US3712761A

US3712761A - Liquid fuel injection pumping apparatus

Info

Publication number: US3712761A
Application number: US00077687A
Authority: US
Inventors: D Mowbray
Original assignee: CAV Ltd
Current assignee: CAV Ltd
Priority date: 1969-10-03
Filing date: 1970-10-02
Publication date: 1973-01-23
Anticipated expiration: 1990-01-23
Also published as: CA929028A; FR2064961A5; GB1317567A; ES384534A1; TR16741A; DE2047514A1; ZA706453B

Abstract

A liquid fuel pumping apparatus including an axially movable shuttle, the extent of movement of which is limited by fluid pressure operable piston member having a cylindrical portion which is eccentrically disposed relative to the axis of the bore containing the piston member, the surface of the cylindrical portion defining a stop surface for the shuttle.

Description

United States Patent [191 v Mowbray [451 Jan. 23, 1973 i 1 LIQUID FUEL INJECTION PUMPING APPARATUS [75] inventor: Dorian Farrar Mowbray, Burnham,

England [73] Assignee: C. A. V. Limited, Birmingham, En-

gland [22] Filed: Oct. 2, 1970 [21] Appl.No.: 77,687

[30] Foreign Application Priority Data Oct. 3, i969 Great Britain ..48,628l69 [52] U.S. Cl ..-..4l7/462 [5 1] Int. Cl ..F04b 19/02 [58] Field of Search 417/462, 245, 212, 485

i561 References Cited UNITED STATES PATENTS Kemp ..'....4l7/2l2 3,433,!60 3/1969 Kemp ..4l7/245 3,506,381 4/1970 Kemp ..4l7/485 3,507,579 4/l970 Kemp r ..4l7/485 3,500,749 3/1970 Kemp et al. ..4l7/485 Primary Examiner-William L. Freeh Attorney-Holman & Stern [5 7] ABSTRACT A liquid fuel pumping apparatus including an axially movable shuttle, the extent of movement of which is limited by fluid pressure operable piston member having a cylindrical portion which is eccentrically disposed relative to the axis of the bore containing the piston member, the surface of the cylindrical portion defining a stop surface for the shuttle.

3 Claims, 2 Drawing Figures 1 LIQUID FUEL INJECTION PUMPING APPARATUS This invention relates to liquid fuel pumping apparatus for supplying fuel to internal combustion engines and of the kind comprising a shuttle movable in a bore and adjustable stop means positioned at one end of the bore for limiting the excursion of said shuttle.

The object of the invention is to provide such a pumping apparatus in a simple and convenient form.

According to the invention a liquid fuel pumping apparatus of the kind specified comprises in combination, an axially movable member disposed for movement along an axis disposed substantially at right angles to the axis of the bore, a cylindrical portion of said member being eccentrically disposed relative to the axis of movement of the member, and the cylindrical portion having a contoured stop surface against which the shuttle bears, the arrangement being that axial movement and angular movement of the member or both will vary the permitted excursion of the shuttle in the bore.

ln the accompanying drawings:

F [G 1 is a sectional side elevation of one example of a pumping apparatus in accordance with the invention, and

FIG. 2 is a part section on the line 2-2 of FIG. 1.

With reference to the drawings there is provided a body part in which is mounted a rotary cylindrical distributor 11. This is arranged to be driven in timed relationship with the engine with which the apparatus is associated and at one end is provided with a transverse bore which accommodates a pair of plungers 12. The portion of the bore lying between the plungers communicates by way of a longitudinal passage in the distributor with a radial delivery passage 13 also formed in the distributor and this is arranged to communicate in turn and as the distributor rotates, with a plurality of outlet ports 14 formed in the body part and in communication respectively with injection nozzles mounted in known manner on the associated compression ignition engine.

The plungers 12 are arranged to be moved inwardly as the distributor rotates, by means of cam followers 40 which co-act with cam surfaces formed on a surrounding annular cam ring 41. The cam ring, followers and plungers constitute an injection pump which partakes of an injection stroke so that fuel is expelled from the bore containing the plungers 12 during the time the delivery passage 13 is in register with an outlet port 14.

At a point axially removed from the delivery passage 13 the longitudinal passage communicates with a plurality of radial inlet passages 15 and these are arranged to register in turn as the distributor rotates, with an inlet port formed in the body part and in communication with one end of a cylinder 16 containing an axially movable cylindrical shuttle 17. The aforesaid registration of the inlet port and an inlet passage 15 takes place during a filling period of the injection pump during the time when the plungers 12 are allowed to move outwardly and whilst the delivery passage I3 is out of register with a delivery port 14.

