JP4243991B2 - Hydrocarbon emission reduction device for internal combustion engine - Google Patents

Description

The present invention relates to a hydrocarbon emission reduction device for an internal combustion engine that reduces the emission of hydrocarbons (hereinafter also referred to as “HC”) from the internal combustion engine.

In an internal combustion engine, fuel (HC) remains in the vicinity of an intake port due to fuel leaking from a fuel injection valve (oil-tight leak), fuel blowback from a combustion chamber, fuel inflow from a PCV (Positive Crankcase Ventilation) passage, and the like. The fuel (HC) remains even after the operation of the internal combustion engine is stopped. In a multi-cylinder internal combustion engine, fuel (HC) remains in the intake manifold. If this residual HC is left unattended, the next time the engine is started, the floating hydrocarbons near the intake port are sucked into the combustion chamber along with cranking by a starter motor or the like, and are further discharged unburned. Arise.

Therefore, Patent Documents 1 to 3 listed below have been proposed as conventional techniques for solving the above inconvenience. That is, in Patent Document 1, an adsorbent is provided between the throttle valve of the internal combustion engine and the engine body, and the fuel leaked from the fuel injection valve is adsorbed by the adsorbent. In Patent Document 2, HC is provided in an intake passage of an internal combustion engine.
An adsorbent is provided, and HC remaining in the intake passage is removed by the HC adsorbent. Further, in Patent Document 3, while the internal combustion engine is stopped, HC remaining in the intake passage is temporarily stored in the HC adsorbent, and the stored HC is released after the catalyst is activated or a predetermined time has elapsed since the engine is started. I am doing so.

Each of the above prior arts is consistent in that an HC adsorbent is installed in the intake passage of the internal combustion engine, and such a configuration can effectively adsorb HC components.
JP 11-82192 A JP 2001-227421 A Japanese Patent Laid-Open No. 2001-234781

However, the following problems occur in the above-described conventional technology. That is, during the operation of the internal combustion engine, high boiling point HC is mixed and floats in the vicinity of the intake port due to fuel blowback from the combustion chamber, fuel inflow from the PCV passage (especially engine oil inflow in the fuel), and the like. In such a case, in the configuration in which the HC adsorbent is installed in the intake passage as described above, HC having a high boiling point adheres to the HC adsorbent. Since the high boiling point HC once adsorbed to the HC adsorbent is not released thereafter, the HC adsorbing performance of the HC adsorbent is remarkably deteriorated, resulting in a problem that a sufficient HC reduction effect cannot be obtained.

In Patent Document 2, it is proposed to install the HC adsorbent upstream of the throttle valve, for example, in an air cleaner, or to use a canister for adsorbing fuel evaporative gas generated in the fuel tank as the HC adsorbent. ing. Since the high boiling point HC has a shorter floating distance from the engine body than the low boiling point HC, the above configuration makes it difficult for the high boiling point HC to adhere to the HC adsorbent during engine operation. Conceivable. However, in the configuration in which the HC adsorbent is installed upstream of the throttle, or in the configuration in which the canister is used as the HC adsorbent, the low boiling point HC remaining in the vicinity of the intake port is effective even if the engine temperature drops after the engine stops. When the engine is started next time, there is a problem that HC in the vicinity of the intake port is sucked into the combustion chamber along with cranking by a starter motor or the like, and is discharged unburned.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a hydrocarbon emission reduction device for an internal combustion engine that can effectively reduce the emission of hydrocarbons.

In the hydrocarbon emission reduction device according to the first aspect, the air suction passage is connected to the downstream portion of the throttle valve in the intake passage of the internal combustion engine. Further, a hydrocarbon adsorbent for adsorbing hydrocarbons and a suction pump for performing an air suction operation are provided in the air suction passage. Then, when the suction pump is driven while the operation of the internal combustion engine is stopped, hydrocarbons floating near the intake port are sucked through the air suction passage. Thereby, the hydrocarbon floating in the vicinity of the intake port is adsorbed by the hydrocarbon adsorbent.

