JPH09158772A - Control device of diesel engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the detection accuracy of the engine load in controlling the fuel injection timing, the EGR amount, the air intake throttling, the swirl ratio, or the like of a diesel engine according to the engine speed and the engine load. SOLUTION: The number of revolution Ne (= engine speed) of an input shaft and the number of revolution of an output shaft Np of a torque converter are detected (S1, S2). The speed ratio e=Np/Ne is calculated (S3), and the capacity coefficient C is retrieved (S4) from the speed ratio (e) by referring to the table. The engine torque T=C.Ne<2> from the number of revolution Ne of the input shaft of the torque converter and the capacity coefficient C (S5). The control is realized by using the engine torque T as the engine load.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diesel engine control device. In particular, the present invention relates to a diesel engine control device that controls various variables of the engine according to at least the engine load, targeting a diesel engine whose engine output shaft is connected to an automatic transmission through a torque converter.

[0002]

2. Description of the Related Art Conventionally, in a distributed electronically controlled fuel injection pump for a diesel engine, the injection amount of fuel is determined by the position of the control sleeve, and the injection timing is from the high pressure chamber on one end side of the timer piston to the other end side. It is adjusted by controlling the duty of a timing control valve that adjusts the amount of leakage into the low-pressure chamber (see Ryoji Kihara, "Diesel Passenger Cars", pages 130-141, published by Grand Prix Publishing Co., Ltd. in 1984).

In a row-type electronically controlled fuel injection pump used in a large diesel engine, the fuel injection amount is determined at the control rack position, and the injection timing is the leakage of the timer piston from the high pressure chamber to the low pressure chamber. It is adjusted by controlling the duty of a timing control valve that adjusts the quantity (see Miyashita and Kuroki, “Diesel Engines for Automobiles”, pages 213 to 214, issued in 1994). The control rack position is equivalent to the control sleeve position (both are variables that adjust the fuel injection amount), and the timer control mechanism that controls the injection timing is also almost the same, so the distribution type electronically controlled fuel injection pump will be taken as an example below. explain.

On the other hand, when controlling the fuel injection amount of the engine, the fuel injection timing, the exhaust gas recirculation (hereinafter referred to as "EGR") amount, the swirl ratio, etc., the target value of each control target is generally set by the rotation and the load. However, at that time, since the fuel injection amount can be regarded as approximately engine torque, the fuel injection amount is used as a parameter of the engine load.In the case of a diesel engine, the fuel injection amount is adjusted at the control sleeve position and the control is performed. The fuel injection amount obtained from the sleeve position is used as the engine load as a control parameter. The engine speed and engine load (fuel injection amount)
As a known example of determining the target EGR amount from the above, there is JP-A-63-94036.

By the way, a diesel engine always performs diffusion combustion in an atmosphere with a high excess air ratio, and generally, reducing nitrogen oxides (NOx) increases particulate matter (PM) and black smoke, which is a trade-off relationship. There is. on the other hand,
Due to the aggravation of environmental problems centering on metropolitan areas in recent years,
There is a growing demand for reduction of exhaust pollutants (NOx / PM) socially, and substantial exhaust emission regulations are being implemented in Japan and overseas.

In response to this, research on exhaust gas purification is being carried out more than ever, and one of the findings is that engine modification (combustion chamber shape, fuel injection system,
If the injection timing and swirl ratio are adjusted appropriately for each operating load by improving the EGR system), there is a region where PM does not deteriorate even if the EGR amount is increased compared to the conventional one, and contrary to the conventional knowledge. It has been found that there is an area where PM can be reduced.

However, since the range in which NOx and PM can be simultaneously reduced as described above differs depending on the rotation and load, it is necessary to precisely control the injection timing, EGR amount, and swirl ratio according to the operating conditions, especially the load. ing.

[0008]

However, the control sleeve position is based on the fuel injection amount conversion map matched from the correlation between the control sleeve position and the fuel injection amount for the fuel having the standard fuel property at a constant fuel temperature. In the fuel injection pump that adjusts, there is a problem in that the actual fuel injection amount at the control sleeve position increases or decreases due to changes in the viscosity of the fuel (see FIG. 17).

