JP7555866B2 - Valve timing change device - Google Patents

Description

The present invention relates to a valve timing change device that changes the opening and closing timing (valve timing) of the intake valve or exhaust valve of an internal combustion engine depending on the operating conditions.

A conventional valve timing change device is known that includes a housing that rotates synchronously with the crankshaft on the axis of the camshaft, a vane rotor that rotates integrally with the camshaft and can rotate within a predetermined angular range relative to the housing, and a bottomed cylindrical bush that fits into a concave fitting hole in the vane rotor, with the bush and vane rotor having a through hole centered on the axis to allow a fixing bolt to pass through (see, for example, Patent Document 1, etc.).

In this device, the vane rotor is fixed to the camshaft by threading a bolt through an opening in the housing and through holes in the bush and vane rotor and into the camshaft.
Here, if the vane rotor is formed from an aluminum material or the like that is softer than the bolts, the bushing can function as a washer. However, since the vane rotor has a concave fitting hole, machining the concave fitting hole increases costs.

Another known valve timing change device includes a housing that rotates synchronously with the crankshaft on the axis of the camshaft, and a vane rotor that rotates integrally with the camshaft and can rotate within a predetermined angular range relative to the housing, with the vane rotor having a through hole centered on the axis to allow a fixing bolt to pass through (see, for example, Patent Document 2, etc.).

In this device, a bolt is passed through an opening in the housing and a through hole in the vane rotor, and the head of the bolt is screwed into the camshaft so as to abut the front end face of the vane rotor, thereby fixing the vane rotor to the camshaft. Here, if the vane rotor is made of a material softer than the bolt, it is necessary to use a washer to suppress wear and deformation of the seat surface (contact area of the front end face) of the vane rotor.
However, in this device, the washer cannot be pre-assembled so that it will not fall off. In particular, if the device and the washer were to be provided as a product excluding the bolt and camshaft, this would result in poor handling convenience and increased management costs.

JP 2008-232010 A JP 2009-68448 A

In consideration of the problems with the conventional technology described above, the present invention aims to provide a valve timing change device that can reduce the cost of the device and improve ease of use.

a housing rotor that houses the vane rotor and is rotatable within a predetermined angular range relative to the vane rotor about the axis of the camshaft; and a washer that is interposed between an end face of the vane rotor and a head of a bolt when the bolt is tightened to secure the vane rotor to the camshaft. The housing rotor has a circular opening centered on the axis for passing the bolt, and a washer accommodating portion that holds the washer adjacent to the end face of the vane rotor to prevent it from falling off . The vane rotor includes a contact end face that contacts an inner wall surface of the housing rotor in the axial direction. The washer accommodating portion is formed as an annular recess around the opening to face the end face of the vane rotor in the axial direction. The end face of the vane rotor against which the washer abuts is defined on the same plane as the contact end face .

In the above variable valve timing device , the washer may have an outer diameter larger than that of the opening.

In the above valve timing change device, the vane rotor may include a circular through hole centered on the axis so that the bolt can pass through without contact, the washer may include a circular hole through which the threaded portion of the bolt passes, and the washer receiving portion may receive the washer movably in a direction perpendicular to the axis within a range in which the circular hole of the washer does not deviate from the area facing the through hole of the vane rotor.

In the above valve timing change device, the washer receiving portion may be configured to receive the washer movably in the axial direction within a gap that is smaller than the plate thickness of the washer.

In the above valve timing change device, the vane rotor may be made of an aluminum material, and the washer may be a flat washer made of an iron-based material.

In the above-mentioned valve timing change device, the housing rotor may be configured to include a cylindrical front housing with a bottom having an opening and a washer receiving portion, and a disk-shaped rear housing having a sprocket on its outer periphery and connected to the front housing.

In the above valve timing change device, the front housing may be formed as a die-cast or sintered body.

The valve timing change device configured as above can reduce the cost of the device and improve ease of use.

