JP6231392B2 - Solenoid valve - Google Patents

Description

  The present invention relates to a solenoid valve in which a valve member is displaced when energization / energization is stopped with respect to an electromagnetic coil constituting a solenoid unit.

  A variable valve timing mechanism that varies the opening / closing timing of an intake / exhaust valve of an automobile engine operates by circulating and supplying hydraulic oil adjusted to a predetermined pressure. Switching between supplying hydraulic oil to the variable valve timing mechanism or stopping the supply, or switching the supply destination to either the retarding chamber or the advance chamber, etc. Is done by. As described in Patent Document 1, this type of solenoid valve has a solenoid portion including a bobbin coil in which an electromagnetic coil is wound around a bobbin.

  Here, in the case of the solenoid valve disclosed in Patent Document 1, the solenoid portion further includes an upper fixed core as a housing (yoke), a lower fixed core composed of a stator and a collar, and a plunger as a movable core. Including. The collar is provided with a cylindrical protrusion protruding toward the stator, and the cylindrical protrusion is inserted into the through hole of the stator together with the vicinity of the lower end of the cylindrical portion of the cup-shaped member.

  In this configuration, when the electromagnetic coil is energized, the plunger (movable core) is drawn toward the lower fixed core (stator and collar) side. That is, the plunger is displaced. Along with this, the shaft member connected to the plunger presses the spool that is the valve member while being displaced in the same direction as the plunger. As a result, the spool is displaced by this pressing, and as a result, the supply destination of the hydraulic oil discharged from the variable valve timing mechanism and introduced into the valve hole of the solenoid valve is changed from, for example, the retard chamber to the advance chamber of the variable valve timing mechanism. Can be switched.

  The shaft member is passed through the loose insertion hole formed in the cylindrical projection of the collar so that a predetermined play is provided.

JP 2007-182938 A

  The hydraulic fluid discharged from the variable valve timing mechanism includes metal powder (swarf) generated as members slide inside the engine. As described above, since the hydraulic oil is returned to the solenoid valve, the solenoid valve is provided with a filter in order to prevent chips from entering the valve hole.

  Nevertheless, for example, there is a concern that chips smaller than the eyes of the filter enter the valve hole, and then reach the plunger through play between the loose insertion hole and the shaft member. When such a situation occurs, the magnetic characteristics of the solenoid unit are affected. Further, when the chips are caught between the plunger and the cup-shaped member, the plunger is prevented from being displaced.

  The present invention has been made to solve the above-described problems, and can prevent foreign matters such as chips from reaching the plunger, and therefore, the magnetic characteristics of the solenoid portion are affected by the foreign matters. It is an object of the present invention to provide a solenoid valve capable of avoiding hindrance and obstruction of plunger displacement.

In order to achieve the above-described object, the present invention includes a bobbin coil in which an electromagnetic coil is wound around a bobbin, and includes a solenoid unit housed in a housing, and the inside of a valve body as the electromagnetic coil is energized or stopped. A solenoid valve having a valve member that displaces
The solenoid unit further includes:
A first core having an outer core member having a cylindrical portion in which a press-fitting hole is formed, and an inner core member having a through-hole formed therein and accommodated in the press-fitting hole;
A plunger that is displaced in the housing in accordance with energization or deenergization of the electromagnetic coil,
A shaft portion that is passed through the through hole of the inner core member and abuts on the valve member, and is displaced following the displacement of the plunger;
A second core inserted into an inner hole of the bobbin;
A guide collar made of a cylindrical body with a bottom, the opening end of which is inserted into the press-fitting hole of the cylindrical portion, and the plunger is inserted therein so as to be displaceable.
Comprising
The inner core member is located between a large diameter end portion having a maximum diameter, a small diameter end portion having a minimum diameter, and between the large diameter end portion and the small diameter end portion, and the diameter is the large diameter end portion. A medium diameter portion smaller than the portion and larger than the small diameter end portion,
A first step portion is formed that is recessed inward in the diametrical direction from the bottom surface of the large-diameter end portion to the middle diameter portion, and is spaced apart from the first step portion by a predetermined angle. Over the bottom surface of the small-diameter end portion, a second stepped portion is formed that is depressed inward in the diameter direction.
The small-diameter end portion faces the opening end of the guide collar, and the large-diameter end portion is press-fitted into the press-fitting hole.

  In the solenoid valve having this configuration, in order for the pressure fluid (for example, hydraulic oil) to move from the valve hole to the plunger side, the fluid flows through the flow path formed by the first step portion, the middle diameter portion, and the second step portion. There must be. Here, the first step portion and the second step portion are separated by a predetermined angle (most preferably about 180 °), and a phase difference is generated. For this reason, the flow path has a labyrinth structure including a so-called crank flow path.

  When foreign substances such as chips are accompanied with the pressure fluid, the foreign substances pass through the crank flow path (labyrinth structure) together with the pressure fluid. In this flow process, foreign matter in the pressure fluid is captured by the crank passage.

  That is, by providing the inner core member with a diameter difference in the axial direction and providing a step at a predetermined angle on the side wall, it is possible to form a flow path that easily captures foreign matter. In other words, it is difficult for the foreign matter that has entered the valve hole to pass through the flow path forming the labyrinth structure and reach the plunger side.

