JP2012092924A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce sliding resistance generated between a guide hole and a shaft part of a movable body.SOLUTION: When a movable body 34 is in a state attracted to a stator core 33 side by electromagnetic force, a spring seat surface 3422 is located on a valve element 36 side relative to an end of a shaft part guide hole 351 on an armature part 341 side. Accordingly, when the movable body 34 is driven to the side opposite to the stator core side by energization force of a valve spring 37, inclination of a shaft part 342 by a spring load is hardly generated, and sliding resistance between the shaft part guide hole 351 and the shaft part 342 can be reduced.

Description

  The present invention relates to an electromagnetic valve in which a movable body is slidably held by a guide member.

  In the conventional solenoid valve, the movable body is attracted to the stator core side by the electromagnetic force of the stator core, and the movable body is biased to the anti-stator core side by the spring. The movable body includes a shaft portion that is slidably inserted into the guide hole of the guide member, a plate-shaped armature portion that is fixed to one end side of the shaft portion and forms a magnetic circuit, and the other end side of the shaft portion. And a valve body that opens and closes the fluid passage. The spring is disposed in the center portion inside the stator core, and one end of the spring is in contact with a spring seat surface formed on the shaft portion. The movable body is configured to reciprocate in a predetermined direction when the shaft portion is guided by the guide member (see, for example, Patent Document 1).

JP 2007-1000065

  However, in the conventional solenoid valve, the spring seat surface is located further on the stator core side than the armature portion side end portion of the guide hole. For this reason, when the movable body is moved to the anti-stator core side by the spring load, the shaft portion is inclined by the spring load, and the shaft portion is strongly pressed against the guide hole at both ends of the sliding portion, and the gap between the guide hole and the shaft portion is increased. There was a problem that a large sliding resistance would occur.

  In view of the above points, an object of the present invention is to reduce sliding resistance generated between a guide hole and a shaft portion.

  In order to achieve the above object, according to the first aspect of the present invention, a coil (32) that forms a magnetic field when energized, a stator core (33) that is excited by the coil (32) to generate electromagnetic force, and a stator core (33) ), A movable body (34) that is attracted to the stator core (33) side, a valve body (36) that is displaced together with the movable body (34) to open and close the fluid passage, and the movable body (34) as an anti-stator core. In a solenoid valve comprising a spring (37) biased to the side and a guide member (35) having a guide hole (351) for slidably holding the movable body (34), a stator core (33) and a guide An armature housing space (42) is defined between the member (35) and the movable body (34) is formed with a spring seat surface (3422) for receiving one end of the spring (37). The valve body (36) is arranged on one end side and is slidably inserted into the guide hole (351). The shaft part (342) is fixed to the other end side of the shaft part (342) and accommodates the armature. A plate-like armature portion (341) disposed in the space (42) and constituting a magnetic circuit, and when the movable body (34) is attracted to the stator core (33) side, the spring seat surface ( 3422) is located closer to the valve body (36) than the armature portion side end of the guide hole (351).

  According to this, since it becomes difficult to generate | occur | produce the inclination of the shaft part (342) by a spring load, the sliding resistance between a guide hole (351) and a shaft part (342) can be reduced.

  According to a second aspect of the present invention, in the electromagnetic valve according to the first aspect, when the movable body (34) is attracted to the stator core (33) side, the spring seat surface (3422) has a guide hole ( 351) is located closer to the valve body (36) than the central portion in the sliding direction.

  According to this, since the inclination of the shaft portion (342) due to the spring load is less likely to occur, the sliding resistance between the guide hole (351) and the shaft portion (342) can be further reduced.

  According to a third aspect of the present invention, in the electromagnetic valve according to the first or second aspect, when the movable body (34) is attracted to the stator core (33) side, the spring seat surface (3422) is a guide. It is located in the valve body (36) side rather than the valve body side edge part in a hole (351), It is characterized by the above-mentioned.

  According to this, since the inclination of the shaft portion (342) due to the spring load hardly occurs, the sliding resistance between the guide hole (351) and the shaft portion (342) can be further reduced.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is sectional drawing which shows the whole structure of a fuel injection valve provided with the solenoid valve which concerns on one Embodiment of this invention. It is sectional drawing which shows the structure of the solenoid valve vicinity of FIG. It is sectional drawing which expands and shows the principal part of the solenoid valve of FIG.

