EP2449224A1

EP2449224A1 - Manifold mounted divider for turbocharger turbine inlet

Info

Publication number: EP2449224A1
Application number: EP10794524A
Authority: EP
Inventors: Michael D. Bartkowicz; Luis Carlos Cattani; Qianfan Xin
Original assignee: International Engine Intellectual Property Co LLC
Current assignee: International Engine Intellectual Property Co LLC
Priority date: 2009-06-29
Filing date: 2010-05-26
Publication date: 2012-05-09
Also published as: WO2011002566A1; EP2449224A4

Abstract

An engine exhaust system includes a turbocharger turbine with an undivided inlet. The engine includes two exhaust pipes, each exhaust pipe receives an exhaust gas portion from a group of cylinders. The exhaust pipes terminate at a common connection face and are in communication with the undivided inlet of the turbine when the connection face is connected to the turbine housing. A divider extends outward from the connection face with a base end located between the exhaust pipes, the divider adapted in shape to fit within the undivided inlet of the turbine.

Description

MANIFOLD MOUNTED DIVIDER FOR TURBOCHARGER TURBINE INLET

FIELD OF THE INVENTION

[0001] This invention relates to internal combustion engines, including but not limited to control and operation of a turbocharger, and engine braking for an internal combustion engine.

BACKGROUND OF THE INVENTION

[0002] Multi-cylinder internal combustion engines, particularly diesel engines for large tractor-trailer trucks, may include an exhaust-gas turbocharger. The turbocharger includes a turbine that drives a compressor via a shaft, which generates an increased intake air pressure in the intake duct during normal operation.

[0003] Turbochargers having divided turbine housings are known. Such a turbine construction is disclosed for example in U.S. Patent 3,292,364. This patent describes a divided housing turbocharger that receives exhaust gas from two exhaust ducts conducting exhaust gas from groups of cylinders such as to minimize energy losses from the pulsating exhaust gas stream. This design incorporates a fully divided turbocharger turbine design. This conserves the pulse energy inside the turbocharger and does not allow communication of the gas from the front and back engine cylinders.

[0004] Adequate and reliable braking for vehicles, particularly large tractor-trailer vehicles, is desirable. While drum or disc wheel brakes are capable of absorbing a large amount of energy over a short period of time, the absorbed energy is transformed into heat in the braking mechanism. An engine braking system can be used to assist in braking the vehicle.

[0005] Braking systems are known which include exhaust brakes which inhibit the flow of exhaust gases through the exhaust system, and compression release systems wherein the energy required to compress the intake air during the compression stroke of the engine is dissipated by exhausting the compressed air through the exhaust system.

[0006] An engine braking method disclosed in U.S. Patent No. 4,395,884 includes employing a turbocharged engine equipped with a double entry turbine and a compression release engine retarder in combination with a diverter valve. During engine braking, the diverter valve directs the flow of gas through one scroll of the divided volute of the turbine. When engine braking is employed, the turbine speed is maximized, and the inlet manifold pressure is also maximized, thereby maximizing braking horsepower developed by the engine.

[0007] Other methods of using turbochargers for engine braking are disclosed in U.S. Patent Nos. 6,594,996; 6,223,534; 6,148,793 and 4,474,006.

[0008] Although a divided turbine housing may offer advantages in both engine operation and engine braking, the present inventors have recognized that a divided housing turbine type of turbocharger is more expensive to manufacture and may add risk of thermal cracks at the divided flow passages. The present inventors have recognized that it would be desirable to provide an engine exhaust system that provides the advantages of a divided turbine housing at a reduced cost.

SUMMARY OF THE INVENTION

[0009] The exemplary embodiment of the present invention incorporates a flow divider that extends into the entrance of an undivided turbine housing far enough to direct the exhaust gas moving in the direction of the turbine wheel and prevents or minimizes exhaust gas short circuit or mixing through the otherwise open housing.

[0010] According to the embodiment, this flow divider can be independent of the turbocharger and not touch the internal walls of the turbine casting.

[0011] An exemplary engine exhaust system includes a turbine having a turbine housing having a scroll volume therein and a turbine wheel rotatably held within the scroll volume. The housing has an undivided inlet. A first exhaust pipe receives a first exhaust gas portion from the engine and a second exhaust pipe receives a second exhaust gas portion from the engine. The first and second exhaust pipes have respective first and second output ends terminating at a common connection face. The connection face is fastened to the turbine housing with the first and second output ends communicating the first and second exhaust gas portions separately into the undivided inlet. A divider extends outward from the connection face with a base end located between the first and second output ends. The divider is adapted in shape to fit within the undivided inlet of the turbine. [0012] The divider can extend into the turbine housing without contact with the turbine housing.

