JP2010001758A - Secondary air supplying device of internal combustion engine and vehicle equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secondary air supplying device 4 in which condensed water generated therein can be easily discharged to the sides of exhaust passages 2b, and 6 regardless of an installed location of a valve device 23, and defects, as in the conventional example, can be eliminated. <P>SOLUTION: The secondary air supplying device 4 includes a secondary air supplying passage 21 for leading secondary air to upstream from a catalyst 10 of exhaust passages 2b and 6 of an internal combustion engine, an air pump 22 arranged upstream of the secondary air supplying passage 21 and for sucking ambient air as needed and sending out the air to downstream of the secondary air supplying passage 21, a valve device 23 for opening and closing the secondary air supplying passage 21, a reservoir part 15 for condensed water, arranged between the valve device 23 and the exhaust passages 2b and 6 in the secondary air supplying passage 21, and a sending means 16 for sending the condensed water inside the reservoir part 15 to the side of the exhaust passages 2b and 6 along with secondary air. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a secondary air supply device for an internal combustion engine (hereinafter also referred to as an engine) and a vehicle including the same.

  The vehicle includes the secondary air supply device, and a surge tank that is provided in the middle of the intake passage and is disposed in an upper portion of the internal combustion engine so as to be deformed when an impact is applied and absorb the impact. is there.

  In an internal combustion engine mounted on a vehicle or the like, generally, a catalyst having an oxidation function (for example, a three-way catalyst) is disposed in an exhaust passage, and CO (carbon monoxide), HC (hydrocarbon), There is provided an exhaust purification device that reduces exhaust gas by reducing NOx (nitrogen oxide) components.

  Further, an internal combustion engine equipped with such an exhaust purification device includes an exhaust gas for the internal combustion engine in order to promote the exhaust gas purification function during a period when the catalyst is not yet activated, such as during cold start. A secondary air supply device (AI: Air Injection System) for supplying secondary air to the system is provided.

  Specifically, the secondary air supply device for an internal combustion engine supplies secondary air upstream of the catalyst in the exhaust passage to increase the oxygen concentration, thereby secondary combustion (post-combustion) of CO and HC in the exhaust gas. And the exhaust gas purification is promoted, and the temperature of the catalyst is quickly raised by the secondary combustion to bring the catalyst into an active state at an early stage.

  The secondary air supply device mainly includes a secondary air supply passage for supplying secondary air upstream of the catalyst in the exhaust passage, a valve device for opening and closing the secondary air supply passage, and external air. And an air pump for sucking and feeding it into the secondary air supply passage. The valve device has a configuration in which an on-off valve and a check valve are incorporated in a case.

  In brief, the operation of the secondary air supply device is such that when the internal combustion engine is cold started, the air pump is driven and the on-off valve and the check valve are opened to send the secondary air into the exhaust passage. ing.

  By the way, after the operation of the internal combustion engine is stopped, the secondary air remaining in the secondary air supply passage, the backflowed exhaust gas, or the like is cooled, so that the secondary air or the exhaust gas in the secondary air supply passage is cooled. It is known to generate acidic condensed water in which moisture contained therein is condensed.

  If the condensed water stays inside the valve device, non-metallic components (such as rubber seals) provided inside the valve device may corrode and deteriorate over time.

  Therefore, it is conceivable that the condensate can be easily discharged to the secondary air supply passage on the downstream side of the valve device by installing the valve device at a location higher than the connecting portion of the secondary air supply passage to the exhaust passage. .

  In this case, condensed water stays in the secondary air supply passage. In this case, the pipe made of metal or synthetic resin constituting the secondary air supply passage may be deteriorated by corrosion over time. There is.

  For this, for example, as shown in Patent Document 1, the secondary air supply passage is formed of stainless steel having excellent corrosion resistance, or the secondary air supply passage is subjected to rust prevention treatment. Is considered.

  The conventional example according to this Patent Document 1 is a technique that makes it difficult for the secondary air supply passage to be corroded by the condensed water accumulated in the secondary air supply passage, which inevitably increases the manufacturing cost.

  By the way, Patent Documents 2 and 3 are technologies for forcibly discharging condensed water to the exhaust passage side.

  Patent Document 2 discloses a secondary air supply device that supplies, as secondary air, outside air sucked and sent from an air pump to an exhaust pipe (exhaust manifold) of an internal combustion engine, and opens an air switching valve after the internal combustion engine is completely warmed up. By forcibly scavenging the inside of the secondary air supply passage by operating the air, in addition to discharging the condensed water in the passage to the exhaust pipe, and performing scavenging by air suction while the air pump is stopped The condensed water in the passage is discharged to the exhaust pipe.

