US3742926A

US3742926A - Delivery valves

Info

Publication number: US3742926A
Application number: US00175510A
Authority: US
Inventors: K Kemp
Original assignee: CAV Ltd
Current assignee: CAV Ltd
Priority date: 1970-08-27
Filing date: 1971-08-27
Publication date: 1973-07-03
Anticipated expiration: 1990-07-03
Also published as: DE2140893A1; SE373637B; JPS5145731B1; CA948510A; ZA715140B; ES172067Y; ES172067U; BR7105581D0; GB1347260A

Abstract

A delivery valve for a fuel injection pumping apparatus includes a body portion which is slidable within a bore between a pair of abutments. The bore forms part of a passage between an injection pump and an injection nozzle and the member is provided with a valve which when the member is moved under the action of fuel into contact with one of the abutments opens to permit flow of fuel from the injection pump to the nozzle. When the flow of fuel from the injection pump ceases the valve closes and the member moves back towards the other abutment under the action of fuel under pressure in the pipe line connecting the injection pump with the nozzle. A predetermined volume of fuel is therefore allowed to flow from the pipe line towards the injection pump.

Description

United States Patent 1191 [11] 3,742,926 Kemp July 3, 1973 DELIVERY VALVES [75] Inventor: Kenneth Albert Walters Kemp, pmfwry Croyle London, England Assrsram Exammer-R1chard J. Sher Attorney-Holman 8:. Stern [73] Assignee: C.A.V. Limited, Birmingham,

' E l d 57 ABSTRACT [22] Flled' 1971 A delivery valve for a fuel injection pumping apparatus [21] Appl. N0.: 175,510 includes a body portion which is slidable within a bore between a pair of abutments. The bore forms part of a passage between an injection pump and an injection [30] Forelgn Apphcatlmf p'nomy Data nozzle and the member is provided with a valve which Aug. 27, Great Bl'ltaln n e mbe i 'mo ed de he cti n o uel 1 into contact with one of the abutments opens to permit [52] 123/139 123/139 137/5122 flow of fuel from the injection pump to the nozzle. 137/5123 When the flow of fuel from the injection pump ceases [5 the valve closes d the member moves back towards [5 8] Flam of Search 123/139 139 the other abutment under the action of fuel under pres- 137/5125 512'3 sure in the pipe line connecting the injection pump with the nozzle. A predetermined volume of fuel is therefore [5 6] References C'ted allowed to flow from the pipe line towards the injection UNITED STATESPATENTS pump, 2,044,629 6/1936 Parker 137/5123 3,547,148 12 1970 Drori 123/139 DP 5 2 D'awmg F'gures DELIVERY VALVES This invention relates to delivery valves for use in liquid fuel pumping apparatus, the valves being of the kind which are disposed in or adjacent the fuel injection pump and which open during an injection stroke to permit fuel to flow to an associated engine and which then close and allow a predetermined quantity of fuel to flow back towards the pump at the end of the injection stroke.

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

According to the invention a delivery valve of the kind specified comprises in combination, a member slidable within a bore between a pair of abutments, said bore constituting part of the flow passage from the injection pump to the associated engine, and valve means contained within the member and disposed to open when the member has been moved a predetermined amount by the flow of fuel during an injection stroke towards one of said abutments, said valve means opening to allow continued flow of fuel during the injection stroke but closing at the end of the injection stroke, the member then moving into contact with the other abutment thereby allowing a predetermined quantity of fuel to flow back towards the injection pump.

One example of a delivery valve in accordance with the invention will now be described with reference to the accompanying drawings in whichz.

FIG. 1 is a diagram of an apparatus including the valve, and

FIG. 2 is a view to an enlarged scale of the valve.

With reference to the drawing there is provided a rotary cylindrical distributor member 1 in which is formed a longitudinally extending bore 3. The distributor member is housed in a body 1a and is driven in timed relationship with the associated engine. At one end the bore 3 defines an abutment 4 and this end of the bore communicates with the pumping chamber of an injection pump 1b. Located at the other end of the bore 3 is a further abutment in the form of a plug 15. Moreover, extending from this end of the bore 3 is a delivery passage 14 which extends outwardly to the periphery of the distributor member and which is arranged to register in turn and during successive injection strokes of the injection pump, with a plurality of outlet ports 14a only one of which is shown, in the body. The outlet ports are connected respectively to the injection nozzles 14b of the associated engine respectively.

Slidable within the bore 3 is a cylindrical delivery valve body 2. Formed within the body 2 is a spring chamber having a seating 7 defined at one end. Moreover, for co-operation with the seating there is provided a valve element in the form of a ball 6. The ball is contacted by a spring abutment 9 and the spring abutment 9 locates against one end of a coiled compression spring 8. The other end of the coiled compression spring is located about a stop 10 which extends from a plug 5 serving to close the end of the spring chamber remote from the seating. Adjacent the plug 5 the spring chamber communicates with the periphery of the cylindrical member 2 by way of short radially disposed passages 16 and these are in constant communication with an enlarged portion 'of the bore 3 from which extends the delivery passage 14.

Also provided in the cylindrical member 2 is a transverse drilling 11 which opens into the spring chamber by way of the seating. Moreover, the end of the cylindrical member 2 adjacent the abutment 4 is of reduced diameter and defines an annular space 13 which during movement of the cylindrical member as will be described, can be brought into registration with a circumferential groove 12 formed in the distributor member and communicating with the transversely extending passage 11.

