JP3228111B2 - Valve timing changing device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake engine for an internal combustion engine.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing changing device for changing the opening / closing timing of an exhaust valve according to an operation state, and more particularly to an improvement of an assembly structure in the device.

[0002]

2. Description of the Related Art Conventionally, as a technique relating to a valve timing changing device for an internal combustion engine, there is one disclosed in Japanese Patent Laid-Open No. 4-171205. The valve timing control device described in the publication includes a cam shaft supported by a cam bearing at an upper end portion of a cylinder head for driving an intake valve to open and close, a sleeve fixed to a tip end of the shaft, and a sleeve fitted to the sleeve. And a cylindrical cam sprocket. External teeth are formed on an outer peripheral portion of the cam sprocket, and a timing chain is mounted on the external teeth. The rotational driving force of the crankshaft is transmitted to the cam sprocket via the timing chain. Further, between the sleeve and the cam sprocket, the valve timing is changed by changing the rotation phase of the cam shaft and the cam sprocket such as a cylindrical gear.
Because member is disposed with that.

[0003] An assembling operation of the valve timing control device having the above-described configuration will be described below. First, the cam sprocket is fitted on the sleeve. At this time, a member for changing the valve timing such as the cylindrical gear is assembled between the cam sprocket and the sleeve. Next, the timing chain is mounted on the external teeth formed on the cam sprocket. In this way, the timing chain is previously mounted on the external teeth of the cam sprocket because the timing chain does not have elasticity, so that the sleeve on which the cam sprocket is fitted is fixed to the tip of the camshaft.
This is because the timing chain cannot be mounted on the external teeth of the sprocket. After the timing chain is mounted on the external teeth of the cam sprocket, the cylinder head is assembled to the cylinder block. Then, the sleeve is fixed to a distal end portion of a cam shaft supported by an upper end portion of the cylinder head with a bolt or the like.

A cam sprocket on which a timing chain is mounted includes a member for changing a valve timing such as a cylindrical gear, so that the cam sprocket must be large in shape. Therefore, when assembling the cam sprocket with the sleeve or the like to the tip of the camshaft, the large-sized cam sprocket has to be routed with the timing chain mounted thereon as described above.
As a result, the conventional valve timing control apparatus has a problem that workability at the time of assembly is poor.

Therefore, in order to improve workability at the time of assembling the valve timing changing device, as shown in FIG. 6, a member corresponding to the cam sprocket is connected to a sprocket portion 83 on which a timing chain 80 is mounted. It is conceivable to adopt a configuration in which it is divided into the housing part 82. The figure shows a camshaft 81 supported on the top of a cylinder head 84, a sleeve 85 in which the tip of the shaft 81 is inserted, and a flange 85 of the sleeve 85.
3A shows a housing portion 83 fixed by bolts 86 and the like. By adopting such a configuration, members constituting the valve timing control device, such as the housing portion 82 or the sleeve 85, are assembled in advance to the distal end portion of the cam shaft 81, and the cylinder head 84 is connected to a cylinder block (not shown). After the arrangement, the sprocket portion 83 on which the timing chain 80 is mounted can be fixed to the housing portion 82 by the bolt 87 or the like.

[0006]

However, in the valve timing control device shown in FIG. 6, when assembling the sprocket portion 83 on which the timing chain 80 is mounted, the housing portion provided at the distal end portion of the cam shaft 81 is used. Since the members such as 82 and the sprocket portion 83 interfere with each other, as shown in FIG.
After being moved to the tip side of the housing part 82, it is necessary to fit the housing part 82 outside. Therefore, in the valve timing control device shown in FIG. 6, a working space 88 having a sufficient size must be secured on the tip end side of the camshaft 81, which leads to an increase in the size of the engine.

