JP3859023B2 - Supercharging pressure control device for supercharged engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a supercharging pressure control device for an engine with a supercharger. In particular, when control is performed to open and close an opening / closing control valve to bypass supply air during deceleration, the opening / closing control valve is controlled to open for a predetermined time by a control means. The turbocharger can control the delay of the turbocharger and improve the response of the turbocharger, and the series of movements from the accelerator operation to the brake operation is less likely to cause a sense of incongruity than the normal one, and can prevent deterioration of drivability The present invention relates to a supercharging pressure control device for a machine equipped engine.
[0002]
[Prior art]
Some engines are equipped with a supercharger that turns a turbine with exhaust gas, rotates a compressor with the turning force of the turbine, and pressurizes and supplies an air-fuel mixture.
[0003]
As a supercharging pressure control device for the supercharged engine, there is one disclosed in Japanese Patent Application Laid-Open No. 59-28042. The turbocharger internal combustion engine deceleration control device disclosed in this publication is a turbocharger internal combustion engine in which a throttle valve that responds to an accelerator pedal is provided on the outlet side of a turbocharger compressor. Has a throttle valve holding device for holding the valve at a predetermined value equal to or higher than the idle opening. In a turbocharged internal combustion engine having a throttle valve that responds to an accelerator pedal on the outlet side of a compressor of a turbocharger and that controls the ignition timing of fuel with a required advance angle determined according to predetermined engine operating conditions A throttle valve holding device is provided to hold the throttle valve opening at a predetermined value that is greater than or equal to the idle opening when the engine is decelerating while the turbocharger is operating, and the ignition timing is advanced when the engine is decelerating while the turbocharger is operating. The turbocharger is retarded from the angle to maintain the turbocharger at high speed even when decelerating, eliminating the response delay during reacceleration.
[0004]
[Problems to be solved by the invention]
Incidentally, in a conventional supercharging pressure control device for an engine with a supercharger, the one disclosed in Japanese Patent Laid-Open No. 59-28042 described above holds the throttle opening at a predetermined value equal to or higher than the idle opening during deceleration. At the same time, the ignition timing is advanced when the engine is decelerated during operation of the turbocharger.
[0005]
The holding device that holds the throttle opening at a predetermined value is turned on regardless of deceleration.
[0006]
In addition, for the purpose of improving the response of the supercharger, there is one that guides the supercharged air to the exhaust manifold and burns the discharged raw gas to rotate the turbine.
[0007]
However, since the throttle opening does not close below a certain level when decelerating, the engine brake at the moment of closing is not effective (see Fig. 3 (a)), and the engine brake cannot be used to trigger braking. This affects the feeling of stepping on the brake pedal and is inconvenient.
[0008]
In addition, when there is a certain amount of air, the engine output cannot be sufficiently reduced with a small advance angle, and conversely, if the engine is in a retarded state at a level where the engine output is sufficiently reduced, there is no compression and ignition is performed. If it is broken or not ignited, the ignition state becomes unstable, and there is an inconvenience that it becomes unstable as a post-ignition fire type.
[0009]
Further, the gas passing through the cylinder is extremely rich, that is, in an overrich state, the effect remains even after returning to the normal state, and the ignition state of the engine itself deteriorates, which is disadvantageous in practice. is there.
[0010]
Furthermore, in order to apply the engine brake, the operation of opening the throttle valve after the engine brake has been applied once with the fully closed opening (idle opening) as it is is realized only by the movement of the throttle valve. In order to do so, it is sufficient to open the throttle valve to a predetermined opening after being fully closed once, but since a device such as a fly pie wire is required, the cost is increased, which is economically disadvantageous. At the same time, when using an actuator to open and close the throttle valve, the slack of the throttle cable may have an adverse effect, and improvements have been made.
