JP4613129B2 - Turbocharged engine - Google Patents

Description

  The present invention relates to an engine with a supercharger, and more particularly to an engine with a supercharger that can reduce engine manufacturing cost and suppress the occurrence of smoke during a rapid acceleration operation.

As in the present invention, as in the present invention, a turbocharger is connected to the exhaust passage so that the intake passage is supercharged with the energy of the exhaust gas passing through the exhaust passage, and EGR gas is supplied from the exhaust passage to the intake passage. There is an EGR gas passage to be introduced, an EGR valve provided in the EGR gas passage, and the EGR valve opened and closed by a valve actuator.
In this type of engine, it is possible to increase the output by supercharging, refluxed for EGR gas (exhaust) into the intake, by lowering the maximum combustion temperature in the combustion chamber, to reduce the generation amount of the NO _X There is an advantage that can be.

  However, in the above conventional engine, there is a problem because an electric actuator is used as the valve actuator of the EGR valve, and this electric actuator is linked to the engine speed sensor and the load sensor via the control means. In this engine, the EGR valve is controlled based on the engine speed and the load, but there is a problem because the EGR valve is not controlled based on the supercharging pressure.

The above prior art has the following problems.
<Problem> Engine manufacturing cost is high.
Since an electric actuator is used as a valve actuator of the EGR valve and this electric actuator is linked to an engine speed sensor and a load sensor via a control means, a large number of electronic components are required for EGR valve control. In addition, since the electric actuator is vulnerable to heat, it is necessary to use a highly accurate gas seal for the EGR valve. For this reason, parts cost becomes high and engine manufacturing cost is high.

<Problem> Smoke is likely to occur during sudden acceleration operations.
Since the control of the EGR valve based on the supercharging pressure is not performed, when the rapid acceleration operation is performed from the idling operation, the fuel is increased and the EGR valve is opened while the supercharging pressure is not sufficiently increased. Sometimes. In such a case, smoke is likely to occur due to insufficient intake.

  The present invention is an engine with a supercharger that can solve the above-described problems, that is, an engine with a supercharger that can reduce the engine manufacturing cost and suppress the occurrence of smoke during a rapid acceleration operation. It is an issue to provide.

Invention specific matters of the invention according to claim 1 are as follows.
As illustrated in FIG. 2, the supercharger (2) is connected to the exhaust passage (1), and the intake passage (3) is supercharged with the energy of the exhaust gas passing through the exhaust passage (1). The EGR gas passage (4) for introducing EGR gas from the exhaust passage (1) to the intake passage (3) is provided, the EGR valve (5) is provided in the EGR gas passage (4), and the EGR valve (5) is provided. In a turbocharged engine that is opened and closed by a valve actuator (6),
As illustrated in FIG. 1 or FIG. 4, a supercharging pressure actuator (7) is used as the valve actuator (6) of the EGR valve (5), and the intake passage (3) is connected to the supercharging pressure introduction passage (8). The supercharging pressure chamber (9) of the supercharging pressure actuator (7) is communicated, and the pressure receiving body (10) is exposed to the supercharging pressure chamber (9), and the supercharging introduced into the supercharging pressure chamber (9). The pressure receiving body (10) is actuated by the pressure (11), the EGR valve (5) is linked to the pressure receiving body (10), and the EGR valve (5) is opened by the operation of the pressure receiving body (10). The EGR valve (5) is provided with a valve closing biasing means (12), and the valve closing biasing force (13) of the valve closing biasing means (12) provides an EGR valve ( 5) can be urged in the valve closing direction,
When the supercharging pressure (11) introduced into the supercharging pressure chamber (9) is less than a predetermined value, the EGR valve (5) is controlled by the valve closing biasing force (13) of the valve closing biasing means (12). When the valve closing state is maintained and the supercharging pressure (11) introduced into the supercharging pressure chamber (9) exceeds a predetermined value, EGR is performed with the supercharging pressure (11) introduced into the supercharging pressure chamber (9). When the rapid acceleration operation is performed from the idle operation with the valve (5) opened , the EGR valve (5) can be kept closed while the supercharging pressure (11) does not rise. And
A temperature sensitive operation passage shut-off valve (14) is provided in the supercharging pressure introduction passage (8) so that heat generated by the engine is transmitted to the heat input portion (15) of the passage shut-off valve (14). When the heat input temperature of (15) exceeds a predetermined value, the passage shut-off valve (14) is opened so that the supercharging pressure (11) can be introduced into the supercharging pressure chamber (9). When the heat input temperature of (15) is less than a predetermined value, the passage shutoff valve (14) is closed so that the supercharging pressure (11) is not introduced into the supercharging pressure chamber (9). An engine with a supercharger, characterized in that the closed state of the valve (5) is maintained.