In short, after the operation of the internal combustion engine is stopped, hydrocarbons (unburned fuel) and oil remain near the intake port of the intake passage, and some of them float near the intake port. By performing suction through the suction passage, hydrocarbons floating in the vicinity of the intake port are efficiently adsorbed by the hydrocarbon adsorbent. Further, during the operation of the internal combustion engine, hydrocarbons having a high boiling point are mixed and floated in the vicinity of the intake port due to fuel blowback from the combustion chamber, etc., but in the present invention, the hydrocarbon adsorbent is taken into the intake air via the air suction passage. Since it is provided away from the passage, floating hydrocarbons are not adsorbed to the hydrocarbon adsorbent during engine operation, and a decrease in hydrocarbon adsorption performance can be suppressed. As described above, at the time of the next engine start, it is possible to suppress a situation in which floating hydrocarbons near the intake port are sucked into the combustion chamber and discharged unburned with cranking. As a result, hydrocarbon emissions can be effectively reduced.
Further, the engine temperature is detected, and when the detected engine temperature is equal to or higher than a predetermined temperature, air suction by the suction pump is prohibited. When the engine temperature such as engine water temperature, intake air temperature, engine oil temperature, etc. is high, it is considered that high boiling point hydrocarbons are filled in the vicinity of the intake port. Adsorption of hydrocarbons may lead to deterioration of the hydrocarbon adsorbent. Therefore, air suction by the suction pump is prohibited until the engine temperature is lowered and hydrocarbons having a high boiling point are liquefied. It is also possible to estimate the engine temperature from the transmission oil temperature and prohibit the air suction by the suction pump when the estimated temperature is equal to or higher than a predetermined temperature.

In the second aspect of the present invention, since the air suction passage is connected to the branch portion branched from the intake manifold portion in the multi-cylinder internal combustion engine, hydrocarbons mainly floating in the vicinity of the intake port can be efficiently removed. If the air suction port of the air suction passage is provided in the immediate vicinity of the throttle valve, air suction is performed from the upstream side of the throttle, and the floating hydrocarbons may not be sufficiently removed. Inconvenience is also eliminated. The branch portion corresponds to an intake manifold.

In the invention according to claim 3, since the hydrocarbon adsorbent is installed in a place where an air flow to the intake passage is generated during operation of the internal combustion engine, the hydrocarbon once adsorbed by the hydrocarbon adsorbent is When the engine is operating, it is separated by the air flow to the intake passage and discharged to the intake passage. Thereby, the hydrocarbon adsorption capacity in the hydrocarbon adsorbent is recovered.

According to a fourth aspect of the present invention, during operation of the internal combustion engine, an air suction passage between the intake passage and the hydrocarbon adsorbent is opened, and is adsorbed on the hydrocarbon adsorbent through the air suction passage. The released hydrocarbon was discharged into the intake passage. In this case, the hydrocarbon once adsorbed by the hydrocarbon adsorbent can be released into the intake passage by opening the air suction passage.

According to a fifth aspect of the present invention, a fuel evaporative gas emission suppression device is provided, and the fuel evaporative gas (evaporative gas) generated in the fuel tank is temporarily adsorbed by the canister, and the fuel adsorbed by the canister is engine. During operation, the air is discharged to the intake passage through the purge passage. In this configuration, the canister is used as the hydrocarbon adsorbent, and the intake passage and the canister are communicated with each other while the operation of the internal combustion engine is stopped. In this case, the cost can be prevented by diverting the existing canister as the hydrocarbon adsorbent. In this configuration, the purge passage corresponds to the air suction passage.

According to a sixth aspect of the present invention, in the fuel evaporative emission control device, a purge control valve for opening or closing the purge passage is provided in the purge passage, and the internal combustion engine is operated according to the state of the engine during the operation. The purge control valve is opened to release the hydrocarbon adsorbed on the canister. In this case, since the canister purge is performed according to the operating state of the internal combustion engine, an unstable behavior of the internal combustion engine can be prevented at the time of hydrocarbon release.

According to the seventh aspect of the invention, there is provided a leak check module for performing air suction on at least the fuel evaporative gas flow path from the fuel tank to the canister to detect the presence or absence of leakage in the fuel evaporative gas flow path. A negative pressure pump used in the leak check module is used as the suction pump. In this case, the cost increase can be prevented by using the negative pressure pump of the existing leak check module as a suction pump.

According to an eighth aspect of the present invention, a bypass passage that bypasses the throttle valve provided in the intake passage and an idle speed control valve provided in the bypass passage are provided, and the bypass passage is used as the air suction passage. The hydrocarbon adsorbent was provided in the middle of the bypass passage. In this case, cost can be prevented from being increased by diverting the existing bypass passage as an air suction passage.

