WO2024089843A1 - Pompe à carburant - Google Patents

Pompe à carburant Download PDF

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Publication number
WO2024089843A1
WO2024089843A1 PCT/JP2022/040166 JP2022040166W WO2024089843A1 WO 2024089843 A1 WO2024089843 A1 WO 2024089843A1 JP 2022040166 W JP2022040166 W JP 2022040166W WO 2024089843 A1 WO2024089843 A1 WO 2024089843A1
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WO
WIPO (PCT)
Prior art keywords
plunger
seal member
annular groove
fuel
cylinder
Prior art date
Application number
PCT/JP2022/040166
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English (en)
Japanese (ja)
Inventor
悠登 石塚
裕之 山田
Original Assignee
日立Astemo株式会社
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Filing date
Publication date
Application filed by 日立Astemo株式会社 filed Critical 日立Astemo株式会社
Priority to PCT/JP2022/040166 priority Critical patent/WO2024089843A1/fr
Publication of WO2024089843A1 publication Critical patent/WO2024089843A1/fr

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    • 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
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/20—Varying fuel delivery in quantity or timing
    • F02M59/24—Varying fuel delivery in quantity or timing with constant-length-stroke pistons having variable effective portion of stroke
    • F02M59/26—Varying fuel delivery in quantity or timing with constant-length-stroke pistons having variable effective portion of stroke caused by movements of pistons relative to their cylinders
    • 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
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston

Definitions

  • the present invention relates to a fuel pump that supplies fuel to an engine at high pressure.
  • Patent Document 1 An example of a fuel pump is described in Patent Document 1.
  • the high-pressure fuel supply pump described in Patent Document 1 has a pump body, a plunger attached to the pump body, and a cylinder that slidably holds the plunger.
  • the pump body has a cylindrical space that houses the cylinder and forms a pressurizing chamber.
  • Such high-pressure fuel supply pumps draw in and discharge fuel by moving a plunger up and down due to the rotational movement of a cam attached to the camshaft of the internal combustion engine.
  • the plunger is also fitted with a seal member that prevents high-pressure fuel from leaking to the low-pressure side. This increases the efficiency of the discharge flow rate of the fuel pump.
  • the high-pressure fuel supply pump described in Patent Document 1 is configured so that the seal member is movable within an annular groove provided on the sliding surface of the plunger.
  • both axial end faces of the seal member collide with the wall surfaces of the annular groove in the plunger, causing deformation or damage.
  • a leak path is formed in the seal member, causing a problem of reduced sealing function.
  • the object of the present invention is to provide a fuel pump that takes into consideration the above problems and prevents the seal member attached to the plunger from being deformed or damaged.
  • the fuel pump of the present invention comprises a plunger, a cylinder that guides the reciprocating motion of the plunger, a seal member that is disposed in an annular groove provided on the outer peripheral surface of the plunger and contacts the inner peripheral surface of the cylinder, and a pump body having a pressurized chamber whose volume increases and decreases with the reciprocating motion of the plunger.
  • a pressing portion that presses the seal member is provided on the bottom surface of the annular groove.
  • a gap is formed between the annular groove and the seal member on the pressurized chamber side of the pressing portion, allowing fuel to seep in from the pressurized chamber side.
  • FIG. 1 is an overall configuration diagram of a fuel supply system using a high-pressure fuel supply pump according to a first embodiment of the present invention
  • 1 is a vertical sectional view (part 1) of a high-pressure fuel supply pump according to a first embodiment of the present invention
  • FIG. FIG. 2 is a vertical sectional view (part 2) of the high-pressure fuel supply pump according to the first embodiment of the present invention
  • 1 is a horizontal cross-sectional view of a high-pressure fuel supply pump according to a first embodiment of the present invention, as viewed from above.
  • FIG. FIG. 4 is a vertical sectional view (part 3) of the high-pressure fuel supply pump according to the first embodiment of the present invention.
  • FIG. 4 is a cross-sectional view showing an annular groove of the plunger according to the first embodiment of the present invention.
  • FIG. 11 is a cross-sectional view showing an annular groove of a plunger according to a second embodiment of the present invention.
  • FIG. 11 is a cross-sectional view showing an annular groove of a plunger according to a third embodiment of the present invention.
  • FIG. 10 is a cross-sectional view showing an annular groove of a plunger according to a fourth embodiment of the present invention.
  • FIG. 13 is a cross-sectional view showing an annular groove and a seal member of a plunger according to a fifth embodiment of FIG. 13 is a cross-sectional view showing an annular groove and a seal member of a plunger according to a sixth embodiment of the present invention.
  • FIG. 1 is a diagram showing the overall configuration of a fuel supply system using a high-pressure fuel supply pump according to this embodiment.
  • the fuel supply system includes a high-pressure fuel supply pump (fuel pump) 100, an ECU (Engine Control Unit) 101, a fuel tank 103, a common rail 106, and multiple injectors 107.
  • the components of the high-pressure fuel supply pump 100 are integrally incorporated into a pump body 1.
  • Fuel in the fuel tank 103 is pumped up by a feed pump 102 that is driven based on a signal from the ECU 101.
  • the pumped up fuel is pressurized to an appropriate pressure by a pressure regulator (not shown) and sent to the low-pressure fuel intake port 51 of the high-pressure fuel supply pump 100 through a low-pressure pipe 104.
  • the high-pressure fuel supply pump 100 pressurizes the fuel supplied from the fuel tank 103 and sends it to the common rail 106.
  • the common rail 106 is equipped with multiple injectors 107 and a fuel pressure sensor 105.
  • the multiple injectors 107 are installed in accordance with the number of cylinders (combustion chambers), and inject fuel according to the drive current output from the ECU 101.
  • the fuel supply system of this embodiment is a so-called direct injection engine system in which the injectors 107 inject fuel directly into the cylinders of the engine.
  • the fuel pressure sensor 105 outputs the detected pressure data to the ECU 101.
  • the ECU 101 calculates the appropriate fuel injection amount (target fuel injection length) and appropriate fuel pressure (target fuel pressure) based on engine state quantities (e.g. crank angle, throttle opening, engine speed, fuel pressure, etc.) obtained from various sensors.
  • the ECU 101 also controls the operation of the high-pressure fuel supply pump 100 and the multiple injectors 107 based on the calculation results of the fuel pressure (target fuel pressure) and the like. That is, the ECU 101 has a pump control unit that controls the high-pressure fuel supply pump 100 and an injector control unit that controls the injectors 107.
  • the high-pressure fuel supply pump 100 has a pressure pulsation reduction mechanism 9, a variable capacity electromagnetic intake valve mechanism 3, a relief valve mechanism 4 (see FIG. 2), and a discharge valve mechanism 8. Fuel flowing in from the low-pressure fuel intake port 51 reaches the intake port 31b of the electromagnetic intake valve mechanism 3 via the pressure pulsation reduction mechanism 9 and the intake passage 10b.
  • the fuel that flows into the electromagnetic intake valve mechanism 3 passes through the valve portion 32, flows through the intake passage 1d formed in the pump body 1, and then flows into the pressurized chamber 11.
  • a plunger 2 is inserted into the pressurized chamber 11 so that it can reciprocate. The plunger 2 reciprocates when power is transmitted by the engine cam 91 (see Figure 2).
  • the pressurizing chamber 11 fuel is sucked in through the electromagnetic intake valve mechanism 3 during the downward stroke of the plunger 2, and the fuel is pressurized during the upward stroke.
  • the discharge valve mechanism 8 opens and the high-pressure fuel is pumped through the discharge passage 12a to the common rail 106.
  • the discharge of fuel by the high-pressure fuel supply pump 100 is controlled by opening and closing the electromagnetic intake valve mechanism 3.
  • the opening and closing of the electromagnetic intake valve mechanism 3 is controlled by the ECU 101.
