JP5502806B2 - Solenoid valve and high-pressure pump using the same - Google Patents

Description

  The present invention relates to a solenoid valve and a high-pressure pump using the same.

  Conventionally, a fuel supply device that supplies fuel to an engine is provided with a high-pressure pump that pumps high-pressure fuel. Generally, in a high-pressure pump, the plunger reciprocates in accordance with the rotation of the engine, and the fuel drawn from the fuel tank is connected to the fuel injection valve by repeating the stroke cycle of the intake stroke, the metering stroke, and the pressurization stroke. Discharge to common rail.

  In order to create this stroke cycle, an electromagnetic valve that opens and closes according to the reciprocating movement of the plunger is applied as an intake valve of the high-pressure pump. Specifically, (1) when the plunger is lowered, the intake valve is opened to suck in the fuel, and (2) while the plunger is raised halfway through the stroke, the intake valve is opened, and a part of the fuel is returned and metered. (3) The stroke cycle of closing the intake valve and pressurizing and discharging fuel by raising the remaining stroke of the plunger is repeated. Here, by adjusting the switching timing from the metering stroke of (2) to the pressurization stroke of (3), metering corresponding to the required supply amount is realized.

Here, the solenoid valve applied to the high-pressure pump is classified into a normally open type and a normally closed type depending on the relationship between energization and non-energization of the coil and opening and closing.
A high-pressure pump to which a normally open solenoid valve is applied performs an intake stroke and a metering stroke when not energized, and pressurizes and discharges fuel when energized.
On the other hand, a high-pressure pump to which a normally closed solenoid valve is applied performs a suction stroke and a metering stroke when energized, and pressurizes and discharges fuel when de-energized.

  For example, a normally closed electromagnetic valve applied to the high pressure pump of Patent Document 1 includes a plunger rod 31 (corresponding to the “valve element” of the present invention) and an anchor 35 (corresponding to the “movable core” of the present invention). Are integrally formed. When the coil is not energized, the spring member 34 biases the anchor 35 in a direction away from the first core portion 33 (corresponding to the “fixed core” of the present invention), whereby the plunger formed integrally with the anchor 35. The rod 31 is in a closed state in which the suction valve portion 31a contacts the seat portion 32a (see FIGS. 4 and 5 of Patent Document 1).

JP 2010-106947 A

  In the electromagnetic valve applied to the high-pressure pump of Patent Document 1, since the movable core and the valve body are integrally formed, the weight of moving integrally becomes heavy, and the moving speed when the power is off is slow. Accordingly, the “valve closing response time” from the energization-off command to the completion of valve closing becomes longer. That is, the “valve closing response” is not good. During the time until the valve closing is completed, the fuel in the pressurizing chamber is returned to the upstream side as the plunger is raised, and the pumping amount is reduced. As a result, particularly when a large flow rate is required at a high rotation speed, the pumping amount is insufficient with respect to the required supply amount.

  Further, another normally closed type solenoid valve has a configuration in which “the movable core and the valve body are provided separately, and the urging means of the movable core makes the movable core in the suction direction of the electromagnetic suction force. In other words, a configuration in which the valve body is energized in the direction opposite to the valve closing direction (the valve opening direction) is assumed. While this configuration is advantageous for opening the valve body when the coil is energized, the valve body and the movable core are moved in the valve closing direction against the biasing force of the biasing means of the movable core when the coil is off. It needs to be moved together. In other words, when the valve element closes, the weight of the movable core becomes a load, and the total weight of the movable part including the valve element becomes heavy. Therefore, the moving speed when the power is off is slowed down, and the valve closing response time of the valve body is lengthened. Therefore, like the electromagnetic valve according to Patent Document 1 described above, there is a possibility that the pumping amount is insufficient.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to improve valve closing response when a coil is turned off in a normally closed electromagnetic valve.

The electromagnetic valve according to claim 1 includes a valve body that can reciprocate, a seat member, first urging means, a coil around which a conducting wire is wound, a fixed core, a movable core, a stem, and second urging means.
The seat member has a seat portion on which the valve body can be seated or separated.
The first urging means urges the valve body in a valve closing direction in which the valve body is seated on the seat portion.
The fixed core generates an electromagnetic attractive force by energizing the coil.
The movable core moves in the suction direction when an electromagnetic suction force is generated between the movable core and the fixed core.
The stem is formed integrally with the movable core. When the stem moves together with the movable core in the suction direction, the stem contacts one end of the valve body and presses the valve body in the valve opening direction.
The second urging means urges the movable core and the stem in the anti-suction direction that is opposite to the suction direction.

Here, the second urging means is coaxially disposed on the radially outer side of the first urging means. The valve closing direction, which is the urging direction of the first urging means, and the counter-suction direction, which is the urging direction of the second urging means, are the same direction. Then, when the off energization of the coil, the valve body by the biasing force of the first urging means to move in the closing direction, the movable core and stem, by the biasing force of the second biasing means, the valve body It moves in counter-direction of suction at a speed higher than the speed of moving in the closing direction.

