JP2017014920A - Solenoid valve and high pressure fuel supply pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low cost solenoid valve which can achieve both high responsiveness and high reliability of a movable part by making a collision part shape which can reduce a stress when the movable part tilts and collides, without lowering a magnetic attraction force, and to provide a high pressure fuel supply pump mounting the same.SOLUTION: A solenoid valve 30 includes a movable part which is driven by a magnetic force, and a stopper 35 with which the movable part collides. A movable part side curve surface part 34f is formed on an outer peripheral side on an opposing surface of the movable part which faces the stopper, and also, a stopper side curve surface part 35f which inclines in the same direction as the movable part side curve surface part is formed in the position corresponding to the movable part side curve surface part on the outer peripheral side on the opposing surface of the stopper which faces the movable part.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an electromagnetic valve that opens and closes a fluid flow path by moving a valve element using, for example, the magnetic force of an electromagnet (solenoid). For example, the present invention relates to a high-pressure fuel supply pump using the electromagnetic valve as an electromagnetic intake valve.

  In recent years, vigorous efforts have been made to reduce the size, output, and efficiency of internal combustion engines. In response, high-pressure fuel supply pumps are strongly required to reduce the size of the body to improve its mounting capability in internal combustion engines, and to increase the pressure of discharged fuel and improve the reliability of the mover in response to higher output and higher efficiency. ing. In particular, improving the reliability of the mover has become an indispensable issue in order to cope with the severer use environment.

  An example of a high-pressure fuel supply pump to which a solenoid valve is applied is shown in Patent Document 1, for example. This patent document 1 states that “when cavitation occurs in the plunger rod biasing spring inner space, the surface of the fixed core forming the inner space is prevented from being eroded by cavitation. The member of the plunger rod biasing spring seating portion is a hard cup-shaped member having a surface hardness higher than that of the fixed core, and is press-fitted and fixed to the fixed core ”(see summary).

  Since the magnetic material of the electromagnetic valve has a lower surface hardness than general structural steel, a structure in which a hard plating film or a protective member is provided on the surface is conceivable as a method for suppressing damage to the collision part. Patent Document 2 discloses a structure in which a hard plating film is provided on both the mover and the stopper of the solenoid valve of the fuel injection valve (see FIG. 3 of Patent Document 2). In Patent Document 3, the collision surface of the stopper is disclosed. The structure which provides a stopper disk is disclosed (refer FIG. 2 of patent document 3).

JP 2014-136966 A JP 2010-71123 A Japanese Patent No. 4499951

  However, in the structures of Patent Documents 2 and 3, since hard plating is performed on the collision surface or another protective member is provided on the collision surface, the number of parts and the number of processes increase, and the cost increases. In addition, if a hard plating film or a protective member that is inferior in magnetic properties compared to a magnetic material is provided between the mover and the stopper, the magnetic attractive force is reduced and the response of the mover is lowered. It is considered that the film or the protective member cannot be thicker than a certain thickness, and it becomes difficult to protect the underlying magnetic material when the operating environment of the mover becomes more severe.

  In view of the above problems, the present invention provides a low-cost solenoid valve that achieves both high responsiveness and high reliability of a mover without reducing the magnetic attractive force, and a high-pressure fuel supply pump equipped with the solenoid valve. With the goal.

  In a valve mechanism including a movable part that is attracted by an electromagnetic attraction force and a stopper that collides with the movable part, a movable part-side curved surface part is formed on the outer peripheral side of the opposed surface of the movable part that faces the stopper. At the same time, a stopper-side curved surface portion that is inclined in the same direction as the movable portion-side curved surface portion is formed at a position corresponding to the movable portion-side curved surface portion on the outer peripheral side of the facing surface of the stopper facing the movable portion.

  According to the present invention configured as described above, a low-cost solenoid valve that achieves both high responsiveness and high reliability of the mover without reducing the magnetic attractive force, and a high-pressure fuel supply pump equipped with the solenoid valve are provided. It is possible to provide.

  Other configurations, operations, and effects of the present invention will be described in detail in the following examples.

It is a figure which shows an example of sectional drawing of a solenoid valve collision part periphery. It is a system schematic diagram of the entire high-pressure fuel supply pump. It is sectional drawing which looked at the high pressure fuel supply pump from the front. It is explanatory drawing of the collision of the needle | mover of the solenoid valve of a high pressure fuel supply pump. It is detailed sectional drawing of the electromagnetic suction valve in 1st Example of this invention. It is a stress analysis result which shows the effect of the 1st Example of this invention. It is detailed sectional drawing of the electromagnetic suction valve in the modification of the 1st Example of this invention. It is detailed sectional drawing of the electromagnetic suction valve in the modification of the 1st Example of this invention. It is detailed sectional drawing of the electromagnetic suction valve in 2nd Example of this invention. It is detailed sectional drawing of the electromagnetic suction valve in the 3rd Example of this invention.

