Electromagnetic switching valve

Abstract

In an electromagnetic switching valve for switching an oil passage, the present invention seeks to simplify the structure without increasing the number of parts, and suppress or prevent foreign matter from invading the plunger side. The electromagnetic switching valve includes a sleeve, a sliding column, a plunger having a through passage, an electromagnetic actuator including a stator that applies a magnetic potential to the plunger, and a cylindrical transmission member interposed between the plunger and the sliding column to transmit a driving force. The stator includes an insertion through hole through which the transmission member is inserted. The transmission member includes an opposing wall facing the through passage, a first internal passage formed on the plunger side of the opposing wall and communicating with the through passage, a first opening portion that radially opens the first internal passage on the plunger side of the insertion through hole, a second internal passage formed on the sliding column side of the opposing wall, and a second opening portion that radially opens the second internal passage on the sliding column side of the insertion through hole.

Description

Technical Field

[0001] The present invention relates to an electromagnetic switching valve that switches the oil passage of working oil by operating a spool with an electromagnetic actuator, and more particularly to an electromagnetic switching valve applied to a valve timing change device that changes the opening and closing timing (valve timing) of an intake valve or an exhaust valve in an internal combustion engine mounted on a vehicle such as an automobile or a two-wheeler. Background Art

[0002] As a conventional electromagnetic switching valve, an electromagnetic spool valve is known, which includes: a spool valve having a sleeve, a spool slidably disposed within the sleeve, and a return spring for returning the spool to a rest position; an electromagnetic actuator having a coil, a plunger, and a stator; and a cylindrical shaft interposed between the plunger and the spool to transmit a driving force (for example, refer to Patent Document 1).

[0003] In the electromagnetic spool valve, a shaft breathing hole communicating with the breathing passage of the plunger is provided on the shaft, a breathing hole and an outer surface breathing groove communicating with the shaft breathing hole are provided on the sleeve, and the oil discharge path passing through the spool is made independent of the actuator breathing path, thereby preventing foreign matter from invading the plunger side.

[0004] However, in the electromagnetic spool valve, the actuator breathing path is also an area exposed to the working oil, and there is a concern that foreign matter in the working oil is sucked into the shaft through the breathing hole of the sleeve and the breathing hole of the shaft. Moreover, the foreign matter sucked into the shaft easily reaches the back space of the plunger through the breathing passage of the plunger, and there is a concern that the plunger is worn or locked due to the jamming of the foreign matter.

[0005] On the other hand, if the passage of the working oil communicating with the breathing passage of the plunger is made too narrow, it becomes the same structure as a dush pot and a damping action is generated, and there is a concern that the plunger cannot operate normally.

[0006] [Prior Art Documents]

[0007] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-63022 Summary of the Invention

[0009] [Problems to be Solved by the Invention]

[0010] The present invention has been made in view of the above circumstances, and an object thereof is to provide an electromagnetic switching valve that can simplify the structure without increasing the number of parts, and at the same time suppress or prevent foreign matter from invading the plunger side of the electromagnetic actuator.

[0011] [Technical means for solving the problem]

[0012] The electromagnetic switching valve of the present invention includes: a sleeve defining a port communicating with an oil passage for supplying or discharging working oil; a slide rod disposed in the sleeve to be reciprocally movable in a specified axial direction to open and close the port; an electromagnetic actuator including a plunger and a stator, the plunger having a through-hole extending in the axial direction, and the stator applying a magnetic potential to the plunger; and a cylindrical transmission member interposed between the plunger and the slide rod to transmit a driving force. The electromagnetic switching valve is configured such that: the stator includes an insertion through-hole through which the transmission member is inserted, the transmission member includes an opposing wall facing the through-hole of the plunger, a first internal passage formed on the plunger side of the opposing wall and communicating with the through-hole, a first opening portion opening the first internal passage in the radial direction on the plunger side of the insertion through-hole, a second internal passage formed on the slide rod side of the opposing wall, and a second opening portion opening the second internal passage in the radial direction on the slide rod side of the insertion through-hole.

[0013] In the electromagnetic switching valve configured as described above, the following configuration may also be adopted: a plurality of second opening portions are formed at intervals in the axial direction.

[0014] In the electromagnetic switching valve, the following configuration may also be adopted: the passage area of the first internal passage is larger than or equal to the passage area of the through-hole.

[0015] In the electromagnetic switching valve, the following configuration may also be adopted: the passage area of the first opening portion is larger than or equal to the passage area of the first internal passage.

[0016] In the electromagnetic switching valve, the following configuration may also be adopted: the passage area of the gap defined around the transmission member in the insertion through-hole is smaller than or equal to the passage area of the first opening portion.

[0017] In the electromagnetic switching valve, the following configuration may also be adopted: the passage area of the second opening portion is larger than or equal to the passage area of the second internal passage.

[0018] In the electromagnetic switching valve, the following configuration may also be adopted: the transmission member includes a large-diameter cylindrical portion disposed in the sleeve and a small-diameter cylindrical portion inserted into the insertion through-hole of the stator. The small-diameter cylindrical portion includes an opposing wall, a first internal passage, a first opening portion, a second internal passage, and a second opening portion, and the large-diameter cylindrical portion includes a second internal passage and a second opening portion.

[0019] In the electromagnetic switching valve, the following configuration may also be adopted: the transmission member includes an annular stepped portion formed at the boundary between the small-diameter cylindrical portion and the large-diameter cylindrical portion, and the stator includes an annular opposing portion facing the annular stepped portion in the axial direction.

[0020] In the electromagnetic switching valve, the following configuration may also be adopted: The transmission member includes an annular abutting portion that defines an opening portion through which the second internal passage opens toward the spool and abuts against the spool.

[0021] In the electromagnetic switching valve, the following configuration may also be adopted: The stator includes an annular facing surface that faces the plunger in the axial direction and an annular inner wall surface that can face the outer peripheral surface of the plunger.

[0022] In the electromagnetic switching valve, the following configuration may also be adopted: The plunger includes a receiving recess around the through passage, and the receiving recess receives and abuts against the end portion of the transmission member.

[0023] In the electromagnetic switching valve, the following configuration may also be adopted: The sleeve includes a communication passage that communicates the internal space where the transmission member is disposed with the oil passage.

[0024] In the electromagnetic switching valve, the following configuration may also be adopted: The spool includes a communication passage that communicates the second internal passage of the transmission member with the oil passage.

[0025] In the electromagnetic switching valve, the following configuration may also be adopted: The transmission member is formed of a resin material.

[0026] [Advantages of the Invention]

[0027] According to the electromagnetic switching valve configured as described above, the structure can be simplified without increasing the number of parts, and at the same time, intrusion of foreign matter into the plunger side of the electromagnetic actuator can be suppressed or prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a configuration diagram when the electromagnetic switching valve of the present invention is applied to a valve timing change device of an internal combustion engine.

[0029] Figure 2 is an exploded perspective view of the electromagnetic switching valve according to the first embodiment of the present invention as viewed from the sleeve side.

[0030] Figure 3 is an exploded perspective view of the electromagnetic switching valve according to the first embodiment of the present invention as viewed from the electromagnetic actuator side.

[0031] Figure 4 is an exploded perspective view of the electromagnetic actuator included in the electromagnetic switching valve according to the first embodiment.

[0032] Figure 5 is an external perspective view of the transmission member included in the electromagnetic switching valve according to the first embodiment.

[0033] Figure 6 is Figure 5A three-dimensional sectional view obtained by cutting the shown transmission member along a plane passing through the axis.

[0034] Figure 7 The operation of the electromagnetic switching valve of the first embodiment is described, and it is a sectional view showing the state where the spool and the plunger are in the rest position.

[0035] Figure 8 The operation of the electromagnetic switching valve of the first embodiment is described, and it is a sectional view showing the state where the spool and the plunger have advanced and moved to the maximum movement position.

[0036] Figure 9 It is a sectional view showing the flow state of the working oil around the plunger and the transmission member when the plunger advances in the electromagnetic switching valve of the first embodiment.

[0037] Figure 10 It is a sectional view showing the flow state of the working oil around the plunger and the transmission member when the plunger retracts in the electromagnetic switching valve of the first embodiment.

[0038] Figure 11 It is a sectional view showing the electromagnetic switching valve of the second embodiment of the present invention.

[0039] Figure 12 It is a sectional view showing the electromagnetic switching valve of the third embodiment of the present invention.

[0040] Figure 13 It shows the electromagnetic switching valve of the fourth embodiment of the present invention, and it is a sectional view showing the state where the plunger is in the rest position.

[0041] Figure 14 It shows the electromagnetic switching valve of the fourth embodiment of the present invention, and it is a sectional view showing the state where the plunger has advanced and moved to the maximum movement position.

[0042] [Description of Reference Signs]

[0043] S: Axis

[0044] 3: Supply oil passage

[0045] 4: Discharge oil passage

[0046] 5: First oil passage

[0047] 6: Second oil passage

[0048] V1, V2, V3, V4: Electromagnetic switching valves

[0049] SS: Internal space

[0050] 10, 210, 310: Sleeves

[0051] 11b, 311b: Supply ports

[0052] 11c, 11d, 311c: Discharge ports

[0053] 11e, 311d: First ports

[0054] 11f, 311e: Second ports

[0055] 11i, 228, 329: Communication paths

[0056] 20, 220, 320: Slide posts

[0057] 60: Transmission member

[0058] 61: Small-diameter cylindrical part

[0059] 61a: End part

[0060] 61b: Opposing walls

[0061] 61c: First internal passage

[0062] 61d: First opening

[0063] 61e: Second internal passage

[0064] 61f: Second opening

[0065] 62: Large-diameter cylindrical part

[0066] 62a: Second internal passage

[0067] 62b: Second opening

[0068] 62d: Annular abutting part

[0069] 63: Annular step part

[0070] A: Electromagnetic actuator

[0071] 70: Plunger

[0072] 71: Outer peripheral surface

[0073] 74: Through passage

[0074] 75: Accommodating recess

[0075] 90, 190: Stators

[0076] 91a, 191: Insertion through holes

[0077] 91b, 192: Annular opposing surfaces

[0078] 91c, 193: Annular inner wall surfaces

[0079] 91e, 194: Annular facing parts DETAILED DESCRIPTION

[0080] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0081] like Figure 1 As shown, the electromagnetic switching valve V1 according to the first embodiment of the present invention is applied to a valve timing changing device M of an internal combustion engine.

[0082] The electromagnetic switching valve V1 is appropriately driven and controlled by the control unit ECU according to the operating conditions of the vehicle and the internal combustion engine.

[0083] The engine body EB includes: a fitting hole H for inserting the electromagnetic switching valve V1; an oil supply passage 3 for supplying the working oil in the oil pan 1 via an oil pump 2; an oil discharge passage 4 for discharging the working oil from the electromagnetic switching valve V1 to the oil pan 1; a first oil passage 5 connected to one of the retarded angle chamber RC and the advanced angle chamber AC of the valve timing changing device M; and a second oil passage 6 connected to the other of the retarded angle chamber RC and the advanced angle chamber AC of the valve timing changing device M.

[0084] The valve timing changing device M includes a vane rotor 7 that rotates integrally with the camshaft CS, and a housing rotor 8 that accommodates the vane rotor 7 so as to be relatively rotatable within a predetermined angle range and rotates in conjunction with the crankshaft.

[0085] Furthermore, an advance angle chamber AC and a retard angle chamber RC, through which hydraulic oil is supplied and discharged, are defined by the internal space of the casing rotor 8 and the vane rotor 7 .

[0086] Here, when the valve timing changing device M is applied to the intake-side camshaft CS, the first oil passage 5 is connected to the advanced angle chamber AC, and the second oil passage 6 is connected to the retarded angle chamber RC.

[0087] On the other hand, when the valve timing changing device M is applied to the exhaust-side camshaft CS, the first oil passage 5 is connected to the retard angle chamber RC, and the second oil passage 6 is connected to the advance angle chamber AC.

[0088] like Figure 2 and Figure 3 As shown, the electromagnetic switching valve V1 includes a sleeve 10 , a spool 20 , a biasing spring 30 , a sealing member 40 , a sealing member 50 , a transmission member 60 , and an electromagnetic actuator A.

[0089] like Figure 4 , Figure 7 , Figure 8As shown, the electromagnetic actuator A includes a plunger 70, a guide sleeve 80, a stator 90, a sealing member 100, a bracket 110, an inner yoke 120, a molding unit 130, a sealing member 140, and an outer yoke 150.

[0090] The sleeve 10 is formed of a metal material such as aluminum into a cylindrical shape centered on the axis S, and as Figure 2 , Figure 3 , Figure 7 shown, includes an outer peripheral surface 11, a sealing groove 11a, a supply port 11b, a discharge port 11c, a discharge port 11d, a first port 11e, a second port 11f, a communication path 11g, a communication path 11h, a communication path 11i, an inner peripheral surface 12, an inner peripheral surface 13, a receiving portion 14, and a flange portion 15.

[0091] The outer peripheral surface 11 is formed into a cylindrical surface centered on the axis S and is fitted into the fitting hole H of the engine body EB.

[0092] The sealing groove 11a is formed as an annular groove on the outer peripheral surface 11 for embedding the sealing member 40.

[0093] The supply port 11b communicates with the supply oil passage 3. The discharge ports 11c and 11d communicate with the discharge oil passage 4. The first port 11e communicates with the first oil passage 5. The second port 11f communicates with the second oil passage 6.

[0094] The communication path 11g is formed at the end of the sleeve 10 to connect the space where the biasing spring 30 is disposed to the discharge oil passage 4.

[0095] The communication path 11h opens radially at the end portion of the sleeve 10 to connect the space where the biasing spring 30 is disposed to the discharge oil passage 4.

[0096] The communication path 11i is in the region of the inner peripheral surface 13 of the sleeve 10 to connect the internal space SS where the transmission member 60 is disposed to the discharge oil passage 4.

[0097] The inner peripheral surface 12 is formed into a cylindrical surface centered on the axis S and closely contacts and slidably guides the outer peripheral surface 21 of the slide column 20.

[0098] The inner peripheral surface 13 is formed into a conical surface centered on the axis S with an inner diameter larger than that of the inner peripheral surface 12 and gradually expanding toward the flange portion 15, and is formed to ensure the internal space SS around the transmission member 60 in a state where the transmission member 60 is disposed.

[0099] The receiving portion 14 functions to receive the first end portion 26 of the slide column 20 to stop the slide column 20 at the maximum forward position, and also functions to receive one end portion of the biasing spring 30.

[0100] The flange portion 15 is joined to the stator 90 and the end of the outer yoke 150 is riveted, so that the flange portion 15 is fixedly connected to the electromagnetic actuator A. In addition, a ring-shaped recess 15a is provided in the flange portion 15, and the ring-shaped recess 15a cooperates with the stator 90 to accommodate the sealing member 50 in a manner of clamping the sealing member 50.

[0101] As Figure 2 , Figure 3 , Figure 7 shown, the slide column 20 is formed to extend in the direction of the axis S, and includes an outer peripheral surface 21, a first valve portion 22, a second valve portion 23, a recess 24, a receiving portion 25, a first end portion 26, and a second end portion 27.

[0102] The outer peripheral surface 21 is formed in a cylindrical shape centered on the axis S, and has an outer diameter that is substantially the same as or slightly smaller than the inner diameter of the inner peripheral surface 12 of the sleeve 10, so as to slide on the inner peripheral surface 12 of the sleeve 10.

[0103] The first valve portion 22 is formed to define an outer peripheral surface 21 that is wider than the opening width of the first port 11e in the direction of the axis S, and opens and closes the first port 11e of the sleeve 10 by moving in the direction of the axis S.

[0104] The second valve portion 23 is formed to define an outer peripheral surface 21 that is wider than the opening width of the second port 11f in the direction of the axis S, and opens and closes the second port 11f of the sleeve 10 by moving in the direction of the axis S.

[0105] The recess 24 is formed on one side of the first end portion 26 to accommodate the biasing spring 30 in a telescopic manner.

[0106] A receiving portion 25 is formed as the bottom wall of the recess 24 to receive the other end portion of the biasing spring 30 accommodated in the recess 24.

[0107] The first end portion 26 is formed as an annular end surface and is separably abutted against the receiving portion 14 of the sleeve 10.

[0108] The second end portion 27 is formed in a circular ring shape centered on the axis S and is a convex curved surface so as to abut against the annular abutting portion 62d of the transmission member 60 in the direction of the axis S.

[0109] The biasing spring 30 is a compression-type helical spring and is assembled in such a manner that one end portion abuts against the receiving portion 14 of the sleeve 10 and the other end portion abuts against the receiving portion 25 of the slide column 20.

[0110] Moreover, when in the rest state, the biasing spring 30 applies a force as Figure 7As shown, the plunger 70 is retracted to the rest position, and the slide pillar 20 is stopped at a position where the first valve portion 22 blocks the communication between the first port 11e and the supply port 11b and connects the first port 11e to the discharge port 11c, and the second valve portion 23 connects the second port 11f to the supply port 11b and blocks the communication between the second port 11f and the discharge port 11d.

[0111] The sealing member 40 is a rubber O-ring and is inserted into the sealing groove 11a of the sleeve 10 to seal between the engine body EB and the sleeve 10.

[0112] The sealing member 50 is a rubber O-ring and is disposed in the annular recess 15a of the flange portion 15 of the sleeve 10 to seal between the sleeve 10 and the stator 90.

[0113] The transmission member 60 is formed of a resin material into a cylindrical shape extending in the axial direction of the axis S so as to transmit the driving force between the plunger 70 and the slide pillar 20. As Figures 5 to 7 shown, the transmission member 60 includes a small-diameter cylindrical portion 61 inserted into the insertion hole 91a of the stator 90, a large-diameter cylindrical portion 62 disposed in the region of the inner peripheral surface 13 within the sleeve 10, and an annular step portion 63.

[0114] The small-diameter cylindrical portion 61 includes an end portion 61a, opposing walls 61b, a first internal passage 61c, two first openings 61d, a second internal passage 61e, and two second openings 61f.

[0115] The end portion 61a is formed into a circular ring shape centered on the axis S and is a convex curved surface that abuts against the receiving recess 75 of the plunger 70.

[0116] The opposing walls 61b are formed as blocking walls that face the through-path 74 of the plunger 70 in the axial direction of the axis S.

[0117] The first internal passage 61c is formed at a position closer to the plunger 70 side than the opposing walls 61b in the axial direction of the axis S and is formed as a cylindrical hole extending in the axial direction of the axis S so as to communicate with the through-path 74 of the plunger 70.

[0118] The passage area of the first internal passage 61c is formed to be equal to or larger than the passage area of the through-path 74. Here, the passage area of the first internal passage 61c refers to the passage area of the first internal passage 61c in a cross-section perpendicular to the axis S, and the passage area of the through-path 74 refers to the passage area of the through-path 74 in a cross-section perpendicular to the axis S.

[0119] As Figure 7 and Figure 8As shown, the first opening 61d is formed at a position closer to the plunger 70 side than the insertion through-hole 91a of the stator 90 in the axial direction of the axis S, and is formed as a circular hole that radially opens the first internal passage 61c.

[0120] The passage area of the first opening 61d is formed to be equal to or larger than the passage area of the first internal passage 61c. Here, the passage area of the first opening 61d refers to the passage areas of the two first openings 61d formed as circular holes.

[0121] The second internal passage 61e is formed at a position closer to the slide pillar 20 side than the opposing wall 61b in the axial direction of the axis S, and is formed as a cylindrical hole extending in the axial direction of the axis S.

[0122] The inner diameter (passage area) of the second internal passage 61e is formed to be larger than the inner diameter (passage area) of the first internal passage 61c.

[0123] As Figure 7 and Figure 8 shown, the second opening 61f is formed at a position closer to the slide pillar 20 side than the insertion through-hole 91a of the stator 90 in the axial direction of the axis S, and is formed as a circular hole that radially opens the second internal passage 61e.

[0124] The passage area of the second opening 61f is formed to be equal to or larger than the passage area of the second internal passage 61e. Here, the passage area of the second opening 61f refers to the passage areas of the two second openings 61f formed as circular holes, and the passage area of the second internal passage 61e refers to the passage area of the second internal passage 61e in a cross-section perpendicular to the axis S.

[0125] The large-diameter cylindrical portion 62 includes a second internal passage 62a, four second openings 62b, four thinning portions 62c formed around the second openings 62b, and an annular abutting portion 62d.

[0126] The second internal passage 62a is formed at a position closer to the slide pillar 20 side than the opposing wall 61b in the axial direction of the axis S and is formed as a cylindrical hole extending in the axial direction of the axis S so as to communicate with the second internal passage 61e.

[0127] The inner diameter (passage area) of the second internal passage 62a is formed to be larger than the inner diameter (passage area) of the second internal passage 61e.

[0128] As Figure 7 and Figure 8 shown, the second opening 62b is formed at a position closer to the slide pillar 20 side than the insertion through-hole 91a of the stator 90 in the axial direction of the axis S, and is formed as a substantially rectangular hole that radially opens the second internal passage 62a.

[0129] The passage area of the second opening portion 62b is formed to be equal to or larger than the passage area of the second internal passage 62a. Here, the passage area of the second opening portion 62b refers to the passage areas of the four second opening portions 62b formed as substantially rectangular holes, and the passage area of the second internal passage 62a refers to the passage area of the second internal passage 62a in a cross section perpendicular to the axis S.

[0130] The thinning portion 62c is formed such that the area around the second opening portion 62b is recessed radially inward from the outer peripheral surface of the large-diameter cylinder portion 62. Accordingly, when the transmission member 60 is disposed within the sleeve 10, a sufficient clearance space for the working oil to flow can be ensured between the transmission member 60 and the inner peripheral surface 13.

[0131] The annular contact portion 62d is formed as a circular ring centered on the axis S and is a concave conical surface so as to define an opening through which the second internal passage 62a opens toward the sliding column 20 and to contact the second end portion 27 of the sliding column 20.

[0132] The annular step portion 63 is formed at the boundary between the small-diameter cylinder portion 61 and the large-diameter cylinder portion 62 and faces the annular facing portion 91e of the stator 90 in the direction of the axis S.

[0133] In the above configuration, the second opening portion 61f and the second opening portion 62b are arranged at intervals in the direction of the axis S. That is, in the transmission member 60, a plurality of second opening portions 61f and second opening portions 62b are formed at intervals in the direction of the axis S.

[0134] The plunger 70 is formed of a ferromagnetic material such as iron into a cylindrical shape extending in the direction of the axis S, and as Figure 4 and Figure 7 shown, includes an outer peripheral surface 71, a first end portion 72, a second end portion 73, a through passage 74, and a receiving recess 75.

[0135] The outer peripheral surface 71 is slidably guided along the direction of the axis S by the inner wall surface 81 of the guide sleeve 80.

[0136] The first end portion 72 is formed as an annular flat surface perpendicular to the axis S.

[0137] The second end portion 73 is formed as an annular flat surface perpendicular to the axis S and contacts the stopper 83 of the guide sleeve 80 at the rest position.

[0138] The through passage 74 is disposed on the axis S and extends in the direction of the axis S and is formed as a cylindrical hole penetrating from the first end portion 72 to the second end portion 73.

[0139] The accommodation recess 75 is formed in a circular shape centered on the axis S and as a concave conical surface around the through passage 74 at the first end portion 72, so as to accommodate and abut against the end portion 61a of the transmission member 60.

[0140] The guide sleeve 80 is formed into a bottomed cylindrical shape centered on the axis S by deep drawing a thin metal material, and as Figure 4 and Figure 7 shown, includes an inner wall surface 81, a bottom wall surface 82, a stopper 83 protruding from the bottom wall surface 82, and a flange portion 84.

[0141] The inner wall surface 81 guides the plunger 70 to slide freely in the direction of the axis S.

[0142] The stopper 83 is formed to protrude inward from the bottom wall surface 82 in the direction of the axis S, and functions to define a rest position of the specified plunger 70.

[0143] Thus, since the stopper 83 is formed to protrude inward, a clearance space is defined between the second end portion 73 of the plunger 70 and the bottom wall surface 82 in a state where the plunger 70 abuts against the stopper 83. Thereby, it is possible to prevent the plunger 70 from being in close contact with the bottom wall surface 82 of the guide sleeve 80 and being unable to operate.

[0144] The flange portion 84 includes a region formed in a multi-stage conical shape so as to cover the transmission member 60 from the outside in the radial direction, and is clamped and fixed together with the sealing member 100 between the stator 90 and the bracket 110.

[0145] In the relationship between the guide sleeve 80 and the plunger 70, when the plunger 70 is in the forward position in the direction of compressing the biasing spring 30, as Figure 8 and Figure 9 shown, a retraction movement space RS that enables the plunger 70 to retract to the rest position is defined by the inner wall surface 81 and the bottom wall surface 82 of the guide sleeve 80 and the second end portion 73 of the plunger 70.

[0146] The stator 90 is formed of a ferromagnetic material, and is integrally fixed by riveting a front yoke 91 formed in a multi-stage cylindrical shape and a rear yoke 92 formed in a substantially disc shape, so as to form a part of the magnetic circuit and apply a magnetic potential to the plunger 70 by energizing the coil 132.

[0147] As Figure 4 and Figure 7 shown, the stator 90 includes an insertion through hole 91a, an annular facing surface 91b, an annular inner wall surface 91c, a guide portion 91d, an annular facing portion 91e, a joint surface 92a, and a joint surface 92b.

[0148] The insertion through-hole 91a is formed as a cylindrical hole centered on the axis S so that the small-diameter cylindrical portion 61 of the transmission member 60 is inserted therethrough with a specified gap G therebetween.

[0149] Here, the passage area of the gap G defined around the transmission member 60 in the insertion through-hole 91a is formed to be equal to or smaller than the passage area of the first opening portion 61d. The passage area of the gap G refers to the passage area of the annular gap G in a cross-section perpendicular to the axis S.

[0150] In addition, it is preferable to minimize the gap G as much as possible within a range where the viscous resistance of the working oil does not increase.

[0151] The annular facing surface 91b is formed as a circular flat surface so as to face the first end portion 72 of the plunger 70 in the direction of the axis S.

[0152] The annular inner wall surface 91c is formed as a substantially cylindrical surface centered on the axis S so as to face the outer peripheral surface 71 of the plunger 70 with a specified gap therebetween in the radial direction in a state where the plunger 70 has moved forward.

[0153] The guide portion 91d is formed as a circular ring centered on the axis S and is a concave conical surface. When the transmission member 60 is inserted into the insertion through-hole 91a of the stator 90, the guide portion 91d functions to guide the end portion 61a of the transmission member 60 toward the axis S.

[0154] The annular facing portion 91e is formed as a circular ring centered on the axis S so as to face the annular stepped portion 63 of the transmission member 60 in the direction of the axis S.

[0155] The joint surfaces 92a and 92b are in close contact with the sealing members 50 and 100 in the assembled state, and are formed as flat surfaces so as to be clamped and fixed between the flange portion 15 of the sleeve 10 and the bracket 110.

[0156] In the relationship between the stator 90 and the plunger 70, when the plunger 70 is in the rest position, as Figure 7 and Figure 10 shown, an advancing movement space FS that allows the plunger 70 to move forward in the direction of compressing the biasing spring 30 is defined by the annular facing surface 91b and the annular inner wall surface 91c of the stator 90 and the first end portion 72 of the plunger 70.

[0157] The sealing member 100 is a rubber O-ring and is disposed between the joint surface 92b of the stator 90 and the flange portion 84 of the guide sleeve 80 to seal the joint area between the stator 90 and the guide sleeve 80.

[0158] The bracket 110 is formed of a metal material and includes an annular portion 111 and a mounting portion 112.

[0159] The annular portion 111 is clamped by the molding unit 130 and the stator 90 (end yoke 92), and is fixed by being inserted into the fitting recess 152 of the outer yoke 150.

[0160] The mounting portion 112 extends outward from the outer yoke 150 and is fixed to the engine body EB using screws or the like.

[0161] The inner yoke 120 forms part of the magnetic circuit, is formed of a ferromagnetic material into a bottomed cylindrical shape with a flange, and as Figure 4 and Figure 7 shown, includes a cylindrical portion 121 and a flange portion 122.

[0162] The cylindrical portion 121 is formed such that the guide sleeve 80 is inserted into its inner side and the bobbin 131 of the molding unit 130 is inserted into its outer side.

[0163] The flange portion 122 is inserted into the fitting recess 153 of the outer yoke 150 and is fixed by riveting.

[0164] As Figure 4 and Figure 7 shown, the molding unit 130 includes: a resin bobbin 131 inserted into the cylindrical portion 121 of the inner yoke 120; an exciting coil 132 wound around the bobbin 131; and a connector 133 formed integrally with the cylindrical portion surrounding the periphery of the coil 132 to surround the terminal.

[0165] The sealing member 140 is a rubber O-ring and is disposed between the flange portion 122 of the inner yoke 120 and the bobbin 131 of the molding unit 130 to seal between the bobbin 131 and the inner yoke 120.

[0166] The outer yoke 150 forms part of the magnetic circuit, is formed of a ferromagnetic material into a cylindrical shape, and as Figure 4 and Figure 7 shown, includes a cylindrical portion 151, a fitting recess 152, and a fitting recess 153.

[0167] The cylindrical portion 151 is formed into a cylindrical shape centered on the axis S, and is formed in such a way as to cover the region where the coil 132 is wound of the molding unit 130, the flange portion 122 of the inner yoke 120, the annular portion 111 of the bracket 110, the stator 90 (end yoke 92), and the flange portion 15 of the sleeve 10 from the radially outer side.

[0168] In a state where the fitting recess 152 has the annular portion 111 of the bracket 110, the stator 90 (end yoke 92), and the flange portion 15 of the sleeve 10 inserted therein along the axis S direction, a riveting process is performed on the front end side region, thereby fixing the annular portion 111, the stator 90 (end yoke 92), and the flange portion 15.

[0169] In a state where the inner yoke 120 is embedded in the flange portion 122, the fitting recess 153 performs a riveting process on the front end side region, thereby fixing the flange portion 122.

[0170] Next, the switching operation of the electromagnetic switching valve V1 will be described.

[0171] First, in a state where the coil 132 is not energized, by the force applied by the biasing spring 30 and via the slide post 20 and the transmission member 60, the plunger 70 Figure 7 stops at the rest position where the second end portion 73 abuts against the stopper 83 as shown.

[0172] In addition, the slide post 20 stops at the retracted position corresponding to the rest position of the plunger 70 via the transmission member 60.

[0173] In the retracted position, the first valve portion 22 of the slide post 20 is in a state of closing the oil passage between the first port 11e and the supply port 11b and opening the oil passage between the first port 11e and the discharge port 11c.

[0174] In addition, the second valve portion 23 of the slide post 20 is in a state of opening the oil passage between the second port 11f and the supply port 11b and closing the oil passage between the second port 11f and the discharge port 11d.

[0175] At this time, the first oil passage 5 discharges the working oil, and the second oil passage 6 supplies the working oil.

[0176] Subsequently, when the coil 132 is appropriately energized to generate a magnetic potential, the plunger 70 moves forward while resisting the force applied by the biasing spring 30, and as Figure 8 shown, the first end portion 26 of the slide post 20 abuts against the receiving portion 14, so that the slide post 20 is positioned at the maximum forward position.

[0177] In the maximum forward position, the first valve portion 22 of the slide post 20 is in a state of opening the oil passage between the first port 11e and the supply port 11b and closing the oil passage between the first port 11e and the discharge port 11c.

[0178] In addition, the second valve portion 23 of the slide post 20 is in a state of closing the oil passage between the second port 11f and the supply port 11b and opening the oil passage between the second port 11f and the discharge port 11d.

[0179] At this time, the first oil passage 5 supplies the working oil, and the second oil passage 6 discharges the working oil.

[0180] In addition, the energization of the coil 132 can be appropriately controlled so that the slide post 20 stops at the intermediate position.

[0181] At the intermediate position, the first valve portion 22 of the sliding column 20 is in a state of closing the oil passage between the first port 11e and the supply port 11b and closing the oil passage between the first port 11e and the discharge port 11c.

[0182] In addition, the second valve portion 23 of the sliding column 20 is in a state of closing the oil passage between the second port 11f and the supply port 11b and closing the oil passage between the second port 11f and the discharge port 11d.

[0183] At this time, the supply and discharge of the working oil in the first oil passage 5 and the second oil passage 6 are both blocked.

[0184] When the electromagnetic switching valve V1 that performs the switching operation is applied to, for example, a valve timing change device M of the intake side camshaft CS of an internal combustion engine, the first oil passage 5 is connected to the advance angle chamber AC, and the second oil passage 6 is connected to the retard angle chamber RC.

[0185] Therefore, when the plunger 70 is in the rest position, the valve timing of the intake valve is held at the retard angle position, and by the forward movement of the plunger 70 according to the operating conditions, the valve timing of the intake valve is set at the advance angle position.

[0186] On the other hand, when the electromagnetic switching valve V1 that performs the switching operation is applied to, for example, a valve timing change device M of the exhaust side camshaft CS of an internal combustion engine, the first oil passage 5 is connected to the retard angle chamber RC, and the second oil passage 6 is connected to the advance angle chamber AC.

[0187] Therefore, when the plunger 70 is in the rest position, the valve timing of the exhaust valve is held at the advance angle position, and by the forward movement of the plunger 70 according to the operating conditions, the valve timing of the exhaust valve is set at the retard angle position.

[0188] Next, the flow of the working oil around the plunger 70 and the transmission member 60 in the electromagnetic switching valve V1 that performs the switching operation will be described.

[0189] When the plunger 70 moves forward from the rest position, as Figure 9 shown, the working oil in the forward movement space FS flows into the backward movement space RS defined at the rear side of the plunger 70 via the first opening 61d and the first internal passage 61c of the transmission member 60 and through the through-passage 74 of the plunger 70 as indicated by the arrow. Thus, the plunger 70 can move forward smoothly.

[0190] Here, the passage area of the first internal passage 61c is formed to be larger than the passage area of the through passage 74. In addition, the passage area of the first opening 61d is formed to be larger than the passage area of the first internal passage 61c. Therefore, when the working oil moves from the forward movement space FS to the backward movement space RS, it is possible to prevent the generation of damping effects caused by contraction resistance, etc., and thus the plunger 70 can work smoothly.

[0191] In addition, as the plunger 70 moves forward, the outer peripheral surface 71 of the plunger 70 faces the annular inner wall surface 91c of the stator 90 with a small clearance in the radial direction, and the first end portion 72 of the plunger 70 faces the annular facing surface 91b of the stator 90 in the axial direction of the axis S. Therefore, the working oil in the forward movement space FS surrounded by the first end portion 72 and the annular facing surface 91b actively points to the first opening 61d and the first internal passage 61c, thereby promoting the flow of the working oil from the forward movement space FS toward the backward movement space RS.

[0192] On the other hand, in the internal space SS of the sleeve 10, the transmission member 60 is pushed by the plunger 70 and moves forward together with the slide column 20.

[0193] Here, the passage area of the clearance G defined around the small-diameter cylinder portion 61 of the transmission member 60 in the insertion through hole 91a of the stator 90 is formed to be equal to or smaller than the passage area of the first opening 61d, that is, it is formed extremely small within a range where the viscous resistance does not increase. Therefore, the working oil in the internal space SS, especially foreign matters, is not easily introduced into the forward movement space FS through the insertion through hole 91a.

[0194] In this state, since the separation distance between the annular step portion 63 and the annular facing portion 91e is enlarged, the working oil in the internal space SS, for example, as shown by the arrow in Figure 9 , the working oil in the second internal passage 61e of the transmission member 60 flows from the second opening 61f to the internal space SS. In addition, the working oil in the internal space SS outside the transmission member 60 flows from the second opening 62b into the second internal passage 62a and the second internal passage 61e, or the working oil near the discharge port 11d and the discharge oil passage 4 flows into the internal space SS through the communication passage 11i. In this way, the working oil in the internal space SS circulates around the transmission member 60 as a whole.

[0195] When the plunger 70 moves backward from the forward position toward the rest position, the working oil in the backward movement space RS, as shown by the arrow in Figure 10 , flows into the forward movement space FS defined in front of the plunger 70 through the through passage 74 of the plunger 70 and the first internal passage 61c and the first opening 61d of the transmission member 60. Thus, the plunger 70 can move backward smoothly.

[0196] Here, similarly to the foregoing, the passage area of the first internal passage 61c is formed to be larger than the passage area of the through passage 74, and the passage area of the first opening 61d is formed to be larger than the passage area of the first internal passage 61c. Therefore, when the working oil moves from the retraction movement space RS to the forward movement space FS, it is possible to prevent the generation of damping effects due to contraction resistance and the like, and thus the plunger 70 can operate smoothly.

[0197] On the other hand, in the internal space SS of the sleeve 10, the transmission member 60 follows the plunger 70 and moves backward together with the slide column 20 by the force applied by the biasing spring 30.

[0198] Here, similarly to the foregoing, the passage area of the clearance G defined around the small-diameter cylinder portion 61 of the transmission member 60 in the insertion through hole 91a of the stator 90 is formed to be equal to or smaller than the passage area of the first opening 61d, that is, it is formed extremely small within a range where the viscous resistance does not increase. Therefore, the working oil in the internal space SS, particularly foreign matters, is less likely to flow into the forward movement space FS through the insertion through hole 91a.

[0199] In the above state, since the separation distance between the annular step portion 63 and the annular facing portion 91e becomes narrow, the working oil in the internal space SS, for example, as shown by the arrow in Figure 10 , the working oil in the internal space SS outside the transmission member 60 flows from the second opening 61f of the transmission member 60 into the second internal passage 61e. In addition, the working oil in the second internal passage 62a and the second internal passage 61e inside the transmission member 60 flows from the second opening 62b into the internal space SS outside the transmission member 60, or the working oil in the internal space SS flows out to the discharge port 11d and the discharge oil passage 4 through the communication passage 11i. Thus, the working oil in the internal space SS as a whole circulates around the transmission member 60.

[0200] Here, the second opening 61f and the second opening 62b are formed to be separated in the axial direction of the axis S. The passage area of the second opening 61f is formed to be larger than the passage area of the second internal passage 61e, and the passage area of the second opening 62b is formed to be larger than the passage area of the second internal passage 62a.

[0201] Thereby, the working oil in the internal space SS outside the transmission member 60 is actively introduced into the second internal passage 61e and the second internal passage 62a inside the transmission member 60, or the working oil in the second internal passage 61e and the second internal passage 62a inside the transmission member 60 is actively introduced into the internal space SS outside the transmission member 60, so that it can circulate between the inside and the outside of the transmission member 60.

[0202] In addition, since the annular stepped portion 63 of the transmission member 60 faces the annular facing portion 91e of the stator 90 in the axial direction of the axis S, the working oil can be actively circulated in the internal space SS by changing the separation distance between the two.

[0203] Therefore, when foreign matter is mixed in the working oil in the internal space SS, it is possible to prevent the foreign matter from flowing into the working area of the plunger 70 through the insertion hole 91a. Thus, it is possible to prevent the wear or locking of the plunger 70 caused by the jamming of foreign matter.

[0204] If foreign matter in the working oil jams around the slide pillar 20, by appropriately reciprocatingly driving the plunger 70, the jamming state can be eliminated.

[0205] According to the electromagnetic switching valve V1 configured as described above, an opposing wall 61b that faces the through-path 74 of the plunger 70 is provided as a blocking wall inside the cylindrical transmission member 60, and in addition, the gap G defined between the insertion hole 91a of the stator 90 and the transmission member 60 is extremely reduced, thereby restricting the direct flow of the working oil on the slide pillar 20 side into the plunger 70 side.

[0206] Moreover, the working oil filling the periphery of the transmission member 60 is circulated around the transmission member 60, and the working oil filling the periphery of the plunger 70 is circulated around the plunger 70. Thus, the structure can be simplified without increasing the number of parts, and at the same time, it is possible to suppress or prevent foreign matter from invading the plunger 70 side of the electromagnetic actuator A.

[0207] Therefore, it is possible to suppress or prevent the occurrence of wear or locking of the plunger 70, so that the electromagnetic actuator A can operate normally.

[0208] Figure 11 The electromagnetic switching valve V2 showing the second embodiment of the present invention is the same as the first embodiment except that the stator is changed. Therefore, the same components and operations are denoted by the same reference numerals and the description thereof is omitted.

[0209] The electromagnetic switching valve V2 of the second embodiment includes a sleeve 10, a slide pillar 20, a biasing spring 30, a sealing member 40, a sealing member 50, a transmission member 60, a plunger 70, a guide sleeve 80, a stator 190, a sealing member 100, a bracket 110, an inner magnetic yoke 120, a molding unit 130, a sealing member 140, and an outer magnetic yoke 150.

[0210] The stator 190 is a member integrally formed with a multi-stage cylindrical portion and a disk portion by press-forming a metal plate containing a ferromagnetic material having a specified thickness, and as Figure 11As shown, it includes an insertion through-hole 191, annular facing surfaces 192, an annular inner wall surface 193, an annular facing portion 194, a joint surface 195, and a joint surface 196.

[0211] The insertion through-hole 191 allows the small-diameter cylinder portion 61 of the transmission member 60 to be inserted with a clearance G, and the hole depth is shallower than the insertion through-hole 91a of the stator 90 in the first embodiment. Therefore, corresponding to the shallower hole depth, the area subjected to the viscous resistance of the working oil is also smaller. Thus, the clearance G can be made smaller compared to the insertion through-hole 91a.

[0212] The annular facing surfaces 192, the annular inner wall surface 193, the joint surface 195, and the joint surface 196 respectively correspond to the annular facing surface 91b, the annular inner wall surface 91c, the joint surface 92a, and the joint surface 92b of the stator 90 in the first embodiment.

[0213] The annular facing portion 194 is formed as the bottom surface of the annular recess so as to face the annular stepped portion 63 of the transmission member 60 in the axial direction of the axis S. Regarding its function, it is the same as the annular facing portion 91e of the stator 90 in the first embodiment.

[0214] Similar to the electromagnetic switching valve V1, the electromagnetic switching valve V2 according to the second embodiment circulates the working oil filling the periphery of the transmission member 60 around the transmission member 60 and circulates the working oil filling the periphery of the plunger 70 around the plunger 70. Thus, the structure can be simplified without increasing parts, and at the same time, the intrusion of foreign matter into the plunger 70 side of the electromagnetic actuator A can be suppressed or prevented.

[0215] Therefore, the occurrence of wear or seizure of the plunger 70 can be suppressed or prevented, so that the electromagnetic actuator A can operate normally. In particular, since the stator 190 is an integrally formed product, the manufacturing cost of parts can be reduced.

[0216] Figure 12 The electromagnetic switching valve V3 showing the third embodiment of the present invention is the same as the first embodiment except that a part of the sleeve and the slide column is changed. Therefore, the same components and operations are denoted by the same reference numerals and the description thereof is omitted.

[0217] The electromagnetic switching valve V3 of the third embodiment includes a sleeve 210, a slide column 220, a biasing spring 30, a sealing member 40, a sealing member 50, a transmission member 60, a plunger 70, a guide sleeve 80, a stator 90, a sealing member 100, a bracket 110, an inner yoke 120, a molding unit 130, a sealing member 140, and an outer yoke 150.

[0218] The sleeve 210 eliminates the communication path 11i of the sleeve 10 of the first embodiment and, other than that, is the same as the first embodiment, including an outer peripheral surface 11, a sealing groove 11a, a supply port 11b, a discharge port 11c, a discharge port 11d, a first port 11e, a second port 11f, a communication path 11g, a communication path 11h, an inner peripheral surface 12, an inner peripheral surface 13, a receiving portion 14, and a flange portion 15.

[0219] The slide pillar 220 includes an outer peripheral surface 21, a first valve portion 22, a second valve portion 23, a concave portion 24, a receiving portion 25, a first end portion 26, a second end portion 27, and a communication path 228.

[0220] The communication path 228 is formed as a cylindrical hole that penetrates along the axis S with the axis S as the center, connecting the second internal passage 62a and the second internal passage 61e of the transmission member 60 to the communication path 11g and the discharge oil passage 4, allowing the working oil to flow.

[0221] The communication path 228 functions the same as the communication path 11i of the sleeve 10 in the first embodiment and, as the transmission member 60 reciprocates, assists in the circulating flow of the working oil in the internal spaces SS inside and outside the transmission member 60.

[0222] In the electromagnetic switching valve V3 configured as described above, similar to the electromagnetic switching valves V1 and V2, the working oil filling the periphery of the transmission member 60 circulates around the transmission member 60, and the working oil filling the periphery of the plunger 70 circulates around the plunger 70. Thus, the structure can be simplified without increasing parts, and at the same time, the intrusion of foreign matter into the plunger 70 side of the electromagnetic actuator A can be suppressed or prevented.

[0223] Therefore, the wear or locking of the plunger 70 can be suppressed or prevented, enabling the electromagnetic actuator A to operate normally.

[0224] Figure 13 and Figure 14 The electromagnetic switching valve V4 representing the fourth embodiment of the present invention is the same as the first embodiment except for a change in a part of the sleeve and the slide pillar. Therefore, the same components and operations are labeled with the same reference numerals and the description is omitted.

[0225] The electromagnetic switching valve V4 of the fourth embodiment includes a sleeve 310, a slide pillar 320, a biasing spring 30, a sealing member 40, a sealing member 50, a transmission member 60, a plunger 70, a guide sleeve 80, a stator 90, a sealing member 100, a bracket 110, an inner magnetic yoke 120, a molding unit 130, a sealing member 140, and an outer magnetic yoke 150.

[0226] The sleeve 310 is formed of a metallic material such as aluminum into a cylindrical shape centered on the axis S, and includes an outer peripheral surface 311, a sealing groove 311a, a supply port 311b, a discharge port 311c, a first port 311d, a second port 311e, an inner peripheral surface 312, an inner peripheral surface 313, a receiving portion 314, a receiving portion 314a, and a flange portion 315.

[0227] The outer peripheral surface 311 is formed as a cylindrical surface centered on the axis S, and is fitted into the fitting hole H of the engine body EB.

[0228] The sealing groove 311a is formed as an annular groove in the outer peripheral surface 311 for embedding the sealing member 40.

[0229] The supply port 311b communicates with the supply oil passage 3. The discharge port 311c communicates with the discharge oil passage 4. The first port 311d communicates with the first oil passage 5. The second port 311e communicates with the second oil passage 6.

[0230] The inner peripheral surface 312 is formed as a cylindrical surface centered on the axis S, and closely contacts and slidably guides the outer peripheral surface 321 of the slide column 320.

[0231] The inner peripheral surface 313 is formed as a conical surface centered on the axis S with an inner diameter larger than that of the inner peripheral surface 312 and gradually expanding toward the flange portion 315, and is formed to ensure an internal space SS around the transmission member 60 in a state where the transmission member 60 is disposed.

[0232] The receiving portion 314 functions to receive the first end portion 327 of the slide column 320 and stop the slide column 320 at the maximum forward position. The receiving portion 314a functions to receive one end portion of the biasing spring 30.

[0233] The flange portion 315 is joined to the stator 90 and the end portion of the outer magnetic yoke 150 is riveted, so that the flange portion 315 is connected and fixed to the electromagnetic actuator A. Further, an annular recess 315a is provided in the flange portion 315, and the annular recess 315a cooperates with the stator 90 to receive the sealing member 50 in a manner of clamping the sealing member 50.

[0234] The slide column 320 is formed to extend in the direction of the axis S, and includes an outer peripheral surface 321, a first valve portion 322, a second valve portion 323, a small-diameter portion 324, a recess 325, a receiving portion 326, a first end portion 327, a second end portion 328, and a communication path 329.

[0235] The outer peripheral surface 321 is formed as a cylindrical shape centered on the axis S, and has an outer diameter substantially the same as or slightly smaller than the inner diameter of the inner peripheral surface 312 so as to slide on the inner peripheral surface 312 of the sleeve 310.

[0236] The first valve portion 322 is formed so as to define an outer peripheral surface 321 that is wider than the opening width of the first port 311d in the direction of the axis S, and opens and closes the first port 311d of the sleeve 310 by moving in the direction of the axis S.

[0237] The second valve portion 323 is formed so as to define an outer peripheral surface 321 that is wider than the opening width of the second port 311e in the direction of the axis S, and opens and closes the second port 311e of the sleeve 310 by moving in the direction of the axis S.

[0238] The small-diameter portion 324 is formed between the first valve portion 322 and the second valve portion 323, and cooperates with the inner peripheral surface 312 of the sleeve 310 to define a space allowing the working oil to flow.

[0239] The recess 325 is formed on one side of the first end portion 327 so as to accommodate the biasing spring 30 in a telescopic manner.

[0240] A receiving portion 326 is formed as the bottom wall of the recess 325 so as to receive the other end portion of the biasing spring 30 accommodated in the recess 325.

[0241] The first end portion 327 is formed as an annular end surface and is separably abutted against the receiving portion 314 of the sleeve 310.

[0242] The second end portion 328 is formed as a convex curved surface that is circular and centered on the axis S so as to abut against the annular abutting portion 62d of the transmission member 60 in the direction of the axis S.

[0243] The communication path 329 is formed as a cylindrical hole penetrating in the direction of the axis S, and connects the second internal passage 62a and the second internal passage 61e of the transmission member 60 to the discharge port 311c.

[0244] Next, the switching operation of the electromagnetic switching valve V4 will be described.

[0245] First, in a state where the coil 132 is not energized, by the force applied by the biasing spring 30 and via the slide pin 320 and the transmission member 60, the plunger 70 Figure 13 stops at the rest position where the second end portion 73 abuts against the stopper 83 as shown.

[0246] In addition, the slide pin 320 stops at a retracted position corresponding to the rest position of the plunger 70 via the transmission member 60.

[0247] In the retracted position, the first valve portion 322 of the slide pin 320 is in a state of closing the oil passage between the first port 311d and the supply port 311b and opening the oil passage between the first port 311d and the discharge port 311c.

[0248] In addition, the second valve portion 323 of the sliding column 320 is in a state where the oil passage between the second port 311e and the supply port 311b is open and the oil passage between the second port 311e and the discharge port 311c is closed.

[0249] At this time, the first oil passage 5 discharges the working oil, and the second oil passage 6 supplies the working oil.

[0250] Subsequently, when the coil 132 is properly energized to generate a magnetic potential, the plunger 70 moves forward while resisting the force applied by the biasing spring 30, as Figure 14 shown, the first end portion 327 abuts against the receiving portion 314, so that the sliding column 320 is positioned at the maximum forward position.

[0251] At the maximum forward position, the first valve portion 322 of the sliding column 320 is in a state where the oil passage between the first port 311d and the supply port 311b is open and the oil passage between the first port 311d and the discharge port 311c is closed.

[0252] In addition, the second valve portion 323 of the sliding column 320 is in a state where the oil passage between the second port 311e and the supply port 311b is closed and the oil passage between the second port 311e and the discharge port 311d is open via the internal space SS, the second opening 62b, the second opening 61f, the second internal passage 62a, the second internal passage 61e, and the communication path 329.

[0253] At this time, the first oil passage 5 supplies the working oil, and the second oil passage 6 discharges the working oil.

[0254] In addition, the energization of the coil 132 can be appropriately controlled to stop the sliding column 320 at the intermediate position.

[0255] At the intermediate position, the first valve portion 322 of the sliding column 320 is in a state where the oil passage between the first port 311d and the supply port 311b is closed and the oil passage between the first port 311d and the discharge port 311c is closed.

[0256] In addition, the second valve portion 323 of the sliding column 320 is in a state where the oil passage between the second port 311e and the supply port 311b is closed and the oil passage between the second port 311e and the discharge port 311c is closed.

[0257] At this time, the supply and discharge of the working oil in both the first oil passage 5 and the second oil passage 6 are blocked.

[0258] When the electromagnetic switching valve V4 that performs the switching operation is applied to the operation of the valve timing change device M of the camshaft CS on the intake side of, for example, an internal combustion engine, and to the operation of the valve timing change device M of the camshaft CS on the exhaust side of the internal combustion engine, it is the same as the electromagnetic switching valve V1 of the first embodiment.

[0259] Next, the flow of the working oil around the plunger 70 and the transmission member 60 in the electromagnetic switching valve V4 that performs the switching operation will be described.

[0260] When the plunger 70 moves forward from the rest position, as Figure 14 shown, the working oil in the forward movement space FS flows into the backward movement space RS defined at the rear side of the plunger 70 as indicated by the arrow, via the first opening 61d and the first internal passage 61c of the transmission member 60 and through the through-hole 74 of the plunger 70. Thereby, the plunger 70 can move forward smoothly.

[0261] Here, similarly to the first embodiment, the passage area of the first internal passage 61c is formed to be larger than the passage area of the through-hole 74, and the passage area of the first opening 61d is formed to be larger than the passage area of the first internal passage 61c. Therefore, when the working oil moves from the forward movement space FS to the backward movement space RS, it is possible to prevent the damping effect caused by the contraction resistance and the like, and thus the plunger 70 can work smoothly.

[0262] In addition, as the plunger 70 moves forward, the outer peripheral surface 71 of the plunger 70 faces the annular inner wall surface 91c of the stator 90 with a small clearance in the radial direction, and the first end portion 72 of the plunger 70 faces the annular facing surface 91b of the stator 90 in the axial direction of the axis S. Therefore, the working oil in the forward movement space FS surrounded by the first end portion 72 and the annular facing surface 91b actively points to the first opening 61d and the first internal passage 61c, thereby promoting the flow of the working oil from the forward movement space FS to the backward movement space RS.

[0263] On the other hand, in the internal space SS of the sleeve 310, the transmission member 60 is pushed by the plunger 70 and moves forward together with the slide column 320.

[0264] Here, the passage area of the clearance G defined around the small-diameter cylinder portion 61 of the transmission member 60 in the insertion hole 91a of the stator 90 is formed to be not larger than the passage area of the first opening 61d, that is, it is formed extremely small within the range where the viscous resistance does not increase. Therefore, the working oil in the internal space SS, especially foreign matters, is not easily introduced into the forward movement space FS through the insertion hole 91a.

[0265] In this state, since the separation distance between the annular stepped portion 63 and the annular facing portion 91e is increased, the working oil in the internal space SS, for example, as shown by the arrow in Figure 14 , the working oil in the second internal passage 61e of the transmission member 60 flows from the second opening 61f into the internal space SS. In addition, the working oil in the internal space SS outside the transmission member 60 flows from the second opening 62b into the second internal passage 62a and the second internal passage 61e, or flows toward the discharge port 311c from the communication path 329 together with the flow of the working oil flowing into the internal space SS from the second port 311e. Thus, the working oil in the internal space SS as a whole circulates around the transmission member 60 and flows toward the discharge port 311c from the communication path 329.

[0266] When the plunger 70 moves backward from the advanced position toward the rest position, the working oil in the backward movement space RS, as shown by the arrow in Figure 13 , flows into the forward movement space FS defined in front of the plunger 70 through the through-hole 74 of the plunger 70 and through the first internal passage 61c and the first opening 61d of the transmission member 60. Thereby, the plunger 70 can move backward smoothly.

[0267] Here, similarly to the foregoing, the passage area of the first internal passage 61c is formed to be equal to or larger than the passage area of the through-hole 74, and the passage area of the first opening 61d is formed to be equal to or larger than the passage area of the first internal passage 61c. Therefore, when the working oil moves from the backward movement space RS to the forward movement space FS, it is possible to prevent the damping effect caused by the contraction resistance and the like, and thus the plunger 70 can work smoothly.

[0268] On the other hand, in the internal space SS of the sleeve 310, the transmission member 60 moves backward following the plunger 70 together with the slide column 320 by the force applied by the biasing spring 30.

[0269] Here, similarly to the foregoing, the passage area of the gap G defined around the small-diameter cylinder portion 61 of the transmission member 60 in the insertion through-hole 91a of the stator 90 is formed to be equal to or smaller than the passage area of the first opening 61d, that is, it is formed extremely small within the range where the viscous resistance does not increase. Therefore, the working oil in the internal space SS, especially foreign matters, is not easily flowed into the forward movement space FS through the insertion through-hole 91a.

[0270] In this state, since the separation distance between the annular stepped portion 63 and the annular facing portion 91e is narrowed, the working oil in the internal space SS, for example, as shown by the arrow in Figure 13As shown by the arrow in , the working oil in the internal space SS outside the transmission member 60 flows from the second opening 61f of the transmission member 60 into the second internal passage 61e. In addition, the working oil in the second internal passage 62a and the second internal passage 61e of the transmission member 60 flows from the second opening 62b into the internal space SS outside the transmission member 60, or the working oil in the communication path 329 leading to the discharge port 311c flows toward the second internal passage 62a and the second internal passage 61e. Thus, the working oil in the internal space SS circulates around the transmission member 60 as a whole.

[0271] Here, similarly to the above, the second opening 61f and the second opening 62b are formed at a distance from each other in the axial direction of the axis S. The passage area of the second opening 61f is formed to be equal to or larger than the passage area of the second internal passage 61e. In addition, the passage area of the second opening 62b is formed to be equal to or larger than the passage area of the second internal passage 62a.

[0272] Thereby, the working oil in the internal space SS outside the transmission member 60 is actively made to flow into the second internal passage 61e and the second internal passage 62a inside the transmission member 60, or the working oil in the second internal passage 61e and the second internal passage 62a inside the transmission member 60 is actively made to flow into the internal space SS outside the transmission member 60, so that circulation can occur between the inside and the outside of the transmission member 60.

[0273] In addition, since the annular stepped portion 63 of the transmission member 60 faces the annular facing portion 91e of the stator 90 in the axial direction of the axis S, by changing the separation distance between the two, the working oil can be actively circulated in the internal space SS.

[0274] Therefore, in the case where foreign matter is mixed in the working oil in the internal space SS, the foreign matter can be prevented from flowing into the working area of the plunger 70 through the insertion hole 91a. Thereby, wear or locking of the plunger 70 due to the jamming of foreign matter can be prevented.

[0275] If foreign matter in the working oil jams around the slide column 320, by appropriately reciprocatingly driving the plunger 70, the jammed state can be eliminated.

[0276] According to the electromagnetic switching valve V4 configured as described above, an opposing wall 61b facing the through-hole 74 of the plunger 70 is provided as a blocking wall inside the cylindrical transmission member 60, and in addition, the gap G defined between the insertion hole 91a of the stator 90 and the transmission member 60 is minimized, thereby restricting the direct flow of the working oil on the slide column 320 side into the plunger 70 side.

[0277] Moreover, the working oil filling the periphery of the transmission member 60 is circulated around the transmission member 60, and the working oil filling the periphery of the plunger 70 is circulated around the plunger 70. Thereby, the structure can be simplified without increasing parts, and at the same time, intrusion of foreign matter into the plunger 70 side of the electromagnetic actuator A can be suppressed or prevented.

[0278] Therefore, generation of wear or seizure of the plunger 70 can be suppressed or prevented, and thus the electromagnetic actuator A can operate normally.

[0279] In particular, the slide column 320 has a configuration having two land portions (first valve portion 322, second valve portion 323) on both end sides, so that its overall length can be shortened, and miniaturization of the electromagnetic switching valve V4 can be achieved as a whole.

[0280] In the above-described embodiment, the transmission member 60 having the small-diameter cylindrical portion 61 and the large-diameter cylindrical portion 62 is shown as the transmission member, but it is not limited thereto, and a cylindrical member having a single outer diameter may also be applied as the transmission member.

[0281] In the above-described embodiment, the transmission member 60 formed of a resin material is shown as the transmission member, but it is not limited thereto, and a transmission member formed of other non-magnetic materials may also be used.

[0282] In the above-described embodiment, the transmission member 60 having a plurality of second openings 61f and 62b spaced apart in the axial direction S is shown as the second opening of the transmission member, but it is not limited thereto, and a single second opening having a large opening area may also be used.

[0283] In the above-described embodiment, the case where the transmission member 60 can be formed as a separate part separable from the slide columns 20, 220, and 320 is shown, but it is not limited thereto, and a configuration in which the transmission member is fixed to the slide column may also be used, or a configuration in which the transmission member is integrally formed with the slide column may also be used.

[0284] In the above-described embodiment, the case where the electromagnetic switching valves V1, V2, V3, and V4 are fitted into the fitting holes H of the engine body EB is shown, but it is not limited thereto, and they may also be installed in other parts.

[0285] [Industrial Applicability]

[0286] As described above, the electromagnetic switching valve according to the present invention simplifies the structure without increasing the number of parts, and at the same time can suppress or prevent foreign matter from invading the plunger side of the electromagnetic actuator. Therefore, it can of course be applied to the engines mounted on automobiles and the like, and can also be effectively used for the engines mounted on other vehicles such as two-wheelers. Furthermore, it can also be effectively used for controlling the flow of working oil in other hydraulic equipment and the like.

Claims

1. An electromagnetic switching valve, characterized in that, comprising: a sleeve defining a port communicating with an oil passage for supplying or discharging working oil; a slide rod configured to reciprocate freely in the sleeve in a specified axial direction to open and close the port; an electromagnetic actuator including a plunger and a stator, the plunger having a through passage extending in the axial direction, and the stator applying a magnetic potential to the plunger; and a cylindrical transmission member interposed between the plunger and the slide rod to transmit a driving force, the stator including an insertion through hole through which the transmission member is inserted, the transmission member including an opposing wall facing the through passage of the plunger, a first internal passage formed on the plunger side of the opposing wall and communicating with the through passage, a first opening portion radially opening the first internal passage on the plunger side of the insertion through hole, a second internal passage formed on the slide rod side of the opposing wall, and a second opening portion radially opening the second internal passage on the slide rod side of the insertion through hole.

2. The electromagnetic switching valve according to claim 1, characterized in that, a plurality of the second opening portions are formed at intervals in the axial direction.

3. The electromagnetic switching valve according to claim 1 or 2, characterized in that, the passage area of the first internal passage is not less than the passage area of the through passage.

4. The electromagnetic switching valve according to claim 1 or 2, characterized in that, the passage area of the first opening portion is not less than the passage area of the first internal passage.

5. The electromagnetic switching valve according to claim 1 or 2, characterized in that, the passage area of the gap defined around the transmission member in the insertion through hole is not more than the passage area of the first opening portion.

6. The electromagnetic switching valve according to claim 1 or 2, characterized in that, the passage area of the second opening portion is not less than the passage area of the second internal passage.

7. The electromagnetic switching valve according to claim 1 or 2, characterized in that, the transmission member includes a large-diameter cylindrical portion disposed in the sleeve and a small-diameter cylindrical portion inserted into the insertion through hole of the stator, the small-diameter cylindrical portion including the opposing wall, the first internal passage, the first opening portion, the second internal passage, and the second opening portion, the large-diameter cylindrical portion including the second internal passage and the second opening portion.

8. The electromagnetic switching valve according to claim 7, characterized in that, the transmission member includes an annular stepped portion formed at the boundary between the small-diameter cylindrical portion and the large-diameter cylindrical portion, the stator includes an annular opposing portion facing the annular stepped portion in the axial direction.

9. The electromagnetic switching valve according to claim 1 or 2, characterized in that, the transmission member includes an annular abutting portion defining an opening portion through which the second internal passage opens toward the slide rod and abutting against the slide rod.

10. The electromagnetic switching valve according to claim 1 or 2, characterized in that, The stator includes an annular facing surface facing the plunger in the axial direction and an annular inner wall surface capable of facing the outer peripheral surface of the plunger.

11. The electromagnetic switching valve according to claim 1 or 2, characterized in that the plunger includes a receiving recess around the through passage, and the receiving recess receives and abuts against an end portion of the transmission member.

12. The electromagnetic switching valve according to claim 1 or 2, characterized in that the sleeve includes a communication passage that communicates an internal space in which the transmission member is disposed with the oil passage.

13. The electromagnetic switching valve according to claim 1 or 2, characterized in that the slide column includes a communication passage that communicates the second internal passage of the transmission member with the oil passage.

14. The electromagnetic switching valve according to claim 1 or 2, characterized in that the transmission member is formed of a resin material.

Images