JP2013148033A - Valve timing adjusting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve timing adjusting device capable of reducing external leakage.SOLUTION: A rear cover 72 is integrally formed from an annular plate part 74 and an annular rib part 82. The annular plate part 74 has a thickness in an axial direction of a camshaft 218, is disposed so as to close the other end of a cylindrical part 16 of a shoe housing 14, and is integrally fixed to the shoe housing 14. The annular plate part 74 has a through hole 78 through which the camshaft 218 is inserted. An inner wall of the through hole 78 forms a second annular clearance 80 between the inner wall and an outer wall of the camshaft 218. The annular rib part 82 is an annular projection integrally projecting from a radial inner edge part of the annular plate part 74 to the opposite side of a vane rotor 44. The annular rib part 82 has a through hole 84 through which the camshaft 218 is inserted. An inner wall of the through hole 84 forms a third annular clearance 86 between the inner wall and the outer wall of the camshaft 218.

Description

  The present invention relates to a valve timing adjusting device that adjusts the opening / closing timing of an intake valve or an exhaust valve of an engine.

  2. Description of the Related Art Conventionally, a vane type valve timing adjusting device that adjusts the opening / closing timing of an intake valve or an exhaust valve by changing the rotational phase of an engine drive shaft and a driven shaft is known. This vane type valve timing adjusting device includes a housing that rotates integrally with a drive shaft, and a vane rotor that is integrally fixed to a driven shaft in the housing, and supplies the working oil to a pressure chamber in the housing, thereby supplying the vane rotor. Are rotated relative to each other to adjust the opening / closing timing.

  In the valve timing adjusting device disclosed in Patent Document 1, a storage chamber of a vane rotor is defined by a cylindrical housing and plates fixed to both ends thereof. The vane rotor is rotatably supported by the inner wall of the housing, and both sides in the axial direction can slide on the plate. An axial gap is formed between the rotor and the plate.

  The camshaft is fixed to the rotor through the plate. A radial gap is formed between the plate and the camshaft. In the valve timing adjusting device disclosed in Patent Document 1, the hydraulic oil in the advance chamber and the retard chamber leaks outside through the axial gap between the rotor and the plate and the radial gap between the plate and the camshaft. Leakage occurs.

JP 2005-325836 A

  In the valve timing adjusting device disclosed in Patent Document 1, since the axial thickness of the plate is thin in order to reduce the physique and weight of the device, the plate is used for the hydraulic fluid in the advance chamber and the retard chamber. When pressure is applied, it tends to deform in a direction away from the vane rotor. Therefore, there is a problem that the axial clearance between the rotor and the plate is increased due to deformation of the plate, and external leakage increases.

Further, the radial gap between the plate and the camshaft cannot be made smaller than the radial gap between the bearing portions of the housing and the rotor. Therefore, there is a limit in reducing external leakage by reducing the radial gap between the plate and the camshaft.
The present invention has been made in view of the above points, and an object thereof is to provide a valve timing adjusting device capable of reducing external leakage.

The invention according to claim 1 is a valve timing adjusting device that adjusts the opening / closing timing of an intake valve or an exhaust valve that is driven to open and close by changing the rotational phase of the drive shaft and the driven shaft of the engine. , A housing, a first plate, a second plate, a vane rotor, and an annular rib.
The housing is a cylindrical member disposed coaxially with the driven shaft, and rotates integrally with the drive shaft.

The first plate is a plate-like member having a thickness in the axial direction of the driven shaft. The driven shaft or the fixing member fixed to the driven shaft passes through the first plate. The first plate forms a first annular gap between the driven shaft and the fixed member, and is fixed to one end of the housing.
The second plate is a plate-like member having a thickness in the axial direction of the driven shaft. The driven shaft passes through the second plate. The second plate forms a second annular gap with the driven shaft and is fixed to the other end of the housing.

