JPH109000A - Stopping device for engine provided with slow down function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To additionally provide a slow down function by a simple and inexpensive method, in a Diesel engine. SOLUTION: A stopping device 10 for an engine is constituted by including at least a slow down signal output part 11, control part 12, duty ratio change part 13 and an engine speed sensor 14. By an output from the duty ratio change part 13, a stopping solenoid 25, driving a control rack of a fuel injection pump to a fuel amount reducing side at engine stopping time through a solenoid driver part 27, is driven. In the control part 12, in response to outputting of a slow down signal, a preset slow down rotational speed is compared with an actual engine speed, so that the actual engine speed is approximated to the slow down rotational speed, duty ratio of the duty ratio change part 13 is changed, so as to realize a slow down function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine stopping device, and more particularly to a diesel engine stopping device.

[0002]

2. Description of the Related Art Conventionally, as a stop device of a diesel engine used in a work machine, a method of stopping a control rack for adjusting an injection amount of a fuel injection pump by driving the control rack to a reduction side by a stop solenoid. Is known. By the way, there is an engine for a working machine applied to an agricultural machine, a construction machine, or the like, which has a so-called slow-down function as a kind of automatic driving function.

[0003] The slowdown function is a function of reducing the rotation of the engine to a slowdown rotation speed when necessary in an agricultural machine, a construction machine or the like using the engine. This slowdown function is used, for example, in applications in which useless fuel consumption is reduced by reducing the number of revolutions when no power generation operation is performed in an engine generator or the like. It is also used for automatically lowering the engine speed when the working element of the rear means of the tractor is raised during work on the tractor.

[0004]

However, when a slowdown device for realizing a slowdown function is added to a diesel engine provided with an engine stop device of a type that drives the control rack, the following problems arise. Had occurred. (1) In an engine employing a centrifugal mechanical governor, the simplest configuration is to drive the speed adjusting lever with an actuator as a slowdown device and to set the slowdown speed. However, in this case, an actuator having a large power to drive the speed adjusting lever is required. A large output actuator is generally large, and it is very difficult to provide such a large actuator in or near a governor room where a governor is provided.

(2) A general-purpose diesel engine used for an engine working machine generally requires low cost.
Providing a new actuator or actuator driver that can drive the speed adjustment lever to realize the slowdown function increases the cost and diminishes the advantage as an inexpensive general-purpose diesel engine. (3) If the speed adjustment lever is driven by a newly installed actuator, two solenoids for stopping the engine and a solenoid for the slowdown function are required independently, and two wirings and an electric system are also required. The configuration becomes complicated.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is an engine capable of realizing a slowdown function at a small space and at low cost without changing the mechanical configuration around the governor chamber of a conventional engine. It is an object of the present invention to provide a stop device. Another object of the present invention is to provide an engine stop device that can realize both an engine stop function and a slowdown function in a small space.

[0007]

An engine stop device according to claim 1 will be described with reference to, for example, FIGS.
A stop solenoid 25 for stopping the engine by driving the control rack 2a for adjusting the injection amount of the fuel injection pump 1 of the diesel engine to a decreasing side, and a solenoid driver 27 for driving the stop solenoid 25
In the engine stop device provided with: a rotation speed detecting means 14 for detecting the rotation speed of the engine, a slowdown signal output means 11 for outputting a slowdown signal, and a duty ratio of a voltage supplied to the solenoid driver 27 Ratio changing means 13 for changing the rotation speed of the engine and the slowdown signal output means 1
In response to the output of the slowdown signal from 1, the preset slowdown speed is compared with the actual engine speed, and the duty ratio is set so that the actual engine speed approaches the slowdown speed. And a control unit for changing the duty ratio of the changing unit.

The engine stopping device according to a second aspect of the present invention is characterized in that, as shown in FIG. 1, for example, the stop solenoid 25 is a type of solenoid that can take only two states of a projected position and a retracted position. For example, as shown in FIG. 5, the engine stop device according to claim 3 includes a rotation speed detection unit 14 for detecting the rotation speed of the engine, a slow down signal output unit 30 that outputs a slow down signal, and a diesel engine. By inputting an actuator 33 for stopping the engine by driving a control rack for adjusting the injection amount of the fuel injection pump of the engine to the decreasing side, a driver means 32 for driving the actuator 33, and an engine speed, In response to the output of the slowdown signal from the slowdown signal output means 30, the preset slowdown speed is compared with the actual engine speed, and the actual engine speed is converted to the slowdown speed. And a control means 31 for sending a command to the driver means 32 so as to be close to each other.

