JPS61237825A - Engine having rotary valve - Google Patents

Abstract

PURPOSE:To adjust a rotational phase of a rotary valve for controlling the amount of intake air smoothly and quickly by permitting the adjustment of the valve through the engagement of an adjustable sleeve movable in an axial direction depending upon load and a spline groove. CONSTITUTION:When an engine 1 is in operation and a cylinder 2 goes to a suction stroke to open an intake valve 3, an independent intake passage 7a communicating with the cylinder 2 coincides with a corresponding opening 9b in an rotary valve 9 in an overlapping state with the time when the valve is opened thereby to supply air into the cylinder 2. When an accelerator pedal is depressed to increase an engine output, a lever 21 is angularly swung in an x direction by an accelerator wire 22 in a phase adjustment unit 17 disposed on an actuating system 11 of the rotary valve 9 thereby to move an adjusting sleeve 18 in a right direction. Then, the rotational phase of a driven shaft 13 corresponding to a drive shaft 12 and the rotary valve 9 is changed to a delay side by the action of spline grooves 12a, 13a.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine with a rotary valve in which the amount of intake air is adjusted by a rotary valve.

(Prior art) Engine output is generally controlled by adjusting the amount of intake air with a throttle valve installed in the intake passage. Since the opening degree of the throttle valve becomes smaller, so-called throttling loss increases, resulting in a problem of worsening fuel efficiency at low loads. Therefore, as disclosed in Japanese Patent Publication No. 58-55329, for example, a rotary valve for opening and closing the intake passage is provided on the upstream side of the intake valve in the intake passage, and by changing the timing of opening and closing of the valve, the gap between the intake air is An engine has been proposed that adjusts the That is, as shown in FIG. 4, a rotary valve C that opens and closes the passage A'4r is provided on the upstream side of the intake valve B in the intake passage, and the rotary valve C is rotationally driven by the engine output shaft. As shown in Figure 5, the opening timing of the rotary valve C and the intake valve B
The timing when the valve opening timing (shaded area) overlaps with the valve opening timing (shaded area)
The device is configured to inhale air. 〇-If the opening timing of the tally valve C is made variable according to the engine load, and the rotational phase of the valve C relative to the crank angle is advanced, for example, as shown by the arrow (A), the above-mentioned overlap period (■) will be shortened. As a result, the amount of intake air is reduced, and if the rotational phase of the rotary valve C is delayed as shown by the arrow (b), the overlap period (2) becomes longer, thereby increasing the amount of intake air. According to such an engine, the intake air amount is determined by the overlap period (■) between the opening timing of the rotary valve C and the opening timing (■) of the intake valve B, that is, the period during which the intake passage is open from the upstream side until combustion. Since the amount of intake air is adjusted, there is no throttling loss that occurs when the amount of intake air is adjusted by the opening degree of the throttle valve, and therefore fuel efficiency at low loads is improved.

Incidentally, in the above-mentioned engine, the rotational phase of the rotary valve C is usually adjusted by a configuration as shown in FIG. 6, as also shown in the above-mentioned publication. That is, a drive shaft E, which rotates in synchronization with the engine output shaft, and a driven shaft F, which is integrated with the rotary valve C, are arranged on the same axis, and the opposing ends of the shafts E and F are inclined in opposite directions on the outer periphery. The spline grooves E' and F' are formed to form spline grooves E' and F', and the adjustment sleeve G is engaged with these splines W4E' and F'. The information is configured to be transmitted to C. When accelerating, the sleeve G is moved in the (C) direction via the accelerator wire H and the lever L, which are linked to the depression of the accelerator pedal, so that the driven shaft F is moved relative to the drive shaft E (8').
) direction to retard the rotational phase of the driven shaft F or rotary valve C with respect to the overall rotational direction (d), and when decelerating, the adjustment sleeve G is moved in the (e) direction by the return spring J. , the driven shaft F or the rotary valve C is rotated relative to the drive shaft E in the (E') direction to advance their rotational phases. As a result, the opening timing of the rotary valve C is adjusted according to the load as shown in FIG. 5, and the amount of intake air is adjusted accordingly.

