US 3641802 A
A method and apparatus wherein a tapered plug member, e.g. a cone or a ball, is forcibly engaged with a nozzle body member to progressively deform the latter to decrease the flow capacity through the swirl slots in the body member until a desired fluid flow rate is achieved.
Description (OCR text may contain errors)
I United States Patent [151 3,641,802
Segro 1 Feb. 15, 1972  METHOD AND APPARATUS FOR  References Cited SETTING THE FLOW RATE OF A FUEL INJECTION NOZZLE UNITED STATES PATENTS 3,095,175 6/1963 Taisho lketani ..239/S46 [721 Segm 3,150,442 9/1964 Straw et al. ..29/157  Assignee: Parker-Hannifin Corporation, Cleveland,
Ohio Primary Examiner-Lowell A. Larson  Filed: Sept- 17 1969 Attorney0berlin, Maky, Donnelly & Renner  Appl. No.: 858,680  ABSTRACT A method and apparatus wherein a tapered plug member, e.g.  US. Cl. ..72/377, 29/157 C, 239/546 a cone or a ball, is forcibly engaged with a nozzle body  Int. Cl ..B2ld 51/ 38 member to progressively deform the latter to decrease the Field Of C, 404, l flow capacity through the Swirl slots in [he member until 2 2 461, 546, a desired fluid flow rate is achieved. 72/377 14 Claims, 7 Drawing Figures PATENTEDFEB 15 1972 INVENTOR HAS/L 5. SEGRO mi ATTORNEYS METHOD AND APPARATUS FOR SETTING 'I'I-IE FLOW RATE OF A FUEL INJECTION NOZZLE BACKGROUND OF THE INVENTION In known nozzles of the type having swirl slots leading tangentially into the periphery of a vortex chamber to impart whirling motion to the fuel for discharge from the central discharge orifice of the vortex chamber in the form ofa hollow conical spray, the swirl slots are generally formed as grooves on the conical end of a plug member which is seated against a complemental conical recess in a nozzle body member. Accordingly, when the plug member is assembled in the body member, the flow rate of the nozzle is determined by the width and depth of the swirl slots, and there is no way of adjusting the flow rate except by removing the plug member and increasing the width and/or depth of the swirl slots therein. This expedient requires that the swirl slots in the plug member first be made of smaller size than desired, and, as evident, it would be an expensive and time consuming operation to progressively increase the flow area of the swirl slots to provide a desired precisely set flow rate. As an example of this type of nozzle construction reference may be had to the patents to Cleminshaw et al. US Pat. No. 3,024,045, granted Mar. 6, 1962, and to Moebius et al. U.S. Pat. No. 3,159,971, granted Dec. 8, 1964.
It is also known from the Gillet US. Pat. No. 3,453,859, granted July 8, 1969, to utilize a coining apparatus for accurately forming swirl slots in a nozzle plug member. However, as in any manufacturing operation, a tolerance must be provided, and although coining of slots is accurate as taught in the aforesaid Gillet patent, there nevertheless will be slight variation in flow rate from one nozzle to the next.
SUMMARY OF THE INVENTION Contrary to the foregoing, in the present method and by the use of the apparatus herein, the swirl slot flow rate of a nozzle may be precisely set over a relatively wide range so that the flow rate of a series of nozzles may be matched exactly (within the limits of accuracy and readability of a pressure gauge and a flow meter) while yet the parts of the nozzle may be manufactured to usual tolerances as applied in the nozzle art, this being a principal object of the present invention.
Another object of this invention is to provide a method and apparatus wherein plug and body members of different hardnesses are forcibly engaged with each other while fluid is flowing through the swirl slots defined between said members until the deformation of the softer member, and resulting decrease in swirl slot area, reaches the point where the flow rate is precisely a desired value.
Other objects and advantages of the present invention will appear from the ensuing description.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a central vertical cross section view of apparatus for accurately setting the flow rate ofa fuel injection noule;
FIGS. 2, 3 and 4 are enlarged fragmentary cross section views illustrating the manner in which the seat at the upstream end of the vortex chamber of a nozzle body member is progressively deformed to progressively decrease the depth of a swirl slot in said body member thus to accurately set the flow rate of fuel therethrough, FIG. 3 being a cross section view taken substantially along line 33, FIG. 4, and FIG. 4 being a cross section view taken substantially along line 44, FIG. 3 with the plug member removed;
FIG. 5 is a diametrical cross section view illustrating an assembled fuel injection nozzle having a precise flow rate as set by use of the FIG. 1 apparatus and method;
FIG. 6 is a fragmentary cross section view of a modified form of apparatus wherein a ball rather than a conical plug member is employed to deform the seat at the upstream end of the vortex chamber to predeterminately set the flow rate through the swirl slot; and
FIG. 7 illustrates the assembled nozzle which utilizes a ball as the plug member to determine the depth of the swirl slot leading into the injection nozzle vortex chamber.