[0009]

According to the first aspect of the present invention, the control means responds to the output of the slow-down signal from the slow-down signal output means to determine the preset slow-down speed and the actual speed. The engine speed is compared with the engine speed, and the duty ratio is changed so that the actual engine speed approaches the slowdown speed. Therefore, the stop solenoid controls the rack pin position of the control rack to a rack position corresponding to the slowdown rotation speed. In this way, the stop solenoid can function as a slow-down device by changing the duty ratio of the voltage supplied to the solenoid driver, and it is necessary to provide a large actuator that drives the speed adjustment lever. And the space can be saved without changing the mechanical configuration around the governor chamber of the engine. According to the second aspect of the present invention, since the stop solenoid is a type of solenoid that can take only two states of the protruding position and the retracted position, a conventional stopping solenoid can be used as it is and can be implemented at low cost. effective.

According to the third aspect of the present invention, the control means inputs the number of revolutions of the engine, and the slowdown number of revolutions set in advance in response to the output of the slowdown signal from the slowdown signal output means. Is compared with the actual engine speed, and a command is sent to the driver means to bring the actual engine speed closer to the slow down speed. Therefore, the actuator for stopping the engine is also used as the slow down function realizing means. be able to. Further, unlike the first aspect of the present invention, the method of controlling the driver means is not limited to the method of changing the duty ratio.
It is possible to use a variety of digital control techniques to quickly and accurately shift to the slowdown rotation speed. Further, also in the third aspect of the present invention, it is not necessary to newly provide a large-sized actuator for driving the speed adjusting lever, and the embodiment can be implemented in a small space.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of an engine stop device according to the present invention will be described with reference to the drawings. FIG. 1A is a schematic block diagram showing a basic configuration of the first embodiment, FIGS. 1B and 1C each show a change in duty ratio, and FIG. 2 is provided with a stop solenoid. It is a front view of the governor of an engine.

As shown in FIG. 1, the engine stop device 10 includes a slowdown signal output unit 11 and a control unit 12.
And a duty ratio changing unit 13 and an engine speed sensor 14. The output from the duty ratio changing unit 13 is supplied via a solenoid driver unit 27 to a stop solenoid 25 for driving the control rack 2a of the fuel injection pump 1 to the fuel reduction side when the engine is stopped.
Is transmitted to The slowdown signal output unit 11 and the control unit 12 can be configured by MPU software. Further, the stop solenoid 25 is a type of solenoid that can take only two states of a protruding position and a retracted position, and the solenoid driver 27 and the stop solenoid 25 can use conventional components as they are.

The diesel engine in this embodiment employs a centrifugal mechanical governor for performing mechanical speed control as shown in FIG. FIG. 2 is a view showing a centrifugal mechanical governor, in which a governor weight 6 is operatively connected to a rack pin 2 of a control rack 2a of the fuel injection pump 1 via a governor lever 3, and speed is adjusted via a governor spring 4 to the governor lever 3. Lever 5
Are linked. The governor spring 4 presses the rack pin 2 toward the fuel increasing side, while the governor weight 6 presses the rack pin 2 toward the fuel decreasing side.

The governor lever 3 comprises a first lever 3a and a second lever 3b. The governor weight 6 is connected to the input portion of the first lever 3a via a governor sleeve 15, and the output portion is connected to the rack pin 2. The spring 8 is interlocked, the speed adjusting lever 5 is connected to the second lever 3b via the governor spring 4, and the second lever 3b can be received at a position corresponding to full load (4/4) by the fuel limiting pin 9. It is composed. Further, a torque increasing device 16 is interposed between the first lever 3a and the second lever 3b, and the torque increasing device 16 moves the first lever 3a from the position corresponding to the full load (4/4) to the maximum torque (T).
r) It is configured to be movable to a corresponding position, and is configured to exhibit tenacity by increasing the amount of fuel against overload applied to the engine.

The stop solenoid 25 is disposed on the left side wall of the governor case in FIG. 2, and presses the control rack 2a by its plunger 26 to move the position of the rack pin 2 to the reduced side (L) to stop the engine. It is composed. In FIG. 1, a slow-down signal output unit 11 has a function of generating a slow-down signal and releasing the slow-down signal. For example, the microcomputer detects the load of the engine, and the no-load state continues for 10 seconds or more. A slowdown signal is generated in such a case, and the slowdown signal is released when the load is applied to the engine and the vehicle exits the no-load state.