  The present invention relates to a valve mechanism that opens and closes a fluid flow path by moving a valve body using the magnetic force of an electromagnet (solenoid), for example. In this embodiment, a high-pressure fuel supply pump using this valve mechanism as an electromagnetic intake valve will be described as an example. In addition, the valve mechanism of the present invention can be used for a fuel injection valve (injector), or is not limited to an electromagnetic valve, and may be used for a relief valve of a high-pressure fuel supply pump.

  The first embodiment of the present invention will be described below with reference to FIGS.

  First, FIG. 1 shows a cross-sectional view of an electromagnetic valve in a high-pressure fuel supply pump as an example of a valve mechanism that opens and closes a fluid flow path by moving a valve body using the magnetic force of an electromagnet (solenoid). The high-pressure fuel supply pump has an electromagnet, a valve body, a mover and a stopper made of a magnetic material, a first spring and a second spring, and a rod part directly connected to the mover (the mover and the rod part are In order to make the same movement, it is described as a movable part). The first spring applies a force in the right direction in FIG. 1 and the second spring applies a force in the left direction in FIG. 1 to the valve body. The first spring is stronger in the first spring than the second spring. . When the electromagnet is not energized, the valve element is pressed in the valve opening direction via the rod portion by the spring force of the first spring, and the fuel flows from the suction passage toward the pressurizing chamber.

  When the electromagnet is strongly energized, the magnetic circuit shown in FIG. 1 is formed, and a magnetic attraction force in the same direction as the second spring force acts on the mover, and the mover and the rod portion resist the first spring. Therefore, the valve element is pressed in the valve closing direction (left direction in FIG. 1) by the spring force of the second spring. By controlling the operation of the mover in accordance with the operation cycle of the pump, the valve timing of the valve body is changed.

  Especially in the high-pressure fuel supply pump, since the flow rate through the valve section is large, the stroke of the mover is large, and since only a minimum guide part can be provided from the viewpoint of miniaturization and cost reduction, the mover is inclined. As shown in FIG. 1, the outer peripheral portion of the mover collides with the flat portion of the stopper at one side. A curved surface is formed on the outer periphery of the mover in order to suppress the occurrence of excessive stress in the collision part.

  Here, in addition to improving the strength of the collision part as shown in Patent Document 2 or 3 above, as a method for improving the reliability of the collision part, the corner part of the movable part is large as shown by the broken line in FIG. By setting the radius of curvature, there can be considered a method for preventing the generation of excessive stress even when a piece is hit. However, in this method, if a large R shape is provided, the magnetic attraction area of the movable portion is reduced, and the responsiveness of the mover is lowered. Therefore, it is difficult to ensure a sufficiently large R shape.

Therefore, in the present embodiment, the high response and high reliability of the mover are achieved by adopting a collision part shape that can reduce the stress when the mover tilts and collides without reducing the magnetic attractive force. An object of the present invention is to provide a low-cost solenoid valve and a high-pressure fuel supply pump equipped with the solenoid valve.
First, the configuration and operation of the system will be described with reference to the overall schematic diagram of FIG. FIG. 2 is a diagram schematically showing the overall configuration of the high-pressure fuel supply pump.

  A portion surrounded by a broken line indicates a high-pressure fuel supply pump main body, and a mechanism and components shown in the broken line indicate that the high-pressure fuel supply pump main body 1 is integrally incorporated. The fuel in the fuel tank 20 is pumped up by the feed pump 21 and sent to the suction joint 10 a of the pump body 1 through the suction pipe 28. The fuel that has passed through the suction joint 10a reaches the suction port 30a of the electromagnetic suction valve 30 that constitutes the variable capacity mechanism via the pressure pulsation reducing mechanism 9 and the suction passage 10b.

  The electromagnetic suction valve 30 includes an electromagnetic coil 30b. When the electromagnetic coil 30b is not energized, the movable element 34 moves to the right in FIG. 2 and the spring 33 is not compressed. A suction valve body 31 attached to the tip of the mover 34 opens a suction port 32 connected to the pressurizing chamber 11 of the high-pressure pump. Due to the biasing force of the spring 33, the suction valve body 31 is biased in the valve opening direction, and the suction port 32 is open.

  Specifically, it operates as follows.

  When the plunger 2 is displaced downward in FIG. 2 due to the rotation of the cam 5 to be described later and is in the suction process state, the volume of the pressurizing chamber 11 increases and the fuel pressure in the pressurizing chamber 11 decreases. In this step, the fuel pressure in the pressurizing chamber 11 becomes lower than the pressure in the suction passage 10b (suction port 30a), and fuel flows from the suction port 30a through the suction port 32 into the pressurization chamber 11.

When the plunger 2 finishes the suction process and moves to the compression process (a state of moving upward in FIG. 2),
The suction valve body 31 remains open. 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 passes through the suction valve body 31 in the valve opening state again, and the suction passage 10 b (suction). Since the pressure is returned to the port 30a), 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 engine control unit 27 (hereinafter referred to as ECU) is applied to the electromagnetic intake valve 30, a current flows through the electromagnetic coil 30b of the electromagnetic intake valve 30, and the mover 34 is caused by the magnetic attractive force. Moves to the left in FIG. 2 and the spring 33 is compressed. As a result, the suction valve body 31 also moves to the left in FIG. 2 and the suction port 32 is closed.

