Mazda Motor Corporation

Seiji Tashima

Haruo Okimoto

Toshimichi Akagi

Masanori Shibata

Ikuo Matsuda

Yasushi Niwa

Ikuo Onimura

Masaru Yamamoto

Tomoo Tadokoro

Masami Nakao

Einosuke Suekuni

Ritsuharu Shimizu

Kaoru Yamada

Masashi Ohmori

Akihrio Nakamoto

Naoyuki Koyama

Naoyuki Matsumoto

Takayoshi Hashimoto

Akihiro Nakamoto

An engine is provided with a primary turbocharger and a secondary turbocharger having blowers disposed in the intake passage of the engine in parallel to each other and turbines disposed in the exhaust passage of the engine in parallel to each other. An exhaust cutoff valve disposed in the exhaust passage opens to feed exhaust gas to the turbine of the secondary turbocharger to operate the secondary turbocharger only in a large intake air mass range. A waste gate valve opens to relieve exhaust gas fed to the turbochargers when the supercharging pressure exceeds a predetermined value. The waste gate valve is kept closed for a predetermined time after the operating condition of the engine shifts into the large intake air mass range and the exhaust cutoff valve opens when shift of the operating condition of the engine from a small intake air mass range to the large intake air mass range is required.

Exhaust control system for engine with turbochargers

An engine is provided with primary and secondary turbochargers. In a small intake air mass range, only the primary turbocharger is caused to operate, and in a large intake air mass range, both the primary and secondary turbochargers are caused to operate. A waste gate valve and an exhaust bypass valve are controlled so that the supercharging pressure approximates to a target supercharging pressure. The target supercharging pressure in the large intake air mass range is set lower than that in the small intake air mass range.

Supercharging pressure control system for engine with turbochargers

An air and fuel supply control system for an internal combustion engine comprises a plurality of superchargers including a turbosupercharger, an intake air cutoff valve operative selectively to be open and closed respectively for opening and closing one of separated intake passages in which a compressor of the turbosupercharger is disposed, an intake air relief valve operative selectively to be open and closed respectively for opening and closing a relief passage provided for detouring the compressor of the second supercharger, a cutoff valve controller operative to control the intake air cutoff valve to be closed so that the turbosupercharger is restrained from supercharging the engine and to be open so that the turbosupercharger works for supercharging the engine, a relief valve controller operative to control the intake air relief valve to be closed before the intake air cutoff valve is opened and to be open after the intake air cutoff valve is closed, an air flow sensor for detecting intake air mass flow passing through an intake passage from which the separated intake passages are branched, a fuel supply controller operative to control quantity of fuel supplied to the engine in accordance with a detection output obtained from the air flow sensor, and a fuel supply revising device operative to revise the quantity of fuel supplied to the engine when the intake air relief valve is caused to be open and closed selectively.

Air and fuel supply control systems for internal combustion engines

An air and fuel supply control system for an internal combustion engine comprises a plurality of superchargers including a turbosupercharger, an intake air cutoff valve operative selectively to be open and closed respectively for opening and closing one of separated intake passages in which a compressor of the turbosupercharger is disposed, a cutoff valve controller operative to control the intake air cutoff valve to be closed so that the turbosupercharger is restrained from supercharging the engine when intake air mass flow fed to the engine is to be relatively small and to control the intake air cutoff valve to be open so that the turbosupercharger works for supercharging the engine when the intake air mass flow fed to the engine is to be relatively large, and air flow sensor for detecting intake air mass flow passing through an intake passage from which the separated intake passages are branched, a fuel supply controller operative to control quantity of fuel supplied to the engine in accordance with a detection output obtained from the air flow sensor, and a fuel supply revising device operative to revise the quantity of fuel supplied to the engine when the intake air cutoff valve is caused to be open and closed selectively.

An air supply control system for an internal combustion engine comprises first and second turbosuperchargers, an exhaust cutoff valve operative to open and close one of separated exhaust passages in which a turbine of the second turbosupercharger is disposed, a first valve driving device for controlling the exhaust cutoff valve so that only the first turbosupercharger works when intake air mass flow fed to the engine is to be relatively small and both of the first and second turbosuperchargers work when the intake air mass flow is to be relatively large, an exhaust bypass valve operative to open and close an exhaust bypass passage provided for forming a partial exhaust passage detouring the exhaust cutoff valve, a second valve driving device for causing the exhaust bypass valve to open the exhaust bypass passage when intake air pressure applied to the engine reaches a predetermined value under a condition in which the intake air mass flow is to be relatively small, a waste gate valve operative to open and close a bypass passage provided for forming a partial exhaust passage detouring the turbines of the first and second turbosuperchargers, and a third valve driving device for causing the waste gate valve to open the bypass passage when the pressure of intake air reaches substantially the predetermined value under a condition in which the intake air mass flow is to be relatively large.

