JPH075236Y2 - Fuel supply control device for internal combustion engine with turbo heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an internal combustion engine with a turbo heater that generates warm air in a cold internal combustion engine to accelerate warming up of the engine.

[Conventional technology]

A so-called turbo heater has a turbine provided in an exhaust system of an internal combustion engine and a compressor driven by the turbine. The rotating energy of the compressor generates warm air, and the warm air promotes warm-up of the engine. Or
Or to get the heated air in the passenger compartment. A turbo heater is mechanically similar to a so-called turbocharger, but unlike a turbocharger that obtains air pressurized by so-called adiabatic compression, adiabatic compression is not performed and only the heating effect is obtained by the rotational energy of the compressor. The design of the compressor throat, etc. is different from that for turbochargers.

As an example of a turbo heater, for example, SAIkai Sho 58-100222
The issue proposes that the air heated by the supercharger is used to heat the passenger compartment. A control valve is provided to suppress air from the supercharger, and the control valve normally introduces air from the supercharger into the engine, but during heating, air from the supercharger is introduced into the heating device.

[Problems to be solved by the device]

In the related art, the torque of the engine changes depending on the state of the control valve, that is, whether or not the turbo heater is operated. Therefore, the depression amount of the accelerator pedal for obtaining the same torque varies depending on whether or not the turbo heater is operating. As a result, the turbo heater
When the boundary between the ON condition and the OFF condition is crossed, the engine torque changes abruptly, which causes a driver discomfort.

In this invention, the same torque can be obtained for the same depression amount of the accelerator pedal regardless of whether the turbo heater is operating or stopped.

[Means for Solving the Problems]

According to this invention, in FIG. 1, an internal combustion engine is equipped with an intake system A, an exhaust system B, and a fuel supply device C, and a turbine 24 provided in the exhaust system of the internal combustion engine and driven and heated by the turbine 24 are heated. In an internal combustion engine that has a turbo heater 22 including a compressor 26 that generates air, and a control valve 36 that introduces exhaust gas into the turbine 24 when the turbo heater 22 operates, a state in which the turbo heater 22 operates or stops The fuel for the internal combustion engine with a turbo heater further includes a turbo heater state detecting means D for detecting the fuel consumption, and a fuel increasing means E for increasing the amount of fuel supplied from the fuel supply device C for the internal combustion engine when the turbo heater 22 is in operation. A supply controller is provided.

[Action]

The turbo heater state detecting means D detects whether or not the turbo heater 22 is operating, for example, by the state of the control valve 36. When the turbo heater state detecting means D determines that the turbo heater 22 is operating, the increasing means E The amount of fuel supplied from the fuel supply means C is increased more than usual.

〔Example〕

In FIG. 2 showing the application of the present invention to a diesel engine, 10 is a main body of the diesel engine, 12 is an intake pipe, 14 is an air cleaner, and 16 is an exhaust pipe. 18 is a fuel injection pump, 20
Indicates a vacuum pump, and as is well known, the fuel injection pump 18 and the vacuum pump 20 are rotationally driven by a crankshaft.

The turbo heater 22 includes a turbine 24, a compressor 26, and a rotating shaft 28 connecting the turbine 24 and the compressor 26. The turbine 24 is arranged in an exhaust gas branch passage 30 whose upstream end branches from the exhaust pipe 16. Exhaust gas branch passage 30
The downstream of is connected to the exhaust pipe 16. The compressor 26 is provided on the air passage 32, the downstream end of the air passage 32 is connected to the intake pipe 12, and the upstream end of the air passage 32 is connected to the air cleaner 34. A butterfly type control valve 36 is provided in the exhaust pipe 16 upstream of the connection point with the air distribution passage 30, and the control valve 36
A lever 40 is provided on the valve shaft 36-1 of 36, and the lever 40 is a rod.
It is connected to one end of 42. The other end of the rod 42 is connected to the diaphragm 44-1 of the diaphragm actuator 44. The diaphragm actuator 44 opens and closes the control valve 36 by selectively introducing a negative pressure. The diaphragm actuator 44 is connected to the vacuum pump 20 via a negative pressure pipe 50. Three-way switching solenoid valve (VS
V) 52 is provided and when the solenoid valve 52 is energized (ON), the vacuum pump 20 communicates with the actuator 44, the negative pressure from the vacuum pump 20 is introduced into the actuator 44, and the rod 42 moves to the left in the figure. Driven by the contraction control valve 36
Is closed (solid line). De-energize solenoid valve 52 (OFF)
Then, the actuator 44 is connected to the air cleaner 56, atmospheric pressure is introduced into the actuator 44, the rod 42 is extendedly moved to the right in the drawing, and the control valve 36 is opened (broken line).

