JPH0639057Y2 - Exhaust control device for 2-cycle engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to an exhaust control device of a two-cycle engine, and in particular, an exhaust timing valve and a rotary on-off valve can be suitably self-cleaned at engine start. The present invention relates to an exhaust control device for a two-cycle engine.

(Prior Art) Conventionally, in a two-cycle engine, in order to improve the output of the engine, as shown in, for example, Japanese Patent Laid-Open No. 60-26121, an exhaust chamber is connected in the middle of an exhaust passage to form an exhaust chamber. Rotation of the rotary on-off valve at the inlet changes the engine exhaust volume sent to the exhaust chamber, and exhaust pulsation is used to prevent blow-through of the new air-fuel mixture to increase efficiency and improve output. There is something I did.

As another engine output improvement measure, for example, Japanese Utility Model Sho 61
-As shown in the 199677 specification, an exhaust timing valve is arranged above and below the exhaust port so that it can be retracted, the exhaust timing is delayed in the low and medium engine speed range, and the exhaust timing valve is installed from the exhaust port in the high engine speed range. It is considered that the engine is moved backward to accelerate the exhaust timing and thus improve the filling rate of the new air-fuel mixture to improve the output.

(Problems to be solved by the device) By the way, in order to further improve the engine output in the entire engine speed range, the above two technologies are combined to adjust the engine exhaust amount sent to the exhaust chamber and the exhaust timing adjustment function. An exhaust control device for a two-cycle engine in which and are incorporated into one device is conceivable.

That is, in the low engine speed region, the exhaust timing valve is deeply inserted into the exhaust port (Low state) to delay the exhaust timing, and the rotary on-off valve is opened to guide the engine exhaust to the exhaust chamber. When the engine reaches the specified number of revolutions in the medium to high revolution range, the rotary on-off valve is suddenly opened, and the exhaust timing valve is kept deeply inserted into the exhaust port during a predetermined revolution range thereafter (Low state). Furthermore, when the engine speed has risen and reached a high speed range, the exhaust timing valve begins to retract from the exhaust port,
The exhaust timing valve is gradually retracted in proportion to the increase in engine speed to accelerate the exhaust timing.

However, in such an exhaust control device, when the engine is operated for a long time, carbon or the like may adhere to the sliding surfaces of the exhaust timing valve and the rotary opening / closing valve, which may interfere with the sliding of these valves. .

Therefore, the actuator controller of the exhaust control device that drives the exhaust timing valve and the rotary opening / closing valve is configured to self-clean these valves before the engine is started.

As shown in FIG. 3, when the ignition switch 3 is turned on and the engine rotates, the motor drive circuit 2 of the actuator controller 1 operates according to the engine speed detected by the engine speed detection circuit 4. 5 is rotated to drive the rotary opening / closing valve and the exhaust timing valve. The rotation angle of the motor 5, that is, the rotation angle of the rotary on-off valve is detected by the valve position detector 6 and input to the motor drive circuit 2 to correct the rotation angle.

Further, the actuator controller 1 is provided with the above-mentioned self-cleaning function. That is, the timer circuit 7 operates from immediately after the ignition switch is turned on to before the engine is started, and the motor drive circuit 2 is operated for about 1 to 2 seconds. As a result, the motor 5 operates and self-cleaning of the rotary opening / closing valve and the exhaust timing valve is executed before the engine is started.

However, in order to realize the above-mentioned self-cleaning, a dedicated timer circuit 7 must be installed, which complicates the structure of the actuator controller 1 and inevitably causes an increase in cost due to this. .

This invention was made in consideration of the above facts,
An object of the present invention is to provide an exhaust control device of a two-cycle engine, which can realize cost reduction by realizing self-cleaning of an exhaust timing valve and a rotary valve before starting the engine with an actuator controller having a simple structure.

[Constitution of device]

(Means for Solving the Problems) This invention is directed to a rotary on-off valve for controlling the inflow of engine exhaust into an exhaust chamber provided in communication with an exhaust passage of a two-cycle engine, and the rotary rotary valve via an interlocking mechanism. An exhaust timing valve that is driven by an opening / closing valve and adjusts the exhaust timing of the two-cycle engine, and an actuator controller that operates a valve actuator that drives the rotary opening / closing valve based on the engine speed, etc. Is connected to a warning light check circuit, and is configured to operate the valve actuator when the warning light check circuit is activated.