DETAILED DESCRIPTION OF THE INVENTION As shown in FIGS. 5 and 7, the nozzle body 1 is of a type which is adapted to have screw-threaded engagement with an adapter (not shown) secured on a fuel manifold ring or the like, said body 1 being provided with a fuel discharge orifice 2, a vortex chamber 3, of which the rear wall is defined by a tapered plug member 4 which in FIG. 7 is a ball 5. The plug member 4 (or 5) is engaged with a seat 6 of the vortex chamber 3 to span the upwardly open swirl slot or groove 7, In FIG. 5 the plug member 4 has a fuel supply passage 8, the fuel flowing through the strainer 9 and around the lower end of the plug member 4 into the swirl slot or slots 7 from whence it enters the vortex chamber 3 tangentially so that the fuel has imparted thereto a whirling motion for emergence from the discharge orifice 2 in the form of a hollow spray cone 10, In FIG. 7 the plug member constitutes the ball 5 and a ball retainer 11 which has a passage 12 and strainer 13. In both cases, the'plug member 4 in FIG. 5 and the ball retainer 11 in FIG. 7 are locked in place as by staking.
Referring now in detail to FIGS. 1 to 4, the nozzle body I is inserted into the housing 15 and is sealed therein by means of the O-ring or like seal 16 and is accurately held in said housing 15 as by means of a cap 17 which has threaded engagement with said housing 15.
A hardened pressing member 18 has screw-threaded engagement with said housing and has a conical end 19 which is of the same taper as the conical end of the plug member 4 which later is to be installed in the nozzle body I. By way of example, the conical end of the plug member 4 and of the pressing member 18 has an apex angle of about 170. The conical end 19 of the pressing member 18 first engages the relatively sharp-edged seat 6 in substantially line contact as best shown in FIG. 2 and as the member 18 is turned by its knob 20, the lower end 19 progressively deforms the seat 6 to frustoconical form as shown in FIGS. 3 and 4.
The housing 15 is provided with a fuel inlet port 21 to which is connected a fuel supply line 22 having a flow meter 23 and a pressure gauge 24 therein, and as the pressing member 18 is turned, the rate of flow of fuel through swirl slot or slots 7 will decrease as indicated by the flow meter 23. When the flow rate is of desired precise value, the turning of the pressing member 18 is discontinued and the nozzle body I may be removed and heat treated to harden the same. Thereafter, the plug member 4 with its strainer 9 will be screwed into the body 1 until the lower conical end of the plug member 4 engages the seat 6 to provide a noule body and plug assembly having the desired flow rate as previously set by deformation of the seat 6 and consequent decrease of the depth of the swirl slot 7.
When the swirl slot or slots 7 are formed in the body 1 as by coining as disclosed for example in the patent to Gillet US Pat. No. 3,453,859, the width and depth thereof will provide a swirl slot flow area which is greater than desired when the pressing member 18 initially engages the seat 6 in line contact as shown in FIG. 2. To secure a precise swirl slot flow rate, the member 18 will be turned slowly until the flow rate through the swirl slot or slots 7 is of desired value, and as the pressing member 18 is turned, the lower end 19 thereof will compress the seat 6 progressively to frustoconical form while the depth of the swirl slot or slots 7 is progressively decreased. As an example, one nozzle body 1 was made with swirl slots 7 having a nominal capacity of approximately 18 lbs/hr. flow at a pressure of p.s.i. when the plug member 4 or pressing member 18 is engaged in substantially line contact with the seat 6 as shown in FIG. 2. In said example, it was desired to provide a precise flow rate of 12 lbs./hr. at 100 p.s.i. pressure. As evident, it is possible, by practicing the present method and by using the apparatus herein, to precisely set an entire series of nozzles exactly to a certain flow rate within the limits of accuracy and readability of the flow meter 23 and pressure gauge 24.
Another feature of this invention is that by reason of the conical bore 25 of the retaining cap or nut 17 it is possible to observe and measure the spray cone l angle and the accuracy of alignment of the spray cone axis with the axis of the discharge orifice 2.
Yet another feature of the present invention is that the pressing member 18 illustrated in FIGS. 1, 2, and 3, turns on the seat 6 while it presses against the seat 6 thus to effect a burnishing action to render the seat 6 smooth so that a fluidtight joint is readily obtained when the plug member 4 is screwed into the body 1.
