JPH09151754A - Control device of rotary valve for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve various characteristics of an engine of output, torque, fuel consumption, exhaust emission control degree, etc., over a wide maneuvering range, by variably controlling open/close timing of a rotary valve. SOLUTION: In a rotary valve for an internal combustion engine constituted so that an operating fluid may pass in a haft of the rotary valve, a turn unit 19 having a control part 20, coming into close contact with or touching an internal peripheral surface of the shaft of the rotary valve 6, is provided. By turning the control part 20 in accordance with an operating condition of the engine, a communication condition between inside the shaft of the rotary valve 6 and a combustion chamber 3 is periodically changed, further a communication path 10 in the valve provided in the downstream from the turn unit 19 is divided by a separating wall 23, and a substantial capacity of a part, communicating with not inside the shaft of the rotary valve 6 but the combustion chamber 3 of the communication path 10 in the valve, is lessened by separating with the control part 20 and the separating wall 23 in accordance with the operating condition of the engine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling the valve opening / closing timing of a rotary valve for an internal combustion engine.

[0002]

2. Description of the Related Art First, a rotary valve for an internal combustion engine having a structure in which a working fluid flows into the cylinder through the shaft of the rotary valve according to the present invention will be described. In FIG. 1 (a), the rotary valve 6 provided in the cylinder head 4 has rotary sliding surfaces 7 arranged so as to face each other,
Driven synchronously by the main shaft (crank shaft) of the engine, for example, via a chain or sprocket 5 (1/2 or 1
Decelerate to / 4). A seal device S is closely attached to each rotary sliding surface 7 by a spring to seal the pressure in the combustion chamber. Although various sealing devices S are conceivable, in the figure, first, a cylindrical sealing tube is brought into close contact with the rotary sliding surface 7, and a sealing ring having a special closed type opening is brought into close contact with this sealing tube by a spring. Has become. When the in-valve communication passages 9 and 10 formed in the rotary valve 6 are communicated with the combustion chamber 3, the intake air flowing through the shaft of the rotary valve 6 is introduced into the cylinder 1 and is formed in the rotary valve 6. When the in-valve communication passages 11 and 12 communicated with the combustion chamber 3, the cylinder 1
The exhaust gas inside is discharged through the valve communication passages 11 and 12. A mixture of air and fuel is supplied to the in-valve communication passages 9 and 10 (lubrication of the rotary valve 6 is performed by oil mixed in the mixture), and thus intake, compression and
Perform expansion and exhaust strokes. Reference numeral 8 denotes a seal plate, which is pressed against the rotary sliding surface 7 by a spring and blocks the communication between the valve communication passage 9 (10) and the valve communication passage 11 (12). FIG.
1B corresponds to the valve communication passage 11 removed in FIG. 1A, and FIG. 1C shows the valve communication passage 10 in FIG. 1B.
The rotary sliding surface 7 is not perpendicular to the axis, but is a conical surface with a certain inclination angle (of course, it may be perpendicular to the axis, The sliding surface 7 may be spherical.
It is also conceivable that the rotary sliding surface 7 in (b) has a conical surface shape or a spherical surface shape). However, making the rotary sliding surface 7 perpendicular to the axis has the advantage that no radial load is applied to the axis of the rotary valve 6. FIG. 1D shows a rotary valve 6 having rotary sliding surfaces 7 which are arranged to face each other.
It is applied to a cycle engine, and a scavenging passage 14 (which communicates with a crank chamber or a scavenging pump) is connected to the shaft of the rotary valve 6, and an in-valve communication passage 13 is formed after the exhaust port 15 is opened.
Is communicated with the combustion chamber 3, fresh air flows into the cylinder 1 from the inside of the shaft of the rotary valve 6 through the in-valve communication passage 13 to perform the scavenging process. The rotary valve 16 shown in FIG. 1 (e) is of a cylindrical type, and the intake air that has passed through the inside of the rotary valve 16 via the valve communication passage 17 is transferred to the cylinder 1
The exhaust gas in the cylinder 1 is discharged through the in-valve communication passage 18. In the rotary valve for an internal combustion engine as described above, when the working fluid flows into the cylinder 1, it is better to advance the valve opening timing of the rotary valve 6 and delay the valve closing timing in the high speed range. Although torque was obtained, it decreased in the low speed range, and in the low load range, the fuel deteriorated due to an increase in the residual gas amount in the cylinder 1. In this way, the rotary valve with fixed valve opening and closing times could not improve various engine characteristics such as output, torque, fuel consumption, and exhaust cleanliness over a wide operating range.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention An object of the present invention is to make variable the valve opening timing and valve closing timing of a rotary valve so that output, torque, fuel consumption, exhaust gas cleanliness, etc. It is an attempt to improve various characteristics of the engine.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a rotary valve for an internal combustion engine, in which a working fluid is configured to pass through the inside of a shaft of a rotary valve, a control for closely contacting or contacting an inner peripheral surface of the shaft of the rotary valve. A rotating body having a portion, and by rotating the control unit of the rotating body according to the operating state of the engine, the communication state between the shaft of the rotary valve and the combustion chamber is changed with time.
Further, the in-valve communication passage on the downstream side of the rotating body is divided by a partition wall, and the substantial volume of the portion which does not communicate with the shaft of the rotary valve while communicating with the combustion chamber of the in-valve communication passage is operated by the engine. According to the state, the size is reduced by separating the rotating body by the control portion and the separating wall.

