JP4533808B2 - Supercharging pressure control device for an internal combustion engine with a supercharger - Google Patents

Description

  The present invention relates to an apparatus for controlling a supercharging pressure in an internal combustion engine including a supercharger such as an exhaust turbocharger in a portion upstream of a throttle valve.

  In general, in an internal combustion engine having a turbocharger or other supercharger at the upstream side of the throttle valve, the supercharging pressure in the supercharger is reduced during deceleration after the throttle valve is suddenly closed. Will rise abnormally.

  Therefore, Patent Document 1 as a prior art discloses an air bypass valve comprising a valve body that is closed by a spring in a bypass passage that bypasses the supercharger and connects the downstream side and the upstream side thereof. And a valve body in the air bypass valve is connected to a diaphragm partitioned into a first pressure chamber and a second pressure chamber, and an intake pressure downstream from the throttle valve is connected to the first pressure chamber. When the pressure becomes low, the valve body is introduced so as to open, while in the path for introducing the intake pressure downstream of the throttle valve into the second pressure chamber, the second pressure chamber is delayed by delaying the reduction of the intake pressure. It has been proposed to provide a configuration in which a delay means is provided for transmission to the network.

According to this configuration, when the throttle valve is rapidly closed and decelerated, the intake pressure downstream of the throttle valve is immediately transmitted to the first pressure chamber, while being delayed by the delay means to the second pressure chamber. As a result, there is a pressure difference between the first pressure chamber and the second pressure chamber, in which the pressure in the second pressure chamber increases, and this pressure difference causes the valve body to move to the spring. Since the supercharged air on the downstream side of the supercharger can be released to the upstream side of the supercharger, the supercharging pressure can be prevented from rising abnormally during deceleration.
Japanese Utility Model Publication No.59-196523

  However, although the prior art can prevent the boost pressure from becoming abnormally high at the time of deceleration, as described below, the acceleration performance decreases when the throttle valve is opened from a certain opening degree. Besides, there is a problem that noise increases.

  That is, the intake pressure downstream of the throttle valve increases when the throttle valve is opened from a certain opening, and if the opened opening is continued for a while, the intake pressure becomes the rotational speed in the internal combustion engine. As it rises, it becomes lower.

  The reduction in the intake pressure is immediately transmitted to the first pressure chamber of the air bypass valve, while being delayed by the delay means and transmitted to the second pressure chamber, the first pressure chamber and the first pressure chamber. There is a pressure difference between the two pressure chambers, in which the pressure in the second pressure chamber increases, and when this pressure difference exceeds the pressure difference when the valve body of the air bypass valve opens, the spring is resisted. Then, the supercharging pressure is lowered and the boosting pressure is lowered, so that the acceleration performance thereafter decreases. In addition, in the above state, the valve body in the air bypass valve repeatedly opens and closes, so that the noise increases. To do.

  Furthermore, in recent internal combustion engines with a supercharger, in order to prevent the rotational speed from abnormally increasing due to the supercharging, control is performed so that the supercharging pressure in the supercharger is reduced when a certain rotational speed is exceeded. When the supercharging pressure in the supercharger is reduced by this control method, the pressure drop is immediately transmitted to the first pressure chamber in the air bypass valve as described above, while the first By transmitting to the two pressure chambers after being delayed by the delay means, a pressure difference in which the pressure in the second pressure chamber increases between the first pressure chamber and the second pressure chamber can be generated. Since the valve body in the bypass valve opens against the spring, not only the acceleration performance thereafter decreases, but also the noise increases as the valve body in the air bypass valve repeatedly opens and closes. .

  It is a technical object of the present invention to suppress the occurrence of such a problem.