According to the ninth aspect of the present invention, an air-assisted fuel injection valve is applied in which air is ejected from the tip of the fuel injection valve to atomize the fuel spray, and an assist air supply passage for the fuel injection valve is applied. Was used as the air suction passage, and the hydrocarbon adsorbent was provided in the middle of the assist air supply passage. In this case, since the air intake port is the tip of the fuel injection valve, even if a large amount of hydrocarbon remains in the vicinity of the intake port, it can be efficiently removed. Further, by using the existing assist air supply passage as an air suction passage, it is possible to prevent an increase in cost.

According to a tenth aspect of the present invention, there is provided a vehicle brake system having a brake booster as a brake booster and a negative pressure pump for generating a negative pressure with respect to the brake booster, and the suction pump is sucked into the suction pump. Use as a pump. In this case, it is possible to prevent an increase in cost by using the existing negative pressure pump for securing the brake negative pressure as a suction pump.

In the invention described in claim 11, the air suction flow rate of the suction pump is limited to a flow rate at which hydrocarbons do not blow through the hydrocarbon adsorbent. Due to the limitation of the air suction flow rate, hydrocarbons are reliably adsorbed on the hydrocarbon adsorbent.

In the invention according to claim 12, after the operation of the internal combustion engine is stopped, air suction by the suction pump is performed after a predetermined soak time has elapsed. Specifically, after the operation of the internal combustion engine is stopped, air suction by a suction pump may be performed after a time when the concentration of hydrocarbons floating in the vicinity of the intake port is predicted to be stable. As a result, it is possible to avoid a situation where floating hydrocarbons are generated again after air suction.

In the inventions according to claims 13 and 14 , when the internal combustion engine is stopped, the release of the door lock or the door opening of the vehicle on which the internal combustion engine is mounted is detected, and air suction by the suction pump is performed at the time of detection. . In order to reliably prevent hydrocarbon emissions during cranking, it is desirable to remove hydrocarbons floating in the vicinity of the intake port immediately before the start of cranking. According to claims 13 and 14 , the floating hydrocarbons Can be suitably removed. Thereby, the discharge | emission of the hydrocarbon at the time of cranking can be prevented more reliably.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings. The present embodiment embodies a hydrocarbon emission reduction device for a four-cylinder gasoline injection engine mounted on a vehicle, and FIG. 1 is a configuration diagram showing an outline of the engine control system.

As shown in FIG. 1, in the engine 10, an air cleaner 12 is provided at the most upstream portion of the intake pipe 11, and an air flow meter 13 for detecting the intake air amount is provided downstream thereof. The air flow meter 13 incorporates an intake air temperature sensor for detecting the intake air temperature. A throttle valve 14 whose opening degree is adjusted by a throttle actuator such as a DC motor is provided on the downstream side of the air flow meter 13. A surge tank 15 is provided on the downstream side of the throttle valve 14, and an intake manifold 16 that introduces air into each cylinder of the engine 10 is connected to the surge tank 15. A fuel injection valve 17 is attached to the intake port of each cylinder of the intake manifold 16. The intake pipe 11, the surge tank 15, and the intake manifold 16 constitute an intake passage.

The exhaust pipe 21 is provided with a catalyst 22 such as a three-way catalyst for purifying CO, HC, NOx and the like in the exhaust gas, and the upstream side of the catalyst 22 detects the exhaust gas as a detection target, or the air-fuel ratio of the air-fuel mixture or An air-fuel ratio sensor 23 (linear air-fuel ratio sensor, oxygen sensor, etc.) for detecting rich / lean is provided.

Further, the engine 10 is provided with a fuel evaporative emission control device for suppressing the evaporative gas (evaporative gas) generated in the fuel tank 31 from being discharged to the outside. That is, one end of a conduit 32 is connected to the fuel tank 31, and a canister 33 is connected to the other end of the conduit 32. The canister 33 stores a large number of adsorbents made of activated carbon, for example, for adsorbing fuel evaporative gas generated in the fuel tank 31. The canister 33 can communicate with the atmosphere side through a path including the conduit 37, the electromagnetic switching valve 41, the filter 39, and the like, and fresh air is introduced into the canister 33 through the path. Canister 3
3 is connected to the intake manifold 16 through a purge pipe 34, and an electromagnetically driven purge control valve 35 is provided in the middle of the purge pipe 34. Therefore,
When the purge control valve 35 is opened, intake negative pressure acts on the purge pipe 34,
At this time, fresh air is introduced into the canister 33 through the conduit 37 and the like, so that the adsorbed fuel is released from the adsorbent in the canister 33 and discharged to the intake manifold 16. The amount of gas discharged to the intake manifold 16 (purge gas amount) is controlled by the purge control valve 35.