[0007] The present invention has been made in view of the circumstances in the prior art as described above, and an object of the present invention is to improve workability during assembly without increasing the size of the engine. It is an object of the present invention to provide an apparatus for changing the valve timing of an internal combustion engine that can perform the above.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a sprocket portion which is drivingly connected to a crankshaft via a chain, a housing connected to the sprocket portion, and a housing. rotatably while being disposed around the axis of one of the camshaft on the intake side and the exhaust side has integrally rotatably linked rotator relative to the one of the camshaft, the rotation relative to said housing A phase change mechanism for changing the rotation phase of the one camshaft with respect to the sprocket by rotating the body relative to the sprocket, wherein the sprocket and the phase change are separate. is constituted by a body, wherein the sprocket portion through hole is formed, the a phase change mechanism other hand
In a state of arranging the sprocket portion between the cam shaft, the rotating body and said one cam shaft tip portion is connected through the through hole, the one of the camshaft
The sleeve through which is rotatable relative to
Drive gear fixed to the outer periphery of the formed flange
The doors provided on the other camshafts on the intake and exhaust sides
Meshes with the Ribungiya, the sprocket portion, the inserted through a plurality of bolts in the housing, together with a flange formed on the distal end side of the <br/> sleeve being fastened to said housing This is the gist.

(Operation) The operation of the first aspect of the present invention will be described. In the valve timing changing device for an internal combustion engine according to the first aspect, a chain is mounted on the sprocket portion, and the rotational driving force of the crankshaft is transmitted to the sprocket portion via the chain. Further, the rotational driving force is transmitted to the camshaft via the housing and the rotating body of the phase changing mechanism. Then, the valve is driven to open and close as the camshaft rotates.

The phase changing mechanism changes the rotational phase of the camshaft with respect to the sprocket by rotating the rotating body relative to the housing. Then, the valve opening / closing timing is changed in accordance with the change in the rotation phase of the camshaft.

In the assembling step of the valve timing changing device, first, a chain is mounted on a sprocket portion. Next, in a state where the sprocket portion is disposed between the phase changing mechanism and the camshaft, the rotating body and the tip portion of the camshaft are connected via a through hole of the sprocket portion, and the sprocket portion and the housing are connected to each other. Are linked. As a result, the phase changing mechanism and the sprocket are assembled to the camshaft.

As described above, in the present valve timing changing apparatus, since the sprocket portion is formed separately from the phase changing mechanism, it is necessary to operate the phase changing mechanism with the timing chain mounted. Therefore, workability at the time of assembly is improved.

Further, with the sprocket portion disposed between the phase changing mechanism and the camshaft, the rotating body and the tip portion of the camshaft are connected via a through hole formed in the sprocket portion. Since the part and the housing are connected, it is not necessary to move the sprocket part to the distal end side of the phase changing mechanism and then fit the sprocket part to the outer periphery of the mechanism. As a result, there is no need to provide a space for assembling the sprocket on the tip side of the phase changing mechanism.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied as a valve timing changing device provided in a gasoline engine as an internal combustion engine will be described below.

FIGS. 1 and 2 show a cylinder block 11 of a gasoline engine, a cylinder head 12 mounted on the cylinder block 11, and an intake-side camshaft provided on the cylinder head 12 (hereinafter referred to as "camshaft"). 13 and a valve timing changing device 14 and the like provided on the camshaft 13. FIG. 3 shows FIG.
FIG. 4 is a sectional view taken along line III-III of FIG. 2, and FIG. 4 is a sectional view taken along line IV-IV of FIG.

As shown in FIG. 1, on the tip side (left side in FIG. 1) of the cylinder head 12 and the cylinder block 11,
Timing chain 15, chain guide 2 described later
7 and spaces 16 and 17 in which a chain tensioner (not shown) is arranged, respectively.
Covers 11a and 12a are formed on the distal end sides of 6, 17 respectively. As shown in FIG.
2 has a notch 12b formed in the cover 12a.
A resin cap 70 is fitted to 2b.

