JP4158041B2 - solenoid valve - Google Patents

Description

  The present invention relates to a solenoid valve.

  A solenoid valve that is a valve housing (yoke) that covers the outer periphery of the coil and that is joined to a suction member (fixed core) that also constitutes a magnetic circuit by press-fitting and is welded to a flange (housing) It is known (see, for example, Patent Document 1). In the electromagnetic valve described in Patent Document 1, an electromagnetic coil (coil) is sandwiched between the yoke and the housing while the electric connector is positioned at a specified position.

  A solenoid valve for a high-pressure pump having a configuration in which the solenoid valve main body portion includes a screw portion and is coupled to the screw portion on the high-pressure pump main body side is also known (see, for example, Patent Document 2). According to the electromagnetic valve described in Patent Document 2, the assembly of the electromagnetic coil (including the yoke) is performed after the electromagnetic valve main body is assembled to the high-pressure pump, and the electrical connector portion can be positioned with respect to the high-pressure pump main body.

JP 2001-304446 A JP 2002-195128 A

  However, according to the solenoid valve described in Patent Document 1, when the press-fitting load is excessive when the yoke is press-fitted into the fixed core, the intermediate member of the non-magnetic material which is a thin portion is deformed, and the fixed core and the mover are deformed. There is a problem in that the gap between them becomes small, which affects the dynamic characteristics of the valve operation, resulting in large variations in product performance. Therefore, in this fixing method, it is necessary to manage the diameter of the press-fitted portion of each member with strict tolerances, and since expensive welding equipment is required, there is a problem that the manufacturing cost increases.

In addition, according to the electromagnetic valve described in Patent Document 2, a method for fixing an electromagnetic coil (including a yoke) is not declared.
The present invention has been created in view of such a problem, and an object thereof is to provide an electromagnetic valve that can be fixed to a housing without press-fitting and welding a yoke that covers the outer periphery of the coil.

According to the first aspect of the present invention, since the yoke is fixed to the housing by the fixing member, there is no need to fix the yoke by press-fitting it into the fixed core or welding it to the housing. For this reason, it is not necessary to manage the diameter of the press-fitting portion with strict tolerances and expensive welding equipment, and the manufacturing cost can be reduced.
In addition, since the cylindrical member has a tapered surface, when the yoke is pressed by the fixed member, the yoke is pressed against the tapered surface of the cylindrical member and is surely contacted by the cylindrical member, and the yoke and the housing are in contact with each other. It is possible to prevent malfunction of the magnetic circuit due to the defect.
According to the second aspect of the present invention, since the fixing member is screwed to the fixing core, it is easy to fix the yoke.

According to the third aspect of the invention, since the fixing member is formed of a magnetic material, the fixed core and the yoke are securely connected via the fixing member, and the magnetic circuit caused by poor contact between the fixed core and the yoke is obtained. Malfunctions can be prevented .

According to the invention of claim 4 , since the tapered surface of the yoke is in surface contact with the tapered surface of the cylindrical member, the yoke and the cylindrical member can be more stably brought into contact with each other.
According to the invention of claim 5 , the yoke and the fixed core are formed of the same kind of material. In the case of fixing by press-fitting, if the yoke and the fixing core are made of the same material, for example, both ferritic stainless steel, adhesion (seizure) may occur and the press-fitting load may be further increased. According to the sixth aspect of the present invention, even if the yoke and the fixed core are made of the same material, they are not fixed by press-fitting, so that no adhesion occurs and the press-fitting load does not increase.

The best mode for carrying out the present invention will be described with reference to a plurality of drawings.
(First reference form)
The fuel supply system having a solenoid valve according to a first referential embodiment of the present invention shown in FIG. The fuel supply device 1 is a fuel device that controls the pumping amount of high-pressure fuel by opening and closing an electromagnetic valve as an on-off valve. For example, the fuel supply device 1 is a high-pressure supply pump that supplies fuel to an injector of a diesel engine or a gasoline engine. The fuel supply device 1 includes an electromagnetic valve 10 and a pump unit 50 that pressurizes and pumps inhaled fuel.

