US3449948A - Nozzle spray test device - Google Patents

Description

L. KAHLE ET AL NOZZLE SPRAY TEST DEVICE June 17, 1969 Sheet Filed June 15, 1967 L Q, D llll llrll INVENTORS LLOYD L. KAHLE JOHN J SHANDOR BY 0 MQMqM ATTORNEYS Sheet 2 of 3 INVENTORS LLOYD L. KAHLE JOl-l/V .1. .Sh'AA/DOR a M m ATTORNEYS L. L. KAHLE ET AL NOZZLE SPRAY TEST DEVICE June 17, 1969 Filed June 13, 1967 mm mm 8 m 8 @m I 33 m m v o O o mm 8 mv ow n n #0 mm mm 5 on on 3 I L; L 55 3 i=5: n on o O U o 0 m mm R 3 g June 17, 1969 L. KAHLE ET AL 3,449,948

NOZZLE SPRAY TEST DEVICE 4 Filed June 13, 1967 She et 3 as 57(ON 53) 46(ON 45) 53 (BOTTOM) 56 (INTERMEDIATE) 45 ('TOP) 2 I ma.

JOHN J. SIM/V005 BY I ATTORNEYS United States Patent US. Cl. 73-119 18 Claims ABSTRACT OF THE DISCLOSURE Nozzle spray test device for determining spray cone vertex angle of fuel injection nozzle and the like.

Background of the invention In a jet engine or gas turbine for aircraft and the like it is a conventional practice to provide a multiplicity of fuel spray nozzles (often arranged in circular series) to spray fuel into an annular combustion chamber; and in order to achieve efficient operation of the engine the nozzles must break up the fuel into small particles of predetermined size and must uniformly distribute the same in the form of spray cones of substantially equal vertex angles without excessive overlap or underlap of the spray cones of successive nozzles. For this purpose, the nozzles must be manufactured within close tolerances with reference to assuring certain spray cone angles at specified flow rates of fuel emerging from the discharge orifices of the nozzles and with reference to maintaining the nozzle and spray cone axes coaxial.

Summary of the invention The present invention is characterized in that a fuel injection nozzle to be tested is clamped in the test device and is connected to a fuel pressure source, the conical fuel spray issuing from the nozzle being directed into a chamber having aligned detectors or probes which are adjustable radially inwardly or outwardly to be just contacted or impinged by diametrically opposite slant height elements of the conical fuel spray.

The present invention is further characterized in that the distances of the ends of the probes from the spray cone axis are plotted in relation to vertex angles as lines on relatively movable visual graph means, preferably in the form of nested cylindrical charts or graphs, of which the respective lines will intersect at a point which denotes the vortex angle of the spray cone being measured. The charts are rotated by the same mechanisms that drive the respective probes to move them radially inward or outward. Furthermore, if the aforesaid point of intersection of the lines of the moving charts is above or below a fixed center line extending parallel to the axis of said cylindrical charts, an indication is given as to the number of degrees that the spray cone axis departs from the ideal nozzle axis in the plane of the slant height elements which impinge on the probe ends.

The present invention is still further characterized in that accurate movements of the probes are achieved by eliminating backlash of gear and rack motion transmitting means; and in that means are provided for accurate calibration of the device by the use of a master templet which is mounted in place of the nozzle and which has diverging sides of desired vertex angle. With such tem- 3,449,948 Patented June 17, 1969 plet in place the probes may be adjusted to contact the diverging sides of the templet, and if the charts or graph means do not register the desired vertex angle, couplings may be adjusted to bring the charts to proper indicating position without movement of the probes out of contact with the sides of the templet.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principle of the invention may be employed.

Brief description of the drawing In said annexed drawing:

FIG. 1 is a front elevation view of a nozzl spray test device embodying the present invention;

FIG. 2 is a cross-section view taken substantially along the line 2-2, FIG. 1 illustrating the mechanisms for independently adjusting the probes toward or away from the spray cone axis;

FIG. 3 is a cross-section view taken substantially along the line 33, FIG. 1 to illustrate the manner of clamping a typical fuel injection nozzle for taking readings of the spray cone angle thereof;

FIG. 4 is a developed view of a stationary chart and two movable charts in superimposed relation;

FIG. 5 is a diagram showing the movements of a probe as the vertex angle of the spray cone increases; and

FIG. 6 shows a templet by which the test device may be checked and calibrated.

