JPS60240825A - Supercharging device of engine - Google Patents

Abstract

PURPOSE:To prevent a supercharger from being damaged by controlling a load adjusting means which adjusts the load of said supercharger when the vibration of said supercharger is detected to be greater than a certain value, and lowering the load of said supercharger. CONSTITUTION:A vane type supercharger 14 is provided on the upper course side of the throttle valve 15 of an intake passage 11 which is connected to an intake port 7, while a bypass 21 which bypasses the supercharger 14 and in which a selector valve 22 is installed, is connected to the upper course side of the valve 15. The supercharger 14 is driven by a crank shaft 5 via a timing belt 18, an electromagnetic clutch 19, etc., and the electromagnetic clutch 19 which also functions as a load adjusting means, is controlled, together with a fuel injection valve 16, by a control unit 23. When a vibration value detected by a vibration sensor 26 which is installed in the casing of the supercharger 14, becomes above a certain value, the electromagnetic clutch 19 is disconnected regardless of the opening of the throttle valve 15, to reduce the load of the supercharger 14.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an engine supercharging device.

(Prior Art) Recently, many engines are equipped with a supercharger, as shown in Japanese Utility Model Application Publication No. 58-25630.

There are two types of superchargers: the so-called supercharger type, which is mechanically driven by the engine's output shaft, and the turbocharger type, which is driven by exhaust gas, but either type rotates at a fairly high speed. It is said to be accurate and accurate. Therefore, if the turbocharger continues to operate while applying a large load while there is an abnormality in its rotation due to bearing wear, for example, it will lead to damage to the turbocharger and, for example, the blades of the compressor wheel may come into contact with the casing. The resulting fragments may even cause damage to the engine body.

(Object of the invention) The present invention has been made in consideration of the above circumstances, and
An object of the present invention is to provide a supercharging device for an engine that promptly detects an abnormality in the rotation of a supercharger and prevents damage to the supercharger itself.

(Structure of the Invention) The present invention has been made by focusing on the fact that when the rotation of a turbocharger becomes abnormal, abnormal vibration occurs, and the abnormal vibration of the turbocharger is detected by a vibration sensor. Detect and
When this abnormal vibration occurs, the load adjustment means that adjusts the load on the supercharger is controlled to reduce the load on the supercharger, for example by stopping the operation of the supercharger or reducing the supercharging pressure. It's Nishide.

(Example) In FIG. 1, 1 is an engine body, and this is caused by the reciprocating movement of a piston 3 provided in a cylinder 2, which causes a connecting rod 4 to
It is of a reciprocating type in which the crankshaft 5 is rotated via. An intake boat 7 and an exhaust port 8 are opened in the combustion chamber 6 defined in the cylinder 2 by the piston 3, and the intake boat 7 is opened by an intake valve 9, and the exhaust port 8 is opened by an exhaust valve 10, respectively. It is designed to open and close in synchronization with the rotation of the crankshaft 5.

In the intake passage 11 connected to the intake boat 7, an air cleaner 12 and an air flow meter 13 are installed in order from the upstream side.
, supercharger 14, throttle valve 15, fuel injection valve 16
is installed. The supercharger 14 is mechanically driven by the crankshaft 5, and in the embodiment is of a vane type, and includes a pulley 17 provided on the crankshaft 5, a timing belt 18, and an electromagnetic clutch 19 shown in FIG. is driven via an integrated pulley 20. Further, the intake passage 11 is provided with a bypass passage 21 that bypasses the supercharger 14, and its upper liquid end is located between the air flow meter 13 and the supercharger 14, and its downstream end is located between the supercharger 14 and the throttle valve 15,
It is connected to the intake passage 11. A switching valve 22 is provided in the bypass passage 21, and the opening of the switching valve 22 becomes smaller as the opening of the throttle valve 15 becomes larger.

Reference numeral 23 in FIG. 1 is a control unit, which receives a rotational speed signal SI from a rotational speed sensor 24 that detects the engine rotational speed, that is, the rotational speed of the crankshaft 5, and an intake pressure from an intake pressure sensor 25 that detects the intake pressure. Signal S2. In addition to inputting the intake air amount signal S3 from the air flow meter 13,
A vibration signal S4 from a vibration sensor 26 attached to the casing of the supercharger 14 is input. The control unit 23 outputs power to the fuel injection valve 16 and the electromagnetic clutch 19 which also functions as a load adjustment means. Of course, a signal corresponding to the fuel amount determined based on the rotational speed signal S1 and the intake pressure signal S2 is output to the fuel injection valve 16. Further, when the intake pressure becomes a high load of a predetermined value or more, the electromagnetic clutch 19
9 is output, and the vibration sensor 26
When the output from, that is, the vibration value, exceeds a predetermined value, a signal is output to disconnect the electromagnetic clutch 19 regardless of the opening degree of the throttle valve 15.

Here, among the controls by the control unit 23,
A specific circuit example of the control portion for the electromagnetic clutch 19 will be explained with reference to FIG. First, the electromagnetic clutch 19 is connected by the output from the AND circuit 29 when there are outputs from the two comparators 27 and 28. 7.28, the comparator 27 is used for the intake pressure, and the comparator 28 is used for the vibration sensor 26. That is, the comparator 27 receives the intake pressure signal S2 from the intake pressure sensor 25 and also receives the reference pressure signal S'2 from the reference pressure setting circuit 30, so that the intake pressure is lower than the reference intake pressure. When the load is large and high, the comparator 27 outputs the signal to the AND circuit 29.