Patent Document 3 discloses a delivery path (2) provided above the exhaust port inside the cylinder head in a secondary air supply device that supplies the outside air sucked and sent from the air pump to the exhaust port of the cylinder head of the internal combustion engine as secondary air. A condensate water storage portion is provided at the bottom of a part of the secondary air supply passage so that the condensate water generated in the secondary air supply passage after the internal combustion engine is stopped is stored in the storage portion; Condensed water in the storage portion is evaporated due to a temperature rise associated with start-up, and is discharged little by little from the communication passage (part of the secondary air supply passage) to the exhaust port.
JP-A-8-218858 JP 2003-227331 A JP 2006-312909 A

  In the conventional example according to Patent Document 2, first, after completely warming up the internal combustion engine, by scavenging the inside of each element (air switching valve and secondary air supply passage) constituting the secondary air supply device, It is intended to prevent the generation of condensed water inside, and there are the following concerns.

  That is, in the case of the conventional example according to Patent Document 2, since the condensed water in the secondary air supply device is discharged to the exhaust pipe by scavenging at a stretch, an air-fuel ratio sensor or catalyst installed in the exhaust pipe is used. There is a concern that the air-fuel ratio sensor and the catalyst may be adversely affected, for example, the condensed water is directly applied.

  On the other hand, in the conventional example according to Patent Document 3, the secondary air is supplied to the exhaust port of the cylinder head, and the condensed water generated in the storage portion below the delivery passage formed inside the cylinder head is used as the internal combustion engine. Since it is made to evaporate with the heat | fever in operation | movement of an engine and it is made to discharge | emit to an exhaust port, although concerns like the prior art example of the above-mentioned patent document 2 are eliminated, the following concerns are mentioned.

  First, since it is necessary to form a delivery passage and a condensate storage part inside the cylinder head, there is a concern about an increase in the size and weight of the cylinder head.

  Condensed water is originally likely to be generated when the internal combustion engine is cold, but the temperature drops while the internal combustion engine is stopped, so that the condensed water in the reservoir is less likely to evaporate. There is a concern that the inner wall of the cylinder head to be formed is likely to be corroded by condensed water.

  In that case, in order to suppress the progress of corrosion, it is considered necessary to take measures such as setting the vicinity of the reservoir in the cylinder head to be thick, but in that case, it leads to an increase in the weight of the internal combustion engine. There is room for improvement.

  In view of such circumstances, the present invention enables the condensed water generated in the secondary air supply device to be easily discharged to the exhaust passage regardless of the installation location of the valve device. The purpose is to make it possible to eliminate the problems of the conventional example.

  Further, the present invention provides a secondary air supply device in a vehicle equipped with an internal combustion engine provided with a surge tank having a shock absorbing structure as shown in, for example, Japanese Patent Laid-Open No. 2007-71154 and a secondary air supply device. The purpose of this invention is to improve the collision safety performance while improving the visibility of the driver and the maintenance workability of the internal combustion engine.

  In addition, in the above-mentioned Japanese Patent Application Laid-Open No. 2007-71154, for example, at the time of impact application, in order to reduce as much as possible the impact applied to the impacted body at the time of collision between the vehicle and the impacted object such as a pedestrian. For example, there is described a technique capable of absorbing an impact by facilitating deformation of a vehicle hood member (referred to as a bonnet) and a surge tank.

  The present invention is a secondary air supply device for supplying secondary air to an upstream side of a catalyst in an exhaust passage of an internal combustion engine, and a secondary air for guiding the secondary air to an upstream side of the catalyst of the exhaust passage. An air supply passage, an air pump that is arranged upstream of the secondary air supply passage and sucks outside air as necessary and sends it to the downstream side of the secondary air supply passage; and opens and closes the secondary air supply passage And a condensate storage portion disposed between the valve device and the exhaust passage in the secondary air supply passage, and sending the condensate water in the storage portion to the exhaust passage side together with the secondary air Means.

  According to this configuration, even if condensed water is generated in the secondary air supply device when the internal combustion engine is cold, the condensed water is recovered and stored in the storage unit, and stored in the storage unit. The condensed water to be discharged is discharged to the exhaust passage as needed by the delivery means. Thereby, it becomes possible to prevent the component of a secondary air supply apparatus from corroding with condensed water.

  And since the condensate storage part is provided in the middle of the secondary air supply passage, the cylinder head is increased in size and weight compared to the case where it is provided inside the cylinder head of the internal combustion engine as in the conventional example. Can be prevented.

  In addition, since only the reservoir is formed of a corrosion-resistant material or only the reservoir is subjected to rust prevention treatment, the entire secondary air supply passage is formed of a corrosion-resistant material as in the conventional example, or the anti-corrosion material is used. Compared with the case where rust treatment is performed, it is possible to suppress an increase in cost.

  Furthermore, since it is not necessary to install the valve device at a high place, the valve device can be arranged at a place away from the upper part of the internal combustion engine. Therefore, it is not necessary to secure a space for arranging the valve device in the upper part of the internal combustion engine. As a result, for example, the overall height of the internal combustion engine can be set as low as possible, and the workability of replacing the ignition plug of the internal combustion engine is improved. Becomes better.

  Preferably, the delivery means sucks out the condensed water in the reservoir and sends it to the exhaust passage side together with the secondary air.

  Preferably, the valve device is arranged in the vicinity of the connection position of the secondary air supply passage to the exhaust passage or vertically below the position, and a section from the valve device to the exhaust passage in the secondary air supply passage. Is bent into a U-shape so as to rise and descend toward the exhaust passage after descending from the downstream side of the valve device, and the storage portion is provided so as to surround the descending portion of the secondary air supply passage It is made a container.

