US2180475A - Fuel injector pump - Google Patents

Description

Nov. 21, 1939.- \o. LJUNGSTROM FUEL INJECTOR PUMP Filed Dec. 13, 1957 FIGS INVENTOR OLOF.

ATTORNEYS LJUNGSTROM ently of the aforesaid means for initially prede-,

Patented'Nov. 21, 1939 UNITED STATES PATENT OFFICE 2,180,475 FUEL INJECTOR. PUMP Olof Ljungstrom, Detroit, Mich. Application December 13, 1937, Serial No.'179,584

tively simple and highly effective fuel pump composed of a comparatively few parts capable of being inexpensively manufactured, assembled, and installed.

Another advantageous feature of this invention resides in the provision of a fuel injector pump of the reciprocating plunger type having improved means for adjusting the efiective stroke of the plunger to vary the volume of fuel injected and having means operable independtermining the effective stroke of the plunger. This latter feature is of prime importance in multi-cylinder internal combustion engines where a separate injector is provided for each cylinder, since it offers the possibility of individually adjusting the plunger of each pump so that the latter will provide a uniform quantity of fuel in each 'cylind g A further object of the present invention resides in the provision of a fuel injector pump of the character set forth wherein the plunger is carried by a reciprocable member having a constant stroke and thereby capable of being operated by a cam driven from one of the engine shafts. 1 p

The foregoing, as well as other objects, will be made more apparent as this description proceeds,

especially when consideredin connection with the accompanying drawing, wherein:

Figure l is a longitudinal sectional view through a fuel injector pump constructed in accordance with this invention;

Figure 2 is a cross sectional view taken substantially on the plane indicated by the line 22 of Figure 1; and

Figure 3 is a cross sectional view taken substantially on the plane indicated by the line 3-3 of Figure 1.

Referring now to the drawing, it will be noted that there is illustrated in Figure 1 a fuel injector pump of the plunger type having a cylinder l closed at one end by means of a head I! and at the op site end by means of a reciprocable piston l2. The end of the cylinder 80 adjacent the head I l is provided with a radially outwardly extending flange l3 removably clamped to a corresponding flange it on the head by means of the fastener elements l5 which injector pumps also function to secure the injector on the supporting structure it, shown in Figure 1 by the dot and dash lines.

The head II is provided with a laterally directed fuel intake passage l1 communicating with a source of fuel under pressure (not shown) 5 I and also communicating with a-bore it formed in the headon the axis of the cylinder III. The bore I 8 is provided with a reduced axially extending discharge passage l9 having an annular recess 20 in the side wall thereof forming an 10 annular valve seat 2| for engagement with the head 22- of a valve member 23. The valve member 23 is in the form of a relatively light sleeve reciprocably mounted in the reduced portion IQ of the bore l8, and the head 22 of the valve memher cooperates with the adjacent end of the plunger. to form a fuel receiving chamber 25. Upon reference to Figure 1; it will be notedthat the side walls of the valve member are provided with angularly spaced openings 26 adjacent the head 22. The purpose of these openings is to permit fuel to flow from the chamber into the valve member, when the latter is retracted from its seat by the pressure produced in the chamber 25 by movement of the plunger toward 25 the head 22 of the valve member. The fuel entering the valve member under pressure flows axially through the latter out of the discharge opening 21 in the head. It will be observed from Figure 1 that the valve member is yieldably urged in 'a direction to engage the head 22 thereof with its seat 2| by means of a coil spring 28 housed in the valve member with one end abutting a shoulder 29 extending radially inwardly from the side walls of the valve member and with the other end enga ing an adjustable abutment 30. The abutment 30 is threaded in the discharge opening 27 of the head and is centrally apertured, as at 3|, to permit the passage of the fuel-therethroug The abutment 30 also acts as a stop to limit movement of the valve member in a direction away from its seat andis so located in the bore I!) to stop the valve member before the openings 26 move out of communication with the annular recess 20. The flow of fuel under pressure from the passage l1 into the chamber 25 is controlled by the plunger 24 mounted in the sleeve 32 for reciprocation axially of the cylinder It. Upon reference to- Figure 1, it will be noted that the outer end of the sleeve 32 has a pressed fit within the enlarged portion of the bore l8 and seats against an annular shoulder 33 formed by the reduced DOltion IQ of the bore l8 between the valve member 23 and the fuel intake passage ll. The exchamber 34 beyond the opening 35 and having a sliding engagement with the plunger. With v the above construction, it will be noted that when the plunger 24 is in the position thereof shown in Figure 1, the fuel under pressure in the passage I1 is prevented from entering the chamber 25 and is confined to the chamber 34 until the plunger has been retracted to its dotted line position, illustrated in Figure 1, wherein communication is established between the passage l1 and chamber 25. In this connection, it is to be noted that the strength of the spring 28 acting on the valve member 23 is sufliciently greater than the normal pressure of the fuel in the supply passage to maintain the valve closed until the plunger commences its working stroke.