1 is an external perspective view showing a state in which a variable valve timing device according to an embodiment of the present invention is mounted on a camshaft of an internal combustion engine. 1 is an exploded perspective view, viewed obliquely from the front, showing a state before a variable valve timing device according to an embodiment of the present invention is mounted on a camshaft. FIG. 1 is an exploded perspective view of a valve timing changing device according to an embodiment of the present invention before it is mounted on a camshaft, as viewed obliquely from the rear. FIG. 1 is an exploded perspective view of a variable valve timing device according to an embodiment of the present invention, viewed obliquely from the front. FIG. 1 is an exploded perspective view of a variable valve timing device according to an embodiment of the present invention, viewed obliquely from the rear. FIG. 1 is a cross-sectional view showing a state in which a variable valve timing device according to an embodiment is attached to a camshaft of an internal combustion engine. 1 is a cross-sectional view showing a state in which a variable valve timing device according to an embodiment is attached to a camshaft of an internal combustion engine. 1 is a cross-sectional view showing a state in which a variable valve timing device according to an embodiment is attached to a camshaft of an internal combustion engine. 2 is a partial cross-sectional view showing the positional relationship between a housing rotor (front housing), a washer, and a vane rotor in a variable valve timing device according to one embodiment of the present invention. FIG. FIG. 4 is a rear view seen from inside the housing, illustrating the positional relationship between a housing rotor (front housing) and a washer in the variable valve timing device according to one embodiment. 4 shows an operation of mounting the variable valve timing device according to the embodiment on a camshaft. 4 shows an operation of mounting the variable valve timing device according to the embodiment on a camshaft. 4 shows an operation of mounting the variable valve timing device according to the embodiment on a camshaft. 4 is a cross-sectional view showing a state in which a vane rotor is in a most retarded position and an advance passage in the variable valve timing device according to the embodiment; FIG. 4 is a cross-sectional view showing a state in which a vane rotor is at a most advanced angle position and an advance passage communicating with an advance chamber in the variable valve timing device according to the embodiment; FIG. 4 is a cross-sectional view showing a state in which a vane rotor is in a most retarded position and a retard passage communicating with a retard chamber in a valve timing variable device according to one embodiment; FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
A valve timing change device M according to one embodiment is attached to a camshaft 1 of an internal combustion engine E as shown in FIG. 1, and includes a vane rotor 10, a housing rotor 20, a washer 30, and a locking mechanism 40 that locks the vane rotor 10 to the housing rotor 20 as shown in FIGS. 4 and 5.

The camshaft 1 is rotatably supported about an axis S by bearings formed in a cylinder head of the internal combustion engine E, and rotates in the direction of an arrow R to open and close the intake valve or the exhaust valve by cam action. As shown in Figures 2 and 3, the camshaft 1 is provided with a circular shaft portion 1a that rotatably supports a housing rotor 20, an advance passage 1b that supplies and discharges hydraulic oil, a retard passage 1c that supplies and discharges hydraulic oil, a female screw hole 1d into which a bolt B is screwed, and a fitting hole 1e into which a positioning pin P is fitted.
The bolt B is made of a hard ferrous metal material, and includes a head portion B ₁ with a flange, a threaded portion B ₂ , and a neck portion B ₃ .

In the valve timing changing device M, with the vane rotor 10 fixed to the camshaft 1 by the bolts B, the housing rotor 20 is linked to the rotation of the crankshaft via a chain or the like, and transmits the rotational driving force of the crankshaft to the camshaft 1 via the vane rotor 10. In addition, by being connected to a hydraulic control system 2 that controls the flow of hydraulic oil, the valve timing changing device M performs the function of changing the valve timing in the internal combustion engine E.
As shown in Figures 2 and 3, the hydraulic control system 2 is composed of a hydraulic control valve 2a that controls the flow of hydraulic oil discharged from the pump, an advance side passage 2b that connects the hydraulic control valve 2a and the advance passage 1b, a retard side passage 2c that connects the hydraulic control valve 2a and the retard passage 1c, and a control means (not shown) that controls the operation of the hydraulic control valve 2a.
Here, in the valve timing varying device M, the side where the bolt B is inserted is referred to as the "front side," and the side where the camshaft 1 is connected is referred to as the "rear side."

The vane rotor 10 is made of aluminum material, which is softer than iron-based materials, and as shown in Figures 4 and 5, has a front surface 10a and a rear surface 10b as end faces, four vane sections 11, a cylindrical hub section 12, a through hole 13, a mounting hole 14 for mounting the locking mechanism 40, a retard passage 15, an advance passage 16, a fitting recess 17 for fitting the camshaft 1, four seal insertion grooves 18 formed at the tip of the vane section 11, and a positioning hole 19 for fitting the positioning pin P of the camshaft 1.

