JP4392689B2 - Cylinder group individually controlled engine - Google Patents

Description

The present invention relates to a multi-cylinder turbocharged diesel engine, wherein each cylinder is divided into a plurality of cylinder groups, the fuel supply amount for each cylinder group can be adjusted, and intake air, EGR gas, and The exhaust passages do not mix with each other in the flow passage circuit, and the intake / exhaust control devices of the turbocharger, the air supply intercooler, the EGR device, and the exhaust gas aftertreatment device are arranged independently in the flow passage circuits of each cylinder group. It is possible to individually control the supply air pressure, the intake air amount, the EGR rate, etc. for each cylinder group, and each cylinder group can perform a rest operation of a part of the cylinder group, so that the thermal efficiency in a wide operating range of the engine The present invention relates to a cylinder group individual control engine that can improve the engine and reduce exhaust gas.

Currently, gasoline engines are mainly used to reduce emissions by using three-way catalysts, while diesel engines are designed to improve combustion by turbocharging and exhaust gas re-circulation (hereinafter referred to as EGR). In addition, diesel particulate filter (Diesel Particulate Filter) (hereinafter referred to as DPF device) and NOx, CO, HC for reducing diesel-specific black smoke and diesel particulate matter (hereinafter referred to as “PM”) NOx storage / reduction catalyst device (hereinafter referred to as NOx storage catalyst device), urea reduction NOx catalyst device (Urea Selective Catalytic Reduction system) (hereinafter referred to as urea SCR) Research and development of diesel exhaust aftertreatment devices (hereinafter referred to as exhaust gas aftertreatment devices) Yes.
Conventional diesel engines are mainly responsible for reducing exhaust emissions when the engine is under high load, where a large amount of exhaust gas is emitted. However, in order to achieve further emission reductions in the future, in addition to the application of new emission reduction technologies, the emission reduction function must be fully demonstrated even under operating conditions when the engine is partially loaded. is necessary.
By the way, in general, in order for the catalyst of the exhaust gas aftertreatment device to function sufficiently, it is necessary to maintain the temperature of the catalyst at a high temperature above a certain level. In the case of a DPF device, it is necessary to remove the collected PM from the filter and regenerate the DPF device in a timely manner. For example, when the collected PM is oxidized and removed by a catalyst, exhaust gas that passes through the DPF device. The temperature needs to be maintained at a high temperature. Further, in a diesel engine, an oxidation catalyst device, a urea SCR device, and a urea SCR device have been researched and developed as devices for purifying exhaust gas with a catalyst. In this case as well, in order for the catalyst to function sufficiently, the exhaust gas temperature of diesel must always be kept high regardless of the operating conditions of the engine in order to maintain the catalyst at a high temperature. However, the conventional diesel engine partial load has a problem that the exhaust gas temperature is low, the activity of the catalyst is inferior, and the purification rate of the exhaust gas of these devices is remarkably lowered. Also, when the turbocharged diesel engine is partially loaded, both the exhaust temperature and the exhaust pressure are low and the exhaust energy is low, so the boost pressure rise by the turbocharger is insufficient and the required intake amount cannot be obtained. The problem is that a sufficient reduction effect of PM and the like due to engine combustion improvement is not obtained.
As a document related to such technology, the function of the catalytic device is improved by operating the multi-cylinder engine with the exhaust gas reduction catalytic device in partial load at the time of partial load and operating in the active cylinder group and the idle cylinder group. For example, Patent Document 1 relating to a non-supercharged spark ignition engine and Patent Document 2 relating to a non-supercharged diesel engine are examples that can be sufficiently exhibited.

The technique of Patent Document 1 is a direct injection type multi-cylinder non-supercharged engine in which intake air is controlled by an electronic throttle and fuel is directly injected into a cylinder. The exhaust passages of the cylinders included in the cylinder are gathered, and an exhaust gas aftertreatment device is attached to each cylinder group downstream of the gathered portion, and fuel supply and ignition are performed for the idle cylinder group during partial load operation of the engine. The operation is stopped, and fuel is supplied and ignited to the operating cylinder group. As a result, the high-temperature exhaust gas discharged from the working cylinder group is guided to the exhaust gas aftertreatment device of the working cylinder group, so that the temperature reduction of the exhaust gas aftertreatment device is prevented and the exhaust gas reduction function of the aftertreatment device is exhibited. It is made to be done.
The technique of Patent Document 2 has a first throttle valve disposed on the inlet side of an intake passage of a multi-cylinder non-supercharged engine and a second throttle valve disposed in an intake passage of a part of the cylinder group downstream of the first throttle valve. During partial load, the second throttle valve is closed and fuel injection to the partial cylinder group is stopped, and fuel is injected into cylinders other than the partial cylinder group, and intake by adjusting the opening of the first throttle valve is performed. By reducing the intake air amount by reducing the pressure of the exhaust gas and reintroducing exhaust gas into the cylinder by opening the exhaust valve near the intake bottom dead center, the temperature of exhaust gas exhausted from cylinders other than that part of the cylinder group increases. The exhaust gas reduction function of the aftertreatment device is exhibited.
JP 2002-349304 A JP 2001-336440 A Automotive Technology, 53-9 (1999), 4-9 “Engine Technology November 1999, Vol. 1, No. 5, pages 15 and 16