As shown in FIG. 1, a sleeve 18 into which a journal 13a of a camshaft 13 is inserted is rotatably supported by an upper portion of a cylinder head 12 and a bearing cap 19. A cam (not shown) for driving an intake valve is formed at a predetermined position (right side in the figure) of the camshaft 13, and the intake valve (not shown) is opened and closed as the shaft 13 rotates. ing. The camshaft 13 is rotatable relative to the sleeve 18.

Flanges 18a and 18b are formed on the distal end and the proximal end of the sleeve 18, respectively. The outer periphery of the flange 18b formed on the proximal end is used to drive the exhaust camshaft 13 to rotate. Drive gear 20
Is press-fitted and fixed. The drive gear 20 is meshed with a driven gear (not shown) provided on an exhaust camshaft (not shown), and the rotational force of the intake camshaft 13 is transmitted to the exhaust camshaft by the drive gear 20 and the driven gear. You. Also, sleeve 1
A cam sprocket 21 and a phase changing mechanism 22 are attached to a flange 18a formed on the distal end side of the motor 8, respectively.

A cam sprocket 21 as a sprocket portion is superimposed on the side surface of the tip of the flange 18a. The cam sprocket 21 has a substantially disk shape, and a through hole 23 is formed at the center thereof. An annular recess 24 is formed on the side surface of the cam sprocket 21 on the sleeve 18 side. As shown in FIG.
The annular concave portion 24 is locked by an annular convex portion 25 formed on the tip side surface of the flange 18a. In the present embodiment, the engagement means is constituted by the annular concave portion 24 and the annular convex portion 25.

As shown in FIGS. 3 and 4, external teeth 26 are formed on the outer peripheral portion of the cam sprocket 21, and the external teeth 26 are attached to the timing chain 15 (FIG. 3) constituting the chain of the present invention. , 4 are not shown). This timing chain 15 is a chain guide 2
7 and a chain tensioner (not shown), and is mounted on a crank sprocket (both not shown) provided at the tip of the crankshaft. The cam sprocket 21 is configured to transmit the rotational driving force of the crankshaft via the timing chain 15.

The phase changing mechanism 22 includes a housing 28,
A rotating member 29 as a rotating body is provided. A center hole 30 is formed in the front end side portion of the housing 28, and the center hole 30 is closed by a lid 31.
Also, the base end side opening of the housing 28 is provided with an insertion hole 3 at the center.
3 is covered by a cover 32.

The housing 28 and the cover 32 are fastened and fixed to the flange 18a of the sleeve 18 together with the cam sprocket 21 by a plurality of bolts 34 inserted through their outer peripheral portions. Further, the housing 28, the cover 32, the cam sprocket 21, and the distal end flange 18a of the sleeve 18 are fixed by a knock pin 59 at the outer peripheral side thereof. Therefore, these members 28, 32, 21, 18 can be integrally rotated by the rotational driving force transmitted from the crankshaft to the cam sprocket 21.

The distal end side of the rotating member 29 is a pressure receiving portion 35. The pressure receiving portion 35 has three vanes 36 projecting radially outward of the camshaft 13 as shown in FIGS.
Are formed every 120 ° around the axis of the camshaft 13.

On the inner peripheral wall of the housing 28 surrounding the pressure receiving portion 35, grooves 37 for forming a hydraulic chamber are formed at positions 120 ° around the axis of the camshaft 13, and each vane 36 is formed in each groove 37. Are located. The space formed by the inner peripheral wall of each groove 37 and the cover 32 is divided into two hydraulic chambers by each vane 36. 3 and 4, a pressure chamber on the counterclockwise side of each vane 36 constitutes an advance side hydraulic chamber 38, respectively.
The pressure chamber on the clockwise side of each vane 36 constitutes a retard side hydraulic chamber 39.

The camshaft 1 is located at the base end of the rotating member 29.
A columnar connecting portion 40 protruding toward the third side is formed. The connecting portion 40 has a smaller diameter than the insertion hole 33 of the cover 32 and the through hole 23 of the cam sprocket 21, and is fitted into the concave portion 13 b formed at the tip of the camshaft 13 through both holes 32, 23. .

