JPH11229939A - Assist air supply device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the readjusting work of a duty ratio by displaying the matching of the duty ratio when the duty ratio is matched to a prescribed value by adjustment made by a manual adjusting means. SOLUTION: After the passage of specified running time from the state of a new engine product, it is necessary to readjust a duty ratio by operating a manual valve. For carrying out this readjusting work of the duty ratio, an engine running mode is switched to a duty ratio verification adjusting mode by operating a mode changeover switch 48. A control unit 31 is programmed to display the matching of the duty ratio on LED 50 when an operator adjusts the manual valve to match the duty ratio with a prescribed value. Thus, a user easily executes the readjusting work of the duty ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assist air supply device for supplying necessary air at the time of starting or idling operation in a fuel injection type engine.

[0002]

2. Description of the Related Art In a fuel injection type engine, a throttle valve is fully closed when a throttle operation is not performed, such as when starting, idling, or when using an engine brake. An assist air supply device is provided for introducing a small amount of air (assist air) from the outside into the downstream intake passage to supplement a necessary amount of air.

This assist air supply device includes an assist air supply valve provided in an intake passage downstream of a throttle valve, and valve driving means such as a solenoid for electrically and automatically driving the assist air supply valve. The assist air supply valve is opened and closed by a duty control of the valve drive means, and a manual valve is provided in addition to the assist air supply valve.

The control means sets the duty ratio (opening / closing ratio) of the assist air supply valve based on various operating conditions such as the rotational speed of the crankshaft, the opening of the throttle valve, the shift position, the engine temperature, etc. Supply assist air. As a result, the opening of the assist air supply valve is increased at the time of starting, so that the startability is improved. At the time of idling operation, the opening of the assist air supply valve is finely controlled to stabilize the rotation speed.

When the engine is manufactured and shipped, the manual valve is adjusted, the duty ratio of the assist air supply valve is adjusted to a specified value by this adjustment, and the initial supply amount of the assist air is set to an optimum value.

However, even when the duty ratio of the assist air supply valve and the initial supply amount of assist air are set to specified values when the engine is new, the required amount of assist air increases as the total operation time of the engine increases. For example, after the engine break-in operation is completed or when the engine is deteriorated, the amount of assist air actually required is set to the upper limit or the lower limit with respect to the assist air supply range based on the duty ratio set when the product is new. In some cases, the start-up performance may be degraded due to insufficient assist air, or the idling rotation speed may not be able to be maintained stable depending on the fluctuation of the load applied to the engine.

In addition, when the engine is deteriorated, the intake air amount in the entire operation range decreases, so that the assist air supply valve is frequently opened other than at the time of starting or idling operation. For this reason, there is a concern that power consumption by valve driving means such as a solenoid will increase.

Therefore, in general, when the total operation time of the engine reaches a predetermined time, the duty ratio of the assist air supply valve is readjusted by operating the manual valve. For example, when the required amount of assist air is increased as compared with a new product, the opening degree of the manual valve may be increased accordingly, and the amount of assist air flowing from the manual valve may be increased.

[0009]

However, the operation of re-adjusting the duty ratio of the assist air supply valve by operating the manual valve as described above requires the use of an expensive dedicated measuring instrument (duty tester or the like). Since the duty ratio must be strictly measured in each operation situation, a well-equipped maintenance shop and engineers with specialized knowledge are required.

Therefore, it is difficult for the user to perform such re-adjustment work by himself, and the user is forced to bring the engine to the maintenance yard and request the re-adjustment work. In the case of vehicles such as automobiles, there is no problem because it is easy to bring them to maintenance facilities (auto shops, gas stations, etc.), but in the case of engines such as ships and outboard motors, it is difficult to bring them to the maintenance facilities. Many engines were run in poor conditions, causing re-adjustment work to be neglected.

An engine assist air supply device according to the present invention has been invented in order to solve the above problems, and a first object of the invention is to readjust a duty ratio of an assist air supply valve. The task is to make the work easier for the user of the engine.

