Control valve and valve timing control device of internal combustion engine with control valve employed therein

Abstract

To provide a control valve which can suppress the enlargement of a valve body by improving an attachment structure of a filter member to a port of the control valve.SOLUTION: A valve body 31 comprises a valve accommodation hoe 31a which is formed along an internal axial direction, and an advance port 37, an introduction port 39, and a retardancy port 38 which are formed side by side in an axial direction. A spool valve has: first and second land parts 32a, 32b which are arranged at an internal peripheral face of the valve accommodation hole so as to be slidable in the axial direction; and a connecting part 32c for connecting the first and second land parts, and smaller in outside diameter than the first and second land parts. A filter member 21 has: a frame part 22 which is fit and held to a fitting groove 40; a filter part 23 arranged at the frame part; and a lock part 24 which is arranged while protruding to the inside from the frame part, and locked to an inside opening edge 39a of the introduction port by an elastic force.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a control valve and a valve timing control device for an internal combustion engine to which the control valve is applied. [Background technology]

[0002] For example, the conventional control valve described in Patent Document 1 is applied to a valve timing control device, and includes a frame member that is fitted into a frame housing portion provided at each opening of three ports formed on the outer periphery of a cylindrical control valve body, a filter portion provided in this frame member, and a pair of fixing portions that are formed integrally with the filter portion and are fixed to the port portions by fitting the frame member into the frame housing portion.

[0003] The pair of fixing portions have a pair of locking portions that lock onto a pair of latched portions formed on the inner edges of the port portions, and when the pair of fixing portions are inserted into each of the port portions, the pair of locking portions open away from each other and are locked onto the pair of latched portions.

[0004] A spool valve that selectively connects and disconnects each of the ports is provided inside the control valve body and is slidable in the axial direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6497882 (Figs. 5 and 6) Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, there is a demand for the control valve to have a smaller diameter in order to ensure good mounting properties of the valve timing control device on the internal combustion engine.

[0007] However, in the conventional control valve, the interlocking portion is formed on the inner peripheral surface of the control valve body so as to protrude radially inward. Meanwhile, the outer diameter of the spool valve is required to be at least a certain size in order to ensure control precision (performance). Therefore, the control valve body is forced to have a large radial thickness due to the presence of the interlocking portion, which may result in a large outer diameter.

[0008] An object of the present invention is to provide a control valve capable of suppressing an increase in the size of the valve body by improving the mounting structure of a filtering member to a port of the control valve. [Means for solving the problem]

[0009] According to a preferred aspect of the present invention, inter alia, a control valve comprises: a valve body having a valve accommodating hole formed along an internal axial direction, and first, second and third ports formed from an outer circumferential surface toward the valve accommodating hole and arranged side by side in the axial direction; a spool valve having first and second land portions arranged on an inner circumferential surface of the valve accommodating hole to be slidable in the axial direction, and a connecting portion connecting the first and second land portions in the axial direction and having an outer diameter smaller than that of the first and second land portions, the spool valve being capable of changing communication between the first port and the third port with respect to the second port depending on a moving position in the axial direction; and a filtering member disposed in the second port, the filtering member having a frame portion held on an outer opening edge of the second port, a filter portion provided on the frame portion, and a locking portion protruding from an inner surface of the frame portion, penetrating an inner circumferential surface of the valve accommodating hole, and locking with an inner opening edge of the second port formed on the same plane as the inner circumferential surface, or with a portion recessed radially inward from the inner opening edge of the second port. Effect of the Invention

[0010] According to the present invention, it is possible to suppress an increase in size of the valve body of the control valve. [Brief description of the drawings]

[0011] [Figure 1] 1 is a vertical sectional view of a valve timing control device for an internal combustion engine according to the present invention; [Diagram 2] FIG. 2 is an exploded perspective view of the main components of the valve timing control device. [Diagram 3] 2 is a cross-sectional view taken along line AA in FIG. 1. [Figure 4] FIG. 2 is an exploded perspective view of the control valve used in the present embodiment. [Diagram 5] FIG. 2 is a vertical cross-sectional view of a control valve used in the present embodiment. [Figure 6] 6 is a cross-sectional view taken along line BB in FIG. 5. [Figure 7] 2 is an enlarged view, partly in section, showing a main portion of a control valve used in the present embodiment; FIG. [Figure 8] FIG. 2A is a top view showing a filter member used in the present embodiment, and FIG. 2B is a perspective view showing the filter member as viewed from below. [Figure 9] 1A is a plan view of the main part showing the inlet port side of the control valve, and FIG. 1B is a side view of the main part on the inlet port side. [Figure 10] 1A is a plan view of the essential part showing a state in which a filter member is attached to a fitting groove, and FIG. 1B is a side view of the essential part showing a state in which the filter member is attached to the fitting groove. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment in which a control valve according to the present invention is applied to a valve timing control device for an internal combustion engine will be described with reference to the drawings. In this embodiment, the valve timing control device is applied to the exhaust valve side of an internal combustion engine, but it is also possible to apply it to the intake valve side.

[0013] FIG. 1 is a vertical sectional view of a valve timing control device for an internal combustion engine to which a control valve according to the present invention is applied, FIG. 2 is an exploded perspective view of main components of the valve timing control device, and FIG. 3 is a sectional view taken along line AA in FIG.