  The vane rotor has a boss portion and a vane portion. The boss portion is integrally fixed to the driven shaft in the housing, and is supported by the inner wall of the housing so as to be relatively rotatable. The vane portion extends radially outward from the boss portion, and divides the space between the housing and the boss portion into an advance chamber and a retard chamber in the circumferential direction. The vane rotor is rotatable to the advance side or the retard side with respect to the housing according to the pressure difference of the hydraulic oil between the advance chamber and the retard chamber.

  The annular rib projects integrally from the inner diameter end of at least one of the first plate and the second plate to the vane rotor side or the opposite side of the vane rotor. The annular rib forms a third annular gap between the driven shaft or the fixed member.

  Therefore, since at least one of the first plate and the second plate is formed integrally with the annular rib, the rigidity is increased. Therefore, this plate is difficult to deform in the direction away from the vane rotor due to the pressure of the hydraulic oil in the advance chamber and the retard chamber. Therefore, it is possible to suppress an increase in the axial gap between the plate and the vane rotor due to deformation of the plate, and external leakage can be reduced.

  Further, the third annular gap formed by the annular rib makes the outflow path longer than the case where the hydraulic oil outflow path from the advance chamber and the retard chamber to the outside is only the first annular gap or the second annular gap. Increase the pressure loss of hydraulic fluid flowing through the outflow path. Therefore, external leakage can be reduced.

  Further, for example, when the axial thickness of the first plate and the second plate is increased, the gap between each plate and the driven shaft is extended in the axial direction to increase the pressure loss of the outflow passage. The physique and weight do not increase significantly.

1 is a longitudinal sectional view of a valve timing adjusting device according to a first embodiment of the present invention. It is a figure which shows the engine to which the valve timing adjustment apparatus of FIG. 1 was applied. It is III-III sectional drawing of FIG. It is IV-IV sectional drawing of FIG. It is an enlarged view of the arrow V part of FIG. It is a longitudinal cross-sectional view of the valve timing adjustment apparatus by 2nd Embodiment of this invention. It is an enlarged view of the arrow VII part of FIG. It is a longitudinal cross-sectional view of the valve timing adjustment apparatus by 3rd Embodiment of this invention. It is an enlarged view of the arrow IX part of FIG. It is an expanded sectional view of the diameter inner end part of the rear cover of the valve timing adjustment device by a 4th embodiment of the present invention. It is an expanded sectional view of the diameter inner end part of the rear cover of the valve timing adjustment device by a 5th embodiment of the present invention. It is an expanded sectional view of the diameter inside end part of the rear cover of the valve timing adjustment device by a 6th embodiment of the present invention. It is an expanded sectional view of the diameter inner end part of the rear cover of the valve timing adjustment device by a 7th embodiment of the present invention. It is an expanded sectional view of a diameter inner end part of a rear cover of a valve timing adjustment device by an 8th embodiment of the present invention. It is an expanded sectional view of the diameter inner end part of the rear cover of the valve timing adjustment device by a 9th embodiment of the present invention. It is an expanded sectional view of the diameter inside end part of the rear cover of the valve timing adjustment device by a 10th embodiment of the present invention. It is a longitudinal cross-sectional view of the valve timing adjustment apparatus by 11th Embodiment of this invention. It is a longitudinal cross-sectional view of the valve timing adjustment apparatus by 12th Embodiment of this invention.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In the embodiments, substantially the same components are denoted by the same reference numerals and description thereof is omitted.
(First embodiment)
The valve timing adjusting device according to the first embodiment of the present invention is used in the valve timing adjusting system shown in FIG. This valve timing adjustment system 10 is for adjusting the opening / closing timing of the intake valve 202 of the engine 200 shown in FIG. As shown in FIG. 2, the rotation of the gear 208 of the crankshaft 206 of the engine 200 is transmitted to the camshafts 216 and 218 via a chain 214 wound around the gears 208, 210 and 212. The camshaft 216 drives the exhaust valve 204 to rotate, and the camshaft 218 drives the intake valve 202 to rotate.

