JP2010038136A - Valve timing adjusting device and its installing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve timing adjusting device securing the relative turn of bearings. <P>SOLUTION: The first bearing 81 is formed of a first outer wall 71 of a camshaft 7 in the radially outward direction and a first inner wall 122 of a sprocket 12 having a shaft hole 121 for bearing the first outer wall 71. The second bearing 82 is formed of a second outer wall 67 of a vane rotor 16 in the radially outward direction and a second inner wall 137 of a housing 11 for bearing the second outer wall 67. Deformable interference materials 83, 84 are formed on at least one of the first bearing 81 and the second bearing 82 to absorb the radial expansion of the camshaft 7 caused by the fastening of a center bolt 21. This suppresses pinch between one side of the first bearing part 81 in the radial direction and the other side of the second bearing part 82 which faces one side thereof across the axial center in the radial direction when projecting on a plane perpendicular to the axial center. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a valve timing adjusting device that adjusts the opening / closing timing (hereinafter, “opening / closing timing”) of at least one of an intake valve and an exhaust valve of an internal combustion engine, and an assembling method thereof.

  Conventionally, a sprocket that receives a driving force of a crankshaft of an internal combustion engine (hereinafter referred to as “engine”) and a vane rotor that is housed in a housing connected to the sprocket and transmits the driving force of the crankshaft to a camshaft, By adjusting the pressure of the working fluid supplied to the retard chamber and advance chamber, the vane rotor is driven to rotate relative to the housing on the retard side or advance side, and the camshaft phase relative to the crankshaft, that is, the valve timing. There is known a valve timing adjusting device that adjusts (see Patent Document 1).

Such a valve timing adjusting device that receives the driving force of the crankshaft on the sprocket includes a first bearing portion formed by the camshaft and the sprocket, and a second bearing portion formed by the vane rotor and the housing. The inclination of the shaft and the rotating shaft of the vane rotor is prevented.
However, in assembling the valve timing adjusting device, for example, as shown in FIG. 7A, when the housing 11, the sprocket 12, the vane rotor 16, and the bush 22 fitted to the vane rotor are fixed to the camshaft 9, the housing, etc. The sprocket 12 comes into contact with the upper portion of the camshaft 9 due to its own weight. When the center bolt 21 is tightened in this state, as shown in FIG. 7B, the camshaft 9 is compressed and expanded in the radial direction by the axial force of the center bolt 21, and the camshaft 9, the vane rotor 16 and the bush 22 are On the other hand, the sprocket 12 and the housing 11 move together in the direction of the arrow 100. Then, the upper side of the first bearing portion 81 and the lower side of the second bearing portion 85 are twisted, and the first and second bearing portions 81 and 85 may not rotate smoothly.

  To solve this problem, as shown in FIG. 8, these components are assembled using precision jigs 41 and 42 for positioning the vane rotor 16, the housing 11, and the sprocket 12, and thereafter, as shown in FIG. 9. It has been considered that the vane rotor 16 and the camshaft 9 are assembled using the precision jig 43 for positioning the housing 11 and the camshaft 9.

  In Patent Document 2, a structure is considered in which the vane rotor and the housing are aligned by a leaf spring that urges the seal member. However, if the second bearing portion is not formed, the sprocket and camshaft will be twisted when the sprocket teeth are overhanged with respect to the first sliding portion. And the first sliding portion should be substantially on the same line, ”“ Because there is a frictional force between the vane rotor and the housing, it is necessary to increase the biasing force of the leaf spring to some extent, ”“ the resultant force of each leaf spring. There were restrictions on the design of the sprocket and leaf spring, such as “the center of the vane rotor must be set”.

JP 2000-02106 A JP 2000-170511 A

An object of the present invention is to provide a valve timing adjusting device that secures relative rotation of a bearing portion and an assembling method thereof.
An object of the present invention is to provide a valve timing adjusting device and an assembling method thereof that simplify the manufacturing process.

