JPH0647963B2 - Electric governor for diesel engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electric governor for a diesel engine, and in particular, in the case where an abnormality occurs in the accelerator operation amount detection means of the diesel engine, the accelerator operation amount detection means is used in place of the abnormality. The present invention relates to a diesel engine electric governor capable of giving an accelerator operation amount by setting means used for setting other set amounts.

[Prior Art] In recent years, an electronic control device for controlling a fuel injection amount or a fuel injection timing of a diesel engine has been developed for the purpose of improving fuel efficiency performance and exhaust characteristics of the diesel engine. A target fuel injection amount is calculated by an electronic control device based on detection results from various detectors arranged in each part of the diesel engine, and a fuel injection amount adjusting member of a fuel injection pump is controlled by the electronic control device. The target fuel injection amount is compared with the actual fuel injection amount obtained from the detector that detects the position of the fuel injection amount adjusting member, and the deviation between the two is corrected. An electric governor, which adjusts the fuel injection amount to a target fuel injection amount, is one of the typical devices.

However, in the electric governor as described above, when an abnormality occurs in various detectors, the above-described control may not be possible in some cases. Therefore, as a measure for improving the above-mentioned drawbacks, for example, in an injection pump in which the fuel injection amount to the internal combustion engine is controlled by a microcomputer and its peripheral circuits, etc., an abnormality of an operating condition detector is detected and In this case, change the data of the operating condition detector to a set value and use it fixedly, or stop the feedback control of the injection amount and switch to open loop control. Japanese Patent Application No. 57-212, which is configured to prevent abnormal increase and decrease, calculate the fuel injection amount even when the operating condition detector is abnormal, and enable emergency travel in the case of a vehicle.
Japanese Patent No. 337 and the like have been proposed.

[Problems to be Solved by the Invention] By the way, when an abnormality occurs in, for example, the accelerator operation amount detection means of the electric governor for a diesel engine as described above, the fuel injection control of the diesel engine is performed in a predetermined manner. It is performed based on the set value. Therefore, there is a problem in that the diesel engine cannot be operated according to the driver's intention.

Conventionally, it is known that the driver can manually control the injection amount when the injection pump is abnormal (JP-A-58-58).
No. 214650 and Japanese Patent Laid-Open No. 59-190432) are not assumed until the driver neglects to operate at an abnormal time or the driver does not know the operating method, and the emergency evacuation operation is performed. I couldn't do it. In addition, since the control amount directly set by the driver is not the control amount corresponding to the accelerator operation amount under normal conditions, these things operate in the same way as when the driver operates the accelerator under normal conditions. However, since the injection amount characteristic at the time of abnormality is different from that at the time of normal, it is difficult to realize the operation at the time of abnormality as requested by the driver.

On the other hand, Japanese Patent Application No. 58-244826 (Japanese Patent Application Laid-Open No. 60-4826)
No. 138250) generates a preliminary signal of the accelerator operation amount from a cruise volume or the like at the time of an abnormality, but always switches to the preliminary signal at the time of an abnormality. Therefore, if the driver turns the cruise volume and the like without noticing that the driver has switched to the standby signal, there is a risk that the engine output will change without the driver's intention.

The present invention has been made in view of the above problems.When an abnormality of the accelerator operation amount detection means is detected, the driver is first alerted, and the driver recognizes an emergency and permits emergency driving. For the first time, the safety is enhanced by switching to the emergency mode.In the emergency mode, the first means set by the setting means used by the driver to set another operation amount instead of the accelerator operation amount detecting means. By making it possible to manually control the fuel injection amount by using the set amount as the accelerator operation amount, the driver can control the injection amount in the emergency mode with the same feeling as the accelerator operation in the normal mode, In addition, even if the driver forgets to give the emergency driving permission even if an abnormality in the accelerator operation amount detection means is detected, the second set amount is automatically set as the accelerator operation amount. Aims to allow continue emergency operation.

[Means for solving problems]

Therefore, in the present invention, as shown in FIG. 1, the fuel of the fuel injection pump of the diesel engine is based on the operating state obtained from the operating state detecting means of the diesel engine and the accelerator operating amount obtained from the accelerator operating amount detecting means. In an electric governor for a diesel engine that controls an injection amount, an alarm unit that warns a driver when an abnormality in the accelerator operation amount detection unit is detected, an emergency operation switching permission switch operated by the driver, and an emergency operation In response to the switching permission signal, instead of the accelerator operation amount detecting means, the first set amount set by the setting means used by the driver to set another operation amount is used as the accelerator operation amount. The first control means for manually controlling the fuel injection amount and the abnormality of the accelerator operation amount detection means are detected and the emergency operation switching permission signal is received. Is when not obtained, a second set amount that is set in advance and a second diesel engine for an electric governor and a control unit for automatically controlling the fuel injection quantity as the accelerator operation amount.