In the normally closed type electromagnetic valve having the above configuration, the valve body is provided separately from the movable core and the stem. Therefore, compared with the prior art in which the valve body and the movable core are integrally formed, the lightweight valve body can move alone when the coil is turned off.
Further, since the second urging means urges the movable core and the stem in the same direction as the valve closing direction of the valve body, the urging force of the second urging means does not become a load for the valve closing operation of the valve body. Therefore, the valve closing response time when the power is off is shortened, and the valve closing response is improved. Therefore, when this solenoid valve is applied to a high-pressure pump, it is possible to appropriately secure the pumping amount with respect to the required supply amount.

Also, when turning off the energization of the coil, the movable core and the stem is moved in a counterclockwise direction of suction at a rate faster than the valve body is moved in the valve closing direction, when de-energization of the coil, the movable core The stem is moved in the anti-suction direction in advance, and the valve body is moved in the valve closing direction. That is, the movable core, the stem, and the valve body move independently rather than integrally. Therefore, the weight of the movable core and the stem does not become a load, and the total weight of the movable part including the valve body is reduced. Therefore, the valve closing response of the valve body when energization is turned off can be further improved.

Claims 2 and 3 specifically show the configuration related to the installation position of the second urging means.
According to the invention described in claim 2, the second biasing means has one end in contact with the fixed core, and the other end abuts against the movable core. In other words, the second urging means is sandwiched between the fixed core and the movable core, and urges the movable core in a direction in which the movable core is separated from the fixed core (anti-suction direction).
In this case, a relatively simple configuration in which the second urging means directly presses the movable core can be obtained. However, the area of the magnetic path on which the electromagnetic attractive force acts is reduced by the amount of space for accommodating the second urging means at the end of the fixed core facing the movable core.

According to the third aspect of the present invention, the second urging means has one end abutting on the flange provided on the stem and the other end fixed. For example, the other end is provided on the side opposite to the sheet portion of the sheet member and in contact with the end surface on the movable core side.
In this case, the second urging means presses the collar portion of the stem. In addition, since a space for accommodating the second urging means is not required at the end of the fixed core facing the movable core, it is advantageous to secure a magnetic path area on which the electromagnetic attractive force acts. Conversely, if the magnetic path area to secure the equivalent structure according to claim 2, it is possible to reduce the outer diameter of the movable core with respect to the second aspect. Therefore, the weight of the movable core can be reduced, and the valve closing response can be further improved.

The invention according to claim 4 relates to a high-pressure pump. The high pressure pump includes a plunger, a cylinder, a housing, and a suction valve unit.
A cylinder accommodates a plunger so that a reciprocation is possible. The housing has a pressurizing chamber in which fuel is pressurized by a plunger, and an introduction passage for introducing fuel into the pressurizing chamber. The suction valve portion is constituted by the electromagnetic valve according to any one of claims 1 to 3 , and opens and closes in response to the reciprocating movement of the plunger to communicate or block the introduction passage and the pressurizing chamber.

  The high-pressure pump is required to have a high-speed response on the order of, for example, several ms, particularly when used at a high speed. Therefore, the effect of improving the valve closing response by the electromagnetic valve of the present invention is remarkably exhibited.

It is sectional drawing which shows the whole structure of the high pressure pump which applied the solenoid valve by 1st Embodiment of this invention as an intake valve part. It is sectional drawing which shows the suction valve closed state in the high pressure pump of FIG. It is sectional drawing which shows the suction valve open state in the high pressure pump of FIG. (A) FIG. 2, (b) It is a principal part expanded sectional view of FIG. It is a characteristic view explaining the action | operation of the high pressure pump to which the solenoid valve by 1st Embodiment of this invention is applied. It is explanatory drawing which compares the valve closing responsiveness of the solenoid valve by 1st Embodiment of this invention, and a comparative example. It is sectional drawing which shows the suction valve closed state in the high pressure pump which applied the solenoid valve by 2nd Embodiment of this invention as a suction valve part. It is sectional drawing which shows the suction valve closed state in the high pressure pump which applied the solenoid valve of the comparative example as a suction valve part. It is a characteristic view explaining the action | operation of the high pressure pump to which the solenoid valve of a comparative example is applied.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
As shown in FIG. 1, the electromagnetic valve of the first embodiment is applied as the suction valve portion 30 </ b> A of the high-pressure pump 10. The high-pressure pump 10 is used in a common rail fuel injection device for a vehicle diesel engine. The common rail fuel injection device mainly includes a fuel tank, a high-pressure pump 10, a common rail (not shown), and a fuel injection valve.
The high-pressure pump 10 pressurizes the normal-pressure fuel sucked up from the fuel tank and supplies the high-pressure fuel to the common rail. The common rail accumulates high-pressure fuel supplied from the high-pressure pump 10 and distributes high-pressure fuel in the common rail to fuel injection valves provided in each cylinder of the engine. The fuel injection valve injects and supplies the distributed high-pressure fuel to the combustion chamber of the cylinder.

The pump housing 11 of the high-pressure pump 10 mainly includes a cam housing 70, a bearing cover 75, and a valve housing 12.
The cam housing 70 and the bearing cover 75 house the drive shaft 80, and constitute a pre-feeding part made up of a feed pump 72 and a pressure-feeding part made up of a cam 83, a plunger 13, and the like.

