Title of Invention

ELEMENT WITH EXTERNAL ORIENTATION IN SINGLE CYLINDER(PF)PUMPS

Abstract

As per the invention herein described, in PF pumps, the element barrel fixing arrangement for the pump assembly has been dispensed with &. a simple methodology for barrel orientation has been evolved. As per the invention, the pump housing has been modified to access the barrel inlet port by an external tool. During the pump assembly, an external tool locates and orients the element barrel in the pump housing and there abr the Delivery Valve holder is tightened. The external tool is removed after tightening the Delivery Valve holder to the required torque.

Full Text

In a PF type fuel injection pump, the element comprising of Plunger 6. Barrel assembly is the key component in pressuring the specified quantity of diesei fuel & delivering it in to the engine. The external size of the pump is mainly dependent on the size of the element and the maximum permissible peak pressure. If the size of the element barrel can be reduced then the overall size of the pump can be reduced. The main object of the invention is to reduce the overall size of the element and in turn, the size of the PF pump, so that a compact PF pump can be offered for smaller engines. In a conventional PF pump, the element barrel has twin stepped collar. The bigger step of the collar provides the sealing between pump housing and the element barrel, so that the diesel fuel is prevented from leaking downwards into the engine crank case. The smaller step of the barrel collar has a specially milled key way slot, which accommodates a locking / fixing pin protruding from the housing. The procedure for assembling the element into the pump in the convention method is as follows : The pump housing has a small hole, into which a locating pin is pressed using interference fit This pin is made to protrude from the housing f wall by a pre-defined extent. The barrel is held such that the key slot in its collar Is aligned with the pin projecting in the housing and then dropped down gently into the housing. Due to the presence of the fixing pin, the barrel is prevented from rotation. Then the Delivery Valve is placed on top of it a. the Delivery Valve holder is tightened to the required torque. As per the Invention herein described. In PF pumps, the element barrel fixing arrangement for the pump assembly has been dispensed with 8t a simple methodology for barrel orientation has been evolved. As per the invention, the pump housing has been modified to access the barrel inlet port by a tool externally. During the pump assembly, an external tool locates and orients the element barrel in the pump housing and there after the Delivery Valve holder is tightened. The external tool is removed after tightening the Delivery Valve holder to the required torque. An external assembly orientation arrangement for use with PF type fuel injection pump configured for orientation of the element of PF type injection pump, said element means plunger and barrel assembly, comprising :- i. a pump housing wherein the said pump housing has an inlet hole at right angle to its axis and at a pre-defined distance from the barrel sealing surface. ii. a fixture device wherein said pump housing Is mounted on and held such that the inlet connection of the said pump housing in towards an assembler, iii. a barrel configured such that the said barrel having a barrel collar with a single step for sealing between the said pump housing and the said barrel, and configured to be being gently dropped into the said pump housing, said barret being held such that its inlet port is in same Hne as that of inlet hole of said pump housing just prior to drop of said barrel into the said pump housing, iv. an external tool having a spherical tip and an expanding cone, the said expanding cone with spherical tip locates the said inlet port in the said barrel, where upon the said barrel is capttvely positioned in the said pump housing, v. A tightening means to tighten the delivery valve holder wherein the Delivery Valve of PF type fuel injection pump thereafter is placed on top of the said pump housing and the Delivery Valve holder is tightened to the specified torque and thereafter the said external tool is withdrawn from the said external orientation assembly. In the embodiment described, the orientation arrangement of external element assembly for use with PF type Fuel Injection Pump as per the invention consisting of pump housing and barrel element assembly, wherein the element and pump housing of PF type fuel injection pump is configured for orientation by means of a tool externally: (0 wherein the said element means plunger and barrel assembly; (ii) wherein the said pump housing has its Inlet hole at right angle to its axis and at a pre-defined distance from the barrel sealing surface; (ill) wherein said pump housing is mounted and held onto a fixture device; (iv) wherein said barrel has a barrel collar with a single step for sealing between the said pump housing end the said barrel; has a shape to fit into the said pump housing and has its inlet port at the same height as that of inlet hole of said pump housing; (v) wherein said tool has a spherical tip and an expanding cone; (vi) wherein further said pump housing is mounted on said fixture device and held such that the inlet hole of said pump housing is towards the assembler; (vii) wherein further said barrel is held just above the said pump housing such that the inlet port of said barrel is in line with the inlet hole of said pump housing and then gently dropped into the said pump housing; (viii) wherein further external tool is inserted