  An embodiment of the present invention will be described. FIG. 1 is a cross-sectional view showing an overall configuration of a fuel injection valve including an electromagnetic valve according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing a configuration in the vicinity of the electromagnetic valve in FIG. 1, and FIG. It is sectional drawing which expands and shows the principal part. In addition, the arrow in a figure has shown the vertical direction in the state in which the fuel injection valve was mounted in the internal combustion engine.

  The fuel injection valve is attached to a cylinder head of an internal combustion engine (more specifically, a diesel engine, not shown), and injects high-pressure fuel stored in a common rail (not shown) into a cylinder of the internal combustion engine. is there.

  As shown in FIG. 1, the fuel injection valve has a nozzle 2 disposed on one end side in the injection valve axial direction of the holder body 1 and an electromagnetic valve 3 disposed on the other end side in the injection valve axial direction of the holder body 1. The holder body 1 and the nozzle 2 are fastened by a first retaining nut 51, and the holder body 1 and the solenoid valve 3 are fastened by a second retaining nut 52.

  A cylindrical command piston 7 is slidably inserted into the holder body 1 to urge the nozzle needle 22 in the valve closing direction under the pressure of the control chamber 6 (described later in detail). The holder body 1 is formed with a high-pressure fuel passage 11 through which high-pressure fuel supplied from the common rail flows, and the high-pressure fuel supplied from the common rail is guided to the control chamber 6 through the high-pressure fuel passage 11. Further, the holder body 1 is formed with a low-pressure fuel passage 12 through which leaked fuel or the like flows.

  The nozzle 2 includes a nozzle body 21 in which an injection hole 211 for injecting fuel into the internal combustion engine is formed, a nozzle needle 22 that is slidably held in the nozzle body 21 and opens and closes the injection hole 211, and the nozzle needle 22 Is provided with a nozzle spring 23 that urges the valve in the valve closing direction. The nozzle spring 23 is disposed in the holder body 1, and the space in which the nozzle spring 23 is disposed is connected to the low pressure fuel passage 12.

  The high-pressure fuel supplied from the common rail is guided to the injection hole 211 side through the high-pressure fuel passage 11 of the holder body 1 and the high-pressure fuel passage 212 formed in the nozzle body 21. The pressure of the high-pressure fuel acts on the nozzle needle 22, thereby urging the nozzle needle 22 in the valve opening direction.

  As shown in FIGS. 2 and 3, the holder body 1 is formed with a piston guide hole 13 into which the command piston 7 is inserted. The upper space of the piston guide hole 13 is the control chamber 6, and the pressure in the control chamber 6 acts on the command piston 7.

  The electromagnetic valve 3 includes a control chamber plate 31 in which a discharge hole 311 for discharging fuel from the control chamber 6 is formed, a coil 32 that forms a magnetic field when energized, a stator core 33 that is excited by the coil 32 and generates electromagnetic force, and its electromagnetic A movable body 34 that is attracted to the stator core 33 side by force, a guide member 35 that slidably holds the movable body 34, a valve body 36 that is held by the movable body 34 and opens and closes the discharge hole 311, and the movable body 34 A valve spring 37 that biases toward the stator core side, a ring-shaped shim 38 that adjusts the set load of the valve spring 37, a stopper 39 that limits the moving range of the movable body 34 when the movable body 34 is attracted by electromagnetic force, and the stator core A housing 40 arranged adjacent to the other end side in the injection valve axial direction of 33 and a connector connected to the mating connector to supply power to the coil 32. It has a Kuta 41.

  An armature housing space 42 is formed between the coil 32 and the stator core 33 and the guide member 35. The armature housing space 42 is connected to a fuel tank (not shown) via a pipe (not shown).

  The disc-shaped control chamber plate 31 is made of a high-hardness metal (for example, SKD) and is disposed on the upper portion of the holder body 1 so as to close the piston guide hole 13, and cooperates with the holder body 1 to control the control chamber. 6 is defined. The control chamber plate 31 is formed with a high pressure introduction passage 312 for guiding the high pressure fuel from the high pressure fuel passage 11 to the control chamber 6 and the discharge hole 311 described above.