  For this reason, it is avoided that the magnetic characteristics of the solenoid portion are affected due to foreign matters. Further, it is possible to prevent foreign matter from being caught between the plunger and a member surrounding the plunger and preventing the plunger from being displaced. Therefore, the magnetic characteristics are maintained well, and the attractive force of the plunger is maintained.

  As described above, by providing a flow path that forms a labyrinth structure between the valve hole and the plunger, a solenoid valve that can maintain the magnetic characteristics of the solenoid part satisfactorily and maintain the plunger's attractive force is configured. can do.

  When using this solenoid valve, that is, when positioning and fixing the solenoid valve to a variable valve timing mechanism or the like, the large-diameter end of the inner core member is positioned on the lower side, and the small-diameter end is on the upper side. It is preferable to set the attitude of the solenoid valve so as to be positioned at the position.

  In this case, the valve hole is downward and the plunger is upward. Therefore, when the pressure fluid flows from the valve hole to the plunger side via the flow path, the pressure fluid moves from the lower side to the upper side in the solenoid valve. For this reason, gravity acts on the hydraulic oil flowing through the flow path and the foreign matter contained in the hydraulic oil.

  Accordingly, the foreign matter is easily captured by the lower wall in the flow path. This makes it more difficult for foreign matter to pass through the flow path, so that foreign matter can be captured more easily.

  Moreover, it is preferable that the clearance formed between the inner wall of the through-hole formed in the inner core member and the shaft portion passed through the through-hole is 20 μm or less. This is because, if the clearance is this level, it is difficult for foreign matter to pass through and the shaft portion is not prevented from sliding.

  According to the present invention, the inner core member is provided with a difference in diameter in the axial direction, and the side wall thereof is provided with a step separated by a predetermined angle. Therefore, the inner core member and the outer core member are provided. In between, a labyrinth structure can be formed to form a channel that easily captures foreign matter. For this reason, even if a foreign substance enters the valve hole, it is difficult for the foreign substance to pass through the flow path and reach the plunger side.

  For this reason, it is avoided that the magnetic characteristics of the solenoid portion are affected due to foreign matters. Further, it is possible to prevent foreign matter from being caught between the plunger and a member surrounding the plunger and preventing the plunger from being displaced. Eventually, a solenoid valve can be configured in which the magnetic characteristics are maintained well and the attractive force of the plunger is kept good.

1 is an overall schematic cross-sectional view along the axial direction of a solenoid valve according to an embodiment of the present invention. 2A is an overall schematic perspective view of the inner core member, and FIG. 2B is an overall schematic front view. FIG. 3A is a developed view of the housing, and FIG. 3B is an overall schematic perspective view. It is a perspective sectional view of a core assembly constituted by a lower core (outer core member and inner core member) as a first core and a guide collar that houses a plunger.

  Preferred embodiments of the solenoid valve according to the present invention will be described below in detail with reference to the accompanying drawings. In the following description, “down”, “up”, “left”, and “right” in the description with reference to FIG. 1 mean “down”, “up”, left, and right in FIG. The same applies to other drawings.

  FIG. 1 is an overall schematic cross-sectional view along the axial direction of a solenoid valve 10 according to the present embodiment. The solenoid valve 10 includes a solenoid portion 14 accommodated in a housing 12 and a spool 18 (valve member) that is displaced in the valve body 16 under the electromagnetic action of the solenoid portion 14. That is, a valve hole 20 is formed in the valve body 16, and the spool 18 is slidably accommodated in the valve hole 20.

  For example, the solenoid valve 10 can be used as a predetermined external device (for example, a variable valve timing mechanism that can change the opening / closing timing of an intake / exhaust valve of an automobile engine) such that the valve body 16 is downward and the solenoid portion 14 is upward. Provided. That is, the vertical direction shown in FIG. 1 corresponds to the vertical direction during actual use according to one embodiment.

  A recess is formed at the lower end of the valve body 16 so that the first spring receiving portion 22 and the spool receiving portion 24 are connected. On the other hand, at the lower end of the spool 18, a second spring receiving portion 26 is formed so as to be recessed upward at a position facing the first spring receiving portion 22. A coil spring 28 is disposed on the first spring receiving portion 22 and the second spring receiving portion 26. That is, the lower end portion and the upper end portion of the coil spring 28 are respectively seated on the bottom surface of the first spring receiving portion 22 and the ceiling surface of the second spring receiving portion 26. Therefore, the coil spring 28 always urges and urges the spool 18 toward the solenoid portion 14 side.

  The spool 18 is a hollow body in which an inner chamber 30 is formed along the axial direction. The inner chamber 30 is opened by the second spring receiving portion 26 formed at the lower end portion of the spool 18. Further, four first passage holes 32 and four second passage holes 34 communicating with the inner chamber 30 are formed on the side wall of the spool 18. In FIG. 1, three of them are shown.

  A relatively long annular groove 36 is formed in the outer peripheral wall of the spool 18 so as to be recessed inward in the diameter direction. On the other hand, the valve body 16 is formed with an input port 38, a first output port 40, a second output port 42, and a drain port 44 that communicate with the valve hole 20. Depending on the position of the spool 18, the output destination of the pressure fluid (for example, hydraulic fluid) input from the input port 38 is switched to either the first output port 40 or the second output port 42.

  At least the input port 38, the first output port 40, and the second output port 42 are provided with a filter (not shown). These filters are intended to prevent foreign matters such as chips (metal powder) from entering the valve hole 20 along with the pressure fluid (for example, hydraulic oil).