A bolt hole 42 extending in the axial direction of the camshaft 13 is formed inside the rotating member 29. A fixing bolt 43 is inserted into the bolt hole 42 through the lid 31, and the lid 31 and the rotating member 29 are fastened and fixed to the tip of the camshaft 13 by the fixing bolt 43. The connecting portion 40 and the tip of the camshaft 13 are connected to the same shaft 1 by a knock pin 41.
Relative rotation about three axes is regulated. Therefore, the rotating member 29 and the lid 31 can rotate integrally with the camshaft 13.

Each of the advance and retard hydraulic pressure chambers 38 and 39 formed in the housing 28 of the phase changing mechanism 22 has an advance and retard hydraulic supply passages and an oil control valve (hereinafter referred to as "OCV"). The lubricating oil of the oil pan is supplied as working oil via 44 or the like.
Hereinafter, each of the hydraulic pressure supply passages and the OCV 44 will be described.

The journal 13a of the camshaft 13 has two circumferential grooves 45, 46 extending in the circumferential direction thereof. Further, in the sleeve 18, the circumferential grooves 4
Oil holes 47 and 48 are formed at positions corresponding to 5 and 46, respectively. Oil grooves 49 and 5 each having a semicircular arc shape are provided in an upper portion of the cylinder head 12 and the bearing cap 19.
0 is formed in each of the oil grooves 49 and 50, and the advance side head oil passage 5 formed in the cylinder head 12 is formed in each of the oil grooves 49 and 50.
1. Lubricating oil is supplied through the retard side head oil passage 52.
The lubricating oil supplied to each oil groove 49, 50 is
Are supplied to the circumferential grooves 45 and 46 through the respective oil holes 47 and 48.

An oil pan, an oil pump, an oil filter and the like (all not shown) provided in the engine constitute a lubricating device for lubricating each part of the engine. When the oil pump is operated in conjunction with the operation of the engine, lubricating oil is sucked and discharged from the oil pan by the pump. The discharged lubricating oil is supplied to the head oil passages 5 by the OCV 44 via an oil filter.
1 and 52 are selectively fed to lubrication of the journal 13a and are supplied to the oil grooves 49 and 50.

In the camshaft 13 and the rotating member 29, an advanced shaft oil passage 53 for supplying a hydraulic pressure by lubricating oil to each of the advanced hydraulic chambers 38 is provided in the axial direction of the camshaft 13. Are formed along. An advance-side oil supply hole 55 extending in the radial direction of the camshaft 13 is formed in the pressure receiving portion 35 of the rotating member 29, and a leading end of each advance-side shaft oil passage 53 is provided with an advance-side oil supply hole. It communicates with each advance angle side hydraulic chamber 38 through 55. The proximal end side of each advance shaft oil passage 53 communicates with the one peripheral groove 45 via an oil hole 57 formed in the radial direction of the camshaft 13.

On the other hand, the camshaft 13 and the rotating member 29
Inside, a retard-side shaft oil passage 54 for supplying hydraulic pressure by lubricating oil to each of the retard-side hydraulic chambers 39 is provided.
The respective advance-side shaft oil passages 53 are formed in parallel with each other. A retard-side oil supply hole 56 extending in the radial direction of the camshaft 13 is formed in the pressure receiving portion 35 of the rotating member 29, and a distal end side of each retard-side shaft oil passage 54 is provided with a retard-side oil supply hole. Each of the retard-side hydraulic chambers 39 communicates with the corresponding one of the retard-side hydraulic chambers 39 through 56. The proximal end of each of the retard shaft oil passages 54 communicates with the other circumferential groove 46 via an oil hole 58 formed in the radial direction of the camshaft 13.