[0011]
[Means for Solving the Problems]
Accordingly, in order to eliminate the above-described disadvantages, the present invention provides a supercharger with a supply of air from the supercharger to the engine and a throttle valve provided in the middle of the air supply passage downstream of the supercharger. In the engine, a bypass passage that bypasses the throttle valve is provided, and an opening / closing control valve is provided in the middle of the bypass passage. A time lag until the start of the opening control is set in the valve, the opening control of the opening / closing control valve is controlled to be delayed for a predetermined time, and the engine is controlled to perform the engine decimation at the same time as the opening control of the opening / closing control valve is started, When the amount of change per unit time of the throttle valve exceeds a set value, the open control of the open / close control valve and the ignition decimation control are stopped. Characterized in that a control means for controlling.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
As a result of the invention as described above, when control is performed to open the opening / closing control valve and bypass the supply air during deceleration, a time lag until the opening control starts is set in the opening / closing control valve, and the control means opens and closes for a predetermined time. Controls to delay the opening control of the control valve, and controls to perform engine decimation at the same time as the opening control of the opening / closing control valve starts, improving the response of the turbocharger and a series from accelerator operation to brake operation The movement is less likely to cause a sense of incongruity than normal, and it prevents the drivability from deteriorating.
In addition, when the amount of change per unit time of the throttle valve becomes equal to or greater than a set value, normal control is performed in which the opening and closing control of the opening and closing control valve is stopped by the control means.
[0013]
【Example】
Embodiments of the present invention will be described below in detail with reference to the drawings.
[0014]
1 to 3 show an embodiment of the present invention. In FIG. 2, 2 is a supercharging pressure control device for a supercharged engine (not shown), and 4 is an air supply passage between the supercharger and the engine.
[0015]
The engine with a supercharger supplies air from a supercharger (not shown) to the engine (not shown), and a throttle valve 6 is provided in the air supply passage 4 on the downstream side of the supercharger. .
[0016]
Then, a bypass passage 8 for bypassing the throttle valve 6 is provided, and an opening / closing control valve (ABV) 10 is provided in the middle of the bypass passage 8, and the opening / closing control valve 10 is opened during deceleration to control to bypass the supply air. In this case, a time lag until the opening control is started is set in the opening / closing control valve 10 so as to delay the opening control of the opening / closing control valve 10 for a predetermined time. A control means (ECM) 12 for controlling to perform thinning is provided.
[0017]
More specifically, the control means 12 may use a potential time lag generated when a route is formed when setting the time lag until the opening control is started in the opening / closing control valve 10, and if necessary, A predetermined time that is a time lag is set in a timer (not shown) in the control means 12, and the opening control of the open / close control valve 10 is delayed by this predetermined time.
[0018]
When the control means 12 performs control to open the opening / closing control valve 10 and bypass the supply air at the time of deceleration, the control means 12 performs control so as to perform engine ignition decimation simultaneously with the start of opening control of the opening / closing control valve 10.
[0019]
At this time, when the amount of change per unit time of the throttle valve 6 exceeds a set value, the control means 12 stops the opening control of the opening / closing control valve 10 and the ignition thinning-out control. It has the composition to do.
[0020]
That is, after the opening / closing control valve 10 is opened, the opening degree of the throttle valve 6 suddenly returns, and the amount of change (dThrθ / dt) per unit time of the throttle valve 6 is equal to or greater than the set value ((dθ / dt) 2). The following formula dThrθ / dt ≧ (dθ / dt) 2
When is established, the control means 12 performs normal control for stopping the opening / closing control of the opening / closing control valve 10 and the ignition thinning-out control.
[0021]
As shown in FIG. 2, when the opening / closing control valve 10 is provided in the middle of the bypass passage 8, the pressure chamber 14 of the opening / closing control valve 10 is opened to the atmosphere, and the diaphragm chamber 16 is separated from the bypass passage 8 by the pressure passage 18. A spring 22 for urging the valve body 20 in the closing direction of the bypass passage 8 is provided in the diaphragm chamber 16.
[0022]
Further, a pressure switching valve (VSV) 24 is provided in the middle of the pressure passage 18, and the control means 12 is connected to the pressure switching valve 24.