Specifically, when the drive amount given to the actuator for driving the control sleeve is matched with the reference fuel, if the fuel viscosity becomes low due to the use of the light fuel, the pump efficiency inside the pump decreases, In addition, since the amount of leakage in the plunger pressure stroke increases, the actual fuel injection amount decreases even if the control sleeve position is the same. On the contrary, if the fuel viscosity increases due to the use of heavy fuel,
Since the pump efficiency inside the pump is increased and the leak amount in the plunger pressure feeding stroke is reduced, the fuel injection amount is increased even with the same control sleeve position.

The fuel supplied from the gas station is not always a fuel having a constant property, but the fuel property is slightly different depending on the oil manufacturer or region. Especially in cold regions, JI
Light fuel such as S special No. 3 light oil is supplied. JIS Tokushu No. 3 light oil is designed to prevent waxing of light oil in cold regions and to obtain viscosity characteristics suitable for the environment in which it is used. In cold regions in winter, clean drivability can be obtained. . However, there are times when the temperature is relatively high in early spring and autumn, and when JIS Special No. 3 diesel oil is used in such a case, the above-mentioned problems occur. Conversely, the same applies when the fuel to be supplied in the summer is used when the temperature is low.

Further, when the fuel injection pump is operated for an extremely long period of time, the inside of the fuel injection pump is worn and the effective stroke of the plunger of the fuel injection pump changes, so that the actual fuel injection amount at the control sleeve position increases. There is a problem that it will end up (see Fig. 18). Furthermore, due to the mounting error of the control sleeve position sensor of the fuel injection pump and the production variation of the injection system (set residual pressure of the delivery valve, nozzle opening pressure, variation of rotor flow rate), the actual fuel injection amount is controlled. There is a problem that the fuel injection amount obtained from the sleeve position contains an error (see Fig. 19).

With the above-mentioned problems, the control variables such as the injection timing of the diesel engine, the EGR amount, and the swirl ratio are generally set to the target values according to the rotation and the load, and the control sleeve is used as the load. Since the fuel injection amount estimated from the position is used, the following problems occur. For example, even if the control sleeve position is the same, if the actual fuel injection amount decreases (if the actual injection amount decreases due to light fuel / high fuel temperature, sensor and injection system variations, etc.), the estimated fuel injection amount However, it is overestimated than it actually is.
Therefore, the fuel injection amount estimated from the control sleeve position is calculated to be larger than the actual fuel injection amount, and it is determined that the load is high. Therefore, the injection timing is advanced from the desired injection timing, the EGR amount is decreased, and the swirl is increased. Emissions may deteriorate as a result of problems such as a ratio lowering than necessary.

In Japanese Patent Laid-Open No. 59-185832, a fuel property discriminating means is provided to correct the duty ratio to the timing control valve so that the timer piston position does not change. It is not intended to accurately estimate the amount or load, and when the above-mentioned problem occurs, it is not possible to accurately control the control variables such as the injection timing of the diesel engine, the EGR amount, the swirl ratio and the like.

The present invention has been made by paying attention to such conventional problems, and estimates from the position of the control sleeve where load detection cannot always be performed accurately due to fuel properties, fuel temperature, wear due to operation, and production variations. By adopting a load detection method that replaces the fuel injection amount, it completely solves the problems related to various controls of diesel engines, improves control accuracy and robustness, and greatly purifies exhaust gas, and at the same time requires instant An object of the present invention is to provide a diesel engine control device that enables torque detection, simplification of control logic, reduction of adaptation man-hours, and has no malfunction.

[0015]

Therefore, in the invention according to claim 1, in a diesel engine control device for controlling various variables of the engine at least according to the engine load, as shown in FIG. A torque converter input shaft speed detecting means for detecting an input shaft speed of a torque converter provided between the automatic transmission and a torque converter, and a torque converter output shaft speed detecting means for detecting an output shaft speed of the torque converter, A speed ratio calculating means for calculating the speed ratio of the torque converter from the ratio of the input shaft speed and the output shaft speed of the torque converter; a capacity coefficient calculating means for calculating a capacity coefficient based on the speed ratio of the torque converter; The engine torque calculating means for calculating the engine torque from the input shaft speed of the converter and the capacity coefficient is provided, and As Jin load, characterized in that to detect the engine torque.

