JP4539439B2 - In-cylinder direct injection spark ignition internal combustion engine controller - Google Patents

Description

  The present invention relates to an in-cylinder direct injection type spark ignition internal combustion engine that directly injects fuel into a cylinder, and in particular, at a cold start in which early temperature rise (early activation) of an exhaust system catalytic converter is required. It relates to control of injection timing and ignition timing.

In Patent Document 1, as a catalyst warm-up method for a direct injection spark ignition internal combustion engine, a period from an intake stroke to an ignition timing when the exhaust gas catalytic converter is in an unwarmed state lower than an activation temperature. In this case, it is possible to spread the fuel by the late injection in which the air-fuel mixture having a partial air-fuel ratio concentration is formed in the combustion chamber, the fuel is injected before this late injection, and the fuel of the late injection and the combustion of the late injection And at least two split injections of early injection for generating an air-fuel mixture leaner than the stoichiometric air-fuel ratio in the combustion chamber, and retarding the ignition timing by a predetermined amount from the MBT point, and no engine load A technique is described in which the ignition timing is set before the compression top dead center in the region, and the ignition timing is retarded until the compression top dead center in the low speed and low load region excluding the no-load region. The latter-stage injection is performed after the middle of the compression stroke, for example, at 120 ° BTDC to 45 ° BTDC.
Japanese Patent No. 3325230

  For early activation of the catalyst when the internal combustion engine is cold and HC reduction due to afterburning, retarding the ignition timing is effective. To obtain a greater effect, ignition after compression top dead center (ATDC) Ignition) is desirable. In order to perform stable combustion by ATDC ignition, it is necessary to shorten the combustion period. For this reason, it is necessary to increase the combustion speed (flame propagation speed) by strengthening the turbulence in the cylinder.

  In order to strengthen such disturbance, it is conceivable that the disturbance is generated in the cylinder by the energy of the fuel spray injected at a high pressure in the cylinder.

  However, in Patent Document 1, the first fuel injection (early injection) is performed during the intake stroke, and the second fuel injection (late injection) is performed from 120 ° BTDC to 45 ° BTDC during the compression stroke. Yes. As described above, before the last fuel injection is before the compression top dead center, even if the spray generates turbulence in the cylinder, the turbulence is attenuated after the compression top dead center, and the flame propagation in ATDC ignition Does not contribute to speed increase.

  For example, FIG. 8 shows the magnitude of turbulence in a cylinder when a gas flow control valve (for example, a tumble control valve) provided in an intake port is operated and when such a gas flow control valve is not provided. As shown, the turbulence (part A) generated during the intake stroke by operating the gas flow control valve is attenuated as the compression stroke progresses, and is temporarily accompanied by the collapse of the tumble flow in the latter half of the compression stroke. Although the turbulence increases (the portion indicated by reference symbol B), after the compression top dead center, as shown by the reference symbol C, it rapidly attenuates, and combustion improvement (improving flame propagation) using the turbulence cannot be expected so much. The same applies to turbulence caused by fuel spray, and even if turbulence is generated by fuel injection before compression top dead center, it does not contribute to ignition combustion after compression top dead center.

  Therefore, ATDC ignition is more advantageous for exhaust temperature rise and HC reduction, but combustion stability is not established. Therefore, in Patent Document 1, the ignition timing is set to before compression top dead center (BTDC ignition) in the no-load region. Yes.

  The present invention aims to improve the combustion stability in ATDC ignition for early activation of the catalyst, reduction of HC, and the like based on such a situation.

  The present invention provides a control device for an in-cylinder direct injection spark ignition internal combustion engine that includes a fuel injection valve that directly injects fuel into a cylinder and that includes an ignition plug. When the exhaust gas temperature needs to be raised, such as when the engine is cold, the ignition timing is set after the compression top dead center, and super retard combustion is performed to inject fuel before the ignition timing and after the compression top dead center. It is characterized by that. Note that in a NOx trap catalyst that adsorbs NOx, the sulfur component (SOx) adheres to the catalyst, so that the NOx adsorption performance deteriorates. Therefore, the SOx release treatment (sulfur coating) that forcibly raises the temperature of the catalyst and releases SOx. However, it is also possible to raise the temperature of the exhaust gas during the SOx release process using the above-mentioned super retard combustion. In the present invention, in particular, a part of fuel is injected during the intake stroke or the first half of the compression stroke at the time of a transient in which the load increases at a speed higher than a predetermined change speed during the operation in the super retard combustion. Yes.

