JP2001280174A - Output control device of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an output control device of an engine for stabilizing the rotational speed of a PTO shaft. SOLUTION: This output control device of the engine is provided with the PTO shaft 7 for transmitting the rotation of the engine 1 to an auxiliary device, a connection detecting means for detecting the connection state of the PTO shaft 7 to the engine 1, an accelerator lever (an engine output operating means) for commanding request output to be taken out of the PTO shaft 7, a target engine rotational speed calculating means for calculating the target engine rotational speed according to the operating amount of the accelerator lever, and an engine output adjusting means for adjusting the opening of a sub throttle valve 22 so that the actual engine rotational speed may approach the target engine rotational speed when connecting the PTO shaft 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine output control device.

[0002]

2. Description of the Related Art Conventionally, as an output control device of an engine,
For example, JP-A-6-257452, JP-A-10-683
There is one disclosed in Japanese Patent Publication No. 50 (JP-A) 50/90.

[0003] Crane trucks and cleaning trucks are equipped with a PTO shaft capable of transmitting the rotation of the engine to an auxiliary device, and operate the accelerator lever when the auxiliary device is operated to adjust the output of the engine. ing.

[0004]

However, in the case of a spark ignition type engine having no governor mechanism for limiting the engine speed, such as a diesel engine, the throttle valve opening is fixed via an accelerator lever when the auxiliary device is operated. Then, there is a problem that the rotation speed of the engine fluctuates greatly according to the load fluctuation of the auxiliary device, and the rotation speed of the PTO shaft becomes unstable.

The present invention has been made in view of the above problems, and has as its object to provide an engine output control device that stabilizes the rotational speed of a PTO shaft.

[0006]

According to a first aspect of the present invention, there is provided a PTO shaft capable of transmitting rotation of an engine to an auxiliary device;
Connection detection means for detecting a connection state of the PTO shaft to the engine, engine output operation means for instructing a required output taken out of the PTO shaft, and a target engine for calculating a target engine rotation speed according to an operation amount of the engine output operation means It is provided with a rotational speed calculating means and an engine output adjusting means for adjusting the output of the engine such that the actual engine rotational speed approaches the target engine rotational speed when the PTO shaft is connected.

In a second aspect based on the first aspect, a main throttle valve for adjusting an intake air amount of the engine in accordance with an operation amount of an engine output operation means and an actual engine rotation speed target when a PTO shaft is connected. A sub-throttle valve for adjusting the intake air amount of the engine so as to approach the engine speed is provided.

[0008]

According to the first aspect of the present invention, the output of the engine is automatically adjusted in response to the load fluctuation of the auxiliary device, the rotation speed of the engine is stabilized, and the rotation speed of the PTO shaft is kept substantially constant. be able to.

In the second aspect, even when the opening of the main throttle valve is fixed via the engine output operation means, the opening of the sub-throttle valve is automatically adjusted in response to the load fluctuation of the auxiliary device. In addition, the rotation speed of the engine is stabilized, and the rotation speed of the PTO shaft can be kept substantially constant.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, an engine 1 draws an air-fuel mixture from an intake passage 2 into each cylinder as an intake valve of each cylinder is opened, compresses the air-fuel mixture with a piston, and generates a spark plug. And the exhaust gas is discharged to the exhaust passage 3 as the exhaust valve is opened, and these steps are repeated continuously. In the middle of the exhaust passage 3, a catalyst 15 is provided.
Is installed to purify the exhaust.

CNG, LP stored in fuel cylinder 10
Gas fuel such as G is supplied to the fuel injection nozzle 4 through the fuel supply passage 11. In the middle of the fuel supply passage 11,
An electromagnetic shut-off valve 13 and a gas control valve 14 for adjusting the amount of fuel injected from the fuel injection nozzle 4 are provided.
A control device (not shown) inputs detection signals of various operating conditions, and controls the gas control valve 1 so that the air-fuel mixture reaches the target air-fuel ratio.
7 is driven to adjust the amount of fuel injected from the fuel injection nozzle 4.

A main throttle valve 21 and a sub-throttle valve 21 for adjusting the amount of intake air are interposed in the intake passage 2. A fuel injection nozzle 4 for injecting fuel is provided on the upstream side of the main throttle valve 24 in the intake passage 2, and the intake path and the fuel are sufficiently mixed by taking a long fuel transport path. .

In FIG. 1, reference numeral 5 denotes a transmission, and the transmission 5 includes an output shaft 6 and a PTO.
(Power Take Off) shaft 7 is provided. The rotation of the output shaft 6 is transmitted to wheels via a propeller shaft (not shown), a differential gear, a drive shaft, and the like (not shown). The PTO shaft 7 is connected to an auxiliary device 8 such as a vehicle-mounted crane or a garbage device. The rotation of the engine 1 is transmitted to the PTO shaft 7 via a clutch mechanism 9.