The valve housing 12 accommodates the intake valve portion 30 </ b> A in the valve accommodation hole 16. Further, the cylindrical portion 18 of the valve housing 12 is accommodated by being inserted into an insertion hole 77 whose outer wall communicates with the cam chamber 71 of the cam housing 70. A cylinder (plunger sliding hole) 14 that supports the plunger 13 so as to be reciprocally movable is formed inside the cylindrical portion 18. A pressurizing chamber 95 in which fuel is pressurized is formed in the space defined by the inner wall of the cylinder 14 of the cylinder portion 18, the axial end surface of the plunger 13, the seat member 31 and the valve body 32 of the intake valve portion 30 </ b> A.
The valve housing 12 corresponds to a “housing” described in the claims.

The cam housing 70 is formed with a support hole 76 for inserting and supporting the bearing cover 75 in the axial direction, and the support hole 76 communicates with the cam chamber 71.
The bearing cover 75 is fixed to the cam housing 70 by a fixing member such as a bolt illustrated by a broken line in FIG. An oil seal 89 seals between the bearing cover 75 and the driving force input portion 81 of the driving shaft 80.

  The first bearing bush 86 is press-fitted and fixed to the bearing cover 75, and rotatably supports the driving force input portion 81 that is the shaft end portion of one of the driving shafts 80 (upper side in FIG. 1). The second bearing bush 87 is press-fitted and fixed to the cam housing 70, and rotatably supports the feed pump drive unit 82 which is the shaft end of the other drive shaft 80 (downward in FIG. 1). By fixing the bearing cover 75 to the cam housing 70, the first bearing bush 86 and the second bearing bush 87 are arranged coaxially.

  The drive shaft 80 includes a drive force input unit 81, a feed pump drive unit 82, and a cam 83. The cam 83 is formed between the driving force input unit 81 and the feed pump driving unit 82 and is accommodated in the cam chamber 71 of the cam housing 70. The cam 83 has a circular outline. The eccentric shaft 83j of the cam 83 is eccentric with respect to the driving shaft input portion 81 and the central shaft 80j of the feed pump driving portion 82.

The feed pump 72 is connected to the feed pump drive unit 82 of the drive shaft 80 directly or via a joint member.
The feed pump 72 is a low-pressure supply pump that sucks fuel from a fuel tank and pre-pressurizes it, and has a known pump structure such as an inner gear pump or a vane pump.

  The fuel pre-pressurized by the feed pump 72 is adjusted by a pressure adjusting device (not shown) so as to keep the fuel pre-pressure (feed pressure) constant. The feed fuel discharged from the feed pump 72 is supplied to the pressurizing chamber 95 via the feed fuel supply port 90 provided in the cam housing 70 and the introduction passage 91 of the valve housing 12. A part of the feed fuel is supplied to the cam chamber 71 through a throttle portion (not shown).

  The high-pressure pump 10 includes a pump 83 that includes a cam 83 of the drive shaft 80, a plunger 13, and a cam ring 84 that is provided between the cam 83 and the plunger 13 and transmits the driving force of the drive shaft 80 to the plunger 13. . The pumping unit pressurizes and feeds the feed fuel discharged from the feed pump 72 to a higher pressure in the pressurizing chamber 95.

The plunger 13 is arranged in a direction perpendicular to the central axis 80j and the eccentric shaft 83j with respect to the cam 83 of the drive shaft 80.
At the end of the plunger 13 on the cam 83 side, a tappet portion 13 a is formed that is slidably movable in the left-right direction in FIG. 1 with respect to the sliding contact portion 85 on the outer wall side of the cam ring 84. That is, the end portion of the tappet portion 13a of the plunger 13 and the end portion of the sliding contact portion 85 of the cam ring 84 are formed by planes parallel to each other.

  The cam ring 84 has an outer wall formed in a polygonal shape including a flat surface corresponding to the sliding contact portion 85 and an arcuate curved surface, and an inner wall formed in a circular shape. A third bearing bush 88 is fixed to the inner wall of the cam ring 84. The third bearing bush 88 is rotatable relative to the circular cam 83.

A plunger spring 19 is installed between the tappet portion 13 a of the plunger 13 and the valve housing 12 along the axial direction of the cylindrical portion 18. Thereby, the tappet portion 13 a of the plunger 13 is always pressed against the sliding contact portion 85 of the cam ring 84.
The rotation of the cam ring 84 is regulated by the biasing force of the plunger spring 19 and the acting force received by the plunger 13 due to the fuel pressure in the pressurizing chamber 95. As a result, the cam ring 84 does not rotate (autorotates) itself, and reciprocates around the central axis 80j of the drive shaft 80 according to the movement of the cam 83 by the rotation of the drive shaft 80, and reciprocates in the left-right direction in FIG. Moving.

Then, as the cam ring 84 reciprocates, the plunger 13 reciprocates along the inner wall of the cylinder 14. Hereinafter, the movement of the plunger 13 in the right direction in FIG. 1 is referred to as “raising”, and the movement of the plunger 13 in the left direction in FIG. 1 is referred to as “lowering”.
When the plunger 13 is lowered, the feed fuel is sucked into the pressurizing chamber 95 from the introduction passage 91 via the suction valve portion 30A. Further, when the plunger 13 is raised, the fuel in the pressurizing chamber 95 is pressurized and increased to a fuel pressure corresponding to the fuel injection pressure.

