GB2151700A

GB2151700A - IC engine turbocharger and exhaust gas by-pass valve arrangement

Info

Publication number: GB2151700A
Application number: GB08428501A
Authority: GB
Inventors: E S Marchant
Original assignee: ELFORD TURBO Ltd
Current assignee: ELFORD TURBO Ltd
Priority date: 1983-11-11
Filing date: 1984-11-12
Publication date: 1985-07-24
Also published as: GB8330144D0; GB8428501D0; GB2151700B

Abstract

A turbocharger turbine 12 is connected at one end of an exhaust manifold 11 and an exhaust by-pass valve 18 is connected at the other end of the manifold. The valve is actuated by the diaphragm of an actuator 19 in response to the pressure difference across the turbocharger compressor 14. The actuator is mounted on a plate (43, Figs. 2 and 3) fixed in one of a plurality of angular positions about the axis of a shaft (31), in the valve housing (33,37), forming part of the linkage between the diaphragm and the valve member (35). <IMAGE>

Description

SPECIFICATION Turbocharger installations This invention relates to turbocharger installations for fitting to internal combustion engines.

According to the invention, there is provided a turbocharger installation for an internal combustion engine including an exhaust manifold connected at or near one end to a turbocharger turbine to drive a compressor of air or air/fuel mixture for the engine, and valve means fastened to the other end of the exhaust manifold and arranged to be actuated by outlet pressure of the compressor to open at a predetermined value of said pressure to by-pass exhaust gases around the turbine to an exhaust pipe.

Preferably the valve means includes a valve to close or open a port, the valve being rotatable on a spindle.

Conveniently the turbocharger installation includes an actuator responsive to the compressor outlet pressure and actuator mounting means to mount the actuator relative to the valve spindle, the mounting means being rotatable about the spindle to a plurality of optional mounting positions.

The invention is described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side view, in diagramatic form of the inlet and exhaust systems of an internal combustion engine, Figure 2 is an enlarged view of part of Figure 1, Figure 3 is a section along the line Ill-Ill in Figure 2, Figure 4 is a section along the line IV-IV in Figure 3, and Figure 5 is a section along the line V-V in Figure 3.

In Figure 1, the side view of an internal combustion engine is shown generally at 10. Pressurised and hot exhaust gases pass from the engine 10 into an exhaust manifold 11 and thence into the centripetal turbine 12 of a normal turbocharger 13.

The turbocharger 13 is of a kind well known to those versed in the art of internal combustion engines and comprises the turbine 12 connected by an unshown shaft to drive a centrifugal compressor 14.

The expanded and cooled exhaust gases leave the turbine 12 through an exhaust pipe 15. Combustion air for the engine 10 enters a normal carburettor 16 where fuel is added to the air to form a combustible mixture. The mixture passes along a duct 17 from the carburettor 16 to the compressor 14 from which it passes to the engine 10 through an unshown inlet manifold.

At the opposite end of the exhaust manifold 11 from the turbine 12, there is fastened a waste gate 18, to be described more fully later, including a capsule 19. the capsule 19 is connected by a pipe 20 to the duct 17 and by a pipe 21 to the outlet for the pressurised mixture from the compressor 14.

An outlet pipe 22 from the waste gate 18 leads by-passed exhaust gases to the exhaust pipe 15.

In figures 2 to 5, the capsule 19 has a rigid cylin drical case at the mid-position along the axis thereof there is fastened an unshown transverse flexible diaphragm to seal one end of the capsule 19 from the other.

The centre of the diaphragm is fastened to a push-rod 23 which passes out through the end of the capsule 19 but is sealed thereto.

Two tubes 24, 25 are fastened into the capsule 19 on either side of a central diaphragm. The pipes 20, 21 are fitted on the tubes 24, 25 respectively.

The push-rod 23 has a threaded adjustment portion 26 screwed into a clevis 27, which is pivotted by a pin 28, held by a clip 29, to a lever 30. The lever 30 is welded to a shaft 31 which passes through a bore to the interior of a valve body 33.

