KR20160052862A

KR20160052862A - Fuel injection pump with variable injection pressure chamber

Info

Publication number: KR20160052862A
Application number: KR1020140148010A
Authority: KR
Inventors: 박득진
Original assignee: 현대중공업 주식회사
Priority date: 2014-10-29
Filing date: 2014-10-29
Publication date: 2016-05-13
Also published as: KR101881867B1

Abstract

The purpose of the present invention is to provide a fuel injection pump with multiple variable pressure chambers, which controls initial injection pressure of fuel per engine load with a simple structure and inexpensive manufacturing costs in comparison to a conventional fuel injection pump, and injection timing without any separate device for controlling initial injection pressure, a device for moving a barrel, and shape transformation of a plunger. In order to achieve this purpose, the fuel injection pump with multiple variable pressure chambers, comprises: a barrel installed and inserted into a pump housing; a plunger coupled into the barrel to be slid; and an upper cover coupled to an upper surface of the pump housing. In addition, the fuel injection pump is characterized in that a main fuel pressurizing hole is formed in the barrel and the upper cover to communicate with a plunger insertion hole of the barrel; and a pressure adjusting part is connectively installed on the upper cover such that a pressure adjusting hole communicates with the main fuel pressurizing hole. In regards to this, the pressure adjusting part is characterized in that a pressure adjusting housing, in which the pressure adjusting hole is formed, is connectively installed on the upper cover; multiple adjusting cylinders are connectively installed on the pressure adjusting housing in parallel; and a total volume of the pressure adjusting hole is adjusted by the adjusting cylinders such that injection timing of the fuel injection pump is delayed or advanced.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a fuel injection pump,

The present invention relates to a fuel injection pump having a plurality of variable pressure chambers, in which a plurality of regulating cylinders having therein a variable pressure chamber connected to a plunger insertion hole of a fuel injection pump are provided in parallel, To a fuel injection pump having a plurality of variable pressure chambers capable of reducing the generation of NOx while reducing the amount of smog that is a noxious gas.

Generally, the fuel injection pump used in a conventional engine requires an ignition delay due to the use of Bunker-C (HFO) which is a viscosity of different fuel, The technique of compensating the combustion delay part is generally referred to as VIT (Variable Injection Timing) technology. In practice, it means a technique of optimizing the combustion by compensating using FQS (Fuel Quality Setting).

The above-mentioned VIT or FQS is used for increasing the combustion maximum pressure in the combustion cylinder to improve the combustion efficiency while reducing the fuel consumption.

Normally, VIT is able to automatically adjust the injection timing during engine operation and to make it possible to consume the optimum fuel at low load.

Normally, the Bosch type fuel injection pump is a type in which the plunger blocks the spill port of the barrel and the pressure of the fuel starts to increase so that the high-pressure fuel is injected. At this time, The position of the spill port formed on the barrel is adjusted up or down, or the shape of the plunger is modified to suit the load.

However, as described above, the conventional VIT technique for adjusting the fuel injection timing in the related art requires a complicated device for changing the position of the spill port of the barrel, or the plunger is complicatedly changed in shape, The fuel injection timing is changed and it is difficult to adjust the fuel injection timing externally.

Registered Patent Registration No. 10-1219977 (2013.01.02)

It is an object of the present invention to provide a fuel injection device for a fuel injection control device, which is capable of controlling the initial injection pressure of an engine load without a device for controlling a separate initial injection pressure and without a device for moving a barrel, And a plurality of variable pressure chambers for adjusting the pressure and adjusting the injection timing.

The present invention provides a fuel injection pump including a barrel inserted into a pump housing, a plunger slidingly coupled to the barrel, and an upper cover coupled to an upper surface of the pump housing,

The fuel injection pump includes a main fuel pressurizing hole formed in a barrel and an upper cover to communicate with a plunger insertion hole of a barrel, a pressure regulating unit connected to the upper cover so that the pressure regulating hole communicates with the main fuel pressurizing hole,

Wherein the pressure regulating portion is formed by connecting a pressure regulating housing having a pressure regulating hole formed therein to an upper cover, a plurality of regulating cylinders being connected in parallel to the pressure regulating housing, So that the fuel injection timing of the fuel injection pump is delayed or advanced.

