JPS6193254A - Engine protective device at running trouble - Google Patents

Abstract

PURPOSE:To make engine running continuable even in time of trouble happening in the engine running, by installing an engine protective device which controls an engine speed controller so as to cause a fuel control value to become within the range of an engine protective running fuel limiting value. CONSTITUTION:On the basis of a deviation between a speed setter 1 and a revolving speed detector 2 of an engine 1, an engine speed controller 3 is operated and a fuel regulating device 4 is regulated whereby an engine speed is controlled. An engine protective device 6 controls the engine speed controller 3 so as to cause a fuel control value to smaller than that in time of normal running and to become an engine protective running fuel limiting value larger than a running maintenance fuel value in time of idle running. Thus, engine running is continuable even in time of trouble happening in engine running.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a protection device for preventing engine abnormalities from progressing during operational abnormalities such as poor lubrication or overheating, and the invention relates to a protection device that prevents engine abnormalities from progressing during operational abnormalities such as poor lubrication and overheating. By continuing to operate with a limit on the number or amount of fuel supplied. There are various problems associated with the engine stopping completely, such as piston seizure due to the cooling fan stopping when the water temperature of a forced water-cooled engine rises abnormally. To provide a device that prevents engine-equipped vehicles from stalling at intersections or railroad crossings.

Further details of the application field of the technology on which the present invention is based include, for example, as shown in FIG. 1 or 2. By operating the rotation speed control device 3 and adjusting the fuel regulator 4 based on the difference i between the detection value of the rotation speed detector 2 and the setting value of the speed setting device 1 of the engine E. The engine E is configured to control the rotational speed of the engine E to a set value.
Or, based on the abnormality detected by the abnormality detector 5 of the equipment equipped with this, the engine protection means 6 is activated and the rotation speed control device 3 is activated to the engine protection state, so that the engine abnormality does not progress. This article relates to an engine protection device in the event of an abnormality.

<Prior Art> Conventional engine protection devices for diesel engines include, for example, when an oil pressure sensor detects an abnormal drop in lubricating oil pressure, or a water temperature sensor detects an abnormal rise in cooling water temperature. As shown in the imaginary line in Figure 2,
Actuators linked to these sensors operate immediately to slide the fuel injection rank to the no-injection position and cut fuel. The engine was completely stopped to prevent abnormalities such as seizure from progressing.

<Problem to be solved by the invention> In a forced water-cooled engine, when the engine is suddenly stopped when the cooling water temperature rises abnormally, the cold B7 engine is also stopped at the same time, so the combustion heat is dissipated from the sill. Otherwise, it will cause the piston to seize.

In addition, for work vehicles equipped with an engine, if the engine malfunctions at an intersection, railroad crossing, or extremely cold location. The engine had stopped, making it impossible to move the work vehicle at all, which was extremely inconvenient.

<Means for solving the problems> The present invention solves the above problems. This system was proposed for the purpose of allowing the engine to continue operating while maintaining the load and rotation speed that the engine can withstand even when the engine is operating abnormally.In order to achieve this purpose, the system is configured as follows. It is.

That is, the engine protection means 6 has a fuel control value smaller than the fuel limit value N during normal operation, and an engine protective operation fuel limit value S which is larger than the operation maintenance fuel value I during no-load operation. By controlling the rotation speed control device 3 as shown in FIG. be.

<Use> Therefore, to describe the effect of the present invention brought about by the above configuration, when a lubrication failure or an abnormality in the cooling water temperature occurs in the engine, the abnormality detector 5 detects this and activates the engine protector y6. Activate the fuel adjustment ff5 and set the fuel limit value of the fuel adjustment ff5 (fuel injection pump rack or fuel/air mixer throttle valve) to the fuel limit value N during normal operation (for example, corresponds to the MAPI curve in Figure 3). ) and larger than the fuel value I during no-load operation (corresponding to the curve I in FIG. 3, for example), so to speak. This allows the engine to continue operating at lower rotations and lower loads without putting a heavy burden on the engine.・ <Effects of the invention> Therefore, even during abnormal operation, the engine can continue to operate with reduced power. For example, even if the cooling water temperature rises abnormally in a forced water-cooled engine, the cooling fan can continue to rotate. Since the cooling of the shilling can be continued by cooling the piston, seizing of the piston can be prevented.

Also. Even if a work vehicle equipped with an engine, such as a tractor or a plowing rock, malfunctions at an intersection or railroad crossing, it can be quickly moved from these locations to a safe zone, and as a whole, Not only can you easily eliminate the negative effects caused by the engine stopping all the time, but also limit operation to low buff, so the engine/
Furthermore, the present invention can smoothly prevent the abnormality from progressing further. For example, by limiting the fuel limit value of the engine protection device to a predetermined range and adjusting the fuel, for example, the rack or throttle valve (this is a structure that can be used). ,
It can also be easily applied to existing protection devices.

<Example> Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an engine protection device, FIG. 2 is a schematic system diagram thereof, and FIG. 4 is a flowchart thereof. The protection device A includes an accelerator sensor 1. A rotation speed sensor 2 that detects the engine rotation speed, a rotation speed limiter 3 (conventionally used electronic
(corresponding to a banner) and a protective operation control circuit 7.

The rotation speed limiting device 3 includes a rotation speed PID control circuit 8, a minimum value selection circuit 10, a rack position PID control circuit 11, an actuator 12, a rack 4 that adjusts the fuel injection amount of the fuel injection pump 5, and a rack position sensor 14. The accelerator sensor 1 and the rotation speed sensor 2 are connected to the rotation speed PID control circuit 8 to correct the deviation of the engine rotation speed from the set rotation speed of the accelerator lever. A signal is issued to the actuator 12.