In the above configuration, each advance-side head oil passage 51, oil groove 49, oil hole 47, peripheral groove 45, oil hole 57, each advance-side shaft oil passage 53, and each advance-side oil supply hole. 55 is
The advance hydraulic pressure supply passage for supplying the hydraulic pressure of the lubricating oil to each advance hydraulic pressure chamber 38 is configured. The retard head oil passage 52, the oil groove 50, the oil hole 48, the circumferential groove 46, the oil hole 58, the retard shaft oil passage 54, and the retard oil supply hole 56 The retard hydraulic pressure supply passage for supplying hydraulic pressure by lubricating oil to the hydraulic pressure chamber 39 is configured.

An OCV provided in the middle of both hydraulic supply passages
Reference numeral 44 denotes that the opening is duty-controlled,
It controls the hydraulic pressure supplied to each of the advance side and retard side hydraulic chambers 38 and 39. Hereinafter, the configuration of the OCV 44 will be described.

The casing 60 constituting the OCV 44 is
It has first to fifth ports 61, 62, 63, 64, 65. The first port 61 communicates with the advance head oil passage 51, and the second port 62 communicates with the retard head oil passage 52. In addition, the third and fourth ports 63, 6
4 is connected to an oil pan (not shown), and the fifth port 65 is connected to a discharge side of an oil pump (not shown) via an oil filter (not shown).

A skewer-shaped spool 66 is provided inside the casing 60. The spool 66 has four cylindrical valve bodies 67 and can reciprocate in its axial direction. Also, the casing 60 has an electromagnetic solenoid 68 for moving the spool 66 between a first operating position shown in FIG. 1 and a second operating position shown in FIG.
Is provided. Further, a spring 69 is provided in the casing 60, and the spool 69 is biased by the spring 69 toward the first operation position.

As shown in FIG. 2, when the spool 66 is disposed at the second operating position against the urging force of the spring 69, the discharge side of the oil pump and the advance side head oil passage 51 communicate with each other. The retard head oil passage 52 communicates with the oil pan. Accordingly, the lubricating oil is supplied to each advance-side hydraulic chamber 38 through the advance-side hydraulic supply passage, while the lubricating oil in each retard-side hydraulic chamber 39 is supplied through the retard-side hydraulic supply passage. Returned to the bread. As a result, the vane 36 of the pressure receiving portion 35
Is urged by the oil pressure in each advance-side hydraulic chamber 38, which is relatively increased from the oil pressure in each retard-side hydraulic chamber 39, so that the rotating member 29 It rotates in the direction shown. By rotating the rotating member 29 with respect to the housing 28 in this manner, the camshaft 1
The rotation phase of No. 3 advances more than the cam sprocket 21, and the opening / closing timing of the intake valve advances.

On the other hand, as shown in FIG.
When the spool 66 is disposed at the first operating position by the urging force of the oil pump, the discharge side of the oil pump and the retard side head oil passage 52
Are communicated, and the retard head oil passage 52 and the oil pan are communicated. Accordingly, lubricating oil is supplied to each of the retard-side hydraulic chambers 39 via the retard-side hydraulic supply passages, while lubricating oil of each of the advance-side hydraulic chambers 39 is supplied with oil through the retard-side hydraulic supply passages. Returned to the bread. As a result, the vane 36 of the pressure receiving portion 35 is urged by the hydraulic pressure in each retard hydraulic chamber 39 which is relatively increased from the hydraulic pressure in each advance hydraulic chamber 38,
The rotation member 29 rotates with respect to the housing 28 in the direction indicated by the arrow in FIG. By rotating the rotating member 29 with respect to the housing 28 in this manner, the rotation phase of the camshaft 13 lags behind that of the cam sprocket 21, and the opening / closing timing of the intake valve is delayed.

In this embodiment, as described above, the OCV4
By controlling the opening degree of 4, the opening / closing timing of the intake valve can be changed continuously (steplessly). The operation of the present embodiment having the above configuration will be described.

The valve timing changing device 14 according to the present embodiment has a feature in its assembling process. Hereinafter, an assembling process of the valve timing changing device 14 will be described with reference to FIG.

