JPS61169622A - Engine supercharge pressure controller - Google Patents

Abstract

PURPOSE:To improve the durability of control system having diaphragm means for leading the supercharge pressure into pressure chamber and electromagnetic means for controlling the pressure in the pressure chamber by controlling the electromagnetic means only under such operating region as enable of the highest supercharge pressure control. CONSTITUTION:In a system for controlling the highest supercharge pressure in the downstream of supercharger 4 through function of diaphragm means 51 to predetermined level, the diaphragm means 51 is provided with a pressure chamber to be fed with the supercharge pressure in the downstream of the supercharger 4 to control the pressure in the pressure chamber by means of the electromagnetic means 52 and to lead the supercharge pressure into the pressure chamber at least upon malfunction of the electromagnetic means 52. Here, control stop means 53 for stopping control of the solenoid valve 52 is provided when the supercharge pressure to be detected through supercharge detecting means 54 is lower than the spring setting pressure of diaphragm means 51. Consequently, control of the solenoid valve 52 under the region where supercharge pressure control is substantially disabled is stopped to reduce the load of the control system.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine boost pressure control device.

(Prior art) In engines equipped with a supercharger, if the supercharging pressure rises excessively, it may cause damage to the engine and impair the reliability of the engine. and an electromagnetic means such as a solenoid valve for controlling the introduction of supercharging pressure into the pressure chamber of the diaphragm mechanism, and the supercharging pressure control device controls the maximum supercharging pressure that is permissible in terms of engine strength. The setting value is controlled to ensure the reliability of the engine.

In such a boost pressure control device, its operation becomes effective (that is, the diaphragm means operates to suppress the increase in supercharging pressure) when the pressure in the pressure chamber of the diaphragm means is controlled by the diaphragm. This is the area where the pressure is equal to or higher than the set pressure of the force spring.

However, in the conventional supercharging pressure control device such as the above-mentioned known example, regardless of the operating state of the diaphragm means (in other words, regardless of whether or not supercharging pressure control is necessary), during engine operation, Since the control system for the electromagnetic means is continuously operated, the burden on the control system becomes unnecessarily large, which is not desirable in terms of durability of the control system.

In addition, in this type of boost pressure control device, in order to ensure the reliability of the engine by controlling the maximum boost pressure to the set value even in the event of a failure of the electromagnetic means, the electromagnetic means is generally used. When the diaphragm means is not in operation, supercharging pressure is introduced into the pressure chamber of the diaphragm means so that the diaphragm means operates in the direction of reducing the supercharging pressure.

(Object of the Invention) The present invention is intended to solve the problems pointed out in the above section of the prior art, and consists of a diaphragm means for introducing supercharging pressure into a pressure chamber, and an electromagnetic means for controlling the pressure in the pressure chamber. The purpose of this invention is to reduce the burden on the control system and improve its durability by narrowing the control area of the electromagnetic means to the necessary minimum in a boost pressure control system for an engine equipped with a be.

(Means for achieving the object) The present invention provides a first method for achieving the above object.
As shown in the figure, it is provided with a diaphragm means 51 through which the supercharging pressure downstream of the supercharger 4 is introduced into the pressure chamber, and an electromagnetic means 52 that controls the pressure within the pressure chamber, and at least when the electromagnetic means 52 is not activated. In the engine supercharging pressure control device, the supercharging pressure control device is configured such that supercharging pressure is introduced into the pressure chamber, and controls the maximum supercharging pressure downstream of the supercharger to a predetermined value by operating the diaphragm means 52. A supercharging pressure detection means 54 detects the pressure, and the supercharging pressure is in the vicinity of the spring set pressure of the diaphragm means 51 and lower than a predetermined value below the spring set pressure (i.e., when the supercharging pressure is lower than a predetermined value below the spring set pressure). A control stop means 53 is provided to stop the control of the electromagnetic means 52 in an operating region where supercharging pressure control is not substantially performed regardless of the operating range, and control in a region where supercharging pressure control is substantially impossible is provided. By stopping the engine, the control range of boost pressure control can be narrowed to the minimum necessary range.