Description of the preferred embodiment Referring now more particularly to the drawing, the test device as best shown in FIG. 1, comprises a base 1 on which is mounted a tubular spray chamber 2 having a transparent window 3 through which the fuel spray cone C emerging from a nozzle N under test may be viewed during adjustment of the probes 4, 4. Each probe 4 has a ball-shaped end which facilitates longitudinal movement of the probe until the ball surface is just tangent to a slant height element of the fuel spray cone C. Centrally within the chamber 2 is a light transmitting rod 5 as of clear acrylic plastic disposed to illuminate the spray cone C to facilitate accurate adjustment of the probes 4, 4 as aforesaid, the rod -5 being capable, as Well known, of transmitting light longitudinally therethrough from a light source, not shown, disposed adjacent the lower end thereof.

As shown in FIG. 3, a typical nozzle N may comprise a nozzle body assembly 6 having fuel lines 7 and 8 connected thereto and terminating in a discharge orifice (not shown) within a surrounding shroud 9 which is accurately fitted within a tapered wedge bushing 10 as of nylon. The top plate 11 of the test device also has mounted thereon a suitable nozzle clamp 12 and a nozzle locator 14, the clamp 12 herein being shown as a more or less conventional screw actuated clamping jaw 15. It is to be understood that other forms of releasable clamping devices may be employed to accurately locate and clamp the particular nozzles to be tested.

Because the probes 4, 4 and associated adjusting mechanisms 20, are the same except for being left-hand and right-hand as viewed in FIGS. 1 and 2, the same reference numerals have been used to denote the same parts thereof.

As aforesaid, each probe 4 has a hemispherical end formed as by Welding a ball 21 to the end thereof. The ends of the probes 4, 4 are coaxial and move along a line which is perpendicular to the axis of the ideal spray cone. Each probe 4 is bent to provide a forwardly extending portion 23 and an upwardly extending portion 24 which extends through slots 25 in the top plate 11 and the body 26 of the mechanism 20. The upper end of each probe 4 extends through a gear rack 27 and is clamped therein by a setscrew 27, said gear rack 27 having its end portions longitudinally slidable in the nylon or like guide bushings 28, 28 disposed in the ends of said body 26.

Meshing with said gear rack 27 is a drive pinion 29, the shaft 30 of which extends through an eccentric bushing 31. By rotating the bushing 31 the gear teeth of the pinion 29 and rack 27 may be wedged together to eliminate any backlash or looseness, and thus greater accuracy of adjustment of the probe 4 is achieved. The shaft 30 of each gear 29 is connected to an adjustable coupling 32 such as for example a coupling of the type disclosed in the patent to Raskhodoff, No. 3,024,629. Each coupling 32 has secured thereto an adjusting shaft 34 which is adapted to be turned in opposite directions as by the knob 35 at the end thereof, said shaft 34 being supported for rotation as in nylon or like bushings 36, 36 in a body 37 fixed on the top plate 11. Each adjusting shaft 34 has keyed thereon a bevel gear 38 which meshes with a bevel gear 39.

Extending between the bodies 37, 37 and fixed thereto as by the pins 40 is an outer tube member 41 as of stainless steel which has a window 42 provided with indicia ranging from 70 to 120 to denote the vertex angles of fuel spray cones being measured and with the numerals 0 to 5 above and below the 0 point to denote the angular misalignment or skewing of the spray cone under test from the true centerline of the perfect spray cone. Affixed to the outer cylinder 41 as by the pins 43, is a transparent cylinder 45 which has uniformly spaced vertical lines 46 scribed on its inside diameter which are the vertex angle degrees for the 70 to 120 numbers appearing longitudinally along the upper edge of the window 42. This transparent cylinder also has lines 47 scribed longitudinally along its inside diameter which diverge slightly toward the right to correspond with the numbers 0 to 5 appearing vertically at the right-hand edge of the outer cylinder window 42.

In the case of the left-hand mechanism 20, the shaft 50 of the bevel gear 39, through the bellows spring 51 and the drive pins 52 rotates the innermost or first cylindrical chart or graph 53, whereas in the case of the righthand mechanism 20, the rotation of the bevel gear shaft 50 through the bellows spring 51 and the drive pin 54, rotates the intermediate or second cylindrical and transparent chart 56.

It is to be understood that the spray cone vertex angle range of 70 to 120 has been selected because it has been found that fuel nozzles all have spray cone vertex angles in this range.

Reference will now be made to the lines which are scribed on the respective first and second rotatable cylinders 53 and 56 and the third stationary cylinder 45 as shown in FIG. 4 which show said cylinder in developed fiat form and superimposed on one another.

In FIG. 4 the curved line 57 is scribed on the outside diameter of the first cylinder 53 which is rotated by the left knob 35 of the test device; the curved line 58 is scribed on the inside diameter of the second cylinder 56 which is rotated by the right-hand knob 35 of the test device; and the vertical lines 46; and the diverging lengthwise extending lines 47 are scribed on the inner surface of the stationary third cylinder 45, the vertical lines 46 corresponding to the spray cone apex angle markings 70 to along the upper edge of the window 42 of the outer metal tube 41.