(Invention according to Claim 1)
<< Effect >> Engine manufacturing costs can be reduced.
As illustrated in FIG. 1 or FIG. 4, a supercharging pressure actuator (7) is used as the valve actuator (6) of the EGR valve (5), and the intake passage (3) is connected to the supercharging pressure introduction passage (8). The supercharging pressure chamber (9) of the supercharging pressure actuator (7) is communicated, and the pressure receiving body (10) is exposed to the supercharging pressure chamber (9), and the supercharging introduced into the supercharging pressure chamber (9). The pressure receiving body (10) is actuated by the pressure (11), the EGR valve (5) is linked to the pressure receiving body (10), and the EGR valve (5) is opened by the operation of the pressure receiving body (10). The EGR valve (5) is provided with a valve closing biasing means (12), and the valve closing biasing force (13) of the valve closing biasing means (12) provides an EGR valve ( Since 5) can be urged in the valve closing direction, no electronic component is required for valve control of the EGR valve (5). Further, since the supercharging pressure actuator (7) has higher heat resistance than the electric actuator, it is not necessary to use a highly accurate gas seal (39) for the EGR valve (5). For this reason, parts cost becomes low and engine manufacturing cost can be reduced.

<Effect> Smoke generation at the time of rapid acceleration operation can be suppressed.
As illustrated in FIG. 1 or FIG. 4, when the supercharging pressure (11) introduced into the supercharging pressure chamber (9) is less than a predetermined value, the valve closing urging means (12) When the EGR valve (5) is kept closed by the force (13) and the supercharging pressure (11) introduced into the supercharging pressure chamber (9) exceeds a predetermined value, the supercharging pressure chamber (9) and EGR valve the introduced supercharging pressure (11) (5) so as to open, if the rapid accelerating operation was performed from the idle operation, while the boost pressure (11) does not increase, the EGR valve ( 5) to be able to maintain closed the. For this reason, it is possible to suppress the occurrence of smoke during the rapid acceleration operation due to insufficient intake.

<Effect> It is possible to suppress the generation of blue and white smoke during start-up and warm-up operation.
As illustrated in FIG. 1 or FIG. 4, a temperature-sensitive actuating passage shut-off valve (14) is provided in the supercharging pressure introduction passage (8), and the heat generation of the engine is caused by the heat input portion (15 When the heat input temperature of the heat input section (15) is lower than a predetermined value, the passage shut-off valve (14) is closed and the supercharging pressure (11) is supercharged pressure chamber. Since the closed state of the EGR valve (5) is maintained without being introduced in (9), the closed state of the EGR valve (5) is maintained during start-up and warm-up operation. For this reason, the malfunction which combustibility falls by EGR gas (34) at the time of start-up and warm-up operation can be prevented, and generation | occurrence | production of blue and white smoke can be suppressed.

(Invention of Claim 2)
<< Effect >> A supercharging pressure actuator having a small output can be used, and the reduction rate of the EGR gas can be accurately adjusted.
As illustrated in FIG. 4, since the EGR valve (5) is constituted by the butterfly valve (16), the resistance at the time of valve opening is small compared to the case where the EGR valve (5) is constituted by a poppet valve, and the supercharging pressure actuator (7) is small. The output one can be used. Further, since the butterfly valve (16) has the valve shaft (16a) supported at two locations, there is little backlash and the reduction rate of the EGR gas (34) can be adjusted accurately.

Embodiments of the present invention will be described with reference to the drawings. 1 to 3 show the first embodiment, and FIGS. 4 and 5 show the second embodiment.
The configuration of the supercharged engine according to the first embodiment is as follows.
As shown in FIG. 3, the cylinder head (18) is assembled to the upper part of the cylinder block (17), and the head cover (19) is assembled to the upper part of the cylinder head (18). A gear case (20) and a cooling water pump (21) are assembled to the front part of the cylinder block (1), and a fuel injection pump (22) is assembled to the rear part of the gear case (20). A cooling fan (24) is attached to the pump shaft (23) of the cooling water pump (21), and the pump shaft (23) and the cooling fan (24) are driven by the crankshaft (26) via the fan belt (25). ing. As shown in FIG. 2, an intake manifold (27) serving as an intake passage (3) is attached to one side of the cylinder head (19), and an exhaust serving as an exhaust passage (1) is provided on the other side of the cylinder head (19). A manifold (28) is attached.