(Function) In the present invention, the electromagnetic means is controlled by the above means only in the operating region where the maximum boost pressure can actually be controlled by the operation of the diaphragm means. The burden on the control system is reduced compared to the case where the means are controlled, and the durability of the control system is improved accordingly.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. 2 to 4.

(Structure) FIG. 2 shows an automobile engine 1 equipped with a boost pressure control device according to an embodiment of the present invention. The intake passage 2 of the engine 1 is provided with a blower 41 and a throttle valve 5 of the turbocharger 4, and the exhaust passage 3 is provided with a turbine 42 of the turbocharger 4.

Furthermore, a bypass passage 6 is connected to the exhaust passage 3 so as to bypass the turbine 42 . A control valve 7 is attached to the bypass passage 6 and is driven by an actuator 8, which will be described later, to control the opening and closing of the bypass passage 6.

The actuator 8 corresponds to the diaphragm means in the claims, and includes a diaphragm 81 that is always urged in one direction by a spring 83, and one end connected to the diaphragm 81 and the other end connected to the diaphragm 81 via a link lever 85. and an actuator 84 connected to the control valve 7, so that the internal pressure of the pressure chamber 82 formed on the surface of the diaphragm 81 on the ring spring 83 side and the spring force of the spring 83 are balanced. The diaphragm 81 is displaced accordingly to open and close the control valve 7. In this embodiment, when the internal pressure of the pressure chamber 82 becomes greater than the spring force of the spring 83 and the diaphragm 81 is displaced toward the side opposite to the pressure chamber 82, the control valve 7
The operating direction is set so that the valve is opened.

Furthermore, the pressure chamber 82 is connected to the blower downstream position of the intake passage 2 via a supercharging air introduction passage IO having a first electromagnetic passage 12 formed of a dual-chill valve in the middle thereof, and is connected to the blower downstream position of the intake passage 2. It is opened to the atmosphere via an atmosphere opening passage 2 equipped with a second electromagnetic valve 13 constituted by a duty valve.

The first solenoid valve 12 and the second solenoid valve 13 correspond to the solenoid means in the claims, and their operation mode is to control the boost pressure via the actuator 8 even in the event of a failure. In order to make this possible, the first solenoid valve 12 is set to a normally open type that is kept fully open when it is not in operation, and the second solenoid valve 13 is set to a normally closed type that is kept fully closed when it is not operated. has been done. Further, both the first solenoid valve 12 and the second solenoid valve I3 operate in response to control signals output from the controller 14 depending on the operating state of the engine, and their operating range is set as follows. There is. That is, in this embodiment, the control valve 7 is opened to control the maximum boost pressure when the pressure in the pressure chamber 82 of the actuator 8 is increased by the spring 83.
The supercharging pressure is limited to the operating region that is higher than the set pressure of , and in other operating regions, no matter how much the solenoid valve 12 or 13 operates, the actuator 8 is inactive and the maximum supercharging pressure is not controlled. Based on the characteristics of the diaphragm means which uses the operating pressure as shown in FIG. Set pressure Ps of spring 83
Based on the supercharging pressure Pl which is slightly lower than the supercharging pressure P1
The higher pressure region is defined as a control region where the control of the solenoid valve 12.13 is performed, and the boost pressure P and the lower pressure region are defined as a control stop region where the control of the solenoid valve 12.13 is stopped. Therefore, the supercharging pressure P is the same as that of the first and second solenoid valves 12.
This becomes the control start reference pressure of No. 13.

In Fig. 2, reference numeral 16 is a rotational speed sensor that detects the engine rotational speed, I7 is an oil level sensor that detects the lubricating oil level of the engine l, 18 is an oil temperature sensor that detects the lubricating oil temperature, and I9 is a sensor downstream of the blower. 20 is a water temperature sensor that detects the engine cooling water temperature, 21 is an intake air temperature sensor that detects the intake air temperature, and 22 is the sensor that detects the opening degree of the throttle valve 5. This is the throttle opening sensor.

(Operation and Effect thereof) Next, the operation and effect of this supercharging pressure control device will be explained with reference to the system diagram shown in FIG. 2 and the control routine shown in FIG. 3.

When the engine I is operated, the turbine 42 is rotated by receiving the gas energy of the exhaust gas discharged from the engine I, and further, the rotation of the turbine 42 is transmitted to the blower 41 via the rotating shaft 43. Intake supercharging is performed by the blower 41.

