JPS6235866Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a knocking prevention device for an ignition type engine that uses gasoline or combustible gas as fuel.

Conventionally, ignition engines that use gasoline or combustible gas as fuel usually mix gasoline or combustible gas fuel with air using a carburetor to create a mixed gas.
The mixed gas is supplied into a cylinder, compressed by a piston, and ignited by an ignition plug to combust it.The higher the degree of compression of the mixed gas by the piston, that is, the compression ratio, the higher the combustion efficiency. On the other hand, if the compression ratio is too high, knocking may occur and there is a risk of engine damage.

On the other hand, the above-mentioned knocking does not occur over the entire rotational range of the engine, but tends to occur during high-load, low-speed rotation.

In other words, knotting is thought to occur when unburned gas spontaneously ignites and burns instantaneously, and this spontaneous ignition of unburned gas is more likely to occur as the mixed gas concentration is higher and the amount of mixed gas supplied is larger. Furthermore, if the engine speed is low, the time from the start of compression to ignition is longer, so knocking is more likely to occur. Knocking is more likely to occur when the rotation speed is low.

Therefore, in the past, a knocking detector was installed in the engine, and when knocking occurred in the engine, the ignition timing of the ignition plug was delayed from normal times using a signal from the knocking detector to prevent spontaneous ignition of the gas from occurring. This prevents knotting.

However, as mentioned above, if the ignition timing is delayed, the start of combustion of the mixed gas will be delayed, and the end of combustion will also be delayed, resulting in high temperature exhaust gas, which will flow to exhaust valves, mufflers, etc. Therefore, heat-resistant measures must be taken to prevent exhaust valves, mufflers, etc. from prematurely deteriorating due to heat, making the engine expensive.

This is particularly true in the case of stationary ignition type engines, which are often operated at high loads and low speeds.

The present invention was developed in view of the above circumstances, and its purpose is to provide a knocking prevention device for an ignition type engine that can reliably prevent knocking without raising the temperature of exhaust gas. .

This invention will be described in detail below with reference to an illustrated embodiment. In the figure, 1 is an ignition type engine having a high compression ratio, 2 is an intake manifold of the engine 1,
The inlet side includes a throttle valve 3 and a carburetor 4 that mixes gasoline or combustible gas with air to form a mixed gas.
It is connected to an air cleaner (not shown) via. The throttle valve 3 has a lever 5 in the intake pipe 3a.
A butterfly valve 3b that is opened and closed by the lever 5 is provided to control the amount of mixed gas supplied to the engine. , are connected via link 8. The plunger 6 is supported by a support member 9 so as to be movable between a normal position and a closed operating position in which the throttle valve 3 is operated in the closing direction, and is biased by a tension spring 10 in a direction away from the throttle valve 3. and the tension spring 10 is held in the steady position.
On the opposite side is a solenoid 12 which is excited by a signal from a rotation detector 11 provided in the engine 1.
is provided. That is, when the rotational speed of the engine 1 enters a knocking range where knocking is likely to occur, the rotation detector 11 detects this and sends a signal to the solenoid 12. This causes solenoid 1
2 is energized, the solenoid 12 attracts the plunger 6 to the closed operating position. This moves the fulcrum of the bell crank 7 and operates the butterfly valve 3b of the throttle valve 3 in the closing direction, so the intake pipe 3
The mixed gas flowing through the engine is throttled, the amount of mixed gas supplied to the engine is reduced, and spontaneous combustion of the gas becomes less likely to occur, thereby preventing knocking. The other end of the bell crank 7 is connected to an accelerator member such as an accelerator pedal (not shown) via a connecting rod 13, and opens and closes the butterfly valve 3b of the throttle valve 3, regardless of whether the plunger 6 is in operation or not, to supply the engine to the engine. The engine output can be controlled by increasing or decreasing the amount of mixed gas supplied.

The present invention is as described above, and when the rotational speed of the engine 1 reaches the knocking range, the solenoid 12 is energized, the plunger 6 is closed and moved to the operating position, the throttle valve 3 is operated in the closing direction, and the mixture is supplied to the engine 1. By reducing the amount of gas supplied, spontaneous combustion of the gas becomes less likely to occur and knocking can be prevented, and since only the amount of mixed gas supplied is reduced, the temperature of the exhaust gas does not rise. This prevents high-temperature exhaust gas from flowing through the exhaust valve, muffler, etc., and does not require much heat resistance measures, so the cost of the engine 1 does not increase and is economical.

The throttle valve 3 is opened and closed by an accelerator member to control the amount of mixed gas supplied to the engine 1 and engine output, and the solenoid 12 closes the plunger 6 to the operating position regardless of the amount of operation of the accelerator member. Since the opening of the throttle valve 3 is closed, no matter what output state the engine is in, when the load increases and the engine speed decreases to the knocking range, the opening of the throttle valve 3 is closed to prevent knocking. This can be prevented, and when the load decreases and the engine speed increases and goes out of the knocking range, the solenoid 12 is demagnetized, the plunger 6 is moved to the normal position by the tension spring 10, and the opening of the throttle valve 3 is controlled by the operation of the accelerator member. The engine output returns to a value commensurate with the amount of operation, and the engine output becomes a value corresponding to the amount of operation of the accelerator member.

Therefore, no matter what output state the engine is operating at, knocking can be automatically prevented when the engine speed drops due to an increase in load, and if the engine speed increases again due to a decrease in load, the accelerator member will automatically prevent knocking. automatically returns to the original engine output state.

[Brief explanation of the drawing]

The drawing is a schematic diagram showing an embodiment of this invention. 1 is the engine, 3 is the throttle valve, 4 is the carburetor, 6 is the plunger, 7 is the bell crank, 10
11 is a rotation detector, 12 is a solenoid.

Claims (1)

[Scope of utility model registration request] The intake manifold 2 of the engine 1 is opened to the atmosphere through a carburetor 4 that mixes gasoline or combustible gas and air to form a mixed gas, and the amount of mixed gas supplied to the engine 1 is adjusted at the outlet side of the carburetor 4. A throttle valve 3 that opens and closes as desired is provided, and the throttle valve 3 and an accelerator member are connected via a bell crank 7 pivotally connected to a plunger 6, and the plunger 6 is operated in the normal position and the throttle valve 3 is operated in the closing direction. A solenoid 12 is provided, which supports the plunger 6 movably across a closed operating position, holds the plunger 6 in a normal position with a tension spring 10, and moves the plunger 6 to the closed operating position, and when the rotation speed of the engine 1 is in the knocking range A rotation detector 11 is provided to detect whether the
A knocking prevention device for an ignition type engine, characterized in that the device is configured to excite the ignition type engine.