JP5937913B2 - engine - Google Patents

Description

  The present invention relates to an engine. In detail, it is related with the engine provided with the fuel-injection control apparatus.

  Conventionally, the startability of a diesel engine may decrease as the ignitability of fuel deteriorates during cold start. Therefore, a fuel injection control device that intentionally increases the fuel injection amount during cold start is known. When the engine coolant temperature is lower than the predetermined temperature, the engine startability is improved by increasing the fuel injection amount from the steady fuel injection amount until the engine rotation speed reaches the predetermined rotation speed. is there. For example, as described in Patent Document 1.

  The fuel injection control device described in Patent Document 1 ends the control for increasing the fuel injection amount when the engine speed reaches a predetermined speed at the start of the engine. For this reason, when starting control to reduce the fuel injection amount to suppress the generation of black smoke according to the engine operating environment, or when a heavy load is applied to the engine, the engine operating state becomes unstable. Or engine stalls may occur.

JP 2011-157484 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an engine capable of improving startability and stabilizing the driving state regardless of the driving environment and usage mode.

According to a first aspect of the present invention, in the engine including the fuel injection control unit that calculates the reference maximum injection amount based on the target engine speed and the coolant temperature, the fuel injection control unit is configured to start the engine after the engine has been started. Is determined to be equal to or greater than a predetermined time, and when it is determined that the coolant temperature is equal to or higher than the predetermined temperature after the start of the engine is completed, the reference maximum injection amount, the target rotational speed, and the large Fuel injection with the smallest value set as the final maximum injection amount between the atmospheric pressure limited injection amount calculated based on atmospheric pressure and the black smoke limited injection amount calculated from the excess air ratio based on atmospheric pressure and intake air flow rate The fuel injection control unit controls the fuel injection amount as a final maximum injection amount using a value obtained by increasing the fuel injection amount by a predetermined amount until a predetermined time elapses after the start of the engine is completed. injection The fuel injection control unit increases the fuel injection amount by a predetermined amount when the cooling water temperature does not reach the predetermined temperature even after a predetermined time has elapsed after the start of the engine is completed. The fuel injection control is performed using the value as it is as the final maximum injection amount until the cooling water temperature reaches a predetermined temperature .

In the present invention, the fuel injection control unit calculates the predetermined amount based on the cooling water temperature.

According to a third aspect of the present invention, the fuel injection control unit calculates the predetermined time based on the cooling water temperature.

According to a fourth aspect of the present invention, the fuel injection control unit calculates the predetermined temperature based on the cooling water temperature.

  As effects of the present invention, the following effects can be obtained.

  That is, according to the first aspect of the present invention, the engine can be reliably started even in an operating environment where the fuel injection amount is limited, and the occurrence of engine stall can be suppressed. Thereby, the startability is improved, and the driving state is stabilized regardless of the driving environment and the usage mode.

  According to the invention which concerns on Claim 2, a fuel can be injected on the suitable fuel-injection conditions according to a driving | running environment. Thereby, the startability is improved, and the driving state is stabilized regardless of the driving environment and the usage mode.

  According to the invention which concerns on Claim 3, a fuel can be injected on the suitable fuel-injection conditions according to a driving | running environment. Thereby, the startability is improved, and the driving state is stabilized regardless of the driving environment and the usage mode.

  According to the invention which concerns on Claim 4, a fuel can be injected on the suitable fuel-injection conditions according to a driving | running environment. Thereby, the startability is improved, and the driving state is stabilized regardless of the driving environment and the usage mode.

Schematic which showed the structure of the fuel-injection control apparatus which concerns on this invention. The figure which shows the flowchart showing the control aspect of the fuel-injection control apparatus which concerns on this invention. (A) The final maximum injection amount and the coolant temperature that the fuel injection control device according to the present invention injects when the coolant temperature reaches the predetermined temperature when the elapsed time from the completion of the engine start is less than the predetermined time. The graph which shows the relationship which shows. (B) The final maximum injection amount injected by the fuel injection control device according to the present invention and the cooling water temperature when the cooling water temperature reaches the predetermined temperature after the elapsed time from the completion of the engine startup has passed the predetermined time. The graph which shows the relationship which shows. The figure which shows the flowchart showing the control aspect of the fuel-injection control apparatus in 2nd embodiment of the fuel-injection control apparatus which concerns on this invention. The figure which shows the flowchart showing the control aspect of the fuel-injection control apparatus in 3rd embodiment of the fuel-injection control apparatus which concerns on this invention.