In order to reduce the weight of the fuel injector to the minimum, the plunger 24 is shown herein as being formed of hollow tubing drawn, or otherwise suitably fashioned to the contour shown. The outer or working end of the plunger is, of course, closed to-impart the pressure on the fuel in the chamber 25 required to open the valve member 28 and eject the fuel through the discharge opening 21. The contacting surfaces of the plunger and sleeve may be lubricated from the pressure feed of' the engine (not shown) through the medium of a radial passage 38 formed in the head II and having the radially inner end communicating with the recess 39 formed in the sleeve 32 around the plunger 24.

The quantity of fuel ejected through the discharge opening 21 by the plunger 24, of course, depends upon the displacement of the chamber 25, and this displacement may be varied by altering the effective stroke of the plunger. The plunger 24 is operatively connected to the piston l2 for reciprocation by the latter, and this connection is capable of adjustment to vary the position of the outer end of the plunger with respect to the head 22 of the valve 23. In other words, the capacity of the chamber 25 is increased, or reduced, by adjusting the connection between the piston l2 and plunger 24 to locate the latter farther from or closer to the valve 23.

The above adjustment is accomplished without disturbing the stroke of the piston I2 and, in the present instance, the latter is reciprocated axially of the cylinder by means of a cam 45 mounted upon a shaft 4|, which is driven by the motor (not shown). The cam 4|) is engaged by a roller 42 rotatably supported on a pin 43 extending transversely through the head 44 of the piston and having one end extending beyond the adjacent side wall of the piston for engagement in an axially extending recess 45 formed in the cylinder wall. The projecting end of the pin 43 forms a key, and the recess 45 forms a keyway which cooperates with the key to permit axial sliding movement of the piston, but to prevent rotation of the latter.

The adjustable connection between the piston l2 and plunger 24 includes an internally threaded sleeve 41 having a reduced annular portion 43 journalled in the adjacent end of the piston and forming a radially extending shoulder engageabie with a radially extending flange 45 on the piston for receiving a driving thrust from the latter. Threaded within the opposite end of the sleeve is a tubular member 49 having a portion 55 forming an axial extension of the sleeve 41 and hav- 4 ing a flange 5| extending radially inwardly from the end thereof adjacent the sleeve. The flange 5| forms an abutment for engaging 'a radially outw'ardly extending flange 52 on the adjacent end of the plunger 24, and the two flanges are normally yieldably maintained into engagement with each other by means of a coil spring 53 which surrounds both the plunger and its supporting sleeve 32. One end of the spring 53 abuts the head II, and the opposite end of the spring engages the radial flange 52 on the end of the plunger adjacent the piston to not only maintain the same in contact with the flange 5| on the tubular member 49, but to also urge the sleeve 41 into engage-- ment with the piston l2. Thus, from the foregoing, it will be noted that the plunger 24 is moved in a direction to force fluid from the chamber 25 past the valve member 23 when the piston I2 is moved in a corresponding direction by the cam 4|), and both the plunger and piston are retracted, or moved, inthe opposite direction by the spring 53. In other words, the spring 53 maintains 'the follower or roller 42 in frictional engagement with the cam so that the actual stroke of the plunger is constant and depends upon the throw of the cam 40.