The conduit 37 connected to the canister 33 is used for performing a leak check (leakage diagnosis) on the fuel evaporative gas flow path from the fuel tank 31 to the purge control valve 35 via the canister 33. A leak check module 40 is provided. The leak check module 40 includes an electromagnetic switching valve 41, a check valve 42, a suction pump 43, a pressure sensor 44, and a reference orifice 45. The electromagnetic switching valve 41 is held in a state of communicating between a and b in the figure when not energized, and shifts to a state of communicating between a and c in the figure with energization.

During operation of the engine 10, the purge control valve 35 is turned on (opened) and the electromagnetic switching valve 41 is held in the state shown in the figure (communication between a and b), and fresh air is introduced by the intake negative pressure as described above. Then, the adsorbed fuel of the canister 33 is taken into the intake manifold 16.
To be released. For example, when the leak check of the fuel evaporative gas flow path is performed immediately after the operation of the engine 10 is stopped, the purge control valve 35 is turned off (closed).
At the same time, the electromagnetic switching valve 41 is energized to establish a communication state between a and c. Thereby, the inside of the fuel evaporative gas flow path becomes a sealed space. Then, the suction pump 43 is driven to depressurize the inside of the fuel evaporative gas passage, and a leak check is performed based on the pressure change at that time.

An electronic control unit (hereinafter referred to as an ECU) 50 is configured around a microcomputer, and the ECU 50 includes an air-fuel ratio detection signal of the air-fuel ratio sensor 23 described above,
In addition, an intake air amount signal, an intake air temperature signal, an engine coolant water temperature signal, an engine speed signal, an accelerator opening signal, an ignition switch (hereinafter referred to as IG switch) 52 operation signal, and the like are input. The ECU 50 controls the drive of the fuel injection valve 17 based on various input signals, as well as the purge control valve 35 and the electromagnetic switching valve 4.
1. The drive of the suction pump 43 and the like is controlled. The ECU 50 is provided with a soak timer 51 for measuring the elapsed time after the engine is stopped.

In the engine 10, HC remains in the vicinity of the intake port such as the intake manifold 16 due to fuel leaking from the fuel injection valve 17 (oil tight leak), fuel blow back from the combustion chamber, fuel inflow from the PCV passage, and the like. The HC remains even after the 10 operation is stopped. If this residual HC is left unattended, floating HC in the vicinity of the intake port is sucked into the engine combustion chamber along with cranking at the next engine start, and is further discharged unburned. Therefore, in the present embodiment, floating HC in the vicinity of the intake port is sucked while the engine is stopped, thereby suppressing HC discharge when starting the engine. Details will be described below.

FIG. 2 is a flowchart showing an air suction process performed while the engine is stopped. This process is performed as a function of the ECU 50. This air suction process is started by the ECU 50 when the time measured by the soak timer 51 reaches a predetermined time. Specifically, the air suction process is started after the engine is stopped (ignition OFF).
Implemented when minutes have passed. In practice, however, the fuel injection valve 1
It is desirable that the air suction process be performed after the time when it is predicted that the floating HC concentration in the vicinity of the intake port will be stable, and in this embodiment, when 6 hours have passed since the engine stopped. This air suction process is performed.

In FIG. 2, in step S101, ECU power ON processing is performed to turn on the power supply system of various devices related to air suction. In subsequent steps S102 to S104, air suction execution conditions are determined. That is, in step S102, it is determined whether or not the engine water temperature is within a predetermined temperature range (for example, 0 to 60 ° C.).
In 103, it is determined whether or not the intake air temperature is within a predetermined temperature range (for example, 0 to 60 ° C.), and in step S104, it is determined whether or not air suction is not performed after the engine is stopped. As conditions for performing air suction, it is possible to use that the engine oil temperature and the transmission oil temperature are within a predetermined temperature range in addition to the above. If all of the execution conditions are satisfied, the process proceeds to step S105, and the purge control valve 35, the electromagnetic switching valve 41, and the suction pump 43 are all turned on to perform air suction. That is, when the engine water temperature or the intake air temperature is equal to or higher than a predetermined value, the temperature in the vicinity of the intake port (intake manifold 16) is high, and it is considered that the high boiling point HC is filled in the vicinity of the intake port. Therefore, air suction by the suction pump 43 is prohibited until the temperature in the vicinity of the intake port decreases and the high boiling point HC is liquefied.

