Control valve and valve timing control device of internal combustion engine using the same

Abstract

To provide a control valve capable of reducing the size of a cam bearing, and adjusting a tightening torque between a male thread part and a female thread part to the required size for a desired axial force.SOLUTION: A control valve comprises a cylindrical valve body 27 in which a plurality of retard ports 34 and advance ports 35 are formed, and a spool valve 29 that is axially movable in a valve hole 27a formed inside the valve body. The valve body has: a large diameter part 27e where a shaft part 27c is within an axial movement range of the spool valve; and a small diameter part 27f that is outside the movement range of the spool valve, has a smaller outer diameter than the large diameter part, and has a male thread part 27h formed on its outer periphery. The valve body has a cylindrical inner peripheral convex part 51 that protrudes inward in an axial range that radially overlaps with the male thread part on the inner periphery of the small diameter part.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 using this control valve.

Background Art

[0002] For example, as a conventional control valve described in Patent Document 1, the one applied to the valve timing control device for an internal combustion engine described in Patent Document 1 previously filed by the present applicant is known.

[0003] This control valve includes a cylindrical valve body having a plurality of ports penetrating in the radial direction, a sleeve disposed inside the valve body and having two systems of oil passages for supplying and discharging hydraulic oil in the inner axial direction, and a spool valve disposed between the inner peripheral surface of the valve body and the outer peripheral surface of the sleeve. The inner peripheral surface is provided so as to be axially slidable with respect to the outer peripheral surface of the sleeve, and depending on the axial movement position of the inner peripheral surface with respect to the outer peripheral surface of the sleeve, it communicates with either one of the two systems of oil passages and the plurality of ports or blocks the communication.

[0004] The valve body of the control valve is formed in a bolt shape, and a male screw portion is formed on the outer periphery of the tip of the shaft portion to be fastened to a female screw hole formed inside one end of the camshaft. The entire outer diameter of the shaft portion except for the head on the side opposite to the male screw portion is formed to be uniform and relatively large.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] As described above, the shaft portion of the valve body has a relatively large outer diameter uniformly formed, and the outer diameter of the male screw portion is the same as that of the shaft portion. For this reason, the outer diameter on the female screw hole side of the camshaft also has to be made large. Therefore, there is a possibility that the cam bearing that bears the outer peripheral surface on the female screw hole side of the camshaft may also become large.

[0007] Further, since the outer diameter of the male screw portion is large, there is a possibility that the fastening torque may become larger than necessary with respect to the desired axial force when fastening to the female screw hole.

[0008] One object of the present invention is to provide a control valve that can reduce the size of the cam bearing by making the outer diameter of the second portion on the male screw portion side of the shaft portion of the valve body smaller than the outer diameter of the first portion, and can make the fastening torque between the male screw portion and the female screw hole the required magnitude.

Means for Solving the Problems

[0009] According to a preferred aspect of the present invention, in particular, the valve body has a first portion within the axial movement range of the spool valve, and a second portion outside the movement range of the spool valve, having an outer diameter smaller than that of the first portion, and a male screw portion formed on the outer periphery thereof for fastening to a female screw portion formed on the camshaft. The inner periphery of the second portion has a cylindrical inner peripheral convex portion protruding radially inward in an axial range that overlaps the male screw portion in the radial direction.

Effects of the Invention

[0010] According to the present invention, it is possible to reduce the size of the cam bearing and make the fastening torque between the male screw portion and the female screw portion the required magnitude with respect to the desired axial force.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

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

[0013] FIG. 1 is an overall configuration diagram showing a cross-section of a valve timing control device of an internal combustion engine according to the first embodiment of the present invention, FIG. 2 is an overall schematic diagram showing the hydraulic circuit of the valve timing control device of this embodiment, FIG. 3 is a front view showing a valve timing control device with the front cover removed, showing the state in which the vane rotor has rotated relatively to the most retarded angle side, and FIG. 4 is a front view similarly showing the state in which the vane rotor has rotated relatively to the most advanced angle side.

[0014] As shown in FIGS. 1 to 4, the valve timing control device includes a timing sprocket 1 (hereinafter referred to as a sprocket), which is a driving rotating body rotationally driven by a crankshaft of an engine via a timing chain (not shown); an intake camshaft 2 provided rotatably relative to the sprocket 1; a phase change mechanism 3 disposed between the sprocket 1 and the camshaft 2 for changing the relative rotational phase between the two; a locking mechanism 4 for locking the phase change mechanism 3 at the relative rotational position on the most retarded angle side; and a hydraulic circuit 5 for operating the phase change mechanism 3 and the locking mechanism 4.

[0015] Note that as the driving rotating body, a timing pulley through which a rotational force is transmitted by a timing belt may be used.

[0016] The sprocket 1 is formed in an annular shape and is provided with a gear portion 1a around which a timing chain is wound on the outer periphery. The sprocket 1 is provided integrally with a housing main body 6a described later.

[0017] The camshaft 2 is rotatably supported on the cylinder head 01 via a plurality of cam bearings 02. The camshaft 2 is provided with a rotary cam for opening an intake valve (not shown) against the spring force of a valve spring at a predetermined position in the axial direction of the outer peripheral surface for each cylinder. Further, a female screw hole 2b into which a male screw portion 27h of a valve body 27 described later is screwed is formed in the inner axial direction of one end portion 2a in the axial direction of the camshaft 2.

[0018] As shown in FIGS. 1 to 4, the phase change mechanism 3 includes a housing 6 provided integrally with the sprocket 1 and having an operating chamber inside; a vane rotor 7 which is a driven rotating body rotatably accommodated in the housing 6; and a plurality (four in this embodiment) of retard angle operating chambers 9 which are first hydraulic chambers and advance angle operating chambers 10 which are second hydraulic chambers formed in the operating chamber of the housing 6.