The front surface 10a is a plane perpendicular to the axis S, and defines the front end faces of the four vane portions 11 and the hub portion 12. The front surfaces 10a in the vane portion 11 region and the outer region of the hub portion 12 function as contact end surfaces that slidably contact the inner wall surface 21d of the housing rotor 20 in the direction of the axis S. The front surface 10a in the inner region of the hub portion 12 functions as a bearing surface against which the washer 30 abuts.
That is, the end face of the vane rotor 10 with which the washer 30 abuts is defined on the same plane as the contact end face that contacts the inner wall surface 21 d of the housing rotor 20 .
The rear surface 10b is a plane perpendicular to the axis S, and defines the rear end faces of the four vane portions 11 and the hub portion 12. The rear surface 10b functions as a contact end surface that slidably contacts the inner wall surface 22d of the housing rotor 20 in the direction of the axis S.

The four vane portions 11 are disposed at substantially equal intervals with respect to the hub portion 12. Each vane portion 11 is formed with an attachment hole 14 for attaching a lock mechanism 40 thereto.
The hub portion 12 is an area that is pressed by the bolt B to be fixed to the camshaft 1, and by tightening the bolt B via a washer 30, the surface pressure is reduced and the occurrence of scratches, etc. due to the rotation of the head _B1 of the bolt B is suppressed or prevented.
The through hole 13 is formed in a circular shape with an inner diameter _Hr centered on the axis S and penetrating from the front surface 10a to the rear surface _10b so as to define a passage for hydraulic oil around the neck portion _B3 by passing the threaded portion B2 and the neck portion B3 of the bolt B without contacting the bolt.

The mounting hole 14 opens to the rear surface 10b and is formed to fit a cylindrical holder 41 of the lock mechanism 40. The mounting hole 14 is also formed to communicate with passages 14a, 14b for adjusting pressure. The passage 14a communicates with a long groove _14a1 formed in the front surface 10a so as to communicate with the outside through the opening 21a. The passage 14b opens to the side surface of one of the vanes 11 and communicates with the retard chamber RC, supplying hydraulic oil in the retard chamber RC that acts in a direction to sink the lock pin 42.

5, 8 and 16, the retard passage 15 is formed of two groove-like passages 15a formed in the bottom surface of the fitting recess 17 and communicating with the retard passage 1c of the camshaft 1, and four passages 15b opening on the outer circumferential surface of the hub portion 12. The retard passage 15 supplies hydraulic oil to the retard chamber RC and discharges hydraulic oil from the retard chamber RC via a passage defined around the neck portion _B3 of the bolt B in the through hole 13.
5, 7 and 15, the advance passage 16 is formed by two passages 16a that open into the bottom surface of the fitting recess 17 and extend in the direction of the axis S to communicate with the advance passage 1b of the camshaft 1, and four passages 16b that open into the outer circumferential surface of the hub portion 12. The advance passage 16 supplies hydraulic oil to the advance chambers AC and discharges hydraulic oil from the advance chambers AC.
The fitting recess 17 is formed as a cylindrical recess on the rear surface 10b side of the vane rotor 10 so that the front end portion of the shaft portion 1a of the camshaft 1 can be fitted therein.
The seal insertion groove 18 is formed to have a rectangular cross section, and a seal member 18a that is in slidable contact with the inner circumferential surface 21f of the housing rotor 20 is fitted into the seal insertion groove 18.

The vane rotor 10 is accommodated in the housing rotor 20 and can rotate relatively within a predetermined angle range, i.e., within the angle range between the most retarded position shown in FIG. 14 and the most advanced position shown in FIG. 15, dividing the accommodation chamber into an advanced angle chamber AC and a retarded angle chamber RC. The vane rotor 10 is fixed to the camshaft 1 by a bolt B via a washer 30 and rotates integrally with the camshaft 1.

The housing rotor 20 has a two-piece structure including a cylindrical front housing 21 with a bottom and a disk-shaped rear housing 22 that is connected to the front housing 21 by a screw b.
The housing rotor 20 accommodates the vane rotor 10 so as to be relatively rotatable within a predetermined angular range.