[0014] As shown in Figures 1 to 3, the valve timing control device includes a timing sprocket (hereinafter referred to as the sprocket) 1 which is a driven rotating body that is rotated by the engine crankshaft via a timing chain (not shown), an exhaust-side camshaft 2 that is arranged to be rotatable relative to sprocket 1, a phase change mechanism 3 that is disposed between sprocket 1 and camshaft 2 and changes the relative rotational phase between the sprocket 1 and camshaft 2, a locking mechanism (not shown) that locks the phase change mechanism 3 at a relative rotation position on the most advanced angle side, and a hydraulic circuit 5 that actuates the phase change mechanism 3 and the locking mechanism.

[0015] The driving rotor may be a timing pulley to which a rotational force is transmitted by a timing belt.

[0016] Sprocket 1 is formed in the shape of an annular plate and is provided with a gear portion 1a around which a timing chain is wound. Housing 6, which will be described later, is connected to sprocket 1 from the direction of the rotation axis, and sprocket 1 also functions as a cover member that closes one axial end opening of housing 6. Sprocket 1 is formed with an insertion hole 1b at its central position through which one axial end 2a of camshaft 2 is inserted so as to be rotatable relative to the housing, and four female screw holes 1c are provided at equal intervals in the circumferential direction on the inner surface of the outer periphery facing housing 6.

[0017] The camshaft 2 is rotatably supported on a cylinder head (not shown) via a plurality of cam bearings. The camshaft 2 is provided with a rotating cam for each cylinder at a predetermined position in the rotation axis direction on the outer circumferential surface, which opens an exhaust valve (not shown) against the spring force of a valve spring. An insertion hole 2b is formed in the internal axial direction of one end 2a of the camshaft 2, into which the other axial end of a valve body 31 (described later) is inserted. A stepped drain passage hole 2c is formed in the internal axial direction of the one end 2a, which is continuous with the insertion hole 2b and discharges hydraulic pressure discharged from a control valve 20 (described later) to the outside.

[0018] 2, the camshaft 2 has three female threaded holes 2d formed radially outward from the insertion hole 2b of the one end 2a along the inner axial direction from the tip surface of the one end 2a. Male threaded portions of a plurality of bolts 12 (three in this embodiment) that connect a rotor 14 (described later) are screwed into each of the female threaded holes 2d.

[0019] As shown in Figures 1 to 3, the phase change mechanism 3 is axially connected to the sprocket 1 by multiple (four in this embodiment) bolts 13, and comprises a cylindrical housing 6 having an operating chamber therein, a vane rotor 7 which is a driven rotor accommodated inside the housing 6 so as to be rotatable relative to the housing 6, and a plurality of (four each in this embodiment) advance operating chambers 9 and retard operating chambers 10 formed within the operating chamber of the housing 6 via the vane rotor 7.

[0020] The housing 6 is formed into a cylindrical shape from sintered metal formed by sintering compacted metal powder. A front cover 11 is provided on one axial end of the housing 6 to close an opening on the one end.

[0021] A plurality of shoes 8a to 8d (four in this embodiment) are provided on the inner peripheral surface of the housing 6. Each of the shoes 8a to 8d is formed in a substantially trapezoidal shape when viewed from the front, and each of the shoes 8a to 8d has four bolt insertion holes 8e, into which the bolts 13 are inserted, formed therethrough in the internal axial direction.

[0022] The front cover 11 is formed in a disk shape from, for example, an iron-based metal, and has a relatively large-diameter insertion hole 11a formed therethrough in the center. The front cover 11 also has four bolt insertion holes (not shown) formed at approximately equally spaced positions in the circumferential direction of the outer periphery, into which the bolts 13 are inserted.

[0023] The sprocket 1, the housing 6 and the front cover 11 are joined in the axial direction by four bolts 13 which are inserted into the bolt insertion holes and the bolt insertion holes 8e and have their tips screwed into the female threaded holes 1c.

[0024] The vane rotor 7 is integrally formed from sintered metal like the housing 6. As shown in Figures 1 and 3, the vane rotor 7 has a central rotor 14 and a plurality of (four in this embodiment) vanes 15a to 15d radially protruding from the outer circumferential surface of the rotor 14 at equal intervals of approximately 90° in the circumferential direction.

[0025] The rotor 14 is formed in a relatively large-diameter cylinder shape, and a valve hole 14a that is continuous with the insertion hole 2b of the camshaft 2 is formed penetrating the rotor 14 in the axial direction at the center. A circular fitting groove 14b into which the tip of one end 2a of the camshaft 2 fits is formed on one end face of the rotor 14 in the axial direction (the rear end face on the camshaft 2 side). A disk-shaped protrusion 14c that rotatably fits into the insertion hole 11a of the front cover 11 is integrally formed on the other end face of the rotor 14 in the axial direction.

[0026] Four advance angle passage holes 17 and four retard angle passage holes 18 are formed radially through the rotor 14. One inner end of each of the advance angle passage holes 17 and retard angle passage holes 18 opens into the valve hole 14a (control valve 20), while the other outer end opens into the corresponding advance angle working chamber 9 and retard angle working chamber 10, respectively.

[0027] Furthermore, the rotor 14 has a plurality of (three in this embodiment) bolt holes 14d formed therethrough along the rotation axis direction at positions radially outward from the valve holes 14a.