[0019] The housing 6 has a housing body 6a integrally formed with the sprocket 1 by a so-called sintered metal material obtained by sintering powder metal, a front cover 11 that closes one end opening in the axial direction of the housing body 6a, and a rear cover 12 that closes the other end opening in the axial direction of the housing body 6a.

[0020] The housing body 6a is formed in a substantially cylindrical shape, and a plurality (four in this embodiment) of shoes 8a to 8d project from the inner peripheral surface. In the inner axial direction of each of these shoes 8a to 8d, a plurality (four in this embodiment) of bolt insertion holes 8e are respectively formed therethrough.

[0021] The front cover 11 is formed in a disc shape by, for example, an iron-based metal, and a relatively large-diameter insertion hole 11a is formed through the center. The front cover 11 has four bolt insertion holes (not shown) through which a plurality (four in this embodiment) of bolts 13 are inserted at substantially equal intervals in the circumferential direction of the outer peripheral portion.

[0022] The rear cover 12 is formed in a disc shape by an iron-based metal, and a bolt insertion hole 12a through which one end portion 2a of the camshaft 2 is slidably inserted from the axial direction is formed through the center. The rear cover 12 has four female screw holes (not shown) through which male screw portions formed at the tip ends of the shaft portions of the bolts 13 are screwed and fastened at substantially equal intervals in the circumferential direction of the outer peripheral portion.

[0023] The housing body 6a (sprocket 1), the front cover 11, and the rear cover 12 are coupled from the rotational axis direction by four bolts 13 inserted through the respective bolt insertion holes and having their tip portions screwed into the female screw holes.

[0024] The vane rotor 7 is integrally formed by a sintered metal material like the housing body 6a. As shown in FIGS. 1 to 4, the vane rotor 7 has a rotor portion 14 and a plurality (four in this embodiment) of vanes 15a to 15d radially projecting from the outer peripheral surface of the rotor portion 14 at substantially 90° equal intervals in the circumferential direction.

[0025] The rotor part 14 is formed in a relatively large-diameter cylindrical shape, and a bolt insertion hole 14a that communicates with the female screw hole 2b of the camshaft 2 in the central inner axial direction is formed therethrough. Further, the rotor part 14 has a circular fitting groove 14b formed on one end surface in the rotation axis direction (the rear end surface on the camshaft 2 side).

[0026] As shown in FIG. 1, the bolt insertion hole 14a is adapted to insert the shaft part 27c of the valve body 27, and two first and second annular oil passages 32, 33 are provided in parallel in the axial direction on the inner peripheral surface. Further, this rotor part 14 is fixed to one end part 2a of the camshaft 2 by the fastening torque of the valve body 27.

[0027] The first annular oil passage 32 on the front cover 11 side communicates one end opening on the radially inner side of the retard passage hole 17 described later with the four retard ports 34. The second annular oil passage 33 (annular oil passage) on the rear cover 12 side communicates one end opening on the radially inner side of the advance passage hole 18 described later with the four advance ports 35. Further, the second annular oil passage 33 communicates one end opening on the radially inner side of a lock release oil passage 24 described later formed in the inner axial direction of the rotor part 14 with one lock port 36.

[0028] The tip of one end part 2a of the camshaft 2 in the rotation axis direction is fitted into the fitting groove 14b from the outside in the rotation axis direction.

[0029] Each of the vanes 15a to 15d is formed with a relatively short protruding length in the radial direction, and each is disposed between the respective shoes 8a to 8d. The first vane 15a is formed with a larger circumferential width compared to the other vanes 15b to 15d, and a part of the lock mechanism 4 is provided inside.

[0030] Each of the vanes 15a to 15d is provided with a seal member 16 that seals the space between the inner peripheral surface of the housing body 6a and a seal groove formed on the outer peripheral surface thereof. Further, the arc-shaped tip surfaces 8f of the shoes 8a to 8d of the housing body 6a are in metal contact with the outer peripheral surface of the rotor portion 14 while sliding in contact therewith.

[0031] Also, as shown in FIG. 3, when the vane rotor 7 rotates relatively in the retard angle side (counterclockwise direction), one side surface of the first vane 15a abuts against the opposing side surface 8g of one shoe 8a that the one side surface faces, and the rotational position at the maximum retard angle side is regulated. Further, as shown in FIG. 4, when the vane rotor 7 rotates relatively in the advance angle side (clockwise direction), the other side surface of the first vane 15a also abuts against the opposing side surface 8h of the other shoe 8 that the other side surface faces, and the rotational position at the maximum advance angle side is regulated.

[0032] Between both side surfaces in the forward and reverse rotation directions of each of the vanes 15a to 15d and both side surfaces of each of the shoes 8a to 8d, the above-described respective retard angle operating chambers 9 and advance angle operating chambers 10 are provided. In the rotor portion 14, four retard angle passage holes 17 and advance angle passage holes 18 are formed from the first and second annular oil passages 32, 33 substantially radially outward. Each of these retard angle passage holes 17 and each of the advance angle passage holes 18 communicate with the hydraulic circuit 5 via a retard angle port 34 and an advance angle port 35, which are respectively four operating ports described later.

[0033] The locking mechanism 4 holds the vane rotor 7 in the rotational position on the most retarded angle side (the position shown in Fig. 4) with respect to the housing 6. As shown in Fig. 1, it mainly consists of a locking hole 19 formed at a predetermined position on the inner surface of the sprocket 1, a locking pin 21 provided so as to be able to move forward and backward in a pin receiving hole 20 formed in the internal axial direction of the first vane 15a of the vane rotor 7, a coil spring 22 that biases the locking pin 21 in the direction of the locking hole 19, a pressure receiving chamber 23 for release which is a locking hydraulic chamber that moves the locking pin 21 backward from the locking hole 19 against the spring force of the coil spring 22 by the supplied hydraulic pressure to release the insertion, and a lock release oil passage 24 that supplies hydraulic pressure to the pressure receiving chamber 23 for release.

