JP4661976B2 - Fuel supply pump - Google Patents

Description

  The present invention relates to a fuel supply pump that pressurizes and discharges fuel.

  In the conventional fuel supply pump 100, as shown in FIG. 8, a pump element 104 having a plunger 101 and a cylinder body 102 to form a fuel pressurization chamber 103, an upstream fuel flow path 105, and pressurization. And a valve device 106 for intermittently flowing fuel into and out of the chamber 103, and the operating state of the valve device is controlled in accordance with the vertical movement of the plunger 101 in the illustrated vertical direction (axial direction). A device for increasing and decreasing the fuel pressure at 103 is known.

  According to the fuel supply pump 100, the valve device 106 is, for example, an electromagnetic valve device having a solenoid coil (not shown). The valve body 108 forms the valve chamber 109 and is provided integrally with the armature 110. The valve body 111 is accommodated in the valve chamber 109 so as to be vertically movable in the axial direction. Here, the pressurizing chamber 103 and the valve chamber 109 are partitioned by a stopper member 112 which will be described later, and are communicated by a communication passage 113 provided in the stopper member 112.

  When the armature 110 is magnetically attracted and moved upward by energization of the solenoid coil, the valve body 111 also moves upward and is seated on the valve body 108, and the pressurizing chamber 103 and the valve chamber 109 are connected to the upstream fuel. The flow path 105 is closed.

  The armature 110 is always urged downward by a predetermined urging means (not shown). Further, a check valve (not shown) is arranged further downstream of the fuel flow path 114 downstream of the pressurizing chamber 103, and the check valve has a fuel pressure of a predetermined pressure ( The valve opens when the valve opening pressure is exceeded. Further, the plunger 101 moves up and down according to the rotation of a predetermined cam (not shown).

  Further, the stopper member 112 is disposed between the cylinder body 102 and the valve body 108. The stopper member 112 allows the pressurizing chamber 103 and the valve chamber 109 to communicate with each other through the communication passage 113 and restricts the downward movement of the valve body 111.

  The stopper member 112 is pressed against the valve chamber opening surface 117 of the valve body 108 by the upper surface 116 to maintain the fluid tightness of the valve chamber 109, and the stopper member 112 is connected to the pressurization chamber opening surface 119 of the cylinder body 102 by the lower surface 118. The liquid tightness of the pressurizing chamber 103 is maintained by pressure contact. The pressure contact between the upper surface 116 and the valve chamber opening surface 117 and the pressure contact between the lower surface 118 and the pressure chamber opening surface 119 are realized by a fastening axial force generated by screwing the valve device 106 to the cylinder body 102. Yes.

  With such a configuration, according to the fuel supply pump 100, when the plunger 101 is lifted, energization of the solenoid coil is performed, whereby the upstream fuel flow path 105 is closed with respect to the pressurizing chamber 103, and the pressurization is performed. The fuel pressure in the chamber 103 is increased. When the fuel pressure in the pressurizing chamber 103 exceeds the valve opening pressure of the check valve, the pressurized fuel is discharged from the pressurizing chamber 103.

Further, after the energization of the solenoid coil is stopped, the plunger 101 turns from rising to lowering, whereby the upstream fuel flow path 105 is opened to the pressurizing chamber 103, and the upstream fuel flow path 105 is connected to the pressurizing chamber. The fuel is sucked into 103.
The discharge amount from the pressurizing chamber 103 is manipulated by changing the energization start timing of the solenoid coil.

  By the way, according to the fuel supply pump 100, the upper surface 116 and the valve chamber opening surface 117 are pressed against each other by the fastening axial force, but the fuel pressure in the valve chamber 109 acts in a direction that weakens the pressure contact caused by the fastening axial force. For this reason, relative sliding in the left-right direction (radial direction) is repeatedly generated between the upper surface 116 and the valve chamber opening surface 117 due to repeated increase and decrease in fuel pressure in the valve chamber 109.

  That is, the lower end portion of the valve body 108 having the valve chamber opening surface 117 is strongly pressed against the stopper member 112 by the fastening axial force when the fuel pressure in the valve chamber 109 is reduced, and is slightly elastically deformed outward. is doing. When the fuel pressure in the valve chamber 109 is increased, the pressure contact due to the fastening axial force is weakened, and the lower end portion of the valve body 108 is restored to the inner peripheral side.

  As a result, the relative slip in the radial direction repeatedly occurs between the upper surface 116 and the valve chamber opening surface 117 by repeatedly increasing and decreasing the fuel pressure in the valve chamber 109. Such a radial slip occurs in the same manner between the lower surface 118 and the pressurizing chamber opening surface 119 by repeatedly increasing and decreasing the fuel pressure in the pressurizing chamber 103.

  For this reason, there is a possibility that fretting wear may progress between the upper surface 116 and the valve chamber opening surface 117 and between the lower surface 118 and the pressurizing chamber opening surface 119. In order to suppress such fretting wear, Various countermeasures have been considered (see, for example, Patent Documents 1 and 2).