through the inlet hole of pump housing, such that its spherical tip locates the said inlet port in the said barrel and whereupon due to expanding cone, the said barret is captively positioned in the said pump housing, and (ix) wherein further the said external tool is withdrawn after the delivery valve holder is tightened by means of known tightening methods to desired torque. As per the invention described herein : - a. the barrel collar has a single step for sealing between the pump housing and barrel. The second collar step with key way slot has been eliminated. b. The pump housing has been designed to have the inlet hole at right angle to its axis and at a pre-defined distance from the barrel sealing surface. There is no provision made in the pump housing for the fixing pin. c. An external toot with spherical tip and expanding cone. d. Tightening means the tightening of the delivery valve holder into the pump housing after the placement of the delivery valve, its spring and a filler piece In a PF pump. The assembly procedure is as follows : The pump housing is held in a fixture such that the inlet connection is towards the assembler. The barrel(2) is held such that its inlet port is in the same line as that of the inlet hole(3) in the pump housing and then gently dropped down into the pump housing. An external tooi(4) with spherical tip and an expanding cone locates the barret port. This ensures the accurate location of the barrel(2) in the pump housing. Then the Delivery Valve is placed on top of It ft. the Delivery Valve holder(5) is tightened to the specified torque. The external tool is withdrawn after tightening the Delivery Valve holder. An embodiment of the invention will now be described with reference to the accompanying drawings: - In fig la. illustrates a conventional type PF pumps which consists of the barrel element(2) which has twin stepped collar and a fixing pin(l) provided to prevent the barrel from rotation. The smaller step of the barrel collar has a specially milled key way slot, which accommodates a locking/fixing pin protruding from the housing. In fig lb. the drawings shows the orientation arrangement of external element assembly for use with PF type Fuel Injection Pump as per the invention consisting of pump housing and barrel element(2} assembly. The barret assembly is configured to have a single step collar for sealing between the pump housing and the barrel. The second collar step with key way slot known in prior art is eliminated and also fixing pin(l) existing in conventional type PF pumps is also eliminated. An external tool (4) with spherical tip and an expanding cone is provided instead to align the position. The expanding cone of the external tool ensures accurate location of the barrel port in the pump housing. The delivery valve holder (5)of the delivery valve which is placed on top of pump housing is tightened to required torque. The external tool (4) Is thereafter removed from the assembly. • Blmtnates the need for element locating pin • Reduced barrel cottar diameter and In turn the pump shank diameter • amplified components; pump housing without hole for locating pin and barrel without second collar and key way slot • Reduced pump cost • Lower cost of the spare part - element ADVANTAGES OF INVENTION This orientation of the barrel by an external tool reduces the number of components, simplifies the components and the assembly process. Besides, this concept helps in reducing the overall size of the pump without compromising on the sealing surface area. COMPARISON OF TECHNICAL FEATURES BETWEEN PRIOR ART * INVENTION WE CLAIMS: 1. An element and pump housing of PF type fuel injection pump configured for orientation by means of a tool externally: (i) wherein the said element means plunger and barret assembly; (ti) wherein the said pump housing has its inlet hole at right angle to its axis and at a pre-defined distance from the barrel sealing surface; (iii) wherein said pump housing is mounted and held onto a fixture device; (iv) wherein said barrel has a barrel collar with a single step for sealing between the said pump housing and the said barrel; has a shape to fit into the said pump housing and has its inlet port at me same height as that of inlet hole of said pump housing; (v) wherein said tool has a spherical tip and an expanding cone; (vi) wherein further said pump housing is mounted on said fixture device and held such that the inlet hole of said pump housing is towards the assembler; (vii) wherein further said barrel is held just above the said pump housing such that the inlet port of said barrel is in line with the inlet hole of said pump housing and then gently dropped into the said pump housing; i (viii) wherein further external tool is inserted through the inlet hole of pump housing, such that its spherical tip locates the said inlet port in the said barrel end whereupon due to expanding cone, the said barrel is captively positioned in the said pump housing, and (ix) Wherein further the said external tool is withdrawn after the delivery valve holder is tightened by means of known tightening methods to desired torque. Dated on this the 17th day of October, 2002. To, The Controller of Patent, The Patent Office, Chennai.

Documents:

1016-mas-2001 abstract duplicate.pdf

1016-mas-2001 claims duplicate.pdf

1016-mas-2001 claims.pdf

1016-mas-2001 correspondence others.pdf

1016-mas-2001 correspondence po.pdf

1016-mas-2001 description (complete) duplicate.pdf

1016-mas-2001 description (complete).pdf

1016-mas-2001 drawing.pdf

1016-mas-2001 form-1.pdf

1016-mas-2001 form-19.pdf

1016-mas-2001 form-26.pdf

1016-mas-2001 form-5.pdf