According to the first aspect of the present invention, the first bearing portion is formed by the radially outer first outer wall of the driven shaft and the first inner wall that forms the shaft hole of the sprocket and supports the first outer wall. A second bearing portion is formed by the second outer wall in the radially outward direction of the vane rotor and the second inner wall of the housing that supports the second outer wall. The deformable interference material formed on at least one of the first bearing portion and the second bearing portion is deformed when the vane rotor accommodated between the sprocket and the housing is fixed to the driven shaft by the center bolt. It absorbs the radial expansion of the driven shaft due to the axial force of tightening the center bolt. As a result, the deformable interference member has a force that the expansion in the radial direction of the driven shaft acts on one side in the radial direction of the first bearing portion, and the one side and the shaft when projected on a plane perpendicular to the shaft center. The force acting on the other side of the second bearing portion facing the radial direction across the center is absorbed. For this reason, the twisting of the first bearing portion and the second bearing portion is suppressed, and the relative rotation of the first bearing portion and the second bearing portion can be ensured.
Here, the deformable interference material refers to a member that can be elastically deformed or plastically deformed by expansion of the driven shaft and prevents interference between opposing members.

According to the second aspect of the present invention, the total thickness of the deformable interference members formed in the first bearing portion and the second bearing portion is formed larger than the expansion amount of the radius of the driven shaft. Therefore, direct contact between the first inner wall and the first outer wall forming the first bearing portion is avoided, and direct contact between the second inner wall and the second outer wall forming the second bearing portion is avoided. The Thereby, the friction of each bearing part reduces and the relative rotation of a 1st bearing part and a 2nd bearing part is securable.
According to the invention described in claim 3, the deformable interference material is formed including any one of the group consisting of rubber, silicon, resin, paper, wood, soft plating and soft anodized.

According to the invention described in claim 4, the removable surface treatment layer is such that when the driven shaft expands in the radial direction by tightening the center bolt, the surface treatment layer itself breaks down, so that the radial direction of the first bearing portion It is possible to absorb the force acting on one side and the force acting on the other side of the second bearing portion facing the radial direction across the one side and the shaft center when projected onto a plane perpendicular to the shaft center. .
Here, the surface treatment layer that can be removed refers to a surface treatment layer that can be removed or peeled off by the surface treatment layer itself being destroyed by expansion of the driven shaft.
According to the fifth aspect of the present invention, the removable surface treatment layer includes any one of the group consisting of molybdenum disulfide, polytetrafluoroethylene, paint, polyfluorinated ethylene, and boron.

According to the sixth aspect of the present invention, the removable surface treatment layer is made of a material that can be melted into the working fluid.
According to the seventh aspect of the present invention, the vane rotor includes the cylindrical bush on the axially driven shaft side, and the front plate has the shaft hole through which the bush passes. The second outer wall is an outer wall of the bush, and the second inner wall is an inner wall that forms a shaft hole of the front plate.

  According to the invention described in claim 8 or 9, the deformable interference member or the detachable surface treatment layer absorbs the expansion of the driven shaft due to the axial force tightening the center bolt. Therefore, the manufacturing process can be simplified by performing assembly without using a precision jig for positioning the housing, the chain sprocket and the vane rotor, and a precision jig for positioning the housing and the camshaft.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
A valve timing adjusting apparatus according to a first embodiment of the present invention is shown in FIGS. As shown in FIG. 3, in the driving force transmission system, a chain is connected to a gear 98 fixed to a crankshaft 8 as a driving shaft of the engine 6 and gears 97 and 99 fixed to camshafts 7 and 9 as driven shafts. 5 is wound around and the driving force is transmitted from the crankshaft 8 to the camshafts 7 and 9. One camshaft 7 drives the intake valve 93 to open and close, and the other camshaft 9 drives the exhaust valve 92 to open and close. The valve timing adjusting device 10 of this embodiment is a hydraulic control type that uses hydraulic oil as a working fluid, and connects the sprocket gear 97 to the chain 5 and the vane rotor to the camshaft 7 to adjust the valve timing of the intake valve 93. To do.

As shown in FIGS. 1 and 2, the valve timing adjustment device 10 includes a sprocket 12, a housing 11, a vane rotor 16, and the like.
The sprocket 12 is formed by sintering or forging with iron or aluminum, for example, and has a shaft hole 121 through which the camshaft 7 is passed in the axial direction.
The housing 11 is formed of, for example, iron or aluminum by sintering or forging. The housing 11 includes a shoe housing 13 and a front plate 14. In the shoe housing 13, shoes 131 to 134 as partition members and an annular peripheral wall 130 are integrally formed. The shoes 131 to 134 formed in a substantially trapezoid shape extend radially inward from the peripheral wall 130 and are provided at substantially equal intervals in the rotation direction of the peripheral wall 130. A fan-shaped storage chamber 50 is formed in the gap between the shoes adjacent in the rotation direction. The shoe housing 13 and the front plate 14 are fixed coaxially with the sprocket 12 by bolts 19.