[0028] Furthermore, an operation hole 19 is formed on the inner periphery of one axial end of the valve hole 14a. In addition, between the valve hole 14a and the operation hole 19, a pair of circumferential and axial locking portions (not shown) are provided into which an elastic clip 36 (described later) is fitted.

[0029] The work hole 19 is formed in an inverted R shape when viewed from the front (when viewed from the front cover 11 side) extending radially from the inner circumferential surface of the valve hole 14a, with one circumferential portion 19a (wall surface) cut out in an arc shape and the other portion 19b (wall surface) formed in a straight line parallel to the radial direction of the rotor 14. The inside of the one portion 19a of this work hole 19 is configured as a space, and this space is used to clamp an elastic clip 36, which will be described later.

[0030] Each of the vanes 15a-15d is formed with a relatively short radial protrusion length and is disposed between each of the shoes 8a-8d. The three vanes 15b-15d other than the first vane 15a are formed with a relatively thin wall with approximately the same circumferential width. The first vane 15a is formed with a large circumferential width and has a part of a locking mechanism (not shown) provided therein.

[0031] A seal groove is formed in each of the outer circumferential surfaces of the vanes 15a to 15d, and a seal member 16 is provided in each of the seal grooves to provide a seal between the vanes 15a to 15d and the inner circumferential surface of the housing 6. In addition, the opposing tip surfaces of the shoes 8a to 8d of the housing 6 are formed in an arc shape following the outer circumferential surface of the rotor 14, so as to provide a metal seal while sliding against the outer circumferential surface of the rotor 14.

[0032] Furthermore, when the vane rotor 7 rotates to the maximum relative angle toward the advance angle side, one side surface of the first vane 15a comes into contact with the opposing side surface of one of the opposing shoes 8a. This restricts the rotation position of the vane rotor 7 on the maximum advance angle side. Furthermore, when the vane rotor 7 rotates to the maximum relative angle toward the retard angle side, as shown in FIG. 3, the other side surface of the first vane 15a comes into contact with the opposing side surface of the other opposing shoe 8d. This restricts the rotation position of the vane rotor 7 on the maximum retard angle side.

[0033] The above-mentioned advance angle working chambers 9 and retard angle working chambers 10 are provided between both side surfaces of each vane 15a to 15d in the forward / reverse rotation direction and both side surfaces of each shoe 8. In each advance angle working chamber 9 and each retard angle working chamber 10, the other end of each advance angle passage hole 17 and each retard angle passage hole 18 formed radially inside the rotor 14 is open.

[0034] Each of the advance passage holes 17 and each of the retard passage holes 18 has a circular cross-sectional shape, and is connected to the hydraulic circuit 5 via four advance ports 37 and four retard ports 38 of the control valve 20, which will be described later.

[0035] The lock mechanism holds the vane rotor 7 at the most advanced rotation position relative to the housing 6.

[0036] As shown in FIG. 1, the hydraulic circuit 5 includes: a supply passage 25 formed in the bearing journal portion of the camshaft 2 and in the internal axial direction of the camshaft 2; an oil pump 26 provided upstream of the supply passage 25 and discharging hydraulic pressure to the supply passage 25 via a discharge passage 26a; a control valve 20 provided in the internal axial direction of the rotor 14 and switching the flow paths of the advance passage holes 17 and the retard passage holes 18 in accordance with the engine operating state; a discharge passage 26b that discharges the hydraulic pressure of either one of the advance and retard working chambers 9, 10 to an oil pan 28 by switching the flow paths of the control valve 20; and a check valve 29 provided inside the rotor 14 for allowing the hydraulic pressure supplied from the oil pump 26 to the supply passage 25 only in the direction of the control valve 20.

[0037] The supply passage 25 has an upstream portion communicating with a discharge passage 26a of an oil pump 26, and a downstream portion communicating with a recess 30 provided in the rotor 14 via a check valve 29, which will be described later.

[0038] The oil pump 26 is of a general type, for example a vane type or a trochoid type.

[0039] 4 is an exploded perspective view of a control valve, FIG. 5 is a vertical cross-sectional view of the control valve used in this embodiment, FIG. 6 is a cross-sectional view taken along line BB in FIG. 5, FIG. 7 is an enlarged view of a part of the control valve used in this embodiment, FIG. 8(a) is an overhead view of a filter member used in this embodiment, (b) is a perspective view of the filter member as viewed from below, FIG. 9(a) is a plan view of the part showing the inlet port side of the control valve, (b) is a side view of the part showing the inlet port side, FIG. 10(a) is a plan view of the part showing the filter member attached to the fitting groove, and (b) is a side view of the part showing the filter member attached to the fitting groove. As shown in Figures 1, 2, and 4 to 6, the control valve 20 is mainly composed of a cylindrical valve body 31 accommodated in the valve hole 14a of the rotor 14, a spool valve 32 slidably disposed in a valve accommodating hole 31a formed through the valve body 31 in the internal axial direction, a valve spring 33 that urges the spool valve 32 leftward in Figure 1, and an electromagnetic actuator 34 that pushes the spool valve 32 rightward in Figure 1 against the spring force of the valve spring 33.