  The valve timing adjustment system 10 accelerates the opening / closing timing of the intake valve 202 by relatively rotating the camshaft 218 forward in the rotational direction with respect to the gear 212 that rotates integrally with the crankshaft 206. Thus, relative rotation of the camshaft 218 in order to accelerate the opening / closing timing of the intake valve 202 is referred to as “advance”.

  In addition, the valve timing adjustment system 10 delays the opening / closing timing of the intake valve 202 by relatively rotating the camshaft 218 rearward in the rotational direction with respect to the gear 212. The relative rotation of the camshaft 218 in order to delay the opening / closing timing of the intake valve 202 is referred to as “retarding”.

  First, the valve timing adjustment system 10 will be described with reference to FIGS. 1 and 3. 1 is a cross-sectional view taken along the line II of FIG. As shown in FIGS. 1 and 3, the valve timing adjustment system 10 includes a valve timing adjustment device 12, an oil pump 90, an oil passage switching valve 96, an electronic control device 98, and the like.

  The valve timing adjusting device 12 includes a shoe housing 14, a vane rotor 44, a front cover 66, a rear cover 72, and the like. The shoe housing 14 corresponds to a “housing” described in the claims.

  The shoe housing 14 integrally forms a gear 212. The rotation of the crankshaft 206 is transmitted to the shoe housing 14 via the chain 214. The shoe housing 14, the front cover 66, and the rear cover 72 are integrally connected to each other and rotate integrally with the crankshaft 206. The shoe housing 14, the front cover 66, and the rear cover 72 define a rotor accommodating space, and accommodate the vane rotor 44 in the rotor accommodating space.

  The vane rotor 44 is integrally coupled to the camshaft 218 and rotates integrally with the camshaft 218. In the shoe housing 14, advance chambers 28 to 34 are formed on the advance side in the circumferential direction with respect to the vane rotor 44, and retard chambers 36 to 42 are formed on the retard side in the circumferential direction with respect to the vane rotor 44. Yes. The advance chambers 28 to 34 communicate with an advance oil passage 48 of the vane rotor 44. The retard chambers 36 to 42 communicate with a retard oil passage 50 included in the vane rotor 44. The vane rotor 44 rotates relatively to the advance side or the retard side with respect to the shoe housing 14 according to the pressure difference between the hydraulic oil in the advance chambers 28 to 34 and the retard chambers 36 to 42.

The oil pump 90 discharges hydraulic oil pumped from the oil pan 92 to the supply oil passage 94.
The oil passage switching valve 96 includes an advance position that connects the supply oil passage 94 and the advance oil passage 48, a retard position that connects the supply oil passage 94 and the retard oil passage 50, and a supply oil passage 94. It operates to a blocking position where the connection with the advance oil passage 48 and the retard oil passage 50 is cut off. The oil passage switching valve 96 is, for example, an electromagnetic type.

  The electronic control unit 98 operates the oil passage switching valve 96 so that the rotational phase of the vane rotor 44 with respect to the shoe housing 14 matches the target rotational phase. Specifically, the electronic control unit 98 supplies hydraulic oil to the advance chambers 28 to 34 of the valve timing adjusting device 12 when the rotation phase is retarded from the target rotation phase. 96 is moved to the advanced position. Further, when the rotational phase is on the advance side with respect to the target rotational phase, the electronic control unit 98 supplies the hydraulic oil to the retard chambers 36 to 42 of the valve timing adjusting device 12, so that the oil path switching valve 96 is retarded. Actuate to angular position. In addition, when the rotational phase matches the target rotational phase, the electronic control unit 98 operates the oil passage switching valve 96 to the shut-off position.

Next, the valve timing adjusting device 12 will be described in more detail with reference to FIGS. 1 and 3 to 5.
The shoe housing 14 is integrally formed from the cylindrical portion 16, the gear 212, and the shoe portions 18, 20, 22, 24. The cylindrical portion 16 is a cylindrical member disposed coaxially with the camshaft 218. The gear 212 is formed on the outer wall of the cylindrical portion 16. The shoe portions 18, 20, 22, and 24 are fan-shaped protrusions that protrude in the radially inward direction from the tubular portion 16. Each shoe part 18-24 is provided in the position mutually spaced apart in the circumferential direction.