(Operation) Therefore, according to the exhaust control device for a two-cycle engine according to the present invention, while the ignition switch is turned on to activate the warning light check circuit for a predetermined time to turn on the warning light, the actuator controller simultaneously controls the valve. The actuator is operated to drive the exhaust timing valve and the rotary opening / closing valve to remove carbon and the like adhering to both valves before the engine is started.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 10 indicates a two-cycle engine,
A piston 12 is slidably accommodated in a cylinder 11 of the engine 10. On the side wall of the cylinder 11, the piston 12
The scavenging port (not shown) that guides the new air-fuel mixture into the cylinder chamber 13 and the exhaust port 14 that discharges the combustion gas burned in the cylinder chamber 13 are open. 14
An exhaust passage 15 extends from there to the outside.

A branch passage 16a is provided in the middle of the exhaust passage 15, and the exhaust chamber 16 is connected to the branch passage 16a. In the vicinity of the branch passage 16a, an exhaust control device 17 that controls the engine exhaust sent from the exhaust passage 15 to the exhaust chamber 16 and accelerates the exhaust timing when the engine reaches a certain rotational speed is provided.

The exhaust control device 17 includes an exhaust timing valve 18 for adjusting exhaust timing, a rotary opening / closing valve 19 for controlling engine exhaust sent to the exhaust chamber 16, and an actuator controller 20 (FIG. 1) for driving the rotary opening / closing valve 19. And is configured.

A piston device 21 is connected to the exhaust timing valve 18. The exhaust timing valve is always provided so as to protrude into the exhaust passage 15 by the pressing force of the set spring 23 incorporated in the piston device 21. The projection amount of the exhaust timing valve 18 is set so that the exhaust port 14 at the time of full projection of the exhaust timing valve 18 has the exhaust timing at low engine speed. Also, set spring
The spring force of 23 is freely adjusted by adjusting the screwing amount of the cap 24.

On the other hand, the rotary opening / closing valve 19 is rotatably provided in a branch passage 16a connecting the exhaust passage 15 and the exhaust chamber 16. The rotary on-off valve 19 can be rotated in the forward and reverse directions by a stepping motor 25 as a valve actuator. Further, the rotary opening / closing valve 19 is provided with a through hole 26.
Is changed, which controls the inflow of engine exhaust sent from the exhaust passage 15 to the exhaust chamber 16.

Further, an interlocking protrusion 27, for example, a pin or the like is screwed or integrally coupled to the rotary on-off valve 19. An interlocking engagement portion 28 with which the interlocking protrusion 27 engages is formed at the base end portion of the exhaust timing valve 18. The interlocking protrusion 27 and the interlocking engaging portion 28 function as an interlocking mechanism. That is, the interlocking protrusion 27 is interlocked with the interlocking engaging portion 28 as the rotary on-off valve 19 rotates.
When the rotary on-off valve 19 is further rotated,
This rotational force causes the interlocking protrusion 27 to become an exhaust timing valve.
18 is provided to be retracted from the exhaust passage 15.

Now, as shown in FIG. 1, the actuator controller 20 includes a motor drive circuit 29 and an engine speed detection circuit 30.
And a valve position detection circuit 31 and the like.

The engine speed detection circuit 30 inputs and counts the engine speed signal from a speed detection sensor (not shown) to detect the actual engine speed. Motor drive circuit 29
Receives a detection signal from the engine speed detection circuit 30 to calculate a rotation angle according to the engine speed, and rotates the stepping motor 25 by that speed.

The rotation angle of the stepping motor 25, that is, the rotation angle of the rotary on-off valve 19 is detected by a valve position detection circuit 31 equipped with a potentiometer 31a, and this signal is input to a motor drive circuit 29. Therefore, the motor drive circuit 29 drives the stepping motor 25 in response to the position signal from the valve position detection circuit 31, and the rotary opening / closing valve 19
Correct and correct the rotation angle of.

The motor drive circuit 29, the engine speed detection circuit 30 and the valve position detection circuit 31 include an ignition switch 32.
Connected to the battery 33 via. Further, the motor drive circuit 29 among them is also connected to the oil warning light check circuit 34.