  A check valve 68 is provided in the fuel passage 96 on the discharge side of the pressurizing chamber 95. The check valve 68 prevents the discharged fuel supplied to the common rail and the fuel injection valve from flowing back to the pressurizing chamber 95. When the internal pressure of the pressurizing chamber 95 exceeds the valve opening pressure of the check valve 68, the pressurized high-pressure fuel is pumped from the discharge port 98 via the discharge passage 97 and supplied to the common rail and the fuel injection valve. .

Next, the suction valve portion 30A and the electromagnetic actuator 50A will be described with reference to FIGS.
The intake valve portion 30A includes a seat member 31, a valve body 32, a first spring 33 as a "first biasing means", a holding member 34, and a plug screw 39, and a fuel passage from the introduction passage 91 to the pressurizing chamber 95. Open and close.
The seat member 31 is formed in a substantially cylindrical shape and is provided at the bottom of the valve housing hole 16 of the valve housing 12. The sheet member 31 includes a shaft hole 311 formed along the central axis, and a plurality of communication holes 313 that penetrate the shaft hole 311 and the outer wall 312 in the radial direction. A space between the seat member 31 and the electromagnetic actuator 50 </ b> A in the valve housing hole 16 forms a fuel reservoir chamber 93.

The surface of the sheet member 31 on the side of the electromagnetic actuator 50A in the axial direction is formed in a step shape. The radially inner end surface 314 serves as a seating surface for the first spring 33. The plug screw 39 is assembled to the valve housing 12 with a male screw having an outer diameter screwed into a female screw on the inner wall of the valve housing hole 16. When the step surface 315 on the radially outer side of the seat member 31 is pressed against the plug screw 39, the seat member 31 is pressed against the bottom of the valve accommodation hole 16 and fixed.
A concave taper-shaped sheet portion 316 is formed around the shaft hole 311 on the surface of the sheet member 31 on the side of the pressurizing chamber 95 in the axial direction. The seat portion 316 can seat a valve portion 321 provided at the tip of the valve body 32.

The valve body 32 has a shaft shape, and a valve portion 321, an intermediate diameter portion 322, and a small diameter portion 323 are formed in the axial direction from the pressurizing chamber 95 side. The valve portion 321 has the largest outer diameter in the valve body 32, and the opposite side of the pressurizing chamber 95 is formed in a tapered shape corresponding to the seat portion 316 on the seat member 31 side.
The medium diameter part 322 is slidably accommodated in the shaft hole 311 of the sheet member 31. Further, a flat portion 325 for securing a fuel passage between the shaft hole 311 and the shaft portion 311 is formed in a part of the middle diameter portion 322 in the circumferential direction.
A constricted portion 324 that continues from the tapered portion of the valve portion 321 is formed between the valve portion 321 and the medium diameter portion 322. The constricted portion 324 is provided at a position corresponding to the shaft hole 311 of the sheet member 31, and forms an annular passage 92 in a gap with the inner wall of the shaft hole 311.

The holding member 34 is fitted to the small diameter portion 323 of the valve body 32 by press fitting or the like on the electromagnetic actuator 50A side of the seat member 31. A flange 341 is formed on the outer wall of the holding member 34 near the electromagnetic actuator 50A. The first spring 33 is sandwiched between the flange portion 341 of the holding member 34 and the end surface 314 of the sheet member 31. Further, a groove portion 342 for securing a fuel passage is formed in a part of the holding member 34 in the circumferential direction.
By fixing the holding member 34 to the valve body 32, the movable range in the axial direction of the valve body 32 and the holding member 34 is restricted. When no external force is applied, the urging force of the first spring 33 urges the valve body 32 in the valve closing direction in which the valve portion 321 is seated on the seat portion 316.

Next, the electromagnetic actuator 50A includes a coil 51, a first stator 52, a movable core 53, a second stator 54, a flange (third stator) 55A, a stem 41, a second spring 43A as “second biasing means”, A stopper 57, a spool 58, and a spacer 59 are provided.
The coil 51 has a conductive wire wound around a spool 58 made of resin. By energizing the coil 51, an electromagnetic attractive force is generated between the flange 55A and the movable core 53, and the movable core 53 moves to the left in FIGS. Hereinafter, the left direction in FIGS. 2 to 4 is referred to as “suction direction”, and the right direction in FIGS. 2 to 4 is referred to as “anti-suction direction”.

The first stator 52, the second stator 54, and the flange (third stator) 55A are made of a magnetic material. The first stator 52 is provided on the radially inner side of the coil 51 on the side opposite to the pressurizing chamber 95 of the flange 55A. The second stator 54 is provided so as to cover the outer side in the radial direction of the coil 51, and magnetically connects the flange 55 </ b> A and the first stator 52.
The flange 55 </ b> A that is the third stator is attached to the end of the valve housing 12 opposite to the pressurizing chamber 95. In the flange 55 </ b> A, the suction surface 551 </ b> A opposite to the pressurizing chamber 95 faces the movable core 53. The flange 55A is formed with a shaft hole 552 through which the stem 41 is inserted, and a spring accommodating chamber 553 that opens to the suction surface 551A around the shaft hole 552.