  The vane rotor 44 is integrally formed from the boss portion 46 and the vane portions 52, 54, 56, and 58. The boss portion 46 is located in the shoe housing 14 and is supported by the inner diameter end portions of the shoe portions 18 to 24 so as to be relatively rotatable. The radially inner end portions 26 of the shoe portions 18 to 24 function as journal bearings for the vane rotor 44. The boss portion 46 is integrally fixed to the outer wall of the camshaft 218 by, for example, press fitting. The boss portion 46 defines, together with the shoe housing 14, the front cover 66 and the rear cover 72, four vane accommodation chambers partitioned by the shoe portions 18 to 24 in the circumferential direction.

  The vane portions 52, 54, 56, and 58 are wing-like protrusions extending radially outward from the boss portion 46 in the vane accommodating chamber. The vane accommodating chamber accommodates the vane portions 52 to 58 so as to be relatively rotatable within a predetermined angle range. The vane portions 52 to 58 partition the vane accommodation chamber into the advance chambers 28, 30, 32, and 34 and the retard chambers 36, 38, 40, and 42 in the circumferential direction. The vane rotor 44 rotates relatively to the advance side with respect to the shoe housing 14 when the pressure of the hydraulic oil in the advance chambers 28 to 34 is higher than the pressure of the hydraulic oil in the retard chambers 36 to 42. On the other hand, the vane rotor 44 rotates relative to the shoe housing 14 toward the retard side when the pressure of the hydraulic oil in the retard chambers 36 to 42 is higher than the pressure of the hydraulic oil in the advance chambers 28 to 34.

  The vane part 52 has an accommodation hole 60 penetrating in the axial direction. The accommodation hole 60 accommodates the lock pin 62 so as to be capable of reciprocating in the axial direction. The lock pin 62 is urged toward the rear cover 72 by a spring 64 disposed on the front cover 66 side. The lock pin 62 is engaged with the fitting recess 76 of the rear cover 72 when the vane rotor 44 is positioned at the engine start optimal position, thereby restricting relative rotation of the vane rotor 44 with respect to the shoe housing 14 at the engine start optimal position.

  The front cover 66 is composed of an annular plate having a thickness in the axial direction of the camshaft 218. The front cover 66 is disposed so as to close one end of the cylindrical portion 16 of the shoe housing 14, and is fixed to the shoe housing 14 together with the rear cover 72 by bolts 88. The front cover 66 has a through hole 68 through which the camshaft 218 is inserted. A first annular gap 70 is formed between the inner wall of the through hole 68 and the outer wall of the camshaft 218. The front cover 66 corresponds to a “first plate” recited in the claims.

  The rear cover 72 is integrally formed from the annular plate portion 74 and the annular rib portion 82. The annular plate portion 74 has a thickness in the axial direction of the camshaft 218, is disposed so as to close the other end of the cylindrical portion 16 of the shoe housing 14, and is fixed to the shoe housing 14 together with the front cover 66 by bolts 88. The annular plate portion 74 has a through hole 78 through which the camshaft 218 is inserted. A second annular gap 80 is formed between the inner wall of the through hole 78 and the outer wall of the camshaft 218. The annular plate portion 74 corresponds to a “second plate” recited in the claims.

  The annular rib portion 82 is an annular protrusion that protrudes integrally from the radially inner end portion of the annular plate portion 74 to the side opposite to the vane rotor 44. The annular rib portion 82 functions as a reinforcing means for the annular plate portion 74. The annular rib portion 82 has a through hole 84 through which the camshaft 218 is inserted. A third annular gap 86 is formed between the inner wall of the through hole 84 and the outer wall of the camshaft 218. The annular rib portion 82 corresponds to an “annular rib” recited in the claims.

  There is a gap in the axial direction between the vane rotor 44 and the front cover 66 and between the vane rotor 44 and the annular plate portion 74 of the rear cover 72 so that the vane rotor 44 can rotate relative to the front cover 66 and the rear cover 72. Is formed.

