JPS6027714A - Controller of valve timing of engine - Google Patents

Abstract

PURPOSE:To obtain strong press-in effect due to suction inertia by preventing blow- back of suction air, by a method wherein the valve-closing timing of a suction valve is led in a low speed region and the valve-closing timing is made into lag side in a high speed region, in an engine having the two suction valves per cylinder. CONSTITUTION:The titled engine possesses two suction ports and two suction valves per cylinder, the operation state of the engine is detected by an engine speed detector and a load detector, and when it is revealed that they are in a low speed region, the valve-closing timing of the two suction valves are set up at lead sides (a), (b). When they are in a high load region the two suction valves are set up at lag sides (c), (d). With this construction, blow-back at the terminal of a suction stroke in the low speed region is prevented from occurring, strong press-in effect due to strong suction inertia is obtained in the high speed region, filling efficiency is improved and then a high output is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a valve timing control device that controls the opening phase of an intake valve or an exhaust valve in response to changes in operating conditions.

(Description of Prior Art) Generally, it is preferable to change the opening/closing timing of the intake and exhaust valves of an engine depending on the operating state of the engine. For example, in high-load engine operation, it is necessary to increase the charging efficiency by increasing the valve opening time in order to obtain high output, but if the valve opening period is lengthened by delaying the timing of closing the intake valve, The problem of intake air blowback occurs during high-load, low-speed operation. In addition, during the overlap period between the intake and exhaust valves, residual burnt gas in the intake air has an effect on the amount of gas, but when the engine is operating at low load, this overlap period is made as short as possible to reduce the amount of residual burnt gas. It is preferable to obtain combustion stability,
As a result, the idling speed can be lowered, and advantageous results such as improved fuel economy and reduced unburned harmful components in the exhaust gas can be obtained. It is conventionally known to variably control the engine valve opening timing in accordance with the engine operating state in consideration of the above 4S circumstances. For example, Tokko Akari 2-,'? ! ;G/A discloses a structure in which the meshing relationship between the timing chain and the sprocket of the camshaft is changed, thereby changing the valve timing in response to changes in the operating condition. Also, Tokko Akira! ; 2-33g/No. 9 discloses that a planetary gear mechanism whose centrifugal rotation is controlled by a pannier is interposed between the output shaft of the engine and the camshaft, and the rotation between the engine output shaft and the camshaft is adjusted according to the engine speed. A structure is disclosed in which a phase change is caused between the two. 1. In addition to this, a cam whose shape changes in the axial direction is formed on the camshaft, and the camshaft is moved in the axial direction according to the engine operating conditions.A4-
1. A structure in which the valve opening timing is changed is also known. These conventional devices control pulp timing according to changes in operating conditions, but for one cylinder,
This control is for an engine equipped with one intake and exhaust valve, and therefore, these devices cannot perform nocleave timing control that adequately responds to changes in operating conditions.

(Objective of the Present Invention) Accordingly, the object of the present invention is to control the no-no-resonance timing of this one intake valve in an engine equipped with λ intake valves, thereby achieving a desired engine output according to changes in operating conditions. It is an object of the present invention to provide a valve timing control device for an engine that can provide characteristics, particularly, a valve timing control device for an engine that can obtain high output over a wide range from low rotation to high rotation.

(Configuration of the present invention) The above object of the present invention is achieved by the following configuration. That is, in the present invention, in an engine equipped with a rotation speed detection means for detecting the rotation speed of the engine engine and λ intake valves in one cylinder, when the operating state is in a low rotation region, the two At least the valve closing timing of the intake valve nozzle timing is set to the advanced side, and the valve closing timing is set to 1? The pipe machine is equipped with means for changing valve timing to be set on the opposite side.

The configuration of the present invention will be explained with reference to FIG.

The engine according to the present invention has a number of intakes per cylinder, I
? ) and one intake valve that opens and closes this, and at least the closing timing of the two intake valves is changed according to the operating state.

In detecting the operating state, the engine rotation speed can be used, and engine load and the like may also be taken into consideration. When the operating state is in a low rotation range, the valve timing changing means sets at least the valve closing timing of the λ intake valves to the advanced side, that is, to advance the valve timing,
If it is in a high rotation area, set it to the delay side. In this case, one intake valve is used to open and close these hoards for the seventh intake port that supplies intake air in all operating regions and the secondary intake port that supplies intake air in relatively high load regions. Although it can be configured as a next-side intake valve and a secondary-side intake valve, it is not limited to this more S configuration.

Note that a conventionally known variable mechanism can be used as the variable mechanism used for the valve timing changing means.

(Effects of the present invention) According to the present invention, the intake valve is closed relatively quickly in the low rotation range, so it is possible to prevent blowback at the end of the intake stroke that tends to occur in this operating range, and to increase high output. Obtainable. Further, in the high rotation range, the closing timing of the intake valve is set to the delayed side.

As a result, a pushing effect due to strong intake inertia can be obtained, the filling efficiency can be increased, and a high output can therefore be obtained. In the present invention, since both of the λ intake valves are controlled, the above control can be performed effectively. Also,
In low-speed, low-load regions such as during idling, if the overship period is controlled to be short, the amount of residual burnt gas in the combustion chamber can be reduced, resulting in stable combustion and, therefore, stable idling. can be obtained. Furthermore, if a means for changing the pulp timing of the exhaust valve is provided and the valve opening timing is controlled to be advanced at least in a high load region, the exhaust efficiency can be improved and even higher output can be obtained.

(Description of Embodiments) Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

Referring to FIG. 1, the engine 10 of this example has a plurality of cylinders 12, and each cylinder 12 has a primary intake port 16 communicating with the primary intake passage 14 and a secondary intake port 16 communicating with the primary intake passage 14. There are λ intake ports of the secondary side intake ports 20 communicating with the side intake passage 18, and these ports 16 and 20 are provided with λ intake ports.
The primary side intake valve 22 and the secondary side intake valve 24 are respectively combined. Also, there is one exhaust passage 26゜2 on the exhaust side.
Exhaust yl connected to 8? ) 30 and 32, and a first exhaust valve 34 and a first exhaust valve 34 connected thereto are provided, respectively.

The intake valves 22,24 are connected to a cam 40 formed on the camshaft 38.
and cam 42.

The exhaust valves 34 and 36 are connected to cams 46 formed on the camshaft 44.
．． 48 respectively. The camshafts 3s and 44 are connected to a timing belt 5 synchronized with a crankshaft (not shown).
Rotationally driven by 0.

The seventh intake passage 14 and the next intake passage 18 are branched from the =mm path, and a throttle valve is installed in the intake passage.
■ will be provided. - An on-off valve 54 is provided in the next intake passage, and the on-off valve 54 is opened during high-load operation. A variable mechanism 56 is provided to change the knob timing of the seventh intake valve 22 and the secondary intake valve 24.

If FIG. 3 is also referred to, the variable mechanism 56 is connected to the cam shaft 3.
8, a drive shaft 60 attached to the rotation member 58, and a drive shaft 60 that is operated to rotate the rotation member 58 around the camshaft 38. 3, and a motor 64 for moving the operating member 62 left and right in FIG. 3. Secondary intake A24
Regarding the variable mechanism 56, the rotary member 58 is provided with a fitting hole 58a that slidably accommodates the wristwatch 66. The tappet 66 is interposed between the cam 42 and the pulp stem 24a of the intake valve 24, and is normally pushed upward by a spring 68. When the cam 42 rotates, the tappet 66 is pushed down while contacting the cam surface. The acting force from the cam 42 is transmitted to the valve stem 24a, thereby opening and closing the secondary intake valve 24.

When the actuator 64 is activated, the operating member 62 moves left and right.
This causes the drive shaft 60 to move the rotating member 58 to the camshaft 38.
rotate it around. When the rotating part 58 rotates, the tappet 66 housed therein also moves, and the relative position between the tappet 66 and the cam 42 changes, causing a shift in contact timing and changing the opening/closing timing of the secondary intake valve 24. . Similarly, the pulp timing of the seventh intake valve 22 is changed by a variable mechanism 56. The engine of this example is provided with a variable mechanism 57 that changes the first exhaust valve 34 and the pulp timing of the first exhaust valve 34.
7 includes a rotary member 59, a drive shaft 61, an operating member 63, a motor 65, and a rotary member 67 and a spring 69 regarding the a-th exhaust valve, and their operation is the same as that of the variable mechanism 56, so they will not be explained. is omitted.

As shown in FIG. 7, a microcomputer (hereinafter referred to as a microcomputer) is preferably used to drive the motor 64.
A control device 71 is provided. Control device 71
A rotational speed signal S1 outputted by a rotational speed sensor 70 that detects the engine rotational speed, and a load signal S2 outputted by a load sensor 72 that detects the engine load are input. The control device 71 outputs control signals to the motors 64 and 65.

The motors 64 and 65 are reversible motors, and rotate the gears 74 and 75 by a predetermined amount in a predetermined direction in response to the control signal, and move the operating members 62 and 63 left and right to operate the seventh intake valve 2.
An operating member 62.6 that changes the valve timing of the second and second intake valves 24, the first exhaust valve 34, and the second exhaust valve 36.
3, that is, the valve timings of the exhaust valve and intake valve are detected by position sensors 76 and 77, and this signal is input to the control device 71. Control device 71
The control details when using a microcomputer are shown in Fig. 3 in a Frochyard format. The microcomputer 71 first calculates the rotation speed R from the rotation speed signal S1, and then calculates the engine load P from the load signal S2. The RAM in the microcomputer 71 stores the rotation speed R, load P, and the operating member 62.
A map showing the relationship between the target position T and the target position T is read in advance, and the target position T of the corresponding operating member G2 is read from the rotation speed R and engine load P calculated above.

Next, the current position P8 of the operating member 62 is calculated based on the signal S3 from the position sensor 76.

Then, the deviation between the target position T and the current position Ps is calculated. When the deviation is zero, the motor 64 is not driven and the operating member 62 is not operated. If the deviation is positive, the motor 64 is driven to operate the sweeping member 62 in the advancing direction in accordance with the deviation.

If the deviation is negative: IIIj1, the motor 64 is driven in accordance with the value, and the operating member 62 is returned by a predetermined value. The exhaust valve variable mechanism 57 is independently controlled by inputting the rotation speed signal S4 and load signal S2 similar to those described above.

(Control Example) Referring to FIG. 6, the seventh intake valve 22 and the second intake valve 24 are each driven by line a in the low rotation range.

As shown by b, the opening/closing timing is set to the advanced side.

Therefore, it is possible to prevent sucking back at the end of the intake stroke, especially when the load is high, and it is possible to obtain the desired output.

In addition, in the high rotation range, the pulp timing of the primary intake valve 22 and the secondary intake valve 24 is as shown by lines c and d.
Set to the delayed side. As a result, a pushing effect at the end of the intake stroke can be obtained in a high load region, the filling efficiency can be increased, and high output can be obtained. Further, in this example, when the load is high, the pulp timings of the first exhaust valve 34 and the first exhaust valve 34 are set to advance from the timings shown by lines e and f, respectively, as shown by lines j and h. This increases exhaust efficiency and allows for even higher output.

In this example, one variable mechanism is installed on the intake side and one on the exhaust side.
The primary side intake valve 22, the secondary side intake valve 24, the first exhaust valve 34, and the first exhaust valve 34 are synchronized to change the timing, but a variable machine tM is installed independently for each. It can also be controlled.

Further, the present invention is applicable to an engine having one intake valve in each intake valve but not having an on-off valve 54, that is, an engine having no special distinction between full load and high load in the intake passage. The same can be applied to engines.

[Brief explanation of drawings]

Figure 1 is a claim correspondence diagram of the present invention, Figure 2 is Kinoto J1
FIG. 3 is a partial plan cross-sectional view of the engine according to the embodiment.
2 is an explanatory diagram of the system for operating the variable mechanism, FIG. 3 is a flowchart showing seven examples of pulp timing control of the present invention, and FIG. 6 is a suction,
Explanation 1 showing the pulp timing of the exhaust valve. Explanation of symbols 10... Engine, 12 Circumference/Cylinder, 22.../Next fi111 Intake valve,
24... time... next example - intake valve, 34...
・No. 1 exhaust valve, 36... No. 1 exhaust valve,
38.44・Song...Camshaft, 40.42,46
．． 48...Song cam, 50...Song/timing belt, 58.59...Song rotation member, 64.6
5...Motor, 66, (i7・
Curved tappet patent applicant Toyo Kogyo Co., Ltd.

Claims (1)

[Claims] In an engine equipped with a rotation speed detection means for detecting the engine rotation speed and two intake valves in seven cylinders, when the operating state is in a low rotation region, the pulp timing of one intake valve is 1. A valve timing control device for an engine, comprising a pulp timing changing means for setting the valve closing timing on an advanced side in both cases and setting the valve closing timing on a delayed side in a high rotation region.