  As shown in FIG. 2, the supercharger (2) is connected to the exhaust passage (1), and the intake passage (3) is supercharged with the energy of the exhaust gas passing through the exhaust passage (1). An EGR gas passage (4) for introducing EGR gas (exhaust gas) from the exhaust passage (1) to the intake passage (3) is provided, an EGR valve (5) is provided in the EGR gas passage (4), and the EGR valve (5 ) Is opened and closed by a valve actuator (6). The supercharging to the intake passage (3) is performed from the supercharger (2) through the supercharging passage (2a). The EGR valve (5) is accommodated in the EGR valve case (29). The EGR valve case (29) is disposed at the end of the EGR gas passage (4). The valve actuator (6) is attached to the EGR valve case (29).

The drive mechanism of the EGR valve is as follows.
As shown in FIG. 1, a supercharging pressure actuator (7) is used as a valve actuator (6) of an EGR valve (5), and a supercharging pressure actuator is connected to an intake passage (3) via a supercharging pressure introduction passage (8). The supercharging pressure chamber (9) of (7) is made to communicate, the pressure receiving operating body (10) is brought into contact with the supercharging pressure chamber (9), and the supercharging pressure (11) introduced into the supercharging pressure chamber (9) is introduced. The pressure receiving actuating body (10) is actuated, and the pressure receiving actuating body (10) is linked to the EGR valve (5), and the pressure receiving actuating body (10) is actuated to drive the EGR valve (5) in the valve opening direction. In addition, the EGR valve (5) is provided with a valve closing biasing means (12), and the valve closing biasing force (13) of the valve closing biasing means (12) closes the EGR valve (5). The valve can be urged in the direction of the valve. The EGR valve (5) is a pohet valve (30), the pressure receiving actuator (10) is a diaphragm (31), and the valve closing biasing means (12) is a push spring (32). The code | symbol (34) in FIG. 1 has shown EGR gas. The periphery of the valve shaft of the poppet valve (30) is sealed with a gas seal (39).

The operation of the EGR valve is as follows.
As shown in FIG. 1, when the supercharging pressure (11) introduced into the supercharging pressure chamber (9) is less than a predetermined value, the valve closing biasing force (13) of the valve closing biasing means (12). When the EGR valve (5) is kept closed and the supercharging pressure (11) introduced into the supercharging pressure chamber (9) exceeds a predetermined value, the supercharging pressure introduced into the supercharging pressure chamber (9) is increased. When the EGR valve (5) is opened by the supply pressure (11) and the sudden acceleration operation is performed from the idle operation, the boost pressure (11) is not sufficiently increased even if the fuel is increased. Is configured to keep the EGR valve (5) closed.

Other ideas are as follows.
As shown in FIG. 1, a temperature-sensitive actuating passage shut-off valve (14) is provided in the supercharging pressure introduction passage (8), and the heat generated by the engine is transmitted to the heat input section (15) of the passage shut-off valve (14). When the heat input temperature of the heat input section (15) exceeds a predetermined value, the passage shutoff valve (14) is opened and the supercharging pressure (11) is introduced into the supercharging pressure chamber (9). When the heat input temperature of the heat input section (15) is lower than a predetermined value, the passage shut-off valve (14) is closed and the supercharging pressure (11) is transferred to the supercharging pressure chamber (9). It is not introduced and the closed state of the EGR valve (5) is maintained. The passage shut-off valve (14) includes a valve mechanism that opens and closes with a bimetal, the heat input portion (15) faces the cylinder jacket (35), and the heat of the cooling water in the cylinder jacket (35) is applied to the heat input portion (15 ) Is heat input. The heat input portion (15) of the passage shut-off valve (14) is not limited to the heat of the cooling water as long as the heat generated by the engine can be transmitted. The heat of the engine oil, the heat of the engine machine wall, the radiator The heat of the cooling exhaust air may be input.

