JP2018071443A - Fuel supply pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel supply pump that is compatible with a large flow rate while sufficiently exerting pulsation reduction effect for a metallic damper by a simple configuration capable of reducing manufacturing cost.SOLUTION: A fuel supply pump includes: a damper storage part in which a metallic damper is disposed; a pump body formed with a fuel passage port through which fuel flows into or out relative to the damper storage part; and a communication passage for communicating an upper-side space to a lower-side space of the metallic damper, where the communication passage and the fuel passage port of the pump body are arranged in a position so as to be superposed each other in viewed from a direction orthogonal to the metallic damper.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a fuel supply pump.

  2. Description of the Related Art There is known a fuel supply pump that has a stable liquid pulsation reduction effect and includes a simple and small metal diaphragm damper (metal damper) mechanism (see, for example, Patent Document 1).

  This Patent Document 1 states that “a metal damper is sandwiched between a body body and a damper cover and fixed to a damper housing portion, and the cover is formed of a metal plate and protrudes toward the body side. A plurality of convex outer curved surfaces and a plurality of outer convex curved surfaces protruding in a direction away from the main body are alternately provided, the tip of the inner convex curved surface abuts against one surface of the edge of the metal damper and contacts the opposite surface of the edge. The metal damper is sandwiched between the metal damper holding part on the main body side that comes into contact with the metal damper holding part, and is fixed to the damper accommodating part. "

JP 2008-286144 A

  In the technique disclosed in Patent Document 1, the positional relationship between the communication passage formed by the outer convex curved surface portion and communicating between the upper and lower sides of the metal damper and the fuel passage port provided in the pump body is not defined. Similarly, the positional relationship between the communication path that communicates the upper and lower sides of the metal damper and the penetrating portion provided in the holding member that forms the metal damper holding portion is not defined. For this reason, when the discharge flow rate is increased, depending on the positional relationship described above, the fuel flow may be biased and the pressure distribution becomes non-uniform, and the pulsation reduction effect of the metal damper may not be fully demonstrated. There is.

  An object of the present invention is to provide a fuel supply pump that fully exhibits the effect of reducing the pulsation of a metal damper and can cope with a large flow rate.

  In order to achieve the above object, in the present invention, a damper housing portion in which a metal damper is disposed, a pump body in which a fuel passage port for allowing fuel to flow into or out of the damper housing portion is formed, and The communication passage that connects the upper space and the lower space of the metal damper and the communication passage and the fuel passage port of the pump body overlap each other when viewed from a direction orthogonal to the metal damper.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel supply pump which fully exhibits the pulsation reduction effect of a metal damper and respond | corresponds to large flow volume can be provided. Problems, configurations, and effects other than those described above will become apparent from the description of the following examples.

It is a longitudinal cross-sectional view of the fuel supply pump which implements this invention. It is horizontal direction sectional view seen from the upper direction of the fuel supply pump which implements this invention. It is the longitudinal cross-sectional view seen from FIG. 1 of the fuel supply pump which implements this invention from another direction. It is an expanded longitudinal cross-sectional view of the electromagnetic suction valve mechanism of the fuel supply pump which implements this invention, and shows the state which has an electromagnetic suction valve mechanism in the valve opening state. The block diagram of the engine system with which the fuel supply pump which implements this invention was applied is shown. 1 shows a state in which a metal damper is assembled to a damper cover by a holding member before the damper cover of the fuel supply pump embodying the present invention is attached to the pump body and is unitized independently. It is a bird's-eye view which shows the example of the shape of the holding member shown in FIG. It is an external view of the damper cover and holding member by 1st Example of this invention. 1 is a cross-sectional view of a fuel supply pump according to a first embodiment of the present invention. It is an external view of the damper cover and holding member by 2nd Example of this invention. It is sectional drawing of the fuel supply pump by the 2nd Example of this invention. It is an external view of the damper cover and holding member by the modification of a 2nd Example. It is sectional drawing of the fuel supply pump by the modification of a 2nd Example.

  Hereinafter, the configuration and operational effects of the fuel supply pump according to the first to second embodiments of the present invention will be described with reference to the drawings. In each figure, the same numerals indicate the same parts.

(overall structure)
First, the configuration and operation of the system will be described using the overall configuration diagram of the engine system shown in FIG. A portion surrounded by a broken line indicates a main body of the fuel supply pump, and a mechanism / part shown in the broken line indicates that the pump body 1 is integrally incorporated.

  The fuel in the fuel tank 20 is pumped up by the feed pump 21 based on a signal from an engine control unit 27 (hereinafter referred to as ECU). This fuel is pressurized to an appropriate feed pressure and sent to the low-pressure fuel inlet 10a of the fuel supply pump through the suction pipe 28.

  The fuel that has passed through the suction joint 51 (see FIG. 2) from the low-pressure fuel suction port 10a passes through the metal damper 9 (pressure pulsation reducing mechanism) and the suction passage 10d, and the suction port 31b of the electromagnetic suction valve mechanism 300 constituting the variable capacity mechanism. To.