[0034] The pressure receiving chamber 23 for release is formed by a cylindrical space between the outer peripheral surface of the small-diameter tip portion of the locking pin 21 and the pin receiving hole 20.

[0035] The locking pin 21 has its tip inserted into the locking hole 19 by the spring force of the coil spring 22 to lock the vane rotor 7 with respect to the housing 6. When hydraulic pressure equal to or higher than a predetermined value supplied into the pressure receiving chamber 23 for release flows into the stepped portion 21a, the locking pin 21 moves backward by the hydraulic pressure and comes out of the locking hole 19 to release the lock on the vane rotor 7. One end portion on the radially inner side of the lock release oil passage 24 opens to the first annular oil passage 32, while the other end portion on the radially outer side opens to the pressure receiving chamber 23 for release.

[0036] As shown in Figs. 1 and 2, the hydraulic circuit 5 includes a supply passage 25b formed in the bearing journal portion of the camshaft 2 and in the internal axial direction of the camshaft 2, an oil pump 25 provided on the downstream side of the supply passage 25b that discharges hydraulic oil pressure from the discharge passage 25a to the supply passage 25b, a control valve 26 provided in the internal axial direction of the rotor portion 14 that switches the flow paths of the respective retard angle passage holes 17 and the respective advance angle passage holes 18 according to the engine operating state, and a discharge passage 43 that discharges the hydraulic oil of either one of the respective retard angle and advance angle operating chambers 9 and 10 to the oil pan 64 by switching the flow path of the control valve 26.

[0037] The supply passage 25b has an upstream portion communicating with the discharge passage 25a of the oil pump 25, while the downstream side communicates with an oil chamber 2c formed at the tip of the female screw hole 2b of the camshaft 2.

[0038] As the oil pump 25, a general one such as a vane type or a trochoid type is used.

[0039] FIG. 5 is an exploded perspective view of the control valve used in this embodiment, and FIG. 6 is a longitudinal sectional view of the control valve.

[0040] As shown in FIGS. 1, 2, 5, and 6, the control valve 26 mainly includes a valve body 27 which is a cam bolt for axially fixing the vane rotor 7 to one end 2a of the camshaft 2, a sleeve 28 accommodated and disposed in a valve hole 27a formed axially through the inside of the valve body 27, a spool valve 29 disposed between the outer peripheral surface of the sleeve 28 and the inner peripheral surface of the valve hole 27a, a valve spring 30 which is a biasing member for biasing the spool valve 29 in the left direction of FIGS. 1 and 6, and an electromagnetic actuator 31 for pushing the spool valve 29 in the other direction against the spring force of the valve spring 30.

[0041] The valve body 27 is formed in a hollow cylindrical shape by, for example, an iron-based metal material, and has the valve hole 27a formed axially through the inside, a head 27b whose outer peripheral surface is formed as a hexagonal surface, and a shaft portion 27c inserted into the bolt insertion hole 14a of the rotor portion 14.

[0042] In one end portion on the camshaft 2 side in the axial direction of the shaft portion 27c (inside a cylindrical portion 27g described later), the valve hole 27a is formed with an introduction port 27i communicating with the oil chamber 2c of the camshaft 2.

[0043] The head portion 27b has a flange portion 27d at the base of the shaft portion 27c. When the valve body 27 is fastened to the camshaft 2, the flange portion 27d is disposed within the insertion hole 11a of the front cover 11. Further, the seating surface of the flange portion 27d is seated on the circumferential surface of one end hole edge side of the bolt insertion hole 14a of the rotor portion 14.

[0044] The shaft portion 27c has an outer diameter formed in two steps in the axial direction, including a large diameter portion 27e which is the first portion on the flange portion 27d side, a small diameter portion 27f which is the second portion on the tip side of the large diameter portion 27e, and a cylindrical portion 27g which is a short third portion provided at the tip of the small diameter portion 27f.

[0045] In the large diameter portion 27e, four retard ports 34 are formed to penetrate through the circumferential wall in the cross diameter direction at a position approximately near the head portion 27b in the axial direction, and four advance ports 35 are formed to penetrate through the circumferential wall in the cross diameter direction on the small diameter portion 27f side. Further, between the circumferential directions of the two advance ports 35, 35, one lock port 36 facing the second annular oil passage 33 is formed to penetrate in the radial direction.

[0046] The small diameter portion 27f is formed with an outer diameter smaller than that of the large diameter portion 27e, and a male screw portion 27h for screwing and fastening to the female screw hole 2b of the camshaft 2 is formed on the entire outer peripheral surface. Thus, since the small diameter portion 27f formed with the male screw portion 27h has an outer diameter smaller than that of the large diameter portion 27e, correspondingly, the outer diameter of one end portion 2a of the camshaft 2 is also formed smaller.

[0047] Also, as shown in FIG. 6, an inner peripheral convex portion 51 protruding inward is integrally provided on the inner periphery of the small-diameter portion 27f in an axial range overlapping with the male screw portion 27h in the radial direction. The inner peripheral convex portion 51 is formed in a cylindrical shape and has an axial length substantially the same as the axial length of the small-diameter portion 27f. One axial end surface 51a of the inner peripheral convex portion 51 elastically contacts one axial end portion of the valve spring 30. On the other hand, a flange portion 28b (described later) of the sleeve 28 can contact the other axial end surface 51b of the inner peripheral convex portion 51 from the axial direction. Further, the inner peripheral surface 51c of the inner peripheral convex portion 51 protrudes radially inward, that is, inward, from the inner peripheral surface of a spool valve 29 (described later).