To adjust the output of the engine 1, an accelerator pedal and an accelerator lever (not shown) are provided, respectively.
It is mechanically linked to 1. The accelerator pedal is provided in the driver's seat of the vehicle, and the main throttle valve 21 is opened when the accelerator pedal is depressed during traveling of the vehicle, for example.
Engine power is increased.

On the other hand, when the accelerator lever is retracted when the auxiliary device 8 is operated, the state in which the main throttle valve 21 is opened is maintained, and the engine output is adjusted. That is, the accelerator lever constitutes engine output operation means for instructing a required output taken out of the PTO shaft.

However, in an operation state in which the opening of the main throttle valve 21 is fixed via the accelerator lever,
When the load of the auxiliary device 8 fluctuates, the rotation speed of the engine 1 fluctuates according to the load of the auxiliary device 8, and the rotation speed of the auxiliary device 8 cannot be kept constant.

To cope with this, a sub-throttle valve 22 for adjusting the amount of intake air is interposed in the intake passage 2, and the opening of the sub-throttle valve 22 is adjusted so as to keep the rotation speed of the auxiliary device 8 substantially constant. Control unit 2 to control
3 is provided.

As shown in FIG. 2, the control unit 23 includes an accelerator lever opening detecting sensor 24, a connection detecting sensor (connection detecting means) 25 for detecting the connection / disconnection of the clutch mechanism 9, and a rotational speed detecting sensor for the engine 1. 26 and the like, and output to a throttle device 27 including an actuator for driving the sub-throttle valve 22.

The control unit 23 calculates a target engine rotation speed in accordance with a signal from the accelerator lever opening detection sensor 24.

As shown in FIG. 3, the control unit 23 retrieves a throttle opening adjustment amount based on a preset map 31 according to the target engine speed and the current engine speed. The output means 32 outputs a signal obtained by adding the searched throttle opening adjustment amount to the current throttle opening to the throttle driving device 33 to adjust the opening of the sub throttle valve 22.

FIG. 4 shows a routine for adjusting the opening of the sub-throttle valve 22, which is executed by the control unit 23 at regular intervals.

To explain this, a signal from the connection sensor 25 is read in step 1 and a PT
It is determined whether the O-shaft 7 is connected.

If it is determined that the PTO shaft 7 is connected, the process proceeds to step 3 where the opening of the accelerator lever is read, and the target engine speed is calculated according to the opening of the accelerator lever.

In the following step 4, the current engine speed is read. In step 5, the throttle opening adjustment amount is searched based on the map 31 in accordance with the target engine speed and the current engine speed.

A signal obtained by adding the throttle opening adjustment amount retrieved in step 6 to the current throttle opening is output to the throttle driving device 33, and the sub throttle valve 2
Adjust the opening of 2.

The routines of steps 1 to 6 constitute the engine output adjusting means of the present invention.

The PTO shaft 7 is constructed as described above.
At the time of connection, control is performed to calculate the target engine speed in accordance with the operation amount of the accelerator lever, and bring the actual engine speed closer to the target engine speed. As a result, the main throttle valve 2 is controlled via the accelerator lever.
1 is fixed, the opening of the sub-throttle valve 22 is automatically adjusted in response to the load fluctuation of the auxiliary device 8, the rotation speed of the engine 1 is stabilized, and the rotation speed of the PTO shaft 7 is Can be kept substantially constant.

As another embodiment, the sub-throttle valve 22 may be omitted as a configuration for adjusting the opening of the main throttle valve 21 via a motor or the like.

It is apparent that the present invention is not limited to the above-described embodiment, and that various changes can be made within the scope of the technical idea.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram including a control unit and the like.

FIG. 3 is a block diagram for calculating a throttle valve opening.

FIG. 4 is a flowchart showing a routine for controlling the throttle valve opening.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Intake passage 5 Transmission 7 PTO shaft 8 Auxiliary device 9 Clutch mechanism 21 Main throttle valve 22 Subthrottle valve 23 Control unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G065 AA04 CA15 DA04 DA05 DA14 FA12 GA10 GA28 GA46 HA02 JA02 JA04 JA09 JA11 KA02 KA05 KA29 3G093 AA08 BA02 DA01 DA06 DB24 EA03 EA07 EA09 FA04 FA10 3G301 HA28 JA04 LA03 PE01A PF11Z

Claims (2)

[Claims] 1. A PTO shaft capable of transmitting rotation of an engine to an auxiliary device, connection detecting means for detecting a connection state of the PTO shaft to the engine, and an engine output for instructing a required output taken out of the PTO shaft. Operating means; target engine speed calculating means for calculating a target engine speed in accordance with the operation amount of the engine output operating means; and so that the actual engine speed approaches the target engine speed when the PTO shaft is connected. An engine output control device, comprising: engine output adjusting means for adjusting the output of the engine. 2. A main throttle valve for adjusting an intake air amount of the engine in accordance with an operation amount of the engine output operation means, and an actual engine rotation speed close to a target engine rotation speed when the PTO shaft is connected. The engine output control device according to claim 1, further comprising: a sub-throttle valve for adjusting an intake air amount of the engine.