US2188859A

US2188859A - Fuel injection pump

Info

Publication number: US2188859A
Application number: US70805A
Authority: US
Inventors: Herbert C Edwards
Original assignee: Timken Roller Bearing Co
Current assignee: Timken Co
Priority date: 1936-03-25
Filing date: 1936-03-25
Publication date: 1940-01-30
Anticipated expiration: 1957-01-30

Description

5 Sheets-Sheet 1 /N VEA/TOP.'

Jan. 30, v1940. H. c. EDWARDS FUEL INJECTION PUMP Filed March 25, 1956 A 6 y a w 5 y w+ i4 fd H 9 M a 5 k f 1 I :l W mw 45 Jan. 30, v H.. C,I EDWARDS 2,188,859

FUEL INJECTION PUMP Jan. 30, 1940. H c, EDWARDS 2,188,859

FUEL INJECTION PUMP Filed March 25. 1936 `3 Sheets-Sheet 3 /7 /f 8 y L/ l l /A/l/E/vroe: n M'nm,

Patented Jan. 30, 1940 FUEL INJECTION PUMP Herbert C. Edwards. Massillon, Ohio, assignor to The Timken .Roller Bearing Company, Canton,

Ohio, a corporation of Ohio Applicant Mms z5.. 193e, sum1 No. 70,805 1 claims. (ci. 1oz-154) This invention relates principally to fuel injection pumps of the kind having tappet actuated pistons. It has for its principal object to provide simple, eiilcient and easily operable means for axially adjusting the piston to take up wear of the parts and to obtain a proper initial setting of the pistons. 'Ihe invention consists in the construction, combinations and arrangementsof parts hereinafter described and L claimed.

In the accompanying drawings, which form part of this specification and wherein like symbols refer to like parts wherever they occur,

lFlg. 1 is a vertical central section through a cylinder of a fuel injection pump embodying my invention,

Fig. 2 is an enlarged 'fragmentary section through the pump in the region of the tappet mechanism,

zo Figs. 3, 4 and 5 are horizontal sections on the lines 2-8, 44 and 8 8, respectively, in Fig. 2, 6 is a vertical section on the line 8 8 in Figs. 'l and 8 are sections similar to Figs. 2 and 25 6, respectively, illustrating a m'odied form of the invention; and

`Figs. 9 and 10 are sections similar to Figs. 7 and 8, respectively, illustrating another modiiied formoi the invention. a0. In the accompanying drawings, my invention is shown in connection with a fuel injection pump comprising a housing I provided with one or more vertical bores 2, each having an enlarged lower end portion 2a adapted to slldably receive as a tappet cup 8 that Nis engaged at its lower end by a cam or tappet 4 on shaft l located in a chamber 8 in the bottom of said housing. A pump cylinder 1, which contains a piston or plunger 8, has an enlarged upper end portion 8 40 that is held down on an annular; seat I8 provided therefor in the upper portion of the bore y2 by means of a cylindrical shell II threaded into the upper end thereof.

Mounted on the upper end of the cylinder is a therefor in the upper end of the ntting I4 and held in position by means of a cap I1 threaded on the upper end of said tubular iitting.

Inlet and overilow passageways I8 and I9 are located in the pump housing I on opposite sides of the cylinder l. Thev inlet passageway I8 is 5 supplied with liquid fuel by the usual feed pump (not shown) and communicates with an inlet -port I8a in the wall of said cylinder. The overflow or by-pass passageway I9 communicates with an overilowport Isa in said cylinder oppo- 10 site the inlet port I 8a therein. The piston 8 is provided with an annular groove that communicates with a longitudinal peripheral groove 2l with the pressure space above the piston,

whereby delivery of the fuel begins as soon as l5 the piston on its Way up covers the ports I8a and I8a and ends as soon as the annularu groove 20 in the piston is placed in communication with the overflow or by-pass port I9a and relieves the pressure in the space above the piston. The an- 2. nular groove 20 in the piston has an inclined or helical upper edge 22, whereby the quantity of fuel delivered. may be regulated by turning the piston in its cylinder to varygthe point in the delivery stroke of the piston in which 'the over- 25 ow port I8a is placed in communicationwith pressure space through the grooves 20 and The mechanism for turning the reciprocating plungerl or' piston on its axis comprises axially 30 alined upper and lower driving and driven

sleeves

28 and 24 mounted on the lower end portions of the cylinder 1 and piston 8, respectively, and a control rod mounted in a horizontal bore in the pump'housing and provided with rack teeth 35 v28 that cooperate with a gear 21 formed on the upper end of said upper or driving sleeve. The upper or driving sleeve 28 is rotatably mounted on the lower end. of the cylinder l; and the lower or driven sleeve 24 has a driving connection with 40 the lower end of the piston comprising a ilatsided portion 28 on the piston that fits within a similarly shaped opening' in the lower end of said lower or driven sleeve. The driving connection, between the driving sleeve 23 and the driven 45 sleeve 24 preferably comprises upwardly extending tongues 29 on the driven sleeve that fit within downwardly opening notches 30 in the driving sleeve, thereby permitting relative axial movement of the two sleeves but preventing relative 5o rotary movement thereof.

Surrounding the driving and driven

sleeves

23 and 24 is a. helical compression spring 3l that A serves to retract the piston and to hold the driving sleeve upwardly in the enlarged portion 2a 55,

28 with an annular groove 33, above said portion with a collar 34, and terminates below said groove in a squared portion 35 similar to the squared portion 28. The piston retracting spring 3| is seated on the peripheral flange 36a provided on a member 36 that is provided with a laterally opening notch 31 whose upper end flts the annular groove 33 in the piston and whose lower end is widened to accommodate the squared portion 35 of said piston. By this arrangement, relative axial movement of the spring seat 36 and the piston is prevented; and said spring seat cooperates with the collar 34 on said piston to prevent movement on the driven sleeve 24 axially thereof.

The spring seat or collar 36 is provided on its under side with an undercut diametral groove or channel 38 adapted to receive a block 39 having outstanding ribs or flanges 39a along its upper side corners that t the undercut portions of said groove or channel. The block 39 rests on the bottom ofthe tappet cup 3 and is inserted in and removed from the groove 38 in the spring seat member 36 through an opening 40 provided thereforin the side wall of said cup. As shown in Figs. 1 and 2, the adjusting block 39 has a raised middle portion 39h that fits within the lower end of the spring 3|, thereby retaining said block in the groove 38 in the spring seat member 36. The side wall of the pump housing l is also'provided opposite the opening 40 in ythe side wall of the tappet cup with an opening 4| through which the block 39 may be inserted and removed, the opening 4| being closed by a threaded plug 42. By this arrangement, a proper initial axial adjustment of the plunger may be obtained and wear of the tappet mechanism taken up by inserting a block 39 of proper thickness in the groove 38 in the underside of the spring seat member 31. The adjusting block 39 is preferably provided with a threaded bore 43 that extends therethrough from end to end thereof; and said block is removed from and inserted in the spring seat member through the openings 4| and 40 in the pump housing I and tappet cup 3, respectively, by threading the end of a rod (not shown) into one end of the threaded bore 43 in said block. The tappet cup is provided below the spring seat member with an interior shoulder 3a which forms a stop for preventing said member from dropping into the space required for the adjusting block.

In the modification shown in Figs. '7 and 8, the adjusting block is in the form of a cylindrical disk 4'4 that seats within a circular depression provided therefor in the bottom of the tappet cup and is provided with a threaded diametral bore 45 having a pin 46 projecting from one end thereof into a hole 41 provided therefor in the cylindrical wall of said tappet cup. The

pin (not shown) that is threaded into the open end of the threaded bore 45 in said block.

In the modification shown in Figs. 9 and 10, the tappet adjusting mechanism comprises an inverted channel-shaped member 50 mounted in the tappet cup below the spring seat member, which has a hardened steel button 36a seated in its Iunderside provided with a convex head that bears upon the top of said channel shaped member. Said member is provided at the lower edgesof its side walls with outstanding flanges that serve to locate said member centrally within the tappet cup. The undersurface of the top wall of the channel shaped member converges downwardly from its ends to its middle; and blocks 5| are located within said channel shaped member and have inclined opposing end surfaces or planes adapted to engage the inclined under-- sides of said member. A screw 52 extends through axially alined holes provided therefor in the wedge blocks and is provided at its endsl with slots for a screw driver. The screw 52 extends loosely through the hole in one wedge block and is threaded'through the hole in the other wedge block and is provided with a collar 53 that bears against the outer end of said rst mentioned block. One end of the adjusting screw fits within one of a pair of diametrically opposed holes 54 in the` tappet cup, thereby preventing rotary movement ofthe adjusting device in the tappet cup. The pump housing is provided at the level of the holes 54 with an opening 55 whereby access may be had to the adjusting screw 52 to draw the wedge blocks together or force them apart and thus raise or lower the piston. l

- cup and said housing.

2. A fuel injection pump comprising a housing, a piston reciprocable in said housing, a tappet cup surrounding one end of said piston, a tappet for actuating said tappet cup, a member secured to said end of said piston against movement axially thereof and for engagement with and disengagement from said piston transversely thereof, and a second member interposed between said removable member and the bottom of said tappet cup, said tappet cup and said housing having cooperating side openings therein through which said second member isv adapted to be inserted in and removed from said tappe cup and said housing.

3. A fuel injection pump comprising a housing, a. piston reciprocable in said housing, a tappet cup surrounding one end of said piston, a tappet for actuating said tappet cup, a member removably secured to said end of said piston against movement axially thereof and for engagement with and disengagement from said piston transversely thereof, a member interposed between said removable member and the bottom of'said tappet cup, said tappet cup and' said housing having cooperating side openings therein through which said second mentionedmember.is adapted to be inserted in and removed from said tappet cup and said housing, said tappet cup being provided with an internal shoulder adapted to space said first mentioned member away from the bottom of said cup when said second mentioned member is removed from said cup.

4. A fuel injection pump comprising a housing, a piston reciprocable in said housing, a tappet cup surrounding the lower end of said piston, a tappet for actuating said tappet cup, a spring seat member secured to said end of said piston and having a cross groove in the under side thereof, and a member mounted in said groove and bearing against the bottom of said tappet cup, said tappet cup and housing having cooperating openings therein through which said member may be inserted in and removed from the cross groove in said spring seat member.

5. A fuel injection pump comprising a housing, a piston reciprocable in said housing, a tappet cup surrounding the lower end of said piston, a tappet for actuating said tappet cup, a spring support secured to said end of said piston and having an undercut diametral groove in its bottom, and an adjusting blockslidably mounted in said groove, said tappet cup and` said housing having openings therein through which said block may be inserted and removed from said pump, said block having an opening in one end thereof adapted to receive a member for facilitating such insertion and removal of said block.

6. A fuel injection pump comprising a housing, a piston reciprocable in said housing, a tappet cup surrounding the lower end of said piston, f

a tappet for actuating said tappet cup, a spring seat member removably secured to said end oi said piston, an adjusting block interposed between said member and the bottom of said tappet cup. said tappet cup being provided opposite said'block with diametrically opposed openings, and a pin secured to said block and extending into one of said openings, said housing having an opening adapted to cooperate with the other of said diametricallyopposed openings, said block being adapted to be inserted in and removed from said tappet cup and said housing through said cooperating openings and having an opening that is held by said pin in register with said other of said diametrically opposed openings and is adapted to receive a member for facilitating such insertion and removal of said block through said cooperating openings.

7. A fuel injection pump comprising a housing, a piston reciprocable in said housing, a tappet cup surrounding the lower end of said piston, a tappet for actuating said tappet cup, a spring seat member removably secured to said end of said piston, an adjusting block interposed between said member and the bottom of said tappet cup, said tappet cup being provided opposite said block with diametrically opposed openings, and a pin secured to said block and extendinginto one of said openings, said housing having an opening adapted to cooperate with the other of said diametrically opposed openings', said block being adapted to be inserted in and removed from said tappet cup and said housing through said cooperating openings and having an opening that is held by said pin in register with said other of said diametrically opposed openings and is adapted to receive a member for facilitating the insertion and removal of said block through said cooperating openings. said tappet cup being provided with an internal shoulder adapted to limit the movement of said spring seat towards the bottom of said tappet cup.

' HERBERT C. EDWARDS.