JP2021143598A - Engine device - Google Patents

Abstract

To properly adjust a purge rate.SOLUTION: When supplying an evaporation fuel gas into an intake pipe, a purge control valve is controlled by setting a drive duty on the basis of a full-open purge rate when the drive duty of the purge control valve is set to 100%, and a requirement purge rate. In this case, the full-open purge rate is estimated by employing supercharging pressure or a pressure difference, and throttle rear pressure to a predetermined relation among the supercharging pressure being pressure between a compressor of an intake valve and a throttle valve or the pressure difference between the supercharging pressure and compressor front pressure being pressure at an upstream side rather than the compressor of the intake pipe, throttle rear pressure being pressure at a downstream side rather than the throttle valve of the intake valve, and the full-open purge rate.SELECTED DRAWING: Figure 3

Description

The present invention relates to an engine device.

Conventionally, as an engine device of this type, a supercharger having an engine having a throttle valve arranged in an intake pipe while receiving fuel from a fuel tank and a compressor having a compressor arranged upstream of the throttle valve in the intake pipe. It has been proposed to include a machine and an evaporative fuel processing device for supplying a purge gas (evaporative fuel gas) containing evaporative fuel generated in a fuel tank to an intake pipe (see, for example, Patent Document 1). Here, the evaporative fuel processing device has a supply passage for supplying the purge gas to the intake pipe, and a purge control valve and an ejector provided in the supply passage. The supply passage branches into a first branch passage and a second branch passage on the intake pipe side of the purge control valve, and the first branch passage is connected to the downstream side of the throttle valve of the intake pipe. The intake port of the ejector is connected between the compressor of the intake pipe and the throttle valve via a recirculation passage, the exhaust port is connected to the upstream side of the compressor of the intake pipe, and the suction port is sucked into the second branch passage. The port is connected. In this engine device, by opening the purge control valve, purge gas is supplied to the downstream side of the throttle valve of the intake pipe via the first branch passage, or the intake pipe is supplied via the second branch passage and the ejector. It is supplied to the upstream side of the compressor. Then, of the first pressure on the downstream side of the throttle valve of the intake pipe, the second pressure between the supercharger of the intake pipe and the throttle valve, and the third pressure on the upstream side of the supercharger of the intake pipe. Measure the flow rate of the purge gas passing through the second branch passage using at least two, and estimate the flow rate of the purge gas passing through the first branch passage based on the first pressure or the differential pressure between the first pressure and the third pressure. Then, add up the two and measure the flow rate of the purge gas passing through the supply passage.

JP-A-2018-96247

In the engine device described above, the measured value of the flow rate of the purge gas passing through the first branch passage is such that the purge gas passes only through the first branch passage of the first branch passage and the second branch passage, and the purge gas passes through both of them. It will be the same as the time. Therefore, when the purge gas passes through both the first branch passage and the second branch passage, the measured value of the flow rate of the purge gas passing through the supply passage may deviate from the actual value. In this case, the purge rate may not be properly adjusted by the purge control valve.

The main object of the engine device of the present invention is to appropriately adjust the purge rate.

The engine device of the present invention has adopted the following means in order to achieve the above-mentioned main object.

The engine device of the present invention
An engine that receives fuel from the fuel tank and has a throttle valve located in the intake pipe.
A supercharger having a compressor arranged on the upstream side of the throttle valve of the intake pipe, and
A supply passage for supplying the evaporated fuel gas containing the evaporated fuel generated in the fuel tank to the intake pipe, and an evaporative fuel processing apparatus having a purge control valve provided in the supply passage.
When the evaporated fuel gas is supplied to the intake pipe, the drive duty is set based on the fully open purge rate when the drive duty of the purge control valve is set to 100% and the required purge rate, and the purge control is performed. A control device that controls the valve and
It is an engine device equipped with
The supply passage branches into a first branch passage and a second branch passage on the intake pipe side of the purge control valve.
The first branch passage is connected to the downstream side of the intake pipe with respect to the throttle valve.
In the evaporated fuel processing apparatus, an intake port is connected between the compressor of the intake pipe and the throttle valve via a recirculation passage, and an exhaust port is connected to the upstream side of the compressor of the intake pipe. It also has an ejector with a suction port connected to the two-branch passage.
When the evaporative fuel gas is supplied to the intake pipe, the control device receives a boost pressure which is a pressure between the compressor and the throttle valve of the intake pipe or the boost pressure and the compressor of the intake pipe. In a predetermined relationship between the pressure difference from the compressor front pressure, which is the upstream pressure, the throttle rear pressure, which is the pressure downstream of the throttle valve of the intake pipe, and the fully open purge rate. The fully open purge rate is estimated by applying the boost pressure or the pressure difference and the throttle rear pressure.
The gist is that.