[0048] The cylindrical portion 27g is formed thinner than the small-diameter portion 27f, has an inner diameter substantially the same as the inner diameter of the valve hole 27a, and houses and arranges a valve seat 46, an O-ring 48, a filtration filter 49, etc. (described later) inside.

[0049] As shown in FIGS. 1 and 6, each retard port 34 and each advance port 35 have their inner openings facing the valve hole 27a, and their outer openings communicate radially with the respective retard passage holes 17 and advance passage holes 18 through first and second annular oil passages 32, 33.

[0050] Note that the lock port 36 has its inner opening facing the valve hole 27a, and its outer opening communicates radially with the lock release oil passage 24.

[0051] The sleeve 28 is integrally formed of, for example, a synthetic resin material or a metal material, and as shown in FIGS. 5 and 6, is composed of a solid cylindrical sleeve body 28a and a flange portion 28b integrally provided at one axial end portion of the sleeve body 28a.

[0052] The sleeve body 28a has a first oil passage 38, which is an introduction passage, and a second oil passage 39, which is a discharge passage, separated by a partition wall 37 integrally provided inside. Further, a valve accommodation recess 40 is formed inside the sleeve body 28a on the flange portion 28b side. That is, the solid interior of the sleeve body 28a is notched, and the first and second oil passages 38 and 39 are formed along the axial direction.

[0053] The partition wall 37 has a cross-shaped cross-section in the direction perpendicular to the axis and is composed of four partition portions centered on the central axis portion. Further, a first end wall 28d that closes the axial end of the first oil passage 38 is integrally provided at the end of the partition wall 37 on the side opposite to the valve accommodation recess 40 in the axial direction. Also, a second end wall 28e that closes the axial end of the second oil passage 39 is integrally provided at the end on the valve accommodation recess 40 side. Furthermore, a protrusion 28f protruding in the direction of the valve accommodation recess 40 in the form of an extension of the central axis portion is provided at the center position on the second end wall 28e side of the partition wall 37.

[0054] The first oil passage 38 and the second oil passage 39 are formed in parallel along the axial direction of the sleeve body 28a, and two of them are formed at diametrically symmetric positions, that is, 180° symmetric positions, with respect to each other via the cross-shaped partition wall 37. Also, each oil passage 38, 39 is formed in a sector shape in cross-section by the partition wall 37.

[0055] A rectangular first opening hole 38a is formed through the first oil passage 38 near the first end wall 28d of the sleeve body 28a. This first opening hole 38a is adapted to communicate appropriately with each retard port 34, each advance port 35, and the lock port 36 via a communication hole 29d (to be described later) of the spool valve 29.

[0056] A rectangular second opening hole 39a is formed through the second oil passage 39 near the second end wall 28e of the sleeve body 28a. This second opening hole 39a is adapted to communicate appropriately with each retard port 34, each advance port 35, and the lock port 36 via another communication hole 29d (to be described later) of the spool valve 29.

[0057] Also, a discharge port 39b is formed at an end of the second oil passage 39 on the side opposite to the second end wall 28e. This discharge port 39b communicates with a discharge passage 43 via a cylindrical member 50 described later.

[0058] Further, the first end wall 28d has a first inclined surface formed on the inner surface on the first oil passage 38 side for guiding hydraulic oil from the first oil passage 38 to the first opening hole 38a. On the other hand, the second end wall 28e has a second inclined surface formed on the inner surface on the second oil passage 39 side for guiding hydraulic oil from the first cylindrical passage to the second oil passage 39.

[0059] Furthermore, each retard port 34 communicates with the discharge passage 43 via each communication hole 29d of the spool valve 29 and each discharge hole 50c of a cylindrical member 50 described later in a state where the spool valve 29 is held at the maximum rightward movement position shown in FIGS. 1 and 6.

[0060] Also, the outer diameter of the outer peripheral surface of the sleeve body 28a is formed smaller than the inner diameter of the inner peripheral surface 51c of the inner peripheral convex portion 51, and a cylindrical clearance C is formed between the outer peripheral surface and the inner peripheral surface 51c of the inner peripheral convex portion 51.

[0061] As shown in FIGS. 1 and 6, the flange portion 28b is disposed inside the cylindrical portion 27g, one end surface is disposed opposite to the other end surface 51b of the inner peripheral convex portion 51 and is slightly movable in the axial direction, and a slight clearance is formed between the outer peripheral surface and the inner peripheral surface of the small-diameter stepped surface provided on the inner peripheral surface of the cylindrical portion 27g.

[0062] Therefore, the sleeve 28 is held slightly movable in the radial and axial directions with respect to the valve body 27 by the respective clearances C.

[0063] As shown in FIG. 5, a second stopper ring 65 housed inside the cylindrical portion 27g is formed in a C-ring shape from a metal material, is fitted and fixed in an annular groove formed on the inner periphery of the cylindrical portion 27g, and has a hole portion 65a through which oil flows on the inside.

[0064] The valve seat 46 is housed inside the cylindrical portion 27g. Since it is a part of the check valve 44, it will be described later.

[0065] The check valve 44 is housed and arranged in the valve housing recess 40. As shown in FIGS. 1, 5, and 6, this check valve 44 is composed of a valve body 45, a valve seat 46 on which the valve body 45 seats and departs, and a check spring 47 that biases the valve body 45 in the direction of the valve seat 46.

