US2793079A - Ball injector valve - Google Patents

Description

May 21, 195? P. G. L-.A HAYE BALL. INJECTOR VALVE Filed Aug. 11. 1

BALL INJECTOR VALVE Paul G. La Haye, Milwaukee, Wis., assignor to N ordberg Manufacturing Company, Milwaukee, Wis., a corporation of Wisconsin Application August 11, 1954, Serial No. 449,206

4 Claims. (Cl. 299-107.6)

My invention resides in the field of liquid fuel injectors for injecting any type of liquid fuel into the combustion space of an internal combustion engine and more specifically is usable with a diesel engine requiring'the injection of substantial quantities of diesel fuel, a dual fuel engine, or a gas engine with spark ignition.

A primary object of my. invention is a fuel injector assembly with a minimum number of moving and wearing parts constructed and arranged to be highly accurate in operation and at the same time designed to be easily manufactured.

Another object of my invention is an injector assembly of the above type constructed and arranged to employ self-lapping in that the valve surfaces in the unit will auto matically self-lap each other.

Another object of my invention is an injector constructed to automatically clear itself of any foreign material clogged around the valve surface.

Another object of my invention is a ball type injector constructed and arranged to thoroughly atomize the fuel charge injected so as to acquire a thorough intermixing of the fuel and air in the combustion chamber.

Another object of my invention is an injector of the above type constructed so that it is easily adjust-ed for a wide range of selectableopening and closing pressures so as to give accurate injection control.

Other objects will appear from time to time in the ensuing specification and drawings in which:

Figure l is a sectional view of a typical two-cycle engine with my fuel injector assembly mounted in the cylinder head;

Figure 2 is a longitudinal sectional view of my improved fuel injector assembly; and

Figure 3 is an exploded view of the main parts of my fuel injector.

In Figure l, I have shown one cylinder of a conventional diesel engine having a cylinder 10 with a piston 12 reciprocating therein, with inlet ports 14 and exhaust ports 16 in the cylinder walls to provide for the entrance and exhaustion of air and gases respectively from the cylinder in a conventional manner. The cylinder head 18 defines a combustion space 20 in the top of the cylinder with an injector assembly 22 mounted therein projecting slightly into the combustion space.

The injector assembly in Figure 2 includes a nozzle body or base element 24 adapted to be rigidly mounted on the cylinder head by any suitable means. A valve 26 with an elongated stem 28 threadedly engages the body or base element 24, as at 30, in a rigid relationship. A valve body 32 surrounds the valve stem throughout its length and encloses the end with a socket 34.

A fuel delivery channel 36, in the base element 24, delivers fuel from any suitable source through a connection 38 in Figure l to an annular fuel passage 40 in the valve body. A port 42 through the valve body communicates the annular fuel passage 40 with a longitudinal fuel passage 44 extending the length of the valve stem and ternited States Patent Patented May 21, 1957 minating in a discharge opening 46 which is surrounded by a conical valve seat 48. The socket 34 on the valve body has a plurality of fuel ports 50 communicating with the interior through which fuel is injected into the combustion space of the chamber. A ball 52 is loosely mounted in the socket, as shown in Figure 3, and is adapted to engage the conical seat 48 in a generally liquidtight manner.

The valve stem and valve body are longitudinally movable with respect to each other and are slightly spaced. An annular fuel relief 54 in the valve body removes excess fuel leaking between these two movable elements and carries it, by a channel 56, to a spring chamber, designated generally at 58. A suitable fuel leak-off channel 60 is provided in the base element 24, so that the excess fuel or leakage can be carried away by a suitable connection 62 in Figure 1.

The spring chamber '58 includes shoulders 64 on the valve body and 66 on the base element. A spring spacer or cup-like element 68 abuts the shoulder 66 through suitable retraction shims 70 and confines a coil spring 72 which engages at its other end the shoulder 64 on the valve body through an upper spring seat element 74, a lower spring seat' element 76 and suitable shims 78 being positioned between the spring and the spring spacer or cup. The top of the spring spacer or cup 68 is slightly spaced from the shoulder 64 as shown at .79.

The socket 34, closing the end of the valve body, is generally hemispherical in configuration and slightly exceeds the diameter of the ball, so that the ball may rotate. The ball is adapted to engage the conical seat in a circle,

the area of which is substantially less than the crosssectional area of the hemispherical ball socket.

I have found that my injector will operate quite satisfactorily if the socket diameter exceeds the ball diameter by approximately from two to five percent.

I have also found that the diameter of the circle of contact between the ball and its seat should be approximately twenty-five percent of the hemispherical socket diameter as a maximum.