The lines 57 and 58 are plotted as best shown in FIG. 5 by plotting the ball 21 center locations along the line 59 which is a constant distance y from the apex of the spray cone. The ball center location is the distance x plus x from a zero reference line or spray cone axis 60, since the range for the present device is from 70 to 120 apex angle 0.

The following formulae may be used in plotting the distance x plus or at any angle 0/2 from 35 to 60:

(y' and R are constants) It can thus be seen that when the first and second cylinders 53 and 56 are rotated equal amounts in opposite directions from their zero reference points, the lines 57 and 58 will cross at the center "0 horizontal line 47 at a vertical 46 to denote vertex or apex angle 0 of the spray cone C under test. In the example shown in FIG. 4, the lines 57 and 58 cross at about 101 vertex angle and the balls 21 of the probes 4, 4 are equally spaced from the zero reference axis 60 of FIG. 5.

However, if the spray cone axis is tilted, the end of one probe 4 will be closer to the true axis 60 than the end of the other probe 4, and this will be indicated in FIG. 4 (and also FIG. 1) by the intersection of the lines 57 and 58 above or below the center 0 line 47. If the intersection of lines 57 and 58 is above the center line 47, the right-hand probe 4 has not moved in as far as the left-hand probe 4 and vice versa if the intersection of lines 57 and 58 is below the center line 47, the lefthand probe 4 has not moved in as far as the right-hand probe 4. However, in either case, the point of intersection of lines 57 and 58 indicates the total apex .angle 0.

The diverging lines 47 on the stationary third cylinder 45 are a plot of the increasing rate of ball movement along line 59 of FIG. 5 per degree increase of the angle 0/2 from 35 to 60. This is also evident from the increasing slopes of the curves 57 and 58 in FIG. 4.

While in the preferred embodiment of this invention the probes 4, 4 are visually positioned by rotating the left and right knobs 35, 35 to just touch the spray cone slant height elements, it is to be understood that other forms of probes may be employed which will energize a visible or audible signal when the probes just touch the outer surface of the spray cone C. As one example, the probes may comprise pneumatic transducers to measure the force of fluid impingement on the probes, thus to eliminate human visual observance of probe contact with the spray cone C, and, in turn, the transducers may control motors to stop the probe advance or set off a visual or audible signal, due to contact of the outer surface of fuel spray with the probe.

It is to be noted that the lines 57 and 58 scribed on respective first .and second cylinders 53 and 56 are scribed on the outer and inner surfaces thereof thus to eliminate error due to parallax. Likewise, the second cylinder 56 is made quite thin so that the internal markings on the stationary third cylinder 45 will be relatively close to the lines 57 and 58 thus to minimize reading error due to parallax.

In setting up the equipment to test a series of spray nozzles which are to have a specified spray cone angle within certain limits such as plus or minus 2, a templet 61 (FIG. 6) is placed between the probes 4, 4 so that the vertex location corresponds to that of the ideal nozzle spray cone. With the templet 61 thus located, the left and right-hand knobs 35 are turned to bring the ends of the probes 4, 4 into contact with the respective diverging sides 62 of the templet 61. If the templet 61 has, say, a

90 vertex angle, then the lines 57 and 58 should intersect each other and the center 0 line 47 at the 90 angle designation. If the lines 57 and 58 do not thus cross at 90, then either or both couplings 32 are adjusted to turn the knob shaft or shafts 34 with respect to the gear shaft 30 in a direcion such that the line 57 and/or line 58 do cross the center line 47 at the 90 indication.

With the equipment thus calibrated, nozzles N to be tested may then be successively clamped in the test device and connected to a fuel pressure source, whereupon the left .and rightknobs 35 may be manipulated to move the probes 4, 4 into contact with or into close proximity to the surface of the spray cone C. When that has been done, the operator will read charts 53, 56, and 45 to determine whether or not the spray cone angle 0 is within the specified tolerance limits and whether or not the spray cone axis is askew with respect to the desired true axis 60. The maximum amount of skew angle is usually contained in nozzle specifications because excessive variation in that angle in the plane herein shown may result in excessive overlap or excessive spacing between the edges of the sprays C when installed in a jet engine. If it be desired to read spray cone vertex .angles 0 and skew angles in diiferent planes, additional probes 4, 4 may be provided or the nozzle N under test may be rotated about the spray cone axis. However, single readings as contemplated with the present equipment will usually suffice.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such, be employed.