Further, the rack position sensor 14 is connected to the rack position PID control circuit 11 to form a minor loop so that the rack position initially supported by the actuator 12 matches the predetermined rank position issued from the minimum value selection circuit 10. Perform correction control.

On the other hand, the protective operation control circuit 7 consists of an abnormality detector 5 connected to a maximum rack position control circuit 6. It is composed of a group of sensors that detect abnormalities in the engine, such as an oil pressure sensor 17 that detects oil temperature and an oil temperature sensor 18 that detects oil temperature in the lubrication system.

Then, the maximum rack position control circuit 6 is connected to the minimum value selection circuit 10 of the rotation speed setting device 3, and the rotation speed PID is
Among the signals sent from the control circuit 8 and the maximum rack position control circuit 6, the smaller numerical value, that is, the value leaning toward the low load, low rotation side, is selected and set to instruct the actuator 12.

The maximum rack position control circuit 6 has various types of panniers that are on the lower load and lower rotation side than the governor operating curve N (i.e., MAPI) during normal operation and are larger than the no-load operation maintenance fuel value I. The circuit set to take the active line (3rd
Corresponding to MAR2, 3, 4 in the figure) is incorporated, and the relevant setting circuit is connected to various sensors of the abnormality detector 5, and when a specific sensor detects an abnormality, the corresponding setting circuit is activated, causing various abnormalities. A signal matching the state is sent to the minimum value selection circuit 10 of the rotational speed control device 3.

Specifically, as shown in FIGS. 3 and 4, the oil pressure sensor 17 is connected to MAP2, which is a low-load, low-speed setting circuit.
, the water temperature sensor 16 is connected to M, which is a low load medium rotation setting circuit.
AR3, Mako, and oil temperature sensor 18 are each connected to MAP4, which is a medium load setting circuit, and the presence or absence of an abnormality is detected in the order of importance of oil pressure, water temperature, and oil temperature, so-called engine abnormalities. The configuration is such that the optimal setting circuit can be operated in response to an abnormality that occurs.

Therefore, the functions of the protection device as a whole will be described first. Engine El:"A If there is no abnormality, abnormality detector 5
does not operate, the minimum value selection circuit 10 receives only the signal from the rotation speed PID control circuit 8, and normal operation (i.e., MA
However, if an abnormal drop in lubricating oil pressure occurs, the oil pressure sensor 17 detects this abnormality, the maximum rack position limiting circuit 6 selects MAP2, and the minimum value selection circuit 10 selects MAP2. M from signal and accelerator sensor
In order to input the APl signal and select the MAP2 signal which leans toward the lower load and lower rotation side preferentially, the rack 4 continues to operate the engine at low power with the fuel being throttled.

Even if the lubricating oil pressure is maintained normal, if an abnormal rise in the cooling water temperature occurs, the water temperature sensor 16 detects the abnormality and the maximum rank position limiting circuit 6 selects MAP3, and the lubricating oil pressure and cooling water temperature also increases. Even when there is no abnormality in the water temperature, if another non-urgent abnormality occurs, for example, an oil temperature abnormality, the oil temperature sensor 18 detects this abnormality and the maximum rank position limit circuit 6 selects M A P 4. That's what I do.

As described above, according to the present invention, even when an abnormality occurs in the engine, depending on the importance of the abnormality, the rotation of the engine is changed to a predetermined operating state on the low-load, low-speed eaves side compared to normal operation. Since the system automatically switches to low-power operation and continues low-power operation, it can be applied not only to diesel engines that are independent of or combined with the vehicle, but also to gasoline engines and diesel engines. The actuator (and thus the throttle valve of the fuel/air mixer) can be restricted.

Further, it can be applied to either a single engine or an engine assembled to a work vehicle.

Therefore, it is possible to detect an abnormality in the engine working vehicle and prevent the abnormality from progressing while driving the working vehicle at low power.

Furthermore, the present invention can be applied when working at night, for example, when it is desired to satisfy various requests for engine rotation, such as reducing engine rotation noise to prevent noise (therefore, not limited to when the engine is operating abnormally). By simply distinguishing between day and night using an optical sensor, it is possible to easily set up a configuration that automatically switches to low-load, low-speed operation to reduce operating noise.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; tpJ1 is a bronch diagram of an engine protection device, FIG. 2 is a schematic system diagram thereof, FIG. 3 is a governor operating curve diagram, and FIG. 4 is a diagram showing the operation of the protection device. It is a flowchart showing the principle. 1...Speed setter, 2...Rotation speed detector, 3...
・Rotation speed control device, ・1... fuel regulator, 5...
・Abnormality detector, 6...Engine protection means, E...
・Engine, ■... No-load operation maintenance fuel value, N・
...Fuel limit value during normal operation, S...Fuel limit value during protective operation 6

Claims (1)

[Claims] 1. Based on the deviation of the detected value of the rotation speed detector 2 from the setting value of the speed setting device 1 of the engine E, the rotation speed control device 3
The system is configured to control the rotational speed of the engine E to a set value by controlling the fuel regulator 4 and controlling the rotational speed of the engine E to a set value based on the abnormality detected by the abnormality detector 5 of the engine E or equipment equipped with the engine E. In the engine protection device at the time of abnormal operation, which is configured to activate the protection means 6 and operate the rotation speed control device 3 to an engine protection state to prevent engine abnormality from progressing, the engine protection means 6 operates when the fuel control value is normal. Normal operation is achieved by controlling the rotation speed control device 3 so that the engine protection operation fuel limit value S is smaller than the fuel limit value N during operation and larger than the operation maintenance fuel value I during no-load operation. 1. An engine protection device in the event of an abnormal operation, characterized in that the engine protection device is configured to permit engine operation within a range of an engine protection operation fuel limit value S, which is a value smaller than a fuel limit value N during an abnormal operation.