  • Fig. 2 is a first longitudinal cross-sectional view of the high-pressure fuel supply pump 100 taken along a cross section perpendicular to the horizontal direction.
  • Fig. 3 is a second longitudinal cross-sectional view of the high-pressure fuel supply pump 100 taken along a cross section perpendicular to the horizontal direction.
  • Fig. 4 is a horizontal cross-sectional view of the high-pressure fuel supply pump 100 taken along a cross section perpendicular to the vertical direction.
  • Fig. 5 is a third longitudinal cross-sectional view of the high-pressure fuel supply pump 100 taken along a cross section perpendicular to the horizontal direction.
  • the pump body 1 of the high-pressure fuel supply pump 100 is formed in a generally cylindrical shape. As shown in Figures 2 and 3, the pump body 1 has a first chamber 1a, a second chamber 1b, a third chamber 1c, and an intake passage 1d provided therein. The pump body 1 is also in close contact with the fuel pump mounting portion 90 and is fixed with a number of bolts (screws) (not shown).
  • the first chamber 1a is a cylindrical space provided in the pump body 1, and the center line of the first chamber 1a coincides with the center line 1A of the pump body 1.
  • One end of the plunger 2 is inserted into this first chamber 1a, and the plunger 2 reciprocates within the first chamber 1a.
  • the first chamber 1a and one end of the plunger 2 form the pressurized chamber 11.
  • the second chamber 1b is a cylindrical space provided in the pump body 1, and the center line of the second chamber 1b is perpendicular to the center line 1A of the pump body 1 (first chamber 1a).
  • the relief valve mechanism 4 is disposed in this second chamber 1b.
  • the diameter of the second chamber 1b is smaller than the diameter of the first chamber 1a.
  • the first chamber 1a and the second chamber 1b are connected by a circular communication hole 1e.
  • the diameter of the communication hole 1e is the same as the diameter of the first chamber 1a, and the communication hole 1e extends one end of the first chamber 1a.
  • the diameter of the communication hole 1e is larger than the outer diameter of the plunger 2.
  • the center line of the communication hole 1e is perpendicular to the center line of the second chamber 1b.
  • the third chamber 1c is a cylindrical space provided in the pump body 1, and is continuous with the other end of the first chamber 1a.
  • the center line of the third chamber 1c coincides with the center line of the first chamber 1a and the center line 1A of the pump body 1.
  • the diameter of the third chamber 1c is larger than the diameter of the first chamber 1a.
  • a cylinder 6 that guides the reciprocating motion of the plunger 2 is disposed in this third chamber 1c.
  • the third chamber 1c serves as a cylinder insertion hole into which the cylinder 6 is inserted.
  • the cylinder 6 is formed in a cylindrical shape, and its outer periphery is pressed into the third chamber 1c of the pump body 1. One end of the cylinder 6 abuts against the top surface of the third chamber 1c (the step between the first chamber 1a and the third chamber 1c).
  • the plunger 2 is in slidable contact with the inner periphery of the cylinder 6.
  • the cylinder 6 has a press-fit portion 6a that is pressed into the third chamber 1c.
  • the press-fit portion 6a is provided in the middle of the cylinder 6 in the axial direction.
  • the diameter of the cylinder 6 on the pressurized chamber 11 side of the press-fit portion 6a is set smaller than the diameter of the press-fit portion 6a. Therefore, an annular clearance (gap) is created between the cylinder 6 on the pressurized chamber 11 side of the press-fit portion 6a and the third chamber 1c.
  • the pump body 1 is provided with a fixing portion 1x that engages with the approximate center of the cylinder 6 in the axial direction.
  • the fixing portion 1x is formed to be plastically deformable. The fixing portion 1x presses the cylinder 6 upward (upward in FIG. 2).
  • An O-ring 93 which is a specific example of a seat member, is interposed between the fuel pump mounting portion 90 and the pump body 1. This O-ring 93 prevents engine oil from leaking out of the engine (internal combustion engine) through the gap between the fuel pump mounting portion 90 and the pump body 1.
  • a tappet 92 is provided at the lower end of the plunger 2.
  • the tappet 92 converts the rotational motion of a cam 91 attached to the engine's camshaft into vertical motion and transmits it to the plunger 2.
  • the plunger 2 is biased toward the cam 91 by a spring 16 via a retainer 15. This causes the plunger 2 to be pressed against the tappet 92.
  • the tappet 92 reciprocates in conjunction with the rotation of the cam 91.
  • the plunger 2 reciprocates together with the tappet 92, changing the volume of the pressurized chamber 11.
  • a seal holder 17 is disposed between the cylinder 6 and the retainer 15.
  • the seal holder 17 is formed in a cylindrical shape into which the plunger 2 is inserted, and has an auxiliary chamber 17a at its upper end on the cylinder 6 side.
  • the auxiliary chamber 17a is continuous with the lower end of the third chamber 1c in which the cylinder 6 is disposed.
  • the auxiliary chamber 17a is provided at a position opposite the pressurized chamber 11 side (first chamber 1a side) of the plunger 2.
  • the seal holder 17 holds a plunger seal 18 at its lower end on the retainer 15 side.
  • the plunger seal 18 is in slidable contact with the outer periphery of the plunger 2, and when the plunger 2 reciprocates, it seals the fuel in the auxiliary chamber 17a, preventing the fuel from flowing into the inside of the engine.
  • the plunger seal 18 also prevents the lubricating oil (including engine oil) that lubricates the sliding parts inside the engine from flowing into the inside of the pump body 1.
  • the plunger 2 reciprocates in the up and down direction.
  • the volume of the pressurized chamber 11 expands, and when the plunger 2 ascends, the volume of the pressurized chamber 11 decreases.
  • the plunger 2 is arranged to reciprocate in a direction that expands and reduces the volume of the pressurized chamber 11.
  • the plunger 2 is formed in a stepped cylindrical shape extending along the center line 1A (axial direction) of the pump body 1.
  • the center line (axial direction) of the plunger 2 coincides with the center line 1A of the pump body 1, and the plunger 2 reciprocates along the center line (axial direction).
  • the plunger 2 has a large diameter portion 2a and a small diameter portion 2b.
  • a step portion 2c is formed between the large diameter portion 2a and the small diameter portion 2b.
  • the outer peripheral surface of the large diameter portion 2a is in sliding contact with the inner peripheral surface of the cylinder 6.
  • the auxiliary chamber 17a is connected to the low-pressure fuel chamber 10 through a fuel passage 10c (see FIG. 5).
  • the auxiliary chamber 17a contains low-pressure fuel (fuel with a lower pressure than the fuel in the pressurizing chamber 11).
  • the fuel passage 10c is provided in the pump body 1 so as to penetrate the outer periphery of the cylinder 6 (third chamber 1c) in the vertical direction (parallel to the center line 1A of the pump body 1). Through this fuel passage 10c, when the plunger 2 descends, fuel flows from the auxiliary chamber 17a to the low-pressure fuel chamber 10. When the plunger 2 ascends, fuel flows from the low-pressure fuel chamber 10 to the auxiliary chamber 17a. This makes it possible to reduce the amount of fuel flowing into and out of the pump during the intake stroke or return stroke of the high-pressure fuel supply pump 100, and to reduce pressure pulsation generated inside the high-pressure fuel supply pump 100.
  • a low-pressure fuel chamber 10 is provided at the top of the pump body 1 of the high-pressure fuel supply pump 100.
  • an intake joint 5 is attached to the side of the pump body 1.
  • the intake joint 5 is connected to a low-pressure pipe 104 that passes fuel supplied from a fuel tank 103 (see FIG. 1).
  • the fuel in the fuel tank 103 is supplied from the intake joint 5 to the inside of the pump body 1.
  • the intake joint 5 has a low-pressure fuel intake port 51 connected to the low-pressure pipe 104, and an intake passage 52 that communicates with the low-pressure fuel intake port 51.