However, with the above configuration, a problem arises in that the movement of the adjustment sleeve G in the (e) direction by the return spring J is delayed during deceleration. That is, rotary valve C
Since it has a large quality m, it rotates with a large inertial force in the (d) direction, but if we try to overcome this inertial force and change the rotational phase of the rotary valve C, Adjustment sleeve G cannot be adjusted with only the biasing force of spring J.
There is insufficient force to move the sleeve G, and as a result, the movement of the sleeve G in the (E) direction is delayed when the accelerator pedal is released.
The deceleration response of the engine deteriorates. To solve this problem, the spring force of the return spring J can be made sufficiently large, but in this case, the accelerator pedal becomes heavy and a large force is required to press the accelerator pedal.

(Object of the Invention) The present invention includes a rotary valve that opens and closes the intake passage on the upstream side of the intake valve, and adjusts the amount of intake air by changing the rotational phase of the valve according to the load. This is to deal with the above-mentioned problems in engines equipped with rotary valves.By quickly changing the rotational phase of the rotary valve in the direction of reducing the intake air layer during deceleration, Aims to improve responsiveness.

(Structure of the Invention) The engine with a rotary valve according to the present invention is characterized by having the following structure in order to achieve the above object.

That is, the intake passage on the upstream side of the intake valve is provided with a rotary valve for opening and closing the passage, and the drive system of the valve is provided with spline grooves inclined in opposite directions at opposite ends of the engine output shaft side. The drive shaft and the driven shaft on the rotary valve side are arranged on the same axis, and an adjustment sleeve is provided that engages with the spline grooves of these two wheels to transmit power, and the sleeve is adjusted in the axial direction according to the engine load. By moving the driven shaft, the rotational phase of the driven shaft relative to the drive shaft is changed. Then, the inclination direction of both spline grooves is set so that the rotational phase of the driven shaft changes to the advance side when the adjustment sleeve moves in the direction of decreasing the load, and the inclination direction of the spline groove of the drive shaft with respect to the axial center line is set. The angle is made larger than the inclination angle of the spline groove on the driven shaft with respect to the axis.

Incidentally, the inclination angles of the spline grooves of the drive shaft and driven shaft are set so that the amount of change in the rotational phase of the driven shaft with respect to the drive shaft is a desired amount for a constant stroke of the adjustment sleeve in the axial direction. However, if the inclination angle of the spline groove on the drive shaft side is made larger than the inclination angle of the spline groove on the driven shaft side as described above, the inertia force of the adjustment sleeve itself will act in the direction of advancing the rotational phase of the driven shaft. . Therefore, if the inclination direction of both spline grooves is set so that the rotational phase of the driven shaft changes to the advance side during deceleration, the inertia of the adjustment sleeve will assist the action of the return spring to move the sleeve in the deceleration direction. As a result,
As a result, the rotational phase of the driven shaft or rotary valve changes quickly to the leading side.

(Effects of the Invention) As described above, according to the present invention, in an engine in which the amount of intake air is adjusted by changing the rotational phase of the rotary valve according to the engine load, the amount of intake air of the rotary valve can be adjusted. The rotational phase changes quickly in the decreasing direction. Therefore, in an engine equipped with this type of rotary valve, it is possible to improve the deceleration response when the accelerator pedal is released without increasing the spring force of the return spring, that is, without making the accelerator pedal heavier. becomes.

(Example) Examples of the present invention will be described below.

As shown in FIG. 1, each cylinder 2 is provided on one side of the engine 1.
... 2 combustion chambers are provided with an intake system 4 that supplies intake air through intake valves 3 ... 3, and on the other side, exhaust valves 5... An exhaust system 6 is provided which exhausts via 5. The intake system 4 is provided with a hollow cylindrical rotary valve 9 rotatably housed in a case 7 attached to the engine 1 via bearings 8, 8. One end face of this rotary valve 9 is opened to serve as an inlet 9a for introducing air sucked from an air cleaner (not shown) into the valve 9, and the circumferential face has the same number of openings as the number of cylinders. 9b...9b
is provided. In addition, in the case 7, each cylinder 2.
...Independent intake passages 7a...7 that communicate with the two combustion chambers, respectively.
a is provided, and as the rotary valve 9 rotates, the openings 9b...9b align with the respective independent intake passages 7a...7a in a predetermined order, and the internal space of the valve 9 aligns with each independent intake passage 7a. . . 7a is connected sequentially.