  The vane rotor 16 is formed of, for example, iron or aluminum by sintering or forging, and is accommodated between the housing 11 and the sprocket 12 so as to be relatively rotatable. The vane rotor 16 includes a cylindrical rotor 60 and four vanes 61 to 64 that protrude from the rotor 60 in a radially outward direction and are installed at substantially equal intervals in the circumferential direction. The outer diameters of the vanes 61 to 64 are set smaller than the inner diameter of the peripheral wall 130. The outer diameter of the rotor 60 is set smaller than the inner diameters of the shoes 131 to 134.

  Each of the vanes 61 to 64 bisects each of the storage chambers 50 into a retard hydraulic chamber as a retard chamber and an advance hydraulic chamber as an advance chamber. An advance hydraulic chamber 55 is formed between the shoe 131 and the vane 61, an advance hydraulic chamber 56 is formed between the shoe 132 and the vane 62, and an advance hydraulic chamber 57 is formed between the shoe 133 and the vane 63. The advance hydraulic chamber 58 is formed between the shoe 134 and the vane 64. A retard hydraulic chamber 51 is formed between the shoe 132 and the vane 61, a retard hydraulic chamber 52 is formed between the shoe 133 and the vane 62, and a retard hydraulic chamber 53 is formed between the shoe 134 and the vane 63. The retard hydraulic chamber 54 is formed between the shoe 131 and the vane 64. The arrows representing the retard direction and the advance direction shown in FIG. 2 represent the retard direction and the advance direction of the vane rotor 16 with respect to the housing 11.

  A retard oil passage 101 and an advance oil passage 110 are formed inside the camshaft 7 and the vane rotor 16. The hydraulic oil is supplied from the retard oil passage 101 to each retard hydraulic chamber 51 to 54, and the hydraulic oil is supplied from the advance oil passage 110 to each advance hydraulic chamber 55 to 58. The vane rotor 16 is rotated relative to the housing 11 by switching the supply and discharge of the hydraulic oil to and from the oil passages 101 and 110, and the phase difference of the camshaft 7 with respect to the crankshaft 8 is adjusted.

The camshaft 7 is inserted into a shaft hole 121 formed in the sprocket 12. The axial end surface 79 of the camshaft 7 and the axial end surface 69 of the vane rotor 16 are in contact with each other. The vane rotor 16 and the camshaft 7 are fixed by tightening the center bolt 21 through the bolt hole 68 of the vane rotor 16 and the screw hole 73 of the camshaft 7. Positioning of the vane rotor 16 and the camshaft 7 in the rotational direction is performed by fitting the positioning pin 18 into a pin hole 66 provided in the rotor 60 and a pin hole 72 provided in the camshaft 7.
The housing 11, the vane rotor 16 and the camshaft 7 rotate in the clockwise direction when viewed from the arrow X direction shown in FIG. This rotation direction is defined as an advance direction.

The first outer wall 71 in the radially outward direction of the camshaft 7 is supported by a first inner wall 122 that forms the shaft hole 121 of the sprocket 12. Before the center bolt 21 is fastened to the camshaft 7, a clearance of, for example, 10 to 50 μm is formed between the first outer wall 71 and the first inner wall 122. When the center bolt 21 is fastened to the camshaft 7, the camshaft 7 is compressed by an axial force, and expands, for example, 10 to 20 μm in the radial direction by the material, the outer diameter, and the fastening torque.
The second outer wall 67 in the radially outer direction of the rotor 60 is supported by the second inner walls 135 to 138 in the radially inner direction of the shoes 131 to 134. A clearance of, for example, 10 to 20 μm is formed between the second outer wall 67 and the second inner walls 135 to 138 before the center bolt 21 is fastened to the camshaft 7.
A first bearing portion 81 is formed by the first outer wall 71 and the first inner wall 122. A second bearing portion 82 is formed by the second outer wall 67 and the second inner walls 135 to 138. The first bearing portion 81 and the second bearing portion 82 are configured so that the inclination of the rotating shaft of the housing and the rotating shaft of the vane rotor is inclined in the valve timing adjusting device 10 that receives driving force from the crankshaft 8 via the chain 5 to the sprocket 12. It is preventing.