[0023]
The opening / closing control valve 10 is opened by the air supply pipe pressure downstream of the throttle valve 6 and utilizes atmospheric pressure during the closing operation.
[0024]
That is, the pressure switching valve 24 performs a switching operation so that the air supply passage 4 on the downstream side of the throttle valve 6 and the diaphragm chamber 16 of the opening / closing control valve 10 communicate with each other by a control signal from the control means 12 during deceleration. 2), the opening / closing control valve 10 is opened by applying a supply pipe pressure in a negative pressure state, which is a pre-throttle pressure, to the diaphragm chamber 16.
[0025]
Further, the pressure switching valve 24 performs a switching operation (see symbols a and c in FIG. 2) to open the diaphragm chamber 16 of the on-off control valve 10 to the atmosphere by a control signal from the control means 12 when not decelerating. The open / close control valve 10 is closed by the urging force of the spring 22 by applying air to the air.
[0026]
The control means 12 receives various signals such as an exhaust temperature signal, a brake switch signal, a clutch switch signal, a throttle opening signal, a boost (intake pressure) signal, a gear position signal, a vehicle speed signal, and an engine speed Ne signal. The
[0027]
The engine brake becomes difficult to operate by opening the fully closed opening. The fully closed opening remains unchanged (idle opening), and after the engine brake is in effect, the time lag (route It is activated with a potential and physical time lag that occurs when assembling or a predetermined time set in advance. In other words, since the brake operation is started after creating a trigger for braking with a momentary engine brake, the feeling of stepping on the brake pedal of the driver is not greatly affected. That is, if it is opened from the beginning, braking is not applied when the accelerator pedal is released, and the timing is delayed.
[0028]
Further, in order to maintain the rotation of the supercharger, it is necessary to bypass a large amount of air (around 20% of the maximum air amount). The output of an engine that sucks this amount cannot be fully throttled with a slight delay, and it is necessary to perform ignition thinning (cut). For example, if 3 cylinders are cut out of 4 cylinders, the output will be less than 1/4 (because of the mechanical loss of 3 cylinders). By combining this ignition decimation with a slight retard, it is possible to reduce the output to such an extent that engine stall does not occur. In addition, since one cylinder is normally ignited, it serves as a seed for burning the raw gas discharged from the other cylinders. The raw gas lowers the thermal load of the cylinder, the exhaust manifold, and the like by thinning out the ignition, which is effective for durability at high loads.
[0029]
Further, since the throttle valve 6 is merely bypassed, the engine is the same as the throttle valve 6 being opened, and the air-fuel ratio is mapped to the program, so that the air-fuel ratio (A / F ) As an environment, it is not ignited and keeps the best condition.
[0030]
Next, the operation will be described along the control flowchart of the supercharging pressure control device 2 for the supercharged engine shown in FIG.
[0031]
When the control program starts, it is determined (100) whether or not the engine speed N is equal to or greater than the set engine speed N1, and if this determination (100) is YES, the throttle valve 6 is rapidly closed. It is determined whether or not (102) whether or not the expression dThrθ / dt ≦ (dθ / dt) 1
If the determination (100) is NO, ignition return with the pressure switching valve (VSV) 24 turned off or normal control is performed (104).
[0032]
If the determination (102) of whether or not the throttle valve 6 has been suddenly closed is YES, the process proceeds to determination (106) of whether or not the throttle opening Thrθ is equal to or less than the set throttle opening Thrθ1, If the determination (102) of whether or not the throttle valve 6 has been suddenly closed is NO, the process proceeds to a process (104) in which the pressure switching valve (VSV) 24 is turned off or normal control is performed. .
