Developed Technologies of the New Rotary Engine (RENESIS)
2004; Linguagem: Inglês
10.4271/2004-01-1790
ISSN2688-3627
AutoresMasaki Ohkubo, Seiji Tashima, Ritsuharu Shimizu, Suguru Fuse, Hiroshi Ebino,
Tópico(s)Vehicle emissions and performance
Resumonewly developed rotary engine has achieved major progress in high performance, improved fuel economy and clean exhaust gas by innovative action. engine of the next generation is named RENESIS, which stands for The RE (Rotary Engine)'s GENESIS or the rotary engine for the new millennium. peripheral exhaust port of the previous rotary engine is replaced by a side exhaust port system in the RENESIS. This allows for an increase in the intake port area, thus producing higher power. Exhaust opening timing is retarded to improve thermal efficiency. side exhaust port also allows reducing the internal EGR, stabilizing the combustion at idling. improved thermal efficiency and the stabilized idle combustion result in higher fuel economy. In addition, the side exhaust port allows a reduction of the HC mass, realizing reduced exhaust gas emission. A Sequential Dynamic Air Intake System is adopted which optimizes air intake depending on the actual engine speed range, producing high torque ranging from low to high engine speeds. Gas seals were optimized for the side exhaust port RE. INTRODUCTION In order for the rotary engine (RE) to keep meeting a wide range of market needs as an automotive engine, its performance needs to be improved while making a drastic improvement to the fuel economy and the exhaust gas emission at the same time. Therefore Mazda has researched the side exhaust port system as the improvement to RE’s essential area, and have reported its improvement potential for the fuel economy and the exhaust gas emission. [1] Compared to the peripheral exhaust port of previous RE, the side exhaust port offers more design freedom for the intake/exhaust port shape. This allows for port timing and shape setting, which enables balanced output, fuel economy and exhaust gas emission. This paper describes an overview of the RENESIS and technologies. TARGET OF RENESIS DEVELOPMENT RENESIS was developed targeting at high output power with natural aspiration, but at the same time stringent emission regulations in relevant markets and a high fuel economy were to be met to target high performance RE accepted in the 21 century. engine development aimed at: (1) Realizing smooth and high power from low to high engine speed. (2) Drastic improvement in fuel economy. (3) Reduction of exhaust emissions. RENESIS MAJOR SPECIFICATIONS RENESIS is more simple and compact outside view than the previous model turbo-charged as shown in Fig. 1. Fig.1: Photo of RENESIS Engine 2004-01-1790 Masaki Ohkubo, Seiji Tashima, Ritsuharu Shimizu, Suguru Fuse and Hiroshi Ebino Copyright © 2004 SAE International AS shown in Table 1, RENESIS has two versions of High power and Standard power, and they have the different output characteristics and allowable engine speed. RENESIS has the exhaust ports in the side housings and higher compression ratio than the previous model (13B-REW). Fig. 2 shows the schematic of the fuel and the emission control system. high-power RENESIS is fitted with a 32-bit PCM operation for optimum fuel injection supported by three injectors per rotor to improve fuel economy, response and power simultaneously. For the aim of the RENESIS development, additional technologies are adopted based on the side exhaust as shown in Table 2. BASIC PERFORMANCE 1. Engine Output Performance high-power RENESIS output performance is 177kW at 8500rpm, 216N·m at 5500rpm. standard-power RENESIS is 147kW at 7200rpm, 222N·m at 5000rpm. Torque curves are shown in Fig.3. Fig.2: Fuel & Emission Control System (High-Power) 13B-REW High-Power Standard-Power (RX-7) 654 × 2 654 × 2 654 × 2 15 × 105 × 80 15 × 105 × 80 15 × 105 × 80 Side Intake Side Intake Side Intake Side Exhaust Side Exhaust Peripheral Exhaust 10.0 10.0 9.0 I.O(ATDC) 3° 3° 45° I.C(ABDC) 65° 60° 50° I.O(ATDC) 12° 12° 32° I.C(ABDC) 36° 45° 50° I.O(ATDC) 38° n/a n/a I.C(ABDC) 80° n/a n/a E.O(BBDC) 50° 40° 75° E.C(BTDC) 3° 3° 48° ATDC S-DAIS S-DAIS Non Variable Natural Aspiration Natural Aspiration Sequential Twin-Turbo Intake Charge Type RENESIS Auxiliary Exhaust Port Timing Intake System Exhaust Type Compression ratio Primary Secondary Eccentricity × Generating Radius × Width (mm) Engine Displacemet (cc) Intake Type Table 2: Major Technologies Fig.3: Engine Output Performance 1 2 3 4 5 6 7 8 9 Engine speed (×1000rpm) To rq ue (N •m ) High power Standard Power 216N•m/5500rpm 222N•m/5000rpm 147kW/7200rpm 177kW/8500rpm Table 1: Major Specifications Higher and Smoother Output Power Side Exhaust Port Enlarged Intake Port Area Enlarged Exhaust Port Area Improved Fuel Economy Side Exhaust Port No Intake/Exhaust Overlap Retarded Exhaust Open Timing Cut-Off Seal Improved Exhaust Emission Side Exhaust Port Improved HC Emissions S-DAIS Sequential Dynamic Air Intake System Dual Wall Exhaust Manifold Jet Air/Fuel Mixing System
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