That is, the present invention focuses on the fact that the engine torque can be estimated by using the speed ratio of the input / output shaft of the torque converter of the automatic transmission and the capacity coefficient peculiar to the torque converter. The speed ratio of the torque converter is calculated from the rotation speed, the capacity coefficient is calculated from this speed ratio, and finally the engine torque is calculated from the input shaft rotation speed and the capacity coefficient of the torque converter. The engine torque is used as an engine load to control various variables of the engine.

According to a second aspect of the present invention, the torque converter output shaft speed detecting means detects the vehicle speed, a means for detecting a shift stage of the automatic transmission, and a torque converter based on the vehicle speed and the shift stage. And a means for calculating the output shaft rotation speed. This can be realized without adding a special sensor for detecting the output shaft speed of the torque converter.

In the invention according to claim 3, the capacity coefficient calculating means retrieves a capacity coefficient corresponding to an actual speed ratio from a table in which the capacity coefficient is stored in advance corresponding to the speed ratio of the torque converter. It is characterized by being.
This allows the capacity coefficient to be calculated during control in a short time. The invention according to claim 4 is characterized in that the capacity coefficient calculating means comprises means for correcting a capacity coefficient determined from a speed ratio of the torque converter in accordance with an oil temperature of the torque converter.

This makes it possible to compensate the torque detection error due to the change in the oil temperature of the torque converter. In the invention according to claim 5, at least one of the fuel injection timing, the EGR amount, the intake throttle, and the swirl ratio is controlled according to the torque converter input shaft rotation speed that is the engine rotation speed and the engine torque that is the engine load. It is characterized by being

As a result, it is possible to greatly improve the control accuracy of the fuel injection timing or the like, which requires accurate detection of the engine load.

[0021]

Embodiments of the present invention will be described below. [First Embodiment] FIGS. 2 to 4 are system diagrams of a first embodiment of the present invention. 2 and 3 are connected by a portion marked with *, and FIGS. 3 and 4 are connected by a portion marked with **.

Referring to FIG. 2, a diesel engine (main body) 1 is supplied with high-pressure fuel from a distributed electronically controlled fuel injection pump 2 by a fuel injection nozzle 3 provided for each cylinder. The output shaft 4 of the diesel engine 1 is
Through the torque converter 5, the planetary gear type automatic transmission 6
It is connected to the. Reference numeral 7 is a shift knob of the transmission 6, and 8 is an output shaft of the transmission 6.

First, the distributed electronically controlled fuel injection pump 2 will be described with reference to FIG. The distributed electronically controlled fuel injection pump 2 includes a drive shaft 10 that rotates in synchronization with an engine, and a feed pump 11 that is driven by the drive shaft 10 and precompresses fuel sucked from a fuel tank.
A pump chamber 12 that stores the fuel pressurized by the feed pump 11 and that lubricates the inside, a roller holder 13 that is arranged so as to surround the drive shaft 10, and a rotation on the roller holder 13 by the drive shaft 10. Then, the face cam 14 that reciprocates while rotating and the reciprocating motion that rotates together with the face cam 14
Plunger 15 that inhales and pressurizes the fuel in 12 and distributes it
And the fuel injection nozzles 3 provided in the distribution passage for each cylinder.
And a delivery valve 16 for delivering high-pressure fuel to.

The distribution type electronically controlled fuel injection pump 2
As a fuel injection amount control device, a control sleeve 17 capable of controlling the injection end by leaking the fuel pressurized by the plunger 15 into the pump chamber 12 and adjusting the fuel injection amount, and the position of the control sleeve 17. Rotary solenoid 18 for controlling fuel injection amount
And a fuel cut valve 19 capable of stopping the engine by stopping the fuel supply.