A second object of the engine assist air supply device according to the present invention is to make the readjusted duty ratio more suitable for the state of the engine.

A third object of the engine assist air supply device according to the present invention is to improve the operation efficiency of the assist air supply valve in a multi-cylinder engine.

[0014]

In order to achieve the first object, an assist air supply device for an engine according to the present invention is provided in an intake passage downstream of a throttle valve. The assist air supply valve provided, valve driving means for driving the assist air supply valve by duty control, adjusting means manually operated, display means, and setting the operation mode of the engine to the duty ratio confirmation adjustment mode. A mode changeover switch and a duty control of the valve driving means are performed based on various operating conditions of the engine, and the operation of the mode changeover switch compares the duty ratio with a preset specified value. If the duty ratio does not conform to the above, it is displayed on the above display means that the duty ratio is not conforming. When the duty ratio conforms to the specified value, and when the operator adjusts the adjusting means to adjust the duty ratio to the prescribed value, the display means indicates that the duty ratio is suitable. And a control means configured as described above.

According to a second aspect of the present invention, there is provided an assist air supply device for an engine according to the present invention, wherein the specified value of the duty ratio is changed according to a total operation time of the engine. The control means is configured so as to be appropriately changed.

Further, in order to achieve the third object,
In the engine assist air supply device according to the present invention, as described in claim 3, the assist air supply valve is provided in a surge tank provided downstream of the throttle valve and in which intake pipes of respective cylinders gather. .

According to the first aspect of the present invention, there is provided an assist air supply apparatus for an engine, wherein the control means controls the duty of the valve drive means based on various operating conditions of the engine to operate the assist air supply valve and to control the mode. When the operation mode of the engine is set to the duty ratio confirmation adjustment mode by operating the changeover switch, the duty ratio is compared with a preset specified value, and the quality is displayed on the display means.

When the total operation time of the engine reaches a predetermined time and the duty ratio needs to be readjusted, first, the mode changeover switch is operated to change the operation mode of the engine to the duty ratio confirmation adjustment mode. Next, the adjustment means is manually adjusted while paying attention to the display means. When the display means indicates that the duty ratio is appropriate, the adjustment operation is completed. According to this, the user of the engine can easily perform the readjustment operation of the duty ratio.

Further, if the specified value of the duty ratio is appropriately changed according to the total operation time of the engine, the readjusted duty ratio will correspond to a change in friction loss, etc. Better fits the condition.

Further, if an assist air supply valve is provided in the surge tank in which the intake pipes of the cylinders are gathered, the assist air introduced by the assist air supply valve is uniformly distributed to each cylinder. Therefore, the operation efficiency of the assist air supply valve in the multi-cylinder engine is improved.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an engine 2 to which an assist air supply device 1 according to the present invention is applied and an intake device 3 thereof.

The engine 2 is, for example, a fuel injection type four-cycle reciprocating engine having a plurality of cylinders. A piston 5 inserted into each cylinder bore 4 is connected to a crankshaft 7 by a connecting rod 6. The upper part of the cylinder bore 4 is a combustion chamber 8 where an intake port 9 and an exhaust port 10 are provided.
Are communicated from the outside, the intake port 9 is an intake valve 11, and the exhaust port 10 is an exhaust valve 12, which is opened and closed. An exhaust pipe 13 is connected to the exhaust port 10.

Further, the engine 2 is provided with a crank angle sensor 15 for detecting the rotation angle of the crankshaft 7 and an engine temperature sensor 16 for detecting the engine temperature (cooling water temperature or the like).

On the other hand, the intake device 3 is provided on a large-capacity surge tank 18, a plurality of intake pipes 19 extending from the surge tank 18 and connected to each intake port 9 of the engine 2, and on the inlet side of the surge tank 18. Throttle body
20 and a suction pipe 21 connected to the inlet side of the throttle body 20. A fuel injection device (injector) is provided at the tip of the intake pipe 19.
22 are provided.