First, as shown in the figure, a cam sprocket 21 is mounted on the timing chain 15 and held between the chain guide 27 and the chain tensioner. Next, the sleeve 18 into which the tip of the camshaft 13 is inserted is placed on the upper part of the cylinder head 12 and is rotatably supported between the upper part and the bearing cap 19.

The cylinder head 12 on which the sleeve 18 and the camshaft 13 are assembled is attached to the cylinder block 11.
Place on top. Here, the phase changing mechanism 22 has not yet been assembled to the flange of the sleeve 18, and the camshaft 13 has not protruded to the distal end side of the sleeve 18. Therefore, when the cylinder head 12 is mounted on the cylinder block 11, the sprocket 21 held between the chain guide 27 and the chain tensioner does not interfere with the phase change mechanism 22 or the camshaft 13.

Cylinder head 12 and cylinder block 1
When the sprocket 21 is assembled, the sprocket 21
And the annular concave portion 24 of the sprocket 21 is locked by the annular convex portion 25 of the flange 18a. Thus, the sprocket 21 can be temporarily fixed in a state where the sprocket 21 is accurately positioned with respect to the sleeve 18.

Next, a rotating member 29 is disposed in the housing 28, and the phase changing mechanism 22 with the base end covered by the cover 32 is moved from above the space 16 formed in the cylinder head 12 to the same space. 16 is inserted. Then, the connecting portion 40 is inserted into the through hole 23 of the cam sprocket 21 and is fitted into the concave portion 13 b at the tip of the cam shaft 13. At this time, the connecting portion 40 is fixed to the camshaft 13 by the knock pin 41,
Further, the housing 28 and the cover 32 are similarly fixed to the flange 18a of the sleeve 18 by the knock pin 59.

Thereafter, the fixing bolt 43 is tightened through the notch 12b formed in the cover 12a, and the lid 31 and the rotating member 29 are fixed to the tip of the camshaft 13. The housing 28, the cover 32, and the sprocket 21 are fastened and fixed to the flange 18 a of the sleeve 18 by bolts 34 inserted through the outer periphery of the housing 28. At this time, some bolts 34 are tightened through the notches 12b. When the fastening of the fixing bolt 43 and the bolt 34 is completed, the notch 1
A cap 70 is fitted to 2b.

As described above, the camshaft 13 is assembled to the cylinder head 12, and
The phase change mechanism 22 and the sprocket 21 are assembled to the.

The embodiment described above has the following features. (A) In the present embodiment, since the cam sprocket 21 is formed separately from the phase changing mechanism 22, the space formed in the cylinder head 12 is different from the case where the phase changing mechanism 22 and the cam sprocket 21 are integrated. It is not necessary to route the phase change mechanism 22 on which the timing chain 15 is mounted in the inside 16, so that the workability in the assembling work can be improved.

(B) In this embodiment, the cam sprocket 21 is disposed between the phase changing mechanism 22 and the camshaft 13.
Is arranged, the connecting portion 40 of the rotating member 29 is inserted into the through hole 23 formed in the cam sprocket 21 to be connected to the tip of the shaft 13, and further, the cam sprocket 21 is connected to the phase changing mechanism 22. At the same time, the sleeve 18 is fixed to the flange 18a.

Therefore, at the time of assembling, it is not necessary to move the cam sprocket 21 on which the timing chain 15 is mounted to the tip side of the phase change mechanism 22 and externally fix the cam sprocket 21 to the outer periphery of the phase change mechanism 22. Become. as a result,
In order to assemble the cam sprocket 21, it is not necessary to secure a large space 16, 17 between the tip side of the phase changing mechanism 22 and the cylinder head 12 or the cylinder block 11, which may lead to an increase in the size of the engine. Absent.

In order to attach the cam sprocket 21 to the phase changing mechanism 22, the spaces 16 and 17 are required to be large or the cover 12 of the cylinder head 12 is secured.
After separating a as a separate member and attaching the cam sprocket 21 to the phase changing mechanism 22, the cover 12a must be assembled to the cylinder head 12 with bolts or the like. However, according to the present embodiment, since it is not necessary to divide the cover 12a as described above,
The number of components of the cylinder head 12 does not increase.