The present invention is characterized in that a plurality of adjustment cylinders having variable pressure chambers communicating with the plunger insertion holes of the fuel injection pump are connected in parallel and the volume of the variable pressure chambers in the regulation cylinder is individually adjusted, Delay effect of the fuel injection pump can be seen, and the fuel injection timing of the fuel injection pump can be delayed or widened.

In the present invention, since the volume of the variable-pressure chamber in the regulating cylinder through which the pressure of the fuel is transmitted is adjusted by the rotation of the rotary guide bar by the rotation of the rotary part, the volume of each variable- The volume of the entire variable pressure chamber through which the fuel pressure is transmitted can be constantly and variously adjusted.

The present invention has no separate injection initial pressure regulating device and there is no apparatus for moving the barrel, and it is possible to complete combustion with a simpler structure and lower manufacturing cost than the conventional general fuel injection pump without changing the shape of the plunger, It is possible not only to achieve reduction effect but also to increase combustion rate by increasing fuel injection pressure and to reduce the generation of harmful NOx by controlling fuel injection timing for each engine rod and smog which is harmful gas can be reduced to reduce environmental pollution There are many effects such as can.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an exemplary diagram showing the configuration of a fuel injection pump according to the present invention; Fig.
FIG. 2 is an exemplary view showing an operating relationship of the pressure regulator according to the present invention. FIG.
FIG. 3 is a graph showing a fuel injection rate variable graph according to the position of the variable pressure chamber according to the present invention. FIG.

FIG. 1 is an exemplary view showing the construction of a fuel injection pump according to the present invention, FIG. 2 is an exemplary view showing an operation of a pressure regulator according to the present invention, and FIG. 3 is a cross- Fuel injection rate (Injection Rate) variable graph,

The present invention may be applied to a barrel (120) inserted into a pump housing (110). A plunger 130 slidably coupled to the barrel 120; And an upper cover 140 fastened to the upper surface of the pump housing 110. The pressure of the fuel starts rising due to closing of the outflow hole of the barrel 120 by the plunger 130, In the fuel injection pump,

The fuel injection pump has a main fuel pressure hole 200 formed in a barrel 120 and an upper cover 140 so as to communicate with a plunger insertion hole 121 of a barrel 120, The pressure regulating unit 300 is connected to the upper cover 140 so that the pressure regulating hole 310 is communicated with the pressure regulating hole 310,

The pressure regulating unit 300 includes a pressure regulating housing 320 having a pressure regulating hole 310 therein and a plurality of regulating cylinders 330 connected to the pressure regulating housing 320, The entire volume of the pressure adjusting hole 310 is adjusted by the plurality of regulating cylinders 330 so that the fuel injection timing of the fuel injection pump 100 is retarded or advanced.

That is, the fuel injection pump 100 according to the present invention is configured such that the barrel 120 and the upper cover 140 are coupled to the pump housing 110 and connected to the plunger insertion hole 121 in the barrel, The main fuel pressurizing hole 200 is formed in the upper cover 140 and the pressure regulating portion 300 is formed in the upper cover 140 so that the main fuel pressurizing hole 200 and the pressure adjusting hole 310 are communicated with each other. Is connected,

The pressure regulating unit 300 includes a pressure regulating housing 320 having a pressure regulating hole 310 formed in a tight contact with the upper cover 140 and a pressure regulating housing 320 connected to the variable pressure regulating chamber 320, A plurality of adjusting cylinders 330 connected in parallel to the adjusting cylinder 330 and a tightening plug 340 for coupling the adjusting cylinder 330 to the pressure adjusting housing 320.

The main fuel pressurizing hole 200 communicates with the plunger insertion hole 121 by transmitting the pressure of the fuel pressurized by the plunger 130 to the piston 331 of the regulating cylinder through the pressure regulating hole 310. [ The first fuel pressurizing hole 210 formed in the barrel 120 and the first fuel pressurizing hole 210 are formed so that one end communicates with the first fuel pressurizing hole 210 and the pressure adjusting hole 310 in the pressure regulating housing 320 communicates with the other end. And a second fuel pressure hole (220) formed in the upper cover (140).

The barrel 120 is formed with a plunger insertion hole 121 into which a plunger 130 is inserted and a first fuel pressure hole 210 of the main fuel pressure hole is formed so as to be connected to the plunger insertion hole 121 .