Here, in the oil warning light check circuit 34, the oil warning light check timer 35 operates for a fixed time (about 1 to 2 seconds) immediately after the ignition switch 32 is turned on, and the current from the battery 33 is supplied to the oil warning light 36 and It is a circuit for checking whether or not the oil warning lamp 36 can be turned on by flowing it to the diode 37. Reference numeral 38 is an oil level switch connected in series with the oil warning light 36.

Since the motor drive circuit 29 is connected to the oil warning light check circuit 34, a start signal indicating that the oil warning light check circuit 34 is in a starting state is input to the motor drive circuit 29. Therefore, when the oil warning light check circuit 34 is activated (about 1 to 2 immediately after the ignition switch 32 is turned on).
In the second), the motor drive circuit 29 outputs a signal for operating the stepping motor 25. As a result, the rotary on-off valve 19 is rotationally driven by the stepping motor 25,
The exhaust timing valve 18 slides to remove carbon and the like adhering to the sliding surfaces of both valves 19 and 18.

Next, the operation will be described.

For a certain period of time immediately after the ignition switch 32 is turned on, the oil warning light check circuit 34 is activated to check whether or not the oil warning light 36 is lit up. Then, the motor drive circuit 29 operates the stepping motor 25. By the operation of the stepping motor 25, the rotary opening / closing valve 19 and the exhaust timing valve 18 rotate and slide to remove carbon and the like adhering to the sliding surfaces of both valves, so that the self-cleaning of both valves 19 and 18 can be performed. Will be realized. In this way, since the self-cleaning is performed by using the oil warning light check timer 35 of the oil warning light check circuit 34, the structure of the actuator controller 20 can be simplified.

Also, since the oil warning light check circuit 34 stops after a certain period of time immediately after the ignition switch 32 is turned on,
The rotary on-off valve 19 and the exhaust timing valve 18 stop rotating and sliding. After that, the motor drive circuit 29 operates the stepping motor 25 according to the engine speed from the engine speed detection circuit 30 and the rotation angle of the rotary on-off valve 19 from the valve position detection circuit 31, and the rotary on-off valve 19 and the exhaust gas are discharged. The timing valve 18 is driven.

[Effect of device]

As described above, according to the exhaust control device for a two-cycle engine according to the present invention, the valve actuator that drives the exhaust timing valve and the rotary on-off valve is operated by the actuator controller, and the actuator controller is connected to the warning light check circuit. Since the warning light check circuit is configured to operate the valve actuator when the warning light check circuit is activated, the timer of the warning light check circuit can be used, so that the structure of the actuator controller can be simplified.
As a result, the exhaust timing valve and the rotary opening / closing valve can be self-cleaned before starting the engine with a simple circuit, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an actuator controller and the like of an embodiment in an exhaust control device for a two-cycle engine according to the present invention, and FIG. 2 is a sectional view showing a rotary on-off valve, an exhaust timing valve and the like of the embodiment, FIG. 3 is a diagram showing a configuration of an actuator controller in a conventional two-cycle engine exhaust control device. 10 ... Engine, 14 ... Exhaust port, 15 ... Exhaust passage, 16 ...
Exhaust chamber, 17 Exhaust control device, 18 Exhaust timing valve, 19 Rotary opening / closing valve, 20 Actuator controller, 25 Stepping motor,
27 …… Interlocking protrusion, 28 …… Interlocking engagement part, 29 …… Motor drive circuit, 32 …… Ignition switch, 34 …… Oil warning light check circuit, 35 …… Oil warning light check timer.

Claims (2)

[Scope of utility model registration request] 1. A rotary on-off valve for controlling the inflow of engine exhaust into an exhaust chamber provided in communication with an exhaust passage of a two-cycle engine, and driven by the rotary on-off valve via an interlocking mechanism to perform the two-cycle. An exhaust timing valve that adjusts the exhaust timing of the engine and an actuator controller that operates a valve actuator that drives the rotary opening / closing valve based on the engine speed, etc., and this actuator controller is connected to a warning light check circuit, An exhaust control device for a two-cycle engine, which is configured to operate the valve actuator when the warning light check circuit is activated. 2. The exhaust control device for a two-cycle engine according to claim 1, wherein the warning light check circuit is an oil warning light check circuit.