A throttle valve 23 is installed on the throttle body 20. The opening of the throttle valve 23 is controlled by an operator of the engine 2 (a driver of a vehicle or a boat equipped with the engine 2) by operating a throttle device (not shown). It is set by doing. The throttle valve 23 is provided with a throttle sensor 24 for detecting the opening.

During operation of the engine 2, fresh air flows into the surge tank 18 via the suction pipe 21 and the throttle body 20 due to the negative pressure of the intake air of the engine 2, and is uniformly distributed to each intake pipe 19. Then, fuel is injected into fresh air from the fuel injection device 22 in the most downstream portion of the intake pipe 19,
The fresh air is supplied to the engine 2 as a mixture.

An assist air supply valve 26 and a manual valve 27 functioning as an adjusting means are provided in the intake passage downstream of the throttle valve 23, that is, in the surge tank 18 here. The assist air supply valve 26 is opened and closed by valve driving means such as a built-in solenoid 28, and the opening of the manual valve 27 is adjusted by manual rotation of an adjustment screw 29. These two valves 26 and 27 introduce a small amount of air (assist air) from the outside into the surge tank 18 when the throttle valve 23 is fully closed, such as when the engine 2 is started or idling. To supplement the required air volume.

In the assist air supply device 1,
Surge tank 18 where intake pipes 19 of each cylinder gather
Is provided with the assist air supply valve 26, the assist air introduced by the assist air supply valve 26 is uniformly distributed to each cylinder. Therefore, the assist air supply valve 26 in such a multi-cylinder engine 2
Operating efficiency has been improved.

FIG. 2 is a block diagram showing the configuration of the assist air supply device 1 according to the present invention. The assist air supply device 1 includes a control unit 31 functioning as control means.

Inside the control unit 31, a rotation detecting section 33, a valve opening degree judging section 34, a shift position judging section 35, a duty ratio detecting section 36, a duty controlling section, together with a calculating section 32 using a small CPU or the like 37, mode determination unit 38,
Engine temperature detector 39, nonvolatile memory 40, timer
A large number of circuit elements such as 41 and a display control unit 42 are accommodated, and a plurality of A / D converters 43 to 46 are built in.

The components provided outside the control unit 31 as components of the assist air supply device 1 include, in addition to the crank angle sensor 15, the throttle sensor 24, the engine temperature sensor 16, and the solenoid 28, There are a changeover switch 48, a shift position sensor 49, and a display means 50 using an LED, a buzzer, or the like. Although not shown in FIG. 2, the above-described assist air supply valve 26 and manual valve 27 are also important elements constituting the assist air supply device 1.

The solenoid 28 is connected to, for example, an ignition timing fixing terminal (not shown). This makes it possible to share the lead wires and terminals and simplify the overall configuration. The ignition timing fixing terminal is a terminal for canceling the correction of the ignition timing at the time of malfunction in the idling operation and identifying the cause of failure of sensors, mechanical parts, and the like.

In the assist air supply device 1, the rotation angle of the crankshaft 7 detected by the crank angle sensor 15 passes through an A / D converter 43 and a rotation detector 33.
, Where the crankshaft rotation speed is obtained.
The data is output from the rotation detection unit 33 to the mode determination unit 38 and the duty control unit 37, and further output from the mode determination unit 38 to the calculation unit 32.

The movement of the throttle valve 23 detected by the throttle sensor 24 is determined by an A / D converter
The signal is output to the valve opening determination unit 34 via 44, where it is determined whether the throttle valve 23 is open or whether the throttle valve 23 is fully closed. The data is output from the valve opening determination section 34 to the calculation section 32 and the duty control section 37.

Further, the shift position detected by the shift position sensor 49 (switching position of the vehicle or the ship between forward and reverse) is output to the shift position determining section 35 via the A / D converter 45, where the shift position is determined. Is determined. The data is output from the shift position determination unit 35 to the calculation unit 32 and the duty control unit 37.