[0005]

When the rotating body is rotated, the control portion that is in close contact with or in contact with the inner peripheral surface of the shaft of the rotary valve rotates, and the communication state between the shaft of the rotary valve and the valve communication passage changes with time. However, the state of communication between the inside of the rotary valve shaft and the combustion chamber also changes with time.
Since the rotating body is driven by a servomotor or the like, and therefore the valve opening and closing timings of the rotary valve are controlled according to the operating condition of the engine, various characteristics of the engine can be improved over a wide operating range. Further, since the in-valve communication passage is divided, the reverse flow rate of the working fluid into the in-valve communication passage is extremely small even if the fluid flows backward from the cylinder.

[0006]

FIG. 2A shows an embodiment of a rotary valve control device for an internal combustion engine according to the present invention, in which the rotary valve 6 is closely contacted with the inner surface of the shaft (with a minute gap). A rotating body 19 having a control unit 20 for keeping non-contact) is provided. In this case, the inner peripheral surface of the shaft of the rotary valve 6 and the outer peripheral surface of the rotating body 19 are tapered to bring them into contact with each other,
As shown in FIG. 2 (g), a slit 22 is formed in the rotating body 19,
The spring action (like a piston ring) may be brought into light contact with the inner peripheral surface of the shaft of the rotary valve 6. The rotary valve 6 on the left side is shown in FIG. 2 (B). The in-valve communication passage 10 on the downstream side of the rotating body 19 is separated by the separating wall 23 into 10a and 1a.
0b (the same applies to the rotary valve 6 on the right side, so the rotary valve on the left side will be described hereinafter). Although the rotating body 19 does not rotate together with the rotary valve 6, the rotary valve 6 is rotated to an arbitrary position to control the valve opening / closing timing of the rotary valve 6. Now, when the control unit 20 of the rotating body is rotated to the position shown in FIG.
0 and the communication state between the inside of the shaft of the rotary valve 6 and the fuel chamber 3 change accordingly (when the communication state changes with time). Is that the start or cutoff time of communication changes.) Next, this will be described in detail. When the control unit 20 of the rotating body is between θ in FIG. 2B, the communication between the valve communication passage 10 and the fuel chamber 3, that is, the valve communication passage 10 The communication with the seal device S starts at 20 ° before the top dead center at the crank angle and is cut off at 60 ° after the bottom dead center, so that the charging efficiency in the high speed range (high load) of the engine is improved. Higher output and higher torque can be obtained. In the low speed range, the control unit 20 of the rotating body is rotated to the position shown in the figure, and therefore the timing of disconnecting the communication between the shaft of the rotary valve 6 and the combustion chamber 3 (sealing device S) is, for example, 20 ° after bottom dead center. As soon as possible, the filling efficiency in the low speed range is increased and high output and high torque can be obtained. In this case, the working fluid in the cylinder flows backward into the valve communication passage 10 from 20 ° to 60 ° after bottom dead center, but into the shaft of the rotary valve 6 while communicating with the combustion chamber 3 in the valve communication passage. Since the substantial volume that does not communicate with each other is reduced by separating it by the control unit 20 and the separation wall 23 of the rotating body (the volume of the valve communication passage 10 is reduced from the total volume to 10b). The reverse flow rate of the working fluid is negligible. Even in the medium speed range, since the control unit 20 of the rotating body is rotated to the optimum position for optimum control, the charging efficiency is increased and high output and high torque are obtained. The start timing and cutoff timing of communication between the combustion chamber 3 and the shaft of the rotary valve 6 will be referred to as the valve open timing and valve close timing of the rotary valve, respectively.
