JPS581635Y2 - Throttle valve control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a carburetor for a vehicle, and in particular to opening/closing control of a throttle valve that is pressed when the vehicle is decelerating.

For deceleration braking, wheel brakes or engine brakes are used depending on the situation.
Either one of the brakes is used, but even if the former is activated, the engine brake will work because the foot is removed from the accelerator pedal, so the engine and brake will be activated in either case.

When the engine brake is activated, the throttle valve in the carburetor intake passage is almost closed (in this case, there is a slight gap between the intake passage and the throttle valve that sucks air), and the amount of air sucked becomes minute and the throttle valve closes. There is a reduced pressure downstream of the valve.

In this case, no fuel is injected from the main nozzle, but since the engine is still driven by the drive wheels and continues to rotate at high speed, a small amount of fuel is sucked and injected from the slow system of the carburetor.

Since the amount of intake air downstream of the throttle valve is extremely small, complete combustion cannot be achieved inside the engine, causing afterburn in the exhaust gas pipe, and the exhaust gas purification device connected to the wake of the exhaust gas pipe. There were drawbacks such as overheating of the catalyst inside the tank, causing it to deteriorate or melt away.

In order to solve these drawbacks, a device was developed to fully close the throttle valve during deceleration.In this case, the throttle valve is fully closed in the intake passage to reduce the suction of fuel. Consideration has been given to

However, if the throttle valve is suddenly fully opened after the start of deceleration, the valve will hit the intake passage wall violently, causing damage and galling (valve galling phenomenon), or damage to the wall if the wall is made of relatively soft material such as aluminum alloy. will occur.

Also, since the throttle valve is fully closed when the engine is stopped, if left unattended for a long time, the valve will stick to the wall of the intake passage, and the oil solidification type will rust, making it difficult to open the valve when restarting.
There was a problem that occurred next.

The present invention provides an improved throttle valve control device that solves the above-mentioned secondary problem by fully opening the throttle valve after passing through a temporary half-open transient state when the vehicle decelerates. .

Embodiments of the present invention will be described with reference to the accompanying drawings.

In the intake passage 1 of the carburetor, there is a rotatable well 2 that is rotatably provided to adjust the amount of intake air, and a shaft 3 provided in the throttle valve 2 penetrates the wall of the intake passage 1 and extends outward. The throttle valve 2 and the lever 4 are integrated by protruding toward the side and being connected to the lever 4.

An adjusting bolt 5 is screwed into a screw hole provided at the free end of the lever 4 via a compression spring 6 that prevents the bolt from loosening, and the free end of the lever 4 is held back by a return thread ring (not shown). It is biased to rotate clockwise.

2 (broken line) and 2B (solid line L2G (dotted line) indicate the position of the throttle valve 2 when the vehicle is fully open, transient, and fully closed. Lever 4 in human and 2C positions, adjustment bolt 5,
The drawing of the compression spring 6 is omitted.

A diaphragm chamber I is fixed on the vehicle, and inside it there is a compression spring 9 on the left side of the figure via a diaphragm 8.
A rod 10 is provided on the right side, and a collar-shaped stopper 11 is fixed to the rod 10 and abuts against a fixing member 12.

The rod 10 is pushed by the compression spring 9 and the stopper 11
When the rod is in contact with the fixed member 12, the end of the rod is in contact with the adjustment bolt 5 on the lever 4, and the throttle valve 2 is in the middle of the fully open position 2A and the fully closed position (during deceleration) 2C when accelerating. It is set to hold the transitional position 2B.

The return spring is stronger than the compression spring 9, and a negative pressure intake port 13 is opened at the left end of the diaphragm chamber.

A slow system 14 is provided on the wall of the intake passage 1, and an idle port 27 and a slow port 28 of the slow system are arranged vertically and open into the intake passage 1.

15 is a negative pressure outlet opened in the wall of the intake passage 1, and its opening position is upstream of the fully open position 2A during acceleration, and the throttle valve position 2B during idle link (transient) and during deceleration. The throttle valve is located downstream of the throttle valve position 2C (when fully closed).

Reference numeral 16 indicates a negative pressure operation switching valve 17 and a negative pressure transmission timer valve 17, which will be described later, between the negative pressure outlet 15 and the diaphragm chamber 7.
This is a pipe that connects the lug mechanism 19.

The negative pressure operation switching valve 11 includes three valves 17A and 17B. 17
17A and 17B and 17B and 17C are connected to each other, and 17C is connected to the outside air.

An engine speed detection circuit 18 is provided adjacent to the negative pressure operation switching valve 17, and switches the set of valves according to the engine speed using a known method.