First, the configuration of the electromagnetic valve 10 will be described. The electromagnetic valve 10 includes a valve part 30, a coil part 11, and a fixing member 37.
The valve unit 30 includes a pump housing 51, a fixed core 32, a movable core 33, a valve member 35, a valve spring 34 that urges the movable core 33 downward in FIG. 1, and a valve seat 36a on which the valve member 35 can be seated. It has a body 36 and the like. In the first embodiment, the pump housing 51 of the fuel supply device 1 also serves as the housing of the electromagnetic valve 10, and the pump housing 51 and the pipe member 31 as a cylindrical member constitute the housing described in the claims. Yes. The fixed core 32 has one end 32b in the axial direction inserted into a fitting hole 40 formed in the yoke 16 to be described later, and is fixed to one end of the pipe member 31 so that the one end of the pipe member 31 is fixed. Block. The other end 32a in the axial direction of the fixed core 32 protrudes from the pipe member 31, and a helical thread is formed in the circumferential direction on the outer peripheral wall of the protruding end 32a. The movable core 33 is covered by the pipe member 31 so as to be reciprocally movable. The movable core 33 faces the end 32 b of the fixed core 32. The valve member 35 reciprocates together with the movable core 33. The fixed core 32, the movable core 33, the fixed member 37, the pipe member 31, and the yoke 16 are made of a magnetic material.

The other end of the pipe member 31 is located in the pump housing 51 and faces the valve body 36. The pipe member 31 is fitted to the outer peripheral wall of the valve body 36 and is welded to the valve body 36. An O-ring 200 as a seal member seals between the outer peripheral wall of the pipe member 31 and the inner peripheral wall of the pump housing 51.
The valve spring 34 biases the movable core 33 in a direction away from the fixed core 32. The fixed core 32, the movable core 33, the fixed member 37, the pipe member 31, and the yoke 16 constitute a magnetic circuit, and resist the urging force of the valve spring 34 by the magnetic attraction generated by energizing the coil 14. The movable core 33 is sucked upward in FIG. 1 toward the fixed core 32.

  The valve body 36 is entirely accommodated in a pump housing 51 and a cylinder 52 constituting a housing of the pump unit 50. A screw thread formed on the outer peripheral wall of the valve body 36 and a screw thread formed on the inner peripheral wall of the cylinder 52 are screwed together. The screw joint between the valve body 36 and the cylinder 52 is immersed in the fuel.

  The valve body 36 is formed in a cylindrical shape, and a communication hole 103 that connects the cylindrical internal flow path 102 and the fuel inflow path 100 is formed in a portion facing the fuel inflow path 100. The internal flow path 102 and the communication hole 103 constitute a communication path that allows the fuel inflow path 100 and the fuel pressurizing chamber 101 to communicate with each other. When the valve member 35 is seated on the valve seat 36 a of the valve body 36, the internal flow path 102 is closed and the communication between the fuel inflow path 100 and the fuel pressurizing chamber 101 is blocked. Low pressure fuel is supplied to the fuel inflow passage 100 from a low pressure pump (not shown). The valve body 36 holds a stopper plate 38 that restricts the amount of movement of the valve member 35 in the valve opening direction below FIG. 1 by the biasing force of the valve spring 34 when the coil 14 is not energized. . The stopper plate 38 has a notch on the outer periphery, and the fuel flows from the fuel inflow path 100 through the communication hole 103 and the internal flow path 102 into the fuel pressurizing chamber 101 through the notch. The annular member 39 is fixed to the fuel pressurizing chamber 101 side in the valve body 36 and supports the stopper plate 38.

  The coil unit 11 is an electromagnetic drive unit that applies a driving force to the valve unit 30. The coil unit 11 is installed on the outer peripheral side of the fixed core 32 and the movable core 33. The coil portion 11 includes a bobbin 13 and a coil 14 wound around the bobbin 13, and the outer periphery is covered with a yoke 16. The connector 12 is a mold resin that covers the bobbin 13 and the coil 14. The terminal 15 is electrically connected to the coil 14. The coil part 11 is rotatable around the pipe member 31.