FIG. 3 shows a fuel injection pump 18 and a control circuit for controlling the fuel injection amount. The fuel injection pump 18 is a so-called distribution type fuel injection pump in this embodiment, and is equipped with a spill control device by electric control. The fuel injection pump 18 has a plunger 60, and the plunger 60 reciprocates while rotating in the cylinder 62. Face cam at one end of plunger 60
64 is provided, and the face cam 64 contacts the roller 66.
On the other hand, the plunger is connected to the drive shaft 70 via the coupling 68, and the drive shaft 70 is connected to the crank shaft of the engine 10. Therefore, the drive shaft 70
When is driven to rotate, the plunger 60 reciprocates left and right while rotating due to the cooperative action of the roller 66 and the face cam 64. When the plunger 60 moves to the right in the figure against the return spring 65, the volume of the pump chamber 72 formed between the tip of the plunger 60 and the cylinder 62 decreases, and the fuel in the pump chamber 72 increases. When the recessed portion 76 that is pressed and communicates with the passage 74 formed in the plunger 60 communicates with one of the small holes 78 provided in the cylinder 62 in the radial direction by the number of cylinders, the discharge valve 80 is opened, and the discharge valve 80 is opened. Fuel injection is performed from the fuel injection valve (illustration) of the cylinder connected to 80. When the plunger 60 moves to the left side in the drawing by the return spring 65, the volume of the pump chamber 72 formed between the tip of the plunger 60 and the cylinder 62 increases, the pressure in the pump chamber 72 is reduced, and the fuel When the supply small holes 83 communicate with the recesses 84 formed at the tip of the plunger 60 at angular intervals in the same number as the number of cylinders, the fuel from the fuel chamber 86 is sucked into the pump chamber 72. Pump blades 87 are provided on the drive shaft 70, and fuel from a fuel tank (not shown) is sucked into the intake port 87.
-1 is sucked, and the fuel chamber 86 is filled from the discharge port 87-2.

The above-described reciprocating motion of the plunger is repeated for the number of cylinders per revolution of the plunger (that is, one cycle of the engine), and the fuel injection from the fuel injection valve opening of the cylinder is executed. A spill ring 90 is slidably disposed on the plunger 60. By controlling the relative position between the spill ring 90 and the spill port 92, the stroke position of the plunger where the fuel spin occurs can be changed and the fuel injection amount can be controlled. That is, the further to the right the position of the spill ring 90 is, the plunger when the spill port 92 is opened.
The stroke of 60 in the compression direction increases, that is, fuel injection is performed until the end of the stroke, and the fuel injection amount increases. Conversely, the further to the left the position of the spill ring 90, the smaller the stroke of the plunger 60 in the compression direction when the spill port 92 is opened, i.e., the fuel injection is completed within the beginning of the stroke. , The amount of fuel injection decreases. That is, the fuel injection amount is variably controlled by the position control of the spill ring 90.

The electronic spin controller is an actuator solenoid 94
And a spill position sensor 96. A core 98 made of a magnetic material is located inside the actuator solenoid 94, and the position of the core 98 is controlled according to the voltage applied to the solenoid 94. The core 98 controls the position of the spill ring 90 via a spill control lever 100 biased by the spill 99. That is, the lever 100 is rotatably provided around the fulcrum 102, and when the voltage applied to the solenoid 94 is low, the spring 98 causes a large protrusion of the core 98,
The lever 100 is rotated clockwise, the spill ring 90 is moved to the left in the figure, and the spill port 92 is opened while the stroke amount of the plunger 60 is small, and the fuel injection amount is reduced. On the other hand, when the voltage applied to the solenoid 94 is high, the core 98 is attracted to the left against the spring 104, the amount of protrusion of the core rod 98 becomes small, and the lever 10
0 is rotated counterclockwise, the spill ring 90 is moved to the right in the figure, the spill port 92 is opened after the stroke amount of the plunger 60 is increased, and the fuel injection amount is increased.

