JPS6030453Y2 - York valve control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for controlling the opening degree of a carburetor choke valve.

The choke valve controls the flow cross-sectional area upstream of the venturi when starting in cold weather, and is designed to open only a small predetermined opening after cranking. However, when starting after a long stop, the inner wall of the intake pipe becomes When the engine is dry, the fuel is used to moisten the inner wall of the intake pipe, and the amount of fuel sent to the combustion chamber immediately after startup is reduced, resulting in a lean mixture in the combustion chamber.
There is a risk that the engine may malfunction or stop.

The purpose of this invention is to eliminate the need for adding almost any new parts.
The object of the present invention is to effectively avoid malfunction or stoppage of the engine when starting it after being stopped for a long period of time.

In a normal internal combustion engine, the air-fuel mixture in the combustion chamber becomes abnormally rich during deceleration due to the choke breaker as an actuator that is activated by the negative pressure in the intake pipe generated after cranking, and the fuel adhering to the inner wall of the intake branch pipe. In order to prevent this, there are already control valves that open for a predetermined period of time during deceleration to introduce atmospheric air into the intake branch pipe through an atmospheric air introduction passage.

According to the invention, the control chamber of the choke breaker is communicated with the atmosphere introduction passage.

When the intake pipe negative pressure increases after cranking, the atmospheric pressure on the atmospheric outlet side of the control valve is maintained at approximately atmospheric pressure, so the operation of the choke breaker is still delayed for a predetermined time even after the intake pipe negative pressure increases during startup. be done.

In this way, during this predetermined period of time, the choke valve is still maintained in a substantially fully closed state, and the amount of fuel supplied from the carburetor to the intake passage increases, and despite the fact that fuel adheres to the inner wall of the intake branch pipe in a dry state, Supply of a predetermined amount of fuel to the combustion chamber is ensured, and malfunction and stoppage of the engine are prevented.

Next, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, a carburetor 1 defines an intake passage 2 and is connected to each combustion chamber of the engine via an intake branch pipe 3.

A vent 1]4 is formed in the intake passage 2 of the carburetor 1,
A choke valve 5 and a throttle valve 6 interlocked with an accelerator pedal in the driver's cab are provided upstream and downstream of the venturi 4, respectively.

The control valve 10 is formed in a port 12 communicating with the atmosphere via a filter 11, a port 14 connected to the intake branch pipe 3 via a passage 13, and a partition wall provided between the ports 12 and 14. Valve seat 15, chambers 17, 18 separated from each other by diaphragm 16, valve body 19 that opens and closes the opening of valve seat 15 in conjunction with diaphragm 16, spring 20 that biases diaphragm 16 toward chamber 17, and diaphragm 16 is provided.

The chamber 18 is connected to the intake manifold 3 via a passage 22 .

The choke breaker 28 includes a diaphragm 29, an atmospheric chamber 30 and a control chamber 31 delimited by the diaphragm, a spring 32 biasing the diaphragm 29 toward the atmospheric chamber 30, and a rod 33 connected to the diaphragm 29.

Rod 33 has a bent end 34.

The lever 35 is fixed to the shaft of the choke valve 5 and can come into contact with the bent end 34 of the rod 33.

The construction of the control valve 10 and the choke breaker 28 is well known, and they are already installed in conventional fuel supply systems.

The present invention is characterized by the connection of the control chamber 31 of the choke breaker 28, and in this embodiment, the control chamber 31 is connected to the passage 13 via a passage 38.

The well-known operation of the control room 10 will be briefly described.

During deceleration, a large negative pressure in the intake pipe is generated, and this large negative pressure in the intake pipe leads the fuel that had previously adhered to the inner wall of the intake branch pipe 3 to the combustion chamber, making the air-fuel mixture abnormally rich. There is a risk.

However, the intake pipe negative pressure is immediately transmitted to the chamber 18 and is transmitted to the chamber 17 after being delayed by a predetermined time T by the orifice 21.

The diaphragm 16 therefore deflects against the spring 20, causing the valve body 19 to separate from the valve seat 15, thereby causing the passage 13
Atmospheric air is introduced into the intake branch pipe 3 through the intake branch pipe 3, thereby preventing abnormal enrichment of the air-fuel mixture.