The control unit 12 includes a slowdown signal output unit 11
When a slowdown signal, an engine speed signal and a power switch (ACC) are input and a slowdown signal is input, the duty ratio is changed so that the engine speed becomes a preset slowdown speed. The switching signal is sent to the duty ratio changing unit 13. When an engine stop signal from the power switch (ACC) is input,
The change of the duty ratio is stopped, and the stop solenoid 25 is made to function as a means for pressing the control rack toward the decreasing side in the same manner as the normal stop solenoid. The duty ratio changing unit 13 is a circuit that changes the duty ratio of the voltage supplied to the solenoid driver unit 27 based on a switching signal from the control unit 12, and uses a switching regulator or the like. The effective power is changed by changing the duty ratio (τ / T) as shown in FIGS. 1B and 1C, and the amount of protrusion d of the plunger 26 of the on / off type stop solenoid 25 is substantially linear with respect to the duty ratio. To change the position of the rack pins. If the duty ratio is changed in this way, the stop solenoid 25 frequently repeats a minute protruding operation and a retracting operation. Therefore, the solenoid 25 and the solenoid driver unit 27 need to have excellent switch stability. It needs to be adopted.

FIG. 3 is a flowchart for explaining the operation of the control unit 12 and the duty ratio changing unit 13.
In step SP1 of FIG. 3, the control unit 12 turns on the slowdown signal from the slowdown signal output unit 11 (Hi
gh), and if the slowdown signal does not turn on, the determination process is repeated. If it is determined that the slowdown signal has turned on, the duty ratio changing unit 13 increases the duty ratio in step SP2 to increase the fuel The rack pin position is moved to the increasing side, and it is determined in step SP3 whether or not the current engine speed N is greater than a preset slowdown speed Ns.

If it is determined in step SP3 that the current engine speed N is greater than the preset slowdown speed Ns, the duty ratio changing unit 13 reduces the duty ratio in step SP4 to reduce the fuel consumption. In step SP5, the controller 12 determines whether or not the slowdown signal is turned on. If it is determined that the slowdown signal is turned on, the current engine speed N is set in advance in step SP6. It is determined whether it is smaller than the slowdown rotation speed Ns. If it is determined in step 6 that the current engine speed N is smaller than the preset slowdown speed Ns, the process returns to step SP2,
The duty ratio is increased to move the rack pin position to the fuel increasing side.

On the other hand, if it is determined in step 6 that the current engine speed N is not smaller than the preset slowdown speed Ns, the process returns to step SP4, in which the duty ratio is reduced to reduce the fuel. Move the rack pin position. If it is determined in step SP3 that the current engine speed N is not greater than the preset slowdown speed Ns, it is determined again in step SP7 whether the slowdown signal is ON. If it is determined that the slowdown signal is on, the process returns to step SP2. With the above operation, the actual engine speed can be made closer to the slowdown speed. On the other hand, if it is determined in step SP7 that the slowdown signal is not on, that is, it is determined to be off (Low), the duty ratio is turned off in step SP8 to release the slowdown function and return to the normal speed control operation. Return to SP1.

If it is determined in step 5 that the slowdown signal is not on, the process jumps to step SP8, turns off the duty ratio, and returns to step SP1. FIG. 4 is a view showing an engine stop operation by the stop solenoid 25. In FIG. 4, in step SP1, the control unit 12 determines whether or not the power switch (ACC) is turned off. If it is determined that the power switch is turned off, the engine is stopped. When the stop solenoid 25 is turned on and the plunger 26 is protruded, the control rack 2a is pushed toward the fuel reduction side, and in a step SP3, the stop solenoid 25 is turned on for 10 seconds by the timer (that is, the control rack is set to the fuel stop position). State), the stop solenoid 2 is turned on in step SP4.
Turn 5 off. That is, immediately after the power switch is operated to the stop position, the engine is reliably stopped by operating the lap pin 2 to the fuel stop position by the stop solenoid 25 for 10 seconds. Note that the control unit 12
In addition, the overall control of the flowchart shown in FIG. 4 is performed, and at least two operations of an engine stop operation and a slowdown function realizing operation are performed.

[0021]

Embodiment 2 FIG. 5 is a schematic block diagram for explaining a second embodiment of the engine stop device of the present invention, and FIG. 6 is a flowchart showing the operation thereof. While the first embodiment employs a simple method of controlling the on / off type solenoid to the slow down rotation speed by changing the duty ratio, the second embodiment employs a structure for stopping the engine. Movable part 34 of the actuator 33
Is characterized in that it is configured to be able to accurately control the amount of movement by an analog signal or a digital signal.
Examples of such an actuator include a stepping motor and a linear motor.