  • the fuel that passes through the intake passage 52 passes through an intake filter 53 provided inside the pump body 1 and is supplied to the low-pressure fuel chamber 10.
  • the intake filter 53 removes foreign matter present in the fuel and prevents foreign matter from entering the high-pressure fuel supply pump 100.
  • the low-pressure fuel chamber 10 is provided with a low-pressure fuel flow path 10a and an intake passage 10b (see Figure 2).
  • the low-pressure fuel flow path 10a is provided with a pressure pulsation reduction mechanism 9.
  • the pressure pulsation reduction mechanism 9 reduces the spread of pressure pulsation generated in the high-pressure fuel supply pump 100 to the low-pressure piping 104.
  • the pressure pulsation reduction mechanism 9 is made of a metal diaphragm damper made of two corrugated, disk-shaped metal plates bonded together at their periphery and with an inert gas such as argon injected into the interior.
  • the metal diaphragm damper of the pressure pulsation reduction mechanism 9 absorbs or reduces pressure pulsations by expanding and contracting.
  • the intake passage 10b is connected to the intake port 31b (see Figure 2) of the electromagnetic intake valve mechanism 3.
  • the fuel that passes through the low-pressure fuel passage 10a reaches the intake port 31b of the electromagnetic intake valve mechanism 3 via the intake passage 10b.
  • the electromagnetic intake valve mechanism 3 is inserted into a horizontal hole formed in the pump body 1.
  • the electromagnetic intake valve mechanism 3 has an intake valve seat 31 press-fitted into a horizontal hole formed in the pump body 1, a valve portion 32, a rod 33, a rod biasing spring 34, an electromagnetic coil 35, and an anchor 36.
  • the suction valve seat 31 is formed in a cylindrical shape.
  • a seat portion 31a is provided on the inner periphery of the suction valve seat 31.
  • the suction valve seat 31 also has a suction port 31b that reaches from the outer periphery to the inner periphery. This suction port 31b is connected to the suction passage 10b in the low-pressure fuel chamber 10 described above.
  • a stopper 37 is disposed in a horizontal hole formed in the pump body 1, facing the seating portion 31a of the suction valve seat 31.
  • the valve portion 32 is disposed between the stopper 37 and the seating portion 31a.
  • a valve biasing spring 38 is disposed between the stopper 37 and the valve portion 32. The valve biasing spring 38 biases the valve portion 32 toward the seating portion 31a.
  • the valve portion 32 abuts against the seat portion 31a to close the communication portion between the suction port 31b and the pressurized chamber 11.
  • the electromagnetic suction valve mechanism 3 is in a closed state.
  • the valve portion 32 abuts against the stopper 37 to open the communication portion between the suction port 31b and the pressurized chamber 11.
  • the electromagnetic suction valve mechanism 3 is in an open state.
  • the rod 33 passes through a cylindrical hole in the suction valve seat 31, and one end abuts the valve portion 32.
  • the rod biasing spring 34 biases the valve portion 32 in the valve opening direction toward the stopper 37 via the rod 33.
  • One end of the rod biasing spring 34 engages with the other end of the rod 33, and the other end of the rod biasing spring 34 engages with a magnetic core 39 arranged to surround the rod biasing spring 34.
  • the anchor 36 faces the end face of the magnetic core 39.
  • the anchor 36 also engages with a flange provided in the middle of the rod 33.
  • the electromagnetic coil 35 is disposed so as to go around the magnetic core 39.
  • a terminal member 40 is electrically connected to the electromagnetic coil 35, and a current flows through the terminal member 40.
  • the rod 33 In a non-energized state where no current flows through the electromagnetic coil 35, the rod 33 is urged in the valve-opening direction by the force of the rod-biasing spring 34, pressing the valve portion 32 in the valve-opening direction. As a result, the valve portion 32 moves away from the seating portion 31a and abuts against the stopper 37, and the electromagnetic suction valve mechanism 3 is in an open state.
  • the electromagnetic suction valve mechanism 3 is of a normally open type, which opens in a non-energized state.
  • the anchor 36 When current flows through the electromagnetic coil 35, the anchor 36 is attracted in the valve closing direction by the magnetic attraction force of the magnetic core 39. As a result, the anchor 36 moves against the biasing force of the rod biasing spring 34 and comes into contact with the magnetic core 39. When the anchor 36 moves in the valve closing direction toward the magnetic core 39, the rod 33 with which the anchor 36 engages moves together with the anchor 36. As a result, the valve portion 32 is released from the biasing force in the valve opening direction and moves in the valve closing direction due to the biasing force of the valve biasing spring 38. Then, when the valve portion 32 comes into contact with the seating portion 31a of the suction valve seat 31, the electromagnetic suction valve mechanism 3 is in the valve closed state.
  • the discharge valve mechanism 8 is connected to the outlet side (downstream side) of the pressurized chamber 11.
  • the discharge valve mechanism 8 has a discharge valve seat 81 that communicates with the pressurized chamber 11, a valve portion 82 that moves toward and away from the discharge valve seat 81, a discharge valve spring 83 that urges the valve portion 82 toward the discharge valve seat 81, and a discharge valve stopper 84 that determines the stroke (travel distance) of the valve portion 82.
  • the discharge valve mechanism 8 also has a plug 85 that prevents fuel from leaking to the outside.
  • the discharge valve stopper 84 is press-fitted into the plug 85.
  • the plug 85 is joined to the pump body 1 by welding at a welded portion 86.
  • the discharge valve mechanism 8 is connected to a discharge valve chamber passage 87 that is opened and closed by a valve portion 82.
  • the discharge valve chamber passage 87 is formed in the pump body 1.
  • the pump body 1 has a horizontal hole that communicates with the second chamber 1b (see Figure 2), and a discharge joint 12 is inserted into this horizontal hole.
  • the discharge joint 12 has the above-mentioned discharge passage 12a that communicates with the horizontal hole of the pump body 1 and the discharge valve chamber passage 87, and a fuel discharge port 12b that is one end of the discharge passage 12a.
  • the fuel discharge port 12b of the discharge joint 12 communicates with the common rail 106.
  • the discharge joint 12 is fixed to the pump body 1 by welding at the welded portion 12c.
  • the valve portion 82 When the difference in fuel pressure (fuel pressure difference) between the pressurized chamber 11 and the discharge valve chamber passage 87 is small, the valve portion 82 is pressed against the discharge valve seat 81 by the biasing force of the discharge valve spring 83. As a result, the discharge valve mechanism 8 is in a closed state. When the fuel pressure in the pressurized chamber 11 becomes greater than the fuel pressure in the discharge valve chamber passage 87, the valve portion 82 moves against the biasing force of the discharge valve spring 83. As a result, the discharge valve mechanism 8 is in an open state.
  • the discharge valve mechanism 8 When the discharge valve mechanism 8 is in an open state, the (high pressure) fuel in the pressurized chamber 11 passes through the discharge valve mechanism 8 and reaches the discharge valve chamber 80 (discharge valve chamber passage 87). The fuel that reaches the discharge valve chamber passage 87 is then discharged through the fuel discharge port 12b of the discharge joint 12 into the common rail 106 (see Figure 1). With the above configuration, the discharge valve mechanism 8 functions as a check valve that limits the direction of fuel flow.
  • the relief valve mechanism 4 shown in Figure 2 is a valve that is configured to operate when some problem occurs with the common rail 106 or the components beyond it, causing the common rail 106 to exceed a predetermined pressure, and to return the fuel in the discharge passage 12a to the pressurized chamber 11.
  • This relief valve mechanism 4 is positioned higher than the discharge valve mechanism 8 (see Figure 5) in the direction in which the plunger 2 reciprocates (up and down).
  • the relief valve mechanism 4 has a relief spring 41, a relief valve holder 42, a relief valve 43, and a seat member 44.