When the suction port 32 is closed, the fuel pressure in the pressurizing chamber 11 increases with the upward movement of the plunger 2 from this time. When the pressure exceeds the pressure of the fuel discharge port 12, high pressure discharge of the fuel remaining in the pressurizing chamber 11 is performed via the discharge valve mechanism 8 and supplied to the common rail 23. This process is called a discharge process. That is, the compression process of the plunger 2 (the ascending process from the bottom dead center to the top dead center) includes a return process and a discharge process. In this state, when the control signal from the ECU 27 is canceled and the electromagnetic coil 30b is de-energized, the magnetic attraction force acting on the mover 34 is after a certain time (after magnetic and mechanical delay time). Erased. Since the urging force of the spring 33 is acting on the mover 34, it tries to move to the right in FIG. However, during the compression stroke of the plunger 2, the pressure in the pressurizing chamber 11 is high, and the suction valve body 31 is maintained in the closed state by the pressure. Therefore, even after the control signal from the ECU 27 is released, the mover 34 is maintained in the state of moving to the left in FIG. 2 during the compression stroke of the plunger 2.
When the compression stroke of the plunger 2 is completed and the suction stroke is started again, the pressure in the pressurizing chamber 11 decreases, the suction valve body 31 moves to the right in FIG. 2, and the suction port 32 is opened. Accordingly, the mover 34 also moves to the right in FIG.

  By controlling the timing of starting energization of the electromagnetic coil 30b of the electromagnetic intake valve 30, the amount of high-pressure fuel discharged can be controlled. If the timing of starting energization to the electromagnetic coil 30b is advanced, the ratio of the return process in the compression process is small and the ratio of the discharge process is large. That is, the amount of fuel returned to the suction passage 10b (suction port 30a) is small, and the amount of fuel discharged at high pressure is large. On the other hand, if the timing of starting the input voltage is delayed, the ratio of the return process in the compression process is large and the ratio of the discharge process is small. That is, the amount of fuel returned to the suction passage 10b is large, and the amount of fuel discharged at high pressure is small. The timing at which the electromagnetic coil 30b is de-energized is controlled by a command from the ECU.

By configuring as described above, the amount of fuel discharged at high pressure can be controlled to the amount required by the internal combustion engine by controlling the timing at which the energization of the electromagnetic coil 30b is released.

  A discharge valve mechanism 8 is provided at the outlet of the pressurizing chamber 11. The discharge valve mechanism 8 includes a discharge valve seat 8a, a discharge valve 8b, and a discharge valve spring 8c. When there is no fuel differential pressure in the pressurizing chamber 11 and the fuel discharge port 12, the discharge valve 8b is biased by the discharge valve spring 8c. Is pressed against the discharge valve seat 8a and is in a closed state. Only when the fuel pressure in the pressurizing chamber 11 becomes higher than the fuel pressure in the fuel discharge port 12, the discharge valve 8 b opens against the discharge valve spring 8 c, and the fuel in the pressurization chamber 11 is discharged from the fuel discharge port. 12 is discharged to the common rail 23 through a high pressure.

  Thus, the fuel guided to the fuel inlet 10a is pressurized to a high pressure by the reciprocating motion of the plunger 2 in the pressurizing chamber 11 of the pump body 1, and is pumped from the fuel outlet 12 to the common rail 23.

  An injector 24 and a pressure sensor 26 are attached to the common rail 23. The injectors 24 are mounted in accordance with the number of cylinders of the internal combustion engine, and are opened and closed according to a control signal from an engine control unit (ECU) 27 to inject fuel into the cylinders.

  The pump body 1 is further provided with a relief passage 100A that communicates the downstream side of the discharge valve 8b and the pressurizing chamber 11, bypassing the discharge valve, separately from the discharge flow path. The relief passage 100A is provided with a relief valve 102 that restricts the flow of fuel in only one direction from the discharge passage to the pressurizing chamber 11. The relief valve 102 is pressed against the relief valve seat 101 by a relief spring 104 that generates a pressing force. When the pressure difference between the pressurizing chamber and the relief passage exceeds a specified pressure, the relief valve 102 is The valve is set to be opened away from the seat 101.

  When an abnormally high pressure is generated in the common rail 23 or the like due to a failure of the injector 24 or the like, when the differential pressure between the relief passage 100A and the pressurizing chamber 11 becomes equal to or higher than the opening pressure of the relief valve 102, the relief valve 102 opens and the abnormally high pressure is generated. The fuel thus obtained is returned from the relief passage 100A to the pressurizing chamber 11, and the high-pressure section piping such as the common rail 23 is protected.

  Hereinafter, the configuration and operation of the high-pressure fuel pump will be described in more detail with reference to FIG. FIG. 3 is a cross-sectional view seen from the front of the high-pressure fuel supply pump.