  However, in the above-mentioned Patent Document 1, the exhaust passage of the deactivated cylinder group of the multi-cylinder engine is independent for each cylinder group, but the intake passage is common to all the cylinder groups. Not independent. Therefore, for example, when the PFI (port fuel injection) system is adopted as the fuel injection system, the intake ports of the active cylinder group and the idle cylinder group communicate with each other, so that the fuel injected into the intake port of the active cylinder group becomes the idle cylinder group. There is a problem in that it is inhaled and released into the atmosphere as exhaust gas in an unburned state. The technique disclosed in Patent Document 1 cannot be employed in the PFI system in which fuel is injected into the intake port because exhaust gas deteriorates. Further, since the high-temperature exhaust gas discharged from the active cylinder group at the partial load is led to the exhaust gas aftertreatment device of the active cylinder group, the temperature reduction of the exhaust gas aftertreatment device is prevented. The exhaust gas temperature is not high enough only by making the exhaust passages of the group independent, and the exhaust gas temperature can be sufficiently increased by engine combustion combined with the control of the EGR rate and intake air amount of the operating cylinder group. It is also clear that the exhaust gas reduction function of the exhaust gas aftertreatment device is not fully exhibited depending on the load conditions under which the engine is operated. In order to further reduce the exhaust gas during partial load operation of the engine, the exhaust gas temperature can be increased to fully demonstrate the exhaust gas reduction function of the exhaust gas aftertreatment device, and at the same time the engine operating cylinder It is necessary to reduce harmful substances by improving the combustion of each cylinder in the group. However, in the thing of the said patent document 1, since combustion improvement is not combined, it is a problem that exhaust gas reduction cannot fully be performed. Further, Patent Document 1 does not show a form of increasing the exhaust gas temperature by making the exhaust passage of the exhaust turbocharged engine independent.

  In the above-mentioned Patent Document 2, an intake throttle valve is provided in the intake passage of the operating cylinder group to reduce the intake air amount so as to increase the exhaust temperature of the operating cylinder group. However, in the diesel engine, a decrease in the intake air amount causes an increase in PM emission due to a deterioration in engine combustion in the operating cylinder and a deterioration in the engine thermal efficiency of the operating cylinder.

The present invention has been devised in view of the above problems. Each cylinder of a multi-cylinder turbocharged diesel engine equipped with an exhaust turbocharger is divided into a plurality of cylinder groups, and a circuit of a flow path in which intake air, EGR gas, and exhaust gas of each cylinder group do not mix with each other is formed. In order to control the intake air amount, EGR gas amount, and exhaust gas purification of the engine, each intake of the supercharger, the air supply intercooler, the EGR valve, the EGR passage, the EGR cooler, and the exhaust gas aftertreatment device is controlled. The exhaust-related control device is provided independently in the circuit of the flow passage for each cylinder group so that optimum control can be performed for the operating load condition of each cylinder group independently for each cylinder group. Under specific partial load operation conditions of the engine, some cylinder groups of the plurality of cylinder groups are supplied with fuel and burned to generate engine output, and the remaining cylinder groups are fuel. Operates as a deactivated cylinder group whose supply is stopped. In the high load operation region, all cylinder groups are supplied with fuel and all cylinder groups are operated as operating cylinder groups.

  When operating with partial cylinder operation of some cylinder groups as active cylinder groups and other remaining cylinder groups as idle cylinder groups, the pressure and temperature of the combustion gas in each cylinder in the active cylinder group are all Since the cylinder group is operated in a higher state than when operating as the active cylinder group, the engine thermal efficiency is increased. In this way, operating a part of the cylinder group as a deactivated cylinder group at the time of partial engine load makes it possible to operate the engine with higher thermal efficiency than when operating with all the cylinder groups.

Further, the intake / exhaust-related control device is provided independently for each cylinder group and can be controlled independently. Therefore, when an EGR valve capable of controlling the valve opening degree is mounted on the intake / exhaust related control device, the EGR rate is adjusted by controlling the valve opening degree of the EGR valve of the working cylinder group to improve the combustion of the working cylinder group. NOx can be reduced by the above, and it is possible to raise the exhaust temperature discharged from the working cylinder by performing the combustion control for raising the exhaust temperature of the working cylinder group to an appropriate temperature.
In addition, when a variable displacement turbocharger (hereinafter referred to as VG turbocharger) is installed in the intake / exhaust related control device, the exhaust turbine nozzle valve of the working cylinder group VG turbocharger By controlling the intake and adjusting the intake air amount, PM can be reduced by improving the combustion of the active cylinder group, and exhaust control is performed to raise the exhaust temperature of the active cylinder group to an appropriate temperature and exhausted from the active cylinder. It is possible to raise the exhaust temperature.
As described above, by increasing the exhaust temperature of the active cylinder group under the control of the intake / exhaust related control device, the regeneration function of the catalyst regeneration type DPF device arranged in the active cylinder group is exhibited and the PM collection function is maintained. So that the exhaust gas reduction function in the exhaust gas after-treatment device is fully exhibited.
Thus, the present invention divides a multi-cylinder turbocharged diesel engine into a plurality of cylinder groups, disposed intake and exhaust passage and the intake and exhaust associated control device for each cylinder group, associated individual intake and exhaust for each cylinder group by controlling the control device, it is an object to be able to sufficiently reduce the exhaust emissions is discharged to the atmosphere from the engine.