In this case, when the purge control valve 35 is turned on (opened), the intake manifold 16 and the canister 33 communicate with each other, and in this state, air suction is performed by the suction pump 43. As a result, HC floating in the vicinity of the intake port is sucked through the purge pipe 34 and is adsorbed by the canister 33. At this time, the pump 43 is driven while the air suction flow rate of the suction pump 43 is limited so that HC does not blow through the canister 33. Specifically, the air suction flow rate is limited by intermittently driving the suction pump 43 or limiting the drive voltage or drive current of the suction pump 43.

Thereafter, in step S106, it is determined whether or not a predetermined time (for example, about 1 minute) has elapsed after the start of air suction. If the predetermined time has not elapsed, the present processing is terminated. If the predetermined time has elapsed, the process proceeds to step S107, and the ECU power is turned off.

After the fuel (HC) is adsorbed to the canister 33 as described above, the purge control valve 35 is opened according to the engine operating state at that time during engine operation, and the HC adsorbed to the canister 33 is released. FIG. 3 shows the ECU 5 during engine operation.
7 is a flowchart showing a purge control process executed by 0.

In FIG. 3, first, in step S <b> 201, the electromagnetic switching valve 41 and the suction pump 43.
In step S202, the conditions for performing canister purge are determined. As is well known, the purge execution condition includes that the engine 10 is in a driving state, the engine speed is a predetermined value or more, the intake air amount is a predetermined value or more, and the like.

If the purge execution condition is satisfied, the process proceeds to step S203, where the purge control valve 35
Turn on and perform canister purge. By performing the canister purge in this way, the HC adsorption capacity in the canister 33 is recovered. If the purge execution condition is not satisfied, the process proceeds to step S204, the purge control valve 35 is kept OFF, and the canister purge is not performed.

  According to the embodiment described above in detail, the following excellent effects can be obtained.

Air suction through the purge pipe 34 is performed while the engine is stopped, so that floating HC in the vicinity of the intake port is efficiently adsorbed to the canister 33. Further, during engine operation, high boiling point HC is mixed and floats in the vicinity of the intake port due to fuel blowback from the combustion chamber, but the floating HC is not adsorbed to the canister 33 as a hydrocarbon adsorbent. , A decrease in HC adsorption performance can be suppressed. As described above, at the next engine start, floating H
A situation in which C is sucked into the combustion chamber and discharged without being burned can be suppressed. As a result, the HC emission amount can be effectively reduced.

By diverting the canister 33 as a hydrocarbon adsorbent and diverting the suction pump 43 (negative pressure pump) of the leak check module 40, it is possible to prevent an increase in cost.

Since the air suction port is provided in the intake manifold 16, HC floating mainly in the vicinity of the intake port can be efficiently removed. If the air suction port is provided in the immediate vicinity of the throttle valve 14, air suction is performed from the upstream side of the throttle, and the floating HC may not be sufficiently removed. However, according to the above configuration, such inconvenience is solved. The Incidentally, it is considered that a configuration in which the air suction port is installed on the downstream side of 1/2 of the entire volume of the surge tank 15 and the intake manifold 16 is considered desirable.

In addition, this invention is not limited to the content of description of the said embodiment, For example, you may implement as follows.

In the above embodiment, the canister 33 of the fuel evaporative emission control device is used as the hydrocarbon adsorbent, but this configuration is changed. Configuration examples as other forms are shown in FIGS. Hereinafter, the difference from FIG. 1 will be mainly described. First, in FIG. 4, an HC adsorbent 63 is provided in the bypass passage 61 in a configuration in which an ISC valve (idle speed control valve) 62 is provided in the bypass passage 61 provided in the intake pipe 11. Further, the branch passage 61 is provided in the bypass passage 61, and the suction pump 65 is provided in the branch portion 61a. In this configuration, when the suction pump 65 is driven while the engine is stopped, the floating HC in the vicinity of the intake port flows through the bypass passage 61 and is adsorbed by the HC adsorbent 63. In this case, by using the bypass passage 61 (including the branch portion 61a) as an air suction passage, it is possible to prevent an increase in cost. When the engine is in operation, the adsorbed HC of the HC adsorbent 63 is released by opening the ISC valve 62.