  A pressurizing chamber 11 is formed at the center of the pump body, and an electromagnetic suction valve 30 for supplying fuel to the pressurizing chamber 11 and a discharge valve mechanism for discharging fuel from the pressurizing chamber 11 to the discharge passage. Is provided.

  A cylinder 6 that guides the forward and backward movement of the plunger 2 is attached so as to face the pressurizing chamber 11. The outer periphery of the cylinder 6 is held by a cylinder holder 7 and is fixed to the pump body 1. The cylinder 6 holds the plunger 2 that moves forward and backward in the pressurizing chamber so as to be slidable along the forward and backward movement direction.

  The lower end of the plunger 2 is provided with a tappet 3 that converts the rotational motion of the cam 5 attached to the camshaft of the engine into a vertical motion and transmits it to the plunger 2. Thereby, the plunger 2 can be moved back and forth (reciprocated) up and down with the rotational movement of the cam 5. The damper cover 14 is provided with a pressure pulsation reduction mechanism 9 that reduces the pressure pulsation generated in the pump from spreading to the fuel pipe 28.

  The fuel that has passed through the pressure pulsation reducing mechanism 9 flows into the pressurizing chamber 11 through the suction port 32 in the order of the suction passage 10b and the suction port 30a. As described above, the electromagnetic suction valve 30 includes the electromagnetic coil 30b. When the electromagnetic coil 30b is not energized, the spring 33 is compressed while the mover 34 made of a magnetic material moves to the right in FIG. It is a state that has not been done. A suction valve body 31 attached to the tip of a rod portion 34a directly connected to the mover 34 opens a suction port 32 connected to the pressurizing chamber 11 of the high-pressure pump. Due to the biasing force of the spring 33, the suction valve body 31 is biased in the valve opening direction, and the suction port 32 is open.

  When a control signal is applied to the electromagnetic intake valve 30 during the compression period of the plunger 2, a current flows through the electromagnetic coil 30b of the electromagnetic intake valve 30, and the mover 34 moves to the left in FIG. 33 is compressed. At this time, the mover 34 moves to a stopper 35 made of a magnetic material. When the mover 34 moves, the rod portion 34 a also moves to the left in FIG. 3, so that the urging force of the spring 33 does not act on the suction valve body 31, and the suction valve body 31 is urged by the urging force of the spring 37. Move to the left of When the suction port 32 is open, the distance between the movable element 34 and the stopper 35 is longer than the distance between the suction valve body 31 and the suction port 32. For this reason, the urging force from the spring 33 does not act on the suction valve body 31 even after the suction valve body 31 comes into contact with the suction port 32 by the urging force of the spring 36 by the movable element 34 being sucked by the stopper 35. The state where the suction port 32 is closed is maintained. When the control signal from the ECU 27 is canceled and the electromagnetic coil 30b is de-energized, the magnetic attractive force acting on the mover 34 is erased after a certain time (after the magnetic and mechanical delay time). Since the urging force of the spring 33 is acting on the mover 34, it tries to move to the right in FIG. However, during the compression stroke of the plunger 2, the pressure in the pressurizing chamber 11 is high, and the suction valve body 31 is maintained in the closed state by the pressure. Therefore, even after the control signal from the ECU 27 is released, the mover 34 is maintained in the state of moving to the left in FIG. 3 during the compression stroke of the plunger 2. When the compression stroke of the plunger 2 is completed and the suction stroke is started again, the pressure in the pressurizing chamber 11 decreases, the suction valve body 31 moves to the right in FIG. 3, and the suction port 32 is opened. Accordingly, the mover 34 moves to the right in FIG.

Hereinafter, a mechanism in which the movable element 34 comes into contact with the stopper 35 will be described with reference to FIG. In FIG. 4, the clearance is exaggerated for easy understanding of the mechanism, so members not used in the description, such as the spring 33, are not shown. In order to allow the movable parts (the movable element 34 and the rod part 34a) to move leftward in FIG. 4, a clearance is provided between the guide part 38 and the rod part 34a. [Phi ₁ the diameter of the rod portion 34a, the diameter of the hole of the guide portion 38 when the [Phi _2, clearance is given by Φ ₂ -Φ _1. When the magnetic coil 30b is energized to form a magnetic circuit, the mover 34 receives not only the stopper 35 but also the magnetic force in the upward or downward direction of FIG. 4 from the electromagnetic coil 30b. Since the bias of the magnetic force from the two electromagnetic coils 30b on the side surface of the mover 34 is not strictly zero, the mover 34 is slightly pulled in the direction in which the magnetic force is strong. When approaching the direction in which the magnetic force is strong, the bias of the magnetic force from the two electromagnetic coils 30b further increases. By repeating this, as shown in FIG. 4, the movable element 34 continues to move in one direction until the rod portion 34 a is supported by the guide portion 38, and an inclination occurs with respect to the stopper 35. When the length of the guide portion 38 is L, the inclination angle θ is approximately given by tan θ = (Φ ₂ −Φ ₁ ) / L. Therefore, in order to reduce the tilt angle θ to weaken the one-side contact and reduce the stress at the time of collision, it is effective to reduce the clearance Φ ₂ −Φ ₁ or increase the length L of the guide portion 38. is there. However, in order to reduce the clearance, it is necessary to increase the dimensional accuracy, resulting in an increase in cost, and increasing the length of the guide portion causes an increase in the size of the solenoid valve. It is difficult to reduce the angle θ.