  • the relief valve mechanism 4 is inserted from the discharge joint 12 and disposed in the second chamber 1b (relief valve chamber).
  • the relief spring 41 is a coil spring. One end of the relief spring 41 abuts against the pump body 1 (one end of the second chamber 1b). The other end of the relief spring 41 abuts against the relief valve holder 42.
  • the relief valve holder 42 engages with the relief valve 43. The urging force of the relief spring 41 acts on the relief valve 43 via the relief valve holder 42.
  • the relief valve 43 is pressed by the force of the relief spring 41, blocking the fuel passage of the seat member 44.
  • the movement direction of the relief valve 43 (relief valve holder 42) is perpendicular to the direction in which the plunger 2 reciprocates.
  • the center line of the relief valve 43 (center line of the relief valve holder 42) is perpendicular to the center line of the plunger 2 (center line 1A of the pump body 1).
  • the seat member 44 has a fuel passage facing the relief valve 43, and the side of the fuel passage opposite the relief valve 43 is connected to the discharge passage 12a. The movement of fuel between the pressurized chamber 11 (upstream side) and the seat member 44 (downstream side) is blocked when the relief valve 43 comes into contact (closes in close contact) with the seat member 44 to block the fuel passage.
  • the movement direction of the relief valve 43 (relief valve holder 42) in the relief valve mechanism 4 is different from the movement direction of the valve portion 82 in the discharge valve mechanism 8 described above. That is, the movement direction of the valve portion 82 in the discharge valve mechanism 8 is a first radial direction of the pump body 1, and the movement direction of the relief valve 43 in the relief valve mechanism 4 is a second radial direction different from the first radial direction of the pump body 1. This allows the discharge valve mechanism 8 and the relief valve mechanism 4 to be in the same vertical position or to have only a portion of the same vertical position, making it possible to effectively utilize the space inside the pump body 1 and to reduce the size of the pump body 1.
  • the electromagnetic intake valve mechanism 3 As described above, if the electromagnetic intake valve mechanism 3 is closed during the ascending stroke, the fuel sucked into the pressurized chamber 11 during the intake stroke is pressurized and discharged towards the common rail 106. On the other hand, if the electromagnetic intake valve mechanism 3 is open during the ascending stroke, the fuel in the pressurized chamber 11 is pushed back towards the intake passage 1d and is not discharged towards the common rail 106. In this way, the discharge of fuel by the high-pressure fuel supply pump 100 is controlled by opening and closing the electromagnetic intake valve mechanism 3. The opening and closing of the electromagnetic intake valve mechanism 3 is controlled by the ECU 101.
  • the volume of the pressurized chamber 11 increases, and the fuel pressure in the pressurized chamber 11 decreases. This reduces the fluid pressure difference between the intake port 31b and the pressurized chamber 11 (hereinafter referred to as the "fluid pressure difference across the valve portion 32").
  • the rod 33 moves in the valve opening direction, the valve portion 32 separates from the seating portion 31a of the intake valve seat 31, and the electromagnetic intake valve mechanism 3 enters an open state.
  • the ascending stroke begins.
  • the electromagnetic coil 35 remains in a non-energized state, and no magnetic attraction force acts between the anchor 36 and the magnetic core 39.
  • the valve portion 32 is subjected to a force in the valve opening direction that corresponds to the difference in the force between the rod biasing spring 34 and the valve biasing spring 38, as well as a force pressing in the valve closing direction due to a fluid force generated when fuel flows back from the pressurized chamber 11 to the low-pressure fuel flow path 10a.
  • the difference in the biasing force between the rod biasing spring 34 and the valve biasing spring 38 is set to be greater than the fluid force.
  • the volume of the pressurized chamber 11 decreases as the plunger 2 rises. Therefore, the fuel that was sucked into the pressurized chamber 11 passes between the valve portion 32 and the seat portion 31a again and is returned to the intake port 31b, and the pressure inside the pressurized chamber 11 does not increase. This stroke is called the return stroke.
  • the valve portion 32 When the anchor 36 (rod 33) moves in the valve closing direction, the valve portion 32 is released from the biasing force in the valve opening direction and moves in the valve closing direction due to the biasing force of the valve biasing spring 38 and the fluid force caused by the fuel flowing into the intake passage 10b. Then, when the valve portion 32 comes into contact with the seating portion 31a of the intake valve seat 31 (the valve portion 32 seats on the seating portion 31a), the electromagnetic intake valve mechanism 3 is in the valve closed state.
  • the fuel in the pressurized chamber 11 is pressurized as the plunger 2 rises, and when the pressure exceeds a predetermined level, it passes through the discharge valve mechanism 8 and is discharged into the common rail 106 (see Figure 1).
  • This stroke is called the discharge stroke.
  • the upward stroke from the lower starting point of the plunger 2 to the upper starting point consists of a return stroke and a discharge stroke.
  • the amount of high-pressure fuel discharged can be controlled by controlling the timing of energization of the electromagnetic coil 35 of the electromagnetic intake valve mechanism 3.
  • the timing of energizing the electromagnetic coil 35 is made earlier, the proportion of the return stroke during the upward stroke will be smaller and the proportion of the discharge stroke will be larger. As a result, less fuel will be returned to the intake passage 10b and more fuel will be discharged at high pressure.
  • the timing of energizing the electromagnetic coil 35 is made later, the proportion of the return stroke during the upward stroke will be larger and the proportion of the discharge stroke will be smaller. As a result, more fuel will be returned to the intake passage 10b and less fuel will be discharged at high pressure. In this way, by controlling the timing of energizing the electromagnetic coil 35, the amount of fuel discharged at high pressure can be controlled to the amount required by the engine (internal combustion engine).
  • FIG. 6 is a cross-sectional view showing the annular groove of the plunger 2. As shown in FIG.
  • the seal member 20 is capable of moving relative to the plunger 2 when the plunger 2 reciprocates. As a result, the seal member 20 repeatedly collides with the wall surface (surface approximately perpendicular to the direction of reciprocation) of the annular groove 21 of the plunger 2. As a result, the seal member 20 may become deformed or damaged due to wear, and the sealing performance may deteriorate. In this embodiment, the seal member 20 is prevented from moving relative to the plunger 2, thereby preventing deformation or damage of the seal member 20 due to wear.
  • annular groove 21 is provided on the outer peripheral surface of the large diameter portion 2a of the plunger 2.
  • a seal member 20 is disposed in the annular groove 21.
  • the annular groove 21 extends along the circumferential direction of the large diameter portion 2a.
  • the annular groove 21 has a bottom surface 211 facing the inner peripheral surface of the cylinder 6, a wall surface 212 on the pressurizing chamber 11 side, and a wall surface 213 on the auxiliary chamber 17a side.
  • a pressing portion 214 is provided on the bottom surface 211 of the annular groove 21.
  • the pressing portion 214 protrudes from the bottom surface 211 of the annular groove 21 and is continuous in the circumferential direction of the plunger 2.
  • the pressing portion 214 presses the seal member 20 towards the cylinder 6.
  • the pressing portion 214 has a side surface 214a on the pressurized chamber 11 side and a side surface 214b on the sub-chamber 17a side (opposite the pressurized chamber 11).
  • the side surface 214a of the pressing portion 214 is approximately perpendicular to the bottom surface 211 of the annular groove 21.
  • the side surface 214b of the pressing portion 214 is a tapered surface that slopes closer to the bottom surface 211 of the annular groove 21 as it moves away from the pressurized chamber 11.
  • the sealing member 20 is a band of an appropriate thickness and is formed into an endless ring shape.
  • the thickness of the sealing member 20 is smaller than the depth of the annular groove 21.
  • the sealing member 20 is preferably formed from a resin material, but is not limited to this and may be formed from other materials such as rubber.
  • the seal member 20 contacts the inner circumferential surface of the cylinder 6 between the pressurized chamber 11 and the sub-chamber 17a.