In FIG. 5, the fuel injection valve 17 is an air-assisted fuel injection valve in which air is ejected from the tip portion so as to atomize the fuel spray. Specifically, an assist air supply passage 71 that connects the intake pipe 11 and the tip of the fuel injection valve 17 is provided, and an electromagnetic opening / closing valve 72 and an HC adsorbent 73 are provided in the middle of the assist air supply passage 71. Further, a branching portion 71 a is provided in the assist air supply passage 71 and this branching portion 7 is provided.
A suction pump 75 is provided at 1a. In this configuration, when the suction pump 75 is driven while the engine is stopped, the floating HC near the intake port flows through the assist air supply passage 71 and is adsorbed by the HC adsorbent 73. In particular, the air intake port is the fuel injection valve 17.
Therefore, even if a lot of HC remains in the vicinity of the intake port, it can be efficiently removed. In this case, the cost increase can be prevented by using the assist air supply passage 71 (including the branching portion 71a) as an air suction passage. By opening the electromagnetic on-off valve 72 during engine operation,
The adsorbed HC of the HC adsorbent 73 is released.

In FIG. 6, in a vehicle brake system having a brake booster 81 as a brake booster and a negative pressure pump 82 for generating a negative pressure with respect to the brake booster 81, the negative pressure pump 82 is used as a suction pump. It is configured to use. Specifically, the intake pipe 11 and the brake booster 81 are connected by a pipe 83, and another pipe 84 leading to the negative pressure pump 82 is connected in the middle of the pipe 83. Further, a bypass pipe 85 is connected to the pipes 83 and 84, and an HC adsorbent 86 is provided in the bypass pipe 85. A three-way solenoid valve 87 is provided at the connection portion between the pipe 84 and the bypass pipe 85. If the three-way solenoid valve 87 is turned off, the flow in the direction A in the figure is allowed, and the three-way solenoid valve 87 is turned on. B in the figure
Directional flow is allowed. In this configuration, the negative pressure pump 82 is driven and the three-way solenoid valve 87 is turned on while the engine is stopped, so that the floating HC in the vicinity of the intake port is removed by the HC adsorbent 86. In this case, it is possible to prevent an increase in cost by using the existing negative pressure pump 82 for securing the brake negative pressure as a suction pump.

The HC adsorbent may be formed of at least one of zeolite and a catalyst component having HC adsorption action in addition to activated carbon.

When the engine is stopped, the vehicle door lock is released or the door is opened,
It is good also as a structure which implements air suction with a suction pump at the time of the detection. In order to surely prevent HC discharge during cranking, it is desirable to remove floating HC in the vicinity of the intake port immediately before the start of cranking.
C can be suitably removed. As a result, HC during cranking
Emission can be prevented more reliably.

It is a block diagram which shows the engine control system in embodiment of invention. It is a flowchart which shows an air suction process. It is a flowchart which shows a purge control process. It is a block diagram which shows the HC discharge | emission amount reducing device in another example. It is a block diagram which shows the HC discharge | emission amount reducing device in another example. It is a block diagram which shows the HC discharge | emission amount reducing device in another example.

Explanation of symbols

10 ... Engine,
11 ... Intake pipe,
14 ... Throttle valve,
15 ... Surge tank,
16 ... intake manifold,
17 ... Fuel injection valve,
31 ... Fuel tank,
33 ... canister,
34 ... Purge piping,
35 ... Purge control valve,
40 ... Leak check module
43 ... suction pump,
50 ... ECU,
61 ... Bypass passage,
62 ... ISC valve,
63 ... HC adsorbent,
65 ... suction pump,
71 ... assist air supply passage,
72 ... Solenoid on-off valve,
73 ... HC adsorbent,
75 ... suction pump,
81 ... Brake booster,
82 ... negative pressure pump,
83, 84 ... piping,
85 ... Bypass piping,
86: HC adsorbent.