  Below, the engine 1 which concerns on 1st embodiment of this invention is demonstrated using FIG.

  As shown in FIG. 1, the engine 1 is a diesel engine. In the present embodiment, as shown in FIG. 1, the engine 1 is an in-line four-cylinder engine having four cylinders 3, 3, 3, and 3.

  The engine 1 mixes and burns the air supplied through the intake pipe 2 and the fuel supplied from the fuel injection valves 4, 4, 4, 4 in the cylinders 3, 3, 3, 3. To rotate the output shaft. The engine 1 discharges exhaust generated by fuel combustion to the outside through an exhaust pipe 5. The engine 1 includes a fuel injection control device 10 that controls the fuel injection amount injected from the fuel injection valves 4, 4, 4, 4 and an ECU that controls the engine 1.

  The fuel injection control device 10 controls fuel injection. The fuel injection control device 10 includes an engine speed detection unit 11 that detects the speed of the engine 1, an operation amount detection unit 12 that detects the operation amount S of the accelerator pedal 7, an atmospheric pressure detection unit 13 that detects the atmospheric pressure P, It includes an intake air flow rate detection unit 14 that detects the flow rate of intake air, a cooling water temperature detection unit 15 that detects the cooling water temperature Tm of the engine 1, and a fuel injection control unit 16 that is a control means for controlling fuel injection.

  The engine speed detection unit 11 detects the speed N of the engine 1. The engine speed detection unit 11 includes a sensor and a pulsar and is provided on the output shaft of the engine 1. In the present embodiment, the engine speed detection unit 11 is composed of a sensor and a pulsar. However, any engine capable of detecting the speed N may be used.

  The operation amount detection unit 12 detects the operation amount S of the accelerator pedal 7. The operation amount detection unit 12 includes a stroke sensor or an angle sensor, and is provided on the output lever of the accelerator pedal 7. In the present embodiment, the operation amount detection unit 12 is composed of a stroke sensor or an angle sensor. However, any device that can detect the operation amount S such as a CAN signal may be used.

  The atmospheric pressure detection unit 13 detects the atmospheric pressure P. The atmospheric pressure detection unit 13 includes an atmospheric pressure sensor or the like, and is installed at a location where the atmospheric pressure P can be measured.

  The intake flow rate detector 14 detects the intake flow rate F of the engine 1. The intake flow rate detection unit 14 includes a flow rate sensor and the like, and is installed in the intake pipe 2 of the engine 1. In the present embodiment, the intake flow rate detection unit 14 is configured by a flow rate sensor or the like, but may be calculated by calculation.

  The cooling water temperature detection unit 15 detects the cooling water temperature Tm of the engine 1. The cooling water temperature detection unit 15 includes a temperature sensor and the like, and is disposed in the radiator 6 that performs heat exchange of the cooling water of the engine 1. In the present embodiment, the cooling water temperature detection unit 15 is constituted by a temperature sensor or the like, but it may be one that detects a representative value of the engine thermostud.

  The fuel injection control unit 16 serving as a control means includes various programs for performing fuel injection control, a rotational speed map M1 for calculating the target rotational speed Nt of the engine 1 based on the operation amount S, and the target rotational speed. A reference maximum fuel injection amount map M2 for calculating the reference maximum injection amount Qs based on Nt and the cooling water temperature Tm, a large amount for calculating the atmospheric pressure limited injection amount Qp based on the target rotational speed Nt and the atmospheric pressure P. A pressure limit injection amount map M3, a black smoke limit injection amount map M4 for calculating the black smoke limit injection amount Qλ based on the excess air ratio λ, and the like are stored.

  The target rotational speed Nt is the rotational speed at which the engine 1 rotates at a constant speed when the accelerator pedal 7 is operated by the operation amount S.

