JPS6131623A - Engine equipped with turbo-supercharger - Google Patents

Abstract

PURPOSE:To prevent knocking by suppressing the increase of the charging efficiency when the outside air temperature is low, by opening a control valve for opening and closing an exhaust passage at the less number of engine revolution than a set value of a control means when intake-air temperature is lower than a set value. CONSTITUTION:The air feeding blower 11 of a turbo-supercharger 10 is arranged into a suction passage 8, and inside the turbine casing 16 in an exhaust passage 9, an exhaust turbine 17 for driving the air feeding blower 11 is arranged. In one eddy-current exhaust passage 9b divided by a separator 19 in the exhaust passage 9, a control valve 20 for opening and closing the exhaust passage 9b is installed. In this case, the signal supplied from an intake temperature sensor 25 is input into a control-wire selecting circuit 4, and when the intake temperature is lower than a set value, a step motor 21 is controlled by a control circuit 23 through an operating circuit 22 so that the control valve 20 is opened with the number of engine revolution less than the set value, in reference to each signal supplied from an engine revolution speed sensor 26 and a throttle opening- degree sensor 27.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a turbocharged engine.

(Prior art) As this type of engine, for example, Japanese Patent Application Laid-Open No. 58-796
The one disclosed in Publication No. 22 is known. The supercharged engine disclosed in this patent publication includes an exhaust turbine housed in a turbine casing, two parallel swirl exhaust passages connected to an exhaust intake port of the turbine casing, and one of these exhaust passages. A control valve that opens and closes the exhaust passage, and a control device that opens the control valve when the engine speed exceeds a set value, and the supply is supplied through the open exhaust passage. The turbine rotates the intake air blower to supercharge the intake air.

This supercharged engine has the advantage that a sufficient supercharging effect can be obtained over a wide operating range from the low speed range to the high speed range of the engine due to the action of the control valve. Since it is not a control parameter,
When the outside temperature is low, such as in a cold region or during the winter, charging efficiency increases and there is a risk that knocking may occur.

(Objective of the Invention) Therefore, an object of the present invention is to provide a turbocharged engine that can prevent the occurrence of non-king even when the outside temperature is low.

(Structure of the Invention) The present invention provides an exhaust turbine housed in a turbine casing, a plurality of parallel vortex exhaust passages connected to an exhaust intake port of the turbine casing, and an exhaust gas in any one of the plurality of exhaust passages. Exhaust gas supplied through the open exhaust passage, comprising a control valve provided in the passage and for opening and closing the exhaust passage, and a control means for opening the control valve at least when the engine speed reaches a set value or more. In a turbocharged engine configured to supercharge intake air by rotating an intake blower by the turbine driven by gas, an intake air temperature detection means for detecting an intake air temperature; The present invention is characterized in that a correction means is provided for correcting the control valve so that when the intake air temperature is lower than the set value, the engine rotation speed in the control means is lower than the set value.

(Effects of the Invention) In the turbocharged engine according to the present invention configured as described above, when the intake air temperature is lower than a predetermined value, regardless of the control by the control means, the engine rotation speed is lower than the set value of the control means. Since the control valve is opened at this time, the filling efficiency does not increase abnormally even when the outside temperature is low, and therefore, non-king can be prevented.

(Embodiment) Hereinafter, a turbocharged engine according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an overall configuration diagram of a turbocharged engine according to an embodiment of the present invention.

The engine E includes a cylinder 1, within which a piston 2 is slidably disposed.

A combustion chamber 3 is formed above the piston 2 within the cylinder 1 . An intake hole 4 and an exhaust hole 5 are open in the combustion chamber 3, and the intake hole 4 is provided with an intake valve 6, and the exhaust hole 5 is provided with an exhaust valve 7, respectively. An intake passage 8 is also connected to the intake hole 4, and an exhaust passage 9 is connected to the exhaust hole 5.

In the middle of the intake passage 8, there is a turbo supercharger*i.

A supply air blower 11 is arranged, a slot valve 12 and a surge tank 13 are arranged downstream thereof, and an air flow meter 14 and an air cleaner 15 are arranged upstream.

On the other hand, a turbine casing 16 is arranged in the upstream exhaust passage 9, and inside this turbine casing 16,
An exhaust turbine 17 of the turbocharger 10 that drives the air supply blower 11 is provided. An exhaust intake port 8 is formed in a part of the turbine casing 16,
First and second vortex exhaust passage sections 9a and 9b, which are formed by longitudinally dividing the inside of the exhaust passage 9 near the turbine casing 16 by a separate rake 19, are connected to the exhaust intake port 18. ing.