[0040] The valve body 31 is made of an iron-based metal material and is cylindrical and hollow inside, with the valve accommodating hole 31a formed therethrough in the axial direction. As shown in Figures 4 and 5, the valve body 31 has an annular locking groove 35 in which an elastic clip 36 is locked on the outer periphery of one axial end portion on the electromagnetic actuator 34 side. The valve body 31 is detachably attached inside the valve hole 14a by the elastic clip 36 locked in the locking groove 35.

[0041] The valve body 31 has an advance port 37, which is a first port (first communication port), formed radially through the peripheral wall at a position near one end in the axial direction, and a retard port 38, which is a third port (second communication port), formed radially through the peripheral wall at a position near the other end in the axial direction.

[0042] Between the advance port 37 and the retard port 38, an introduction port 39 is formed as a second port for introducing the hydraulic pressure that has passed through the check valve 29 into the advance port 37 or the retard port 38 via the spool valve 32. As shown in Figs. 5 to 7 and 10(a) and (b), this introduction port 39 is formed to penetrate the peripheral wall of the valve body 31 along the radial direction and is formed in the shape of a rectangular elongated hole along the circumferential direction of the valve body 31. A fitting groove 40 is formed on the outer opening edge of the introduction port 39. This fitting groove 40 is formed in the shape of a rectangular elongated groove that follows the outer shape of the introduction port 39, and a filter member 21 (described later) is fitted and held in this fitting groove.

[0043] A first drain hole 41a that appropriately communicates with the first passage groove 32d of the spool valve 32 is formed in the peripheral wall at one axial end of the valve body 31. This first drain hole 41a communicates with the inside of the oil pan 28 via the discharge passage 26b.

[0044] A second drain hole 41b that appropriately communicates with the retard port 38 via the spool valve 32 is formed through the center of the disk-shaped end wall at the other end of the valve body 31. This second drain hole 41b communicates with the inside of the oil pan 28 via the drain passage hole 2c of the camshaft 2 and the discharge passage 26b.

[0045] As shown in FIG. 1, the advance port 37 and the retard port 38 have their inner openings facing the valve accommodating hole 31a (spool valve 32), and their outer openings radially communicate with the advance passage holes 17 and the retard passage holes 18.

[0046] The locking groove 35 is basically formed in an annular shape on the outer periphery of the advance port 37 of the valve body 31, and the entire groove serves as an axial retaining portion for the elastic clip 36. The locking groove 35 has a flat lower side as a non-circular groove 35a, and this non-circular groove 35a serves as a circumferential positioning portion for the elastic clip 36.

[0047] As shown in FIG. 4, the elastic clip 36 is formed by bending an iron-based metal wire into an approximately ohmic shape, and has a circular portion 36a and a pair of protrusions 36b, 36c provided at opposing ends of the circular portion 36a.

[0048] Both sides of the circular portion 36a are formed in an approximately arc-like shape along the engagement groove 35, but the lower portion opposite each of the protrusions 36b, 36c forms a straight portion 36d, which is a non-circular portion that fits into the non-circular groove 35a.

[0049] Therefore, as described above, the elastic clip 36 is elastically engaged with the locking groove 35 to prevent it from coming loose in the axial direction, and is positioned circumferentially with the straight portion 36d fitted into the non-circular groove 35a.

[0050] The pair of protrusions 36b, 36c extend radially outward in parallel and linearly from the opposing ends of the circular portion 36a, and are formed such that their axial length is shorter than the radially outer surface of the inner circumferential surface of the working hole 19 when fitted into the locking groove 35 of the valve body 31. Furthermore, inside the working hole 19, the pair of protrusions 36b, 36c are adapted to be locked by an axial locking portion and a circumferential locking portion (not shown) formed on the rotor 14 due to their own elastic force in the radial expansion direction.

[0051] 1 and 4 to 6, the spool valve 32 is formed in a cylindrical shape with one axial end (one end side of the valve body 31) closed, and has a drain hole 50 formed in the internal axial direction that communicates with the second drain hole 41b. The spool valve 32 is provided with first and second annular guide parts on the outer periphery of one and the other axial ends thereof, which guide the valve accommodating hole 31a slidably.

[0052] The spool valve 32 is provided with first and second land portions 32a, 32b on both sides near the center in the axial direction, which selectively switch communication between the advance port 37 and the retard port 38 with respect to the inlet port 39 depending on the sliding position. A connecting portion 32c is provided between the first and second land portions 32a, 32b, which connects the two land portions 32a, 32b in the axial direction. The connecting portion 32c is formed to have an outer diameter smaller than the first and second land portions 32a, 32b, and a cylindrical passage groove 32h that communicates with the inlet port 39 is formed on the outer periphery of the connecting portion 32c.

[0053] Furthermore, in the peripheral wall in which the discharge hole 50 of the spool valve 32 is formed, first and second communication holes 32f, 32g are formed radially penetrating the peripheral wall, which communicate with the discharge hole 50 via first and second passage grooves 32d, 32e located axially outside each of the land portions 32a, 32b depending on the axial sliding position of the spool valve 32.

[0054] The valve spring 33 is disposed between an inner circumferential step portion at the other end of the valve body 31 and the other end edge of the spool valve 32, and biases the spool valve 32 leftward in Fig. 1. The maximum leftward movement position of the spool valve 32 in Fig. 1 is restricted by a stopper ring 48 provided on the inner periphery of one end 31b of the valve body 31.

