JP2000513782A - Low leak plunger and barrel assembly for high pressure fluid systems - Google Patents

Abstract

(57) Abstract: A plunger reciprocally mounted within a cavity formed in a barrel and a leakage flow reduction device disposed within the cavity to reduce fluid leakage flow around the plunger. Thus, there is provided an improved plunger and barrel assembly with increased system efficiency. The leak flow reduction device includes a sealing sleeve removably mounted in the cavity between the plunger and the barrel, which includes a bore for slidably receiving the plunger, and an annular between the plunger and the bore. Form a gap. The sealing sleeve is designed to flex elastically to minimize fluid leakage from the annular gap in response to fluid pressure to reduce the annular gap. The sealing sleeve is formed as a separate part from the barrel for easy low cost replacement. The sealing sleeve is desirably applied to a fuel pump having a pump plunger for pressurizing fuel in a high-pressure chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION         Low leak plunger and barrel assembly for high pressure fluid systems Technical field   The present invention effectively prevents leakage from the clearance between the plunger and the barrel assembly. A plunger and barrel assembly for a fluid system to be minimized. Background of the Invention   Engine designers continually seek engine design improvements that improve engine efficiency are doing. One way to improve engine efficiency is to improve the operating efficiency of the fluid system. It is good. In particular, leakage of high-pressure fuel in a fluid system can reduce engine efficiency. Means energy loss that can be reduced. Improve fuel economy, Attempts to reduce emissions in accordance with recent and forthcoming legislative requirements As the firing pressure levels increase, the loss of high-pressure fuel has become an increasingly It has become to.   Undesirable fuel leaks reciprocate into a bore formed in the body As well as sliding fit with the inner surface of the body (close sliding fit) The valve element is sized to form a partial fluid seal between adjacent surfaces. Components of a fuel system that have components such as element or fuel plungers appear. As the fuel pressure increases, along the length of the seal, i.e. A pressure gradient is created along the clearance between the member and the opposing wall forming the bore . The leakage flow rate from the clearance mainly depends on the magnitude of the pressure gradient, the length of engagement, Depends on the size of the operating clearance and the viscosity of the fluid You. The size of the operating clearance depends on the fuel pressure induction of the body forming the bore. Affected by the amount of expansion or deformation. One way to reduce leakage is to use the Design components to make clearance between the lancer and the barrel smaller It is to be. But trying to make the tolerances smaller increases manufacturing costs I do. Another way to reduce leakage is to increase the size of the body or housing that forms the bore. To counter pressure-induced expansion by increasing its strength and / or strength, Body It is to design. However, this method does not involve components and consequently fuel systems. Is undesirable because it increases the size and weight of   Many fuel systems used in modern engines are, for example, U.S. Pat. A single fuel injector as disclosed in US Pat. No. 5,072,709, or US Pat. No. 4,530,335, incorporated in a fuel pump assembly as disclosed in US Pat. And a fuel pressurizing plunger mounted to reciprocate. Each plunge The compressor is typically operated mechanically or hydraulically to pressurize fuel in Inject into engine cylinder. For example, US Pat. No. 5,096,121 and No. 5,441,027 discloses a hydraulically operated pressure booster plunger assembly. You. However, these references do not cover leakage between the plunger and the adjacent bore wall. It does not imply a reduction, and thus suffers from the disadvantages mentioned above.   Loegel, Sr. U.S. Pat. No. 4,991,495 discloses that a bore mounted Sealed plunger and the space between said plunger and its housing A plurality of inserts arranged in series along the plunger to Discloses a pumping mechanism. Inserts are given by adjacent inserts Thrust and radial deformation and expansion in response to the induced axial fluid And seal rings. But this sealing assembly is costly to maintain Requires extra disks and other parts of complex and expensive equipment that is difficult to access And In addition, the device provides for the insertion of the insert during each pumping stroke of the plunger. Reseal two gaps, one on each side, thus allowing for less than minimal leakage This is not desirable because it is necessary to enhance the properties.   