The front housing 21 is formed by die casting or as a sintered body using an aluminum material into a cylindrical shape with a bottom, having a cylindrical wall and a front wall.
As shown in Figures 4 to 6, 9 and 10, the front housing 21 has an opening 21a, four circular holes 21b for passing screws b, four shoe portions 21c, an inner wall surface 21d, a washer accommodating portion 21e, and an inner surface 21f with which the seal member 18a attached to the vane rotor 10 comes into slidable contact.

The opening 21a is formed in a circular shape having an inner diameter Hh that is larger than the outer diameter of the head _{B1, as shown in FIG. 9, centered on the axis S, so that the bolt B can be passed therethrough, as shown in FIG. 6} to FIG. 8.
The four circular holes 21b are formed so as to penetrate in the direction of the axis S in the region of the four shoe portions 21c.
The four shoe portions 21c protrude from the cylindrical wall toward the center (axis S) and are disposed at equal intervals in the circumferential direction.
As shown in FIG. 9, the inner wall surface 21d forms a plane perpendicular to the axis S, and is in slidable contact with the front surface 10a, which is the end surface of the vane rotor 10, in the direction of the axis S.

As shown in FIGS. 9 and 10, the washer receiving portion 21e is formed as an annular recess around the opening 21a so as to face the end face (front face 10a) of the vane rotor 10 in the direction of the axis S.
Furthermore, before the valve timing change device M is fixed to the camshaft 1 by the bolt B, the washer accommodating portion 21e holds the washer 30 adjacent to the end face (front face 10a) of the vane rotor 10, thereby preventing it from falling off.

As shown in FIG. 9, the washer accommodating portion 21e is formed to accommodate the washer 30 in a freely movable manner within a gap C that is smaller than the thickness T of the washer 30 in the direction of the axis S. This makes it possible to suppress rattling of the washer 30 when the valve timing change device M is transported, and also ensures a gap so that the washer 30 does not come into contact with the housing rotor 20 when the device M is attached to the camshaft 1.

In addition, as shown in Figure 10, the washer accommodating portion 21e is formed to accommodate the washer 30 so as to be freely movable in a direction perpendicular to the axis S, within a range in which the circular hole 31 of the washer 30 does not deviate from the area facing the through hole 13 of the vane rotor 10.
Specifically, even when the washer 30 is maximally displaced from the position centered on the axis S, the movement range is restricted so that most of the circular hole 31 of the washer 30 faces the through hole 13.
Here, “facing the through hole 13 ” is a concept that includes not only a state in which the entire circular hole 31 faces the through hole 13 , but also a state in which a part of the circular hole 31 partially faces the through hole 13 .

According to this, when the bolt B is inserted with the washer 30 biased relative to the through hole 13, the tip of the threaded portion _B2 can be inserted into the circular hole 31 to center the washer 30, that is, while aligning the center of the circular hole 31 with the axis S which is the center of the through hole 13, the bolt B can be inserted into the through hole 13. Therefore, the valve timing changing device M can be easily attached to the camshaft 1.
Here, a form has been shown in which most of the washer 30 faces the through hole 13 even when the washer 30 is maximally displaced from the position centered on the axis S, but the entire area of the circular hole 31 may be restricted to a range that does not deviate from the area facing the through hole 13. In this case, the operation of inserting the bolt B can be performed more smoothly.
In addition, since the front housing 21 is formed as a die-cast or sintered body, the washer receiving portion 21e can be integrally formed, which can reduce costs compared to when the washer receiving portion is formed by machining.

The rear housing 22 is formed into a disk shape as a sintered body using an iron-based metal material, and as shown in Figures 4 to 8, it has a sprocket 22a, a mating inner peripheral surface 22b, four screw holes 22c into which the screws b are screwed, an inner wall surface 22d, a groove-like passage 22e, and a mating hole 22f.

A chain that transmits the rotational driving force of the crankshaft is wound around the sprocket 22a.
The fitting inner peripheral surface 22b is rotatably fitted to the shaft portion 1a of the camshaft 1.
The inner wall surface 22d forms a plane perpendicular to the axis S, and is in slidable contact with the rear surface 10b, which is the end surface of the vane rotor 10, in the direction of the axis S.
The passage 22e is formed in the inner wall surface 22d in a groove shape and in communication with the advance passage 16 (passage 16a) so as to supply and discharge hydraulic oil to and from the fitting hole 22f.
The fitting hole 22f is formed in the inner wall surface 22d so that a lock pin 42 included in the lock mechanism 40 can be fitted therein.