[0033]
In the determination (106) of whether or not the throttle opening Thrθ is equal to or less than the set throttle opening Thrθ1, if the determination (106) is YES, a predetermined time that becomes a potential time lag or a preset time lag has elapsed. After the opening control of the opening / closing control valve 10 is delayed for a predetermined time, the pressure switching valve (VSV) 24 is turned on by a control signal from the control means 12 to supply the air supply passage downstream of the throttle valve 6. 4 and the diaphragm chamber 16 of the open / close control valve 10 are communicated, and the open / close control valve 10 is opened by applying a supply pipe pressure in a negative pressure state to the diaphragm chamber 16. At this time, ignition thinning (retard) is also performed (108).
[0034]
Further, when the above-mentioned determination (106) is NO, the routine proceeds to a process (104) in which the pressure switching valve (VSV) 24 is turned off or the ignition is returned or normal control is performed.
[0035]
After the opening / closing control valve 10 is opened, it is determined whether or not the opening degree of the throttle valve 6 has suddenly returned (110) by the formula dThrθ / dt ≧ (dθ / dt) 2
If the determination (110) is NO, the process proceeds to the determination (112) of the OFF operation timing of the pressure switching valve (VSV) 24. If the determination (110) is YES, the pressure switching valve (VSV) ) Shift to the process (104) for performing ignition return or normal control in which 24 is turned off.
[0036]
The determination (112) of the OFF operation timing of the pressure switching valve (VSV) 24 is to determine whether or not the elapsed time T is equal to or longer than the set elapsed time T1, and when the determination (112) is NO. Is repeated until the elapsed time T becomes equal to or greater than the set elapsed time T1, and if the determination (112) is YES, ignition return or normal control for turning off the pressure switching valve (VSV) 24 is performed. Shift to processing (104).
[0037]
Thereby, as shown in FIG.3 (b), the response of a supercharger can be improved and it is practically advantageous.
[0038]
Further, at the moment of deceleration, as shown in FIG. 3 (b), after the engine brake is applied and a predetermined time has elapsed, the opening / closing control valve 10 is controlled to be opened, so that a series of operations from the accelerator operation to the brake operation is performed. Is less likely to cause a sense of incongruity than the normal movement, and drivability can be prevented from deteriorating.
[0039]
Further, the control means 12 performs ignition decimation at the same time as the opening control of the opening / closing control valve 10 is started, so that at least one of the cylinders is reliably ignited and a fire type for afterburning can be secured. is there.
[0040]
Furthermore, the opening / closing control valve 10 is opened by the supply pipe pressure downstream of the throttle valve 6 and the atmospheric pressure is used during the closing operation, so that the opening / closing operation of the opening / closing control valve 10 is controlled by the supply pipe pressure. Therefore, so-called self-feedback can be performed as shown in FIG.
[0041]
The present invention is not limited to the above-described embodiments, and various application modifications are possible.
[0042]
For example, in the embodiment of the present invention, when the open / close control valve 10 is opened, the supply pipe pressure downstream of the throttle valve 6 is used and the atmospheric pressure is used during the closing operation. When the opening / closing control valve 32 is opened, the supply pipe pressure downstream of the throttle valve 6 may be used, and the supply pipe pressure upstream of the throttle valve 6 may be used during the closing operation.
[0043]
That is, as shown in FIG. 4, when the opening / closing control valve 10 is provided in the middle of the bypass passage 8, the diaphragm chamber 16 of the opening / closing control valve 32 is connected to the supply passage 4 downstream of the bypass passage 8 by the pressure passage 18. A spring 22 for urging the valve body 20 in the closing direction of the bypass passage 8 is provided in the diaphragm chamber 18.
[0044]
A pressure switching valve (VSV) 24 is disposed in the middle of the pressure passage 18, and the control means 12 is connected to the pressure switching valve 24.
[0045]
In addition, a pressure intake passage 34 that connects the opening portion of the pressure switching valve 24 (see c in FIG. 4) and the supply passage 4 upstream of the opening / closing control valve 32 is provided. Is provided in communication with the pressure chamber 14 of the open / close control valve 10.