U.S. Pat. No. 5,038,826 to Kabay et al. 3 discloses a three-way valve that includes a retracted piston. The high-pressure fuel is supplied to the valve body and the pin. It is fed into the valve via an alignment port formed in the ston. Piston or The integral portion of the valve is actuated by fuel pressure and the piston And the clearance between the valve body and the valve body, thereby reducing leakage between components. Deformation of the one piece tends to close the clearance and reduce leakage, but as a result Small tolerances may be caused by wear or possibly friction of the disc or piston. Excessive clearance over time, causing increased scuffing May occur. In the case of the design of Kabay et al. This requires replacement of the entire ston and / or valve element, which adds cost. Also , The integral part only reduces the pressure gradient of the localized part with a limited seal length And therefore the leakage cannot be optimally minimized, which is disadvantageous. In addition, the integral part is machined by machining the internal flow path into the valve body or piston Forming increases manufacturing time and cost.   Thus, while minimizing the cost and size of the assembly, the plunger and Improved, effectively and optimally minimizing fluid leakage from the clearance with the There is a need for a plunger and barrel assembly. Summary of the Invention   Accordingly, it is an object of the present invention to overcome the disadvantages of the prior art and to provide a plunger and barrel That can optimally minimize fuel leakage during It is to provide an improved plunger and barrel assembly.   Another object of the invention can be applied to either valves or pumps, To effectively reduce fluid leakage between the pump or valve member and its body forming the bore To provide an improved plunger and barrel assembly.   Still another object of the present invention is to provide a single fuel injector in a high pressure fuel system and Applicable to fuel pumps including reciprocating plunger pumps located upstream of fuel injectors To provide an improved plunger and barrel assembly.   Still another object of the present invention is to provide a method for controlling the distance between the plunger and the barrel as the fuel pressure increases. Improved plunger and barrel assembly with reduced operating clearance Is to provide.   Yet another object of the invention is to meet component lubrication and structural requirements. Including an elastic part that allows the material of the elastic part to be selected independently of the barrel, It is to provide an improved plunger and barrel assembly.   Yet another object of the present invention is to provide a blind bore formed in a barrel. To provide an improved plunger and barrel assembly that minimizes the cost of manufacturing Is to provide.   Yet another object of the present invention is to provide a plunger bore for an assembly. Improved without being substantially affected by the strain effects of tightening or mounting loads. To provide an improved plunger and barrel assembly.   Yet another object of the present invention is to provide a new bore-forming surface without replacing the barrel. Improved plunger and barrel assembly that can be retrofitted easily and inexpensively It is to be.   Yet another object of the present invention is to provide an elastomeric seal for removing a fluid-tight function from a barrel. Providing an improved plunger and barrel assembly, including is there.   Yet another object of the present invention includes an easily replaceable elastic sealing sleeve. , An improved plunger and barrel assembly.   Yet another object of the present invention is to design the barrel to limit its operating stress and its Sized to determine size and to limit radial expansion Instead, an elastic sealing sleeve that allows for increased radial expansion of the barrel An improved plunger and barrel assembly is provided.   Yet another object of the present invention is to increase the efficiency of Plunger and Barrel Assembly for Fuel Pump to Minimize Pump Discharge It is to provide.   These and other objects of the present invention include cavities and high pressure flow circuits. Body, a plunger arranged to reciprocate in the cavity, and a fluid circuit Leak reduction device located in the cavity to reduce the leakage flow of fluid from By providing a fluid control device for a high pressure fluid system, comprising Is done. The leak flow reduction device is removed between the plunger in the cavity and the device body. Movably mounted and includes a bore for slidably receiving the plunger, A sealing sleeve defining an annular gap between the jaws and the bore. Ceiling The sleeve elastically flexes against fluid pressure to reduce the annular gap, and from the annular gap Designed to minimize fluid leakage. Sealing sleeve is fluid pressure Acts directly to deflect the sealing sleeve radially inward, reducing the annular clearance An outer annular surface may be included to reduce. Sealing sleeve is also available inside It may also include a flexure and an outer portion