The washer 30 is disposed between the end face (front surface 10a) of the vane rotor 10 and the head _B1 of the bolt B, and is formed as a circular flat washer having an outer diameter Dw from a hard iron-based material, and is provided with a circular hole 31 having an inner diameter Hw.
The washer 30 is accommodated in the washer accommodating portion 21e in the housing rotor 20 before the bolt B is tightened.

Here, as shown in FIG. 9, the outer diameter Dw of the washer 30 is formed to be larger than the inner diameter Hh of the opening 21a of the housing rotor 20, and the inner diameter Hw of the circular hole 31 is formed to be smaller than the inner diameter Hr of the through hole 13 of the vane rotor 10.
This makes it possible to prevent the washer 30 from passing through the opening 21a and falling off when the washer 30 is accommodated in the washer accommodating portion 21e of the housing rotor 20, and also makes it possible to keep the circular hole 31 in the area facing the through hole 13 even when the washer 30 is maximally biased away from the through hole 13.

As shown in FIG. 6 , the lock mechanism 40 includes a cylindrical holder 41 , a lock pin 42 , and a coil spring 43 .
The cylindrical holder 41 is fitted into the mounting hole 14 of the vane rotor 10 so as to hold the lock pin 42 biased by the coil spring 43 so as to be capable of reciprocating motion.
The lock pin 42 is freely movable back and forth in the direction of the axis S, and protrudes from the rear surface 10b of the vane rotor 10 due to the biasing force of the coil spring 43 to fit into a fitting hole 22f of the rear housing 22. The lock pin 42 is also configured to be embedded in the vane rotor 10 when it receives the hydraulic pressure of the hydraulic oil guided to the fitting hole 22f or the hydraulic pressure of the hydraulic oil guided through the passage 14b.
The coil spring 43 exerts a biasing force in a direction that causes the lock pin 42 to protrude from the rear surface 10 b of the vane rotor 10 .

In the lock mechanism 40 configured as described above, when the oil pressure of the hydraulic oil supplied through the advance passage 16 and passage 22e drops and the oil pressure of the hydraulic oil supplied through passage 14b drops, the lock pin 42 fits into the fitting hole 22f of the housing rotor 20 by the biasing force of the coil spring 43, and the vane rotor 10 is locked in the most retarded position relative to the housing rotor 20.
On the other hand, when the hydraulic pressure of the hydraulic oil guided through the advance passage 16 and the passage 22e becomes greater than the biasing force of the coil spring 43, the lock pin 42 retracts from the rear surface 10b of the vane rotor 10, unlocking the vane rotor 10. When the hydraulic pressure of the hydraulic oil supplied through the passage 14b becomes greater than the biasing force of the coil spring 43, the unlocked state is maintained.

Next, a method of assembling the variable valve timing device M will be described.
The vane rotor 10 with the lock mechanism 40 assembled therein, the four seal members 18a, the front housing 21, the rear housing 22, the washer 30, and the four screws b are prepared in advance.
First, the front housing 21 is set so that the housing chamber of the front housing 21 faces upward. Then, the washer 30 is placed in the washer housing portion 21e of the front housing 21. At this time, since the washer housing portion 21e is formed as an annular recess, the washer 30 can be easily placed by simply dropping it in.
Next, the vane rotor 10 is inserted into the accommodation chamber of the front housing 21 so that the front surface 10a faces the washer 30. Then, the seal members 18a are fitted into the four seal insertion grooves 18 of the vane rotor 10, respectively.
Next, the rear housing 22 is joined opposite the front housing 21 so as to cover the rear surface 10b of the vane rotor 10, and the four screws b are passed through the circular holes 21b and screwed into the screw holes 22c to connect the rear housing 22 to the front housing 21.
This completes the assembly of the variable valve timing device M. Note that the assembly procedure is not limited to the above procedure, and other procedures may be used.