In order to achieve the above object, the present invention adopts the following configuration.
That is, the cylinder group individual control engine according to the invention of claim 1 is a multi-cylinder turbocharged diesel engine, wherein each cylinder is divided into a plurality of cylinder groups and air is supplied to each cylinder of the cylinder group. An independent intake passage is provided for each cylinder group, and an independent exhaust passage is provided for each cylinder group for discharging the exhaust gas of each cylinder of the cylinder group. The multi-cylinder turbocharged diesel engine has an EGR valve, EGR EGR-related devices such as coolers and VG turbochargers, superchargers with waste gates, supercharger-related devices such as intake air intercoolers, and exhaust gas aftertreatment devices such as DPF devices, oxidation catalyst devices, and urea SCR devices Regardless of which exhaust control device is mounted, the intake / exhaust control device is connected to the intake / exhaust circuit for each cylinder group from the intake passage to the exhaust passage for each cylinder group. Middle disposed independently, a circuit of the intake air flow passage EGR gas and the exhaust gas do not mix with each other for each said cylinder group, by a signal from the engine ECU, the intake which is arranged for each of the cylinder groups Each device of the exhaust related control device enables independent control for each cylinder group in accordance with each load condition for each cylinder group, and fuel supply to the cylinder group enables independent control for each cylinder group. The engine load for each cylinder group is independently controlled, and in a specific partial load operation of the multi-cylinder turbocharged diesel engine, an operation is performed in which fuel is supplied to some of the cylinder groups and burned to generate engine output. when the cylinder group in comparison to when driving by all remaining equivalent engine output by driving a suspendable cylinder group to stop the fuel supply in addition to the above cylinder groups of the cylinder group稼The exhaust gas temperature of the cylinder group by high temperature, other in an engine operating region by driving all of the above cylinder groups performing fuel supply to all of the cylinder groups as the operating cylinder group for each said cylinder group engine including a high load By independently controlling the load, intake air amount, and EGR rate, the exhaust gas temperature of the operating cylinder group is increased, and the exhaust gas temperature is increased to improve the regeneration function of the DPF device of the operating cylinder group and the urea SCR device. The exhaust gas reduction function of the exhaust gas aftertreatment device can be sufficiently exhibited to improve the NOx reduction function and the exhaust gas reduction function of the oxidation catalyst device .

In the first aspect of the invention, each cylinder of the multi-cylinder turbocharged diesel engine is divided into a plurality of cylinder groups. Here, a case where a six-cylinder engine is divided into two cylinders of a first cylinder group and a second cylinder group will be described as an example of a plurality of cylinder groups. The ignition intervals of the cylinders in each cylinder group are desirably equal intervals.

  For example, if an in-line six-cylinder four-cycle equidistant ignition engine has an ignition cylinder order of 1-5-3-6-2-4, the first cylinder, the second cylinder, and the third cylinder are defined as 1-cylinder groups. The ignition is performed at an interval of 240 degrees (crank angle) in the order of 3-2 cylinders, and 240 degrees (crank angle) in the cylinder order of 5-6-4 with the fourth cylinder, the fifth cylinder, and the sixth cylinder as the second cylinder group. ).

  In addition, as for the intake passage, in order to supply air to each cylinder of the first cylinder group and the second cylinder group, a first cylinder group intake passage that is independently connected to the first cylinder group and the second cylinder group downstream of the air cleaner, A second cylinder group intake passage is provided. As for the exhaust passage, a first cylinder group that is independently connected to the first cylinder group and the second cylinder group upstream of the exhaust muffler in order to exhaust the exhaust gas of each cylinder of the first cylinder group and the second cylinder group. An exhaust passage and a second cylinder group exhaust passage are provided.

  In this way, between the downstream of the air cleaner and the upstream of the exhaust muffler, a flow passage is formed in which the intake and exhaust gases of the first cylinder group and the second cylinder group do not mix with each other.

Also, the EGR valve, EGR cooler, EGR passage, supercharging device, air supply intercooler and exhaust gas aftertreatment device (DPF device, oxidation catalyst device, NOx occlusion reduction device, urea SCR device) of this multi-cylinder turbocharged diesel engine Etc.) is independently provided for each cylinder group. An intake / exhaust related control device for controlling intake air, EGR gas, and exhaust gas of the first cylinder group is a first cylinder group intake / exhaust circuit of the first cylinder group extending from the first cylinder group intake passage to the first cylinder group exhaust passage. The intake / exhaust related control device for controlling the intake air, EGR gas, and exhaust gas of the second cylinder group is provided in the middle of the second cylinder group intake passage from the second cylinder group intake passage to the second cylinder group exhaust passage. Arranged in the middle of the exhaust circuit. In this way, the intake / exhaust related control devices are independently provided in the intake / exhaust circuit of the first cylinder group and the intake / exhaust circuit of the second cylinder group, respectively, so that intake of the first cylinder group and the second cylinder group is performed. A circuit of a flow path in which air, EGR gas, and exhaust gas do not mix with each other.

  Thus, in the present invention, EGR related devices such as EGR valve, EGR cooler, EGR passage, VG turbocharger, supercharger with wastegate, supercharger related devices such as air supply intercooler, DPF device, oxidation When exhaust gas aftertreatment devices such as a catalyst device, NOx occlusion reduction device, urea SCR device and the like are arranged as necessary, these devices are respectively provided in the intake and exhaust passages of the first cylinder group and the second cylinder group. It is characterized by being arranged independently. Thereby, it is avoided that the intake pulsation and exhaust pulsation of one cylinder group of the first cylinder group and the second cylinder group amplify the pressure fluctuation of the intake passage, the exhaust passage and the EGR gas passage of each cylinder of the other cylinder group. It can be so.

The case where the 6-cylinder engine is divided into two cylinder groups as an example has been described above. However, in a multi-cylinder turbocharged diesel engine having 6 cylinders or more, it may be divided into 3 or more cylinder groups. . Further, for example, if the in-line 4-cylinder 4-cycle equidistant ignition engine has an ignition cylinder order of 1-2-4-3, the first cylinder and the fourth cylinder are the first cylinder group and 360 degrees in the order of 1-4. Ignition is performed at intervals of (crank angle), and ignition is performed at intervals of 360 degrees (crank angle) in the order of 2-3 with the second cylinder and the third cylinder as the second cylinder group.