securely attached to the device body. Outside The part has an annular step for sealingly adjoining an annular land formed on the apparatus body. May be included. Use the axial clamping force acting on the outer The sleeve in place so that it presses against the annular land. Can be. The sealing sleeve is pressed into the cavity so as to press against the main body of the device. can do. Due to the pressure of the fluid acting on the inner end of the sealing sleeve And the sleeve is easily biased so that it seals adjacent to the annular land. The inner end of the sleeve is spaced from the inner end of the cavity. did Thus, the cavity is formed in the device body composed of one part, and the sealing sleeve is formed. Can be held in the cavity by an axial clamping force, or Alternatively, the device body is composed of two parts, which are connected when they are connected together. A cavity for fixing the sealing sleeve can be formed.   The invention is based on the fact that the plunger moves with a periodic pumping stroke, A straw is operable to pressurize the fuel in a high pressure fuel chamber formed at the end. It is desirable to incorporate it into a fuel pump for high pressure fuel systems. BRIEF DESCRIPTION OF THE FIGURES   FIG. 1 shows a conventional plunger and barrel used in a prior art fuel pump. It is a fragmentary sectional view of an assembly.   FIG. 2 shows a plunger and barrel designed according to a preferred embodiment of the present invention. It is a fragmentary sectional view of an assembly.   FIG. 3 is a partial sectional view of a second embodiment of the plunger and barrel assembly of the present invention. It is.   FIG. 4 illustrates the leakage reduction of the present invention as compared to a conventional assembly as disclosed in FIG. It is a graph which shows an effect.   FIG. 5 shows the plunger and barrel half of the plunger and barrel assembly of the present invention. Radial displacement and radial clearance of gaps along the length of the sealing sleeve 6 is a graph showing the graph of FIG.   FIG. 6 shows the pressure in the annular gap along the length of the sealing sleeve of the present invention. This is a graph. DESCRIPTION OF THE PREFERRED EMBODIMENTS   FIG. 1 shows another fuel pump using a conventional plunger and barrel assembly. On the other hand, when the plunger and barrel assembly of the present invention is incorporated in a fuel pump, Presented to clarify benefits. FIG. 1 shows a barrel including a plunger bore 14. And a plunger 16 mounted for reciprocation in a bore 14. 1 illustrates a prior art plunger and barrel assembly, generally designated 10. Plunger 16 moves on the forward and backward strokes to form one end of bore 14. It operates to periodically pressurize the fluid, ie, fuel, in the pressurized high pressure chamber 18. High pressure The high pressure fuel in chamber 18 is delivered to the engine via high pressure flow circuit 20. plan The jar 16 and the bore 14 are mutually connected by a barrel in which the plunger 16 forms the bore 14. An annular gap formed between adjacent surfaces forming a sliding fit with the inner surface of It is sized to form a partial fluid seal therebetween. Round trip of plunger 16 During movement, a pressure gradient in the axial direction along the length of the engagement or sealing of the annular gap The leakage flow rate is formed outward from the high-pressure chamber 18. The high pressure chamber 18 As the fuel pressure inside increases, the leakage flow increases. The pressure in the high pressure chamber 18 is often If so, the barrel 12 is expanded, that is, elastically deformed radially outward. High enough to increase the size of the annular gap and therefore undesirable In addition, the leakage flow rate increases. This leakage flow functions to lubricate the plunger 16 Is desirable, but leakage flow reduces the efficiency of the fuel system It also means a loss of energy which increases the required pump delivery of the assembly.   The plunger and barrel assembly of the present invention shown in FIGS. Functioning to minimize leakage flow around the Increase the size of the assembly while increasing the pumping capacity and reducing the required pump output And allows an effective reciprocating movement of the plunger. Referring to FIG. Plunger and barrel of the present invention applied to a fuel pump indicated by reference numeral 30 A preferred embodiment of the assembly is shown. The fuel pump 30 has a cavity 34 formed therein. Body or barrel 32 and a reciprocating motion within a cavity 34. Attached between the plunger 36 and the barrel 32 in the cavity 34. A leakage flow reduction device 38. The fuel pump 30 of the present invention is a single fuel injector. And the fuel in the high pressure fuel system located upstream of the fuel injector. It can be incorporated into various applications, such as charge pumps. Plunger and barrel The assembly can also be incorporated into a hydraulically actuated pressure boost pump device. Also, The plunger and barrel assembly of the present invention allows the plunger 36 to be shaped, for example, into a barrel. Another type, such as a high-pressure fuel valve that acts as a valve body to engage a formed valve seat It is also possible to incorporate in a fluid control device.   