In the engine device of the present invention, when supplying the evaporated fuel gas to the intake pipe, the drive duty is set based on the fully open purge rate when the drive duty of the purge control valve is set to 100% and the required purge rate. Controls the purge control valve. In this case, the pressure difference between the boost pressure or boost pressure, which is the pressure between the intake pipe compressor and the throttle valve, and the compressor prepressure, which is the pressure on the upstream side of the intake pipe compressor, and the throttle valve of the intake pipe. The fully open purge rate is estimated by applying the boost pressure or the pressure difference and the throttle rear pressure to the predetermined relationship between the throttle rear pressure, which is the pressure on the downstream side, and the fully open purge rate. This makes it possible to properly estimate the fully open purge rate regardless of whether the purge gas is supplied to either or both of the downstream side of the throttle valve of the intake pipe and the upstream side of the compressor. can. Then, by setting the required duty based on the fully open purge rate and the required purge rate and controlling the purge control valve, it is possible to suppress a deviation of the actual purge rate from the required purge rate. That is, the purge rate can be adjusted appropriately.

In the engine device of the present invention, the control device may estimate the fully open purge rate so that the larger the boost pressure or the pressure difference is, the larger the boost pressure or the lower the throttle rear pressure is. In this way, the full-open purge rate can be estimated more appropriately.

In the engine device of the present invention, the control device may estimate the fully open purge rate based on the temperature in the intake pipe. In this case, the control device may estimate the fully open purge rate so that the higher the temperature in the intake pipe, the higher the temperature. In this way, the full-open purge rate can be estimated more appropriately.

In the engine device of the present invention, the control device may estimate the fully open purge rate based on the intake air amount of the engine. In this case, the control device may estimate the fully open purge rate so that the larger the intake air amount, the smaller the intake air amount. In this way, the full-open purge rate can be estimated more appropriately.

It is a block diagram which shows the outline of the structure of the engine device 10 as one Example of this invention. It is explanatory drawing which shows an example of the input / output signal of an electronic control unit 70. It is a flowchart which shows an example of the purge control routine executed by the electronic control unit 70. It is explanatory drawing which shows an example of the map for full-open purge flow rate estimation.

Next, a mode for carrying out the present invention will be described with reference to examples.

FIG. 1 is a configuration diagram showing an outline of the configuration of an engine device 10 as an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing an example of an input / output signal of the electronic control unit 70. The engine device 10 of the embodiment is mounted on a general automobile or various hybrid automobiles, and as shown in FIGS. 1 and 2, an engine 12, a supercharger 40, an evaporative fuel processing device 50, and electronic control are provided. It includes a unit 70.

The engine 12 is configured as an internal combustion engine that outputs power using fuel such as gasoline or light oil supplied from the fuel tank 11 via a feed pump or a fuel passage (not shown). The engine 12 sucks the air cleaned by the air cleaner 22 into the intake pipe 23 and passes it through the intercooler 25, the throttle valve 26, and the surge tank 27 in this order, and injects fuel downstream of the surge tank 27 of the intake pipe 23. Fuel is injected from the valve 28 to mix air and fuel. Then, this air-fuel mixture is sucked into the combustion chamber 30 through the intake valve 29, and is explosively burned by the electric spark from the spark plug 31. Then, the reciprocating motion of the piston 32 pushed down by the energy generated by the explosive combustion is converted into the rotational motion of the crankshaft 14. The exhaust gas discharged from the combustion chamber 30 to the exhaust pipe 35 via the exhaust valve 34 is a catalyst (three-way catalyst) that purifies harmful components of carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). ) Is discharged to the outside air through the purification devices 37 and 38.