  • the plunger 2 and the cylinder 6 sandwich the seal member 20.
  • a gap 210 is formed between the annular groove 21 on the pressurized chamber 11 side of the pressing portion 214 and the seal member 20, through which (high-pressure) fuel can seep in from the pressurized chamber 11 side.
  • the pressing portion 214 presses the seal member 20 toward the cylinder 6, and therefore the pressing portion 214 serves as a stopper that stops the movement of the seal member 20. This makes it possible to suppress or prevent the seal member 20 from moving relative to the plunger 2 when the plunger 2 reciprocates. As a result, deformation or damage to the seal member 20 due to wear can be prevented.
  • high-pressure fuel penetrates into the gap 210 formed between the annular groove 21 and the seal member 20. This causes the high-pressure fuel to press the seal member 20 toward the cylinder 6 on the pressurized chamber 11 side of the contact portion between the pressing portion 214 and the seal member 20.
  • a surface (sealing surface) where the seal member 20 is in close contact with the inner circumferential surface of the cylinder 6 due to the pressing of the pressing portion 214, and a surface (sealing surface) where the seal member 20 is in close contact with the inner circumferential surface of the cylinder 6 due to the pressing of the high-pressure fuel can be formed. Therefore, the reliability of the liquid-tightness provided by the seal member 20 can be significantly improved.
  • the fuel can be sealed at the surface (sealing surface) of the sealing member 20 that comes into close contact with the inner peripheral surface of the cylinder 6 due to the pressure of the pressing portion 214.
  • the gap between the outer peripheral surface of the plunger 2 and the inner peripheral surface of the cylinder 6 is 50 ⁇ m or less. This makes it possible to prevent the seal member 20 from getting caught in the gap between the outer peripheral surface of the plunger 2 and the inner peripheral surface of the cylinder 6, even if the seal member 20 is made of a resin material. As a result, the sealing function of the seal member 20 can be ensured.
  • the distance a from the end face of the seal member 20 on the pressurized chamber 11 side (wall surface 212 side) to the end face of the pressing portion 214 on the pressurized chamber 11 side is equal to or greater than the thickness b of the seal member 20. This allows the seal member 20 to be pressed against the cylinder 6 side by the high-pressure fuel that has entered the gap 210. In other words, a sufficient portion of the seal member 20 can be secured to be pressed against the cylinder 6 side by the high-pressure fuel.
  • the pressing portion 214 is provided on the sub-chamber 17a side of the axial center of the plunger 2 on the bottom surface 211 of the annular groove 21. This allows the distance a to be secured while shortening the axial length of the plunger 2 in the annular groove 21 (groove width) and the width of the seal member 20.
  • the side surface 214a of the pressing portion 214 is approximately perpendicular to the bottom surface 211 of the annular groove 21. This allows the area of the sealing member 20 that is pressed by the high-pressure fuel to be large, without the need to extend the sealing member 20 in the axial direction of the plunger 2.
  • the side surface 214b of the pressing portion 214 is a tapered surface that is inclined so as to approach the bottom surface 211 of the annular groove 21 as it moves away from the pressurized chamber 11. This makes it easier for the seal member 20 to deform in accordance with the side surface 214b (tapered surface), making it easier for the seal member 20 to bite into the plunger 2. As a result, the stopper effect of the pressing portion 214 is enhanced, and movement of the seal member 20 relative to the plunger 2 can be more effectively suppressed or prevented.
  • FIG. 7 is a cross-sectional view showing an annular groove of a plunger according to the second embodiment.
  • the high-pressure fuel supply pump according to the second embodiment has a similar configuration to the high-pressure fuel supply pump 100 according to the first embodiment described above.
  • the high-pressure fuel supply pump according to the second embodiment differs from the high-pressure fuel supply pump 100 in the plunger 201. Therefore, here, the plunger 201 according to the second embodiment will be described, and a description of the configuration common to the first embodiment will be omitted.
  • the plunger 201 is formed in a stepped cylindrical shape extending along the center line 1A (axial direction) of the pump body 1.
  • the center line (axial direction) of the plunger 201 coincides with the center line 1A of the pump body 1, and the plunger 201 reciprocates along the center line (axial direction).
  • the plunger 201 has a large diameter portion 2a and a small diameter portion 2b (see FIG. 2).
  • a step portion 2c is formed between the large diameter portion 2a and the small diameter portion 2b.
  • annular groove 22 is provided on the outer peripheral surface of the large diameter portion 2a of the plunger 201.
  • a seal member 20 is disposed in the annular groove 22.
  • the annular groove 22 extends in the circumferential direction of the large diameter portion 2a.
  • the annular groove 22 has a bottom surface 211 facing the inner peripheral surface of the cylinder 6, a wall surface 212 on the pressurizing chamber 11 side, and a wall surface 213 on the sub-chamber 17a side (the side opposite the pressurizing chamber 11).
  • a pressing portion 215 is provided on the bottom surface 211 of the annular groove 22.
  • the pressing portion 215 protrudes from the bottom surface 211 of the annular groove 22 and is continuous in the circumferential direction of the plunger 2.
  • the pressing portion 215 presses the seal member 20 toward the cylinder 6.
  • the pressing portion 215 is provided on the sub-chamber 17a side of the axial center of the plunger 2 on the bottom surface 211 of the annular groove 22.
  • the pressing portion 215 has a side surface 215a on the pressurized chamber 11 side and a side surface 215b on the sub-chamber 17a side.
  • the side surfaces 215a, 215b of the pressing portion 215 are approximately perpendicular to the bottom surface 211 of the annular groove 22.
  • the pressing portion 215 presses the seal member 20 toward the cylinder 6, and the pressing portion 215 serves as a stopper that stops the movement of the seal member 20. This makes it possible to suppress or prevent the seal member 20 from moving relative to the plunger 2 when the plunger 2 reciprocates. As a result, deformation or damage due to wear of the seal member 20 can be prevented.
  • a gap 210 is formed through which (high-pressure) fuel can seep in from the pressurized chamber 11 side.
  • This allows the high-pressure fuel to pressurize the seal member 20 toward the cylinder 6 on the pressurized chamber 11 side of the contact portion between the pressing portion 215 and the seal member 20.
  • a surface (sealing surface) where the seal member 20 is in close contact with the inner circumferential surface of the cylinder 6 due to the pressing of the pressing portion 215, and a surface (sealing surface) where the seal member 20 is in close contact with the inner circumferential surface of the cylinder 6 due to the pressing of the high-pressure fuel can be formed. Therefore, the reliability of the liquid-tightness provided by the seal member 20 can be significantly improved.
  • the fuel can be sealed at the surface (sealing surface) of the sealing member 20 that comes into close contact with the inner peripheral surface of the cylinder 6 due to the pressure of the pressing portion 215.
  • the side surfaces 215a and 215b of the pressing portion 215 are approximately perpendicular to the bottom surface 211 of the annular groove 22. This allows the area of the sealing member 20 that is pressed by the high-pressure fuel to be large, without the need to extend the sealing member 20 in the axial direction of the plunger 2. Furthermore, the area that presses the sealing member 20 can be made larger than that of the pressing portion of the first embodiment, thereby improving the robustness of the pressing portion 215.
  • the distance from the end face of the seal member 20 on the pressurized chamber 11 side (wall surface 212 side) to the end face of the pressing portion 215 on the pressurized chamber 11 side is equal to or greater than the thickness of the seal member 20. This allows the seal member 20 to be pressed against the cylinder 6 side by the high-pressure fuel that has entered the gap 210. In other words, a sufficient portion of the seal member 20 can be secured to be pressed against the cylinder 6 side by the high-pressure fuel.
  • FIG. 8 is a cross-sectional view showing an annular groove of a plunger according to the third embodiment.
  • the high-pressure fuel supply pump according to the third embodiment has a similar configuration to the high-pressure fuel supply pump 100 according to the first embodiment described above.