On the other hand, the data detected by the engine temperature sensor 16 is output to the engine temperature detecting section 39 via the A / D converter 46, where the engine temperature is obtained, and the data is output to the calculating section 32. .

The mode changeover switch 48 is a switch for switching the operation mode of the engine 2 between the normal mode and the duty ratio confirmation adjustment mode, and is manually operated by the operator of the engine 2. Each selected mode is determined by the mode determination unit 38 and input to the calculation unit 32.

The nonvolatile memory 40, the timer 41, and the display control unit 42 are connected to the calculation unit 32, and the display means such as the LED 50 is connected to the display control unit 42.

When operating the engine 2, the normal mode is selected by the mode changeover switch 48. In the normal mode, the duty control unit 37 operates based on various operating conditions of the engine 2, that is, as described above, the crankshaft rotation speed, the engine temperature, the throttle opening, the shift, Based on data such as position,
An appropriate duty ratio is set in accordance with a predetermined duty ratio adjusted in advance, and the duty of the solenoid is controlled to open and close the assist air supply valve.

Thus, even when the throttle valve 23 is fully closed, for example, during start-up or idling operation,
An appropriate amount of assist air is introduced into the surge tank 18 from the assist air supply valve 26 to improve the startability and stabilize the idling rotational speed. The duty ratio set by the duty control unit 37 is output to the duty ratio detection unit 36 and fed back to the calculation unit 32.

As described above, the amount of assist air required by the engine 2 changes as the total operation time of the engine 2 increases, and usually tends to decrease. This is because the friction loss (mechanical friction resistance) inside the engine 2 decreases as the total operation time increases. Therefore, the duty ratio in the duty control also decreases as the total operation time increases.

As shown in FIG. 3, the friction loss of the engine 2 is maximum in a new product having the shortest total operation time T. Since the required amount of assist air is large due to the load, the duty ratio is also 70%. Around and high,
At the end of the break-in operation, friction loss is greatly reduced, and the required amount of assist air is reduced.
The duty ratio is reduced to about 25-30%. Thereafter, the duty ratio stabilizes to a substantially constant value as the total operation time B increases.

Therefore, the actual duty ratio does not match the specified value of the duty ratio set when the engine 2 is new, at the end of the break-in operation or as the total operation time T further increases. For this reason, after a predetermined operation time has elapsed since the engine 2 was new,
It is necessary to readjust the duty ratio by operating the manual valve 27.

When re-adjusting the duty ratio,
First, the mode changeover switch 48 is operated to switch the operation mode of the engine 2 from the normal mode to the duty ratio confirmation adjustment mode.

When the operation mode is switched to the duty ratio confirmation adjustment mode, the control unit 31 compares the current duty ratio with a preset specified value. If the duty ratio does not conform to the specified value, the duty ratio is adjusted. Is programmed to indicate by LED 50 that the device is not compatible. If you see such a display,
The operator adjusts the manual valve 27 to readjust the duty ratio.

In addition, the control unit 31 adjusts the duty ratio when the duty ratio conforms to the specified value and when the operator adjusts the manual valve 27 to adjust the duty ratio to the specified value. It is programmed to display what is being done with the LED 50. Therefore, the readjustment of the duty ratio by the manual valve 27 may be performed until the LED 50 indicates that the duty ratio is appropriate.

FIG. 4 is a flowchart showing a control flow in the control unit 31 when the duty ratio is readjusted by the manual valve 27. In this flowchart, the control steps are S1, S
Indicated by 2, ...

When this control is started, first, in S1, it is determined whether or not the operation mode of the engine 2 is the duty ratio confirmation adjustment mode. If S1 is YES, the connection of the solenoid 28 is confirmed in S2. As described above, since the solenoid 28 is connected to the ignition timing fixing terminal, its confirmation is made in S2.

If S2 is YES, the program proceeds to S3, where the throttle valve is controlled based on the input from the throttle sensor 24.
It is determined whether or not 23 is fully closed. If YES, S4
Then, it is determined whether or not the shift position is neutral based on the input from the shift position sensor 49.

If S4 is YES, the process proceeds to S5, where the engine temperature is set to A ° C. based on the input from the engine temperature sensor 16.
It is determined whether or not this is the case. If YES, the process proceeds to S6. If any one of S1 to S5 is NO, S1
Is programmed to return to

At S6, the duty ratio B is detected.
Next, the total operation time T is detected in S7. This total operation time T is calculated from the time when the engine 2 is new,
And stored in the non-volatile memory 40.

Further, at S8, the total operation time T
, The specified value X of the duty ratio at the engine temperature A ° C is set. The specified value X is appropriately set according to the total operation time T. As shown in FIG. 5, for example, a map corresponding to the total operation time T and the engine temperature A is stored in the duty control unit 37, and the specified value X is selected in the range from X11 to Xnn based on this map. It may be. In this case, another setting condition may be added in addition to the engine temperature A.

Thereafter, in S9, the duty ratio B is compared with the specified value X, and an absolute value α of the difference is calculated. Then, according to the value of α, the LED 50 is set at S10.
Is moved. The type of the display will be described in detail later. When α is large, that is, when the duty ratio B does not conform to the prescribed value X, and when α is small, that is, when the duty ratio B conforms to the prescribed value X, Is different from the case where If the display means indicates that the duty ratio B is incompatible at S10, the operator operates the manual valve 27.
Is manually adjusted to readjust the duty ratio B.

While the readjustment operation is being performed, in S11, as shown in FIG.
It is determined whether control is performed within%. S11 is N
In the case of O, the process shifts to S14, the count of the timer 41 is cleared, and the process returns to S9. The count of the timer 41 is S
This is started when the determination at 12 becomes NO.

If S11 is YES, the process proceeds to S12, and it is determined whether or not the state where α is controlled within ± β% of the specified value X has continued for C seconds. If this S12 is NO, the process moves to S13, where the counting of the timer 41 is started and S9 is started.
Return to If S12 is YES, the process proceeds to S15, and the display means displays that the duty ratio B has conformed to the specified value X. Thus, the adjustment work of the duty ratio B is completed. Then, in S16, the number of adjustments so far is stored in the non-volatile memory 40, and this control ends.

In S10, there are the following methods for changing the type of display on the display means according to the value of α.

For example, when the display means is a light-emitting means such as the LED 50 as in this embodiment, the degree of α is displayed by blinking the display means. That is, FIG.
As shown in (a) and (b), as α is larger, that is, as the duty ratio B is far from the specified value X, the blinking speed is reduced, and as α becomes smaller, the blinking speed is increased,
When α is within ± β% of the specified value X, the light is continuously turned on.

If the display means is a sound generator such as a buzzer or a horn, the degree of α is displayed by intermittently sounding the sound. That is, the intermittent interval is made longer as α becomes larger, and the intermittent interval is made shorter as α becomes smaller. When α becomes within ± β% of the specified value X, the sound is emitted continuously.

In addition to this, for example, the display means may be a meter, and when α is within ± β% of the specified value X, the pointer indicates an applicable area. May be configured to indicate the region. In either case, the display means is controlled by the display control unit 42.

As described above, the display means displays the duty ratio B
Therefore, a person who re-adjusts the duty ratio B only needs to pay attention to the display means while manually adjusting the manual valve 27. Therefore, there is no need for special measuring instruments or specialized knowledge, and the engine 2
Can very easily readjust the duty ratio B.

In addition, in the assist air supply device 1, the specified value X of the duty ratio B is controlled so as to be appropriately changed according to the total operation time T of the engine 2, so that the readjusted duty ratio is reduced by the friction loss. , Etc., and better adapts to the state of the engine 2. Therefore, the startability of the engine 2 and the stability of the idling rotational speed can be further improved.