[0055] A filtering member 21 is attached to a fitting groove 40 on the outer circumferential opening edge of the introduction port 39 of the valve body 31. As shown in Figures 4 to 8(a)(b) and 10(a)(b), the filtering member 21 has a frame portion 22 that fits into the fitting groove 40 of the introduction port 39, a filter portion 23 provided integrally on the inside of the frame portion 22, and a pair of locking portions 24, 24 provided integrally on both ends of the frame portion 22 in the longitudinal direction.

[0056] The frame 22 is made of synthetic resin and formed in a shape similar to the shape of the fitting groove 40, and is formed in a rectangular shape that is long in the circumferential direction of the valve body 31. The frame 22 has both longitudinal ends 22a, 22b formed to be wide, and holding pieces 22c, 22d extending in parallel from the left and right ends of the both ends 22a, 22b are formed in a narrow arc shape.

[0057] The filter portion 23 is made of stainless steel and formed in a mesh shape, and its outer periphery is fixed integrally to the inner periphery of the frame portion 22 during injection molding of the frame portion 22. The mesh size of the filter portion 23 is set to a level that filters out metal powder (contaminants) mixed in with the hydraulic oil flowing through the inlet port 39.

[0058] The pair of locking portions 24 are molded into an approximately L-shape from synthetic resin material during injection molding of the frame portion 22, and have a plate-shaped base portion 24a fixed to the inner surface of both end portions 22a, 22b of the frame portion 22, plate-shaped support portions 24b bent vertically inward from each tip edge of each base portion 24a, and claw portions 24c folded back inward from the lower edge of each support portion 24b.

[0059] Each of the locking portions 24 is formed such that each of the support portions 24b can be elastically deformed in the direction of expanding and contracting with each of the base portions 24a as a fulcrum. Each of the base portions 24a is formed to protrude substantially horizontally in the direction facing each other, while each of the support portions 24b is formed to a length that allows insertion from the tip edge of each of the base portions 24a into the introduction port 39. Each of the claw portions 24c is formed in a hook shape with each tip edge 24d facing the lower surface direction of each of the base portions 24a, and the distance W from each tip edge 24d to the inner surface of each of the ends 22a, 22b of the frame portion 22 in a free state is formed slightly shorter than the width length from the bottom surface of the fitting groove 40 to the inner peripheral surface of the valve accommodating hole 31a. In other words, each of the claw portions 24c is configured such that when each of the locking portions 24 is engaged with the introduction port 39 while being elastically deformed, each tip edge 24d is engaged with the inner opening edge 39a of the introduction port 39 by an elastic return force. The inner opening edge 39a is formed on the same plane as the valve receiving hole 31a.

[0060] When the filter member 21 is attached to the inlet port 39 and the engine is started in a cold state, a gap is formed between the frame portion 22 and the inner peripheral surface of the fitting groove 40 in the axial and circumferential directions. After the engine is warmed up, the gap becomes smaller due to the difference in the thermal expansion coefficient between the metal valve body 31 and the synthetic resin frame portion 22, so that the outer surface of the frame portion 22 comes into close contact with the inner surface of the fitting groove 40.

[0061] As shown in FIG. 1, the check valve 29 is provided in a recess 30 formed along the internal axial direction from one end face of the rotor 14 on the camshaft 2 side, and has a valve body 42 that can slide along the axial direction within the recess 30, an annular valve seat 43 that is fixed to the opening end of the recess 30 and on which the valve body 42 can be seated and removed, and a check spring 44 that urges the valve body 42 in the direction in which it seats on the valve seat 43.

[0062] The recess 30 is formed in a cylindrical shape, and a small-diameter cylindrical protrusion 45 that maintains the position of the check spring 44 in a straight line is provided on the bottom surface opposite the valve seat 43 and protrudes toward the valve seat 43.

[0063] Further, an axial passage groove 46 is formed in the lower surface of the inner circumferential surface of the recess 30, along the axial direction of the rotor 14. This axial passage groove 46 is formed in a substantially U-shaped cross section, with one axial end located on the inner surface of the valve seat 43 and the other axial end extending to the bottom surface of the recess 30. Further, a radial hole 47 is provided in the inner circumferential surface of the valve hole 14a of the rotor 14, which connects the axial passage groove 46 with the introduction port 39 of the valve body 31.

[0064] The radial hole 47 has one end opening to the axial center of the axial passage groove 46 and the bottom of the other end, and the other end opening to the inlet port 39 of the valve body 31, thereby communicating between the axial passage groove 46 and the inlet port 39.

[0065] As shown in FIG. 1, the electromagnetic actuator 34 comprises a casing 51 made of synthetic resin, a ring-shaped coil 53 housed inside the casing 51 via a bobbin 52 made of magnetic material, a cylindrical member 54 made of magnetic material arranged to surround the outer periphery of the coil 53, and a pair of first and second fixed iron cores 55, 56 made of magnetic material arranged and fixed on the inner periphery of the bobbin 52.