In a multi-cylinder turbocharged diesel engine divided into a plurality of cylinder groups, in the case of a diesel engine, the fuel is injected directly into each cylinder by an electronically controlled fuel injection nozzle disposed in each cylinder. In that case, an electronically controlled fuel injection device capable of independently controlling the amount of fuel injected into each cylinder is used. As the electronic control fuel injection device at this time, for example, an electronic control unit injector or a common rail unit injector described in Non-Patent Document 1 or Non-Patent Document 2 is used.

Hereinafter, a case where a six-cylinder engine is divided into two cylinders, a first cylinder group and a second cylinder group, will be described as an example of a plurality of cylinder groups. The fuel supply to the first cylinder group and the second cylinder group of the multi-cylinder turbocharged diesel engine provided with the electronically controlled fuel injection device is independently controlled. For example, under specific partial load operation conditions of the engine, engine output is generated as an operating cylinder group that is supplied with fuel by an electronically controlled fuel injection device to the first cylinder group and burned, and fuel supply fuel is supplied to the second cylinder group. The supply is stopped and the engine is operated as a deactivated cylinder group.

Conversely, when the second cylinder group is an active cylinder group, the first cylinder group is operated as a deactivated cylinder group. On the other hand, in the high load operation region of the engine, fuel is supplied to both the first cylinder group and the second cylinder group, and both the first cylinder group and the second cylinder group are operated as operating cylinder groups. In this way, the first cylinder group and the second cylinder group are operated by switching the operating states of the active cylinder group and the deactivated cylinder group as predetermined according to the operating conditions of the multi-cylinder turbocharged diesel engine. It can be so.

  EGR-related devices such as EGR valves, EGR coolers, and EGR passages that are independently provided in the intake passage and the exhaust passage for each of the plurality of cylinder groups, a VG turbocharger, a supercharger with a wastegate, an air supply Exhaust gas after-treatment devices such as supercharger-related devices such as intercoolers, DPF devices, oxidation catalyst devices, NOx occlusion reduction devices, urea SCR devices, etc. are provided for each cylinder group according to the respective engine load operating conditions for each cylinder group. Independent control is possible.

Hereinafter, a case where a 6-cylinder turbocharged diesel engine is divided into two cylinders, a first cylinder group and a second cylinder group, will be described as an example of a plurality of cylinder groups.
For example, when a VG turbocharger or an EGR device is installed, when the engine is operated at a specific partial load, the first cylinder group is operated as the active cylinder group and the second cylinder group is operated as the idle cylinder group. The VG turbocharger adjusts the opening of the exhaust turbine nozzle valve in accordance with the engine load operating condition of the first cylinder group. The EGR valve of the first cylinder group also adjusts the opening degree of the EGR valve according to the engine load operating condition of the first cylinder group.

  On the other hand, the opening degree of the exhaust turbine nozzle valve and the opening degree of the EGR valve of the VG turbocharger of the second cylinder group are adjusted to the opening degree corresponding to the idle cylinder group different from the first cylinder group.

As described above, according to the first aspect of the present invention, in the multi-cylinder turbocharged diesel engine divided into a plurality of cylinder groups, an independent intake passage, exhaust passage, and EGR gas passage are provided for each cylinder group, In order to control exhaust gas purification by controlling the engine intake amount, intake boost pressure, EGR rate for each cylinder group, EGR valve, EGR cooler, EGR passage, supercharger, air supply intercooler, exhaust Intake / exhaust related control devices of gas aftertreatment devices (DPF device, oxidation catalyst device, NOx occlusion reduction device, urea SCR device, etc.) are arranged independently for each cylinder group. Therefore, the circuit is a flow path in which intake air, EGR gas, and exhaust gas are not mixed with each other for each cylinder group.
This prevents a problem that the intake pulsation and exhaust pulsation of one cylinder group interfere with each other and the intake pulsation and exhaust pulsation of the other cylinder group, and is effective in reducing stable exhaust gas under all engine operating conditions.

  Fuel supply to the plurality of cylinder groups is independently controlled, and fuel is supplied to some cylinder groups of the plurality of cylinder groups to generate engine output under specific partial load operation conditions of the engine. The operating cylinder group is operated, and the remaining cylinder group is operated as a deactivated cylinder group in which fuel supply is stopped. When operating a part of the cylinder group as a deactivated cylinder group under such an engine partial load operation condition, the combustion pressure and the combustion temperature are increased in each cylinder of the operating cylinder group, so that the engine cycle efficiency is increased, As compared with the case where the engine output is operated by all the cylinder groups, an effect of improving the thermal efficiency of the entire engine can be obtained.

Further, during the idle operation of some cylinder groups, the exhaust temperature of the active cylinder group becomes high, so that the exhaust gas aftertreatment device (DPF device, oxidation catalyst device, NOx occlusion reduction device, urea SCR device, etc.) of the active cylinder group The exhaust gas reduction function can be fully exerted, and a large exhaust gas reduction can be obtained.

In the partial load of the multi-cylinder turbocharged diesel engine, when the engine is operated with one cylinder group of the first cylinder group or the second cylinder group as an active cylinder group and the other remaining cylinder group as a deactivated cylinder group The independent control of the control elements in the individual devices of the intake / exhaust-related control device according to the operating state of each cylinder group, without being affected by the operating state of other cylinder groups, That is, it is possible to optimally control the intake air amount, the intake and intake boost pressure, the EGR rate, and the exhaust gas temperature of each of the first cylinder group and the second cylinder group.
For this reason, when operating part of the engine as a part of the operating cylinder group while operating part of the cylinders as the active cylinder group and other remaining cylinder groups as the idle cylinder group, the exhaust energy of the active cylinder group is used to pressurize the intake air of the idle cylinder group. Since all of them are used for pressurizing the intake air of the operating cylinder group, the supercharging efficiency of the operating cylinder group is improved, the pumping loss of the engine is reduced, and the engine thermal efficiency is improved.