The control circuit 110 controls the solenoid valve 52 and spill position control according to the present invention, and is configured as, for example, a microcomputer system. The control circuit 110 is connected to each sensor and receives a detection signal from each sensor. The spill position sensor 96 can be configured as a differential transformer or the like that generates an electric signal according to the position of the rod 112 extending from the core 98 of the actuator 94 (that is, the position of the spill ring 90). The rotation speed sensor 114 is composed of, for example, a Hall element, and the water temperature sensor 116 that generates a pulse signal according to the rotation speed of the drive shaft 70 of the fuel injection pump generates a signal according to the cooling water temperature THW of the engine. The accelerator pedal position sensor 118 generates a signal Accp according to the amount of depression of the accelerator pedal. Reference numeral 119 is a switch for operating the turbo heater according to the driver's request.

4 and 5 are flowcharts for explaining the operation of the control circuit 110. FIG. 4 shows a control routine for the turbo heater. At step 120, it is judged if the turbo heater switch 119 is ON. Turbo heater switch 119
When is OFF, the routine proceeds to step 128, where VSV52 is turned OFF.
Therefore, the control valve 36 takes the fully open position indicated by the broken line in FIG.
Most of the exhaust gas from the exhaust pipe 16 is guided to the passage portion 16-1 and the turbo heater is not operated.

When the turbo heater switch 119 is ON at step 120, the routine proceeds to step 122, where it is judged if the water temperature THW is smaller than a predetermined value T ₁ . When THW ≧ T ₁ , it is determined that the engine has warmed up, the routine proceeds to step 128, where the turbo heater is not operated. When THW <T ₁ where the engine is not warmed up, the routine proceeds from step 128 to step 124, where it is judged if it is in the operating range of the turbo heater. FIG. 6 schematically shows the operating range of the turbo heater with respect to the engine speed NE and the accelerator pedal opening Accp. The operating range of the turbo heater is shown by hatching, and is a low rotation range in which the accelerator pedal opening Accp is not so large. That is, there is a margin in the output of the engine in the low rotation range where the opening of the accelerator pedal is not large, and a part of the energy can be used for driving the turbo heater. In step 124, the current accelerator pedal opening Accp and the engine speed NE are detected by the sensors 118, 114.
Detected, and the turbo heater is turned on from the map in FIG.
It is determined whether it is the operating range or the OFF operating range. Step 124
If it is determined from the accelerator pedal opening Accp and the engine speed NE that the turbo heater is in the OFF region, the routine proceeds to step 122. On the other hand, when it is determined that the turbo heater is in the ON region, the routine proceeds to step 126, the VSV 52 is turned on, the negative pressure from the negative pressure pump is introduced into the actuator 44, and the control valve 36 is as shown by the solid line in FIG. To be closed. As a result, the exhaust gas from the exhaust pipe 16 is introduced into the turbine 24 of the turbo heater 22 and rotationally drives it, and the rotation is transmitted to the compressor 26. As a result, the outside air starts from the passage 32 and is introduced into the engine 10 by starting the intake pipe 12, but the temperature of the air introduced into the engine from the passage 32 is increased by being compressed by the compressor 26. Therefore, the combustion in the engine 10 is efficiently performed, and the warm-up thereof is promoted. for that reason,
The water temperature of the engine is immediately raised, and vehicle interior heating using the water temperature as a heat source is performed rapidly.

FIG. 5 shows a spill control routine. V in step 130
It is determined whether the SV52 is ON, that is, whether the turbo heater is operating. When VSV is ON, that is, while the turbo heater is operating, the routine proceeds to step 132, where the fuel injection amount V when the turbo heater is operating is calculated from the map A. This map A is configured as the value of the fuel injection amount for each combination of the accelerator pedal opening Accp and the value of the engine speed NE.
This map is constructed as follows, for example.

In the table, the fuel injection amount (mm ³ ) shall be indicated per stroke. The process of step 132 is performed by measuring the current accelerator pedal opening A measured by the sensors 118 and 114.
The fuel injection amount X for one combination of the value of ccp and the engine speed NE is calculated by a well-known two-dimensional interpolation calculation.