In order to achieve this technical problem, the present invention as described in claim 1,
“In the bypass passage that bypasses the supercharger in the intake passage to the internal combustion engine and connects the downstream side and the upstream side thereof, an air bypass valve comprising a valve body that is held closed by a spring is provided, When the valve body in this air bypass valve is connected to a diaphragm partitioned into a first pressure chamber and a second pressure chamber, the intake pressure downstream of the throttle valve is reduced in the first pressure chamber, and the intake pressure is reduced. In the second pressure transmission passage for introducing the intake pressure downstream of the throttle valve into the second pressure chamber while introducing the valve body through the first pressure transmission passage so as to open against the spring, In the supercharging pressure control device for an internal combustion engine, provided with a delay means for delaying the lowering of the intake pressure and transmitting it to the second pressure chamber,
Of the first pressure transmission passage and the second pressure transmission passage, a passage opening / closing valve for both of these pressure transmission passages is provided at a portion upstream of the delay means, and the passage opening / closing valve is provided in the passage opening / closing valve. The pressure difference between the pressure on the downstream side and the pressure on the upstream side is configured to open when the pressure difference when the valve body in the air bypass valve opens is larger. "
It is characterized by that.

Further, claim 2 of the present invention is
“In the first aspect of the present invention, a throttle orifice is provided in parallel with the passage opening / closing valve, or a check valve is provided in parallel to be opened only in the direction toward the air bypass valve.”
It is characterized by that.

In the configuration described in claim 1, at the time of deceleration after the throttle valve is suddenly closed from a large opening to a small opening, the intake pressure downstream of the throttle valve is low so as to be a negative pressure lower than the atmospheric pressure. The lower intake pressure causes the passage opening / closing valve to open, so that it is immediately transmitted to the first pressure chamber in the air bypass valve via the first pressure transmission passage , There is a pressure difference that the pressure in the second pressure chamber is increased between the first pressure chamber and the second pressure chamber because the transmission is delayed by the delay means provided in the second pressure transmission passage. In addition, this pressure difference causes the valve body of the air bypass valve to open against the spring, so that it is possible to prevent the supercharging pressure from rising abnormally during deceleration.

  Next, at the time of acceleration when the throttle valve is further opened from a certain degree of opening, the intake pressure downstream of the throttle valve increases. If this opening degree is continued for a while, the intake pressure once decreases as the rotational speed of the internal combustion engine increases.

  In the prior art, since the intake pressure drop is transmitted to both pressure chambers in the air bypass valve, the air bypass valve may open and operate.

On the other hand, the present invention is provided with passage opening / closing valves for both the first pressure transmission passage and the second first pressure transmission passage, and only when the passage opening / closing valve is opened, the decrease in the intake pressure is reduced by the air pressure. The passage on-off valve is configured to transmit to both pressure chambers in the bypass valve, and the pressure difference between the pressure on the downstream side and the pressure on the upstream side is a value when the valve body in the air bypass valve opens. By being configured to open when the pressure difference becomes larger, the passage opening / closing valve is opened when the decrease in the intake pressure does not exceed the pressure difference when the passage opening / closing valve is opened. Therefore, even when the intake pressure once decreases as described above, the air bypass valve can be securely held in the closed state, and it is confirmed that the acceleration performance thereafter decreases. It is possible to prevent the noise in the air bypass valve can be reliably prevented from increasing.

  According to the configuration described in claim 2, during acceleration with the throttle valve opened, the increased intake pressure is transmitted through the throttle orifice or check valve provided in parallel to the passage opening / closing valve. Since it is transmitted to the second pressure chamber in the air bypass valve and the air bypass valve can be reliably held in the closed state, there is an advantage that the acceleration performance can be further improved.

  An embodiment of the present invention will be described below with reference to the drawing of FIG.

  In this figure, reference numeral 1 denotes an internal combustion engine.

  Reference numeral 2 denotes an exhaust turbocharger formed by directly connecting an exhaust turbine 2a and a blower compressor 2b. An exhaust manifold 1a of the internal combustion engine 1 is connected to an inlet of the exhaust turbocharger 2 of the exhaust turbocharger 2. An exhaust passage 3 to the atmosphere is connected to the outlet of the exhaust passage 3 from the exhaust turbine 2a.