[0066] The electromagnetic actuator 34 also includes a sleeve 57 made of a non-magnetic material arranged in contact with the inner circumferential surfaces of the first and second fixed iron cores 55, 56, a cylindrical movable iron core 58 arranged inside the sleeve 57 so as to be able to slide in the axial direction, a push rod 59 attached to the tip of the movable iron core 58, and a retaining plate 60 made of a magnetic material fixed to the front end side of the front first fixed iron core 55.

[0067] The casing 51 includes a cylindrical portion 51a and a connector portion 51b that is integral with the rear end of the cylindrical portion 51a and is electrically connected to an ECU 61, which is an electronic control unit. The cylindrical portion 51a is formed in a thin-walled cylinder shape with a bottom, has an open front end, and has a cylindrical member 54 fixed to its inner circumferential surface. The connector portion 51b has a pair of terminal pieces that are almost entirely embedded in the casing 51, and each of the terminals is connected to a coil 53. Meanwhile, each of the other ends 51c that are exposed to the outside is connected to a terminal of a male connector on the ECU 61 side.

[0068] The push rod 59 is formed in a cylindrical shaft shape, and a steel ball-shaped pressing portion is insert-molded on the tip end surface of the axial tip of the push rod 59. This pressing portion abuts against the tip end surface of the small diameter portion 32h at one axial end of the spool valve 32 in the axial direction.

[0069] The holding plate 60 is formed in a disk shape and has an annular recess on its inner periphery that is recessed toward the movable iron core 58. An insertion hole is formed through the center of this annular recess, into which the tip of the push rod 59 is slidably inserted.

[0070] The coil 53 is excited by the current from the ECU 61, and this exciting force moves the movable iron core 58 and the push rod 59 to the right in FIG. 1. As a result, the push rod 59 moves the spool valve 32 to the right against the spring force of the valve spring 33. The amount of current supplied to the coil 53 is variably controlled by a pulse current from the ECU 61. When the coil 53 is de-energized, the spool valve 32 is controlled to move to the maximum leftward position shown in Fig. 1 by the spring force of the valve spring 33. The spool valve 32 is also controlled to move to the maximum rightward position in Fig. 1 in accordance with the amount of electricity supplied to the coil 53. The spool valve 32 can also be held in an intermediate axial position by controlling the amount of electricity supplied to the coil 53.

[0071] In this intermediate position, the first and second land portions 32a, 32b open the advance port 37 and the retard port 38, and these ports 37, 38 communicate with the introduction port 39. This supplies hydraulic pressure to the working chambers 9, 10, and holds the vane rotor 7 in an intermediate rotation position between the maximum advance angle and the maximum retard angle.

[0072] The ECU 61 detects the current engine operating state by inputting information signals from various sensors, such as a crank angle sensor (not shown) (for detecting engine speed), an air flow meter, an engine water temperature sensor, an engine temperature sensor, a throttle valve opening sensor, and a cam angle sensor that detects the current rotational phase of the camshaft 2. [Action of this embodiment] The operation of the valve timing control device according to this embodiment will now be described.

[0073] When the engine is stopped, the oil pump 26 is also stopped, so that no hydraulic pressure is supplied from the discharge passage 26a, and no current is passed from the ECU 61 to the coil 53, resulting in a de-energized state. Therefore, the spool valve 32 is held in its maximum leftward movement position by the spring force of the valve spring 33, as shown in Fig. 1. At this time, the valve element 42 of the check valve 29 is seated on the valve seat 43 by the spring force of the check spring 44, closing the passage hole 43a.

[0074] Next, when the engine is started, the oil pump 26 is also driven to pump the hydraulic oil pressure from the discharge passage 26a to the supply passage 25. This hydraulic oil pressure at the beginning of the start acts on the head of the valve element 42 through the passage hole 43a. As a result, the valve element 42 moves backward against the spring force of the check spring 44, and opens the passage hole 43a while moving away from the valve seat 43. At this time, the valve element 42 moves backward as far as possible due to the hydraulic pressure until it hits the protrusion 45, ensuring a sufficient flow rate of the hydraulic oil pressure.

[0075] As a result, the working oil pressure that flows from the discharge passage 26a into the supply passage 25 passes between the annular seat surface 43b of the valve seat 43 and the head of the valve body 42 and flows directly into the axial passage groove 46. The working oil pressure that flows into the axial passage groove 46 passes through the radial holes 47 and flows from the filter portion 23 of the filter member 21 into the introduction port 39, and further passes through the cylindrical passage groove 32h of the connecting portion 32c of the spool valve 32 into each advance port 37, and is supplied from there to each advance working chamber 9 via each advance passage hole 17, causing the internal pressure to increase.

[0076] At the same time, the spool valve 32 communicates between each retard port 38 and the second passage groove 32e. Therefore, the hydraulic pressure in each retard working chamber 10 flows through each retard passage hole 18 and the like into the drain hole 50. From there, the hydraulic pressure passes through the second drain hole 41b of the valve body 31, the drain passage hole 2c, and the drain passage 26b, and is then discharged into the oil pan 28.

[0077] Therefore, the vane rotor 7 is maintained in the most advanced relative rotation position, so that the opening and closing timing of the exhaust valve is controlled to the advanced side, thereby improving the startability of the engine.

[0078] At this point, the vane rotor 7 is locked by the locking mechanism. Therefore, flapping of the vane rotor 7 caused by the alternating torque generated in the camshaft 2 can be suppressed.