Here, when the outer diameter of the suction surface 551A of the flange 55A is φd1, and the chamfered opening diameter of the spring accommodating chamber 553 is φd2, the magnetic path area SA that is the area of the suction surface 551A is expressed by the following equation 1.
SA = π / 4 × (φd1−φd2) ² (Formula 1)

  A spacer 59 formed of a nonmagnetic material is interposed between the first stator 52 and the flange 55A. The spacer 59 is connected to the first stator 52 and the flange 55A by welding or brazing. The spacer 59 blocks the magnetism so that the magnetism is not short-circuited between the first stator 52 and the flange 55A.

  The movable core 53 is formed in a cylindrical shape with a magnetic material. The movable core 53 is accommodated between the first stator 52 and the flange 55A in the axial direction and radially inward of the first stator 52 and the spacer 59 in the radial direction so as to be reciprocally movable in the axial direction. When the coil 51 is energized, the movable core 53 is attracted and moved by the flange 55A that is the third stator. The movable core 53 has a communication hole 531 that penetrates in the axial direction. Thereby, the pressure before and behind the axial direction of the movable core 53 is equally maintained at the time of reciprocation.

  The stem 41 is integrally provided with the movable core 53 by welding, brazing, caulking, or the like, and constitutes the armature assembly 40A together with the movable core 53. The stem 41 is inserted into the shaft hole 552 of the flange 55 </ b> A and reciprocates in the axial direction together with the movable core 53. Further, the end of the stem 41 in the suction direction faces the end of the valve body 32. Hereinafter, the movement of the armature assembly 40A in the suction direction is referred to as “forward”, and the movement in the anti-suction direction is referred to as “backward”.

  The second spring 43A is accommodated in the spring accommodating chamber 553 of the flange 55A, one end abuts on the bottom surface of the spring accommodating chamber 553, and the other end abuts on the end surface of the movable core 53 on the flange 55A side. The second spring 43A biases the movable core 53 and the stem 41 in the anti-suction direction. At this time, the end of the stem 41 in the anti-suction direction comes into contact with a stopper 57 provided on the inner bottom of the first stator 52, so that the backward limit is restricted.

(Operation)
Next, the operation of the high-pressure pump 10 will be described. The high-pressure pump 10 operates by repeating the cycle of the suction stroke, the metering stroke, and the pressurization stroke as the plunger 13 moves up or down in the left-right direction in FIG. 1 in conjunction with the rotation of the cam 83 of the drive shaft 80. To do.

(0) Initial State When the coil 51 is not energized, the movable core 53 is pressed against the stopper 57 by the urging force of the second spring 43A (see FIG. 2). At that time, the valve body 32 is seated on the seat portion 316 by the urging force of the first spring 33 (see FIGS. 2 and 4A).
The fuel in the annular passage 92 can circulate with the fuel reservoir chamber 93 via the flat portion 325 formed in the middle diameter portion 322 of the valve body 32 and the groove portion 342 of the holding member 34 (FIG. ), The fuel pressure in the annular passage 92 and the fuel reservoir 93 is balanced.

(1) Suction stroke When the cam lift starts to descend during the suction stroke, the pressure chamber 95 is depressurized, so that a differential pressure is generated between the annular passage 92 and the pressure chamber 95. When the fuel pressure in the annular passage 92 exceeds the urging force of the first spring 33, the valve body 32 starts to be separated (opened) from the seat portion 316.
When the coil 51 is energized, an electromagnetic attractive force proportional to the magnetic path area SA is generated between the flange 55A and the movable core 53. When this electromagnetic attractive force exceeds the urging force of the second spring 43A, the armature assembly 40A (stem 41 and movable core 53) starts to lift (advance) in the attractive direction. And the front-end | tip of the stem 41 contact | abuts to the valve body 32, and pushes the valve body 32 in the valve opening direction. While the coil 51 is energized, the stem 41 keeps the valve element 32 open (see FIGS. 3 and 4B).

  In the valve open state, the fuel flows from the introduction passage 91 into the pressurizing chamber 95 via the annular passage 92 (solid arrow F1 in FIG. 4B). Part of the fuel flows through the fuel reservoir chamber 93 via the flat portion 325 formed in the middle diameter portion 322 of the valve body 32 and the groove portion 342 of the holding member 34 (broken line arrow F2 in FIG. 4B). ). As a result, the fuel pressure in the annular passage 92 and the fuel reservoir chamber 93 is balanced, and the flowing fuel lubricates the sliding portion between the valve body 32 and the seat member 31.

(2) Metering stroke When the cam lift starts to rise from the bottom dead center, the intake stroke shifts to the metering stroke. At this time, energization to the coil 51 is continued, and the valve body 32 is kept open. As the plunger 13 moves up, the fuel sucked into the pressurizing chamber 95 is discharged back into the annular passage 92 and metering is performed.