  That is, Patent Document 1 and Patent Document 2 disclose a technique for suppressing elastic deformation of the lower end portion of the valve body 108 due to the fastening axial force by expanding the pressure contact area between the upper surface 116 and the valve chamber opening surface 117. ing. Further, Patent Document 2 discloses a technique for limiting the degree of freedom of the stopper member 112 by press-fitting the stopper member 112 into the valve body 108 and the cylinder body 102, and the stopper member 112 is provided in a reverse concave shape. A technique is disclosed in which a cylindrical stopper member 112 is press-fitted into a cylinder body 102 in the vicinity of the opening of the pressurizing chamber 103 to limit the degree of freedom of the cylinder body 102 in the vicinity of the opening of the pressurizing chamber 103.

  However, even if the pressure contact area is increased, the elastic deformation due to the fastening axial force is not completely eliminated, and the slip amount in the radial direction is reduced, but the slip is inevitably generated. Further, even if the slip due to the fastening axial force is reduced, the slip due to the difference in the amount of elastic deformation becomes significant. That is, the cylinder body 102 in the vicinity of the lower end of the valve body 108 and the opening of the pressurizing chamber 103 and the stopper member 112 have a large difference in the diameter of the fuel flow portion, so that the amount of elastic deformation in the radial direction due to the fuel pressure is significant. There is a big difference.

  That is, the fuel flow portion of the stopper member 112 is the communication passage 113, and the diameter of the fuel flow portion of the stopper member 112 is the passage diameter of the communication passage 113. Further, the lower end portion of the valve body 108 and the fuel flow portion of the cylinder body 102 in the vicinity of the opening of the pressurizing chamber 103 are the valve chamber 109 and the pressurizing chamber 103, respectively. The diameters of the fuel flow portions of the cylinder body 102 in the vicinity of the opening are the opening diameters of the valve chamber 109 and the pressurizing chamber 103, respectively.

  The passage diameter of the communication passage 113 is significantly smaller than the opening diameters of the valve chamber 109 and the pressurizing chamber 103. For this reason, the amount of elastic deformation in the radial direction accompanying the increase or decrease of the fuel pressure in the valve chamber 109, the pressurizing chamber 103 and the communication passage 113 is the cylinder body near the lower end of the valve body 108 and the opening of the pressurizing chamber 103. 102 is larger than the stopper member 112, and slippage due to the difference in the amount of elastic deformation becomes remarkable.

  Further, when the degree of freedom of each part is limited by press-fitting, the surfaces of the valve body 108, the cylinder body 102, and the stopper member 112 are hardened by heat treatment. There is a risk of delayed fracture at the stress accumulation site.

Japanese Patent Laid-Open No. 3-219178 JP 2006-170169 A

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to increase the fuel pressure in the pressurizing chamber or the like without generating a portion where tensile stress is accumulated in the fuel supply pump. The object is to suppress fretting wear by reducing slippage between members due to repeated decompression.

[Means of Claim 1]
A fuel supply pump according to claim 1, wherein a valve body that forms a valve chamber that reciprocally accommodates a valve body, and a cylinder body that accommodates a plunger that reciprocates in an axial direction to form a fuel pressurizing chamber. And a stopper member that partitions the pressurizing chamber and the valve chamber and restricts the movement of the valve body toward the pressurizing chamber. The stopper member has a communication path that connects the pressurizing chamber and the valve chamber, and is freely fitted in a recess provided in one or both of the valve body and the cylinder body, and is movable in the radial direction and the axial direction. is there. Further, the valve body and the cylinder body are in pressure contact with each other in the axial direction, so that the liquid tightness of the valve chamber and the pressurizing chamber is maintained.

  As a result, even if radial slip occurs between the pressure contact portion of the valve body and the pressure contact portion of the cylinder body due to repeated increases and decreases in fuel pressure in the valve chamber and the pressurization chamber, the slip amount is greatly increased. To reduce.

  That is, the difference between the opening diameter of the valve chamber and the opening diameter of the pressurizing chamber is relatively much smaller than the difference between the opening diameter of the valve chamber and the opening diameter of the pressurizing chamber and the flow path diameter of the communication passage. As a result, the amount of radial slip due to repeated increases and decreases in the fuel pressure in the valve chamber and the pressurizing chamber is greater when the valve body and the cylinder body are in pressure contact with each other. It is smaller than when both are pressed.

  For this reason, in the fuel supply pump, the fretting wear is suppressed by reducing the slippage between members due to repeated increase and decrease of fuel pressure in the valve chamber and pressurizing chamber, etc. can do.

[Means of claim 2]
According to the fuel supply pump of the second aspect, the valve body and the cylinder body are in pressure contact with each other in plane contact.
Thereby, since the press-contact area of a valve body and a cylinder body can be expanded, the elastic deformation | transformation by a fastening axial force can be suppressed and the amount of radial slip can be reduced.

[Means of claim 3]
According to the fuel supply pump of the third aspect, the recess is provided only in the cylinder body.
As a result, the stopper member and the valve body can be mounted on the cylinder body only from above. For this reason, it is possible to reduce the number of manufacturing steps of the fuel supply pump that achieves the function and effect of the means of claims 1 and 2, thereby reducing the cost.

[Means of claim 4]
The fuel supply pump according to claim 4 includes an actuator that drives the valve body, and the valve body is driven by the actuator to reciprocate within the valve chamber, thereby connecting the upstream fuel flow path to the pressurizing chamber. Is opened and closed with respect to the pressurizing chamber, and the volume of the pressurizing chamber is reduced by the displacement of the plunger in one axial direction and is increased by the displacement of the plunger in the other axial direction.