Next, the operation of the valve timing adjusting device 12 will be described.
When the rotational phase of the vane rotor 44 relative to the shoe housing 14 is retarded from the target rotational phase, the oil pump 90 advances through the supply oil passage 94, the oil passage switching valve 96, and the advance oil passage 48. Hydraulic fluid is supplied to the chambers 28-34. On the other hand, the hydraulic oil in the retard chambers 36 to 42 is discharged to the oil pan 92 via the retard oil passage 50 and the like. As a result, the vane rotor 44 rotates forward with respect to the shoe housing 14.

  Further, when the rotational phase of the vane rotor 44 with respect to the shoe housing 14 is on the more advanced side than the target rotational phase, the oil pump 90 passes through the supply oil passage 94, the oil passage switching valve 96, and the retarded oil passage 50. Hydraulic oil is supplied to the retard chambers 36-42. On the other hand, the hydraulic oil in the advance chambers 28 to 34 is discharged to the oil pan 92 via the advance oil passage 48 and the like. As a result, the vane rotor 44 rotates toward the retard side with respect to the shoe housing 14.

  Here, the hydraulic oil supplied to the advance chambers 28 to 34 and the retard chambers 36 to 42 acts to separate the annular plate portion 74 from the vane rotor 44. On the other hand, the annular rib portion 82 suppresses the deformation of the annular plate portion 74 and suppresses the expansion of the axial clearance between the vane rotor 44 and the annular plate portion 74.

  The hydraulic fluid that has flowed out from the advance chambers 28 to 34 and the retard chambers 36 to 42 into the axial gap between the vane rotor 44 and the annular plate portion 74 flows out of the second annular gap 80 and the third annular gap 86. Leak outside through the road. The third annular gap 86 formed by the annular rib portion 82 makes the outflow path longer than the case where the outflow path is only the second annular gap 80, and increases the pressure loss of the hydraulic oil flowing through the flow path.

  As described above, in the first embodiment, the rear cover 72 is integrally formed from the annular plate portion 74 and the annular rib portion 82. The annular plate portion 74 has a thickness in the axial direction of the camshaft 218, is disposed so as to close the other end of the cylindrical portion 16 of the shoe housing 14, and is integrally fixed to the shoe housing 14. The annular plate portion 74 has a through hole 78 through which the camshaft 218 is inserted. A second annular gap 80 is formed between the inner wall of the through hole 78 and the outer wall of the camshaft 218.

  The annular rib portion 82 is an annular protrusion that protrudes integrally from the radially inner end portion of the annular plate portion 74 to the side opposite to the vane rotor 44. The annular rib portion 82 has a through hole 84 through which the camshaft 218 is inserted. A third annular gap 86 is formed between the inner wall of the through hole 84 and the outer wall of the camshaft 218.

  Therefore, since the annular plate portion 74 of the rear cover 72 is formed integrally with the annular rib portion 82, the rigidity is increased. Therefore, the annular plate portion 74 is not easily deformed in the direction away from the vane rotor 44 due to the pressure of the hydraulic oil in the advance chambers 28 to 34 and the retard chambers 36 to 42. Therefore, it is possible to suppress an increase in the axial clearance between the annular plate portion 74 and the vane rotor 44 due to the deformation of the annular plate portion 74, and external leakage can be reduced.

  In addition, the third annular gap 86 formed by the annular rib portion 82 flows out in comparison with the case where the hydraulic oil flowing out from the advance chambers 28 to 34 and the retard chambers 36 to 42 is only the second annular gap. Lengthen the path and increase the pressure loss of hydraulic fluid flowing through the flow path. Therefore, external leakage can be reduced.

In addition, for example, when the axial thickness of the entire rear cover is increased, the radial clearance between the rear cover and the camshaft is extended in the axial direction to increase the pressure loss in the outflow passage. There is no significant increase.
In the first embodiment, the annular rib portion 82 protrudes on the side opposite to the vane rotor 44. Therefore, it is not necessary to change the shape of the vane rotor 44 when the annular rib portion 82 is provided, and the conventional vane rotor can be used as it is.