In the control of the control unit 31 when the duty ratio is readjusted, it is programmed to return to the start when any of S1 to S5 in the flowchart of FIG. Therefore, it is possible to prevent the duty ratio from being readjusted to an inappropriate value due to careless readjustment.

Further, since the number of times the above control is executed is programmed so as to be stored in the non-volatile memory 40, the adjustment history of the engine 2 can be easily found out, and the checking work at the time of inspection or the like becomes easy. .

[0064]

As described above, the assist air supply device for an engine according to the present invention includes the assist air supply valve provided in the intake passage downstream of the throttle valve and the assist air supply valve provided by the duty control. Valve driving means for driving, adjusting means manually operated, display means, a mode changeover switch for setting the operation mode of the engine to the duty ratio confirmation adjustment mode, and the valve driving means based on various operating conditions of the engine. Operating the mode changeover switch, and comparing the duty ratio with a preset specified value. If the duty ratio does not conform to the specified value, the display means indicates that the duty ratio is incompatible. Displayed when the duty ratio conforms to the specified value When the operator adjusts the adjustment means to adjust the duty ratio to a specified value, the control means is configured to display on the display means that the duty ratio is appropriate. According to this configuration, the user of the engine can easily execute the readjustment operation of the duty ratio.

In the assist air supply device for an engine according to the present invention, the control means is configured to appropriately change the specified value of the duty ratio in accordance with the total operation time of the engine. The ratio can be better adapted to the condition of the engine.

Further, in the engine assist air supply device according to the present invention, the assist air supply valve is provided in the surge tank provided downstream of the throttle valve and where the intake pipes of the respective cylinders gather. The operation efficiency of the assist air supply valve in the engine can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an engine to which an assist air supply device according to the present invention is applied and an intake device thereof.

FIG. 2 is a block diagram of an assist air supply device showing one embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between a total operating time of an engine, a friction loss, and a duty ratio.

FIG. 4 is a flowchart showing a flow of control of the control unit when the duty ratio is readjusted.

FIG. 5 is a diagram showing a map for selecting a prescribed value of a duty ratio according to a total operation time of an engine and an engine temperature.

6A is a diagram showing a relationship between a duty ratio and a specified value when the duty ratio is readjusted, and FIG. 6B is a diagram showing an operation state of an LED or the like when the duty ratio is readjusted. (C) is a diagram showing the ON-OFF state of the mode changeover switch when the duty ratio is readjusted.

[Explanation of symbols]

 Reference Signs List 1 assist air supply device 2 engine 3 intake device 18 surge tank 19 intake pipe 23 throttle valve 26 assist air supply valve 27 manual valve functioning as adjusting means 28 solenoid functioning as valve driving means 31 control unit functioning as control means 48 mode Changeover switch 50 LED that functions as a display means B Duty ratio T Total operating time of engine X Specified value of duty

Claims (3)

[Claims] 1. An assist air supply valve provided in an intake passage downstream of a throttle valve and valve driving means for driving the assist air supply valve by duty control are manually operated. Adjusting means (27), display means (50), a mode changeover switch 48 for setting the operation mode of the engine 2 to the duty ratio confirmation adjustment mode, and the valve driving means (28) based on various operating conditions of the engine 2. The duty ratio B is compared with a preset specified value X by operating the mode changeover switch 48. If the duty ratio B does not conform to the specified value X, the duty ratio B is determined to be incompatible. Is displayed on the display means (50), and when the duty ratio B conforms to the specified value X and when the operator Control means (31) configured to display on the display means (50) that the duty ratio B is suitable when the duty ratio B is adapted to the specified value X by adjusting the means (27); An assist air supply device for an engine, comprising: 2. The assist air supply device for an engine according to claim 1, wherein said control means (31) is configured to appropriately change a prescribed value X of said duty ratio B according to a total operation time T of the engine 2. . 3. The engine assist air according to claim 1, wherein said assist air supply valve is provided in a surge tank provided downstream of said throttle valve and in which intake pipes of respective cylinders are gathered. Feeding device.