  Further, when a supercharger having a variable capacity of a VG turbocharger or a supercharger with a wastegate is provided as a supercharger, the exhaust turbine nozzle valve opening of the VG turbocharger of the working cylinder group Alternatively, the intake air amount of the operating cylinder group can be controlled by adjusting the wastegate valve opening. Thereby, it is possible to raise the temperature of the exhaust gas flowing into the exhaust gas aftertreatment device disposed downstream of the exhaust gas outlet of the supercharger. Here, when an exhaust gas aftertreatment device (oxidation catalyst device, NOx occlusion reduction device, urea SCR device, etc.) that applies catalytic action to the operating cylinder group is disposed, the exhaust gas is caused by the inflow of the exhaust gas at a high temperature. Since the purification rate of the engine becomes high, it has a great effect on engine exhaust gas reduction. Further, when a catalyst regeneration type DPF device is disposed in the operating cylinder group, since the exhaust gas having a high temperature flows into the DPF device, a sufficient regeneration function of the DPF device by the catalyst is exhibited. There is an effect that the continuous operation of the PM collection function of the regenerative DPF device can be realized.

As described above, by raising the exhaust temperature of the operating cylinder group under the control of the specific intake / exhaust related control device, the regeneration function of the catalyst regeneration type DPF device arranged in the operating cylinder group is exhibited, and the PM collection function is achieved. It is possible to realize a continuous operation and to fully exhibit the exhaust gas reduction function in the exhaust gas aftertreatment device.
Similarly, even when an EGR valve is provided in the operating cylinder group, the exhaust gas exhausted from the engine is improved by controlling the EGR rate of the operating cylinder group without being affected by the deactivated cylinder group. Can be greatly reduced. Therefore, combustion improvement of high temperature and operating cylinder group of the temperature of exhaust gas flowing into the exhaust gas after the exhaust gas reduced by improved combustion of the operating cylinder group is effective in purifying gases exiting exhaust further engines .

A first embodiment of the present invention will be described in detail with reference to FIGS. First, the division into a plurality cylinder groups of the respective cylinders of a multi-cylinder turbocharged diesel engine body in the first embodiment, a specific configuration for the intake and exhaust manifold connected to each cylinder group and the divided A description will be given based on FIG. 1 which is a schematic plan view. The cylinder group individual control engine according to the first embodiment is an in-line six-cylinder four-cycle direct injection turbocharged diesel engine for automobiles. Each cylinder of the in-line 6-cylinder engine main body 10 is numbered “1” to “6” in order from the cylinders near the cooling fan 11 as shown in the figure. ".

  The first cylinder 1 is provided with one electronically controlled fuel injector 130a, two intake valves 20a, one intake port 23a, two exhaust valves 40a, and one exhaust port 43a. 2 includes one electronically controlled fuel injector 131a, two intake valves 21a, one intake port 24a, two exhaust valves 41a, and one exhaust port 44a. One electronically controlled fuel injector 132a, two intake valves 22a, one intake port 25a, two exhaust valves 42a, and one exhaust port 45a are provided. An electronically controlled fuel injector 130b, two intake valves 20b, one intake port 23b, two exhaust valves 40b, and one exhaust port 43b are provided. The fifth cylinder 5 has one electronically controlled fuel. 2 injectors 131b The intake valve 21b, one intake port 24b, two exhaust valves 41b, and one exhaust port 44b are provided. The sixth cylinder 6 has one electronically controlled fuel injector 132b, two intake valves 22b. One intake port 25b, two exhaust valves 42b, and one exhaust port 45b are provided.

  Since the in-line 6-cylinder engine body 10 is ignited at an equal interval of 120 degrees (crank angle) and the order of ignition is 1-5-3-6-2-4, the first cylinder 1, the second cylinder 2, and the second cylinder Three cylinders 3 are set as a first cylinder group 70a and ignition is performed at an interval of 240 degrees (crank angle) in the order of cylinders 1-3-2, and the fourth cylinder 4, the fifth cylinder 5, and the sixth cylinder 6 are set as a second cylinder group. 70b is assumed to be ignited at intervals of 240 degrees (crank angle) in the order of 5-6-4 cylinders.

  The intake manifolds 30a of the first cylinder group 70a are connected to the intake ports 23a, 24a and 25a of the respective cylinders of the first cylinder group 70a, and the intake manifolds 30b of the second cylinder group 70b are connected to the intake manifolds 30b of the second cylinder group 70b. The intake ports 23b, 24b and 25b of each cylinder are connected. The exhaust manifolds 50a of the first cylinder group 70a are connected to the exhaust ports 43a, 44a and 45a of the respective cylinders of the first cylinder group 70a, and the exhaust manifolds 50b of the second cylinder group 70b are connected to the respective exhaust cylinders 50b of the second cylinder group 70b. The cylinder exhaust ports 43b, 44b and 45b are connected.

Next, the overall system of the multi-cylinder turbocharged diesel engine of the first embodiment will be described with reference to FIG. 2 which is a schematic plan view showing a specific configuration. First, intake and exhaust of the first cylinder group 70a and EGR will be described. The intake air of the first cylinder group 70a sucked from the air cleaner 111 passes through the intake pipe 34a and is pressurized by the supply air blower 61a of the VG turbocharger 60a of the first cylinder group 70a. The pressurized and high-temperature and high-pressure intake air is led to the air-cooled supply intercooler 32a by the intake pipe 33a and cooled, and the cooled intake air is led to the intake manifold 30a by the intake pipe 31a and The air is sucked into each cylinder of the first cylinder group 70a via the intake ports 23a, 24a, 25a and the intake valves 20a, 21a, 22a of each cylinder of the cylinder group 70a. The exhaust gas of each cylinder of the first cylinder group 70a passes through the exhaust manifold 50a from the exhaust valves 40a, 41a, 42a and the exhaust ports 43a, 44a, 45a of each cylinder of the first cylinder group 70a, and then through the exhaust pipe 51a. It is guided to the VG turbocharger 60a of the first cylinder group 70a.