Further, the distribution type electronically controlled fuel injection pump 2
As a fuel injection timing control device, is a lever 20 connected to the roller holder 13, and is connected to the roller holder 13 via the lever 20. By changing the rotational position of the roller holder 13, the phase of the reciprocating motion of the face cam 14 is changed. By changing
Timer piston 21 with adjustable fuel injection timing
And a fuel injection timing adjustment timing control valve for controlling the position of the timer piston 21 by leaking fuel in the high pressure chamber on one end side of the timer piston 21 to the low pressure chamber on the other end side to control the position of the timer piston 21. 22 and.

Next, the EGR control device will be described with reference to FIG. The EGR control device includes an intake passage 23 and an exhaust passage.
The EGR passage 25 that connects the EGR passage 25 and the EGR passage 25 is provided in the EGR passage 25, and is operated by the negative pressure created by the vacuum pump.
An EGR control valve 26 for adjusting the amount and a duty control valve 27 for adjusting the control negative pressure for controlling the opening degree (lift amount) of the EGR control valve 26 are provided.

Next, the intake throttle control device will be described with reference to FIG. The intake throttle control device is provided in the intake passage 23, operates by a negative pressure created by a vacuum pump, and controls the opening of the intake throttle valve 28 and the intake throttle valve 28 for adjusting the pressure of the intake manifold collector section. And a solenoid valve 29 for adjusting the control negative pressure of the.

Next, the swirl control device will be described with reference to FIG. The swirl control device is installed in the intake manifold branch and operates with a negative pressure created by a vacuum pump to control the swirl ratio in the cylinder.
30 and a solenoid valve (not shown) that adjusts the control negative pressure for controlling the opening degree of the swirl control valve 30.

Next, the control unit 31 and various sensors will be described. The control unit 31 receives the signals of the respective sensors, processes them, and outputs a command signal to each actuator. As the sensors, referring to FIG. 3, a pump rotation speed sensor 32 for detecting the rotation speed of the fuel injection pump, a control sleeve position sensor 33 for detecting the position of the control sleeve 17, and a fuel supply pump A fuel temperature sensor 34 for detecting the temperature, a viscosity sensor 35 for detecting the viscosity of the fuel, a nozzle lift sensor 36 for detecting the valve opening timing (actual injection timing) from the needle valve lift of the fuel injection nozzle 3, and an engine cooling water temperature. A water temperature sensor 37 for detecting the water temperature and an accelerator opening sensor 38 for detecting the accelerator opening.

Further, referring to FIG. 4, an air flow meter 39 for measuring the mass flow rate of intake air and an EGR control valve lift sensor 40 for detecting the lift amount (actual EGR amount) of the EGR control valve 26 are provided. There is. Further, referring to FIG. 2, the time between the ring gear 41 attached to the engine output shaft (the input shaft of the torque converter) 4 and the pitch of the teeth of the ring gear 41 is input to determine the rotational speed of the torque converter input shaft (engine rotation speed). Torque sensor input shaft speed sensor (engine speed sensor) 42 for detecting the
And a torque converter output shaft rotation speed sensor 44 for detecting the torque converter output shaft rotation speed by inputting the time between the tooth pitches of the timing plate 43. .

Next, the outline of the control will be described. The present invention provides a load detection method that substitutes the fuel injection amount estimated from the control sleeve position where load detection cannot always be accurately performed due to fuel properties, fuel temperature, wear due to operation, and production variations, It focuses on the fact that the engine torque can be estimated using the speed ratio of the input and output shafts of the torque converter and the capacity coefficient peculiar to the torque converter. By using this engine torque as the engine load, various variables of the engine can be controlled. , Completely solve the problems related to control of diesel engine injection timing, EGR amount, swirl ratio, etc., improve control accuracy and robustness, greatly purify exhaust gas, and detect and control instantaneous required torque. Enables simplification of logic and reduction of adaptation man-hours.

For the engine torque, the speed ratio is calculated from the ratio of the input shaft speed and the output shaft speed of the torque converter,
The capacity coefficient is calculated from this speed ratio, and is calculated from the input shaft speed of the torque converter and the capacity coefficient by the following equation. T = C · Ne ² where T is engine torque (Nm), C is capacity coefficient (Nm / rpm ² ), and Ne is torque converter input shaft speed = engine speed (rpm).