On the other hand, the vibration signal S4 from the vibration sensor 26 is output to the comparator 28 after vibrations in a frequency band unrelated to the rotation of the supercharger 14 are removed by the filter circuit 31. Further, the rotation speed signal S1 representing the rotation speed of the crankshaft 5 from the rotation speed sensor 24 is sent to the slice level determination circuit 32.
The slice level determination circuit 32 determines the reference vibration value S' of the supercharger 14 according to the engine speed.
, (the boundary value that is the boundary between normal vibration and abnormal vibration,
In the embodiment, the reference vibration value S' is determined and outputted to the comparator 28. And comparator 28
In this case, the vibration value from the filter circuit 31 is output to the AND circuit 29 only when the vibration value from the filter circuit 31 is smaller than the reference vibration value S'4 determined by the slice level determination circuit 32.

Therefore, when there is no abnormality in the rotation of the supercharger 14, the electromagnetic clutch 19 is engaged and engaged depending on the magnitude of the intake pressure, that is, the engine load, and performs supercharging as appropriate.
When an abnormality occurs in the rotation of the supercharger 14, there is no output from the comparator 28, so the electromagnetic clutch 14 is disconnected regardless of the magnitude of the intake pressure, thereby keeping the supercharger 14 in a stopped state. It turns out. Note that when the rotation of the supercharger 14 is abnormal, the electromagnetic clutch 14 is kept connected and the opening degree of the switching valve 22 is increased (□ In other words, by reducing the supercharging pressure, the supercharging The load on the machine 14 may be reduced.

FIG. 3 and FIG. 4 show another embodiment of the present invention, and the same components as those in the previous embodiment are given the same reference numerals, and the explanation thereof will be omitted.

In this embodiment, the supercharger is a turbocharger type, and the turbine wheel of the turbocharger type supercharger 41 is in the exhaust passage 40 connected to the exhaust boat 8, and the compressor of the supercharger 41 is in the intake passage 11. A wheel is provided. A wastegate valve 43 functioning as a load adjustment means is provided in a bypass passage 42 that bypasses the turbine wheel, and this wastegate valve 43 is operated by an actuator 44. This actuator 44 has two pressure regulating chambers 47,48 defined by two diaphragms 45,46, and an opening of the bypass passage 42 at the tip of a rod 49 connected to the two diaphragms 45,46. A valve body 50 of the wastegate valve 43 to be adjusted is attached.

Of the two pressure regulating chambers 47 and 48, the pressure regulating chamber 47 is always communicated with the intake passage 11 downstream of the throttle valve 15, and can communicate with the atmosphere via the switching valve 51. Further, the other pressure regulating chamber 48 is always open to the atmosphere via a switching valve 51. Such an actuator 44 is normally operated by a return spring 52.5.
3, the waste gate valve 43
When the pressure in the pressure regulating chamber 47 increases due to the increased boost pressure, the diaphragm 45, 46 and therefore the valve body 50 are displaced upward, and the opening degree of the waste gate valve 43 is increased.

In this way, the opening degree of the waste gate valve 43 is adjusted according to the boost pressure.

The switching valve 51 described above is connected to the control unit 23.
When the vibration from the vibration sensor 26 attached to the casing of the supercharger 41 exceeds a predetermined value, the switching valve 51 is switched to open the pressure regulating chamber 47 to the atmosphere. As a result, the opening degree of the waste gate valve 43 is forcibly increased, that is, the supercharging pressure is kept low, and the load on the supercharger 41 is reduced.

FIG. 5 shows a specific circuit example of a portion of the control unit 23 that controls the switching valve 51, and when the switching valve 51 receives the output from the comparator 28, It should be opened to the atmosphere.

Although the embodiments have been described above, the present invention can be similarly applied to rotary piston engines. Furthermore, by reducing the load on the turbocharger, the driver senses a change in the operating state and becomes aware that an abnormality has occurred in the turbocharger. , it may be possible to clearly notify that an abnormality has occurred in the supercharger.

Note that fuel may be reduced as a means for reducing the load on the supercharger.

(Effects of the Invention) As is clear from the above description, the present invention reduces the load when an abnormality occurs in the rotation of the supercharger so that no undue burden is placed on the supercharger. This can prevent damage to the supercharger and, in turn, to the engine body.

[Brief explanation of the drawing]

FIG. 1 is an overall system diagram showing one embodiment of the present invention. FIG. 2 is a side view showing the supercharger used in FIG. 1. FIG. 3 is a circuit diagram showing an example of a control circuit for an electromagnetic clutch as a load adjustment means in the embodiment of FIG. 1. FIG. 4 is an overall system diagram showing another embodiment of the present invention. FIG. 5 is a circuit diagram showing an example of a control circuit for a waste gate valve as a load adjusting means in the embodiment shown in FIG. 4. l: Engine body 14: Supercharger 19: Electromagnetic clutch (load adjustment means) 23: Control unit (control means) 26: Vibration sensor 41: Supercharger 43: Waste gate valve (load adjustment means) 1st cause 3rd figure

Claims (1)

[Claims] (1) In an engine equipped with a supercharger, a vibration sensor that detects vibrations of the supercharger, a load adjustment means that adjusts the load of the supercharger, and a vibration sensor that receives the output from the vibration sensor, A supercharging device for an engine, comprising: control means for controlling the load adjusting means to reduce the load on the supercharger when vibrations of the charger exceed a predetermined value.