  • the high-pressure fuel supply pump according to the third embodiment differs from the high-pressure fuel supply pump 100 in the plunger 202. Therefore, here, the plunger 202 according to the third embodiment will be described, and a description of the configuration common to the first embodiment will be omitted.
  • the plunger 202 is formed in a stepped cylindrical shape extending along the center line 1A (axial direction) of the pump body 1.
  • the center line (axial direction) of the plunger 202 coincides with the center line 1A of the pump body 1, and the plunger 202 reciprocates along the center line (axial direction).
  • the plunger 202 has a large diameter portion 2a and a small diameter portion 2b (see FIG. 2).
  • a step portion 2c is formed between the large diameter portion 2a and the small diameter portion 2b.
  • annular groove 23 is provided on the outer peripheral surface of the large diameter portion 2a of the plunger 202.
  • a seal member 20 is disposed in the annular groove 23.
  • the annular groove 23 extends in the circumferential direction of the large diameter portion 2a.
  • the annular groove 23 has a bottom surface 211 facing the inner peripheral surface of the cylinder 6, a wall surface 212 on the pressurizing chamber 11 side, and a wall surface 213 on the sub-chamber 17a side (the side opposite the pressurizing chamber 11).
  • a pressing portion 216 is provided on the bottom surface 211 of the annular groove 23.
  • the pressing portion 216 protrudes from the bottom surface 211 of the annular groove 23 and is continuous in the circumferential direction of the plunger 2.
  • the pressing portion 216 presses the seal member 20 toward the cylinder 6.
  • the pressing portion 216 is provided on the auxiliary chamber 17a side of the axial center of the plunger 2 on the bottom surface 211 of the annular groove 23.
  • the pressing portion 216 has a side surface 216a on the pressurized chamber 11 side.
  • the side surface 216a of the pressing portion 216 is approximately perpendicular to the bottom surface 211 of the annular groove 23.
  • the end of the pressing portion 216 on the auxiliary chamber 17a side reaches the wall surface 213 of the annular groove 23.
  • the pressing portion 216 presses the seal member 20 toward the cylinder 6, and therefore the pressing portion 216 serves as a stopper that stops the movement of the seal member 20. This makes it possible to suppress or prevent the seal member 20 from moving relative to the plunger 2 when the plunger 2 reciprocates. As a result, deformation or damage to the seal member 20 due to wear can be prevented.
  • a gap 210 is formed through which (high-pressure) fuel can seep in from the pressurized chamber 11 side. This allows the high-pressure fuel to pressurize the seal member 20 toward the cylinder 6 on the pressurized chamber 11 side of the contact portion between the pressing portion 216 and the seal member 20.
  • the fuel can be sealed by the surface (sealing surface) of the seal member 20 that comes into close contact with the inner peripheral surface of the cylinder 6 due to the pressure of the pressing portion 216.
  • the side surface 216a of the pressing portion 216 is approximately perpendicular to the bottom surface 211 of the annular groove 23. This allows the area of the sealing member 20 that is pressed by the high-pressure fuel to be large, without the need to extend the sealing member 20 in the axial direction of the plunger 2.
  • the end of the pressing portion 216 on the auxiliary chamber 17a side reaches the wall surface 213 of the annular groove 23. This allows the area pressing the sealing member 20 to be larger than that of the pressing portion 214 of the first embodiment, and the robustness of the pressing portion 215 to be improved.
  • the distance from the end face of the seal member 20 on the pressurized chamber 11 side (wall surface 212 side) to the end face of the pressing portion 216 on the pressurized chamber 11 side is equal to or greater than the thickness of the seal member 20. This allows the seal member 20 to be pressed against the cylinder 6 side by the high-pressure fuel that has entered the gap 210. In other words, a sufficient portion of the seal member 20 can be secured to be pressed against the cylinder 6 side by the high-pressure fuel.
  • FIG. 9 is a cross-sectional view showing an annular groove of a plunger according to the fourth embodiment.
  • the high-pressure fuel supply pump according to the fourth embodiment has a similar configuration to the high-pressure fuel supply pump 100 according to the first embodiment described above.
  • the high-pressure fuel supply pump according to the fourth embodiment differs from the high-pressure fuel supply pump 100 in the plunger 203. Therefore, here, the plunger 203 according to the fourth embodiment will be described, and a description of the configuration common to the first embodiment will be omitted.
  • the plunger 203 according to the fourth embodiment is formed in a stepped cylindrical shape extending along the center line 1A (axial direction) of the pump body 1.
  • the center line (axial direction) of the plunger 203 coincides with the center line 1A of the pump body 1, and the plunger 203 reciprocates along the center line (axial direction).
  • the plunger 203 has a large diameter portion 2a and a small diameter portion 2b (see FIG. 2).
  • a step portion 2c is formed between the large diameter portion 2a and the small diameter portion 2b.
  • annular groove 24 is provided on the outer peripheral surface of the large diameter portion 2a of the plunger 203.
  • a seal member 20 is disposed in the annular groove 24.
  • the annular groove 24 extends in the circumferential direction of the large diameter portion 2a.
  • the annular groove 24 has a bottom surface 211 facing the inner peripheral surface of the cylinder 6, a wall surface 212 on the pressurizing chamber 11 side, and a wall surface 213 on the sub-chamber 17a side (opposite the pressurizing chamber 11).
  • a pressing portion 217 is provided on the bottom surface 211 of the annular groove 23.
  • the pressing portion 217 protrudes from the bottom surface 211 of the annular groove 24 and is continuous in the circumferential direction of the plunger 203.
  • the pressing portion 217 presses the seal member 20 toward the cylinder 6.
  • the pressing portion 217 is provided on the sub-chamber 17a side of the axial center of the plunger 2 on the bottom surface 211 of the annular groove 24.
  • the pressing portion 217 has a side surface 217a on the pressurized chamber 11 side and a side surface 217b on the sub-chamber 17a side.
  • the side surface 217a of the pressing portion 217 is a tapered surface that is inclined so as to approach the bottom surface 211 of the annular groove 24 as it moves away from the sub-chamber 17a.
  • the side surface 214b of the pressing portion 217 is a tapered surface that is inclined so as to approach the bottom surface 211 of the annular groove 21 as it moves away from the pressurized chamber 11.
  • the pressing portion 217 presses the seal member 20 toward the cylinder 6, and the pressing portion 217 serves as a stopper that stops the movement of the seal member 20. This makes it possible to suppress or prevent the seal member 20 from moving relative to the plunger 2 when the plunger 2 reciprocates. As a result, deformation or damage to the seal member 20 due to wear can be prevented.
  • a gap 210 is formed through which (high-pressure) fuel can seep in from the pressurized chamber 11 side.
  • This allows the high-pressure fuel to press the seal member 20 toward the cylinder 6 on the pressurized chamber 11 side of the contact portion between the pressing portion 217 and the seal member 20.
  • a surface (sealing surface) where the seal member 20 is in close contact with the inner circumferential surface of the cylinder 6 due to the pressing of the pressing portion 217, and a surface (sealing surface) where the seal member 20 is in close contact with the inner circumferential surface of the cylinder 6 due to the pressing of the pressing portion 217 can be formed. Therefore, the reliability of the liquid-tightness provided by the seal member 20 can be significantly improved.
  • the fuel can be sealed at the surface (sealing surface) of the sealing member 20 that comes into close contact with the inner peripheral surface of the cylinder 6 due to the pressure of the pressing portion 217.
  • the side surfaces 217a, 217b of the pressing portion 217 are each tapered surfaces that become smaller toward the tip of the pressing portion 217. This makes it easier for the sealing member 20 to deform in accordance with the side surfaces 217a, 217b (tapered surfaces), making it easier for the sealing member 20 to bite into the plunger 203.
  • the seal member 20 can be easily returned to its original position.