The supercharger 40 is configured as a turbocharger, and includes a compressor 41, a turbine 42, a rotating shaft 43, a wastegate valve 44, and a blow-off valve 45. The compressor 41 is arranged on the upstream side of the intercooler 25 of the intake pipe 23. The turbine 42 is arranged on the upstream side of the purification device 37 of the exhaust pipe 35. The rotating shaft 43 connects the compressor 41 and the turbine 42. The wastegate valve 44 is provided in a bypass pipe 36 that connects the upstream side and the downstream side of the turbine 42 in the exhaust pipe 35, and is controlled by the electronic control unit 70. The blow-off valve 45 is provided in the bypass pipe 24 that connects the upstream side and the downstream side of the compressor 41 in the intake pipe 23, and is controlled by the electronic control unit 70.

In the supercharger 40, by adjusting the opening degree of the wastegate valve 44, the distribution ratio between the displacement through the bypass pipe 36 and the displacement through the turbine 42 is adjusted, and the rotational driving force of the turbine 42 is adjusted. Then, the amount of compressed air by the compressor 41 is adjusted, and the supercharging pressure (intake pressure) of the engine 12 is adjusted. Here, in detail, the distribution ratio is adjusted so that the smaller the opening degree of the wastegate valve 44, the smaller the displacement through the bypass pipe 36 and the larger the displacement through the turbine 42. When the wastegate valve 44 is fully opened, the engine 12 can operate in the same manner as a naturally aspirated type engine without a supercharger 40.

Further, in the supercharger 40, when the pressure on the downstream side of the intake pipe 23 on the downstream side of the compressor 41 is higher than the pressure on the upstream side to some extent, the blow-off valve 45 is opened to cause a surplus on the downstream side of the compressor 41. The pressure can be released. The blow-off valve 45 is configured as a check valve that opens when the pressure on the downstream side of the compressor 41 in the intake pipe 23 becomes higher than the pressure on the upstream side to some extent, instead of the valve controlled by the electronic control unit 70. It may be done.

The evaporative fuel processing device 50 is the reverse of the introduction passage 52, the on-off valve 53, the bypass passage 54, the relief valves 55a and 55b, the canister 56, the purge passage 60, the buffer portion 64, and the purge control valve 65. It is provided with check valves 66 and 67, a return passage 68, and an ejector 69.

The introduction passage 52 is connected to the fuel tank 11 and the canister 56. The on-off valve 53 is provided in the introduction passage 52, and is configured as a normally closed type solenoid valve. The on-off valve 53 is controlled by an electronic control unit 70.

The bypass passage 54 has branch portions 54a and 54b that bypass the fuel tank 11 side and the canister 56 side of the opening / closing valve 53 of the introduction passage 52 and branch into two to join. The relief valve 55a is provided at the branch portion 54a and is configured as a check valve, and opens when the pressure on the fuel tank 11 side becomes to some extent higher than the pressure on the canister 56 side. The relief valve 55b is provided at the branch portion 54b and is configured as a check valve, and opens when the pressure on the canister 56 side becomes to some extent higher than the pressure on the fuel tank 11 side.

The canister 56 is connected to the introduction passage 52 and is open to the atmosphere through the atmosphere opening passage 57. The inside of the canister 56 is filled with an adsorbent such as activated carbon capable of adsorbing the evaporated fuel from the fuel tank 11. An air filter 58 is provided in the air opening passage 57.

The purge passage 60 is connected to the vicinity of the canister 56 of the introduction passage 52, and branches into the branch passage 62 and the branch passage 63 at the branch point 60a in the middle. Hereinafter, the portion of the purge passage 60 on the introduction passage 52 side of the branch point 60a is referred to as a “common passage 61”. The branch passage 62 is connected between the throttle valve 26 of the intake pipe 23 and the surge tank 27. The branch passage 63 is connected to the suction port of the ejector 69.

The buffer portion 64 is provided in the common passage 61. The inside of the buffer portion 64 is filled with an adsorbent such as activated carbon capable of adsorbing the evaporated fuel from the fuel tank 11 and the canister 56. The purge control valve 65 is provided on the branch point 60a side of the buffer portion 64 of the common passage 61. The purge control valve 65 is configured as a normally closed type solenoid valve. The purge control valve 65 is controlled by the electronic control unit 70.