  As shown in FIG. 4, a deformable interference member 83 is formed on one of the first outer wall 71 and the first inner wall 122 that form the first bearing portion 81. The interference material 83 is formed including soft plating such as rubber, silicon, resin, paper, crushed wood, copper, soft anodized, and the like. When the center bolt 21 is fastened to the camshaft 7, the interference member 83 is formed thicker than the camshaft 7 expands in the radial direction, and before the center bolt 21 is fastened to the camshaft 7, the interference member 83 is a thin place on the entire circumference. For example, it is formed thicker than 20 μm.

  A deformable interference member 84 is formed on one of the second outer wall 67 and the second inner walls 135 to 138 forming the second bearing portion 82. Before the center bolt 21 is fastened to the camshaft 7, the thickness of the interference member 84 is set to 20 μm, for example. The total thickness of the interference member 83 formed on the first bearing portion 81 and the interference member 84 formed on the second bearing portion 82 is formed larger than the amount of expansion of the radius of the camshaft 7. Just do it.

  The seal member 28 is formed of, for example, resin, and is fitted to the outer walls of the vanes 61 to 64 in the radially outward direction. The seal member 28 is urged toward the peripheral wall 130 by the urging force of the leaf spring 29, and each advance hydraulic chamber 55 to 58 passes between the radially outer wall of each vane 61 to 64 and the peripheral wall 130. And the hydraulic oil chambers 51 to 54 are prevented from leaking.

  The stopper piston 30 is formed in a bottomed cylindrical shape, and is accommodated in a hole formed so as to penetrate the vane 61 in the rotation axis direction so as to be reciprocally movable in the rotation axis direction. The stopper piston 30 houses a spring 34 therein. The spring 34 biases the stopper piston 30 toward the sprocket 12 side. A fitting ring 36 is press-fitted and held in a recess formed on the vane 61 side of the sprocket 12.

  The pressure of the hydraulic oil supplied to the pressure chamber 32 formed on the sprocket 12 side of the stopper piston 30 and the pressure chamber 33 formed on the outer periphery of the stopper piston 30 works in the direction in which the stopper piston 30 comes out from the fitting ring 36. . The pressure chamber 32 communicates with the advance hydraulic chamber 55, and the pressure chamber 33 communicates with the retard hydraulic chamber 51. The tip of the stopper piston 30 can be fitted into the fitting ring 36 when the vane rotor 16 is positioned at the most retarded position with respect to the housing 11. In a state where the stopper piston 30 is fitted to the fitting ring 36, the relative rotation of the vane rotor 16 with respect to the housing 11 is restricted.

Next, the assembly process of the valve timing adjusting device 10 will be described.
<Interference material formation process>
Deformable interference members 83 and 84 are formed on at least one of the first bearing portion 81 and the second bearing portion 82.
A case where the interference member 83 is formed on the first bearing portion 81 will be described. In the case of the interference material 83 including rubber, silicon, and resin, the interference material 83 is formed by applying rubber, silicon, or resin to one of the first outer wall 71 and the first inner wall 122, and spraying, dripping, or the like. . In the case of an interference material including paper and crushed wood, it is formed by adhering paper and crushed wood to one of the first outer wall 71 and the first inner wall 122. In the case of the interference material 83 by soft plating, it is formed by electroplating one of the first outer wall 71 and the first inner wall 122 with, for example, copper. The interference material 83 made of soft alumite is formed by anodizing one of the first outer wall 71 and the first inner wall 122 made of aluminum. After the above process, the thickness of the interference member 83 is adjusted by passing a cylindrical member having a predetermined diameter through the first outer wall 71 or the first inner wall 122 on which the interference member 83 is formed.
When the deformable interference member 84 is formed on the second bearing portion 82, the above-described process is performed on one of the second outer wall 67 and the second inner walls 135 to 138.

