US1941947A - Cylinder head assembly for internal combustion engines - Google Patents

Description

2 Sheets-Sheet l Jan. 2, 1934.

s. MQCPHERSON CYLINDER HEAD ASSEMBLY FOR INTERNAL COMBUSTION ENGINES Filed NOV. 26, 1928 Jan. 2, 1934.

E. S. MacPHERSON CYLINDER HEAD ASSEMBLY FOR INTERNAL COMBUSTION ENGINES Filed Nov. 25, 1928 2 Sheets-Sheet 2 & I 2/ g I I 2 /7 l U W I i J l J ll INVENTOR ATTORNEY- S Patented Jan. 2, 1934 UNITED STATES CYLINDER HEAD ASSEMBLY FOR INTER- NAL COMBUSTION ENGINES Earle S. MacPherson, Detroit, Mich, assignor,

by direct and mesne assignments, of one-half to Hupp Motor Car Corporation, Detroit, Mich., a corporation of Virginia, and one-half to Societe pour 'lExploitation 'des Gadoux, Paris, France Brevets Application November 26, 1928 Serial No. 321,979

3 Claims.

This invention relates to internal combustion engines and refers more particularly to improve ments in cylinder heads formed of aluminum or other similar material having as one of its char- 5 acteristics relatively high thermal conductivity.

Many advantages result from the use of cylinder heads formed from a metal of relatively high thermal conductivity since metals of this character are not only light in weight but offer the possibility of obtaining relatively higher compression ratios in the combustion chamber due primarily to the rapidity with which the same will dissipate the heat developed in the latter chamber. However, several disadvantages are also encountered with cylinder heads of this character with the result that they have generally been considered impractical. One of the greatest disadvantages experienced in the use of cylinder heads formed of aluminum or similar metals is the in-.

go ability to properly fit the head to a cast iron or steel block and maintain a rigid connection therebetween irrespective of temperature changes. This is due to the fact that metals of the above type have a relatively higher co-efficient of expan- 95 sion than cast iron or steel and as a consequence is more responsive to temperature changes.

Hence if the cylinder head is fitted properly at room temperature it is frequently too loose with v the increase in temperatures existing when the motor is operating. This is especially true of a motor requiring a comparatively long cylinder head such as for example the straight eight motors wherein the eight cylinders are arranged in alignment.

Furthermore the tensile and compressive strength of aluminum or equivalent metal is not equal to that of steel or cast iron and in order to obtain the required tensile and compressive strength, it has been necessary, heretofore, to either materially increase the size of an aluminum head relative to that of a cast iron or steel head of equal strength or to treat the aluminum head to increase its density or both.

It is therefore one of the primary objects of this invention to provide means for minimizing the expansion of the head as well as reinforcing the same. In practicing the invention I propose clamping the head to the cylinder block by means of a reinforcing member which is preferably formed of a metal having ,a relatively lower coefiicient of expansion than the metal from which the head is formed and having higher tensile strength. This reinforcing member may be formed of steel, cast iron or any other similar metal and is provided with a water passage therein adapted to extend the fulllength of the head and cooperate with the customary water jackets in the latter to form an enlarged chamber for the passage of the cooling medium. Thus the reinforcing member not only materially strengthens the head structurally but also operates to increase the cooling area and as a consequence reduces to a certain extent, the expansion of the head.

A further advantageous feature of the present invention is to accurately control the direction of expansion of the head by forming the same of a plurality of sections slightly spaced from each other and locating each of these sections upon the block at the centers thereof so that any expansion that takes place will be in directions away from the central locating pins.

The several objections, advantages and novel details of construction of the invention will be made more apparent as this description proceeds especially when considered in connection with the accompanying drawings wherein: 7

Figure l is a fragmentary sectional plan view through an internal combustion engine constructed in accordance with this invention;

Figure 2 is a sectional view taken on the line 2-2 of Figure 1;

Figure 3 is a sectional view taken on the line 3-3 of Figure 2.

Referring now to the drawings it will be noted that there is fragmentarily illustrated in Figure 1 an internal combustion engine 10 having a cylinder block 11 within which the pistons 12 are reciprocably mounted in the conventional manner; The reference character 13 indicates generally the cylinder head which is clamped to the block 11 in a manner to be more fully hereinafter set forth.

