JPS61205334A - Turbocharger - Google Patents

Abstract

PURPOSE:To prevent a decrease of rigidity in the vicinity of a scroll winding start part, by forming mounting bolt holes of a turbine housing, mounted to a center housing, in a position excepting a part in the vicinity of the scroll winding start part of the turbine housing. CONSTITUTION:A turbocharger 1 mounts by bolts 7, 8 a turbine housing 3 and a blower housing 4 so as to hold flange parts 2a, 2b in both sides of a center housing 2 respectively by set plates 5, 6. Here bolt holes 2c of the bolts 7, mounting the turbine housing 3 to the center housing 2, are formed in an equal angular space in the peripheral direction excepting a position and departing from said position corresponding to a part in the vicinity of a scroll winding start part 9 in the turbine housing 3. In this way, the turbocharger 1, eliminating a decrease of rigidity in the vicinity of the scroll winding start part 9, can prevent generation of a crack due to thermal stress in the vicinity of said part 9.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a turbocharger, and particularly to a structure for mounting a turbine housing of a turbocharger to a center housing.

(Prior Art) Conventionally, a turbocharger is known in which exhaust gas drives a turbine wheel, thereby rotating a blower impeller connected to the turbine wheel via a rotating shaft to supply supercharging air to the combustion chamber of an engine. (For example, see Japanese Utility Model Application Publication No. 58-149535).

Incidentally, in the above-mentioned turbocharger, a rotating shaft, which is usually provided with a turbine wheel and a blower impeller at both ends, is supported by a center housing, and the turbine housing is attached to the turbine wheel side of the center housing with bolts. Conventionally, this turbine housing
As shown in the figures and FIG. 4, one of the bolt holes for attachment to the center housing is provided at a position corresponding to the vicinity of the start of scroll winding of the turbine housing a.

However, while the turbine housing a becomes hot due to the exhaust gas, the rigidity near the start of the scroll winding is reduced due to the bolt holes C, so cracks d occur in the vicinity due to thermal stress generated during operation. However, the crack d grows and reaches the bolt hole C, causing problems such as leakage of exhaust gas to the outside and generation of abnormal noise.

(Objective of the Invention) An object of the present invention is to provide a turbocharger in which the occurrence of cracks in the vicinity of the scroll winding start portion of the turbine housing is suppressed.

(Structure of the Invention) The present invention provides a turbocharger as described above, in which bolt holes through which bolts for attaching the turbine housing to the center housing are inserted are formed at positions other than the vicinity of the scroll winding start portion of the turbine housing. It is characterized by:

(Example) An embodiment of the present invention will be described below with reference to the drawings.

In a turbocharger 1 whose overall configuration is shown in FIG.
The housing is constructed by attaching a turbine housing 3 to one part of a center housing 2 and a proar housing 4 to the other side. Turbine housing 3
and blower housing 4 are each set piece 1”
5.6 The flange portion 2a of the center housing 2
, 2b are clamped and fixed with bolts 7.8. As shown in FIG. 2, the bolt holes 2c of the bolts 7 for attaching the turbine housing 3 to the center housing 2 are inserted into the turbine housing 3 at a circumferential distance apart from the position corresponding to the vicinity of the scroll winding start portion 9. They are formed at equal angular intervals in the direction.

A pair of bearing parts 11 formed in the center housing 2.
At 11, a rotating shaft 14 having a turbine wheel 12 integrally formed at one end and a pro-ain R 13 fixedly attached to the other end is rotatably supported. Note that the turbine wheel 12 is connected to the exhaust passage 1 of the turbine housing 3.
5, the blower impeller 13 is attached to the blower housing 4.
are located in the middle of the intake passages 16 of the.

Each of the bearings 11 is operated by an oil pump (not shown).
Lubricating oil trunk passage 17. Lubricating oil is supplied through lubricating oil passages 18 and 19, and is returned to an oil tank (not shown) through a lubricating oil recovery passage 20.

A heat shroud 21 blocks heat conduction from the turbine housing 3 to the center housing 2. 22
2 is a float metal provided on each bearing portion 11, and 23 is a snap ring that restricts the movement of the float metal 22 in the axial direction.

With the above configuration, the bolt hole 2c is located at a position away from the vicinity of the scroll winding start portion 9 of the turbine housing 3.
is formed, so there is no decrease in rigidity near that part, and even if the turbine housing 3 becomes high temperature and thermal stress is generated near the scroll winding start part 9, the occurrence of cracks in that area is suppressed. be done.

Therefore, leakage of exhaust gas to the outside, generation of abnormal noise, etc. do not occur.

(Effects of the Invention) As described above, the present invention provides bolt holes for mounting to the center housing at positions other than the vicinity of the start of scroll winding of the turbine housing where thermal stress is concentrated. There is no decrease in rigidity near the beginning, and it is possible to prevent cracks from occurring in the vicinity due to thermal stress.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, in which FIG. 1 is a central vertical sectional view of a turbocharger, FIG. 2 is a side view of a turbine housing with a flange attached to the center housing,
3 and 4 show a conventional example, with FIG. 3 being a side view of a turbine housing similar to FIG. 2, and FIG. 4 being a partial sectional view of the turbine housing. ■...Turbocharger, 2...Center housing, 2c...Bolt hole, 3...
...Turbine housing, 7...Bolt, 9
・・・・・・Start of scroll winding.

Claims (1)

[Claims] (1) In a turbocharger in which a rotating shaft having a turbine wheel and a blower impeller at both ends is supported by a center housing, and the turbine housing is attached to the turbine wheel side of the center housing with bolts,
A turbocharger characterized in that a bolt hole of the turbine housing through which the bolt is inserted is formed at a position other than a vicinity of a scroll winding start portion of the turbine housing.