  The exhaust gas of the first cylinder group 70a guided to the VG turbocharger 60a drives the exhaust turbine 62a, rotates the intake blower 61a coaxial with the exhaust turbine 63a, and takes in the intake air to the first cylinder group 70a. Pressurize. In the VG turbocharger 60a, the opening degree of the variable exhaust turbine nozzle valve 63a is adjusted by an electronically controlled variable exhaust turbine nozzle valve actuator 64a by a signal from an engine ECU (not shown), and the rotational speed of the exhaust turbine 62a is controlled. By adjusting the rotational speed of the exhaust turbine 62a, the boost pressure of the intake air pressurized by the supply blower 61a coaxially driven with the exhaust turbine 62a is adjusted, and the intake air amount sucked into the first cylinder group 70a is adjusted. .

  As described above, in the cylinder group individual control engine of the first embodiment, the energy of the exhaust gas in the first cylinder group 70a is supercharged by increasing the boost pressure of the intake air only in the first cylinder group 70a. ing.

Next, the exhaust gas of the first cylinder group 70a flowing out from the exhaust turbine 63a flows into the oxidation catalyst regeneration type DPF device 90a through the exhaust pipe 52a, and PM in the exhaust gas is captured by the oxidation catalyst regeneration type DPF device 90a. PM collected in the exhaust gas is purified. Next, the exhaust gas of the first cylinder group 70a flowing out from the oxidation catalyst regeneration type DPF device 90a flows into the urea SCR device 100a through the exhaust pipe 53a to purify NOx, and then flows into the exhaust muffler 110, Then it is released into the atmosphere.
Here, in order to reduce and purify NOx in the exhaust gas of the first cylinder group 70a by the urea SCR device 100a, urea water supplied from a urea water tank (not shown) is pressurized by the urea water pressurizing pump 102, and urea water is supplied. It is injected into the exhaust gas immediately before flowing into the urea SCR device 100a from the injection electromagnetic valve nozzle 101a. By the injected urea water, NOx in the exhaust gas is reduced in the urea SCR device 100a, and the exhaust gas of the first cylinder group 70a is purified. The amount of urea water injected from the urea water injection electromagnetic valve nozzle 101a is adjusted by a signal from an engine ECU (not shown) as predetermined by the engine load condition of the first cylinder group 70a.

  Further, a part of the exhaust gas of the first cylinder group 70a is diverted as EGR gas by the EGR pipe 82a connected to the exhaust pipe 51a. This EGR gas is cooled by being guided to the EGR cooler 81a via the electronically controlled EGR valve 80a and the EGR pipe 83a, led to the intake pipe 31a via the EGR pipe 84a, and recirculated during the intake of the first cylinder group 70a. This EGR gas amount is adjusted by controlling the opening degree of the electronically controlled EGR valve 80a by a signal from an engine ECU (not shown) as predetermined by the engine load condition of the first cylinder group 70a.

  Next, the fuel supply of the first cylinder group 70a will be described. Light oil fuel supplied from a fuel tank (not shown) is pressurized by a fuel supply pump 120 and guided to a common rail 122 through a high-pressure fuel pipe 121. The high pressure fuel led to the common rail 122 is directly fed into the combustion chamber from the electronically controlled fuel injectors 130a, 131a, 132a disposed in the combustion chambers of the respective cylinders of the first cylinder group 70a through the high pressure fuel pipes 123a, 124a, 125a. Be injected.

On the other hand, regarding the flow of intake air, exhaust gas and EGR gas and fuel supply in the second cylinder group 70b, as shown in FIG. 2, the intake pipes 23b, 24b and 25b of the second cylinder group 70b, the VG turbocharger 60b, intake manifold 30b, exhaust manifold 50b, oxidation catalyst regeneration type DPF device 90b, urea SCR device 100b, urea water injection electromagnetic valve nozzle 101b, exhaust pipes 51b, 52b, 53b, EGR pipes 82b, 83b, 84b, EGR valve 80b Since the EGR cooler 81b is provided independently for the second cylinder group 70b as in the first cylinder group 70a, the description thereof is omitted.
The VG turbochargers 60a and 60b are independently provided with capacities suitable for the output of the respective cylinder groups of the first cylinder group 70a and the second cylinder group 70b.
However, as shown in FIG. 2, the fuel supply pump 120, the fuel common rail 122, the urea water pressurizing pump 102, the air cleaner 111, and the exhaust muffler 110 are shared by the first cylinder group 70a and the second cylinder group 70b.
As described above, between the downstream of the air cleaner 111 and the upstream of the exhaust muffler 110, the flow paths of the intake air, EGR gas, and exhaust gas of the first cylinder group 70a and the second cylinder group 70b are independent, and the engine is in operation. The intake air, EGR gas, and exhaust gas of the first cylinder group 70a and the second cylinder group 70b are not mixed with each other.