The leakage flow reduction device 38 includes a sealing sleeve 40 disposed in the cavity 34. And includes a bore 42 for receiving the plunger 36. Sealing pickpocket The sleeve 40 is adjacent to an annular land 48 formed inside the bore 34 of the barrel 32. Outer portion 44 including an annular step 46 for sealing. Sealing three The valve 40 maintains the annular step 46 sealed adjacent to the annular land 48. 50 provided by a mounting device or a tightening device (not shown) Is securely held in place in the cavity 34 by the axial tightening force indicated by It is. Accordingly, the sealing sleeve 40 is removably disposed within the cavity 34. Designed to be Axial clamping force 50 is incorporated herein by reference U.S. Pat. No. 5,503,128, which is hereby incorporated by reference. In this case, the fuel pump 30 is integrated with the injector and tightened The fuel injector is located at a predetermined position in an injector mounting bore formed in the engine. And also provide sufficient force to hold barrel 32.   The sealing sleeve 40 is also formed integrally with the outer portion 44 and within the cavity 34. Also includes an inner flexible portion 52 that extends inwardly. The inner end portion 54 of the inner flexible portion 52 , Ends at an interval from the inner end of the cavity 34. The plunger 36 is a cavity 34 Reciprocating in bore 42 so as to form a high pressure fluid chamber 56 at the inner end of It is attached. The high pressure fuel circuit 58 directs the supplied fuel into the high pressure chamber 56, The flow of high pressure fuel from the chamber 56 is controlled, for example, through a fuel injector nozzle assembly. Inject into gin.   The inner flexible portion 52 is generally cylindrical and is vacant such that an outer annular chamber 60 is formed. The outer diameter is sufficiently smaller than the inner diameter of the body 34. The outer annular chamber 60 includes the inner flexible portion 5. 2 through an end gap 61 formed between the inner end 54 of the second cavity and the inner end of the cavity 34. Thus, it is in continuous fluid communication with the high-pressure chamber 56. Therefore, the fuel pressure of the outer annular chamber 60 Is substantially the same as the fuel pressure in the high pressure chamber 56 throughout the movement of the plunger 36. You. The outer diameter of the plunger 36 and the inner diameter of the sealing sleeve 44 A gap 62 is formed between the outer surface of the sealer 36 and the inner surface of the sealing sleeve 40. And sized such that a sliding interference fit and a partial fluid seal are formed. That As a result, the fuel pressure in the outer annular chamber 60 is reduced by the fuel pressure in at least a portion of the annular gap 62. Higher, so that the inner flexible portion 52 bends inward and the gap 62 becomes larger. The size and the leakage flow from the gap are reduced.   During operation, when the plunger 36 is retracted, the high pressure chamber 56 expands and is supplied from the circuit 58. Fuel flows into the high pressure chamber 56. The plunger 36 faces inward toward the high pressure chamber 56. At some point during the advance process, the fuel in the high-pressure chamber 56 is compressed by the plunger 36. And thereby the fuel pressure in both the high pressure chamber 56 and the outer annular chamber 60 is similarly increased I do. Therefore, the high-pressure fuel of the same pressure is supplied to the flexible portion 52 adjacent to the high-pressure chamber 56. Both the inner surface and the outer annular surface of the inner flexible portion 52 forming the outer annular chamber 60 Act on. As a result, the inner end of the inner flexible portion 52 receives the same pressure, Thus, the fuel pressure-induced expansion of the portion of the inner flexible portion 52 located adjacent to the high pressure chamber 56 is Evaded. Further, an annular gap 62 between the plunger 36 and the inner flexible portion 52 is formed. The partial fluid seal created reduces pressure along the axial length of the annular gap 62. It tends to produce an aperture effect. However, the outer annular ring located on the opposite side of the annular gap 62 The fuel pressure in the chamber 60 is maintained at a high pressure level equal to the pressure in the high pressure chamber 56. Accordingly The inner plunger 36 overlaps the plunger 36, i.e. is located adjacent to the annular gap 62. The portion of the flexure 52 receives fluid pressure on its outer surface, and That portion tends to bend inward in the radial direction, that is, elastically deform. did Accordingly, the annular gap 62 is reduced by the fluid pressure induced bending of the sealing sleeve 40. A little, as a result, the leakage flow from the annular gap 62 is reduced. In the outer annular chamber 60 High pressure fuel may cause fuel-induced expansion of barrel 32, which expansion is The seal between the plunger 36 and the sealing sleeve 40 is not adversely affected.   