In this way, the valve timing change device M can be easily assembled by the simple process of sequentially dropping the washer 30, vane rotor 10, and seal member 18a into the bottomed cylindrical front housing 21, covering it with the rear housing 22, and joining the front housing 21 and the rear housing 22 with screws b.
In addition, by arranging the washer 30 in the washer receiving portion 21 e of the front housing 21 , the washer 30 can be held adjacent to the end face (front face 10 a ) of the vane rotor 10 to prevent it from falling off from the housing rotor 20 .
Therefore, when the variable valve timing device M is supplied to an assembly line for the internal combustion engine E, rattling of the washer 30 can be suppressed and the washer 30 can be prevented from falling off no matter what state the device is transported in. This improves the convenience of handling the variable valve timing device M.

Next, the work of mounting the variable valve timing device M on the camshaft 1 in an assembly line for the internal combustion engine E will be described with reference to FIGS.
For example, in an assembly line for an internal combustion engine E, when the axis S of the camshaft 1 is set to be horizontal, as shown in FIG. 11 , the valve timing change device M is brought close to the camshaft 1 from the horizontal direction, and the shaft portion 1a of the camshaft 1 is fitted into the mating inner surface 22b of the housing rotor 20, and the positioning pin P is fitted into the positioning hole 19, while the tip portion of the shaft portion 1a of the camshaft 1 is fitted into the mating recess 17 of the vane rotor 10.
In this state, gravity acts on the washer 30, so that the washer 30 is held in a state biased downward from the axis S within the range of the washer receiving portion 21e.
In this state, the washer 30 is held so that the circular hole 31 does not deviate from the area facing the through hole 13 of the vane rotor 10 in the direction perpendicular to the axis S.

Next, the bolt B is brought closer to the opening 21a from the front of the valve timing changing device M, and as shown in Figures 12 and 13, the tip of the threaded portion _B2 of the bolt B is inserted into the circular hole 31 to lift the washer 30, and then the bolt B is inserted into the through hole 13 while aligning the center of the circular hole 31 with the center of the through hole 13.
Thereafter, the bolt B is screwed completely into the female threaded hole 1 d of the camshaft 1 to tighten the washer 30 and the vane rotor 10 , thereby fixing the vane rotor 10 to the camshaft 1 .
In this mounting operation, there is no need to prepare a separate washer 30, and it is sufficient to simply screw in the bolt B, so that the mounting operation can be carried out smoothly and easily, improving the productivity on the assembly line.
In particular, even when the washer 30 is maximally displaced from the position centered on the axis S, the circular hole 31 is kept from escaping from the area facing the through hole 13, so that the bolt B can be inserted smoothly.

Here, we have shown a case where the valve timing change device M is attached to the internal combustion engine E with the axis S of the camshaft 1 set horizontally, but even if the axis S of the camshaft 1 is set at an angle or vertically, the washer 30 is held so that the circular hole 31 does not deviate from the area facing the through hole 13, so the bolt B can be inserted and attached easily in the same way, improving productivity.

Next, the operation of the valve timing varying device M will be described with reference to FIGS.
When the internal combustion engine E is stopped, the hydraulic oil in the advance chamber AC and the retard chamber RC is discharged, and the vane rotor 10 is positioned at the most retarded position, as shown in FIG.
Furthermore, the lock pin 42 of the lock mechanism 40 is fitted into the fitting hole 22 f , and the vane rotor 10 is locked relative to the housing rotor 20 .
As a result, when starting the internal combustion engine E, fluttering of the vane rotor 10 can be prevented and the internal combustion engine E can be started smoothly.

Subsequently, when the internal combustion engine E is started, hydraulic oil is supplied to the tip of the lock pin 42 through the advance passage 16 and the passage 22e, and the lock pin 42 is pressed and disengaged from the fitting hole 22f, thereby releasing the locked state.
After the internal combustion engine E is started, the hydraulic control valve 2a is appropriately switched to perform phase control so that the vane rotor 10 and the camshaft 1 are advanced or retarded or are maintained at a predetermined angular position.

For example, in the advance angle mode, the hydraulic oil in the retard angle chamber RC is discharged via the retard angle passage 15 and the retard angle side passage 2c, and the hydraulic oil is supplied to the advance angle chamber AC via the advance angle side passage 2b and the advance angle passage 16.
As a result, the vane rotor 10 rotates clockwise relative to the housing rotor 20, that is, toward the advance side, as shown in FIG. 15, due to the hydraulic pressure of the hydraulic oil in the advance chamber AC.