  According to this configuration, since the valve device is arranged at a location away from the upper part of the internal combustion engine, it is not necessary to secure a space for arranging the valve device in the upper part of the internal combustion engine. It becomes possible to set it low, and the workability of replacing the ignition plug of the internal combustion engine becomes good.

  In addition, since the reservoir is provided in the middle of the secondary air supply passage that is lower than the valve device, even if condensed water is generated in the valve device, the condensed water will naturally fall and be collected in the reservoir. become.

  Preferably, the delivery means sucks out condensed water in the storage section by increasing a flow rate of secondary air provided and distributed in a descending portion surrounded by the storage section in the secondary air supply passage. It is a venturi that is sent downstream along with the secondary air.

  In this configuration, the delivery means is generally specified as a known venturi. According to this specification, when the secondary air is supplied from the air pump to the secondary air supply passage, the flow rate of the secondary air is increased by the venturi effect, and the condensed water in the reservoir is generated by the vacuum effect generated downstream thereof. Is sucked out and delivered to the exhaust passage side.

  As described above, the condensed water in the reservoir can be discharged to the exhaust passage side without using a special drive source, so there is no waste.

  Preferably, the valve device includes an open / close valve disposed upstream of the secondary air supply passage and opened / closed by an actuator, and a check valve disposed downstream of the secondary air supply passage in the case. The unit is configured as a unit, and further includes control means for controlling the actuator and the air pump. The control means drives the air pump and opens the on-off valve by the actuator when starting the internal combustion engine. It is possible to generate a function of discharging condensed water by the venturi.

  In this configuration, the configurations of the valve device and the secondary air supply device are specified. Since this valve device includes the check valve, the backflow of the exhaust gas from the exhaust passage to the upstream side of the valve device is prevented. Further, at the time of starting the internal combustion engine, in the process of supplying the secondary air to the exhaust passage, it becomes possible to discharge the condensed water in the storage portion, and it is not necessary to perform a special process only for discharging the condensed water. .

  Preferably, the control means can scavenge the secondary air supply passage and the inside of the valve device by driving an air pump and opening an on-off valve by an actuator when the internal combustion engine is stopped.

  In short, in this configuration, the scavenging process is performed so that no external air, exhaust gas, or the like is left in the secondary air supply passage and the valve device, thereby supplying the secondary air after the internal combustion engine is stopped. Condensed water is less likely to be generated inside the device.

  In this way, if the condensed water is less likely to be generated, the amount of condensed water discharged to the exhaust passage side is reduced at the next start of the internal combustion engine, so that the capacity and the external size of the reservoir can be reduced. At the same time, it is advantageous in reducing the installation space of the storage unit.

  Preferably, the secondary air supply passage includes an upstream side external pipe that communicates and connects the air pump and the valve device, a delivery passage that is provided in the cylinder head of the internal combustion engine along the cylinder arrangement direction, and the delivery passage. It is possible to include a communication passage that communicates and connects the exhaust port of the cylinder head, and a downstream external pipe that communicates and connects the delivery passage and the valve device.

  In this configuration, by specifying the configuration of the secondary air supply passage, the secondary air supply destination is clarified as the exhaust port of the cylinder head, and the location of the reservoir is clarified.

  In this case, for example, when the secondary air is supplied as the internal combustion engine is started, the condensed water in the reservoir is discharged to the delivery passage. Since this delivery passage is close to the combustion chamber and has a high temperature, the condensed water is likely to evaporate, so that it is likely to be gradually discharged from the delivery passage to the exhaust port.

  As described above, if the place where the condensed water in the storage part is discharged is specified as the delivery passage instead of the exhaust pipe, the air-fuel ratio concerned when the condensed water is discharged to the exhaust pipe at once as in the conventional example. It is possible to eliminate adverse effects on the sensor and the catalyst.

  In addition, a vehicle according to the present invention is provided in the exhaust passage of the internal combustion engine for supplying secondary air upstream of the catalyst, and is provided in the middle of the intake passage and disposed at the upper part of the internal combustion engine. And a surge tank configured to absorb the shock by being deformed when an impact is applied, and the secondary air supply device is configured as described above.

  In this configuration, even if the valve device of the secondary air supply device is installed at a place lower than the upper part of the internal combustion engine, the valve device is separated from the surge tank because the condensed water does not stay in the valve device. It becomes possible to install in the place. For this reason, when the surge tank is deformed to absorb the shock, the deformation of the surge tank is not hindered by the valve device.

  Thereby, the clearance between the surge tank and the hood member can be set as small as possible. Accordingly, the height position of the hood member can be set as low as possible, which is advantageous in improving visibility by the driver.

  In addition, since the valve device of the secondary air supply device is not arranged at the upper part of the internal combustion engine, it can be said that a relatively large clearance between the upper part of the internal combustion engine and the surge tank can be secured. For example, when the valve device is attached to the upper part of the internal combustion engine For example, the overall height of the internal combustion engine can be set as low as possible, and it can be said that the workability of attaching and detaching the spark plug to the cylinder head of the internal combustion engine is improved.