A method for obtaining the engine torque by using the speed ratio and the capacity coefficient of the torque converter is known (see page 105, "Basic and theoretical editions of the Automotive Technology Handbook, published by the Society of Automotive Engineers of Japan in 1990). , In the present invention,
The engine torque is used as the engine load, and various controls of the diesel engine are performed based on the engine speed and the engine torque.

FIG. 5 is a flowchart for calculating the engine load. This flow is performed in a relatively fast job such as a 4 ms job in order to accurately calculate the change in the instantaneous torque. In S1, the torque converter input shaft speed sensor 42
The torque converter input shaft rotation speed (= engine rotation speed) Ne is read based on the signal from. This portion corresponds to the torque converter input shaft rotation speed detecting means.

At S2, the torque converter output shaft speed Np is read based on the signal from the torque converter output shaft speed sensor 44. This portion corresponds to the torque converter output shaft rotation speed detecting means. In S3, the speed ratio e of the torque converter is calculated from the torque converter input shaft speed Ne and the output shaft speed Np by the following equation. This part corresponds to the speed ratio calculating means.

E = Np / Ne S4 corresponds to the speed ratio e calculated in S1 from the table composed of data of at least 16 grids in which the capacity coefficient measured by the torque converter alone is assigned according to the speed ratio. The capacity coefficient C is searched. This portion corresponds to the capacity coefficient calculating means.

In S5, the engine torque T is calculated from the torque converter input shaft speed Ne and the capacity coefficient C by the following equation. This portion corresponds to the engine torque calculation means. T = C · Ne ² By using this engine torque T as an engine load, various controls of the diesel engine are performed.

Next, the fuel injection amount control will be described with reference to the flowchart of FIG. The fuel injection amount control is the same as that of the conventional technique. In S11, it is determined whether the engine is starting. Specifically, it is determined whether the key switch is in the start position and whether the engine speed is within a predetermined value.

In S12, at the time of starting, the fuel injection amount Qst at the time of starting is searched from the cooling water temperature and the engine speed, and this is made the target fuel injection amount Q = Qst. In S13,
The basic fuel injection amount Qdrv is searched from the fuel injection amount map according to the engine speed and the accelerator opening. In S14, the fuel injection amount correction value Qidl is calculated by PID control from the actual engine speed and the target idle speed so that the target idle speed is reached during idle operation. When not in idle operation, fuel injection amount correction value Q
Let idl = 0. It should be noted that whether or not the engine is idling is determined by whether or not the accelerator opening and the engine speed are within predetermined values.

In S15, the increment Qast of the fuel injection amount with respect to the increase of the engine load due to the accessories is calculated. Specifically, the increment of the fuel injection amount is determined for each of the air conditioner, the battery voltage, and the power steering, and the air conditioner switch, the battery voltage monitor value, and the power steering switch are turned on and off.
From this, the increment of the total fuel injection amount is calculated. In S16,
The target fuel injection amount Q is calculated by the following equation.

Q = Qdrv + Qidl + Qast In S17, in order to prevent smoke, the maximum fuel injection amount Qma
Calculate x. Specifically, the maximum fuel injection amount map set according to the rotation speed and the boost pressure (only for turbo vehicles) is searched. At S18, the target fuel injection amount Q and the maximum fuel injection amount Q
Compare with max.

In S19, when Q> Qmax, Q = Qma
Restrict to x. In S20, the target control sleeve position (rotary solenoid voltage) Uα0 for the engine speed Ne and the target fuel injection amount Q matched with the reference fuel is searched. In S21, a correction coefficient K-Qfv for correcting the target control sleeve position matched with the reference fuel according to the fuel property is searched according to the fuel viscosity detected by the viscosity sensor and the engine speed.

In S22, the target control sleeve position Uα0 obtained in S20 is multiplied by the correction coefficient K-Qfv as in the following equation. Uα1 = Uα0 · K-Qfv In S23, a correction coefficient for correcting the target control sleeve position matched for each fuel property according to the fuel temperature detected by the fuel temperature sensor and the engine speed according to the fuel temperature. Search K-Qtf.