Fuel is supplied to said one end of the cylinder 16 by way of a plurality of longitudinal grooves 18 formed in the periphery of the distributor and extending from a circumferential groove 19. The registration of one of the grooves 18 with a supply passage 20 occurs during an injection stroke of the injection pump so that fuel which is delivered to the groove 19 from an outlet 21 of a feed pump 22, by way of a throttle flows to the inner end of the cylinder 16 and causes the shuttle 17 to be moved outwardly. Fuel leaves the other end of the cylinder 16 by way of a passage 23 in the bodypart.

This passage is in communication with a further circumferential groove 24 formed in the periphery of the distributor and from this groove 24 extend further axial grooves 25 and these during the movement of the shuttle towards the other end of the cylinder, communicate with spill passages 260. During the filling period of the injection pump one of the grooves 25 communicates with a feed passage 26 which is in communication with the outlet 21 of the feed pump, so that fuel under pressure is supplied to the other end of the cylinder 16 and the shuttle is moved towards said one end of the cylinder thereby causing the previously throttled quantity of fuel contained therein to be delivered to the injection pump for delivery to the engine during the next injection stroke. The excursion of the shuttle in the cylinder therefore determines the quantity of fuel which will next be delivered to the engine.

In order to control the maximum quantity of fuel which is supplied to the engine the excursion of the shuttle 17 is limited by a stop. As shown in the drawing the stop has the form of an axially movable cylindrical member in the form of a piston which is slidably mounted within a cylinder 51 the axis of which is at right angles to the axis of rotation of the distributor. The piston 50 is loaded by a pair of coiled compression springs 52 and is moved against the action of the springs by fluid under pressure which is supplied to the right hand end of the cylinder 50 through a passage (not shown). The fuel under pressure is obtained from the outlet of the feed pump, the outlet pressure of the feed pump being controlled in such a manner that it varies in accordance with the speed at which the apparatus is driven.

The right hand end of the cylinder 51 is closed by a plug housing 53 in which is located an angularly adjustable plug 54. At its inner end the plug 54 is provided with a projection 55 of a non-circular section and this is located within a complementary recess formed in the piston 50. In this manner the piston 50 is allowed to move axially but its angular movement is prevented. However, by rotating the plug member 54 the angular setting of the piston can be adjusted. Intermediate its ends the piston is provided with a cylindrical portion 56 which is eccentrically disposed relative to the axis of the bore 51. Furthermore, the surface of the cylindrical portion is contoured and defines a stop surface against which a projection 57 on the shuttle 17 can bear. The arrangement is such that for a given setting of the plug 54 the permitted outward movement of the shuttle l7 will vary inaccordance with the speed at which the apparatus is driven. However, to enable initial adjustment of the maximum fuel quantity to take place the plug member 54 can be moved angularly to adjust the datum position of the stop surface.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

l. A liquid fuel pumping apparatus for supplying fuel to internal combustion engines and comprising an injection pump including a plunger reciprocable within a cylinder, means for imparting movement to the plunger, an outlet communicating with said cylinder and through which fuel flows when movement is imparted to said plunger by said means, an inlet communicating with said cylinder and through which fuel flows to till the injection pump, a bore in which fuel is stored prior to flowing through said inlet to the injection pump, a shuttle movable in said bore, an axially movable member disposed for movement along an axis disposed substantially at right angles to the axis of the bore, a cylindrical portion of said member being eccentrically disposed relative to the axis of movement of the member, and a contoured stop surface formed on the cylindrical portion and against which the shuttle bears, the arrangement being that axial movement and angular movement of the member or both will vary the permitted excursion of the shuttle in the bore to control the volume of fuel flowing to the inlet.

2. An apparatus as claimed in claim 1 in which said member constitutes a fluid pressure operable piston and there is provided a plug member which is angularly adjustable from the exterior of the apparatus, and means connecting the members which permits relative axial movement but which prevents relative angular movement.

3. An apparatus as claimed in claim 2 in which the plug member is provided with a projection of non-circular section and which is engaged within a complementary recess in the piston.

Claims

1. A liquid fuel pumping apparatus for supplying fuel to internal combustion engines and comprising an injection pump including a plunger reciprocable within a cylinder, means for imparting movement to the plunger, an outlet communicating with said cylinder and through which fuel flows when movement is imparted to said plunger by said means, an inlet communicating with said cylinder and through which fuel flows to fill the injection pump, a bore in which fuel is stored prior to flowing through said inlet to the injection pump, a shuttle movable in said bore, an axially movable member disposed for movement along an axis disposed substantially at right angles to the axis of the bore, a cylindrical portion of said member being eccentrically disposed relative to the axis of movement of the member, and a contoured stop surface formed on the cylindrical portion and against which the shuttle bears, the arrangement being that axial movement and angular movement of the member or both will vary the permitted excursion of the shuttle in the bore to control the volume of fuel flowing to the inlet.