  An annular recess 46 is formed above the valve body 16. The first seal member 48 accommodated in the annular recess 46 seals between the solenoid valve 10 and an external device (not shown).

  An annular step portion 52 is formed in a recessed manner on the upper end surface of the maximum diameter portion 50 of the valve body 16. The valve hole 20 opens at the bottom of the annular step 52. The annular step portion 52 accommodates a second seal member 54 that seals between the valve body 16 and the solenoid portion 14.

  The solenoid unit 14 includes a lower core 56 (first core), an upper core 58 (second core), and a plunger 60. Among these, the lower core 56 and the upper core 58 are fixed cores that are positioned and fixed in the housing 12, while the plunger 60 is a movable core that can be displaced in the vertical direction in the housing 12. The housing 12 also functions as a fixed core. The solenoid unit 14 further includes a bobbin coil 66 in which an electromagnetic coil 64 is wound around a bobbin 62.

  The lower core 56 includes an outer core member 68 and an inner core member 70 that is press-fitted into the outer core member 68. The outer core member 68 includes a large-diameter flange portion 72 and a cylindrical portion 74 extending upward from the flange portion 72. The flange portion 72 and the cylindrical portion 74 have an axis line. A press-fit hole 76 is formed through the direction. In addition, the inner diameter of the cylindrical portion 74 is substantially equal, but the outer diameter is reduced in a taper shape near the opening of the press-fitting hole 76 facing the plunger 60. For this reason, the outer diameter of the end of the cylindrical portion 74 on the side facing the plunger 60 is set to be smaller than that of other portions.

  Since the shape of the outer core member 68 is simple as described above, the outer core member 68 can be easily formed by press working.

  The entire inner core member 70 and a part of the guide collar 78 are accommodated in the press-fit hole 76 of the outer core member 68. Here, the guide collar 78 has a cylindrical shape with one end being an open end and the other end having a bottom wall. Only the vicinity of the opening end of the guide collar 78 is inserted into the press-fit hole 76 so that a slight clearance is generated with respect to the inner wall of the press-fit hole 76. A circular hole 80 (see particularly FIG. 4) is formed through the bottom wall of the guide collar 78.

  A through hole 82 is formed in the inner core member 70 at a position having the same axis as the press-fit hole 76 of the outer core member 68. A shaft 84 (shaft portion) whose lower end surface is in contact with the spool 18 and whose upper end surface is in contact with the plunger 60 is passed through the through hole 82. The shaft 84 may be provided integrally with the plunger 60 as a part of the plunger 60 (that is, provided as the same member as the plunger 60).

  The diameter of the through hole 82 is set slightly larger than the diameter of the shaft 84 so that the shaft 84 can be easily displaced in the through hole 82. For this reason, a slight clearance is formed between the shaft 84 and the inner wall of the through hole 82. The clearance is preferably 20 μm or less.

  The inner core member 70 has an outer diameter that changes from the bottom to the top. Specifically, the outer diameter of the lower end portion in FIGS. 1, 2A and 2B is the largest, and the outer diameter of the upper end portion is the smallest. And in the middle part located between a lower end part and an upper end part, the outer diameter is set smaller than a lower end part and larger than an upper end part. Hereinafter, the lower end portion, the middle abdomen portion, and the upper end portion are referred to as a large-diameter end portion, a medium-diameter portion, and a small-diameter end portion, and reference numerals 86, 88, and 90 are used.

  The small diameter end portion 90 is press-fitted into the guide collar 78, and the medium diameter portion 88 and the large diameter end portion 86 are exposed from the guide collar 78. In the exposed portion, the outer wall of the large-diameter end portion 86 that is one end portion of the inner core member 70 contacts the inner wall of the press-fit hole 76. That is, the diameter of the large-diameter end portion 86 is slightly larger than the inner diameter of the press-fit hole 76, and thus the large-diameter end portion 86 is press-fit into the press-fit hole 76. The inner core member 70 is supported in the press-fitting hole 76 by this press-fitting.

  As understood from the above, the inner core member 70 has the large-diameter end portion 86 facing the flange portion 72 side of the outer core member 68 and the small-diameter end portion 90 facing the opening end of the guide collar 78. The entirety is accommodated in the press-fitting hole 76 of the outer core member 68.

  The outer wall of the inner core member 70 is formed with a first step portion 92 and a second step portion 94 that are recessed toward the diametrically inner side (in other words, the through hole 82 side). The first step portion 92 and the second step portion 94 are separated by a predetermined angle, for example, about 180 °. Needless to say, a clearance is formed between the first step portion 92 and the inner wall of the press-fitting hole 76.

  The first step portion 92 extends from the bottom surface of the large diameter end portion 86 to the vicinity of the boundary between the medium diameter portion 88 and the small diameter end portion 90. On the other hand, the second step portion 94 extends from the vicinity of the boundary between the large diameter end portion 86 and the medium diameter portion 88 to the bottom surface of the small diameter end portion 90. Therefore, the position of the upper end of the first step portion 92 is located higher than the lower end of the second step portion 94.

  Returning to FIG. 1, the plunger 60 is accommodated in the guide collar 78. As will be described later, the plunger 60 is displaced (raised or lowered) in the guide collar 78 in accordance with the energization amount to the electromagnetic coil 64 constituting the solenoid unit 14. Note that a breathing hole 96 is formed through the plunger 60 along the axial direction. For example, when the plunger 60 is lowered, the fluid between the inner core member 70 and the lower end surface of the plunger 60 passes between the upper end surface of the plunger 60 and the bottom wall of the guide collar 78 via the breathing hole 96. Moving.

  The upper part of the guide collar 78 from the substantially middle part in the axial direction is inserted into the upper core 58 formed of a bottomed cylindrical body. By this insertion, the upper core 58 is externally mounted on the upper end portion of the guide collar 78. A web washer 98 as an elastic member is interposed between the outer surface of the bottom wall of the guide collar 78 and the inner surface of the bottom wall of the upper core 58.

  In this case, the thickness T1 of the bottom wall of the upper core 58 is set smaller than the thickness T2 of the side wall (that is, a value obtained by subtracting the inner diameter from the outer diameter of the upper core 58). In short, T1 <T2. T2 is preferably 1.2 to 1.4 times T1.

  The outer diameter of the upper core 58 is substantially equal along the axial direction (vertical direction in FIG. 1). That is, the upper core 58 is not provided with a large-diameter portion that protrudes outward in the diameter direction, a small-diameter portion that is recessed inward in the diameter direction, or the like.

  Thus, the upper core 58 is a simple bottomed cylindrical body, and its shape is remarkably simple. For this reason, the upper core 58 can also be easily manufactured by press working.

  The bobbin coil 66 is provided with a resin-made coil mold body 102 integrally molded with the coupler portion 100, and in this state, is disposed above the flange portion 72 of the outer core member 68.

  The coil mold body 102 will be described. A first receiving groove 104 and a second receiving groove 106 are recessed and formed on the lower end surface and the upper end surface, respectively. A third seal member 108 and a fourth seal member 110 are housed in the first housing groove 104 and the second housing groove 106. The third seal member 108 seals between the flange portion 72 of the outer core member 68 and the coil mold body 102, and the fourth seal member 110 seals between the coil mold body 102 and the housing 12.

  A terminal 112 provided in the coupler unit 100 is electrically connected to the electromagnetic coil 64 wound around the bobbin 62. Energization of the electromagnetic coil 64 is performed by a current supply source (not shown) that is electrically connected to the terminal 112.

  An inner hole 114 is formed through the bobbin 62 along the axial direction. A cylindrical portion 74 of the outer core member 68 is inserted below the inner hole 114. An upper core 58 is inserted above the inner hole 114. The upper end portion of the cylindrical portion 74 and the lower end portion of the upper core 58 are slightly separated from each other. For this reason, a part of the guide collar 78 is exposed in the inner hole 114. Of course, a predetermined clearance is formed between the portion of the guide collar 78 exposed from the outer core member 68 and the upper core 58 and the inner wall of the inner hole 114.

  The upper core 58 is merely inserted into the inner hole 114 and is not connected to the housing 12 or the bobbin 62. That is, the upper core 58 is in an unconstrained state with respect to the housing 12 and the bobbin 62. For this reason, for example, when the valve main body is detached from the housing 12 and the lower core 56 is pulled out from the inner hole 114 and the housing 12 or the bobbin 62 is directed downward, the upper core 58 and the like are moved to the bobbin 62 only by the action of gravity. Can be taken out easily.

  As shown in FIGS. 3A and 3B, the housing 12 includes a substantially circular bottom plate portion 116, a pair of sandwiching side plate portions 118, 120 connected to the bottom plate portion 116, and the sandwiching side plate portions 118, 120. And the stay side plate 122. 3A is a developed view, and FIG. 3B is an overall schematic perspective view of the housing 12 manufactured by pressing from FIG. 3A.

  As can be understood from FIGS. 3A and 3B, the housing 12 includes a sandwiching side plate portion 118, 120 and a stay side plate portion 122 (a plurality of side plate portions) that are bent with respect to the bottom plate portion 116. By being curved in an arc shape inward in the diameter direction of the portion 116, a substantially cylindrical body is formed. As shown in FIG. 1, the bottom plate portion 116 is located above and becomes a ceiling portion.

  In the housing 12, a large slit 124 is formed between the holding side plate portions 118 and 120, and the small slit 126 and the stay side plate portion 122 are held between the holding side plate portion 118 and the stay side plate portion 122. A small slit 128 is formed between the side plate portions 120. The solenoid part 14 is mainly held by the holding side plate parts 118 and 120, and the coupler part 100 is exposed from the large slit 124 (see FIG. 1).

  The stay side plate portion 122 is narrower and longer than the sandwiching side plate portions 118 and 120 (see FIG. 3A). A part of the stay side plate portion 122 is bent toward the outside in the diameter direction of the housing 12 so as to include an end portion (tongue piece portion 132) through which the insertion hole 130 is formed (see FIG. 3B). ).

  The insertion hole 130 is a hole through which a fitting (not shown) (for example, a screw) for positioning and fixing the solenoid valve 10 to the attachment target is passed. That is, the tongue piece portion 132 provided by bending the end of the stay side plate portion 122 outward functions as a stay portion.

  Further, a step is provided on the inner surface of each of the sandwiching side plate portions 118 and 120 so as to bulge outward from the housing 12. Due to these steps, a substantially circular fitting step 134 is formed. The fitting step 134 is fitted with the maximum diameter portion 50 of the valve body 16 and the flange portion 72 of the outer core member 68.

  A large bending step 136 (see FIG. 1) in the radial direction is formed on the inner surface of the stay side plate portion 122 in comparison with the fitting step 134 formed on the sandwiching side plate portions 118 and 120.

  The solenoid valve 10 according to the present embodiment is basically configured as described above. Next, the function and effect will be described.

  In the solenoid valve according to the related art, it is necessary to form a housing in which the fixed core functioning as the upper core 58 is integrally connected to the ceiling surface by forging. In addition, it is also necessary to perform a cutting process for the fixed core to have a predetermined protruding length. That is, many steps are required to obtain the housing, which is expensive and complicated.

  On the other hand, in the solenoid valve 10 according to the present embodiment, the housing 12 and the upper core 58 are separate members, and the shape of the upper core 58 (bottomed cylindrical shape) is simple. Therefore, the upper core 58 can be easily manufactured by performing press processing (for example, deep drawing press processing) on the workpiece.

  The pressing is performed so that the thickness T1 of the bottom wall of the upper core 58 is smaller than the thickness T2 of the side wall. If T2 is in the range of 1.2 to 1.4 times T1, press working for forming the side wall of the upper core 58 will not be difficult.

  The housing 12 shown in FIG. 3B cuts out the workpiece shown in FIG. 3A from the plate material, and, for example, the holding side plate portions 118 and 120 and the stay side plate portion 122 are folded relative to the bottom plate portion 116. It is produced by bending and pressing the side plate portions 118, 120, 122 in an arc shape in the direction of approaching each other (inward in the diameter direction). Since the sandwiching side plate portions 118 and 120 are separated from each other, and the sandwiching side plate portion 118 and the stay side plate portion 122 are also separated from each other, the stay side plate portion 122 and the sandwiching side plate portion 120 are also separated from each other. The bending of the side plate portions 118, 120, 122 with respect to the portion 116 proceeds easily. Therefore, the housing 12 can also be easily manufactured.

  As the sandwiching side plate portions 118 and 120 and the stay side plate portion 122 are bent relative to the bottom plate portion 116, small slits 126 and 128 and a large slit 124 are formed. At the same time, the tongue piece 132 (stay portion) is formed by bending the end portion of the stay side plate portion 122 outward at the same time as the pressing.

  That is, in the present embodiment, the stay portion need not be a separate member from the main body of the housing 12. For this reason, the number of parts is reduced. Further, an operation (for example, welding) for joining the stay portion to the housing 12 becomes unnecessary. That is, the number of steps is reduced and the work is simplified. In addition, it is not necessary to perform cutting or drilling on the upper core 58. From the above, the number of steps required to obtain the housing 12 and the upper core 58 is reduced.

  Furthermore, when performing simple bending press processing as described above, it is possible to obtain a molded product from a relatively thick material as compared with deep drawing press processing. For this reason, since the housing 12 in which the small slits 126 and 128 and the large slit 124 are formed can be obtained with a thick wall, a magnetic path area can be secured during energization described later.

  Further, since the small slits 126 and 128 and the large slit 124 are formed, an excessive increase in weight is avoided even when the thick housing 12 is manufactured.

  Moreover, the press working apparatus has a lower capital investment than the forging process apparatus. This and the reduction in the number of steps as described above can reduce the cost.

  Apart from the above processes and operations, as shown in FIG. 4, a core assembly including the lower core 56, the guide collar 78 and the plunger 60 is produced.

  That is, first, the inner core member 70 and the outer core member 68 are individually manufactured. Since both the inner core member 70 and the outer core member 68 have simple shapes, both the core members 68 and 70 can be manufactured by pressing. For this reason, the cost can be reduced for the same reason as described above.

  Next, the inner core member 70 is press-fitted into the guide collar 78 from the opening end of the guide collar 78. Of course, the plunger 60 is inserted into the guide collar 78 in advance. The press-fitting is performed from the small diameter end 90 side of the inner core member 70.

  When a predetermined amount of the small diameter end portion 90 enters the inside of the guide collar 78, the press fitting is stopped. Accordingly, the guide collar 78 exposes the medium diameter portion 88 and the large diameter end portion 86 of the guide collar 78. Next, the guide collar 78 into which the inner core member 70 has been press-fitted is inserted from the opening of the press-fitting hole 76. At this time, the closed end portion side of the guide collar 78 is first inserted from the flange portion 72 side of the cylindrical portion 74.

  As the insertion proceeds, the closed end portion of the guide collar 78 is exposed from the press-fit hole 76, and the large-diameter end portion 86 reaches the press-fit hole 76. Since the diameter of the large diameter end portion 86 is slightly larger than the inner diameter of the press fit hole 76, the large diameter end portion 86 is press fit into the press fit hole 76.

  When the bottom surface of the large-diameter end portion 86 and the end surface of the flange portion 72 are substantially flush with each other, the press-fitting of the large-diameter end portion 86 into the press-fitting hole 76 is stopped. Since the height direction dimension of the inner core member 70 is smaller than the height direction dimension of the press-fit hole 76, the entire inner core member 70 is accommodated in the press-fit hole 76. Thus, a core assembly in which the guide collar 78 in which the plunger 60 is accommodated is supported by the lower core 56 is obtained.

  The press-fitting distance at this time is relatively short because the large-diameter end 86 of the inner core member 70 is press-fitted into the press-fitting hole 76. Therefore, the press-fitting work is easy. In addition, it is easy to avoid the occurrence of scratches, galling, and the like on the inner peripheral wall of the press-fitting hole 76 and the outer wall of the inner core member 70.

  In the core assembly assembled as described above, it is possible to avoid a positional shift between the axial centers of the plunger 60 and the outer core member 68. That is, the accuracy of the coaxiality between the plunger 60 and the outer core member 68 is improved. As described above, the guide collar 78 in which the plunger 60 is housed and the small-diameter end 90 of the inner core member 70 is press-fitted is inserted into the press-fit hole 76, and the large-diameter end of the inner core member 70 is inserted. This is because 86 is press-fitted into the press-fitting hole 76.

  Next, for example, the upper core 58 is attached to the end portion including the bottom wall in which the circular hole 80 of the guide collar 78 is formed via the web washer 98. As a result, the axial centers of the guide collar 78 and the upper core 58 substantially match each other, so that the accuracy of the coaxiality between the guide collar 78 and the upper core 58 is also improved. After all, it becomes easy to ensure the coaxiality of the outer core member 68, the plunger 60, and the upper core 58.

  Next, after passing the shaft 84 through the through hole 82, the flange portion 72 of the outer core member 68 constituting the core assembly, the maximum diameter portion 50 of the valve body 16 in which the spool 18 and the coil spring 28 are assembled in advance. And the cylindrical portion 74 of the outer core member 68 and the upper core 58 are passed through the inner hole 114 of the bobbin coil 66 covered with the coil mold body 102. On the contrary, after passing the cylindrical portion 74 and the upper core 58 of the outer core member 68 through the inner hole 114 of the bobbin coil 66 with the coil mold body 102 covered, the flange of the outer core member 68 is passed. The portion 72 and the maximum diameter portion 50 of the valve body 16 may be brought into contact with each other.

  Thus, in this embodiment, since both the guide collar 78 that houses the plunger 60 and the lower core 56 may be inserted into the inner hole 114 of the bobbin coil 66 as a core assembly, the solenoid portion 14 can be easily moved. Can be assembled.

  Next, the coil mold body 102 is covered with the housing 12. At this time, the phases of the large slit 124 and the coupler unit 100 are matched.

  A fitting step 134 is provided at the lower end of the inner surface of the housing 12. After the flange portion 72 of the outer core member 68 and the maximum diameter portion 50 of the valve body 16 are disposed inside the fitting step 134, so-called crimping is performed. With this caulking, the flange portion 72 and the maximum diameter portion 50 are fitted into the fitting step 134. By this fitting, the valve body 16 and the solenoid portion 14 are held by the housing 12 to constitute the solenoid valve 10.

  In the solenoid valve 10, the upper core 58 is attached to the guide collar 78, so that a support member or the like for positioning and fixing the upper core 58 to the housing 12 is unnecessary. That is, in the present embodiment, the upper core 58 is neither press-fitted into the housing 12 nor connected (restrained). Therefore, the assembling work is simplified and the working time is shortened accordingly. As a result, the solenoid valve 10 can be assembled efficiently. And it is avoided that the number of parts increases.

  In this configuration, the upper core 58 is elastically biased toward the housing 12 by the web washer 98. For this reason, the contact state of the upper core 58 with respect to the inner surface of the bottom plate portion 116 of the housing 12 becomes good. Therefore, the magnetic path is prevented from being interrupted between the housing 12 and the upper core 58.

  Thereafter, the solenoid valve 10 is incorporated in an external device such as a variable valve timing mechanism, and the terminal 112 is electrically connected to a current supply source (not shown). At this time, the first seal member 48 forms a seal between the solenoid valve 10 and the external device.

  The external device and the solenoid valve 10 are connected via an attachment (for example, a screw) that is passed through the insertion hole 130 of the stay side plate 122 that constitutes the housing 12.

  The solenoid valve 10 operates as follows.

  When the electromagnetic coil 64 constituting the bobbin coil 66 is not energized, as shown in FIG. 1, the coil spring 28 expands and elastically biases the spool 18. Accordingly, the spool 18 is located at the top dead center. In this state, the input port 38 and the valve hole 20 communicate with each other, and the valve hole 20 and the first output port 40 communicate with each other via the annular groove 36 of the spool 18. Further, the second output port 42 communicates with the drain port 44 through the valve hole 20, the first passage hole 32 and the inner chamber 30.

  Therefore, the pressure fluid (for example, hydraulic fluid) introduced into the valve hole 20 from the input port 38 is led out from the first output port 40 via the valve hole 20, for example, the retard chamber of the variable valve timing mechanism. Sent to.

  The pressure fluid is led out from the retarding chamber and then returned from the second output port 42 to the valve hole 20. The pressure fluid further enters the inner chamber 30 of the spool 18 through the first passage hole 32 formed in the side wall of the spool 18, and then passes through the opening formed in the second spring receiving portion 26, and then the drain port. 44 is discharged to the outside of the solenoid valve 10.

  From this state, current is supplied to the terminal 112 via the current supply source, whereby the electromagnetic coil 64 is energized. Accordingly, a magnetic field is generated between the lower core 56 (fixed core), the plunger 60 (movable core), the upper core 58 (fixed core), and the housing 12. That is, an electromagnetic force that attracts the plunger 60 to the lower core 56, particularly the tip of the cylindrical portion 74 of the outer core member 68 that is reduced in taper shape, is generated in the solenoid portion 14. As a result, the plunger 60 is displaced downward in the guide collar 78. At this time, the fluid between the inner core member 70 and the plunger 60 passes between the upper end surface of the plunger 60 and the inner surface of the bottom wall of the guide collar 78 through a breathing hole 96 formed in the plunger 60. Moving.

  Here, a circular hole 80 is formed in the bottom wall of the guide collar 78. For this reason, the contact area between the upper end surface of the plunger 60 and the inner surface of the bottom wall of the guide collar 78 is small. Therefore, the plunger 60 is prevented from sticking to the guide collar 78 due to the fluid that has moved between the upper end surface of the plunger 60 and the bottom wall of the guide collar 78. That is, the displacement of the plunger 60 by the fluid is not hindered.

  Further, since the bottom wall of the upper core 58 is in contact with the inner surface of the bottom plate portion 116 of the housing 12, the magnetic path is not blocked between the housing 12 and the upper core 58. In the upper core 58, the bottom wall thickness T1 is set smaller than the side wall thickness T2. For this reason, the inner surface of the bottom wall of the upper core 58 is close to the inner surface of the bottom plate portion 116 of the housing 12. As a result, the magnetic flux density increases, so that the magnetic characteristics (magnetic path efficiency) are improved. Accordingly, the suction force of the plunger 60 is improved.

  When the plunger 60 is displaced downward, the shaft 84 in contact with the lower end surface of the plunger 60 is pressed from the plunger 60 and displaced downward. Since a clearance of 20 μm or less is formed between the shaft 84 and the through hole 82 of the inner core member 70, the shaft 84 can be easily displaced. Further, if the clearance is about this level, the shaft 84 is prevented from being inclined. For this reason, it is avoided that the sliding resistance of the shaft 84 increases and the occurrence of galling.

  Further, for example, even when foreign matter such as chips is mixed into the pressure fluid and the foreign matter passes through the filter and flows into the annular stepped portion 52 from the valve hole 20, the shaft 84 and the through hole 82 Since the clearance between the inner wall and the inner wall is about 20 μm at the maximum, foreign matter is prevented from entering the through hole 82.

  In addition, when a fluid enters between the inner wall of the press-fit hole 76 and the outer wall of the inner core member 70, it is also conceivable that foreign matters are accompanied by the fluid.

  Here, as described above, the first step portion 92 and the second step portion 94 are provided on the inner core member 70 so as to be separated from each other by a predetermined angle (about 180 ° in the present embodiment). Accordingly, the fluid that has entered the press-fitting hole 76 rises along the first step portion 92, then circulates along the outer wall of the medium diameter portion 88, and further rises along the second step portion 94. . That is, in the inner core member 70, the flow path through which the pressure fluid can flow is a crank flow formed by the first step portion 92, the medium diameter portion 88, and the second step portion 94 as shown by arrows in FIG. 2B. Road.

  In the crank flow path, the total distance from the start point to the end point can be set long. In addition, since the crank channel is provided with a bending point, the fluid flow direction is also bent. That is, the crank passage has a labyrinth structure. It is difficult for foreign matter to circulate through the crank passage (labyrinth structure) which is long and has such a shape. Therefore, it is difficult for the foreign substances entrained by the fluid to pass through the crank passage and reach the guide collar 78, in other words, the plunger 60 side.

  In addition, the fluid flows through the crank passage from below to above. For this reason, since gravity acts on the fluid, gravity also acts on the foreign matter. Therefore, fluid or foreign matter is easily captured by the lower wall of the crank passage (particularly, the step between the large diameter end portion 86 and the medium diameter portion 88). This also prevents foreign matter from passing through the crank passage.

  That is, when foreign matter is mixed into the crank flow path, the foreign matter is captured in the course of flowing through the crank flow path. For the reasons described above, it is possible to avoid the foreign matter that has entered the press-fitting hole 76 from reaching the guide collar 78 (plunger 60 side).

  For this reason, it is avoided that the magnetic characteristic of the solenoid part 14 comprised including the bobbin coil 66, the lower core 56, the upper core 58, the plunger 60, etc. exerts the influence resulting from a foreign material. Further, since foreign matter is prevented from being caught between the plunger 60 and the guide collar 78 surrounding the plunger 60, the displacement of the plunger 60 is also prevented from being hindered.

  Therefore, in the solenoid valve 10, the magnetic characteristics of the solenoid portion 14 are maintained well, and the attractive force of the plunger 60 is kept good.

  Since the lower end surface of the shaft 84 is in contact with the upper end surface of the spool 18, the spool 18 is displaced downward following the displacement of the shaft 84. At this time, the coil spring 28 contracts.

  The amount of displacement of the plunger 60 and thus the spool 18 is controlled based on the current supplied to the electromagnetic coil 64. That is, the displacement amount is small when the current value is small and large when the current value is large.

  For example, when the displacement amount of the spool 18 is small, both the first output port 40 and the second output port 42 are blocked by the side wall of the spool 18. That is, the communication between the valve hole 20 and the first output port 40 and the second output port 42 is blocked. For this reason, pressure fluid is not led out from the solenoid valve 10.

  On the other hand, when the displacement amount of the spool 18 is maximum, in other words, when the spool 18 is located at the bottom dead center, the lower end surface of the spool 18 is seated on the spool receiving portion 24. In this case, the input port 38 communicates with the second output port 42 via the valve hole 20 and the annular groove 36. The first output port 40 communicates with the drain port 44 through the valve hole 20, the second passage hole 34, and the inner chamber 30.

  Accordingly, the pressure fluid introduced into the valve hole 20 from the input port 38 is led out from the second output port 42 via the valve hole 20 and the annular groove 36, and is sent, for example, to the advance chamber of the variable valve timing mechanism. It is done.

  After the pressure fluid is led out from the advance chamber, it is returned to the valve hole 20 from the first output port 40, and further enters the inner chamber 30 of the spool 18 through the second passage hole 34. Similarly, the liquid is discharged from the drain port 44 to the outside of the solenoid valve 10 through the opening.

  After an appropriate amount of pressurized fluid has circulated, the current supply from the current supply source to the terminal 112 is stopped, and the energization to the electromagnetic coil 64 is eventually stopped. Along with this, the electromagnetic force that has attracted the plunger 60 disappears. Accordingly, the coil spring 28 is extended to elastically bias the spool 18.

  For this reason, the spool 18, the shaft 84, and the plunger 60 are displaced upward and finally located at the top dead center. At this time, the fluid between the upper end surface of the plunger 60 and the inner surface of the bottom wall of the guide collar 78 moves between the lower end surface of the plunger 60 and the inner core member 70 through the breathing hole 96.

  As described above, the electromagnetic force is formed or disappears as the energization / energization of the electromagnetic coil 64 is repeated. Here, since the inner core member 70 is press-fitted into each of the guide collar 78 and the outer core member 68, and the upper core 58 is mounted on the guide collar 78, the upper core 58, the plunger 60, and the outer core member. 68 and the axial center of the inner core member 70 are substantially matched. That is, the accuracy of the coaxiality is improved. Accordingly, the hysteresis characteristic is improved.

  The present invention is not particularly limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

  For example, the solenoid valve 10 can be used even if it is attached to an external device in a recumbent posture or a posture that is upside down from FIG.

  Further, it is not particularly necessary to employ the spool 18 as the valve member. That is, the solenoid valve may be a so-called normally closed type that is closed when energization is stopped, or a so-called normal open type that is open when energization is stopped.

DESCRIPTION OF SYMBOLS 10 ... Solenoid valve 12 ... Housing 14 ... Solenoid part 16 ... Valve body 18 ... Spool 20 ... Valve hole 28 ... Coil spring 30 ... Inner chamber 36 ... Ring groove 38 ... Input port 40 ... 1st output port 42 ... 2nd output port 44 ... drain port 56 ... lower core 58 ... upper core 60 ... plunger 62 ... bobbin 64 ... electromagnetic coil 66 ... bobbin coil 68 ... outer core member 70 ... inner core member 72 ... flange portion 74 ... cylindrical portion 76 ... press-fitting hole 78 ... guide collar 80 ... circular hole 82 ... through hole 84 ... shaft 86 ... large diameter end 88 ... medium diameter 90 ... small diameter end 92 ... first step 94 ... second step 96 ... breathing hole 98 ... web Washer 100 ... coupler part 102 ... coil mold body 112 ... terminal 114 ... inner hole 116 ... bottom plate part 118, 120 ... side plate part 1 for clamping 2 ... stay for the side plate portions 124 ... Large slits 126, 128 ... small slit 130 ... insertion holes 132 ... tongue piece 134 ... fitting step

Claims (3)

In a solenoid valve including a bobbin coil in which an electromagnetic coil is wound around a bobbin, and having a solenoid part housed in a housing, and a valve member that displaces in the valve body when energization or de-energization of the electromagnetic coil is performed.
The solenoid unit further includes:
A first core having an outer core member having a cylindrical portion in which a press-fitting hole is formed, and an inner core member having a through-hole formed therein and accommodated in the press-fitting hole;
A plunger that is displaced in the housing in accordance with energization or deenergization of the electromagnetic coil,
A shaft portion that is passed through the through hole of the inner core member and abuts on the valve member, and is displaced following the displacement of the plunger;
A second core inserted into an inner hole of the bobbin;
A guide collar made of a cylindrical body with a bottom, the opening end of which is inserted into the press-fitting hole of the cylindrical portion, and the plunger is inserted therein so as to be displaceable.
Comprising
The inner core member is located between a large diameter end portion having a maximum diameter, a small diameter end portion having a minimum diameter, and between the large diameter end portion and the small diameter end portion, and the diameter is the large diameter end portion. A medium diameter portion smaller than the portion and larger than the small diameter end portion,
A first step portion is formed that is recessed inward in the diametrical direction from the bottom surface of the large-diameter end portion to the middle diameter portion, and is spaced apart from the first step portion by a predetermined angle. Over the bottom surface of the small-diameter end portion, a second stepped portion is formed that is depressed inward in the diameter direction.
The solenoid valve characterized in that the small-diameter end portion faces the opening end of the guide collar, and the large-diameter end portion is press-fitted into the press-fitting hole.   2. The solenoid valve according to claim 1, wherein the large-diameter end portion is located on the lower side and the small-diameter end portion is located on the upper side.   3. The solenoid valve according to claim 1, wherein a clearance formed between an inner wall of the through hole and the shaft portion passed through the through hole is 20 μm or less.

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