  In other words, after the compression top dead center, the turbulence generated in the intake stroke and the compression stroke is attenuated, but the in-cylinder turbulence is generated and strengthened by the fuel injection performed during the expansion stroke after the compression top dead center. Flame propagation with ATDC ignition is facilitated. Therefore, super retard combustion with the ignition timing after the compression top dead center is established stably.

  Here, in the super retard combustion as described above, the fuel injection amount during the expansion stroke as described above is increased when the load suddenly increases due to a sudden increase in the accelerator opening or the input of the auxiliary load. Even so, the rise of torque is relatively slow, which is not preferable in terms of torque response. Further, when the fuel injection amount of the expansion stroke injection exceeds a certain level, an excessively rich air-fuel mixture lump is generated, which causes a deterioration of smoke.

  Therefore, in the present invention, during a transient operation in which the load increases at a speed equal to or higher than a predetermined change speed during operation in super retard combustion, a part of the fuel is injected during the intake stroke or the first half of the compression stroke.

  For example, when the super retard combustion is realized by only one fuel injection during the expansion stroke, the fuel injection during the intake stroke or the first half of the compression stroke is added during the transition.

  Thus, the energy of the fuel injected during the intake stroke or the first half of the compression stroke is converted into torque with higher efficiency than the fuel injection during the expansion stroke. Accordingly, the torque response during the transition is improved. The fuel injected during the intake stroke or the first half of the compression stroke is diffused into the cylinder before the injection timing of the expansion stroke injection, and the fuel from the expansion stroke injection is injected into the cylinder. As a result, the generation of smoke is suppressed.

  In one aspect of the present invention, the super retard combustion may include an early injection that is performed during the intake stroke or the first half of the compression stroke prior to the main injection during the expansion stroke, and in this case, The injection amount of this early injection is increased.

  Further, in one aspect of the present invention, the super retard combustion may include an early injection performed in the latter half of the compression stroke prior to the main injection during the expansion stroke. In this case, the early injection is performed during the transient. Is performed in the first half of the compression stroke and the injection amount is increased.

  Desirably, the ignition timing is advanced at the same time during the transition. Thereby, while avoiding the deterioration of combustion accompanying a load increase, torque response is further improved.

  Desirably, the amount of fuel injection during the intake stroke or the first half of the compression stroke is increased as the increase rate of the load increases.

  As the load increases, the total fuel injection amount corresponding to the load itself increases, but the injection amount of the expansion stroke injection increases the injection amount during the intake stroke or the compression stroke or adds the injection. In the meantime, it may be increased as the total fuel injection amount increases, or may be kept constant without changing, or conversely decreased in consideration of the injection amount of the intake stroke injection or the compression stroke injection. You may make it make it.

  Further, the addition of the intake stroke injection or the compression stroke injection or the increase of the injection amount may be performed at the early stage of the transient, and after the transient change, the injection amount of the fuel injection during the intake stroke or the first half of the compression stroke is gradually increased with time. You may make it reduce to. With this decrease, the amount of expansion stroke injection is gradually increased.

  According to the present invention, it is possible to sufficiently ensure the combustion stability of the super retard combustion in which the ignition timing is set after the compression top dead center. For example, at the time of cold start, the catalyst is activated early and the HC due to the afterburning. Reduction can be achieved. When the load increases rapidly, a part of the fuel is injected during the intake stroke or the first half of the compression stroke, whereby the torque response can be improved and the deterioration of smoke can be avoided.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a configuration explanatory view showing a system configuration of a direct injection type spark ignition internal combustion engine to which the present invention is applied.

  An intake passage 4 is connected to the combustion chamber 3 formed by the piston 2 of the internal combustion engine 1 via an intake valve (not shown), and an exhaust passage 5 is connected via an exhaust valve (not shown). Has been. The intake passage 4 is provided with an air flow meter 6 for detecting the amount of intake air, and an electronically controlled throttle valve 7 whose opening degree is controlled via an actuator 8 by a control signal. The exhaust passage 5 is provided with a catalytic converter 10 for purifying exhaust gas, and air-fuel ratio sensors 11 and 12 are provided on the upstream side and the downstream side, respectively. Further, the upstream air-fuel ratio sensor 11 is provided. Is provided with an exhaust gas temperature sensor 13 for detecting the exhaust gas temperature at the inlet side of the catalytic converter 10.