The reference maximum injection amount Qs is the maximum fuel injection amount that is allowed at the target rotational speed Nt when the cooling water temperature is Tm in order to suppress the generation of black smoke from the engine 1 .

  The atmospheric pressure limit injection amount Qp is the maximum fuel injection amount that is allowed at the target rotational speed Nt when the atmospheric pressure is P in order to suppress the generation of black smoke from the engine 1.

  The black smoke limit injection amount Qλ is the maximum fuel injection amount allowed when the excess air ratio λ is set in order to suppress the generation of black smoke from the engine 1.

  The predetermined amount Qv is an increase in the fuel injection amount that is increased at the cooling water temperature Tm in order to improve the startability of the engine 1.

  The predetermined time tv is a time during which the fuel injection amount is continuously increased after the start of the engine 1 is completed at the cooling water temperature Tm in order to improve the startability of the engine 1.

  The predetermined temperature Tmv is a threshold value of the cooling water in which the fuel injection amount is continuously increased after the start of the engine 1 is completed in order to improve the startability of the engine 1.

  The ECU 17 controls the engine 1. Various programs and data for controlling the engine 1 are stored in the ECU 17. The ECU 17 may be configured such that a CPU, a ROM, and a RAM are connected by a bus, or may be configured by a one-chip LSI or the like. The ECU 17 includes a fuel injection control unit 16.

  The fuel injection control unit 16 (ECU 17) is connected to the fuel injection valves 4, 4, 4, and 4 and can control the fuel injection valves 4, 4, 4, and 4.

  The fuel injection control unit 16 is connected to the engine speed detection unit 11 and can acquire the speed N detected by the engine speed detection unit 11.

  The fuel injection control unit 16 is connected to the operation amount detection unit 12 and can acquire the operation amount S detected by the operation amount detection unit 12.

  The fuel injection control unit 16 is connected to the atmospheric pressure detection unit 13 and can acquire the atmospheric pressure P detected by the atmospheric pressure detection unit 13.

  The fuel injection control unit 16 is connected to the intake flow rate detection unit 14 and can acquire the intake flow rate F detected by the intake flow rate detection unit 14.

  The fuel injection control unit 16 is connected to the cooling water temperature detection unit 15 and can acquire the cooling water temperature Tm detected by the cooling water temperature detection unit 15.

  The fuel injection control unit 16 can calculate the target rotational speed Nt from the rotational speed map M1 based on the acquired operation amount S.

  The fuel injection control unit 16 can calculate the excess air ratio λ based on the acquired intake flow rate F and atmospheric pressure P.

  The fuel injection control unit 16 can calculate the reference maximum injection amount Qs from the reference maximum fuel injection amount map M2 based on the acquired cooling water temperature Tm and the calculated target rotational speed Nt.

  The fuel injection control unit 16 can calculate the atmospheric pressure limited injection amount Qp from the atmospheric pressure limited injection amount map M3 based on the acquired atmospheric pressure P and the calculated target rotational speed Nt.

  The fuel injection control unit 16 can calculate the black smoke limited injection amount Qλ from the black smoke limited injection amount map M4 based on the calculated excess air ratio λ.

  The fuel injection control unit 16 can set the final maximum injection amount Qm by selecting the smallest value among the calculated reference maximum injection amount Qs, atmospheric pressure limit injection amount Qp, and black smoke limit injection amount Qλ. is there.

  The ECU 17 can control the engine 1 based on the operation amount S, the rotational speed N, the target rotational speed Nt, and the final maximum injection amount Qm acquired through the fuel injection control unit 16.

  Below, the aspect of the fuel-injection control of the fuel-injection control part 16 after the start-up of the engine 1 which concerns on 1st embodiment of this invention is demonstrated using FIG. 2 and FIG.

  As shown in FIG. 2, after the engine 1 is started, in step S <b> 110, the fuel injection control unit 16 of the fuel injection control device 10 detects the operation amount S detected by the operation amount detection unit 12 and the atmospheric pressure detection unit 13. The atmospheric pressure P, the intake flow rate F detected by the intake flow rate detection unit 14, and the cooling water temperature Tm detected by the cooling water temperature detection unit 15 are acquired, and the process proceeds to step S120.

  In step S120, the fuel injection control unit 16 calculates the target rotational speed Nt from the rotational speed map M1 based on the acquired operation amount S, and calculates the excess air ratio λ based on the acquired atmospheric pressure P and intake air flow rate F. Calculate and move the step to step S130. In the present embodiment, step S110 and step S120 are not limited to this order.

  In step S130, the fuel injection control unit 16 calculates the reference maximum injection amount Qs from the reference maximum fuel injection amount map M2 based on the acquired coolant temperature Tm and the calculated target rotational speed Nt, and the process proceeds to step S140. Let

  In step S140, the fuel injection control unit 16 calculates the atmospheric pressure limited injection amount Qp from the atmospheric pressure limited injection amount map M3 based on the acquired atmospheric pressure P and the calculated target rotational speed Nt, and the process proceeds to step S150. Let

  In step S150, the fuel injection control unit 16 calculates the black smoke limit injection amount Qλ from the black smoke limit injection amount map M4 based on the calculated excess air ratio λ, and the process proceeds to step S160. In the present embodiment, steps S130 to S150 are not limited to this order.

  In step S160, the fuel injection control unit 16 determines whether or not an elapsed time t after the start of the engine 1 is completed is equal to or longer than a predetermined time tv. As a result, when it is determined that the elapsed time t after the start of the engine 1 is completed is equal to or longer than the predetermined time tv, the fuel injection control unit 16 shifts the step to step S170. On the other hand, when it is determined that the elapsed time t from the start of the engine 1 is less than the predetermined time tv, the fuel injection control unit 16 shifts the step to step S280.

  In step S170, the fuel injection control unit 16 determines whether or not the coolant temperature Tm is equal to or higher than the predetermined temperature Tmv after the start of the engine 1 is completed. As a result, when it is determined that the coolant temperature Tm is equal to or higher than the predetermined temperature Tmv after the start of the engine 1 is completed, the fuel injection control unit 16 shifts the step to step S180. On the other hand, when it is determined that the coolant temperature Tm is lower than the predetermined temperature Tmv after the start of the engine 1 is completed, the fuel injection control unit 16 shifts the step to step S280.

  In step S180, the fuel injection control unit 16 selects the smallest value among the calculated reference maximum injection amount Qs, atmospheric pressure limit injection amount Qp, and black smoke limit injection amount Qλ, and sets it as the final maximum injection amount Qm. Return the step to step S110.

  In step S280, the fuel injection control unit 16 sets a value obtained by increasing the calculated reference maximum injection amount Qs by a predetermined amount Qv to the final maximum injection amount Qm, and returns the step to step S110.

  That is, as shown in FIG. 3 (a), the fuel injection control unit 16 does not prevent the coolant temperature Tm from reaching the predetermined temperature Tmv until the predetermined time tv elapses after the start of the engine 1 is completed ( Control is performed so that the fuel injection amount is increased by a predetermined amount Qv until a predetermined time tv elapses (see line B in FIG. 3A) (see line B in FIG. 3A). Further, as shown in FIG. 3B, the fuel injection control unit 16 determines the coolant temperature even if a predetermined time tv elapses after the start of the engine 1 is completed (see line A in FIG. 3B). Control is performed such that the fuel injection amount is increased by a predetermined amount Qv until Tm reaches a predetermined temperature Tmv (see line B in FIG. 3B).

  Thereby, the startability of the engine 1 can be improved, and engine stall immediately after the engine 1 is started in a low temperature environment can be suppressed. Further, it is possible to prevent engine stall when the engine 1 mounted on the work machine or the like is subjected to a high load immediately after starting or when a high load is applied in a low temperature environment.

  As described above, the engine 1 according to the first embodiment of the present invention is a fuel injection that is a control means for calculating the reference maximum injection amount Qs based on the target rotational speed Nt of the engine 1 and the coolant temperature Tm of the engine 1. In the engine 1 including the control unit 16, the fuel injection control unit 16 is based on the reference maximum injection amount Qs, the atmospheric pressure limit injection amount Qp calculated based on the target rotational speed Nt and the atmospheric pressure P, and the excess air ratio λ. The smallest value of the black smoke limit injection amount Qλ calculated in this way is set as the final maximum injection amount Qm, and the elapsed time t after the start of the engine 1 is completed is less than the predetermined time tv, or the coolant temperature When Tm is lower than the predetermined temperature Tmv, a value obtained by increasing the reference maximum injection amount Qs by the predetermined amount Qv is set as the final maximum injection amount Qm.

  With this configuration, the engine can be reliably started even in an operating environment where the fuel injection amount is limited, and the occurrence of engine stall can be suppressed. Thereby, the startability is improved, and the driving state is stabilized regardless of the driving environment and the usage mode.

  Next, the engine 18 which is 2nd embodiment of the engine which concerns on this invention is demonstrated using FIG.1 and FIG.4. The engine 18 includes a fuel injection control device 19. The fuel injection control device 19 includes a fuel injection control unit 20, and calculates a predetermined amount Qv, a predetermined time tv, and a predetermined temperature Tmv based on the coolant temperature Tm. In the following embodiments, the same points as those of the above-described embodiments will not be specifically described, and different portions will be mainly described.

  As shown in FIG. 1, the fuel injection control unit 20 calculates a predetermined amount calculation map M5 for calculating a predetermined amount Qv for increasing the fuel injection amount from the coolant temperature Tm, and calculates a predetermined time tv from the coolant temperature Tm. A predetermined time calculation map M6, a predetermined temperature calculation map M7 for calculating the predetermined temperature Tmv from the cooling water temperature Tm, and the like are stored. The fuel injection control unit 20 performs a predetermined calculation according to these programs and the like, and stores the result of the calculation.

  The fuel injection control unit 20 calculates a predetermined amount Qv from the predetermined amount calculation map M5, a predetermined time tv from the predetermined time calculation map M6, and a predetermined temperature Tmv from the predetermined temperature calculation map M7 based on the acquired cooling water temperature Tm. Is possible.

  Below, the aspect of the fuel-injection control of the fuel-injection control part 20 after the start of the engine 18 which concerns on 2nd embodiment of this invention is demonstrated using FIG.

  As shown in FIG. 4, after the engine 18 is started, in step S151, the fuel injection control unit 20 converts the predetermined amount Qv from the predetermined amount calculation map M5 to the predetermined time calculation map M6 based on the acquired cooling water temperature Tm. And the predetermined temperature Tmv is calculated from the predetermined temperature calculation map M7, and the process proceeds to step S160. In the present embodiment, any one or two of the predetermined amount Qv, the predetermined time tv, and the predetermined temperature Tmv may be calculated based on the cooling water temperature Tm.

  In step S160 to step S280, the fuel injection control unit 20 performs fuel injection control using the calculated predetermined amount Qv, predetermined time tv, and predetermined temperature Tmv.

  As described above, in the engine 18 according to the second embodiment of the present invention, the fuel injection control unit 20 as the control means calculates the predetermined amount Qv based on the coolant temperature Tm.

  The fuel injection control unit 20 calculates a predetermined time tv based on the cooling water temperature Tm.

  The fuel injection control unit 20 calculates a predetermined temperature Tmv based on the cooling water temperature Tm.

  By comprising in this way, a fuel can be injected on the suitable fuel-injection conditions according to a driving | running environment. Thereby, the startability is improved, and the driving state is stabilized regardless of the driving environment and the usage mode.

  Next, an engine 21 that is a third embodiment of the engine according to the present invention will be described with reference to FIGS. 1 and 5. The engine 21 includes a fuel injection control device 22. The fuel injection control device 22 includes a fuel injection control unit 23 and calculates a predetermined amount Qv, a predetermined time tv, and a predetermined temperature Tmv based on the atmospheric pressure P. In the following embodiments, the same points as those of the above-described embodiments will not be specifically described, and different portions will be mainly described.