  The first embodiment of the present invention will be described below with reference to FIG. A magnetic circuit is formed by energizing the electromagnetic coil 30b, the movable element 34 is attracted to the stopper 35, and the operating principle of moving the suction valve body 31 in the valve closing direction and the movable element 34 is stopped by the stopper 35 in the event of a collision. Since it is as described above to incline with respect to the outer peripheral side of the mover 34, the details are omitted.

  FIG. 5A shows an enlarged view of the vicinity of the mover when the valve is opened. The mover 34 is formed with a central side surface 34b and an outer peripheral side surface 34c close to the central axis of the electromagnetic valve 30 passing through the center of the hole of the guide portion 38. A flat portion 34d serving as a magnetic attraction surface is formed on the facing surface of the mover 34 facing the stopper, and a curved surface portion 34f is formed on the outer peripheral side. A connection portion between the flat portion 34d and the curved surface portion 34f is defined as an inclination start portion 34e. A flat portion 35d serving as a magnetic attraction surface is formed on the facing surface of the stopper 35 facing the mover 34, and a curved surface portion 35f is formed on the outer peripheral side. A connection portion between the flat portion 35d and the curved surface portion 35f is defined as an inclination start portion 35e. Here, the curved surface portion 35f on the stopper side is formed at a position corresponding to the curved surface portion 34f on the mover side, and is inclined in the same direction as the curved surface portion 34f on the mover side.

  FIG. 5B shows an enlarged view of the vicinity of the collision portion when the valve is closed. The mover 34 is inclined with respect to the stopper 35 and comes into contact with the curved surface portion 34f on the outer peripheral side. In the present embodiment, a stopper-side curved surface portion 35f is provided at a position corresponding to the movable member-side curved surface portion 34f, and the inclination direction of the stopper-side curved surface portion 35f is the same as that of the movable element-side curved surface portion 34f. Since the directions are the same, the collision surface is a combination of a convex curved surface and a concave curved surface. On the other hand, as shown in FIG. 1, in the conventional solenoid valve, since the flat portion of the stopper and the curved surface portion of the mover collide, the collision surface is a combination of a convex curved surface and a flat surface. Therefore, compared with the conventional solenoid valve, this embodiment can increase the contact area of the collision portion and disperse the collision force. Therefore, the stress of the collision portion can be increased without changing the shape of the mover 34. Can be reduced. Further, in the present embodiment, the outer peripheral curved surface 35f of the stopper 35 is inclined in the same direction as the curved surface portion 34f of the movable element 34, so that the gap between the movable element 34 and the stopper 35 is made small in the entire facing surface. This makes it possible to suppress the magnetic attraction force from decreasing, and the responsiveness of the movable element 34 is ensured.

  Next, conditions that the curved surface portions 34f and 35f in this embodiment should satisfy will be described.

  In FIG. 5, the mover 34 cannot be sized larger than a certain size in order to avoid sliding with the outer peripheral side surface 39. Since it is necessary to enlarge the stopper 35 in order to secure the magnetic attractive force, the diameter of the outer peripheral surface 35c of the stopper 35 is larger than the diameter of the outer peripheral surface 34c of the mover 34 as shown in FIG. It is getting bigger. Further, as shown in FIG. 5B, the mover 34 is inclined with respect to the stopper 35 and collides on the outer peripheral side. Therefore, in this embodiment, the curved surface portion 34f of the mover 34 and the curved surface portion 35f of the stopper 35 are caused to collide, and therefore, as shown in FIG. It forms so that it may incline in the direction from the stopper 35 to the needle | mover 34 toward the outer peripheral side 34c, and the curved-surface part 35f of the stopper 35 is also from the stopper 35 to the needle | mover 34 toward the outer peripheral side 35c from the center side 35b. The curvature radius in the vicinity of the collision portion of the curved surface portion 34f of the movable element 34 is set to be smaller than the curvature radius in the vicinity of the collision portion of the curved surface portion 35f of the stopper 35.

  As a modification of FIG. 5, it is conceivable to make the diameter of the outer peripheral surface 35 c of the stopper 35 smaller than the diameter of the outer peripheral surface 34 c of the mover 34. In this case, the curved surface portion 34f on the mover side is formed so as to incline in the direction from the movable member 34 to the stopper 35 from the central side 34b toward the outer peripheral side 34c, and the curved surface portion 35f of the stopper 35 is also formed in the center. It is formed so as to incline in the direction from the mover 34 to the stopper 35 from the side 35b toward the outer peripheral side 35c, and the radius of curvature in the vicinity of the collision portion of the curved surface portion 34f of the movable member 34 is set to the collision of the curved surface portion 35f of the stopper 35. If the radius of curvature is larger than the radius of curvature in the vicinity of the portion, the curved surface portion 34f of the mover 34 and the curved surface portion 35f of the stopper 35 collide with each other, and the stress can be reduced. However, in this case, since the magnetic attractive force is lower than that in the first embodiment shown in FIG. 5, the outer peripheral side end portion 35 c of the opposing surface of the stopper 35 is the outer periphery of the opposing surface of the mover 34 as shown in FIG. 5. It is desirable that the stopper 35 and the mover 34 are arranged so as to be positioned on the outer peripheral side with respect to the side end portion 34c.