(Second Embodiment)
As shown in FIGS. 6 and 7, in the second embodiment of the present invention, the front cover 100 is integrally formed from an annular plate portion 101 and an annular rib portion 103. The annular plate portion 101 has a plate shape that closes one end of the cylindrical portion 16 of the shoe housing 14, and forms a first annular gap 102 between the annular plate portion 101 and the camshaft 218. The annular plate portion 101 corresponds to a “first plate” recited in the claims.

The annular rib portion 103 projects integrally from the radially inner end portion of the annular plate portion 101 to the side opposite to the vane rotor 44, and forms a third annular gap 104 between the annular rib portion 103 and the camshaft 218. The annular rib portion 103 corresponds to an “annular rib” recited in the claims.
According to the second embodiment, since the annular rib portion 103 increases the rigidity of the annular plate portion 101 and lengthens the outflow path, external leakage is reduced as in the first embodiment.

(Third embodiment)
As shown in FIGS. 8 and 9, in the third embodiment of the present invention, the annular rib portion 111 of the rear plate 110 protrudes integrally from the radially inner end portion of the annular plate portion 74 toward the vane rotor 113 side, and the camshaft 218. A third annular gap 112 is formed between them. The annular rib portion 111 corresponds to an “annular rib” recited in the claims.

The boss portion 114 of the vane rotor 113 has an annular groove 116 into which the annular rib portion 111 is inserted and a fourth annular gap 115 is formed between the boss portion 114 and the annular rib portion 111. The fourth annular gap 115 is a maze-like gap having two refracting portions 117 and 118.
According to the third embodiment, the labyrinth-shaped fourth annular gap 115 having two refracting portions 117 and 118 is formed, so that external leakage is further reduced as compared with the first embodiment.

(Fourth embodiment)
As shown in FIG. 10, in the fourth embodiment of the present invention, the annular rib portion 124 of the rear plate 123 is inserted into the boss portion 121 of the vane rotor 120, and the fourth annular gap 125 is formed between the annular rib portion 124. An annular groove 122 is formed. The annular rib portion 124 corresponds to an “annular rib” recited in the claims. The fourth annular gap 125 includes a throttle section in which the passage area is reduced between each advance chamber and each retard chamber and the outside.

Specifically, the fourth annular gap 125 has a first throttle section 126 whose passage area continuously decreases toward the outside, and a passage area continuously from the outside toward the first throttle section 126. And a second aperture section 127 that becomes smaller.
According to 4th Embodiment, there exists an effect similar to 3rd Embodiment, Furthermore, it can suppress that air flows in from the outside by the 2nd aperture | diaphragm | squeeze area 127. FIG. Therefore, it is possible to suppress the vane rotor control failure that occurs due to air entering the advance chamber or the retard chamber.

(Fifth embodiment)
As shown in FIG. 11, in the fifth embodiment of the present invention, the boss 131 of the vane rotor 130 has an annular groove 132 that forms a fourth annular gap 133 between the boss 131 and the annular rib 111. The fourth annular gap 133 includes a throttle section 134 whose passage area continuously decreases toward the outside.
According to 5th Embodiment, there exists an effect similar to 3rd Embodiment.

(Sixth embodiment)
As shown in FIG. 12, in the sixth embodiment of the present invention, the boss portion 141 of the vane rotor 140 has an annular groove 142 that forms a fourth annular gap 143 with the annular rib portion 111. The fourth annular gap 143 includes a throttle section 144 whose passage area continuously decreases toward the outside.
According to 6th Embodiment, there exists an effect similar to 3rd Embodiment.

(Seventh embodiment)
As shown in FIG. 13, in the seventh embodiment of the present invention, a fourth annular gap 152 is formed between the annular rib portion 151 of the rear plate 150 and the inner wall of the annular groove 116 of the vane rotor 113. The annular rib portion 151 corresponds to an “annular rib” recited in the claims. The fourth annular gap 152 includes a throttle section 153 in which the passage area continuously decreases toward the outside.
According to 7th Embodiment, there exists an effect similar to 3rd Embodiment.