If this intake boost pressure becomes too high, the engine l
This may cause damage to the engine, which may impair the reliability of the engine.
When the boost pressure reaches a set value (maximum boost pressure) determined from the viewpoint of engine reliability, the first solenoid valve 12 is activated based on a control signal from the controller 14, as will be described in detail later. The actuator 8 opens the control valve 7 to introduce supercharging air into the pressure chamber 82 of the actuator 8 through the supercharging air introduction passage 10, and the actuator 8 opens the control valve 7 to discharge part of the exhaust gas through the bypass passage 6. , by controlling the rotation of the turbine 42, the supercharging pressure is reduced to the above-mentioned set value, and conversely, when the supercharging pressure falls below the above-mentioned set value, the second electromagnetic valve 13 is opened and the above-mentioned pressure chamber 82 is is opened to the atmosphere and the control valve 7 is closed to accelerate the rotation of the turbine 42 and increase the boost pressure to the above set value (maximum boost pressure control).

Furthermore, in this boost pressure control device, in parallel with the maximum boost pressure control based on the level of boost pressure downstream of the turbine as described above, the engine cooling water temperature, intake air temperature, lubricating oil temperature, and lubricating oil level are Correction control is performed based on the correction factors, and the above set value is adjusted to the acceleration state 1 of the engine l. The increase or decrease is corrected based on the engine cooling water temperature, the intake air temperature, the lubricating oil temperature, and the lubricating oil level. The maximum supercharging pressure control including correction control based on each of these correction factors will be described in detail below with reference to FIG. 3.

First, the overall control flow will be explained with reference to the main control routine shown in FIG.

After starting the engine, first, check the current engine speed N, lubricating oil level LO1 lubricating oil temperature TO1, cooling water temperature TW1, intake temperature T
a, throttle opening θ, and current supercharging pressure Pa are read (step S).

Next, in step S, the current supercharging pressure (detected supercharging pressure) Pa is compared with the preset control start reference pressure PI of the solenoid valve 12.13, and if Pa-PI<0, It is determined that the detected supercharging pressure Pa is in the control stop region (see FIG. 4), and the first. Control of the second magnetic valve 12 and 13 is stopped. On the other hand, if PaP+>0, it is determined that the detected supercharging pressure Pa is within the control region (that is, it is necessary to start supercharging pressure control), and the solenoid valve 12. Now we move on to execution of the control flow for 13.

First, based on each of the above detected values, the optimum target maximum boost pressure Pα (-P ox CtwxCta
x Ctax Co, o ) is calculated (step S2
). Here, PO is the preset basic maximum boost pressure setting value, Ctw (≧l) is the water temperature correction coefficient calculated based on the height of the cooling water temperature, and Cta (≧1) is the intake air temperature. Intake correction coefficient calculated based on height, Cto (≧
1) is an oil temperature correction coefficient calculated based on the level of the lubricating oil temperature, and C(10 (+≧1) is a lubricating oil level correction coefficient calculated based on the level of the lubricating oil level.

Next, proportional control (P
control value (pulse width) t+(-P gX (
Find P a P a ), Pg; proportional gain) (
Step S,). Furthermore, the current detected supercharging pressure Pa(n)
The difference between the previously detected supercharging pressure Pa(n-1) (Pa(n)-
Pa (n-1)), that is, the differential control (
control value tz(= DgX (P a(n
) −P a(n −1), Dg: differential gain) is determined (step S).

Add these two control values and the same t (step SS)
, this sum t (= Lt + tt) is the actual control value.

Next, the control direction of the boost pressure is determined. That is, in step S?, the detected supercharging pressure Pa and the target maximum supercharging pressure Pα are compared. )
, Pa-Pa>0, it is determined that pressure reduction is necessary, and in this case, the first solenoid valve 12 is driven to open based on the above control value (step 5ll), and the control valve 7 is opened. The rotation of the turbine 42 is suppressed to reduce the boost pressure downstream of the blower. Conversely, if Pa-Pa<0, it is determined that there is a need to increase the pressure. The turbine 42 is opened and the control valve 7 is closed.
This aims to increase the supercharging pressure by promoting the rotation of the engine.