  Preferably, the internal combustion engine is a V-type multi-cylinder engine, and two sets of secondary air supply passages and valve devices provided in the secondary air supply device are provided corresponding to the exhaust passages for the left and right banks, The surge tank is a container that is sized to cover the left and right cylinder head covers and is flat in the vertical direction, and the left and right sides of the surge tank fall into the cylinder head cover side when an impact is applied from a hood member that covers the internal combustion engine. The valve device is arranged in a state of being separated from the surge tank on each side of the left and right cylinder head covers.

  In this configuration, the arrangement of the valve device is specified after specifying the type of the internal combustion engine, the configuration of the secondary air supply device, and the shock absorption form of the surge tank.

  In particular, since it is clear that no valve device is arranged between the surge tank disposed above the internal combustion engine and the upper part of the internal combustion engine, when the surge tank is deformed for shock absorption, the surge tank The deformation is not hindered by the valve device.

  In the secondary air supply device using an air pump, the present invention makes it possible to easily discharge the condensed water generated in the secondary air supply device to the exhaust passage side regardless of the installation location of the valve device. It will be advantageous in solving the problem.

  Further, the present invention can improve the durability of the components of the secondary air supply device in a vehicle equipped with a secondary air supply device using an air pump and an internal combustion engine provided with a surge tank having a shock absorbing structure. At the same time, it is possible to improve the collision safety performance while improving the driver's visibility and the maintenance workability of the internal combustion engine.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best embodiment of the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 and FIG. 2 show an embodiment of the present invention. In these drawings, 1 is a cylinder block, 2 is a cylinder head, 3 is a cylinder head cover, and 4 is a secondary air supply device.

  The cylinder block 1 is provided with an appropriate number of cylinders (not shown), and a piston (reference numeral omitted) is slidably accommodated in each cylinder. A combustion chamber is defined by the inner peripheral surface of each cylinder, the top surface of each piston, and each recess of the cylinder head 2.

  The cylinder head 2 mounted on the cylinder block 1 is provided with an intake port 2a and an exhaust port 2b for each combustion chamber.

  An intake pipe 5 is connected to the intake port 2a of the cylinder head 2 in communication. The intake pipe 5 is provided with a surge tank 7, an electronically controlled throttle valve 8 for adjusting the intake air amount, and an air cleaner 9. The intake port 2a, the intake pipe 5, and the surge tank 7 constitute an intake passage.

  An exhaust pipe 6 is connected to the exhaust port 2b of the cylinder head 2 in communication. The exhaust port 2b and the exhaust pipe 6 constitute an exhaust passage. The exhaust pipe 6 is provided with a catalyst 10 as an exhaust purification device. Examples of the catalyst 10 include a three-way catalyst that oxidizes HC and CO and reduces NOx.

  Although not shown, an intake valve is provided in the intake port 2a, an exhaust valve is provided in the exhaust port 2b, and an ignition plug is provided in the cylinder head 2. Further, an intake pipe 5 is provided. Is provided with a fuel injection valve.

  The secondary air supply device 4 supplies secondary air upstream of the catalyst 10 in the exhaust passage (including the exhaust port 2b and the exhaust pipe 6) of the internal combustion engine to increase the oxygen concentration, thereby increasing the concentration of oxygen in the exhaust gas. The secondary combustion (post-combustion) of CO and HC promotes the purification of exhaust gas, and the catalyst is quickly heated by the secondary combustion to be brought into an active state at an early stage.

  Specifically, the secondary air supply device 4 mainly includes a secondary air supply passage 21, an air pump 22, an air switching valve (ASV) 23 as a valve device, and a controller 24.

  The secondary air supply passage 21 guides secondary air upstream of the catalyst 10 in the exhaust passage of the internal combustion engine. In this embodiment, the downstream end of the secondary air supply passage 21 is connected to the exhaust port 2b of the cylinder head 2 so as to supply secondary air to the exhaust port 2b.

  The secondary air supply passage 21 includes an upstream external pipe 21 a that connects the air pump 22 and the air switching valve 23, and a downstream external pipe that connects the air switching valve 23 and the delivery path 21 c of the cylinder head 2. 21b, a delivery passage 21c provided in the cylinder head 2 along the cylinder arrangement direction, and a communication passage 21d for individually connecting the delivery passage 21c and the exhaust ports 2b of the cylinder head 2 in communication with each other. ing.

  The upstream end of the delivery passage 21c is open to the end face of the cylinder head 2, and the downstream side external pipe 21b is connected to the open end of the delivery passage 21c. The downstream end of the delivery passage 21 c is closed without being opened to the outer surface of the cylinder head 2.

  The air pump 22 is provided on the upstream side of the secondary air supply passage 21 and is, for example, an electric type. The air pump 22 sucks outside air through the air filter 25 and discharges it to the downstream side of the secondary air supply passage 21.

  The air switching valve 23 is provided in the middle of the secondary air supply passage 21 to open and close the secondary air supply passage 21 and is generally known and is not shown in detail. 26, an actuator 27, and a check valve 28 are assembled into a case to form a unit.