In S24, the target control sleeve position Uα1 obtained in S22 is multiplied by the correction coefficient K-Qtf as in the following equation. Uα2 = Uα1 · K-Qtf In S25, based on the target control sleeve position Uα2 obtained in S24, while comparing with the actual control sleeve position detected by the control sleeve position sensor, PI
The PWM (duty ratio) of the rotary solenoid is calculated by D control and output.

Although not shown in the flow chart, during control, it is monitored whether or not there is an abnormality in the fuel injection pump or the engine, and if an abnormality is detected, the control sleeve is set so that the engine is stopped. To the leak position and close the fuel cut valve. Next, the fuel injection timing control will be described with reference to the flowchart of FIG.

Here, when the fuel injection timing is controlled by the engine speed and the engine load, the target injection timing is determined by using the engine torque T obtained in the flow of FIG. 5 as the engine load. At S31, the engine speed Ne and the engine torque T are read. In S32, the target injection timing IT is searched from the engine speed Ne and the engine torque T with reference to the fuel injection timing map.

At S33, the fuel temperature and the water temperature are read, and the target injection timing IT obtained at S32 is corrected in accordance with these values.
In S34, based on the corrected target injection timing IT, the injection timing control actuator (timing control valve 22) is controlled by PID control while comparing with the actual injection timing detected from the needle valve lift of the fuel injection nozzle by the nozzle lift sensor. To calculate and output an injection timing control command signal to.

Next, the EGR control will be described with reference to the flowchart of FIG. Here, when the EGR control valve 26 is controlled by the engine speed and the engine load, the target EGR amount is determined by using the engine torque T obtained in the flow of FIG. 5 as the engine load. In S41, the engine speed Ne and the engine torque T are read.

At S42, the target EG is calculated from the engine speed Ne and the engine torque T by referring to the EGR amount map.
The R amount (EGR control valve lift amount) is searched. In S43,
The fuel temperature and the water temperature are read, and the target EGR amount obtained in S42 is corrected according to these values. In S44, the corrected target EG
Based on the R amount, the control command signal to the EGR control valve driving actuator (duty control valve 27) is calculated and output by PID control while comparing with the actual EGR amount detected by the EGR control valve lift sensor.

Next, the intake throttle control will be described with reference to the flowchart of FIG. Here, when the intake throttle valve 28 is controlled by the engine speed and the engine load, the target intake throttle valve opening is determined by using the engine torque T obtained in the flow of FIG. 5 as the engine load. S
At 51, the engine speed Ne and the engine torque T are read.

In S52, the target intake throttle valve opening is searched from the engine speed Ne and the engine torque T with reference to the intake throttle valve opening map. In S53, the target intake throttle valve opening is converted into a control command signal and output to the intake throttle valve drive actuator (solenoid valve 29). Next, the swirl control will be described with reference to the flowchart of FIG.

Here, when the swirl control valve 30 is controlled by the engine speed and the engine load, the engine torque T obtained in the flow of FIG. 5 is used as the engine load to determine the target swirl ratio. At S61, the engine speed Ne and the engine torque T are read. In S62,
From the engine speed Ne and the engine torque T, the target swirl ratio is searched with reference to the swirl ratio map.

In S63, the target swirl ratio is converted into a control command signal and output to the swirl control valve driving actuator (solenoid valve). As described above, by providing the control map of the fuel injection timing of the diesel engine, the EGR amount, the intake throttle, the swirl ratio, etc. with the engine speed and the engine torque, the load detection accuracy is significantly improved (see FIG. 11). . Also, since various factors of variation are greatly reduced, the robustness of load detection accuracy is improved, and exhaust gas can be significantly cleaned (see Fig. 12). Further, in the evaluation of a normal engine, various characteristics are measured with reference to the engine speed and the engine torque, and in order to achieve compatibility, there is no need to replace the engine torque with the fuel injection amount as in the conventional case.
The number of conforming steps is reduced. Further, since there is no need for a correction logic for correcting the variation in the fuel injection amount, there is no need for a matching man-hour for that portion, and the control logic can be simplified.

Next, the second and third embodiments of the present invention will be described. Second Embodiment In the second embodiment, instead of directly detecting the output shaft rotation speed of the torque converter with a sensor,
This is indirectly detected by calculating based on the vehicle speed and the gear position.