<Vane rotor assembly process>
The sprocket 12 is inserted into a jig corresponding to the camshaft (see the lower jig 42 in FIG. 8). Next, the vane rotor 16 and the shoe housing 13 are installed on the sprocket 12 and the front plate 14 is covered. The vane rotor 16, the shoe housing 13 and the front plate 14 are fixed with bolts 19.

<Camshaft installation process>
After the vane rotor assembly process, the camshaft 7 is inserted into the shaft hole 121 of the sprocket 12. The axial end surface 79 of the camshaft 7 abuts on the axial end surface 69 of the vane rotor 16. The center bolt 21 is passed through the bolt hole 68 of the vane rotor 16 from the front plate 14 side and tightened into the screw hole 73 of the camshaft 7.
At this time, the interference members 83 and 84 formed on at least one of the first bearing portion 81 and the second bearing portion 82 are deformed to absorb the expansion in the radial direction of the camshaft due to the axial force of tightening the center bolt 21. To do. Therefore, the assembly can be performed without using the precision jig for positioning the housing 11, the sprocket 12 and the vane rotor 16, and the precision jig for positioning the housing 11 and the camshaft 7, thereby simplifying the manufacturing process.

Next, the operation of the valve timing adjusting device 10 will be described. 1 and 2 show a state of the valve timing adjusting device 10 before the engine is started, that is, when the engine 6 is stopped.
<When starting the engine>
When the engine 6 is stopped, the stopper piston 30 enters the fitting ring 36. In the state immediately after starting the engine 6, the hydraulic oil is not sufficiently supplied from the hydraulic pump 1 to the retard hydraulic chambers 51 to 54, the advance hydraulic chambers 55 to 58, and the pressure chambers 32 and 33. For this reason, the stopper piston 30 maintains the state of entering the fitting ring 36, and the camshaft 7 is held at the most retarded position with respect to the crankshaft 8. As a result, the occurrence of a hitting sound due to the collision between the housing 11 and the vane rotor 16 due to the torque fluctuation received by the camshaft 7 is prevented until the hydraulic oil is supplied to each hydraulic chamber.

<After starting the engine>
When the hydraulic oil is sufficiently supplied from the hydraulic pump 1 after the engine is started, the stopper piston 30 comes out of the fitting ring 36 by the hydraulic pressure supplied to the pressure chambers 32 and 33, and the vane rotor 16 rotates relative to the housing 11. Be free. By controlling the hydraulic pressure applied to each retarded hydraulic chamber 51 to 54 and each advanced hydraulic chamber 55 to 58, the phase difference of the camshaft 7 with respect to the crankshaft 8 can be adjusted.

<At retarded angle operation>
When the valve timing adjusting device 10 is retarded, the electronic control unit (ECU) 4 controls the drive current supplied to the switching valve 3. The switching valve 3 connects the hydraulic pump 1 and the retard oil passage 101, and connects the advance oil passage 110 and the oil pan 2. The hydraulic oil discharged from the hydraulic pump 1 is supplied to the retarded hydraulic chambers 51 to 54 via the retarded oil passage 101. The hydraulic oil in the advance hydraulic chambers 55 to 58 is discharged to the oil pan 2 via the advance oil passage 110. The hydraulic pressure in the retarded hydraulic chambers 51-54 acts on the vanes 61-64, generating torque that biases the vane rotor 16 in the retarded direction. As a result, the vane rotor 16 rotates in the retarding direction with respect to the housing 11.

<Advance angle operation>
When the valve timing adjusting device 10 is advanced, the ECU 4 controls the drive current supplied to the switching valve 3. The switching valve 3 connects the hydraulic pump 1 and the advance oil passage 110, and connects the retard oil passage 101 and the oil pan 2. The hydraulic oil discharged from the hydraulic pump 1 is supplied to the advance hydraulic chambers 55 to 58 via the advance oil passage 110. The hydraulic oil in the retarded hydraulic chambers 51 to 54 is discharged to the oil pan 2 via the retarded oil passage 101. The hydraulic pressure in the advance hydraulic chambers 55 to 58 acts on the vanes 61 to 64 to generate torque that urges the vane rotor 16 in the advance direction. As a result, the vane rotor 16 rotates in the advance direction with respect to the housing 11.

