JPH0828225A - Variable valve timing mechanism with hydraulic lash adjuster - Google Patents

Abstract

PURPOSE:To improve dynamic characteristics of a valve system during high speed rotation of an engine in a variable valve timing mechanism provided with a hydraulic lash adjuster. CONSTITUTION:A variable valve timing mechanism is provided with an intake valve or an exhaust valve, a low speed cam 12, a high speed cam 13, the first valve drive member 14 and the second valve drive member 15 driven by the low speed cam 12 and the high speed cam 13 respectively so as to swing around a swing shaft 16, a mode switching means 17 capable of switching the second valve drive member 15 to the mode of coupling or to the mode of uncoupling with the first valve drive member 14, and an arm member 80 for swing integrally with the first valve drive member 14. Therefore, a hydraulic lash adjuster which adjusts relative phase between the first valve drive member 14 and the arm member 80 by abutting on the arm member 80 is provided to the swing shaft and its arrangement position is set in such a state as deviated from the center of the arm member 80 in the width direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable valve timing mechanism capable of switching the valve timing of a valve operating system provided in an internal combustion engine between low speed operation and high speed operation. Can be adjusted automatically,
The present invention relates to a variable valve timing mechanism with a hydraulic lash adjuster.

[0002]

2. Description of the Related Art In recent years, with the maturity of the automobile society, the demand for internal combustion engines (hereinafter simply referred to as "engines") has become more sophisticated and diversified, and in addition to engine performance, vibration and noise reduction and maintenance free Is being promoted. For example, in order to improve engine performance, a mechanism has been developed in which a valve operating system that opens and closes an intake valve and an exhaust valve is operated to change the opening and closing timing of these intake and exhaust valves.

In such a mechanism (that is, a variable valve timing mechanism), for example, a camshaft is equipped with a high speed cam and a low speed cam, and either the high speed cam or the low speed cam is mounted. By selecting and using it, the opening / closing timing of the intake / exhaust valve corresponding to the operating state can be obtained. The high speed cam has a cam profile capable of obtaining an opening / closing timing corresponding to a high speed operation, and the low speed cam has a cam profile capable of obtaining an opening / closing timing corresponding to a low speed operation.

As a mechanism for selecting the high speed cam and the low speed cam, in the rocker arm type cam device, the valves are driven by the high speed cam by connecting or disconnecting the rocker arms to each other. Alternatively, the valve is driven by a low speed cam to obtain the opening / closing timing of the intake / exhaust valve corresponding to the operating state.

By the way, in order to adjust the clearance between the rocker arm and the valve, the valve abutting portion of the rocker arm is provided with an adjusting screw (tappet screw) or a hydraulic crush adjuster (hereinafter referred to simply as "H").
It is considered to provide LA). However, when the adjust screw is provided, it is necessary to maintain an appropriate gap between the adjust screw and the stem end of the valve.If this gap becomes excessive, the adjust screw will cause the valve to move when the valve is driven by rocking the rocker arm. There was a case where the striking sound was generated by contacting the end of the stem. In particular, in a valve train with a variable valve timing mechanism, if the clearance between the rocker arm and the valve is not properly adjusted, the required operation may be hindered when trying to connect the rocker arms to each other. There is also a risk that the valve timing may not be adjusted smoothly.

In order to avoid this, the clearance between the rocker arm and the valve must always be managed, and the screwing state of the adjusting screw must be adjusted according to the wear of the end of the adjusting screw. On the other hand, if a hydraulic lash adjuster is installed instead of the adjusting screw at the valve contact part of the rocker arm, the clearance between the rocker arm and the valve can be automatically adjusted, and the valve train can be maintenance-free. It is possible to

However, when the HLA is arranged at the valve contact portion of the rocker arm, the valve-side equivalent weight of the valve operating system becomes large and the dynamic characteristics of the valve deteriorate, so that the valve does not operate as designed. There is a risk. For this reason, there are problems in the output and durability especially at high engine speeds. In addition, the HLA arranged at the valve contact portion of the rocker arm
Has the following problems because it is far from the rocking center of the rocker arm. In other words, especially at high engine speed, H
The LA receives acceleration and centrifugal force due to rocking of the rocker arm, and the check valve ball built into the HLA is prone to rampage, so that oil in the high pressure chamber inside the HLA flows out and the valve lift loss increases. , The challenges of engine power and durability become even more critical.

Therefore, in Japanese Patent Laid-Open No. 6-33715, in order to surely realize the reduction of vibration and noise in such a variable valve timing mechanism and the maintenance-free operation, the HLA is provided rather than the valve contact portion in the rocker arm. There is disclosed a variable valve timing mechanism which is installed at a position close to the center of swinging, and is capable of reliably realizing reduction of vibration and noise and maintenance-free operation.

The technique disclosed in this publication will be briefly described as follows. As shown in FIG. 8, this valve operating system is provided with two intake valves or exhaust valves (hereinafter simply referred to as valves), and the valve operating system is operated to open and close these valves 2 and 3. It is configured.

This valve train includes cams 12 and 13 that rotate in response to the rotation of the crankshaft of the engine, and rocker arms (first valve drive member and second valve drive) that are driven by these cams 12 and 13. (Members) 14 and 15. The cams 12 and 13 are both camshafts 11 that rotate in conjunction with the rotation of the crankshaft of the engine.
The cam 12 is a low speed cam having a cam profile for low speed valve timing, and the cam 13 is a high speed cam having a cam profile for high speed valve timing. They have the same base circle diameter. The cam profiles of the low speed cam 12 and the high speed cam 13 are set so that the cam profile of the high speed cam 13 includes the cam profile of the low speed cam 12.

The rocker arms 14 and 15 are both rocker arms with rollers, and the rocker arm 14 is a low speed rocker arm that contacts the valves 2 and 3 via a swing arm (arm member) 80. The valves 2 and 3 are opened and closed. Also, the rocker arm 15
Contacts the valves 2 and 3 via the low speed rocker arm 14 to open / close these valves 2 and 3.

As shown in FIG. 9, the low speed rocker arm 14 is integrally provided with a rocker shaft (swing shaft) 16. The rocker shaft 16 is pivotally supported by a bearing portion 1A provided on a cylinder head or the like of the engine, and the low speed rocker arm 14 can rotate about the rocker shaft 16. Rocker arm 14 for low speed
As shown in FIGS. 8 and 9, an intermediate portion of the low speed cam 1
There is provided a low speed roller 18 which can be brought into contact with 2.
The low speed roller 18 is pivotally supported by a shaft 18A pivotally supported at an intermediate portion of the low speed rocker arm 14 via a roller bearing so that the low speed roller 18 can smoothly rotate. Also, axis 1
8A also serves as a swing arm shaft.

The swing arm 80 is pivotally attached to the low speed rocker arm 14 so as to be swingable. here,
An intermediate portion of a swing arm 80 is pivotally attached to a shaft 18A of the low speed roller 18. At one end of the swing arm 80, a valve contact portion 80 that contacts the stem end portions of the valves 2 and 3 is provided.
C is provided. Further, at the other end of the swing arm 80, a hydraulic lash adjuster (hydrollash adjuster, abbreviated as HLA) 81 (see FIG. 10) is provided so that the relative phase of the swing arm 80 and the low speed rocker arm 14 can be adjusted. Is installed.

As shown in FIG. 9, the rocking shaft side base portion 14B is located between the main body of the low speed rocker arm 14 and the high speed rocker arm 15, and the rocking shaft side base portion 14B is sandwiched between the rocking arm base 14B and the high speed rocker arm 15. Equipment hole 79 for HLA81 on side base 14B
Are formed. The HLA 81 is mounted in the equipment hole 79 of the swing shaft side base portion 14B. This HLA81
Allows swing arm 80 and low-speed rocker arm 14
The relative phase with is automatically adjusted. For example, when the clearance of the corresponding portion increases, the above HLA 81 causes the clearance between the swing arm 80, the low speed rocker arm 14 and the valves 2 and 3, and thus the low speed rocker arm 14 and the valves 2 and 3 via the swing arm 80. The valve clearance of is adjusted.

On the other hand, the high-speed rocker arm 15 is shown in FIG.
As shown in FIG. 9, the tubular base portion 15B is pivotally supported so as to be rotatable with respect to the rocker shaft 16 (that is, the low speed rocker arm 14), and the rocking end portion 15A thereof has a high speed cam 13 thereon. Roller 1 for high speed that can come into contact with
It has nine. This high-speed roller 19 also has a shaft 19A pivotally supported by the rocking end 15A of the high-speed rocker arm 15.
It is pivotally supported by a roller bearing so that it can smoothly rotate.

Between the high-speed rocker arm 15 and the rocker shaft 16, a mode (non-coupling mode) in which the high-speed rocker arm 15 is rotatable with respect to the rocker shaft 16 and does not operate in association with the low-speed rocker arm 14;
A hydraulic piston mechanism 17 is provided as a mode switching unit that can switch a mode (coupling mode) in which the high-speed rocker arm 15 rotates integrally with the rocker shaft 16 and operates in cooperation with the low-speed rocker arm 14.

As shown in FIGS. 9 and 11, the hydraulic piston mechanism 17 as the mode switching means includes a rocker shaft 1 in a piston chamber formed in the rocker shaft 16.
6 is provided with a piston 17A movably arranged in the diameter direction. In addition, the tubular base 1 of the rocker arm 15 for high speed
At the required position of 5B, the other end of the piston 17A (the upper end in the figure, hereinafter, this end is referred to as the tip).
Is formed with a hole 17C through which the entry can be made.

The working oil is introduced from an oil passage 16A formed in the axial center portion of the rocker shaft 16, and the tip of the piston 17A is fitted into the hole 17C by the hydraulic pressure of this working oil. It has become. And
When hydraulic oil is supplied, the hole 1 at the tip of the piston 17A
By being inserted into 7C, the high-speed rocker arm 15 rotates integrally with the rocker shaft 16 and becomes a mode in which the low-speed rocker arm 14 operates in a linked manner (cooperative mode, that is, high-speed operation mode).

On the other hand, when the supply of hydraulic oil is cut off, the piston 17A is driven toward the base end by the biasing force of the spring 17B, and the tip of the piston 17A comes out of the hole 17C. A mode in which the high-speed rocker arm 15 is rotatable with respect to the rocker shaft 16 and does not work in association with the low-speed rocker arm 14 by disengaging the piston 17A from the hole 17C (non-coupling mode, that is, low-speed operation mode) Becomes Note that reference numeral 16
C is an oil passage for supplying hydraulic oil to the HLA 81.

With the above construction, when the engine is rotating at a low speed, the working oil pressure is eliminated and the piston 17A is opened in the hole 17C.
Remove from inside. This enables high-speed rocker arm 1
The mode 5 is rotatable with respect to the rocker shaft 16 and does not operate in association with the low speed rocker arm 14 (non-operation mode). Then, the low speed rocker arm 14 is driven according to the cam profile for low speed valve timing of the low speed cam 12 through the low speed roller 18 that is driven in contact with the low speed cam 12 to swing the swing arm 80.
The valves 2 and 3 are driven via.

As a result, the valves 2 and 3 are driven at a valve timing suitable for low speed rotation, and the engine operates efficiently. On the other hand, when the engine rotates at a high speed, the working hydraulic pressure is supplied through a hydraulic pressure supply system (not shown) to fit the piston 17A into the hole 17C as shown in FIG.
As a result, the high-speed rocker arm 15 is integrated with the rocker shaft 16 to be in a mode in which the high-speed rocker arm 15 and the low-speed rocker arm 14 work together (cooperation mode). Then, the low speed rocker arm 14 is driven according to the cam profile for the high speed valve timing of the high speed cam 13 through the high speed roller 19 and the high speed rocker arm 15 that are driven by contacting the high speed cam 13. The valves 2 and 3 are driven via the arm 80.

As a result, the valves 2 and 3 are driven at valve timing suitable for high speed rotation, and the engine operates efficiently. When the valve operating system is operated, the HLA 81 interposed between the low speed rocker arm 14 and the swing arm 80 automatically adjusts the relative phase between the swing arm 80 and the low speed rocker arm 14, so The relative phase between the arm 80 and the low-speed rocker arm 14 is appropriately maintained, and the clearance between the low-speed rocker arm 14 and the valves 2 and 3 is always properly maintained through the swing arm 80 without requiring special maintenance. Will be done. Therefore, vibration and noise that are likely to occur in the valve train are reduced, and the reliability of the variable valve timing mechanism is improved.

Further, in this example, since the HLA 81 is disposed on the swing center of the low speed rocker arm 14, the increase in the valve-side converted weight of the valve train is suppressed, and the valves 2, 3 are suppressed.
The dynamic characteristics of the engine are improved, and the valves 2 and 3 are properly operated even when the engine is operating at a high speed, so that the output performance of the engine can be improved particularly in the high speed performance.

Further, since the HLA 81 is arranged on the swing center of the low speed rocker arm 14, the HLA 81 is
The acceleration and centrifugal force applied to the HLA 81 are suppressed, and the HLA 81 operates properly. Therefore, the variable valve timing mechanism can operate properly, and the overall performance of the engine (performance including output and fuel consumption) can be improved.

During high speed operation, the lift of the high speed cam 13 is transmitted from the high speed rocker arm 15 to the rocker shaft 16 via the piston (plunger) 17A.
Furthermore, the rocker arm 14 for low speed to the swing arm 80
The torque is transmitted to the valves 2 and 3 through the rocker shaft 16 which transmits the swing of the high speed rocker arm 15 to the low speed rocker arm 14 at that time, and a twisting torque is generated, which causes a reduction in the overall rigidity of the valve train. Can be considered.

On the other hand, in this structure, HLA81
However, low-speed rocker arm 14 and high-speed rocker arm 15
Since the piston 17A and the center of the swing arm 80 are close to each other, since the piston 17A and the center of the swing arm 80 are located close to each other, the rigidity of the rocker shaft 16 due to the twisting of the valve train as a whole. Impact is reduced.

[0027]

However, as shown in FIG.
As shown in FIG. 7, by forming the equipment hole 79 of the HLA 81 in the rocker shaft 16, the cross-sectional area of the rocker shaft 16 is greatly reduced at the center of the swing arm 80 in the width direction, and the rigidity at this portion is inevitable. Will decrease. Such a decrease in the rigidity of the rocker shaft 16 causes
Since this is the largest factor in the dynamic characteristics of the valve train, we would like to suppress this decrease in rigidity as much as possible and improve the dynamic characteristics of the valve train.

The present invention was devised in order to meet such a demand, and secures sufficient rigidity with respect to the torsional torque input to the swing shaft, and particularly, the dynamics at the time of high engine rotation. An object of the present invention is to provide a variable valve timing mechanism with a hydraulic lash adjuster, which further improves the dynamic characteristics of the valve system.

[0029]

Therefore, a variable valve timing mechanism with a hydraulic lash adjuster according to the present invention as defined in claim 1 is provided for an intake valve or an exhaust valve provided in an internal combustion engine and a valve timing at low speed. A low speed cam having a cam profile and rotating in response to rotation of the crankshaft of the internal combustion engine; and a high speed cam having a cam profile for high speed valve timing and rotating in response to rotation of the crankshaft. A first valve drive member that abuts against the low speed cam and is driven by the low speed cam and can swing about a swing shaft; and a swing shaft that contacts the high speed cam and is driven by the high speed cam. A mode switching hand capable of switching between a second valve drive member that can swing around and a non-coupling mode in which the second valve drive member is not linked to the first valve drive member and a non-coupling mode that is linked to the first valve drive member. And a valve contact portion that abuts against the valve to drive the valve, and is pivotally attached to the first valve drive member in a variable relative phase to rotate around the swing shaft integrally with the first valve drive member. A hydraulic lash adjuster for adjusting the relative phase of the first valve drive member and the arm member by abutting against the arm member. The arrangement position of the lash adjuster is deviated from the center of the arm member in the width direction.

According to the variable valve timing mechanism with a hydraulic lash adjuster of the present invention as defined in claim 2, in addition to the structure of claim 1, the disposition position of the hydraulic lash adjuster is the arm member. It is characterized in that it is biased in a direction away from the second valve drive member with respect to the center in the width direction. According to the variable valve timing mechanism with a hydraulic lash adjuster of the present invention described in claim 3, in addition to the configuration described in claim 1 or 2, the low speed cam contact portion of the first valve drive member has a low speed. And a high-speed roller is interposed at the high-speed cam contact portion of the second valve drive member.

A variable valve timing mechanism with a hydraulic lash adjuster of the present invention according to claim 4 is configured such that the arm member drives a plurality of valves in addition to the configuration according to claim 1 or 2. It is characterized by being. Further, in the variable valve timing mechanism with a hydraulic lash adjuster of the present invention according to claim 5, in addition to the configuration according to claim 1 or 2, the valve contact portion is provided with respect to the pivotal attachment portion of the arm member. It is arranged on the opposite side of the hydraulic lash adjuster, and the distance between the pivotal attachment portion of the arm member and the hydraulic lash adjuster is greater than the distance between the pivotal attachment portion of the arm member and the valve contact portion. Is also set to be large.

A variable valve timing mechanism with a hydraulic lash adjuster according to a sixth aspect of the present invention has an intake valve or an exhaust valve provided for an internal combustion engine, and a cam profile for low speed valve timing. Of the low-speed cam that rotates in response to the rotation of the crankshaft, a high-speed cam that rotates in response to the rotation of the crankshaft with a cam profile for high-speed valve timing, and the low-speed cam. A first valve drive member that is in contact with the high-speed cam and that can be swung around the swing axis, and a first valve drive member that is in contact with the high-speed cam and that is driven by the high-speed cam and can swing around the swing axis. A two-valve drive member and a third valve drive which is formed coaxially with the swing center axes of the first valve drive member and the second valve drive member and can be linked with the first valve drive member or the second valve drive member. Members, A valve contact portion that abuts on the valve to drive the valve, and is pivotally attached to the third valve drive member so that the relative phase is variable, and swings around the swing shaft integrally with the third valve drive member. A low-speed linkage mode in which the third valve drive member is linked only to the first valve drive member, a high-speed linkage mode in which the third valve drive member is linked to the second valve drive member, and the first valve drive member, Mode switching means for switching between a cylinder deactivation mode in which neither the second valve drive member is linked, and a hydraulic lash for contacting the arm member to adjust the relative phase of the third valve drive member and the arm member. An adjuster is provided on the swing shaft, and a position where the hydraulic lash adjuster is disposed is deviated from the center of the arm member in the width direction.

Further, in the variable valve timing mechanism with a hydraulic lash adjuster of the present invention according to claim 7, in addition to the structure according to claim 6, the disposition position of the hydraulic lash adjuster is the arm member. It is characterized in that it is biased in a direction away from the second valve drive member with respect to the center in the width direction. According to the variable valve timing mechanism with a hydraulic lash adjuster of the present invention described in claim 8, in addition to the configuration described in claim 6 or 7, the low speed cam contact portion of the first valve drive member has a low speed. And a high-speed roller is interposed at the high-speed cam contact portion of the second valve drive member.

A variable valve timing mechanism with a hydraulic lash adjuster according to a ninth aspect of the present invention is configured such that the arm member drives a plurality of valves in addition to the configuration according to the sixth or seventh aspect. It is characterized by being. Further, in the variable valve timing mechanism with a hydraulic lash adjuster of the present invention according to claim 10, in addition to the configuration according to claim 6 or 7, the valve contact portion is provided with respect to the pivotal attachment portion of the arm member. It is arranged on the opposite side of the hydraulic lash adjuster, and the distance between the pivotal attachment portion of the arm member and the hydraulic lash adjuster is greater than the distance between the pivotal attachment portion of the arm member and the valve contact portion. Is also set to be large.

[0035]

In the variable valve timing mechanism with a hydraulic lash adjuster according to the present invention as described above, the low speed cam and the high speed cam rotate in response to the rotation of the crankshaft of the internal combustion engine. The first valve drive member and the second valve drive member swing around the swing shaft in conjunction with the cam and the high-speed cam. The arm member swings integrally with the first valve drive member about the swing shaft, and the intake valve or the exhaust valve is driven to open and close through the arm member.

At this time, when the mode switching means sets the second valve drive member to the non-coupling mode in which the second valve drive member is not linked to the first valve drive member, the first valve drive member responds to the cam profile of the low speed cam. As a result of the movement, the arm member drives the intake valve or the exhaust valve to open and close at the valve timing at low speed. On the other hand, when the mode switching means sets the second valve drive member to the linkage mode in which the second valve drive member is linked to the first valve drive member,
The first valve drive member moves together with the second valve drive member. As a result, the first valve drive member moves according to the cam profile of the high speed cam through the second valve drive member, and the intake valve or the exhaust valve is opened and closed by the arm member at the high speed valve timing.

Further, the hydraulic lash adjuster provided on the swing shaft automatically adjusts the relative phase between the arm member and the first valve drive member, and the relative phase between the arm member and the first valve drive member. Is properly maintained, and the clearance between the arm member and the valve is appropriately maintained. At this time, since the arrangement position of the hydraulic lash adjuster is deviated with respect to the center of the arm member in the width direction, a large cross-sectional area near the center of the swing member in the width direction of the arm member can be obtained. The torsional rigidity in the vicinity is improved.

In the variable valve timing mechanism with a hydraulic lash adjuster according to the present invention as defined in claim 2, the position of the hydraulic lash adjuster is separated from the second valve drive member with respect to the widthwise center of the arm member. Since it is biased in the direction, sufficient rigidity is secured against the torsional stress input from the second valve drive member driven by the high speed cam.

In the variable valve timing mechanism with a hydraulic lash adjuster of the present invention as defined in claim 3, the low speed roller rotates between the first valve drive member and the low speed cam,
Wear of the contact portion between the first valve drive member and the low speed cam is suppressed. Similarly to this, the high speed roller rotates between the second valve drive member and the high speed cam, and wear of the contact portion between the second valve drive member and the high speed cam is suppressed.

In the variable valve timing mechanism with a hydraulic lash adjuster according to the fourth aspect of the present invention, since the plurality of valves are driven by the arm member, the intake efficiency or the exhaust efficiency is improved. In the variable valve timing mechanism with a hydraulic lash adjuster of the present invention according to claim 5, the variable valve timing mechanism with a hydraulic lash adjuster is disposed on the side opposite to the hydraulic lash adjuster with respect to the pivotally connecting portion of the arm member, and the pivotally connecting portion of the arm member and the liquid The distance from the hydraulic lash adjuster is set to be larger than the distance between the pivotally attached part of the arm member and the valve abutting part, so that the hydraulic lash adjuster is more suitable than when the hydraulic lash adjuster is provided at the valve abutting part of the arm member. Burden is reduced.
Further, since the hydraulic lash adjuster can be set to a small one having a small capacity, the weight of the valve train can be reduced.

In the variable valve timing mechanism with a hydraulic lash adjuster of the present invention as defined in claim 6, the low speed cam and the high speed cam rotate in response to the rotation of the crankshaft of the internal combustion engine. The first valve drive member and the second valve drive member swing around the swing shaft in conjunction with the high speed cam. Then, when the mode switching means sets the third valve drive member to the low speed linkage mode in which only the first valve drive member is linked, the movement of the first valve drive member that swings according to the cam profile of the low speed cam. Is transmitted to the arm member via the third valve drive member. Then, the intake member or the exhaust valve is opened and closed by the arm member at the valve timing at low speed. When the third valve drive member is set to the low speed linkage mode in which the third valve drive member is linked to the second valve drive member, the movement of the second valve drive member that swings according to the cam profile of the high speed cam causes the movement of the third valve drive member. Is transmitted to the arm member via.
Then, the intake member or the exhaust valve is opened and closed by the arm member at the valve timing at the time of high speed.

Further, when the mode switching means sets the third valve drive member to the cylinder deactivation mode in which neither the first valve drive member nor the second valve drive member is linked, the cam profile of the low speed cam is changed. The movement of the first valve drive member that oscillates accordingly and the movement of the second valve drive member that oscillates according to the cam profile of the high-speed cam are not transmitted to the third valve drive member, and the intake and exhaust valves are driven to open and close. It disappears, and the cylinder is suspended.

On the other hand, the hydraulic lash adjuster provided on the swing shaft automatically adjusts the relative phase between the arm member and the third valve drive member, and the relative phase between the arm member and the third valve drive member. Is properly maintained, and the clearance between the arm member and the valve is appropriately maintained. At this time, since the arrangement position of the hydraulic lash adjuster is deviated with respect to the center of the arm member in the width direction, a large cross-sectional area near the center of the swing member in the width direction of the arm member can be obtained. The torsional rigidity in the vicinity is improved.

In the variable valve timing mechanism with a hydraulic lash adjuster of the present invention as defined in claim 7, the position of the hydraulic lash adjuster is separated from the second valve drive member with respect to the center of the arm member in the width direction. Since it is biased in the direction, sufficient rigidity is secured against the torsional stress input from the second valve drive member driven by the high speed cam.

In the variable valve timing mechanism with a hydraulic lash adjuster according to the present invention as defined in claim 8, the low speed roller rotates between the first valve drive member and the low speed cam,
Wear of the contact portion between the first valve drive member and the low speed cam is suppressed. Similarly to this, the high speed roller rotates between the second valve drive member and the high speed cam, and wear of the contact portion between the second valve drive member and the high speed cam is suppressed.

In the variable valve timing mechanism with a hydraulic lash adjuster according to the ninth aspect of the present invention, since the plurality of valves are driven by the arm member, the intake efficiency or the exhaust efficiency is improved. In the variable valve timing mechanism with a hydraulic lash adjuster according to the present invention as set forth in claim 10, the variable valve timing mechanism with a hydraulic lash adjuster is disposed on the side opposite to the hydraulic lash adjuster with respect to the pivotally connecting portion of the arm member. The distance from the hydraulic lash adjuster is set to be larger than the distance between the pivotally attached part of the arm member and the valve abutting part, so that the hydraulic lash adjuster is more suitable than when the hydraulic lash adjuster is provided at the valve abutting part of the arm member. Burden is reduced. Further, since the hydraulic lash adjuster can be set to a small one having a small capacity, the weight of the valve train can be reduced.

[0047]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 6 show a variable valve timing mechanism with a hydraulic lash adjuster as a first embodiment of the present invention. FIG. 10 is a schematic cross-sectional view showing the configuration of the main part thereof and is a view corresponding to FIG. 9 (a cross-sectional view taken along the line AA of FIG. 8), and FIG. 2 is a schematic cross-sectional view showing the cross-sectional shape of the swing shaft. It is (C-C arrow sectional drawing of FIG. 1), (a) is a figure which shows the cross-sectional shape of the rocking | fluctuation shaft of the conventional mechanism, (b) is a figure which shows the cross-sectional shape of the rocking | fluctuation shaft of the mechanism of this invention. 3A and 3B are schematic diagrams for explaining a force acting on the arm member. FIG. 3A is a schematic diagram when the arm member is symmetrical, and FIG. 3B is a schematic diagram when the arm member is asymmetrical. Figure 4 (a)
5B is a schematic view showing a contact portion between the arm member and the hydraulic lash adjuster, FIG. 5 is a schematic vertical sectional view showing the hydraulic lash adjuster, and FIG. 6 is a view showing the cam profile. FIG. 7 shows a variable valve timing mechanism with a hydraulic lash adjuster as a second embodiment of the present invention, and is a schematic cross-sectional view showing the configuration of the main part thereof.

First, the first embodiment will be described. The valve operating system of this embodiment has substantially the same structure as the conventional variable valve timing mechanism (FIGS. 8 to 11) described above. In other words, the valve operating system is provided with two intake valves or exhaust valves, and the valve operating system is configured to drive the valves 2 and 3 to open and close. Therefore, this mechanism is similar in appearance to the conventional one shown in FIG.

That is, as shown in FIG. 8, this valve system includes cams 12 and 13 that rotate in response to the rotation of the crankshaft of the engine, and the first valve that is driven by these cams 12 and 13. Rocker arm 1 as a driving member
4, and a rocker arm 15 as a second valve drive member. The cams 12, 13 are both camshafts 1 that rotate in conjunction with the rotation of the crankshaft of the engine.
1, the cam 12 is a low-speed cam having a cam profile for low-speed valve timing, and the cam 13 is a high-speed cam having a cam profile for high-speed valve timing. , Have the same base circle diameter. The cam profiles of the low speed cam 12 and the high speed cam 13 are as shown in FIG. 6, and the cam profile 3b of the high speed cam 13 is set to include the cam profile 3a of the low speed cam 12. Has been done.

The rocker arms 14 and 15 are both rocker arms with rollers, and the rocker arm 14 is a main rocker arm. The rocker arms 14 and 15 are in contact with the valves 2 and 3 via a swing arm 80 as an arm member, and these valve 2 , 3 are opened and closed. Further, the rocker arm 15 is adapted to open and close the valves 2 and 3 via the low speed rocker arm 14.

As shown in FIG. 1, the low speed rocker arm 14 is formed integrally with a rocker shaft 16 as a swing shaft. The rocker shaft 16 is shown in FIG.
As shown in FIG. 1, the low-speed rocker arm 1 is pivotally supported by a bearing portion 1A provided on the engine cylinder head or the like.
4 can turn around the rocker shaft 16.

As shown in FIG. 1, a low speed roller 18 that can contact the low speed cam 12 is provided in the middle of the low speed rocker arm 14. This low speed roller 18
Is a shaft 1 that is rotatably supported in the middle of the low-speed rocker arm 14.
It is pivotally supported by 8A via a roller bearing so that it can rotate smoothly. That is, the shaft 18A also serves as a swing arm shaft.

The swing arm 80 is pivotally attached to the low speed rocker arm 14 in a swingable manner. Here, the intermediate portion of the swing arm 80 is pivotally attached to the shaft 18A of the low speed roller 18. There is. This swing arm 8
A valve contact portion 80C that contacts the stem ends of the valves 2 and 3 is provided at one end of 0. Further, at the other end of the swing arm 80, a hydraulic lash adjuster (a hydraulic lash adjuster, abbreviated as H) as shown in FIG.
LA) 81 is interposed, and this swing arm 80
The relative phase between the low speed rocker arm 14 and the low speed rocker arm 14 is automatically adjusted.

In the variable valve timing mechanism of the present invention, the HLA 81 is separated from the rocker arm 15 with respect to the center of the swing arm 80 in the width direction (hereinafter, simply referred to as the "center of the swing arm 80"). It is arranged in a biased manner. That is, as shown in FIG. 1, the rocker shaft 16 is provided with an equipment hole 79 for equipping the HLA 81. The center of the equipment hole 79 (that is, the center of the HLA 81) is the swing arm 8
It is provided offset to the low speed rocker arm 14 side with respect to the center of zero. The offset distance between the HLA 81 and the equipment hole 79 is within a range in which the HLA 81 can reliably adjust the relative phase between the swing arm 80 and the low speed rocker arm 14, and is set to the maximum distance within this range. To explain this in detail, HL
The HLA 81 and the swing arm 80 are provided on the tip side of the A81.
An abutting portion 81N (see FIG. 1) with which the and can abut is provided. Then, the offset distance between the HLA 81 and the equipment hole 79 is set to a distance such that at least half of the area of the contact portion 81N contacts the swing arm 80. In other words, this HLA81
Is set at a position such that the center of the contact portion 81N (that is, the center of the HLA 81) is always covered by the swing arm 80.

As a result, the cross-sectional area of the rocker shaft 16 near the center of the swing arm 80 is as shown in FIG. 2B, and the conventional rocker shaft shown in FIG. Compared with the center of the HLA 81), the cross-sectional area of the rocker shaft 16 can be made larger, and the rocker shaft 16 for high speed of the rocker shaft 16 that receives a large force from the rocker arm 15 for high speed 1
The rigidity of the 5 side part is improved, and the rocker shaft 16 is substantially
The overall rigidity is improved.

The distance a between the axis of the HLA 81 and the swing axis of the swing arm 80 (the axis of the swing arm shaft 18A) is the same as the swing axis of the swing arm 80 and the axis of the valve 2. The distance relationship is set to be larger than the distance b of (that is, a> b). Here, the structure of the HLA 81 will be described. HL
As shown in FIG. 5, the A81 has a plunger 81B built in a body 81A. A high pressure chamber 81G is formed between the plunger 81B and the body 81A, and a spring 81J for biasing the plunger 81B in a direction separating from the body 81A is interposed inside the high pressure chamber 81G.

A plunger cap 81D is in contact with the tip end side of the plunger 81B and connects the lower end of the body 81A to the tip end of the plunger cap 81D by HL.
The axial length of A81 can be expanded by the biasing force of the spring 81J. In addition, the plunger cap 8
1D is held by the plunger cap retainer 81E so as not to come off from the body 81A.

Further, a reserve chamber 81F is formed inside the plunger 81B, and the reserve chamber 81F is formed.
Is supplied with working oil as working liquid through an oil passage (working liquid supply passage) 16C shown in FIG. Further, a hole 81L communicating with the high pressure chamber 81G is formed in the lower portion of the reserve chamber 81F (base end of the plunger 81B).

Further, to close the hole 81L,
A check valve mechanism 81C is provided. The check valve mechanism 81C includes a check valve retainer 81I and a check valve ball 81H. This check valve ball 81H
Is abutted against the hole 81L by a check valve spring 81K so as to close the hole 81L.

In this check valve mechanism 81C, when hydraulic oil is supplied to the reserve chamber 81F to increase the pressure, the check valve ball 81H is driven against the check valve spring 81K, the hole 81L is opened, and the high pressure chamber is opened. The hydraulic oil is supplied to and held by 81G. Therefore, the axial length of the HLA 81 depends on the spring 81.
When expanded by the urging force of J, the hydraulic oil pressure in the reserve chamber 81F rises, the hydraulic oil is supplied to the high pressure chamber 81G through the check valve mechanism 81C, and the hydraulic pressure in the high pressure chamber 81G is maintained.

In such an HLA 81, the body 81A is attached to one member between two members whose clearance is to be adjusted.
The tip of the plunger cap 81D that is movable by burying and fixing the side to make the plunger cap 81D side movable or by burying and fixing the plunger cap 81D side and making the body 81A side movable and movable The base or the end portion of the body 81A is installed so as to abut against the other member.

As shown in FIG. 1, the rocking shaft side base portion 14B is positioned between the main body of the low speed rocker arm 14 and the high speed rocker arm 15, and the rocking shaft side base portion 14B is sandwiched between the main body portion and the high speed rocker arm 15. Equipment hole 79 for HLA81 on side base 14B
Are formed. The HLA 81 is mounted in the equipment hole 79 of the swing shaft side base portion 14B. In addition, this HL
An oil passage 16C for supplying hydraulic pressure to A81 is formed in the axial center portion of the rocker shaft 16.

Therefore, when the relative phase of the swing arm 80 and the low speed rocker arm 14 changes and the clearance of the corresponding portion increases, the plunger cap 81D projects upward due to the urging force of the spring 81J, and the axial length of the HLA 81 increases. While expanding, the clearance between the swing arm 80, the low speed rocker arm 14 and the valve 2 and the valve clearance between the low speed rocker arm 14 and the valves 2 and 3 via the swing arm 80 are adjusted. .

At this time, the hydraulic pressure in the high pressure chamber 81G is held through the check valve mechanism 81C, and the swing arm 80 and the low speed rocker arm 1 are kept even after the clearance adjustment.
A predetermined pressing force is maintained between 4 and 4, and the valve clearance state is stably maintained. On the other hand, as shown in FIG. 1, the high-speed rocker arm 15 is rotatably supported at its tubular base portion 15B so as to be rotatable with respect to the rocker shaft 16 (that is, the low-speed rocker arm 14), and its swing end. The portion 15A is provided with a high speed roller 19 that can come into contact with the high speed cam 13. The high-speed roller 19 is also pivotally supported by a shaft 19A pivotally supported by the swinging end 15A of the high-speed rocker arm 15 via a roller bearing so that the high-speed roller 19 can smoothly rotate.

Between the high-speed rocker arm 15 and the rocker shaft 16, a mode in which the high-speed rocker arm 15 is rotatable with respect to the rocker shaft 16 and does not operate in association with the low-speed rocker arm 14 (non-coupling mode, that is, low speed mode). The hydraulic piston mechanism 17 serves as a mode switching unit capable of switching between an operation mode) and a mode in which the high-speed rocker arm 15 rotates integrally with the rocker shaft 16 and cooperates with the low-speed rocker arm 14 (coordination mode, that is, high-speed operation mode). It is provided.

As shown in FIG. 1, the hydraulic piston mechanism 17 as the mode switching means has a piston chamber 17 formed in the rocker shaft 16 and a piston 17A movably arranged in the diameter direction of the rocker shaft 16. ing. A concave surface (not shown) is formed on the axial center portion of one end of the piston 17A (the lower end portion in FIG. 1, this end portion is referred to as a base end portion). The concave surface and the rocker arm 15 for high speed
A hydraulic chamber 17G is formed between the inner peripheral surface of the cylindrical base portion 15B.

Further, a return spring 17B for urging the piston 17A toward the base end portion is interposed in a compressed state at the base end portion of the piston 17A. Further, the other end portion of the piston 17A (the upper end portion in FIG. 1, hereinafter, this end portion will be referred to as a tip end portion) can enter the required position of the cylindrical base portion 15B of the high speed rocker arm 15. A hole 17C is formed.

The hydraulic oil is introduced into the hydraulic chamber 17G from an oil passage 16A formed in the axial center of the rocker shaft 16, and the hydraulic oil is supplied to the hydraulic chamber 17G. The piston 17A is driven toward the tip end side thereof against the biasing force of the spring 17B, so that the tip end portion of the piston 17A is fitted into the hole 17C. On the other hand, if the hydraulic oil supply to the hydraulic chamber 17G is cut off,
The piston 17A is driven toward the base end side by the urging force of the spring 17B, and the tip end of the piston 17A moves into the hole 17
It is designed to get out of C.

That is, when the hydraulic oil is supplied to the hydraulic chamber 17G, the high speed rocker arm 15 rotates integrally with the rocker shaft 16 by the fitting of the tip end of the piston 17A into the hole 17C, so that the high speed rocker arm 15 operates in cooperation with the low speed rocker arm 14. When the hydraulic oil supply to the hydraulic chamber 17G is cut off, the high-speed rocker arm 15 is rotatable with respect to the rocker shaft 16 because the piston 17A is disengaged from the hole 17C. Low speed rocker arm 1
4 is set so as to be in a mode (coordination mode) in which no coordination operation is performed.

The hydraulic oil is supplied to the hydraulic chamber 17G through a hydraulic oil supply system (not shown). This hydraulic oil supply system includes a hydraulic pump driven by an engine, pressure adjusting means for adjusting the hydraulic oil pressurized by the hydraulic pump to a required hydraulic pressure, and hydraulic oil adjusted by the pressure adjusting means. Is provided to the hydraulic chamber 17G through the oil passage 16A and a supply stop state in which it is not supplied to the hydraulic chamber 17G. And
It is conceivable that the switching valve is configured by, for example, a solenoid valve, and the switching valve can be electronically controlled by a controller (not shown). As a result, it is possible to appropriately switch between the linked mode and the non-linked mode of the high-speed rocker arm 15 while controlling the switching valve according to the engine speed or the like.

By the way, the high speed rocker arm 15 receives the biasing force of the valve spring 4 integrally with the low speed rocker arm 14 in the linking mode, but does not receive it in the non-linking mode, so it is biased to the cam 13 side. Means must be provided to allow the high speed rocker arm 15 to follow the cam 13. Therefore, the high speed rocker arm 15 is provided with a lost motion mechanism (not shown). Note that the lost motion mechanism is publicly known and its description is omitted here.

The valve clearance between the low speed rocker arm 14 and the valves 2 and 3 is automatically adjusted by the HLA 81. However, the valve clearance when the low speed rocker arm 14 moves integrally with the high speed rocker arm 15 in the linkage mode. Is different from the one in the non-coordination mode, so by some means, in the coordination mode (that is, at high speed)
I want to be able to adjust the valve clearance of. In addition, the adjustment of the valve clearance considered here is
Mainly the initial adjustment at the time of assembly.

Therefore, in this valve train structure, a plurality of high speed rollers 19 having different outer diameters are prepared.
In order to make the valve clearance of the low speed rocker arm 14 appropriate in the linkage mode, an appropriate outer diameter is selected and the high speed roller 19 is assembled to the high speed rocker arm 15. Further, in this valve system, the low speed roller 18 is formed of a material lighter than the high speed roller 19. That is, the high speed roller 19 is formed of a general iron-based metal material or the like, while the low speed roller 1 is used.
8 is made of a material such as ceramic which is lightweight and has a required abrasion resistance.

Further, as described above, in order to simultaneously drive a plurality of valves 2 and 3 with a precise timing by one swing arm 80, each valve contact portion 80 of the swing arm 80 is required.
It is necessary to properly adjust the clearance between C and 80C and the stem end of each valve 2 and 3. Therefore, in this embodiment, a shim 82 (see FIG. 10) is attached to one or both valve stem ends of the valves 2 and 3 to adjust the clearance. That is, the clearance can be adjusted by mounting the shim 82 having an appropriate thickness according to the clearance state.

Since the variable valve timing mechanism with the hydraulic lash adjuster as the first embodiment of the present invention is constructed as described above, the working hydraulic pressure in the hydraulic chamber 17G is eliminated when the engine rotates at a low speed. , Piston 1
7A is removed from the inside of the hole 17C. As a result, the high-speed rocker arm 15 is rotatable with respect to the rocker shaft 16 and is in a mode in which the low-speed rocker arm 14 does not work in cooperation (non-coupling mode). The low-speed rocker arm 14 is driven according to the low-speed valve timing cam profile of the low-speed cam 12 through the low-speed roller 18 that is driven in contact with the low-speed cam 12, and through the swing arm 80. The valves 2 and 3 are opened and closed.

As a result, the valves 2 and 3 are driven at the valve timing suitable for low speed rotation, and the engine operates efficiently. On the other hand, when the engine rotates at high speed, the working hydraulic pressure is supplied into the hydraulic chamber 17G through the hydraulic pressure supply system (not shown) to fit the piston 17A into the hole 17C.
As a result, the high-speed rocker arm 15 is integrated with the rocker shaft 16 to be in a mode in which the high-speed rocker arm 15 and the low-speed rocker arm 14 work together (cooperation mode). Then, the low speed rocker arm 14 is driven according to the cam profile for the high speed valve timing of the high speed cam 13 through the high speed roller 19 and the high speed rocker arm 15 that are driven by contacting the high speed cam 13. The valves 2 and 3 are driven via the arm 80.

As a result, the valves 2 and 3 are driven at valve timing suitable for high speed rotation, and the engine operates efficiently. During operation of the main valve system, the HLA 81 interposed between the low speed rocker arm 14 and the swing arm 80 automatically adjusts the relative phase between the swing arm 80 and the low speed rocker arm 14, so The relative phase between the arm 80 and the low speed rocker arm 14 is appropriately maintained, and the clearance between the low speed rocker arm 14 and the valve 2 is always appropriately maintained via the swing arm 80 without requiring special maintenance. Like For this reason, vibration and noise that are likely to occur in the valve train are reduced, and the reliability of the variable valve timing mechanism is improved.

Further, the HLA 81 is the swing arm 80.
2A and 2B, the cross-sectional area of the rocker shaft 16 near the center of the swing arm 80, as shown in FIGS. 2A and 2B, is arranged so as to be away from the center of the rocker arm 15. Rocker shaft 16
The torsional rigidity of is greatly improved, and the dynamic characteristics of the valve train are improved.

Therefore, during high speed operation, the torsional torque transmitted from the high speed rocker arm 15 to the swing arm 80 via the piston 17A of the mode switching means 17,
That is, from the center of the piston 17A to the swing arm 8
In the range up to the center of 0, it becomes possible to secure sufficient rigidity with respect to the twisting torque that tries to twist the rocker shaft 16, and it is possible to easily cope with high engine rotation.

Further, the improvement in the dynamic characteristics of the valve train reduces the restrictions in designing the cam profile of the high-speed cam 13 and increases the degree of freedom in designing the engine performance characteristics. In the present invention, the position of the HLA 81 is provided offset with respect to the swing arm 80 so that the rocker shaft 16 has a large cross-sectional area at the center of the swing arm 80.
The size of 9 itself is not changed. Therefore, the reaction force from the swing arm 80 acts as a bending stress centering on the equipment hole 79, but the bending rigidity of the rocker shaft 16 has a small contribution to the overall rigidity of the rocker shaft 16, and Since the rocker shaft 16 has sufficient rigidity, it does not cause any problem.

When the HLA 81 is provided with an offset with respect to the swing arm 80, if the swing arm 80 is laterally asymmetrical as shown in FIG.
It is possible to further increase the offset distance of the LA 81 and further increase the cross-sectional area of the rocker shaft 16 near the center of the swing arm 80. However, when the swing arm 80 is configured in this way, a twisting moment acts on the swing arm 80, and reinforcement to cope with this causes an increase in weight,
As a result, the dynamic characteristics of the entire valve mechanism are deteriorated.

Therefore, the offset distance between the HLA 81 and the equipment hole 79 is as shown in FIG.
With the conventional symmetrical shape as shown in Fig.
The contact portion 81N has an area at least half of the area of the contact portion 81N as described above, where the LA 81 and the swing arm 80 are in contact with each other.
The range is in contact with 0.

Further, as shown in FIGS. 4 (a) and 4 (b), the position where the HLA 81 receives the reaction force from the swing arm 80 deviates from the center of the HLA 81, and this reaction force causes the HLA 81 to rotate, There is also an advantage that the HLA 81 is not only partially worn. Further, in this embodiment, since the HLA 81 is arranged on the swing center of the low speed rocker arm 14, the increase in the valve-side converted weight of the valve train is suppressed and the dynamic characteristics of the valves 2 and 3 are improved. However, the valves 2 and 3 can operate properly even when the engine is operating at a high speed, so that the output performance of the engine can be improved especially in the high speed performance.

Further, since the HLA 81 is arranged on the swing center of the low speed rocker arm 14, the HLA 81 is
The acceleration and centrifugal force applied to the check valve ball 81H are suppressed, and the HLA 81 operates properly. Therefore, the variable valve timing mechanism can operate properly, and the overall performance of the engine (performance including output and fuel consumption) can be improved.

Further, the force acting between the swing arm 80 and the HLA 81 is P1, and the force acting between the swing arm 80 and the valve 2 is P2, and the axis of the HLA 81 and the swing axis of the swing arm 80 are set. Considering the moment in the swing arm 80 based on the distance a between the swing arm 80 and the distance b between the swing axis of the swing arm 80 and the axis of the valve 2, the relationship of P1 · a = P2 · b is established. .

By the way, in this structure, the distance a between the axis of the HLA 81 and the swing axis of the swing arm 80 is equal to the distance b between the swing axis of the swing arm 80 and the axis of the valve 2.
Since it is set larger than (that is, b <a),
b / a <1, and the above equation is modified to b / a = P1 / P
From 2, P1 / P2 <1, that is, P1 <P2. That is, the force P1 acting on the HLA 81 is smaller than the force P2 acting on the valve 2.

Therefore, the load on the HLA 81 can be reduced as compared with the case where the HLA 81 is provided at the positions of the valves 2 and 3.
A81 can be set to a small one with a small capacity. As a result,
The weight of the valve train can be reduced, the high speed performance of the valve train can be improved,
As a result, the weight of the entire engine can be reduced. As a matter of course, the leverage ratio between the distance a between the axis of the HLA 81 and the swing axis of the swing arm 80 and the distance b between the swing axis of the swing arm 80 and the axis of the valve 2 is set as follows.
HL that you can freely perform under the condition of b / a <1
The lever ratio (b / a) can be set according to the ability of A81.

Further, the low speed cam 12 and the high speed cam 13
It is possible to secure a sufficient distance between
There is also an effect of eliminating the possibility that the grindstone interferes with the high-speed cam 13 protruding from the low-speed cam 12 when polishing 2. Further, since the swing arm 14 is supported by the shaft 18A of the low speed roller 18, the structure of this portion is simplified, the valve train can be configured in a more compact manner, and the degree of freedom in design is increased, and the durability is improved. It can also contribute to improvement.

Further, by forming the oil passage 16C for supplying the working oil to the HLA 81 at the axial center portion of the rocker shaft 16, the oil passage 16C can be easily machined, and the structure is simplified, so that the operation can be performed. The oil can be reliably supplied, and the reliability of the HLA 81 is improved. The variable valve timing mechanism further has a simple and small structure of the hydraulic piston mechanism 17 and is installed near the axial center of the rocker arm 16, so that the degree of freedom in design is increased and the valve operating system is improved. It is possible to suppress an increase in the equivalent weight on the valve side. Therefore, the low speed rocker arm 14 can be provided with the low speed roller 18, and the high speed rocker arm 15 can be provided with the high speed roller 19. By abutting against the low speed cam or the high speed cam via the rollers 18 and 19, abrasion of the contact portion with the cam is suppressed, and the valve train is required for a long period of time. Performance can be maintained.

The HLA 81 is directed upward (toward the cap 81D upward) in the recessed portion of the rocking shaft side base portion 14B of the low speed rocker arm 14 located between the low speed rocker arm 14 and the high speed rocker arm 15. Since it is attached to the HLA 81, the HLA 81 has the advantages that it does not fall off and the assembly workability is good. Next, a second embodiment of the present invention will be described. FIG. 7 is a schematic sectional view showing the configuration of the main part thereof.

That is, as shown in FIG. 7, this valve operating system is the same as that of the first embodiment with a cylinder deactivating function, and the low speed cam 12 is used for the low speed as the first valve drive member. The rocker arm 26 as the third valve drive member is driven by the low speed cam 12 via the low speed rocker arm 26 so that the rocker arm 26 abuts. Further, as in the case of the first embodiment described above,
A high speed rocker arm 15 as a second valve drive member is in contact with the high speed cam 13, and the rocker arm 24 is driven by the high speed cam 13 via the high speed rocker arm 15.

The rocker arm 24 is integrally provided with a rocker shaft 16 as a swing shaft. The rocker shaft 16 is pivotally supported by a bearing portion 1A provided on the cylinder head or the like of the engine, and the rocker arm 24 can rotate about the rocker shaft 16. On the rocker arm 24, a swing arm 8 as an arm member is provided on the rocking end side via a pin 80B '.
0'is pivotally attached. Also in this example, as in the first embodiment, two valves are provided, and the valve contact portions 80C ', 80C' formed at one end of the swing arm 80 '.
Are in contact with these valves 2, 3.

At the other end of the swing arm 80 ', the HLA 8 is provided so that the relative phase between the swing arm 80' and the rocker arm 24 can be adjusted, as in the first embodiment.
1 is installed. As a result, similarly to the first embodiment, the clearance of the rocker arm 24 to the valves 2 and 3 is automatically adjusted via the swing arm 80 '.

In this embodiment also, the HLA81
And the swing arm 80 'are set in the same positional relationship as in the first embodiment. That is, as shown in FIG. 7, the rocker shaft 16 has an equipment hole 79 for equipping the HLA 81. The center of the equipment hole 79 (that is, the HLA 81) is the center of the swing arm 80 '. On the other hand, it is provided offset to the low-speed rocker arm 14 side.

The offset distance between the HLA 81 and the equipment hole 79 is within a range in which the HLA 81 can reliably adjust the relative phase between the swing arm 80 'and the low speed rocker arm 14, and is set to the maximum distance within this range. Has been done. As a result, the cross-sectional area of the rocker shaft 16 near the center of the swing arm 80 can be increased (see FIG. 2), and the rigidity of the rocker shaft 16 is improved.

The high-speed rocker arm 15 has the same structure as that of the first embodiment, and the rocker shaft 16 (that is, the rocker arm 2) is provided at the cylindrical base portion 15B thereof.
4) is rotatably supported with respect to 4), and has a swinging end portion 15A provided with a high speed roller 19 capable of contacting the high speed cam 13. The high-speed roller 19 is also pivotally supported by a shaft 19A pivotally supported by the swinging end 15A of the high-speed rocker arm 15 via a roller bearing so that the high-speed roller 19 can smoothly rotate.

On the other hand, the low-speed rocker arm 26 is a rocker arm with a roller like the high-speed rocker arm 15, and the rocker shaft 16 is provided at the cylindrical base portion 26B.
(That is, the rocker arm 24) is rotatably supported. The rocking end portion 26A of the low speed rocker arm 26 is provided with a low speed roller 18 capable of contacting the low speed cam 12. This low speed roller 18
Is pivotally supported by a shaft 18A pivotally supported by the swinging end 26A via a roller bearing so as to smoothly rotate.

Between the rocker arms 26 and 15 and the rocker shaft 16, a mode (non-coupling mode) in which the rocker arms 26 and 15 are rotatable with respect to the rocker shaft 16 and are not linked to the rocker arm 24, and a rocker arm is provided. Hydraulic piston mechanisms 27 and 17 are provided as mode switching means capable of switching a mode in which 26 and 15 rotate integrally with the rocker shaft 16 and operate in cooperation with the rocker arm 24 (cooperation mode).

Of these, the hydraulic piston mechanism 17 provided for the high speed rocker arm 15 is constructed in substantially the same manner as that of the first embodiment. A hydraulic piston mechanism 27 provided for the low speed rocker arm 26 is also provided.
Is in the piston chamber formed on the rocker shaft 16,
The rocker shaft 16 is provided with a piston 27A movably arranged in the diameter direction. One end of the piston 27A (the lower end in FIG. 7, which will be referred to as the base end hereinafter) and the cylindrical base 26B of the low speed rocker arm 26.
A spring 27B is interposed in a compressed state between the inner peripheral surface and the inner peripheral surface of the spring. Therefore, this piston 27A is the other end (the upper side end portion in FIG. 7 by the spring 27B,
Hereinafter, this end portion is urged toward the side).

On the inner peripheral surface of the cylindrical base portion 26B of the low speed rocker arm 26, a hole is formed on the tip end side of the piston 27A and is closed by a lid 27E. The inner wall of this hole and the piston 27A. Between the tip of the hydraulic chamber 27
G is formed. The tip portion of the piston 27A can enter into the hydraulic chamber 27G. The hydraulic oil is introduced into the hydraulic chamber 27G from an oil passage 16B formed in the axial center portion of the rocker shaft 16. When the hydraulic oil is supplied to the hydraulic chamber 27G, the spring 27B is supplied. 27A against the urging force of the piston
Is driven to the base end side, and the tip end of the piston 27A has a hole 2
7C, and when the supply of hydraulic oil to the hydraulic chamber 27G is cut off, the piston 27A is driven toward the tip end side by the urging force of the spring 27B, so that the tip end portion of the piston 27A fits into the hole 27C. Has become.

In other words, when the hydraulic oil is supplied to the hydraulic chamber 27G, the low speed rocker arm 26 is rotatable with respect to the rocker shaft 16 and does not operate in cooperation with the rocker arm 24 because the tip end portion of the piston 27A is fitted into the hole 27C. When the mode (non-coupling mode) is entered and the supply of hydraulic oil to the hydraulic chamber 27G is cut off, the hole 2 at the tip of the piston 27A is cut off.
By being disengaged from 7C, the low-speed rocker arm 26 rotates integrally with the rocker shaft 16 and is set in a mode in which the low-speed rocker arm 26 is linked with the rocker arm 24 (coupling mode).

The hydraulic oil is supplied to the hydraulic chambers 17G, 27G through a hydraulic oil supply system (not shown). This hydraulic oil supply system includes a hydraulic pump driven by an engine, pressure adjusting means for adjusting the hydraulic oil pressurized by the hydraulic pump to a required hydraulic pressure, and hydraulic oil adjusted by the pressure adjusting means. To the above oil passage 16
It is provided with a switching valve capable of independently switching between a supply state in which it is supplied to the hydraulic chambers 17G and 27G through A and 16B and a supply stopped state in which it is not supplied. Then, it is conceivable that the switching valve is constituted by, for example, a solenoid valve, and the switching valve can be electronically controlled by a controller (not shown). As a result, it is possible to appropriately switch the linked mode and the non-linked mode of the rocker arms 15 and 26 described above while controlling the switching valve according to the engine speed and the like.

Further, the rocker arms 26 and 15 are connected to the cam 1
Although not shown, a lost motion mechanism is provided in order to follow 2 and 13 respectively, as in the first embodiment. Particularly, here, the same lost motion mechanism is installed in both the low speed low speed rocker arm 26 and the high speed high speed rocker arm 15. Also in this valve system, the low speed roller 18 is made of a lighter material than the high speed roller 19. That is, the high speed roller 19
Is formed of a general iron-based metal material, etc.,
The low speed roller 18 is made of a material such as ceramic that is lightweight and has a required abrasion resistance.

By the way, also in the second embodiment, in order to simultaneously drive a plurality of valves 2 and 3 with a precise timing by one swing arm 80 ', the swing arm 80' is required.
It is necessary to properly adjust the clearance between the valve contact portions 80C ', 80C' and the stem 6 end portions of the valves 2, 3. Therefore, in the valve train structure with the variable valve timing mechanism of the second embodiment, as in the first embodiment, the shim 82 is attached to the end of the stem to adjust the clearance (FIG. 10). reference).

The valve train system structure of the second embodiment has the same structure as that of the first embodiment except the structure of the above-mentioned portion. Since the variable valve timing mechanism with hydraulic lash adjuster as the second embodiment of the present invention is configured as described above, the same operation and effect as those of the first embodiment can be obtained.

That is, since the HLA 81 is arranged so as to be offset from the center of the swing arm 80 'in the direction away from the high-speed rocker arm 15, the rocker shaft 16 is broken near the center of the swing arm 80'. The area is increased, the torsional rigidity of the rocker shaft 16 is significantly improved, and the dynamic characteristics of the valve train are improved. Therefore, during high speed operation, the swing arm 8 is moved from the high speed rocker arm 15 through the piston 17A of the mode switching means 17.
Torsional torque transmitted to 0 ', ie piston 1
In the range from the center of 7A to the center of the swing arm 80 ', it is possible to secure sufficient rigidity with respect to the twisting torque that tries to twist the rocker shaft 16, and it is possible to easily cope with high engine rotation. Like

Also, by switching the hydraulic piston mechanisms 27 and 17 as the mode switching means, it is possible to realize a cylinder deactivation mode in which the rocker arm 24 is not linked to either the low speed rocker arm 26 or the high speed rocker arm 15, and, for example, a plurality of By deactivating some of the cylinder-equipped engines, a fuel-efficient engine can be realized.

[0108]

As described in detail above, according to the variable valve timing mechanism with a hydraulic lash adjuster of the present invention as set forth in claim 1, the intake valve or the exhaust valve provided in the internal combustion engine and the valve timing at low speed are provided. Low-speed cam that rotates in response to the rotation of the crankshaft of the internal combustion engine, and a high-speed cam that rotates in response to the rotation of the crankshaft with a cam profile for valve timing at high speed A cam, a first valve driving member that abuts against the low speed cam and can be swung around a swing shaft by being driven by the low speed cam, and a cam that abuts against the high speed cam and is driven and swung by the high speed cam. Mode switching capable of switching between a second valve drive member that can oscillate around the moving shaft and a non-coupling mode in which the second valve drive member is not linked to the first valve drive member and a linked mode that is linked A step and a valve contact portion that contacts the valve to drive the valve, and is pivotally attached to the first valve drive member in a variable relative phase with respect to the first valve drive member to form the swing shaft integrally with the first valve drive member. A hydraulic lash adjuster is provided on the swing shaft, the hydraulic lash adjuster having an arm member that swings around and adjusting the relative phase of the first valve drive member and the arm member by contacting the arm member. Since the arrangement position of the pressure type lash adjuster is deviated from the center of the arm member in the width direction, the cross-sectional area of the swing shaft near the center of the arm member in the width direction becomes large, and the hydraulic type The torsional rigidity on the side where the lash adjuster is not biased is greatly improved.

Therefore, it becomes possible to secure sufficient rigidity with respect to the torsional torque input in this portion, and it is possible to easily cope with the high rotation of the internal combustion engine. Further, the improvement in the dynamic characteristics of the valve train reduces restrictions in designing the cam profile of the high-speed cam, and increases the degree of freedom in designing the performance characteristics of the engine.

Further, since the position where the reaction force is received from the arm member of the hydraulic lash adjuster is displaced from the center of the hydraulic lash adjuster, the reaction force causes the hydraulic lash adjuster to rotate and a part of the hydraulic lash adjuster. The only advantage is that it will not wear out.
Further, according to the variable valve timing mechanism with a hydraulic lash adjuster of the present invention as set forth in claim 2, in addition to the configuration of claim 1, the arrangement position of the hydraulic lash adjuster is the width of the arm member. Second to center of direction
Due to the configuration in which the arm member is biased away from the valve driving member, the cross-sectional area of the swing shaft near the center of the arm member in the width direction is increased, and the swinging between the second valve driving member and the arm member is increased. The torsional rigidity of the moving shaft is greatly improved. Therefore, during high-speed operation, sufficient rigidity can be ensured against the torsional torque input from the second valve drive member to the swing shaft via the mode switching means, and the internal combustion engine can be rotated at high speed. You will be able to respond easily. Further, the improvement in the dynamic characteristics of the valve train reduces restrictions in designing the cam profile of the high-speed cam, and increases the degree of freedom in designing the performance characteristics of the engine.

According to the variable valve timing mechanism with a hydraulic lash adjuster of the present invention as defined in claim 3, in addition to the structure of claim 1 or 2, the low speed cam of the first valve drive member is provided. A low-speed roller is interposed in the contact portion, and a high-speed roller is interposed in the high-speed cam contact portion of the second valve drive member, whereby the first valve drive member and the low-speed cam are connected. Wear of the contact portion and the contact portion between the second valve drive member and the high-speed cam is suppressed. Therefore, there is an effect that the durability of the valve train is improved.

According to the variable valve timing mechanism with a hydraulic lash adjuster of the present invention as defined in claim 4, in addition to the structure of claim 1 or 2, the arm member drives a plurality of valves. With this configuration, intake efficiency or exhaust efficiency is improved, and the performance of the internal combustion engine can be improved. Furthermore, according to the variable valve timing mechanism with a hydraulic lash adjuster of the present invention as set forth in claim 5, in addition to the configuration as set forth in claim 1 or 2, the valve contact portion is provided at a pivot portion of the arm member. On the other hand, it is arranged on the opposite side of the hydraulic lash adjuster, and the distance between the pivotal attachment portion of the arm member and the hydraulic lash adjuster is the distance between the pivotal attachment portion of the arm member and the valve contact portion. Due to the configuration that is set to be larger than the distance, the increase in the valve-side equivalent weight of the valve train is suppressed, and the acceleration and centrifugal force applied to the hydraulic lash adjuster are suppressed, so that the hydraulic lash adjuster is appropriate. Operate. Therefore, there is an effect that the reliability of the variable valve timing mechanism is improved.

The force acting on the hydraulic lash adjuster can be made smaller than the force acting on the valve. Therefore, the load on the hydraulic lash adjuster can be reduced as compared with the case where the hydraulic lash adjuster is provided at the position of the valve, and the hydraulic lash adjuster can be set to a small one with a small capacity. As a result, the weight of the valve train can be reduced, the high-speed performance of the valve train can be improved, and the weight of the entire internal combustion engine can be reduced.

According to the variable valve timing mechanism with a hydraulic lash adjuster of the present invention as defined in claim 6, an intake valve or an exhaust valve provided for an internal combustion engine and a cam profile for low speed valve timing are provided. A low-speed cam that rotates in response to the rotation of the crankshaft of the internal combustion engine, a high-speed cam that includes a cam profile for high-speed valve timing and that rotates in response to the rotation of the crankshaft, and a low-speed cam A first valve drive member that is in contact with the first speed control cam and is capable of swinging about the swing axis driven by the low speed cam; and a first valve drive member that is in contact with the high speed cam and is driven by the high speed cam and swings about the swing axis. Second valve drive member and the first valve drive member
A third valve drive member which is formed coaxially with the swing center axes of the valve drive member and the second valve drive member and can be linked to the first valve drive member or the second valve drive member; An arm member that has a valve contact portion that drives the valve and that is pivotally attached to the third valve driving member in a variable relative phase and that swings integrally with the third valve driving member around the swing axis. Providing the third
A low speed linkage mode in which the valve drive member is linked only to the first valve drive member, a high speed linkage mode in which the valve drive member is linked to the second valve drive member, and linkage to both the first valve drive member and the second valve drive member. A mode switching means for switching between a cylinder deactivation mode that does not allow the cylinder to operate and a hydraulic lash adjuster that contacts the arm member and adjusts the relative phase of the third valve drive member and the arm member, The arrangement position of the hydraulic lash adjuster is biased with respect to the center of the arm member in the width direction, so that the cross-sectional area of the swing shaft near the center of the arm member in the width direction becomes large, The torsional rigidity input to the swing shaft from the side where the hydraulic lash adjuster is not biased is greatly improved.

Therefore, it becomes possible to secure sufficient rigidity with respect to this torsion torque, and it becomes possible to easily cope with the high rotation of the internal combustion engine. Further, the improvement in the dynamic characteristics of the valve train reduces restrictions in designing the cam profile of the high-speed cam, and increases the degree of freedom in designing the performance characteristics of the engine. Also, the position where the reaction force from the arm member of the hydraulic lash adjuster shifts from the center of the hydraulic lash adjuster, so this reaction force rotates the hydraulic lash adjuster, and only part of the hydraulic lash adjuster wears. There is an advantage of not doing.

According to the variable valve timing mechanism with a hydraulic lash adjuster of the present invention as set forth in claim 7, in addition to the structure of claim 6, the arrangement position of the hydraulic lash adjuster is the arm. Due to the configuration in which it is biased in the direction away from the second valve drive member with respect to the center of the width direction of the member, the cross-sectional area of the swing shaft near the center of the arm member in the width direction becomes large, and the second valve The torsional rigidity of the swing shaft between the drive member and the arm member is significantly improved. Therefore, during high-speed operation, sufficient rigidity can be ensured against the torsional torque input from the second valve drive member to the swing shaft via the mode switching means, and the internal combustion engine can be rotated at high speed. You will be able to respond easily. Further, the improvement in the dynamic characteristics of the valve train reduces restrictions in designing the cam profile of the high-speed cam, and increases the degree of freedom in designing the performance characteristics of the engine.

According to the variable valve timing mechanism with a hydraulic lash adjuster of the present invention as defined in claim 8, in addition to the structure of claim 6 or 7, the low speed cam of the first valve drive member is provided. A low-speed roller is interposed in the contact portion, and a high-speed roller is interposed in the high-speed cam contact portion of the second valve drive member, whereby the first valve drive member and the low-speed cam are connected. Wear of the contact portion and the contact portion between the second valve drive member and the high-speed cam is suppressed. Therefore, there is an effect that the durability of the valve train is improved.

According to the variable valve timing mechanism with a hydraulic lash adjuster of the present invention described in claim 9, the arm member drives a plurality of valves in addition to the configuration of claim 6 or 7. With this configuration, intake efficiency or exhaust efficiency is improved, and the performance of the internal combustion engine can be improved. Furthermore, according to the variable valve timing mechanism with a hydraulic lash adjuster of the present invention as set forth in claim 10, in addition to the configuration of claim 6 or 7, the valve contact portion is provided at the pivot portion of the arm member. On the other hand, it is arranged on the opposite side of the hydraulic lash adjuster, and the distance between the pivotal attachment portion of the arm member and the hydraulic lash adjuster is the distance between the pivotal attachment portion of the arm member and the valve contact portion. By setting it to be larger than the distance, the increase in the valve-side equivalent weight of the valve train is suppressed and the acceleration and centrifugal force applied to the hydraulic lash adjuster are suppressed, and the hydraulic lash adjuster operates properly. To do. Therefore, there is an effect that the reliability of the variable valve timing mechanism is improved.

The force acting on the hydraulic lash adjuster can be made smaller than the force acting on the valve. Therefore, the load on the hydraulic lash adjuster can be reduced as compared with the case where the hydraulic lash adjuster is provided at the position of the valve, and the hydraulic lash adjuster can be set to a small one with a small capacity. As a result, the weight of the valve train can be reduced, the high-speed performance of the valve train can be improved, and the weight of the entire internal combustion engine can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a main part configuration of a variable valve timing mechanism with a hydraulic lash adjuster as a first embodiment of the present invention, and a diagram corresponding to FIG. 9.

FIG. 2 is a schematic cross-sectional view (cross-sectional view taken along the line CC in FIG. 1) showing the cross-sectional shape of the swing shaft in the variable valve timing mechanism with a hydraulic lash adjuster as the first embodiment of the present invention. (A) is a view showing a sectional shape of a swing shaft of a conventional mechanism, and (b) is a view showing a sectional shape of a swing shaft of a mechanism of the present invention.

FIG. 3 is a schematic diagram for explaining a force acting on an arm member in a variable valve timing mechanism with a hydraulic lash adjuster as a first embodiment of the present invention, in which (a) the arm member is symmetrical. Schematic diagram of the case,
(B) is a schematic diagram when an arm member is left-right asymmetrical.

FIG. 4 is a schematic diagram showing a contact portion between an arm member and a hydraulic lash adjuster in a variable valve timing mechanism with a hydraulic lash adjuster as a first embodiment of the present invention, FIG. (B) is the side view.

FIG. 5 is a schematic vertical sectional view showing a hydraulic lash adjuster in a variable valve timing mechanism with a hydraulic lash adjuster as a first embodiment of the present invention.

FIG. 6 is a diagram showing a cam profile in a variable valve timing mechanism with a hydraulic lash adjuster as a first embodiment of the present invention.

FIG. 7 is a schematic cross-sectional view showing the main configuration of a variable valve timing mechanism with a hydraulic lash adjuster as a second embodiment of the present invention.

FIG. 8 is a schematic perspective view showing a main configuration of a variable valve timing mechanism.

9 is a schematic cross-sectional view showing a main part configuration of a conventional variable valve timing mechanism with a hydraulic lash adjuster, which is a cross-sectional view taken along the line AA in FIG.

FIG. 10 is a schematic cross-sectional view showing a main part configuration of a conventional variable valve timing mechanism with a hydraulic lash adjuster, and is a cross-sectional view taken along the line BB in FIG.

11 is a schematic cross-sectional view for explaining the operation of the conventional variable valve timing mechanism with a hydraulic lash adjuster and is a diagram corresponding to FIG. 9. FIG.

[Explanation of symbols]

1A Bearing part 2,3 Intake valve or exhaust valve 11 Cam shaft 12 Low speed cam 13 High speed cam 14 Rocker arm as the first valve driving member 14B Rocking shaft side base 15 Rocker arm as the second valve driving member 15A Swing end Part 15B Cylindrical base 16 Rocker shaft as rocking shaft 16A Oil passage 16C Oil passage 17,27 Hydraulic piston mechanism as mode switching means 17A, 27A Piston 17B, 27B Return spring 17C, 27C Hole 17G, 27G Hydraulic chamber 18 Low speed Roller 18A shaft (swing arm shaft) 19 high speed roller 19A shaft 24 rocker arm as the third valve drive member 26 rocker arm as the first valve drive member 26A swinging end 26B tubular base 27E lid 79 mounting holes 80, 80 ′ Swing arm as arm member 80B 'pin 80C, 80C' valve contact part 81 hydraulic lash adjuster (hydraulic lash adjuster or HLA) 81A body 81B plunger 81C check valve mechanism 81D plunger cap 81E plunger cap retainer 81F reserve chamber 81G high pressure chamber 81H check valve ball 81I Valve retainer 81J Spring 81K Check valve spring 81L Hole 81N Abutment 82 Shim

Claims (10)

[Claims] 1. A low-speed cam which has an intake valve or an exhaust valve provided for an internal combustion engine and a cam profile for low-speed valve timing and which rotates in response to rotation of a crankshaft of the internal-combustion engine; A high-speed cam that has a cam profile for valve timing and that rotates in response to rotation of the crankshaft; and a high-speed cam that comes into contact with the low-speed cam and that is driven by the low-speed cam and can swing about a swing axis. A first valve driving member, a second valve driving member that is in contact with the high speed cam and is driven by the high speed cam and can swing about a swing axis; and a second valve driving member that is the first valve driving member. A mode switching means capable of switching between a non-coupling mode in which the valve is not linked to the valve and a linking mode in which the valve is linked to the valve, and a valve contact portion that contacts the valve to drive the valve and changes the relative phase with respect to the first valve drive member To An arm member that is pivotally mounted and swings around the swing shaft integrally with the first valve drive member is provided, and the relative phase between the first valve drive member and the arm member is adjusted by contacting the arm member. A hydraulic lash adjuster is provided on the oscillating shaft, and the position of the hydraulic lash adjuster is deviated from the center of the arm member in the width direction. Variable valve timing mechanism with. 2. The arrangement position of the hydraulic lash adjuster is biased in a direction away from the second valve drive member with respect to the center of the arm member in the width direction.
A variable valve timing mechanism with a hydraulic lash adjuster according to claim 1. 3. A low speed roller is interposed in the low speed cam contact portion of the first valve drive member, and a high speed roller is interposed in the high speed cam contact portion of the second valve drive member. The variable valve timing mechanism with a hydraulic lash adjuster according to claim 1 or 2, characterized in that. 4. The variable valve timing mechanism with hydraulic lash adjuster according to claim 1, wherein the arm member is configured to drive a plurality of valves. 5. The valve contact portion is disposed on the opposite side of the pivotal attachment portion of the arm member from the hydraulic lash adjuster, and the pivotal attachment portion of the arm member and the hydraulic lash adjuster are disposed. The variable valve with a hydraulic lash adjuster according to claim 1 or 2, characterized in that the distance from the valve is set to be larger than the distance between the pivotally attached portion of the arm member and the valve contact portion. Timing mechanism. 6. A low speed cam which is provided with an intake valve or an exhaust valve provided for an internal combustion engine, and a cam profile for low speed valve timing, and which rotates in response to rotation of a crankshaft of the internal combustion engine; A high-speed cam that has a cam profile for valve timing and that rotates in response to rotation of the crankshaft; and a high-speed cam that comes into contact with the low-speed cam and that is driven by the low-speed cam and can swing about a swing axis A first valve drive member, a second valve drive member that abuts against the high speed cam and is driven by the high speed cam and can swing around a swing axis; and a first valve drive member and a second valve drive member. A third valve drive member which is formed coaxially with the swing center axis and can be linked to the first valve drive member or the second valve drive member, and a valve contact portion which contacts the valve and drives the valve. Together with the third valve drive member The third valve driving member is provided with an arm member pivotably rotatably variably in phase with respect to the third valve driving member and swinging integrally with the third valve driving member, and the third valve driving member is linked only to the first valve driving member. A mode switching means for switching between a low-speed link mode, a high-speed link mode in which the second valve drive member is linked, and a cylinder deactivation mode in which neither the first valve drive member nor the second valve drive member is linked, and the arm member. A hydraulic lash adjuster that adjusts the relative phase between the third valve drive member and the arm member is provided on the swing shaft, and the position of the hydraulic lash adjuster is set to the arm member. A variable valve timing mechanism with a hydraulic lash adjuster, which is deviated from the center in the width direction. 7. A position where the hydraulic lash adjuster is disposed is biased in a direction away from the second valve drive member with respect to a center of the arm member in the width direction.
A variable valve timing mechanism with a hydraulic lash adjuster according to claim 6. 8. A low speed roller is interposed in the low speed cam contact portion of the first valve drive member, and a high speed roller is interposed in the high speed cam contact portion of the second valve drive member. The variable valve timing mechanism with a hydraulic lash adjuster according to claim 6 or 7, characterized in that. 9. The variable valve timing mechanism with a hydraulic lash adjuster according to claim 6 or 7, wherein the arm member is configured to drive a plurality of valves. 10. The valve contact portion is disposed on the opposite side of the pivotal attachment portion of the arm member from the hydraulic lash adjuster, and the pivotal attachment portion of the arm member and the hydraulic lash adjuster are disposed. The variable valve with a hydraulic lash adjuster according to claim 6 or 7, characterized in that the distance between the valve and the pivot member of the arm member is set to be larger than the distance between the valve contact portion. Timing mechanism.