(Eighth embodiment)
As shown in FIG. 14, in the eighth embodiment of the present invention, a fourth annular gap 162 is formed between the annular rib portion 161 of the rear plate 160 and the inner wall of the annular groove 116 of the vane rotor 113. The annular rib portion 161 corresponds to an “annular rib” recited in the claims. The fourth annular gap 162 includes a throttle section 163 in which the passage area continuously decreases toward the outside.
According to the eighth embodiment, there are the same effects as in the third embodiment.

(Ninth embodiment)
As shown in FIG. 15, in the ninth embodiment of the present invention, the annular rib portion 172 of the rear plate 171 and the inner wall of the annular groove 174 of the vane rotor 173 form a fourth annular gap 175. The annular rib portion 172 corresponds to an “annular rib” recited in the claims. The fourth annular gap 175 has one refracting portion 176. Thus, even if there is one refracting portion 176 of the fourth annular gap 175, the fourth annular gap 175 has a labyrinth shape, so that external leakage can be reduced compared to the first embodiment.

(10th Embodiment)
As shown in FIG. 16, in the tenth embodiment of the present invention, the annular rib portion 182 of the rear plate 181 and the inner wall of the annular groove 184 of the vane rotor 183 form a fourth annular gap 185 having no refraction portion. The annular rib portion 182 corresponds to an “annular rib” recited in the claims. The fourth annular gap 185 has two bent portions 186 and 187. Thus, even if the fourth annular gap 185 does not have a refracting portion, since the fourth annular gap 185 has a maze shape, external leakage can be reduced from the first embodiment.

(Eleventh embodiment)
As shown in FIG. 17, in the eleventh embodiment of the present invention, the front cover 190 is integrally formed from an annular plate portion 191 and an annular rib portion 193. The annular plate portion 191 has a plate shape that closes one end of the cylindrical portion 16 of the shoe housing 14, and forms a first annular gap 192 between the annular plate portion 191 and the camshaft 218. The annular plate portion 191 corresponds to a “first plate” recited in the claims.

  The annular rib portion 193 protrudes integrally from the radially inner end portion of the annular plate portion 191 toward the vane rotor 195 side, and forms a third annular gap 194 between the annular rib portion 193 and the camshaft 218. The annular rib portion 193 corresponds to the “annular rib” recited in the claims.

The boss portion 196 of the vane rotor 195 has an annular groove 198 into which the annular rib portion 193 is inserted and a fourth annular gap 197 is formed between the boss portion 196 and the annular rib portion 193. The fourth annular gap 197 is a maze-like gap having two refracting portions 199.
According to the eleventh embodiment, since the maze-like fourth annular gap 197 having two refracting portions 199 is formed, external leakage is further reduced as compared with the first embodiment.

(Twelfth embodiment)
As shown in FIG. 18, in the twelfth embodiment of the present invention, the vane rotor 220 is fixed to the camshaft 222 by bolts 221. A third annular gap 224 is formed between the annular rib portion 103 of the front cover 100 and the center washer 223 that is fastened together with the bolt 221. The center washer 223 corresponds to a “fixing member” recited in the claims.
According to the twelfth embodiment, since the annular rib portion 103 increases the rigidity of the annular plate portion 101 and lengthens the outflow path, external leakage is reduced as in the first embodiment.

(Other embodiments)
In the second embodiment, the eleventh embodiment, and the twelfth embodiment, the annular rib portion is provided on both the front cover and the rear cover. On the other hand, in other embodiments, the annular rib portion may be provided only on the front cover.
In another embodiment, an annular rib portion protruding toward the vane rotor side may be provided on both the front cover and the rear cover.
Moreover, in other embodiment, the shape as shown in FIGS. 10-16 may be sufficient as the cyclic | annular rib part which a front cover has.
In another embodiment of the present invention, in the form in which the vane rotor is fixed to the camshaft by a bolt, the annular rib portion may be provided on one of the front cover and the rear cover. Further, the annular rib portion may be provided so as to protrude to the vane rotor side.
In another embodiment of the present invention, the fixing member may be a member other than the center washer.