[Embodiment] Next, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a system configuration diagram of an electric governor for a diesel engine which is an embodiment of the present invention.

In the figure, a column-type fuel injection pump 1 for injecting fuel into each cylinder of a diesel engine (not shown) is a camshaft 1a which is driven by being connected to a crankshaft of the diesel engine (not shown), and a well-known plunger control (not shown). A control rack 1b is provided which controls the fuel injection amount by engaging the pinion of the sleeve and rotating the control sleeve to adjust the rotational position of the plunger.

Further, the row-type fuel injection pump 1 includes the camshaft 1
A rotation speed sensor RS1 which is provided near the 24 tooth pulse generating gear attached to a and outputs one pulse signal for each tooth of the pulse generating gear, and is connected to the control rack 1b and the link 1c. Then, a rack position sensor LPS1 which is a variable inductance type position sensor for detecting the position of the control rack 1b, and a movable iron core type which is connected to the control rack 1b by a link 1d and controls the position of the control rack 1b. Electromagnetic actuator EA consisting of linear solenoid
1 is provided.

On the other hand, the diesel engine intake system (not shown)
An intake pressure sensor PS1 for detecting the intake air pressure, an intake temperature sensor ATS1 for detecting the intake air temperature, and an engine cooling water temperature sensor WTS1 for detecting the engine cooling water temperature are provided in the cooling system, and the operation amount of the driver is set. The accelerator sensor AS1, the idle speed setting volume IRS1, the starter switch ST
S1 and a key switch KS1 are provided.

In addition, a warning lamp WL1 that warns the driver
However, the electromagnetic actuator EA1 is provided on an operation panel (not shown), and corrects the deviation between the target injection amount command voltage Vs described later and the above-described detection signal voltage of the rack position sensor LPS1 of the column fuel injection pump. There is also provided a positioning servo circuit PSC1 including a servo amplifier that drives and controls the positioning of the control rack 1b via the link 1d and a drive circuit.

Then, the signals from the above-mentioned sensors or switches are
It is input to an electronic control unit (hereinafter simply referred to as ECU) 10, and the ECU 10 drives and controls the warning lamp WL1 and the positioning servo circuit PSC1.

Next, the configuration of the ECU 10 will be described.

The ECU 10 inputs and calculates data output from the above-described sensors and switches according to a control program, and performs processing for controlling the above-described various devices by a central processing unit (hereinafter simply referred to as CP.
Call it U. ) 10a, a read-only memory (hereinafter simply referred to as R) in which the control program and the initial data are stored.
Called OM. ) 10b, a random access memory (hereinafter simply referred to as RAM) 10 in which data input to the ECU 10 and data necessary for arithmetic control are temporarily read and written.
It has c.

Further, the ECU 10 is provided with the above-mentioned intake pressure sensor PS1,
Intake air temperature sensor ATS1, engine cooling water temperature sensor WTS
1, the accelerator sensor AS1, the idle speed setting volume IRS1, the starter switch STS1, the key switch KS1, the buffer 10d, 10e, 10f, 10g, 10h of the output signal from the rack position sensor LPS1, 1
0i, 10j, and 10k are provided, and a multiplexer 10l that selectively outputs the output signals of each sensor to the CPU 10a and an A / D converter 10m that converts an analog signal into a digital signal are provided.

Further, the ECU 10 has the above-described rotation speed sensor RS1.
A waveform shaping circuit 10n for shaping the waveform of the output signal of is provided.

Then, the waveform shaping circuit 10n or the buffer 10
d, 10e, 10f, 10g, 10h, 10i, 10
j, 10k, the multiplexer 10l, and the A / D converter 10m, the above sensor signals are sent to the CPU 10a, and the multiplexer 10l from the CPU 10a,
An input / output port 10p for outputting a control signal to the A / D converter 10m is also provided.