[0066] The valve body 45 is formed by processing a plate-shaped metal material into a cup shape with a U-shaped longitudinal section, and the spherical tip portion 45a seats and departs from the hole edge of the passage hole 46a of the valve seat 46 to open and close the passage hole 46a. The outer diameter of the sliding portion 45b formed in a cylindrical shape of the valve body 45 is formed to be sufficiently smaller than the inner diameter of the valve housing recess 40, and a relatively large gap is formed between the two. Further, four notches 45c along the axial direction are formed at equal intervals in the circumferential direction on the sliding portion 45b. Due to each of these notches 45c, the valve body 45 can be bent and deformed in the radial direction, ensuring good slidability within the valve housing recess 40.

[0067] The valve seat 46 is formed in a disc shape by a metal material, and a passage hole 46a is formed through the central portion that bulges and deforms in the direction of the valve body 45. The outer peripheral portion 46b of the valve seat 46 is inserted and arranged axially on the inner peripheral side of the cylindrical portion 27g.

[0068] Further, the valve seat 46 has an inner annular portion 46c that constitutes a seating portion between the passage hole 46a and the outer peripheral portion 46b. This inner annular portion 46c is formed in an inclined protruding shape in the direction of the valve body 45. The valve seat 46 is integrally provided with an annular protrusion 46d on the back surface (the O-ring 48 side) of the outer peripheral portion 46b side of the inner annular portion 46c.

[0069] The check spring 47 biases the valve body 45 in the direction of seating on the hole edge of the passage hole 46a. The spring force is set to such a magnitude that it is compressed and deformed by a predetermined hydraulic pressure acting on the valve body 45 from the passage hole 46a, causing the valve body 45 to move backward to open the passage hole 46a.

[0070] Also, a filter 49 is fixed in a sandwiched state between the O-ring 48 and the second stopper ring 65. This filter 49 is adapted to collect dust and the like in the hydraulic oil passing through the filter portion 49a at the center.

[0071] As shown in FIGS. 1, 5, and 6, the spool valve 29 is formed in a substantially cylindrical shape and is provided slidably in the axial direction between the inner peripheral surface of the large-diameter portion 27e of the valve body 27 and the outer peripheral surface of the sleeve body 28a. The spool valve 29 is provided with three first land portions 29a to third land portions 29c at predetermined intervals between both axial ends and between these both ends. Also, a plurality of communication holes 29d for appropriately communicating the retard port 34 and the first oil passage 38, and the advance port 35 and the lock port 36 and the second oil passage 39 are formed to penetrate in the radial direction between the respective land portions 29a to 29c.

[0072] Each communication hole 29d is formed to penetrate the peripheral wall of the spool valve 29 in a substantially cross shape from the radial direction. Also, two first and second groove grooves 29e and 29f are formed on the outer peripheral surface of the spool valve 29 where each communication hole 29d is located. The first and second groove grooves 29e and 29f are formed facing the outer openings of the respective communication holes 29d.

[0073] The valve spring 30 is formed with a relatively short axial length, and one axial end is elastically contacted with one end surface 51a of the inner peripheral convex portion 51 as described above. On the other hand, the other axial end is elastically contacted with one axial end surface on the side of the third land portion 29c of the spool valve 29, biasing the spool valve 29 in the direction of the electromagnetic actuator 31.

[0074] On the axial end face on the side of the first land portion 29a of the spool valve 29, as shown in FIG. 1, a cylindrical member 50 is provided which receives the pressing force from the electromagnetic actuator 31 in the right direction and transmits it to the spool valve 29.

[0075] As shown in FIGS. 5 and 6, this cylindrical member 50 has an outer diameter formed in a large and small diameter shape in the axial direction, and has a large diameter cylindrical portion 50a on the spool valve 29 side and a small diameter cylindrical portion 50b on the electromagnetic actuator 31 side.

[0076] One end portion in the axial direction of the large diameter cylindrical portion 50a is axially abutted against the axial end face of the spool valve 29, and the other end edge is elastically abutted against a first stopper ring 52 fixed to the valve hole 27a in the axial direction. As a result, the movement of the spool valve 29 to the maximum left direction in FIGS. 1 and 6 is restricted by the cylindrical member 50.

[0077] The small diameter cylindrical portion 50b is formed in a bottomed shape, and the push rod 61 of the electromagnetic actuator 31 abuts against the bottom wall 50d in the axial direction. Further, the small diameter cylindrical portion 50b has a plurality of discharge holes 50c formed therethrough in the radial direction for discharging the hydraulic oil passing through the second oil passage 39 to the outside on the peripheral wall of the tip portion. These discharge holes 50c are provided at four equal intervals at the 90° positions in the circumferential direction of the small diameter cylindrical portion 50b.

[0078] The first stopper ring 52 has a drain hole 52a formed therethrough at the center. This drain hole 52a communicates the second oil passage 39 and the discharge passage 43 through each discharge hole 50c of the cylindrical member 50.

[0079] As shown in FIG. 1, the electromagnetic actuator 31 includes a casing 53 made of a synthetic resin material, an annular coil 55 housed therein via a bobbin 54 made of a magnetic material, a cylindrical member 56 made of a magnetic material disposed so as to surround the outer periphery of the coil 55, and a pair of first and second fixed cores 57, 58 made of a magnetic material disposed and fixed on the inner peripheral side of the bobbin 54.

[0080] The electromagnetic actuator 31 includes a non-magnetic sleeve 59 disposed in contact with the inner peripheral surfaces of both fixed cores 57 and 58, a cylindrical movable core 60 slidable axially inside the sleeve 59, a push rod 61 attached to the tip of the movable core 60, and a holding plate 62 made of a magnetic material fixed to the front end side of the front first fixed core 57.

[0081] The casing 53 includes a cylindrical portion 53a and a connector portion 53b integrally formed at the rear end of the cylindrical portion 53a and electrically connected to an ECU 63 which is a control unit.