  On the other hand, an air intake passage 6 from the air cleaner 5 is provided on the suction side of the blower compressor 2b of the exhaust turbocharger 2, and an intake passage 7 to the intake manifold 1b in the internal combustion engine 1 is provided on the discharge side. A throttle body 10 having a throttle valve 9 for controlling intake air is provided in the middle of the intake passage 7.

  Reference numeral 11 indicates a bypass passage that bypasses the blower compressor 2b and connects the upstream air cleaner 5 or the atmospheric intake passage 6 and the downstream intake passage 7 to the middle of the bypass passage 11. The air bypass valve 12 is provided.

  The air bypass valve 12 includes a valve body 12a and a diaphragm chamber 12b. The valve body 12a is connected to a diaphragm 12e that divides the inside of the diaphragm chamber 12b into a first pressure chamber 12c and a second pressure chamber 12d. The valve body 12a is held in a closed state by a spring 12f provided in the first pressure chamber 12c, and a second pressure chamber 12d is interposed between the first pressure chamber 12c and the second pressure chamber 12d. When a pressure difference is generated such that the internal pressure increases, the valve body 12a is configured to open against the spring 12f due to the pressure difference.

  In the air bypass valve 12, a first pressure transmission passage 13 is connected to the first pressure chamber 12c, and a second pressure transmission passage 14 is connected to the second pressure chamber 12d. Is provided with a delay means 15 for delaying the transmission of pressure to the second pressure chamber 12d.

  The delay means 15 has a configuration in which a throttle orifice 15a and an opening / closing valve 15b are provided in parallel, and the opening / closing valve 15b is biased by a spring 15c so as to be closed toward the upstream side of the delay means 15. When the pressure difference between the upstream side pressure and the downstream side pressure of the delay means 15 increases, and the pressure difference becomes a predetermined value, the pressure difference is increased. Thus, it is configured to open toward the downstream direction of the delay means 15 against the spring 15c. Further, the throttle orifice 15a may be provided with a check valve 15d that opens only in the upstream direction.

  The first pressure transmission passage 13 and the second pressure transmission passage 14 are joined to one main pressure transmission passage 16 to the intake manifold 1b on the upstream side of the delay means 15, and the main pressure transmission passage 16 A passage opening / closing valve 18 and a throttle orifice 19 are provided in parallel in a chamber 17 provided in the middle.

  The passage opening / closing valve 18 is urged by a spring 18a so as to be closed in the downstream direction of the passage opening / closing valve 18, and the upstream pressure P2 is subtracted from the downstream pressure P1 in the passage opening / closing valve 18. When the pressure difference ΔP is appropriately larger than the pressure difference ΔP0 when the valve body 12a of the air bypass valve 12 is opened, the pressure difference ΔP moves in the upstream direction against the spring 18a. Configured to open. Further, the throttle orifice 15a may be provided with a check valve 20 that opens only in the downstream direction.

  In this configuration, at the time of deceleration with the throttle valve 9 being suddenly closed from a large opening to a small opening, the intake pressure downstream of the throttle valve 9 is reduced to a negative pressure lower than the atmospheric pressure. The passage opening / closing valve 18 is opened against the spring 18a by the intake air pressure, so that it is immediately transmitted to the first pressure chamber 12C in the air bypass valve 12, while the delay means 15 in the second pressure chamber 12d. Since the transmission is delayed by the on-off valve 15b, there is a pressure difference between the first pressure chamber 12c and the second pressure chamber 12d such that the pressure in the second pressure chamber 12d increases, Due to this pressure difference, the valve body 12a of the air bypass valve 12 opens against the spring 12f, so that it is possible to prevent the supercharging pressure from rising abnormally during deceleration.

