JP2605282Y2 - Valve mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve mechanism, and more particularly, to a variable structure of a valve lift, a valve operating angle and a valve opening / closing timing.

[0002]

2. Description of the Related Art As is well known, in a valve mechanism used in an automobile engine, one end of a rocker arm is used as a fulcrum, and the other end is pressed by a valve opening / closing cam to slide a valve stem. There is a structure that opens and closes a valve. At one end of the rocker arm in the above-described valve mechanism, a lash adjuster that doubles as a fulcrum and automatically adjusts the valve clearance is provided. By the way, in the above-described valve mechanism, although the valve clearance can be automatically adjusted, the maximum opening amount of the valve corresponds to the maximum lift amount from the cam profile, and moreover, this amount is At present, it is not possible to set the intake / exhaust efficiency according to the load from the engine speed and the accelerator opening because it is always constant. That is, for example, in the case of an engine that requires high-speed rotation, the above-described cam profile is set in consideration of increasing the intake ratio and the exhaust efficiency of the air-fuel mixture. Fuel consumption rate tends to be sacrificed. On the other hand, when the cam profile is set in consideration of the fuel consumption rate, the output may not be sufficiently obtained at the time of high-speed rotation or high-load operation.

In order to eliminate such a problem, the inventor of the present invention has proposed a structure capable of obtaining the intake and exhaust efficiencies required in each operation range, particularly at low speed, low load operation and at high speed, high load operation. did. In this structure, as shown in FIG. 14, an oil supply oil passage B and an oil discharge oil passage C are connected to a space between the bottom side of the lash adjuster A and the cylinder head. A lash adjuster A provided on the cylinder head is supplied / discharged to / from this space by using on-off valves B1 and C1 disposed on the cylinder head.
Can be slid with the cylinder head, and as the sliding position, a position where the rocker arm D can come into non-contact with the cam E or an opposing relationship in which the smallest valve lift can be set (see FIG. 14A); A position (see FIG. 14B) at which the rocker arm D can abut on the entire area from the base circle of the cam E to the maximum diameter portion is set. FIG.
The position shown in (A) is set at the time of low-speed, low-load operation. When the lash adjuster A is arranged at this position, the rocking time of the rocker arm D is minimized, and Valve lift is also minimized. Also,
The position shown in FIG. 14 (B) is set at the time of high-speed, high-load operation. When the lash adjuster A is arranged at this position, the rocker arm D is moved up to the maximum diameter portion of the cam E. The swing amount obtained in the range is set, whereby the swing amount of the rocker arm D is maximized, and a state in which the valve lift is the largest is obtained.

[0004]

By the way, in a structure in which the valve lift is changed by changing the position of the lash adjuster A, for example, FIG.
In the case of switching from a valve lift shown by a solid line to a state where a small valve lift is obtained as shown by a two-dot chain line, in the case of a large lift amount (in the area indicated by the symbol A in FIG. 15) at the valve opening / closing timing, In comparison, in the case of a small lift amount (the area indicated by the symbol A ′ in FIG. 15), the operation time is short. Therefore, in this case, there is no overlap period (the area indicated by the symbol T in the figure) required for exchange of the new air-fuel mixture and the combustion gas, and there is a possibility that the combustion cannot be maintained.

[0005] Further, when the above-mentioned small lift amount is set, there is a high-speed and low-load condition. In this case, a phenomenon similar to the above-mentioned case may occur.

Accordingly, an object of the present invention is to solve the above-described problem of the variable valve lift structure, and to maintain an appropriate combustion when the lift amount is set according to the operating conditions of the engine. An object of the present invention is to provide a valve mechanism having a structure capable of improving fuel efficiency and easily securing a required engine output for high-speed, high-load operation and low-speed, low-load operation without causing malfunction.

[0007]

In order to achieve this object, the present invention provides a method for sliding a lash adjuster by supplying and discharging oil to and from a space between a bottom side of the lash adjuster and a cylinder head. The lift amount changes the valve lift by changing the operating state of the rocker arm by the valve opening / closing cam by changing the facing position of the lash adjuster and the rocker arm.
Further means Te valve mechanism odor with, et provided between the timing belt pulley and the valve opening and closing cam shaft driven by class link shaft is, the phase that changes the phase of the valve opening and closing camshaft relative to the timing belt pulley and the change means, at least, the engine of rotation
The lift amount changing means according to the information and the load information;
A control unit that controls the operation of the phase changing unit, wherein the control unit is configured to reduce the valve lift to a minimum during idle operation.
While controlling the lift amount changing means so that
Even when the valve lift is at a minimum, the mixture
Valve opening / closing timing that provides an overlap that can be changed
It is characterized in that the phase changing means is controlled so as to be synchronized.

[0008]

[0009]

According to the present invention, the lash adjuster allows
In addition to the lift amount changing means for changing the
Change the phase of the imming belt pulley and camshaft
Providing phase changing means for changing valve timing
Lift and overlap can be changed independently
This makes it necessary even in the operating range where the lift amount is minimized.
Large amount of overlap .

[0010]

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described in detail with reference to FIGS.

FIG. 1 is a schematic diagram showing a hydraulic circuit configuration of a valve mechanism according to an embodiment of the present invention. This hydraulic circuit has a space between a bottom surface of a lash adjuster having the structure shown in FIG. 14 and a cylinder head. This is for supplying and discharging oil to and from the intake side (in the figure, the symbol I
This indicates that lash adjusters having the structure shown in FIG. 14 are provided on the exhaust side (represented by the symbol EX in the figure) and on the exhaust side (represented by the symbol EX in the figure). That is, in the valve mechanism 1 according to the present embodiment, the oil supply passage for the oil from the oil pan via the oil pump 2 connects the bottom surface of the lash adjuster 3 having the structure shown in FIG. A first oil passage 4 is provided in the space between the first oil passage 4 and a connection between the first oil passage 4 and the space in the oil passage. The check valve and the first oil passage 4 allow only the flow of oil toward the space. One on-off valve 5 is provided. Further, a second opening / closing valve 7 is provided in the oil passage 6 for discharging oil from the space between the bottom surface side of the lash adjuster 3 and the cylinder head to the oil pan.

On the other hand, the above-described oil supply oil passage 4 is provided with a third oil passage 8 for supplying oil to a phase changing means described later. A third on-off valve 9 is provided for controlling the supply of the gas and setting the state of the phase changing means. Although the phase changing means is not shown in detail, for example, a piston capable of performing displacement along the lead direction by being connected via a helical spline between the timing belt pulley and the valve opening / closing cam is arranged. By changing the sliding position of the piston in the axial direction by hydraulic control, the phase of the valve opening / closing cam shaft, which is helically spline-coupled to the timing belt pulley, is changed. It has become.

The above-described first and second on-off valves 5, 7
Can be set to switch between an open position and a closed position, and the third on-off valve 9 switches the position of a piston 9A that can slide in an oil path as shown in FIG. Thereby, a state for setting an oil path for discharging oil from the phase changing means (see FIG. 2 (A)) and a state for supplying oil to the phase changing means (see FIG. 2 (B)) And a two-way switching valve that can set the pressure.

Each of the first, second and third on-off valves 5, 7, and 9 is set to an operation state by a control unit described later. That is,
In FIG. 3, the control unit 10 has a main part constituted by a microcomputer, and outputs, on its input side, oil pressure sensors 11, 12, and 13 arranged in each oil passage, and engine load information. An accelerator opening sensor (referred to as a throttle opening in the figure) 14, an engine speed sensor 15, an idle switch 16, a starter switch 17, an intake air amount sensor 18, and, for example, a TCL mode switch 19 for optimizing the slip characteristic, automatic mode switch 20, vehicle speed reed switch 21, vehicle speed sensor 2
2 are connected. Each of the above-mentioned sensors and switches is also provided with a switch for discriminating between an automatic vehicle and a manual vehicle in a gear shift operation. In the case of a manual vehicle, an MVTLS described later is set to a fixed mode. Has become.

On the output side of the control unit 10, a first on-off valve 5 and a second on-off valve 5, which are provided on the intake side and the exhaust side, respectively, are provided.
The on-off valve 7 and the third on-off valve 9 (in the figure, for convenience, the symbol IN is assigned to the intake side to mean the intake side and the exhaust side,
The exhaust side is denoted by EX.) In addition to the above, the hydraulic warning light 23, the A / T control unit 24, and the first
And a hydraulic circuit section for executing a mode for controlling a valve lift, a valve operating angle and a valve opening / closing timing using the third opening / closing valve (hereinafter referred to as MVTLS: multi-valve timing and lift system). MVTLS warning lights 25 for warning the failure of the MVTLS are respectively connected.

In the control unit 10, the above-described MVTL
S, that is, the valve lift, the valve operating angle, and the valve opening / closing timing are controlled. The valve lift and the valve operating angle are controlled by opening / closing control of the first opening / closing valve 5 and the second opening / closing valve 7. As shown in FIG. 4, the valve lift is set from a minimum to a maximum state, and as shown in FIG. 5, the valve lift is set from a state in which the opening and closing of the valve is stopped to a maximum state. Furthermore, the state is changed by setting the opposite state. As for the valve opening / closing timing, as shown in FIG. 6, the state in which the valve opening / closing timing is advanced can be set by changing the position of the piston by controlling the supply of oil to the phase changing means. I have. In each of these controls, there are a case where both the intake side and the exhaust side are set to the same state, and a case where different states are set according to different conditions.
Further, in this embodiment, when executing MVTS (a multi-valve timing system for changing a valve opening / closing timing) and MVLS (a multi-valve lift system for changing a valve lift) to be described later, one intake / It is assumed that the exhaust valve is operated by a set practical cam having a profile allowing normal running, and the other intake / exhaust valve is operated by a high-speed cam set to a high-speed performance-oriented profile. For this reason, such a change in the valve lift, the valve operating angle, and the valve opening / closing timing is set in a pattern shown in FIG. In FIG. 7, the MVTS changes the valve opening / closing timing using the third opening / closing valve 9, and
S changes the valve lift using the first and second on-off valves 5 and 7, and the symbol S in FIG.
IN indicates the intake side, and EX indicates the exhaust side. When the MVTS is off, the valve opening / closing timing is not changed. When the MVLS is off, the valve lift is minimum. It means that the status has been set. That is, FIG. 7A shows a state where both the MVTS and the MVLS on the intake side and the exhaust side are off. In this case, the valve lift is set to a minimum, for example, and the valve opening / closing timing is set to a normal value. That is, the state is not advanced. Therefore, in this case, for example, the valve is opened and closed at a timing at which combustion can be performed with a required minimum amount of intake air, such as during idling. Since this pattern is set so that the engine does not stop, it is forcibly set, for example, when a failure occurs in the hydraulic system of the engine. FIG. 7 (B) shows the MVT
S is performed only on the intake side, and MVLS shows a case where both the intake and exhaust sides are off. In this case,
The valve lift is minimized on both the intake side and the exhaust side, and the valve opening / closing timing is advanced on the intake side. Therefore, in this case, while the amount of intake air due to the minimum valve lift is reduced, a problem that occurs when simply shifting to a low lift, that is, as described with reference to FIG. The problem that the lap period cannot be set is solved to prevent the combustion from becoming abnormal. This pattern is used to prevent MVTLs from running when a failure occurs in MVTLS during running.
In the event of a failure in S, it is forcibly set. FIG. 7C shows a case where the MVTS is performed on the intake side and the exhaust side, and the MVLS is performed only on the intake side. In this case, the valve lift on the intake side is, for example, , Increased from the state shown by the dashed line,
Then, the valve opening / closing timing on the intake side is advanced from the position shown by the two-dot chain line as shown by the solid line. Therefore, in this case, in addition to the increase in the valve lift, the valve overlap corresponding to the increase is set, and is applied to, for example, a high-load operation range at a medium speed rotation of the engine. FIG. 7D shows a case where the MVTS is executed only on the intake side and the MVLS is executed on the intake side and the exhaust side. In this case, the valve lifts on the intake side and the exhaust side are shown. Increases from the state shown by the one-dot chain line, and the valve opening / closing timing on the intake side is advanced from the state shown by the two-dot chain line as shown by the solid line. Therefore, in this case, it is possible to prevent the intake delay when increasing the output by advancing the start of the intake, and to sufficiently set the overlap period necessary for the exchange of the air-fuel mixture and the combustion gas. It can be applied to the full-load operation range when the engine is rotating at medium speed. FIG. 7E shows a case where MVTS is not executed on the intake side and the exhaust side, and MVLS is executed only on the intake side. In this case, FIG.
As in (D), the intake valve operating angle and valve lift
And set it so that a sufficient air-fuel mixture can be inhaled.
For example, it is applied at the time of low load operation at the time of high speed rotation. Further, FIG. 7F shows a case where MVST is not executed on the intake side and the exhaust side , and MVLS is executed. In this case, the intake amount and the emission amount of the combustion gas are maximized. At the same time, the overlap period is set to a sufficient amount . Therefore, in this case, as in the case of high-speed rotation and high-load operation, suction for obtaining the required output is performed.
With exhaust amount is set, the overlap mentioned above is also sufficient state.

Each of the above-described patterns is applied to, for example, a map corresponding to the operation mode shown in FIG. In FIG. 8, “POWER”, “NORMAL” and “EC
The display "ONO" means the operation mode, and "POWE
The “R” mode is a case where the output corresponding to the high load operation range, in other words, a state in which a high output is desired is requested, and a so-called output priority mode is set. The “NORMAL” mode is the above-described high output mode. This is a case in which a so-called operation mode in which a normal output is obtained is required without requiring the above, and the “ECONO” mode is a case in which the “POWER” mode is a fuel efficiency priority mode.

FIG. 9 shows a case where the pattern shown in FIG. 7 is used for TCL control (traction control), control relating to the first gear stage and maximum speed control.
In this control, the TCL control adjusts the intake air amount on the engine side and the valve opening / closing timing so as to suppress the occurrence of a slip at the time of starting and effectively utilize the output of the engine between the tire and the road surface to reduce the slip. This is a control for eliminating the motor, especially in an automatic car.
This control is suitable for automatically suppressing the occurrence of slip due to excessive depression of the accelerator. Therefore, in a manual vehicle, this control is basically not performed. The control at the time of driving by the first shift is a control for not giving a jerky feeling to the running feeling when the accelerator is depressed and when the accelerator is not depressed. This is control to make it easier to cut overpower.

Since the present embodiment has the above configuration,
The operation will be described below with reference to a flowchart showing the operation of the control unit. In the flow charts shown in FIG. 10 and subsequent figures, the items shown in parentheses indicate that the contents of the signals input prior to the processing in the flow chart are shown, and the MVTLS pattern is used.
It should be noted that the pattern corresponds to the pattern shown in FIG. When the electric circuit is turned on by setting the engine key, when the engine is started by turning on the starter switch, the rotation speed in a state where the starter switch is turned off is a predetermined value, in this case, 350 rpm. Determine if there is. If the engine speed is equal to or lower than the predetermined value, the MVTLS fixed mode is set. The MVTLS fixed mode in this case is a mode that is set when it is determined that a failure has occurred in the hydraulic system of the engine, and as shown in FIG. 8, the pattern shown in FIG. The pattern shown in FIG. When this pattern is set, it is determined whether or not the engine has been started. If the engine has been started, the above-described fixed mode is set until the vehicle travels, that is, until the gear is changed.

On the other hand, if the rotation speed is at a predetermined value with the starter switch turned off, the operation mode is switched to the operation mode as shown in FIG. It is determined whether the vehicle is in operation or not.
The pattern shown in FIG. 7A in the VTLS is set. When the pattern shown in FIG. 7A is set, the on / off state of the vehicle speed reed switch is determined, and when it is on, it is determined whether or not the first shift stage is set. At the time of selection setting of the first stage, the control for the first stage shown in FIG. 9 is executed, and the pattern shown in FIG. 7 is selected based on the control.

On the other hand, when the vehicle speed reed switch is off, the pattern shown in FIG. 7A in the MVTLS is set in the case of the manual vehicle, and according to the determination of the select position in the case of the automatic vehicle. If it is determined that the vehicle is not traveling, the pattern shown in FIG. 7 (A) is set, and the select gear for traveling (each range of L, 2, and D) is selected. In this case, it is determined whether the power control is being performed. If the power control is being performed, the TCL control shown in FIG. 9 is executed.

When the power control is not performed, the MVLS failure mode shown in FIG. 8 is selected and executed.

On the other hand, if the result of the determination as to whether or not the first stage is selected does not correspond to the first stage, it is determined whether or not the vehicle is at an excessively high cut speed based on an input signal from a vehicle speed sensor. When the vehicle is in the overspeed range,
When the maximum speed control mode shown in FIG. 9 is set, and the vehicle speed is not in the maximum speed range, the MVTLS is normally controlled. In this case, it is determined whether the throttle switch, the engine speed, and the idle switch corresponding to the operation of the engine brake are in the ON state, respectively, and the pattern shown in FIG. 7 according to each operation mode shown in FIG. 8 is determined. Is set. Until the engine key is turned off, the above-described respective determinations are continued, and the MV according to the pattern shown in FIGS.
TLS is performed.

FIG. 11 shows an initial check routine executed during the processing shown in FIG. 10. In this processing, the operation of the control unit 10 is checked by a predetermined method, and necessary checks are made in accordance with the result. Perform various processing.

FIG. 12 shows a failure check routine of a hydraulic circuit used for executing MVTLS. The failure detection routine detects the oil pressure of the oil from each oil passage. The pattern shown in FIG. 7 is selected based on the failure mode shown in FIG.

FIG. 13 shows a routine for checking the operation of the MVTLS.
When the TLS is executed, by inputting the signals of the engine speed, the intake air amount and the throttle opening, the currently set MVTLS pattern and the basic pattern shown in FIG. If they do not match the basic pattern, the MVTLS fixed mode shown in FIG. 8 is set and a warning is displayed. The criterion for determining an error in this case is, for example, that the intake air amount obtained from the engine speed and the throttle opening is 10%.
As described above, when the basic map is different from the basic map, or when the valve lift is changed, that is, the first and second on-off valves 5,
After the duty control by the operation control of 7 is executed,
It is assumed that an error occurs in the intake air amount.

[0028]

[Effect of the invention] As described above, according to the invention, the rush
Lift amount change to change valve lift amount by adjuster
In addition to further measures, the timing belt pulley and camshaft
Phase change to change valve timing by changing valve phase
The lifting and overlapping amounts
Can be changed independently, which minimizes lift
The required overlap amount can be secured even in the restricted operating range
To prevent the combustion state from becoming abnormal,
Good combustion even in the operating range with minimum
Was made possible .

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a hydraulic circuit configuration of a valve mechanism according to an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining a configuration of a phase changing unit used by the hydraulic pressure circuit shown in FIG. 1;

FIG. 3 is a block diagram for explaining a configuration of a control unit used in the hydraulic circuit shown in FIG.

FIG. 4 is a diagram illustrating an example of a change state of a valve lift set by a control unit illustrated in FIG. 3;

5 is a diagram for explaining another example of a change state of a valve lift set by the control unit shown in FIG. 3;

FIG. 6 is a diagram for explaining an example of a change state of valve opening / closing timing set by a control unit shown in FIG. 3;

FIG. 7 is a diagram for explaining a pattern of a valve lift, a valve operating angle, and a valve opening / closing timing in a hydraulic circuit obtained by setting of a control unit shown in FIG. 3;

FIG. 8 is a selection map for explaining a valve lift and a valve opening / closing timing set according to a set operation mode.

FIG. 9 is a selection map for explaining a valve lift and a valve opening / closing timing for each function in an operation mode of the automatic vehicle.

FIG. 10 is a flowchart for explaining the operation of the control unit shown in FIG. 3;

FIG. 11 is a flowchart showing an initial check routine executed by the control unit shown in FIG. 3;

FIG. 12 is a flowchart showing a hydraulic circuit check routine executed by a control unit shown in FIG. 3;

FIG. 13 is an MVT executed by the control unit shown in FIG. 3;
9 is a flowchart for explaining an LS operation check routine.

FIG. 14 is a schematic diagram illustrating a schematic configuration of a lash adjuster used in the valve mechanism according to the embodiment of the present invention.

FIG. 15 is a diagram showing valve lift and valve opening / closing timing for describing a problem in the valve mechanism shown in FIG. 14;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 valve mechanism 3 lash adjuster 4 first oil path 5 first on-off valve 6 second oil path 7 second on-off valve 8 oil path to phase changing means 9 third for setting attitude of phase changing means Open / close valve 10 control unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-163916 (JP, A) JP-A-5-44508 (JP, A) JP-A-62-151155 (JP, A) JP-A-3-151 151509 (JP, A) Japanese Utility Model Showa 60-118316 (JP, U) Japanese Utility Model 1-173307 (JP, U) Japanese Utility Model 3-17106 (JP, U) Japanese Utility Model Utility Model 63-200607 (JP, U) Japanese Utility Model Application Showa 63-200608 (JP, U) Japanese Utility Model Application Hei 3-99806 (JP, U) Japanese Utility Model Application Showa 60-52323 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 13/02 F01L 1/00-13/00

Claims (1)

(57) [Scope of request for utility model registration] The lash adjuster slides by supplying and discharging oil to and from a space between a bottom surface side of the lash adjuster and a cylinder head, thereby changing a position where the lash adjuster faces the rocker arm. Lift amount change that changes the valve lift amount by changing the operating state of the rocker arm by the valve opening / closing cam
Means Te valve mechanism odor with a et provided between the timing belt pulley and the valve opening and closing cam shaft driven by class link shaft is, over
A phase changing means for changing the phase of the valve opening and closing camshaft for serial timing belt pulley, at least, in response to the rotation information and load information of the engine
A control unit that controls the operation of the lift amount changing unit and the phase changing unit, wherein the control unit is configured to minimize a valve lift during idle operation.
Controlling the lift amount changing means so as to be in a state.
Even when the valve lift is at a minimum, the mixture and combustion gas
Valve opening and closing to obtain overlap that can be replaced
Valve mechanism, wherein the this <br/> for controlling the phase changing means such that the timing.