[0082] The cylindrical portion 53a is formed in a bottomed thin-walled cylindrical shape with an open front end, and a cylindrical member 56 is fixed to the inner peripheral surface.

[0083] In the connector portion 53b, one end of each of a pair of terminal pieces almost entirely embedded in the casing 53 is connected to the coil 55. On the other hand, the other exposed ends 53e are connected to the terminals of the male connector on the ECU 63 side.

[0084] The push rod 61 is formed in a cylindrical shaft shape, and a steel spherical pressing portion insert-molded at the axial tip abuts against the bottom surface of the small-diameter cylindrical portion 50b of the cylindrical member 50 axially. Further, an air vent hole (not shown) penetrates the push rod 61 in the inner axial center direction from the rear end to the front end.

[0085] The holding plate 62 is formed in a disk shape and has an annular recess recessed in the direction of the movable core 60 at the inner peripheral portion. An insertion hole into which the tip of the push rod 61 is slidably inserted is formed through the center of this annular recess.

[0086] The coil 55 is excited by energization from the ECU 63, and by this excitation, the movable core 60 and the push rod 61 are moved rightward in FIG. 1. As a result, the push rod 61 moves the spool valve 29 rightward against the spring force of the valve spring 30.

[0087] Note that the spool valve 29 is controlled to move to the maximum leftward position (first movement position) shown in FIGS. 1 and 6 by the spring force of the valve spring 30 when the coil 55 is de-energized.

[0088] Also, the spool valve 29 is controlled to move to an intermediate movement position (second movement position, holding position) in the right direction and a maximum rightward position (third movement position) in FIG. 1 according to the amount of energization during energization of the coil 55.

[0089] The ECU 63 detects the current engine operating state by inputting information signals from various sensors such as a crank angle sensor (engine speed detection), 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 rotation phase of the camshaft 2, which are not shown, by an internal computer.

[0090] Also, as described above, the ECU 63 cuts off the energization of the coil 55 of the electromagnetic actuator 31 to control the spool valve 29 to the first movement position. Alternatively, a pulse signal is output to the coil 55 to control the amount of energization (duty ratio) so as to continuously variably control to the second movement position and the third movement position.

[0091] FIG. 7 is a longitudinal sectional view showing a state in which oil is supplied and controlled from the advance operation chamber to the retard operation chamber by a control valve, FIG. 8 is a longitudinal sectional view showing a state in which oil is supplied and controlled to the advance operation chamber and the retard operation chamber by a control valve, and FIG. 9 is a longitudinal sectional view showing a state in which the flow of oil from the retard operation chamber to the advance operation chamber is controlled by a control valve. 〔Operation and Effect of Valve Timing Control Device of the Present Embodiment〕 Hereinafter, the operation of the valve timing control device provided in the present embodiment will be described.

[0092] When the engine is in a stopped state, the oil pump 25 also stops and hydraulic oil is not supplied from the discharge passage 25a, and the coil 55 is not energized from the ECU 63 and is in a de-energized state.

[0093] Therefore, as shown in FIG. 6, the spool valve 29 is held at the first movement position in the maximum leftward direction by the spring force of the valve spring 30.

[0094] At this time, the check valve 44 has the valve body 45 seated on the valve seat 46 by the spring force of the check spring 47 to close the passage hole 46a.

[0095] Next, when the engine is started, the oil pump 25 is also driven to pump the hydraulic oil from the discharge passage 25a. Due to the hydraulic oil pressure at the initial stage of starting, as shown in FIG. 7, the valve body 45 moves backward against the spring force of the check spring 47, separates from the valve seat 46, and opens the passage hole 46a.

[0096] Therefore, the hydraulic oil flowing into the supply passage 25b from the discharge passage 25a flows into each first oil passage 38 through the filter 49 as shown by the arrow in FIG. 7. Further, from here, it flows into each retard port 34 through the first opening hole 38a, the first groove 29e of the spool valve 29, the communication hole 29d, and the first annular oil passage 32, and is supplied into each retard working chamber 9 from each retard passage hole 17.

[0097] At the same time, the spool valve 29 connects each advance port 35 and the second groove 29f. Therefore, the hydraulic oil in each advance working chamber 10 flows into the second oil passage 39 from the second opening hole 39a through each advance passage hole 18, the second annular oil passage 33, and each advance port 35. Further, from here, it passes through the inside of the cylindrical member 50 and is discharged into the oil pan 64 through each discharge hole 50c and the discharge passage 43.

[0098] Therefore, since the vane rotor 7 is maintained at the most retarded relative rotation position, the valve timing of the intake valve is controlled to the retarded side. As a result, the starting performance of the engine is improved.

[0099] Also, at this time, the unlocking oil passage 24 is in a state of being in communication with the second oil passage 39 via the second annular oil passage 33 and the second opening hole 39a. Therefore, the vane rotor 7 is in a locked state by the lock pin 21 whose tip is inserted into the lock hole 19. Accordingly, it is possible to suppress the flutter of the vane rotor 7 due to the alternating torque generated in the camshaft 2.

[0100] Next, when the energization amount from the ECU 63 to the coil 55 increases along with the change in the engine operating state, the spool valve 29 slightly moves rightward to the second moving position shown in FIG. 8.

[0101] In this state, the retard port 34 and the advance port 35 communicate with the first oil passage 38 via the second groove 29f, and hydraulic oil is supplied to each retard operating chamber 9 and each advance operating chamber 10.