  A spark plug 14 is disposed at the central top of the combustion chamber 3. A fuel injection valve 15 that directly injects fuel into the combustion chamber 3 is disposed on the side of the combustion chamber 3 on the intake passage 4 side. The fuel that has been regulated to a predetermined pressure by the high-pressure fuel pump 16 and the pressure regulator 17 is supplied to the fuel injection valve 15 via the high-pressure fuel passage 18. Therefore, when the fuel injection valve 15 of each cylinder is opened by the control pulse, an amount of fuel corresponding to the valve opening period is injected. Reference numeral 19 denotes a fuel pressure sensor that detects the fuel pressure, and 20 denotes a low-pressure fuel pump that sends fuel to the high-pressure fuel pump 16.

  In addition, the internal combustion engine 1 is provided with a water temperature sensor 21 for detecting the engine cooling water temperature and a crank angle sensor 22 for detecting a crank angle. Further, an accelerator opening sensor 23 is provided for detecting the amount of depression of the accelerator pedal by the driver.

  The fuel injection amount, injection timing, ignition timing, etc. of the internal combustion engine 1 are controlled by the control unit 25. The control unit 25 receives detection signals from the various sensors described above. The control unit 25 determines the combustion method, that is, the homogeneous combustion or the stratified combustion, in accordance with the engine operating conditions detected by these input signals, and according to this, the electronic control throttle valve 7 is opened. The fuel injection timing and fuel injection amount of the fuel injection valve 15, the ignition timing of the spark plug 14, and the like are controlled. After the warm-up is completed, in a predetermined region on the low-speed and low-load side, as normal stratified combustion operation, fuel injection is performed at an appropriate time in the compression stroke, and ignition is performed before the compression top dead center. Done. The fuel spray is collected in the vicinity of the spark plug 14, thereby achieving extremely lean stratified combustion with an air-fuel ratio of about 30 to 40. Further, in a predetermined region on the high speed and high load side, as normal homogeneous combustion operation, fuel injection is performed during the intake stroke, and ignition is performed in the vicinity of the MBT point before the compression top dead center. In this case, the fuel becomes a homogeneous mixture in the cylinder. As the homogeneous combustion operation, there are homogeneous stoichiometric combustion in which the air-fuel ratio is the stoichiometric air-fuel ratio and homogeneous lean combustion in which the air-fuel ratio is lean about 20 to 30 depending on the operating conditions.

  The present invention performs super retard combustion so that the exhaust gas temperature becomes high at the time of cold start of the internal combustion engine 1 where early temperature rise of the catalytic converter 10 is required. The fuel injection timing and ignition timing will be described with reference to FIG.

  FIG. 2 shows a first embodiment of super retard combustion. In this embodiment, as shown in FIG. 2A, the ignition timing is 15 ° to 30 ° ATDC (for example, 20 ° ATDC), The fuel injection timing (specifically, the fuel injection start timing) is set after the compression top dead center and before the ignition timing. At this time, the air-fuel ratio is set to the stoichiometric air-fuel ratio or slightly lean (about 16 to 17).

  That is, in order to promote catalyst warm-up and reduce HC, ignition timing retardation is effective, and ignition after top dead center (ATDC ignition) is desirable, but in order to perform stable combustion with ATDC ignition, It is necessary to shorten the combustion period, and for this purpose, flame propagation due to turbulence must be promoted. As described above, after the compression top dead center, the turbulence generated in the intake stroke and the compression stroke is attenuated, but in the present invention, by the high pressure fuel injection performed during the expansion stroke after the compression top dead center. The gas flow is generated, and thereby the turbulence in the cylinder can be generated and strengthened. Therefore, flame propagation by ATDC ignition is promoted and stable combustion is possible.

  In particular, by retarding the ignition timing from 15 ° to 30 ° ATDC, a sufficient afterburning effect for early activation of the catalyst and reduction of HC can be obtained. In other words, even if the ignition timing is greatly delayed in this way, the fuel injection is delayed until just before that, and the generation time of the turbulence is also delayed, so that the combustion improvement by improving the flame propagation can be achieved.

