Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
  • F02M61/14—Arrangements of injectors with respect to engines; Mounting of injectors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/85—Mounting of fuel injection apparatus
  • F02M2200/855—Mounting of fuel injection apparatus using clamp elements or fastening means, e.g. bolts or screws

Definitions

• the invention relates to a holding fork of an element to a support, such as a holding fork of an injector holder to a cylinder head of a heat engine.
• the invention also relates to a device for fixing an injector holder to a cylinder head of a heat engine comprising such a fork.
• Maintaining an injector holder on a thermal engine cylinder head may be provided by a fork type holding member having an end bearing on an upper surface of the injector holder, and another end bearing on a corresponding surface of the breech.
• This fork also comprises a central opening in which is engaged the clamping screw which is screwed into the cylinder head. After positioning this fork, the engagement and tightening of the screw can block in translation the injector holder in position in the cylinder head.
• the injector holder has a generally cylindrical shape, and the maintenance or attachment thereof by a fork does not allow to lock in rotation with the required accuracy.
• Such an injector comprises an injection end located in the combustion chamber, from which each injection gives several separate jets which are regularly spaced from each other around the axis of revolution of the injector.
• reference jet is very close to the end of the engine spark plug.
• a fork comprising two branches which bear against an upper surface of the injector holder while surrounding a head of the injector body.
• the head is provided with two flats, so that the engagement of the fork on the head can directly immobilize the injector in rotation during its assembly.
• the object of the invention is to provide a holding fork or attachment of an injector holder to ensure accurate angular positioning of the injector during its assembly.
• the invention relates to a holding fork of an element to a support, such as a holding fork of an injector holder to an engine cylinder head, this fork comprising a tail intended to bear on the support and provided with a central opening for receiving a clamping element to the support, and two branches intended to bear on the element by surrounding a head of this element and comprising at least one flat part. to lock this rotating element.
• the fork comprises a resilient element equipping one of its branches and defining two elastic supports interposed between an inner face of this branch and the head of the element in order to maintain a flat part of this head resting on a inner side of the opposite branch.
• the central opening further comprises a seat having a shape of revolution ensuring a centering of the fork relative to a head of the clamping element when the clamping screw is tightened.
• the invention also relates to a fork as defined above, wherein the clamping element to the support is a screw.
• the invention also relates to a fork as defined above, wherein the seat has a spherical cap shape to define with the head of the clamping element a ball joint type.
• the invention also relates to a fork as defined above, comprising a resilient element equipping one of its branches and defining two elastic supports interposed between an inner face of this branch and the head of the element to maintain a flat part of this head resting on an inner face of the opposite branch.
• the invention also relates to a fork as defined above, wherein the elastic element comprises two resilient supports spaced apart from each other along the inner face of the branch to bear on a flat of the head of the element.
• the invention also relates to a fork as defined above, wherein the elastic element comprises a metal blade, and wherein the elastic bearing points are curved portions of the metal blade.
• the invention also relates to a fork as defined above, wherein the elastic element is formed from a sheet having a general shape of T, each curved portion being obtained by bending one end of the head. of this T, and in which the leg of the T is bent so as to partially surround the branch to be attached thereto by stapling.
• the invention also relates to a fork as defined above, comprising a spherical cap shaped key at the tail to ensure a one-off support of the tail on the support, and a portion-shaped touch of cylinder at each branch to provide a linear support of the branches on the element.
• the invention also relates to a device for holding a nozzle holder on a thermal engine cylinder head comprising a fork as defined above.
• FIG. 1 is an overall perspective view of an injector holder held by a fork according to the invention
