JP2016133012A - Exhaust system for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust system for an engine capable of reducing an interference of a dynamic pressure of exhaust gas and improving turbo-characteristics in a single scroll type turbo charger.SOLUTION: An exhaust manifold of a four-cylinder engine 30 is formed to be divided into two exhaust manifolds 40, 41 not producing any exhaust interference and both exhaust ports 43, 44 are collected at a collecting pipe 42 in a state of being divided into two, the collecting pipe 42 is connected to an inlet pipe 55 of a single scroll 57 of a single scroll turbo-charger 50, and a partition plate 10 which divides exhaust gas from the two exhaust manifold parts 40, 41, introduces the exhaust gas to turbine blades 53, and deforms in accordance with the dynamic pressure, is provided to the inlet pipe 55.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an engine exhaust system in which a turbocharger is connected to an intake / exhaust system of an engine.

  Turbochargers connected to the intake / exhaust system of the engine include a single scroll turbocharger having a single scroll on the exhaust side and a twin scroll turbocharger having a twin scroll.

  The single scroll turbocharger operates in a narrow rotation range, and the twin scroll turbocharger has the advantage of operating from a low rotation to a high rotation range by making the scroll twin.

  Normally, in order to operate the turbocharger from a low rotation range, it is necessary to reduce the A / R ratio of the turbine housing to narrow the exhaust gas passage area. On the other hand, in the high rotation range, the exhaust gas hardly flows. The engine output reaches its peak.

  Although the twin scroll turbocharger has a twin scroll, it has one turbine and has a function of controlling exhaust like a variable nozzle turbo. Therefore, the characteristics are the same as those of a single scroll turbocharger except in a low rotation range.

  When a twin scroll turbocharger is used, a 4-cylinder engine uses a 4-2 exhaust manifold to avoid interference between the cylinders.

  FIG. 5 shows a schematic diagram in which a four-cylinder engine 100 having a 4-2 exhaust manifold and twin scrolls 154 and 155 of a twin scroll turbocharger 110 are combined.

  In the case of the four-cylinder engine 100, the exhaust from the first exhaust port 101 and the fourth exhaust port 104 among the first exhaust port 101, the second exhaust port 102, the third exhaust port 103, and the fourth exhaust port 104 are collected. The first exhaust manifold 105 is divided into a second exhaust manifold 106 in which the second exhaust port 102 and the third exhaust port 103 are assembled. The first exhaust manifold 105 is connected to one twin scroll 154, and Two exhaust manifolds 106 are connected to the other twin scroll 155.

JP 2010-084579 A JP 2008-215179 A

  By the way, in the case of a diesel engine, there is a variable capacity turbocharger that uses a variable nozzle at the turbine inlet because of operating in a wide load range and increasing low-speed torque.

  Therefore, it is conceivable to provide a variable nozzle vane on the outer periphery of the twin-scroll turbine 153 shown in FIG. 5, but since the exhaust manifold is divided into two parts, the durability of the variable nozzle vane supported in a cantilever manner is considered. It is impossible to provide nozzle vanes, and conversely, it is impossible to twin scroll the variable capacity turbocharger.

  Therefore, the exhaust manifold in the case of providing the nozzle vane in order to increase the low speed torque has to be 4-1 exhaust manifold, and there is a problem that the dynamic pressure effect is reduced by the exhaust interference and the low speed torque cannot be further improved.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problems and to provide an engine exhaust device that can improve turbo characteristics by reducing interference of exhaust dynamic pressure in a single scroll type.

  In order to achieve the above object, the present invention divides the exhaust manifold of a four-cylinder engine into two exhaust manifolds that do not cause exhaust interference, and collects the exhaust manifolds by collecting pipes that are divided into two exhaust ports. The pipe is connected to the single scroll inlet pipe of the single scroll turbocharger, and the inlet pipe is provided with a partition plate that separates the exhaust from the two exhaust manifolds and introduces it into the turbine blade and deforms according to the dynamic pressure. This is an engine exhaust device.

  A variable nozzle vane is preferably provided on the outer periphery of the single scroll turbine blade.

  It is preferable that the partition plate is attached to a partition plate flange attached between flanges connecting the collecting pipes of two exhaust manifolds and the inlet pipe of the single scroll.

  The partition plate is preferably made of a stainless steel plate having a thickness of 0.1 to 0.2 mm.

  In the present invention, an exhaust manifold is divided into two systems to avoid exhaust interference, and connected to a single scroll of a single scroll turbocharger, and an inlet pipe of the single scroll is divided into two systems by two partition plates. An excellent effect that the turbo characteristics can be improved while preventing the interference of the dynamic pressure is exhibited.

1 is a schematic view including a partial cross section of an engine exhaust device showing an embodiment of the present invention. (A) is the sectional view on the AA line of FIG. (B) is an external perspective view of a partition plate using the engine exhaust device of the present invention. It is a partially broken side view of the exhaust turbocharger using the engine exhaust device of the present invention. (A), (b) is a figure explaining the action | operation of the partition plate of the exhaust apparatus of the engine of this invention. It is sectional drawing of the conventional exhaust apparatus.

  A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic view including a partial cross-section of an engine exhaust device.

  As shown in FIG. 1, the exhaust system of the four-cylinder engine 30 is connected to a single scroll 57 of a single scroll turbocharger 50 to constitute an engine exhaust device.

  The engine 30 includes a first cylinder 31, a second cylinder 32, a third cylinder 33, and a fourth cylinder 34.