<Intermediate holding operation>
When the vane rotor 16 reaches the target phase, the ECU 4 controls the duty ratio of the drive current supplied to the switching valve 3. The switching valve 3 cuts off the connection between the hydraulic pump 1 and the retard oil passage 101 and the advance oil passage 110, and hydraulic oil is supplied to the oil pan 2 from the retard hydraulic chambers 51 to 54 and the advance hydraulic chambers 55 to 58. Is controlled to be discharged. For this reason, the vane rotor 16 is held at the target phase.

<Operation when the engine is stopped>
When the engine stop is instructed during the operation of the valve timing adjusting device 10, the vane rotor 16 rotates in the retard direction with respect to the housing 11 by the same operation as that in the retard operation, and rotates at the most retarded position. Stops. In this state, the ECU 4 stops the operation of the hydraulic pump 1 and connects the retarded oil passage 101 and the oil pan 2 by the switching valve 3. As a result, the pressure in the pressure chamber 33 decreases, and the stopper piston 30 enters the fitting ring 36 by the biasing force of the spring 34.

  In the present embodiment, when the camshaft 7 is compressed by the axial force of tightening the center bolt 21 and expands in the radial direction, the deformable interference members 83 and 84 are deformed, whereby the radial direction of the first bearing portion 81 is obtained. The force applied to one side and the force applied to the other side of the second bearing portion 82 facing the radial direction across the one side and the axis center when projected onto a plane perpendicular to the axis center are absorbed. The deformable interference material is such that the first inner wall 122 and the first outer wall 71 that form the first bearing portion 81 are in direct contact with each other, and the second inner walls 135 to 138 that form the second bearing portion 82 and the first 2 Prevents the outer wall 67 from coming into direct contact and reduces the friction of the first and second bearing portions 81 and 82. Therefore, the twist generated by the force applied to one side in the radial direction of the first bearing portion 81 and the force applied to the other side of the second bearing portion 82 is suppressed, and the relative relationship between the first bearing portion 81 and the second bearing portion 82 is suppressed. Rotation can be ensured.

(Second Embodiment)
The second embodiment is a modification of the first embodiment. Either one of the first outer wall 71 and the first inner wall 122 forming the first bearing portion 81 is provided with a removable surface treatment layer instead of the deformable interference material of the first embodiment. The surface treatment layer is formed including molybdenum disulfide, polytetrafluoroethylene (PTFE), coating, polyfluorinated ethylene, boron, and the like.
A removable surface treatment layer is formed on one of the second outer wall 67 and the second inner walls 135 to 138 forming the second bearing portion 82. The total thickness of the surface treatment layer formed on the first bearing portion 81 and the surface treatment layer formed on the second bearing portion 82 is the amount of expansion of the radius of the camshaft 7 when the center bolt 21 is tightened. It is formed larger than this.

Next, the formation process of the surface treatment layer in the assembly | attachment process of the valve timing adjustment apparatus of 2nd Embodiment is demonstrated.
A removable surface treatment layer is formed on at least one of the first bearing portion 81 and the second bearing portion 82. The case where a surface treatment layer is formed in the 1st bearing part 81 is demonstrated. In the case of a surface treatment layer containing molybdenum disulfide, the surface treatment layer is formed by attaching or applying a molybdenum disulfide seal to one of the first outer wall 71 and the first inner wall 122. In the case of a surface treatment layer containing PTFE, coating, polyfluorinated ethylene, and boron, it is formed by coating or the like on one of the first outer wall 71 and the first inner wall 122. After the above-described steps, the thickness of the surface treatment layer is adjusted by passing a cylindrical member having a predetermined diameter through the first outer wall 71 or the first inner wall 122 on which the surface treatment layer is formed.
When the surface treatment layer that can be removed is formed on the second bearing portion 82, the above-described steps are performed on the second outer wall 67 or the second inner walls 135 to 138 on which the surface treatment layer is formed.

  In this embodiment, since a removable surface treatment layer is formed on at least one of the first bearing portion 81 and the second bearing portion 82, the camshaft expands in the radial direction by tightening the center bolt 21. When the surface treatment layer itself is destroyed, the force applied to one side of the first bearing portion 81 in the radial direction, and when projected onto a plane perpendicular to the shaft center, the one side and the shaft center are sandwiched in the radial direction. A force applied to the other side of the second bearing portion 82 facing each other can be absorbed.