• FIG. 2 is a perspective view of the fork according to the invention and of an upper part of the injector holder which it holds;
• Figure 3 is a top view of a fork according to the invention and the injector holder that maintains;
• Figure 4 is a sectional view of the fork according to the invention with its fixing screw
• FIG. 5 is a perspective view of the branches of the fork according to the invention.
• FIG. 6A is a view from above of the branches of the fork according to one embodiment of the invention, the elastic element being generally T-shaped;
• FIG. 6B is a view from above of the branches of the fork according to another embodiment of the invention, the elastic element being generally U-shaped;
• FIG. 7 is a front view of the fork according to the invention and of an upper part of the injector holder which it holds;
• Figure 8 is a side view of the fork according to the invention and an upper part of the injector holder that maintains.
• an injector holder 1 shown in perspective comprises a generally cylindrical main body 2 extending along a vertical axis AX.
• This main body 2 comprises a lower end 3 of fuel injection, and an upper portion on which bears a fork 4 to hold it in position in a cylinder head not shown.
• the lower end opens into a not shown combustion chamber, in which also opens an end 6 of a candle 7 to produce a spark to trigger combustion.
• the lower end 3 injects the fuel, in the case here represented in the form of six separate equidistant jets marked by 8, 9, 11, 12, 13, 14 which are regularly distributed around the axis AX being spaced from each other by an angle of sixty degrees.
• this injector holder 1 also comprises, in its upper part, an electrical connector 17 and a fuel return nozzle 18. It also comprises an upper support surface. 19 extending in a plane normal to the axis AX with a high pressure injection head 21 located in a central zone of this upper face.
• the injector occupies an ideal angular position with respect to its axis of revolution AX, so that the jet identified by 8 tangents the end 6 of the spark plug 7, which corresponds to an ideal situation with regard to combustion conditions.
• the fork 4 exerts a force along the axis AX, on the upper bearing surface 19 of the injector holder, to maintain it in position in the cylinder head by maintaining a shoulder 16 of a lower portion of the main body 2 resting on a corresponding non-represented seat of the breech.
• This fork 4 which appears more clearly in the top view of Figure 3, comprises a tail 23 bearing on a stud 24 forming part of the yoke or attached thereto. It also comprises two branches 26 and 27 extending parallel to each other, which bear on the bearing surface 19 surrounding the head 21.
• a central opening 28, located between the shank 23 and the branches 26 and 27 is provided in the fork to receive a clamping element, in this case a clamping screw 29 which is screwed into the cylinder head, the head 31 this clamping screw being supported on the fork. It is also possible to substitute the screw 29 for example a nut. As shown in Figure 4, the opening 28 defines an inner surface having a general funnel shape, forming a seat on which the head 31 of the screw bears. The tightening of the screw 29 thus spontaneously causes the centering of the fork 4 relative to the head 31 of the screw.
• the opening 28 comprises a central bore emerging on a lower face of the fork and traversed by the rod of the screw 29, this hole widening in a spherical cap shape 32 on which is supported by a complementary bottom surface 33 of the head of the screw 29.
• This spherical cap 32 forming the home seat of the head 31 widens further along a frustoconical surface 35 to reach an upper surface of the fork 4.
• the fork 4 is necessarily centered relative to the position of the head 31 of the screw 29 during the tightening of this screw.
• branches 26 and 27 of the fork which extend parallel to each other to surround the head 21 of the injector holder, are designed to accurately block the angular position of the injector with respect to the fork 4.
• the head 21 comprises two flats marked 34 and 36 in Figure 7, one of which bears on an inner face 37 of the branch 26.
• the angular positioning of the nozzle holder relative to the fork is improved by means of elastic means visible in Figures 5 and 6, which ensure the flattening of the flat 36 against the inner face 37 of the branch 26.
• These elastic means form two elastic supports 38 and 39 which are located on the inner face 41 of the branch 27 being spaced apart from each other along this branch.
• these elastic means are formed from an elastic sheet 42 having a generally T-shaped outline.