[0079] Next, when the amount of electricity supplied from the ECU 61 to the coil 53 increases with a change in the engine operating condition, the movable core 58 moves the push rod 59 to the maximum right in Figure 1. As a result, the spool valve 32 moves to the maximum right against the spring force of the valve spring 33.

[0080] In this state, the second land portion 32b of the spool valve 32 communicates between the retard port 38 and the cylindrical passage groove 32h, while the first land portion 32a communicates between each of the advance ports 37 and the first passage groove 32d.

[0081] Therefore, the hydraulic oil pressure passing through the axial passage groove 46 and the radial hole 47 from the open valve body 42 of the check valve 29 passes through the filter portion 23, the introduction port 39, the cylindrical passage groove 32h of the connecting portion 32c and the retard port 38, and is supplied from each retard passage hole 18 to each retard working chamber 10. Meanwhile, the hydraulic oil pressure in each advance working chamber 9 flows from each advance passage hole 17 through each advance port 37 and the first passage groove 32d into the inside of the drain hole 50. The hydraulic oil pressure that flows in here is further discharged into the oil pan 28 through the second drain hole 41b and the drain passage hole 2c and the drain passage 26b. Note that a part of the hydraulic oil pressure that flows into the drain hole 50 is discharged into the oil pan 28 through the first passage groove 32d and the first drain hole and the drain passage 26b. Therefore, the internal pressure of each advance working chamber 9 decreases, and the internal pressure of each retard working chamber 10 increases.

[0082] Moreover, the hydraulic pressure supplied to the retard angle working chamber 10 releases the locked state of the lock mechanism, whereby the vane rotor 7 is released from the rotation restriction and becomes free to rotate.

[0083] Therefore, the vane rotor 7 rotates in the other direction in response to an increase in the hydraulic pressure in each retard working chamber 10, rotating relatively to the maximum retard side. As a result, the opening and closing timing of the exhaust valve has the maximum retard phase characteristic, increasing the valve overlap with the intake valve, improving the intake charging efficiency and improving the output torque of the engine. [Method of attaching the filter member used in this embodiment] A method of attaching the filter member 21 of this embodiment to the valve body 31 will be described below.

[0084] As described above, to attach the filtering member 21 to the outer opening edge of the introduction port 39 of the valve body 31, first, the frame portion 22 is held and each locking portion 24 is pushed into the introduction port 39. Then, when each claw portion 24c passes through the inner circumferential surface of the introduction port 39, each locking portion 24 is deformed to expand in diameter due to its own elastic force, and then, after passing through the inner circumferential surface of the introduction port 39, each tip edge 24d is deformed to contract in diameter, as shown in Fig. 6, so that each tip edge 24d locks with the inner opening edge 39a of the introduction port 39, i.e., the inner circumferential surface of the valve accommodation hole 31a.

[0085] As a result, the filter member 21 is attached and fixed to the opening edge of the introduction port 39 by each of the locking portions 24 while the frame portion 22 is fitted and held in the fitting groove 40 .

[0086] In this way, each locking portion 24 that has passed through the introduction port 39 is directly locked, by its own elastic deformation, to the inner opening edge 39a on the inner circumferential surface of the valve accommodating hole 31a of the valve body 31. For this reason, there is no need to provide a locked portion protruding from the inner circumferential surface of the valve body as in the prior art described in the above publication, so that the necessary outer diameter of the spool valve 32 can be secured while preventing the outer diameter of the valve body 31 from becoming large.

[0087] As a result, when this control valve 20 is applied to a valve timing control device for an internal combustion engine as in this embodiment, the size of the entire valve timing control device can be prevented from increasing, thereby achieving good ease of installation on the internal combustion engine.

[0088] As described above, the valve body 31 need not be increased in diameter, and since there is no need to form a locked portion, an increase in the weight of the valve body 31 itself can also be suppressed.

[0089] Furthermore, since the inner circumferential surface of the valve accommodating hole 31a is formed into a uniform cylindrical surface overall, the manufacturing process is simplified compared to when a conventional locked portion is provided, and the manufacturing workability is also improved.

[0090] Furthermore, by engaging each of the claws 24c with the inner opening edge 39a of the introduction port 39, a strong engagement state can be obtained, so that the filter member 21 can be fixed stably and reliably.

[0091] Furthermore, by forming the inner opening edge 39a of the introduction port 39 in the space between the first and second land portions 32a, 32b of the spool valve 32, i.e., in the axial space of the connecting portion 32c (cylindrical passage groove 32h), the claw portions 24c of the locking portions 24 that lock onto the inner opening edge 39a do not interfere with the first and second land portions 32a, 32b during axial movement of the spool valve 32. This makes it possible to suppress damage or breakage of the locking portions 24.

[0092] In other words, the inner opening edge 39a of the introduction port 39 is formed at a position that utilizes the space of the connecting portion 32c of the spool valve 32 on the inner circumferential surface of the valve housing hole 31a, and the claw portions 24c of the locking portions 24 are disposed there. As a result, the locking portions can be locked without the need to provide a protrusion on the inner circumferential surface of the valve housing hole 31a for locking, as in the prior art. This makes it possible to prevent the wall thickness of the valve body 31 from increasing.

