JP2016169870A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve capable of securing a circulation area while maintaining strength of a spool.SOLUTION: A spool 23 includes: a first small diameter part 30 and a second small diameter part 33 set to a predetermined outer diameter a little smaller than an inner diameter of a valve body 22; a first land part 31 and a second land part 32 set to substantially the same outer diameter as the inner diameter of the valve body 22; a discharge passage 23b provided on an inner peripheral side of the spool 23 and opened and formed so that one end side on the inner peripheral side faces a discharge port P4; and a communication hole 23e for communicating discharge holes 23c, 23d formed so as to penetrate in a radial direction of the discharge passage 23b and the spool 23 and a drain chamber 25. The discharge holes 23c and 23d penetrate to the discharge passage 23b from the outer peripheral side, and are formed in a shape in which circumferential width (opening width) on the outer peripheral side is larger than circumferential width (opening width) on the inner peripheral side.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a solenoid valve.

  In general, an electromagnetic valve is used to control a hydraulic actuator such as a hydraulic valve timing control device. In recent years, there has been a demand for improving the mountability by making the electromagnetic valve as small as possible. is there.

  For example, in Patent Document 1, the inner periphery of the spool is used as an oil passage, and a plurality of through holes that penetrate the inner and outer periphery are provided in the large-diameter portions at both ends that support the spool that slides within the valve body. Yes.

  Furthermore, even if the spool stroke is reduced with the miniaturization of the solenoid valve, a sufficient flow area of the through hole and the annular groove in the valve body must be ensured. As shown in FIG. 8, if the through hole is formed in a slit shape extending in the circumferential direction, a distribution area can be secured.

JP 2000-205435 A

  However, when a slit-like through hole extending in the circumferential direction is formed in the spool as in Patent Document 1, depending on the required distribution area, the spool is deformed when the spool is cut or polished due to insufficient strength. There was a problem.

  The objective of this invention is providing the solenoid valve which can ensure a distribution area, maintaining the intensity | strength of a spool.

  Preferably, in the present invention, a plurality of through holes are provided in the circumferential direction of the large diameter portion with respect to the large diameter portion of the spool, and the through holes are formed in a slit shape extending in the circumferential direction. Is characterized in that it is larger than the width on the outer peripheral side of the partition wall between the through holes of the large diameter portion.

  According to the present invention, a distribution area can be secured while maintaining the strength of the spool.

It is a hydraulic-pressure supply circuit diagram of the valve timing control apparatus of the Example with which the solenoid valve which concerns on this invention is applied. FIG. 2 is a longitudinal sectional view of the electromagnetic valve shown in FIG. 1, showing a state in which the valve timing control device is retarded. It is a fragmentary sectional view showing the assembly state to the engine of the solenoid valve shown in FIG. It is the perspective view (A) and front view (B) which showed an example of the spool which concerns on this invention. FIG. 5 is a cross-sectional AA view of the front view (B) of FIG. 4. FIG. 5 is a sectional BB view of the front view (B) of FIG. 4. FIG. 5 is a cross-sectional view for explaining another example of the spool according to FIG. 4 (a view corresponding to the cross-section BB in FIG. 6). It is a longitudinal cross-sectional view of the solenoid valve shown in FIG. 1, and is a view showing a state in which the valve timing control device is subjected to intermediate holding control. FIG. 2 is a longitudinal sectional view of the solenoid valve shown in FIG. 1, showing a state in which the valve timing control device is advanced.

  Embodiments of a solenoid valve according to the present invention will be described below in detail with reference to the drawings. In the present embodiment, the electromagnetic valve is applied to a hydraulic valve timing control device for an internal combustion engine (engine) as in the conventional case.

[Hydraulic valve timing control device explanation]
First, a hydraulic valve timing control device to which the solenoid valve according to the present invention is applied will be described. As shown in FIG. 1, the valve timing control device 1 is, for example, a camshaft 2 on the intake side of an engine not shown. A phase conversion mechanism 3 that continuously changes the rotational phase of the camshaft 2 with respect to a crankshaft (not shown) using hydraulic pressure, and a hydraulic supply / discharge means 4 that supplies and discharges hydraulic pressure to and from the phase conversion mechanism 3. And an electronic control unit (ECU) 5 which is a control means for controlling the operation of the hydraulic supply / discharge means.

  The phase conversion mechanism 3 can rotate integrally with the housing 6 linked to the crankshaft via a timing chain (not shown) and the end of the camshaft 2 with a plurality of teeth 6a integrally formed on the outer periphery. The vane rotor 7 is mainly composed of a vane rotor 7 fixed to the housing 6 and accommodated in the housing 6 so as to be rotatable relative to the housing 6. Further, on the outer periphery of the vane rotor 7, for example, a plurality (four in FIG. 1) of vanes 7b configured so that the outer peripheral surface is in sliding contact with the inner peripheral surface of the housing 6 are radially arranged at predetermined intervals in the circumferential direction. On the other hand, on the inner periphery of the housing 6, for example, a plurality of (four in FIG. 1) shoes 6 b whose inner peripheral surface is in sliding contact with the outer peripheral surface of the annular base portion 7 a of the vane rotor 7 are vane rotors. 7 projecting radially inward at a predetermined interval corresponding to the relative rotation range of 7, and a predetermined sealing member (between the inner peripheral surface of the housing 6 and each vane 7b and between the annular base 7a and each shoe 6b, respectively). It is sealed in a liquid-tight manner. With this configuration, a retard chamber Pr and an advance chamber Pa, which are a pair of hydraulic oil chambers separated by the vanes 7b, are formed between the housing 6 and the vane rotor 7, and the pair of both In the chambers Pr and Pa, the rotational phase of the vane rotor 7 is controlled by supplying the hydraulic fluid to one chamber and discharging the hydraulic fluid in the other chamber. The number of the plurality of vanes 7b and the plurality of shoes 6b corresponding to the plurality of vanes 7b is not particularly limited, and can be arbitrarily set according to the specifications of the internal combustion engine.

  Further, one of the vanes 7b accommodates a lock pin 7c urged so as to protrude in a direction perpendicular to the axis of the vane rotor 7 by an urging member (not shown). When the lock pin 7c is engaged with a pin engagement hole (not shown) which is opposed to the most retarded angle when moving to the most retarded angle side, the most retarded angle state is maintained particularly when the engine is stopped. . As a result, the engine is stabilized at the time of starting the engine or idling.

  The hydraulic supply / discharge means 4 is a pump 8 that is a hydraulic pressure supply source that pumps hydraulic oil stored in the oil pan 9, and the hydraulic oil pumped by the pump 8 according to a control signal from the electronic control unit 5. An electromagnetic valve EV which is a flow path switching valve for supplying the other hydraulic oil to the oil pan 9 and supplying the other hydraulic oil to one of the retard chamber Pr or the advance chamber Pa, and the electromagnetic valve EV and the oil pan 9 and the retard chamber The oil passage L mainly communicates with Pr and the advance chamber Pa. The vane rotor 7 is rotated forward and backward with respect to the housing 6 by supplying and discharging the hydraulic oil in the retard chamber Pr or the advance chamber Pa via the electromagnetic valve EV, thereby rotating the camshaft 2 relative to the crankshaft. The phase is changed.

  The oil passage L communicates a retard port P1 and a retard chamber Pr, which will be described later, in the solenoid valve EV, and a retard passage L1 which supplies and discharges hydraulic oil to and from the retard chamber Pr, and a later description in the solenoid valve EV. An advance passage L2 that communicates the advance port P2 and the advance chamber Pa to supply and discharge hydraulic fluid to the advance chamber Pa, and an intake passage LO that communicates the oil pan 9 and the suction port of the pump 8. And the introduction port P3 described later in the solenoid valve EV and the discharge port of the pump 8 are communicated to introduce the hydraulic fluid discharged by the pump 8 to the phase conversion mechanism 3 side. The drain port L4 communicates with the oil pan 9 and mainly includes a drain passage L4 for returning the hydraulic oil discharged from the discharge port P4 to the oil pan 9. In this way, the oil passage L is branched into two systems, and this is switched by the electromagnetic valve EV.

  The solenoid valve EV is a so-called slide spool type four-port proportional electromagnetic switching valve, which is generated based on a control current from the electronic control unit 5 as shown in FIG. A solenoid component 11 that constitutes an electromagnetic solenoid that drives a spool 23 described later with electromagnetic force, and the communication state of each port P1 to P4 provided in a valve body 22 described later according to the axial position of the spool 23 is switched. It is mainly composed of a valve component 21 that constitutes a valve. Then, as shown in FIG. 3, the solenoid valve EV is fixed to the side of the engine 10 by a bolt 46 via a bracket 45 attached to the outer periphery of the yoke 12 described later constituting the exterior of the solenoid component 11. Has been.

[Description of solenoid components]
The solenoid component 11 includes a yoke 12 formed in a substantially cylindrical shape by a magnetic material, a coil 13 accommodated and disposed on the inner peripheral side of the yoke 12, and flanges 14b and 15b at one end thereof. The cylindrical portion 14a, 15a on the other end side is fixed to each end portion of the yoke 12 and is housed on the inner peripheral side of the coil 13 and is made of a magnetic body arranged to face each other on the inner peripheral side. A first fixed iron core 14 and a second fixed iron core 15; an armature 16 which is a movable iron core made of a magnetic material slidably housed on the inner peripheral side of the second fixed iron core 15; and the first fixed iron core 14 A non-magnetic member provided on the inner peripheral side of the first member, the one end surface of which is in contact with the other end surface of the spool 23 described later, and the other end surface of the member is in contact with one end surface of the armature 16. And a rod 17.

  The yoke 12 is configured to surround the outer periphery of the coil 13 with a magnetic metal material such as iron, for example, and one end thereof (the end on the X-axis positive direction side in FIG. 2) is at the end. It is caulked and fixed to a flange 22a described later provided at one end of the valve body 22 via the provided claw 12a, while the other end is connected via a claw 12b provided at the end. The second fixed iron core 15 is caulked and fixed to the flange portion 15b provided at one end.

  The coil 13 is wound around the outer periphery of a bobbin 18 formed in a substantially cylindrical shape by a resin material, and a resin connector 19 fixed to the other end of the yoke 12 and a harness (not shown) connected to the connector To the electronic control unit 5. When the electric control unit 5 is energized, a magnetic path is formed by the yoke 12, the first and second fixed iron cores 14 and 15, and the armature 16, whereby the first fixed iron core 14 and the armature 16 are connected to each other. A magnetic attractive force will be generated between them.

  Here, the electronic control unit 5 detects the engine operating state based on signals from various sensors such as a crank angle sensor for detecting the rotational speed of the engine and an air flow meter for detecting the intake air amount. The oil passage L is switched as described later by supplying a control current to the coil 13 of the electromagnetic valve EV or cutting it off according to the state.

  The first fixed iron core 14 is formed in a substantially cylindrical shape by a magnetic metal material such as iron, for example, and has a rear end portion (in FIG. 2, the positive direction of the X axis in FIG. 2) that extends along the axial direction. The flange portion 14b having an enlarged diameter is integrally provided on the side end portion. The cylindrical portion 14a is coaxially accommodated on the inner periphery of one end of the coil 13 (bobbin 18) so that the second fixed iron core 15 and the armature 16 face each other, and the flange portion 14b is disposed on the bobbin 18 and the valve body 22. And is magnetically coupled to the peripheral wall of the yoke 12. A well-known O-ring 20 is interposed between both axial end surfaces of the flange portion 14b and the axial end surfaces of the bobbin 18 and the valve body 22 facing the flange portions 14b, so that each of them is liquid-tightly sealed. Therefore, leakage of hydraulic oil to the coil 13 side and the outside is suppressed.

  Further, a concave portion 14c having a shape corresponding to one end portion of the armature 16 is formed in the center portion of the distal end portion of the cylindrical portion 14a. The recess 14c forms a so-called air gap (main gap) between the first fixed iron core 14 and the armature 16 when the coil 13 is not energized, while the magnetic attraction generated by the energization when the coil 13 is energized. One end of the armature 16 attracted to the first fixed iron core 14 by force is accommodated in a fitted state, and the movement of the armature 16 is regulated by the inner wall of the recess 14c. Further, a conical tapered portion 14d is provided on the outer periphery of the distal end portion of the cylindrical portion 14a, and the tapered portion 14d suppresses a change in magnetic attraction force accompanying the movement of the armature 16, and the magnetic attraction The characteristic of keeping the force constant is maintained.

  On the other hand, the second fixed iron core 15 is also formed in a substantially cylindrical shape from, for example, a magnetic metal material such as iron and has a rear end portion (in FIG. 2, an X-axis negative electrode) extending in the axial direction. On the other end side of the coil 13 (bobbin 18), the diameter-increased flange portion 15b is integrally provided at the end of the direction side, and the cylindrical portion 15a faces the first fixed iron core 14. The flange portion 15b is fixed together with the bobbin 18 in a fastened state, and is magnetically coupled to the peripheral wall of the yoke 12.

  The armature 16 is formed in a substantially cylindrical shape having an outer diameter slightly smaller than the inner diameter of the second fixed iron core 15 by using a magnetic metal material such as iron, for example, and the inner circumference of the cylindrical portion 15a of the second fixed iron core 15. By being arranged substantially coaxially, an air gap (side gap) which is a minute radial gap is formed between the second fixed iron core 15 and the second fixed iron core 15. In addition, a so-called breathing hole 16a set to a predetermined inner diameter is formed in the inner peripheral portion of the armature 16 along the axial direction of the armature 16, and the main gap is filled by the breathing hole 16a. The axial movement of the armature 16 in the hydraulic oil is secured by letting the oil escape (move) to the second fixed iron core 15 side (X-axis negative direction side in FIG. 2). With such a configuration, the armature 16 can be moved relative to the second fixed iron core 15 on the inner peripheral side of the second fixed iron core 15 so as to be guided by the peripheral wall. Sometimes, the magnetic flux formed in the first fixed iron core 14 attracts the first fixed iron core 14 so that one end thereof (the X-axis positive direction end in FIG. 2) comes into contact with the inner surface of the recess 14c. It moves in the axial direction within the range of.

  The rod 17 is formed in a bottomed cylindrical shape that opens to the armature 16 side by using a nonmagnetic material such as stainless steel or aluminum, and is accommodated on the inner peripheral side of the first fixed iron core 14 so as to be relatively movable. It is disposed and constantly biased toward the armature 16 side (X-axis negative direction side in FIG. 2) by the pressing force from the spool 23 side based on the biasing force of the return spring 26 described later, so that both ends of the armature 16 and the spool 23 are always in contact with the opposing end surfaces, so that they move together with the armature 16 and the spool 23.

  Further, on the outer periphery of the rod 17, axial grooves 17a that are recessed inward in the radial direction are provided at substantially equal intervals in the circumferential direction, and each of the axial grooves 17a has an inner periphery of the first fixed iron core 14. An oil passage through which hydraulic oil flows is formed between the surface and the surface. A communication hole 17b that communicates with the inner and outer circumferences of the rod 17 is formed in the end of each axial groove 17a on the negative side in the X-axis direction along the radial direction. The hydraulic oil that has flowed into the axial grooves 17a from the pipes is released (moved) to the inner peripheral side of the rod 17 through the communication holes 17b, and the breathing of the amateur 16 is performed through the inner peripheral part of the rod 17. By escaping to the hole 16a, the axial movement of the rod 17 in the hydraulic oil is ensured. Further, an enlarged diameter flange portion 17c is provided at the end of the rod 17 on the X axis negative direction side, and this flange portion 17c moves forward of the rod 17 (the X axis positive direction in FIG. 2). Functioning as a stopper that regulates the maximum amount of movement during movement to the side), and by surrounding the one end opening edge of the breathing hole 16a of the armature 16 by the flange portion 17c, the inner peripheral portion of the breathing hole 16a and the rod 17 Connectivity is improved.

[Explanation of valve components]
The valve component 21 is inserted into a cylinder head (not shown) and is connected to the passages L1 to L4. The valve body 22 has ports P1 to P4 described later, and the inside of the valve body 22. And a spool 23 that is slidably housed and switches the communication state of the ports P1 to P4 according to the axial position in the valve body 22.

  The valve body 22 is formed in a substantially cylindrical shape by a nonmagnetic metal material such as aluminum, for example, and has a flange portion 22a having an enlarged diameter at one end thereof (the end on the X axis negative direction side in FIG. 2). And the flange portion 14b of the first fixed iron core 14 and the end portion of the bobbin 18 (the end portion on the X-axis positive direction side in FIG. 2). A spool housing chamber 24 for slidably housing the spool 23 is provided along the axial direction on the inner peripheral side of the valve body 22, and the peripheral wall has a retarding passage connected to the retarding passage L1. An angle port P1, an advance port P2 connected to the advance passage L2, and an introduction port P3 connected to the introduction passage L3 are formed with a certain axial width along the circumferential direction, and are formed on the other end walls. The discharge port P4 connected to the discharge passage L4 is formed penetrating along the axial direction. The retardation port P1, the advance port P2, and the introduction port P3 are each provided in three at regular intervals in the circumferential direction.

  The spool housing chamber 24 is configured to be in sliding contact with the outer peripheral surface of each land portion 31, 32 by setting the inner diameter slightly larger than the outer diameter of each land portion 31, 32 described later of the spool 23. One end side of the discharge port P4 is formed as an opening, while the other end side is connected to the discharge port P4 via a communication hole 23e, a discharge hole 23c and a discharge passage 23b described later provided in the spool 23. A communicating drain chamber 25 is formed with an enlarged diameter.

  The drain chamber 25 is formed to have a stepped diameter increase with respect to the inner diameter of the spool housing chamber 24 and is formed to open toward the other end side of the spool housing chamber 24. On the side, the hydraulic oil discharged from the retarded angle chamber Pr, which is defined by the first land portion 31 described later, the first fixed iron core 14 and the rod 17 in the spool 23, enters the interior through the retarded port P1. Introduced and discharged to the discharge port P4 through the discharge hole 23c and the discharge passage 23b of the spool 23 (see FIG. 9). In the drain chamber 25, a return spring 26, which is a coil spring that constantly urges the spool 23 in the negative direction of the X axis, is accommodated.

  The return spring 26 is tapered so that the diameter of the return spring gradually decreases from one end side toward the other end side, and one end thereof (the X-axis positive direction end in FIG. 2) forms the drain chamber 25 with a larger diameter. As a result, the spool is seated on the first spring locking portion 22b, which is a step formed on the inner peripheral portion of the valve body 22, and the other end is on the solenoid component 11 side of the first spring locking portion 22b. It is elastically mounted between the valve body 22 and the spool 23 so as to be seated on a second spring locking portion 23a, which will be described later, provided on the outer peripheral portion on the other end side of 23.

  The retard port P1 is provided on one end side of the valve body 22 so as to face the spool accommodating chamber 24, and is configured to be opened and closed by a first land portion 31 described later of the spool 23. On the other hand, the advance port P2 is provided on the other end side of the valve body 22 so as to face the spool housing chamber 24, and is configured to be opened and closed by a second land portion 32 described later of the spool 23. In addition, the introduction port P3 is located between the retard port P1 and the advance port P2 in the spool housing chamber 24 at an axial position that is not blocked by any of the land portions 31 and 32 of the spool 23. It is provided so as to face an introduction chamber 27 defined between first and second land portions 31 and 32 described later. Each of the ports P1 to P3 is provided with a mesh-like filter F1 to F3, respectively, as shown in FIG. 3 in particular, to remove foreign substances contained in the hydraulic oil passing through the ports P1 to P3. It is offered to.

  On the other hand, the spool 23 is formed in a stepped reduced diameter at a position that always faces the introduction port P3 in its moving range, and is set to a predetermined outer diameter that is slightly smaller than the inner diameter of the valve body 22. The first small-diameter portion 30 is provided on both sides in the axial direction of the first small-diameter portion 30 so as to face the retard port P1 and the advance port P2, and is substantially the same as the inner diameter of the valve body 22. A pair of first land portion 31 and second land portion 32 set to a diameter, and adjacent to the first land portion 31 on the opposite side of the first small diameter portion 30, the first small diameter portion A second small diameter portion 33 having an outer diameter substantially the same as 30, and a stepped portion having a stepped diameter increase at the end opposite to the second land portion 32 with respect to the second small diameter portion 33. A second spring locking portion 23a used for seating on the other end side of the return spring 26, and an inner peripheral side of the spool 23. A discharge passage 23b formed so that one end of the inner peripheral side (X-axis positive direction side in FIG. 2) faces the discharge port P4, and the radial direction of the discharge passage 23b and the spool 23 Discharge holes 23c and 23d penetratingly formed in the Y-axis direction in FIG. 2 and a communication hole 23e communicating the drain chamber 25 are provided.

  The discharge holes 23c and 23d are formed so as to penetrate the discharge passage 23b from the outer peripheral side in the first land portion 31 and the second land portion 32 which are large diameter portions of the spool 23 as described above. The outer circumferential side width (opening width) is formed in a shape larger than the inner circumferential side circumferential width (opening width). When a plurality of discharge holes 23c and 23d having such a shape are provided in the circumferential direction of the spool 23 (for example, when a pair is provided symmetrically), a well-known structure (only the outer peripheral side and the inner peripheral side is formed when through holes are formed. Compared with the structure in which each circumferential width is the same, in the first land portion 31 and the second land portion 32, the width of the outer peripheral side between the holes (the partition walls 31a and 32a in FIGS. 6 and 7) ( (Width in the circumferential direction) is larger than the width on the inner circumference facing the discharge passage 23b (width in the circumferential direction). Thereby, for example, the minimum required hole diameter (flow area) is secured on the inner peripheral side of the discharge holes 23c and 23d, and at the same time, the gaps between the holes (the partition walls 31a and 32a in FIGS. 6 and 7) are made as much as possible. A thick structure (a structure having sufficient strength) can be obtained.

  Thus, by providing a thick structure between the holes of the first land portion 31 and the second land portion 32, for example, compared to the known structure, the strength of the spool 23 itself is improved. Therefore, even if a non-magnetic metal material with low strength is applied (such as an aluminum alloy), sufficient strength can be secured in the spool 23 (the first land portion 31 and the second land portion 32). It becomes. In addition, for example, when holding the spool 23 with a clamp or the like and performing various types of processing (for example, cutting processing, polishing processing other than the through-hole forming processing of the discharge holes 23c and 23d in the first land portion 31 and the second land portion 32), It is possible to suppress the spool 23 from being deformed during the various processing.

  In the through formation of the discharge holes 23c and 23d, for example, a process of notching from the outer periphery to the inner periphery of the spool 23 with a disk-shaped cutter within the range indicated by the broken line in FIG. And a process of notching from the outer periphery to the inner periphery of the spool 23 using a cutting tool within a range indicated by a broken line in FIG. As a result, the outer peripheral side width (circumferential width) is larger than the inner peripheral width (circumferential width) facing the discharge passage 23b, and the partition portions 31a and 32a having a substantially fan-shaped cross section remain. Will do.

  The communication hole 23e is formed so as to penetrate the discharge passage 23b from the outer peripheral side in the second small diameter portion 33 of the spool 23 as described above, and, like the discharge holes 23c and 23d, the outer peripheral side The circumferential width (opening width) may be larger than the inner circumferential circumferential width (opening width). As a result, the same operational effects as in the case where the discharge holes 23c and 23d are formed can be obtained.

  The first and second land portions 31 and 32 are set to have predetermined axial widths larger than the axial widths of the corresponding ports P1 and P2, respectively, and as shown in FIGS. Of course, both the ports P1 and P2 can be opened simultaneously, and as shown in FIG. 8, both the ports P1 and P2 can be closed simultaneously.

  The discharge passage 23b is formed along the axial direction from one end of the spool 23 to a predetermined axial position that overlaps the second small diameter portion 33 in the radial direction, while the discharge holes 23c and 23d The communication hole 23e is formed so as to penetrate along the radial direction of the spool 23 so that the drain chamber 25 and the inner end of the discharge passage 23b communicate with each other on the other end side of the spool 23. With this configuration, the hydraulic oil discharged from the retard chamber Pr through the retard port P1 to the drain chamber 25 is guided to the discharge port P4 provided on one end side of the valve body 22 through the communication hole 23e and the discharge passage 23b. <(See Fig. 9) In this way, both ends of the spool 23 are configured to be able to communicate with the discharge passage 23b and the discharge holes 23c and 23d via the communication hole 23e, and the discharge port P4 is provided only on the other end of the valve body 22. As a result, the axial length of the valve body 22 can be shortened compared to the case where the discharge ports P4 are provided on both ends of the valve body 22, and the electromagnetic valve EV is miniaturized.

  Further, on the inner peripheral surface of the valve body 22, a pair of first annular groove 41 and second annular groove 42 are formed at axial positions corresponding to both axial ends of the retard port P1 and the advance port P2, respectively. Notches are continuously formed along the circumferential direction. That is, the annular grooves 41 and 42 are provided so as to be separated from each other in the axial direction, and at least the inner opening width of each of the ports P1 and P2 is expanded. The ports P1 and P2 are provided so as to overlap with both axial ends of the ports P1 and P2 in the X-axis direction. In this embodiment, the center of the groove is substantially coincident with the axial ends of the ports P1 and P2. Is provided.

  In addition, by providing the annular grooves 41 and 42 as described above, the annular grooves 41 and 42 protrude between the annular grooves 41 and 42 radially inward with a certain axial width, and when the spool 23 moves, Guide protrusions 43, which are protrusions as guide portions for sliding the respective land portions 31 and 32 to guide the movement of the spool 23, are continuously formed along the circumferential direction. That is, the guide projection 43 is integrated with the valve body 22 at the entire circumference except for the circumferential range where the ports P1 and P2 are formed at the axial position corresponding to the intermediate portion of the ports P1 and P2. The inner diameter of the valve body 22 is the same as that of the valve body 22. With such a configuration, the guide projections 43 support the spool 23 by contacting the outer peripheral surfaces of the land portions 31 and 32 when the spool 23 is stationary, and when the spool 23 is moved, By guiding the movement of the spool 23 in sliding contact with the portions 31 and 32, the spool 23 is smoothly moved.

  A third annular groove 44 having a groove width substantially the same as the axial width of the introduction port P3 is formed on the inner peripheral surface of the valve body 22 so as to surround the first small diameter portion 30 of the spool 23. Are provided continuously along the circumferential direction. As a result, the amount of hydraulic oil introduced into the introduction chamber 27 via the introduction port P3 is increased, and as a result, more hydraulic oil can be supplied to the ports P1 and P2. ing.

[Operation explanation of solenoid valve]
Hereinafter, the operation of the electromagnetic valve EV according to the present embodiment will be described with reference to FIGS.

<Delay control>
First, when the control current is not supplied to the coil 13 from the electronic control unit 5 such as when the engine is started or when the engine is idling, the solenoid valve EV is operated only by the urging force of the return spring 26 on the spool 23. As shown in FIG. 2, the spool 23 pushes the armature 16 through the rod 17 and is maximally biased toward the X-axis negative direction, and is in the most retracted state. In such a state, both the land portions 31 and 32 are biased toward the negative side of the X axis with respect to both the ports P1 and P2, and the retard port P1 is introduced through the introduction chamber 27 into the introduction port P3. On the other hand, the advance port P2 communicates with the discharge port P4 through the discharge hole 23d. As a result, in the phase conversion mechanism 3, the hydraulic oil is supplied to the retard chamber Pr and the hydraulic oil in the advance chamber Pa is discharged, and the relative rotational phase of the camshaft 2 is set to the most retarded angle side. It is controlled and used for good engine startability, engine stability during idle operation, and fuel efficiency improvement.

<Intermediate retention>
Subsequently, for example, when the operation shifts to the normal operation and is held in a predetermined operation state, a predetermined control current for holding the spool 23 at the intermediate position is supplied to the coil 13 and a magnetic field is generated around the coil 13. And the armature 16 is attracted to the first fixed iron core 14 side based on the magnetic flux formed in the yoke 12 and the first and second fixed iron cores 14 and 15 provided around the coil 13. Become. That is, the armature 16 moves forward in the positive direction of the X axis against the urging force of the return spring 26 so as to push the spool 23 through the rod 17, so that the spool 23 moves to the intermediate position as shown in FIG. It will be in the state where it advanced. In such a state, the retard port P1 is closed by the first land portion 31, and the advance port P2 is closed by the second land portion 32. Thereby, in the phase conversion mechanism 3, the hydraulic pressures in both the retard chamber Pr and the advance chamber Pa are maintained, and the wasteful energy consumption of the pump 8, for example, is reduced.

<Advance control>
Further, for example, when the state is shifted to a high speed operation state, the maximum control current is supplied to the coil 13 and the attraction force is maximized. Therefore, as shown in FIG. 9, the armature 16, the rod 17 and the spool When 23 further advances toward the X-axis positive direction side against the urging force of the return spring 26, it is in the most advanced state in which it is maximally biased toward the X-axis positive direction side. In such a state, both the land portions 31 and 32 are biased toward the X axis positive direction side with respect to the both ports P1 and P2, and the retard port P1 is connected to the drain chamber 25, the communication hole 23e, the discharge hole 23c, The advance port P2 communicates with the introduction port P3 via the introduction chamber 27 while communicating with the discharge port P4 via the discharge passage 23b. As a result, in the phase conversion mechanism 3, the hydraulic oil in the retard chamber Pr is discharged and the hydraulic oil is supplied to the advance chamber Pa, so that the relative rotational phase of the camshaft 2 is set to the most advanced angle side. Controlled and used to increase engine output.

  As described above, according to the solenoid valve EV according to the present embodiment, in the spool 23 having the oil passage switching discharge holes (23c and 24d), the shape of the through-hole formation of the discharge holes 23c and 23d intersecting the discharge passage 23b Is possible by ensuring the minimum required hole diameter (distribution area) on the inner periphery side by making the hole diameter variably cut from the outer periphery to the inner periphery of the spool 23 (slit shape or arc shape) As much as possible, the spool is provided with a wall thickness (for example, a wall thickness such as the partition walls 31a and 32a), and the strength can be sufficiently secured. Further, since the hole diameters of the discharge holes 23c and 23d are variably changed from the outer periphery to the inner periphery of the spool 23, the opening amount (circulation area) at the time of oil passage switching is gradually changed.

  Although the present invention has been described in detail only for the specific examples described above, it is obvious to those skilled in the art that various modifications can be made within the scope of the technical idea of the present invention. It is natural that such changes and the like belong to the scope of the claims.

  Here, the technical ideas that can be grasped from the specific examples shown above are listed below.

<A> A cylinder having a supply passage communicating with a hydraulic pressure source, a plurality of annular grooves communicating with the first passage and the second passage on the inner periphery, and an opening communicating with the drain passage at one end in the axial direction. -Shaped valve body, a pair of large diameter portions, a small diameter portion provided between the large diameter portions, and an axial direction communicating with the opening portion. A spool provided with a hole and a through hole provided in each large-diameter portion and penetrating from the outer peripheral side to the axial hole, and fixed to the other end of the valve body and energized to attract the amateur. An electromagnetic solenoid that moves the spool in the axial direction, and a coil spring that generates a biasing force in a direction opposite to the suction direction of the armature,
The spool slides in the valve body to control the communication state of the supply passage, the first passage, and the second passage, and the first passage, the second passage, and the drain passage. A solenoid valve for controlling the communication state of
A plurality of the through holes are provided in the circumferential direction of the large diameter portion and are formed in a slit shape extending in the circumferential direction, and the width of the outer circumferential side between the through holes of the large diameter portion is set in the axial hole. A solenoid valve characterized in that it is larger than the width of the inner peripheral side facing.

<B> A cylinder having a supply passage communicating with a hydraulic pressure source, a plurality of annular grooves communicating with the first passage and the second passage on the inner periphery, and an opening communicating with the drain passage at one end in the axial direction. -Shaped valve body, a pair of large diameter portions, a small diameter portion provided between the large diameter portions, and an axial direction communicating with the opening portion. A spool provided with a hole and a through hole provided in each large-diameter portion and penetrating from the outer peripheral side to the axial hole, and fixed to the other end of the valve body and energized to attract the amateur. An electromagnetic solenoid that moves the spool in the axial direction, and a coil spring that generates a biasing force in a direction opposite to the suction direction of the armature,
The spool slides in the valve body to control the communication state of the supply passage, the first passage, and the second passage, and the first passage, the second passage, and the drain passage. A solenoid valve for controlling the communication state,
A plurality of the through holes are provided in the circumferential direction of the large diameter portion, and are cut out in an arc shape in a cross section orthogonal to the axis of the spool.

<C> A cylindrical valve body having an annular groove communicating with the passage on the inner periphery and having an opening communicating with the passage at one end in the axial direction, and slidable in the axial direction within the valve body. A spool having an axial hole communicating with the opening, a through hole penetrating from the outer peripheral side to the axial hole, and being fixed to the other end of the valve body and energizing to attract the armature. An electromagnetic solenoid that moves the spool in the axial direction; and a biasing member that generates a biasing force in a direction opposite to the suction direction of the armature,
An electromagnetic valve that controls the communication state of the passage by sliding the spool in the valve body,
A plurality of the through holes are provided in the circumferential direction of the spool, and have a portion in which the circumferential width on the outer circumferential side is larger than the circumferential width on the inner circumferential side.

  <D> The electromagnetic valve according to claim 1, wherein a pair of the through holes are provided symmetrically with respect to one large diameter portion.

  <E> The electromagnetic valve according to claim 1, wherein the large-diameter portion of the spool is at least cut.

  <F> The electromagnetic valve according to claim 1, wherein the large diameter portion of the spool is at least polished.

  <G> The electromagnetic valve according to claim 1, wherein the spool is formed of an aluminum alloy.

  <H> In the electromagnetic valve according to claim 1, a second small diameter portion is provided at a tip of the large diameter portion on the electromagnetic solenoid side, and the coil spring is disposed on an outer periphery of the second small diameter portion. In addition, a slit-like through hole extending in the circumferential direction is also formed in the second small diameter portion.

  <Re> In the solenoid valve according to <H>, the second small diameter portion is provided with a plurality of slit-like through holes, and the width of the outer diameter side between the through holes of the small diameter portion is: An electromagnetic valve characterized by being larger than the width of the inner peripheral side facing the axial hole.

  The solenoid valve according to claim 2, wherein the through hole is processed by a disk-shaped cutter from the outer peripheral side of the spool.

EV ... Solenoid valve
11… Solenoid component
21… Valve component
22… Valve body
22b ... 1st spring locking part
23 ... Spool
23b… Discharge passage
23c, 23d ... discharge hole
23e… Communication hole
24… Spool storage room
30 ... 1st small diameter part
31 ... 1st land
31a, 32a ... Bulkhead
32 ... Second Land
33 ... 2nd small diameter part
P1 ... retarded port
P2 ... Advance port
P3 ... Introduction port
P4 ... discharge port

Claims (5)

A cylindrical valve body having a supply passage communicating with a hydraulic pressure source, a first passage, a second passage, and an opening provided at one end in the axial direction and communicating with the drain passage;
A pair of large-diameter portions, a small-diameter portion provided between the large-diameter portions, an axial hole communicating with the opening, and the large-diameter portion are provided in the valve body so as to be slidable in the axial direction. A spool provided in at least one of the parts and having a through hole penetrating from the outer peripheral side to the axial hole;
An electromagnetic solenoid fixed to the other end of the valve body and moving the spool in the axial direction by energization;
With
An electromagnetic valve that controls communication between the supply passage, the first passage, the second passage, and the drain passage by sliding the spool in the valve body;
A plurality of the through holes are formed in the circumferential direction of the large diameter portion and formed in a slit shape extending in the circumferential direction,
The solenoid valve according to claim 1, wherein the plurality of through holes have a width on the outer peripheral side that is greater than a width on the outer peripheral side of the partition between the through holes of the large diameter portion. The electromagnetic valve according to claim 1,
The through-hole is formed in two places in the circumferential direction in the large-diameter portion, and is opposed to each other in the radial direction. The electromagnetic valve according to claim 2,
The partition wall is formed at two locations in the circumferential direction and is opposed to each other in the radial direction. The electromagnetic valve according to claim 1,
The solenoid valve, wherein the through hole is provided in each of the pair of large diameter portions. The electromagnetic valve according to claim 1,
The total of the width length of the outer peripheral side in the said several through-hole is larger than the sum total of the width length of the outer peripheral side in the partition part between the said through-holes of the said large diameter part.

Images