JPS585429A - Exhaust turbine supercharger - Google Patents

Abstract

PURPOSE:To both prevent exhaust gas from intruding into a housing and suppress a temperature rise, by providing plural sheets of heat shielding plates in an air chamber and forming the plates to a small gap in their center hole part and housing end side. CONSTITUTION:Annular heat shielding plates 13a, 13b are set in such a manner as to divide internally an air chamber 20, and their peripheral part is held between a step difference part 16 of a turbine case 1 and a flange part 17 of a housing 5. While their gap G1 and a gap G2, between the plate and the housing 5, are formed smaller than width S of a seal ring 11. Accordingly, heat of exhaust gas, flowing in a turbine wheel 3, is shielded to prevent the housing 5 from its temperature rise. When the seal ring 11 is inserted into a groove part 10, the ring is compressed to a small diameter before mounting to a rotary shaft 6, here internal diameter of the heat shielding plates 13a, 13b and end part hole diameter of the housing 5 are gradually formed to small dimensions, further G1, G2 are smaller than S, and intrusion of exhaust gas into the seal ring 11 can be reduced, thus smooth operation can be performed for a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust turbine supercharger for an internal combustion engine, and particularly to a structure for suppressing a temperature rise in a turbine side bearing portion, etc.

FIG. 1 is a sectional view of the turbine side of a conventional exhaust turbine supercharger. Exhaust gas discharged from the internal combustion engine is guided to a passage 2 in a turbine case 1, and is ejected from a nozzle portion 4 facing the outer circumference of a turbine wheel 3, thereby rotating the turbine wheel 3.

Bearing portions 7 are provided in holes at both ends of the housing 5 that connects the turbine case 1 and the compressor case (not shown).
is installed and supports a rotating shaft 6 to which a turbine wheel 3 and a compressor wheel (not shown) are attached. A large amount of lubricating oil is supplied to this bearing portion through passages 8 and 9 formed within the housing 5. That is,
This bearing portion 7 is lubricated and cooled.

Further, a seal ring 11 is fitted into the annular groove 10 formed in the rotating shaft 6, and the outer periphery of the seal ring 11 contacts the surface of the tip hole 12 of the housing 5, preventing hot exhaust gas from entering. This prevents the bearing portion 7 from becoming stuck. Further, a metal heat shield plate 130 is installed between the seventh rank portion on the outer periphery of the housing 5 and the stepped portion of the turbine case 1.
The central portion of the heat shield plate is inserted between the turbine wheel 3 and the housing 5 to prevent exhaust gas from coming into contact with the seal ring 11. That is, by installing the heat shield plate 13, the space surrounded by the turbine case 1, the turbine wheel 3, and the housing 5 is divided into two to form an air chamber 14. temperature rise is suppressed.

However, in an internal combustion engine that uses gasoline as fuel, the exhaust gas reaches a high temperature, so even if the heat shield plate 13 as described above is provided, the temperature of the seal ring 11 reaches a maximum of 500 to 600'C, which weakens the elasticity of the seal ring 11. At the same time, the lubricating oil in the vicinity of the lubricating oil may seize, and the rotation of the bearing portion 7 may become unstable. Therefore, the efficiency and durability of the supercharger are reduced.

An object of the present invention is to provide an exhaust turbine supercharger that can prevent exhaust gas from entering the housing and suppress temperature rise. In the air chamber formed by the turbine wheel and the turbine case, and the end surface of the housing that forms the bearing part of the rotating shaft to which the turbine case and the compressor case are attached, and the turbine wheel and the turbine case, there are a plurality of sheets that overlap and surround the end surface of the housing. Before installing the turbine wheel, install heat shield plates, and make sure that the distance between the center holes of these heat shield plates and the distance between them and the end face of the housing is smaller than the width of the seal ring installed in the groove provided on the rotating shaft. The structure is such that a seal ring can be inserted into the rotating shaft of the rotary shaft.

FIG. 2 is a sectional view of the turbine side of a supercharger according to an embodiment of the present invention, and the same parts as in FIG. 1 are given the same reference numerals. In this case, it is an annular heat shield plate 13a.

13b is installed so as to divide the inside of the air chamber 20,
Its outer peripheral portion is held between a stepped portion 16 of the turbine case 1 and a flange portion 17 of the housing 5. Further, the central portions of the heat shield plates 13a and 13b are parallel flat plates, and the interval therebetween is Gl.

The distance G2 between the heat shield plate 13b and the housing 5 is smaller than the width S of the seal ring 11. In addition, the heat shield plate 13
The inner diameter of the heat shield plate 13b is smaller than the inner diameter of the heat shield plate 13b, and the inner diameter of the tip of the housing 5 is also smaller than the inner diameter of the heat shield plate 13b.

In the supercharger configured in this way, the heat of the exhaust gas discharged from the passage 2 through the space between the turbine wheels 3 is blocked by the double heat shield plates 13a and 13b, so that the temperature rise in the housing 5 is prevented. Few. The seal ring 11 is made by cutting out a part of an elastic metal ring, and when inserting it into the groove 10, the seal ring 11 is compressed to a small diameter before the turbine wheel 3 is attached to the rotating shaft 6. It is inserted and installed. At this time, the inner diameter of the heat shield plates 13a, 13b and the hole diameter at the end of the housing 5 gradually become smaller, and the intervals Gl, G2 are smaller than S, so that the seal ring 11 is inserted between the heat shield plates 13a, 13b or Hot plate 13b
and the housing 5.
It can be set within 0. Therefore, the assembly work is facilitated, and the temperature rise of the bearing portion 7 is small, allowing smooth operation for a long period of time.