Further, the ECU 10 uses the above-mentioned warning lamp WL.
Drive circuit 10r for supplying a drive current to CPU 1, CPU 10a
Convert the digital command signal from to an analog signal,
The positioning servo circuit PSC1 includes a D / A converter 10s that outputs a command voltage, and an output port 10q that outputs a control signal to the drive circuit 10r and the D / A converter 10s. It also has a bus line 10t which serves as a passage for control signals and data between the above-mentioned elements, and a clock circuit 10u which sends a clock signal serving as a control timing to the ROM 10b, the RAM 10c, and the like including the CPU 10a at predetermined intervals.

Next, the process executed by the ECU 10
This will be described with reference to the flowcharts shown in FIG. 4, FIG. 5 and FIG. FIG. 3 is a flow chart showing a main control process executed by the ECU 10, FIG. 4 is a first interrupt process executed by the ECU 10, and FIG. 5 is a flowchart showing a second interrupt process executed by the ECU 10. The three-digit number in parentheses represents the step number of each process.

In FIG. 3, after the ECU 10 is started, if this process is the first one, the initialization process is performed (10
0). That is, memory clear, flag reset, and timer reset are performed. Next, it is determined whether the starter switch signal is ON (102). That is,
Whether or not the diesel engine is in a starting state is determined based on the signal from the starter switch STS1. If this condition is not met, the process waits in step 102 until the starter switch signal turns ON. On the other hand, when the condition of step 102 is satisfied,
That is, when it is determined that the diesel engine is in the starting state, the process proceeds to step 104. Here, the intake pressure of the diesel engine, the intake air temperature, the engine cooling water temperature, the accelerator operation amount, and the idle speed setting amount are detected from the above-described sensors (104). Next, it is determined whether the accelerator operation amount signal voltage Vα detected in step 104 is abnormal (106).

Here, there is a relationship as shown in FIG. 6 between the accelerator operation amount signal voltage Vα [V] and the accelerator operation amount α [%]. That is, in the case of the accelerator operation amount α0 [%], the accelerator operation amount signal voltage Vα takes a value of the lower limit value Vα0 [V], while when the accelerator operation amount α is 100 [%], the accelerator operation amount signal voltage. Vα is the upper limit value Vα100 [V]
Takes the value of. And, during this period, both have a linear relationship.

Returning to FIG. 3 again, in step 106, as described above, it is determined whether or not the accelerator operation amount signal voltage that does not occur during the normal accelerator operation is detected. That is, the accelerator operation amount signal voltage Vα detected in step 104 is less than the accelerator operation amount signal voltage lower limit value Vα0, or the accelerator operation amount signal voltage upper limit value Vα1.
It is determined whether it exceeds 00. If this condition is met, the process proceeds to step 108. Here, the switching flag C
It is determined whether or not F is set. This switching flag CF is a flag that is set when the detection of the accelerator operation amount from the accelerator sensor is switched to be detected from the idle speed setting volume. If this condition is not met, the routine proceeds to step 110, where the warning lamp WL1 is turned on to warn the driver that the accelerator operation amount signal is abnormal. Then, it is determined whether the accelerator switching operation is performed by the driver (112). Here, the accelerator switching operation is performed by the driver rotating the idle speed setting volume IRS1 to the minimum position in accordance with the warning by the warning lamp WL1 lighting in step 110. If this condition is met, step 118
Then, the switching flag CF is set. Then, the accelerator operation amount signal voltage Vα is detected from the idle speed setting volume IRS1 which has become the substitute accelerator sensor (120). Then, the warning lamp WL1 is blinked at a predetermined cycle to display the completion of the switching operation to the driver (122). Then, the process proceeds to step 126. on the other hand,
When the condition of step 112 is not satisfied, that is, when the driver does not perform the switching operation, step 1
Proceeding to 14, the accelerator operation amount α is set to 10 [%]. Then, the warning lamp WL1 is turned on in step 122.
It is made to blink in a cycle different from that, and the driver is again warned of the occurrence of an abnormality (116). Then, the process proceeds to step 126.

On the other hand, when the condition of step 108 is satisfied, that is, when the switching flag CF is already set, the process proceeds to step 120.

Further, when the condition of step 106 is not satisfied, that is, when it is determined that the accelerator operation amount signal voltage Vα detected in step 104 is normal, step 1
Proceed to 24. Here, it is determined whether or not the switching flag CF is set. If this condition is met,
That is, if the accelerator sensor AS1 has already been switched, the routine proceeds to step 120. On the other hand, when the condition of step 124 is not satisfied, that is, when the accelerator sensor AS1 is not switched, the process proceeds to step 126.