(Third embodiment)
A valve timing adjusting apparatus according to a third embodiment is shown in FIGS. Components substantially the same as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.
In the valve timing adjusting device 20 of the third embodiment, a recess 65 is formed on the vane rotor 16 on the side opposite to the cam shaft in the axial direction, and a bush 22 formed in a bottomed cylindrical shape is fitted in the recess 65. The bush 22 passes through a shaft hole 15 formed in the front plate 14. The outer wall 23 in the radially outward direction of the bush 22 is supported by an inner wall 141 that forms the shaft hole 15 of the front plate 14. A clearance of, for example, 10 to 20 μm is formed between the outer wall 23 and the inner wall 141 before the center bolt 21 is fastened to the camshaft 7. In the present embodiment, the second bearing portion 85 is formed by the outer wall 23 and the inner wall 141.

A deformable interference member 84 is formed on one of the radially outer wall 23 of the bush 22 forming the second bearing portion 85 and the inner wall 141 forming the shaft hole 15 of the front plate 14. Before the center bolt 21 is fastened to the camshaft 7, the thickness of the interference member 84 is set to 20 μm, for example. The total thickness of the interference member 83 formed on the first bearing portion 81 and the interference member 84 formed on the second bearing portion 82 only needs to be larger than the expansion of the radius of the camshaft 7.
Since the assembly process and operation of the valve timing adjusting device 20 are substantially the same as those in the first embodiment, description thereof is omitted.

  In the present embodiment, when the camshaft 7 is expanded in the radial direction by tightening the center bolt 21, the deformable interference members 83 and 84 are deformed, and thereby the force applied to one side in the radial direction of the first bearing portion 81. And, when projected onto a plane perpendicular to the axis center, the force applied to the other side of the second bearing portion 85 facing the radial direction across the one axis and the axis center is absorbed. The deformable interference material is such that the first inner wall 122 and the first outer wall 71 that form the first bearing portion 81 are in direct contact with each other, and the outer wall in the radially outward direction of the bush 22 that forms the second bearing portion 85. 23 and the inner wall 141 forming the shaft hole 15 of the front plate 14 are prevented from coming into direct contact, and the friction of the first and second bearing portions 81 and 85 is reduced. Accordingly, the twisting caused by the one side in the radial direction of the first bearing portion 81 and the force applied to the other side of the second bearing portion 85 is suppressed, and the relative rotation of the first bearing portion 81 and the second bearing portion 85 is prevented. Can be secured.

(Other embodiments)
In the second embodiment, a removable surface treatment layer containing molybdenum disulfide or the like is formed on at least one of the first bearing portion 81 and the second bearing portion 82. On the other hand, a surface treatment layer that can be melted in the working fluid may be formed on at least one of the first bearing portion 81 and the second bearing portion 82. The surface treatment layer that can be melted into the working fluid is formed including, for example, wax.
In the third embodiment, a deformable interference material is formed on at least one of the first bearing portion 81 and the second bearing portion 85. In contrast, a surface treatment layer that can be removed or a surface treatment layer that can be melted into the working fluid may be formed on at least one of the first bearing portion 81 and the second bearing portion 85.
In the above embodiment, the valve timing adjusting device that controls the intake valve of the internal combustion engine has been described. On the other hand, you may apply this invention to the valve timing adjustment apparatus which controls the exhaust valve of an internal combustion engine.
As described above, the present invention is not limited to the above-described embodiment, and can be applied to other various embodiments in addition to combining the plurality of embodiments without departing from the gist thereof.

Sectional drawing which shows the valve timing adjustment apparatus by 1st Embodiment of this invention. II-II sectional view taken on the line of FIG. The schematic diagram which shows the valve timing adjustment apparatus by 1st Embodiment of this invention. The schematic diagram which shows the principal part of the valve timing adjustment apparatus by 1st Embodiment of this invention. Sectional drawing which shows the valve timing adjustment apparatus by 2nd Embodiment of this invention. VI-VI sectional view taken on the line of FIG. The schematic diagram which shows the conventional valve timing adjustment apparatus. The schematic diagram which shows the conventional valve timing adjustment apparatus. The schematic diagram which shows the assembly | attachment method of the conventional valve timing adjustment apparatus. The schematic diagram which shows the assembly | attachment method of the conventional valve timing adjustment apparatus.

Explanation of symbols

  6: engine (internal combustion engine), 7: camshaft (driven shaft), 8: crankshaft (drive shaft), 10: valve timing adjusting device, 11: housing, 12: sprocket, 14: front plate, 16: vane rotor, 21: Center bolt, 50: Storage chamber, 51, 52, 53, 54: Retarded hydraulic chamber (retarded chamber), 55, 56, 57, 58: Advanced hydraulic chamber, 67: Second outer wall, 71: First 1 outer wall, 81: first bearing portion, 82: second bearing portion, 83, 84: interference material, 92: intake valve, 93: exhaust valve, 121: shaft hole, 122: first inner wall, 130: peripheral wall, 131 132, 133, 134: Shoe (partition member), 135, 136, 137, 138: Second inner wall

Claims (9)

Provided in a driving force transmission system for transmitting a driving force from a driving shaft of an internal combustion engine to a driven shaft that opens and closes at least one of an intake valve and an exhaust valve, and adjusts an opening / closing timing of at least one of the intake valve and the exhaust valve In the valve timing adjustment device,
A sprocket having a shaft hole through which the driven shaft passes, and rotating by being transmitted with a driving force of the driving shaft;
An annular peripheral wall, a partition member extending inwardly from the peripheral wall and provided in a predetermined angle range in the rotational direction, and a front plate connected to one axial end of the peripheral wall, the other axial end of the peripheral wall being A housing fixed to the sprocket;
A storage chamber formed between the partition members adjacent to each other in the rotation direction is partitioned to form an advance chamber and a retard chamber, and retarded by the pressure of the working fluid supplied to the advance chamber and the retard chamber A vane rotor that is driven in a direction or an advance direction and rotates relative to the housing;
A first bearing portion formed by a first outer wall in a radially outward direction of the driven shaft and a first inner wall that forms the shaft hole of the sprocket and receives the first outer wall;
A second bearing portion formed by a radially outer second outer wall of the vane rotor and a second inner wall of the housing bearing the second outer wall;
Formed in at least one of the first bearing portion and the second bearing portion;
When the vane rotor accommodated between the sprocket and the housing is fixed to the driven shaft by a center bolt, the deformable interference that absorbs the radial expansion of the driven shaft due to the axial force of the center bolt tightening. Material,
A valve timing adjusting device comprising:   The total thickness of the deformable interference member formed in the first bearing portion and the second bearing portion is formed to be larger than an expansion amount of a radius of the driven shaft. Valve timing adjustment device.   The deformable interference material is formed to include any one of the group consisting of rubber, silicon, resin, paper, wood, soft plating, and soft anodized. Valve timing adjustment device. The valve timing adjusting device according to claim 1 or 2,
A valve timing adjusting device comprising a surface treatment layer that can be removed in place of the deformable interference material.   5. The removable surface treatment layer is formed by including any one of the group consisting of molybdenum disulfide, polytetrafluoroethylene, paint, polyfluorinated ethylene, and boron. Valve timing adjustment device.   The valve timing adjusting device according to claim 4, wherein the detachable surface treatment layer is made of a material that can be melted into the working fluid. The vane rotor is provided with a cylindrical bush on the axial anti-driven shaft side,
The front plate has a shaft hole through which the bush passes,
The valve timing according to any one of claims 1 to 6, wherein the second outer wall is an outer wall of the bush, and the second inner wall is an inner wall that forms the shaft hole of the front plate. Adjustment device. In the assembly method of the valve timing adjusting device according to claim 1,
Forming the deformable interference material on at least one of the first bearing portion and the second bearing portion;
Accommodating the vane rotor between the housing and the sprocket, and fixing the sprocket and the housing;
Inserting the driven shaft into the shaft hole of the sprocket, contacting the axial end surface of the driven shaft with the axial end surface of the vane rotor, and fastening the center bolt to fix the driven shaft and the vane rotor. And a method for assembling the valve timing adjusting device. In the assembly method of the valve timing adjusting device according to claim 8,
A method for assembling a valve timing adjusting device, wherein a removable surface treatment layer is formed instead of forming the deformable interference material.

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