On the other hand, in the case of the retard mode, the hydraulic oil in the advance chamber AC is discharged via the advance passage 16 and the advance side passage 2b, and the hydraulic oil is supplied to the retard chamber RC via the retard side passage 2c and the retard passage 15.
As a result, the vane rotor 10 rotates counterclockwise relative to the housing rotor 20, that is, toward the retard side, as shown in FIG. 16, due to the hydraulic pressure of the hydraulic oil in the retard chamber RC.
Furthermore, when the vane rotor 10 moves to the most retarded position, the lock pin 42 faces the fitting hole 22f. However, since the hydraulic oil in the retard chamber RC acts through the passage 14b in a direction to sink the lock pin 42, the lock pin 42 does not engage with the fitting hole 22f and the unlocked state is maintained.

In addition, in the case of a holding mode in which the vane rotor 10 is held in an intermediate position between the most advanced position and the most retarded position, the hydraulic control valve 2a is switched to supply hydraulic oil to the advanced angle chamber AC and the retarded angle chamber RC, and the vane rotor 10 is held in a predetermined intermediate position by the hydraulic pressure of the hydraulic oil in the advanced angle chamber AC and the retarded angle chamber RC.

According to the valve timing change device M of the above embodiment, the housing rotor 20 includes a washer receiving portion 21e that holds the washer 30 adjacent to the end face (front face 10a) of the vane rotor 10 to prevent it from falling off. Therefore, when the device M is provided without the bolt B and the camshaft 1, the convenience of handling is improved and the productivity in the assembly line of the internal combustion engine E is improved.

The end face of the vane rotor 10 against which the washer 30 abuts is defined on the same plane as the contact end face (front face 10a) that contacts the inner wall surface 21d of the housing rotor 20 in the direction of the axis S, so there is no need to perform special processing on the vane rotor 10 to create a seating surface, and the vane rotor 10 can be manufactured at a low cost.

The washer accommodating portion 21e is formed as an annular recess around the opening 21a so as to face the end face (front surface 10a) of the vane rotor 10 in the direction of the axis S, and since the washer 30 has an outer diameter Dw that is larger than the inner diameter dimension of the opening 21a, it is possible to reliably prevent the washer 30 from falling off from the housing rotor 20.
In addition, the washer accommodating portion 21e accommodates the washer 30 so that it can move freely in a direction perpendicular to the axis S, within a range in which the circular hole 31 of the washer 30 does not deviate from the area facing the through hole 13 of the vane rotor 10. Therefore, when attaching the device M to the camshaft 1, the bolt B can be easily inserted and tightened, and after attachment, the washer 30 can be fixed by ensuring a gap so that it does not come into contact with the housing rotor 20.
Furthermore, the washer accommodating portion 21e accommodates the washer 30 so as to be freely movable in the direction of the axis S within a gap C whose dimension is smaller than the plate thickness T of the washer 30, thereby suppressing rattling when the device M is transported, and also enabling the washer 30 to be fixed in place with a sufficient gap to prevent it from coming into contact with the housing rotor 20 after installation.

Since the vane rotor 10 is made of an aluminum material and the washer 30 is a flat washer made of an iron-based material, it is possible to achieve a lightweight structure while preventing scratches and wear on the vane rotor 10 due to the screwing and tightening of the bolt B.
Furthermore, by configuring the housing rotor 20 to include a cylindrical front housing 21 with a bottom having an opening 21a and a washer accommodating portion 21e, and a disk-shaped rear housing 22 having a sprocket 22a on its outer periphery and connected to the front housing 21, the washer 30 can be easily positioned within the housing rotor 20, and the device M can be easily assembled.
Furthermore, by forming the front housing 21 as a die-cast or sintered body, the washer receiving portion 21e can be integrally formed, which can reduce costs compared to forming the washer receiving portion 21e by machining.