Here, the basic fuel injection amount Qbase is calculated from the map based on the already detected engine speed Ne and the accelerator operation amount α (126). Here, the map means the basic injection amount Qbase [mm ³ / st · cy as shown in FIG. 7.
1] and engine speed Ne [r. p. m. ] And the accelerator operation amount α [%] are defined, and are stored in the ROM 10b in advance.

Returning to FIG. 3 again, next, the smoke limit injection amount Qs is determined based on the intake pressure and the intake temperature detected in step 104.
m is calculated from a map such as that shown in FIG. 8 which is previously stored in the ROM 10b (128). Further, the idle speed Nid is calculated based on the output signal of the idle speed setting volume and the engine cooling water temperature from a map as shown in FIG. 9 which is stored in advance in the ROM 10b (130). Then, based on the difference in rotation speed between the engine rotation speed Ne and the idle rotation speed Nid, the idle injection amount Q
The id is calculated from a map stored in the ROM 10b in advance as shown in FIG. 10 (132). Furthermore, the target injection amount Qf is calculated based on the basic injection amount Qbase, the smoke limit injection amount Qsm, and the idle injection amount Qid by a method such as equation (1) (134).

Qf = Max {Min (Qbase, Qsm), Qid} (1) where Max (A, B) is the larger value Min of A and B.
(A, B) indicates the smaller value of A and B, respectively.

Then, the target injection amount Qf calculated in the above step 134
The target injection amount command voltage Vs corresponding to is calculated by an arithmetic expression (136). The above two are in a substantially linear relationship. Next, the target injection amount command voltage Vs is output to the output port 10q.
It is output to the D / A converter 10s (138). Then, the target injection amount command voltage Vs converted into the analog signal by the D / A converter 10s is the positioning servo circuit PSC.
1 is input as a target value. As a result, the electromagnetic actuator EA1 is drive-controlled, the control rack 1b is set at a predetermined position, and fuel injection is performed.

Next, it is determined whether the signal of the key switch KS1 is ON (140). If this condition is met, the process returns to step 104 again. On the other hand, when the above conditions are not met, that is, the signal of the key switch KS1 is OFF.
If so, the process proceeds to step 142. Here, the target injection amount command voltage Vs is set to 0 (142). Then, the target injection amount command voltage Vs is output to the D / A converter (144). Then, similarly to the case described above, the electromagnetic actuator E is moved by the positioning servo circuit PSC1.
A1 is driven, the control rack 1b is moved, fuel injection is stopped, and the diesel engine is stopped. Then, the process returns to step 102. After that, the above respective processes are repeated.

Next, the first interrupt processing will be described in detail with reference to FIG.

This process is started according to the output signal of the rotation speed sensor RS1. First, the time interval between the output signal of the previous rotation speed sensor RS1 and the output signal of this rotation speed sensor RS1 is
Measured with a constant frequency clock signal and the result is RAM
It is stored in 10c (200). Next, in Step 20 above.
The engine speed Ne is calculated by taking the reciprocal of the time interval detected at 0 (202). Then, this process ends. Thereafter, this processing is appropriately interrupted by the main control processing and repeatedly executed.

Next, the second interrupt processing will be described in detail with reference to FIG. The main purpose of this process is to detect the engine stall during the main control process.

This process is executed by interrupting the main control process at regular intervals. First, the output signal of the rotation speed sensor RS1 is detected (300). If the output signal of the rotation speed sensor RS1 is not continuously detected within the predetermined time interval, it is determined that the engine stall has occurred (30
2). Next, for example, the timer for setting the blinking cycle of the warning lamp WL1 is counted up and the electromagnetic actuator current is cut off (30
4). Then, this process ends. This process is executed by interrupting the main control process at regular time intervals thereafter.

The emergency operation changeover permission switch of the present invention is step 110, the first control means for controlling the fuel injection amount is step 120, and the second control means for automatically controlling the fuel injection amount is step. This corresponds to 114.