[0102] Also, the hydraulic oil supplied to the first oil passage 38 flows from the lock port 36 into the unlocking oil passage 24 via the second annular oil passage 33, and is supplied from here to the pressure receiving chamber 23 for unlocking, increasing the hydraulic pressure in the pressure receiving chamber 23 for unlocking. As a result, the lock pin 21 moves backward against the spring force of the coil spring, and the locked state with the lock hole 19 is released. Thus, the rotation restriction of the vane rotor 7 is released and it becomes a free state. Therefore, first, the vane rotor 7 becomes relatively rotatable by the release of the lock by the lock pin 21.

[0103] Accordingly, the vane rotor 7 is controlled to an intermediate phase position between the most retarded angle and the most advanced angle of the valve timing. Accordingly, each intake valve has an intermediate characteristic of the opening and closing timing being retarded and advanced, and the engine rotation can be stabilized and the fuel consumption can be improved during steady operation.

[0104] Subsequently, when the energization amount to the coil 55 further increases, the spool valve 29 moves further rightward to the maximum (third moving position) as shown in FIG. 9. In this state, the spool valve 29 opens the retard port 34, and the retard port 34 communicates with the second oil passage 39 via the first groove 29e and the communication hole 29d.

[0105] Therefore, the hydraulic oil in each retard angle working chamber 9 flows into the inside of the cylindrical member 50 through each retard angle port 34 from each retard angle passage hole 17 and through the first groove 29e and the communication hole 29d. The hydraulic oil that has flowed in here is quickly discharged from the discharge passage 43 into the oil pan 64 through each discharge hole 50c of the cylindrical member 50.

[0106] At the same time, the spool valve 29 communicates the first oil passage 38 and each advance angle port 35 through the second groove 29f and the communication hole 29d.

[0107] Therefore, the hydraulic oil pumped from the oil pump 25 flows into each first oil passage 38 through the check valve 44 that has been pushed open in advance by the hydraulic pressure of the supply passage 25b. This hydraulic oil flows from the second groove 29f and each communication hole 29d of the spool valve 29 into each advance angle port 35 and the second annular oil passage 33, and then into each advance angle passage hole 18, and is supplied from here to each advance angle working chamber 10. As a result, the internal pressure of each retard angle working chamber 9 decreases, and the internal pressure of each advance angle working chamber 10 increases.

[0108] Therefore, the vane rotor 7 rotates clockwise from the position shown in FIG. 3 and relatively rotates to the maximum advance angle side shown in FIG. 4 as the hydraulic pressure in each advance angle working chamber 10 increases. As a result, the intake valve has the most advanced opening and closing timing phase characteristics, the valve overlap with the exhaust valve increases, the intake filling efficiency increases, and the output torque of the engine can be improved.

[0109] And according to the present embodiment, since the outer diameter of the small diameter portion 27f of the valve body 27, that is, the outer diameter of the male screw portion 27h, is smaller than the outer diameter of the large diameter portion 27e, it is possible to reduce the inner diameter of the female screw hole 2b of the camshaft 2 to which the male screw portion 27h is screwed. In other words, since the outer diameter of one end portion 2a in the axial direction of the camshaft 2 can be reduced, the outer diameter of the cam bearing 02 such as a bearing bracket that rotatably supports the one end portion 2a can also be reduced. As a result, the compactness around the one end portion 2a of the camshaft 2 can be achieved, and the degree of freedom of the layout is improved.

[0110] Moreover, by reducing the outer diameter of the male screw portion 27h, it becomes possible to reduce the fastening torque with the female screw hole 2b. That is, when the outer diameter of the male screw portion 27h is large, there is a possibility that the fastening torque may become large with respect to the axial force desired to be obtained in relation to the female screw hole 2b. However, as described above, by reducing the outer diameter of the male screw portion 27h, an appropriate fastening torque can be obtained with respect to the axial force desired to be obtained.

[0111] Also, in the present embodiment, since the inner peripheral convex portion 51 is provided on the inner periphery of the small-diameter portion 27f, the rigidity of the small-diameter portion 27f can be increased. For this reason, a stable fastening force can be obtained between the male screw portion 27h on the outer periphery of the small-diameter portion 27f and the female screw hole 2b of the camshaft 2.

[0112] Furthermore, when the sleeve 28 is inserted into the valve body 27, since the inner peripheral surface 51c of the inner peripheral convex portion 51 functions as an insertion guide for the sleeve 28, it is possible to suppress the sleeve 28 from falling over.

[0113] The inner peripheral convex portion 51 is provided outside the axial movement range of the spool valve 29, and since the inner peripheral surface 51c protrudes radially inward from the inner peripheral surface of the spool valve 29 and is formed with a large diameter, a sufficient wall thickness can be ensured without reducing the inner and outer diameters of the spool valve 29.

[0114] Furthermore, since one axial end portion of the valve spring 30 is supported by one end surface 51a of the inner peripheral convex portion 51, the axial length of the valve spring 30 can be shortened. Also, since there is no need to provide a separate member such as a valve retainer to support one end portion of the valve spring 30, an increase in the number of parts can be suppressed.

[0115] The sleeve 28 has a flange portion 28b that regulates the axial movement of the sleeve 28 in one direction by using the other end surface 51b of the inner peripheral convex portion 51, so that stable axial slidability of the spool valve 29 can be obtained on the outer peripheral surface of the sleeve 28.

[0116] Furthermore, according to the present embodiment, no male thread portion is formed on the outer periphery of the cylindrical portion 27g, and no fastening torque is applied to the female screw hole 2b. Therefore, each member such as the valve seat 46 and the filter 49 disposed inside the cylindrical portion 27g is not affected by the fastening torque, so that the occurrence of unnecessary deformation and the like can be suppressed.

[0117] Since the inner annular portion 46c of the valve seat 46 is formed in an inclined shape toward the valve body 45, it has a guiding function of guiding the oil flowing from the introduction port 27i of the valve body 27 toward the passage hole 46a in the direction of the passage hole 46a.