  The on-off valve 26 is disposed upstream of the secondary air supply passage 21 and is opened / closed by an actuator 27.

  The actuator 27 converts, for example, rotational power generated by an electric motor or the like into a linear motion by a reduction mechanism (such as a planetary mechanism or a feed screw mechanism) not shown, and opens or closes the valve body of the on-off valve 26. It is to be operated. The actuator 27 closes the opening / closing valve 26 when not energized, and opens the opening / closing valve 26 when energized.

  The check valve 28 is, for example, for preventing exhaust gas from flowing into the secondary air supply passage 21 from the exhaust port 2b side, and is, for example, a reed valve.

  The controller 24 controls at least the operation of the secondary air supply device 4 and includes an electronic control unit (ECU) 31 and a driver unit (EDU) 32. The controller 24 corresponds to control means described in the claims.

  Although not shown in detail, the ECU 31 includes a CPU that performs control processing and arithmetic processing, a storage device (memory such as ROM, RAM, SRAM, and EEPROM) that stores various programs and data, an input circuit, an output circuit, and a power supply circuit. It is assumed that the computer has a well-known structure including the above. The EDU 32 may be built in the case of the ECU 31.

  The ECU 31 controls the operation of the secondary air supply device 4 based on the read signals of various sensors (operation parameters: signals according to the running state of the vehicle and the operating state of the internal combustion engine). In other words, the ECU 31 gives the EDU 32 an operation control signal for the electric air pump 22 and an operation control signal for the actuator 27 in the secondary air supply device 4 as necessary. The EDU 32 applies a drive voltage to at least the electric air pump 22 and the actuator 27 based on the control signal input from the ECU 31.

  Although not shown, the various sensors for detecting the operating parameters include an accelerator sensor for detecting the accelerator opening, a rotational speed sensor for detecting the engine speed and the crank angle, and the cooling water temperature of the internal combustion engine. At least an A / F (air-fuel ratio) sensor disposed upstream of the catalyst 10 in the exhaust pipe 6, an O 2 sensor disposed downstream of the catalyst 10 in the exhaust pipe 6, and the like.

  Next, the basic operation of the secondary air supply device 4 will be briefly described.

  In the first place, the catalyst 10 disposed in the exhaust pipe 6 cannot sufficiently exhibit the exhaust purification function when the catalyst temperature is lower than the activation temperature. Therefore, under conditions where the temperature of the catalyst 10 is lower than the activation temperature, for example, when the internal combustion engine is cold started, the temperature of the catalyst 10 is raised to the activation temperature at an early stage.

  In this embodiment, the controller 24 opens the on-off valve 26 by driving the actuator 27 of the air switching valve 23 simultaneously with driving the air pump 22 of the secondary air supply device 4 immediately after the cold start of the internal combustion engine. Then, the outside air (secondary air) sucked by the air pump 22 is supplied from the secondary air supply passage 21 to the exhaust port 2b.

  By supplying such secondary air, HC and CO in the exhaust gas react with oxygen in the secondary air and burn (oxidize) to improve exhaust emission characteristics.

  In addition, since the HC and CO in the exhaust gas are combusted by supplying the secondary air to the exhaust port 2b, the temperature of the exhaust gas can be increased as compared with the case where the secondary air is not supplied, and the catalyst 10 can be quickly activated. Can be activated. As a result, exhaust emission immediately after the start of the internal combustion engine can be improved.

  On the other hand, during normal operation when the internal combustion engine is above a certain temperature, or when the catalyst 10 has reached the activation temperature, the controller 24 does not drive the air pump 22 and closes the on-off valve 26. Thus, the secondary air is not supplied to the exhaust port 2b.

  Here, the part to which the features of the present invention are applied will be described in detail.

  In short, in this embodiment, the condensate generated in the secondary air supply device 4 while the internal combustion engine is stopped is not stored in the air switching valve 23 but is stored in the middle of the secondary air supply passage 21. In addition, the condensate in the reservoir 15 is forcibly sent to the delivery passage 21c of the secondary air supply passage 21 when the internal combustion engine is started.

  Specifically, first, as shown in FIG. 1, the air switching valve 23 of the secondary air supply device 4 is set in the vicinity of the connection position of the downstream side external pipe 21 b to the delivery passage 21 c or vertically below the position. The downstream external pipe 21b for connecting the air switching valve 23 and the delivery passage 21c of the cylinder head 2 in communication with each other is installed in a side of the internal combustion engine so as to be disposed in a substantially U shape when viewed from the side. It is formed in a bent shape.

  A condensate reservoir 15 is attached to the lowermost region of the U-shaped downstream external pipe 21b.

  As shown in FIG. 2, the storage portion 15 is a container that is provided so as to cover a region that is the lowest position of the downstream side external pipe 21 b. Since the storage unit 15 made of this container stores acidic condensed water generated inside the secondary air supply device 4, is it made of stainless steel or the like having excellent corrosion resistance to prevent corrosion? Alternatively, it is preferable to carry out a rust prevention treatment.

