in the intake passage 104 becomes better and the distribution of the recirculated gas with respect to cylinders becomes more uniform than that of the case of the 10th embodiment.
  • Figure 34 and Fig. 35 show the exhaust gas recirculation device 133 according to a 12th embodiment of the present invention.
  • the characteristic feature of the 12th embodiment resides in that, while maintaining the substantive configuration of the exhaust gas recirculation device 130 of the 11th embodiment as it is, the pipe part 122 of the recirculated gas control valve 121 and the part 105a of the intake pipe 105 on the downstream side are combined so as to provide the recirculated gas inflowing member 134.
  • part of the recirculated gas inflowing member 134 corresponds to the pipe part 122 in the 11th embodiment, therefore only the valve part excluding the pipe part 122 from the recirculated gas control valve 121 in the 11th embodiment is shown as the recirculated gas control valve 121' in the 12th embodiment.
  • an EGR valve is provided in a upper portion of an intake pipe, and a valve seat portion thereof is separated from the intake pipe by a partition flange. An EGR gas passing through the EGR valve flows from the inflowing port of an inflowing passage into an intake air and is mixed with this.
  • An oil component is contained in a blow-by gas flowing from the inflowing port on the upstream side, therefore this is adhered to the inner surface of the intake pipe and forms an oil film, but this oil flows downward due to gravity and the valve seat located above is covered by the partition flange, therefore it is possible to prevent the oil intruding into the EGR valve and the carbon particles in the EGR gas mixing with the oil in the blow-by gas to form a deposit.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Exhaust-Gas Circulating Devices (AREA)
  • Lubrication Details And Ventilation Of Internal Combustion Engines (AREA)
EP97107793A 1996-05-14 1997-05-13 Dispositif de recirculation de gaz d'échappement Expired - Lifetime EP0809012B1 (fr)

Applications Claiming Priority (9)

Application Number Priority Date Filing Date Title
JP11911296 1996-05-14
JP119112/96 1996-05-14
JP11911296 1996-05-14
JP31649696 1996-11-27
JP31649696 1996-11-27
JP316496/96 1996-11-27
JP3030497 1997-02-14
JP9030304A JPH1030504A (ja) 1996-05-14 1997-02-14 排出ガス再循環装置
JP30304/97 1997-02-14

Publications (3)

Publication Number Publication Date
EP0809012A2 true EP0809012A2 (fr) 1997-11-26
EP0809012A3 EP0809012A3 (fr) 1999-03-24
EP0809012B1 EP0809012B1 (fr) 2003-08-20

Family

ID=27286919

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97107793A Expired - Lifetime EP0809012B1 (fr) 1996-05-14 1997-05-13 Dispositif de recirculation de gaz d'échappement

Country Status (2)

Country Link
EP (1) EP0809012B1 (fr)
DE (1) DE69724180T2 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1152141A1 (fr) * 2000-05-05 2001-11-07 Siemens Aktiengesellschaft Procédé et dispositif de recirculation de gaz d'échappement dans le courant d'air d'admission
US8181633B2 (en) 2008-12-17 2012-05-22 Aisin Seiki Kabushiki Kaisha Intake manifold
FR3028555A1 (fr) * 2014-11-19 2016-05-20 Renault Sa Connecteur d'entree de turbocompresseur avec connexions egr et blow-by
EP3657004A4 (fr) * 2017-08-25 2020-05-27 Mazda Motor Corporation Système d'admission de moteur

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008023381A1 (de) * 2008-05-13 2009-11-19 GM Global Technology Operations, Inc., Detroit Saugrohranordnung
US8423269B2 (en) 2009-07-08 2013-04-16 Cummins Inc. Exhaust gas recirculation valve contaminant removal

Citations (4)

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Publication number Priority date Publication date Assignee Title
US4373496A (en) * 1981-04-01 1983-02-15 Robert Bosch Gmbh Apparatus for controlling an exhaust recirculation device in internal combustion engines
US4615324A (en) * 1983-09-13 1986-10-07 Mazda Motor Corporation Exhaust gas recirculation system for a V-type engine
EP0586123A2 (fr) * 1992-08-31 1994-03-09 Hitachi, Ltd. Dispositif d'admission d'air pour moteur à combustion interne
US5333456A (en) * 1992-10-01 1994-08-02 Carter Automotive Company, Inc. Engine exhaust gas recirculation control mechanism

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4373496A (en) * 1981-04-01 1983-02-15 Robert Bosch Gmbh Apparatus for controlling an exhaust recirculation device in internal combustion engines
US4615324A (en) * 1983-09-13 1986-10-07 Mazda Motor Corporation Exhaust gas recirculation system for a V-type engine
EP0586123A2 (fr) * 1992-08-31 1994-03-09 Hitachi, Ltd. Dispositif d'admission d'air pour moteur à combustion interne
US5333456A (en) * 1992-10-01 1994-08-02 Carter Automotive Company, Inc. Engine exhaust gas recirculation control mechanism

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1152141A1 (fr) * 2000-05-05 2001-11-07 Siemens Aktiengesellschaft Procédé et dispositif de recirculation de gaz d'échappement dans le courant d'air d'admission
US8181633B2 (en) 2008-12-17 2012-05-22 Aisin Seiki Kabushiki Kaisha Intake manifold
FR3028555A1 (fr) * 2014-11-19 2016-05-20 Renault Sa Connecteur d'entree de turbocompresseur avec connexions egr et blow-by
WO2016079390A1 (fr) * 2014-11-19 2016-05-26 Renault S.A.S Connecteur d'entree de turbocompresseur avec connexions egr et blow-by
EP3657004A4 (fr) * 2017-08-25 2020-05-27 Mazda Motor Corporation Système d'admission de moteur
US11118546B2 (en) 2017-08-25 2021-09-14 Mazda Motor Corporation Engine intake system

Also Published As

Publication number Publication date
EP0809012B1 (fr) 2003-08-20
DE69724180T2 (de) 2004-04-01
DE69724180D1 (de) 2003-09-25
EP0809012A3 (fr) 1999-03-24

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