  As described in FIG. 5, the exhaust manifold is divided into two exhaust manifolds 40 and 41 to prevent exhaust interference. In the illustrated example, the exhaust ports of the first cylinder 31 and the fourth cylinder 34 are gathered in one exhaust manifold 40, and the exhaust ports of the second cylinder 32 and the third cylinder 33 are gathered in the other exhaust manifold 41. .

  The exhaust manifolds 40 and 41 are assembled by the collecting pipe 42 in a state where the exhaust ports 43 and 44 are divided.

  The single scroll 57 of the single scroll turbocharger 50 is provided with a turbine blade 53, an inlet pipe 55 for introducing exhaust in the tangential direction of the single scroll 57 is provided, and an exhaust outlet 54 is provided in the axial direction of the turbine blade 53. Provided.

  As shown in FIGS. 1 and 3, the nozzle vane 56 is attached to the outer periphery of the turbine blade 53 via a guide ring 58, and the angle of the turbine blade 53 can be varied by an actuator 59.

  The collecting pipe 42 of the two exhaust manifolds 40 and 41 and the inlet pipe 55 of the single scroll 57 are formed in a quadrangular cross section, and are joined by flanges 60 and 61. A partition plate 10 is provided to partition the exhaust gas flowing in the inlet pipe 55 of the scroll 57 into two systems.

  2A is a cross-sectional view taken along line AA in FIG. 1, and FIG. 2B is an external perspective view of a partition plate using the exhaust structure of the present invention.

  As shown in FIGS. 2A and 2B, the partition plate 10 is formed on the partition plate flange 11 formed in a square frame shape in accordance with the shapes of the flanges 60 and 61 of the collecting pipe 42 and the inlet pipe 55. It is integrally formed.

  The partition plate 10 has elasticity, and is formed of, for example, a stainless plate having a thickness of 0.1 mm to 0.2 mm.

  As shown in FIG. 3, the partition plate 10 is attached to the straight portion in the inlet pipe 55 before joining the flange 61 of the inlet pipe 55 of the single scroll 57 and the flange 60 of the collecting pipe 42. After that, the partition plate flange 11 is sandwiched and fixed between the flanges 60 and 61.

  Next, the operation of the present embodiment will be described.

  First, the engine 30 is driven, and exhaust gas is discharged from the exhaust port of each cylinder.

  At this time, the exhaust gas is exhausted to the two exhaust manifolds 40 and 41 that do not cause exhaust interference and flows from the collecting pipe 42 to the inlet pipe 55 of the single scroll 57, but the inlet pipe 55 is also partitioned by the partition plate 10. The turbine blade 53 can be driven without being subjected to exhaust interference up to the vicinity of flowing into the turbine blade 53 in the single scroll 57.

  Since the partition plate 10 has elasticity, as shown in FIGS. 4A and 4B, the partition plate 10 is deformed by the exhaust dynamic pressure P and smoothly guides the flow path and the dynamic pressure P to the turbine blade 53. Can do.

  Even when the engine 30 is in the low rotation range, the inlet pipe 55 is partitioned by the partition plate 10, so that the flow velocity of the exhaust gas flowing into the inlet pipe 55 from the exhaust manifolds 40 and 41 does not decrease, and the blade angle of the nozzle vane 56 is increased. By narrowing down, you can further improve the characteristics.

  At this time, the exhaust gas in the single scroll 57 is merged or diffused at the tip of the partition plate 10 and the exhaust gas uniformly hits the nozzle vane 56. Therefore, even if the nozzle vane 56 is cantilevered, no trouble occurs.

  Thus, according to the present invention, the exhaust manifold is divided into two systems, the partition plate is provided in the single scroll inlet pipe of the single scroll turbocharger, and the turbo characteristics can be improved while reducing the interference of the exhaust dynamic pressure. it can.

  The collecting pipe 42 and the inlet pipe 55 are shown as an example in which the collecting plate 42 and the inlet pipe 55 are formed to have a quadrangular cross section so as not to hinder the movement of the dividing plate 10 that is deformed by the dynamic pressure. There is no need to partition, and the collecting pipe 42 and the inlet pipe 55 may be circular, and the width of the partition plate 10 may be reduced so that it can move within the circular inlet pipe 55.

10 Partition plate 11 Partition plate flange (flange)
30 Engine 40, 41 Exhaust manifold 42 Collecting pipe 43, 44 Exhaust port 50 Single scroll turbocharger 53 Turbine blade 55 Inlet pipe 57 Single scroll

Claims (4)

  The exhaust manifold of a 4-cylinder engine is divided into two exhaust manifolds that do not cause exhaust interference, and the exhaust pipes are gathered together in a collecting pipe, and the collecting pipe is assembled into a single scroll turbocharger single scroll. An exhaust system for an engine, wherein the exhaust pipe is connected to an inlet pipe, and provided with a partition plate that introduces the exhaust from the two exhaust manifolds separately into the turbine blade and deforms according to the dynamic pressure.   The engine exhaust device according to claim 1, wherein a variable nozzle vane is provided on an outer periphery of the single scroll turbine blade.   3. The engine exhaust system according to claim 1, wherein the partition plate is attached to a partition plate flange that is attached between a flange connecting a collecting pipe of two exhaust manifolds and an inlet pipe of the single scroll.   The engine exhaust device according to any one of claims 1 to 3, wherein the partition plate is a stainless steel plate having a thickness of 0.1 to 0.2 mm.

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