  In addition, through holes 21e penetrating in the radial direction are provided at several circumferential positions in a region surrounded by the storage portion 15 in the downstream side external pipe 21b. The through-hole 21e is provided to drop condensed water generated in the downstream side external pipe 21b and the air switching valve 23 into the storage unit 15, and when discharging the condensed water stored in the storage unit 15. It is provided to suck out condensed water.

  Further, a venturi 16 serving as a sending means for sucking the condensed water in the storing part 15 and sending it to the delivery passage 21c together with the secondary air is provided in a region surrounded by the storing part 15 in the downstream side external pipe 21b. It has been.

  This venturi 16 has a throttle pipe 16a for increasing the flow velocity of the secondary air flowing in the downstream side external pipe 21b, and the secondary air passing through the throttle pipe 16a is disposed on the outer diameter side of the throttle pipe 16a. By reducing the pressure, the condensed water in the reservoir 15 is sucked by the vacuum effect associated with the pressure drop and is sent to the downstream side together with the secondary air.

  When such a storage unit 15 or venturi 16 is provided, for example, when starting the internal combustion engine, the controller 24 drives the air pump 22 and the actuator 27 opens the on-off valve 26 to exhaust the secondary air. If the process of supplying to the port 2b is performed, the function of discharging the condensed water by the venturi 16 can be generated in the process of supplying the secondary air.

  That is, when the internal combustion engine is started, the secondary air supply device 4 performs the secondary air supply process so that the condensed water collected and stored in the storage unit 15 can be discharged to the exhaust port 2b side. It becomes. Thus, it is not necessary to perform a special process only for discharging condensed water.

  As described above, according to the embodiment to which the features of the present invention are applied, the following operations and effects can be achieved.

  In short, even if condensed water is generated in the secondary air supply device 4 when the internal combustion engine is cold, the condensed water is retained in the air switching valve 23 and the downstream side external piping 21b of the secondary air supply device 4. Instead, it is collected and stored in the storage unit 15.

  As a result, the non-metallic member (rubber seal or the like) provided in the air switching valve 23 or the secondary air supply passage 21 does not suffer from the problem of being corroded with acidic condensed water over time. Therefore, it is only necessary to take countermeasures against corrosion in the storage portion 15, and it is not necessary to form the downstream side external pipe 21 b with a material having excellent corrosion resistance (for example, stainless steel), and it is possible to form with any material. Therefore, it is advantageous for cost reduction.

  In addition, since the condensate storage unit 15 is provided in the middle of the secondary air supply passage 21, the size and weight of the cylinder head 2 can be increased as compared with the case where it is provided inside the cylinder head of the internal combustion engine as in the conventional example. The increase can be prevented.

  In addition, since the condensed water stored in the storage unit 15 can be forcibly sent to the delivery passage 21c by the venturi 16 in the secondary air supply process, the condensed water is not discharged into the exhaust pipe 6 at a stretch as water droplets. That is, the condensed water introduced into the delivery passage 21c is evaporated by the heat of the cylinder head 2 and discharged to the exhaust pipe 6 through the exhaust port 2b. Therefore, it is possible to eliminate the adverse effects on the air-fuel ratio sensor and the catalyst 10 that are concerned when the condensed water is discharged to the exhaust pipe 6 at a stroke as in the conventional example. As described above, the condensed water in the storage unit 15 can be discharged to the exhaust port 2b side without using a special drive source, so there is no waste.

  As a result, it is not necessary to install the secondary air supply passage 21 and the air switching valve 23 as high as possible, so that they can be arranged away from the upper part of the internal combustion engine. Therefore, it is not necessary to secure a space for disposing the air switching valve 23 in the upper part of the internal combustion engine. As a result, for example, the overall height of the internal combustion engine can be set as low as possible, and the ignition plug of the internal combustion engine can be set as low as possible. Good exchange workability.

  In addition, this invention is not limited only to the said embodiment, All the deformation | transformation and application included in the range equivalent to the claim and the said range are possible. Examples are given below.

  (1) In the above embodiment, an example is given in which the actuator 27 for operating the on-off valve 26 of the air switching valve 23 is an electric motor and a speed reducer, but the present invention is not limited to this, and the actuator 27 For example, an electromagnetic solenoid can be used as disclosed in JP-A-2007-285142.

  (2) In the above embodiment, an example using the venturi 16 as the delivery means is given, but the present invention is not limited to this, and for example, an appropriate jet pump can be used. Further, the internal combustion engine is not particularly limited, such as a port injection type or an in-cylinder direct injection type.

  (3) In the above embodiment, when the internal combustion engine is stopped by the controller 24, for example, the air pump 22 is driven and the on-off valve 26 is opened by the actuator 27 to open the secondary air supply passage 21 and the air switching. A process of scavenging the inside of the valve 23 may be performed.

  When such a scavenging process is performed, it is possible to prevent outside air, exhaust gas, and the like from remaining in the components of the secondary air supply device 4, for example, the secondary air supply passage 21 and the air switching valve 23. Thereby, it is possible to make it difficult to generate condensed water inside the secondary air supply device 4 after the internal combustion engine is stopped.