(3) Pressurization stroke When the energization of the coil 51 is turned off, the electromagnetic attractive force between the movable core 53 and the flange 55A disappears. Then, the armature assembly 40A moves in the anti-suction direction by the urging force of the second spring 43A and returns to the initial position. Further, the valve body 32 moves in the valve closing direction by the urging force of the first spring 33.
As a result, the fuel discharge from the pressurizing chamber 95 to the annular passage 92 is completed. Thereafter, when the internal pressure of the pressurizing chamber 95 rises with the rise of the plunger 13 and exceeds the valve opening pressure of the check valve 68, the fuel is discharged from the discharge port 98 via the discharge passage 97 (FIG. 1).

Here, when the energization of the coil 51 is turned off, the springs of the first spring 33 and the second spring 43A are set so that the moving speed of the armature assembly 40A in the counter-suction direction is faster than the valve closing speed of the valve body 32. Load etc. are set. Specifically, the biasing force of the second spring 43 </ b> A is set to be larger than the biasing force of the first spring 33.
As a result, the armature assembly 40A moves backward in the anti-attraction direction with the disappearance of the electromagnetic attraction force, and subsequently, the valve body 32 moves in the valve closing direction. That is, the armature assembly 40A and the valve body 32 move independently by different urging forces.

(Contrast)
Next, the effect of this embodiment will be described in comparison with a comparative example.
FIG. 8 shows a solenoid valve of a comparative example applied as the suction valve portion 20C of the high pressure pump. In the intake valve portion 20 </ b> C, a valve member 21 is installed in a space between the valve outer body 23 and the valve inner body 24. The valve member 21 is urged to be seated on the seat portion 231 of the valve outer body 23 by the urging force of the first spring 22 accommodated in the spring accommodating chamber 242 of the valve inner body 24.

On the other hand, in the electromagnetic actuator 50C, the second spring 56 is provided between the end of the needle 61 opposite to the suction side and the stopper 57, and biases the needle 61 in the suction direction (left direction in FIG. 8). . Here, since the biasing force of the second spring 56 is set to be weaker than the biasing force of the first spring 22, the valve member 21 is biased by the second spring 56 in a state where the coil 51 is not energized. It is seated on the seat part 231 without being affected by the above.
In addition, the member which attached | subjected the code | symbol same as FIG. 2, FIG. 3 in the electromagnetic actuator 50C is substantially the same as the electromagnetic actuator 50A of 1st Embodiment.
Although the reciprocating direction of the plunger 13 and the position of the introduction passage 911 are different from those in the first embodiment, these are not essential differences.

When the coil 51 is energized, an electromagnetic attractive force is generated between the flange 55C and the movable core 53. Then, the needle 61 moves forward in the suction direction (left direction in FIG. 8) by the electromagnetic suction force and the biasing force of the second spring 56.
On the other hand, when the suction valve portion 20C is applied to a high-pressure pump, the valve member 21 is opened by a fuel differential pressure generated between the upstream side and the downstream side of the valve member 21 as in the first embodiment. Even if there is no differential pressure on both sides of the valve member 21, the advanced needle 61 pushes the valve member 21 against the urging force of the first spring 22, so that the valve member 21 1 Open the valve against the urging force of the spring 22. As a result, the introduction passage 911 and the pressurizing chamber 95 communicate with each other via passages inside the valve outer body 23 and the valve inner body 24.
When applied to the high-pressure pump, the flange portion 611 provided in the needle 61 assists in opening the valve member 21 by using a differential pressure generated between the upstream side and the downstream side of the flange portion 611.

  When the energization to the coil 51 is turned off, the electromagnetic attractive force to the movable core 53 disappears. Then, the valve member 21 moves in the valve closing direction by the difference between the urging force of the first spring 22 and the urging force of the second spring 56, and pushes the needle 61 in the anti-suction direction (right direction in FIG. 8). At the same time, it is seated on the seat portion 231. That is, the valve member 21 has an “extra work (load)” of pushing the needle 61 against the urging force of the second spring 56 in addition to its own valve closing operation when the valve is closed. The effect of this will now be described with reference to FIG.

FIG. 9 shows operating characteristics when the solenoid valve of the comparative example is applied as a suction valve of a high-pressure pump. Specifically, (a) one cycle of cam lift (b) energization (on / off) command, (c) current, (d) valve member 21 and needle 61 lift, and (e) pump pumping amount change are shown.
At time ta, the cam lift starts to descend from the top dead center, and the suction stroke is executed. At this time, since the fuel pressure in the pressurizing chamber 95 is reduced, the valve member 21 moves in the valve opening direction due to the differential pressure between the upstream passage 912 side and the pressurizing chamber 95 side of the valve member 21, and opens at time t2. Complete. Further, energization of the coil 51 is started by an energization-on command at time t1, and an electromagnetic attractive force is generated in the electromagnetic actuator 50C. Then, the needle 61 moves forward and reaches the forward limit (full lift) at time t3.

  At time tb, the cam lift reaches the bottom dead center and shifts from the suction stroke to the metering stroke. The current that has reached the maximum value at time t4 is cut off by an energization-off command at time tc determined according to the required pumping amount. Thereafter, the valve member 21 is closed while pushing back the needle 61 in the backward direction as described above. Then, the valve closing response time TvC from the energization OFF time tc to the time t5 when the valve member 21 is closed is longer as the “load for pushing back the needle 61” is larger. Here, “the valve closing response time becomes longer” is called “the valve closing response becomes worse”.