  The movable element 34 and the rod part 34 a can rotate around the central axis of the electromagnetic valve 30 passing through the center of the hole of the guide part 38, and the collision part extends over the entire circumference of the opposing surface of the movable element 34 and the stopper 35. Therefore, the curved surface portion 35f of the stopper 35 is formed over the entire outer peripheral portion of the surface facing the mover 34, and the curved surface portion 34f of the movable member 34 is the entire outer periphery of the surface facing the stopper 35. It is desirable to form over.

  From the viewpoint of controllability of the solenoid valve, it is necessary to increase the magnetic attraction force of the mover 34 to improve the response, and at the same time, make the stroke amount of the mover 34 constant. In order to improve the magnetic attractive force, the distance between the movable element 34 and the stopper 35 (x in FIG. 5A) needs to be short throughout the opposing surface while the movable element 34 is moving. As shown in FIG. 3, a flat surface portion 34d is formed on the inner peripheral side of the tilt start portion 34e of the mover 34 up to the inner peripheral side surface 34b, and on the inner peripheral side of the tilt start portion 35e of the stopper 35, It is desirable that a flat portion is formed up to the inner peripheral side surface 35b (however, as shown in FIG. 5A, chamfering is performed at the connecting portion from the flat portion 34d or 35d to the inner peripheral side surface 34b or 35b. To create R part for the purpose of By providing such a flat portion 34d or 35d, the stroke (x + y in FIG. 5A) is also stabilized.

The effect of this example was verified by stress analysis. As an example, in FIG. 6A, the curvature radius R _s of the curved surface portion 35f of the stopper 35 is (4/3) R _m with respect to the curvature radius R _m of the curved surface portion 34f of the mover 34. The collision stress of the structure and the collision stress in the conventional structure (the collision surface of the stopper 35 is flat) are shown. The impact stress is normalized by the impact stress of the conventional structure. From FIG. 6A, it can be confirmed that the collision stress can be reduced to about 50% of the conventional structure in this embodiment. The present inventors have found by collision analysis that the stress at the collision part has a stress distribution similar to Hertz line contact. According to Hertz's line contact theory, it is known that when the effective curvature radius of the contact surface is R _eff and the load is constant, the contact stress is (1 / R _eff ) ^1/2 . In the case of the present embodiment, the effective radius of curvature is 1 / R _eff = 1 / R _m −1 / R _s . Therefore, assuming that the impact force is constant, the collision stress of the conventional structure in which the collision surface of the stopper 35 is flat is proportional to (1 / R _m ) ^1/2 , and in this embodiment is proportional to (1 / R _eff ) ^1/2 . To do. In the example of FIG. _6A , since R _eff = 4R _m , it can be understood that the structure of this example is (1/4) ^1/2 = 0.5 compared to the conventional structure.

FIG. 6B shows a change in stress at the collision portion when the curvature radius R _s of the curved surface portion 35f is changed while keeping the curvature radius R _m of the curved surface portion 34f of the mover 34 constant. The horizontal axis of the bottom of the graph is the ratio R _{m /} R _s of the radius of curvature R _m and the radius of curvature R _s, the horizontal axis of the graph is the actual value of the curvature radius R _s. The impact stress is normalized by the impact stress of the conventional structure (impact radius of curvature of impact portion is R _m ). FIG. 6B also shows the collision stress of the conventional structure having the radius of curvature of the collision surface equal to R _{s in} this example. 6B, when the curvature radius R _{m of} the curved surface portion 34f and the curvature radius R _s of the curved surface portion 35f are 2R _m , the curvature radius of the curved surface portion 34f is 2R _m and the collision surface is flat in the conventional structure. It can be seen that the effect is not different from that of the case. This can be understood from the fact that a solution satisfying (1 / R _m ) ^1/2 = (1 / R _eff ) ^1/2 is R _s = 2R _m .

From the above results, when the curvature radius R _s of the curved surface portion 35f of the stopper 35 is 2R _m or more and the difference between the curvature radii of the stopper 35 and the mover 34 is large, the contact surface cannot be made sufficiently large. When the radius of curvature is increased, the stress and cost are superior (however, the magnetic attractive force is reduced). Therefore, it is desirable that the radius of curvature of the curved surface portion 35f on the stopper side in this embodiment be R _m <R _s <2R _m .