By the way, when the communication between the in-valve communication passage 10b and the shaft of the rotary valve 6 is cut off in FIG.
Although there is a throttling resistance that is narrowed by 0, in order to prevent this, as shown in FIG. 2A, in addition to widening the portion of the valve communication passages 9 and 10 connected to the rotating body 19 in the axial direction, Ingenuity is required as shown in (c). That is, as shown in FIG. 3A showing a state slightly before FIG. 2C, the part where the separation wall 23 is connected to the rotary valve 6 of the combustion chamber 3 (the part where the seal device S is located).
When passing through, the valve communication passages 10 on both sides of the separation wall 23
The control unit 20 is formed so that the working fluid can flow into the cylinder 1 from a and 10b. This reduces throttling resistance and increases filling efficiency. Until the in-valve communication passage 10b completely passes through the sealing device S as shown in FIG.
The communication between the in-valve communication passage 10b and the shaft of the rotary valve 6 is blocked by the control unit 20. In the high speed range, the control unit 20 may be rotated to the position where the control unit 20 is rotated sufficiently to the left. still,
In FIG. 3, the valve communication passage 12 is omitted. FIG. 2D shows a case where the valve opening timing of the rotary valve 6 is changed, and the control unit 20 is rotated to the position shown in the figure in the low load region. Therefore, the combustion chamber 3 (seal device S) and the rotary device are rotated. The communication with the shaft of the valve 6 is started, that is, the valve opening timing of the rotary valve 6 is 0 before the top dead center.
It becomes slower and the amount of residual gas in the cylinder can be reduced and combustion can be improved. From 20 ° before top dead center to top dead center, the residual gas in the cylinder flows back into the valve communication passage 10, but communicates with the shaft of the rotary valve 6 while communicating with the combustion chamber 3 of the valve communication passage. The control unit 2 controls the substantial volume
Since it is made small by separating it by 0 and the separating wall 24 (it is made small from the entire volume of the valve communication passage 10 to the volume of 10d), this reverse flow rate becomes insignificant. An example of reducing the throttling resistance when the working fluid begins to flow in is shown in FIG. 2D, and the separation wall 24 is connected to the rotary valve 6 of the combustion chamber 3 as shown in FIG. 3C. When passing through the part to be sealed (the part where the sealing device S is),
The control unit 20 is formed so that the working fluid flows in from the valve communication passages 10c and 10d on both sides of the separation wall 24. 2F corresponds to an embodiment in which FIGS. 2C and 2E are combined, and in the low speed range (high load), the control unit 20 sets the valve closing timing of the rotary valve 6 to 20 ° after bottom dead center. As soon as possible
In the low load region, as shown in FIG. 3D, the control unit 20 is rotated to the illustrated position to delay the valve opening timing of the rotary valve 6 to 0 ° before the top dead center. In the high load / high speed range, the control unit 20 is rotated to the position shown in FIG. 3 (e) so as not to interfere with the suction (the rotary valve 6 is opened and closed at 20 ° before the top dead center, 60 ° after bottom dead center). In this case, the valve opening timing of the rotary valve 6 cannot be delayed and the valve closing timing cannot be advanced in the high load / low speed range, but an embodiment that enables this is shown in FIG. That is, Figure 3 (f)
In the high load / low speed range, the control unit 20 is at the position shown in the figure, whereby the valve opening timing of the rotary valve 6 is delayed to 0 ° before top dead center and the valve closing timing is advanced to 20 ° before bottom dead center. (See FIG. 3G). Control unit 20 even in the low load range
It is advisable to delay the valve opening timing with the same position as shown in the figure.
Delaying the valve opening timing of the rotary valve 6 in the high load / low speed range prevents backflow of the exhaust gas into the valve communication passage, so that the torque is improved. Next, as a method for driving the rotating body 19, a method using an accelerator pedal or a main shaft 2 of the engine as shown in FIG.
There is a method of using the centrifugal force of the ball 26 that rotates together with 5, and when the rotational speed of the engine increases, the ball 26 moves outward against the spring, moves the rod 27, and moves the rotating body 19 via the drive piece 21. Drive. Furthermore, FIG.
There is a method using the servo motor 30 as shown in (b). That is, the engine rotation speed signal obtained from the rotation speed sensor 28 is input to the microcomputer 29, calculated and the output signal is sent to the servo motor 30. This output signal follows the relationship between the engine rotation speed stored in the microcomputer 29 in advance and the desired amount of rotation of the rotating body 19, and the servo motor 30 is driven by this output signal and the worm gear 31 and the rod 32 are used. Revolving body 19
Is optimally controlled according to the engine speed. The rotation speed sensor 28 may be replaced by an accelerator pedal opening sensor, or signals from both sensors may be input to optimally control the rotating body 19. FIG. 5 (a) is shown in FIG.
The present invention is applied to the two-stroke engine of (d), and the exhaust port 15 is opened at 80 ° before bottom dead center and 80 ° after bottom dead center, for example.
The control unit 2 is closed in the low speed range (also in the low load range).
Is rotated to the position shown in the drawing, and the rotary valve 6 is set to 1 before bottom dead center.
The valve opens at 0 ° and closes at 80 ° after bottom dead center. Since the valve opening timing of the rotary valve 6 is very late, the fresh air is prevented from passing through. In the high speed range, for example, when the control unit 20 is sufficiently rotated in the counterclockwise rotation direction, the valve opening timing of the rotary valve 6 is 40 ° before the bottom dead center, which provides a sufficient scavenging period. FIG.
(B) shows that the rotary valve 6 is driven at 1/1 of the rotation of the engine main shaft, and will be described in the same manner. FIG. 5C shows FIG.
The present invention is applied to (e). For example, as in FIG. 2 (f), the control unit 20 delays the valve opening timing of the rotary valve 16 in the low load range, and in the low speed range (high load) as shown in FIG. ), The control unit 20 is rotated to the position shown in the figure to advance the valve closing timing. Of course, when the separation wall 24 (23) passes through the portion of the combustion chamber 3 connected to the rotary valve 16 (the portion where the sealing device S is located), the valve communication passages 17a and 17c on both sides of the separation wall 24 (23) are provided. The control unit 20 is formed so that the working fluid flows into the cylinder 1 from (17a, 17b). In this case, the valve opening timing of the rotary valve 16 cannot be delayed and the valve closing timing cannot be advanced in the high load / low speed range, but an embodiment that enables this is shown in FIG. This is the same as that described with reference to FIGS. Figure 5 (f) is Figure 5 (b)
Corresponds to a cylindrical rotary valve 6, and the control unit 20 controls the rotary valve 3 in the low speed range (also in the low load range).
The valve opening timing of 4 is delayed to prevent fresh air from passing through.
Reference numeral 35 is a separating wall, and 37 is a reinforcing portion that reinforces the rotating body having the control portion 20 (such a reinforcing portion 37 can be formed in another embodiment of the present invention if necessary). The present invention can be applied to a spherical rotary valve in exactly the same manner.
Further, it can be similarly applied to a multi-cylinder engine.

[0007]

According to the present invention, the opening / closing timing of the rotary valve can be optimally controlled by rotating the control unit 20 of the rotating body, so that the output, torque, fuel consumption, and fuel consumption can be reduced over a wide operating range. It is possible to improve various characteristics such as exhaust gas cleanliness.
For example, in the 4-cycle engine of FIGS. 2 and 3, the output and torque can be increased over the entire range from low speed to high speed.
In the low load range, the valve opening timing of the rotary valve 6 can be delayed to stabilize the combustion. In addition, FIG. 5 (a), (b),
(2) In the 2-cycle engine, the rotary valve is opened in the low speed range (also in the low load range) to prevent the fresh air from passing through, and in the high speed range, the valve open time is advanced to provide a sufficient scavenging period. It achieves output and high torque. Further, in the present invention, since the communication passage in the valve is divided by the separating wall, even if there is a backflow from the inside of the cylinder, the backflow becomes very small (see FIGS. 2C and 2D). Figure 5 (a), (b), (f)
In the two-cycle engine, the residual gas in the cylinder and the fresh air in the valve communication passage are mixed in the state shown in the figure, but the volume of the valve communication passages 13b and 36b is reduced by the separating walls 33 and 35. However, the harm to the scavenging action is extremely small.

[Brief description of the drawings]

FIG. 1 is a diagram showing various rotary valves for an internal combustion engine according to the present invention.

FIG. 2 is a diagram of a control device for a rotary valve for an internal combustion engine according to the present invention.

FIG. 3 is a state diagram in each phase of the rotary valve.

FIG. 4 is a diagram of an apparatus for driving a rotary valve.

FIG. 5 is a diagram of various embodiments of a control device for a rotary valve for an internal combustion engine according to the present invention.

[Explanation of symbols]

1 is a cylinder, 2 is a piston, 3 is a combustion chamber, 4 is a cylinder head, 5 is a sprocket, 6 is a rotary valve, 7
Is a rotary sliding surface, 8 is a seal plate, 9 ・ 10 ・ 11 ・ 12 ・
13, 17, 18, 10a, 10b, 10c, 10d,
10e / 13a / 13b / 17a / 17b / 17c / 3
6a and 36b are communication passages in the valve, 14 is a scavenging passage, 15 is an exhaust port, 16 and 34 are rotary valves, 19 is a rotating body, 20 is a control unit, 21 is a drive piece, 22 is a slit, 23 and 24,
33 and 35 are separating walls, 25 is the main shaft of the engine, 26 is a ball, 27 is a rod, 28 is a sensor, 29 is a microcomputer, 30 is a servomotor, 31 is a worm gear, 32 is a rod, 37 is a reinforcing portion, S is It is a sealing device.

Claims (2)

[Claims] 1. A rotary valve provided in a cylinder head that rotates in synchronism with a main shaft of an engine, and an internal valve communication passage formed in the rotary valve communicates with a combustion chamber according to the rotation of the rotary valve. In an internal combustion engine in which a working fluid flows into a cylinder through the in-valve communication passage to compress and then burn and expand the working fluid in the cylinder, the working fluid is brought into close contact with or in contact with an inner peripheral surface of a shaft of the rotary valve. A rotating body having a control unit for controlling the rotation of the rotating body according to the operating state of the engine to change the communication state between the shaft of the rotary valve and the combustion chamber with time. The in-valve communication passage on the downstream side of the rotating body is divided by a partition wall, and the substantial volume of a portion that does not communicate with the inside of the rotary valve shaft while communicating with the combustion chamber of the in-valve communication passage is brought into the motion state of the engine. According to A rotary valve control device for an internal combustion engine, which is configured to be made smaller by separating it by a control part of a rotating body and a separating wall. 2. The working fluid can flow into the cylinder from the communication passages on both sides of the separation wall when the separation wall dividing the communication passage in the valve passes through a portion of the combustion chamber connected to the rotary valve. The control device for a rotary valve for an internal combustion engine according to claim 1, wherein a control unit for the rotating body is formed in the control unit.