The plunger insertion hole 121 is provided with a delivery valve 150 for delivering the fuel in the barrel pressurized by the plunger 130 to a fuel injection valve (not shown), and an overpressure due to pulsation of the fuel injection valve A constant valve 160 is connected.

The plunger 130 linearly reciprocates in the plunger insertion hole 121 of the barrel to deliver the fuel. The functions of the barrel 120 and the plunger 130 are well known in the art, It is omitted.

The upper cover 140 is fixed to the pump housing 110 and has a second fuel pressurizing hole 220 formed therein so as to communicate with the fuel pressurizing hole 210 of the barrel. And an installation hole 141 in which the pressure adjusting housing 320 is installed to be connected to the hole 220 is formed.

The pressure regulating housing 320 of the pressure regulating part is integrally connected to one end of the upper cover by screwing into the installation hole 141 of the upper cover and the second fuel pressurizing hole 220 and the plurality of regulating cylinders 330, And a plurality of coupling holes 321 through which the control cylinder 330 is coupled to be connected to the pressure adjustment hole 310 are formed.

The pressure adjusting hole 310 includes a main pressure hole 311 communicating with the second fuel pressurizing hole 220 of the main fuel pressurizing hole and a pressure adjusting hole 311 branched from the main pressure hole 311 and communicating with the fastening hole 321 And includes a plurality of branch pressure holes 312.

The tightening plug 340 is for tightly and tightly fitting the adjusting cylinder 330 in the tightening hole 321 of the pressure adjusting housing and is formed in a body that is screwed to the tightening hole 321 of the pressure adjusting housing, And a cylinder fastening hole 342 formed to penetrate the body 341 and to which the adjustment cylinder 330 is fastened.

The adjusting cylinder 330 includes a cylinder body 333 having a variable pressure chamber 332 communicated with the pressure adjusting hole 310 of the pressure adjusting housing and having one side inserted into the close plug,

A piston 331 installed to be movable in the variable pressure chamber 332 of the cylinder body in the left and right direction,

A rotation guide bar 335 which is spaced apart from the piston 331 by a predetermined distance and in which an outer surface is screwed to the screw coupling hole 334 formed in the cylinder body in communication with the variable pressure chamber,

An elastic member 336 installed between the piston 331 and the rotation guide bar 335,

And a position adjusting unit 337 installed on the cylinder body 333 for connecting one side of the rotation guide bar 335 to the rotation guide bar 335 and rotating the position of the rotation guide bar 335 in the screw tightening hole 334 do.

The cylinder body 333 includes a variable pressure chamber 332 having one side inserted into the cylinder engagement hole 342 of the close plug and having a piston 331 inserted therein and a variable pressure chamber 332 communicating with the variable pressure chamber 332 A screw hole 338 formed for threading with the rotation guide bar 335 and a plug hole 339 formed to communicate with the screw hole 338 and provided with the position adjusting part 336, .

The piston 331 is resiliently supported by the elastic member 336 in the variable pressure chamber 332 so that the pressure of the fuel fed from the plunger 130 causes the elastic member 336 to move in the variable pressure chamber 332 of the cylinder body, The reciprocating movement distance in the variable pressure chamber 332 is adjusted by adjusting the elastic force of the elastic member 336 by the position adjusting unit 337. [

The rotation guide bar 335 has an outer surface screwed to the screw coupling hole 338 of the cylinder body and has an elastic member 336 supported on one side thereof and one side of the position adjusting portion 337 is inserted A polygonal engaging groove 335a is formed. The polygonal coupling groove 335a has a polygonal shape such as a triangular shape, a square shape, a pentagonal shape, a hexagonal shape, an octagonal shape and the like and is formed to a predetermined depth.

The rotation guide bar 335 is rotated together with the position adjusting part 337 and rotated in the screw coupling hole 338 when the position adjusting part 337 having one side inserted into the polygonal coupling groove 335a is rotated do.

The elastic member 336 is disposed between the rotation guide bar 335 and the piston 331 to elastically support the upper end of the piston 331 with respect to the rotation guide bar 335. At this time, the elastic member 336 may use an elastic spring.