As previously stated, I propose forming th cylinder head of two sections 14 and 15 formed of aluminum or some similar metal having as one of its characteristics relatively high thermal conductivity. These sections are secured in longitudinal alignment upon the block with a slight space 16 between the adjacent ends thereof so as to permit each section to expand independently 100 of the other. Each section is provided with a combustion chamber 17 and a water compartment 18 extending around and over the combustion chamber as is customary in present day manufacture. The water jacket compartments 105 are provided with ribs 19 for carrying off the heat of the combustion chambers and are open at the upper ends thereof as indicated at 20. Suitable openings 21 being formed in the sections 14 and 15 adjacent the water jackets and communicating 110 with the interior of the combustion chamber for receiving the usual spark plugs 22.

For closing the upper end of the water jackets I provide a header 23 formed of a material having a comparatively low co-efiicient of expansion and adapted to extend substantially the full length of the sections 14 and 15. The header 23 is of sufiicient width to conceal the water jackets -18 and is preferably hollow or substantially U- shaped in cross section so asto cooperate with the water jackets 18 in the sections to form enlarged water compartments. Thisarrangement offers the possibility of circulatinga relatively large volume of cooling medium "through the engine and renders possible minimizing the expansion of the sections 14 and 15. It will further be noted from Figure l of the drawings that the header is formed of a one piece construction and in addition to performing the foregoingfunction operates to establish communication between the water jacketsformedin each of the head sections 14 and 15. Furthermore by reason of the fact that this header is preferablyformed of cast iron or steel, it will function as a' reinforcement orstiffener for the sections 14 and 15 which as pointed out above, are formed of aluminum or some similar material.

In order to secure the header 23 to the sections 14 and 15 as well as secure the latter to the block,I provide a series of aligned apertures in these members for receiving the bolts 24. The header 23 being utilized to clamp the sections 14 and 15 rigidly to the block. Inasmuch as the adjacent ends of the sections 14 and 15 are spaced only a slight distance apart, the same are provided with cooperating recesses 25 adapted in theassembledposition of the .sections, to form an opening for receiving the securing bolts 26. These openings'together with the openings 27, 28 and 29 of each section are formed with a diameter slightly larger than the diameter of the bolts so as to permit a limited relative movement between the sections andv securing bolts therefor. The sections 14 and15 however, are accurately located upon the cylinder block by the bolts 30 adapted to extend through openings 31 formed in the center of each section. In other words the central openings 30 in each section are formed to fit the bolts 31 snugly. This construction not only definitely locates the sections 14 and 15 relative to each other'and to the block but also controls to a certain extent, the direction of expansion of the sections. The arrangement being such that present instance is substantially the same as in internal combustion engines now commercially produced in that the water flows from the radiator (not shown) tothe circulating pump which forces the same into the water distribution manifold or header 23 and through the water jackets 18. Thewater is then directed through the thermostat 33 back to the radiator.

Thus from the foregoing it will be apparent to those skilled in this art that in accordance with the provisions of this invention it is possible to produce a cylinder head formed of aluminum or other like material in which however, the tendencyto expand is minimized and in which the structural strength of the head is increased.

What I claim as my invention is:

1. The combination with a cylinder block, of a cylinder head therefor formed'of aluminum or similar material and composed of a plurality of longitudinally spaced sections having chambers therein fora cooling medium, and means for stiffening and clamping the sections to the block including a hollow header extending substantially the full length of said sections thereof and establishing communication between the chambersaforesaid.

2. The combination with a cylinder block, of a head for said block formed of a metal of relatively highthermal conductivity and composed of a plurality of sections spaced from each other longitudinally of the-block, and means for fixing each of the sections intermediate the ends thereof to the block whereby expansion of the sections in the direction of the block .is substantially equally apportioned to the spaces between the sections.

3. The combination with a cylinder block, of a cylinder head therefor formed of a metal of relatively high thermal conductivity and comprising a plurality of sections spaced from each other longitudinally of the "block, and a cap member superimposed upon the sections aforesaid for clamping the latter to the block and formed of a metal possessing a greater tensile strength than the metal from which the said sections are formed so as to effectively reinforce the latter.

EARLE S. MACPHERSON.

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