[0013] The engine can be an inline six cylinder engine having cylinders 1 through 6 in order from front to back, and the first exhaust portion is from cylinders 1-3 and the second exhaust gas portion is from cylinder 4-6.

[0014] The divider can comprise a tapered height substantially from its base end to its distal end.

[0015] The divider can have a height dimension that extends perpendicularly to a rotation axis of the turbine wheel.

[0016] The turbine housing can include an inlet nozzle that defines the undivided inlet and extends to the scroll volume, and the divider extends through the inlet nozzle and to a position near to a beginning of the scroll volume.

[0017] Numerous other advantages and features of the present invention will be become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a schematic diagram of an engine system that includes a turbocharger and an engine braking system incorporating a turbine divider in accordance with an exemplary embodiment of the invention;

[0019] FIG. 2 is a perspective view of a portion of the system shown in FIG. 1 with some components removed to view underlying parts;

[0020] FIG. 3 is a sectional view of a portion of the system shown in FIG. 1;

[0021] FIG. 4 is a sectional view of the turbine illustrating a second embodiment of the divider; and

[0022] FIG. 5 is a perspective view of the alternate embodiment divider shown in FIG. 4.

DETAILED DESCRIPTION

[0023] While this invention is susceptible of embodiment in many different forms, there are shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated.

[0024] An engine 100 is shown schematically in FIG. 1. The engine 100 has a block 101 that includes a plurality of cylinders. The cylinders in the block 101 are fluidly connected to an intake system 103 and to an exhaust system 105. The exhaust system includes a first pipe or duct 105 a from cylinders 1, 2 and 3 of one bank of cylinders and a second pipe or duct 105b from cylinders 4, 5 and 6. Although an inline arrangement of six cylinders is illustrated, inline or V- arrangements or other arrangements of plural cylinders of any number of cylinders are also encompassed by the invention.

[0025] A turbocharger 107 includes a turbine 109. The turbine 109 shown has a single flanged turbine inlet port 113 connected to a connection face 114 of the exhaust system 105. The turbocharger 107 includes a compressor 111 connected to the intake system 103 through an inlet air passage 115.

[0026] During operation of the engine 100, air may enter the compressor 111 through an air inlet 117. Compressed air may exit the compressor 111 through an outlet 207 (described below), pass through the inlet air passage 115, and pass through an optional charge air cooler 119 and an optional inlet throttle 120 before entering an intake air mixer 121 and an intake air manifold 122 of the intake system 103. The compressed air enters the engine cylinders 1-6.

[0027] A stream of exhaust gas from the exhaust system 105 may be routed through an EGR passage or conduit 124, through an exhaust gas recirculation (EGR) valve 125, through an exhaust gas recirculation (EGR) cooler 126 and pass through a further EGR conduit 127 before meeting and mixing with air from the inlet throttle 120 at the mixer 121.

[0028] The inlet port 113 of the turbine 109 may be connected to the exhaust pipes 105a, 105b in a manner that forms a distribution manifold 129 (Figure 4). Exhaust gas passing through the turbine 109 may exit the engine 100 through a tailpipe 134. Emissions and sound treating components can be arranged to receive the exhaust gas from the tailpipe, before exhausting to atmosphere, as is known. [0029] At times when the EGR valve 125 is at least partially open, exhaust gas flows through the first pipe 105a, through the conduit 124, through the EGR valve 125, through the EGR cooler 126, through the further conduit 127 and into the mixer 121 where it mixes with air from the inlet throttle 120. An amount of exhaust gas being re- circulated through the EGR valve 125 may depend on a controlled opening percentage of the EGR valve 125.

[0030] Figures 2 and 3 illustrate a first embodiment divider 160. The first and second pipes 105a, 105b have output ends 164, 166 that terminate at about the connection face 114 of the manifold 129 and blend into a common separator wall 168 that keeps exhaust flow within the pipes 105a, 105b separated up to the connection face 114. The divider 160 is carried by the separator wall 168. The divider has a base end 172 that can be fastened or otherwise secured to the separator wall 168. The divider distal end 178 and/or portions of the divider between the base and distal ends can also be restrained by interaction with the inside wall 182 of the turbine. The distal end 178 can terminate at a position around the scroll at about the beginning of the scroll volume or just before the beginning of the scroll volume. Advantageously, the divider can extend into the scroll as deeply as is practical.