Claims (14)

In the intake passage of the internal combustion engine, an air suction passage is connected to the downstream portion of the throttle valve, and a hydrocarbon adsorbent for adsorbing hydrocarbons and a suction pump for performing an air suction operation are provided in the air suction passage. A device for reducing hydrocarbon emissions, wherein the suction pump is driven while the operation of the internal combustion engine is stopped, and hydrocarbons floating near the intake port are sucked through the air suction passage ;
An apparatus for reducing a hydrocarbon emission amount of an internal combustion engine , wherein an engine temperature is detected and air suction by the suction pump is prohibited when the detected engine temperature is equal to or higher than a predetermined temperature .   2. The hydrocarbon emission reduction device for an internal combustion engine according to claim 1, wherein the air suction passage is connected to a branch portion branched from an intake manifold portion in a multi-cylinder internal combustion engine.   The hydrocarbon emission reduction device for an internal combustion engine according to claim 1 or 2, wherein the hydrocarbon adsorbent is installed in a place where an air flow to the intake passage is generated during operation of the internal combustion engine.   During operation of the internal combustion engine, an air suction passage between the intake passage and the hydrocarbon adsorbent is opened, and hydrocarbons adsorbed on the hydrocarbon adsorbent through the air suction passage are released to the intake passage. The hydrocarbon emission reduction device for an internal combustion engine according to any one of claims 1 to 3, wherein   A fuel evaporative emission control device having a canister for temporarily adsorbing fuel evaporative gas generated in a fuel tank and discharging the fuel adsorbed on the canister to the intake passage through a purge passage during engine operation 3. The hydrocarbon discharge of the internal combustion engine according to claim 1, wherein the canister is used as the hydrocarbon adsorbent, and the intake passage and the canister are communicated with each other while the operation of the internal combustion engine is stopped. Quantity reduction device.   In the fuel evaporative emission control device, the purge passage is provided with a purge control valve for opening or closing the passage, and during operation of the internal combustion engine, the purge control valve is opened according to the state of the engine operation at that time. 6. The hydrocarbon emission reduction device for an internal combustion engine according to claim 5, wherein the hydrocarbon adsorbed on the gas is released.   A leakage check module that detects air leakage from at least the fuel evaporative gas flow path from the fuel tank to the canister to detect the presence of leakage in the fuel evaporative gas flow path is provided. 7. The hydrocarbon emission reduction device for an internal combustion engine according to claim 5, wherein a pressure pump is used as the suction pump.   A bypass passage that bypasses the throttle valve provided in the intake passage; and an idle speed control valve provided in the bypass passage, and the hydrocarbon adsorption is performed in the middle of the bypass passage using the bypass passage as the air suction passage. The hydrocarbon emission reduction device for an internal combustion engine according to claim 1 or 2, wherein a material is provided.   Applying a fuel injection valve with air assist, in which air is ejected from the tip of the fuel injection valve to atomize the fuel spray, and the assist air supply passage for the fuel injection valve is used as the air suction passage. The hydrocarbon emission reduction device for an internal combustion engine according to claim 1 or 2, wherein the hydrocarbon adsorbent is provided in the middle of the air supply passage.   A brake system for a vehicle having a brake booster as a brake booster and a negative pressure pump for generating a negative pressure with respect to the brake booster is provided, and the negative pressure pump is used as the suction pump. The hydrocarbon emission reduction device for an internal combustion engine according to claim 1 or 2.   11. The hydrocarbon emission reduction of the internal combustion engine according to claim 1, wherein an air suction flow rate of the suction pump is limited to a flow rate at which hydrocarbons do not blow through the hydrocarbon adsorbent. apparatus.   The carbonization of an internal combustion engine according to any one of claims 1 to 11, wherein after the operation of the internal combustion engine is stopped, air suction by the suction pump is performed after a predetermined soak time has elapsed. Hydrogen emission reduction device.   13. The system according to claim 1, wherein when the internal combustion engine is stopped, the release of the door lock or the opening of the door of the vehicle on which the internal combustion engine is mounted is detected, and air suction by the suction pump is performed at the time of detection. The hydrocarbon emission reduction device for an internal combustion engine according to any one of the above.   In the intake passage of the internal combustion engine, an air suction passage is connected to the downstream portion of the throttle valve, and a hydrocarbon adsorbent for adsorbing hydrocarbons and a suction pump for performing an air suction operation are provided in the air suction passage. A device for reducing hydrocarbon emissions, wherein the suction pump is driven while the operation of the internal combustion engine is stopped, and hydrocarbons floating near the intake port are sucked through the air suction passage;
  A hydrocarbon discharge of the internal combustion engine, wherein when the internal combustion engine is stopped, the release of the door lock of the vehicle equipped with the internal combustion engine or the opening of the door is detected, and air suction is performed by the suction pump at the time of detection. Quantity reduction device.

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