  As described above, if the condensed water is less likely to be generated, the amount of condensed water discharged to the exhaust port 2b side is reduced at the next start of the internal combustion engine, so that the capacity and the external size of the storage unit 15 can be reduced. In addition, it is advantageous in reducing the installation space of the storage unit 15.

  (4) FIGS. 3 to 5 show other embodiments of the present invention. In this embodiment, the internal combustion engine to be used for the secondary air supply device is a V-type multi-cylinder engine, and the surge tank 7 provided in the intake system is disposed directly above the V-type multi-cylinder engine. Therefore, a structure that absorbs the impact by intentionally deforming or dropping when the impact is applied from the hood member 11 is used.

  Specifically, with reference to FIG. 3, the configuration of the internal combustion engine that is a target of use of the secondary air supply device according to the present invention and the peripheral portion thereof will be described. Here, only differences from FIG. 1 will be described, and descriptions of the same parts will be omitted.

  The cylinder block 1 is a cylinder block of a V-type multi-cylinder engine, for example, and an appropriate number of cylinders (not shown) are provided in the two banks 1L and 1R. In each cylinder, a piston (not shown) is slidably accommodated. A combustion chamber is defined by the inner peripheral surface of each cylinder, the top surface of each piston, and each concave portion of the cylinder heads 2 and 2. Cylinder heads 2 and 2 are mounted on both banks 1L and 1R of the cylinder block 1, respectively.

  Two sets of secondary air supply devices 4 are provided corresponding to the exhaust ports 2b, 2b of both banks 1L, 1R. The configuration of the secondary air supply device 4 is basically the same as that of the above embodiment, and the secondary air supply passages 21 and 21 and the air switching valves 23 and 23 are not located above the cylinder head covers 3 and 3 but are cylinders. It is arranged on the side of the heads 2 and 2.

  As shown in FIG. 3, the surge tank 7 is disposed in a non-contact manner via an appropriate clearance immediately above the cylinder head covers 3 and 3 of the internal combustion engine and directly below the hood member 11 covering the internal combustion engine. .

  The surge tank 7 is a container that is large in the left-right direction (width direction) so as to cover the left and right cylinder head covers 3 and 3 and is flat in the up-down direction (for example, the vertical direction).

  A space of a predetermined capacity is secured inside the surge tank 7, but this internal space is divided into left and right by a central wall 7a. As shown in FIG. 4, intake ducts 7b and 7c for individually introducing outside air into the left and right internal spaces are provided on the left and right side walls of the surge tank 7 so as to protrude toward the front of the vehicle. It has been. Each intake pipe 5 is attached to the bottom wall 7 d of the surge tank 7 so as to communicate with the left and right internal spaces of the surge tank 7.

  Although not shown, a throttle valve 8 is provided in the middle of the intake ducts 7b and 7c, and a single air cleaner 9 is attached to the projecting ends of the intake ducts 7b and 7c via a 2-in-1 structure pipe. ing.

  The shock absorbing structure for such a surge tank 7 will be described. Specifically, as shown in FIG. 5, when the shock G is applied from the hood member 11, the left and right side portions of the surge tank 7 are shown by arrows and virtual lines in FIG. The structure is such that the shock is absorbed by being deformed or dropped so as to fall into the cylinder head covers 3 and 3 side.

  Specifically, the surge tank 7 is formed of a flexible material such as synthetic resin, and the bottom wall 7d has a fragile portion 7e in a region outside the position where the intake pipes 5 and 5 are connected. , 7f are provided.

  The fragile portions 7e and 7f are formed by partially thinning the bottom wall 7d. When an impact G is applied through the hood member 11, the fragile portions 7e and 7f are damaged, With the fragile portions 7e and 7f as fulcrums, as shown by arrows and phantom lines in FIG. 5, the left and right side portions of the surge tank 7 are guided so as to fall down to the cylinder head cover 3 side.

  As described above, the secondary air supply device 4 is similar to the above embodiment in that the secondary air supply passages 21 and 21 and the air are installed even if the air switching valves 23 and 23 are installed in a place lower than the upper part of the internal combustion engine. The condensate does not stay in the switching valves 23, 23, and the air switching valves 23, 23 are installed not on the surge tank 7 and the cylinder head covers 3, 3, but on the side of the cylinder heads 2, 2. ing.

  As a result, when the surge tank 7 is deformed to absorb shock, for example, when a valve device (air switching valve) is attached to the upper part of the internal combustion engine, the deformation of the surge tank 7 is changed to the valve device (air switching). No need to worry about being blocked by a valve.

  Therefore, while the clearance between the surge tank 7 and the hood member 11 is made as small as possible, a space in which the surge tank 7 is deformed for shock absorption can be easily secured. Therefore, for example, the overall height of the internal combustion engine can be set as low as possible as compared with a case where a valve device (air switching valve) is attached to the upper part of the internal combustion engine, and ignition for the cylinder head 2 of the internal combustion engine. The plug attachment / detachment workability is improved. Furthermore, the height position of the hood member 11 can be set as low as possible, which is advantageous in improving the visibility by the driver.