FIG. 3 shows a second embodiment of the plunger and barrel assembly of the present invention, Here, the leak flow rate reducing device 70 is provided between the two-piece barrel 74 and the plunger 75. It includes a generally cylindrical sealing sleeve 72 disposed therebetween. Two-piece barrel 74 is a first piece 76 and a second piece 76 each having a respective cavity 80,82. The first piece 76 is positioned adjacent to the second piece 78 in a straight line. When completed, a complete cavity 84 is formed. The second barrel piece 78 is an upper ring The sleeve 72 into a second barrel piece 78 including a sleeve 86 and an annular recess 88. For a secure connection, the sealing sleeve 72 is pressed into it. C The outer end of the ring sleeve 72 is adjacent to the upper annular land 86 and has a sealing thread. The lobe 72 is disposed in the cavity 84 in the axial direction. Sealing sleeve 72 is annular concave After being pressed into location 88, first barrel piece 76 may be compressed in any conventional manner, for example, The second barrel piece 78 is threadably engaged with the side retainer so that the first and second By holding the threads 76, 78 in a compressed abutting relationship, the second barrel piece 78 Can be connected. The sealing sleeve 72 is structurally and functionally second. It includes an inner flexible portion 90 that is the same as the inner flexible portion 52 of the previous example of the figure. Fuel pressure of high pressure chamber 56 Acts on the inner end 54 of the inner flexible portion 80 and causes the sealing sleeve 72 to It is biased upward so as to be adjacent to the land 86, and the sealing sleeve 72 and the second Assists in sealing the connection with the relpiece 78. The tightening force shown at 92 is The first and second barrel pieces 76 , 78 to secure them adjacent to each other.   Sealing sleeves 40, 72 provide improved leakage flow for any application. A material that allows for the optimal amount of radial deflection or displacement to achieve the reduction; It is formed with the thickness of the flexible portion. The desired radial displacement of the sleeves 40, 70 is 62, the size of the initial radial clearance at the time of no load and the pressure in the high pressure chamber 56. Depends on fuel pressure.   The low-leakage plunger and barrel assembly of the present invention is less than a conventional high pressure fluid control device. This results in significant advantages. First, the leak flow rate reducing device of the present invention Effectively reduces fluid leakage between the valve member and the body forming the member bore, Improve the efficiency of fluid systems. In a fuel pump application, the present invention further provides: It functions to minimize the required pump discharge of the fuel pump. Fig. 4 6 to FIG. As shown in FIG. 4, the sealing sleeve of the present invention Is reduced by 90% compared to standard barrels and sleeves. Half of the annular gap 62 Radial clearance allows pressure-induced radial deflection of the sleeve It is desirable that the clearance be larger than the conventional clearance in the radial direction of the gap. Needless to say, the deviation gradually increases as the fuel pressure increases, and as a result, the annular gap 62 becomes smaller. Unlike the reverse reaction of the sealing sleeve of the present invention, The smaller the clearance, the more fuel pressure increases, the more fuel pressure induced expansion of the barrel To increase for. FIG. 5 shows the radial displacement of the barrel and plunger, Shows the radial clearance of the gap 62 along the length of the sealing sleeve 40 . As can be seen from the figure, the radial clearance of the gap 62 is In the region adjacent to the outermost region of. Referring to FIG. It can be seen that the force is significantly reduced in the region where the radial clearance is minimal . During operation, the pressure difference at the outermost of the inner flexible portion 52 due to partial fluid sealing of the gap Therefore, the outermost part is displaced or bent radially inward, and as shown in FIG. The magnitude is reduced and the pressure is further reduced. Needless to say, inside deflection The pressure in the portion of the annular gap 62 at a position adjacent to the portion 52 is , The displacement of the inner bending portion 52 occurs at the outermost position.   