We, therefore, particularly point out and distinctly claim as our invention:

1. A test device for spray nozzles and the like comprising nozzle mounting means; aligned probe means movable toward and away from each other into close proximity with opposed slant height elements of a spray cone emerging from a nozzle held in said mounting means; drive means for thus moving said probes; and visual indicating means actuated by movement of said probes from which the vertex angle of the spray cone under test may be read. 7

2. The device of claim 1 wherein said indicating means have indicia thereon converting distances of said probe means from a reference cone axis to a vertex angle readmg.

3. The device of claim 1 wherein said indicating means comprises superimposed movable graphs actuated by movement of the respective probe means, and a stationary graph; said graphs having indicia thereon converting distances of said probe means from a reference cone axis to a vertex angle reading.

4. The device of claim 3 wherein said indicia comprise oppositely sloped lines on the respective movable graphs and vertex angle degree lines on said stationary graph, said oppositely sloped lines intersecting each other at a line of said stationary chart corresponding to the vertex angle of the spray cone of the nozzle under test.

5. The device of claim 4 wherein said stationary graph has a center line transverse to said degree lines thereon, said oppositely sloped lines intersecting along said center line if the angles on opposite sides of a reference cone axis are equal and intersectingto one side or the other of said center line if the angles on opposite sides of a reference cone axis are unequal.

6. The device of claim 3 wherein said graphs comprise nested cylinders of which at least the outer two are transparent to render visible the indicia of all three graphs.

7. The device of claim 3 wherein the indicia of each movable graph comprises a line which represents the distances of the associated probe means from a reference cone axis at various angles of the adjacent slant height element from such reference cone axis.

8. The device of claim 1 wherein said drive means has couplings for adjustment of said indicating means with respect to the respective probe means whereby said probe means and said indicating means may be accurately preset in conjunction with a templet having an accurate vertex angle whose reference axis is perpendicular to the path of movement of said probe means.

9. A test device for spray nozzles and the like comprising a hollow base member having an aperture through the top thereof and having a viewing window through which a spray cone of a nozzle positioned in the aperture may be observed; aligned probe means within said base movable toward and away from each other along a line which is perpendicular to a reference cone axis passing through the center of said aperture; drive means for the respective probes operable to move the ends of said probes into close proximity with opposed slant height elements of a spray cone emerging from a nozzle inserted into said aperture; and visual graph means actuated by movement of the respective probes indicating the position of each probe end in terms of the angle between said reference cone axis and the adjacent slant height element.

10. The device of claim 9 wherein said graph means comprises superimposed movable graphs thus actuated by the respective probes, and a stationary reference graph.

11. The device of claim 10 wherein said movable graphs have oppositely sloping lines thereon that intersect each other at a reference line on said stationary graph denoting the vertex angle of the spray cone of the nozzle being tested.

12. The device of claim 10 wherein said graphs comprise nested cylinders, of which those actuated by the respective probes, are rotated about their coinciding axes in response to movement of said probes.

13. The device of claim 12 wherein the rotatable cylinders have lines of opposite slope thereon that intersect each other at a reference line on said stationary cylinder denoting the vertex angle of the spray cone of the nozzle being tested.

14. Visual graph means for measuring the vertex angle of a liquid spray cone comprising two probes, means mounting said probes for radial movement into close proximity with angularly spaced slant height elements of a liquid spray cone whose vertex angle is to be measured, three cylinders telescoped within one another, means mounting two of said cylinders for rotation in opposite directions in response to such radial movement of said respective probes while said third cylinder is held stationary; said two rotatable cylinders having lines of opposite slope thereon which intersect each other, and said stationary cylinder having reference lines thereon denoting the vertex angle of the liquid spray cone being measured where said lines of opposite slope intersect.

15. The graph means of claim 14 'wherein at least the intermediate and outer cylinders are transparent to render visible said lines of opposite slope on said rotatable cylinders and said reference lines on said stationary cylinder.

16. The graph means of claim 14 wherein said rotatable cylinders are adjacent each other and said lines of opposite slope are disposed on the outer and inner surfaces of said adjacent rotatable cylinders thus to minimize parallax in the observance of the point of intersection of said lines.

17. The graph means of claim 14 wherein said stationary cylinder has an axially extending center line thereon along which said lines of opposite slope intersect if a reference cone axis 'bisects the measured liquid spray cone.

18. The graph means of claim 17 wherein said stationary cylinder has additional lines on opposite sides of said center line which denote the magnitude of inequality of measured angles from said reference cone axis when said lines of opposite slope intersect each other on one side or the other of said center line.

References Cited 'UNITED STATES PATENTS RICHARD C. QUEISSER, Primary Examiner.

JERRY W. MYRACLE, Assistant Examiner.

US. Cl. X.R. 34649, 138

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