In the above embodiment, the washer 30 is a flat washer, but the washer is not limited to this, and a spring washer, a wave washer, a disc washer, or a washer of other shape may be used.
In the above embodiment, the washer accommodating portion 21e having an annular recess is shown as the washer accommodating portion, but this is not limited to this, and washer accommodating portions having other shapes may be adopted as long as they hold the washer 30 adjacent to the end face (front face 10a) of the vane rotor 10 and prevent it from falling off.
In the above embodiment, a circular opening 21a is shown as the opening of the housing rotor 20, but this is not limited to this, and openings of other shapes may be used as long as they allow the insertion of the bolt B and prevent the washer from falling off.

In the above embodiment, the housing rotor 20 is shown as a two-part structure consisting of a front housing 21 and a rear housing 22, but the present invention is not limited to this. For example, the present invention may be adopted in a configuration with a housing rotor having a three-part structure consisting of a flat front housing, a cylindrical outer housing, and a flat rear housing, or in other forms.

In the above embodiment, the housing rotor 20 is provided with a sprocket 22a that transmits the rotational force of the crankshaft, but this is not limited to this. For example, if the means for transmitting the rotational driving force of the crankshaft has another structure, such as a toothed timing belt, a housing rotor provided with a toothed pulley that matches that structure may be used.

In the above embodiment, the locking mechanism 40 includes a cylindrical holder 41, a lock pin 42, and a coil spring 43, and is configured to lock the mechanism at the most retarded position, but is not limited to this. For example, other locking mechanisms may be used as long as they are capable of locking the vane rotor 10 relative to the housing rotor 20, and the locking position is not limited to the most retarded position, but may be the most advanced position or another position as necessary.

As described above, the valve timing change device of the present invention can reduce the cost of the device and improve ease of use, so it can be applied to internal combustion engines mounted on automobiles, etc., and is also useful for small internal combustion engines mounted on motorcycles, etc., and internal combustion engines mounted on other vehicles or ships, etc.

1 Camshaft S Axis B Bolt _B Head M Valve timing change device 10 Vane rotor 10a Front surface (end surface, contact end surface)
13 through hole 20 housing rotor 21 front housing (housing rotor)
21a Opening 21d Inner wall surface 21e Washer receiving portion 22 Rear housing (housing rotor)
22a Sprocket 30 Washer 31 Circular hole 40 Locking mechanism

Claims (7)

A valve timing change device that changes the opening and closing timing of an intake valve or an exhaust valve driven by a camshaft,
a vane rotor fixed to rotate integrally with the camshaft;
a housing rotor that accommodates the vane rotor and is rotatable relative to the vane rotor within a predetermined angular range around the axis of the camshaft;
a washer that is interposed between an end surface of the vane rotor and a head of the bolt when the bolt is fastened to fix the vane rotor to the camshaft,
the housing rotor includes a circular opening centered on the axis for passing the bolt therethrough, and a washer receiving portion for holding the washer adjacent to an end face of the vane rotor to prevent it from falling off ,
the vane rotor includes a contact end surface that contacts an inner wall surface of the housing rotor in the axial direction,
The washer receiving portion is formed as an annular recess around the opening so as to face an end surface of the vane rotor in the axial direction,
The end surface of the vane rotor against which the washer abuts is defined on the same plane as the contact end surface.
A valve timing varying device. The washer has an outer diameter larger than the opening.
2. The valve timing changing device according to claim 1 . the vane rotor includes a circular through hole centered on the axis so that the bolt passes through the through hole without contacting the vane rotor,
the washer includes a circular hole through which the threaded portion of the bolt passes,
the washer receiving portion receives the washer so as to be freely movable in a direction perpendicular to the axis, within a range in which the circular hole of the washer does not deviate from a region facing the through hole of the vane rotor.
3. The valve timing changing device according to claim 1 or 2 . The washer receiving portion receives the washer movably within a gap range smaller than a plate thickness of the washer in the axial direction.
4. The valve timing changing device according to claim 3 . The vane rotor is made of an aluminum material,
The washer is a flat washer made of an iron-based material.
5. The valve timing changing device according to claim 1, wherein the valve timing changing device is a valve timing changing device. the housing rotor includes a cylindrical front housing having a bottom, the front housing having the opening and the washer receiving portion, and a disk-shaped rear housing having a sprocket on an outer periphery and coupled to the front housing.
6. The valve timing changing device according to claim 1, wherein the valve timing changing device is a valve timing changing device. The front housing is formed as a die-cast or sintered body.
7. The valve timing changing device according to claim 6 .

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