Air supply control systems for internal combustion engines

An air supply control system for an internal combustion engine comprises a supercharging device operative to perform selectively a first supercharging operation by which supercharging efficiently under a first condition wherein the engine operates with relatively small intake air flow is improved and a second supercharging operation by which supercharging efficiency under a second condition wherein the engine operates with relatively large intake air flow is improved, an operation detector for detecting engine operations, a traveling condition detector for detecting traveling conditions to a vehicle equipped with the engine, a supercharging operation controller operative to cause the supercharging device to perform the first supercharging operation when a first engine operation attended with relatively small intake air flow is detected by the operation detector and to perform the second supercharging operation when a second engine operation attended with relatively large intake air flow is detected by the operation detector, and an operating area changer operative to vary, in accordance with traveling conditions detected by the traveling condition detector, a boundary between first and second operating areas provided on an operating characteristic chart of the engine for defining the first and second engine operations, respectively.

Air supply control systems for turbocharged internal combustion engines

An air supply control system for an internal combustion engine includes a plurality of superchargers including a turbosupercharger, an exhaust cutoff valve operative selectively to open and close an exhaust passage in which a turbine of the turbosupercharger is disposed, and an intake air cutoff valve operative selectively to open and close an intake passage in which a blower of the turbosupercharger is disposed, wherein both the exhaust cutoff valve and the intake air cutoff valve are closed when intake air mass flow fed to the engine is to be relatively small and are open when the intake air mass flow is to be relatively large, the intake air cutoff valve is delayed to be open compared with the exhaust cutoff valve when the operating condition of the engine is changed into the situation in which the intake air mass flow is to be relatively large from the situation in which the intake air mass flow is to be relatively small, and the intake air cutoff valve is delayed to be closed compared with the exhaust cutoff valve when the operating condition of the engine is changed into the situation in which the intake air mass flow is to be relatively small from the situation in which the intake air mass flow is to be relatively large.

An air supply control system for an internal combustion engine comprises a plurality of superchargers including a turbosupercharger, an exhaust cutoff valve operative selectively to open and close an exhaust passage in which a turbine of the turbosupercharger is disposed, an intake air cutoff valve operative selectively to open and close an intake passage in which a blower of the turbosupercharger is disposed, an intake air relief valve operative selectively to open and close a relief passage provided for detouring the blower of the turbosupercharger, an engine operation detector for detecting operating conditions of the engine, a cutoff valve controller operative, in response to the detection output from the engine operation detector, to cause both the exhaust cutoff valve and the intake air cutoff valve to be closed when intake air mass flow fed to the engine is to be relatively small and to cause both the exhaust cutoff valve and the intake air cutoff valve to be open when the intake air mass flow fed to the engine is to be relatively large, and a relief valve controller operative, in response to the detection output from the engine operation detector, to cause the intake air relief valve to be closed at a time point earlier than another time point at which the exhaust cutoff valve is fully opened.

An air supply and exhaust control system for an internal combustion engine comprises at least first and second turbosuperchargers, an operation prohibiting portion for prohibiting the second turbosupercharger from working as occasion demands, an exhaust gas flow detecting portion, an air supply control portion for causing the operation prohibiting portion to prohibit the second turbosupercharger from working when a detection output from the exhaust gas flow detecting portion indicates that the exhaust gas flow is less than a first predetermined value, an exhaust gas discharging device connected to an exhaust passage in possession of variable exhaust resistance for discharging the exhaust gas, an exhaust resistance changing portion for changing the variable exhaust resistance, and an exhaust control portion for controlling the exhaust resistance changing portion to set the variable exhaust resistance to be relatively small when the detection output from the exhaust gas flow detecting portion indicates that the exhaust gas flow is more than a second predetermined value which is smaller than the first predetermined value and to be relatively large when the detection output from the exhaust gas flow detecting portion indicates that the exhaust gas flow is equal to or less than the second predetermined value.