  The movable body 34 is disposed in the armature housing space 42 so as to face the lower end surfaces of the coil 32 and the stator core 33, and a disk-shaped armature portion 341 constituting a magnetic circuit, and the armature portion 341 is disposed at one end side. And a bottomed cylindrical shaft portion 342 extending from the radial center portion of the armature portion 341 toward the control chamber plate 31 side. Note that the armature portion 341 and the shaft portion 342 are coupled by welding, caulking, or the like. The armature portion 341 is made of a high permeability metal (for example, 2LSS), and the shaft portion 342 is made of a high hardness metal (for example, SKH, SUJ2).

  The shaft portion 342 is formed with a spring accommodation hole 3421 that opens on the stator core 33 side, and the bottom surface of the spring accommodation hole 3421 is a spring seat surface 3422 that receives one end of the valve spring 37. A shim 38 is disposed on the bottom side of the spring accommodation hole 3421. A valve spring 37 is inserted into the spring accommodating hole 3421, and one end of the valve spring 37 is supported by the spring seat surface 3422 through the shim 38 and the other end is supported by the stopper 39.

  The valve body 36 is made of, for example, ceramic, and has a shape in which one flat portion is formed on a spherical member. Further, the valve body 36 is rotatably held at the other end side (that is, the lower end portion) of the shaft portion 342 and is integrated with the movable body 34. The flat surface of the valve body 36 is brought into contact with and separated from the control chamber plate 31 to open and close a discharge hole 311 as a fluid passage.

  The cylindrical guide member 35 is made of a high-hardness metal (for example, SCM), and a shaft portion guide hole 351 into which the shaft portion 342 is slidably inserted is formed in the central portion of the guide member 35 in the radial direction. Has been. Further, a valve chamber 352 into which fuel discharged from the discharge hole 311 flows is formed at the center in the radial direction of the guide member 35 and at the lower end side of the shaft portion guide hole 351. A low-pressure communication hole 353 that allows the armature accommodating space 42 and the low-pressure fuel passage 12 to communicate with each other is formed at a position shifted from the radial center of the guide member 35. Further, the valve chamber 352 and the low pressure communication hole 353 communicate with each other via a sub low pressure communication hole 354 formed in the guide member 35.

  A disc-shaped stopper 39 is press-fitted into the radial center portion on the lower end side of the stator core 33. The lower end surface of the stopper 39 slightly protrudes from the stator core 33. When the movable body 34 is attracted by electromagnetic force, the shaft portion 342 of the movable body 34 abuts on one end of the stopper 39, whereby the movable body 34 The moving range of the movable body 34 when the is attracted by the electromagnetic force is limited. The stopper 39 is made of a high hardness metal (for example, SKH, SUJ2), and the stator core 33 is made of a high magnetic permeability metal (for example, 3LSS).

  The housing 40 is made of a nonmagnetic metal (for example, stainless steel) and is disposed adjacent to the upper end side of the stator core 33.

  The connector part 41 includes a connector housing 411 and a terminal 412. The connector housing 411 includes a fitting portion 413 that is molded integrally with the housing 40 with resin and into which the mating connector is fitted. One end of the terminal 412 protrudes from the fitting portion 413 and the other end is connected to the coil 32.

  Here, when the movable body 34 is attracted to the stator core 33 side by electromagnetic force, the spring seat surface 3422 is the end portion on the armature portion 341 side in the shaft portion guide hole 351 (in other words, the armature accommodating space 42 side). It is located on the valve body 36 side with respect to the end portion.

  More specifically, when the movable body 34 is attracted to the stator core 33 side by electromagnetic force, the spring seat surface 3422 is located closer to the valve body 36 than the central portion in the sliding direction of the shaft portion guide hole 351. More specifically, the shaft portion guide hole 351 is at a position close to the valve body 36 (in other words, a position close to the valve chamber 352).

  Further, between the end of the shaft portion guide hole 351 on the valve body 36 side (in other words, the end on the valve chamber 352 side) and the spring seat surface 3422 in a state where the movable body 34 is attracted to the stator core 33 side by electromagnetic force. L / D ≦ 0.5, where L is the length in the sliding direction and D is the outer diameter of the shaft portion 342.