The check valve 66 is provided near the branch point 60a of the branch passage 62. The check valve 66 allows the flow of the evaporated fuel gas (purge gas) containing the evaporated fuel in the direction from the common passage 61 side of the purge passage 60 to the branch passage 62 (intake pipe 23) side, and the evaporated fuel gas in the opposite direction. Prohibit the flow of. The check valve 67 is provided near the branch point 60a of the branch passage 63. The check valve 67 allows the flow of the evaporated fuel gas in the direction from the common passage 61 side of the purge passage 60 to the branch passage 63 (executor 69) side, and prohibits the flow of the evaporated fuel gas in the reverse direction.

The return passage 68 is connected between the compressor 41 of the intake pipe 23 and the intercooler 25, and the intake port of the ejector 69. The ejector 69 has an intake port, a suction port, and an exhaust port. The intake port of the ejector 69 is connected to the return passage 68, the suction port is connected to the branch passage 63, and the exhaust port is connected to the upstream side of the compressor 41 of the intake pipe 23. The tip of the intake port is tapered.

In this ejector 69, when the supercharger 40 is operating (when the pressure between the compressor 41 of the intake pipe 23 and the intercooler 25 becomes positive pressure), the pressure between the intake port and the exhaust port becomes positive. A difference occurs, and a recirculation intake air (intake air recirculated from the downstream side of the compressor 41 of the intake pipe 23 via the recirculation passage 68) flows from the intake port to the exhaust port. At this time, the reflux intake air is depressurized at the tip of the intake port, and a negative pressure is generated around the tip. Then, due to the negative pressure, the evaporated fuel gas is sucked from the branch passage 63 through the suction port, and the evaporated fuel gas is brought to the upstream side of the compressor 41 of the intake pipe 23 through the exhaust port together with the negative pressure recirculation intake. Be supplied.

In the evaporated fuel processing device 50 configured in this way, the pressure on the downstream side of the throttle valve 26 of the intake pipe 23 (surge pressure Ps described later) is negative, and the on-off valve 53 and the purge control valve 65 are in the open state. At this time, the check valve 66 is opened, and the evaporated fuel gas (purge gas) generated in the fuel tank 11 and the evaporated fuel gas desorbed from the canister 56 pass through the introduction passage 52, the common passage 61, and the branch passage 62. It is supplied to the downstream side of the throttle valve 26 of the intake pipe 23 via the air. Hereinafter, this is referred to as "downstream purge". At this time, if the pressure between the compressor 41 of the intake pipe 23 and the intercooler 25 (supercharging pressure Pc described later) is negative pressure or zero, the ejector 69 does not operate and the check valve 66 closes. It becomes a state.

Further, when the pressure between the compressor 41 of the intake pipe 23 and the intercooler 25 is positive and the on-off valve 53 and the purge control valve 65 are in the open state, the check valve 67 is opened by the operation of the ejector 69. In the valve state, the evaporated fuel gas is supplied to the upstream side of the compressor 41 of the intake pipe 23 via the introduction passage 52, the common passage 61, the branch passage 63, and the ejector 69. Hereinafter, this is referred to as "upstream purge". At this time, if the pressure difference between the pressure in the common passage 61 and the pressure on the downstream side of the throttle valve 26 of the intake pipe 23 is equal to or greater than the opening pressure of the check valve 66, for example, the surge pressure Ps is a negative pressure. If there is), the check valve 66 is also opened, and downstream purging is also performed. That is, both downstream purging and upstream purging are performed (evaporated fuel gas is supplied to both the downstream side of the intake pipe 23 from the throttle valve 26 and the upstream side from the compressor 41). On the other hand, if this pressure difference is less than the valve opening pressure of the check valve 66, the check valve 66 is closed and downstream purging is not performed. That is, only upstream purging is performed.

The electronic control unit 70 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. Signals from various sensors are input to the electronic control unit 70 via input ports.