The engine stop device includes a slowdown signal output unit 30 for outputting a slowdown signal under predetermined conditions, an engine frequency sensor 14, and a control unit 31.
And a driver section 32 as the actuator means
And an actuator 33. The control unit 31 is the same as the first embodiment in that it is configured to perform two operations of an engine stop operation and a slowdown function realizing operation, as shown in FIG. The speed control function of the electronic governor can be performed by the actuator 33 in FIG. 5, and in this case, it has three functions.

The operation will be briefly described below with reference to FIG. 6. In step SP1, it is determined whether or not an engine stop signal has been input. If it is determined that the engine stop signal has been input, in step SP2, Drive the control rack to the weight reduction side to stop the engine. On the other hand, if it is determined in step SP1 that the engine stop signal has not been input, it is determined in step SP3 whether a slowdown signal has been input from the slowdown signal output unit 30 and the slowdown signal has been input. In this case, in step SP4, various controls are performed to drive the motor to the slowdown rotation speed and stably maintain the slowdown rotation speed. If the slowdown signal is not input, a normal speed control operation (by the mechanical governor) is performed in step SP5. (Including a speed control operation and a speed control operation by an electronic governor).

The present invention is not limited to the above-described embodiment, but can be implemented with various modifications within the gist of the present invention. For example, in the first embodiment, the slow-down signal output unit 11 is configured by a microcomputer, and when no load is applied for 10 seconds, the slow-down signal is generated. However, as shown in FIG. It goes without saying that the conditions for generating the slowdown signal can be changed depending on the application of the applied engine. Also, the flowchart shown in FIG. 3 is only one of the simplest examples of the control. For example, it is possible to employ a PID control or the like so that the engine speed can be quickly and stably controlled to the slowdown speed. is there. Further, it is clear that the present invention can be applied to an electronic governor-controlled diesel engine.

[Brief description of the drawings]

FIG. 1A is a schematic block diagram showing a basic configuration of a first embodiment, and FIGS. 1B and 1C are diagrams each showing a change in duty ratio.

FIG. 2 is a diagram showing an example of a centrifugal mechanical governor device.

FIG. 3 is a flowchart for explaining a slowdown function operation of the engine stop device.

FIG. 4 is a flowchart illustrating an engine stop operation of the engine stop device.

FIG. 5 is a schematic block diagram showing a basic configuration of a second embodiment of the present invention.

FIG. 6 is a flowchart showing a basic operation of the second embodiment of the present invention.

[Explanation of symbols]

1 ... fuel injection pump 1, 2 a ... control rack, 1
DESCRIPTION OF SYMBOLS 1 ... Slow down signal output part, 12 ... Control part, 13 ... Duty ratio change part, 14 ... Engine speed sensor, 25
... Stop solenoid, 27 ... Solenoid driver, 30
... Slow down signal output unit, 31 ... Control unit, 32 ... Driver unit, 33 ... Actuator.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display F02D 35/00 388 F02D 35/00 388A 41/04 380 41/04 380C 380H 41/14 330 41 / 14 330D 41/20 380 41/20 380 41/38 41/38 D 45/00 305 45/00 305B

Claims (3)

[Claims] 1. A fuel injection pump for a diesel engine.
A stop solenoid (25) for stopping the engine by driving the control rack (2a) for adjusting the injection amount of (1) to the decreasing side and a solenoid driver (27) for driving the stop solenoid (25) are provided. In the stopped device of the engine, the rotation speed detecting means (1) for detecting the rotation speed of the engine.
4), a slowdown signal output means (11) for outputting a slowdown signal, a duty ratio changing means (13) for changing a duty ratio of a voltage supplied to the solenoid driver (27), and an engine speed. At the same time, in response to the output of the slowdown signal from the slowdown signal output means (11), a preset slowdown speed is compared with the actual engine speed, and the actual engine speed is determined. A control device (12) for changing a duty ratio of a duty ratio changing device (13) so as to approach a slow down rotation speed. An engine stopping device having a slow down function. 2. The engine stop device with a slow-down function according to claim 1, wherein the solenoid (25) is a type of solenoid that can take only two states of a protruding position and a retracted position. 3. An engine speed detecting means for detecting an engine speed, a slowdown signal output means for outputting a slowdown signal, and an injection amount of a fuel injection pump of a diesel engine. (33) for stopping the engine by driving the control rack to decrease the amount of the engine, driver means (32) for driving the actuator (33), and inputting the rotation speed of the engine to output a slowdown signal. In response to the output of the slowdown signal from the means (30), the preset slowdown speed is compared with the actual engine speed,
Control means (31) for sending a command to the driver means (32) so as to bring the actual engine speed closer to the slowdown speed;
An engine stopping device provided with a slowdown function, comprising: