JPH11210423A - Valve system for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently prevent damage to a camshaft without enlarging the axial diameter of the camshaft. SOLUTION: In this valve system for an engine equipped with a camshaft 1 driving the intake valve or exhaust valve of the engine, a plurality of oil passages 9, 10 is formed, which extends from the journal part 1b of the camshaft 1 supported by a bearing member comprising a cam cap 4 to the end part side of the camshaft 1, and also this plurality of oil passages 9, 10 is arranged in a position that it may not be overlapped on the projected part 14 of a cam profile when viewed from the end part side of the camshaft 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve train for an engine having a camshaft for driving an intake valve and an exhaust valve of the engine.

[0002]

2. Description of the Related Art Conventionally, as shown in, for example, Japanese Patent Application Laid-Open No. 9-250311, a valve timing adjusting mechanism for adjusting the operation timing of a valve is provided at an end of a cam shaft for driving an intake valve or an exhaust valve of an engine. In the engine valve gear provided, an oil passage for supplying operating oil pressure to the valve timing adjusting mechanism is formed in the camshaft, and the valve timing adjusting mechanism is operated according to the operating oil pressure supplied from the oil passage. There is known a configuration in which the rotation phase of the camshaft with respect to the output shaft of the engine is adjusted by controlling the rotation phase.

[0003]

The camshaft has a plurality of oil passages extending from at least a journal portion supported by a bearing member to an end of the camshaft provided with a valve timing adjusting mechanism. Since an advance shaft passage for supplying operating hydraulic pressure for squaring and a retard shaft passage for supplying operating hydraulic pressure for retarding the valve are formed, these oil passages are cammed. In the case of installation in the axial direction of the shaft, at least one of them is disposed on the outer peripheral side with respect to the axis of the camshaft. It is inevitable that the thickness is reduced.

Therefore, the driving force transmitted from the output shaft of the engine to the cam pulley provided on the camshaft and the driving reaction force of the intake valve or the exhaust valve driven in accordance with the rotation of the camshaft are reduced by the camshaft. Therefore, there is a problem that the camshaft is easily damaged at a portion of the oil passage corresponding to the journal portion. In order to prevent damage to the camshaft, it is conceivable to increase the diameter of the camshaft. However, in such a case, the bearing portion of the camshaft becomes large and the overall height of the engine increases. There is a problem that is inevitable.

The present invention has been made in view of the above circumstances, and provides an engine valve train capable of effectively preventing the camshaft from being damaged without increasing the shaft diameter of the camshaft. Things.

[0006]

The invention according to claim 1 is
In an engine valve gear having a camshaft that drives an intake valve or an exhaust valve of an engine, a plurality of oil passages extending from a journal portion of the camshaft supported by a bearing member to an end portion of the camshaft are formed. The plurality of oil passages are arranged at positions that do not overlap the protrusions of the cam profile when viewed from the end of the camshaft.

[0007] According to the above construction, the position where the projection exists is avoided so that the plurality of oil passages formed in the camshaft do not overlap with the projection of the cam profile when viewed from the end of the camshaft. The driving reaction force of the intake valve or the exhaust valve of the engine driven by the camshaft is prevented from being directly input to the installation portion of the oil passage.

According to a second aspect of the present invention, in the engine valve operating apparatus according to the first aspect, an oil passage extending from a journal portion of the camshaft to an end portion of the camshaft is formed by a drill hole, and the journal is formed. The hole diameter of the oil passage located at the portion is set to be smaller than the hole diameter of the oil passage located at the end of the camshaft.

According to the above construction, after forming a large-diameter drill hole at the end of the camshaft, a small-diameter drill hole is formed from the bottom of the large-diameter drill hole, so that the small-diameter hole located at the journal portion is formed. And a large-diameter drill hole located on the end side of the cam shaft. Therefore, the operation of forming the oil passage by the drill can be facilitated, and the rigidity against the load input to the camshaft from the journal portion can be further increased.

According to a third aspect of the present invention, in the valve train of the engine according to the first or second aspect, a cam pulley is disposed at an end of a camshaft in which an oil passage is formed. An oil passage is formed extending from a cam journal portion disposed closest to the installation portion to an end portion of the camshaft.

According to the above construction, the cam pulley is disposed at the end of the camshaft in which the oil passage is formed, and the cam journal is disposed at the position closest to the cam pulley mounting portion. The length of the oil passage extending toward the end is shortened, and the supply of oil through this oil passage is performed promptly.

According to a fourth aspect of the present invention, in the valve operating device for an engine according to the third aspect, a cam pulley is provided at an end of the camshaft having the oil passage formed therein, and a valve timing adjusting mechanism for adjusting the operation timing of the valve. Are arranged close to each other to supply hydraulic pressure to the valve timing adjusting mechanism from the oil passage.

According to the above construction, the working oil pressure can be easily and appropriately supplied to the oil passage via the oil passage formed in the bearing member formed of the cam cap and the like provided on the journal portion of the cam shaft. At the same time, the total length of the oil passage extending from the journal to the end of the camshaft can be reduced.

According to a fifth aspect of the present invention, there is provided a case provided at an end of a camshaft, and a rotor surrounded by the case, and formed between the rotor and a vane projected from the case. 5. The valve operating system for an engine according to claim 4, further comprising a valve timing adjusting mechanism configured to adjust the operation timing of the valve by supplying operating hydraulic pressure to the advance hydraulic chamber and the retard hydraulic chamber. In the above, a plurality of oil passages are arranged in a divergently inclined state so as to avoid an installation portion of an attachment member for attaching the rotor to the camshaft.

According to the above construction, the plurality of oil passages are arranged in a diverging and inclined state so as to avoid the mounting holes of the mounting member formed by the mounting bolts and the like of the rotor formed at the end of the camshaft. Accordingly, the oil passage located in the journal portion of the camshaft is disposed on the center side of the camshaft, and the shaft diameter of the journal portion can be reduced, so that the bearing portion of the camshaft is reduced in size. Become.

[0016]

FIG. 1 shows an embodiment of a valve train for an engine according to the present invention. In this valve train,
A camshaft 1 for driving an intake valve or an exhaust valve (not shown), a cam pulley 2 rotatably supported by an enlarged diameter portion 1a formed at one end of the camshaft 1, and an inner side of the enlarged diameter portion 1a. A cam cap 4 for rotatably supporting a journal portion 1b disposed at a position closest to the cam pulley 2 at a portion side, that is, a center portion in the output shaft direction of the engine, at an upper end portion of the cylinder head 3; Timing adjustment mechanism 5 attached to one end of the valve
And an oil control valve 6 for controlling the supply and discharge of the operating oil pressure to and from the valve timing adjusting mechanism 5.

A rotary plate 8 having a detected portion 8a of a cam position sensor 7 is attached to the camshaft 1 on the inner side of the journal portion 1b. An oil passage 9 on the advance side and an oil passage 10 on the retard side that extend to the side are formed. The cam position sensor 7 includes an electromagnetic pickup sensor or the like using a Hall element or an MRE (magnetic resistance element), and is provided on the cylinder head cover 11 on the inner side of the oil control valve 6.
The rotary plate 8 is attached in an oblique direction so as to be directed to the installation position, that is, in a state where the tip end is inclined so as to face the lower outer side of the cylinder head cover 11. Also,
The detected portion 8a of the rotating plate 8 is bent obliquely in accordance with the installation direction of the cam position sensor 7.

The two oil passages 9 and 10 are arranged in an inclined manner so as to be widened to avoid a mounting portion of a mounting member including a mounting hole 13 into which the mounting bolt 12 of the valve timing adjusting mechanism 5 is screwed. The end side of the camshaft 1,
That is, the large-diameter drill holes 9a, 10a formed on the enlarged-diameter portion 1a side of the camshaft 1 and the large-diameter drill holes 9a, 10a,
It comprises small diameter drill holes 9b and 10b extending from the bottom of 10a to the installation side of the journal 1b. As a result, the hole diameter of the oil passages 9 and 10 located on the journal portion 1b side is set smaller than the hole diameter of the oil passages 9 and 10 located on the end side of the camshaft 1.

As shown in FIG. 2, the two oil passages 9 and 10 have projecting portions of the cam profile 4 so as not to overlap with the projecting portions 14 of the cam profile when viewed from the end of the camshaft 1. It is arranged avoiding the position where the part 14 exists. That is, in the four-cylinder type engine, the projections 14 of the cam profile are arranged at four regular intervals around the camshaft 1 corresponding to the number of cylinders. Passage 9, 9
And a pair of retarded oil passages 10 and 10 are disposed between the protrusions 14 of the cam profile at positions offset by a predetermined distance in the radial direction from the center of the camshaft 1. By disposing the oil passages 9 and 10 at regular intervals, the oil passages 9 and 10 are arranged at positions where they do not overlap with the protrusions 14 of the cam profile.

As shown in FIG. 1, the cam pulley 2 and the valve timing adjusting mechanism 5 are arranged close to each other, and the cam pulley 2 is fixed to a housing 15 of the valve timing adjusting mechanism 5 by mounting bolts 16. .
Then, the cam pulley 2 is rotationally driven by the timing belt 17 wound around the output shaft of the engine,
The driving force is transmitted to the camshaft 1 via the valve timing adjusting mechanism 5, whereby the camshaft 1 is driven to rotate.

The cam cap 4 has oil passages 18 and 19 for supplying hydraulic pressure to the oil passages 9 and 10 and ring grooves 20 and 21 extending over the cylinder head 3. In addition, on the upper surface of the cam cap 4, the oil grooves 18,
An adapter 24 having oil passages 22 and 23 communicating with 19 is attached, and the cam cap 4 is connected to the oil control valve 6 via the adapter 24. The operating oil pressure supplied from the oil control valve 6 to the oil passages 22 and 23 of the adapter 24 is applied to the oil passages 9 and 9 of the camshaft 1 via the oil passages 18 and 19 of the cam cap 4 and the ring grooves 20 and 21. 10.

The valve timing adjusting mechanism 5 includes a housing 15 mounted on the enlarged diameter portion 1a of the camshaft 1.
And a case 26 and an outer plate 27 fixed to the outer end of the housing 15 by mounting bolts 25, and a rotor 28 attached to an end of the camshaft 1. The housing 15 and the case 26 are rotatably supported by bearings 29 held by the cam cap 4 and the cylinder head 3. The rotor 28 is fixed to the end of the camshaft 1 by a mounting member including the mounting bolt 12 in a state surrounded by the case 26 between the housing 15 and the outer plate 27.

The inner peripheral surface of the case 26 and the rotor 28
As shown in FIG. 3, four vanes 30 and 31 are respectively provided on the outer peripheral surface of the outer periphery of the vane to face each other.
Between the cam pulley 2 and the vane 31 protruding from the rotor 28 and the advancing hydraulic chamber 32 for rotating the camshaft 1 to the advancing side with respect to the cam pulley 2. Retard side hydraulic chamber 3 that rotates to the corner side
3 are formed. Sealing materials for sealing the advance hydraulic chamber 32 and the retard hydraulic chamber 33 are provided at the distal ends of the vanes 30, 31, respectively.

Then, as shown in FIG. 4, from the oil passage 9 on the advance side formed in the camshaft 1, the oil on the advance side through the oil passage 34 formed on the inner side of the rotor 28. When the hydraulic pressure is supplied to the hydraulic chamber 32, the vane 3
By rotating the camshaft 1 clockwise in the drawing, the rotational phase of the camshaft 1 with respect to the output shaft of the engine is advanced. As shown in FIG. 3, the retard-side hydraulic chamber 33 extends from the retard-side oil passage 10 formed in the camshaft 1 via an oil passage 35 formed outside the rotor 28. Is supplied with the operating oil pressure, the vane 31 protruding from the rotor 28 is driven to rotate counterclockwise in the drawing,
The rotation phase of the camshaft 1 with respect to the output shaft of the engine is retarded.

As shown in FIG. 5, a positioning pin 36 protrudes from the end surface of the camshaft 1 and a positioning hole formed in the rotor 26 of the valve timing adjusting mechanism 5 has a long hole extending in the radial direction. A hole 37 is formed. The positioning pin 36 of the camshaft 1
Is inserted into the positioning hole 37 of the rotor 26, so that the rotor 26 is fixed to the camshaft 1 by the mounting bolts 12 in a state where the rotor 26 is accurately positioned in the rotation direction of the camshaft 1. ing.

As shown in FIG. 6, a pair of positioning pins 38 and 39 project from the housing 15 of the valve timing adjusting mechanism 5, and
Are formed with a positioning hole 40 formed of a round hole and a positioning hole 41 formed of a long hole extending in the radial direction of the cam pulley 2. By inserting the positioning pins 38 and 39 into the positioning holes 40 and 41, the cam pulley 2 is fixed to the housing 15 by the mounting bolt 16 in a state where the cam pulley 2 is accurately positioned in the rotation direction of the cam shaft 1. It is supposed to be.

As shown in FIG. 1, the control valve 6 includes a valve case 42 attached to the upper end surface of the cylinder head cover 11 and a spool 4 installed in a spool installation hole 43 formed in the valve case 42.
4, a spool drive means 45 comprising an electromagnetic solenoid for driving the spool 44, a union bolt 47 and an oil filter 48 installed in an inlet hole 46 formed in the valve case 42, The upper end of the adapter 24 is configured to be inserted into a fitting insertion hole 49 formed in 42.

The spool 44 is, as shown in FIG.
The spool drive means 45 is installed at one end of the engine body E in the width direction, that is, in a direction orthogonal to the output shaft of the engine body E, and is provided on the outer end side of the spool 44.
Is installed. That is, the engine body E is mounted horizontally on the front of the vehicle body, and the spool 44 is disposed in the front-rear direction of the vehicle body above the intake valve camshaft 1 located on the rear side of the vehicle body. In this case, a spool driving means 45 composed of an electromagnetic solenoid is installed behind the spool 44 on the vehicle body side, and the spool 44 is driven by the spool driving means 45 in the axial direction.

Further, the adapter 24 is disposed on the inner side of the spool 44 (the center in the output shaft direction of the engine body E) and the outer side of the spool 44 (the engine). Outer end side of main body E in the output shaft direction)
The union bolt 47 is disposed, and an oil pipe 50 for supplying an operating oil pressure to an installation portion of the union bolt 47 is connected to the union bolt 47.

The oil pipe 50 has one end connected to an oil gallery (not shown) formed on the side wall of the engine body E by an oil joint 52, and the other end connected to the installation portion of the cylinder head cover 11. At the detoured position, the union bolt 47 is connected to the installation portion of the union bolt 47 by an oil joint 51. The operating oil pressure supplied from the oil pipe 50 to the installation portion of the union bolt 47 is applied to the oil passage 5 formed in the union bolt 47.
3 through the oil filter 48 and the spool 44
(See FIG. 1).

When the spool 44 is operated by the spool driving means 45, one of the oil passages 54 and 55 formed in the valve case 42 is connected to the oil passages 22 and 23 formed in the adapter 24. On the other hand, the operating oil pressure is selectively supplied. In addition, the above adapter 2
4 at the same time as the operating oil pressure is supplied to one of the oil passages 22, 23, the oil passages 54,
Hydraulic oil led to the installation portion of the spool 44 through the drain 55 is supplied to a drain passage 56 formed in the valve case 42.
Thus, the fluid is returned into the cylinder head cover 11 via a drain receiver 57 formed between the valve case 42 and the cylinder head cover 11. In addition,
A sealing material 5 is provided between the cylinder head cover 11 and the cam cap 4 to prevent the hydraulic oil flowing down from the drain receiver 55 from flowing into the installation portion of the cam pulley 2.
8 are installed.

In the above configuration, when the output shaft of the engine rotates, the driving force is transmitted to the cam pulley 2 by the timing belt 17 to rotate the cam pulley 2, and the driving force is transmitted via the valve timing adjusting mechanism 5. The intake valve or exhaust valve (not shown) is opened and closed at a predetermined timing by rotating the camshaft 1.

The rotational phase of the camshaft 1 is detected by the cam position sensor 7 and the detection signal is input to a control unit (not shown), so that the operation timing of the intake valve or the exhaust valve is controlled by the control unit. Is detected. Then, a control signal corresponding to the operating state of the engine is output from the control unit to the spool driving means 45 of the oil control valve 6, whereby the operation timing of the intake valve and the like is adjusted.

When adjusting the operation timing of the intake valve and the like, the operating oil pressure supplied from the oil gallery of the engine body E is supplied from the oil pipe 50 to the installation portion of the union bolt 47, and the union bolt 4
The oil is supplied from the oil passage 53 through the oil filter 48 to the installation portion of the spool 44. When the operation timing is advanced, the camshaft 1 is connected to the oil passage 54 formed in the valve case 42 via the oil passage 22 of the adapter 24, the oil passage 18 of the cam cap 4, and the ring groove 20. The spool 44 is driven by the spool driving means 45 so that the operating oil pressure is supplied to the formed advanced oil passage 9. As a result, after the working oil pressure is sent to the end of the camshaft 1 through the oil passage 9 on the advance side, it is supplied from the oil passage 34 of the rotor 28 to the hydraulic chamber 32 on the advance side. As a result, the vane 31 of the rotor 28 rotates in the advance direction to advance the operation timing of the intake valve and the like.

When the operation timing is retarded, the cam from the oil passage 55 formed in the valve case 42 through the oil passage 23 of the adapter 24, the oil passage 19 of the cam cap 4, and the ring groove 21. The spool 44 is operated by the spool drive unit 45 so that the operating oil pressure is supplied to the retarded oil passage 10 formed in the shaft 1. As a result, after the operating oil pressure is sent to the end of the camshaft 1 through the oil passage 10 on the retard side,
When the operating oil pressure is supplied from the oil passage 35 of the rotor 28 to the hydraulic chamber 33 on the retard side, the vane 31 of the rotor 28 rotates in the retard direction, and the operation timing of the intake valve and the like is delayed.

The operation timing of the intake valve and the like is adjusted as described above, and the operation timing of this valve is detected based on the detection signal of the cam position sensor 7. In addition, the deviation between the actual valve operation timing detected based on the detection signal of the cam position sensor 7 and the target operation timing set in accordance with the operating state of the engine becomes equal to or less than a predetermined value, and When the control unit confirms that the operation timing has been properly adjusted, the control signal for operating the spool 44 to the neutral holding position is maintained, so that the operation timing is maintained until the operation timing adjustment operation is started again. Is done.

In the engine valve operating apparatus having the camshaft 1 for driving the intake valve or the exhaust valve of the engine as described above, the journal portion 1 of the camshaft 1 supported by the bearing member including the cam cap 4 and the like.
b, a plurality of oil passages 9, 10 extending toward the end of the camshaft 1 are formed, and the plurality of oil passages 9, 10 are formed on the protrusions 14 of the cam profile when viewed from the end of the camshaft 1. Because it is located in a position that does not overlap,
Even when the thickness between the installation portions of the oil passages 9 and 10 and the outer peripheral portion of the camshaft 1 is reduced to some extent, it is possible to effectively prevent the camshaft 1 from being damaged.

That is, the protrusion 1 of the cam profile
By arranging the oil passages 9 and 10 avoiding the installation position of the cam profile 4 so as to prevent the plurality of oil passages 9 and 10 from overlapping with the projections 14 of the cam profile, the cam profile is prevented from overlapping. The driving reaction force generated when the intake valve or the exhaust valve is driven by the protrusion 14 is not directly input to the installation portions of the oil passages 9 and 10, and the camshaft 1 is damaged by the driving reaction force. Can be effectively prevented. Therefore,
The bearing of the camshaft 1 can be reduced in size and the overall height of the engine can be reduced without taking measures such as increasing the shaft diameter more than necessary to prevent the camshaft 1 from being damaged. In particular, as shown in FIG. 2, when the oil passages 9 and 10 are arranged so as to avoid a line connecting each projection 14 of the cam profile and the axis of the camshaft 1, the driving reaction force of the valve As a result, the camshaft 1 is damaged by the pressing force when the upper end of the camshaft 1 is pressed against the cam cap 4, or the camshaft 1 is bent by the bending moment acting in response to the driving reaction force of the valve. There is an advantage that breakage can be effectively prevented.

Further, as shown in the above embodiment, oil passages 9 and 10 extending from the journal portion 1b of the camshaft 1 to the end portion of the camshaft 1 are formed by drilling, and the oil passages 9 and 10 located in the journal portion 1b are formed. If the hole diameter of the passages 9 and 10 is set smaller than the hole diameter of the oil passages 9 and 10 located on the end side of the camshaft 1, the large diameter drill holes 9a,
After the formation of the large-diameter drill holes 9a, 10a
By forming small diameter drill holes 9b and 10b from the bottom of the small diameter drill hole 9 located in the journal portion 1b.
b, 10b and large-diameter drill holes 9a, 10a located on the end side of the camshaft 1, the oil passage 9,
10 can be formed.

According to the above configuration, the drill is frequently broken because the shaft diameter is small, as in the case where the oil passage composed of a long drill hole having a small hole diameter is formed in the camshaft 1 by one small diameter drill. In order to prevent the occurrence of such a situation or to reduce the rigidity of the camshaft 1 as in the case where an oil passage composed of a long drill hole having a large hole diameter is formed in the camshaft 1 by one large diameter drill. In addition, the oil passages 9 and 10 having appropriate diameters can be easily formed without adverse effects such as an increase in the diameter of the camshaft 1 according to the hole diameter of the drill.

In the above embodiment, the oil passage 9,
The cam pulley 2 is attached to the end of the camshaft 1 on which the camshaft 10 is formed.
And the oil passages 9 and 10 extending from the cam journal portion 1b disposed closest to the installation portion of the cam pulley 2 to the end portion of the camshaft 1 are formed. The oil passages 9 and 10 are formed through oil passages 18 and 19 and ring grooves 20 and 21 formed in a bearing member including the cam cap 4 and the like.
The operating hydraulic pressure can be easily and appropriately supplied to the vehicle. Moreover, the length of the oil passages 9 and 10 is reduced as compared with a case where an oil passage extending from the cam journal portion disposed at a position away from the installation portion of the cam pulley 2 toward the end of the cam shaft 1 is formed. Therefore, when the valve timing adjusting mechanism 5 is operated by the operating oil pressure supplied from the oil control valve 6, the operation responsiveness can be effectively improved.

In the above embodiment, the oil passages 9 and
The cam pulley 2 is attached to the end of the camshaft 1 on which the camshaft 10 is formed.
And a valve timing adjusting mechanism 5 for adjusting the operation timing of the valve are arranged close to each other, and the operating oil pressure is supplied from the oil passages 9 and 10 to the valve timing adjusting mechanism 5. By disposing the cam pulley 2 driven by a shaft and a valve timing adjusting mechanism 5 for changing the rotational phase of the camshaft with respect to the cam pulley 2 at one end of the camshaft 1, the valve timing is improved. When adjusting the operation timing of the valve by operating the adjusting mechanism 5, the camshaft 1 can be suppressed from being twisted.

That is, the cam pulley 2 and the valve timing adjusting mechanism 5 can be arranged separately from each other. In this case, the driving force of the cam pulley 2 driven by the output shaft of the engine is reduced. When being transmitted to the valve timing adjusting mechanism 5, it is inevitable that the camshaft 1 is greatly twisted in accordance with the driving force,
Due to the torsional displacement of the camshaft 1, a valve timing adjustment error is likely to occur. Therefore, by bringing the cam pulley 2 and the valve timing adjusting mechanism 5 close to each other at one end of the camshaft 1 as described above, the valve timing adjustment error due to the torsional displacement of the camshaft 1 is made. It is desirable to suppress the occurrence of the phenomenon.

Further, in the above embodiment, the case 26 attached to the end of the camshaft 1 and the case 2
And a rotor 28 disposed so as to be surrounded by the rotor 6. The advance hydraulic chamber 32 and the retard hydraulic chamber 33 formed between the rotor 28 and the vanes 30, 31 protruding from the case 26. In the valve operating apparatus for an engine having the valve timing adjusting mechanism 5 configured to adjust the operation timing of the valve by supplying the operating oil pressure to the mounting bolt 12, the rotor 28 is attached to the camshaft 1. Since the plurality of oil passages 9 and 10 are arranged so as to avoid the installation portion in a tapered and splayed state, the operating oil pressure introduced into the oil passages 9 and 10 is applied to the mounting portion formed at the end of the camshaft 1. The oil passage 9 located in the journal portion 1b of the camshaft 1 does not cause any adverse effects such as flowing out through the mounting hole 13 of the bolt 12 to the outside. , To reduce the shaft diameter of the journal portion 1b by disposing the 10b toward the center of the cam shaft 1,
Thus, the size of the bearing of the camshaft 1 can be reduced.

In the above-described embodiment, an example in which the present invention is applied to a four-cylinder type in-line engine in which the protrusions 14 of the cam profile are arranged at regular intervals at four locations around the camshaft 1 has been described. However, the present invention is not limited to the above-described four-cylinder type, but may be applied to a three-cylinder or six-cylinder in-line engine. For example, 3
In the cylinder type engine, as shown in FIG. 8, the oil passages 9 and 10 are arranged so as to avoid the positions where the protrusions 14 of the cam profiles arranged at regular intervals at three places around the camshaft 1 are present. By doing so, this oil passage 9,
Even if the thickness between the installation portion 10 and the outer peripheral portion of the camshaft 1 is reduced to some extent, the breakage of the camshaft 1 can be effectively prevented.

The present invention also relates to a valve operating device configured to adjust the valve operating timing by a vane type valve timing adjusting mechanism 5 in which vanes 30 and 31 are protruded from the case 26 and the rotor 28. The present invention is not limited to this. The present invention is also applicable to a valve gear having a valve timing adjustment mechanism such as a helical gear type in which a ring gear having a helical gear portion is moved by hydraulic pressure to adjust the operation timing of a valve by the movement. The present invention is also applicable to a valve train in which an oil passage for supplying lubricating oil is formed at one end.

[0047]

As described above, the present invention relates to a camshaft supported by a bearing member such as a cam cap in an engine valve train having a camshaft for driving an intake valve or an exhaust valve of the engine. A plurality of oil passages extending from the journal portion to the end of the camshaft, and the plurality of oil passages are arranged at positions that do not overlap the protrusions of the cam profile when viewed from the end of the camshaft. Even when the thickness between the installation portion of the oil passage and the outer peripheral portion of the camshaft is reduced to some extent, according to the reaction force when the intake valve or the exhaust valve is driven by the projection of the cam profile. There is an advantage that breakage of the camshaft can be effectively prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an engine valve train according to the present invention.

FIG. 2 is a sectional view showing a relationship between a cam profile and an oil passage.

FIG. 3 is a cross-sectional view showing a state where a rotor is rotated in a retard direction.

FIG. 4 is a cross-sectional view showing a state where a rotor is rotated in an advance direction.

FIG. 5 is an end view showing an attached state of a rotor and a camshaft.

FIG. 6 is an end view showing a mounting state of a cam pulley and a housing.

FIG. 7 is a plan view showing the overall configuration of an engine body to which the valve train is mounted.

FIG. 8 is a view corresponding to FIG. 2, showing another embodiment of the valve train of the engine according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Camshaft 1a Journal part 2 Cam pulley 5 Valve timing adjustment mechanism 9,10 Oil passage 9a, 10a Large diameter drill hole 9b, 10b Small diameter drill hole 30,31 Vane 32 Advance hydraulic chamber 33 Delay hydraulic chamber

Claims (5)

[Claims] 1. An engine valve operating apparatus having a camshaft for driving an intake valve or an exhaust valve of an engine, wherein a plurality of oils extending from a journal portion of the camshaft supported by a bearing member to an end portion of the camshaft. A valve train for an engine, wherein a passage is formed, and the plurality of oil passages are arranged at positions not overlapping with the protrusions of the cam profile when viewed from the end of the camshaft. 2. An oil passage extending from a journal portion of a camshaft to an end portion of the camshaft is formed by a drill hole, and a hole diameter of an oil passage located in the journal portion is set to an oil diameter located on an end portion side of the camshaft. 2. The valve train according to claim 1, wherein the diameter of the passage is set smaller than the diameter of the passage. 3. A cam pulley is provided at an end of a camshaft in which an oil passage is formed, and extends from a cam journal provided at a position closest to an installation portion of the cam pulley toward an end of the camshaft. 3. The valve train for an engine according to claim 1, wherein an oil passage is formed. 4. A cam pulley and a valve timing adjusting mechanism for adjusting an operation timing of a valve are disposed close to each other at an end of a camshaft having an oil passage formed therein. 4. The valve train for an engine according to claim 3, wherein the hydraulic pressure is supplied. 5. A case provided at an end of a camshaft, and a rotor surrounded by the case, and an advanced hydraulic chamber formed between the rotor and a vane protruding from the case. 5. The valve operating apparatus for an engine according to claim 4, further comprising a valve timing adjusting mechanism configured to adjust an operation timing of the valve by supplying an operating oil pressure to the retard hydraulic chamber. A valve train for an engine, wherein a plurality of oil passages are arranged in a divergently inclined state so as to avoid an installation portion of a mounting member attached to a shaft.