US 2417363 A
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March 11, 1947. HQLLEY, JR 2,417,363
gurmcnmena CONTROL Filed A i-il 17, 1944 INVENFOR.
',and vice versa.
Patented Mar. 11, 1947 SUPERCHARGER CONTROL George M. Holley, J12, Grosse Pointe, Mich, assignor to George M. Holley and Earl Holley Application April 17, 1944, Serial No. 531,479
1 The object of this invention is to control an exhaust-driven turbo supercharger for an airplane engine. It has been common practice for many years to regulate the pressure generated by an exhaust turbo supercharger so that the absolute pressure delivered by the supercharger is a constant value regardless of altitude. It is desirable to regulate this pressure with reference to atmospheric pressure because the engine should develop its maximum power at sea level and power should slightly diminish at altitude because obviously maximum power is needed ing off at sea level.
The figure shows diagrammatically the elements of my invention.
In the figure, lllis a manually controlled throttle lever connected by the link H to the throttle lever i2 controlling a throttle l3. Air enters at M, is compressed by the supercharger I5, is discharged through an intercooler l6, and is delivered to the carburetor ii in which is located the throttle l3. The air is then discharged into the manifold l8, and so to the engine cylinders 9. The xhaust escapes from the engine through the pipe 20 and out'through the exhaust pipe 2|. The exhaust leaving pipe 20 can take two paths, one past a throttle 22, or the other past the exhaust turbine 23. Obviously, when the valve 22 is closed, the maximum supercharging takes, place.
The throttle valve 22 is contrblled by the lever 24, which is connected to the servomotor A, which is controlled by the manually controlled supercharger regulating lever 25. -Lever 25 engages with the link 26, which engages with lever 21, which engages with a button 28, which compresses the spring 29 imposing a load oh diaphragm 30. Diaphragm chamber 3|v is connected through pipe 32' with annular chamber 33 into which th supercharger delivers air. The pipe 32 thus imposes the supercharger pressure on the diaphragm 30. The valve 34 is an extension of the rod 35 and acts as a servomotor valve. The rod 35 also engages with the diaphragm 30. Thus, the valve 34 controls the servomotor piston 31. Oil under pressure is delivered through the pipe 38. This pressure is applied to either the left or right hand side of piston 31 depending on the movement of the valve 34 to the left or the right side. When the rod 35 moves to the left, then the piston 31 moves to the left 011 pressure escapes through pipe 39. The oil pressur admitted through the pipe 38 is also conveyed through a passage 40 to engage with a small piston 4| which locks when takmatically.
button 28 ,to rod 35 when the oil pressure in passage 40 is zero so that on the failure of the oil supply or before the oil pressure is built up, the lever 25 has control over the mechanism. Another small piston 42 is also unseated as soon as oil pressure is available in pipe 38. v
A piston 43 is connected through a yoke 44 to a lever. 45, which engages with the roller 46, which engages a roller 47, which acts as the fulcrum of the lever 21. A fiat spring 48. applies pressure through thisfulcrum 47 through the roller,
engaging the cam surface of the lever 45. The lever 45 has a fulcrum '43 and is connected through a rod 50 to the yoke 44 of the piston 53. A servomotor valve 5| supplied with oil under pressure through the pipe 52 provides the motive force for the piston 43. Oil under pressure escapes through a pipe 54. An evacuated or partially evacuated barometric element 53 moves the valve 5| and thus the piston 43 which moves the cam 45. The restrictions 55 and 56 are provided to make th mechanism operate. The spring 51 pushes the piston 43 to the left so that when the oil pressure fails, the lever 45 is rotated anti-clockwise and allows the fulcrum 41' of the lever 21 to move to the left, which reduces the pressure on the spring 29. When the oil pressure fails, a third small piston 58 is pushed into a locking engagement with rod 50. Oil under pressure from line 52 unlocks this small piston 53 so that wheneveroil pressure is available, the mechanism will function auto- Operation Assume that oil pressure is available and that the three locking pistons, 42 and 58 are free,-
then if the engine is running, pipe 32 delivers supercharger pressure to the chamber 3|, the exhaust flowing along pipe 20 rotates the turbine 23 and thus operates the supercharger l5. If the pressure in 3i is not high enough to balance the combined force of the atmospheric pressure and of the spring 29, then the throttle 22 is closed until such time as the supercharger l5 generates sufficient pressure to bring the servomotor valve 34 back into the neutral position in which it is shown.
When the altitude varies, the barometric element 53 expands and contracts. The valve 5| moves to the left and right and as it moves, so moves the piston 43, which regulates the fulcrum 41, which determines the spring pressure 29 so that the degree of supercharg determined by in atmospheric pressure. Hence, any desired relationship between altitude and the boost pressure measured above the-atmospheric pressure (=gage Pressure) can be maintained. For example: as the plane ascends into the air, the de-' gree of supercharge (relative to the atmospheric pressure) can be arranged to increase. However, relative to zero pressure, the degree of supercharge may at the same time decrease slightly so that the power will not increase with altitude.
' If the superchargewas held at a constant pressure (absolute), the power would increase with altitude, which is an undesirable characteristic of constant boost pressure devices now in general use.
What I claim is:
1. A turbo supercharger control for an internal combustion engine, comprising an exhaust outlet from said engine, a turbine therein, a supercharger driven by said turbine, another exhaust outlet, an exhaust valve therein; means responsive to the pressure above the atmosphere generated by said exhaust driven supercharger for causing said valve to open when a preselected supercharger pressure is exceeded. and to close when the supercharger pressure is below the preselected pressure, manual and barometeric means adapted to jointly select said pressure above the atmosphere.
2. A device as set forth in claim 1, inwhich the means responsive to the pressure'for causing said exhaust valve to open and close includes a servomotor.
3. A device as set forth in claim 1 in which the barometric means adapted to select the pressure above the atmosphere generated by said supercharger includes a servomotor.
4. Adevice as set forth in claim 1 in which the means responsive to the pressurefor causing said exhaust valve to open and-close includes a servomotor,and in which the-barometric means adapted to selectthe pressure above the atmosphere, generated by said supercharger includes a servomotor.
5. A turbo supercharger control for an internal combustion engine comprising an exhaust outlet from said engine, a turbine therein, a super- 4 charger driven by said turbine, another exhaust outlet, an exhaust valve therein, control means for said exhaust valve comprising an air chamber, a moving wall therein, a pipe connecting said chamber with the outlet from said supercharger, spring means for opposing the pressure exerted by said supercharger pressure on said wall, a lever, one portion of which is adapted to engage with said spring, barometeric means adapted to engage with another portion of said lever, manual means adapted to'engage with said lever at a third point whereby the load on said spring is jointly controlled by said manual means and by said barometric means.
6. A device as set forth in claim 5 in which the control means for said exhaust valve comprising a servomotor and in which the barometric means engaging with said lever also includes a servomotor.
- 7. A control for an internal combustion engine having an exhaust driven turbo supercharger, an exhaust valve controlling the turbo supercharger, a controlling means responsive to the pressure produced by the supercharger relative to atmospheric pressure for opening and closing said valve so as to regulate the flow of exhaust gases to said turbo supercharger, manually operated means adapted to select said pressure, barometric means also adapted to select said pressure, said barometric means being adapted to control the exhaust valve jointly with the manually oper at'ed means whereby the pressure is controlled jointly by the manual means and by the barometric means.
GEORGE M. HOLLEY, Ja.
' REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,346,563 Sherbondy July/13, 1920 1,508,707 Moss Sept. 16, 1924 2,024,202 Berger Dec. 17,- 1935 2,187,737 Gregory Jan. 23, 1940 r