  Here, when the load suddenly increases, specifically, during a transient in which the load increases at a speed equal to or higher than a predetermined change speed, as shown in FIG. 2 (b), the intake air precedes the main injection I1 during the expansion stroke. During the stroke, part of the fuel is injected as early injection I2. The injection amount of the early injection I2 varies depending on the load increasing speed. As shown in FIG. 5, the larger the load increasing speed, for example, the change rate ΔTVO of the throttle valve opening TVO, the greater the injection amount of the early injection I2. It is done. In the region where the change rate ΔTVO is small, the fuel injection valve 15 is limited to a predetermined minimum injection time determined in terms of responsiveness, control accuracy, and the like, and the injection amount of the early injection I2 does not decrease any further.

  Further, the injection amount of the main injection I1 when performing the early injection I2 is obtained by subtracting the injection amount of the early injection I2 from the total fuel injection amount commensurate with the required torque.

  As one of the sudden increases in load, when dealing with an auxiliary load applied on and off, the injection amount of the early injection I2 may be given as a constant value determined for each auxiliary device. That is, when a certain auxiliary machine is turned on, a predetermined amount of early injection I2 is performed for a short time immediately after the switching.

  In addition, the ignition timing is advanced with a load increase in order to avoid deterioration of combustion. The final torque of the internal combustion engine can be finely adjusted with good responsiveness by correcting the ignition timing.

  As described above, when the load increases rapidly, the ignition timing is corrected to advance, and the early injection I2 is additionally performed during the intake stroke, so that the torque responsiveness at the time of transition is improved. Then, the fuel from the early injection I2 diffuses into the cylinder before the injection timing of the main injection I1 during the expansion stroke, and the fuel from the main injection I1 is injected here, so that the rich air-fuel mixture lump and the smoke Occurrence is suppressed.

  FIG. 6 shows the operation mode during cold operation. As shown in FIG. 6, even during cold operation, the super retard combustion is canceled in the high load region and the high speed region, and normal stratification is performed. A combustion operation or a homogeneous combustion operation is performed.

  FIG. 7 is a flowchart showing an outline of the control of this embodiment. First, in step 1, it is determined whether or not a prohibition condition for super retard combustion is satisfied. For example, when the cooling water temperature exceeds 80 ° C., or in the high load region or high speed region shown in FIG. 7, super retard combustion is prohibited, so the process proceeds to step 2 and the normal stratified combustion operation or homogeneous is performed as the normal mode. Perform combustion operation. If the super retard combustion is not prohibited, the process proceeds to step 3 to determine whether or not it is within a predetermined period after the load increases rapidly. If “NO” here, the process proceeds to a step 4 to perform the operation only by the super retard combustion, particularly the main injection I1 during the expansion stroke.

  On the other hand, if “YES” in the step 3, the process proceeds to a step 5, and the operation by the early injection I2 and the main injection I1 is performed. Specifically, at the first time, the injection amount of the early injection I2 is determined on the basis of the change rate ΔTVO of the throttle valve opening TVO, and the injection amount of the main injection I1 is considered in consideration of the injection amount of the early injection I2. To decide. Then, early injection I2 is performed during the intake stroke, and main injection I1 is performed during the expansion stroke after compression top dead center. From the second time onward, the injection amount of the early injection I2 is gradually decreased from the initial value, and the injection amount of the main injection I1 is gradually increased correspondingly, and each injection is similarly performed at a predetermined timing.

  Next, FIG. 3 shows a second embodiment of super retard combustion. This is an example in which the fuel injection in the super retard combustion at normal time is divided into two as shown in FIG. 5A, and the first fuel injection is performed during the intake stroke, and the second fuel injection is performed. Perform after compression top dead center. The ignition timing and the air-fuel ratio (the air-fuel ratio obtained by combining two injections) are the same as those in the first embodiment.

  Thus, if fuel injection (early injection I2) is performed during the intake stroke prior to fuel injection (main injection I1) during the expansion stroke after compression top dead center, the disturbance due to fuel spray in the early injection I2 is compressed. It attenuates in the second half and has little effect on gas flow enhancement after compression top dead center, but the injected fuel diffuses throughout the combustion chamber and contributes to the promotion of HC afterburning by ATDC ignition. It is effective for reducing HC and raising exhaust temperature.