FIG. 13 is a system diagram of the second embodiment.
It corresponds to FIG. 2 of the first embodiment. The difference is that the torque converter output shaft speed sensor has been abolished, and instead,
A vehicle speed sensor 51 (vehicle speed detecting means) that detects the vehicle speed VSP from the rotation of the output shaft 8 of the automatic transmission 6 and an inhibitor switch 52 (shift speed detecting means) that detects the shift speed of the automatic transmission 6 are used.

FIG. 14 is a flow chart for calculating the engine load in the second embodiment, which corresponds to FIG. 5 in the first embodiment. The difference is that in S2 ′ of FIG. 14, the torque converter output shaft rotation speed Np is calculated as follows (output shaft rotation speed calculation means). That is, the vehicle speed VSP is detected based on the signal from the vehicle speed sensor 51, and the gear ratio im stored in correspondence with this is obtained from the gear position detected based on the signal from the inhibitor switch 52.

Then, the torque converter output shaft speed Np is calculated from the tire effective radius r stored in advance and the final reduction ratio if by the following equation. Np = (VSP.im.if.1000) / (2.pi.r.60) In this embodiment, the first diesel engine and the sensor already provided in the electronically controlled transmission are used to make the first
The feature is that the engine load can be detected in the same manner as in the above embodiment. [Third Embodiment] In the third embodiment, since the capacity coefficient of the torque converter changes depending on the oil temperature of the hydraulic oil of the torque converter, the capacity coefficient obtained from the speed ratio of the torque converter is used as the oil temperature of the torque converter. It is corrected accordingly.

FIG. 15 is a system diagram of the third embodiment.
It corresponds to FIG. 2 of the first embodiment. The difference is that an oil temperature sensor 53 that detects the oil temperature of the torque converter is used. FIG.
5 is a flowchart of engine load calculation in the third embodiment, which corresponds to FIG. 5 of the first embodiment. The difference is
After the retrieval of the capacity coefficient C corresponding to the speed ratio e of the torque converter in S4 of FIG. 16, the processing (correction means) of S101 to S103 is added.

In S101, the oil temperature Toil of the torque converter is read based on the signal from the oil temperature sensor 53. S10
In step 2, the correction coefficient α corresponding to the actual oil temperature Toil read in S101 is retrieved from the correction coefficient table for correcting the capacity coefficient according to the oil temperature of the torque converter.

In S103, the capacity coefficient C retrieved in S4 is multiplied by the modification coefficient α to correct the capacity coefficient C as in the following equation. C = C · α In this embodiment, since the torque detection error due to the change of the torque converter can be compensated, the torque detection accuracy can be further improved.

Even in S2 of the flow of FIG. 16, FIG.
The output shaft rotation speed Np may be calculated from the vehicle speed, the gear ratio, and the like, as in S2 ′ of the flow of FIG. In the above-described embodiments, the one applied to the distributed fuel injection pump is shown, but the present invention is not limited to this, and the present invention can be applied to a column fuel injection pump and other fuel injection pumps.

[0062]

As described above, according to the first aspect of the invention, the engine torque is calculated from the input / output shaft speed of the torque converter and the engine torque is used as the engine load. Since the control is performed, fuel properties, fuel temperature, wear due to operation,
The load detection error due to production variations can be made extremely small, the control accuracy and robustness of various controls can be improved, the exhaust gas can be significantly cleaned, the instantaneous required torque can be detected, the control logic can be simplified, and the adaptation man-hours can be improved. The effect that reduction is possible is obtained.

According to the second aspect of the present invention, since the output shaft speed of the torque converter is calculated based on the vehicle speed and the gear position, it is already provided in a general diesel engine and an electronically controlled transmission. Using a sensor that
The effect that the engine load can be detected is obtained. According to the invention of claim 3, by using the table in which the capacity coefficient is stored in advance corresponding to the speed ratio of the torque converter, it is possible to obtain the effect that the capacity coefficient can be calculated during control in a short time. To be

According to the fourth aspect of the present invention, since the capacity coefficient determined from the speed ratio of the torque converter is corrected according to the oil temperature of the torque converter, the torque detection error due to the change of the oil temperature of the torque converter is eliminated. Since the compensation can be performed, the effect of further improving the torque detection accuracy can be obtained. According to the invention of claim 5, fuel injection timing control, EGR control, which requires accurate detection of engine load,
The effect that the control accuracy of the intake throttle control and the swirl control can be significantly improved is obtained.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of the present invention.