When VSV is OFF in step 130, that is, when the turbo heater is not operating, the process proceeds to step 134, and the fuel injection amount when the turbo heater is not operating is calculated from map B. This map B is constructed as the fuel injection amount value for each combination of the accelerator pedal opening Accp and the engine speed NE value.
An example of that map is Becomes The fuel injection amount is the same in the region above the boundary line between the turbo heater ON and OFF in FIG. 6, but the fuel injection amount is the same in the region below that line when the turbo heater is ON and OFF. Even when the opening Accp and the engine speed NE are set, the turbo heater is ON more than it is OFF.
This is for the following reasons. That is, the turbo heater is ON
Since the control valve is closed and opened between ON and OFF, the resistance of the exhaust system changes, so even if the same accelerator pedal opening Accp and engine speed NE are combined, the engine torque will be It is lower than when the turbo heater is off. Therefore, when the turbo heater is ON to obtain the same torque, the driver has to step on the accelerator pedal more than when the turbo heater is OFF to obtain the same torque, which means that the driver runs less when the turbo heater is ON. It gives a sense of incongruity. Also, the torque changes abruptly at the switching point, causing a shock. FIG. 7 explains this. If acceleration is started from the operating range of the turbo heater ON and the torque is increased (B), it is assumed that the turbo heater is turned OFF (B) at time t. If the same fuel injection map is used for turning the turbo heater on and off, the torque will change suddenly and you will feel a shock. In this invention, when the turbo heater is ON, the fuel injection amount map is a different map, and the torque is set as shown by the broken line. Therefore, when the turbo heater is switched from ON to OFF, a smooth increase in torque is realized. In other words, in this invention, when the turbo heater is turned on, a larger fuel injection amount is given at the same combination of the accelerator pedal opening Accp and the engine speed NE compared to when it is turned off.
The fuel amount is corrected so that the same torque as at the time is obtained. Therefore, it is possible to obtain an acceleration feeling without any discomfort when the turbo heater is turned on.

In FIG. 5, in step 136, a calculation for converting the fuel injection amount V into the position P of the spill ring 90 is performed. The function f for this conversion can be set by using a map or an algebraic function. In step 138, the spill voltage E is calculated by E = E + α (PP ′). Where P'is the spill position sensor
The actual spill position detected by 96, P-P '
The deviation between the spill position calculated by and the actually measured spill position is calculated. α is a feedback coefficient. By such feedback control, the position of the spill ring 90 is controlled to the position calculated in step 132 when the turbo heater is turned on, and to the position calculated in step 134 when the turbo heater is turned off, so that a required amount of fuel is supplied to the fuel injection pump 18. After that, the fuel is injected from the fuel injection valve. Step 140 shows the output of spill voltage E to actuator 94.

In the above embodiment, there are two fuel injection amount maps according to ON / OFF of the turbo heater, but instead, there is one map for turning off the turbo heater, and it is possible to increase the amount when the turbo heater is turned on. . As the increase factor, the accelerator pedal opening Accp may be used, but instead, the exhaust pressure may be changed.

FIG. 8 shows another embodiment of the present invention. In this embodiment, the present invention is implemented by a normal mechanical fuel injection pump of the distribution type. The fuel injection pump includes a diaphragm actuator 200 for controlling the fuel injection amount. This actuator 200 is called a so-called boost compensator and has the same structure as that used for controlling the upper limit of the fuel injection amount in the intake supercharged diesel engine. That is, the actuator 200 has diaphragm cases 202 and 204, and the diaphragm 206 is arranged between the diaphragm cases. Diaphragm 206
The stopper pin 208 is fixed to. When the control pin 228 hits the stopper pin 208, the spill ring
The maximum injection amount is controlled by prohibiting the movement of 0 in the increasing direction. The stopper pin 208 has a tapered surface 208-1, and the tapered surface 208-1 corrects the maximum fuel injection amount. On the other hand, the accelerator pedal is connected to one end of a lever 212 via a wire 210, the other end of the lever 212 is connected to a shaft 214, and a lever 224 is fixed to the shaft 214, and the lever 224 is controlled via a spring 226. It is connected to the lever 228. One end of the control lever 228 is connected to the spill ring 90. Further, the end of the governor shaft 227 contacts the control lever, and the position of the governor shaft is controlled according to the engine speed. Therefore, mechanical spill position control is performed according to the accelerator pedal opening and the engine speed.
Since the operation of such a fuel injection valve is well known, detailed description thereof will be omitted. As described above, the other end of the lever 228 engages with the stopper 208 to control the maximum fuel injection amount. Since other configurations of the fuel injection pump are the same as those in FIG. 3, the same parts are designated by the same reference numerals and the description thereof will be omitted.