A second advantage of the present invention is that the sealing sleeves 40, 72 of the present invention can be easily removed. Can be removed and replaced with a new sealing sleeve, which makes it easier That is, low-cost maintenance can be performed quickly. Third, the inner flexures 52, 80 By forming it as part of a sealing sleeve separately from the body or barrel Therefore, the leakage flow reduction device of the present invention is capable of forming the sealing sleeve with the material selection of the barrel. Independently achieves its requirements: lubrication, wear resistance, and elasticity. It can be formed from a material that can be formed. Therefore, Shilin The grease sleeves 40, 72 may have a leakage flow rate, such as a metal, non-metal, or composite material. Optimal flexibility and elasticity to optimally minimize the shape from any material Can be achieved. Fourth, the leakage flow reduction device of the present invention provides a higher pressure level. Unlike prior art devices, which increase clearance in the fuel tank, as fuel pressure increases, It functions to reduce the working gap between the ranger and the barrel. Fifth, Fig. 1 By comparing FIG. 2 with FIG. 2, the sleeves 40, 72 of the present invention The length of engagement between 36 and its complementary bore is increased, thus further reducing leakage flow. It can be seen that it can be reduced to Sixth, the present invention forms a sealing sleeve. Is a through bore, which allows the formation of a blind bore with a precise diameter. The associated high manufacturing costs are avoided. Seventh, the present invention also provides a sealing function from the barrel. Barrel while designing the barrel to limit operating stress by removing Pressure induced expansion of plunger does not affect plunger clearance seal It is advantageous because it can. Eighth, the plunger and barrel assembly of the present invention Often due to the clamping or mounting loads 50, 92 applied to the assembly. Form a plunger bore that is substantially unaffected by the distortion effects being tested. Inner flexible part 52, 90 are not directly supported by the barrel and are surrounded by high pressure fuel So the distortion effect of the mounting load is substantially separated from this part of the sealing sleeve Is done. Industrial applicability   The plunger and barrel assembly including the leak flow reduction device of the present invention is a movable plunger. It is often desirable to effectively minimize the leakage flow between the jar and the corresponding bore Can be used in high pressure fluid systems. The present invention is applied to, for example, automobiles and industrial Equipment for use in high pressure fuel pumps located in high pressure fuel systems of internal combustion engines It is particularly advantageous.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // F16K 25/00 F16K 25/00 (81) Designated countries EP (AT, BE, CH, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), OA (BF, BJ, CF, CG, CI, CM, GA, GN, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CZ, DE, DK, EE, ES, FI, GB, GE, GH, GM, GW, HU, ID, IL, IS, JP, KE, KG, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ , PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, UZ, VN, YU, ZW (72) Inventor Benson, Donald J. United States 47203 Columbus, Indiana Greenbrier Road 3954

Claims (1)

[Claims] 1. An apparatus body including a cavity and a high-pressure flow circuit;   A plunger having a diameter range and arranged to reciprocate within the cavity When,   Leakage located within the cavity to reduce fluid leakage flow from the fluid circuit Flow rate reducing means, wherein the leakage flow rate reducing means includes the plunger and the device main body. A sealing sleeve removably mounted in the cavity between the body and the body. Wherein the sealing sleeve defines a bore for slidably receiving the plunger. An inner annular surface, wherein the bore has a diameter range greater than the diameter range of the plunger. Having an enclosure, forming an annular gap between the plunger and the inner annular surface; The sealing sleeve resiliently bends in response to fluid pressure to flow through the annular gap. Decrease the annular clearance to minimize body leakage flow but maintain the annular clearance Wherein the sealing sleeve includes an outer annular surface and the fluid pressure is less than the outer annular surface. Acting directly on the surface of the seal to deflect the sealing sleeve radially inward, The sealing sleeve is firmly attached to the inner flexible part and the main body of the device. Outer annular surface formed on the inner flexible portion, further comprising An outer annular chamber formed adjacent to the outer annular surface, the outer portion including the outer annular chamber; An annular land formed on the device body so as to seal one end of the side annular chamber with a fluid An annular step for abutting and sealing with the sealing sleeve, An axial clamping force acting on the outer side brings the annular land into a sealed position. Means for reducing leakage flow rate, characterized in that they are retained A fluid control device used in a high-pressure fluid system constituted by: 2. Pressure is applied into the cavity so that the sealing sleeve presses against the device body. Fluid pressure acting on the inner end of the sealing sleeve And displacing the annular land in a sealingly adjacent state with the annular land. Fluid control device. 3. The sleeve is made of a material having higher elasticity than a material forming the device main body. The fluid control device according to claim 1, wherein the fluid control device is formed. 4. The apparatus main body includes a first portion and a second portion in contact with the first portion. Wherein the cavity is formed in both the first and second portions, and wherein the sealing is A sleeve is press fit into the first portion and the second portion of the body along the cavity. The outer annular chamber is formed to extend at a distance from the outer annular chamber. Onboard fluid control device. 5. A barrel including a cavity and a high pressure fuel circuit;   A high-pressure fuel chamber disposed in the cavity;   It is arranged to reciprocate in the cavity and pressurizes fuel in the high-pressure fuel chamber. A plunger that operates to move in a periodic pumping stroke to   Located in the cavity to reduce fluid leakage from the high pressure fuel chamber Leak flow rate reducing means, wherein the leak flow rate reduction means includes the plunger and the barrel. A sealing sleeve removably mounted between said cavity and said cavity. The sealing sleeve slidably receives the outer annular surface and the plunger An annular gap between the plunger and the bore, The ring sleeve responds to the fuel pressure induced force acting on the outer annular surface by the annular gap. Resiliently flex to reduce the annular clearance so as to minimize fluid leakage flow between The sealing sleeve is securely attached to the inner flexible part and the barrel And the inner flexible portion is free from axial contact with the barrel. Leak flow rate reducing means, characterized by defining a fuel flow gap, including a remote end, Fuel pump for high-pressure fuel systems composed of: 6. The fuel pressure acts directly on the outer annular surface to release the sealing sleeve. The fuel pump according to claim 5, wherein the fuel pump is bent inward in a radial direction. 7. So that the outer portion abuts against and seals the annular land formed in the barrel. 7. The fuel pump according to claim 6, comprising an annular step. 8. The sealing sleeve is acted upon by an axial clamping force acting on the outer part. That it is firmly held in place to press against the annular land The fuel pump according to claim 7, wherein: 9. Press-fit into the cavity so that the sealing sleeve presses against the barrel And the fuel pressure acting on the inner end of the sealing sleeve acts on the sleeve. 8. The fuel according to claim 7, wherein the annular land is displaced in a sealing contact state. Charge pump. 10. The sleeve is made of a material having higher elasticity than the material forming the barrel. 6. The fuel pump according to claim 5, wherein the fuel pump is formed. 11. The barrel includes a first portion and a second portion in contact with the first portion. Wherein the cavity is formed in both the first and second portions, and wherein the sealing is A sleeve is press fit into the first portion and the second portion of the body along the cavity. The annular high-pressure chamber is formed by extending at an interval from the above. Fluid control device. 12. A barrel including a cavity; a high pressure fuel chamber disposed within the cavity; and a high pressure fuel chamber. A high pressure fuel circuit for providing flow to and from the cavity; and a reciprocating motion within the cavity. And moves in a periodic pumping stroke to pressurize the fuel in the high pressure fuel chamber Leak reduction device used in a high pressure fuel pump including a plunger operatively operated In place   Between the plunger and barrel to reduce fuel leakage from the high pressure fuel chamber A replaceable sealing sleeve removably mounted in the cavity, The replaceable sealing sleeve slidably receives the outer annular surface and the plunger. An annular gap between the plunger and the bore, High pressure fuel from the pressure chamber acts on the outer annular surface to cause fuel leakage through the annular gap. To prevent expansion of the replaceable sealing sleeve so as to prevent increased flow. Stop and the replaceable sealing sleeve is radially Internal flexure including the distal end attachable to a barrel for unsupported orientation Leaks constituted by replaceable sealing sleeves characterized by having Flow reduction device. 13. Fuel exchange induced by the replaceable sealing sleeve acting on the outer annular surface Resiliently deflect in response to the force to reduce the annular gap, thereby reducing the annular 13. The flow rate according to claim 12, wherein the flow rate of the fuel leak in the gap is reduced. Reduction device.