The signals input to the electronic control unit 70 include, for example, the pressure Pt from the pressure sensor 11a that detects the pressure in the fuel tank 11 and the crank position sensor 14a that detects the rotational position of the crankshaft 14 of the engine 12. Examples include the crank angle θcr, the cooling water temperature Tw from a water temperature sensor (not shown) that detects the temperature of the cooling water of the engine 12, and the throttle opening TH from the throttle position sensor 26a that detects the opening degree of the throttle valve 26. Cam position θca from a cam position sensor (not shown) that detects the rotational position of the intake camshaft that opens and closes the intake valve 29 and the exhaust cam shaft that opens and closes the exhaust valve 34 can also be mentioned. The intake air amount Qa from the air flow meter 23a attached to the upstream side of the compressor 41 of the intake pipe 23, the intake pressure Pin from the pressure sensor 23b attached to the upstream side of the compressor 41 of the intake pipe 23, and the intake pipe. The boost pressure Pc from the pressure sensor 23c mounted between the compressor 41 of the 23 and the intercooler 25 can also be mentioned. Examples include surge pressure Ps from the pressure sensor 27a attached to the surge tank 27 and surge temperature Ts from the temperature sensor 27b attached to the surge tank 27. The front air-fuel ratio AF1 from the front air-fuel ratio sensor 35a attached to the upstream side of the purification device 37 of the exhaust pipe 35, and the rear air-fuel ratio sensor attached between the purification device 37 of the exhaust pipe 35 and the purification device 38. The rear air-fuel ratio AF2 from 35b can also be mentioned. The opening degree Op of the purge control valve 65 from the purge control valve position sensor 65a can also be mentioned.

Various control signals are output from the electronic control unit 70 via the output port. Examples of the signal output from the electronic control unit 70 include a control signal to the throttle valve 26, a control signal to the fuel injection valve 28, and a control signal to the spark plug 31. A control signal to the wastegate valve 44, a control signal to the blow-off valve 45, and a control signal to the on-off valve 53 can also be mentioned. A control signal to the purge control valve 65 can also be mentioned.

The electronic control unit 70 calculates the rotation speed Ne of the engine 12 based on the crank angle θcr from the crank position sensor 14a. Further, the electronic control unit 70 has a load factor (air actually sucked in one cycle with respect to the stroke volume per cycle of the engine 12) based on the intake air amount Qa from the air flow meter 23a and the rotation speed Ne of the engine 12. KL is calculated.

In the engine device 10 of the embodiment configured in this way, the electronic control unit 70 controls the intake air amount that controls the opening degree of the throttle valve 26 based on the required load factor KL * of the engine 12, and the fuel injection valve 28. Fuel injection control that controls the fuel injection amount, ignition control that controls the ignition timing of the ignition plug 31, supercharging control that controls the opening degree of the wastegate valve 44, purge control that controls the opening degree of the purge control valve 65, etc. To do.

Next, the operation of the engine device 10 of the embodiment thus configured, particularly the purge control, will be described. FIG. 3 is a flowchart showing an example of a purge control routine executed by the electronic control unit 70. This routine is repeatedly executed when purging control is performed.

When the purge control routine is executed, the electronic control unit 70 first inputs data such as intake air amount Qa, intake pressure Pin, boost pressure Pc, surge pressure Ps, surge temperature Ts, and target purge rate Rptg. (Step S100). Here, a value detected by the air flow meter 23a is input as the intake air amount Qa. A value detected by the pressure sensor 23b is input to the intake pressure Pin. The value detected by the pressure sensor 23c is input to the boost pressure Pc. A value detected by the pressure sensor 27a is input as the surge pressure Ps. A value detected by the temperature sensor 27b is input as the surge temperature Ts. The target purge rate Rptg is set so as to gradually increase from the start purge rate Rp1 when the purge control is executed for the first time in each trip, and when the purge control is executed for the second time or later (the purge control is interrupted). When restarting from), the restart purge rate is set to gradually increase from Rp2. A relatively small value is used as the start purge rate Rp1 in order to suppress the disturbance of the air-fuel ratio in the combustion chamber 29. Examples of when the purge control is interrupted include when the accelerator is off while the vehicle on which the engine device 10 is mounted is running and the fuel of the engine 12 is cut. As the restart purge rate Rp2, a value equal to or less than the required purge rate Rprq immediately before interruption (see step S150 described later) is used.

When the data is input in this way, the fully open purge flow rate Qpmax is estimated based on the surge pressure Ps and the value obtained by subtracting the intake pressure Pin from the boost pressure Pc (Pc-Pin) (step S110). Here, the fully open purge flow rate Qpmax is the purge flow rate (volumetric flow rate of the evaporated fuel gas supplied to the intake pipe 23) when the drive duty of the purge control valve 65 is 100%, and the map for estimating the fully open purge flow rate is provided. Obtained using. The fully open purge flow rate estimation map is predetermined by experiments and analysis as the relationship between the surge pressure Ps and the value (Pc-Pin) and the fully open purge flow rate Qpmax, and is stored in a ROM (not shown). FIG. 4 is an explanatory diagram showing an example of a map for estimating the fully open purge flow rate. As shown in the figure, the fully open purge flow rate Qpmax is estimated to increase as the surge pressure Ps decreases (as a negative pressure) and increases as the value (Pc-Pin) increases.