As described above, this supercharging pressure control device controls the first it only in the control region and the control stop region, which are set based on the set pressure of the spring 83 of the actuator 8.
The first solenoid valve 12 and the second solenoid valve 13 are controlled, and the control is stopped in the control stop region. Second
The control range of the solenoid valves 12 and 13 is kept to the necessary minimum to reduce the burden on the control system. and,
The first and second solenoid valves 12 and 13 in this control stop region
The controlled stop is performed by the actuator 8 whose operating pressure is the supercharging pressure.
The unique advantage of the boost pressure control device equipped with
2 is a normal oven type valve, and the second solenoid valve 13 that opens the pressure chamber 82 to the atmosphere is a normal closed type valve, and the first and second solenoid valves 12.1
This was achieved by effectively utilizing the structural advantage of the electromagnetic valve in that the supercharging pressure is introduced into the pressure chamber 82 when the first and second electromagnetic valves are inoperative. While the control of the valves 12, 13 is stopped, the actuator 8 is always kept in a state where it can operate on the safe side, that is, in the direction in which the control valve 7 is always opened and the supercharging pressure is reduced. Therefore, even if, for example, the first and second solenoid valves 12.13 break down and become uncontrollable, a dangerous situation such as boost pressure rising beyond the maximum boost pressure will not occur. This will be prevented in advance and reliably, and the reliability of the boost pressure control device will be improved accordingly.

(Effects of the Invention) The engine supercharging pressure control device of the present invention includes a diaphragm means through which supercharging pressure downstream of a supercharger is introduced into a pressure chamber, and an electromagnetic means for controlling the pressure inside the pressure chamber. ,
The supercharging pressure of the engine is configured such that supercharging pressure is introduced into the pressure chamber at least when the electromagnetic means is not activated, and the maximum supercharging pressure downstream of the supercharger is controlled to a predetermined value by the operation of the diaphragm means. In the control device, a supercharging pressure detecting means for detecting the supercharging pressure; and a supercharging pressure detecting means for detecting the supercharging pressure; The present invention is characterized in that a control stop means for stopping control of the electromagnetic means is provided.

Therefore, according to the engine boost pressure control device of the present invention,
Since the control range of the electromagnetic means is minimized, the burden on the control system is reduced compared to the case where the control of the electromagnetic means is continued throughout the entire operating range of the engine, and the durability of the control system is improved accordingly. This has the effect of being forced twice.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of a boost pressure control device for an engine according to the present invention, FIG. 2 is a system diagram of an engine equipped with a boost pressure control device according to an embodiment of the present invention, and FIG. FIG. 4 is a control area diagram of the boost pressure control device shown in FIG. 2. 1 ... Engine 2 ... Intake passage 3 ... Exhaust passage 4 ... Supercharger 5 ... Throttle valve □ 6 ... Bypass passage 7 ... Control valve 8 ... Actuator (diaphragm means) 10 ... Supercharging air introduction passage 11 ... Atmospheric pressure introduction passage 12.13 ... Solenoid valve ( Electromagnetic means) I4...
・Controller 16...Rotational speed sensor 17...Oil level sensor 18...Oil temperature sensor 19...Supercharging pressure sensor 20...Water temperature sensor 21... ... Intake temperature sensor 22 ... Throttle opening sensor 41 ... Blower 42 ... Turbine 81 ... Diaphragm 82 ... Pressure chamber 83 ... ··spring

Claims (1)

[Claims] 1. A diaphragm means for introducing boost pressure downstream of the turbocharger into a pressure chamber, and an electromagnetic means for controlling the pressure in the pressure chamber, and at least when the electromagnetic means is not in operation, the boost pressure is kept at the above pressure. Configured to be introduced indoors,
In the engine supercharging pressure control device that controls the maximum supercharging pressure downstream of the supercharger to a predetermined value by the operation of the diaphragm means, the supercharging pressure detecting means detects the supercharging pressure; Engine supercharging pressure control, characterized in that a control stop means is provided for stopping control of the electromagnetic means in an engine operating state where the spring set pressure of the diaphragm means is near and lower than a predetermined value below the spring set pressure. Device.