The second vortex exhaust passage section 9b is provided with a control valve 20 that opens and closes this passage section 9b. As shown in FIG. 2, the opening and closing of the control valve 20 is controlled by a step motor 21, which is connected to an operating circuit 22. This operating circuit 22 is connected to a control circuit 23 that controls the operation of this operating circuit 22, and a control line selection circuit 24 is connected to this control circuit 23.

The control line selection circuit 24 is connected to an intake air temperature sensor 25 that detects the intake air temperature T and outputs eight intake air temperature signals. This control line selection circuit 24 determines that the intake temperature T is the set temperature To.
For example, there is a main control line LM used during normal operation at temperatures above 10°C, and a main control line LM which is placed on the low engine speed and low throttle opening side of this control line LM and is used during cold operation when the intake temperature T is below the set temperature To. The control valve control map (see Fig. 3) with the auxiliary control edge L^ to be used is memorized;
When T>To, the control line LM is output to the control circuit 23, and when T≦To, the auxiliary control edge L^ is output to the control circuit 23.

In the above map, the horizontal axis represents the engine speed, and the vertical axis represents the throttle opening.
3 includes an engine rotation speed sensor 26 that detects the engine rotation speed and generates an engine rotation speed signal 5Et, and a throttle that detects the opening degree of the throttle valve 12 and outputs a throttle opening signal Ss indicating the opening degree. An opening sensor 27 is connected. The control circuit 23 receives the signals S E % S s from these sensors 26 and 27 , applies these signals to the control line LM or L^, and controls the step motor via the operating circuit 22 . 21 to open and close the control valve 20.

In addition, 30 shown in Fig. 2 is a cooling water passage, which guides the cooling water cooled by a radiator (not shown) or the cooling water that has circulated inside the engine, so that the step motor is not affected by heat damage caused by exhaust gas. This is what I did.

(Operation) The operation of the supercharged engine will be explained below with reference to FIG.

First, the engine speed N and the throttle opening (■) are measured, and then the outside temperature T is measured.

It is determined whether the measured outside temperature T is higher than the set value To. When this determination is YES, that is, when T>To, read the main control line LM and determine whether the coordinates (N, V) based on N and V measured above are to the right of this main control line LM. do.

When this determination is YES, the control valve 20 is opened, and when the determination is NO, the control valve 20 is closed.

From the above, especially when the engine speed N is small,
Since the amount of exhaust gas is small, the passage area of the passage that supplies exhaust gas to the exhaust turbine 17 is reduced to increase the flow velocity of the exhaust gas, thereby increasing the rotation of the turbine 17 and ensuring sufficient supercharging. ing.

On the other hand, when the above-mentioned judgment "T>TO" is NO, the auxiliary control line L^ is read, and the same judgment as above is made based on this control line, and the opening/closing of the control valve 20 is controlled. Let's do it. In this way, in cold weather, the opening and closing of the control valve 20 is controlled using the auxiliary control edge L^ described above, so the control valve 20 opens at a relatively low engine speed and a low throttle opening. , the filling efficiency is increased too much and no 7-king occurs.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of a turbocharged engine according to an embodiment of the present invention, Fig. 2 is an enlarged view of the main parts of the turbocharger shown in Fig. 1, and Fig. 3 is a control diagram. FIG. 4 is a graph showing a control map used to control the opening and closing of the valve. FIG. 4 is a flowchart showing the above control. E, -0-Engine, 9a, 9b... Vortex exhaust passage section, 1o... Turbo supercharger, 11...
...Air supply blower, 16...Turbine casing, 17...Exhaust turbine, 18...
Exhaust intake, 2o...Control valve, 22...
- Operating circuit, 23... Control circuit, 24---
0-control line selection circuit, 25...intake temperature sensor,
26...Engine speed sensor. Figure 2

Claims (1)

[Claims] an exhaust turbine housed in a turbine casing; a plurality of parallel vortex exhaust passages connected to the exhaust intake of the turbine casing; A control valve that opens and closes, and a control means that opens the control valve at least when the engine speed exceeds a set value, and is powered by the turbine driven by exhaust gas supplied through an open exhaust passage. Rotate the air blower,
In a turbocharged engine that supercharges intake air, an intake temperature detection means for detecting an intake air temperature, and when the intake air temperature detected by the detection means is lower than a set value, the set value in the control means is set. A turbocharged engine characterized by comprising: a correction means for correcting the control valve to open at a lower engine speed.