Subsequently, the correction coefficient k is set based on the surge pressure Ps and the surge temperature Ts (step S120). Here, the correction coefficient k is a coefficient that reflects the volume of the evaporated fuel gas (purge gas), and can be obtained by using the correction coefficient setting map. The correction coefficient setting map is predetermined by experiment or analysis as the relationship between the surge pressure Ps and the surge temperature Ts and the correction coefficient k, and is stored in a ROM (not shown). The correction coefficient k is set so that the larger the surge pressure Ps is, the smaller the correction coefficient k is, and the higher the surge temperature Ts is, the larger the correction coefficient k is. This is based on the fact that the larger the surge pressure Ps, the smaller the volume of the evaporated fuel gas, and the higher the surge temperature Ts, the larger the volume of the evaporated fuel gas.

Then, the combustion chamber air, which is the amount of air in the combustion chamber 30, is based on the intake air amount Qa and the upstream purge amount (past Qvup) estimated in the process of step S180 described later when this routine is executed in the past. The quantity Qcc is estimated (step S130). Here, the upstream purge amount Qvup is the flow rate of the evaporated fuel gas on the introduction passage 52 side with respect to the purge control valve 65. For the combustion chamber air amount Qcc, for example, the intake air amount Qa and the past upstream purge amount (past Qvup) are applied to the relationship between the intake air amount Qa and the past upstream purge amount (past Qvup) and the combustion chamber air amount Qcc. Can be obtained. As the past upstream purge amount (past Qvup), it is preferable to use the previous upstream purge amount Qvup for a longer time as the rotation speed Ne of the engine 12 is smaller, but for the sake of simplicity, it is upstream by a certain time. The purge amount Qvup may be used.

When the fully open purge flow rate Qpmax, the correction coefficient k, and the combustion chamber air amount Qcc are obtained in this way, the fully open purge rate Rpmax is estimated based on these (step S140). The fully open purge rate Rpmax can be calculated by the equation (1) using, for example, the fully open purge flow rate Qpmax, the correction coefficient k, and the combustion chamber air amount Qcc. Therefore, the fully open purge rate Rpmax increases as the fully open purge flow rate Qpmax based on the surge pressure Ps and the value (Pc-Pin) increases, and increases as the correction coefficient k based on the surge pressure Ps and surge temperature Ts increases. The larger the air volume Qa and the combustion chamber air volume Qcc based on the past upstream purge amount Qvup, the smaller the air volume Qa.

Rpmax = Qpmax ・ k / Qcc (1)

Subsequently, the target purge rate Rptg is limited by the fully open purge rate Rpmax (upper limit guard) to set the required purge rate Rprq (step S150), and the required purge rate Rprq is divided by the fully open purge rate Rpmax to divide the purge control valve 65. The required duty Drq is set (step S160), and the purge control valve 65 is controlled using the set required duty Drq (step S170). Then, the upstream purge amount Qvup is estimated based on the intake air amount Qa and the required purge rate Rprq (step S180), and this routine is terminated.

Fully open by estimating the fully open purge flow rate Qpmax by applying the surge pressure Ps and the pressure difference ΔP to the relationship between the pressure difference ΔP obtained by subtracting the intake pressure Pin from the surge pressure Ps and the boost pressure Pc and the fully open purge flow rate Qpmax. The purge flow rate Qpmax can be estimated appropriately. At this time, by using the pressure difference ΔP instead of the boost pressure Pc, the pressure difference between the intake port and the exhaust port of the ejector 69 can be taken into consideration more appropriately. Therefore, the fully open purge flow rate Qpmax should be estimated more appropriately. Can be done.

