JPH01247715A - Exhaust gas turbine supercharger - Google Patents

Abstract

PURPOSE:To increase the rotation efficiency of a turbine in an engine low rotation zone especially by providing plural fins in the exhaust gas flowing path of the turbine housing stored with a turbine and constituting so that one part of the exhaust gas may flow between the fins. CONSTITUTION:An exhaust turbine supercharger 1 has the turbine 3 radially provided with the plural blades driven by an exhaust gas and this is stored in a spiral turbine housing 8. The housing 8 is provided with an exhaust gas flow-in path 9 at the outer peripheral side and an exhaust gas flow-out port at the center part in the shaft center direction. In this case, plural fins 13 are projected in the direction of the exhaust gas flow-in path 9 thereto. These fins 13 are integrally provided with the housing 8 at equal intervals and continuously formed over the inlet port part 14 of a scroll chamber 12 from the vicinity of a turbine housing inlet port 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exhaust turbine supercharger mainly used in automobile engines.

[Prior Art] This type of supercharger uses exhaust gas to rotate a turbine, and also rotates a compressor coaxial with the turbine to compress intake air, dramatically increasing engine output. It is possible.

However, since it is difficult to rotate the turbine efficiently over the entire engine speed range from the low speed range to the high speed range, the turbine is designed to be highly effective in one of the ranges. For example, by reducing the narrowest area of the exhaust gas inflow passage that guides exhaust gas into the turbine housing, it is possible to obtain high efficiency in the low engine speed range.
By increasing the narrowest area, high efficiency can be obtained in a high rotation range.

However, since such a supercharger uses exhaust gas, there is a time lag (turbo lag) between when the throttle valve is opened and when supercharged intake air is obtained. For this reason, if the engine is set to achieve high efficiency in the high-speed range where the amount of exhaust gas is large, turbo lag becomes noticeable in the low-speed range where the amount of exhaust gas is small, resulting in poor responsiveness during acceleration. Getting worse. Therefore, as a prior art of the present invention, there is a technique in which a movable member is provided in the exhaust gas inflow passage of the turbine housing and the movable member is connected to an actuator, as shown in Japanese Patent Laid-Open No. 54-84123, for example. . The movable member is moved according to the rotation range of the engine to change the narrowest area of the exhaust gas inflow passage.

[Problems to be Solved by the Invention] According to what is shown in the second prior art, it is possible to change the inflow speed of exhaust gas flowing into the turbine housing depending on the rotation range of the engine. However, such a configuration requires a movable member, an actuator for moving the movable member, and a control mechanism for detecting the rotation range of the engine and appropriately operating the actuator. Therefore, the number of parts increases, the structure becomes complicated, and the cost increases significantly.

An object of the present invention is to improve the responsiveness of an exhaust turbine supercharger in a low rotation range without causing the above-described problems.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an exhaust turbine supercharger with a plurality of fins in the exhaust gas inflow passage for guiding exhaust gas into the turbine housing. The structure is characterized in that a part of the gas can flow between the fins.

[Operation] According to such a configuration, when the amount of exhaust gas is small and its flow velocity is slow, the influence of frictional resistance between the exhaust gas flowing on the fin side and the fins on the exhaust gas flow increases.

Therefore, the exhaust gas guided into the exhaust gas inflow passage,
The main stream flows laminarly in the region away from the fins, and the flow speed is increased by the throttling effect, increasing the rotational efficiency of the turbine in the low rotation range.

On the other hand, as the engine speed increases, the amount of exhaust gas gradually increases, and its flow velocity gradually increases. This, together with the increase in turbulence on the fin side, causes the exhaust gas flowing on the fin side to The effect of frictional resistance on the exhaust gas flow is reduced. Therefore, the exhaust gas guided into the exhaust gas inflow passage is guided to the turbine almost unaffected by frictional resistance with the fins.

[Example 1] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 5.

As schematically shown in FIG. 1, this exhaust turbine supercharger 1 includes a compressor 2 for compressing intake air, and a turbine 3 for rotating this compressor 2.
A compressor 2 and a turbine 3 are fixed to both ends of a common shaft 5 supported by a center housing 4.

The compressor 2 has a plurality of blades arranged radially, and is housed in a compressor housing 6 interposed in an intake passage. The compressor housing 6 has a spiral shape, and has an intake intake lower part provided at the center in the axial direction, and an intake outlet connected to an intake pipe or the like on the outer circumferential side.

The turbine 3 has a plurality of blades arranged radially, and is housed in a turbine housing 8 interposed in an exhaust passage. This turbine housing 8 has a spiral shape, and has an exhaust gas inflow passage 9 provided on the outer peripheral side, and an exhaust gas outlet 10 provided in the central portion in the axial direction. The exhaust gas inflow passage 9 is formed by gradually decreasing the opening area from the turbine housing 11 connected to the exhaust manifold to the scroll chamber 12 side.

Further, the exhaust gas inflow passage 9 is provided with a plurality of fins 13 protruding in the direction of the passage 9. Each fin 13 is integrally provided with the turbine housing 8 at equal intervals on the inner wall surface 9a on the turbine 3 side, and is continuously formed from the vicinity of the turbine housing 11 to the inlet portion 14 of the scroll chamber 12. .