The yoke 16 is made of metal and covers the outer periphery of the coil portion 11. The tolerance of the yoke 16 is controlled so as to come into contact with the pipe member 31, and the yoke 16 is rotatable around the pipe member 31 like the coil portion 11.
The fixing member 37 is a female screw in which a thread that meshes with the thread of the fixed core 32 described above is formed on the inner peripheral wall of the bottomed hole. The hole may be an opening that penetrates instead of a bottomed hole. The fixing member 37 is screwed to the screw thread of the fixing core 32. When the fixing member 37 is screwed, the surface facing the pump housing 51 abuts against the yoke 16 and presses the yoke 16 against the pump housing 51. Thereby, the yoke 16 is clamped and fixed between the fixing member 37 and the pump housing 51. When the yoke 16 is fixed by the fixing member 37, the connector is first rotated around the axis of the pipe member 31 to finely adjust the angle of the connector. Next, the yoke 16 is pressed against the pump housing 51 by screwing the fixing member 37.

  Next, the pump unit 50 will be described. The housing of the pump unit 50 includes a pump housing 51 and a cylinder 52. The pump housing 51 forms a fuel inflow passage 100 and is separate from the cylinder 52. The pump housing 51 covers the fuel pressurizing chamber 101 side of the cylinder 52 and is coupled to the mounting member 55 with a plurality of bolts 56. The cylinder 52 is sandwiched between the pump housing 51 and the mounting member 55 by the coupling force of the bolts 56. An O-ring 201 seals between the pump housing 51 and the cylinder 52.

  The cylinder 52 supports a plunger 60 as a movable member so as to be able to reciprocate. A fuel pressurizing chamber 101 is formed by the inner peripheral wall of the cylinder 52, the plunger 60 and the valve member 35. One end of the plunger spring 61 is in contact with the spring seat 62 and the other end is in contact with the spring seat 63. The plunger spring 61 presses the spring seat 62 against the bottom inner wall of the tappet 64. The spring seat 62 locks the head 60 a of the plunger 60. The spring seat 63 is sandwiched between the upper portion of the tappet guide 65 and the cylinder 52. The bottom outer wall 64a of the tappet 64 is in contact with a pump cam attached to the valve camshaft of the engine. The tappet guide 65 is formed in a substantially cylindrical shape, and the tappet 64 is slidably supported by the inner peripheral wall. The cylinder 52 and the spring seat 63, the spring seat 63 and the tappet guide 65, and the gap between the tappet guide 65 and the attachment member 55 are sealed with O-rings.

  The delivery valve 70 is screw-coupled to the cylinder 52 and forms a fuel discharge passage 104 that can communicate with the fuel pressurizing chamber 101. The delivery valve 70 includes a valve seat member 71, a valve member 72, and a spring 73. When the fuel pressure in the fuel pressurizing chamber 101 exceeds a predetermined pressure, the valve member 72 is separated from the valve seat member 71 against the urging force of the spring 73, and the fuel pressurizing chamber 101 and the fuel discharge passage 104 communicate with each other. To do. Then, the fuel is pumped to a fuel pipe (not shown) connected to the delivery valve 70. The fuel pumped from the delivery valve 70 is supplied to a pressure accumulating pipe (not shown).

Next, the operation of the fuel supply device 1 will be described by dividing it into (1) a fuel intake stroke and (2) a fuel pressurized pressure delivery stroke.
(1) Fuel intake stroke As the valve cam shaft rotates, the pump cam rotates, and the plunger 60 reciprocates together with the tappet 64 and the spring seat 62. When the energization of the coil 14 of the solenoid valve 10 is interrupted and the plunger 60 moves from the upper side of FIG. 1 which is the top dead center to the lower side of FIG. Is separated from the valve seat 36a and the solenoid valve 10 is opened. At this time, when the plunger 60 moves downward in FIG. 1, the low-pressure fuel discharged from the low-pressure fuel pump flows into the fuel pressurizing chamber 101 through the fuel inflow path 100, the communication hole 103, and the internal flow path 102. . When the plunger 60 is located at the bottom dead center, the maximum amount of low-pressure fuel flows into the fuel pressurizing chamber 101.