In addition, this low-return valve 9 and the output shaft 10 of the engine 1
A drive system 11 for the valve 9 is provided between the valve 9 and the valve 9. This drive system 11 includes a drive shaft 1 disposed parallel to the engine output shaft 10 and on the axis of the rotary valve 9.
2, and a driven shaft 1 that is integrally provided on the end face of the rotary valve 9 and is disposed opposite to the drive shaft 12 on the same axis.
3, a timing belt 16 wound between a pair of pulleys 14 and 15 attached to the engine output shaft 10 and the drive shaft 12, respectively, and a timing belt 16 provided between the drive shaft 12 and the driven shaft 13 to transmit rotation. It also includes a phase adjustment device 17 that changes the rotational phase of the driven shaft 13 relative to the drive shaft 12. Here, in this embodiment, the drive shaft 12, driven shaft 13, and rotary valve 9 are rotated in the X direction by the engine output shaft 10, and the rotational speed of the rotary valve 9 is It is said to be 1/2 of the rotation speed of 10. Also, each cylinder 2
. . .2 so that the corresponding openings 9b . , the phase of the engine output shaft 10 and the rotary valve 9, and the openings 9b...9 in the valve 9.
The opening position of b is set.

On the other hand, as shown in an enlarged view in FIG. 2, the phase adjustment device 17 includes spline grooves 12a and 1 formed on the outer periphery of the opposing ends of the drive shaft 12 and the driven shaft 13 and inclined in mutually opposite directions.
an adjustment sleeve 18 whose both ends are engaged with the adjustment sleeve 3a, and an adjustment sleeve 18 disposed outside the adjustment sleeve 18;
A support sleeve 20 that rotatably supports both ends of the support sleeve 19 through bearings 19, 19, and a lever 21 that is connected at one end to the support sleeve 20 and moves the support sleeve 20 or the adjustment sleeve 18 in the axial direction. As shown in FIG.
An accelerator wire 22 that swings the lever 21 in the X direction and a return spring 23 that biases the lever 21 in the Y direction opposite to the swing direction of the wire 22 are connected. When the accelerator pedal is depressed, the lever 21 swings in the X direction, causing the support sleeve 120 and the adjustment sleeve 1 to move.
8 moves in the y' direction, at this time, the adjustment sleeve 18 rotates in the y' direction relative to the drive shaft 12, and the driven shaft 13 rotates in the same direction relative to the adjustment sleeve 18.
The lever 21 is rotated in the opposite direction by the tensile force of the return spring 23.
When the drive shaft 1 swings in the y direction and the support sleeve 20 and adjustment sleeve 18 move in the y' direction accordingly, the drive shaft 1
2, the adjusting sleeve 18 rotates in the V LJ force direction, and the driven shaft 13 rotates relative to the adjusting sleeve 18 in the y'' direction, which is the same direction. The movement of the adjusting sleeve 18 in the y' direction changes the rotational phase of the driven shaft 13 or the rotary valve 9 to the lag side with respect to the rotational direction The rotational phase changes to the leading side.

In the present invention, the angle of inclination of the spline grooves 12a and 13a of the drive shaft 12 and the driven shaft 13, which are inclined in opposite directions to each other, with respect to the axial center line, which causes such a change in the rotational phase, is set on the drive shaft 12 side. The spline groove 128 is made larger (for example, 45 degrees), and the spline groove 13a on the driven shaft 13 side is made smaller (for example, 15 degrees).

Next, the operation of the above embodiment will be explained.

During operation of the engine 1, when one of the cylinders 2 enters the intake stroke and the intake valve 3 opens, the corresponding openings in the independent intake passage 7a and the rotary valve 9 that communicate with the cylinder 2 overlap with the opening timing. Since the portions 9b and 9b coincide with each other, air that has been sucked in from an air cleaner (not shown) and introduced into the internal space of the rotary valve 9 is sucked into the combustion chamber of the cylinder 2 through the opening portion 9b1, the independent intake passage 7a, and the intake valve 3. be done. At this time, the amount of intake air is
As shown in the figure, the opening timing of the intake valve 3 and the valve opening timing of the rotary valve 9 (the opening 9b and the independent intake passage 7a
The period in which the period overlaps with
will be determined by.