In the modified apparatus which has been fragmentarily illustrated in FIG. 6, the pressing member comprises a ball 5 which is pressed against the seat 6 by a screw-actuated member 26. As evident, when the screw actuated member 26 is turned in housing 15, the ball 5 will progressively deform the seat 6 thus to progressively decrease the depth of the swirl slot or slots 7 until the desired accurate flow rate is established as in FIG. 1. When a ball 5 is used, as in FIG. 6, the same ball 5 may be used, if desired, in the completed nozzle body and plug assembly shown in FIG. 7.
I, therefore, particularly point out and distinctly claim as my invention:
1. The method of setting the flow rate of a fuel injection nozzle having a swirl slot which enters a vortex chamber and which is defined between two interengaged members of which one spans the width of a groove in the other, said method comprising pressing said members together to progressively decrease the depth of the swirl slot until the flow rate therethrough reaches a desired value.
2. The method of setting the flow rate of a fuel injection nozzle having a swirl slot entering a vortex chamber which comprises deforming the nozzle to progressively decrease the swirl slot flow area until the flow rate therethrough reaches a desired value, the deformation of the nozzle being effected by pressing a tapered member which spans the width of the swirl slot against an initially relatively sharp seat adjacent said slot to progressively deform said seat to thus decrease the depth of said slot.
3. The method of claim 2 wherein said tapered member is a plug member; and wherein said seat is at the juncture of a shoulder in a nozzle body member containing such slot and the peripheral wall of the vortex chamber.
4. The method of claim 3 wherein said tapered member is rotated while pressed against said seat thus to burnish the seat as it is being deformed by said plug member.
5. The method of claim 3 wherein said plug member is a ball.
6. The method of setting the flow rate of a fuel injection nozzle of the type wherein a plug member and a body member define therebetween a swirl slot and a vortex chamber into which said slot opens to impart whirling motion to fuel entering said chamber; said body member having a discharge orifice for emergence of the whirling fuel from said chamber in the form of a hollow spray cone; said method comprising the steps of pressing a simulated plug member against said body member to deform the latter to progressively decrease the swirl slot flow area; conducting fluid through said slot,
chamber, and orifice and observing the rate of flow of fluid as said body member is thus deformed; discontinuing such deformation when the rate of flow of fluid reaches a desired value; and replacing said simulated plug member with said plug member to effect engagement of the latter with the body member as thus predeterminately deformed by said simulated plug member.
7. The method of claim 6 wherein said body member is hardened after such deformation to maintain the swirl slot flow area setting when engaged by said plug member,
8. The method of setting the flow rate of a fuel injection nozzle of the type wherein a tapered plug member and a body member define therebetween a swirl slot and a vortex chamber into which said slot opens to impart Whll'llllg motion to fuel entering said chamber for emergence in the form of a hollow spray cone from a discharge orifice in said body member; said method comprising pressing a simulated tapered plug member against a relatively sharp edged seat at the juncture of a shoulder in said body member containing such slot and the peripheral wall of said vortex chamber to deform said seat to progressively decrease the depth of said slot; observing the rate of flow of fluid through said slot as said seat is thus deformed; discontinuing such deformation when the flow rate is a desired value; and replacing said simulated plug member with said plug member to, effect engagement of the latter with the seat as thus deformed by said simulated plug member.
9. The method of claim 8 wherein said seat is hardened after such deformation to maintain the swirl slot flow area setting when engaged by said plug member.
10. Apparatus for setting the flow rate of the swirl slot of a nozzle body member having a vortex chamber into which said slot opens and a discharge orifice for discharge of whirling fuel from said chamber in hollow spray cone form; said apparatus comprising a housing having an inlet port for connection to a fluid supply source and an outlet port to receive said nozzle body member for flow of fluid through said slot, chamber, and orifice; a plug member in said housing engageable with said body member to close the upstream end of said chamber and to span the width of said slot; and actuating means for forcing said plug member against said body member to progressively deform the latter so as to progressively decrease the depth of said slot until the rate of flow of fluid through said body member reaches a desired value.
11. The apparatus of claim 10 wherein said plug member has a tapered surface which initially engages said body member in substantially line contact, such contact progressively widening radially as such deformation progresses.
12. The apparatus of claim 10 wherein a cap member detachably secured to said housing is operative to clamp said body member in said outlet port, said cap member having an opening through which fluid is sprayed from said orifice.
13. The apparatus of claim 10 wherein a conduit between said inlet port and the fluid supply source has therein flow and pressure indicating means to facilitate precise setting of the flow rate at prescribed pressure.
14. The apparatus of claim I0 wherein said actuating means comprises interengaged screw threads on said housing and plug member whereby, upon rotation of said plug member, said body member is compressively deformed and, at the same time, burnished.