Thus, by appropriately selecting the radius of curvature R _s of the stopper 35 in this embodiment, the curvature radius R _s of the curvature radius R _m and the stopper 35 of the movable element 34, while each suppressed, significant stress Reduction is possible. As a result, the material of the mover 34 and the stopper 35 can be made unnecessary for the hard plating treatment of the collision surface (plating-less) while using magnetic stainless steel having a surface hardness of about Hv200 as in the conventional structure. From the above, according to the first embodiment of the present invention, since the collision stress of the movable element 34 can be greatly reduced, a hard plating process or the like on the collision surface is not required, and a low-cost and highly reliable solenoid valve is provided. Can be provided.

  The present embodiment is not limited to the structure in which the collision occurs at the outermost peripheral portion of the mover 34 as shown in FIG. 5. For example, the structure in which the collision occurs at the inner peripheral side of the mover 34 as shown in FIG. 7. For example, the present invention can also be applied to an injector movable element having a small inclination of the movable element. It is also possible to provide a curved surface portion on each of the inner peripheral side and the outer peripheral side of the mover 34 and provide a curved surface portion on the stopper accordingly. In this case, the tilt angle is not constant, and the collision stress can be reduced even in a structure in which a collision occurs on the outer peripheral side or the inner peripheral side.

  In addition, the present embodiment is not limited to the collision between the magnetic material movable element 34 and the stopper 35 as shown in FIG. 5. For example, as shown in FIG. 8, the movable part (provided on the rod part 34 a). Of course, the present invention can also be applied to a structure in which the non-magnetic flange 39) occurs on the stopper surface 38a of the guide portion facing the flange 39.

  As described above, in this embodiment, the curved surface portion is formed on the outer peripheral side of the movable portion serving as the collision portion, and the outer peripheral side of the opposing surface of the stopper facing the movable portion also corresponds to the movable portion-side curved surface portion. By forming a stopper-side curved surface portion that is inclined in the same direction as the movable portion-side curved surface portion at the position, the collision surface becomes a combination of a convex curved surface and a concave curved surface, so that the contact area increases and the collision force is dispersed. Therefore, the stress at the collision portion is reduced.

  Also, by appropriately combining the curvature radii of the movable part and the curved surface part of the stopper, it is possible to reduce the stress by increasing the effective curvature radius of the collision surface while keeping the respective R shapes small. The response of the movable part can be ensured by suppressing the reduction of the suction area. Further, by reducing the collision stress, it becomes possible to cause the magnetic materials to collide with each other without any special surface treatment or protective material, so that the cost can be reduced.

  In general, by using the configuration of the present embodiment, it is possible to realize a low-cost solenoid valve that achieves both high responsiveness and high reliability of the mover and a high-pressure fuel supply pump equipped with the solenoid valve.

  FIG. 9 shows a second embodiment of the present invention. The difference from the first embodiment is that the inclination start portion 34e of the curved surface portion 34f of the mover 34 is located on the outer peripheral side with respect to the inclination start portion 35e of the curved surface portion 35f of the stopper 35. Since the operation principle of the solenoid valve is the same as that of the first embodiment, the details are omitted.

  As shown in FIG. 4, in the electromagnetic valve of the high-pressure fuel supply pump, the mover 34 is attracted to the electromagnetic coil 30b on one side and collides with the stopper 35 while tilting. Therefore, as shown in FIG. 9, when the mover 34 is attracted by the stopper 35, the curved surface portion 34 f rotates and moves closer to the center of the electromagnetic valve than when the valve is opened. Therefore, by arranging the inclination start portion 34e of the curved surface portion 34f of the movable element 34 on the outer peripheral side with respect to the inclination start portion 35e of the curved surface portion 35f of the stopper 35, the movable element 34 is inclined during movement, and the curved surface portion 34f. Even after the rotational movement, the curved surface portion 34f of the mover 34 can reliably collide with the curved surface portion 35f of the stopper 35. Therefore, according to the second embodiment of the present invention, even when the movable element 34 is inclined, the curved portion of the stopper 35 can be surely made to reduce the collision stress of the movable element 34, so that the guide portion 38 can be minimized. A small and highly reliable solenoid valve can be provided.

  FIG. 10 shows a third embodiment of the present invention. In this embodiment, the movable element 34 and the rod portion 34a are separated. A relay member 40 is fixed to the mover 34 by integral molding or press-fitting. By hooking the rod flange 34g with the hook portion 40a of the relay member 40, when the electromagnetic coil is energized and the mover 34 moves to the left side of FIG. 10, the rod portion also moves to the left. At the time of the collision between the mover 34 and the stopper 35, the rod portion 34a continues to move to the left in the drawing due to inertia. Therefore, since the momentum of the movable part is reduced by the amount that the rod part does not contribute to the collision, the collision noise can be reduced.

  In this structure, in addition to the clearance between the rod part 34a and the guide part 38, there is also a clearance between the guide part 40b of the relay member 40 and the rod part 36, so that the movable element 34 and the rod part 38 are integrated. Thus, since the tilt angle of the rotor 34 is increased, the collision stress at the time of the contact increases in the case of the conventional structure. On the other hand, in the present embodiment, since the collision surface is a combination of the curved surface portion 34f and the curved surface portion 35f, even when the inclination angle is large, the change in the contact area is small, so that an increase in stress can be suppressed. . Therefore, according to the third embodiment of the present invention, it is possible to provide an electromagnetic valve with low impact noise and high reliability of the mover 34.