When the accelerator pedal is depressed to increase engine output, the drive system 11 of the rotary valve 9
In the phase adjustment device 17 in , the lever 21 moves 1'! in the X direction via the accelerator wire 22. By moving the support sleeve 20 and the adjustment sleeve 18 in the X' direction, the rotational phase of the driven shaft 13 and the rotary valve 9 relative to the drive shaft 12 is changed to the lag side.

As a result, the opening timing of the rotary valve 9 changes in the direction shown by the arrow (b) in FIG. 5, and the overlap period (2) with the opening timing (2) of the intake valve 3 becomes longer. As a result, the amount of intake air increases, and the desired engine output can be obtained. Also, if you release the accelerator pedal,
By moving the adjustment sleeve 18 in the y' direction by the return spring 23 via the lever 21,
The rotational phase of the driven shaft 13 or the rotary valve 9 is changed to the advance side, and accordingly, the opening timing of the rotary valve is changed in the direction shown by the arrow (A) in FIG. 5, and the intake valve 3 is opened. The overlap period (■) with the time (■) becomes shorter, and the intake air mass decreases.

However, when the engine 1 is decelerating to reduce the intake air, the adjustment sleeve 18 cannot be quickly moved in the y' direction by the spring force of the return spring 23 alone, and therefore the rotational phase of the rotary valve 9 is not moved quickly in the y' direction. However, in the present invention, this delay is reduced or eliminated as follows. In other words, as shown in FIG. 3, an inertial force corresponding to the mass of the adjusting sleeve 18 rotating in the X direction together with the drive shaft 12, driven shaft 13, etc. acts in the same direction, and this inertial force Force F through the teeth 18a, 18b at both ends of the sleeve 18.

Spline groove 12 of drive shaft 12 and driven shaft 13 as F
a, acts on 13a. At this time, on the side of the drive shaft 12 where the inclination angle of the spline groove is large, the spline groove 12
On the other hand, when the driven shaft 13 has a small inclination angle of the spline groove, a large component force F1 is generated that tries to slide the end 18a of the adjustment sleeve 18 along the direction a and move the sleeve 18 in the y' direction. On the side, only a small force is generated as the component force E2 that attempts to move in the X' force direction. Therefore, a force in the y' direction acts on the adjustment sleeve 18 as a whole based on the inertial force, and this force assists the spring force of the return spring 23.

As a result, the adjustment sleeve 18 can be quickly moved in the y' direction, that is, the movement in the direction of advancing the rotational phase of the low-return valve 9 and reducing the amount of intake air, without increasing the spring force of the return spring 23. engine 1 without any negative effects such as a heavy accelerator pedal.
The deceleration response of the vehicle will be improved.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway view of an engine with a rotary valve showing an embodiment of the present invention, Fig. 2 is an enlarged sectional view showing a rotary valve phase adjustment device in the engine, and Fig. 3 is an operation of the present invention. It is an explanatory diagram. FIG. 4 is a schematic longitudinal sectional view of an engine showing the general arrangement of rotary valves, FIG. 5 is a graph showing the action of the rotary valve, and FIG. 6 is an enlarged sectional view showing a conventional phase adjustment device. . DESCRIPTION OF SYMBOLS 1... Engine, 3... Intake valve, 7a... Intake passage, 9... Rotary valve, 11... Drive system, 12
... Drive shaft, 13 ... Driven shaft, 12a, 13a...
・Spline groove, 18...adjustment sleeve.

Claims (1)

[Claims] (1) A rotary valve is provided in the intake passage on the upstream side of the intake valve, and the rotary valve is driven by the engine output shaft to open and close the intake passage, and a drive shaft and a driven shaft are arranged on the same axis to constitute the drive system of the valve. are formed with spline grooves inclined in opposite directions to each other at opposing ends thereof, and are engaged with these spline grooves to move in the axial direction according to the engine load, thereby controlling the rotation of the driven shaft relative to the drive shaft. The engine is equipped with an adjustment sleeve that changes the phase, and the inclination direction of both spline grooves is set so that the rotational phase of the driven shaft changes to the advance side when the adjustment sleeve moves in the direction of decreasing load. 1. An engine with a rotary valve, wherein the spline groove on the drive shaft has a larger inclination angle with respect to the axial centerline than the inclination angle of the spline groove on the driven shaft.