FIG. 2 is a system diagram (part 1) of the first embodiment of the present invention.

FIG. 3 System diagram of the same as above (Part 2)

FIG. 4 System diagram of the same as above (Part 3)

FIG. 5 is a flowchart of engine load calculation.

FIG. 6 is a flowchart of fuel injection amount control.

FIG. 7 is a flowchart of fuel injection timing control.

FIG. 8 is a flowchart of EGR control

FIG. 9 is a flowchart of intake throttle control.

[Figure 10] Flow chart of swirl control

FIG. 11 is a diagram showing the effect of the present invention on detection accuracy.

FIG. 12 is a diagram showing an effect on exhaust performance of the present invention.

FIG. 13 is a system diagram of a second embodiment of the present invention.

FIG. 14 is a flowchart of engine load calculation according to the second embodiment.

FIG. 15 is a system diagram of a third embodiment of the present invention.

FIG. 16 is a flowchart of engine load calculation according to the third embodiment.

FIG. 17 is a diagram showing conventional problems.

FIG. 18 is a diagram showing conventional problems.

FIG. 19 is a diagram showing conventional problems.

[Explanation of symbols]

 1 Diesel engine (main body) 2 Distribution type electronically controlled fuel injection pump 3 Fuel injection nozzle 4 Engine output shaft 5 Torque converter 6 Planetary gear type automatic transmission 15 Plunger 17 Control sleeve 18 Rotary solenoid 21 Timer piston 22 Timing control valve 23 Intake passage 24 Exhaust passage 25 EGR passage 26 EGR control valve 27 Duty control valve 28 Intake throttle valve 29 Solenoid valve 30 Swirl control valve 31 Control unit 41 Ring gear 42 Torque converter input shaft speed sensor 43 Timing plate 44 Torque converter output shaft speed sensor 51 Vehicle speed sensor 52 Inhibitor switch 53 Oil temperature sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location F02D 41/04 360 F02D 41/04 360C 385 385C F02M 25/07 550 F02M 25/07 550N

Claims (5)

[Claims] 1. A torque converter for detecting an input shaft speed of a torque converter provided between an engine output shaft and an automatic transmission, in a diesel engine control device for controlling various variables of the engine in accordance with at least an engine load. The input shaft speed detection means, the torque converter output shaft speed detection means for detecting the torque converter output shaft speed, and the torque converter speed ratio from the ratio of the torque converter input shaft speed to the output shaft speed. A speed ratio calculating means for calculating, a capacity coefficient calculating means for calculating a capacity coefficient based on the speed ratio of the torque converter, and an engine torque calculating means for calculating an engine torque from the input shaft speed and the capacity coefficient of the torque converter. And the engine torque is detected as the engine load. Control device for a diesel engine that. 2. The torque converter output shaft rotation speed detecting means detects a vehicle speed, a means for detecting a shift speed of an automatic transmission, and an output shaft rotation speed of the torque converter based on the vehicle speed and the shift speed. The control device for a diesel engine according to claim 1, further comprising: a calculating unit. 3. The capacity coefficient calculating means retrieves the capacity coefficient corresponding to the actual speed ratio from a table in which the capacity coefficient is stored in advance in association with the speed ratio of the torque converter. The control device for a diesel engine according to claim 1 or 2. 4. The capacity coefficient calculating means comprises means for correcting a capacity coefficient determined from a speed ratio of the torque converter in accordance with the oil temperature of the torque converter. 3. The diesel engine control device according to any one of 3 above. 5. At least one of a fuel injection timing, an exhaust gas recirculation amount, an intake throttle, and a swirl ratio is controlled according to a torque converter input shaft rotational speed which is an engine rotational speed and an engine torque which is an engine load. The control device for a diesel engine according to any one of claims 1 to 4, wherein: