JPH0442497Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a variable swirl control device that switches and controls swirl intensity according to engine rotation and load.
In particular, the present invention relates to a variable swirl control device that can reduce unnecessary swirl switching operations of swirl control means.

[Prior Art] Generally, variable swirl devices are known as devices for improving low-temperature startability, reducing smoke, and improving fuel efficiency of diesel internal combustion engines.

This variable swirl device is installed in the cylinder head.
An intake port that sucks combustion air into the cylinder as a swirl, and an air passage for adjusting the swirl that is connected to the downstream side of the intake port and introduces air that inhibits and weakens the generated swirl. In addition, an on-off valve is provided in the air passage for controlling the swirl, and the on-off valve is opened and closed according to the engine speed and load by means of a valve operation control means. The valve operation control means detects the engine speed and load, and closes the on-off valve at low engine speeds and low loads according to the engine speed and causes high swirl air to be sucked into the cylinder from the intake port. At times of high rotation and high load, the on-off valve is opened to introduce air that weakens the swirl from the swirl adjustment air passage to the downstream side of the intake port, thereby sucking low-swirl air into the cylinder.

As a result, the internal combustion engine maintains a good combustion state from low-load, low-speed to high-load, high-speed.

[Problems to be solved by the invention] On the other hand, when the clutch of an internal combustion engine is disengaged for a gear change operation, etc., the state of the engine changes from, for example, a low load and low rotation state to a high load and high rotation state. change into a state (or vice versa). However, conventional variable swirl control devices sometimes detect such transient state changes of the internal combustion engine and control the operation of the on-off valve to switch the swirl strength each time the gear is changed. However, it is not necessary to switch the swirl intensity until such a transient state change occurs, and there is a risk that the durability and reliability of the swirl switching means such as the on-off valve may be deteriorated.

By the way, the present applicant has previously proposed the ``Swirl Control Method for Diesel Engines'' (Japanese Patent Application No. 128447/1982) as a way to improve the above-mentioned problems.
This invention provides a method for switching the swirl by the variable swirl means based on a map of swirl intensity zones divided by engine rotation and load, and when the engine state transitions to another swirl intensity zone, for a predetermined period of time from the time of the transition, This is designed to maintain the swirl strength in the swirl strength zone before the transition, which reduces unnecessary swirl switching during optimal swirl control according to engine speed and load, improving system durability and reliability. It can be improved.

However, the applicant has since conducted further studies and has now proposed this as a practical variable swirl control device.

[Purpose of the invention] The present invention was devised in consideration of the above circumstances, and its purpose is to change the swirl strength to the previous state when the clutch is disengaged when controlling the swirl intensity according to the engine speed. maintain strength,
It is an object of the present invention to provide a variable swirl control device that reduces unnecessary operations of a swirl switching means without delaying response to normal operation, and has improved durability and reliability.

[Summary of the invention] In order to achieve the above object, the present invention has an air passage that opens into the intake port and introduces air that weakens the intake swirl strength, an on-off valve provided in the air passage, and controlling the on-off valve to close or open according to whether the number and load belong to high or low swirl intensity zones on the map, and when the clutch is disengaged, the on-off valve is held in the previous state;
After that, when the clutch is engaged, the engine speed and load at that time are read again, and the control valve is controlled in accordance with the swirl intensity zone on the map to which these values belong. .

When the clutch is disengaged for gear change operation, etc., this is detected and the on-off valve is held in the previous state during the disengagement, reducing unnecessary switching operations of the swirl switching means. can be done. Next, when the clutch is engaged, the operation of the on-off valve is again controlled according to the map according to the engine load and rotation speed at that time.
Even if the engine load and engine speed change excessively while the clutch is disengaged, swirl switching will not be performed unnecessarily following it.

In this way, since the control is performed by determining only when the gear is being changed, the response to normal operation is not delayed. Further, even if there are variations in the time width of the gear shifting operation depending on the driver, this is not affected.

[Embodiment] A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIG. 1, the cylinder head 1 is provided with an intake port 3 for sucking combustion air into each cylinder 2, and each branch pipe 5 from an intake pipe 4 is connected to this intake port 3. . Intake port 3
The intake valve hole 6 on the most downstream side has a helical shape, and the combustion air flowing through the intake port 3 is swirled at the intake valve hole 6 and taken into the cylinder 2. .

The cylinder head 1 also has an air passage 7 which is connected to the intake port 3 and introduces air for swirl adjustment to weaken the swirl strength.
is provided. In the illustrated embodiment, the air passage 7 is a bypass passage 8 that bypasses a part of the intake air from the branch pipe 5 to the intake valve hole 6, and a part of the intake air is used for swirl adjustment air. is used. The outflow port 9 of the bypass passage 8 is opened facing substantially the axial center of the helical intake valve hole 6, and a portion of the intake air is introduced into the intake valve hole 6 from the outflow port 9. This structure is configured to inhibit the swirl generated in the intake valve hole portion 6, thereby weakening its strength.

At the inlet 10 portion of the bypass passage 8, an on-off valve 12 for opening and closing the inlet 10 portion as a swirl switching means 11 and an air cylinder 13 as an actuator thereof are fixed to each branch pipe 5 of the intake pipe 4. It is being An air tank 15 is connected to the air cylinder 13 via an air pipe 14. The air pipe 14 is provided with a solenoid valve 16 for opening and closing, and the solenoid valve 16 is controlled to open and close by a valve operation control means 17.

The valve operation control means 17 includes a water temperature sensor 18 that detects the engine cooling water temperature, and an air pressure switch 19 that is turned on and off depending on the air pressure of the air tank 15.
It is connected to a clutch switch 21 that detects engagement and disengagement of the clutch by depressing a clutch pedal 20, and a control unit 22 that controls an electronic timer and an electronic governor outputs a signal a indicating the engine speed and top dead center position. and engine load signal b are input. In addition, the above control unit 2
2, a signal from the water temperature sensor 23, an engine rotation speed signal and a TDC signal detected from the engine flywheel 24, an engine load signal from the injection pump 25, an accelerator opening signal, and a vehicle speed signal are input. . In addition to the control signal for the solenoid valve 16, the outputs of the valve operation control means 17 include a rotation signal for lighting each warning lamp for fuel consumption monitoring, a load signal, an NG signal, and a signal for the control unit 22. The warning signal is configured to be emitted.

Further, the valve operation control means 17 includes a second
A map as shown in the figure is stored. This map divides the switching zones of the strength of swirl (high and low) in the relationship between the internal combustion engine's load and rotational speed. For example, when the engine load L is low ( _L1 or less), or when the engine speed N about
When the engine is rotating at a high speed of N ₂ or more near 2000 rpm, or when the load L is a medium load of L ₁ ≦L≦L ₂ and the engine rotation N is a medium speed of N ₁ (approximately 1700 rpm) ≦N≦N ₂ . Each is in a low swirl zone, and the other times are in a high swirl zone. The valve operation control means 17 controls the on-off valve 12 to close or open depending on whether the load signal b and the rotation speed signal a input thereto belong to high or low swirl intensity zones on the map. When in the low swirl zone, the solenoid valve 16 is opened, and when in the high swirl zone, the solenoid valve 16 is closed.

When the solenoid valve 16 is closed, the air supply from the air tank 15 to the air cylinder 13 is cut off, and the actuation rod 26 of the air cylinder 13 is pushed back by the elastic force of the return spring 27 built into the air cylinder 13. Open/close valve 1
2 opens the inlet 10 of the bypass passage 8, as shown in FIG. When the bypass passage 8 is open, a portion of the intake air from the branch pipe 5 is introduced into the intake valve hole 6 of the intake port 3 through the bypass passage 8 as intake air that inhibits swirl, so that the intake swirl is weakened. Therefore, the intake air drawn into the cylinder 2 has a low swirl.

On the other hand, when the solenoid valve 16 is opened, air is supplied from the air tank 15 to the air cylinder 13, the actuating rod 26 of the air cylinder 13 is extended, and the on-off valve 12 is opened at the inlet 1 of the bypass passage 8.
Close part 0. When the bypass passage 8 is closed,
All intake air passes through the intake port 3 and enters the intake valve hole 6.
Since the air is swirled in the cylinder 2, the intake air drawn into the cylinder 2 has a high swirl.

By the way, the feature of the present invention is that when a clutch discontinuation signal is inputted to the valve operation control means 17 from the clutch switch 21, the swirl strength is maintained at the previous state during the discontinuation. It's what I did. In other words, when the clutch is disengaged for a gear change operation, etc., the engine load and engine speed change due to disengagement of the clutch, and for example, a transition occurs from a low swirl zone to a high swirl zone on the map. (or vice versa), the swirl strength switching operation is not performed while the clutch disengagement signal is input, and the solenoid valve 16
remains closed (or open) to maintain the on-off valve 12 in the state it was in when the clutch was previously engaged, and when the clutch is subsequently engaged, the engine load and rotation at that time will be maintained again. The number is read, and the operation of the on-off valve 12 is controlled according to the swirl intensity zone on the map to which the value belongs. By doing this, even if the engine load and its rotation speed change transiently from the low swirl zone to the high swirl zone or from the high swirl zone to the low swirl zone while the clutch is disengaged, the swirl switching means 11 It is possible to prevent this from being activated by following it unnecessarily.