According to such a configuration, when the amount of exhaust gas is small (in the low rotation range where the flow velocity is slow), the frictional resistance between the exhaust gas flowing on the fin 13 side and the fin 13 has a large influence on the exhaust gas. As a result of the flow velocity of the exhaust gas introduced into the exhaust gas inflow passage 9 being slowed down by frictional resistance on the fin 13 side, the mainstream of the exhaust gas flows laminarly on the side opposite to the turbine, as shown in FIG. In other words, in the low rotation range, the inflow area of the exhaust gas is temporarily narrowed by the plurality of fins 13, and the inlet area of the scroll chamber inlet portion 14, the tip side of the inlet 13, and the inner side of the inlet 13 are narrowed temporarily. The narrowest area A of the exhaust gas inflow passage 9 is between the wall surface 9b and the exhaust gas inflow passage 9. Therefore, the exhaust gas guided into the exhaust gas inflow passage 9 increases the flow velocity and flows into the scroll chamber 12 from the anti-turbine side. In this case, the distance R between the main flow part of the exhaust gas and the rotation center 0 of the turbine 3 becomes large, and the cross-sectional area is substantially narrowed, causing the exhaust gas flow velocity to decrease. Therefore, the rotational efficiency of the turbine 3 is increased.

On the other hand, as the engine speed increases, the amount of exhaust gas gradually increases and its flow velocity gradually increases, so that the exhaust gas also flows between the fins 13, and the inflow area of the exhaust gas gradually increases. It will spread. In a high rotation range where the amount of exhaust gas is large and the flow velocity is high, the frictional resistance between the exhaust gas flowing on the fin 13 side and the fins 13 has less influence on the exhaust gas. Therefore, the exhaust gas introduced into the exhaust gas inflow passage 9 is transferred to the fin 13.
Together with the increased turbulence on the sides, the exhaust gas passes through the exhaust gas inflow passage 9 without being affected by frictional resistance with the fins 13. As a result, the exhaust gas introduced into the exhaust gas inflow passage 9 in the high rotation range gradually reduces the flow area in the exhaust gas inflow passage 9 and increases the flow velocity, and as shown in FIG. is averaged at the inlet portion 14 of the scroll chamber 12, flows into the scroll chamber 12, and flows into the turbine 3.
will be rotated.

Therefore, according to the above configuration, the exhaust gas inflow area automatically changes according to the flow rate of the exhaust gas. Therefore, even when the amount of exhaust gas is small, the flow velocity of the exhaust gas flowing into the scroll chamber 12 can be reliably increased. As a result, the rotation speed of the turbine 3 increases, suppressing turbo lag in the low rotation range,
Responsiveness during acceleration can be improved.

On the other hand, as the engine speed increases and the amount of exhaust gas and its flow velocity increase, the narrowest area A of the exhaust gas inflow passage 9 gradually increases, so that the high rotational efficiency of the turbine 3 is maintained in the high rotation range. be done.

As a result, turbo lag in the high-speed range is suppressed, and problems that would impair responsiveness in the high-speed range can be prevented.

Although one embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to the above embodiment.

For example, the fins 113 shown in FIG. 6 are provided integrally with the turbine housing 108. Both opposing inner wall surfaces 109c, 109 in the exhaust gas inflow passage 109
They are protrudingly provided at equal intervals in the direction d, and are located on the turbine side. The fins 213 shown in FIG. 7 are provided integrally with the turbine housing 208 and protrude from one inner wall surface 209C of the exhaust gas inflow passage 209 at equal intervals. The fin 313 shown in FIG.
It is provided integrally with the turbine housing 308. Both opposing inner wall surfaces 3 in the exhaust gas inflow passage 309
09a, 309b at equal intervals, and are arranged on one half of each inner wall surface 309a, 309b. The fins 413 shown in FIG. 9 are provided integrally with the turbine housing 408. The exhaust gas inflow passage 409 is provided with protrusions at equal intervals on one inner wall surface 409a, and is disposed on one half of the inner wall surface 409a.

Note that each of the illustrated examples above shows the case where the fins are partially protruded from the inner wall surface of the exhaust gas inflow passage, but it is also possible to provide the fins to protrude entirely from the inner periphery of the exhaust gas inflow passage. be.

Further, the fins may be formed of a ceramic heat-resistant member and then fixed to the inner wall surface of the exhaust gas inflow passage.

[Effects of the Invention] Since the present invention has the above-described configuration, it is possible to maintain the rotational efficiency of the turbine at a high value in the high engine speed range and increase the rotational efficiency of the turbine in the low engine speed range. Therefore, it is possible to provide an exhaust turbine supercharger with good responsiveness over a wide range from a low rotation range to a high rotation range.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the present invention, in which FIG. 1 is a schematic sectional view of an exhaust turbine supercharger, FIG. 2 is a sectional view showing main parts, and FIG. ■-■ line cross-sectional view in Figure 2,
Figure 4 is a speed distribution diagram showing the flow of exhaust gas at low rotation speeds.
FIG. 5 is a speed distribution diagram showing the flow of exhaust gas during high rotation. 6 to 9 are sectional views corresponding to FIG. 3 showing other embodiments of the present invention. 1... Exhaust turbine supercharger 2... Compressor 3... Turbine 5... Shaft 8... Turbine housing 9... Exhaust gas inflow passage 10... Exhaust gas outlet 12... Scroll chamber 13...fin

Claims (1)

[Claims] In an exhaust turbine supercharger in which a compressor for pumping intake air and a turbine for rotating this compressor are connected via a common shaft, an exhaust gas inflow passage of a turbine housing housing the turbine is provided. An exhaust turbine supercharger comprising a plurality of fins so that a portion of exhaust gas can flow between the fins.