Although the transition from the metering stroke to the pressurization stroke is apparent after the energization off time tc, the fuel in the pressurization chamber 95 is returned to the upstream passage 912 during the valve closing response time Tvc. The fuel is not pressurized and discharged (pressed).
The fuel is pressurized and discharged from time t5 when the valve closing response time TvC has elapsed. However, at this time, the cam position has already approached the top dead center, and the remaining lift stroke is reduced, so that the pumping amount QC decreases. Therefore, the deterioration of the valve closing response causes a decrease in the pumping amount, that is, a shortage of the pumping amount with respect to the required supply amount.

Thus, when the solenoid valve of the comparative example is applied to an apparatus that requires a high-speed response, the valve closing response becomes a problem. Next, referring to FIG. 5, the operation characteristics of the present embodiment will be compared.
Each parameter in FIG. 5 is the same as FIG. Further, the behavior from the suction stroke to the metering stroke is almost the same as that of the comparative example. In detail, since the urging force of the second spring 43A is lost with respect to the electromagnetic attractive force when energization is on, the time t3 tends to be relatively late. However, this has no effect on the function as a high pressure pump.

After the energization to the coil 51 is cut off by the energization-off command at time tc, the armature assembly 40A is moved in the anti-suction direction (FIG. 1) prior to the valve closing operation of the valve body 32 by the urging force of the second spring 43A. Move backward (to the right). And the valve body 32 moves independently in the valve closing direction by the urging force of the first spring 33 without the armature assembly 40A being a load. Accordingly, since the valve closing operation can be performed quickly, the valve closing response time TvA from the valve closing start time t4 to the valve closing completion time t5 can be shortened, and the valve closing response can be improved.
Then, at time t5, a sufficient lift stroke to the top dead center of the cam remains, so that the pump pressure feed amount QA increases. Therefore, by improving the valve closing response, it is possible to appropriately secure the pumping amount with respect to the required supply amount.

FIG. 6 is a diagram comparing the valve closing responsiveness of the suction valve portion 30A according to the present embodiment and the suction valve portion 20C according to the comparative example.
As shown in FIG. 6, the valve closing response time is shortened as the spring load of the first spring 33 in the present embodiment or the first spring 22 in the comparative example increases. Assuming that all factors other than the first spring (weight of moving part, moving distance, etc.) are equal, when the spring load of the first spring is the same, the suction valve part of this embodiment is more than the suction valve part 20C of the comparative example. 30A can shorten the valve closing response time.

(Second Embodiment)
Next, a solenoid valve according to a second embodiment of the present invention will be described with reference to FIG. Components substantially the same as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.
The solenoid valve of the second embodiment is applied as the intake valve portion 30B of the high-pressure pump, as in the first embodiment. The suction valve portion 30B is different from the suction valve portion 30A of the first embodiment in the shape of the stem and the flange and the installation location of the second spring.

The stem 42 has a flange 421 that protrudes radially outward on the sheet member 31 side of the flange 55B. The second spring 43 </ b> B as “second urging means” is disposed outside the diameter of the first spring 33, one end abuts against the flange portion 421 of the stem 42, and the other end abuts against the end surface 314 of the holding member 34. . Accordingly, the second spring 43B biases the armature assembly 40B (stem 42 and movable core 53) in the anti-suction direction (the right direction in FIG. 7).
Further, unlike the flange 55A of the first embodiment, the flange 55B does not need to be provided with the spring accommodating chamber 553 that opens to the suction surface.

Here, when the outer diameter of the suction surface 551B of the flange 55B is φd3 and the chamfered diameter of the shaft hole 552 is φd4, the magnetic path area SB that is the area of the suction surface 551B is expressed by the following equation 2.
SB = π / 4 × (φd3−φd4) ² (Formula 2)

  When the coil 51 is energized, an electromagnetic attractive force proportional to the magnetic path area SB is generated between the flange 55B and the movable core 53. The armature assembly 40B moves forward in the suction direction (leftward in FIG. 7) against the urging force of the second spring 43B, and the stem 42 pushes the valve body 32. Then, the valve body 32 opens against the urging force of the first spring 33.

  When the energization of the coil 51 is turned off, the armature assembly 40B moves backward in the anti-attraction direction (right direction in FIG. 7) by the urging force of the second spring 43B. Further, the valve element 32 moves in the valve closing direction by the urging force of the first spring 33 and is seated on the seat portion 316. At this time, the first spring 33 is set so that the moving speed of the armature assembly 40B is faster than the closing speed of the valve body 32, in other words, the movement of the armature assembly 40B precedes the valve closing operation of the valve body 32. And the spring load etc. of the 2nd spring 43B are set. Thereby, the valve closing responsiveness of the valve body 32 can be improved similarly to 1st Embodiment.

  Further, in the second embodiment, the magnetic path area SB is determined as in Expression 2 above. Therefore, in order to generate an electromagnetic attraction force equivalent to that of the first embodiment, the magnetic path area SB may be the same as the magnetic path area SA (see Formula 1) of the first embodiment. Then, since the spring housing chamber 553 is not provided in the second embodiment, the chamfered mouth diameter φd4 is smaller than the diameter φd2 of the first embodiment, so the outer diameter φd3 of the suction surface 551B is set to the outer diameter of the first embodiment. It can be made smaller than φd1. Therefore, the outer diameter of the movable core 53 can be reduced and the movable core 53 can be reduced in weight. Therefore, the valve closing response of the suction valve portion 30B can be further improved.

(Other embodiments)
(A) In the above embodiment, the first spring 33 and the second spring 43A are arranged so that the moving speed of the armature assemblies 40A, 40B in the anti-suction direction when energization is off is faster than the valve closing speed of the valve body 32. 43B spring load or the like is set. However, the moving speed of the armature assemblies 40 </ b> A and 40 </ b> B is not necessarily higher than the closing speed of the valve body 32.

When the moving speed of the armature assemblies 40A and 40B is slower than the closing speed of the valve body 32 alone when it is assumed that the armature assemblies 40A and 40B are not present, the valve closing speed of the valve body 32 is that of the armature assemblies 40A and 40B. It will be limited to the moving speed.
However, even in that case, the armature assemblies 40A and 40B are urged in the same direction as the valve body 32 and move in the same direction, so that only the difference in speed is lost with respect to the valve closing operation of the valve body 32. Not too much. That is, the valve closing operation of the valve body 32 is clearly advantageous as compared with the case where the needle 61 is biased in the direction opposite to the valve closing direction of the valve body 32 as in the comparative example of FIG. Therefore, the effect of the present invention can be exhibited.

  (A) In the suction valve portion 30B of the second embodiment, the end of the second spring 43B opposite to the flange portion 421 of the stem 42 abuts against the end surface 314 of the seat member 31. Not only this but the edge part on the opposite side to the collar part 421 of the 2nd spring 43B should just be fixed by one of members. For example, a step portion may be provided on the inner wall of the plug screw, and the end portion of the second spring 43B may come into contact with the step portion.

  (C) In the above embodiment, the high pressure pump 10 is described as being provided with a set of the plunger 13, the intake valve portions 30A and 30B, the electromagnetic actuators 50A and 50B, and the like. In other embodiments, the high-pressure pump may be provided with a plurality of units each including a plunger, a suction valve unit, an electromagnetic actuator, and the like around the drive shaft.

(D) The solenoid valve of the present invention is not limited to a high pressure pump for a diesel engine, and may be applied to a suction valve portion of a high pressure pump for a gasoline engine. The solenoid valve of the present invention is not limited to a high-pressure pump for an engine, and can be applied to various applications that require a high-speed response, such as a fuel injection valve.
As mentioned above, this invention is not limited to such embodiment, In the range which does not deviate from the meaning of invention, it can implement with a various form.

10 ・ ・ ・ High pressure pump,
12 ・ ・ ・ Valve housing (housing),
13 ... Plunger,
14 ・ ・ ・ Cylinder,
30A, 30B ... Suction valve part (solenoid valve),
31 ... Sheet member,
316... Seat part,
32 ・ ・ ・ Valve,
33 ... 1st spring (1st biasing means),
40A, 40B ... Armature assembly (= stem + movable core),
41, 42 ... stem,
43A, 43B ... second spring (second urging means),
50A, 50B ... electromagnetic actuator,
51 ... Coil,
53 ... movable core,
55A, 55B ... flange (third stator, fixed core),
91 ・ ・ ・ Introduction passage,
95: Pressurizing chamber.

Claims (4)

A reciprocating valve body;
A seat member having a seat portion on which the valve body can be seated or separated; and
First urging means for urging the valve body in a valve-closing direction for seating on the seat portion;
A coil around which a conducting wire is wound;
A fixed core that generates an electromagnetic attractive force by energizing the coil;
A movable core that moves in the suction direction when an electromagnetic suction force is generated between the fixed core, and
A stem that is formed integrally with the movable core, and contacts the one end of the valve body when the movable core moves together with the movable core in the suction direction, and presses the valve body in the valve opening direction;
A second urging means for urging the movable core and the stem in an anti-suction direction opposite to the suction direction;
With
The second urging means is coaxially disposed on the radially outer side of the first urging means,
The valve closing direction, which is the urging direction of the first urging means, and the anti-suction direction, which is the urging direction of the second urging means, are the same direction.
When the energization to the coil is turned off, the valve body moves in the valve closing direction by the urging force of the first urging means, and the movable core and the stem are urging forces of the second urging means. Thus , the solenoid valve moves in the anti-suction direction at a speed faster than the speed in which the valve body moves in the valve closing direction . 2. The electromagnetic valve according to claim 1 , wherein one end of the second urging unit abuts on the fixed core and the other end abuts on the movable core. 2. The electromagnetic valve according to claim 1 , wherein one end of the second urging unit abuts against a flange provided on the stem and the other end is fixed. A plunger,
A cylinder for accommodating the plunger in a reciprocating manner;
A pressure chamber in which fuel is pressurized by the plunger, and a housing having an introduction passage for introducing fuel into the pressure chamber;
An intake valve portion configured by the electromagnetic valve according to any one of claims 1 to 3 , which opens and closes in response to the reciprocating movement of the plunger and communicates or blocks the introduction passage and the pressurizing chamber;
A high pressure pump comprising:

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