Next, an example of the logic flow of the control method of the variable swirl control device of the present invention is shown in the flowchart shown in FIG. 3 (control performed by the valve actuation control means 17).
I will explain according to the following.

First, the valve operation control means 17 compares the engine cooling water temperature T inputted from the water temperature sensor 18 with a specified temperature _T0 , and when the cooling water temperature T is lower than the specified temperature _T0 , the solenoid valve 16 is closed to reduce the temperature. Create a swirl. This is because if the swirl is high when the engine temperature is low and the cooling water temperature T is low, the ignitability and startability will deteriorate, and white smoke and odor will become a problem. Cooling water temperature T is specified temperature
When the pressure becomes higher than T ₀ , it is determined whether or not the air pressure P input from the air pressure switch 19 is greater than the specified pressure P _0. If the air pressure P is smaller than the specified pressure P ₀ , a warning lamp for monitoring is turned on. , the electromagnetic valve 16 is closed, and no air is supplied to the air cylinder 13, resulting in a low swirl. This is to preferentially secure air for braking.

Next, when the air pressure P is equal to or higher than the specified pressure _P0 , the on/off state of the clutch is determined based on the signal from the clutch switch 21, and when the clutch is disengaged (that is, when the clutch switch 21 is OFF).
Then, the on-off valve 12 is returned to the upper stage of the air pressure discrimination stage, and the on-off valve 12 is kept in the previous state until it is connected again. When the clutch is engaged, the rotational speed signal a and the load signal b input from the control unit 22 are read, the zone or zone on the map is newly stored in the memory based on these values, and the electromagnetic control is performed according to the memory. Controls the operation of valve 16. At this time, if the rotational speed cannot be read, the load cannot be read, or the on-off valve cannot be controlled, the warning lamp is turned on, the solenoid valve 16 is closed, and the air pressure is returned to the upper stage of the air pressure discrimination stage.

Furthermore, after controlling the solenoid valve 16 according to the memory, it is determined whether the key switch is ON or OFF, and if it is ON, it is returned to the upper stage of the air pressure discrimination stage, and it is turned OFF.
If so, the operation is terminated.

In addition, for swirl switching control when the engine speed changes between the swirl strength zones,
It is made to have hysteresis as shown in FIG. That is, for example, when the rotation speed exceeds N ₁ , the swirl intensity is switched from high swirl (High) to low swirl (Low), but when the rotation speed decreases, the swirl intensity is switched to low unless the rotation speed falls below N ₁ −n ₁ . Does not switch from swirl (Low) to high swirl (High). Similarly, in the case of load, hysteresis is given as shown in Figure 5, and when the load is L ₁
Swirl strength is low when exceeding
However, when the load decreases, the switch from high swirl (High) to low swirl (Low) will not occur unless the load becomes less than L ₁ −l ₁ . By providing hysteresis in this manner, it is possible to reduce the operation of the variable swirl means 11 due to errors in reading the rotational speed or load or hunting. In addition, hysteresis is also given to the rotation speed N ₂ and load L ₂ , and the values of n ₁ , n ₂ , etc. are 30
~100 rpm, and the values of l ₁ , l _2, etc. should be around 0.2 V at the potentiometer output.

[Effects of the invention] In summary, according to the invention, it is possible to eliminate unnecessary swirl switching in optimal swirl control according to the engine speed, reduce the number of operations, and improve the durability and durability of the variable swirl control device. Reliability can be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing a preferred embodiment of the variable swirl control device according to the present invention, FIG. 2 is a map showing the distribution of swirl intensity zones of the variable swirl control device according to the present invention, and FIG. 3 is a diagram showing a preferred embodiment of the variable swirl control device according to the present invention. A flowchart showing an example of control of the variable swirl control device according to the invention, and FIGS. 4 and 5 are diagrams for explaining swirl intensity control having hysteresis. In the figure, 3 is an intake port, 7 is an air passage which is a bypass passage, 12 is an on-off valve, 17 is a valve operation control means, and 20 is a clutch pedal of a clutch.

Claims (1)

[Scope of utility model registration request] Depending on the air passage that opens to the intake port and introduces air that weakens the intake swirl strength, the on-off valve installed in the air passage, and whether the current engine speed and load belong to the high or low swirl strength zone on the map. Controlling the on-off valve to close or open,
When the clutch is disengaged, the on-off valve is held in the previous state, and when the clutch is subsequently engaged, the engine speed and load at that time are read again.
A variable swirl control device comprising means for controlling an on-off valve according to a swirl intensity zone on a map to which the value belongs.