• the two ends of the head 43 of the T are curved to be bulging and forming resilient supports, the head of the T extending generally parallel to the branch 26.
• the leg 44 of the T is also curved so as to at least partially surround the branch 27 to form a fastening clip to this branch.
• the branch 27 comprises a channel 46 in which this leg 44 is embedded to ensure positioning of the elastic member 42 longitudinally with respect to the branch 27.
• the flat portion 36 of the head 21 is held in abutment on the inner face 37 of the branch 26, which makes it possible to overcome the influence of the angular clearance introduced by the game. functional corresponding to the difference between the distance separating the internal faces 41 and 37 and the distance separating the flats 34 and 36.
• the implementation of the elastic supports 38 and 39 makes it possible to cancel the angular clearance of the head 21 of the injector holder with respect to the fork 4, this clearance being represented by ⁇ in FIG. 3.
• the reduction of the angular positioning clearance is further reduced by the implementation of the centering seat 32 detailed above, which avoids a lateral offset of the range likely to result in an additional angular defect.
• the elastic element 42 ' is generally U-shaped, surrounding a branch 27' so that the forces exerted on it are balanced, and not dissymmetrical as in the case of a T-element of Figure 6A.
• a longitudinal channel 46 ' for housing the body of the elastic member, only elastic supports 38' and 39 'remaining protruding. This embodiment allows a simplified assembly.
• the fork is provided with support keys ensuring isostatic support on the injector holder and on the cylinder head, which further reduces the positioning differences of the range may result in an angular offset of the injector holder.
• the tail of the fork is provided on its underside with a key 47 forming a spherical surface, visible in FIG 8, defining a point support on the flat upper surface of the pin 24.
• the branch 26 and the branch 27 are provided with keys 48 and 49 having surfaces in coaxial cylinder portions which define a linear support of these branches on the upper surface 19.
• the point support 47 suppresses a first degree of freedom in vertical translation of the range
• the linear contact provided by the keys 48 and 49 removes two degrees of freedom in rotation about two axes perpendicular to each other and perpendicular to AX axis.
• the other three remaining degrees of freedom include the two possible translations of the fork in a plane normal to the axis AX, and the rotation of the fork around the axis AX.
• the two possible translations are removed by the ball joint formed by the seat 34 and the head 31 of the screw 29.
• the rotation of the fork around the axis AX in a plane normal to this axis is removed. by the engagement of the branches 26 and 27 on the head 21 of the injector holder.
• the fork according to the invention does not induce a fault in the angular positioning of the injector holder in the case of angular deviation between the clamping screw 29 and the axis AX.
• This angular defect is indicated by ⁇ in FIG. 8, and corresponds to the angle separating the axis AX and the axis of the screw 31, in a plane containing the axis AX and the axis of the screw 31.
• the fork according to the invention thus makes it possible to accurately position the reference jet 8 with respect to the head 6 of the spark plug 7, for example to place the head 6 and the reference jet 8 in the same plane passing through AX axis.
• This positioning is obtained simply by mounting the fork and tightening the screw 29, that is to say without having to perform specific adjustment.
• the device according to the invention is particularly advantageous because it allows a blocking of an element both in translation and in rotation with high positioning accuracy.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Fuel-Injection Apparatus (AREA)
• Axle Suspensions And Sidecars For Cycles (AREA)
• Load-Engaging Elements For Cranes (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=38003034

Family Applications (1)

Country Status (7)

Families Citing this family (22)

Family Cites Families (16)

• 2006
  • 2006-07-21 FR FR0653076A patent/FR2904059B1/fr not_active Expired - Fee Related
• 2007
  • 2007-07-10 DE DE602007010637T patent/DE602007010637D1/de active Active
  • 2007-07-10 ES ES07804004T patent/ES2354639T3/es active Active
  • 2007-07-10 US US12/374,667 patent/US20090314258A1/en not_active Abandoned
  • 2007-07-10 EP EP07804004A patent/EP2044322B1/de not_active Not-in-force
  • 2007-07-10 AT AT07804004T patent/ATE488689T1/de not_active IP Right Cessation
  • 2007-07-10 WO PCT/FR2007/051628 patent/WO2008009842A1/fr active Application Filing

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events