  • a gap 210 is formed between the annular groove 23 and the seal member 20, so that the seal member 20 can be pressed tightly against the inner surface of the cylinder 6 by the pressure of the high-pressure fuel.
  • the distance from the end face of the seal member 20 on the pressurized chamber 11 side (wall surface 212 side) to the end face of the pressing portion 217 on the pressurized chamber 11 side is equal to or greater than the thickness of the seal member 20. This allows the seal member 20 to be pressed against the cylinder 6 side by the high-pressure fuel that has entered the gap 210. In other words, a sufficient portion of the seal member 20 can be secured to be pressed against the cylinder 6 side by the high-pressure fuel.
  • FIG. 10 is a cross-sectional view showing an annular groove and a seal member of a plunger according to the fifth embodiment.
  • the high-pressure fuel supply pump according to the fifth embodiment has a similar configuration to the high-pressure fuel supply pump 100 according to the first embodiment described above.
  • the high-pressure fuel supply pump according to the fifth embodiment differs from the high-pressure fuel supply pump 100 according to the first embodiment in the plunger 204 and the seal member 27. Therefore, here, the plunger 204 and the seal member 27 according to the fifth embodiment will be described, and a description of the configuration common to the first embodiment will be omitted.
  • the plunger 204 is formed in a stepped cylindrical shape extending along the center line 1A (axial direction) of the pump body 1.
  • the center line (axial direction) of the plunger 204 coincides with the center line 1A of the pump body 1, and the plunger 204 reciprocates along the center line (axial direction).
  • the plunger 204 has a large diameter portion 2a and a small diameter portion 2b (see FIG. 2).
  • a step portion 2c is formed between the large diameter portion 2a and the small diameter portion 2b.
  • annular groove 25 is provided on the outer peripheral surface of the large diameter portion 2a of the plunger 204.
  • a seal member 27 is disposed in the annular groove 25.
  • the annular groove 25 extends along the circumferential direction of the large diameter portion 2a.
  • the annular groove 25 has a bottom surface 211 facing the inner peripheral surface of the cylinder 6, a wall surface 212 on the pressurizing chamber 11 side, and a wall surface 213 on the auxiliary chamber 17a side (opposite the pressurizing chamber 11).
  • the sealing member 27 is a strip of an appropriate thickness and is formed into an endless ring shape.
  • a protrusion 271 is provided on the surface of the sealing member 27 that faces the bottom surface 211 of the annular groove 25.
  • the protrusion 271 protrudes most on the auxiliary chamber 17a side, and the protrusion length gradually decreases toward the pressurized chamber 11 side. Therefore, the protrusion 271 has a tapered surface that is inclined so as to approach the bottom surface 211 of the annular groove 25 as it approaches the auxiliary chamber 17a side.
  • the sealing member 27 is preferably made of a resin material, but is not limited to this and may be made of other materials such as a rubber material.
  • the plunger 204 and the cylinder 6 sandwich the seal member 27. This causes the protruding portion 271 of the seal member 27 to be compressed. The end of the protruding portion 271 on the sub-chamber 17a side is then in close contact with the bottom surface 211 of the annular groove 25 and the inner circumferential surface of the cylinder 6.
  • a gap 210 is formed between the annular groove 25 and the seal member 27 on the pressurized chamber 11 side of the contact portion between the protruding portion 271 of the seal member 27 and the bottom surface 211 of the annular groove 25. This allows (high-pressure) fuel to seep in from the pressurized chamber 11 side.
  • the protrusion 271 of the seal member 27 is sandwiched between the plunger 204 and the cylinder 6, and is in close contact with the bottom surface 211 of the annular groove 25 and the inner circumferential surface of the cylinder 6. This makes it possible to suppress or prevent the seal member 27 from moving relative to the plunger 204 when the plunger 204 reciprocates. As a result, deformation or damage to the seal member 27 due to wear can be prevented.
  • the protrusion 271 of the seal member 27 contacts the auxiliary chamber 17a side of the bottom surface 211 of the annular groove 25 rather than the axial center of the plunger 204.
  • This ensures a wide gap 210 between the seal member 27 and the annular groove 25, and increases the force with which the high-pressure fuel that has entered the gap 210 presses the seal member 27 toward the cylinder 6.
  • the sealing function of the seal member 27 can be improved.
  • the gap between the outer peripheral surface of the plunger 204 and the inner peripheral surface of the cylinder 6 is 50 ⁇ m or less. This makes it possible to prevent the seal member 27 from getting caught in the gap between the outer peripheral surface of the plunger 204 and the inner peripheral surface of the cylinder 6, even if the seal member 27 is made of a resin material. As a result, the sealing function of the seal member 27 can be ensured.
  • FIG. 11 is a cross-sectional view showing an annular groove and a seal member of a plunger according to the sixth embodiment.
  • the high-pressure fuel supply pump according to the sixth embodiment has a similar configuration to the high-pressure fuel supply pump according to the fifth embodiment described above.
  • the high-pressure fuel supply pump according to the sixth embodiment differs from the high-pressure fuel supply pump according to the fifth embodiment in the sealing member 28. Therefore, here, the sealing member 28 according to the sixth embodiment will be described, and a description of the configuration common to the fifth embodiment will be omitted.
  • a seal member 28 is disposed in the annular groove 25 of the plunger 204.
  • the seal member 28 is a strip of an appropriate thickness, and is formed into an endless ring shape.
  • a protrusion 281 is provided on the surface of the seal member 28 that faces the bottom surface 211 of the annular groove 25.
  • the protrusion 281 protrudes most from the center of the axial direction of the plunger 204, and the protrusion length gradually decreases toward the pressurized chamber 11 side and the auxiliary chamber 17a side. Therefore, the protrusion 281 has a tapered surface that slopes away from the bottom surface 211 of the annular groove 25 toward the pressurized chamber 11, and a tapered surface that slopes away from the bottom surface 211 of the annular groove 25 toward the auxiliary chamber 17a side.
  • the sealing member 28 is preferably made of a resin material, but is not limited to this and may be made of other materials such as a rubber material.
  • the plunger 204 and the cylinder 6 sandwich the seal member 28. As a result, the protruding portion 281 of the seal member 28 is compressed.
  • the axial center portion of the plunger 204 in the seal member 28 is in close contact with the bottom surface 211 of the annular groove 25 and the inner circumferential surface of the cylinder 6.
  • a gap 210 is formed between the seal member 28 and the annular groove 25 on the pressurized chamber 11 side of the contact portion between the protruding portion 281 of the seal member 28 and the bottom surface 211 of the annular groove 25, allowing (high-pressure) fuel to seep in from the pressurized chamber 11 side.
  • the central portion of the seal member 28 in the axial direction of the plunger 204 is sandwiched between the plunger 204 and the cylinder 6, and is in close contact with the bottom surface 211 of the annular groove 25 and the inner peripheral surface of the cylinder 6.
  • the sealing member 28 has a symmetrical shape in the width direction (the up-down direction in FIG. 11). Therefore, when inserting the sealing member 28 into the annular groove 25 of the plunger 204, there is no need to determine whether the positions of both ends in the width direction are correct in the up-down direction (up-down determination). This makes it possible to reduce the equipment required to determine whether the sealing member 28 is up-down and the work process required for determining up-down.
  • the high-pressure fuel supply pump 100 (fuel pump) according to the first embodiment described above includes the plunger 2, the cylinder 6 that guides the reciprocating motion of the plunger 2, the seal member 20, and the pump body 1.
  • the seal member 20 is disposed in an annular groove 21 provided on the outer peripheral surface of the plunger 2, and is in contact with the inner peripheral surface of the cylinder 6.
  • the pump body 1 has a pressurizing chamber 11 whose volume increases and decreases due to the reciprocating motion of the plunger 2.
  • a pressing portion 214 that presses the seal member 20 is provided on a bottom surface 211 of the annular groove 21.