The position adjusting unit 337 adjusts the elastic force of the elastic member 336 by moving the rotation guide bar 335 in the screw engagement hole 334 by rotating the rotation guide bar 335, A coupling plug 337a which is fixed to the plug hole 339 of the cylinder body by adjusting the reciprocating distance of the piston 331 of the cylinder 331, A pressure regulating rotation bar 337b inserted into the coupling groove 335a and an upper end of the pressure regulating rotation bar 337b exposed to the outside of the coupling plug 337a to be connected to the pressure regulating rotation bar 337b And a fixing nut 337d fastened to the upper end of the pressure control rotary bar 337b so as to be brought into close contact with the rotary part 337c.

The coupling plug 337a is fixed to the cylinder body 333 by a fixing means such as bolt fastening so that one side of the coupling plug 337a is inserted into the plug hole 339 of the cylinder body. A sealing ring 350 is further provided.

A leakage oil outlet 360 is further formed in the coupling plug 337a and the cylinder body 333 so that the flow oil introduced into the position adjusting portion 337 is discharged to the outside.

The pressure regulating rotation bar 337b includes a lower connecting rod 337e inserted into the polygonal connecting groove 335a of the rotation guide bar 335 and a lower connecting rod 337b integrally connected to the lower connecting rod 337e, An upper coupling band 337g formed to be positioned above the intermittent support bar 337f and fitted to the rotation portion 337c and an upper coupling band 337g fitted to the upper coupling band 337g, And a fastening portion 337h which is formed to be positioned on the upper side and to which the fixing nut 337d is fastened and is integrally coupled to the coupling plug 337a and the rotation portion 337c by fastening of the fixing nut 337d.

The lower coupling base 337e has a polygonal shape corresponding to the polygonal coupling groove 335a of the rotation guide bar. That is, the lower coupling base 337e is formed of a polygonal column so as to correspond to the polygonal coupling groove 335a. At this time, the lower coupling base 337e is formed to have a larger volume than the intermediate supporting rod 337f so as not to be inserted into the coupling plug 337a.

The lower coupling base 337e formed as described above is interrupted (not integrally coupled) with the rotation guide bar 335 so that when the rotation of the pressure adjustment rotary bar 337b causes the rotation guide bar 335 to rotate, The rotational force of the pressure adjusting rotary bar 337b is continuously transmitted to the rotary guide bar 335 even if the rotary guide bar 335 is moved along the thread in the screw connection hole 334 by rotation .

The lower end support frame 337e is integrally connected to one end of the stop support rod 337f and the upper end support frame 337g is coupled with the rotation part 337c at the other end. . Further, a sealing ring 351 is further provided between the intermittent support bar 337f and the engagement plug 337a.

The upper coupling base 337g is coupled with the rotation unit 337c to transmit the rotational force of the rotation unit to the pressure regulating rotation bar 337b. The upper coupling base 337g may be a triangular, square, And is fitted into the rotation part 337c.

The coupling portion 337h is integrally formed with the upper coupling portion 337g, and a thread for coupling with the fixing nut 337d is formed on the outer surface.

The pressure regulating rotation bar 337b constructed as above is supported on the engaging plug 337a by the lower engaging base 337e and the fixing nut 337d.

The rotation part 337c rotates the pressure adjusting rotation bar 337b to rotate the rotation guide bar 335 in the screw coupling hole 338. The rotation of the rotation adjusting part 337c causes the rotation of the pressure adjusting rotation bar 337b, A ratchet 337q connected to the coupling plug 337a for fixing the position of the flange 337p and a flange 337p connected to the coupling plug 337a And a flange fixing portion 337r fixed to the plug 337a. At this time, the flange fixing portion 337r uses a known bolt nut or the like.

The ratchet 337q includes a spring 337s inserted into the ball groove 337i of the coupling plug to be positioned between the flange and the coupling plug and a ball supported by the spring 337s to contact the lower surface of the flange When the rotation of the rotating part, that is, the loosening of the fixing nut, is performed to rotationally drive the flange (manual operation), the ball is seated into one ball seating groove 337u formed on the lower surface of the flange to position the flange 337p Is fixed.

At this time, the ball grooves 337i are formed on the coupling plug 337a so that twelve ball grooves 337i are spaced 30 ° around the central point o of the flange.