  The fuel that has flowed into the electromagnetic suction valve mechanism 300 passes through the suction valve 30 and flows into the pressurizing chamber 11. The reciprocating power is applied to the plunger 2 by the cam 93 (see FIG. 1) of the engine (internal combustion engine). The reciprocating motion of the plunger 2 sucks fuel from the suction valve 30 during the downward stroke of the plunger 2 and pressurizes the fuel during the upward stroke. Through the discharge valve mechanism 8, the fuel is pumped to the common rail 23 to which the pressure sensor 26 is attached. The injector 24 injects fuel into the engine based on a signal from the ECU 27. The present embodiment is a fuel supply pump applied to a so-called direct injection engine system in which an injector 24 directly injects fuel into a cylinder cylinder of an engine.

  The fuel supply pump discharges a desired fuel flow rate of the supplied fuel in response to a signal from the ECU 27 to the electromagnetic suction valve mechanism 300.

(Configuration of fuel supply pump)
Next, the configuration of the fuel supply pump will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view of the fuel supply pump, and FIG. 2 is a horizontal sectional view of the fuel supply pump as viewed from above. FIG. 3 is a longitudinal sectional view of the fuel supply pump as seen from a different direction from FIG. FIG. 4 is an enlarged view of the electromagnetic suction valve mechanism 300.

  As shown in FIG. 1, the fuel supply pump is attached to the metal damper 9, the pump body 1 (pump body) in which the damper accommodating portion 1p for accommodating the metal damper 9 is formed, and the pump body 1, and the damper accommodating portion. A damper cover 14 that covers 1p and holds the metal damper 9 between the pump body 1 and a holding member 9a that is fixed to the damper cover 14 and holds the metal damper 9 from the opposite side of the damper cover 14. Yes. The holding member 9 a is disposed between the metal damper 9 and the pump body 1, and holds the metal damper 9 from the pump body 1 side.

  The fuel supply pump is attached to a fuel supply pump mounting portion 90 of the internal combustion engine using a mounting flange 1e (see FIG. 2) provided in the pump body 1, and is fixed with a plurality of bolts.

  As shown in FIG. 1, an O-ring 61 is fitted into the pump body 1 for sealing between the fuel supply pump mounting portion 90 and the pump body 1 to prevent engine oil from leaking to the outside.

  A cylinder 6 that guides the reciprocating motion of the plunger 2 and forms a pressurizing chamber 11 together with the pump body 1 is attached to the pump body 1. An electromagnetic suction valve mechanism 300 for supplying fuel to the pressurizing chamber 11 and a discharge valve mechanism 8 (see FIG. 2) for discharging fuel from the pressurizing chamber 11 to the discharge passage are provided.

  As shown in FIG. 1, the cylinder 6 is press-fitted with the pump body 1 on the outer peripheral side thereof, and further, in the fixing portion 6 a, the body is deformed to the inner peripheral side to press the cylinder 6 upward in the figure. The fuel pressurized in the pressurizing chamber 11 is sealed so as not to leak to the low pressure side.

  At the lower end of the plunger 2 is provided a tappet 92 that converts the rotational movement of a cam 93 (cam mechanism) attached to the camshaft of the internal combustion engine into a vertical movement and transmits it to the plunger 2. The plunger 2 is pressure-bonded to the tappet 92 by the spring 4 through the retainer 15. Thereby, the plunger 2 can be reciprocated up and down with the rotational movement of the cam 93.

  A plunger seal 13 held at the lower end of the inner periphery of the seal holder 7 is installed in a slidable contact with the outer periphery of the plunger 2 at the lower part of the cylinder 6 in the figure. Thereby, when the plunger 2 slides, the fuel in the sub chamber 7a is sealed and prevented from flowing into the internal combustion engine. At the same time, lubricating oil (including engine oil) for lubricating the sliding portion in the internal combustion engine is prevented from flowing into the pump body 1.

  A suction joint 51 is attached to the side surface of the pump body 1 of the fuel supply pump. The suction joint 51 is connected to a low-pressure pipe that supplies fuel from the fuel tank 20 of the vehicle, and the fuel is supplied from here to the inside of the fuel supply pump. The suction filter 52 (see FIG. 3) in the suction joint 51 serves to prevent foreign matters existing between the fuel tank 20 and the low-pressure fuel suction port 10a from being absorbed into the fuel supply pump by the flow of fuel.

  As shown in FIG. 1, the fuel that has passed through the low-pressure fuel intake port 10a reaches the intake port 31b of the electromagnetic intake valve mechanism 300 through the metal damper 9 and the intake passage 10d (low-pressure fuel flow path).

  The electromagnetic suction valve mechanism 300 will be described in detail with reference to FIG. The coil section includes a first yoke 42, an electromagnetic coil 43, a second yoke 44, a bobbin 45, a terminal 46, and a connector 47. A coil 43 in which a copper wire is wound around the bobbin 45 is disposed so as to be surrounded by the first yoke 42 and the second yoke 44, and is molded and fixed integrally with a connector which is a resin member. The respective ends of the two terminals 46 are respectively connected to both ends of the copper wire of the coil so as to be energized. Similarly, the terminal 46 is molded integrally with the connector, and the remaining end can be connected to the engine control unit side.

  The coil portion is fixed by press-fitting the central hole of the first yoke 42 into the outer core 38. At that time, the inner diameter side of the second yoke 44 is in contact with the fixed core 39 or close to a slight clearance.

  Both the first yoke 42 and the second yoke 44 are made of magnetic stainless steel in order to constitute a magnetic circuit and in consideration of corrosion resistance, and the bobbin 45 and the connector 47 are made of high strength heat resistant resin in consideration of strength characteristics and heat resistance characteristics. . The coil 43 is made of copper, and the terminal 46 is made of brass plated with metal.

  Thus, when a magnetic circuit is formed by the outer core 38, the first yoke 42, the second yoke 44, the fixed core 39, and the anchor portion 36, and a current is applied to the coil, magnetic attraction is performed between the fixed core 39 and the anchor portion 36. A force is generated, and a force that is attracted to each other is generated. In the outer core 38, the axial portion where the fixed core 39 and the anchor portion 36 generate the magnetic attractive force is made as thin as possible, so that almost all of the magnetic flux passes between the fixed core 39 and the anchor portion 36. The magnetic attractive force can be obtained efficiently.

  The solenoid mechanism part includes a rod 35 that is a movable part, an anchor part 36, a rod guide 37 that is a fixed part, an outer core 38, a fixed core 39, a rod biasing spring 40, and an anchor part biasing spring 41.

  The movable part rod 35 and the anchor part 36 are configured as separate members. The rod 35 is slidably held in the axial direction on the inner peripheral side of the rod guide 37, and the inner peripheral side of the anchor portion 36 is slidably held on the outer peripheral side of the rod 35. That is, both the rod 35 and the anchor portion 36 are configured to be slidable in the axial direction as long as they are geometrically restricted.

  The anchor portion 36 has one or more through holes 36a penetrating in the axial direction of the component in order to move freely and smoothly in the axial direction in the fuel, and eliminates the restriction of movement due to the pressure difference before and after the anchor portion as much as possible. .

  The rod guide 37 is inserted in the radial direction on the inner peripheral side of the hole into which the intake valve of the fuel supply pump main body 1 is inserted, and in the axial direction, is abutted against one end portion of the intake valve seat. The outer core 38 that is fixed to the main body 1 by welding and the fuel supply pump main body 1 are arranged in a sandwiched manner. The rod guide 37 is also provided with a through hole 37a penetrating in the axial direction in the same manner as the anchor portion 36, and the pressure of the fuel chamber on the anchor portion side controls the movement of the anchor portion so that the anchor portion can move freely and smoothly. It is configured not to interfere.

  The outer core 38 has a thin cylindrical shape on the side opposite to the portion to be welded to the fuel supply pump main body, and is fixed by welding in such a manner that a fixed core 39 is inserted on the inner peripheral side thereof. A rod urging spring 40 is arranged on the inner peripheral side of the fixed core 39 with the narrow diameter portion as a guide, the rod 35 comes into contact with the suction valve 30, and the suction valve is pulled away from the suction valve seat portion 31a, that is, suction. Energizing force is applied in the valve opening direction.

  The anchor portion biasing spring 41 is disposed so as to apply a biasing force to the anchor portion 36 in the direction of the rod collar portion 35a while inserting one end into a cylindrical central bearing portion 37b provided on the center side of the rod guide 37 and maintaining the same axis. It is said. The movement amount 36e of the anchor portion 36 is set to be larger than the movement amount 30e of the intake valve 30. This is because the intake valve 30 is surely closed.

  Since the rod 35 and the rod guide 37 slide with each other and the rod 35 repeatedly collides with the suction valve 30, martensitic stainless steel subjected to heat treatment is used in consideration of hardness and corrosion resistance. The anchor portion 36 and the fixed core 39 use magnetic stainless steel to form a magnetic circuit, and the rod urging spring 40 and the anchor portion urging spring 41 use austenitic stainless steel in consideration of corrosion resistance.

  According to the above configuration, the intake valve portion and the solenoid mechanism portion are configured by organically arranging three springs. The suction valve biasing spring 33 configured as a suction valve portion, the rod biasing spring 40 configured as a solenoid mechanism portion, and the anchor portion biasing spring 41 correspond to this. In this embodiment, any spring uses a coil spring, but any spring can be used as long as it can obtain an urging force.

  As shown in FIG. 2, the discharge valve mechanism 8 provided at the outlet of the pressurizing chamber 11 has a discharge valve sheet 8a, a discharge valve 8b that contacts and separates from the discharge valve sheet 8a, and a discharge valve 8b toward the discharge valve sheet 8a. And a discharge valve stopper 8d that determines the stroke (movement distance) of the discharge valve 8b. The discharge valve stopper 8d and the pump body 1 are joined by welding at the contact portion 8e to block the fuel and the outside.

  In a state where there is no fuel differential pressure in the pressurizing chamber 11 and the discharge valve chamber 12a, the discharge valve 8b is pressed against the discharge valve seat 8a by the urging force of the discharge valve spring 8c and is closed. Only when the fuel pressure in the pressurizing chamber 11 becomes higher than the fuel pressure in the discharge valve chamber 12a, the discharge valve 8b opens against the discharge valve spring 8c. The high-pressure fuel in the pressurizing chamber 11 is discharged to the common rail 23 through the discharge valve chamber 12a, the fuel discharge passage 12b, and the fuel discharge port 12.

  When the discharge valve 8b is opened, the discharge valve 8b comes into contact with the discharge valve stopper 8d, and the stroke is limited. Accordingly, the stroke of the discharge valve 8b is appropriately determined by the discharge valve stopper 8d. As a result, the stroke is too large, and it is possible to prevent the fuel discharged at high pressure into the discharge valve chamber 12a from flowing back into the pressurization chamber 11 again due to the delay in closing the discharge valve 8b. Can be suppressed. Further, when the discharge valve 8b repeats opening and closing movements, the discharge valve 8b is guided by the outer peripheral surface of the discharge valve stopper 8d so that the discharge valve 8b moves only in the stroke direction. By doing so, the discharge valve mechanism 8 becomes a check valve that restricts the flow direction of fuel.

  The pressurizing chamber 11 includes a pump body 1 (pump housing), an electromagnetic suction valve mechanism 300, a plunger 2, a cylinder 6, and a discharge valve mechanism 8.

(Operation of fuel supply pump)
When the plunger 2 moves in the direction of the cam 93 due to the rotation of the cam 93 and is in the suction stroke state, the volume of the pressurizing chamber 11 increases and the fuel pressure in the pressurizing chamber 11 decreases. In this process, when the fuel pressure in the pressurizing chamber 11 becomes lower than the pressure in the suction port 31b, the suction valve 30 is opened. As shown in FIG. 4, the fuel flows through the opening 30 e of the intake valve 30 and flows into the pressurizing chamber 11.

  After the plunger 2 completes the suction stroke, the plunger 2 starts to move upward and moves to the compression stroke. Here, the electromagnetic coil 43 remains in a non-energized state and no magnetic biasing force acts. The rod biasing spring 40 is set to have a biasing force necessary and sufficient to keep the suction valve 30 open in a non-energized state. The volume of the pressurizing chamber 11 decreases with the compression movement of the plunger 2. In this state, the fuel once sucked into the pressurizing chamber 11 is again sucked through the opening 30 e of the intake valve 30 in the valve open state. Since the pressure is returned to the passage 10d, the pressure in the pressurizing chamber does not increase. This process is called a return process.

  In this state, when a control signal from the ECU 27 is applied to the electromagnetic suction valve mechanism 300, a current flows through the electromagnetic coil 43 via the terminal 46. Then, a magnetic attractive force acts between the magnetic core 39 and the anchor, whereby the magnetic urging force overcomes the urging force of the rod urging spring 40 and the rod 35 moves away from the intake valve 30. Therefore, the suction valve 30 is closed by the biasing force by the suction valve biasing spring 33 and the fluid force caused by the fuel flowing into the suction passage 10d. After the valve is closed, the fuel pressure in the pressurizing chamber 11 rises with the upward movement of the plunger 2, and when the pressure exceeds the pressure at the fuel discharge port 12, high-pressure fuel is discharged via the discharge valve mechanism 8 to the common rail 23. Supplied. This stroke is called a discharge stroke.

  That is, the compression stroke of the plunger 2 (the upward stroke from the lower start point to the upper start point) includes a return stroke and a discharge stroke. And the quantity of the high-pressure fuel discharged can be controlled by controlling the energization timing to the electromagnetic coil 43 of the electromagnetic intake valve mechanism 300. If the timing of energizing the electromagnetic coil 43 is advanced, the ratio of the return stroke during the compression stroke is small and the ratio of the discharge stroke is large. That is, the amount of fuel returned to the suction passage 10d is small and the amount of fuel discharged at high pressure is large. On the other hand, if the energization timing is delayed, the ratio of the return stroke during the compression stroke is large and the ratio of the discharge stroke is small. That is, the amount of fuel returned to the suction passage 10d is large, and the amount of fuel discharged at high pressure is small. The energization timing to the electromagnetic coil 43 is controlled by a command from the ECU 27. By controlling the energization timing to the electromagnetic coil 43 as described above, the amount of fuel discharged at high pressure can be controlled to an amount required by the internal combustion engine.

(Composition of metal damper)
As shown in FIG. 1, a metal damper 9 is installed in the low pressure fuel chamber 10 to reduce the pressure pulsation generated in the fuel supply pump from spreading to the suction pipe 28 (fuel pipe). When the fuel that has once flowed into the pressurizing chamber 11 is returned to the suction passage 10d through the intake valve 30 (suction valve body) that is opened again for capacity control, the fuel returned to the suction passage 10d is used as a low-pressure fuel. Pressure pulsation is generated in the chamber 10. However, the metal damper 9 provided in the low-pressure fuel chamber 10 is formed of a metal diaphragm damper in which two corrugated disk-shaped metal plates are bonded together on the outer periphery and an inert gas such as argon is injected therein. The pressure pulsation is absorbed and reduced as the metal damper expands and contracts.

  The plunger 2 has a large-diameter portion 2a and a small-diameter portion 2b, and the volume of the sub chamber 7a increases or decreases as the plunger 2 reciprocates. The sub chamber 7a communicates with the low pressure fuel chamber 10 by a fuel passage 10e (see FIG. 3). When the plunger 2 descends, fuel flows from the sub chamber 7a to the low pressure fuel chamber 10, and when it rises, fuel flows from the low pressure fuel chamber 10 to the sub chamber 7a.

  As a result, the flow rate of fuel into and out of the pump during the suction stroke or return stroke of the pump can be reduced, and the pressure pulsation generated inside the fuel supply pump is reduced.

(Configuration of holding member)
Next, an example of the shape of the holding member 9a will be described with reference to FIGS. FIG. 6 is a longitudinal sectional view of a holding member 9a used for the fuel supply pump. FIG. 7 is a bird's-eye view of the holding member 9a shown in FIG.

  As shown in FIG. 6, the holding member 9 a is provided with an elastic portion E that biases the metal damper 9 toward the damper cover 14 by biasing the pump body 1. That is, the holding member 9 a includes an elastic portion E having a spring reaction force that biases the metal damper 9 toward the damper cover 14 by biasing the pump body 1. Therefore, the metal damper 9 (diaphragm) can be securely held in the pump body 1 by this spring reaction force. Furthermore, since it is not necessary to process the pump body 1 to position the holding member 9a, the manufacturing cost can be reduced.

  Further, as shown in FIG. 7, the holding member 9a has a fuel passage FP that is simultaneously formed by cutting and raising the elastic portion E, and the fuel passage FP between the pump body 1 side and the metal damper 9 side. Can be secured. Accordingly, it is not necessary to secure a passage in the processing on the pump body 1 side, the processing can be simplified, and the manufacturing cost can be reduced.

  Also, as shown in FIG. 6, before the damper cover 14 is attached to the pump body 1, it is desirable that the metal damper 9 is assembled to the damper cover 14 by the holding member 9a and is unitized independently. Thus, the metal damper 9 can be simultaneously held in the pump body 1 by assembling the damper cover 14 to the pump body 1 after assembling the independent damper unit with cover.

  As shown in FIG. 7, the elastic portion E of the holding member 9 a includes a bottom portion B configured in a substantially planar shape, and a part of the bottom portion B is formed by being cut and raised toward the pump body 1 side. Is done. Thereby, the elastic part E can be formed easily.

  More specifically, the elastic portion E includes a bottom portion B, an inner peripheral side surface portion IS formed from the bottom portion B toward the damper cover 14, and the side surface portion (inner peripheral side surface portion IS) to the bottom portion B. And the holding member 9 a is fixed to the damper cover 14 by press-fitting the outer diameter side surface OS into the damper cover 14. Thereby, the holding member 9a and the damper cover 14 can be easily fixed. Moreover, the holding member 9a, the metal damper 9, and the damper cover 14 can be easily unitized.

  Further, it is desirable that the holding member 9a and the elastic portion E are formed by a single press plate. Thereby, for example, processing man-hours are reduced and manufacturing costs are reduced.

  The holding member 9a includes a bottom portion B and an edge portion 9aE formed from the bottom portion B toward the damper cover 14, and the edge portion 9aE and the lower surface of the damper cover 14 hold the metal damper from above and below. desirable. Thereby, the metal damper 9 can be held with a smaller number of parts (one point) than the conventional number of parts (two points).

The fuel supply pump according to this embodiment will be described with reference to FIGS.
FIG. 8 shows an external view of the damper cover 14 and the holding member 9a. In the first embodiment, the damper cover 14 is formed of an upper lid part and a side part formed in a direction orthogonal to the lid part. A cutout portion 10b is formed in the side surface portion of the damper cover 14 so as to be recessed toward the outer diameter side. A cover inner passage 10b is formed on the inner diameter side of the side surface of the damper cover 14 by the notch 10b. A communication passage that connects the upper space and the lower space of the metal damper 9 is formed by the cover inner passage 10b. Note that a plurality of cover inner passages 10b (notches 10b) are preferably formed on the inner diameter side of the side surface portion of the damper cover 14. Further, in this embodiment, the respective cover inner passages 10b (notches 10b) are arranged so as to face each other with respect to the horizontal center portion of the damper cover 14.

  Further, with respect to the holding member 9a, the elastic portion E is removed from the holding member 9a shown in FIG. 7, and the holding member 9a is an annular member composed of the outer diameter side surface portion OS and the edge portion 9aE. The holding member 9 a is fixed by press-fitting the outer diameter side surface portion OS into a cover inner diameter portion 14 a formed inside the metal damper 9. The metal damper 9 is desirably held by being sandwiched between the edge 9aE of the holding member 9a fixed in this manner and the lower surface of the damper cover 14. By doing so, the structure of the holding member 9a can be simplified and the manufacturing cost can be reduced.

  Next, FIG. 9 shows a cross-sectional view of a state in which the damper unit with cover obtained by assembling the damper cover 14, the metal damper 9, and the holding member 9 a into a unit is assembled to the pump body 1. It is desirable to provide a plurality of cover inner passages 10b, and it is desirable that each of the cover inner passages 10b be arranged so as to face each other with respect to the center of the damper cover 14. Further, the metal damper 9 is configured by bonding the outer peripheral edges of two metal diaphragms, and the outer peripheral edges are fixed by welding.

  In the present embodiment, as shown in the AA cross section of FIG. 9, the outer peripheral edge portion of the metal damper 9 is disposed in a space formed by a plurality of cover inner passages 10b. Further, the cover inner passage 10 b is formed on the upper side and the lower side with respect to the outer peripheral edge of the metal damper 9 so that the upper space and the lower space of the metal damper 9 communicate with each other.

  The upper portions of the plurality of cover inner passages 10b communicate with each other via an upper space of the metal damper 9 formed between the upper surface portion of the metal damper 9 and the lower surface portion of the lid portion of the damper cover 14. The lower portions of the plurality of cover inner passages 10b communicate with each other through a lower space of the metal damper 9 formed between the lower surface portion of the metal damper 9 and the upper surface portion forming the damper housing portion 1P of the pump body 1. To do. In the present embodiment, the pump body 1 is formed with a recessed portion that is recessed from the lid portion of the metal damper 9 toward the pump body 1 (the direction from the upper side to the lower side), and the holding member 9 a is the pump body 1. In this state, the recess is located below the holding member 9a. The lower portions of the plurality of cover inner passages 10b communicate with the lower space of the metal damper 9 through the lower recesses of the holding member 9a.

  The high-pressure fuel supply pump of the present embodiment includes a damper housing portion 1P in which the metal damper 9 is disposed, a pump body 1 in which a fuel passage port is formed to allow fuel to flow into or out of the damper housing portion 1P. It has. The fuel passage port is the suction passage 10d, the fuel passage 10e, or the vertical hole passage 10f. In this embodiment, the communication passage that connects the upper space and the lower space of the metal damper 9 and the position where the communication passage and the fuel passage port of the pump body 1 overlap when viewed from the direction orthogonal to the metal damper 9. Is arranged. As shown in FIGS. 8 and 9, the communication path is preferably formed by a notch 10 b formed in a part of the damper cover 14. Further, as will be described later, it is desirable that the communication path be formed by a notch formed in a part of the holding member 9.

  In the present embodiment, as an example, as shown in the CC cross section of FIG. 9, the communication path formed by the cover inner path 10 b is a part of the suction path 10 d when viewed from the direction orthogonal to the metal damper 9. The position in the radial direction is adjusted so as to overlap. The direction orthogonal to the metal damper 9 is a direction orthogonal to the plane portion of the metal damper 9, and a drawing viewed from this direction is shown in the CC section of FIG.

  The pump body 1 is provided with an electromagnetic suction valve mechanism 300, and the fuel passage (suction passage 10d) having the above-described fuel passage port as an entrance / exit is a space where the damper accommodating portion 1P and the electromagnetic suction valve mechanism 300 are disposed. Communicate. As a result, even when the flow of fuel that flows into or out of the damper accommodating portion 1P from the suction passage 10d communicating with the electromagnetic suction valve mechanism 300 consistently passes through the low-pressure fuel chamber 10, the discharge flow rate is increased. It is possible to prevent the pressure distribution from becoming non-uniform and to sufficiently exhibit the pulsation reducing effect of the metal damper 9. (In the figure, the flow direction when the fuel flows is indicated by an arrow as an example.) On the other hand, in the cross section B-B, the holding member 9a, the metal damper 9 and the damper cover 14 come into contact with each other to firmly fix the metal damper 9. Is possible.

  The pump body 1 is provided with a sub chamber 7a whose volume is increased or decreased in the opposite phase to that of the pressurizing chamber 11, and a fuel passage 10e having a fuel passage port as an inlet / outlet communicates the damper storage portion 1P and the sub chamber 7a. The pump body 1 is provided with a suction port 10a for sucking fuel from the outside, and a fuel passage (vertical hole passage 10f) having a fuel passage port (low pressure fuel suction port 10a) as an inlet / outlet is connected to the damper storage portion 1P. The fuel passage port (low-pressure fuel suction port 10a) is communicated. As shown in the section CC, the fuel flows into the damper accommodating portion 1P from the fuel passage 10e communicating with the sub chamber 7a and the vertical hole passage 10f communicating with the low-pressure fuel suction port 10a in the same manner as the suction passage 10d. Or flow out. For this reason, the fuel passages of these fuel passages 10e and suction passages 10d and the communication passage formed by the cover inner passage 10b may be arranged to overlap.

  The electromagnetic suction valve mechanism 300 is attached to the suction valve attachment hole 1c, and the discharge valve mechanism 8 is attached to the discharge valve attachment hole 1d.

  As described above, according to the present embodiment, it is possible to provide a fuel supply pump that can make the pressure distribution around the metal damper 9 uniform with a simple structure capable of reducing the manufacturing cost and cope with a large flow rate.

  Next, a fuel supply pump according to a second embodiment of the present invention will be described with reference to FIGS. The description of the same configuration as that of the first embodiment is omitted.

  In the second embodiment, as shown in FIG. 10, uneven portions are provided in each part of the damper cover 14. A concave portion 14 d that is recessed toward the metal damper 9 from a flat portion 14 b that is formed substantially parallel to the metal damper 9, and a convex portion 14 c that is convex on the opposite side of the metal damper 9 are provided. Furthermore, a circular portion 14e may be formed at the center of the damper cover 14 so as to intersect the convex portion 14c. The circular portion 14e is formed to be convex on the side opposite to the metal damper 9, similarly to the convex portion 14c.

  In addition, the holding member 9a changes the shape of the central elastic portion E based on the shape shown in FIG. The holding member 9 a includes an elastic portion E having a spring reaction force that biases the metal damper 9 toward the damper cover 14 by biasing the pump body 1. The elastic part E is formed so as to be substantially circular, and is constituted by four sector parts in the present embodiment when the plane part of the metal damper 9 is viewed from the vertical direction. Each fan-shaped portion is configured to be convex toward the pump body side, and the tip end portion of the fan-shaped portion is pressed against the pump body 1, so that the holding member 9 a conversely causes the metal damper 9 to be attached to the damper cover 14 by the spring reaction force. Press toward the side. As a result, the metal damper 9 can stably hold the pump body 1.

  Four fuel passages FP are formed by adjacent sector portions, and these four fuel passages FP are formed so as to overlap each other at the central portion of the holding member 9a. Compared to the shape shown in FIG. 7 in which the fuel passages FP are separated into four locations, the fuel passages FP are combined into one to prevent a decrease in rigidity and improve workability during press molding. . The holding method of the metal damper 9 is the same as the shape shown in FIG.

  Next, FIG. 11 shows a cross-sectional view of a state in which the damper unit with cover obtained by assembling the damper cover 14, the metal damper 9, and the holding member 9 a into a unit is assembled to the pump body 1. As shown in the A-A cross section, the space formed inside the convex portion 14 c is used as the cover inner passage 10 b, and the communication passage formed thereby is viewed from a direction orthogonal to the plane portion of the metal damper 14. The radial position is adjusted so as to overlap the suction passage 10d.

  Further, when viewed from the direction orthogonal to the flat surface portion of the metal damper 14, the through portion CP (notch portion) provided in the holding member 9a is also disposed so as to overlap at least a part of the suction passage 10d. Thus, a communication path that connects the upper space and the lower space of the metal damper 9 is formed by both the cover inner passage 10b and the through portion CP formed by the convex portion 14c, and the communication passage and the suction passage 10d are Arranged to overlap.

  As in the first embodiment, it is desirable to provide a plurality of cover inner passages 10b. Further, it is desirable that the cover inner passage 10b is provided so as to face each other with respect to the center of the damper cover 14. The convex portion 14 c of the damper cover 14 is preferably formed so as to continue from one end of the outer peripheral portion of the damper cover 14 to the other end facing the center of the damper cover 14. Thereby, it is possible to provide a plurality of cover inner passages 10b.

  As described above, the fuel supply pump of the present embodiment includes the flat portion 14b formed substantially parallel to the metal damper 9, and the convex portions (14c, 14e) that protrude from the flat portion 14b to the opposite side of the metal damper 9. And a holding member 9 that holds the metal damper 9 from the opposite side of the damper cover 14 with respect to the metal damper 9 and in which a through portion CP through which fuel can pass is formed. . The convex portions (14 c, 14 e) form a communication path 10 b that communicates with the upper and lower sides of the metal damper 9, and the through portion CP of the holding member 9 is projected from the convex portion of the damper cover 14 when viewed from the direction orthogonal to the plane portion 14 b. It arrange | positions in the position which overlaps with a part (14c, 14e).

  As a result, the effect of the fuel passing through the low-pressure fuel chamber 10 consistently obtained in the first embodiment is promoted, and the pressure distribution can be made more uniform.

  On the other hand, in the cross section B-B, the metal damper 9 can be firmly fixed by contacting the holding member 9a, the metal damper 9, and the recessed portion 14d formed in the damper cover 14. Similarly to the convex portion 14c, a plurality of the concave portions 14b are desirably arranged so as to face each other with respect to the center of the damper cover 14.

  In other words, the damper cover 14 has a recessed portion 14d that is recessed from the flat surface portion 14b to the metal damper 9 side. And it fixes by pinching the metal damper 9 by 14 d of recessed parts, and a part of holding member 9. As shown in FIG. The elastic portion E has a bottom portion B formed in a plane, an inner peripheral side surface portion IS formed from the bottom portion B toward the damper cover 14, and the side surface portion (inner peripheral side surface portion IS) toward the bottom portion B. The metal damper 9 is sandwiched by an outer peripheral edge portion 9aE that includes the outer diameter side surface portion OS and the inner diameter side surface portion IS and the outer diameter side surface portion OS. The metal damper 9 is sandwiched by the outer peripheral upper edge portion 9aE of the elastic portion E.

  Further, as shown in FIG. 10, the plurality of recessed portions 14 d are arranged so as to face each other with respect to the center of the damper cover 14. The plurality of convex portions 14 c are arranged so as to face each other with respect to the center of the damper cover 14.

  Thereby, it becomes possible to fix the metal damper 9 more firmly. In addition, arranging a plurality of convex portions 14c and concave portions 14b on the damper cover 14 as described above has the same effect as providing ribs, and high rigidity even when the damper cover 14 is press-molded. Is expected to maintain. If the circular portion 14e is added, it is expected that the pulsation reduction effect is improved by expanding the low-pressure fuel chamber 10 in addition to further improving the rigidity.

  In FIG. 11, the fuel passage 10e and the fuel passage opening of the vertical hole passage 10f are arranged at the position overlapping the holding member 9a as shown by the dotted line, but are rotated by 90 degrees for each damper unit with cover. Also good. By doing so, it is possible to arrange the communication path that communicates the upper and lower sides of the metal damper 9 so as to overlap the fuel path 10e and the vertical hole path 10f, and the same effect can be obtained.

  As described above, according to the present embodiment, it is possible to provide a fuel supply pump that can make the pressure distribution around the metal damper 9 uniform with a simple structure capable of reducing the manufacturing cost and cope with a large flow rate.

Next, a modification of the fuel supply pump according to the second embodiment will be described with reference to FIGS.
In the modified example, the entire periphery of the outer peripheral portion is defined as the edge portion 9aE by moving the penetration portion CP provided in the outer peripheral portion of the holding member 9a to the inner peripheral side. By carrying out like this, the metal damper 9 can be fixed more firmly. The damper cover 14 has the same shape as in FIG.

  Next, FIG. 13 shows a cross-sectional view of a state in which the damper unit with cover obtained by assembling the damper cover 14, the metal damper 9, and the holding member 9 a into a unit is assembled to the pump body 1. In this modification, the metal damper 9 is sandwiched between the holding member 9a and the fixing member 9b to form a unit, and is further urged and fixed to the recessed portion 14d of the damper cover 14. By doing so, it is possible to increase the strength of the thin outer peripheral portion of the metal damper 9 and fix it more firmly. Also in this case, as shown in the AA cross section, the projecting portion 14c, the recessed portion 14b, the penetration portion CP, and the radial position of each fuel passage port formed in the body are the same as in the second embodiment described above. It is possible to obtain the same effect by being arranged.

  In addition, since the through portion CP is formed in four directions, it can be advantageously arranged so as to overlap not only the suction passage 10d but also the fuel passage 10e and the fuel passage port of the vertical hole passage 10f.

  As described above, according to the present embodiment, it is possible to provide a fuel supply pump that can make the pressure distribution around the metal damper 9 uniform with a simple structure capable of reducing the manufacturing cost and cope with a large flow rate.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

DESCRIPTION OF SYMBOLS 1 ... Pump body 1P ... Damper accommodating part 2 ... Plunger 6 ... Cylinder 7 ... Seal holder 8 ... Discharge valve mechanism 9 ... Metal damper (pressure pulsation reduction mechanism)
9a ... Holding member 10 ... Low pressure fuel chamber 10a ... Low pressure fuel inlet 10b ... Cover inner passage 11 ... Pressurizing chamber 12 ... Fuel outlet 13 ... Plunger seal 14 ... Damper cover 14c ... Convex part 14d ... Concave part 300 ... Electromagnetic Suction valve mechanism

Claims (12)

A damper accommodating portion in which a metal damper is disposed;
A pump body in which a fuel passage port is formed to allow fuel to flow into or out of the damper accommodating portion;
A communication path communicating the upper space and the lower space of the metal damper;
The fuel supply pump, wherein the communication passage and the fuel passage port of the pump body overlap each other when viewed from a direction orthogonal to the metal damper. The fuel supply pump according to claim 1, wherein
A fuel supply pump, comprising: a holding member that is disposed between the metal damper and the pump body and holds the metal damper from the pump body side. The fuel supply pump according to claim 1, wherein
The fuel supply pump, wherein the communication path is formed by a notch formed in a part of the damper cover. The fuel supply pump according to claim 2, wherein
The fuel supply pump, wherein the communication path is formed by a notch formed in a part of the holding member. The fuel supply pump according to claim 1 or 2,
An electromagnetic suction valve is disposed in the pump body, and a fuel passage having the fuel passage port as an inlet / outlet communicates a space in which the damper housing portion and the electromagnetic suction valve are disposed. The fuel supply pump according to claim 1 or 2,
The pump body is provided with a sub chamber whose volume is increased or decreased in a phase opposite to that of the pressurizing chamber, and a fuel passage having the fuel passage port as an inlet / outlet communicates the damper storage portion and the sub chamber. Fuel supply pump. The fuel supply pump according to claim 1 or 2,
The pump body is provided with a suction port for sucking fuel from the outside, and a fuel passage having the fuel passage port as an inlet / outlet communicates the damper storage part and the suction port. pump. A pump body in which a damper housing portion in which a metal damper is disposed is formed;
A damper cover having a flat portion formed substantially parallel to the metal damper, and a convex portion protruding from the flat portion to the opposite side of the metal damper;
Holding the metal damper from the side opposite to the damper cover with respect to the metal damper, and a holding member formed with a through part through which fuel can pass.
The convex portion forms a communication path communicating with the upper and lower sides of the metal damper, and the penetrating portion of the holding member is disposed at a position overlapping the convex portion of the damper cover when viewed from a direction orthogonal to the plane portion. A fuel supply pump characterized by being made. The fuel supply pump according to claim 8,
The fuel supply pump according to claim 1, wherein the damper cover has a recessed portion that is recessed from the flat portion toward the metal damper. The fuel supply pump according to claim 9, wherein
The fuel supply pump, wherein the metal damper is fixed by being sandwiched between the recess and a part of the holding member. The fuel supply pump according to claim 9, wherein
The fuel supply pump according to claim 1, wherein the recess and the protrusion are arranged so as to face each other with respect to a center of the damper cover. The fuel supply pump according to claim 8,
The fuel supply pump, wherein the convex portion is continuous from one end of the outer peripheral portion of the damper cover to the other end facing the center of the damper cover.

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