' However, it has been stated above that the effective stroke of the plunger, or the capacity of the fuel chamber 25, may be varied by adjusting the operative connection between the plunger and the piston l2. In general, the above is accomplished by rotating the internally threaded sleeve 41 relative to the externally threaded tubular member 45, so as to either increase, or decrease, the capacity of the chamber 25. In other words, rotation of the internally threaded sleeve in one direction causes the tubular member 49 to move outwardly relative to the sleeve and effects a movement oi the free end of the plunger toward the head 22 of the valve member 23 to decrease the capacity of the chamber 25. On the other hand, movement of the internally threaded sleeve 41 in the opposite direction causes the tubular member 49 to move axially relative to the sleeve in a direction toward the piston l2 and thereby increases the capacity of the chamber 25.

In detail, the internally threaded sleeve 41 is provided on its external surface with a series of angularly spaced axially extending teeth or splines 55 adapted to mesh with correspondingLy spaced splines 55 formed on the inner surface of a revoluble sleeve 51. The sleeve 51 rotatably engages the inner side walls of the cylinder II and has a reduced portion 58 journalled on the piston I2. This reduced portion is fashioned to form a beveled pinion having teeth 60 adapted to mesh with corresponding teeth 5| on a ring gear 32 which is rotated in either direction by the throttle control (not shown) in any suitable manner. The tubular member 48 is normally held from rotation in a manner to be more fully hereseries of angularly spaced axially extending teeth or splines 63 on splines with correspondingly spaced splines 64 on the internal surface of asleeve 65 rotatably prevent rotation of the latter and tubular member 49. However, when it is desired to initially adjust the eii'ective stroke of the plunger 24, or the volume'of the chamber 25, the set screw 69 is released from the shaft 68 and the pinion 6'! is rotated to impart a rotative movement to the tubular member 49 through the tube 65. It will, of course, be understood that during this initial adjustment of the injector pump, the internally threaded sleeve 41 is held from rotation by the ring gear 62. Thus, it will be noted that rotation of the pinion 61 also eiiects an axial displacement of the plunger 24 to vary the capacity of the chamber 25 and by reason of this construction, all of the injectors in a multi-cylinder engine may be adjusted to inject a uniform charge of fuel in each of the several cylinders.

It may be pointed out at this time that the fuel injector is preferably supported on the engine in the region of the lubricant reservoir so as to be in the path of the fumes escaping from the reservoir. These fumes are relied upon to a great extent in supplying the necessary lubrication of the various parts of the injector and, for this reason, the cylinder l0, piston l2, sleeve l1, and tube 65 are apertured, as at Ill, to'permit entrance of the fumes into the cylinder. Also, the openings Ill contribute materially to reducing the weight of the injector to the minimum and this is, of course, desirable from the standpoint of performance and cost of manufacture.

What I claim as my invention is:

1. In a fuel-injector of the displacement type having an intake opening for fuel, a reciprocable plunger for displacing the fuel and acting as a slide valve to control theintake port, a reciprocablemember coaxially arranged with respect to the plunger, a sleeve carried by the reciprocable member and rotatable relative thereto, a tubular member carried by the plunger and rotatable relative to the latter, said tubular member having a portion threadedly engaging the sleeve, means for rotating the sleeve relative to the tubular member to adjust the stroke of the plunger, and

separate means for rotating the tubular member relative to the sleeve to initially determine the effective stroke of the plunger.

2. In a fuel injector of the displacement type having an intake opening for fuel, a reciprocable plunger for displacing the fuel and also acting as a slide valve to control the intake opening, a reciprocable member coaxially arranged with respect to the plunger and having a constant stroke, a revoluble sleeve movable with the reciprocable member and positioned between the latter and plunger, a rotatable member movable with the plunger and having a threaded engagement with the sleeve, a second sleeve rotatable relative to the first sleeve and having teeth meshing with corresponding teeth on the rotatable member, and means for rotating the second sleeve to adjust the efiective stroke of the plunger.

3. In a fuel injector-of the displacement type the external surfaceof the portion 50 of the member 49 and by engaging these relative to the second memberv having an intake opening for fuel, a reciprocable plunger for displacing the fuel and also acting as a slide valve to control the intake opening, a reciprocable element coaxially arranged with respect to the plunger and having a constant stroke. a member movable with the reciprocable element and supported for rotation, a second revoluble member movable withthe plunger and threadedly engaging the first membe a sleeve rotatable series of teeth meshing with corresponding teeth on the first member, means for rotating the sleeve to vary the effective stroke of the plunger, 9. second sleeve supported for rotation relative'to the first member and having a series, of "teeth meshing with corresponding teeth onlthe second member, and means for rotating the second sleeve to determine the initial'efl'ective stroke of the plunger: t

4. In a fuel injector of the displacement type having an intake opening for fuel," a reciprocable plunger for displacing the fuel and also acting as a slide valve to control the intake opening, a

- reciprocable member coaxially arranged with re-' spect to the plunger and having a constant stroke, a rotatable 'sleeve concentrically arranged with respect to the plunger and movable with said plunger, a second rotatable sleeve movable with the reciprocable member and having a portion threadedly engaging the first sleeve, a third sleeve concentrically arranged with respect to the first sleeve and keyed to the latter for rotating the same relative to the second sleeve, means accessible exteriorly of the injector for rotating the third sleeve to vary the effective stroke of the plunger, and means also accessible exteriorly of the injector for rotating the second sleeve to vary the effective stroke of the plunger independently of the last named means.

5, In a fuel injector of the displacement type having an intake opening forfuel, a reciprocable and having a plunger for displacing the fuel and also acting as a slide valve to control the intake opening, a reciprocable member coaxially arranged with respect to the plunger and having a constant stroke, a rotatable sleeve concentrically arranged 'stroke of the plunger, a fourth sleeve concentrically arranged with respect to the first sleeve in axial alignment with the third sleeve and keyed to the first. sleeve, and means for rotating the fourth sleeve to adjustthe effective stroke of the plunger independently of the aforesaid means.

6. In a fuel injector of the displacement type having an intake opening for fuel, a reciprocable plunger for displacing the fuel and also acting as a slide valve to control the intake opening, a sleeve revoluble about the axis of the plunger, a reciprocable member having a portion extending into the sleeve and slidably engaging the sleeve, 8. second sleeve mounted on the reciprocable member within the first sleeve, a connection between the sleeves providing for sliding movement of the second sleeve relative to the ,first'sleeve and preventing relative rotation between the 'sleeves, means for rotating the first sleeve about the reciprocable member to impart a corresponding rotation to the second sleeve,

and means responsive to reciprocation of the 75 second sleeve by the reciprocable member to impart a. corresponding reciprocable movement to the plunger and eflective upon rotation of the second sleeve by the first sleeve to adjust the position of the plunger relative to the intake opening and thereby vary the efiective stroke of the plunger by the reciprocable member.

'1. In a fuel injector of the displacement type having an intake opening for fuel, a reciprocable plunger for displacing the fuel and also acting as a slide valve to control the intake opening, a sleeve revoluble about the axis of the plunger, a reciprocable member having a portion extending into the sleeve and slidably engaging the sleeve, a second sleeve mounted on the reciprocable member within the first sleeve, a connection between the sleeves providing for sliding movement of the second sleeve relative to the first sleeve and preventing relative rotation between the sleeves, means for rotating the first sleeve about the-reciprocable member to impart a corresponding rotation to the second sleeve, means responsive to reciprocation of the second sleeve by the reciprocable member to impart a corresponding reciprocable movement to the plunger and efiective upon rotation of the second sleeve by the first sleeve to adjust the position of the plunger relative to the intake opening and thereby vary the eflective stroke of the plunger by the reciprocable member, and means for adjusting said last named means independently of said first named sleeve to also vary the effective stroke of the plunger.

8. In a fuel injector of the displacement type having an intake opening forfuel, a reciprocable plunger for displacing the fuel and also "acting as a slide valve to control the intake opening, a reciprocable member tic-axially arranged with respect to the plunger and having a constant stroke, a sleeve rotatably supported on the reciprocable member, a second sleeve located within the first sleeve and connected to the reciprocable member for movement as a unit with the latter, a connection between the two sleeves preventing rotation of the sleeves relative to each other and permitting reciprocation of the second sleeve relative to the first sleeve, a third sleeve threadedly engaging the second sleeve and having a portion abutting the plunger for moving the latter as a unit with the reciprocable member, means engageable with the third sleeve to hold the latter against rotation with the second sleeve, and means for rotating the first sleeve to effect a corresponding rotation of the second sleeve relative to the third sleeve and thereby adjust the position of the plunger axially with respect to the intake opening.

OLOF LJUNGSTROM.

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