  • a gap 210 through which fuel penetrates from the pressurizing chamber 11 side is formed between the annular groove 21 and the seal member 20 on the pressurizing chamber 11 side of the pressing portion 214.
  • the pressing portion 214 By providing the pressing portion 214, it is possible to suppress or prevent the seal member 20 from moving relative to the plunger 2 when the plunger 2 reciprocates. As a result, it is possible to prevent the seal member 20 from being deformed or damaged due to wear.
  • the high-pressure fuel that has entered the gap 210 presses the seal member 20 toward the cylinder 6 on the pressurizing chamber 11 side from the contact portion between the pressing portion 214 and the seal member 20.
  • the distance a from the end face of the seal member 20 in the first embodiment on the pressurized chamber 11 side to the end face of the pressing portion 214 on the pressurized chamber 11 side is equal to or greater than the thickness of the seal member 20. This allows the seal member 20 to be pressed against the cylinder 6 side by the high-pressure fuel that has entered the gap 210. In other words, a sufficient portion of the seal member 20 can be secured to be pressed against the cylinder 6 side by the high-pressure fuel.
  • the pressing portion 214 according to the first embodiment described above is provided on the sub chamber 17a side (the side opposite to the pressurizing chamber side) of the center portion of the bottom surface of the annular groove 21 . This makes it possible to ensure the distance a while shortening the axial length of the plunger 2 in the annular groove 21 (groove width) and the width of the seal member 20 .
  • the pressing portion 214 presses the seal member 20 toward the cylinder. This allows the seal member 20 to be securely attached to the cylinder 6 .
  • the side surface 214 a of the pressing portion 214 on the pressurizing chamber 11 side is substantially perpendicular to the bottom surface 211 of the annular groove 21 . This makes it possible to increase the range of the seal member 20 that is pressed by the high-pressure fuel without extending the seal member 20 in the axial direction of the plunger 2 .
  • the side surface 214b of the pressing portion 214 on the auxiliary chamber 17a side is a tapered surface that inclines so as to approach the bottom surface 211 of the annular groove 21 as it moves away from the pressurizing chamber 11. This allows the seal member 20 to be easily deformed along the side surface 214b, making it easier for the seal member 20 to bite into the plunger 2. As a result, the effect of the stopper provided by the pressing portion 214 is enhanced, making it possible to more effectively suppress or prevent the seal member 20 from moving relative to the plunger 2.
  • the high-pressure fuel supply pump (fuel pump) includes a plunger 204, a cylinder 6 that guides the reciprocating motion of the plunger 204, a seal member 27, and a pump body 1.
  • the seal member 27 is disposed in an annular groove 25 provided on the outer peripheral surface of the plunger 2, and contacts the inner peripheral surface of the cylinder 6.
  • the pump body 1 has a pressurizing chamber 11 whose volume increases and decreases due to the reciprocating motion of the plunger 204.
  • the seal member 27 has a protruding portion 271 that contacts a bottom surface 211 of the annular groove 25.
  • a gap 210 through which fuel seeps in from the pressurizing chamber 11 side is formed between the seal member 27 and the annular groove 25 on the pressurizing chamber 11 side of the protruding portion 271.
  • the seal member 27 is sandwiched between the plunger 204 and the cylinder 6, and is in close contact with the bottom surface 211 of the annular groove 25 and the inner circumferential surface of the cylinder 6. This makes it possible to suppress or prevent the seal member 27 from moving relative to the plunger 204 when the plunger 204 reciprocates. As a result, it is possible to prevent the seal member 27 from being deformed or damaged due to wear.
  • the high-pressure fuel that has entered the gap 210 presses the seal member 27 toward the cylinder 6 on the pressurizing chamber 11 side from the contact portion between the protruding portion 271 of the seal member 27 and the bottom surface 211 of the annular groove 25.
  • the protrusion 271 according to the fifth embodiment described above comes into contact with the auxiliary chamber 17a side (the side opposite to the pressurizing chamber side) of the bottom surface 211 of the annular groove 25 rather than the central portion. This ensures a wide gap 210 between the seal member 27 and the annular groove 25, and increases the force with which the high-pressure fuel that has entered the gap 210 presses the seal member 27 toward the cylinder 6. As a result, the sealing function of the seal member 27 can be improved.
  • the protrusion 271 according to the fifth embodiment described above elastically deforms and comes into close contact with the bottom surface 211 of the annular groove 25 . This makes it possible to reliably seal between the seal member 27 and the plunger 204. In addition, it is possible to suppress or prevent the seal member 27 from moving relatively to the plunger 204 when the plunger 204 reciprocates.
  • the seal members 20, 27, 28 are made of a resin material, and the gap between the plunger 2, 204 and the cylinder 6 is 50 ⁇ m or less. This makes it possible to prevent the seal members 20, 27, 28 from being wedged into the gap between the outer circumferential surface of the plunger 2, 204 and the inner circumferential surface of the cylinder 6, even if the seal members 20, 27, 28 are made of a resin material. As a result, the sealing function of the seal members 20, 27, 28 can be ensured.
  • the seal member 27 of the fifth embodiment may be disposed in the annular groove 22 of the plunger 201 of the second embodiment.
  • 1...pump body 1a...first chamber, 1b...second chamber, 1c...third chamber, 1d...suction passage, 1e...communication hole, 1x...fixed portion, 2,201,202,203,204...plunger, 2a...large diameter portion, 2b...small diameter portion, 2c...step portion, 3...electromagnetic suction valve mechanism, 4...relief valve mechanism, 5...suction joint, 6...cylinder, 6a...pressure-fit portion, 8...discharge valve mechanism, 9...pressure pulsation reduction mechanism, 10...low-pressure fuel chamber, 11...pressurizing chamber, 12...discharge joint, 15...retainer, 17...seal holder, 17a...auxiliary chamber, 18...plunge Chassis seal, 20, 27, 28...sealing member, 21, 22, 23, 24, 25...annular groove, 100...high pressure fuel supply pump (fuel pump), 101...ECU, 102...feed pump, 103...fuel tank, 104...low pressure piping, 105...fuel pressure sensor, 106...common rail

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)

Abstract

La présente invention concerne une pompe à carburant qui peut empêcher un élément d'étanchéité fixé à un piston plongeur d'être déformé ou endommagé. La pompe à carburant de la présente invention comprend : un piston plongeur ; un cylindre qui guide le mouvement de va-et-vient du piston plongeur ; un élément d'étanchéité qui est disposé dans une rainure annulaire formée dans la surface circonférentielle externe du piston plongeur et qui vient en contact avec la surface circonférentielle interne du cylindre ; et un corps de pompe qui a une chambre de compression, dont la capacité augmente ou diminue en réponse au mouvement de va-et-vient du piston plongeur. La surface inférieure de la rainure annulaire comporte une partie de pression qui presse l'élément d'étanchéité. Dans une zone entre la rainure annulaire et l'élément d'étanchéité sur le côté chambre de compression par rapport à l'élément de pression, un espace qui permet au carburant de s'infiltrer depuis le côté chambre de compression est formé.
PCT/JP2022/040166 2022-10-27 2022-10-27 Pompe à carburant WO2024089843A1 (fr)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001271726A (ja) * 2000-03-29 2001-10-05 Unisia Jecs Corp 燃料加圧用ポンプ
JP2010229924A (ja) * 2009-03-27 2010-10-14 Denso Corp 高圧ポンプ
JP2021188544A (ja) * 2020-05-28 2021-12-13 日立Astemo株式会社 燃料ポンプ

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001271726A (ja) * 2000-03-29 2001-10-05 Unisia Jecs Corp 燃料加圧用ポンプ
JP2010229924A (ja) * 2009-03-27 2010-10-14 Denso Corp 高圧ポンプ
JP2021188544A (ja) * 2020-05-28 2021-12-13 日立Astemo株式会社 燃料ポンプ

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