  In the case of the second embodiment, at the time of transition in which the load increases at a speed greater than or equal to a predetermined change speed, the injection amount of the main injection I1 during the expansion stroke is basically as shown in FIG. Without changing, the injection amount of the early injection I2 during the intake stroke is increased. Similarly, the ignition timing is advanced with a load increase in order to avoid deterioration of combustion. Note that, similarly to the first embodiment, the increase amount of the injection amount of the early injection I2 may be changed according to the increase rate of the load.

  Next, FIG. 4 shows a third embodiment of super retard combustion. This is an example in which the fuel injection in the super retard combustion at the steady state is divided into two as in the second embodiment, as shown in FIG. 5A, and the first fuel injection is performed in the latter half of the compression stroke. The second fuel injection is performed during the expansion stroke after the compression top dead center. The ignition timing and the air-fuel ratio (the air-fuel ratio obtained by combining the two injections) are the same as those in the first and second embodiments. Thus, when fuel injection (early injection I2) is performed in the latter half of the compression stroke prior to fuel injection during the expansion stroke after compression top dead center (main injection I1), the intake stroke injection (early injection) of the second embodiment is performed. Compared with I2), the compression stroke injection has a slower decay of disturbance due to the fuel spray, so the disturbance due to the first fuel injection (early injection I2) remains, and the second injection after compression top dead center. By performing the fuel injection (main injection I1), the turbulence can be strengthened so as to promote the turbulence generated by the first fuel injection, and further gas flow reinforcement near the compression top dead center can be achieved.

  In the case of the third embodiment, the early injection I2 can increase the disturbance near the top dead center by setting the latter half of the compression stroke (after 90 ° BTDC), and more preferably after 45 ° BTDC. If 20 ° BTDC or later, the gas flow after compression top dead center can be further strengthened.

  In the case of the third embodiment, at the time of transition in which the load increases at a speed greater than or equal to a predetermined change speed, the injection amount of the main injection I1 during the expansion stroke is basically as shown in FIG. 4B. Without changing, the injection amount of the early injection I2 during the compression stroke is increased. At the same time, the injection timing of this early injection I2 is advanced to the first half of the compression stroke. Alternatively, as shown in FIG. 4 (c), the injection timing of the early injection I2 is advanced to the intake stroke. As in the first and second embodiments, the ignition timing is corrected to advance with increasing load in order to avoid deterioration of combustion. Note that, similarly to the first embodiment, the increase amount of the injection amount of the early injection I2 may be changed according to the increase rate of the load.

  The super retarded combustion of the present invention can also be used for releasing sulfur poisoning when a NOx trap catalyst is used as the exhaust system catalytic converter 10. The NOx trap catalyst adsorbs NOx when the exhaust air-fuel ratio of the inflowing exhaust gas is lean, and releases the adsorbed NOx when the exhaust air-fuel ratio of the inflowing exhaust gas is rich, and purifies by catalytic action. However, when the sulfur component (SOx) in the fuel is bound to the catalyst, the NOx adsorption performance is lowered. For this reason, it is necessary to perform a process (so-called sulfur poisoning release) for forcibly raising the temperature of the catalyst and releasing SOx at an appropriate time. The super retarded combustion according to the present invention can obtain a very high exhaust temperature, and therefore is suitable for the sulfur poisoning release processing of this NOx trap catalyst.

BRIEF DESCRIPTION OF THE DRAWINGS The structure explanatory drawing which shows the system structure of the whole internal combustion engine which concerns on this invention. The characteristic view which shows the fuel injection timing and ignition timing of the super retard combustion of 1st Example. The characteristic view which shows the fuel injection timing and ignition timing of the super retard combustion of 2nd Example. The characteristic view which shows the fuel injection timing and ignition timing of the super retard combustion of 3rd Example. The characteristic view which shows the relationship between the injection quantity of the early injection I2, and the change speed (DELTA) TVO of the throttle valve opening degree TVO. The characteristic view which shows the operation mode at the time of the cold machine with respect to engine operation conditions. The flowchart which shows the outline of control. Explanatory drawing which shows the change of the disturbance in a cylinder in a prior art.