Next, a time and lug mechanism 19 connected to the pipe 16 by caps 25 and 26 is provided, and the time and lug mechanism 1
9, as shown in the figure, the interior of the room is divided by a partition wall 20, and the partition wall 20 has a one-way valve 21 formed of a ventilation hole 23 and a valve 24 made of an elastic material, and a throttle 22 that is opened in the partition wall 20 in the shape of an orifice.
are arranged in parallel.

Next, the operation of this device will be explained.

When the vehicle is running at high speed, the throttle valve 2 is in a position similar to that of two people, and the negative pressure switching valves 17A and 17B are in communication with each other in response to a command from the rotational speed detection circuit 18 in response to the throttle valve 2. Air coming in from 15 is pipe 16
The one-way valve 21 of the time lag mechanism 19 and the throttle 2
2 and exerts atmospheric pressure on the left side of the diaphragm chamber T, the rod 10 is pushed to the right by the repulsive force of the compression spring 9 and stopped by the stopper 11 at the position shown in the figure.

However, in this case, the adjustment bolt 5 is not in contact with the rods 1,0.

When the throttle valve 2 enters deceleration running (high-speed engine rotation), the throttle valve 2 is rotated by the return spring toward the fully closed position 2C, but in the middle of this movement, an adjustment bolt is attached to the end face of the rod 10 positioned as described above. 5 comes into contact.

On the other hand, negative pressure is generated downstream of the throttle valve 2, and as mentioned above, the engine is still rotating at high speed and there is no change in the communication status between the negative pressure switching valves 17A and 17B, so the generated negative pressure can be passed through the pipe 16. The one-way valve 21 which is about to be transmitted to the diaphragm chamber 7 functions as a check valve due to the pressure difference within the one-way valve chamber, and the negative pressure is transmitted only through the softener 22 with a time lag.

Thus, a negative pressure is created on the left side of the diaphragm chamber, and the diaphragm 8 is moved to the left due to the pressure difference in the chamber, and the rod 10 is retracted to the left.
Throttle valve 2, which had been stationary while in contact, gradually rotates and reaches the fully closed position 2C.

That is, if the throttle valve 2 is set appropriately so that it takes the transient position 2B when the adjusting bolt 5 comes into contact with the rod 10 at the position shown in the figure, it will temporarily take the transient position during deceleration and then move to the fully closed position. can be reached.

Also, when the engine speed falls below a certain value, for example during idling (low speed engine rotation), the negative pressure switching valves 17B and 17C are in communication, and 17C is in communication with the outside air, so the inside of the diaphragm chamber 7 is at atmospheric pressure. Therefore, the throttle valve 2 can take the transient position 2B and draw fuel from the slow nozzle to obtain an appropriate mixture ratio.

Furthermore, when the engine is stopped, the diaphragm chamber is similarly brought to atmospheric pressure and takes the position 2B, and the throttle valve 2 is no longer in contact with the wall of the intake passage 1.

Since the present invention has the above-described structure, the throttle valve temporarily stops at the transition position during the transition from the fully open position to deceleration, and then gradually shifts to the fully open position, and does not suddenly fully close.

Therefore, damage to the throttle valve can be prevented, and since the throttle valve is held in a transient position while the engine is stopped, the valve does not get stuck in the intake passage, and therefore the valve opens smoothly when restarting. It has many advantages such as:

[Brief explanation of drawings]

The figure is a schematic explanatory diagram of the device of the present invention. 1...Intake passage, 2...Throttle valve, 2 people...
Acceleration formula is fully open position, 2B...transient position during idle link, 2C...throttle valve position when fully closed, 4...
Throttle valve lever, 7...Diaphragm chamber, 14.
...Slow system, 15...Negative pressure intake, 17...Negative pressure operation switching valve, 19...Time, lag mechanism, 21...
One-way valve, 22... throttle.

Claims (1)

[Claims for Utility Model Registration] A throttle valve 2 is provided in an intake passage 1 having a slow system 14 on the wall, and an accelerating type throttle valve is located upstream of the two fully open positions on the wall of the intake passage. A negative pressure intake port 15 is provided in a negative pressure region downstream of the transient position 2B during idle link and the fully closed position 2C during deceleration, and a diaphragm means that contacts the throttle valve lever 4 to maintain the opening of the throttle valve. established,
The space between the negative pressure intake port 15 and the diaphragm means is linked to engine rotation, and a manifold negative pressure is applied at a predetermined rotation speed or higher. Further, a negative pressure operating switching valve 17 that applies atmospheric pressure at a rotation speed lower than a predetermined rotation speed and a time lag mechanism 19 for transmitting negative pressure are provided, and the time and lag mechanisms for transmitting negative pressure are arranged in parallel. A throttle valve control device characterized in that the negative pressure intake port 15 is also formed by a one-way valve 21 facing the diaphragm means and a throttle 22, and the throttle valve is fully opened during deceleration.