The second embodiment differs from the first embodiment in the following points.
As shown in FIG. 4, the EGR valve (5) is constituted by a butterfly valve (16). The valve shaft (16a) is supported at two locations. The valve closing urging means (11) is constituted by a torsion spring (32). A stopper (33) is provided in the valve case (29), and the butterfly valve (16) biased by the torsion spring (32) is received by the stopper (33), thereby maintaining the closed state of the butterfly valve (16). . A supercharging pressure actuator (7) is attached to the valve case (29) via a fitting (36). The tip of the output shaft (37) of the supercharging pressure actuator (7) is brought into contact with the input arm (38) of the butterfly valve (16). Other configurations and functions are the same as those of the first embodiment, and in FIGS. 4 and 5, the same elements as those of the first embodiment are denoted by the same reference numerals.

It is a longitudinal cross-sectional view of the supercharging pressure actuator of the engine with a supercharger which concerns on 1st Embodiment of this invention, and its peripheral part. The top view of the engine with a supercharger concerning a 1st embodiment of the present invention is shown. The front view of the engine with a supercharger which is 1st Embodiment of this invention is shown. It is a longitudinal cross-sectional view of the supercharging pressure actuator of the engine with a supercharger which concerns on 2nd Embodiment of this invention, and its peripheral part. 5A is a partial cross-sectional view of the engine of FIG. 4 as viewed from the direction of arrow A, and FIG. 5B is a cross-sectional view taken along line BB of FIG.

(1) Exhaust passage
(2) Turbocharger
(3) Intake passage
(4) EGR gas passage
(5) EGR valve
(6) Valve actuator
(7) Supercharging pressure actuator
(8) Supercharging pressure introduction passage
(9) Supercharging pressure chamber
(10) Pressure receiver
(11) Supercharging pressure
(12) Energizing means for closing the valve
(13) Valve closing force
(14) Passage shut-off valve
(15) Heat input section
(16) Butterfly valve

Claims (2)

The supercharger (2) is connected to the exhaust passage (1), and the intake passage (3) is supercharged with the energy of the exhaust gas passing through the exhaust passage (1), and the intake air is taken from the exhaust passage (1). An EGR gas passage (4) for introducing EGR gas is provided in the passage (3), an EGR valve (5) is provided in the EGR gas passage (4), and the EGR valve (5) is opened and closed by a valve actuator (6). In such a turbocharged engine,
The supercharging pressure actuator (7) is used as the valve actuator (6) of the EGR valve (5), and the supercharging pressure of the supercharging pressure actuator (7) is connected to the intake passage (3) via the supercharging pressure introduction passage (8). The chamber (9) is communicated, and the pressure receiving operating body (10) is exposed to the supercharging pressure chamber (9), and the pressure receiving operating body (10) is supplied by the supercharging pressure (11) introduced into the supercharging pressure chamber (9). And the EGR valve (5) is linked to the pressure receiving body (10) so that the EGR valve (5) can be driven in the valve opening direction by the operation of the pressure receiving body (10). The EGR valve (5) is provided with a valve closing biasing means (12), and the valve closing biasing force (13) of the valve closing biasing means (12) biases the EGR valve (5) in the valve closing direction. To be able to
When the supercharging pressure (11) introduced into the supercharging pressure chamber (9) is less than a predetermined value, the EGR valve (5) is controlled by the valve closing biasing force (13) of the valve closing biasing means (12). When the valve closing state is maintained and the supercharging pressure (11) introduced into the supercharging pressure chamber (9) exceeds a predetermined value, EGR is performed with the supercharging pressure (11) introduced into the supercharging pressure chamber (9). When the rapid acceleration operation is performed from the idle operation with the valve (5) opened , the EGR valve (5) can be kept closed while the supercharging pressure (11) does not rise. And
A temperature sensitive operation passage shut-off valve (14) is provided in the supercharging pressure introduction passage (8) so that heat generated by the engine is transmitted to the heat input portion (15) of the passage shut-off valve (14). When the heat input temperature of (15) exceeds a predetermined value, the passage shut-off valve (14) is opened so that the supercharging pressure (11) can be introduced into the supercharging pressure chamber (9). When the heat input temperature of (15) is less than a predetermined value, the passage shutoff valve (14) is closed and the supercharging pressure (11) is not introduced into the supercharging pressure chamber (9), and the EGR valve ( An engine with a supercharger, characterized in that the closed state of 5) is maintained. The engine with a supercharger according to claim 1,
An engine with a supercharger, wherein the EGR valve (5) is constituted by a butterfly valve (16).

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