US1722350A - Internal-combustion engine - Google Patents

Description

July 30, 1929. 1 M. wooLsoN INTERNAL COMBUSTION ENGINE Filed Dec. 20, 1925 777. Waals 011/ Patented July 30, 1929.

UNITED STATES PATENT oFFlcE.

LIONEL M. WOOLSON, OF DETROIT, MICHIGAN, ASSIGNOR T.0 PACKARD MOTOR CAR COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN. I

INTERNAL-COMBUSTION IElNfirIhl'IEl.

Application led December 20, 1923. Serial No. 681,723.

This invention relates to internal combustion engines and particularly to mixture controlling means therefor'.

A great variety of devices have heretofore been proposed for thermostatically controlling the mixture of an internal combustion engine. Where thermostats are arranged in the mixture line itself the action is usually too slow in winter due to the very cold a'ir being drawn through the carburetor. Vhere the thermostat is arranged in theexhaust pipe the action is usually too sudden and there is the added complication of a packed operating connection extending through the exhaust pipe, the heat of which rapidly deteriorates the packing; where the thermostat is mounted adjacent the exhaust pipe but onvthe outside thereof the action is frequently too slow in cold weather because of the draught of cold air passing over the engine from the fan which is usually arranged at the front of the engine when used in a motor vehicle; when the thermostat is used in the water circulation system its action is usually sluggish; and

there are numerous objections to the various other types of thermostats used.

One of the objects of the present invention is to provide a mixture control means which will act positively upon the mixture device 3o and which will not be too greatly aected by the outside temperature conditions. Also, a

device is sought which will be rather stable d' in its action or which will not fluctuate too much With changes in operati-ng conditions.y

i Another object of the invention is to provide means acted upon by the engine exhaust for controlling in' a positive and accurate manner the carburetor or mixture forming device of the engine.

Other objects of the invention will appear from the following descriptions taken in connection with the drawings, which form a part of this specification, and in which:

Fig. 1 is a perspective view of an internal combustion engine embodying the invention;

Fig. 2 is a side elevation of parts of the engine shown in Fig. 1, together with a somewhat diagrammatic showing of the movable or control parts of the device, and

Fig. 3 is a sectional view of part of the engine carburetor taken through the mixture valve.

Referring to the drawing7 10 represents an lports of the engine.

engine cylinder block which is shown with a detachablehead 11 of usual form. A carbu* retor or mixture device 12 is mounted upon the side of the engine and is suitably connected by a pipe 13' with a passage in the cylinder block which carries the mixture to the inlet The carburetor has a mlxture valve 14 which is yieldingly held closed'by one or more springs 15, the tension of whlcli springs may be varied by a cam 16 mounted upon a rock shaft 17 supported on the carburetor body. Themain intake 18 of the carburetor is controlled by a butterfly valve 19 held yieldingly open by a spring 19 and which may be closed by the rockshaft 17 near the end of its closing stroke, through a link 20, an arm 20 on the shaft of the valve 19 and an arm 21 on the rock shaft 17. In Fig. 2 the cam 16 and valve 19 are shown in full lines in their rich-mixture position and in dotted linesin their lean-mixture position.

Mounted u'pon the side of the cylinder block .10 is the engine exhaust pipe 22. This pipe 1s bolted to the cylinder block by several bolts such as those shown at 23 and it will be noted that these bolts pass through openings 24 which 'are slightly larger than the bolt to thereby allow for expansion lengthwise of the exhaust pipe. The exhaust pipe is usually made of cast iron and it Will, of course, expand as it is heated up by the hot exhaust gas passing into it from the cylinders when the engine is in operation. As the exhaust pipe cools it again contracts to its normal length.

In the form of the invention shown the carr buretor 12 is mounted adjacent the exhaust pipe 22 so that the connecting mechanism for varying the adjustment of the carburetor,

which is about to be described, may be of very simple form. The invention contemplates utilizing the expansion and contraction of' the exhaust pipe for-varying the richness of the mixturesupplied by the carburetor. This is done by suitable connections from the exhaust pipe to the rock shaft 17 above referred A bar or rod 25 of Invar steel is supported lengthwise of the exhaust pipe 22, being attached near the left-hand end of the exhaust pipe as shown at 26. The properties of Invar steel are well known, this steel substantially retaining its original size regardless of 5 nected as at 27 to the short arm 28 of a bell crank lever 29, the short arm extending downwardly from the pivot 30 of the lever and the long'arm 31 extending substantially parallel with the exhaust pipe. The adjusting means is shown at 32.

This lever 29 is mounted near the end of the exhaust pipe which is opposite the connection 26 and as the exhaust pipe expands with the heat andthe rod 25 retains its normal length,

the pivot 30 and'cons'equently the lever 29are moved towards the right in Fig. 2, thus rocking the lever on its pivot and moving the arm 31 upwardly to the dotted line position shown in said Fig. 2.