  Next, the operation of the fuel injection valve will be described. When a drive current is supplied to the coil 32, the movable body 34 and the valve body 36 are attracted by the stator core 33 to open the discharge hole 311, and the fuel in the control chamber 6 flows into the discharge hole 311, the valve chamber 352, the auxiliary low pressure communication. It is returned to the fuel tank through the hole 354, the low pressure communication hole 353, and the armature housing space 42.

  As a result, the pressure in the control chamber 6 is reduced, and the force for urging the nozzle needle 22 toward the valve closing direction via the command piston 7 is reduced. Therefore, the pressure of the high-pressure fuel that directly acts on the nozzle needle 22 Is driven in the valve opening direction to open the nozzle hole 211, and fuel is injected from the nozzle hole 211 into the cylinder of the internal combustion engine.

  Thereafter, when the supply of drive current to the coil 32 is stopped, the attractive force of the stator core 33 disappears, so that the movable body 34 and the valve body 36 are driven by the urging force of the valve spring 37 and the discharge hole 311 is closed. .

  As a result, the pressure in the control chamber 6 is increased by the high-pressure fuel supplied through the high-pressure introduction passage 312, and the force for urging the nozzle needle 22 in the valve closing direction through the command piston 7 is increased. 22 is driven in the valve closing direction, the nozzle hole 211 is closed, and fuel injection is completed.

  Here, when the movable body 34 is attracted to the stator core 33 side by electromagnetic force, the spring seat surface 3422 is located closer to the valve body 36 than the end portion of the shaft portion guide hole 351 on the armature portion 341 side. Therefore, when the movable body 34 is driven to the side opposite to the stator core by the urging force of the valve spring 37, the inclination of the shaft portion 342 due to the spring load is less likely to occur, and accordingly, the shaft portion guide hole 351 and the shaft portion 342 are not generated. The sliding resistance between them can be reduced.

  In the above embodiment, when the movable body 34 is attracted to the stator core 33 side by electromagnetic force, the spring seat surface 3422 is more discreet than the end portion on the armature portion 341 side in the shaft portion guide hole 351. However, when the movable body 34 is attracted to the stator core 33 side by electromagnetic force, the spring seat surface 3422 is further located than the end portion on the valve body 36 side in the shaft portion guide hole 351. You may make it locate in the valve body 36 side (in other words, the control chamber plate 31 side). In such a case, since the inclination of the shaft portion 342 due to the spring load hardly occurs, the sliding resistance between the shaft portion guide hole 351 and the shaft portion 342 can be further reduced.

32 Coil 33 Stator core 34 Movable body 35 Guide member 36 Valve body 37 Spring 42 Armature accommodating space 341 Armature portion 342 Shaft portion 351 Guide hole 3422 Spring seat surface

Claims (3)

A coil (32) that forms a magnetic field when energized;
A stator core (33) excited by the coil (32) to generate electromagnetic force;
A movable body (34) attracted to the stator core (33) side by electromagnetic force of the stator core (33);
A valve body (36) that is displaced together with the movable body (34) to open and close the fluid passage;
A spring (37) for urging the movable body (34) toward the stator core;
A solenoid valve comprising a guide member (35) formed with a guide hole (351) for slidably holding the movable body (34);
An armature accommodating space (42) is defined between the stator core (33) and the guide member (35),
The movable body (34) is formed with a spring seat surface (3422) for receiving one end of the spring (37), and the valve body (36) is disposed on one end side to slide into the guide hole (351). A shaft portion (342) that is movably inserted, and a plate-shaped armature that is fixed to the other end side of the shaft portion (342) and that is disposed in the armature accommodating space (42) to constitute a magnetic circuit. Part (341),
When the movable body (34) is sucked toward the stator core (33), the spring seat surface (3422) is located on the valve body (36) more than the armature side end of the guide hole (351). Solenoid valve characterized by being located on the side.   When the movable body (34) is attracted to the stator core (33) side, the spring seat surface (3422) is located on the valve body (36) more than the center in the sliding direction of the guide hole (351). The solenoid valve according to claim 1, wherein the solenoid valve is located on a side of the) side.   When the movable body (34) is attracted to the stator core (33) side, the spring seat surface (3422) is more than the valve body side end of the guide hole (351) than the valve body (36). The solenoid valve according to claim 1, wherein the solenoid valve is located on a side.

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