(2) Pressurized pressure feeding stroke of fuel When the plunger 60 reaches the position corresponding to the desired fuel feeding amount in the stroke in which the plunger 60 moves from the bottom dead center to the top dead center, the electronic control unit Energization of the coil 14 is turned on. As a result, the movable core 33 is sucked toward the fixed core 32 and the valve member 35 is seated on the valve seat 36a. That is, the electromagnetic valve 10 is closed. Thereafter, when the plunger 60 further moves to the top dead center side, the fuel in the fuel pressurizing chamber 101 becomes a high pressure. When the fuel pressure in the fuel pressurizing chamber 101 rises above a predetermined pressure, the valve member 72 is separated from the valve seat member 71 against the biasing force of the spring 73. Then, the high pressure fuel in the fuel pressurizing chamber 101 is pumped from the fuel discharge passage 104.

According to the electromagnetic valve 10 according to the first reference embodiment of the present invention described above, the fixing member 37 is screwed to the end portion 32a of the fixing core 32, and the screwed fixing member 37 pushes the yoke 16 against the pump housing 51. Since the contact is positioned, the yoke 16 can be fixed to the pump housing 51 without being press-fitted into the fixed core 32 or welded to the pump housing 51. Therefore, strict tolerance is not required for the diameter of the press-fitting portion of each member as compared with the case of press-fitting, and the tolerance management becomes easy. Moreover, since welding is unnecessary, expensive welding equipment is unnecessary. Therefore, according to the solenoid valve 10, the manufacturing cost of the solenoid valve 10 can be reduced.

Further, the coil portion 11 and the yoke 16 of the electromagnetic valve 10 can rotate around the pipe member 31 until they are fixed by the fixing member 37. For this reason, the operator can easily fine-tune the position of the connector. Therefore, according to this electromagnetic valve 10, the positioning of the connector is easier than in the case of press-fitting.
Further, since the fixing member 37 of the first reference form is screwed to the fixing core 32, the yoke 16 can be easily fixed.

(First Embodiment)
A first embodiment of the present invention is shown in FIG. Components that are substantially the same as those of the first reference embodiment are denoted by the same reference numerals, and description thereof is omitted.
The pipe member 112 of the first embodiment has a tapered surface 113 that increases the outer diameter of the pipe member 112 from the fixed core 32 side toward the movable core 33 side. The yoke 111 also has a tapered surface 114 that is in surface contact with the tapered surface 113 of the pipe member 112. When the yoke 111 is pressed against the movable core 33 side of the pipe member 112 by the fixing member 37, the taper surface 114 of the yoke 111 and the taper surface 113 of the pipe member 112 are closely fixed as shown in the figure.

According to the electromagnetic valve 110 of the first embodiment, the pipe member 112 has the tapered surface 113. For this reason, the yoke 111 can be stably brought into contact with the pipe member 112 as a part of the housing, and the operation failure of the magnetic circuit due to the contact failure between the housing and the yoke 111 can be reduced. In addition, since the taper surface of the pipe member 112 can be easily produced by press working, it is possible to reduce operation failure at a low cost.
Further, since the yoke 111 also has the tapered surface 114 that comes into surface contact with the tapered surface 113 of the pipe member 112, the yoke 111 can be brought into more stable contact.

( Second Embodiment)
A second embodiment of the present invention is shown in FIG. Components that are substantially the same as those in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.
The housing of the solenoid valve 120 of the second embodiment includes a first cylindrical member 122 and a second cylindrical member 123 as a cylindrical member instead of the pipe member of the first embodiment. The first cylindrical member 122 is formed of a nonmagnetic material, and is fixed to the fixed core 32 and the second cylindrical member 123 by welding. The second cylindrical member 123 is made of a magnetic material. The second cylindrical member 123 gradually increases in thickness toward the stopper plate 38 side with a constant inner diameter, and extends to the stopper plate 38 side with a constant thickness after reaching a certain thickness. The second cylindrical member 123 has a constant inner diameter and gradually becomes thick, so that a tapered surface 124 is formed as illustrated. Since the first cylindrical member 122 is made of a non-magnetic material, the magnetic flux can move in the order of the second cylindrical member 123, the yoke 111, and the fixed core 32 when energized to generate magnetism in the coil 14. A magnetic circuit flowing in the core 33 can be formed. For this reason, by making it difficult for the magnetic flux to flow through the first cylindrical member 122, more magnetic flux can flow from the fixed core 32 to the movable core 33, and the suction force for attracting the movable core 33 can be increased. .

According to the electromagnetic valve 120 of the second embodiment, since the second cylindrical member 123 has the tapered surface 124 and the yoke 111 has the tapered surface 114, the yoke 111 is more twisted as in the first embodiment. It can be stably brought into contact with the second cylindrical member 123, that is, the housing.

( Second reference form)
A second reference embodiment of the present invention is shown in FIG. FIG. 4A is a top view of the electromagnetic valve 130 according to the second reference embodiment, and FIG. 4B is a cross-sectional view of the electromagnetic valve 130. In FIG. 4, the pump portion is omitted. Components that are substantially the same as those of the first reference embodiment are denoted by the same reference numerals, and description thereof is omitted.

Solenoid valve 130 of the second reference embodiment does not have a second cylindrical member 123 of the second embodiment as shown in FIG. 4 (B), the mounting of the first tubular member 122 as a housing It is fixed to the flange 132 by welding. The yoke 131 is pressed against the mounting flange 132 by the fixing member 37 and fixed. The mounting flange 132 is made of a magnetic material, and forms a magnetic circuit together with the yoke 131 and the like.

If it has a mounting flange 132 formed of a magnetic material as shown in the second reference embodiment, pressing the second yoke 131 not provided with the tubular member 123 as in the second embodiment directly mounting flange 132 You may do it.

(Other embodiments)
In the first reference embodiment, the fitting hole 40 of the yoke 16 is in contact with the pipe member 31, but the length of the pipe member 31 may be shortened and the fitting hole 40 may be in contact with the fixed core 32 .
Further, the yoke and the fixed core may be formed of the same material. Specifically, for example, both may be formed of ferritic stainless steel. In the case of fixing by press-fitting, if the yoke and the fixed core are of the same material, adhesion (burn-in) may occur and the press-fitting load may be further increased. However, as described in each embodiment, the yoke and the fixed core Is not fixed by press-fitting, no adhesion occurs, and even if the yoke and the fixed core are formed of the same material, the press-fitting load does not increase.

It is sectional drawing which shows the solenoid valve by the 1st reference form of this invention. It is sectional drawing which shows the solenoid valve by 1st Embodiment of this invention. It is sectional drawing which shows the solenoid valve by 2nd Embodiment of this invention. It is sectional drawing which shows the solenoid valve by the 2nd reference form of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel supply apparatus, 10 Solenoid valve, 14 Coil, 16 Yoke, 31 Pipe member (housing, cylindrical member), 32 Fixed core, 33 Movable core, 37 Fixed member, 40 Fitting hole, 51 Pump housing (housing), 110 solenoid valve, 111 yoke, 112 pipe member (housing, cylindrical member), 113 taper surface, 114 taper surface, 120 solenoid valve, 122 first cylindrical member (cylindrical member), 123 second cylindrical member (Housing, cylindrical member), 130 solenoid valve, 131 yoke, 132 mounting flange (housing)

Claims (5)

A fixed core;
A movable core facing one end of the fixed core in the axial direction;
A coil that is installed on an outer peripheral side of the fixed core and the movable core, and generates a magnetic force for attracting the movable core to the fixed core;
A housing made of a magnetic material and having a cylindrical member covering the outer periphery of the movable core;
A yoke that covers an outer periphery of the coil and magnetically connects the fixed core and the housing;
A fixing member for fixing the yoke to the housing;
Equipped with a,
The cylindrical member has a tapered surface that increases the outer diameter of the cylindrical member from the fixed core side toward the movable core side,
The electromagnetic valve according to claim 1 , wherein the fixing member is fixed by pressing the yoke against the tapered surface .   The solenoid valve according to claim 1, wherein the fixing member is screwed to an end portion of the fixed core opposite to the one end portion, and the yoke is pressed against the housing to be fixed.   The electromagnetic valve according to claim 1, wherein the fixing member is made of a magnetic material. The electromagnetic valve according to claim 1, wherein the yoke has a tapered surface that is in surface contact with the tapered surface of the cylindrical member. The solenoid valve according to any one of claims 1 to 4, wherein the yoke and the fixed core are made of the same material.

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