In the present embodiment, when the detection of the accelerator operation amount α by the accelerator sensor AS1 is determined to be abnormal, the warning lamp WL1 is first turned on to warn the driver of the occurrence of the abnormality. Then, the driver sets the idle speed setting volume IRS1 to the minimum position, so that the idle speed setting volume IRS1 can be used as a substitute accelerator thereafter. Therefore, even if the accelerator sensor AS1 fails, the failure can be confirmed by turning on the warning lamp, and the diesel engine can be operated based on the driver's will by operating the idle speed setting volume IRS1. You can

Further, in this embodiment, even if the accelerator sensor AS1 fails, the idle speed setting volume IRS1 can be operated as a substitute accelerator, so that the deterioration of fuel efficiency of the diesel engine can be controlled to a minimum.

Further, in the present embodiment, when the driver does not perform the switching operation to the substitute accelerator when the failure of the accelerator sensor AS1 is warned by the lighting of the warning lamp WL1, the accelerator operation amount α is set to 10%. ], The operation of the diesel engine is continued, so that, for example, when the vehicle is equipped with the diesel engine, emergency traveling becomes possible.

In the present embodiment, the idle speed setting volume I
Although RS1 was used as a substitute accelerator, for example, cruise set volume used for automatic drive control for vehicles, or full Q set volume for adjusting the maximum fuel injection amount to set maximum torque of diesel engine, air conditioner related In the case where the volume etc. is equipped, each of these volumes can be used as a substitute accelerator.

Further, in the present embodiment, the switching operation to the substitute accelerator when the accelerator sensor AS1 fails is to adjust the idle speed setting volume to the minimum position. However, for example, a diagnostic switch provided for self-diagnosis, or When a limp home switch or the like provided for fail-safe at the time of failure occurrence is equipped, it is possible to switch to the substitute accelerator by operating each switch.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and it goes without saying that the present invention can be implemented in various modes without departing from the scope of the present invention. .

EFFECTS OF THE INVENTION According to the present invention, it becomes possible for the driver to manually control the injection amount when the accelerator operation amount detecting means is abnormal, in the same manner as when the accelerator is operated normally, and the driver is in an emergency. It is possible to switch to the emergency mode for the first time after the driver recognizes that the emergency driving is permitted, so it is safer than the automatic switching, and even if the driver forgets to give the emergency driving permission, it automatically The excellent effect that emergency driving can be executed is obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing the basic concept of the present invention, FIG. 2 is a system configuration diagram of an embodiment of the present invention, and FIG. 3 is a flowchart showing a main control process executed by an ECU in the embodiment of the present invention, FIG. 4 is a flowchart showing a first interrupt process executed by the ECU in the embodiment of the present invention,
FIG. 5 is a flow chart showing a second interruption process executed by the ECU in one embodiment of the present invention, and FIG. 6 is an explanatory diagram showing a relationship between an accelerator operation amount and an accelerator operation amount signal,
FIG. 7 is a graph showing a map showing the relationship between the rotational speed of the diesel engine, the basic injection amount and the accelerator operation amount, and FIG. 8 is a map showing the relationship between the intake pressure of the diesel engine, the intake temperature and the smoke limit injection amount. FIG. 9 is a graph showing a relationship between a diesel engine idle speed setting volume setting value, engine cooling water temperature, and idle speed, and FIG. 10 is a diesel engine idle speed and engine speed. 6 is a graph showing a map showing a relationship between a rotational speed difference with respect to the engine speed and an idle injection amount. 1 ... In-line fuel injection pump 10 ... Electronic control unit (ECU) LPS1 ... Rack position sensor RS1 ... Rotation speed sensor AS1 ... Accelerator sensor IRS1 ... Idle rotation speed setting volume WL1 ... Warning lamp PSC1 ... Positioning servo circuit EA1 ... Electromagnetic actuator

Claims (1)

[Claims] 1. A diesel engine for controlling a fuel injection amount of a fuel injection pump of the diesel engine based on an operating state obtained from an operating state detecting means of the diesel engine and an accelerator operation amount obtained from an accelerator operation amount detecting means. In the electric governor, an alarm means for warning the driver when an abnormality of the accelerator operation amount detection means is detected, an emergency operation change permission switch operated by the driver, and an emergency operation change permission signal in response to the emergency operation change permission signal, The fuel injection amount is manually controlled by using the first set amount set by the setting device used by the driver to set another operation amount instead of the accelerator operation amount detecting device as the accelerator operation amount. If an abnormality is detected in the first control means and the accelerator operation amount detection means and the emergency operation switching permission signal is not obtained, the setting is made in advance. An electric governor for a diesel engine, comprising: a second control means for automatically controlling a fuel injection amount by using a predetermined second set amount as the accelerator operation amount.