In use, when the injection stroke of the injection pump lb starts, fuel entering the bore 3 from the injection pump will urge the cylindrical member 2 against the action of the spring, and fuel will be expelled from the opposite end of the bore and will flow to the appropriate fuel injection nozzle of the associated engine by way of the delivery passage 14. After a predetermined movement of the cylindrical member the space 13 will be brought into register with the groove 12. When this occurs the fuel pressure acting on the ball 6 is balanced but it remains in contact-with the seating because of the action of the spring, and the cylindrical member will continue to move forwardly until it is halted by the stop. When this occurs further fuel flowing from the injection pump will lift the ball 6 from the seating 7 against the action of the compression spring 8 and the fuel will flow to the delivery passage 14 by way of the spring chamber and the passages 16. At the end of the delivery of fuel by the injection pump the ball 6 will close onto the seating 7 under the action of the spring. Moreover, under the action of fuel under pressure in the pipeline interconnecting the pump and nozzle, the cylindrical member will move towards the abutment 4. During this motion the delivery passage 14 is still in register with a delivery port and a predetermined quantity of fuel will flow back towards the injection pump. This flow of fuel will cease when the cylindrical member strikes the abutment 4.

I claim:

l. A delivery valve for use in a liquid fuel pumping apparatus for supplying fuel to an internal combustion engine, the valve being positioned between an injection pump forming part of the apparatus and an outlet, the delivery valve comprising in combination, a bore, a pair of abutments at the opposite ends of the bore, a member slidable within said bore between the pair of abutments, said bore constituting part of the flow passage between the injection pump and the outlet, valve means contained within the member and disposed to open when the member has been moved by the flow of fuel during an injection stroke of the injection pump into contact with one of said abutments, said valve means opening to allow continued flow of fuel during the injection stroke but closing at the end of the injection stroke, co-operating means on the member and bore for preventing the application of fuel pressure from the injection pump to said valve means until the member has moved a predetermined extent towards said one abutment, the member at the end of the injection stroke, then moving into contact with the other abutment thereby allowing a predetermined quantity of fuel to flow back towards the injection pump.

2. A delivery valve as claimed in claim 1 in which said valve means includes a seating, and a spring loaded valve element-which co-operates with said seating, a passage in the member, said valve means serving to prevent flow of fuel through said passage until the member has contacted said one abutment.

3. A delivery valve as claimed in claim 2 in which said passage includes a transverse portion opening onto the periphery of the member adjacent the end thereof adjacent the other abutment, said transverse portion communicating with a groove formed in the wall of the bore, said member being of reduced diameter at the end thereof adjacent said other abutment, the arrangement being such that as the member moves into contact with the one abutment the transverse portion is placed in communication with the bore adjacent said other abutment.

4. A liquid fuel injection pumping apparatus including an injection pump for supplying fuel to an injection nozzle and a delivery valve disposed adjacent the fuel injection pump, the delivery valve comprising a bore, a valve member slidable within the bore, a pair of abutments at opposite ends of the bore, an inlet from the injection pump communicating with one end of the bore,

an outlet to the nozzle at the other end of the bore, a transverse passage in the valve member, co-operating means on the valve member and the wall of the bore whereby said transverse passage is brought into communication with said inlet only when the valve member has moved a predetermined amount towards the other end of the bore under the action of fuel under pressure delivered by the injection pump, a further passage in the valve member communicating with said passage means and said outlet, a seating in said passage and a spring loaded valve element for co-operation with said seating, said valve element being lifted from its seating when the member contacts the abutment at the other end of the bore.

5. A liquid fuel injection pumping apparatus as claimed in Claim 4 in which said co-operating means comprises a groove in the wall of the bore and a reduced portion on the member adjacent said one end of the bore.

Claims

1. A delivery valve for use in a liquid fuel pumping apparatus for supplying fuel to an internal combustion engine, the valve being positioned between an injection pump forming part of the apparatus and an outlet, the delivery valve comprising in combination, a bore, a pair of abutments at the opposite ends of the bore, a member slidable within said bore between the pair of abutments, said bore constituting part of the flow passage between the injection pump and the outlet, valve means contained within the member and disposed to open when the member has been moved by the flow of fuel during an injection stroke of the injection pump into contact with one of said abutments, said valve means opening to allow continued flow of fuel during the injection stroke but closing at the end of the injection stroke, co-operating means on the member and bore for preventing the application of fuel pressure from the injection pump to said valve means until the member has moved a predetermined extent towards said one abutment, the member at the end of the injection stroke, then moving into contact with the other abutment thereby allowing a predetermined quantity of fuel to flow back towards the injection pump.

2. A delivery valve as claimed in claim 1 in which said valve means includes a seating, and a spring loaded valve element which co-operates with said seating, a passage in the member, said valve means serving to prevent flow of fuel through said passage until the member has contacted said one abutment. Pg,8

4. A liquid fuel injection pumping apparatus including an injection pump for supplying fuel to an injection nozzle and a delivery valve disposed adjacent the fuel injection pump, the delivery valve comprising a bore, a valve member slidable within the bore, a pair of abutments at opposite ends of the bore, an inlet from the injection pump communicating with one end of the bore, an outlet to the nozzle at the other end of the bore, a transverse passage in the valve member, co-operating means on the valve member and the wall of the bore whereby said transverse passage is brought into communication with said inlet only when the valve member has moved a predetermined amount towards the other end of the bore under the action of fuel under pressure delivered by the injection pump, a further passage in the valve member communicating with said passage means and said outlet, a seating in said passage and a spring loaded valve element for co-operation with said seating, said valve element being lifted from its seating when the member contacts the abutment at the other end of the bore.