FIG. 3 is a block diagram showing a basic configuration and control signals of the cylinder group individual control engine according to the first embodiment. In the engine according to the first embodiment, the flow circuit of intake air, EGR gas, and exhaust gas between the downstream of the air cleaner 111 and the upstream of the exhaust muffler 110 includes the first cylinder group intake / exhaust system 150 and the second cylinder group intake. The exhaust system 160 is divided. In the first cylinder group intake / exhaust system 150, the intake air taken in from the air cleaner 111 is pressurized by the air supply blower 61a of the VG turbocharger 60a, cooled by the air-cooled air supply intercooler 32a, and the engine body 10 Inhaled into each cylinder of the one-cylinder group 70a. A part of the exhaust gas of the first cylinder group 70a is cooled by the EGR cooler 81a through the electronic control EGR valve 80a, and is returned to each cylinder of the first cylinder group 70a as EGR gas. The remaining exhaust gas after refluxed as EGR gas rotates the exhaust turbine 62a of the VG turbocharger 60a, and then PM is collected and purified by the catalyst regeneration type DPF device 90a. After that, the exhaust gas of the first cylinder group 70a is injected from the urea water injection electromagnetic valve 101a and mixed with urea water, and the exhaust gas is purified by reducing NOx while passing through the urea SCR device 100a. The exhaust muffler 110 is discharged into the atmosphere.
Further, the configuration of the second cylinder group intake / exhaust system 160 is independent of the first cylinder group intake / exhaust system 150, but the description thereof is omitted here because the flow of intake air, EGR gas, and exhaust gas is the same. .

In the multi-cylinder turbocharged diesel engine according to the first embodiment, the signal of the accelerator pedal position 130 of the automobile and the signals of the engine operating states of the first cylinder group 70a and the second cylinder group 70b are input to the engine ECU 140. . Based on these input signals, control signals are output from the engine ECU 140 to the intake / exhaust related control devices of the first cylinder group intake / exhaust system 150 and the second cylinder group intake / exhaust system 160 according to the stored data and program of the engine ECU 140.

  The engine ECU 140 outputs a fuel injection signal to the first cylinder group 70a and the second cylinder group 70b, and controls the amount of fuel supplied to the first cylinder group 70a and the second cylinder group 70b corresponding to the accelerator pedal position 130. Done. Further, the engine ECU 140 outputs the opening signals of the respective EGR valves to the electronically controlled EGR valves 80a and 80b, and the respective cylinder groups of the first cylinder group 70a and the second cylinder group 70b corresponding to the accelerator pedal position 130 are output. Controlled to EGR rate.

  Further, the engine ECU 140 controls the opening degree of the exhaust turbine nozzle valves of the variable exhaust turbine nozzle valves 63a and 63b corresponding to the accelerator pedal position 130 from the electronically controlled variable exhaust turbine nozzle valve actuators 64a and 64b of the VG turbochargers 60a and 60b. A signal to be adjusted is output to control the rotation speeds of the exhaust turbines 62a and 62b, thereby controlling the optimization of the boost pressures of the intake air of the first cylinder group intake / exhaust system 150 and the second cylinder group intake / exhaust system 160. Do.

  Further, a signal for adjusting the urea water injection amount corresponding to the accelerator pedal position 130 is output from the engine ECU 140 to the urea water injection electromagnetic valves 101a and 101b, and the first cylinder group intake / exhaust system 150 and the second cylinder group intake / exhaust system are output. The amount of urea water mixed with 160 exhaust gases is controlled to be optimized.

  Therefore, for example, when operating the first cylinder group 70a as an active cylinder group and operating the second cylinder group 70b as a deactivated cylinder group under the partial load operation condition of the engine, the VG turbocharger 60a of the active cylinder group is supercharged. The VG turbocharger 60b is not operated as a supercharger. As described above, the supercharger efficiency of the VG turbocharger 60a of the first cylinder group 70a when the first cylinder group 70a is operated as the active cylinder group under the partial load operation condition of the engine is the same as the first output. As a result, the pumping loss of the engine is reduced and the high thermal efficiency of the engine can be obtained. As a result, the engine pumping loss is reduced as compared with the case where both the cylinder group 70a and the second cylinder group 70b are operated.

  Furthermore, since the VG turbochargers 60a and 60b and the air-cooled air supply intercoolers 32a and 32b are independently provided in the first cylinder group 70a and the second cylinder group 70b, the partial load operation condition of the engine When operating some cylinder groups as idle cylinder groups below, the exhaust energy of the active cylinder groups should not be used to pressurize the intake air of the idle cylinder groups, but should be used effectively to pressurize the intake air of the active cylinder groups. This can improve the supercharging efficiency of the operating cylinder group, further reduce the pumping loss of the engine, and improve the thermal efficiency of the engine.

Further, VG turbochargers 60a and 60b are independently arranged in the first cylinder group intake / exhaust system 150 and the second cylinder group intake / exhaust system 160, respectively, and the first cylinder group and the second cylinder group 70b. Since the boost pressure can be controlled independently, the turbocharger can be operated in an optimum state for each engine load condition of the first cylinder group 70a and the second cylinder group 70b. It is possible to reduce exhaust gas and fuel consumption.

  For example, when the first cylinder group 70a is operated as an active cylinder group and the second cylinder group 70b is operated as a deactivated cylinder group under the partial load operation condition of the engine, the VG turbocharger 60a of the first cylinder group 70a is the first cylinder. The variable exhaust turbine nozzle valve 63a is controlled so that the boost pressure is optimal for the engine load conditions of the group 70a, and the VG turbocharger 60b of the second cylinder group 70b minimizes the pumping loss optimal for the idle cylinder group. In this way, the variable exhaust turbine nozzle valve 63b of the second cylinder group 70b is controlled. Under such partial load operation conditions of the engine, it becomes possible to realize a reduction in exhaust gas and high-efficiency engine operation by the idle operation air of some cylinder groups. The idle operation of some cylinder groups during engine partial load operation can significantly increase the exhaust temperature of the active cylinder group compared to operating all cylinder groups as active cylinder groups under the same load operation. It becomes.