[0046]
In other words, at the time of deceleration, the pressure switching valve 24 is switched by the control signal from the control means 12 so that the air supply passage 4 downstream of the throttle valve 6 and the diaphragm chamber 16 of the open / close control valve 10 communicate with each other ( 4a and 4b), the air supply pipe pressure in a negative pressure state is applied to the diaphragm chamber 16 to open the open / close control valve 10, and at the time of non-deceleration, the open / close control valve is controlled by a control signal from the control means 12. The pressure switching valve 24 is switched (see a and c in FIG. 4) so that the pressure pipe 14 upstream of the opening / closing control valve 32 acts on the pressure chamber 14 and the diaphragm chamber 16 (see FIGS. 4A and 4C). The same supply pipe pressure is applied to the diaphragm chamber 16 to close the open / close control valve 10 by the urging force of the spring 22.
[0047]
As a result, the opening / closing operation of the opening / closing control valve 10 is performed only by a change in the supply pipe pressure, and so-called self-feedback can be reliably performed.
[0048]
【The invention's effect】
As described above in detail, according to the present invention, in the supercharged engine in which the supply air from the supercharger is supplied to the engine and the throttle valve is provided in the supply passage on the downstream side of the supercharger. , Provide a bypass passage that bypasses the throttle valve, and provide an opening / closing control valve in the middle of the bypass passage. The time lag of the valve is controlled to delay the opening / closing control valve opening control for a predetermined time. When the amount exceeds the set value, a control means for normally controlling to stop the opening / closing control valve opening control and the ignition thinning control is provided. And give improved response, it is practically advantageous. In addition, after the engine brake is activated at the moment of deceleration and the predetermined time has elapsed, the opening / closing control valve is controlled to open, so that the series of movements from the accelerator operation to the brake operation is not as comfortable as normal. It is difficult to occur, and deterioration of drivability can be prevented. Further, the control means performs the engine thinning-out at the same time as the opening control of the opening / closing control valve is started, so that at least one of the cylinders is reliably ignited, and a fire type for afterburning can be secured. Furthermore, when the amount of change per unit time of the throttle valve becomes equal to or greater than a set value, normal control can be performed in which the opening and closing control of the opening / closing control valve is stopped by the control means.
[Brief description of the drawings]
FIG. 1 is a control flowchart of a supercharging pressure control device for a supercharged engine showing an embodiment of the present invention.
FIG. 2 is a schematic configuration diagram of a supercharging pressure control device for a supercharged engine.
FIG. 3 shows a time chart of a supercharging pressure control device for an engine with a supercharger. FIG. 3 (a) is a conventional time chart, and FIG. 3 (b) is a time chart of an embodiment of the present invention.
FIG. 4 is a schematic configuration diagram of a supercharging pressure control device for a supercharged engine according to another embodiment of the present invention.
[Explanation of symbols]
2 Supercharging pressure control device for engine with supercharger 4 Air supply passage 6 Throttle valve 8 Bypass passage 10 Open / close control valve (ABV)
12 Control means (ECM)
DESCRIPTION OF SYMBOLS 14 Pressure chamber 16 Diaphragm chamber 18 Pressure passage 20 Valve body 22 Spring 24 Pressure switching valve (VSV)

Claims (1)

  In the engine with a supercharger in which the air supply from the supercharger is supplied to the engine and the throttle valve is provided in the middle of the air supply passage downstream of the supercharger, a bypass passage is provided to bypass the throttle valve, When an open / close control valve is provided in the middle of this bypass passage and the open / close control valve is controlled to decelerate and air supply is bypassed during deceleration, a time lag until the start of the open control is set in the open / close control valve, and a predetermined time is set. Control to delay the opening control of the opening / closing control valve only, and control to perform engine ignition decimation at the same time as the opening control of the opening / closing control valve starts, and the amount of change per unit time of the throttle valve exceeds the set value And a control unit for normally controlling to stop the opening control of the on-off control valve and the ignition thinning-out control in the case of becoming a supercharger. Supercharging pressure control device of the engine.

Images