The rotation part 337c configured as described above is configured such that the flange 337p is rotated and fixed by a predetermined amount by the ratchet 337q provided at a predetermined angle, so that the rotation angle can be controlled to be constant. The rotating portion 337c is fixed so as not to rotate on the engaging plug 337a by the flange fixing portion 337r during the operation (operation) of the fuel injection pump.

The operation and effect of the pressure regulating means of the fuel injection pump having the variable pressure chamber according to the present invention will now be described.

3 is a graph showing a fuel injection rate variable according to the position of the variable pressure chamber according to the present invention.

1 and 2, when the operation of the fuel injection pump 100 is started, the pressure regulator 300 of the fuel injection pump having the variable pressure chamber according to the present invention increases the plunger 130, The pre-stroke spill hole 111 is closed by the plunger 130 installed in the barrel 120 through the stroke spill hole 111 and the fuel introduced into the barrel 120 by the plunger 130 Lt; / RTI >

When the fuel in the barrel 120 is pressurized by the plunger 130 as described above, the pressurized fuel is directed to the fuel injection valve (not shown) through the delivery valve 150 and the fuel injection port 170, The excess pressure due to the pulsation of the fuel injection valve is filtered by the constant valve 160.

At the same time, the pressurized fuel in the barrel 120 flows into the pressure regulating part 300 through the main fuel pressurizing hole 200 to transfer pressure to the piston 331 of the regulating cylinder 330, The piston 331 compresses the elastic member 336 and is moved in the variable pressure chamber 332. [

At this time, the stroke of the piston is controlled by the rotation part 337c of the pressure regulating part. That is, when the rotation part 337c of the pressure regulating part 300 is rotated in one direction (forward) to move the position of the rotation guide bar 335 in the screw coupling hole 334 of the cylinder body toward the piston 331, The elastic member 336 is pressed and compressed by the rotation guide bar 335 so that the reciprocating distance of the piston 331 is reduced and the rotation part 337c is rotated in the opposite direction to the screw hole 334 of the cylinder body, The distance between the rotation guide bar 335 and the piston 331 is increased by the movement distance of the rotation guide bar 335 when the rotation guide bar 335 is moved in the direction of the engaging plug 337a, The member 336 is inflated and the reciprocating distance of the piston 331 is increased.

That is, the volume of the variable pressure chamber 332 in each control cylinder 330 (the volume of the variable pressure chamber to which the fuel pressure is transmitted) is adjusted by the reciprocating distance of the piston as described above, The volume of the chamber 332 is controlled by the volume of the main fuel pressurizing hole 200 to control the overall volume of the fuel delivered to the fuel injection hole 200, The fuel injection timing is delayed or accelerated.

Therefore, the fuel injection pump having the variable pressure chamber according to the present invention has no apparatus for moving a separate barrel, and can perform complete combustion with a simpler structure and lower manufacturing cost than the conventional general fuel injection pump without changing the shape of the plunger Thereby reducing the amount of harmful NOx. In addition, it is possible to reduce the amount of harmful NOx and smog, thereby reducing the environmental pollution .

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims and their equivalents. Of course, such modifications are within the scope of the claims.

(100): fuel injection pump
(110): pump housing
(120): barrel
(121): Plunger insertion hole
(130): plunger
(140): upper cover
(141): Installation hole
(150): Delivery valve
(160): Constantine valve
(170): fuel outlet
(200): Main fuel pressure hole
(210): first fuel pressure hole
(220): the second fuel pressure hole
(300): pressure regulator
(310): pressure adjusting hole
(311): Main pressure tube
(312): Branching pressure tube
(320): pressure regulating housing
(321): fastening hole
(330): Adjusting cylinder
(331): piston
(332): variable pressure chamber
(333): cylinder body
(334): Screw-tightening hole
(335): a rotation guide bar
(335a): multiple engaging groove
(336): elastic member
(337): Position adjusting section
(337a): coupling plug
(337b): Pressure regulating rotary bar
(337c)
(337d): Fixing nut
(337e): Lower coupling base
(337f):
(337g): Top coupling
(337h):
(337i): the ball home
(337p): Flange
(337q): Latch
(337r): flange fixing portion
(337s): Ball
(337t): spring
(337u): Ball seating groove
(338): Screw-tightening hole
(339): Plug hole
(340): close contact plug
(350, 351): sealing ring
(360): Leak oil outlet