[0118] Furthermore, since the valve seat 46 is provided with an annular protrusion 46d, when the O-ring 48 falls off from the normal mounting position when the O-ring 48 is assembled inside the cylindrical portion 27g, the annular protrusion 46d can hold the O-ring 48.

[0119] The present invention is not limited to the configurations of the above embodiments, and the control valve can also be applied to other devices and equipment. Also, the inner diameter of the inner peripheral convex portion 51 can be arbitrarily changed in relation to the sleeve 28.

[0120] Furthermore, the cylindrical member 50 can also be formed by press-molding a metal plate.

Description of Reference Numerals

[0121] 1... Timing sprocket (driving rotating body), 2... Camshaft, 2a... One end portion, 2b... Female screw hole, 3... Phase change mechanism, 5... Hydraulic circuit, 6... Housing, 6a... Housing body, 7... Vane rotor, 8... Shoe, 9... Retard operation chamber (first hydraulic chamber), 10... Advance hydraulic chamber (second hydraulic chamber), 14... Rotor portion, 15a - 15d... Vanes, 17... Retard passage hole, 18... Advance passage hole, 26... Control valve, 27... Valve body, 27a... Valve hole, 27b... Head portion, 27c... Shaft portion, 27d... Flange portion, 27e... Large diameter portion (first part), 27f... Small diameter portion (second part), 27g... Cylindrical portion (third part), 27h... Male screw portion, 27i... Introduction port, 28... Sleeve, 28a... Sleeve body, 28b... Flange portion, 29... Spool valve, 30... Valve spring (biasing member), 34... Retard port (operating port), 35... Advance port (operating port), 38... First oil passage (introduction passage), 38a... First opening hole, 39... Second oil passage (discharge passage) 39a... Second opening hole, 44... Check valve, 45... Valve body, 46... Valve seat, 46c... Inner annular portion, 46d... Annular protrusion portion, 47... Check spring, 48... O-ring, 49... Filter, 51... Inner peripheral convex portion, 51a... One end face, 51b... The other end face, 51c... Inner peripheral surface.

Claims

1. A cylindrical valve body in which a plurality of operating ports are formed in the radial direction and an introduction port is formed to open at one end in the axial direction, and a spool valve provided movably in the axial direction within a valve hole formed inside the valve body, The valve body has a first part within the axial movement range of the spool valve and a second part outside the movement range of the spool valve, having an outer diameter smaller than that of the first part and having an external thread formed on the outer circumference for fastening to an internal thread formed on a camshaft, A control valve, characterized in that an inner circumferential convex part protruding radially inward is provided in an axial range where the inner circumference of the second part overlaps with the external thread in the radial direction.

2. The control valve according to claim 1, The spool valve is formed in a cylindrical shape, and has a sleeve disposed radially inside the spool valve and having two oil passages, an introduction passage and a discharge passage, communicating with the introduction port in the internal axial direction, The control valve, characterized in that the sleeve is inserted and disposed radially inside the inner circumferential surface of the inner circumferential convex part.

3. The control valve according to claim 1, The control valve, characterized in that the inner circumferential surface of the inner circumferential convex part protrudes radially inward from the inner circumferential surface of the spool valve.

4. The control valve according to claim 1, The spool valve is formed in a cylindrical shape and is biased in one axial direction by a biasing member, The control valve, characterized in that the biasing member is provided between one end surface on the inner circumferential convex part side in the axial direction of the spool valve and one end surface in the axial direction of the inner circumferential convex part.

5. The control valve according to claim 1, The control valve, characterized in that the inner circumferential convex part is formed over the entire axial region of the second part.

6. The control valve according to claim 1, wherein the sleeve has a flange portion extending in the outer diameter direction at one end on the opening side of the introduction port in the axial direction, the control valve is characterized in that the flange portion abuts against the other end surface in the axial direction of the inner peripheral convex portion from the axial direction to restrict the movement of the sleeve in one axial direction.

7. The control valve according to claim 1, wherein the valve body has a cylindrical third portion having an outer diameter smaller than that of the second portion and not formed with a male screw portion at an axial end on the side opposite to the first portion of the second portion, the control valve is characterized in that a filter for filtering foreign matters of oil flowing into the introduction passage is disposed inside the third portion in the radial direction.

8. The control valve according to claim 7, wherein a check valve for restricting backflow of oil flowing into the introduction port is provided inside the second portion, the check valve has a valve body, a valve seat on which the valve body seats and disengages, and a check spring for urging the valve body in the direction of the valve seat, the control valve is characterized in that the valve seat is formed in a disc shape, a passage hole opened and closed by the valve body is formed through the central portion, and an inner annular portion constituting a seating portion of the outer peripheral edge of the passage hole is bent in an inclined shape toward the valve body.

9. The control valve according to claim 8, wherein an O-ring is press-fitted and fixed between the outer peripheral portion of the valve seat and the outer peripheral portion of the filter, and the control valve is characterized in that an annular protrusion is provided on the outer surface of the outer peripheral portion of the valve seat on the O-ring side.

10. A valve timing control device for an internal combustion engine using the control valve according to claim 1, wherein a housing having an operating chamber inside, to which rotational force from a crankshaft is transmitted, It has a vane fixed to the camshaft and partitioning the working chamber into a first hydraulic chamber and a second hydraulic chamber, and a vane rotor disposed rotatably relative to the inside of the housing. It has The valve body is formed in a bolt shape, and is characterized in that the valve timing control device for an internal combustion engine is fixed to the camshaft by turning the head and fastening the male threaded portion to the female threaded portion of the camshaft.

11. The valve timing control device for an internal combustion engine according to claim 10, The valve timing control device for an internal combustion engine, wherein the first portion is disposed radially inside the vane rotor.

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