JPS5930191Y2 - Throttle valve opening control device in a carburetor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for controlling the opening degree of a throttle valve that is pressed on a carburetor.

Particularly in LPG engines, conventionally the throttle valve control (accelerator operation) at cold start is done by not stepping on the accelerator until the first explosion, and then stepping on the accelerator after the first explosion to open the throttle valve and complete explosion, and then continue to rotate the engine. In order to maintain the warm-up period, continue to press the accelerator during warm-up or operate the throttle button to warm up the engine.As the engine speed increases as the warm-up progresses, accelerate the accelerator according to the warm-up state. Warm up the engine by reducing the amount of pressure on the engine or by returning the throttle button.
The operation was troublesome.

Therefore, the object of the present invention is to propose a device that can automatically perform the above-mentioned operation. That is, the opening and closing of the throttle valve 2 is controlled by a diaphragm device 13, and the diaphragm device 13 and the intake pipe 1 is connected so that the throttle valve 2 is opened by negative pressure in the intake pipe, and a wax-type thermosensor 8 is provided which senses the engine coolant temperature and moves back and forth along the rod 8a, and at the tip of the rod 8a, The diaphragm device 13
A stopper 9 for controlling the amount of movement of the diaphragm 5 in the opening direction of the throttle valve is provided, and a balance spring 10 for a diaphragm that is pressed on the diaphragm device is interposed between the stopper 9 and the diaphragm 5. It is.

Next, an embodiment of the present invention shown in the drawings will be described.

1 is a carburetor main body, and a throttle valve 2 is provided on the main body.

Reference numeral 3 denotes a negative pressure outlet passage, one end of which opens downstream of the throttle valve 2, and the other end communicates with the negative pressure chamber 4 of the diaphragm device 13.

Reference numeral 5 denotes a diaphragm, to which a connecting rod 6 is fixed, and the other end of the connecting rod 6 is connected to the throttle valve 2 via a lever 7.

Reference numeral 9 denotes a stopper slidably provided in the diaphragm negative pressure chamber 4. A balance spring 10 for the diaphragm is interposed between the stopper 9 and the diaphragm 5, and a sensor is provided between the stopper 9 and the main body of the diaphragm device 130. A balance spring 11 for warm wax is interposed.

Reference numeral 8 denotes a wax-type thermosensor, the temperature-sensing part of which is located in the cooling water passage 12, and the rod 8a.
indicates a valve connected to the stopper 9.

Next, the operation will be explained.

When trying to start an LPG engine at low temperatures, turning on the starter switch activates the starter and
When the engine is cranked, negative pressure is generated downstream of the throttle valve 2 of the carburetor body 1, and the negative pressure is transferred to the negative pressure take-off passage 3.
is guided to the negative pressure chamber 4 of the diaphragm device 13 through the diaphragm device 13, and the diaphragm 5 is urged toward the opening side of the throttle valve 2.

However, during low cranking at low temperatures, the degree of negative pressure is low, and the spring does not operate until it hits the diaphragm balance spring 10.

Next, at the same time as the first explosion of the engine, the vacuum degree of the negative pressure downstream of the throttle valve rises, and the negative pressure is guided to the negative pressure chamber 4 of the diaphragm device 13 through the passage 3, and the balance spring 1
The diaphragm 5 moves to the left against zero, and the throttle valve 2 is opened, resulting in a complete explosion.

Then, due to the complete explosion, the degree of negative pressure under the throttle valve 2 becomes even higher, the diaphragm 5 is pulled at the position of the stopper 9, and the throttle valve opening degree becomes sufficient for the engine's self-cutting and warm-up operation. The engine starts.

At that time, the starter switch is turned OFF and then warm-up operation begins.

As the warm-up progresses, the cooling water temperature gradually rises, and the wax-type Mos sensor 8 that senses the temperature gradually projects its rod 8a, causing the stopper 9 to move left and right.

As a result, the diaphragm 5 that is in contact with the stopper 9 moves to the right as described above, and the throttle valve 2 is moved to the closing side via the connecting rod 6 and the lever I, controlling the increase in rotation caused by the warm-up state. Warm-up operation is performed.

When the cooling water temperature further rises, the stopper 9 is moved further to the right by the wax type thermosensor 8, and the diaphragm 5 is moved before the opening of the throttle valve 2 reaches the idle opening, thereby ending the warm-up operation.

If the valve 14 is provided in the negative pressure outlet passage 3, the cooling water temperature, engine speed, etc. can be sensed, the valve 14 can be operated electrically or mechanically, and the throttle control can be released as necessary. is also possible.

As described above, by using the present invention in a starting device for an LPG engine, all starting operations and warm-up operations that were conventionally performed manually can be performed automatically.

In addition, engine rotation control during warm-up is now regulated by directly regulating the amount of diaphragm operation using the stroke of a wax-type thermosensor. Compared to a device that controls negative pressure, it is less susceptible to fluctuations in intake pipe negative pressure, provides a stable throttle valve opening, and even if the vehicle is warmed up, the throttle valve opening will not return. Reproducibility is good and driving is safe.

Furthermore, in this invention, one side of the balance spring for the diaphragm is held by a wax rod via a stopper, so the diaphragm activation pressure can be lower at low temperatures and higher at high temperatures. This device can closely match the negative pressure in the intake pipe during cranking, making it extremely effective as a starting device for LPG engines.

[Brief explanation of the drawing]

The drawing is a sectional view showing an embodiment of this invention. 1... Carburetor main body, 2... Throttle valve, 3... Negative pressure outlet passage, 4...
Negative pressure chamber, 5...Diaphragm, 6...
Connecting rod, 7... Lever 8... Wax type thermosensor, 8a... Rod, 9...
...Diaphragm stopper 10...Spring, 11...Spring, 12...
・Cooling water passage, 13...Diaphragm device, 1
4... Negative pressure release valve.

Claims (1)

[Scope of utility model registration request] The opening and closing of the throttle valve 2 is controlled by a diaphragm device 13, the diaphragm device 13 and the intake pipe 1 are connected so that the throttle valve 2 is opened by the negative pressure in the intake pipe, and the temperature of the engine cooling water is sensed. A wax-type thermosensor 8 that moves forward and backward along the rod 8a is provided, and the diaphragm device 13 is attached to the tip of the rod 8a.
A carburetor characterized in that a stopper 9 is provided to control the amount of movement of the tire phragm 5 in the opening direction of the throttle valve, and a balance spring 10 for the diaphragm in the diaphragm device is interposed between the stopper 9 and the diaphragm 5. Throttle valve opening control device.