The use, operation and function of my invention are as follows:

The valve element 26 with its stem is rigidly mounted in the cylinder head and is surrounded by a valve body which encloses its lower end with an hemispherical socket. A ball is freely mounted in this socket and under the bias of the spring 72 engages the conical seat. The fuel channel is thus closed by the ball, and both the ball and valve body will be moved longitudinally away from the seat when the total pressure in the longitudinal fuel channel 44 exceeds the resistance of the spring. The area of application of fuel pressure opposing the spring is the area of the circle of engagement between the conical seat and the ball, and as soon as the ball moves away from its seat, the fluid pressure in the channel 44 will expand to an area approximately that of the cross-sectional area of the ball socket. This pressure greatly exceeds the resistance of the spring. Once the total pressure from the channel 44 on the ball builds up to exceed the spring resistance and the valve elements are opened, the total force will then rapidly increase, so that the injector has a snap action or a greatly accelerated injecting motion, once the valve elements have opened slightly. The amount that the elements separate is limited by the spacing 79.

The pressure of the fluid supplied to the channel 44 must drop substantially below that required to open the valve elements before the spring 72 will again bring the I rotate, because the upward force supporting the ball is approximately at its center, while the downward force of the valve seat engaging the ball will be concentrated at the point X and this will be augmented by the fluid pressure. Any foreign particle at the point X would cause the ball to rotate counterclockwise slightly in Figure 2 until the valve seat area clears itself.

If a foreign particle became lodged on the seat or on the surface of the ball, the rotary motion of the ball caused by the unbalanced forces applied to it would give a self-lapping action and even though the particle might become so deeply imbedded that it would refuse to be dislodged, the surface would nevertheless become smooth again very quickly, due to this self-lapping action.

It will be realized that whereas I have described and illustrated a practical and operative device, nevertheless, many changes may be made in the size, shape, arrangement, number and disposition of parts without departing materially from the spirit of my invention. Iwish, therefore, that my showing be taken as in a large sense illustrative or diagrammatic rather than as limiting me to my precise illustration.

I claim:

1. In a fuel injector assembly for use with diesel engines and the like, a valve with an elongated valve stem having a generally centrally disposed internal, longitudinal fuel channel terminating in an opening surrounded by a generally conical seat, the fuel channel being adapted to be in communication with a source of high pressure fuel, a valve body with a stem-receiving channel surrounding and movably mounted relative to the stem and terminating in a ball socket with a hemispherical interior having a plurality of ports each of which terminates inside the socket at a point normally spaced from the ball, the inside of the valve body channel being spaced slightly from the outside of the valve stem to provide a restricted leak-off, a leak-01f channel in communication with the restricted leak-off, a ball freely mounted within the hemispherical ball socket positioned opposite the conical seat, the diameter of the socket being two to five percent greater than the ball, and spring means between the valve body and the valve biasing the ball into engagement with the seat, the ball engaging the seat in a diameter which is no greater than one-fourth the diameter of the hemispherical ball socket.

2. In a ball injector valve for diesel engines and the like, a base normally fixed during the use of the valve, a valve stem normally fixed in relation to said base, hav ing a longitudinal, internal fuel channel, a valve body surrounding and slidable along the exterior of said valve stem and having an integral closed lower end, a ball within the said closed lower end abutting the lower end of the valve stem to close the end of said fuel channel, there being a fuel duct connection in communication with the upper end of said fuel channel, an annular chamber .around the valve body between it and the base defined by shoulders on the base and valve body at its upper and lower ends, yielding means between the valve stem and valve body in the annular chamber engaging the shoulders effective normally to urge the valve body and the ball to fuel channel closing position, the valve body being ported adjacent its lower end, the ball being free in the space between the valve body and the end of the valve stem, and a fuel return passage between the closed lower end of the valve body and the annular shoulder.

3. The structure of claim 2 in which the valve body is ported adjacent its lower end by a plurality of ports each of which terminates inside the closed lower end of the valve body at a point normally spaced from the ball.

4. The structure of claim 2 in which the closed lower end'of the valve body is formed into a socket, the diameter of the socket being 2 to 5 percent greater than the ball, the lower end of the valve stem having a conical seatopposite the ball, the ball engaging the seat in a diameter which is no greater than one-fourth the diameter of the ball socket.

' References Cited in the file of this patent UNITED STATES PATENTS 1,386,832 Bailly Aug. 9, 1921 1,597,621 Reichard Aug. 24, 1926 FOREIGN PATENTS 350,731 Great Britain June 18, 1931 472,625 Great Britain Sept. 27, 1937

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