Claims

The present invention may be applied to a barrel (120) inserted into a pump housing (110). A plunger 130 slidably coupled to the barrel 120; And an upper cover 140 fastened to the upper surface of the pump housing 110. The pressure of the fuel starts rising due to closing of the outflow hole of the barrel 120 by the plunger 130, In the fuel injection pump,
The fuel injection pump includes:
A main fuel pressurizing hole 200 is formed in the barrel 120 and the upper cover 140 so as to communicate with the plunger insertion hole 121 of the barrel 120 and the pressure adjusting hole 310 The pressure regulating unit 300 is connected to the upper cover 140,
The pressure regulating unit 300 includes a pressure regulating housing 320 having a pressure regulating hole 310 therein and a plurality of regulating cylinders 330 connected to the pressure regulating housing 320, And the entire volume of the pressure adjusting hole 310 is adjusted by the plurality of regulating cylinders 330 so that the fuel injection timing of the fuel injection pump 100 is delayed or advanced. A fuel injection pump comprising a plurality of variable pressure chambers.

The method of claim 1,
The pressure regulator 300 includes a pressure regulating housing 320 having a pressure regulating hole 310 formed therein and being in tight contact with the upper cover 140 and communicating with the main fuel regulating hole 200, A plurality of regulating cylinders 330 connected in parallel to the pressure regulating housing 320 so as to be connected to the regulating cylinder 320 and a contact plug 340 for connecting the regulating cylinder 330 to the pressure regulating housing 320 And a plurality of variable pressure chambers.

The method of claim 2,
The regulating cylinder 330,
A cylinder body 333 in which a variable pressure chamber 332 communicating with the pressure adjusting hole 310 of the pressure adjusting housing is formed therein and one side of which is inserted into the close contact plug,
A piston 331 installed to be movable in the variable pressure chamber 332 of the cylinder body in the left and right direction,
A rotation guide bar 335 which is spaced apart from the piston 331 by a predetermined distance and in which an outer surface is screwed to the screw coupling hole 334 formed in the cylinder body in communication with the variable pressure chamber,
An elastic member 336 installed between the piston 331 and the rotation guide bar 335,
And a position adjusting unit 337 installed on the cylinder body 333 for connecting one side of the rotation guide bar 335 to the rotation guide bar 335 and rotating the position of the rotation guide bar 335 in the screw tightening hole 334 And a plurality of variable pressure chambers.

The method of claim 3,
The rotation guide bar 335 has an elastic member 336 on one side thereof and a polygonal engaging groove 335a on the other side thereof to which the one side of the position adjusting part 337 is inserted,
The position adjusting portion 337 includes a coupling plug 337a fixed to the plug hole 339 of the cylinder body and a polygonal coupling groove 335a of the rotation guide bar 335 through the coupling plug 337a. And a rotation part 337c which is connected to the upper end of the pressure adjusting rotation bar 337b exposed to the outside of the coupling plug 337a and rotates the pressure adjusting rotation bar 337b, And a fixing nut 337d fastened to an upper end of the pressure regulating rotation bar 337b so as to be brought into close contact with the rotation part 337c.

The method of claim 4,
The pressure regulating rotation bar 337b includes a lower coupling band 337e inserted into the polygonal coupling groove 335a of the rotation guide bar 335 and a lower coupling band 337e integrally connected to the lower coupling band 337e, An upper coupling band 337g formed to be positioned above the intermittent support bar 337f and fitted to the rotation portion 337c and an upper coupling band 337g fitted to the upper coupling band 337g, And a fastening portion (337h) formed to be positioned on the upper side of the valve body and fastening the fastening nut (337d).

The method of claim 4,
The rotating portion 337c includes a flange 337p to which the upper coupling rod 337g of the pressure adjusting rotary bar 337b is fitted and a ratchet 337b connected to the coupling plug 337a to fix the position of the flange 337p. And a flange fixing portion 337r which is connected to the coupling plug 337a and fixes the flange 337p to the coupling plug 337a,
The ratchet 337q includes a spring 337s inserted into the ball groove 337i of the coupling plug to be positioned between the flange and the coupling plug and a ball supported by the spring 337s to contact the lower surface of the flange Wherein the ball is seated in one ball seating groove (337u) formed on the lower surface of the flange when the rotating portion is rotated, so that the position of the flange (337p) is fixed. Fuel injection pump.