  As described above, the engine loads of the first cylinder group 70a and the second cylinder group 70b are independently controlled, and the intake air amount, the EGR rate, and the exhaust gas temperature of each cylinder group are independently controlled, thereby operating cylinders. Emissions can be reduced easily by improving the combustion of the group. In addition, the exhaust gas temperature of the operating cylinder group is increased when the NOx reduction rate is improved by improving the catalytic function of the urea SCR device 100a or 100b of the operating cylinder group, and the engine partial load is continuously operated for a long time. In addition, since the catalyst regeneration type DPF device 90a or 90b can be sufficiently regenerated, there is an effect that it is possible to avoid engine meltdown due to excessive PM collection of the DPF device and filter melting damage due to abnormal combustion of the collected PM.

  By the way, the individual devices of the intake / exhaust related control devices arranged in each engine of the above embodiments are changed to other devices in order to satisfy the optimization of the engine output value, the reduction of exhaust gas, and the reduction of the engine manufacturing cost. Alternatively, a new after-treatment device for reducing exhaust gas may be provided. For example, in the engine according to the first embodiment, a turbocharger with a wastegate is used instead of a VG turbocharger as a supercharger, or a NOx storage reduction device is used instead of a urea SCR device. Or the urea SCR device may be omitted.

FIG. 2 is a schematic plan view showing a specific configuration for dividing each cylinder of the engine body into a plurality of cylinder groups and connecting to intake and exhaust manifolds in the first embodiment. 1 is a schematic plan view showing a specific configuration of the entire multi-cylinder turbocharged diesel engine according to the first embodiment. It is a block diagram which shows the basic composition and control signal of the multicylinder turbo supercharged diesel engine of this 1st Embodiment.

DESCRIPTION OF SYMBOLS 1 1st cylinder 2 2nd cylinder 3 3rd cylinder 4 4th cylinder 5 5th cylinder 6 6th cylinder 10 In-line 6 cylinder engine main body 11 Cooling fan 20a, 21a, 22a, 20b, 21b, 22b Intake valve 23a, 24a, 25a, 23b, 24b, 25b Intake port 30a, 30b Intake manifold 31a, 31b Intake pipe 32a, 32b Air-cooled air supply intercooler 33a, 33b, 34a, 34b Intake pipe 40a, 41a, 42a, 40b, 41b, 42b Exhaust valve 43a, 43b, 44a, 44b, 45a, 45b Exhaust port 50a, 50b Exhaust manifold 51a, 52a, 53a, 51b, 52b, 53b Exhaust pipe 60a, 60b VG turbocharger 61a, 61b Supply air blower 62a, 62b Exhaust turbine 63a, 63b Variable exhaust turbine Nozzle valve 64a, 64b Electronically controlled variable exhaust turbine nozzle valve actuator 70a First cylinder group 70b Second cylinder group 80a, 80b Electronically controlled EGR valve 81a, 81b EGR cooler 82a, 83a, 84a, 82b, 83b, 84b EGR pipe 90a, 90b Oxidation catalyst regeneration type DPF device 100a, 100b Urea SCR device 101a, 101b Urea water injection solenoid valve nozzle 102 Urea water pressurizing pump 110 Exhaust muffler 111 Air cleaner 120 Fuel supply pump 121 High pressure fuel pipe 122 Common rail 123a, 124a, 125a, 123b , 124b, 125b High pressure fuel pipe 130 Accelerator pedal positions 130a, 131a, 132a Electronically controlled fuel injectors 130b, 131b, 132b Electronically controlled fuel injectors 140 Jin ECU
150 First cylinder group intake / exhaust system 160 Second cylinder group intake / exhaust system

Claims (1)

In a multi-cylinder turbocharged diesel engine, each cylinder is divided into a plurality of cylinder groups, and an independent intake passage is provided for each cylinder group for supplying air to each cylinder of the cylinder group. An independent exhaust passage is provided for each of the cylinder groups for exhausting the exhaust gas, and the multi-cylinder turbocharged diesel engine is equipped with an EGR-related device such as an EGR valve and an EGR cooler, a VG turbocharger, and a wastegate supercharger. The above intake / exhaust-related devices can be used regardless of whether supercharger-related devices such as a charger or intake intercooler and intake / exhaust-related control devices of exhaust gas aftertreatment devices such as DPF devices, oxidation catalyst devices, and urea SCR devices are installed. The control device is provided independently in the middle of the intake / exhaust circuit for each cylinder group from the intake passage to the exhaust passage for each cylinder group, and the intake air for each cylinder group, EG The circuit of the flow passage of the gas and the exhaust gas does not mix with each other, by a signal from the engine ECU, the individual devices of the intake and exhaust associated control device which is arranged for each of the cylinder groups according to the respective load condition of each said cylinder group to enable independent control for each of the cylinder groups, the fuel supply to the cylinder group to enable independent control for each of the cylinder groups is controlled independently of the engine load per the cylinder groups, the multi-cylinder turbo In a specific partial load operation of a supercharged diesel engine, when fuel is supplied to some of the cylinder groups and burned to generate engine output, fuel supply to the remaining other cylinder groups is stopped. driving a suspendable cylinder group by high temperature exhaust gas temperature operating cylinders group compared to when driving by all the cylinder groups comparable engine power, other engines including high-load Operation area in an operation to engine load for each said cylinder group all the cylinder groups performing fuel supply to all of the cylinder groups as the operating cylinder groups, intake air amount, operating cylinders by controlling independently the EGR rate The exhaust gas temperature of the group is increased, and by increasing the exhaust gas temperature, the regeneration function of the DPF device of the operating cylinder group is improved, the NOx reduction function of the urea SCR device is improved, and the exhaust gas reduction function of the oxidation catalyst device is improved A cylinder group individual control engine characterized in that the exhaust gas reduction function of the exhaust gas after-treatment device can be fully exhibited .

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