Air supply and exhaust control systems for turbocharged internal

An internal combustion engine comprises a primary supercharger operated in substantially a full range of engine operating conditions of a vehicle and a secondary supercharger operated in a specific range of the engine operating condition. The plurality of supercharger are arranged in parallel in the fore and aft direction of a vehicle in a manner such that the primary supercharger means is disposed forward of the secondary supercharger. The primary supercharger is disposed at a front portion of an engine room, just behind a cooling fan, to easily be provided with a cooling effect by virtue of a fresh air. The secondary supercharger is disposed rearward of the primary supercharger to avoid the cooling effect provided by the fresh air and to receive air warmed by the primary supercharger so to undergo a warming up effect.

Internal combustion engine with turbo supercharger

An air supply control system for an internal combustion engine comprises at least first and second turbosupercharger, an exhaust cutoff valve operative selectively to open and close an exhaust passage in which a turbine of the second turbosupercharger is disposed, an intake air cutoff valve operative selectively to open and close an intake passage in which a blower of the second turbosupercharger is disposed, a cutoff valve controller operative to control the exhaust cutoff valve and the intake air cutoff valve so as to cause the first turbosupercharger to work when intake air mass flow fed to the engine is to be relatively small and to cause both of the first and second turbosuperchargers to work when intake air mass flow fed to the engine is to be relatively large, an engine operation detector, and an operation controller operative to vary, in response to an engine operating condition detected by the engine operation detector, a boundary between first and second operating areas provided on an operating characteristic chart of the engine respectively for a first supercharging operation in which the first turbosupercharger works but the second turbosupercharger does not work and a second supercharging operation in which both of the first and second turbosuperchargers work.

Disclosed is an engine-control apparatus in which an exhaust passageway of the engine is provided with plural sound deadening passages. A portion of the plural sound deadening passages is designed to be opened or closed by a shift valve on the basis of a predetermined switching characteristic, and the pressure of the exhaust gases is changed upon the switching of the shift valve. In order to prevent torque shock to the driven wheels which may occur attendant upon operation of the shift valve to open or close or in order to reduce probability that torque shock would occur, there is provided a torque regulating apparatus which permits an adjustment of torque generator by the engine, of a transmission efficiency of power to the driven wheel, or of a switching speed at which the shift valve is switched to open or close, or a change in the switching characteristic.

Engine-control apparatus

A supercharging apparatus for an internal combustion engine wherein a supercharger is disposed in the intake passage of the engine. A stepwise variable transmission drives the supercharger. The transmission has a plurality of gear stages so that the rotational characteristics of supercharger can be changed. The stepwise variable transmission has a one-way clutch that interrupts the driving relation between a lower gear stage and the engine output shaft during shift-up operation. Therefore, rapid shift-up operation and shockless shift-down operation are obtained.

Supercharging apparatus for an internal combustion engine

An intake system for an internal combustion engine having a plurality of engine sections for utilizing the interference effect between engine sections to increase the intake charge for at least two engine sections, has a first intake passage connected to a first intake port of one engine section of the at least two engine sections, and a second intake passage connected to a second intake port of another engine section. The first and second intake passages are communicated with each other by a communicating passage and join each other at a junction portion at upstream ends thereof. The first and second intake passages and the communicating passage are arranged so as to have a common axis in the vicinity of the communicating passage. The junction portion is communicated with the atmosphere and a valve is provided for controlling the opening of the communicating passage in accordance with engine operating condition. The valve is located within the communicating passage. The respective lengths of a passage consisting of a part of the first and second passages and the communicating passage, and a passage consisting of the first and second intake passages and the junction portion are determined so that a compression wave produced in one of the first and second passages can be transmitted to the intake port connected to the other intake passage just before the intake port is closed. This intake system has an advantage that a dynamic effect, particularly an interference effect can be effectively utilized to remarkably increase the intake charge.

Intake system for internal combustion engine

A rotary piston engine having three or more rotors and provided with an intake system including a primary individual intake passage leading to each rotor unit and a secondary individual intake passage leading to each rotor unit for providing a supply of intake charge under a heavy load engine operation. The secondary individual intake passages are connected together by a junction and have passage lengths which are determined such that the pressure wave produced at the intake port for one rotor unit is transmitted to the intake port for another rotor unit after a time interval corresponding to 180.degree. in terms of angle of rotation of the eccentric shaft.

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Hiroshima, Japan

Seiji Tashima