  Further, the valve body is driven in a direction away from the pressurizing chamber by the actuator when the plunger is displaced to one side in the axial direction to close the upstream fuel flow path with respect to the pressurizing chamber, When the fuel is discharged from the pressurizing chamber through the downstream fuel flow path connected to the pressurizing chamber and the plunger is displaced to the other side in the axial direction, the actuator is driven in the direction approaching the pressurizing chamber and the upstream side By opening the fuel flow path with respect to the pressurizing chamber, the fuel flows into the pressurizing chamber, and the movement toward the pressurizing chamber by being in contact with the stopper member is restricted.

Further, when the plunger is displaced to one side in the axial direction, the stopper member is displaced so as to move away from the pressurizing chamber by being urged by the fuel pressure of the pressurizing chamber, and comes into contact with the valve body to pressurize the pressurizing chamber. After stopping the displacement away from the plunger, the plunger turns in the displacement direction to the other side in the axial direction, and is displaced by the fuel pressure of the valve chamber so as to approach the pressurizing chamber, and comes into contact with the cylinder body and pressurizes the pressurizing chamber. The displacement approaching is stopped.
Then, after the valve member stops the displacement of the stopper member coming into contact with the cylinder body and approaching the pressurizing chamber, the valve body is brought into contact with the stopper member and is restricted from moving toward the pressurizing chamber.

Thereby, it can avoid that a valve body contact | abuts to the stopper member which is moving toward the pressurization chamber. Here, since the stopper member is loosely fitted in the recess, the moving stopper member may not be inclined and perpendicular to the axial direction of the valve body. For this reason, when the valve body comes into contact with the stopper member moving toward the pressurizing chamber, the drag force acting on the valve body from the stopper member includes a radial component force perpendicular to the axial direction of the valve body. Therefore, there is a possibility that smooth movement of the valve element may be hindered by this radial component force.
Therefore, by avoiding the valve body from coming into contact with the stopper member that is moving toward the pressurizing chamber, it is possible to reliably avoid the possibility of hindering the smooth movement of the valve body.

[Means of claim 5]
According to the fuel supply pump of claim 5, the communication passage opens into the valve chamber on the outer peripheral side of the outer peripheral edge of the valve body and on the inner peripheral side of the opening edge of the valve chamber, and opens the pressurizing chamber. It opens to the pressurizing chamber on the inner peripheral side of the edge.
Accordingly, the opening of the communication path is not blocked by the valve body, the cylinder body, and the valve body, so that the valve chamber and the pressurizing chamber can be reliably communicated with each other.

It is a whole block diagram of a fuel supply pump (Example). (A) is a principal part block diagram of a fuel supply pump, (b) is the elements on larger scale of (a) (Example). It is a top view of a stopper member (example). (A) is the elements on larger scale which show the state before a valve body starts a raise, (b) is the elements on larger scale which show the state by which the stopper member was latched by the valve body during the raise of a valve body. (C) is the elements on larger scale which show the state which the valve body contact | abutted to the seat surface and stopped the raise (Example). (A) is a time chart which shows a time-dependent change of the position of a valve body and a stopper member, (b) is a time chart which shows a time-dependent change of the fuel pressure of a valve chamber, (c) is a time-dependent change of the position of a plunger. (Example). (A) is a principal part block diagram of a fuel supply pump, (b) is the elements on larger scale of (a) (modification). (A) is a principal part block diagram of a fuel supply pump, (b) is the elements on larger scale of (a) (modification). (A) is a principal part block diagram of a fuel supply pump, (b) is the elements on larger scale of (a) (conventional example).

The fuel supply pump of the embodiment includes a valve body that forms a valve chamber that reciprocally accommodates a valve body, a cylinder body that accommodates a plunger that reciprocates in an axial direction, and forms a pressure chamber for fuel. The pressure chamber and the valve chamber are partitioned, and a stopper member that restricts the movement of the valve body toward the pressurizing chamber is provided. The stopper member has a communication path that connects the pressurizing chamber and the valve chamber, and is freely fitted in a recess provided in one or both of the valve body and the cylinder body, and is movable in the radial direction and the axial direction. is there. Further, the valve body and the cylinder body are in pressure contact with each other in the axial direction, so that the liquid tightness of the valve chamber and the pressurizing chamber is maintained.
Further, the valve body and the cylinder body are in pressure contact with each other in plane contact. Furthermore, the recess is provided only in the cylinder body.

  The fuel supply pump includes an actuator that drives the valve body, and the valve body is driven by the actuator to reciprocate in the valve chamber, thereby connecting the upstream fuel flow path connected to the pressurization chamber to the pressurization chamber. The volume of the pressurizing chamber is reduced by the displacement of the plunger toward one side in the axial direction, and is increased by the displacement of the plunger in the other side in the axial direction.

  Further, the valve body is driven in a direction away from the pressurizing chamber by the actuator when the plunger is displaced to one side in the axial direction to close the upstream fuel flow path with respect to the pressurizing chamber, When the fuel is discharged from the pressurizing chamber through the downstream fuel flow path connected to the pressurizing chamber and the plunger is displaced to the other side in the axial direction, the actuator is driven in the direction approaching the pressurizing chamber and the upstream side By opening the fuel flow path with respect to the pressurizing chamber, the fuel flows into the pressurizing chamber, and the movement toward the pressurizing chamber by being in contact with the stopper member is restricted.

Further, when the plunger is displaced to one side in the axial direction, the stopper member is displaced so as to move away from the pressurizing chamber by being urged by the fuel pressure of the pressurizing chamber, and comes into contact with the valve body to pressurize the pressurizing chamber. After stopping the displacement away from the plunger, the plunger turns in the displacement direction to the other side in the axial direction, and is displaced by the fuel pressure of the valve chamber so as to approach the pressurizing chamber, and comes into contact with the cylinder body and pressurizes the pressurizing chamber. The displacement approaching is stopped.
Then, after the valve member stops the displacement of the stopper member coming into contact with the cylinder body and approaching the pressurizing chamber, the valve body is brought into contact with the stopper member and is restricted from moving toward the pressurizing chamber.

  The communication passage opens to the valve chamber on the outer peripheral side of the outer periphery of the valve body and on the inner peripheral side of the opening edge of the valve chamber, and to the pressurizing chamber on the inner peripheral side of the opening edge of the pressurizing chamber. It is open.

[Configuration of Example]
The structure of the fuel supply pump 1 of an Example is demonstrated based on drawing.
The fuel supply pump 1 pressurizes and discharges fuel to be injected and supplied to a vehicle engine (not shown), for example.

The fuel supply pump 1 constitutes a part of an accumulator fuel injection device that injects fuel accumulated in a high pressure state in a predetermined accumulator vessel to the engine, and pressurizes the fuel pumped up from the fuel tank. And discharged into the pressure accumulating container (not shown).
The fuel injection device includes an electronic control device (not shown: hereinafter referred to as ECU) that controls the operation of each device, and the operation of the fuel supply pump 1 is also controlled by the ECU.

  As shown in FIGS. 1 and 2, the fuel supply pump 1 includes a pump element 5 having a plunger 2 and a cylinder body 3 to form a fuel pressurizing chamber 4, and an upstream side of the pressurizing chamber 4. A valve device 13 for intermittently flowing in and out of the fuel between the fuel flow paths 8 to 12 and the pressurizing chamber 4 and a plunger drive mechanism 14 for moving the plunger 2 up and down in the illustrated vertical direction (axial direction) are provided. Then, the ECU controls the operating state of the valve device 13 according to the vertical movement of the plunger 2, whereby the fuel pressure in the pressurizing chamber 4 is increased and decreased, and the fuel is discharged and sucked.

  The pump element 5 has a plunger 2 that moves up and down in the axial direction according to the rotation of the cam 16 and a cylinder body 3 that supports the plunger 2 so as to be slidable in the axial direction. That is, the cylinder body 3 has a cylinder hole 17 for supporting and accommodating the plunger 2 in the axial direction. The plunger 2 has a lower end protruding from the cylinder hole 17 and an upper end in the cylinder hole 17. It is supported to move up and down. The pressurizing chamber 4 is formed such that the upper portion of the cylinder hole 17 is partitioned by the upper end of the plunger 2, and the volume is reduced and expanded according to the vertical movement of the plunger 2.

  Moreover, the upper part of the cylinder body 3 is provided in a concave shape. A concave portion 20 in which a stopper member 19 to be described later is disposed is provided at the bottom of the concave portion, and an opening on the upper side of the cylinder hole 17 is formed in the concave portion 20 (that is, a pressurizing chamber). 4 is open in the recess 20). In addition, an annular fuel flow path 10 is formed between the upper portion of the recess 20 and the valve body 21 of the valve device 13. Further, a female screw that is screwed with a male screw of the valve device 13 is provided in a portion above the portion that forms the fuel flow path 10.

  Further, the cylinder body 3 is provided with a fuel flow path 9 connected to the annular fuel flow path 10, and a fuel flow path 24 connecting the screw hole of the valve holder 23 and the pressurizing chamber 4. The fuel flow path 24 is connected to the fuel flow path 25 in the valve holder 23. The fuel flow path 25 is provided with a check valve 26 having a predetermined valve opening pressure. The check valve 26 opens when the fuel pressure in the pressurizing chamber 4 exceeds the valve opening pressure. The fuel in the pressurizing chamber 4 is allowed to flow toward the pressure accumulating container.

  The valve device 13 is an electromagnetic valve device having a solenoid coil (not shown), and is screwed to the cylinder body 3. The valve device 13 includes a valve body 21 that forms the valve chamber 29 and a valve body 30 that is accommodated in the valve chamber 29 so as to be vertically movable in the axial direction. Here, the valve body 30 is integrated with the armature 32 via a sliding shaft portion 31 that is slidably supported by the valve body 21. The armature 32 and the valve body 30 are always urged downward by a predetermined urging means (not shown).

  That is, the valve body 30 of the valve device 13 is driven by an actuator including a solenoid coil (not shown), a biasing means (not shown), a stator (not shown), an armature 32, and the like, and reciprocates in the valve chamber 29.

  In other words, the valve body 30 moves upward in the valve chamber 29 by the armature 32 being magnetically attracted upward and moving toward the stator when the solenoid coil is energized. Further, the valve body 30 is urged by the urging means together with the armature 32 while the energization to the solenoid coil is stopped, and moves downward in the valve chamber 29. The valve body 30 is driven by an actuator to reciprocate in the valve chamber 29, thereby opening and closing the upstream fuel flow paths 8 to 12 connected to the pressurization chamber 4.

  Further, the valve body 21 forms a valve chamber 29 by a lower end portion, and the upper wall surface of the valve chamber 29 is tapered upward, and the valve body 30 is detached from the upper wall surface. A sheet surface 33 is formed. Then, a sliding hole 34 for supporting the sliding shaft portion 31 is opened at the uppermost portion of the seat surface 33. Note that the lower portion of the sliding shaft portion 31 has a reduced diameter, and an annular fuel flow path 12 is formed between the wall surface of the sliding hole 34. A fuel flow path 11 that connects the fuel flow paths 10 and 12 is provided so as to penetrate the valve body 21.

  Here, the downward movement of the valve body 30 is regulated by the stopper member 19. Further, the pressurizing chamber 4 and the valve chamber 29 are partitioned by the stopper member 19 and communicated by a communication path 35 provided in the stopper member 19. That is, the stopper member 19 divides the pressurizing chamber 4 and the valve chamber 29 and restricts the movement of the valve body 30 toward the pressurizing chamber 4, and the pressurizing chamber 4 and the valve chamber by the communication path 35. The movement of the fuel between 29 is permitted. In addition, the stopper member 19 is provided in disk shape, for example (refer FIG. 3).

  The plunger drive mechanism 14 includes a cam 16 that is rotationally driven by the engine, an intermediate mechanism 38 that is disposed between the cam 16 and the lower end of the plunger 2, and a lower end of the plunger 2 that is in contact with the intermediate mechanism 38. The cam 16, the intermediate mechanism 38, and the spring 39 are accommodated in the pump housing 40.

  Here, the intermediate mechanism 38 includes a tappet 42 that contacts the lower end of the plunger 2 and a roller 43 that contacts the cam 16 and rotates with the rotation of the cam 16. The tappet 42 is axially driven by the pump housing 40. The roller 43 is supported by the tappet 42 so as to be rotatable.

  The cylinder body 3 is mounted on the upper portion of the pump housing 40, and an annular fuel flow path 8 is formed between the pump housing 40 and the cylinder body 3. The fuel flow path 8 communicates with the fuel flow path 10 through the fuel flow path 9. Furthermore, an inlet pipe (not shown) is attached to the pump housing 40, and a fuel flow path (not shown) of the inlet pipe is connected to the fuel flow path 8.

[Features of Examples]
The features of the fuel supply pump 1 according to the embodiment will be described with reference to FIGS.
According to the fuel supply pump 1 of the embodiment, the stopper member 19 is loosely fitted in the recess 20. Further, the cylinder body 3 and the valve body 21 are in pressure contact with each other by a fastening axial force generated by screw fastening between the valve device 13 and the cylinder body 3, and the fluid tightness of the valve chamber 29 and the pressurizing chamber 4 is determined by the cylinder body. 3 and the valve body 21 are maintained by pressure contact.

  Here, the pressure contact portion on the valve body 21 side is a surface (hereinafter referred to as a valve chamber opening surface 45) where the valve chamber 29 opens, and the pressure contact portion on the cylinder body 3 side is a surface (hereinafter referred to as the recess 20). , Referred to as a concave opening surface 46). In addition, a surface on which the pressurizing chamber 4 opens (hereinafter referred to as a pressurizing chamber opening surface 47) is formed in the recess 20.

  The stopper member 19 is loosely fitted in the recess 20 so that gaps a and b are generated in both the axial direction and the radial direction, respectively, and increases or decreases the fuel pressure in the valve chamber 29 and the pressurizing chamber 4. It can be finely moved in the axial direction or radial direction by repetition or the like.

The axial gap a is the sum of the gap between the upper surface 49 of the stopper member 19 and the valve chamber opening surface 45 and the gap between the lower surface 50 of the stopper member 19 and the pressurizing chamber opening surface 47.
The radial gap b is, for example, the gap between the outer peripheral surface of the stopper member 19 and the inner peripheral surface of the recess 20 on the left side in the illustrated radial direction, and the outer peripheral surface of the stopper member 19 and the inner periphery of the concave portion 20 on the right side in the illustrated radial direction. It is the sum of the gaps with the surface.

  Here, the gap a is set so that the following operation is possible with respect to the stopper member 19 and the valve body 30. That is, after the fuel discharge from the pressurizing chamber 4 is finished, the gap member a is brought into contact with the pressurizing chamber opening surface 47 of the cylinder body 3 to stop the displacement, and then the valve body 30 of the stopper member 19 is stopped. It is set so that the displacement can be stopped by coming into contact with the upper surface 49 (Note that the operation of each member in the fuel discharge will be described later in [Operation of the embodiment]).

  Also, a plurality of communication paths 35 are provided, and the plurality of communication paths 35 are open on the upper and lower surfaces 49 and 50 so as to form a ring, respectively (see FIG. 3). A breather hole 51 is provided at the center of the ring formed by the plurality of communication passages 35 to guide fuel for separating the valve body 30 from the upper surface 49.

  The gaps b are all such that even if the stopper member 19 moves in the radial direction, the upper openings of all the communication passages 35 are not covered from above by the lower surface of the valve body 30 and the valve chamber opening face 45. The lower opening of the communication path 35 is set so as not to be covered from below by the pressurizing chamber opening surface 47. That is, the upper openings of all the communication passages 35 are opened on the outer peripheral side of the outer peripheral edge of the valve body 30 and on the inner peripheral side of the opening edge of the valve chamber 29, and the lower openings of all the communication passages 35. Is open on the inner peripheral side of the opening edge of the pressurizing chamber 4.

  The thickness of the stopper member 19 in the axial direction is set so that the variation in the air gap between the armature 32 and the stator (not shown) in the valve device 13 is within an allowable range. Here, the allowable range of variation in the air gap is determined according to the control response of the fuel supply pump 1.

(Effects of Example)
The operation of the fuel supply pump 1 of the embodiment will be described mainly with reference to FIGS. 4 and 5.
First, when the plunger 2 reaches the bottom dead center and starts to rise, the volume reduction of the pressurizing chamber 4 starts, and the fuel in the pressurizing chamber 4 tends to flow into the valve chamber 29 through the communication passage 35. Therefore, an upward biasing force due to the difference in fuel pressure between the valve chamber 29 and the pressurizing chamber 4 acts on the stopper member 19, and the stopper member 19 is pressed against the valve body 30.

  Since the valve body 30 is biased downward by the biasing means of the actuator, the stopper member 19 is not displaced even when the biasing force due to the fuel pressure difference acts upward, and the lower surface of the stopper member 19 50 maintains the state which contact | abutted to the pressurization chamber opening surface 47 (refer Fig.4 (a)). The fuel that has flowed into the valve chamber 29 from the pressurizing chamber 4 is returned to the upstream fuel flow paths 8 to 12 through a flow path formed between the valve body 30 and the seat surface 33.

  When the solenoid 2 is energized when the plunger 2 is raised and the armature 32 and the valve body 30 start to rise by magnetic attraction, the stopper member 19 is also pressed against the valve body 30 by the urging force caused by the fuel pressure difference. As a result, the valve body 30 rises together. Eventually, when the upper surface 49 of the stopper member 19 comes into contact with the valve chamber opening surface 45 (see FIG. 4 (b)), the stopper member 19 is locked by the valve chamber opening surface 45 and stops rising. Ascending away from the stopper member 19.

  The valve body 30 continues to rise until it is seated on the seat surface 33, and is seated on the seat surface 33, thereby closing the upstream fuel flow paths 8 to 12 with respect to the valve chamber 29 and the pressurizing chamber 4. (See FIG. 4 (c)). As a result, the outflow of fuel from the valve chamber 29 and the pressurizing chamber 4 to the upstream fuel flow paths 8 to 12 stops, so that the fuel pressure in the pressurizing chamber 4 and the valve chamber 29 is increased and the check valve 26 is increased. The valve opening pressure is exceeded. For this reason, the check valve 26 is opened, and the fuel whose pressure has been increased from the pressurizing chamber 4 is discharged through the fuel passages 24 and 25 on the downstream side.

  Thereafter, the energization of the solenoid coil is stopped, but the fuel pressure in the pressurizing chamber 4 and the valve chamber 29 is maintained in an increased state by continuing the ascent of the plunger 2, and the valve body 30 is strengthened by the fuel pressure in the valve chamber 29. The fuel passages 8 to 12 on the upstream side continue to be closed with respect to the valve chamber 29 and the pressurizing chamber 4. For this reason, the fuel discharge from the pressurizing chamber 4 to the downstream fuel flow paths 24 and 25 continues.

  Eventually, when the plunger 2 reaches the top dead center and starts to descend, the volume expansion of the pressurizing chamber 4 starts, and the fuel in the valve chamber 29 tends to flow into the pressurizing chamber 4 through the communication passage 35. For this reason, a downward biasing force due to the difference in fuel pressure between the valve chamber 29 and the pressurizing chamber 4 acts on the stopper member 19, and the stopper member 19 moves downward when the plunger 2 reaches the top dead center. At substantially the same time as turning, it begins to descend away from the valve chamber opening surface 45 (see FIGS. 5A and 5C).

  Further, as the plunger 2 is lowered, the fuel pressure in the pressurizing chamber 4 and the valve chamber 29 is reduced (see FIG. 5B). As a result, when the fuel pressure in the pressurizing chamber 4 becomes lower than the valve opening pressure of the check valve 26, the check valve 26 closes and the discharge of fuel from the pressurizing chamber 4 ends. Then, in the balance of the forces acting on the valve body 30 due to the reduction of the fuel pressure in the valve chamber 29, the urging force that urges the valve body 30 upward (the urging force due to the fuel pressure in the valve chamber 29) is the valve body 30. Becomes smaller than the urging force (the sum of the urging force by the urging means of the actuator and the urging force by the fuel pressure of the upstream fuel flow paths 8 to 12). .

Then, when the valve body 30 starts to descend, the upstream fuel flow paths 8 to 12 are opened to the valve chamber 29 and the pressurizing chamber 4, and the valve chamber 29 extends from the upstream fuel flow paths 8 to 12. Then, the fuel flows into the pressure chamber 4 and further flows into the pressurizing chamber 4 from the valve chamber 29 through the communication passage 35.
In FIG. 5B, the fuel pressure in the valve chamber 29 is such that the difference between the urging force that urges the valve body 30 upward and the urging force that urges the valve body 30 downward is zero. It is written as “zero”.

  Then, after the stopper member 19 contacts the pressurizing chamber opening surface 47 and stops descending, the valve body 30 contacts the upper surface 49 of the stopper member 19 and stops descending (see FIG. 5A). That is, the axial gap a is set so that the displacement can be stopped by the valve body 30 abutting against the upper surface 49 after the stopper member 19 abuts against the pressurizing chamber opening surface 47 to stop the displacement.

  The gap a enabling such an operation changes depending on the outer diameter of the stopper member 19, the number and the diameter of the communication passage 35, the axial movement distance of the valve body 30, and the like. The numerical value of the gap a is set in consideration of these items.

[Effects of Examples]
According to the fuel supply pump 1 of the embodiment, the stopper member 19 is loosely fitted in the recess 20 so as to form the gaps a and b in the axial direction and the radial direction, respectively. Further, the cylinder body 3 and the valve body 21 are in pressure contact with each other by a fastening axial force generated by screw fastening between the valve device 13 and the cylinder body 3, and the fluid tightness of the valve chamber 29 and the pressurizing chamber 4 is determined by the cylinder body. 3 and the valve body 21 are maintained by pressure contact.

  As a result, even if a radial slip occurs between the pressure contact portion of the valve body 21 and the pressure contact portion of the cylinder body 3 due to repeated increases and decreases in fuel pressure in the valve chamber 29 and the pressurization chamber 4, The slip amount is greatly reduced as compared with the case where the body 21 and the stopper member 19 are pressed against each other and the cylinder body 3 and the stopper member 19 are pressed against each other.

That is, the difference between the opening diameter of the valve chamber 29 and the opening diameter of the pressurizing chamber 4 is relative to the difference between the opening diameter of the valve chamber 29 and the opening diameter of the pressurizing chamber 4 and the flow path diameter of the communication passage 35. Significantly smaller. As a result, the amount of radial slip due to repeated increases and decreases in fuel pressure in the valve chamber 29 and the pressurizing chamber 4 is more likely to occur in the stopper member 19 when the valve body 21 and the cylinder body 3 are in pressure contact. It becomes smaller than the case where both the valve body 21 and the cylinder body 3 are press-contacted.
For this reason, in the fuel supply pump 1, it is possible to reduce fretting wear by reducing slippage between members caused by repeated increases and decreases in fuel pressure in the valve chamber 29, the pressurizing chamber 4, and the like.

Further, the valve body 21 and the cylinder body 3 are in pressure contact with the valve chamber opening surface 45 on the valve body 21 side and the recess opening surface 46 on the cylinder body 3 side in plane contact.
Thereby, since the press-contact area of the valve body 21 and the cylinder body 3 can be expanded, the elastic deformation by a fastening axial force can be suppressed and the amount of radial slip can be reduced.

Further, the recess 20 is provided only in the cylinder body 3.
Accordingly, the stopper member 19 and the valve body 21 can be attached to the cylinder body 3 only from above. For this reason, the number of manufacturing steps of the fuel supply pump 1 in which fretting wear is suppressed can be reduced, and the cost can be reduced.

  In addition, the axial gap a is set so that the valve element 30 stops after the stopper member 19 comes into contact with the pressurizing chamber opening surface 47 of the cylinder body 3 and stops displacement after the fuel discharge from the pressurizing chamber 4 ends. It is set so that the displacement can be stopped by contacting the upper surface 49 of the member 19.

  Thereby, it can avoid that the valve body 30 contact | abuts to the stopper member 19 in descending from the upper part. Here, since the stopper member 19 is loosely fitted in the recess 20, the lowering stopper member 19 may be inclined and not perpendicular to the axial direction of the valve body 30. For this reason, when the valve body 30 contacts the lowering stopper member 19, the drag force acting on the valve body 30 from the stopper member 19 includes a radial component force perpendicular to the axial direction of the valve body 30. There is a possibility that the smooth movement of the valve body 30 may be hindered by the component force in the radial direction.

That is, since the sliding shaft portion 31 is also urged in the radial direction by the component force in the radial direction, there is a possibility that sticking may occur between the outer peripheral surface of the sliding shaft portion 31 and the inner peripheral surface forming the sliding hole 34. There is a possibility that smooth movement of the valve body 30 may be hindered by this adhesion.
Therefore, by avoiding the valve body 30 from coming into contact with the stopper member 19 that is being lowered, there is a possibility that sticking may occur between the outer peripheral surface of the sliding shaft portion 31 and the inner peripheral surface that forms the sliding hole 34. While solving, the possibility of hindering the smooth movement of the valve body 30 can be reliably avoided.

All the communication passages 35 open to the valve chamber 29 on the outer peripheral side of the outer peripheral edge of the valve body 30 and on the inner peripheral side of the opening edge of the valve chamber 29, and more than the opening edge of the pressurizing chamber 4. It opens to the pressurizing chamber 4 on the inner peripheral side.
As a result, the upper and lower openings of the communication passage 35 are not blocked by the lower surface of the valve body 30, the pressurizing chamber opening surface 47 of the cylinder body 3, and the valve chamber opening surface 45 of the valve body 21. The valve chamber 29 and the pressurizing chamber 4 can reliably communicate with each other.

[Modification]
According to the fuel supply pump 1 of the embodiment, the recess 20 for accommodating the stopper member 19 is provided only in the cylinder body 3, but may be provided only in the valve body 21 (see FIG. 6). You may provide in both the body 3 and the valve body 21 (refer FIG. 7).

  When the recess 20 is provided only in the valve body 21, for example, the recess opening surface 46 is provided on the valve body 21 side, and the recess opening surface 46 on the valve body 21 side comes into pressure contact with the pressurizing chamber opening surface 47, And the liquid tightness of the pressurizing chamber 4 is maintained (see FIG. 6). When the recess 20 is provided in both the cylinder body 3 and the valve body 21, for example, the recess opening surfaces 46 are provided on both sides of the valve body 21 and the cylinder body 3, and the recess opening surface 46 on the valve body 21 side and the cylinder are provided. The concave opening surface 46 on the body 3 side is in pressure contact, and the liquid tightness of the valve chamber 29 and the pressurizing chamber 4 is maintained (see FIG. 7).

  Further, according to the fuel supply pump 1 of the embodiment, the pressure contact portion on the valve body 21 side and the pressure contact portion on the cylinder body 3 side are in surface contact and pressure contact, but the mode of pressure contact is not limited to surface contact. . For example, one pressure contact portion may be raised in a curved shape or the like and may be pressure contacted with the other pressure contact portion.

DESCRIPTION OF SYMBOLS 1 Fuel supply pump 2 Plunger 3 Cylinder body 4 Pressurization chamber 8-12 Fuel flow path (upstream fuel flow path)
19 Stopper member 20 Recess 21 Valve body 24, 25 Fuel flow path (downstream fuel flow path)
29 Valve chamber 30 Valve body 32 Armature (actuator)
35 communication path

Claims (5)

A valve body that forms a valve chamber for reciprocatingly accommodating the valve body;
A cylinder body that houses a plunger that reciprocates in the axial direction to form a pressurized chamber of fuel;
A partition member that partitions the pressurizing chamber and the valve chamber, and that restricts movement of the valve body toward the pressurizing chamber;
The stopper member has a communication passage that communicates the pressurizing chamber and the valve chamber, and is loosely fitted in a recess provided in one or both of the valve body and the cylinder body so as to extend in the radial direction and the axial direction. Is movable,
The fuel supply pump according to claim 1, wherein the valve body and the cylinder body are in pressure contact with each other in the axial direction so that liquid tightness of the valve chamber and the pressurizing chamber is maintained. The fuel supply pump according to claim 1, wherein
The fuel supply pump, wherein the valve body and the cylinder body are brought into pressure contact with each other in a plane. The fuel supply pump according to claim 1 or 2,
The fuel supply pump, wherein the recess is provided only in the cylinder body. The fuel supply pump according to any one of claims 1 to 3,
An actuator for driving the valve body;
The valve body is driven by the actuator to reciprocate in the valve chamber, thereby opening and closing the upstream fuel flow path connected to the pressurization chamber with respect to the pressurization chamber,
The volume of the pressurizing chamber is reduced by the displacement of the plunger in one axial direction, and is increased by the displacement of the plunger in the other axial direction,
The valve body is
When the plunger is displaced in one axial direction, the actuator is driven in a direction away from the pressurizing chamber to close the upstream fuel flow path with respect to the pressurizing chamber, Fuel is discharged from the pressurizing chamber through a downstream fuel passage connected to the pressurizing chamber,
When the plunger is displaced to the other side in the axial direction, the actuator is driven in a direction approaching the pressurizing chamber to open the upstream fuel flow path with respect to the pressurizing chamber. While allowing fuel to flow into the pressurizing chamber, the movement toward the pressurizing chamber in contact with the stopper member is restricted,
The stopper member is
When the plunger is displaced in one axial direction, the plunger is biased by the fuel pressure in the pressurizing chamber and displaced away from the pressurizing chamber, and comes into contact with the valve body from the pressurizing chamber. Stop moving away,
After the plunger has changed its displacement direction to the other side in the axial direction, the plunger is biased by the fuel pressure in the valve chamber and displaced so as to approach the pressurizing chamber, and comes into contact with the cylinder body and approaches the pressurizing chamber. Stop displacement,
The valve body is restricted from moving toward the pressurizing chamber by contacting the stopper member after stopping the displacement of the stopper member coming into contact with the cylinder body and approaching the pressurizing chamber. A fuel supply pump characterized. The fuel supply pump according to any one of claims 1 to 4,
The communication path opens to the valve chamber on the outer peripheral side of the outer periphery of the valve body and on the inner peripheral side of the opening edge of the valve chamber, and on the inner peripheral side of the opening edge of the pressurizing chamber. A fuel supply pump having an opening in a pressurizing chamber.

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