Figure 3 is a diagram comparing and showing the relationship between the rotational speed of the internal combustion engine and the temperature of each part, where the one-dot chain line T, 1 is the exhaust gas temperature at the turbine inlet, and the two-dot chain line Ttt is the exhaust gas temperature at the turbine outlet. be. As the rotational speed of the internal combustion engine increases, the temperature of the exhaust gas increases, but Ttl-Ttl remains approximately constant at about 100°C. On the other hand, in the conventional case shown in FIG. 1, the temperature of the seal ring 11 is TRO shown by the broken line, but in the case of the present embodiment shown in FIG. 2, the temperature is 100° as shown by the solid line TRI.
C is also decreasing.

In this way, the temperature of the seal ring 11 of this embodiment is 100
The fact that the temperature has also decreased means that the double heat shield plates 13a, 13
b, and the heat shield plate 13a suppresses the temperature rise of the housing 5.

This is due to the fact that the diameter of the center hole of the seal ring 13b is gradually reduced to reduce the intrusion of exhaust gas into the seal ring 11 as much as possible. Therefore, the deterioration of elasticity of the seal ring 11 due to temperature rise is reduced, and the seal ring 11 operates in a suitable state for a long period of time. Further, since the seal ring 11 maintains airtightness, the bearing portion 7 also operates smoothly without being stuck due to exhaust gas.

In addition, if two or more heat shield plates are welded to the heat shield plate 13H,
Furthermore, the heat shielding effect is improved.

The exhaust turbine type supercharger of this embodiment can operate smoothly for a long period of time by suppressing the temperature rise of the bearing part etc. by forming a plurality of blades so that the gap between them and the rotating shaft is small. This effect can be obtained.

FIG. 4 is a sectional view of a heat shield plate that is a modification of FIG. 2. FIG.

In this case, the flange portion 21 of the outer heat shield plate 13G is connected to the step portion 16 of the turbine case 1 and the flange portion 17 of the no-Uji pufferfish 5.
The inner heat shield plate 13d is welded to the inner surface of the cylindrical part from the collar part 21. In addition, the center hole 1 of the heat shield plate 13C
The diameter DI of No. 8 is slightly larger than the diameter D2 of the center hole 19 of the heat shield plate 13d. Further, since D2 is only slightly larger than the diameter of the tip of the nozzle 5 and passes through the rotating shaft 6, the gap therebetween is small and almost no exhaust gas enters the inside.

The heat shield plate of this embodiment has the same effect as the one shown in FIG. The effect is that it does not change.

The exhaust turbine supercharger of the present invention has the advantage of being able to operate smoothly for a long period of time by preventing temperature increases in bearings and the like and seizure caused by exhaust gas through relatively simple improvements.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a sectional view of the turbine side of a conventional exhaust turbine type supercharger, Fig. 2 is a sectional view of the turbine side of a supercharger according to an embodiment of the present invention, and Fig. 3 is a sectional view of the turbine side of a supercharger according to an embodiment of the present invention. The figure is a diagram comparing and showing the relationship between the rotational speed of the internal combustion engine and the temperature of each part, and FIG. 4 is a sectional view of a heat shield plate that is a modification of FIG. 2. 1... Turbine case, 3... Turbine wheel,
5...Housing, 6...Rotating shaft, 7...Bearing portion, 10...Groove portion, 11...Seal ring, 12...
・Tip hole, 13... Heat shield plate, 14, 15, 20...
Air chamber, 16...step part, 17...7 rank part, 1
8.19...center hole, 21...flange. (Fig. 2/θl)0 2tMyo 3t)m dao
o jtytyo 1tya. Addition inside! kf 1st car - scattered CrP air)

Claims (1)

[Claims] 1. An exhaust turbine-type supercharger in which a turbine is driven by the exhaust gas of the internal combustion engine, and air is forced into the cylinders of the internal combustion engine by a compressor wheel attached coaxially with the turbine wheel, The housing is located within an air chamber formed by the turbine wheel and the turbine case and an end face of a housing that forms a bearing of a rotating shaft to which the turbine wheel and compressor wheel are attached, and that connects the turbine case and compressor case. A seal ring is provided in which a plurality of heat shield plates are installed to overlap and surround the end faces of the heat shield plate, and the seal ring is installed in a groove provided in the rotary shaft such that the distance between the heat shield plates at the center hole and the distance between the heat shield plates and the end face of the housing is adjusted. smaller than the width of
The present invention is characterized in that the seal ring is configured to be able to be inserted into the rotating shaft before the turbine wheel is mounted thereon. Exhaust turbine type supercharger. 2. A peripheral portion of the heat shield plate is held between a flange portion of the housing and a stepped portion of the turbine case;
The exhaust turbine supercharger according to claim 1, wherein the exhaust turbine supercharger is a plurality of metal plates that partition the air chamber. 3. The heat shield plate includes a metal plate whose peripheral portion is sandwiched between the flange portion of the housing and the stepped portion of the turbine case, and other metal plates provided at intervals except for the peripheral portion. The exhaust turbine supercharger according to claim 1, wherein the exhaust turbine supercharger is a plurality of metal plates welded in parallel to partition the air chamber.