  Next, at the time of acceleration when the throttle valve 9 is further opened from a certain opening degree, the intake pressure downstream of the throttle valve 9 rises more than the above. If this opening degree is continued for a while, the intake pressure once decreases as the rotational speed of the internal combustion engine increases.

  When the reduction of the intake pressure does not exceed the pressure difference when the passage opening / closing valve 18 opens against the spring 18a, the passage opening / closing valve 18 does not open. Even when the intake pressure once decreases as described above, the intake pressure can be reliably maintained in the closed state.

  Further, the intake pressure downstream of the throttle valve 9 acts on the first pressure chamber 12c in the air bypass valve 12 through the throttle orifice 19 in parallel with the passage opening / closing valve 18, so that the air bypass is accelerated. It can suppress more reliably that the valve 12 opens.

  The passage opening / closing valve 18 may be configured to be opened and closed by pressure sensors provided before and after the passage opening / closing valve 18.

  The first pressure transmission passage 13 and the second pressure transmission passage 14 are separately connected to the intake manifold 1b and the like downstream from the throttle valve 9, and the passage opening / closing is connected to both the pressure transmission passages 13 and 14. Although the valve 18 and the throttle orifice 19 may be provided in parallel, the first pressure transmission passage 13 and the second pressure transmission passage 14 are connected to a single main pressure as in the above-described embodiment. By joining the transmission passage 16 and providing the main pressure transmission passage 16 with the passage opening / closing valve 18 and the throttle orifice 19 in parallel, it is possible to reduce the number of parts and the installation space. it can.

  Furthermore, the supercharger applied to the internal combustion engine 1 is not limited to the exhaust turbocharger 2, and it is not limited that a mechanical supercharger that is rotationally driven by the internal combustion engine 1 can be used.

  By the way, the pressure difference ΔP when the passage opening / closing valve 18 is opened may be appropriately increased by a value larger than the pressure difference ΔP0 when the valve body 12a in the air bypass valve 12 is opened. Since the opening operation of the air bypass valve 12 is delayed, the degree of making the pressure difference ΔP larger than the pressure difference ΔP0 should be kept to the extent that the opening operation of the air bypass valve 12 is not delayed. .

It is a figure which shows embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 1a Exhaust manifold 1b Intake manifold 2 Exhaust turbocharger 5 Air cleaner 7 Intake passage 11 Bypass passage 12 Air bypass valve 12a Valve body 12c First pressure chamber 12d Second pressure chamber 12f Spring 13 First pressure transmission passage 14 First 2 Pressure transmission passage 15 Delay means 16 Main pressure transmission passage 18 Passage opening / closing valve 19 Throttle orifice

Claims (2)

An air bypass valve comprising a valve body that is held closed by a spring is provided in a bypass passage that bypasses the turbocharger in the intake path to the internal combustion engine and connects the downstream side and the upstream side thereof. The valve body in the air bypass valve is connected to a diaphragm that is divided into a first pressure chamber and a second pressure chamber, and an intake pressure downstream of the throttle valve is connected to the first pressure chamber. The valve body is introduced through the first pressure transmission passage so as to open against the spring, while the second pressure transmission passage introduces the intake pressure downstream from the throttle valve into the second pressure chamber. In a supercharging pressure control device for an internal combustion engine, provided with a delay means for delaying the lowering of the intake pressure and transmitting it to the second pressure chamber,
Of the first pressure transmission passage and the second pressure transmission passage, a passage opening / closing valve for both of these pressure transmission passages is provided at a portion upstream of the delay means, and the passage opening / closing valve is provided in the passage opening / closing valve. An internal combustion engine with a supercharger configured to open when the pressure difference between the downstream pressure and the upstream pressure becomes larger than the pressure difference when the valve body of the air bypass valve opens. Supercharging pressure control device.   In the first aspect of the present invention, a throttle orifice is provided in parallel to the passage opening / closing valve, or a check valve that is opened only in the direction toward the air bypass valve is provided in parallel. A supercharging pressure control device for an internal combustion engine with a charger.

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