After the predetermined time T has elapsed, the valve element 19 is pressed toward the chamber 17 in the control valve 10 and closes the opening of the valve seat 15, thereby stopping the introduction of atmospheric air.

The operation of the embodiment will be explained.

When starting the engine in cold weather, the choke valve 5 is opened almost fully, and the starter is operated by a key switch in the driver's cab.

Before starting, the intake pipe negative pressure is approximately zero, the control chamber 31 of the choke breaker 28 is also maintained at approximately atmospheric pressure, the diaphragm 29 is pressed toward the atmospheric chamber 30 by the spring 32, and the bent end 34 of the rod 33 is It is located at a position sufficiently protruding from the choke breaker 28.

Therefore, the choke valve 5 is almost fully closed.

When cranking ends and the engine starts rotating, the intake pipe negative pressure increases rapidly.

This increased intake pipe negative pressure is transmitted to the chamber 18 of the control valve 10 via the passage 22, and has the same effect as the increased intake pipe negative pressure during deceleration described above.

Therefore, during the predetermined time T, the atmosphere flows through the passage 13, the control chamber of the choke breaker 28 is still maintained at substantially atmospheric pressure, and the choke valve 5 is maintained substantially fully closed.

As a result, the flow rate of intake air introduced via the choke valve 5 decreases, and the fuel supply flow rate in the carburetor 1 increases due to the large negative pressure formed downstream of the choke valve 5, so that a large amount of fuel is transferred to the intake air. Even though it adheres to the dry inner wall of the branch pipe 3.

The supply of a predetermined amount of fuel to the engine combustion chamber is ensured, preventing engine malfunction and stoppage.

After the predetermined time T has elapsed, the control valve 10 opens the chamber 16.1.
7. Since the valve body 19 is kept in close contact with the valve seat 15 while maintaining the same negative pressure, the introduction of atmospheric air from the port 12 is prevented.

As a result, the control chamber 31 of the choke breaker 28 is
3.38, the diaphragm 29 deflects against the spring 32 towards the control chamber 31, the bent end 34 of the rod 33 entrains the lever 35, and the choke valve 5 is slightly is opened to a predetermined opening degree.

After the engine is warmed up, the choke valve 5 is almost fully opened by manual or automatic means (not shown), so the choke valve 5 is not affected by the manual operation of the choke breaker 28.

FIG. 2 shows another embodiment of the invention.

The parts corresponding to those in FIG. 1 will be designated by the same reference numerals and the explanation will be omitted, and only the differences will be explained.
It communicates with the housing interior space 39 on the port 1-4 side.

This housing internal space 39 is connected to the passage 1 via the port 14.
Since the pressure is the same as that of 3, the same operation and effect as in this embodiment can be obtained.

As described above, according to the present invention, the control valve for introducing atmospheric air during deceleration and the choke breaker, which are already provided in a normal fuel supply system, are used, and the control room of the choke breaker is
The control valve communicates with an atmosphere introduction passageway that leads the atmosphere to the intake system downstream of the carburetor throttle valve.

Therefore, the number of additional parts and changes is very small, and even though the choke valve is kept almost fully closed for the predetermined time T during startup, and a large amount of fuel adheres to the inner wall of the intake branch pipe in a dry state, This ensures that a predetermined amount of fuel is supplied to the combustion chamber, and prevents the engine from malfunctioning and stopping when the engine is started after being stopped for a long time.

[Brief explanation of the drawing]

1 and 2 each show an embodiment of the invention. 5...Choke valve, 10...Control valve,
13... Passage (atmosphere introduction passage), 28...
...Choke breaker (actuator), 31...
...Control room, 33...Rod, 39...
...Space inside the housing.

Claims (1)

[Scope of utility model registration request] An atmospheric air introduction passageway connected to the intake system downstream of the carburetor throttle valve, a control valve that opens for a predetermined period of time to introduce atmospheric air into the air introduction passageway after the intake pipe negative pressure rises rapidly, and an air introduction passageway What is claimed is: 1. A choke valve control device, comprising: a communicating control chamber; and an actuator that maintains a carburetor choke valve in a substantially fully closed state when the control chamber is at substantially atmospheric pressure.