Mounted upon the exhaust pipe on a pivot 33, near the free end of the arm 31, is another bell crank lever 34 having a short horizontal arm 35 and a` long downwardly, extending arm 36. An adjustable bolt 37 forms the bearing point of the free end of the arm 31 on the arm 35 thus determining the relative position of those arms.

The arm 36 is connected by a link 38 with an arm 39 on the rock shaft 17 above referred to so that the shaft 17 is rocked as the bell crank lever 34 is moved on its pivot.

By reason of the tension of the springs 15 which rest against the cam 16, there is a constant tendency, of course, for the shaft 17 to 35 be rocked towards the dotted line position shown in Fig. 2. This will cause the arm 35 to be kept in contact with the arm 31 as the latter moves upwardly.

In operation, with Vthe engine cold, the parts 4o will be in the position shownin full lines in '"Fg. 2; This is the rich-mixture position of the carburetor. The spring 15 is holding the valve 14 in closed position and is also holding the bell crank lever 34 so that its arm 35 is in contact with the point 37 of the arm 31. The

valve 19 is also in nearl closed position so that very little air is a lowed to enter the carburetor 12. As the engine is cranked over by the electric starter or otherwise, a

' 50 rich mixture is'fed to it and consequently it starts easily. As the explosions occur in the cylinders and the latter exhaust into the pipe 22, the exhaust pipe is heated and soon begins to expand lengthwise. This expansion of the exhaust pipe together with the non-exp ansion of the rod 25 causes the bell crank lever 29 to be rocked on its pivot 30 so that the arm 31 moves upwardly. This permits the arm 35 to move upwardly also and the arm 36 to move to the left in Fig. 2, the spring 15 acting against the cam 16 to draw the arm 36 in that direction. In this Way the tension on the spring 15 becomes less and the valve 19 is first opened and then there is very little tension on the valve '14 so that the latter will open ver y readily with the suction through the carburetor and thussuicient air is admittedthrough the carburetor to provide a lean running mixture. The exhaust pipe 22 soon reaches its maximum elongation and as long as the engine is running it maintains its elongated form relay tive to the rod 25. This position of the parts is shown in dot-ted lines in Fig. 2 and the exact desired mixture at that point in the runy ning of the engine may be obtained by manipulating` the adjustments 32 and 37.

When the engine is stopped the exhaust pipe 22 cools very readily because of the large exposed surface and the 4parts resume the full line position shown in Fig. 2. In doing so the arm 31 moves downwardly against the arm 35 thereby rocking the lever 34 and mov- Ving the arm 36 towards the right. This rocks and may specifically claim, I do not desire it to be understood that my invention is limited to the exact details of the construction, as it will be apparent that changes may be made therein without departing from the spirit or scope of my invention.

Havingthus described my invention, what v I claim and desire to secure by Letters' Patent is:

1. In an internal combustion engine, the combination with the carburetor and the exhaust pipe thereof, of a rod of Invar steel Aconnected at one end to one end of the exhaust pipe, a bell crank lever pivoted. adjacent the other end of said exhaust pipe and having one of its arms connected to the free end of said rod, a second lever. pivoted on said exhaust pipe, the other arm of the first -lever connected'to operate one of the arms of the second lever, and a connection from the second lever to Jsaid 'carburetor'.

2. In an internal combustion engine, the combination of the exhaust pipe, a rod con-v nected at one end to one end of the exhaust pipe, a bell crank lever having one short arm and one long arm and pivotally supported on said exhaust pipe adjacent its other end, the short arm of said lever being connected to said rod, a second lever pivotally supported upon said exhaust pipe and having one short arm and one'long arm, the long arm of the first lever being adapted to contact with and operate upon the short arm'of the second lever, and a mixture controlling device connected to the long arm of the second lever.

3. In an internal combustion engine, the combination of a cylinder block, an exhaust pipe mounted thereon and adapted to receive the exhaust from the engine, a carburetor having an air valve and adapted to form a combustible fuel mixture for the engine, and

substantially non-expansible means actuated by the elongation of the exhaust pipe for controlling said valve to regulate the quality of said fuel mixture.

4. In an internal combustion engine, the combination of a cylinder block, an exhaust pipe mounted thereon, a carburetor having an air valve, and substantially non-expansible means actuated by the elongation of the exhaust pipe for controlling said valve to Vary the richness of the carburetor mixture in accordance with the temperature of the engine.

5. In an internal combustion engine7 the combination of an expansible exhaust pipe, a substantially non-expansible rod secured at one end to said exhaust pipe, a carburetor having an air Valve, and means connecting the other end of said rod to operate said Valve to increase the proportion of air in the fuel mixture from the carburetor as the engine warms up.

6. In an internal combustion engine, the combination With the mixture forming means thereof including an air valve, of an expansible exhaust pipe, a non-expansible rod, and connecting linkage between the exhast pipe, the rod and said air Valve adapted to regulate the mixture in accordance with engine temperature.

In testimony whereof I afix my signature.

' LIONEL M. VVOOLSON.

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