The space 228 below the diaphragm of actuator 200 is VS
It is connected to a vacuum pump or atmospheric pressure via V230. The VSV230 is driven in conjunction with turning on and off of the turbo heater.When the turbo heater is off, the VSV230 is off, atmospheric pressure is introduced into the space 228, the diaphragm is pushed upward by the spring, and the lever 228 The upper end of the stopper contacts the normal diameter portion below the tapered surface 208-1 of the stopper. Therefore, the normal maximum control of the fuel injection amount is performed.
On the other hand, when the turbo heater is turned on, VSV230 is turned on, negative pressure is introduced into the space 228, the diaphragm is sucked downward against the spring, and the upper end of the lever 228 contacts the tapered surface 208-1 of the stopper. . As a result, the lever is rotated deeper in the counterclockwise direction than usual, and as a result, the fuel injection amount becomes larger than when the turbo heater is off. as a result,
When the turbo heater is turned on, the fuel injection amount is corrected to be larger when the turbo heater is turned on than when the turbo heater is turned off, and torque correction similar to that of the first embodiment is achieved.

In the embodiment, the diaphragm chamber 228 is selectively connected to the vacuum pump by turning the turbo heater on and off. That is, when the vacuum is introduced, the position of the tapered surface 208-1 with which the tip of the lever 228 abuts is constant. Therefore, O
N-OFF-like increase characteristic. Alternatively, the VSV 230 can be duty-controlled to continuously control the vacuum value in the diaphragm chamber 228, that is, the position of the stopper rod 208, and the fuel injection amount can be continuously controlled in accordance with the operating condition.

[Effect of device]

According to this device, when the turbo heater is turned on, the turbo heater OF
By increasing the fuel amount during F, the engine torque can be made uniform for the same accelerator pedal opening regardless of the state of the turbo heater, and smooth operation without shock can be realized.

[Brief description of drawings]

FIG. 1 is a diagram showing the configuration of this invention. FIG. 2 is a diagram showing a configuration of an embodiment of the present invention. FIG. 3 is a diagram showing an outline of the fuel injection pump and the electric control system in FIG. 4 and 5 are flow charts for explaining the operation of this invention. FIG. 6 is a diagram for explaining the operating range of the turbo heater. FIG. 7 is a diagram for explaining the operation of the turbo heater and changes in torque during transient operation. FIG. 8 is a partial view of the fuel injection pump of the second embodiment. 10 ... Main body, 12 ... Intake pipe, 16 ... Exhaust pipe, 18 ... Fuel injection pump, 20 ... Vacuum pump, 22 ... Turbo heater, 24 ... Turbine, 26 ... Compressor, 28 ... Rotation Axis, 32 ... Air passage, 36 ... Control valve, 44 ... Diaphragm actuator, 52 ... Solenoid valve, 60 ... Plunger, 90 ... Spill ring, 94 ... Solenoid, 96 ... Spill position sensor, 100 ...... Spill control lever, 110 ...... Control circuit, 114 ...... Rotation speed sensor, 116 ...... Water temperature sensor, 11
8 …… Accelerator pedal opening sensor, 200 …… Diaphragm actuator, 206 …… Diaphragm, 208 …… Stopper rod, 210 …… Accelerator pedal wire, 228 …… Spill control lever

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-163072 (JP, A) JP-A-1-208217 (JP, A) Actual development Sho-58-100222 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A turbine provided in an exhaust system of an internal combustion engine, the internal combustion engine comprising an intake system, an exhaust system and a fuel supply device,
In an internal combustion engine that has a turbo heater that is driven by a turbine and that generates warmed air, and that has a control valve that introduces exhaust gas into the turbine when the turbo heater operates, the turbo heater operates or stops. Fuel supply for an internal combustion engine with a turbo heater, further comprising turbo heater state detection means for detecting such a state, and fuel increase means for increasing the amount of fuel supplied from the fuel supply device for the internal combustion engine when the turbo heater is operating. Control device.