  When the relay member 40 is made of the same material as that of the mover 34, the mover 34 and the relay member 40 can be formed at a time, thereby reducing the manufacturing cost. On the other hand, when the relay member 40 is made of a material different from that of the mover 34, by using a steel material having higher strength than the mover 34 for the relay member 40, sliding between the guide part 40b of the relay member and the rod part 34a is performed. The strength against wear and collision between the flange 34g of the relay member and the rod portion 34a can be improved. When the relay member 40 and the mover 34 are formed of the same material, it is desirable to use magnetic stainless steel of Hv350 or higher in order to prevent wear due to sliding between the guide portion 40b and the rod portion 34a of the relay member.

  When the mover 34 and the stopper 35 collide, the rod portion 34a continues to move due to inertia, but eventually returns to the right in FIG. 10 by the urging force of the spring 33, so that the electromagnetic coil is energized. If the mover 34 is continuously attracted to the stopper 35, the hook portion 40a of the relay member 40 and the flange 34g of the rod portion 34a collide. Of course, the present invention can be applied to the flange 34g of the rod portion 34a and the relay member 40. It is also possible to improve the reliability with respect to the collision by applying to the collision surface of the hook portion 40a.

DESCRIPTION OF SYMBOLS 1 High pressure fuel supply pump body 2 Plunger 3 Tappet 11 Pressurization chamber 12 Fuel discharge port 8 Discharge valve mechanism 23 Common rail 20 Fuel rank 21 Feed pump 28 Suction piping 10a Suction joint 9 Pressure pulsation reduction mechanism 10b Suction passage 30 Electromagnetic suction valve 102 Relief Valve 30a Suction port 30b Electromagnetic coil 31 Suction valve body 32 Suction port 33 Spring 34 Movable element 34a Rod part 35 Stopper

Claims (12)

A movable part that is attracted by electromagnetic attraction force;
In a solenoid valve comprising a stopper with which the movable part collides,
While the movable portion side curved surface portion is formed on the outer peripheral side of the facing surface of the movable portion facing the stopper,
A stopper-side curved surface portion that is inclined in the same direction as the movable portion-side curved surface portion is formed at a position corresponding to the movable portion-side curved surface portion on the outer peripheral side of the opposing surface of the stopper facing the movable portion. Solenoid valve. The solenoid valve according to claim 1,
The movable part-side curved surface part is formed so as to incline in a direction from the stopper toward the movable part toward the outer peripheral side. The solenoid valve according to claim 1,
The stopper-side curved surface portion is formed so as to be inclined toward the outer peripheral side in the direction from the stopper to the movable portion. The solenoid valve according to claim 1,
The electromagnetic valve according to claim 1, wherein a radius of curvature of the movable portion side curved surface portion is smaller than a radius of curvature of the stopper side curved surface portion and is larger than ½ of a radius of curvature of the stopper side curved surface portion. The solenoid valve according to claim 1,
The electromagnetic valve according to claim 1, wherein an inclination start portion of the movable portion side curved surface portion is located on an outer peripheral side with respect to an inclination start portion of the stopper side curved surface portion. The solenoid valve according to claim 1,
The movable part is a solenoid valve characterized in that a flat part is formed on the inner peripheral side of the inclination start part of the movable part side curved surface part. The solenoid valve according to claim 1,
The electromagnetic valve according to claim 1, wherein the stopper is formed with a flat portion on an inner peripheral side with respect to an inclination start portion of the stopper-side curved surface portion. The solenoid valve according to claim 1,
The stopper-side curved surface portion is formed over the entire outer peripheral portion of the opposing surface of the stopper, and the movable portion-side curved surface portion is formed over the entire outer peripheral portion of the opposing surface of the movable portion. A solenoid valve. The solenoid valve according to claim 1,
The solenoid valve, wherein the stopper and the movable portion are arranged so that an outer peripheral end portion of the opposing surface of the stopper is positioned on an outer peripheral side with respect to an outer peripheral end portion of the opposing surface of the movable portion. The solenoid valve according to claim 1,
The solenoid valve according to claim 1, wherein the opposing surface of the stopper and the opposing surface of the movable portion are formed without plating. In a high pressure fuel supply pump comprising a pressurization chamber, an electromagnetic suction valve disposed on the suction side of the pressurization chamber, and a discharge valve formed on the discharge side of the pressurization chamber,
A high-pressure fuel supply pump using the solenoid valve according to claim 1 as the suction valve. The high-pressure fuel supply pump according to claim 11,
The electromagnetic valve includes a valve body and a rod portion that pushes the valve body toward the pressurizing chamber.
The high-pressure fuel supply pump is characterized in that the mover is configured to move independently of the rod part and is sucked in conjunction with the rod part when an electromagnetic attractive force is applied.

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