Then, the fully open purge rate Rpmax is estimated by using the fully open purge flow rate Qpmax, the correction coefficient k based on the surge pressure Ps and the surge temperature Ts, and the combustion chamber air amount Qcc based on the intake air amount Qa. The rate Rpmax can be estimated more appropriately. Further, by controlling the purge control valve 65 by setting the required duty Drq using the fully open purge rate Rpmax and the required purge rate Rprq, it is possible to suppress the deviation of the actual purge rate from the required purge rate Rprq. .. That is, the purge rate can be adjusted appropriately.

Here, as a comparative example, when the supercharging pressure Pc is not a positive pressure (the supercharger 40 is not operating), the surge pressure Ps is applied to the relationship between the surge pressure Ps and the fully open purge flow rate Qpmax, and the fully open purge flow rate is applied. When Qpmax is estimated and the supercharging pressure Pc is positive pressure (the supercharger 40 is operating), the relationship between the pressure difference ΔP obtained by subtracting the intake pressure Pin from the supercharging pressure Pc and the fully open purge flow rate Qpmax is established. Consider the case where the pressure difference ΔP is applied to estimate the fully open purge flow rate Qpmax. In this case, if only one of the downstream purge and the upstream purge is performed, the fully open purge flow rate Qpmax can be estimated appropriately, but both the downstream purge and the upstream purge are performed (evaporated fuel gas). When the fuel is supplied to both the downstream side of the throttle valve 26 of the intake pipe 23 and the upstream side of the compressor 41), the fully open purge flow rate Qpmax cannot be estimated appropriately. On the other hand, in the embodiment, the surge pressure Ps and the pressure difference ΔP are applied to the relationship between the pressure difference ΔP obtained by subtracting the intake pressure Pin from the surge pressure Ps and the boost pressure Pc and the fully open purge flow rate Qpmax to perform the fully open purge. By estimating the flow rate Qpmax, it is possible to properly estimate the fully open purge flow rate Qpmax whether only one of the downstream purge and the upstream purge is performed, or both the downstream purge and the upstream purge are performed. can.

In the engine device of the embodiment described above, the surge pressure Ps and the pressure difference ΔP are applied to the relationship between the surge pressure Ps, the pressure difference ΔP obtained by subtracting the intake pressure Pin from the boost pressure Pc, and the fully open purge flow rate Qpmax, and the pressure difference ΔP is fully opened. The purge flow rate Qpmax is estimated, and the required duty Drq is set using the fully open purge rate Rpmax and the required purge rate Rprq based on the fully open purge flow rate Qpmax to control the purge control valve 65. As a result, the fully open purge flow rate Qpmax can be estimated more appropriately, and the deviation of the actual purge rate from the required purge rate Rprq can be further suppressed. That is, the purge rate can be adjusted more appropriately.

In the engine device 10 of the embodiment, the surge pressure Ps and the pressure difference ΔP are applied to the relationship between the pressure difference ΔP obtained by subtracting the intake pressure Pin from the surge pressure Ps and the boost pressure Pc and the fully open purge flow rate Qpmax, and the fully open purge flow rate is applied. Qpmax was estimated. However, even if the surge pressure Ps and the boost pressure Pc are applied to the relationship between the surge pressure Ps, the boost pressure Pc, and the fully open purge flow rate Qpmax without using the intake pressure Pin, the fully open purge flow rate Qpmax is estimated. good. Further, in relation to the surge pressure Ps and the pressure difference ΔP or the boost pressure Pc and the engine 12 rotation speed Ne and the fully open purge flow rate Qpmax, the surge pressure Ps and the pressure difference ΔP or the boost pressure Pc and the engine 12 rotation speed Ne May be applied to estimate the fully open purge flow rate Qpmax.

In the engine device 10 of the embodiment, the correction coefficient k is set based on the surge pressure Ps and the surge temperature Ts. However, the correction coefficient k may be set based on only one of the surge pressure Ps and the surge temperature Ts. Further, a constant value may be used as the correction coefficient k regardless of the surge pressure Ps and the surge temperature Ts.

In the engine device 10 of the embodiment and the modified example, in the evaporative fuel processing device 50, the purge passage 60 is connected to the vicinity of the canister 56 of the introduction passage 52. However, it may be connected to the canister 56.

In the engine device 10 of the embodiment, the supercharger 40 is configured as a turbocharger in which a compressor 41 arranged in the intake pipe 23 and a turbine 42 arranged in the exhaust pipe 35 are connected via a rotating shaft 43. I made it. However, instead of this, the compressor driven by the engine 12 or the motor may be configured as a supercharger arranged in the intake pipe 23.