In another embodiment of the present invention, the shoe housing may be composed of the same member as the front cover or the rear cover.
In another embodiment of the present invention, the number of vane portions of the vane rotor and the shoe portions of the shoe housing may be three or less, or five or more.
In another embodiment of the present invention, a gear that can rotate integrally with the shoe housing and is driven by the crankshaft via the chain may be provided on the front cover or the rear cover.

In another embodiment of the present invention, what is wound around the gear of the clan shaft or the gear of each camshaft is not limited to the chain, and may be another transmission member such as a belt.
In another embodiment of the present invention, the oil passage switching valve may employ a driving system other than the electromagnetic type. For example, a direct acting type operated by an electric cylinder or the like, or a pilot actuating type may be used. The oil passage switching valve may be provided inside the camshaft or may be provided outside.

In another embodiment of the present invention, the valve timing adjusting device may adjust the opening / closing timing of the exhaust valve.
The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from the spirit of the invention.

12 ... Valve timing adjusting device 14 ... Shoe housing (housing)
28, 30, 32, 34 ... advance chamber 36, 38, 40, 42 ... retard chamber 44, 113, 120, 130, 140, 173, 183, 195 ... vane rotor 46, 114, 121 , 131, 141, 196... Boss part 52, 54, 56, 58 .. vane part 66... Front cover (first plate)
70, 102, 192 ... first annular gap 74 ... annular plate (second plate)
80 ... second annular gap 82, 103, 111, 124, 151, 161, 172, 182, 193 ... annular rib (annular rib)
86, 104, 112, 194, 224 ... third annular gap 101, 191 ... annular plate (first plate)
223 ... Center washer (fixing member)
206 ... Crankshaft (drive shaft)
218 ... Camshaft (driven shaft)

Claims (5)

A valve timing adjusting device that adjusts the opening / closing timing of an intake valve or an exhaust valve that is driven to open and close by changing a rotational phase between a driving shaft and a driven shaft of an engine,
A cylindrical member disposed coaxially with the driven shaft, and a housing that rotates integrally with the drive shaft;
A plate-like member having a thickness in the axial direction of the driven shaft, the driven shaft or a fixed member fixed to the driven shaft is inserted, and a first annular gap is formed between the driven shaft or the fixed member. A first plate formed and secured to one end of the housing;
A plate-like member having a thickness in the axial direction of the driven shaft, a second annular gap is formed between the driven shaft and the driven shaft, and is fixed to the other end of the housing. Plates,
A boss portion fixed integrally with the driven shaft in the housing and supported so as to be relatively rotatable by an inner wall of the housing, and extending radially outward from the boss portion, between the housing and the boss portion A vane portion that divides the space into an advance chamber and a retard chamber in the circumferential direction, and the advance side or the retard side with respect to the housing according to a pressure difference of hydraulic oil between the advance chamber and the retard chamber. A vane rotor rotatable to the corner side;
A third annular gap is formed between the driven plate or the fixed member by integrally projecting from the inner diameter end of at least one of the first plate and the second plate to the vane rotor side or the opposite side of the vane rotor. An annular rib to
A valve timing adjusting device comprising:   The valve timing adjusting device according to claim 1, wherein the annular rib protrudes on a side opposite to the vane rotor. The annular rib protrudes toward the vane rotor;
2. The valve timing adjusting device according to claim 1, wherein the boss portion of the vane rotor has an annular groove into which the annular rib is inserted and a fourth annular gap is formed between the boss portion and the annular rib.   The valve timing adjusting device according to claim 3, wherein the fourth annular gap is a maze-like gap having at least one bent portion or a refracting portion.   5. The valve timing adjusting device according to claim 3, wherein the fourth annular gap includes a throttle section in which a passage area is reduced between the advance chamber and the retard chamber and an external space.

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