Explanation of symbols

3 ... Combustion chamber 10 ... Catalytic converter 14 ... Spark plug 15 ... Fuel injection valve 25 ... Control unit

Claims (13)

In a control device for a direct injection spark ignition internal combustion engine having a fuel injection valve for directly injecting fuel into a cylinder and having an ignition plug, when the exhaust gas temperature is required to rise , the ignition timing Is set after the compression top dead center, and super retard combustion is performed before the ignition timing and after the compression top dead center is performed, while the speed of the load exceeds a predetermined change rate during the operation in the super retard combustion. During a transient increase, a part of the fuel is injected during the intake stroke or the first half of the compression stroke, and the fuel injection amount during the intake stroke or the first half of the compression stroke gradually decreases with time after the transient change. A control device for an in-cylinder direct injection spark ignition internal combustion engine. In a direct injection type spark ignition internal combustion engine control device having a fuel injection valve for directly injecting fuel into a cylinder and having an ignition plug, the ignition timing is compression top dead center in a predetermined operating state. At a later time, during the transition in which the load increases at a speed higher than a predetermined change speed during the operation in the super retard combustion, the super retard combustion is performed before the ignition timing and after the compression top dead center. A control device for a direct injection type spark ignition internal combustion engine that injects a part of fuel during an intake stroke or in the first half of a compression stroke,
Said super-retard combustion is performed by a single fuel injection during the expansion stroke, when the above-mentioned transition, directly into the cylinder you characterized by adding the fuel injection in the first half during or compression stroke the intake stroke injection spark ignition internal combustion Engine control device.   The super retard combustion includes an early injection that is performed during the intake stroke or the first half of the compression stroke prior to the main injection during the expansion stroke, and the injection amount of the early injection is increased during the transition. The control apparatus for a direct injection type spark ignition internal combustion engine according to claim 1. In a direct injection type spark ignition internal combustion engine control device having a fuel injection valve for directly injecting fuel into a cylinder and having an ignition plug, the ignition timing is compression top dead center in a predetermined operating state. At a later time, during the transition in which the load increases at a speed equal to or higher than the predetermined change speed during the operation in the super retard combustion, the super retard combustion is performed before the ignition timing and after the compression top dead center. A control device for a direct injection type spark ignition internal combustion engine that injects a part of fuel during an intake stroke or in the first half of a compression stroke,
The super retard combustion includes early injection performed in the latter half of the compression stroke prior to the main injection during the expansion stroke, and during the transition, the early injection is performed in the first half of the compression stroke and the injection amount is increased. control device to that cylinder direct injection spark ignition internal combustion engine and.   5. The control apparatus for a direct injection spark ignition internal combustion engine according to claim 1, wherein the ignition timing in the super retard combustion is 15 ° to 30 ° CA after compression top dead center.   6. The control device for a direct injection type spark ignition internal combustion engine according to claim 1, wherein the ignition timing is advanced at the same time during the transition.   The in-cylinder direct injection spark ignition internal combustion engine according to any one of claims 1 to 6, wherein the amount of fuel injection during the intake stroke or the first half of the compression stroke is increased as the load increase rate is increased. Control device. The in-cylinder direct injection spark ignition internal combustion engine according to claim 2 or 4 , wherein after the transient change, the injection amount of the fuel injection during the intake stroke or the first half of the compression stroke is gradually decreased with time. Control device. 9. The control apparatus for a direct injection type spark ignition internal combustion engine according to claim 1 , wherein the fuel injection mode is changed at the time of input of an auxiliary machine load as a transition time.   The control apparatus for a direct injection spark ignition internal combustion engine according to any one of claims 1 to 9, wherein the air-fuel ratio in super retarded combustion is a stoichiometric air-fuel ratio or slightly lean. 5. The control of a direct injection spark ignition internal combustion engine according to claim 2 or 4 , wherein the super retard combustion is executed when the exhaust gas temperature needs to be raised as a predetermined operation state. apparatus. The in-cylinder direct injection according to claim 1 or 11, wherein the temperature of the exhaust gas is required to be raised during a cold start of an internal combustion engine that requires an early temperature rise of an exhaust system catalytic converter. Type spark ignition internal combustion engine control device. The control of an in-cylinder direct injection spark-ignition internal combustion engine according to claim 1 or 11, characterized in that a temperature increase of the exhaust gas is required when performing SOx release processing of an exhaust system catalytic converter. apparatus.

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