[0093] Furthermore, due to heat generated by the engine after the engine is running, the high thermal expansion coefficient of the frame portion 22 causes the frame portion 22 to adhere to the inner surface of the fitting groove 40, thereby reducing the gap between the frame portion 22 and the fitting groove 40, thereby suppressing leakage of hydraulic oil from the gap.

[0094] The present invention is not limited to the configurations of the above-described embodiments. For example, it is possible to form a groove for engagement at the position where each of the claw portions 24c engages on the inner opening edge 39a of the inlet port 39, so that each of the claw portions 24c can be engaged at a position (the bottom surface of the groove) lower than the inner surface of the valve accommodating hole 31a.

[0095] In this embodiment, the filtering member 21 is provided only in the inlet port 39, but it may also be provided in the advance port 37 or the retard port 38, or it may also be provided in each of the multiple ports formed in the valve body 31. [Explanation of symbols]

[0096] 1...timing sprocket (driving rotor), 2...camshaft, 3...phase change mechanism, 5...hydraulic circuit, 6...housing, 7...vane rotor, 9...advance angle working chamber, 10...retard angle working chamber, 14...rotor, 15a-15d...vane, 17...advance angle passage hole, 18...retard angle passage hole, 26...oil pump, 20...control valve, 21...filter member, 22...frame member, 23...filter portion, 24...engagement portion, 24a...base, 24b...support holding portion, 24c...claw portion, 24d...tip edge, 31...valve body, 32...spool valve, 32a...first land portion, 32b...second land portion, 32c...connecting portion, 36...elastic clip, 36a...circular portion, 36b...36c...projection portion, 36d...straight portion, 37...advance port (first port), 38...retard port (third port), 39...introduction port (second port), 39a...inner opening edge, 40...fitting groove (outer opening edge).

Claims

1. a valve body formed in a cylindrical shape, the valve body having a valve accommodating hole formed along an internal axial direction, and first, second and third ports formed from an outer circumferential surface toward the valve accommodating hole and arranged side by side in the axial direction; a spool valve movable in an axial direction within the valve accommodating hole, the spool valve having a first land portion and a second land portion provided on an inner circumferential surface of the valve accommodating hole so as to be slidable in the axial direction, and a connecting portion connecting the first land portion and the second land portion in the axial direction and having an outer diameter smaller than those of the first and second land portions, the spool valve being capable of changing communication between a first port and a third port relative to the second port depending on a movement position in the axial direction; a filtering member disposed in the second port, the filtering member having: a frame portion held by an outer opening edge of the second port; a filter portion provided on the frame portion; and a locking portion provided protruding from an inner surface of the frame portion, penetrating an inner circumferential surface of the valve accommodating hole, and locking to an inner opening edge of the second port formed on the same plane as the inner circumferential surface, or to a portion recessed radially inward from the inner opening edge of the second port; A control valve comprising:

2. 2. The control valve according to claim 1, a connecting portion of the spool valve and an inner opening edge of the second port, the connecting portion being connected to the inner circumferential surface of the valve accommodating hole, the connecting portion being connected to the inner circumferential surface of the valve accommodating hole and the first and second land portions being connected to each other in a radial direction, the connecting portion being connected to the inner circumferential surface of the valve accommodating hole and the first and second land portions being connected to each other in a radial direction.

3. 3. The control valve according to claim 2, a locking portion that keeps the first land portion and the second land portion apart in the axial direction even when the spool valve moves to its maximum axial movement within the valve accommodation hole.

4. 3. The control valve according to claim 2, The control valve according to claim 1, wherein the engaging portion is formed in a hook shape that is engaged with an inner opening edge of the second port by elastic force.

5. 5. A control valve according to claim 4, The control valve is characterized in that the engaging portion has a claw portion at a tip end thereof that engages with the inner opening edge by elastic force.

6. 3. The control valve according to claim 2, a fitting groove is formed on an outer opening edge of the second port along a circumferential direction of the valve body, The frame portion is formed in a shape similar to that of the fitting groove, and is fitted and held in the fitting groove from outside.

7. 7. A control valve according to claim 6, The valve body is made of a metal material, while the frame is made of a synthetic resin material. A control valve characterized in that a gap is formed in the axial and circumferential directions between the outer surface of the frame portion and the inner surface of the fitting groove, and the gap becomes smaller due to the difference in thermal expansion coefficient between the valve body and the frame portion.

8. A valve timing control device for an internal combustion engine to which the control valve according to claim 1 is applied, The valve timing control device for an internal combustion engine includes: A housing to which rotational force from a crankshaft is transmitted; a vane rotor disposed inside the housing and fixed to a camshaft; A relative rotation phase of the vane rotor with respect to the housing is changed by applying hydraulic pressure to a plurality of working chambers formed between the housing and the vane rotor, 13. A valve timing control device for an internal combustion engine, wherein the control valve is disposed axially inside the vane rotor.

9. 9. A valve timing control device for an internal combustion engine according to claim 8, the second port is an introduction port for introducing hydraulic pressure from an oil pump of an engine to the first and third ports, the first and third ports are first and second communication ports for supplying hydraulic pressure from the introduction port to each of the working chambers, a control valve for changing a relative rotational phase of the vane rotor with respect to the housing by switching communication between the inlet port and a first communication port or a second communication port depending on an axial movement position of the spool valve.

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