In the embodiment, the engine device 10 mounted on a general automobile or various hybrid automobiles is used. However, it may be in the form of an engine device mounted on a vehicle other than an automobile, or may be in the form of an engine device mounted on non-moving equipment such as construction equipment.

The correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem will be described. In the embodiment, the engine 12 corresponds to the "engine", the supercharger 40 corresponds to the "supercharger", the evaporated fuel processing device 50 corresponds to the "evaporated fuel processing device", and the electronic control unit 70 corresponds to the "supercharger". Corresponds to "control device".

Regarding the correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem, the invention described in the column of means for solving the problem in the examples is carried out. Since it is an example for specifically explaining the form for solving the problem, the elements of the invention described in the column of means for solving the problem are not limited. That is, the interpretation of the invention described in the column of means for solving the problem should be performed based on the description in the column, and the examples are the inventions described in the column of means for solving the problem. It is just a concrete example.

Although the embodiments for carrying out the present invention have been described above with reference to examples, the present invention is not limited to these examples, and various embodiments are used without departing from the gist of the present invention. Of course, it can be done.

The present invention can be used in the manufacturing industry of engine devices and the like.

10 engine device, 11 fuel tank, 11a pressure sensor, 12 engine, 14 crank shaft, 14a crank position sensor, 22 air cleaner, 23 intake pipe, 23a air flow meter, 23b, 23c, 27a pressure sensor, 24 bypass pipe, 25 intercooler , 26 Throttle valve, 26a Throttle position sensor, 27 Surge tank, 27b Temperature sensor, 28 Fuel injection valve, 29 Intake valve, 30 Combustion chamber, 31 Ignition plug, 32 Piston, 34 Exhaust valve, 35 Exhaust pipe, 35a Front air fuel ratio Sensor, 35b Rear air-fuel ratio sensor, 36 Bypass pipe, 37, 38 Purifier, 40 Supercharger, 41 Compressor, 42 Turbine, 43 Rotating shaft, 44 Waste gate valve, 45 Blow-off valve, 50 Evaporative fuel treatment device, 52 Introduced Passage, 53 Open / Close Valve, 54 Bypass Passage, 54a, 54b Branch, 55a, 55b Relief Valve, 55b Relief Valve, 56 Canister, 57 Open Air Passage, 58 Air Filter, 60 Purge Passage, 60a Branch Point, 61 Common Passage, 62, 63 branch passage, 64 buffer section, 65 purge control valve, 65a purge control valve position sensor, 66 check valve, 67 check valve, 68 return passage, 69 ejector, 70 electronic control unit.

Claims (1)

An engine that receives fuel from the fuel tank and has a throttle valve located in the intake pipe.
A supercharger having a compressor arranged on the upstream side of the throttle valve of the intake pipe, and
A supply passage for supplying the evaporated fuel gas containing the evaporated fuel generated in the fuel tank to the intake pipe, and an evaporative fuel processing apparatus having a purge control valve provided in the supply passage.
When the evaporated fuel gas is supplied to the intake pipe, the drive duty is set based on the fully open purge rate when the drive duty of the purge control valve is set to 100% and the required purge rate, and the purge control is performed. A control device that controls the valve and
It is an engine device equipped with
The supply passage branches into a first branch passage and a second branch passage on the intake pipe side of the purge control valve.
The first branch passage is connected to the downstream side of the intake pipe with respect to the throttle valve.
In the evaporated fuel processing apparatus, an intake port is connected between the compressor of the intake pipe and the throttle valve via a recirculation passage, and an exhaust port is connected to the upstream side of the compressor of the intake pipe. It also has an ejector with a suction port connected to the two-branch passage.
When the evaporative fuel gas is supplied to the intake pipe, the control device receives a boost pressure which is a pressure between the compressor and the throttle valve of the intake pipe or the boost pressure and the compressor of the intake pipe. In a predetermined relationship between the pressure difference from the compressor front pressure, which is the upstream pressure, the throttle rear pressure, which is the pressure downstream of the throttle valve of the intake pipe, and the fully open purge rate. The fully open purge rate is estimated by applying the boost pressure or the pressure difference and the throttle rear pressure.
Engine device.

Images