The inner end of the shaft 31 is rivetted to a valve lever 34. A mushroom shaped valve 35, the stem 36 of which is rivetted loosely to the end of the valve lever 34, remote from the shaft 31.

The valve body 33 has an open face which is closed by a plate 37 having a circular port 38 closed by the head of the valve 35. The outlet pipe 22 from the valve body 33 is fastened thereto by studs 39, and is connected to the interior of the valve body 33 by an outlet port 40. The valve body 33 is fastened to the end of the exhaust manifold 11 by unshown screws which pass through holes 41 through the valve body 33 and the plate 37.

The capsule 19 is fastened by studs 42 and nuts to a bracket 43, which is pivotted at the opposite end around the shaft 31. The bracket 43 is fastened to the valve body 33 by a screw 44 which passes through one of four holes 45, 46 and screws into one of four tapped holes 47, 48 in the valve body 33. The holes 45, 47 are at the same radius from the shaft 31. The holes 46, 48 are at the same radius from the shaft 31, which is different from the radius of the holes 45, 47. The distance between holes 45 is different from the distance between the holes 47. Similarly the holes 46 are spaced differently from the holes 48. In this way the bracket 43 may be fastened at a wide range of angular locations to the valve body 33.

The diaphragm in the capsule 19 is sufficiently stiff, with the assistance of a spring if needed, to hold the valve head 35 in sealing engagement against the plate 37 against the pressure of exhaust gases in the exhaust manifold 11. When the pressure in the outlet from the compressor reaches a predetermined value it applies sufficient force to the diaphragm in the capsule 19 to rotate the lever 30 and 34 and lift the valve head 35 off its seat.

Thus exhaust gas is allowed to pass from the manifold 11 through the outlet pipe 22 and into the exhaust pipe 15, by-passing the turbine 12 and limiting further rise in compressor outlet pressure.

As the mass flow of air through the carburettor 16 rises, as at high engine speeds, the pressure in the pipe 20 falls, causing the valve 35 to start opening at a lower compressor outlet pressure than at lower speeds.

In an alternative embodiment the port 38 is permenantly open and the direction of operation of the valve 35 is reversed so that it normally closes the outlet port 40. Such an arrangement has the disadvantage that the valve body 33, the valve 35 and spindle 31 are always subject to exhaust temperature.

In some arrangements the carburettor 16 is installed downstream of the compressor 14, in known manner. In other embodiments fuel injection into the air intake system or into the engine combustion chamber is used in place of the carburettor 16.

Claims

1. A turbocharger installation for an internal combustion engine including an exhaust manifold connected at or near one end to a turbocharger turbine to drive a compressir of air or air/fuel mixture for the engine, and valve means fastened to the other end of the exhaust manifold and arranged to be actuated by outlet pressure of the compressor to open at a pre-determined value of said pressure to by-pass exhaust gases around the turbine to an exhaust pipe, and in which the valve means includes a valve to close or open a port, the valve being rotatable on a spindle.

2. A turbocharger installation, according to Claim 1 including an actuator responsive to the compressor outlet pressure and actuator mounting means to mount the actuator relative to the valve spindle, the mounting means being rotatable about the spindle to a plurality of optional mounting positions.

3. A turbocharger installation, according to Claim 1 or 2 , in which the valve includes an arm rigidly fastened to the spindle, and a disc shaped valve head mounted on the arm at an end remote from the spindle.

4. A turbocharger installation, according to Claim 3, in which the valve head is fastened to the arm with provision for limited relative universal rotation between the arm and the valve head.

5. A turbocharger installation, according to any preceding claim, in which the valve is rotatable in a chamber having an open face, the chamber is fastened to the exhaust manifold with a plate between the open face and the exhaust manifold, and the plate has an aperture closed and opened by the valve.

6. A turbocharger installation, constructed and arranged and adapted to operate substantially as described herein and as shown in the accompanying drawings.