[0031] Figures 4 and 5 illustrate a second embodiment divider 206. According to this embodiment, the divider has an extending wall 210 formed with a perpendicular mounting base 214. The mounting base 214 has a shape matching the exhaust manifold connection face 114 and the turbine inlet flange 113 including a central opening 215 and fastener holes 216. The mounting base 214 is clamped between the turbine inlet flange 113 and the connection face 114 when the turbine is mounted and fastened to the connection face 114. The extending wall 210 and base 214 are sufficiently rigid such that the extending wall 210 can be shaped to conform closely to, but avoid any contact with, the inside wall of the turbine. The extending wall 210 includes a base end 220 that abuts or comes close to the separator wall 168. Gussets 230a, 230b are formed with or attached to the extending wall 210 to strengthen the connection between the extending wall 210 and the base 214. The gussets 230a, 230b and extending wall 210 span across the opening 215 and can be formed with the base 214. [0032] In addition to providing the divider to improve engine braking, one or more exhaust valves of the engine can be opened during engine braking, as described in U.S. Patents 6,594,996; 6,148,793; 6,779,506; 6,772,742 or 6,705,282, herein incorporated by reference, or a valve can be used to route the exhaust gas from both 105 a and 105b into one side of the turbine inlet to increase backpressure and increase turbine speed, to maximizing braking horsepower developed by the engine.

[0033] Parts List

100 engine

101 block

103 intake system

105 exhaust system

105 a first exhaust pipe

105b second exhaust pipe

107 turbocharger

109 turbine

111 compressor

113 connection flange

114 connection face

115 inlet air passage

119 optional charge air cooler

120 optional inlet throttle

121 inlet air mixer

122 intake manifold

124 EGR conduit

125 EGR valve

126 cooler

127 further conduit

129 distribution manifold

134 tailpipe

160 first embodiment divider

164 output end of pipe 105 a 166 output end of pipe 105b

168 common separator wall

172 divider base end

178 divider distal end

182 turbine inside wall

206 second embodiment divider

210 extending wall

214 perpendicular mounting base

215 central opening

216 fastener holes

220 base end

230a gusset

230b gusset

[0034]From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred.

Claims

The Invention Claimed Is:

1. An engine exhaust system, comprising:

a turbine having a turbine housing having an inside wall defining a scroll volume, and a turbine wheel rotatably held within the scroll volume, the housing having an undivided inlet;

a first exhaust pipe receiving a first exhaust gas portion from the engine and a second exhaust pipe receiving a second exhaust gas portion from the engine, the first and second exhaust pipes having first and second output ends terminating at a common connection face, the connection face fastened to the turbine housing with the first and second output ends separately communicating the first and second exhaust gas portions into the undivided inlet, and a divider extending outward from the connection face with a base end located between the first and second output ends, the divider shaped to fit within the undivided inlet of the turbine.

2. The engine exhaust system according to claim 1, wherein the divider extends into the turbine housing without contact with an inside wall of the turbine housing.

3. The engine exhaust system according to claim 1, wherein the engine is an inline six cylinder engine having cylinders 1 through 6 in order from front to back, and the first exhaust portion is from cylinders 1-3 and the second exhaust gas portion is from cylinder 4-6.

4. The engine exhaust system according to claim 1, wherein the divider comprises a tapered height from its base end to its distal end.

5. The engine exhaust system according to claim 1, wherein the divider has a height dimension that extends perpendicularly to an rotation axis of the turbine wheel.

6. The engine exhaust system according to claim 1, wherein the turbine housing includes an inlet nozzle that defines the undivided inlet and extends to the scroll volume, and the divider extends through the inlet nozzle and to a position near to a beginning of the scroll volume.

7. The engine exhaust system according to claim 1, wherein the divider comprises an extending wall and a perpendicularly arranged base, the base clamped between the connection face and the turbine housing.

8. The engine exhaust system according to claim 1, wherein the divider comprises gussets connecting the extending wall with the base.

10. A method of converting an undivided turbine housing into a divided turbine housing comprising the steps of:

providing a turbine with an undivided inlet;

providing an exhaust manifold having an outlet connection configured to fit to the undivided inlet;

providing a divider at the outlet connection and extending therefrom, the divider shaped to fit into the undivided inlet; and

fastening the outlet connection to the undivided inlet.

11. The method according to claim 10 wherein the step of providing the divider is characterized by the further step of fastening the divider to the exhaust manifold.

12. The method according to claim 10 wherein the step of providing the divider is characterized by the further step of providing the divider having a base configured to be sealingly clamped between the outlet connection and the undivided inlet.

13. The method according to claim 10 wherein the step of providing the divider is characterized by the further step of providing that the divider has a length that locates a distal end of the divider at a position within the undivided inlet that is rotationally nearto the beginning of the volute scroll of the turbine.