(C) In the present embodiment, the sleeve 18
When the cylinder head 12 to which the camshaft 13 and the camshaft 13 are mounted is placed on the cylinder block 11, the phase change mechanism 22 is not yet mounted on the flange 18 a of the sleeve 18, and the camshaft 13 is Does not protrude to the tip side. Therefore, cylinder block 1
When the cylinder head 12 is mounted on the sprocket 1, the sprocket 21 held between the chain guide 27 and the chain tensioner does not interfere with the phase changing mechanism 22 or the tip of the camshaft 13.

The cylinder head 12 is connected to the cylinder block 1
If the sprocket 21 interferes with the phase change mechanism 22 or the tip of the camshaft 13 when assembling the cylinder head 1, it becomes difficult to automate the process of mounting the cylinder head 12 on the cylinder block 11. However, according to the present embodiment, the cam sprocket 21
However, since it does not interfere with the phase change mechanism 22 or the tip of the camshaft 13, the above steps can be automated, and mass production can be supported.

(D) The cam sprocket 21 in the present embodiment is disposed between the phase changing mechanism 22 and the flange 18a on the distal end side of the sleeve 18 and is provided by a plurality of bolts 34 passing through the inside of the housing 28 of the mechanism 22. Tightened and fixed.

In the conventional valve timing changing device shown in FIG. 6, the sprocket portion 83 is fitted on the outer peripheral portion of the housing portion 82 previously mounted on the camshaft 81, and the sprocket portion 83 has the flanges of the housing portion 82 and the sleeve 85. It was configured to be fastened and fixed to the bolts 82a and 85a by bolts 87. Therefore, the sprocket portion 8
3 requires a space S for fixing to the respective housing portions 82 with the bolts 87,
The outer diameter of the sprocket 83 increases.

According to the present embodiment, however, it is not necessary to form such a space S in the sprocket 21. Therefore, by reducing the outer diameter of the sprocket 21, the valve timing changing device 14 can be downsized. it can.

(E) In the present embodiment, the rotating member 29 is rotated by changing the magnitude of the hydraulic pressure supplied to the pressure chambers 38 and 39, and the rotation changes the rotation phase of the camshaft 13. To change the valve opening / closing timing. Therefore, for example, the camshaft and the housing each have a movable member meshed with a helical gear, and the movable member moves in the camshaft axial direction to change the rotation phase of the camshaft relative to the housing. Compared with a phase change mechanism having a structure, the phase change mechanism 22 in the present embodiment can reduce the length in the camshaft axial direction.

The present invention can be embodied as another embodiment described below. (1) In the above embodiment, the intake camshaft 13
The valve opening / closing timing of the intake valve is changed by the valve timing changing device 14 provided in the apparatus.
On the other hand, a valve timing changing device 14 may be provided on the exhaust side camshaft to change the valve opening / closing timing of the exhaust valve.

(2) The hydraulic system in the phase changing mechanism 22 is not limited to the configuration shown in the present embodiment. For example, two or four or more vanes are formed in the pressure receiving portion 35 of the rotating member 29, and The rotation phase of the camshaft 13 may be changed by changing the hydraulic pressure supplied to the advance hydraulic chamber 38 and the retard hydraulic chamber 39 formed on both sides of the vane.

(3) In the above embodiment, the OCV 44
The valve opening / closing timing of the intake valve is continuously changed by duty control of the intake valve. You may make it change selectively.

(4) In the above embodiment, the sleeve 1
The cam sprocket 21 is fixed to the flange 18a formed on the sleeve 8;
May be omitted, and a drive gear for rotatably driving the exhaust-side camshaft may be rotatably fitted to the camshaft 13 so that the cam sprocket 21 is fixed to the gear.

(5) The phase changing means according to the present invention comprises:
The invention is not limited to the one having the configuration shown in the above embodiment. For example, a ring gear that meshes with a helical spline with at least one of the two is provided between a rotating body and a housing provided at an end of a camshaft,
The gear changing the rotation phase of the shaft by moving the gear in the axial direction of the camshaft can also be adopted as the phase changing means.

The technical ideas grasped from the above embodiment will be described below together with their effects. (B) In the valve timing changing device for an internal combustion engine according to claim 1, an outer fitting member is further rotatably fitted on the camshaft, and the sprocket portion is connected to the housing of the phase changing mechanism and the outer portion. It is characterized by being clamped between the fitting member.

According to the configuration (a), substantially the same functions and effects as those of the first aspect can be obtained. still,
The outer fitting member is a sleeve 1 in the above embodiment.
8, or the drive gear described in another embodiment.

(B) A pressure-receiving member extending in the radial direction of the camshaft and rotatably provided integrally with the rotating body, first and second hydraulic chambers formed on both sides of the pressure-receiving member in the housing, First and second hydraulic pressure supply paths for supplying hydraulic pressure to each hydraulic pressure chamber, and by changing the magnitude of hydraulic pressure supplied to each hydraulic pressure chamber by each hydraulic pressure supply path, the rotating body is 2. The valve timing changing device for an internal combustion engine according to claim 1, wherein the rotation phase of the cam shaft with respect to the sprocket portion is changed by rotating the cam shaft relative to the housing.

According to the above configuration (b), the length of the phase changing mechanism in the camshaft axial direction can be reduced, and the size of the valve timing changing device can be reduced to suppress the engine from becoming larger. Can be. The pressure receiving member is constituted by each vane 36 in the embodiment. Further, the first hydraulic chamber and the first hydraulic supply path are constituted by respective advance-side hydraulic chambers and the advance-side hydraulic supply path, and the second hydraulic chamber and the second hydraulic supply path are each constituted by a retard angle. The side hydraulic chamber and the retard side hydraulic supply path.

[0065]

As described above, according to the present invention,
In the valve timing changing device for an internal combustion engine, the workability at the time of assembly can be improved without increasing the size of the engine.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a valve timing changing device and an OCV.

FIG. 2 is a sectional view showing a valve timing changing device and an OCV.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is a sectional view for explaining an assembly process of the valve timing changing device.

FIG. 6 is a sectional view showing a conventional valve timing changing device.

FIG. 7 is a cross-sectional view for explaining an assembling process of a conventional valve timing changing device.

[Explanation of symbols]

13 camshaft, 14 valve timing change device, 15 timing chain (chain), 21 cam sprocket (sprocket part), 22 phase change mechanism, 23 through hole, 28 housing, 29 rotating member (rotation) body).

Claims (1)

(57) [Claims] 1. A sprocket portion which is drivingly connected to the crankshaft via a chain, rotatable about the axis of one of the camshaft on the intake side and the exhaust side in the housing is linked to the sprocket portion, and the housing And one of said
Have integrally rotatably linked rotator relative to the camshaft, by relatively rotating the rotating member relative to said housing, said with respect to the sprocket portion Meanwhile
A valve timing change device for an internal combustion engine, comprising: a phase change mechanism that changes a rotation phase of a camshaft; wherein the sprocket portion and the phase change mechanism are formed separately, and a through hole is formed in the sprocket portion. In a state where a sprocket portion is disposed between the phase change mechanism and the one camshaft, the rotating body and the tip end of the one camshaft are connected via the through hole, and the one camshaft is connected. The shaft through which the shaft is inserted so that it can rotate
The leave is fixed to the outer periphery of the flange formed on its proximal end.
The specified drive gear is the other cam on the intake side and exhaust side
Meshes with the driven gear provided on the shaft, the sprocket portion, a plurality of bolts inserted through the interior of the housing, formed at the tip end of the sleeve
A valve timing changing device for an internal combustion engine, wherein the valve timing changing device is fastened and fixed to the housing together with the flange.