It is a figure which shows schematic structure of the secondary air supply apparatus which concerns on one Embodiment of this invention. It is a figure which expands and shows the principal part of FIG. It is a figure which shows an example of the internal combustion engine used as the usage object of the secondary air supply apparatus shown in FIG. 1, and has shown the state which looked at the internal combustion engine from the back side. It is a figure which shows the surge tank of FIG. 3 by a plane. In FIG. 3, it is a figure which shows a mode that a surge tank deform | transforms for shock absorption, when an impact is applied to a hood member.

Explanation of symbols

1 Cylinder block
2 Cylinder head
2a Intake port
2b Exhaust port
3 Cylinder head cover
4 Secondary air supply device
5 Intake pipe
6 Exhaust pipe
7 Surge tank 10 Catalyst 11 Hood member 15 Reservoir 16 Venturi (delivery means)
21 Secondary Air Supply Passage 21a Upstream External Piping 21b Downstream External Piping 21c Delivery Passage 21d Communication Passage 21e Through Hole in Downstream External Piping 22 Air Pump 23 Air Switching Valve (Valve Device)
24 controller (control means)
26 On-off valve 27 Actuator 28 Check valve

Claims (9)

A secondary air supply device for supplying secondary air upstream of a catalyst in an exhaust passage of an internal combustion engine,
A secondary air supply passage for guiding secondary air upstream of the catalyst in the exhaust passage;
An air pump that is arranged upstream of the secondary air supply passage and sucks outside air as required and sends it to the downstream side of the secondary air supply passage;
A valve device for opening and closing the secondary air supply passage;
A condensate reservoir that is disposed between the valve device and the exhaust passage in the secondary air supply passage;
A secondary air supply device for an internal combustion engine, comprising: a sending means for sending condensed water in the storage part to the exhaust passage side together with the secondary air. The secondary air supply device for an internal combustion engine according to claim 1,
The secondary air supply device for an internal combustion engine, wherein the sending means sucks condensed water in the storage portion and sends the condensed water to the exhaust passage side together with secondary air. The secondary air supply device for an internal combustion engine according to claim 1 or 2,
The valve device is disposed in the vicinity of the connection position of the secondary air supply passage with respect to the exhaust passage, or on the lower side in the vertical direction from the position,
The section from the valve device to the exhaust passage in the secondary air supply passage is shaped to be bent in a U shape so as to rise after descending from the downstream side of the valve device and toward the exhaust passage,
The secondary air supply device for an internal combustion engine, wherein the storage portion is a container provided so as to surround a descending portion of the secondary air supply passage. The secondary air supply device for an internal combustion engine according to claim 3,
The delivery means sucks the condensed water in the storage section by increasing the flow rate of the secondary air that is provided in the descending portion surrounded by the storage section in the secondary air supply passage, and circulates the secondary air. And a secondary air supply device for an internal combustion engine, characterized in that it is a venturi to be sent downstream. The secondary air supply device for an internal combustion engine according to claim 4,
The valve device is a unit in which an open / close valve disposed on the upstream side of the secondary air supply passage and opened / closed by an actuator and a check valve disposed on the downstream side of the secondary air supply passage are incorporated in the case. And the configuration
Control means for controlling the actuator and the air pump,
The control means drives the air pump at the start of the internal combustion engine and opens the on-off valve by an actuator to generate a function of discharging the condensed water by the venturi. Feeding device. The secondary air supply device for an internal combustion engine according to claim 5,
The control means scavenges the secondary air supply passage and the inside of the valve device by driving an air pump and opening an on-off valve by an actuator when the internal combustion engine is stopped. Air supply device. The secondary air supply device for an internal combustion engine according to any one of claims 1 to 6,
The secondary air supply passage includes an upstream external pipe that communicates and connects the air pump and the valve device, a delivery passage that is provided in the cylinder head of the internal combustion engine along the cylinder arrangement direction, and the delivery passage and the cylinder head. A secondary air supply device for an internal combustion engine, comprising: a communication passage that connects and communicates with an exhaust port; and a downstream external pipe that communicates and connects the delivery passage and the valve device. A secondary air supply device for supplying secondary air to the upstream side of the catalyst in the exhaust passage of the internal combustion engine; and provided in the middle of the intake passage and disposed in the upper part of the internal combustion engine to deform when the impact is applied And a surge tank with a structure that absorbs
8. The vehicle according to claim 1, wherein the secondary air supply device is configured as described in any one of claims 1 to 7. The vehicle according to claim 8, wherein
The internal combustion engine is a V-type multi-cylinder engine, and two sets of secondary air supply passages and valve devices provided in the secondary air supply device are provided corresponding to the exhaust passages for each of the left and right banks,
The surge tank is a container that is sized to cover the left and right cylinder head covers and is flat in the vertical direction, and its left and right side portions fall down to the cylinder head cover side when an impact is applied from a hood member that covers the internal combustion engine. It is structured to absorb shocks by deforming or dropping out,
Each of the valve devices is arranged in a state of being separated from the surge tank on a side of each of the left and right cylinder head covers.

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