  As shown in FIG. 1, the fuel injection control unit 23 calculates a predetermined amount Qv for increasing the fuel injection amount from the atmospheric pressure P, and calculates a predetermined time tv from the coolant temperature Tm. A time calculation map M9, a predetermined temperature calculation map M10 for calculating the predetermined temperature Tmv from the cooling water temperature Tm, and the like are stored. The fuel injection control unit 23 performs a predetermined calculation according to these programs and stores the result of the calculation.

  The fuel injection control unit 23 calculates the predetermined amount Qv from the predetermined amount calculation map M8, the predetermined time tv from the predetermined time calculation map M9, and the predetermined temperature Tmv from the predetermined temperature calculation map M10 based on the acquired atmospheric pressure P. It is possible.

  Below, the aspect of the fuel-injection control of the fuel-injection control part 23 after the start of the engine 21 which concerns on 3rd embodiment of this invention is demonstrated using FIG.

  As shown in FIG. 5, after the engine 21 is started, in step S152, the fuel injection control unit 23 calculates the predetermined amount Qv from the predetermined amount calculation map M8 based on the acquired atmospheric pressure P from the predetermined time calculation map M9. The predetermined time tv is calculated for each predetermined temperature Tmv from the predetermined temperature calculation map M10, and the process proceeds to step S160. In the present embodiment, any one or two of the predetermined amount Qv, the predetermined time tv, and the predetermined temperature Tmv may be calculated based on the atmospheric pressure P.

  In Step S160 to Step S280, the fuel injection control unit 23 performs fuel injection control using the calculated predetermined amount Qv, the predetermined time tv, and the predetermined temperature Tmv.

  As described above, in the engine 21 according to the third embodiment of the present invention, the fuel injection control unit 23, which is a control means, calculates the predetermined amount Qv based on the atmospheric pressure P.

  The fuel injection control unit 23 calculates a predetermined time tv based on the atmospheric pressure P.

  The fuel injection control unit 23 calculates a predetermined temperature Tmv based on the atmospheric pressure P.

  By comprising in this way, a fuel can be injected on the suitable fuel-injection conditions according to a driving | running environment. Thereby, the startability is improved, and the driving state is stabilized regardless of the driving environment and the usage mode.

1 Engine 10 Fuel Injection Control Device 16 Fuel Injection Control Unit Nt Target Speed P Atmospheric Pressure Tm Cooling Water Temperature λ Air Excess Ratio Qs Standard Maximum Injection Amount Qp Atmospheric Pressure Limit Injection Amount Qλ Black Smoke Limit Injection Amount Qm Final Maximum Injection Amount t Elapsed time tv Predetermined time Tmv Predetermined temperature

Claims (4)

In an engine including a fuel injection control unit that calculates a reference maximum injection amount based on a target engine speed and a coolant temperature,
The fuel injection control unit determines that the elapsed time after the start of the engine is completed is a predetermined time or more, and determines that the coolant temperature is equal to or higher than the predetermined temperature after the start of the engine is completed. Is, among the reference maximum injection amount, the atmospheric pressure limited injection amount calculated based on the target rotational speed and the atmospheric pressure, and the black smoke limited injection amount calculated from the excess air ratio based on the atmospheric pressure and the intake flow rate, Set the smallest value to the final maximum injection amount and perform fuel injection control,
The fuel injection control unit performs fuel injection control with a value obtained by increasing the fuel injection amount by a predetermined amount until a predetermined time elapses after the start of the engine is completed as a final maximum injection amount. ,
The fuel injection control unit keeps increasing the fuel injection amount by a predetermined amount when the cooling water temperature does not reach the predetermined temperature even after a predetermined time has elapsed since the start of the engine is completed. An engine characterized by performing fuel injection control with a value as a final maximum injection amount until the coolant temperature reaches a predetermined temperature . The engine according to claim 1, wherein the fuel injection control unit calculates the predetermined amount based on the coolant temperature. The engine according to claim 1, wherein the fuel injection control unit calculates the predetermined time based on the coolant temperature. The engine according to claim 1, wherein the fuel injection control unit calculates the predetermined temperature based on the coolant temperature.

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